Database: MEDLINE <: biomedical, nursing & dental literature, 1966 - Oct 2000.> Search Strategy (You Saved Citations 1-53 From Set 55): ----------------------------------------------------------------------------- 1 Strontium/ 2533 2 exp Strontium isotopes/ 3777 3 strontium:.mp. 6471 4 or/1-3 6471 5 exp Tooth demineralization/ 22628 6 demineralization.mp. 1620 7 caries.mp. 15295 8 caires.mp. 1 9 craies.mp. 0 10 careis.mp. 4 11 carise.mp. 0 12 (teeth adj3 cavit:).mp. 422 13 (tooth adj3 cavit:).mp. 217 14 (dental adj3 cavit:).mp. 276 15 (dentin adj3 cavit:).mp. 254 16 (enamel adj3 cavit:).mp. 182 17 (teeth adj3 decay:).mp. 374 18 (tooth adj3 decay:).mp. 321 19 (dental adj3 decay:).mp. 250 20 (dentin adj3 decay:).mp. 12 21 (enamel adj3 decay:).mp. 20 22 (active adj decay).mp. 9 23 (rampant adj3 decay:).mp. 14 24 (recurrent adj3 decay:).mp. 30 25 (white adj spot:).mp. 509 26 carious.mp. 2077 27 cariology.ti,ab. 56 28 (non-cavitated adj3 lesion:).mp. 15 29 (noncavitated adj3 lesion:).mp. 2 30 Tooth remineralization/ 478 31 (dental adj3 fissure:).mp. 99 32 (tooth adj3 fissure:).mp. 50 33 (teeth adj3 fissure:).mp. 98 34 caries-free.mp. 603 35 cariesfree.mp. 17 36 Cariogenic agents/ 728 37 precavit:.mp. 8 38 (filled adj3 teeth).mp. 510 39 (filled adj3 tooth).mp. 117 40 (oral adj fissure:).mp. 6 41 (tooth adj3 remineraliz:).mp. 28 42 (teeth adj3 remineraliz:).mp. 24 43 dft.mp. 413 44 dfs.mp. 1258 45 dmf:.mp. 6397 46 cariogeni:.mp. 1787 47 or/5-46 32256 48 Saliva/ 17356 49 exp Salivary glands/ 22094 50 (saliva or salivary or parotid).mp. 43810 51 or/48-50 51679 52 47 or 51 81519 53 4 and 52 110 54 limit 53 to human 67 55 limit 53 to animal 53 56 from 55 keep 1-53 53 *************************** <1> UI - 96316974 AU - Spets-Happonen S AU - Luoma H AU - Seppa L IN - Department of Preventive Dentistry and Cariology, University of Kuopio, Finland. TI - High strontium addition to chlorhexidine-fluoride gel does not increase its caries-preventive effect in rats. SO - Acta Odontologica Scandinavica 1996 Apr;54(2):92-5 AB - One hundred Osborne-Mendel rats were weaned at the age of 21 to 22 days, inoculated with Streptococcus mutans in the mouth, and fed a semisynthetic diet for the next 43 days. The control group received no treatment. The study groups received gel applications on their molars with placebo, chlorhexidine-fluoride (CXF), CXF plus 50 ppm Sr, or CXF plus 250 ppm Sr daily for the first 21 days of the experiment Although caries was significantly reduced by CXF and CXF plus 50 ppm Sr treatments, the Sr additive did not significantly improve the caries-preventive effect of CXF. The addition of 250 ppm Sr to the CXF gel seemed markedly to weaken the effect of CXF. <2> UI - 96262652 AU - Fukushi Y AU - Suga S AU - Kamimura N AU - Wada J AU - Mio Y AU - Nishiyama A AU - Wakui M IN - Department of Physiology, Hirosaki University School of Medicine, Japan. TI - Stimulated Ca2+ entry activates Cl- currents after releasing Ca2+ from the intracellular store in submandibular gland cells of the rat. SO - Japanese Journal of Physiology 1995;45(6):1071-85 AB - In order to examine whether Ca2+ entry is directly involved in controlling exocrine secretion, the Ca(2+)-activated Cl- currents were recorded in single and clusters of rat submandibular gland cells using the whole-cell patch-clamp method. Extracellularly applied acetylcholine (ACh, 10 nM) as well as intracellularly applied GTP gamma S and InsP3 caused repetitive transients of the Cl- currents activated by intracellular Ca2+. These responses occurred also in the absence of external Ca2+, but disappeared after several minutes. Readmission of Ca2+ to the extracellular solution restored the repetitive current transients, while introduction of Sr2+ failed to restore the current signals in spite of the presence of Sr2+ entry detected by microfluorimetry. On the other hand, direct application of Sr2+ to the cell inside caused activation of the Cl- currents although less