Database: EMBASE <: international biomedical and pharmaceutical literature, 1988 - May 2000. [Trial access until 3/2001. Feedback welcome to medical.library@umich.edu] Search Strategy (You Saved Citations 1-276 From Set 64): ----------------------------------------------------------------------------- 1 exp Tooth demineralization/ 7492 2 demineralization.mp. 879 3 caries.mp. 1798 4 caires.mp. 0 5 craies.mp. 0 6 careis.mp. 1 7 carise.mp. 0 8 (teeth adj3 cavit:).mp. 32 9 (tooth adj3 cavit:).mp. 97 10 (dental adj3 cavit:).mp. 85 11 (dentin adj3 cavit:).mp. 19 12 (enamel adj3 cavit:).mp. 10 13 (teeth adj3 decay:).mp. 58 14 (tooth adj3 decay:).mp. 58 15 (dental adj3 decay:).mp. 47 16 (dentin adj3 decay:).mp. 0 17 (enamel adj3 decay:).mp. 1 18 (active adj decay).mp. 5 19 (rampant adj3 decay:).mp. 4 20 (recurrent adj3 decay:).mp. 5 21 (white adj spot:).mp. 231 22 carious.mp. 109 23 cariology.ti,ab. 2 24 (non-cavitated adj3 lesion:).mp. 0 25 (noncavitated adj3 lesion:).mp. 1 26 Tooth remineralization/ 788 27 (dental adj3 fissure:).mp. 14 28 (tooth adj3 fissure:).mp. 8 29 (teeth adj3 fissure:).mp. 1 30 caries-free.mp. 29 31 cariesfree.mp. 0 32 Cariogenic agents/ 3 33 precavit:.mp. 2 34 (filled adj3 teeth).mp. 45 35 (filled adj3 tooth).mp. 9 36 (oral adj fissure:).mp. 17 37 (tooth adj3 remineraliz:).mp. 1 38 (teeth adj3 remineraliz:).mp. 5 39 dft.mp. 542 40 dfs.mp. 980 41 dmf:.mp. 1235 42 cariogeni:.mp. 164 43 or/1-42 12313 44 Dental leakage/ 609 45 (mineral adj loss).mp. 193 46 or/43-45 12479 47 Fluorescence/ 16320 48 exp Fluorometry/ 6778 49 fluorescen:.mp. 76516 50 QLF.mp. 3 51 DIAGNOdent.mp. 0 52 "LIGHT-SCATTERING".mp. 4345 53 exp Scattering, radiation/ 1414 54 Radiography, dental, digital/ 0 55 (direct adj digital adj radiograph:).mp. 5 56 exp Fluorescent dyes/ 16537 57 exp Iodides/ 1071 58 Ultraviolet rays/ 7989 59 exp Light/ 20105 60 Digital radiography/ 1283 61 exp Dental radiology/ 429 62 60 and 61 29 63 or/47-59,62 119496 64 46 and 63 276 65 from 64 keep 1-276 276 *************************** <1> UI - 2000171603 AU - Olausson B AU - Sagvik J IN - Dr. B. Olausson, Dept. of Psychiat./Neurochemistry, University of Goteborg, Molndals Hospital, S-43180 Molndal; Sweden. TI - Pain threshold changes following acupuncture, measured with cutaneous argon laser and electrical tooth pulp stimulation, a comparative study. SO - Progress in Neuro-Psychopharmacology & Biological Psychiatry Vol 24(3) (pp 385-395), 2000. AB - 1. The present study compared the argon laser technique for pain threshold measurements with the previously often used threshold measurements with electrical tooth pulp (TP) stimulation. 2. Conditioning stimuli with acupuncture was given since it previously has been shown to induce pain threshold changes. Acupuncture needles were inserted in the hands and arms and electrically stimulated. 3. The experiments were performed in a single blind fashion comparing pain threshold effects after either acupuncture or placebo. Pain threshold measurements with a method of limits were used with both electrical TP and the argon laser method. 4. In comparison to placebo the pain thresholds increased after acupuncture, both on the face and on the hand, with the argon laser method, while the TP thresholds were not influenced. No significant pain threshold change was detected with either the argon laser or the TP method following placebo treatment. 5. The results indicate that the argon laser used for sensory testing with a method of limits is a useful method for pain threshold measurements. The difference in pain threshold effects induced by acupuncture measured with the argon laser and the TP stimulation, are discussed and related to mechanisms that may differ between the two types of pain threshold measurements. [References: 25] <2> UI - 2000155678 AU - Mochizuki E AU - Yasui N AU - Kai Y AU - Inaki Y AU - Tohnai N AU - Miyata M IN - Y. Inaki, Dept. of Material and Life Science, Graduate School of Osaka University, Yamadaoka 2-1, Suita, Osaka 565-0871; Japan. TI - Structures and photodimerizations of 1-alkylthymine crystals obtained from N,N-dimethylformamide. SO - Bulletin of the Chemical Society of Japan Vol 73(4) (pp 1035-1041), 2000. AB - Single crystals of 1-alkylthymine (carbon numbers of the alkyl chain were 8, 11, 12, 13, 14, and 16) were obtained from N,N-dimethylformamide (DMF) solution as plates, and the crystal structures were determined by X-ray crystal analysis. The terminal methyl group of the alkyl chain was found to approach to the double bond of the thymine base in the crystal. The thymine bases in these crystals did not give the photodimer by UV irradiation, while the crystals obtained from ethyl acetate and acetonitrile gave the photodimer as reported previously. The terminal methyl group of the alkyl chain was concluded to inhibit the rotation of the thymine bases in crystal, which made the crystal from DMF inactive for the photodimerization. [References: 17] <3> UI - 2000152712 AU - Marks LAM AU - Verbeeck RMH AU - De Maeyer EAP AU - Martens LC IN - R.M.H. Verbeeck, Department Dental Materials Science, Institute Biomedical Technologies, University of Gent, De Pintelaan 185, B-9000 Gent; Belgium. E-Mail: ronald.verbeeck@rug.ac.be. TI - Effect of maturation on the fluoride release of resin-modified glass ionomer and polyacid-modified composite resin cements. SO - Biomaterials Vol 21(13) (pp 1373-1378), 2000. AB - The effect of an early water contact on the fluoride release is studied for the resin-modified glass ionomer cements (RM-GIC) GC Lining LC, PhotacBond, Vitremer and Vitrebond and for the polyacid-modified composite resins (PAM-C) Variglass and Dyract. Six months fluoride release profiles were determined in regularly renewed water (37 [degree] C), for the products directly after light curing and after 24h maturation in a humid atmosphere (85% RH). ANOVA shows that both the short-term and the long-term fluoride release of a RM-GIC are influenced by this maturation. This indicates that direct water contact for this material should be avoided. For the RM-GIC a correlation is found between the initial fluoride release process and the long-term process. For the PAM-C materials, no differences in the fluoride release are found as a function of maturation, indicating that early water contact has no effect. The amounts of fluoride released by PAM-C are low compared to RM-GIC, which can affect their caries preventive potential. The results are explained on the basis of the setting reaction of both types of materials. Copyright (C) 2000 Elsevier Science Ltd. [References: 30] <4> UI - 2000122329 AU - Becker L AU - Poreda RJ AU - Bunch TE IN - L. Becker, Sch. of Ocean/Earth Science/Technol., 602C POST Building, University of Hawaii, 1680 East West Road, Honolulu, HI 96822; United States. E-Mail: lbecker@soest.hawaii.edu. TI - Fullerenes: An extraterrestrial carbon carrier phase for noble gases. SO - Proceedings of the National Academy of Sciences of the United States of America Vol 97(7) (pp 2979-2983), 2000. AB - In this work, we report on the discovery of naturally occurring fullerenes (C60 to C400) in the Allende and Murchison meteorites and some sediment samples from the 65 million-year-old Cretaceous/Tertiary boundary layer (KTB). Unlike the other pure forms of carbon (diamond and graphite), fullerenes are extractable in an organic solvent (e.g., toluene or 1,2,4-trichlorobenzene). The recognition of this unique property led to the detection and isolation of the higher fullerenes in the Kratschmer/Huffmann arc evaporated graphite soot and in the carbon material in the meteorite and impact deposits. By further exploiting the unique ability of the fullerene cage structure to encapsulate and retain noble gases, we have determined that both the Allende and Murchison fullerenes and the KTB fullerenes contain trapped noble gases with ratios that can only be described as extraterrestrial in origin. [References: 28] <5> UI - 2000125424 AU - Whitters CJ AU - Strang R IN - Dr. C.J. Whitters, Department of Clinical Physics, Glasgow Dental Hospital and School, 378 Sauchiehall Street, Glasgow G2 3 JZ; United Kingdom. E-Mail: j.whitters@dental.gla.ac.uk. TI - Preliminary investigation of a novel carbon dioxide laser for applications in dentistry. SO - Lasers in Surgery & Medicine Vol 26(3) (pp 262-269), 2000. AB - Background and Objective: A novel pulsed CO2 laser was examined for its ability to ablate hard dental tissues. Study Design/Materials and Methods: Lased human enamel surfaces were viewed using light and scanning electron microscopy for evidence of adverse structural changes. In vitro shear bond strength tests were conducted on composite resin bonded to lased enamel surfaces and compared with conventionally prepared specimens. A thermal camera was used to monitor temperature changes during cavity preparation in tooth slabs to assess likely changes to the dental pulp. Results: No charring or surface cracks were observed on lased enamel surfaces using both microscopic techniques. Bonding of the lased enamel surfaces to composite resin was not significantly different from the acid-etched control group. For cavities with a remaining dentine thickness of less than 1 mm, the temperature rise was less than 6 [degree] C. Conclusion: A novel pulsed CO2 laser shows promise for cutting cavities in teeth. (C) 2000 Wiley-Liss, Inc. [References: 21] <6> UI - 2000104292 AU - Barth C AU - Goncalves MC AU - Pires ATN AU - Roeder J AU - Wolf BA IN - B.A. Wolf, Institut fur Physikalische Chemie, Johannes Gutenberg-Universitat, Jakob-Welder-Weg 13, D-55099 Mainz; Germany. E-Mail: bernhard.wolf@uni-mainz.de. TI - Asymmetric polysulfone and polyethersulfone membranes: Effects of thermodynamic conditions during formation on their performance. SO - Journal of Membrane Science Vol 169(2) (pp 287-299), 2000. AB - Membranes of polysulfone (PSU) and polyethersulfone (PES) were prepared from ternary and quaternary mixtures containing N,N-dimethylformamide (DMF) as solvent, water as non-solvent, and acetone (AC) as additive. The conditions for phase inversion and the desired phase separation mechanisms were selected on the basis of the phase behavior determined for the solvent/non-solvent/polymer systems. The influences of the composition of the casting solution, of the support, and of film thickness on structure and permeation properties of the membranes were analyzed by scanning electron microscopy (SEM) plus flux and separation experiments. The mechanisms of phase inversion that should prevail under the different conditions according to the measured phase diagrams were corroborated by means of light scattering experiments. (C) 2000 Elsevier Science B.V. [References: 16] <7> UI - 2000098838 AU - Fader DJ AU - Ratner D IN - Dr. D.J. Fader, Department of Dermatology, University of Michigan Health System, 1910 Taubman Center, Ann Arbor, MI 48109; United States. TI - Principles of CO2/erbium laser safety. SO - Dermatologic Surgery Vol 26(3) (pp 235-239), 2000. AB - BACKGROUND. There are a variety of potential hazards with laser technology. METHODS. A review of the literature. OBJECTIVE. To summarize the potential hazards of CO2 and erbium laser technologies and the safety guidelines and equipment developed to minimize them. RESULTS. Laser hazards can be divided into the following categories: mechanical, environmental, macrobiologic, microbiologic, and iatrogenic. CONCLUSION. At the conclusion of this learning activity, the reader should be able to discuss the mechanical, environmental, macrobiologic, microbiologic, and iatrogenic hazards of resurfacing laser technology, the literature cited to support current safety guidelines, and the equipment developed to promote laser safety. [References: 54] <8> UI - 2000093483 AU - Kimura Y AU - Wilder-Smith P AU - Chang JC AU - Matsumoto K IN - Y. Kimura, Department of Endodontics, Showa University School of Dentistry, 2-1-1 Kitasenzoku, Ohta-ku, Tokyo 145-8515; Japan. E-Mail: yukimura@hp.dent.showa-u.ac.jp. TI - Laser effects on the cell growth and migration of fibroblasts derived from human dental pulp in three-dimensional cell culture. SO - Lasers in the Life Sciences Vol 9(2) (pp 81-93), 1999. AB - The purposes of this study were to evaluate the effects on cell growth and migration of fibroblasts derived from human dental pulp by lasers using three-dimensional (3-D) cell culture system, and to compare the results with those from conventional methods using a two-dimensional (2-D) cell culture system. After extirpation from twenty freshly extracted human third molars showing no clinical sign of caries, pulp tissues were cultured in Minimum Essential Medium using a conventional 2-D cell culture. The cells between 5 and 18 passages were used for this experiment, and collagen gel (1 mg/ml) was used for the 3-D cell culture system. The energy densities used were 0.52 and 1.04 J/cm2 for the gallium aluminum arsenide (GaA1As) diode laser emitting at 830 nm, and 0.1 and 1.0 J/cm2 for the argon (Ar)-dye laser emitting at 632 nm. After laser irradiation, cells were counted at 2, 4, 6, and 8 days, and observed at 3 days by stereomicroscopy. There was no significant difference in cell count between the control groups and the laser-irradiated groups (both lasers) on any day using the 2-D cell culture system (p > 0.01). However, there were significant differences in cell count between the control groups and the laser-irradiated groups (both lasers) at 8 days using the 3-D cell culture (p < 0.01). Cell migration appeared more accelerated by laser in 3-D cell culture than in the 2-D system. These results suggest that the 3-D cell culture system is useful for the evaluation of potential stimulative effects of lasers. [References: 27] <9> UI - 2000087771 AU - Cuny M AU - Kramar A AU - Courjal F AU - Johannsdottir V AU - Iacopetta B AU - Fontaine H AU - Grenier J AU - Culine S AU - Theillet C IN - C. Theillet, Genome et Cancer UMR 5535 CNRS, Centre de Recherche, CRLC Val d'Aurelle-Paul Lamarque, 34298 Montpellier Cedex 5; France. E-Mail: theillet@valdorel.fnclcc.fr. TI - Relating genotype and phenotype in breast cancer: An analysis of the prognostic significance of amplification at eight different genes or loci and of p53 mutations. SO - Cancer Research Vol 60(4) (pp 1077-1083), 2000. AB - Breast cancer heterogeneity can be related directly to its variability at the genetic level. Thus, tumor genotyping could be a valuable approach to define breast tumor subtypes. It has been shown that it is possible to delineate subgroups of breast tumors according to specific sets of DNA