effectively than Ca2+. When Ca2+ was introduced to the extracellular solution during an interruption of ACh stimulation after the ACh-induced depletion of intracellular Ca2+ store, the Cl- current was not elicited. However, a subsequent challenge with ACh at the same concentration in the absence of extracellular Ca2+ caused repetitive transient Cl- currents. The results suggest that in this cell type the stimulated Ca2+ entry does not by itself activate the Cl- currents but activates them indirectly by triggering Ca2+ release from the intracellular Ca2+ store which may take up Ca2+ soon after the Ca2+ entry. <3> UI - 96045701 AU - Fukushi Y AU - Ozawa T AU - Wakui M AU - Nishiyama A IN - Department of Physiology, Tohoku University School of Medicine, Sendai, Japan. TI - Sr2+ can pass through Ca2+ entry pathway activated by Ca2+ depletion, but can be hardly taken up by the Ca2+ stores in the rat salivary acinar cells. SO - Tohoku Journal of Experimental Medicine 1995 Jun;176(2):83-97 AB - When Sr2+ was introduced to the external solution after the depletion of Ca2+ from stores of submandibular acinar cells by ACh stimulation, Sr2+ entered cytoplasm of the cell, like the case of Ca2+. SK&F 96365, a Ca2+ channel blocker, or Ni2+ blocked this divalent cation entry. Sr2+ entering the cell continued to increase to a steady level, after the cessation of stimulation, when Sr2+ was present in the external solution, unlike the case of Ca2+. Ca2+ entered cells which had been stimulated with ACh in Sr(2+)-containing external solution. In the cells to which Sr2+ has been applied after the store depletion with ACh, Sr2+ cannot be released by the renewed ACh stimulation, unlike the case of Ca2+. 89Sr2+ uptake by the parotidic microsomal fraction 100 min after addition of ATP was 15.08 +/- 0.70 nmol/mg protein, whereas 45Ca2+ uptake was 144.19 +/- 16.93 nmol/mg protein. It was concluded that in the salivary acinar cells Sr2+ can be a substituent for Ca2+ in the mechanism of entry from the extracellular fluid but cannot be in the mechanism of uptake into the stores. <4> UI - 94296639 AU - Ahlner BH AU - Lind MG IN - Department of Otolaryngology, Karolinska Hospital, Stockholm, Sweden. TI - The effect of irradiation on blood flow through rabbit submandibular glands. SO - European Archives of Oto-Rhino-Laryngology 1994;251(2):72-5 AB - Microspheres labelled with radioactive isotopes were used to study blood flow through irradiated rabbit submandibular glands before and after injection of pilocarpine. The blood flow through the submandibular glands was measured by the microsphere technique with satisfactory accuracy. A single radiation dose of 13.1 Gy at 3 months of age reduced blood flow through the whole gland significantly 4 months later, and even more at 10 months after irradiation. However, the relative blood flow (per gram of gland tissue) was almost unaffected at both 4 and 10 months post-irradiation with 13.1 Gy because of the simultaneous reduction of gland parenchyma. <5> UI - 93305533 AU - Hopewell JW AU - Robbins ME AU - van den Aardweg GJ AU - Morris GM AU - Ross GA AU - Whitehouse E AU - Horrobin DF AU - Scott CA IN - Research Institute (University of Oxford), Churchill Hospital, UK. TI - The modulation of radiation-induced damage to pig skin by essential fatty acids. SO - British Journal of Cancer 1993 Jul;68(1):1-7 AB - The ability of essential fatty acids (EFAs) to modulate radiation-induced normal tissue injury was assessed in pig skin. Female Large White pigs (approximately 25 Kg) received 3 ml/day orally of either an 'active' oil [So-1100, containing 9% gamma-linolenic acid (GLA)] or a 'placebo' oil (So-1129) for just 4 weeks before or for 4 weeks before and for 16 weeks after irradiation; localised irradiation of skin was with single doses of beta-rays from 22.5 mm diameter 90Sr/90Y plaques. The severity of the acute reaction, assessed in terms of erythema or moist desquamation, was significantly less in those pigs that received So-1100 both before and after irradiation, as compared with those receiving that oil only prior to irradiation and the 'placebo' groups. Dose modification factors (DMFs) of between 1.13-1.24 were obtained. A similar reduction in the severity of acute skin injury was seen in pigs receiving So-1100 for only 10 weeks after irradiation. Late skin damage, assessed in terms of late erythema or dermal necrosis, was also reduced with So-1100, with DMFs of 1.14-1.51. No such modification was observed if So-1100 was only administered for 4 weeks prior to irradiation. No adverse side-effects were apparent as a result of EFA administration. So-1100 may represent a safe and valuable method of increasing the therapeutic gain in radiotherapy. <6> UI - 93236483 AU - Spets-Happonen S AU - Luoma H AU - Seppa L AU - Raisanen J IN - Department of Preventive Dentistry and Cariology, University of Kuopio, Finland. TI - The effect of different strontium concentrations on the efficacy of chlorhexidine-fluoride-strontium gel in preventing enamel softening in vitro. SO - Archives of Oral Biology 1993 Feb;38(2):107-12 AB - The effects were compared of strontium concentrations of 0, 15, 50 and 250 parts/10(6) in chlorhexidine(0.20%)-fluoride(0.16%) gel in preventing the softening of bovine enamel during bacterial fermentation. Fresh Streptococcus sobrinus cells were suspended in a buffer solution (pH 6.0) with 3.3% sucrose and centrifuged as a plaque-like layer on the top of enamel slabs covered with 10 microliters gel. AFter 24 h incubation, the pH fall of the fluid was significantly smaller in all test groups than in the placebo group. Strontium seemed to have an inhibitory effect on the pH fall. All test gels significantly prevented softening and dissolution of enamel during bacterial fermentation, which was directly related to strontium concentration. The amounts of calcium and phosphorus in the cells and fluid after incubation were the smallest in the group with 250 parts/10(6) strontium. In a second experiment without bacteria, new enamel slabs were covered with 10 microliters gel containing chlorhexidine and NaF with 0 and 250 parts/10(6) strontium to study the protective effect of strontium. After 24 h gel treatment, each enamel slab was dissolved in 1 ml 0.1 M lactic acid, pH 5.0, for 2 h. Significantly less calcium and phosphorus were dissolved from the enamel in both test groups than in the control and placebo groups. However, the placebo gel also prevented calcium and phosphorus dissolution significantly. These results suggest that the addition of strontium to chlorhexidine-fluoride gel improves the ability of this combination to prevent caries-like enamel softening. The inhibition of bacterial acid production by the strontium-containing gel may explain this enhanced protection of enamel. <7> UI - 92276602 AU - Afflitto J AU - Schmid R AU - Esposito A AU - Toddywala R AU - Gaffar A IN - Colgate-Palmolive Company, Corporate Technology Center, Piscataway, New Jersey 08855. TI - Fluoride availability in human saliva after dentifrice use: correlation with anticaries effects in rats. SO - Journal of Dental Research 1992 Apr;71 Spec No:841-5 AB - Studies were conducted to determine fluoride availability in saliva after dentifrice use and to relate this parameter to cariostatic efficacy in rat caries experiments. Three dentifrices--two commercial formulations (Colgate Winterfresh Gel and Crest Dentifrice with Na-Sr-polyacrylate) and an Experimental dentifrice--were compared with respect to salivary fluoride availability. All of the dentifrices tested contained 1100 ppm F as sodium fluoride. It was observed that the Experimental dentifrice and Crest dentifrice with Sr-polyacrylate exhibited low salivary fluoride availability relative to the Colgate Winterfresh Gel. Salivary fluoride availability was assessed by means of two parameters: (a) the fluoride concentration in the dentifrice saliva slurry