amplifications. The aim of the present work was to study the prognostic significance of these DNA amplifications. We studied DNA amplification at eight genes or loci (AIB1, CCND1, EMS1, ERBB2, FGFR1, MDM2, MYC, and RMC20C001) as well as p53 mutations in a series of 640 breast cancer patients who had not received presurgical therapy and analyzed the correlations with survival. DNA amplification was assessed by Southern blotting and was scored positive when exceeding three to five copies. Mutations in the p53 gene were searched by four-color fluorescent single-strand conformational polymorphism, using an automated sequencer. Of the nine genetic alterations tested, four (CCND1, EMS1, FGFR1, and p53 mutations) showed a significant association with reduced disease-free (DFS) and/or overall survival (OVS) in the unselected set of patients by univariate test. Correlations for p53 were found only when selecting mutations in exons 5 or 7. Analysis of node-negative and -positive subgroups of patients showed that MDM2 amplification and p53 mutations bore prognostic significance in node-negative patients, whereas amplification of CCND1, EMS1, and FGFR1 correlated with poor outcome in node-positive patients. Multivariate analysis on an unselected set of patients retained significance for the amplification of EMS1, FGFR1, and MDM2 with DFS, of CCND1 with OVS, and of RMC20C001 with both DFS and OVS. Interestingly, stratified analysis according to nodal status confirmed results obtained in the univariate tests: significance of MDM2 amplification and p53 mutations in node-negative and that of CCND1, EMS1, and FGFR1 in node-positive patients. We also observed an association between the number of genetic alterations observed in a tumor and poor prognosis. Patients with two or more amplified loci had a worsened outcome. Strongly correlating coamplifications such as CCND1 and FGFR1, as well as ERBB2 and MYC, were associated with a significant reduction of patient survival, thus indicating cooperative effects. Our data support the idea that genetic alterations in breast cancer are not only helpful for phenotyping purposes, but can also represent powerful prognostic indicators in the clinical practice. [References: 35] <10> UI - 2000069396 AU - Takema T AU - Yamaguchi M AU - Abiko Y IN - Y. Abiko, Department of Biochemistry, Nihon University, School of Dentistry at Matsudo, 870-1 Sakaecho-Nishi 2, Matsudo, Chiba 271; Japan. E-Mail: yabiko@mascat.nihon-u.ac.jp. TI - Reduction of plasminogen activator activity stimulated by lipopolysaccharide from periodontal pathogen in human gingival fibroblasts by low-energy laser irradiation. SO - Lasers in Medical Science Vol 15(1) (pp 35-42), 2000. AB - Human gingival fibroblasts (hGF) reside in gingival tissues which are challenged frequently by oral bacteria. Lipopolysaccharide (LPS) from periodontal pathogens can penetrate gingival tissues and stimulate plasminogen activator (PA) activity which is implicated in the PA/plasmin proteolytic system. The PA/plasmin system plays an important role in the degradation of the extracellular matrix and synthesis of kinin in the process of inflammation. Anti-inflammatory effects by low-energy laser irradiation have been reported. However, the mechanisms of biostimulatory effects have not been elucidated in detail. The primarily cultured hGF cells were challenged with LPS isolated from Campylobacter rectus which was known as a periodontal pathogen and Ga-Al-As diode low energy laser was irradiated (830 nm, 7.90 J/cm2). The cultured medium of hGF cells showed a marked elevation in PA activity by LPS, which was significantly inhibited by the laser irradiation in a dose-dependent manner. This effect was involved in the reduction of tPA mRNA levels. [References: 46] <11> UI - 2000066349 AU - Sato H AU - Kagayama M AU - Sasano Y AU - Mayanagi H IN - M. Kagayama, Department of Anatomy, Tohoku Univ. School of Dentistry, Seiryocho 4-1, Sendai 980-8575; Japan. E-Mail: kagayama@mail.cc.tohoku.ac.jp. TI - Distribution of interglobular dentine in human tooth roots. SO - Cells Tissues Organs Vol 166(1) (pp 40-47), 2000. AB - The present study was designed to examine the distribution of interglobular dentine in human tooth roots. The material comprised 17 teeth, of which 3 were premolars extracted for orthodontic reasons from children 10- 12 years of age and the other teeth (4 incisors, 3 canines and 7 molars) were extracted for periodontitis from individuals aged 32-63 years. All teeth were free of caries and cervical dentine defects. Ground sections of the teeth cut longitudinally were stained with basic fuchsin and observed by fluorescence and confocal microscopy as well as transmitted light microscopy. Basic fuchsin stained the dentinal tubules, interglobular dentine and the granular layer of Tomes. These structures appeared intense blue to faint violet with transmitted light microscopy, whereas their staining displayed intense fluorescence with fluorescence microscopy. Therefore, the interglobular dentine could be detected more sensitively with fluorescence and confocal microscopy than with transmitted light microscopy. Typical interglobular dentine was present in coronal dentine in most of the teeth. In the radicular dentin, position and size of the interglobular dentine was different among the teeth examined. Most of the teeth had the interglobular dentine in the cervical part of the roots (type A). Two premolars displayed the interglobular dentine in the coronal half of the root (type B). The types A and B contained large interglobular areas. A small amount of interglobular dentine was restricted to the apical half of the roots of two canines and one molar (type C). In contrast to types A and B which were seen at both labial or buccal and lingual sides of roots, the interglobular dentine of type C was seen only at one side, labial or lingual. Some of the tooth roots did not show any interglobular dentine (type D). Most of the incisors, canines and premolar were types A, B, and C, respectively, and the molars were mixed types A, C, and D. These results suggest that the factors affecting dentinogenesis during root formation are unique for each tooth. Copyright (C) 2000 S. Karger AG, Basel. [References: 26] <12> UI - 2000064636 AU - Himmel H-J AU - Downs AJ AU - Greene TM IN - H.-J. Himmel, Inorganic Chemistry Laboratory, University of Oxford, South Parks Road, Oxford OX1 3QR; United Kingdom. TI - Formation and characterization of the indium hydride molecules H2InCl and HInCl2: Matrix isolation and quantum chemical studies. SO - Journal of the American Chemical Society Vol 122(5) (pp 922-930), 2000. AB - Indium monochloride, InCl, adds HCl or H2 when isolated together with these molecules in an argon matrix at 12 K and photoactivated by broad-band UV-visible radiation. On the basis of the infrared spectra of the matrices (including the effects of 1H/2H and 35Cl/37Cl isotopic change) and of density functional theory (DFT) calculations, the products of the reactions were identified as the discrete indium hydride molecules HIncl2 and H2InCl. HInCl2 is also one of the products of the reactions brought about by photolysis of matrices containing In atoms and HCl; both HGaCl2 and H2GaCl are formed from Ga atoms under similar conditions. All six vibrational fundamental (3a1 + +1b1 2b2) of H2InCl and five of the six vibrational fundamental of HInCl2 have been identified; normal coordinate and DFT calculations provide a framework for evaluating the physical properties of the two molecules. <13> UI - 2000062957 AU - Lee J-H AU - Cornelius CP AU - Schwenzer N IN - Dr. J.-H. Lee, Dept. of Oral/Maxillofacial Surgery, Seoul National University Hospital, 28 Yeon-gun-dong, Chong-no-gu, Seoul; South Korea. TI - Neo-osseous flaps using demineralized allogeneic bone in a rat model. SO - Annals of Plastic Surgery Vol 44(2) (pp 195-204), 2000. AB - Surgical reconstruction with revascularized bone grafts can be compromised by donor tissue limitations and may be refined by prefabrication of compound neoflaps using bone substitutes. The principal suitability of demineralized allogeneic bone (DALB) slabs in fabricating neo-osseous flaps based on the inferior epigastric vascular system was studied and compared with neoflaps with autologous bone (AUB). In 45 rats, the histological pattern of bone formation in response to angiogenesis induced by vessel implantation was assessed, and characteristics of vascularization of the neoflap were studied microangiographically at 2, 4, 6, and 8 weeks. Histological techniques included decalcified and nondecalcified sections, as well as intravital polyfluorochrome labeling. Blood flow of the neoflap was also assessed quantitatively using 15-mum microspheres labeled with technetium 99-methylene diphosphate (99-MDP) 8 weeks after flap fabrication. Although the DALB neoflaps showed consistent bone formation and neovascularization, the bone regeneration process was delayed distinctly in comparison with AUB. Microangiographically, however, no differences between the two types of grafts became apparent during all time periods tested. Furthermore, the radioactivity of the DALB neoflap, which means bone blood flow per dry weight, was significantly higher than in AUB grafts and even more than that of intact iliac bone (p = 0.001). The exact meaning of elevated blood flow in DALB and similar degrees of vascularization corresponding to native AUB grafts remains to be determined, but may be a sign of ongoing bone formation resulting in a suitable DALB-containing neo- osseous flap in the long term. The authors findings support that allogeneic bone could be a potential substitute for AUB in creating a prefabricated neo- osseous flap. [References: 19] <14> UI - 2000057299 AU - Lin C-P AU - Lin F-H AU - Tseng Y-C AU - Kok S-H AU - Lan W-H AU - Liao J-D IN - F.-H. Lin, Institute of Biomedical Engineering, College of Medicine, National Taiwan University, Taipei; Taiwan. E-Mail: double@ha.mc.ntu.edu.tw. TI - Treatment of tooth fracture by medium energy CO2 laser and DP-bioactive glass paste: Compositional, structural, and phase changes of DP-bioglass paste after irradiation by CO2 laser. SO - Biomaterials Vol 21(6) (pp 637-643), 2000. AB - Nowadays, fractured teeth are difficult to treat effectively. Currently, root fractures are usually treated by root amputation, hemisection or tooth extraction. If the fusion of tooth fracture by laser were possible, it would offer a different therapy to repair fracture teeth. We tried to use a developed DP-bioactive glass paste to fuse or bridge the tooth crack line by a medium energy continuous-wave CO2 laser. The study is divided into three parts: (1) The compositional and structure changes in tooth enamel and dentin after laser treatment; (2) The phase transformation and recrystallization of DP-bioactive paste during exposure to the CO2 laser; (3) The thermal interactions and bridge mechanism between DP-bioactive glass paste and enamel/dentin when they are subjected to CO2 laser. The present report will focus on the second part that will examine the changes of laser-exposed DP-bioactive glass paste by means of X-ray diffractometer (XRD), Fourier transforming infrared spectroscopy (FTIR), differential thermal analysis/thermogravimetric analysis (DTA/TGA), and scanning electron microscopy (SEM). From the study, we could find that the temperature increase due to laser irradiation is greater than 900 [degree] C and that the DP-bioactive glass paste could be melted in a short period of time after irradiation. In the study, we successfully developed a DP-bioactive glass paste which could form a melting glass within seconds after exposure to a medium energy density continuous-wave CO2 laser. The paste will be used in the near future to bridge the enamel or dentin surface crack by the continuous-wave CO2 laser. Copyright (C) 2000. [References: 17] <15> UI - 2000048170 AU - Pastoriza-Santos I AU - Serra-Rodriguez C AU - Liz-Marzan LM IN - L.M. Liz-Marzan, Departamento de Quimica Fisica, Facultade de Ciencias, Universidade de Vigo, 36200 Vigo; Spain. E-Mail: lmarzan@uvigo.es. TI - Self-assembly of silver particle monolayers on glass from Ag+ solutions in DMF. SO - Journal of Colloid & Interface Science Vol 221(2) (pp 236-241), 2000. AB - The spontaneous reduction of Ag+ ions in N,N-dimethylformamide (DMF) (in the absence of a protecting agent) leads to the homogeneous deposition of silver nanoparticles on clean glass surfaces in contact with the solution. The process of reduction and deposition can be performed at room temperature and in the dark, but the use of visible or UV radiation affects the reaction rate and the morphology of the deposited films. The deposition conditions can be tuned so that a homogeneous monolayer of silver nanoparticles is deposited on the whole surface. (C) 2000 Academic Press. [References: 14] <16> UI - 2000035371 AU - Kurachi C AU - Eduardo CP AU - Magalhaes DV AU - Bagnato VS IN - C. Kurachi, Instituto de Fisica de Sao Carlos, USP, Caixa Postal 369, 13560-970-Sao Carlos, SP; Brazil. E-Mail: cristina@if.sc.usp.br. TI - Human teeth exposed to argon laser irradiation: Determination of power- time-temperature working conditions. SO - Journal of Clinical Laser Medicine & Surgery Vol 17(6) (pp 255-259), 1999. AB - Objective: This study was conducted to establish the operating parameters of the argon laser without thermal damage to the pulp tissue for clinical applications. Summary Background Data: Previous studies have mainly compared the temperature modifications of the pulp chamber in a very limited situation, where a complete view of the thermal history cannot be obtained nor even extrapolated to new applications. Methods: We used samples of molar and premolar tooth where a class V cavity was prepared and illuminated with an argon laser at different power levels, fixing the exposition area for all cases. Situations including open cavity and teeth restoration were analyzed. High-precision thermistors were placed in four different positions, one of which was inside the pulp chamber. The temperature evolution was monitored continuously by an interfaced computer during all laser exposure. Special attention was paid to the intrapulpal temperature variation because it is considered the most vulnerable thermal region. The temperature time evolution allowed the determination of the operating conditions (power-time-temperature variation) in which the use of the argon laser causes no pulpal damage. As a function of temperature variation, we divided the whole parameter space (power-time-temperature) into