expectorated after brushing, and (b) the area under the curve of salivary F concentration vs. time for up to two hours after dentifrice use. In two rat caries experiments, it was observed that both the Experimental dentifrice and the Sr-polyacrylate dentifrice provided less cariostatic efficacy than the clinically validated Positive Control (Colgate Winterfesh Gel). Analysis of these data provides further evidence in support of the concept that fluoride availability in saliva following dentifrice use is an important parameter related to anticaries efficacy. <8> UI - 91231801 AU - van den Aardweg GJ AU - Hopewell JW AU - Adams GE AU - Barnes DW AU - Sansom JM AU - Stratford IJ AU - Nethersell AB IN - CRC Normal Tissue Radiobiology Research Group, Research Institute (University of Oxford), Churchill Hospital, Headington, UK. TI - Protection of pig epidermis against radiation-induced damage by the infusion of BW12C. SO - International Journal of Radiation Biology 1991 Apr;59(4):1039-51 AB - BW12C, which was developed as an agent for the treatment of sickle cell anaemia, increases the binding of oxygen to haemoglobin and hence reduces the availability of oxygen to tissues. Due to these changes in oxygen availability BW12C could act as a protector against radiation-induced injury to normal tissues. In this study the potential value of BW12C, as a radioprotector, was studied in the irradiated epidermis of the pig. The infusion of BW12C caused an instant left shift of the oxygen dissociation curve, an effect that lasted for approximately 1.5 h. This left shift in the oxygen dissociation curves increased with increasing dose of the drug. There appeared to be no long-term systemic effects produced by doses of 20-100 mg/kg of BW12C. In the first 90 min after the infusion of BW12C skin fields were irradiated with single doses of beta-rays from strontium-90 plaques. The incidence of moist desquamation was used as an endpoint for assessing the severity of the radiation response. With animals breathing approximately 70% oxygen in the anaesthetic gas mixture, the ED50 values for moist desquamation were 30-31 Gy after a dose of 30 and 50 mg/kg, and 37-38 Gy for 75 and 100 mg/kg doses of BW12C. These ED50 values were significantly higher than the value of 27.3 Gy for radiation alone. This indicated dose modification factors (DMF) with mean values of approximately 1.13 and approximately 1.40 for irradiation following the infusion of low (30-50 mg/kg) and high (75-100 mg/kg) doses of the drug, respectively. With the animals breathing air (approximately 21% of oxygen) in the 2% halothane anaesthesia gas mixture, irradiation in the presence of 30 and 50 mg/kg of BW12C resulted in ED50 values of approximately 39 Gy for moist desquamation, which was significantly higher than the value of 31.2 Gy for radiation alone. Surprisingly, a higher dose of 75 mg/kg of BW12C resulted in a lower ED50 value for moist desquamation of 34.38 Gy. Irradiation in the presence of a dose of 100 mg/kg of BW12C produced an ED50 value which was not significantly different from that for radiation alone. In the situation where animals were breathing air (approximately 21% oxygen) during irradiation a DMF of 1.14 was obtained for irradiation alone, when the results were compared with those for irradiation alone with approximately 70% oxygen in the anaesthetic gas mixture.