zones and the optimum zone of operation was determined. Conclusions: We created a diagram called power-time-temperature (PTT) where zones of temperature increased under laser irradiation allow the verification of which condition is safe for clinical laser application. The results have a broad use when this type of analysis is applicable. [References: 14] <17> UI - 2000035370 AU - Yamada Y AU - Nakamura Y AU - Hossain M AU - Joe T AU - Kawanaka T AU - Matsumoto K IN - Dr. K. Matsumoto, Department of Endodontics, Showa University School of Dentistry, 2-1-1 Kitasenzoku, Ohta-ku, Tokyo 145-8515; Japan. TI - Effects of copper vapor laser irradiation in human enamel and dentin: Ablation and morphological studies. SO - Journal of Clinical Laser Medicine & Surgery Vol 17(6) (pp 249-253), 1999. AB - Objective: This investigation was performed to determine the ranges of ablation quantitatively and to evaluate the morphological changes in human enamel and dentine irradiated by a green copper vapor laser. Summary Background Data: Recently, green copper vapor laser (CVL), which is said to have characteristics similar to the argon laser has been introduced in dentistry. Methods: Extracted noncarious human teeth were used in this study. A CVL was used to ablate human dental hard tissues with the output powers of 2.0 W. Ablation extent without water spray using red or black ink was measured, and the morphological changes on enamel and dentin were also investigated by stereoscopy and scanning electron microscopy (SEM). Results: In the samples, irradiated by a CVL after painting red ink on the surface, the ablation depth was increased more than that of irradiation after painting with black ink. Morphological findings by SEM indicated that when irradiated with red ink, brown carbonization was recognized on enamel and dentin surfaces. In addition, cavities with a molten lava-like appearance were produced and an irregular structure with many microholes was observed in the enamel and dentin. Alternatively, a shallow cavity with little carbonization was produced with black ink. Conclusions: Removal of dental hard tissues appears to be possible using the CVL. However, further studies should be performed on the selection of radiation conditions that achieve the desired ablation with minimal side effects. [References: 21] <18> UI - 2000035368 AU - Blankenau RJ AU - Powell GL AU - Ellis RW AU - Westerman GH IN - G.L. Powell, Dental Education, BC101 School of Medicine, 50 North Medical Drive, Salt Lake City, UT 84132; United States. E-Mail: DentalEd@pre.med.utah.edu. TI - In vivo caries-like lesion prevention with argon laser: Pilot study. SO - Journal of Clinical Laser Medicine & Surgery Vol 17(6) (pp 241-243), 1999. AB - Objective: This clinical pilot study was conducted to investigate the effectiveness of argon laser irradiation to reduce demineralization or loss of tooth structure in vivo. Summary Background Data: In vitro research previously demonstrated the ability of argon laser irradiation to reduce demineralization or loss of tooth structure. Methods: Using the Ogaard model of producing demineralization, the experimental teeth were irradiated with argon laser of 250 mW (producing approximately 12 J/cm2) prior to banding. Polarized light evaluation of the sectioned, extracted teeth was used to determine the amount of demineralization. Results: Results showed a 29.1% reduction in demineralization in the experimental teeth as compared to the bilateral control teeth. Conclusion: Low-power argon laser irradiation significantly reduced demineralization clinically. [References: 22] <19> UI - 2000035286 AU - Fontana M AU - Buller TL AU - Dunipace AJ AU - Stookey GK AU - Gregory RL IN - M. Fontana, Oral Health Research Institute, 415 Lansing St., Indianapolis, IN 46202; United States. E-Mail: mfontan@iusd.iupui.edu. TI - An in vitro microbial-caries model used to study the efficacy of antibodies to Streptococcus mutans surface proteins in preventing dental caries. SO - Clinical & Diagnostic Laboratory Immunology Vol 7(1) (pp 49-54), 2000. AB - The first step for a pathogenic bacterium to initiate infection is via attachment (i.e., through surface determinants) to a suitable receptor. An in vitro microbial artificial-mouth model was used to test the efficacy of polyclonal antibodies to Streptococcus mutans cell surface proteins (CsAb) and a cell surface 59-kDa protein (59Ab) in preventing S. mutans colonization and carious lesion formation. In study 1, groups of 12 human teeth specimens were inoculated with S. mutans, which were incubated with different concentrations of CsAb (A1 [positive control], sterile saline, no antibody; A2, 0.007 mg of antibody protein/ml; and A3, 0.7 mg of antibody protein/ml) for 1 h at 37 [degree] C. The negative control group (B1) was not infected and was incubated with Trypticase soy broth (TSB) without dextrose supplemented with 5% sucrose (TSBS). In study 2, the same study design was used except that 59Ab was used instead of CsAb, normal rabbit serum was used in the positive control group (A1), and TSB supplemented with 1% glucose was used as the nutrient to control for sucrose-dependent colonization. All groups were exposed for 4 days to circulating cycles of TSBS and TSB (study 1 and study 2, respectively; 30 min each, three times per day) and a mineral washing solution (21 h per day). Prior to each nutrient cycle, 1 ml of the appropriate CsAb or 59Ab solution was administered to each group and allowed to mix for 30 min before cycling was resumed. Data obtained by confocal laser scanning microscopy demonstrated the presence of a significantly smaller (P < 0.05) lesion area and a smaller total lesion fluorescence in group A3 than in group A1 for both studies. In study 1, group A2 had significantly smaller values than A1 for lesion depth and area. There were no significant differences between groups A2 and A3 for lesion area or between groups A1 and A2 for total lesion fluorescence. In study 2, there were no significant differences among groups A1 and A2 for lesion depth or between groups A2 and A3 for all of the parameters studied. In both studies, there were no significant differences between S. mutans plaque CFU numbers among any of the groups. These studies demonstrated the efficacy of CsAb and 59Ab in reducing primary caries development in this model, although the underlying mechanism remains unclear. [References: 17] <20> UI - 2000030768 AU - Mandapati R AU - Skanes A AU - Chen J AU - Berenfeld O AU - Jalife J IN - Dr. R. Mandapati, Department of Pharmacology, SUNY Health Sciences Center, 766 Irving Ave., Syracuse, NY 13210; United States. E-Mail: mandapar@vax.cs.hscsyr.edu. TI - Stable microreentrant sources as a mechanism of atrial fibrillation in the isolated sheep heart. SO - Circulation Vol 101(2) (pp 194-199), 2000. AB - Background - Atrial fibrillation (AF) has traditionally been described as aperiodic or random. Yet, ongoing sources of high-frequency periodic activity have recently been suggested to underlie AF in the sheep heart. Our objective was to use a combination of optical and bipolar electrode recordings to identify sites of periodic activity during AF and elucidate their mechanism. Methods and Results - AF was induced by rapid pacing in the presence of 0.1 to 0.5 mumol/L acetylcholine in 7 Langendorff-perfused sheep hearts. We used simultaneous optical mapping of the right and left atria (RA and LA) and frequency sampling of optical and bipolar electrode recordings (including a roving electrode) to identify sites having the highest dominant frequency (DF). Rotors were identified from optical recordings, and their rotation period, core area, and perimeter were measured. In all, 35 AF episodes were analyzed. Mean LA and RA DFs were 14.7 +/- 3.8 and 10.3 +/- 2.1 Hz, respectively. Spatiotemporal periodicity was seen in the LA during all episodes. In 5 of 7 experiments, a single site having periodic activity at the highest DF was localized. The highest DF was most often (80%) localized to the posterior LA, near or at the pulmonary vein ostium. Rotors (n = 14) were localized on the LA. The mean core perimeter and area were 10.4 +/- 2.8 mm and 3.8 +/- 2.8 mm2, respectively. Conclusions - Frequency sampling allows rapid identification of discrete sites of high-frequency periodic activity during AF. Stable microreentrant sources are the most likely underlying mechanism of AF in this model. [References: 21] <21> UI - 1999436375 AU - Engebretson RR AU - Von Wandruszka R IN - R. Von Wandruszka, Department of Chemistry, University of Idaho, Moscow, ID 83844-2343; United States. TI - Effects of humic acid purification on interactions with hydrophobic organic matter: Evidence from fluorescence behavior. SO - Environmental Science & Technology Vol 33(23) (pp 4299-4303), 1999. AB - Conventional isolation of humic materials from natural matrixes includes demineralization by treatment with HF/HCl. The possible effect of this on the structural integrity of humic acid (HA) was investigated by comparing the interactions of two aqueous HAs, one produced by the conventional procedure (CHA) and the other by a gentler resin method (RHA), with a hydrophobic probe (pyrene). Although RHA had a substantially higher ash content, it was found that this had relatively little effect on its interaction with the probe molecule. In view of the micellar model of dissolved HAs, however, it was noted that the HF-treated HA had a greater apparent ability to sequester pyrene and isolate it from the aqueous bulk. This was revealed by the kinetics of probe fluorescence enhancement when Mg2+ was added to a solution also containing HA and by the anisotropy excitation spectra of the native humic fluorophores. The effect was ascribed to a lesser degree of conjugation in the HA demineralized with HF, producing polymers of greater flexibility that formed micelle-like structures more quickly and effectively. [References: 47] <22> UI - 1999436355 AU - Mastral AM AU - Callen MS AU - Murillo R AU - Garcia T IN - A.M. Mastral, Instituto de Carboquimica, Maria de Luna, 12, 50015 Zaragoza; Spain. E-Mail: AMastral@carbon.icb.csic.es. TI - Combustion of high calorific value waste material: Organic atmospheric pollution. SO - Environmental Science & Technology Vol 33(23) (pp 4155-4158), 1999. AB - Waste tire combustion in an atmospheric fluidized-bed (AFB) reactor (7 cm i.d., 76 cm height) has been performed in a laboratory plant with the aim of studying the polycyclic aromatic hydrocarbon (PAH) emissions as a function of combustion temperature. The main aim has been to compare these organic emissions with the ones obtained when coal is burned at the same combustion conditions. PAH emissions have been analyzed in solids collected in two cyclons at the exit of the reactor and in a trap system formed by a condenser, a filter (20 mum), and an adsorbent. After PAH extraction with dimethylformamide (DMF) by sonication, fluorescence spectroscopy in the synchronous mode (FS) has been used as an analytical technique to quantify the PAHs emitted. It could be concluded that higher PAH emissions are generated when this waste material is burnt at the same conditions used for coal atmospheric fluidized-bed combustion (AFBC). [References: 25] <23> UI - 1999419148 AU - Keisswetter R AU - Burgemeister T AU - Mannschreck A IN - A. Mannschreck, Department of Organic Chemistry, University of Regensburg, Universitatstrasse 31, D-93040 Regensburg; Germany. TI - 1',3',3'-Trimethyl-6,8-dinitrospiro[2H-1-benzopyran-2,2'-indoline]: Fast thermal enantiomerization and slow thermal equilibration with a ring-opened isomer. SO - Enantiomer Vol 4(3-4) (pp 289-296), 1999. AB - The transformation of the title compound (RS)-2 into the merocyanine 1 was studied by time-dependent 1H-NMR in DMF-D7 at 22 [degree] C. An equilibrium containing 1.9% (RS)-2 is established; the free enthalpy of activation for the (RS)-2 [right arrow] 1 process amounts to 101.3 kJ mol-1. The interconversion of the enantiomers of the title compound was studied by temperature-dependent 1H-NMR in DMF-D7. The barrier to ring opening (60.1 kJ mol-1, 23 [degree] C) was determined for the first time. Apparently (RS)-2 represents the 2H-1-benzopyran with the lowest DeltaG( [not equal] )-value for this process which occurs as often as 155 times per second at 23 [degree] C. The characterization and all 1H-NMR measurements of (RS)-2 were facilitated by its isolation as a solid. The two reactions, namely interconversion of enantiomers and transformation into a merocyanine, are found to be kinetically independent of each other. Their mechanisms are discussed on the basis of the scheme of free enthalpy changes. [References: 29] <24> UI - 1999405729 AU - Zuerlein MJ AU - Fried D AU - Featherstone JDB IN - Dr. D. Fried, University of California, 707 Parnassus, San Francisco, CA 94143-0758; United States. TI - Modeling the modification depth of carbon dioxide laser-treated dental enamel. SO - Lasers in Surgery & Medicine Vol 25(4) (pp 335-347), 1999. AB - Background and Objectives: Many studies of laser-induced thermal decomposition of dental enamel have demonstrated a reduction in the rate of acid dissolution, size of artificial caries like lesions, and acid reactivity. Additionally, studies have correlated the loss of carbonate from dental enamel with a reduction in acid dissolution. Dental mineral consists of hydroxyapatite with many substitutions, the major one being carbonate ( [similar] 3-5% by weight), which markedly affects acid reactivity. The principle objective of the present work was to determine the precise depth of modification, i.e., thermally induced decomposition of dental enamel (carbonate loss), at the predicted optimum laser irradiation parameters. Study Design/Materials and Methods: Bovine enamel blocks were irradiated at lambda = 9.6 mum with 2-musec and 100-musec pulses and at lambda = 10.6 mum with 2- musec pulses. Carbonate loss was calculated from infrared spectra as a function of depth and compared to numerical simulations of the maximum temperature rise. Results: Carbonate loss was initiated at temperatures greater than 400 [degree] C, but was complete only after repeated irradiation of the surface above the melting threshold. Carbonate loss of dental enamel irradiated at 9.6 mum with a 100-musec pulse and at 10.6 mu with a 2-musec pulse was greater than that of enamel irradiated at 9.6 mum with a 2-musec pulse. The depth of carbonate loss in dental enamel irradiated with a 2-musec pulse was greater for lambda = 10.6 mum than for lambda = 9.6 mum. Conclusion: The depth of modification is consistent with the presented model that incorporates the absorption depth and thermal relaxation time/pulse duration. However, repeated irradiation is required for complete removal of carbonate, depending on absorption depth and pulse duration. [References: 34] <25> UI - 1999398101 AU - Xie H AU - Yi S AU - Yang X AU - Wu S IN - H. Xie, Institute of Photographic Chemistry, Chinese Academy of Sciences, Beijing 100101; China. E-Mail: skwu@ipc.ac.cn. TI - Study on host-guest complexation of anions based on a tripodal naphthylurea derivative. SO - NEW J CHEM, Vol 23(11) (pp 1105-1110), 1999. AB - In this paper, we report the synthesis of tripodal naphthylurea tri(2- aminoethyl)amine (i) designed for the recognition of anions (e.g., H2PO4- and HSO4-) by complexation-enhanced changes of fluorescence in DMF solution. The effect of protonation and addition of anions upon the photophysical properties of 1 was investigated for comparison with those of analogous receptors, 1.HCl and the di(2-aminoethyl)amine (2) and n-amylamine (3) naphthylurea derivatives. The fluorescent chemosensor 1 shows obvious changes in its fluorescence spectrum upon addition of H2PO4- and HSO4- anions. The association constants for the complexes of 1 with anions were measured by fluorometric titration and show a higher specific selectivity for the H2PO4- anion with a 1:1 stoichiometry of the complex: These effects, which strongly depend on the interaction of hydrogen-containing oxoanions with the receptor, can be interpreted in terms of anion-induced reduction of the efficiency of photoinduced electron transfer (PET). The results were also confirmed by 1H NMR spectra and a plausible structure for the complex of 1.H+ with HPO42- is proposed. [References: 21] <26> UI - 1999388394 AU - Hossain M AU - Nakamura Y AU - Kimura Y AU - Ito M AU - Yamada Y AU - Matsumoto K IN - Dr. K. Matsumoto, Department of Endodontics, Showa University School of Dentistry, 2-1-1 Kitasenzoku, Ohta-ku, Tokyo 145-8515; Japan. E-Mail: koukichi@senzoku.showa-u.ac.jp. TI - Acquired acid resistance of dental hard tissues by CO2 laser irradiation. SO - Journal of Clinical Laser Medicine & Surgery Vol 17(5) (pp 223-226), 1999. AB - Objective: This investigation was performed to evaluate the effect of CO2 laser irradiation on the acquired acid resistance of dental hard tissues to artificial caries-like formation and the ultrastructure of lased areas was morphologically investigated in vitro. Summary Background Data: In recent years, many studies have been carried out to evaluate the effect of the CO2 laser on the enhanced resistance to artificial caries formation of enamel. However, a limited number of papers concerning its effect on dentin have been published. Methods: A CO2 laser of 10.6 mum wavelength was used to irradiate human enamel and dentin samples from 20 extracted human molar teeth, and samples were subjected to 2 mul of 0.1 M lactic acid solution (pH 4.8) for 24 h at 36 [degree] C. The parts per million (ppm) of calcium ion (Ca2+) dissolved in each solution was determined by atomic absorption spectrophotometry and the morphological changes were investigated by scanning electron microscopy (SEM). Results: The lowest mean Ca2+ ppm was recorded in the samples irradiated at 3 W, followed by 2 W, 1 W, and unlased samples. SEM observation showed that the lased areas were melting with solidification of the smear layer. Even after acid demineralization, the lased surfaces were almost unchanged. Conclusions: The results of this study suggested that CO2 laser irradiation could sufficiently melt and solidify the enamel and dentin surfaces and thus enhance resistance to artificial caries-like formation. [References: 23] <27> UI - 1999388391 AU - Yonaga K AU - Kimura Y AU - Matsumoto K IN - Dr. K. Yonaga, Department of Endodontics, Showa University School of Dentistry, 2-1-1 Kitasenzoku, Ohta-ku, Tokyo 145-8515; Japan. E-Mail: yonaga@senzoku.showa-u.ac.jp. TI - Treatment of cervical dentin hypersensitivity by various methods using pulsed Nd:YAG laser. SO - Journal of Clinical Laser Medicine & Surgery Vol 17(5) (pp 205-210), 1999. AB - Objective: The purpose of this study was to evaluate the results of two irradiated regions, the cervical and apical, for cervical dentin hypersensitivity treatment using pulsed a Nd:YAG laser with or without black ink. Summary Background Data: There has been no reports on the irradiated area(s) except the cervical region for dentin hypersensitivity treatment using pulsed Nd:YAG laser. Methods: A total of 180 teeth diagnosed with cervical dentin hypersensitivity in 54 (39 females, 15 males, aged 21 to 73) healthy adult patients were included in this study, and teeth were randomly divided into four groups of 45 each. Sensitivity was rated using a blast from a fully depressed air syringe on a four-grade scale both before and up to 2 months after laser treatment. The effectiveness was evaluated on the change in the degree of hypersensitivity after laser treatment. The tooth surfaces in groups 1 and 2 were observed by the replica model method using scanning electron microscopy (SEM). Results: The methods of irradiation at the cervical regions were better than those at the apical regions except for the period 2 months later. The laser effect was enhanced by black ink at both areas. The effective (excellent and good) rate was decreased depending on the time in every group. SEM observation at the tooth surfaces from group 2 showed that dentinal tubules were occluded or narrowed after laser irradiation. Conclusions: These results show that the method of irradiation by a pulsed Nd:YAG laser at cervical regions with black ink is the most effective for cervical dentin treatment of hypersensitivity and recurrence by this method is less than in other methods. [References: 47] <28> UI - 1999388389 AU - Romanos G AU - Nentwig G-H IN - Dr. G. Romanos, Department of Oral Surgery, Dental School Frankfurt (Carolinum), Theodor Stern-Kai 7, D-60590 Frankfurt a.M.; Germany. E-Mail: Dr.G.E.Romanos@t-online.de. TI - Diode laser (980 nm) in oral and maxillofacial surgical procedures: Clinical observations based on clinical applications. SO - Journal of Clinical Laser Medicine & Surgery Vol 17(5) (pp 193-197), 1999. AB - Objective: The aim of this study was to examine the wound healing of soft tissue after the application of a diode laser (980 nm) in oral surgical procedures. Summary Background Data: Like the CO2 laser, the diode laser can be used for soft tissue surgery without extensive experience in the field of oral surgical. Methods: A diode laser was used to treat a variety of oral soft tissue lesions in 22 patients. The oral surgical procedures included removal of soft tissue tumors, frenectomies, excision of gingival hyperplasias, vestibuloplasties, hemangioma removal, and periimplant soft tissue surgery. The laser was used in both pulsed and continuous modes, with and without contact to the tissue. Intraoperative and postoperative clinical observations are reported. Results: Our preliminary clinical findings include sufficient hemostasis and precise incision margin with all of the surgical procedures. The coagulation properties, associated with the use of a diode laser, were particularly beneficial during removal of vascular lesions. The postoperative advantages, i.e., lack of swelling, bleeding, pain or, scar tissue formation, and the good wound healing were observed in all of the clinical applications and were dependent only on the laser physical parameters used. Conclusions: The clinical application of the diode (980 nm) laser in oral and maxillofacial surgical procedures seems to be of beneficial effect for daily practice. [References: 11] <29> UI - 1999369404 AU - Shelburne CE AU - Prabhu A AU - Gleason RM AU - Mullally BH AU - Coulter WA IN - C.E. Shelburne, 3M Company, 270-2S-09 3M Center, St. Paul, MI 55144; United States. E-Mail: ceshelburne@mmm.com. TI - Quantitation of Bacteroides forsythus in subgingival plaque: Comparison of immunoassay and quantitative polymerase chain reaction. SO - Journal of Microbiological Methods Vol 39(2) (pp 97-107), 2000. AB - Our objective was to compare three methods (enzyme-linked immunosorbent assay [ELISA], endpoint and quantitative polymerase chain reaction [E-PCR and Q-PCR]) for detection and quantitation of Bacteroides forsythus in 56 plaque samples from seven subjects with progressive periodontal disease. Samples collected in buffer were pelleted and resuspended in 500 mul of water. Fifty mul aliquots were removed for an ELISA performed on bacteria or plaque immobilized on 96-well plates and probed with B. forsythus specific antibody. An occurrence of 3.7+/-0.6.104 or more bacteria were detected by ELISA in pure culture; 26 of 54 plaque samples were positive, two samples could not be analyzed. Samples for PCR were autoclaved for 10 min prior to use. The detection level of E-PCR using primers specific for B. forsythus 16S rRNA was 200 cells and 42 out of 56 samples were positive based on ethidium bromide stained agarose gels. Q-PCR using the same primers combined with a nested fluorescent oligonucleotide probe detected 10+/-0.32 bacteria in pure culture; 43 of 56 plaque samples were positive. The ELISA and Q-PCR obtained identical results with 36 of the 54 samples assayed; there were one false positive and 17 false negative ELISA results using Q-PCR as standard. The positive proportions of plaque samples were almost the same for E-PCR and Q-PCR. We conclude that the PCR methods are more appropriate for a multicenter study because of greater sensitivity and convenience of sample transportation from clinics to a central laboratory. Copyright (C) 2000. [References: 44] <30> UI - 1999369146 AU - Maruo N AU - Uchiyama M AU - Kato T AU - Arai T AU - Akisada H AU - Nishino N IN - N. Nishino, Department of Applied Chemistry, Faculty of Engineering, Kyushu Institute of Technology, Kitakyushu 804-8550; Japan. E-Mail: nishino@che.kyutech.ac.jp. TI - Hemispherical synthesis of dendritic poly(L-lysine) combining sixteen free-base porphyrins and sixteen zinc porphyrins. SO - Chemical Communications Vol 5(20) (pp 2057-2058), 1999. AB - Dendritic poly(L-lysine) combining sixteen free-base porphyrins and sixteen zinc porphyrins hemispherically at the fifth generation was successfully synthesised and showed intramolecular fluorescence energy transfer in DMF. [References: 9] <31> UI - 1999354714 AU - Zhou M AU - Andrews L IN - L. Andrews, Department of Chemistry, University of Virginia, Charlottesville, VA 22901; United States. TI - Infrared spectra of RhCO+, RhCO, and RhCO- in solid neon: A scale for charge in supported Rh(CO) catalyst systems. SO - Journal of the American Chemical Society Vol 121(39) (pp 9171-9175), 1999. AB - Laser-ablated Rh+, Rh, and electrons react with CO on condensation in excess neon at 4 K to form RhCO+, RhCO, RhCO-, and Rh(CO)2+, Rh(CO)2, Rh(CO)2-, and higher carbonyls. These rhodium carbonyls are identified by isotopic substitution (13CO, C18O, and mixtures), electron trapping with added CCl4, and comparison with DFT calculations of isotopic frequencies. This is the first spectroscopy of isolated rhodium carbonyl cations and anions. The isolated monocarbonyl species provide a scale to estimate local charge on Rh(CO) sites in catalyst systems. <32> UI - 1999347759 AU - Anzai M AU - Toda A AU - Ohno H AU - Takemoto Y AU - Fujii N AU - Ibuka T IN - T. Ibuka, Grad. School of Pharmaceutical Sci., Kyoto University, Sakyo-ku, Kyoto 606-8501; Japan. TI - Palladium-catalyzed regio- and stereoselective synthesis of N-protected 2,4-dialkylated azacyclobutanes from amino allenes. SO - Tetrahedron Letters Vol 40(41) (pp 7393-7397), 1999. AB - Palladium-catalyzed reaction of N-arylsulfonyl-1-alkyl-3,4-dienylamines with an aryl iodide in the presence of potassium carbonate in DMF at around 70 [degree] C affords most predominantly the 2,4-cis-disubstituted azacyclobutanes bearing an aryl group on the double bond in good yields. [References: 13] <33> UI - 1999346147 AU - Wang P-L AU - Shirasu S AU - Shinohar M AU - Azuma Y AU - Daito M AU - Yasuda H AU - Ohura K IN - P.-L. Wang, Department of Pharmacology, Osaka Dental University, 8-1 Kuzuhahanazono-cho, Hirakata 573-1121; Japan. E-Mail: wang@cc.osaka-dent.ac.jp. TI - IL-10 inhibits Porphyromonas gingivalis LPS-stimulated human gingival fibroblasts production of IL-6. SO - Biochemical & Biophysical Research Communications Vol 263(2) (pp 372-377), 1999. AB - Lipopolysaccharides (LPS) of Porphyromonas gingivalis have been implicated in the initiation and development of periodontal diseases. In a previous study, we investigated the signal transduction pathway of P. gingivalis and demonstrated that LPS stimulates the production of interleukin (IL)-6 in human gingival fibroblasts (HGFs), which in turn activates osteoclasts in vitro. The cytokine, IL-10, was initially described as cytokine synthesis inhibitory factor. In this study, we examined that effect of IL-10 on P. gingivalis LPS-induced human gingival fibroblast production of IL-6, LPS-induced IL-6 production was inhibited by IL-10 in a dose-dependent manner. Flow cytometric analysis showed that HGFs bind to fluorescein-isothiocyanate (FITC) labeled IL-10. Western blotting analysis demonstrated the expression of IL-10 receptor on the cell surface of these cells. Engagement of LPS initiated the protein tyrosine phosphorylation of several intracellular proteins including extracellular signal-regulated kinase 2 (ERK2), and these events were suppressed by IL-10. These results suggest that IL-10 inhibits the inflammatory response via the IL-10 receptor in P. gingivalis LPS-initiated periodontal diseases. [References: 46] <34> UI - 1999344610 AU - Pelino JEP AU - Mello JB AU - Eduardo CP AU - Jorge AOC IN - J.E.P. Pelino, Av. Francisco Jose Longo, 777, 12201-970 Sao Jose dos Campos-SP; Brazil. E-Mail: pelinoj@dentistry.ucsf.edu. TI - In vitro study of the Nd:YAG laser effect on human dental enamel: Optical and scanning electron microscope analysis. SO - Journal of Clinical Laser Medicine & Surgery Vol 17(4) (pp 171-177), 1999. AB - Objective: The Nd:YAG laser irradiation of dental enamel was evaluated in enamel demineralization experiments in a Streptococcus mutans culture media. Summary Background Data: Previous studies had shown that a continuous wave Nd:YAG laser at an energy of approximately 67 mJ may induce an increased acid resistance in human dental enamel when exposed to severe demineralization conditions. Methods: Enamel windows of 3 x 4 cm in the buccal surface were