(ABSTRACT TRUNCATED AT 400 WORDS) <9> UI - 91189951 AU - Markowitz K AU - Bilotto G AU - Kim S IN - Department of Endodontics, School of Dental and Oral Surgery, Columbia University, New York, NY 10032. TI - Decreasing intradental nerve activity in the cat with potassium and divalent cations. SO - Archives of Oral Biology 1991;36(1):1-7 AB - Nerve activity was recorded from deep dentinal cavities in the canine teeth to assess the possible influence of potassium and divalent cations in decreasing this activity in hypersensitive teeth. The decreased activity after the topical application of 0.756 mol/l KCl to the cavity was primarily due to the cation. KCl elicited a biphasic response from intradental nerves, an initial transient excitatory response followed by a prolonged inhibitory period. During the inhibitory period 3 mol/l NaCl, an effective excitatory stimulus, failed to evoke intradental nerve activity. However, with time the response to 3 mol/l NaCl eventually recovered to its previous control level. Close, intra-arterial injection of KCl showed the same biphasic response and time-course of intradental nerve activity as with topical application. Therefore, whether KCl was applied topically or injected its effectiveness in altering the nerve activity was similar. Pretreatment of the dentinal cavity with CaCl2, MgCl2 or SrCl2 greatly reduced the response of intradental nerves to KCl. Therefore these divalent cations seem to have a depressant action on pulpal nerve fibres. The mechanism of action of KCl seems to be an alteration of K+ concentration immediately surrounding the intradental nerves which presumably depolarizes the nerve fibre membrane and elicits an initial firing of action potentials. Because of the persisting high levels of extracellular potassium a sustained depolarized state occurs that results in an inactivation of the action potential. Divalent cations appear to depress the excitability of the nerve cell membrane without altering membrane potential. Such ionic agents could be used in conjunction with KCl as a possible treatment for hypersensitive teeth. <10> UI - 90254740 AU - Mellberg JR AU - Fletcher R IN - Colgate-Palmolive Company, Piscataway, N.J. TI - Effect of a strontium complex on fluoride uptake by artificial caries lesions and sound enamel in vitro. SO - Caries Research 1990;24(2):93-6 AB - The effect of a strontium-polyacrylate complex on fluoride uptake by bovine enamel was determined. A salivary pellicle was formed on sound enamel and enamel with artificially formed caries lesions. Ten specimens of each were treated with solutions containing (A) 225 ppm F, (B) 225 ppm F plus Sr complex, (C) 200 ppm F, 0.1 M phosphate, pH 4.5 or (D) placebo for 1 h and then washed 24 h to remove labile fluoride. Analysis of ten thin layers of enamel showed that, on both enamel types, solution (C) deposited the largest amount of fluoride. The strontium complex decreased fluoride deposition, particularly in the outermost layer. <11> UI - 90140632 AU - Wroblewski J AU - Sagstrom S AU - Mulders H AU - Roomans GM IN - Department of Medical Cell Genetics, Karolinska Institutet, Stockholm, Sweden. TI - Strontium and bromide as tracers in X-ray microanalysis of biological tissue. SO - Scanning Microscopy 1989 Sep;3(3):861-4 AB - Since energy dispersive X-ray microanalysis cannot distinguish between isotopes of the same element, alternative methods have to be used to get information similar to that obtained in experiments with radioactive tracers. In the present study, strontium was used as a tracer for calcium, and bromide as a tracer for chloride. Rats were injected with strontium chloride in vivo, and the uptake of strontium in the acinar cells of the submandibular gland was studied. Eventually a Sr/Ca ratio of 0.3 was reached. In some animals, secretion of mucus had been elicited by stimulation with isoproterenol 4 h prior to injection of strontium chloride. Exchange of calcium for strontium was enhanced by prior injection with isoproterenol. In a second experiment, rats were injected with sodium bromide, and the uptake of bromide by the submandibular acinar cells was followed in time, both in pilocarpine-stimulated and unstimulated glands. Under the experimental conditions, bromide was rapidly taken up by the cells, and the cellular Br/Cl ratio was close to that found in serum. Submandibular glands take up Br somewhat faster than other tissues (liver, heart muscle, skeletal muscle). The uptake of Br in pancreatic acinar cells was studied in vitro. These experiments