irradiated with a continuous wave Nd:YAG laser at a wavelength of 1,064 mum using energy densities of from 83.75 to 187.50 J/cm2. Enamel windows of 3 x 4 cm on the lingual surface served as control (without the laser irradiation). The enamel windows were then exposed to a Streptococcus mutans culture media at a temperature of 37 [degree] C for 15 and 21 days. The laser effects and demineralization were examined both by optical microscopy and scanning electron microscopy (SEM). Results: A comparison between the lased and the unlased windows of enamel showed fusion and recrystalization of the enamel and increased acid-resistance in all groups irradiated with the Nd:YAG laser. On the other hand, the 3 x 4 delimited enamel surfaces from the control group (not irradiated with the Nd:YAG laser) showed 100% demineralization. Conclusions: These findings are consistent with the finding that laser irradiation of dental results in significant reduction of the effective solubility of enamel mineral. [References: 22] <35> UI - 1999343767 AU - Tsuruoka M AU - Yamamoto S AU - Yamamoto T AU - Kasai H AU - Takeuchi S IN - Dr. M. Tsuruoka, Dept. of Ophthalmol., Toho Univ. Sakura Hosp., 564-1 Shimoshizu, Sakura 285-0841; Japan. TI - Neovascular maculopathy in a patient with multiple evanescent white dot syndrome. [Japanese] SO - Folia Ophthalmologica Japonica Vol 50(7) (pp 578-581), 1999. AB - Multiple evanescent white dot syndrome (MEWDS) generally has a good visual prognosis; however, a few cases have been reported in which subretinal neovascularization developed after MEWDS. We report on a 45-year-old female with MEWDS who developed neovascular maculopathy. The patient presented with blurred vision in her left eye. Her visual acuity was 0.2 (1.2), and fundus examination revealed multiple small gray-white dots at the level of the deep retina in the posterior pole and the midperipheral retina and a yellow-white spot at the macula. On fluorescein angiography, hyperfluorescent spots were seen throughout the entire retina. One month later, without treatment, the patient's vision was normal and the gray-white dots had disappeared. Five months later, however, serous retinal detachment with subretinal hemorrhage developed and was confirmed by angiography as being due to subretinal noevascularization. After successful laser photocoagulation, the submacular noevascularization became fibrotic and final visual acuity was 0. 9. We conclude from this case that MEWDS is a rare but possible cause of subretinal noevascularization, which can be treated successfully by laser photocoagulation. [References: 7] <36> UI - 1999342979 AU - Kozma C AU - Chong SS AU - Meck JM IN - Dr. C. Kozma, Child Development Center, Georgetown University Medical Center, 3307 M Street, Washington, DC 20007-3935; United States. TI - Interstitial deletion of 4p15.32p16.3 in a boy with minor anomalies, hearing loss, borderline intelligence, and oligodontia. SO - American Journal of Medical Genetics Vol 86(4) (pp 316-320), 1999. AB - We describe an 11-year-old boy of Saudi origin with an interstitial deletion in the short arm of chromosome 4 (p15.32p16.3) as determined by G- banding and fluorescent in situ hybridization. His clinical manifestations Were similar but not identical to previously reported cases of interstitial deletion in the same chromosomal region, and were not those associated with Wolf-Hirschhorn syndrome. The boy had normal facial characteristics, short stature, minor anomalies of hands and feet, amblyopia of the right eye, bilateral hearing loss, and hypotonia. On developmental testing, he had borderline intelligence, with a severe sensory integration and motor planning disorder, and severe deficits in the communication domain. In addition, he had severe oligodontia affecting his secondary dentition. This finding supports the presence of one or more genes involved in dentition in this chromosomal region. [References: 19] <37> UI - 1999327957 AU - Mastral AM AU - Callen MS AU - Garcia T IN - A.M. Mastral, Instituto de Carboquimica, CSIC, Maria de Luna 12, 50015 Zaragoza; Spain. E-Mail: AMastral@carbon.icb.csic.es. TI - Polycyclic aromatic hydrocarbons and organic matter associated to particulate matter emitted from atmospheric fluidized bed coal combustion. SO - Environmental Science & Technology Vol 33(18) (pp 3177-3184), 1999. AB - The polycyclic aromatic hydrocarbons (PAH) and the organic matter (OM) content associated with particulate matter (PM) emissions from atmospheric fluidized bed coal combustion have been studied. The two main aims of the work have been (a) to study OM and PAH emissions as a function of the coal fluidized bed combustion (FBC) variables in solid phase and (b) to check if there is any correlation between OM and PAH contained in the PM. The combustion was carried out in a laboratory scale (D(i) = 7 cm and H = 76 cm) plant at different combustion conditions: temperature (650-950 [degree] C), percentage of oxygen excess (5-40%), and total air flow (700-1100 L/h). PAH associated on the particulate matter have been analyzed by fluorescence spectroscopy in the synchronous mode (FS) after PM extraction by sonication with dimethylformamide (DMF). It can be concluded that there is not a direct relationship between the OM content and the PAH supported in the PM emitted. In addition, neither PM or OM show dependence between themselves. [References: 29] <38> UI - 1999318882 AU - Su JYC AU - Duffy S AU - Murphy TH IN - T.H. Murphy, Department of Psychiatry, University of British Columbia, Vancouver, BC; Canada. E-Mail: thmurphy@unixg.ubc.ca. TI - Reduction of H2O2-evoked, intracellular calcium increases in the rat N18-RE-105 neuronal cell line by pretreatment with an electrophilic antioxidant inducer. SO - Neuroscience Letters Vol 273(2) (pp 109-112), 1999. AB - Pretreatment of the neuronal cell line N18-RE-105 with the antioxidant enzyme inducer dimethyl fumarate (DMF) reduced cell death elicited by H2O2 (50 mM for 1 h) as measured 24 h after H2O2 washout. Oxidants like H2O2 may contribute to cell death by increasing intracellular ionized calcium ([Ca2+](i)), suggesting that DMF may in part confer protection by altering H2O2-induced [Ca2+](i) signals. To examine this possibility, we measured [Ca2+](i) of fura-2-loaded cultures of DMF- and vehicle-pretreated cells during H2O2 superfusion. H2O2 exposure induced a delayed [Ca2+](i) increase that was significantly lower in DMF-pretreated cells than controls. Elevation of extracellular cystine also reduced the H2O2 induced [Ca2+](i) elevation. Thus, antioxidant upregulation may contribute to protection during oxidative stress by stabilizing [Ca2+](i). However, since oxidative stress may induce cytotoxicity by multiple pathways, [Ca2+](i) stabilization may not be the only mechanism responsible for the protective effect of DMF. Copyright (C) 1999 Elsevier Science Ireland Ltd. [References: 28] <39> UI - 1999307840 AU - Luttrull JK AU - Marmor MF AU - Nanda M IN - Dr. J.K. Luttrull, 3160 Telegraph Road, Ventura, CA 93003; United States. TI - Progressive confluent circumpapillary multiple evanescent white-dot syndrome. SO - American Journal of Ophthalmology Vol 128(3) (pp 378-380), 1999. AB - PURPOSE: To describe a morphologic variant of the multiple evanescent white-dot syndrome that can mimic other conditions. METHODS: We examined three patients with severe cases of unilateral multiple evanescent white-dot syndrome characterized by an atypical progressive circumpapillary discoloration of the fundus. RESULTS: The confluent circumpapillary lesion progressed toward or beyond the equator of the fundus, raising initial concern of a viral retinitis. However, pinpoint dots at the leading edge evolved into the typical wreath-like spots of multiple evanescent white-dot syndrome, which then coalesced into the advancing edge of a geographic retinitis or retinal pigment epitheliitis, before spontaneous resolution. CONCLUSION: Progressive geographic circumpapillary discoloration, appearing as a giant white spot, occurs rarely in severe cases of multiple evanescent white-dot syndrome. The distinctive appearance may suggest a disorder other than multiple evanescent white-dot syndrome, which can make initial diagnosis more difficult and lead to unnecessary or inappropriate testing and treatment. Copyright (C) 1999 Elsevier Science Inc. [References: 5] <40> UI - 1999303318 AU - Nakamura Y AU - Hossain M AU - Hirayama K AU - Matsumoto K IN - Dr. Y. Nakamura, Department of Endodontics, School of Dentistry, Showa University, 2-1-1, Kitasenzoku, Ohta-ku, Tokyo 145-8515; Japan. E-Mail: yukio@senzoku.showa-u.ac.jp. TI - A clinical study on the removal of gingival melanin pigmentation with the CO2 laser. SO - Lasers in Surgery & Medicine Vol 25(2) (pp 140-147), 1999. AB - Background and Objective: In a previous study, the possibility of removal of dog gingival melanin pigmentation with CO2 laser therapy was reported. The present study was designed to investigate the effect of the CO2 laser on human gingival pigmentation and evaluate the clinical outcome. Study Design/Materials and Methods: A CO2 laser (output: 6-8 W, pulse duration: 0.2 seconds) was irradiated on the melanin pigmented gingival surface of 10 patients, aged 20-49 years. Followup clinical and histopathological evaluations were performed. Results: The CO2 laser was effective in removing melanin pigmentation in all patients. In the histopathological study, no pigmented-laden cells nor any inflammatory cell infiltration was observed following laser irradiation. No re-pigmentation was seen in any case in the first year. However, four of seven cases showed re- pigmentation at 24 months. The re-pigmentation was almost equal to the preoperative state. Conclusions: The CO2 laser has proved to be another effective, safe, and easily applicable therapy for the removal of gingival melanin pigmentation. [References: 20] <41> UI - 1999287265 AU - Baron AC AU - DeCarlo AA AU - Featherstone JDB IN - Dr. J.D.B. Featherstone, Department of Restorative Dentistry, University of California, Box 0758, 707 Parnasus Avenue, San Francisco, CA 94143; United States. E-Mail: jdbf@itsa.ucsf.edu. TI - Functional aspects of the human salivary cystatins in the oral environment. SO - Oral Diseases Vol 5(3) (pp 234-240), 1999. AB - OBJECTIVES: The aim of this study was to investigate the cysteine protease inhibitory properties of the human salivary cystatins S, SA and SN in order to identify potential in vivo target cysteine proteases which may include those involved in periodontal tissue destruction. In addition, the potential role of the salivary cystatins with respect to the tooth mineral balance and pellicle formation was also investigated. METHODS: Salivary cystatins S major, S minor, SA, SA(T) (a truncated form of SA) and SN were purified from human submandibular sublingual saliva. Sensitive fluorometric assays were used to test the inhibitory action of each purified form of salivary cystatin against a variety of cysteine proteases and to determine whether pH affected their inhibitory activity towards the well-characterized cysteine protease papain. Their potential role in the mineral balance of the tooth was assessed by the measurement of calcium binding and the rate of binding to carbonated apatite (CAP). RESULTS AND CONCLUSIONS: Salivary cystatin SN was found to inhibit the human lysosomal cathepsins B, H and L and salivary cystatin SA was found to inhibit human lysosomal cathepsin L in vitro. These proteases are involved in periodontal tissue destruction and these data suggest that salivary cystatins SA and SN are involved in the control of the proteolytic events in vivo. Salivary cystatin S was not an inhibitor of the cysteine proteases tested suggesting that its primary role is not as a cysteine protease inhibitor. However, S was able to bind more calcium and bind more rapidly to CAP than SA or SN, suggesting that its primary role in the oral environment is likely to be the involvement with the mineral balance of the tooth. [References: 39] <42> UI - 1999283171 AU - Aragoni MC AU - Arca M AU - Demartin F AU - Devillanova FA AU - Garau A AU - Isaia F AU - Lelj F AU - Lippolis V AU - Verani G IN - F.A. Devillanova, Dipartimento di Chimica e Tecnologie, Inorganiche e Metallorganiche, Universita di Cagliari, Via Ospedale 72, 09124 Cagliari; Italy. TI - New [M(R,R'timdt)2] metal-dithiolenes and related compounds (M = Ni, Pd, Pt; R,R'timdt = monoanion of disubstituted imidazolidine-2,4,5- trithiones): An experimental and theoretical investigation. SO - Journal of the American Chemical Society Vol 121(30) (pp 7098-7107), 1999. AB - Several new Ni (7a-i), Pd (8a-j), and Pt (9a-j) dithiolenes belonging to the general class [M(R,R'timdt)2] (R,R'timdt = monoanion of di-substituted imidazolidine-2,4,5-trithione) have been synthesized by sulfuring the disubstituted imidazolidine-2-thione-4,5-diones (4) with Lawesson's reagent (5) in the presence of the appropriate metal either as powder or as chloride. The obtained compounds have been characterized by UV-vis-NIR, FT-IR, and FT- Raman spectroscopies, CP-MAS 13C NMR, and cyclic voltammetry, while [Ni(Me,Pr(i)timdt)2] (7c) was also characterized by X-ray diffraction on a single crystal. Isolation from the reaction mixtures of the complex trans- bis[O-ethyl(4-methoxyphenyl)phosphonodithioato]Ni(II) (10a) and of 4,5,6,7- tetrathiocino[1,2-b:3,4-b']diimidazolyl-1,10-diphenyl-3,8-diethyl-2,9- dithione (6a) as byproducts supports a radical mechanism for the one-pot reaction leading to the title dithiolenes. All these complexes absorb in the NIR region in the range 991-1030 nm with extinction coefficients of rarely encountered magnitudes (up to 80000 M-1 cm-1). They are therefore ideal candidates for applications on Nd:YAG laser technology for which the excitation wavelength is 1064 nm. Hybrid-DFT calculations have been used to gain an insight on the properties of this class of dithiolenes compared with those of the simplest [M(S2C2H2)2] [M = Ni (1); M = Pd (2); M = Pt (3)] and of the well-known [M(dmit)2] [dmit = C3S52-, 1,3-dithiole-2-thione- 4,5-dithiolate;M = Ni (11); M = Pd (12); M = Pt (13)] dithiolenes. <43> UI - 1999275413 AU - Ariji Y AU - Shimizu Y AU - Okano T AU - Matsui O AU - Naitoh M AU - Yuasa H AU - Takahashi J AU - Iida H AU - Hasegawa J AU - Senda A AU - Ariji E IN - Dr. Y. Ariji, Dept. of Oral/Maxillofacial Radiol., School of Dentistry, Aichi-Gakuin University, 2-11 Suemori-dori, Chikusa-ku, Nagoya 464-8651; Japan. TI - Influence of x-ray beam angulation in the detection of proximal caries: Interobserver agreement in the CCD system. SO - Oral Radiology Vol 15(1) (pp 27-35), 1999. AB - The aim of this study was to assess the influence of changes in horizontal and vertical X-ray beam angulation on interobserver agreement in the diagnosis of approximal caries using a charge coupled device-based digital dental imaging system (digital system) in comparison with a conventional film-based radiography (film system). A total of 40 teeth were radiographed. Projection angles were varied within a range of +/-20 [degree] in the horizontal and vertical direction using both systems. The resulting radiographs of approximal surfaces were observed by six radiologists, and the presence and absence of caries and the depth of any caries they found were evaluated. Results were analyzed by comparing Cohen's kappa values. The overall kappa values in both systems belonged to the same category of agreement strength for any horizontal or vertical beam angle. The deviation of the horizontal angulation, if anything, reduced the kappa values in the digital system, except for score 2 based on rating score for caries depth. On the other hand, the influence of vertical angulation was smaller than that of horizontal angulation at scores 0, 1 and overall. The results of the present in vitro study, in which there was no apparent discrepancy in the influence of beam angulation on interobserver agreement of the diagnostic abilities, suggest that the digital system plays a useful role in clinical caries diagnosis. [References: 29] <44> UI - 1999275410 AU - Uchida K AU - Takizawa M AU - Wada T AU - Hitomi M AU - Fujiki T AU - Osanai K AU - Shiojima M IN - K. Uchida, Dept. of Oral/Maxillofacial Radiol., Matsumoto Dental Univ. Sch. of Dent., Shiojiri, Nagano 339-0781; Japan. TI - Liquid crystal displays for the evaluation of dental x-ray images: An ROC analysis of observer performance. SO - Oral Radiology Vol 15(1) (pp 1-7), 1999. AB - We assessed whether dental x-ray images observed on a liquid crystal display (LCD) could be applied to diagnosis. A 13-inch TFT (thin film transistor) display was utilized in this study. Fifty x-ray films of radiographically diagnosed periapical lesions and fifty normal films were digitized at 300 DPI. These sample images were randomized and evaluated by five observers who compared them with the original films using a continuously distributed confidence rating method. The data were analyzed with a Receiver Operating Characteristics (ROC) analysis. The CRT images were evaluated in the similar way. The results showed no statistically significant differences between the original dental x-ray films, images on the TFT display and the CRT regarding the diagnosis of periapical lesions. We conclude that a TFT- type liquid display provides sufficient detail for the diagnostic observation of dental radiographs. Thus, such displays may be useful for dental clinics. [References: 10] <45> UI - 1999269500 AU - Wood S AU - Natress B AU - Kirkham J AU - Shore R AU - Brookes S AU - Griffiths J AU - Robinson C IN - S. Wood, Division of Oral Biology, Leeds Dental Institute, University of Leeds, Clarendon Way, Leeds LS2 9LU; United Kingdom. E-Mail: S.R.Wood@leeds.ac.uk. TI - An in vitro study of the use of photodynamic therapy for the treatment of natural oral plaque biofilms formed in vivo. SO - Journal of Photochemistry & Photobiology. B - Biology Vol 50(1) (pp 1-7), 1999. AB - Seven-day oral plaque biofilms have been formed on natural enamel surfaces in vivo using a previously reported in situ device. The devices are then incubated with a cationic Zn(II) phthalocyanine photosensitizer and irradiated with white light. Confocal scanning laser microscopy (CSLM) of the biofilms shows that the photosensitizer is taken up into the biomass of the biofilm and that significant cell death is caused by photodynamic therapy (PDT). In addition, the treated biofilms are much thinner than the control samples and demonstrate a different structure from the control samples, with little evidence of channels and a less dense biomass. Transmission electron microscopy (TEM) of the in vivo-formed plaque biofilms reveals considerable damage to bacteria in the biofilm, vacuolation of the cytoplasm and membrane damage being clearly visible after PDT. These results clearly demonstrate the potential value of PDT in the management of oral biofilms. [References: 23] <46> UI - 1999255228 AU - Yamazaki R AU - Goya C AU - Tomita Y AU - Kimura Y AU - Matsumoto K IN - Dr. K. Matsumoto, Department of Endodontics, Showa University School of Dentistry, 2-1-1 Kitasenzoku, Ohta-ku, Tokyo 145-8515; Japan. E-Mail: koukichi@senzoku.showa-u.ac.jp. TI - Study on apical leakage of the teeth after argon laser treatment and obturation. SO - Journal of Clinical Laser Medicine & Surgery Vol 17(3) (pp 121-125), 1999. AB - Objective: This study was performed to compare the apical leakage degree after laser treatment and obturation with that without laser treatment, and to evaluate the efficiency of argon laser irradiation in removing debris and smear layer from the prepared root canal walls in vitro. Summary Background Data: There has been no report of laser effect on apical leakage after laser treatment and obturation. Methods: Fifty-six human extracted single root teeth were used in this study. Teeth were divided into four groups of 14 teeth each and prepared up to a 60 K-file size at 1 mm short of the apical foramen using a step-back technique. Argon laser at the wavelength of 470 nm and at the output of 0.3 W was irradiated at apical stop for 1, 2, or 3 seconds at the continuous mode. In each group, ten teeth for the microleakage study were obturated and immersed in rhodamine B solution for 48 hours at 37 [degree] C, and the others were used for the observation by scanning electron microscopy (SEM). All teeth were bisected longitudinally and observed by stereoscopy or SEM. Results: The apical leakage degree after laser treatment and obturation was reduced compared to that in the control, but not significantly (p > 0.05). However, debris and smear layer in the laser- treated groups were removed from apical stop even at low energy density. Conclusions: These results suggest that apical leakage after argon laser treatment is not reduced significantly, but that argon laser is useful for removing debris and smear layer from root canals. [References: 24] <47> UI - 1999255226 AU - Kesler G AU - Koren R AU - Kesler A AU - Hay N AU - Gal R IN - Dr. G. Kesler, Dental Clinic Center, P.O. Box-8121, Petah-Tikva 49651; Israel. E-Mail: Keiler@netvision.net.il. TI - Three years of clinical evaluation of endodontically treated teeth by 15 F CO2 laser microprobe: In vivo study. SO - Journal of Clinical Laser Medicine & Surgery Vol 17(3) (pp 111-114), 1999. AB - Objective: Evaluation of the efficiency of 15 F CO2 laser microprobe, in cases of periapical lesions. The elimination of the pathological reaction caused by certain species of bacteria by reduction of reinfection and stimulation of osteogenesis. Summary Background Data: until now, no suitable delivery fiber existed for CO2 laser endodontic radiation in the apical region where it is most difficult to eliminate the pulp tissue using conventional methods. To overcome this problem, Sharplan Lasers designed a microprobe that reaches closer to the apex, distributing the energy density to a smaller area of the root canal, thus favorably increasing the thermal effects. Methods: The study was conducted on 900 teeth, corresponding to 1512 root canals, divided in two groups. Four hundred sixty-eight were new cases, carefully selected according to strict parameters such as wide periapical translucency over 1 mm, supported by digital x-ray, with a lesion of 3 mm and more. All root canals were mechanically prepared in the conventional method up to size 35, Physiological saline solution served as rinsing solution and the root canals were treated by 15 F CO2 laser microprobe for 60 pulses repeatedly. The temperature at the surrounding tissue of the root did not exceed 38 [degree] C. Results: Filling of the canal was possible at the same appointment, without antibiotic treatment. Four hundred thirty-two of the cases, which were referred to us by other dentists after an unsuccessful treatment according to the classic therapy, were treated by the same laser therapy. Follow-up was performed by clinical examination, and a digital x- ray was taken, during and after treatment as well as after 3, 6, 9, and 12 months. Conclusions: There is a 98% success rate in both study groups, according to objective criteria for successful treatment including reduction of apical translucency after 2-6 months, freedom from clinical complaints, and no need for periapical surgery. [References: 10] <48> UI - 1999247851 AU - Hayashi S AU - Hayashi L AU - Abe K AU - Chikuda M IN - S. Hayashi, Department of Ophthalmology, Dokkyo University School of Medicine, Koshigaya Hospital, 2-1-50 Minami-Koshigaya, Koshigaya-shi 343-8555; Japan. TI - A case of severe solar retinopathy. [Japanese] SO - Japanese Journal of Clinical Ophthalmology Vol 53(6) (pp 1145-1149), 1999. AB - A 31-year-old female noted metamorphopsia in her left eye after prolonged reading in the beach in a clear day. Fundus hemorrhage was detected the next day. When seen by us one month later, the corrected visual acuity was 0.6 left. Funduscopy showed a yellowish gray spot in the fovea surrounded by retinal and subretinal hemorrhage and by white spots simulating those after photocoagulation. A serous detachment of retinal pigment epithelium was present including these areas. We diagnosed the condition as solar retinopathy. Her right eye showed normal findings. Fluorescein angiography showed dye leakage posterior to the neuroepithelium and hyperfluorescence from the foveal spot. Observation with monochromatic light with the wavelength of 780 nm showed a higher reflectibility in the foveal spot. These findings indicated that the affected lesion was located in the retinal pigment epithelium and the choroid. [References: 11] <49> UI - 1999247850 AU - Kabasawa S AU - Abe T AU - Anzai K AU - Mori K AU - Murayama K AU - Yoneya S IN - S. Kabasawa, Department of Ophthalmology, Saitama Medical School, 38 Moro-hongo Moroyama-machi, Iruma-gun, Saitama-ken 350-0495; Japan. TI - Optical coherence tomographic features of retinal lesion induced by accidental diode laser irradiation. [Japanese] SO - Japanese Journal of Clinical Ophthalmology Vol 53(6) (pp 1141-1144), 1999. AB - A 45-year-old male engineer suffered an accidental laser exposure in his right eye. The laser was a continuous-wave 810 nm diode laser with the power output of 1.5W. He noted central scotoma immediately after the exposure. When seen by us 2 days later, the right visual acuity was 1.2. Funduscopy showed a small white spot with halo in the foveola. Fluorescein and indocyanine green angiography showed dye leakage in the affected area. Optical coherence tomography (OCT) showed a highly refractile focal area extending from the Henle layer to the choriocapillaris, suggesting a thermal damage. OCT was also useful in elucidating the discrepancy between the retinal injury and visual acuity. [References: 6] <50> UI - 1999215088 AU - Jeng J-H AU - Chen K-W AU - Lin C-P AU - Chou H-G AU - Lan W-H IN - Prof. W.-H. Lan, School of Dentistry, College of Medicine, National Taiwan University, No. 1, Chang-Te Street, Taipei; Taiwan. TI - Ultrastructural changes of the tooth root surface by ND:YAG laser irradiation followed by citric acid and tetracycline. SO - Journal of the Formosan Medical Association Vol 98(4) (pp 242-247), 1999. AB - The neodymium:yttrium-aluminum-garnet (Nd:YAG) laser has been used for treatment of dentinal hypersensitivity, eradicating periodontal pathogens, and facilitating calculus removal. However, Nd:YAG laser irradiation exerts potentially harmful effects on the tooth root surface. The purpose of this study was to examine the ultrastructural changes of the tooth root surface caused by Nd:YAG laser irradiation, and to determine whether chemical and mechanical preparations can correct these ultrastructural changes. Eighteen tooth specimens (3 x 3 x 0.5 mm) with healthy root surfaces were prepared and irradiated with an Nd:YAG laser at various power densities. Root surfaces were irradiated at 100 mJ at 20 pulses per second (pps) for 2 seconds followed by the application of citric acid (pH 1.2) or tetracycline solution (100 mg/mL) for 3 and 5 minutes, respectively, or ultrasonic scaling for 5 strokes of 3 seconds per stroke. As observed with low-vacuum scanning electron microscopy, (Wet-SEM), Nd:YAG laser irradiation at 70 to 100 mJ, 20 pps for 2 seconds caused surface cratering, areas of porosity, pitting, fissures, and lava-like structures in an area 140 to 280 mum in diameter. Irradiation of 50 mJ, 20 pps for 2 seconds, led to only mild surface charring. No evidence of morphologic changes was found when root surfaces were irradiated with the Nd:YAG laser at 20 mJ, 20 pps for 2 seconds or at 50 mJ, 10 pps for 8 seconds. The laser-induced lava-like structures were partially detached by citric acid (pH 1.2) etching and ultrasonic scaling, but not by tetracycline (100 mg/mL). These results indicate that chemical and mechanical preparations can be used effectively in conjunction with Nd:YAG laser irradiation for root surface preparation during both nonsurgical and surgical periodontal treatments. [References: 19] <51> UI - 1999199899 AU - Gimsa J IN - J. Gimsa, Institut fur Biologie, Humboldt-Universitat zu Berlin, D-10115 Berlin; Germany. TI - New light-scattering and field-trapping methods access the internal electric structure of submicron particles, like influenza viruses. SO - Annals of the New York Academy of Sciences Vol 873 (pp 287-298), 1999. AB - A variety of AC-electrokinetic field effects can be exploited for handling or electric characterization of microscopic and submicroscopic particles, like cells, organelles, supramolecular structures, and artificial colloids. Despite the fact that dielectric spectroscopy methods by AC-electrokinetics, like common impedance methods, are based on the impedance properties of the different constituents of the particles, the first methods yield higher parameter resolutions. A drawback of the electrokinetic methods was that they required microscopic observability of field-induced particle movements. New AC-electrokinetic methods like electrorotational light scattering (ERLS), dielectrophoretic phase-analysis light scattering (DPALS), and dielectrophoretic field trapping (DFT) solve