showed a 1:1 ratio (molar) exchange of Cl for Br. <12> UI - 90030332 AU - Kapitola J AU - Jahoda I AU - Kubickova J TI - [The effect of oophorectomy on blood flow, 85Sr uptake and mineral content in the tibia of female rats]. [Czech] SO - Casopis Lekaru Ceskych 1989 Sep 8;128(37):1175-7 AB - The authors investigated in three experiments the blood flow (by retention of 85Sr microparticles), the 85Sr retention and state of mineralization of the tibia in female rats after oophorectomy (OOX). In the first experiment one month after OOX the retention of 85Sr microparticles is increased significantly to 158.6%, as compared with controls, the blood flow is increased insignificantly to 131.3%. In the second experiment the retention of microparticles is increased maximally 4 weeks after OOX to 152.9%, the blood flow after two weeks to 150.0%, as compared with controls; the weight of the ash per unit of bone volume of the tibia is significantly reduced after 8 weeks following OOX--to 90.8%. The two-hour retention of radioactive strontium 85Sr in the third experiment after OOX rises--significantly after 8 weeks to 133.4%. The results of the experiments are consistent with the idea on an increased metabolic activity of osseous tissue in the initial stage of the demineralization process following OOX. <13> UI - 89271918 AU - Bell ET AU - Featherstone JD AU - Bell JE IN - Department of Biochemistry, University of Rochester Medical Center, New York 14642. TI - Interaction of terbium and calcium with chicken cystatin. SO - Archives of Biochemistry & Biophysics 1989 Jun;271(2):359-65 AB - The emission intensity of the fluorescent lanthanide, terbium, is shown to be enhanced upon binding to chicken cystatin. Fluorescence titrations indicate the presence of a single high affinity binding site per molecule. Binding of the terbium results in a 29% quenching of the fluorescence of the single tryptophan residue in the molecule. Calcium displaces the terbium from cystatin as judged by the decrease of terbium fluorescence in competition titrations. Similar titrations with magnesium or strontium demonstrate that the metal binding site of cystatin exhibits specificity for calcium or terbium. Analysis of the N-terminal sequence of chicken cystatin suggests the presence of a putative consensus sequence for a metal binding site between residues 13 and 24. Calcium causes a 17% decrease in the tryptophan fluorescence of cystatin, indicating that an induced conformational change accompanies metal binding. The increased quenching observed with terbium appears to be the result of resonance energy transfer from tryptophan to terbium. From the critical distance for energy transfer from tryptophan to terbium, it is estimated that the terbium binding site lies approximately 12 A from the single tryptophan residue in the molecule. <14> UI - 89233921 AU - van den Aardweg GJ AU - Hopewell JW AU - Barnes DW AU - Sansom JM AU - Nethersell AB IN - CRC Normal Tissue Radiobiology Research Group, Research Institute (University of Oxford), Churchill Hospital, U.K. TI - Modification of the radiation response of pig skin by manipulation of tissue oxygen tension using anesthetics and administration of BW12C. SO - International Journal of Radiation Oncology, Biology, Physics 1989 May;16(5):1191-4 AB - The importance of tissue oxygen tension on radiosensitivity was studied by examining modifications in the incidence of moist desquamation in pig skin after irradiation with strontium-90 plaques. The effects were analyzed using quantal dose-response data and comparisons were made using ED50 values for moist desquamation. Under standard anesthetic conditions of 2% halothane, approximately 70% oxygen, and approximately 30% nitrous oxide, the ED50 value (+/- SE) for moist desquamation was 27.32 +/- 0.52 Gy with no significant variation in radiosensitivity between dorsal, lateral, and ventral skin sites on the flank. Irradiation with 2% halothane and air increased