this problem and access the submicroscopic particle range. This paper gives an introduction to the new methods and presents measurements on influenza viruses. To develop a dielectric virus model, experiments of ERLS were combined with DFT of viruses in microstructured electric-field cages. The model assumes a spherical virus with a radius of 50 nm and a single-shell dielectric structure. The shell thickness of 18 nm summarizes the dimensions of the lipid and viral surface protein layers. For this model, the conductivities of core and shell of 0.1 mS/m and 0.1 muS/m, respectively, and the relative permittivities of 30 and 80, respectively, were obtained. [References: 29] <52> UI - 1999198369 AU - Tsuchiya H IN - Dr. H. Tsuchiya, Department of Dental Pharmacology, Asahi University School of Dentistry, 1851 Hozumi, Hozumi-cho, Gifu 501-0296; Japan. E-Mail: hiro@dent.asahi-u.ac.jp. TI - Effects of green tea catechins on membrane fluidity. SO - Pharmacology Vol 59(1) (pp 34-44), 1999. AB - Catechins originating from green tea have been used in plaque inhibition for caries prevention and treatment for liver damage because of their antibacterial activity against cariogenic bacteria and protective activity on hepatic cells. The effects of catechins on membrane fluidity were studied by a fluorescence polarization method using liposomes prepared with dipalmitoylphosphatidylcholine and dioleoylphosphatidylcholine to assess their pharmacological mechanism at mumol/l levels found in human body fluids after clinical application. All eight catechins tested, ranging from 1 to 1000 mumol/l, significantly reduced membrane fluidity in both hydrophilic and hydrophobic regions of lipid bilayers. Catechin gallate esters were superior in fluidity reduction to the corresponding nonesters. The fluidity-reducing degree was different between the cis and trans forms, suggesting the stereospecific activity of catechins. A reference antiplaque agent, chlorhexidine, similarly reduced membrane fluidity at the antibacterial concentration. (+)-Catechin (250 mumol/l) and (-)-epigallocatechin gallate (2.5 mumol/l) significantly prevented the membrane fluidization induced by hepatotoxic chloroform. These results indicate that the reduction in membrane fluidity is responsible for the antiplaque and hepato-protective effects of green tea catechins. [References: 37] <53> UI - 1999183066 AU - Paster BJ AU - Bartoszyk IM AU - Dewhirst FE IN - B.J. Paster, Forsyth Dental Center, 140 Fenway, Boston, MA 02115; United States. E-Mail: bpaster@forsyth.org. TI - Identification of oral streptococci using PCR-based, reverse-capture, checkerboard hybridization. SO - Methods in Cell Science Vol 20(1-4) (pp 223-231), 1998. AB - A PCR based, reverse capture checkerboard hybridization methodology was designed to rapidly detect and enumerate oral species of Streptococcus and other genera in plaque samples to assess the bacterial etiology of root surface caries or other oral diseases. The procedure circumvents the need for in vitro bacterial cultivation. Up to 30 reverse capture probes that target regions of 16S rRNA genes are deposited on a nylon membrane in separate horizontal lanes using a MiniSlot apparatus. 16S rRNA genes of DNA from plaque or pure cultures are PCR amplified using a digoxigenin-labeled primer. Hybridizations are performed in vertical channels in a Miniblotter apparatus with digoxigenin-labeled amplicons from up to 45 samples. Consequently, 1350 hybridizations are performed simultaneously using a single membrane. Hybridization signals are detected using chemifluorescence procedures. Bacterial numbers are determined by analyzing hybridization signals using a Storm system. A genus-specific probe is used to assess the total number of streptococci and universal probes are used to assess total bacterial counts. Use of this procedure enables laboratories to analyze thousands of clinical or environmental samples with many probes in a relatively short period. This methodology has broad range applications in microbiology to monitor population distributions in a given environment. [References: 23] <54> UI - 1999177231 AU - Tseng Y-C AU - Lin F-H AU - Lin C-P AU - Lan W-H AU - Liao J-D IN - Y.-C. Tseng, Institute of Biomedical Engineering, College of Medicine, National Taiwan University, Taipei; Taiwan. TI - Treatment of dental root fracture by medium energy CO2 laser and DP-bioactive glass paste part II: Compositional, structure, and phase changes of DP-Bioglass paste after exposed to CO2 laser. SO - Biomedical Sciences Instrumentation Vol 35 (pp 285-290), 1999. AB - Fractured teeth are difficult to treat effectively. Currently, such as root fractures are usually treated by full-coverage restoration, root amputation, or tooth extraction. If the fusion of tooth fracture by laser were possible, it could offer a different therapy to repair fracture teeth. We tried to use a developed DP-bioactive glass paste to fuse or bridge the tooth crack line by a medium energy continuous-wave CO, laser. The present report was focused on the phase transformation and rescrystallization of DP-bioactive paste during expose to the CO2 laser. The materials will examine by means of XRD, FTIR, DTA/TGA, and SEM. From the study, we could expect that the temperature increase due to laser irradiation must be over than 900 [degree] C and the DP-bioactive glass paste could be melted in a short period of time after irradiation. In the study, we successfully developed a DP-bioactive glass paste which could form a melting glass within minutes after exposed to a medium energy density continuous-wave CO2 laser. The paste will be used to bridge the enamel or dentine surface crack by the continuous-wave CO2 laser in the near future. [References: 7] <55> UI - 1999175152 AU - Chang S-F AU - Lin C-P AU - Lan W-H AU - Hsieh C-C IN - S.-F. Chang, Shin Kong Wu Ho-Su Memorial Hospital, College of Medicine, National Taiwan University, Taipei; Taiwan. TI - Comparison of post-gel polymerization shrinkage of composite resin cured by conventional visible light and argon laser. [Chinese] SO - CHIN J MED BIOL ENG, Vol 18(4) (pp 209-214), 1998. AB - The clinical significance of polymerization shrinkage in a resin restoration is the potential defects in the composite-tooth bond. This leads to bond failure and enamel microleakage with possible post-operative sensitivity. The argon laser (lambda=488 [similar] 514 nm)emits a blue-green light which is coherent, monochromatic and collimated. It has been shown that enhanced physical properties of composite resins could be obtained following argon laser application when compared to conventional visible light curing. The specific-aims of this study were to compare the shrinkage behaviors of composite resin cured by the conventional visible light and argon laser with the use of the strain gauge methods, and further to investigate the adequate exposure time for polymerizing composite resins by the argon laser. From the results of this study, the following Conclusions can be drawn: (1) The composite polymerization profile of argon laser curing is quite different from that of conventional light curing. (2) The optimal curing time for conventional visible light and argon laser is 44 seconds and 8 seconds, respectively. (3) The argon laser illustrates fast curing rate and more final shrinkage than the conventional visible light. Whether the argon laser is an ideal light source for composite resin curing requires further investigation. [References: 17] <56> UI - 1999175051 AU - Westerman GH AU - Hicks MJ AU - Flaitz CM AU - Blankenau RJ AU - Powell GL IN - Dr. G.H. Westerman, Creighton University, School of Dentistry, 2500 California Plaza, Omaha, NE 68178; United States. E-Mail: ghwester@creighton.edu. TI - Combined effects of acidulated phosphate fluoride and argon laser on sound root surface morphology: An in vitro scanning electron microscopy study. SO - Journal of Clinical Laser Medicine & Surgery Vol 17(2) (pp 63-68), 1999. AB - Objective: The purpose of this in vitro scanning electron microscopy (SEM) study was to evaluate the effects of combining low fluence argon laser (AL) irradiation and acidulated phosphate fluoride (APF) treatment on the surface morphology of sound human root surfaces. Summary Background Data: Previous in vitro investigations have shown that combined APF and AL irradiation of root surfaces provided a protective effect against cariogenic challenges. Materials and Methods: Twelve extracted human molars were sectioned into quarters, and each quarter assigned to 1 of 4 treatment groups: (1) no treatment/control; (2) low fluence (11.5 J/cm2) AL irradiation; (3) 1.23% APF for 4 minutes; (4) APF treatment followed by low fluence AL irradiation. Surface morphology alterations were compared among groups using SEM techniques. Results: AL irradiation alone produced irregular textured surfaces with adherent globular material and fine microporosities in the background. APF treatment, alternatively, only created relatively smooth surface coatings that masked the original underlying root surface. Combining APF treatment followed by AL irradiation resulted in a surface coating composed of relatively small (2 to 3 mum) spherical to ovoid precipitates, morphologically resembling calcium fluoride. Conclusion: Combining APF with AL irradiation may create a more reactive surface that possesses fluoride- rich mineral deposits and protects the underlying root surface from cariogenic challenges. [References: 36] <57> UI - 1999169221 AU - Magalhaes Rego E AU - Gonzaga Tone L AU - Bergamo Garcia A AU - Passetto Falcao R IN - R. Passetto Falcao, Haematology Laboratory, Unversity Hospital, Medical School of Ribeirao Preto, CEP: 14049-900, Ribeirao Preto SP; Brazil. E-Mail: rpfalcao@fmr.usp.br. TI - CD10 and CD19 fluorescence intensity of B-cell precursors in normal and leukemic bone marrow. Clinical characterization of CD10(+ strong) and CD10(+ weak) common acute lymphoblastic leukemia. SO - Leukemia Research Vol 23(5) (pp 441-450), 1999. AB - In order to assess the age-related changes in CD10 and CD19 fluorescence intensity (FI) the present study analyzed by flow cytometry 56 sternal biopsies from 'normal' infants, children and adults undergoing cardiac surgery. The CD10(+weak) subset was predominant in all age groups, representing approximately 50% of the bone marrow (BM) lymphoid cells in children younger than 4 years. Both CD10+ subsets significantly decreased with age but their ratio did not differ significantly. Moreover, the intensity of CD10 and CD19 fluorescence in the strong and weak subsets did not vary with age. The CD19 intensity was significantly higher in CD10(+weak) than in CD10(+ strong) cells. In addition, we classified as CD10(+ weak) or CD10(+ strong) the leukemic cells from BM aspirates of 117 patients with common acute lymphoblastic leukemia (cALL) (78 children and 39 adults). A higher frequency of cases expressing the CD19+ CD10(+ strong) phenotype was observed both in children and adults. Children of the CD10(+ weak) group tended to be older than those of the CD10(+ strong) group (median = 7 vs. 4 years, P = 0.07), and presented a significantly higher frequency of splenomegaly (93.7 vs. 55%, p = 0.04), which was massive in about 60% of these cases. Among adults, a significantly higher frequency of cases expressing the CD10(+ weak) phenotype was observed in females. No other clinical or biological difference was detected between the two groups either for children or adults. Concerning the treatment outcome, we did not observe significant differences in complete remission rate (CRR) or in disease free survival (DFS) among the 32 children and 28 adults analyzed. Finally, we compared the CD10 and CD19 intensity in normal and leukemic BM. Overexpression of either or both antigens in leukemic cells was observed in 42.4% of the cALL cases. In these cases, using cut off values of 110 afu for the CD10 FI and of 100 afu for the CD19 FI, the detection of leukemic cells was possible at levels of 0.2% based on CD10 analysis, of 0.6% based on CD19, and 0.02% when both antigens were overexpressed. In conclusion, we demonstrated that the heterogeneity of CD10 and CD19 fluorescence intensity is of no clinical relevance in cALL, although its study may be helpful for the diagnosis and the detection of minimal residual disease. [References: 45] <58> UI - 1999154030 AU - Kurono N AU - Sugita K AU - Takasugi S AU - Tokuda M IN - M. Tokuda, Division of Molecular Chemistry, Graduate School of Engineering, Hokkaido University, Sapporo 060-8628; Japan. E-Mail: tokuda@org-mc.eng.hokudai.ac.jp. TI - One-step cross-coupling reaction of functionalized alkyl iodides with aryl halides by the use of an electrochemical method. SO - Tetrahedron Vol 55(19) (pp 6097-6108), 1999. AB - Organozinc compounds of functionalized alkyl iodide carrying an alkoxycarbonyl, cyano or alkenyl group were prepared in high yields under mild conditions (0 [degree] C-r.t., 10min in DMF) by the reaction of iodides with an electrogenerated reactive zinc (EGZn). Cross-coupling of the organozinc compounds with various aryl halides in the presence of 5 mol% Pd(P(o- Tol)3)2Cl2 in THF gave the corresponding cross-coupled products in moderate to high yields. These cross-coupling reactions can be also achieved in one step and in one pot by the use of an electrochemical method utilizing a Pt cathode and Zn anode. [References: 9] <59> UI - 1999089528 AU - Mita M AU - Hosobe Y AU - Machida S AU - Nabeshima T AU - Tazawa Y IN - Dr. M. Mita, Dept of Ophthalmol, Iwate Medical Univ School of Med, 19-1 Uchimaru, Morioka 020-8505; Japan. TI - A case of multiple evanesent white dot syndrome diagnosed early by indocyanine green and multifocal electroretinography. [Japanese] SO - Folia Ophthalmologica Japonica Vol 50(1) (pp 70-74), 1999. AB - We report a case of multiple evanescent white dot syndrome (MEWDS) diagnosed early by indocyanine green angiography (ICG) and multifocal electroretinography (m-ERG). A 25-year-old female was referred to us with decreased vision of 0.05 and central scotoma in her left eye. Fundus examination showed multifocal white spots scattered from the macula to the temporal region of the left eye. The white spots were hyperfluorescent in the arteriovenous phase of fluorescent angiography (FAG). Visual field testing of the left eye revealed central relative scotoma and a large blind spot. Multifocal and confluent hypofluorescent spots around the optic disc and the vascular arcade and in the macular region were seen in the late phase of ICG. The response density of m-ERG