the ED50 to 31.25 +/- 0.94 Gy, primarily due to an increased radioresistance of the dorsal sites. When combined with BW12C, a drug which binds oxygen selectively to hemoglobin and hence reduced the oxygen availability to tissues, a further increase in the ED50 values was observed. This was approximately 39 Gy with BW12C concentrations of 30 mg/kg and 50 mg/kg b.w. of BW12C, indicating a dose modification factor (DMF) of approximately 1.26. However, when animals were breathing the standard gas mixture, this DMF was reduced to 1.15 for 30 mg/kg of BW12C, indicating that a higher level of oxygen partly counteracted the effects of the drug in these studies with BW12C. The greatest variability in radiosensitivity was seen in the dorsal fields. This suggested complex physiological adaptation, a phenomenon that might also explain the absence of any modification of the radiation response when 100 mg/kg of BW12C was used. <15> UI - 89151360 AU - Luoma H AU - Nykanen I AU - Seppa L AU - Alakuijala P AU - Spets-Happonen S AU - Raisanen J IN - Department of Preventive Dentistry and Cariology, University of Kuopio, Finland. TI - Protection by F, I, Sr, and combinations against fermentation attack by Streptococcus sobrinus artificial plaque on bovine enamel. SO - Caries Research 1989;23(1):5-13 AB - Labial surfaces of 64 bovine incisors (8 teeth/treatment) were subjected to 1-min treatment with (1) 500 ppm Sr, (2) 0.5% I2 plus 1% KI solution, (3) F varnish treatment (Duraphat) for 24 h, or (4) combined treatments. The treated teeth were incubated under an artificial Streptococcus sobrinus plaque for 10 days. The 'oral fluid' with maleate buffer (pH 5.8) partially saturated with Ca3(PO4)2 and with or without 3.3% sucrose or sucrose plus 25 ppm F, was replaced by a mixture containing thioglycolate broth and the buffer for 4 h daily. This was done in an attempt to maintain the viability of the plaque as it was not renewed. Analysis of the Ca and inorganic P in the fluid phase taken after the 1st and the 10th day of incubation indicated that complete protection was obtained with F varnishing plus 25 ppm F in the fluid, with added sucrose. The Sr plus F treatment was more protective than F or Sr alone. The iodine treatment was slightly protective when combined with F varnishing. The results of the enamel surface and subsurface F and Sr as well as measurements of surface microhardness also indicated the highest protective effect with the double-F treatment and a marked protection provided by the Sr plus F treatment. The efficacy of the double-F treatment was partly explained by the prevention of a fall in 'plaque' pH and partly by the release of bacterial inorganic P in the extracellular fluid. The present caries model is versatile in quantification of changes in numerous parameters (14 parameters measured) involved in the caries-like process and its inhibition. <16> UI - 89106187 AU - Seppa L AU - Nykanen I AU - Spets-Happonen S AU - Luoma H IN - Department of Preventive Dentistry and Cariology, University of Kuopio, Finland. TI - Prevention of fissure caries in rats by dietary F supplement with and without topical application of F and Sr + F. SO - Caries Research 1988;22(6):353-6 AB - In our previous studies, combined dietary and topical fluoride have shown to be more effective than each alone. Moreover, supplementation of chlorhexidine-fluoride solution with Sr was beneficial for caries prevention in rats. In the present study, the caries-preventive effect of fluoride added to the diet plus F and/or Sr applications was studied in two experiments with rats. One group received dietary fluoride supplement only. In other groups, either a Sr solution, a fluoride varnish, or a Sr solution plus fluoride varnish were applied to newly erupted molars. In addition, one group received both topical applications of Sr + F and dietary fluoride. Caries development was followed longitudinally during periods of 15, 30 or 54 days. The