decreased in the areas corresponding to the area around the optic disc and the macular region. Because these results suggested a diagnosis of MEWDS, we treated the patient by observation only. By 9 weeks later, the patient's visual acuity had returned to (1.2), scotoma had resolved, and the results of FAG, ICG, and m-ERG had normalized. In this case, ICG and m-ERG proved of value in the early diagnosis of MEWDS with subtle fundus abnormalities. [References: 15] <60> UI - 1999080242 AU - Smith SC AU - Walsh LJ AU - Taverne AAR IN - Prof. L.J. Walsh, School of Dentistry, University of Queensland, 200 Turbot Street, Brisbane, QLD 4000; Australia. E-Mail: walsh@mailbox.uq.edu.au. TI - Removal of orthodontic bonding resin residues by CO2 laser radiation: Surface effects. SO - Journal of Clinical Laser Medicine & Surgery Vol 17(1) (pp 13-18), 1999. AB - Objective: The purpose of this in vitro study was to evaluate the potential use of pulsed CO2 laser radiation to remove selectively residues of orthodontic bonding resin that remain after debonding of fixed orthodontic appliances. Summary Background Data: Current techniques used for removal of orthodontic bonding resin after removal of fixed appliances include rotary instruments, debonding pliers, and ultrasonic scalers. These techniques, however, are time-consuming and inefficient, and may damage tooth enamel. Methods: A standardized cylinder of orthodontic bonding resin was bonded to the buccal surfaces of 100 extracted premolar teeth, which were then divided into 10 groups of 10 specimens each. In 9 groups, the resin was ablated using 1 of 9 different laser parameters, while in the remaining control group, the resin was removed with a slow speed tungsten carbide bur. Specimens were evaluated by light microscopy and scanning electron microscopy (SEM) to assess the amount of resin remaining and the extent of the damage to the underlying enamel. Results: The 2 W/100 ms combination was optimal, with a high efficiency of resin removal and the least enamel damage. Higher laser powers increased the extent of enamel damage without enhancing resin removal. Conclusions: This laser technique appears promising, however, further studies of the extent of thermal changes at the level of the dental pulp are necessary to establish more fully the risk-benefit ratio. [References: 18] <61> UI - 1999063561 AU - Baird IR AU - Rettig SJ AU - James BR AU - Skov KA IN - B.R. James, Department of Chemistry, University of British Columbia, Vancouver, BC V6T 1Z1; Canada. E-Mail: brj@chem.ubc.ca. TI - Synthesis and characterization of homoleptic ruthenium(II) imidazole complexes, and a carbonyl species derived by CO abstraction from DMF. SO - Canadian Journal of Chemistry Vol 76(10) (pp 1379-1388), 1998. AB - [Ru(II)(L)6]2+ complexes were synthesized from [Ru(DMF)6][CF3SO3]3; DMF = dimethylformamide, L = imidazole (Im), N- methylimidazole (NMeIm) and 5-methylimidazole (5MeIm). The 2-methylimidazole complex trans[Ru(CO)(DMF)(2MeIm)4][CF3SO3]2 (4) was also synthesized via a reaction involving abstraction of CO from DMF; 4 loses CO reversibly at ambient temperature to form [Ru(DMF)(2MeIm)4][CF3SO3]2 (5), and the DMF can be removed to generate a [Ru(CF3SO3)(x)(2MeIm)4][CF3SO3](y) species (x = 2, y = 0, or x = 1 = y), containing coordinated triflate. The complexes were characterized by elemental analysis, conductivity, UV-vis, NMR, and IR spectroscopies. The structures of [Ru(Im)6][CF3SO3]2 (1), [Ru(NMeIm)6][CF3SO3]2 (2), and [Ru(5MeIm)6][CF3SO3]2 (3) were established by X-ray crystallographic analyses. Crystals of 1, are triclinic, a = 7.4010(6), b = 9.9846(15), c = 11.275(2) [Angstrom], alpha = 113.469(5), beta = 92.419(2), gamma = 94.737(2) [degree], Z = 1, space group P1-; those of 2, are trigonal, a = 11.558(2), c = 8.109(3) [Angstrom], Z = 1, space group P3-; and those of 3, are trigonal, a = 12.6547(4), c = 20.4078(12) [Angstrom], Z = 3, space group R3-. The structures were solved by Patterson methods and refined by full- matrix least-squares procedures to R(F) = 0.029, 0.034, and 0.034 (R(w) (F2) = 0.055, R(w) (F) = 0.031, and R(w) (F2) = 0.058), respectively. [References: 34] <62> UI - 1999031776 AU - Kato T AU - Kusakari H AU - Hoshino E IN - Dr. T. Kato, Department of Fixed Prosthodontics, School of Dentistry, Niigata University, Gakkocho-Dori 2-5274, Niigata 951; Japan. E-Mail: taku@dent.niigata-u.ac.jp. TI - Bactericidal efficacy of carbon dioxide laser against bacteria- contaminated titanium implant and subsequent cellular adhesion to irradiated area. SO - Lasers in Surgery & Medicine Vol 23(5) (pp 299-309), 1998. AB - Background and Objective: The aim of this study was to assess CO2 laser ability to eliminate bacteria from titanium implant surfaces. The changes of the surface structure, the rise in temperature, and the damage of connective tissue cells after laser irradiation were also considered. Study Design/Materials and Methods: Streptococcus sanguis and Porphyromonas gingivalis on titanium discs were irradiated by an expanded beam of CO2 laser. Surface alteration was observed by a light, and a scanning electron, microscope. Temperature was measured with a thermograph. Damage of fibroblastic (L-929) and osteoblastic (MC3T3-E1) cells outside the irradiation spot and adhesion of the cells to the irradiated area were also estimated. Results: All the organisms (108) of S. sanguis and P. gingivalis were killed by the irradiation at 286 J/cm2 and 245 J/cm2, respectively. Furthermore, laser irradiation did not cause surface alteration, rise of temperature, serious damage of connective tissue cells located outside the irradiation spot, or inhibition of cell adhesion to the irradiated area. Conclusion: CO2 laser irradiation with expanded beam may be useful in removing bacterial contaminants from implant surface. [References: 46] <63> UI - 1999027065 AU - Twiner MJ AU - Hirst M AU - Valenciano A AU - Zacharewski TR AU - Dixon SJ IN - T.R. Zacharewski, Department of Biochemistry, Michigan State University, East Lansing, MI; United States. TI - N,N-dimethylformamide modulates acid extrusion from murine hepatoma cells. SO - Toxicology & Applied Pharmacology Vol 153(2) (pp 143-151), 1998. AB - N,N-Dimethylformamide (DMF) affects cellular differentiation, causes hepatotoxicity and gastric irritation, and may be carcinogenic. Since these processes involve changes in cellular pH homeostasis, we investigated the effects of DMF on H+ extrusion and cytosolic pH (pH(i)) of mouse hepatoma cells (Hepa 1C1C7). Extracellular pH was monitored using a silicon-based sensor system (Cytosensor microphysiometer) and pH(i) was monitored by fluorescence spectrophotometry. Superfusion of cells with DMF (0.25 to 0.5 M) suppressed the extracellular acidification rate (ECAR) below baseline. Following washout of DMF there was a rapid, concentration-dependent, prolonged overshoot of ECAR above baseline rates. Removal of extracellular Na+ or superfusion with amiloride abolished the overshoot in acidification rate, indicating involvement of Na+/H+ exchange. The overshoot was dependent on extracellular glucose, suggesting that it arises from an increase in metabolic acid production. Fluorescence measurements showed that DMF did not change pH(i). Furthermore, DMF did not alter the rate of pH(i) recovery of cells acid loaded using nigericin, indicating that DMF does not directly alter Na+/H+ exchange activity in these cells. In summary, these data suggest that suppression of acidification rate by DMF is likely due to decreased metabolic acid production. Washout of DMF is then accompanied by increased glucose metabolism and H+ efflux via Na+/H+ exchange. It is possible that alterations in H+ production and transport contribute to the hepatotoxicity of DMF and its effects on cellular differentiation. [References: 41] <64> UI - 1999013907 AU - Subrayan RP AU - Rasmussen PG IN - P.G. Rasmussen, Department of Chemistry, Willard H. Dow Laboratories, University of Michigan, Ann Arbor, MI 48109-1055; United States. TI - High nitrogen chemistry: Synthesis and properties of N,N-bis(4,5- dicyano-1-methyl-2-imidazolyl)cyanamide and N,N,N',N',N'',N''-hexakis(4,5- dicyano-1-methyl-2-imidazolyl) melamine. SO - Tetrahedron Vol 55(2) (pp 353-358), 1999. AB - Cyanation of bis(4,5-dicyano-1-methyl-2-imidazolyl)amine(1) using cyanogen chloride gave N,N-bis(4,5-dicyano-1-methyl-2- imidazolyl)cyanamide(3) as a light yellow solid. Compound 3 is thermally labile and upon heating the N-CN bond is cleaved and the reactive amine intermediate readily reacts with the moisture giving 1. Nucleophilic aromatic substitution(S(N)Ar) reaction of the sodium salt of 1 with cyanuric chloride gave N,N,N',N',N'',N''-hexakis(4,5-dicyano-1-methyl-2-imidazolyl)melamine(5), as a white microcrystalline solid. Compound 5 is thermally stable up to 300 [degree] C in nitrogen and air. Compound 5 showed strong emission bands at 476 nm in acetonitrile and 448 nm in DMF. Therefore, 5 may be used as a fluorescent probe. [References: 21] <65> UI - 1999011309 AU - Khan MFR AU - Yonaga K AU - Kimura Y AU - Funato A AU - Matsumoto K IN - Prof. K. Matsumoto, Department of Endodontics, Showa University School of Dentistry, 2-1-1 Kitasenzoku, Ohta-ku, Tokyo 145-8515; Japan. E-Mail: koukichi@hp.dent.showa-u.ac.jp. TI - Study of microleakage at class I cavities prepared by Er:YAG laser using three types of restorative materials. SO - Journal of Clinical Laser Medicine & Surgery Vol 16(6) (pp 305-308), 1998. AB - Objectives: The purposes of this in vitro study were to investigate microleakage at class I cavities filled with amalgam, composite resin, or glass-ionomer after preparation by Er:YAG laser and to compare the results with those by a conventional method using an air turbine. Summary Background Data: There has been no report of a study of microleakage on class I cavities prepared by Er:YAG laser. Methods: Ninety-six extracted human premolar and molar teeth were used in this study. Forty-eight class I cavities were prepared by Er:YAG laser and 48 class I cavities by air turbine. After preparation, each of the 2 groups was further subdivided into 3 groups, respectively, and cavities in each of these subgroups were filled by 1 of 3 types of restorative materials. Microleakage at the restored cavities was assessed by the dye penetration method and scanning electron microscopy (SEM). Results: Minimal or moderate leakage was evident at most of the composite resin or glass-ionomer restorations, whereas moderate or severe leakage was observed at most of the amalgam restorations as shown by the dye penetration method. There was a significant difference among the 3 restorative materials (p < 0.05), but there was no significant difference in microleakage between the cavities prepared by Er:YAG laser and those by air turbine (p > 0.05). SEM evaluation demonstrated good adaptation with most of the composite resin or glass-ionomer restorations, but amalgam restorations showed slightly poorer adaptation. Conclusion: These results suggest that Er:YAG laser is useful for class I cavity preparation from the viewpoint of microleakage. [References: 22] <66> UI - 1999006659 AU - Wagner S AU - Braner A AU - Thalhammer A AU - Windolf J AU - Jacobi V IN - S. Wagner, Institut fur Rontgendiagnostik, Universitatsklinik, Theodor-Stern-Kai 7, D-60590 Frankfurt, Main; Germany. TI - Stress fractures: Osteomalacia in an immigrant woman. [German] SO - Unfallchirurgie Vol 24(6) (pp 284-288), 1998. AB - Osteomalacia is known as one reason of stress fractures. We report symptomatic hypovitaminosis D in a 33-year-old African woman with multiple stress fractures and deficient mineralisation of the skeleton. We discuss different causes of osteomalacia and underline vitamin D deficiency because of low intake of calcium and minimal exposure to sunlight among immigrant women. [References: 9] <67> UI - 1998412027 AU - Gordeev MF AU - Luehr GW AU - Hui HC AU - Gordon EM AU - Patel DV IN - M.F. Gordeev, Versicor Inc., 34790 Ardentech Ct., Fremont, CA 94555; United States. TI - Combinatorial chemistry of natural products: Solid phase synthesis of D- and L-cycloserine derivatives. SO - Tetrahedron Vol 54(52) (pp 15879-15890), 1998. AB - An efficient methodology for a solid phase synthesis of D- and L- cycloserine derivatives is described, Fmoc-D-cycloserine 4 and its L- enantiomer 5 prepared by a selective amine acylation of bis-silylated parent compounds are immobilized on Sasrin or 2-chlorotrityl linker resins using Mitsunobu-type reaction or direct tritylation, respectively. The resulting Fmoc-cycloserine resins 7, 10, and 11 are deprotected with piperidine in DMF or DCM to generate immobilized cycloserine reagents with a primary amino group exposed for various synthetic transformations. An example of the parallel D-cycloserine library synthesis on a reaction plate is described. [References: 24] <68> UI - 1998378455 AU - Wheeler EF AU - Naftel JP AU - Pan M AU - Von Bartheld CS AU - Byers MR IN - E.F. Wheeler, Division of Life Sciences, University of Texas, 6900 North Loop 1604 West, San Antonio, TX 78249; United States. E-Mail: ewheeler@lonestar.utsa.edu. TI - Neurotrophin receptor expression is induced in a subpopulation of trigeminal neurons that label by retrograde transport of NGF or fluoro-gold following tooth injury. SO - Molecular Brain Research Vol 61(1-2) (pp 23-38), 1998. AB - Tissue responses to injury are regulated by neurotrophins and neurotrophin receptor levels and can involve both retrograde and paracrine/autocrine trophic signaling. To determine how neurotrophins may contribute to the injury response, the timing and the extent of the up-regulation of neurotrophins and their receptors was examined in a model system which is particularly well suited for the analysis of trophic signaling pathways in response to injury. Injury to the occlusal surfaces of rat molar cusps induces a localized increase in nerve growth factor (NGF) expression in the dental pulp within 4-6 h. Radiolabeled NGF was transported in a receptor-mediated fashion from the teeth to a subset of neurons in the trigeminal ganglion within 15 h, indicating that these neurons possess NGF receptors (trk A and/or p75(NTR)). To test for NGF responses in the tooth sensory afferent neurons, levels of expression of neurotrophins and their receptors were examined by in situ hybridization in the trigeminal ganglion at 0, 4, 12, 20, 28 and 52 h post-injury. Within the maxillary division of the trigeminal ganglion, trk A expression was elevated at 4 h post-injury, with a maximum increase (2-fold) after 52 h. p75(NTR) was