greatest and most significant reduction of caries resulted from the combination of fluoride varnish plus dietary fluoride supplement. Treatment with Sr solution at the beginning of the experiment had no effect on caries either alone or combined with fluoride varnish. It was found that caries increased rapidly and then levelled off after the 30-days feeding period in all groups. In the treatment groups, however, caries was arrested at a considerably lower level than in the control group. <17> UI - 87309129 AU - Pearce EI AU - Sissons CH TI - The concomitant deposition of strontium and fluoride in dental plaque. SO - Journal of Dental Research 1987 Oct;66(10):1518-22 AB - We have investigated the feasibility of incorporating Sr into dental plaque by means of an enzyme-dependent system known to increase Ca, P, and F levels in plaque. A solution containing Ca (20 mmol/L), P (12 mmol/L), MFP (4.7 mmol/L), F (0.3 mmol/L), and urea (500 mmol/L) was modified by equimolar replacement of Ca with 1, 2, 5, and 10 mmol/L Sr. Thin films of human salivary sediment incubated in these solutions showed increasing levels of acid-extractable Sr as the solution Sr increased. When the concentration exceeded 2 mmol/L, deposition of Ca, P, and F was reduced. In artificial plaque, grown on bovine enamel, from mixed human salivary organisms and treated with the solution containing 2 mmol Sr/L, there was a slightly smaller uptake of Ca, P, and Sr, but a greater uptake of F than in sediment treated with the same solution. Natural human plaque treated 12 times in vivo over three days with this solution (in the form of a mouthrinse) also showed substantial increases (from five- to 26-fold) in the concentrations of all four ions. Absolute levels of Ca, P, F, and especially Sr were, however, lower than those in the artificial plaque samples. (Ca + Sr)/P ratios suggested apatite deposition, and the correlation between amounts of Ca and Sr deposited in natural plaque samples suggested that Sr, like F, is structurally incorporated into this apatite. Fluctuations in the pH of natural plaque may promote apatite crystal maturation, causing a slow loss of Sr.(ABSTRACT TRUNCATED AT 250 WORDS) <18> UI - 85105747 AU - Brudevold F AU - Tehrani A AU - Attarzadeh F AU - Goulet D AU - van Houte J TI - Effect of some salts of calcium, sodium, potassium, and strontium on intra-oral enamel demineralization. SO - Journal of Dental Research 1985 Jan;64(1):24-7 AB - A newly-developed intra-oral enamel demineralization test was used to evaluate the effect of supplementation of a 10% sucrose solution with various components on enamel demineralization induced by the sucrose. Five human subjects wore a palatal prosthesis holding eight blocks of subsurface bovine enamel covered with a layer of S. mutans cells. The test involved rinsing with sucrose solution or with sucrose solution supplemented with 0.162 mol/l of different calcium salts or equivalent concentrations of Na-, K-, and Sr salts; rinsing was for one min at times zero and 45 min of the 90-minute test period. Ca-propionate, Ca-acetate, and Ca-levulinate completely inhibited sucrose-induced enamel demineralization; Ca-chloride, Ca-lactate, and Ca-ascorbate gave from 65-75%, and K-acetate, Na-lactate, and Sr-lactate 39, 25, and 18% inhibition, respectively. Consideration of the anion dissociation constants and the Ca-anion association constants of the salts suggests that the observed inhibition is caused mainly by common ion effects and, to a lesser extent, by buffer effects. <19> UI - 86186099 AU - Viti M AU - Mazza A AU - Solimei GE TI - [Interaction between various trace elements (II)]. [Italian] SO - Archivio Stomatologico 1984 Oct-Dec;25(4):315-27 <20> UI - 85133353 AU - Marshall CG AU - Lent CM TI - Calcium-dependent action potentials in leech giant salivary cells. SO - Journal of Experimental Biology 1984 Nov;113:367-80 AB - Two pairs of discrete salivary glands are located at the base of the muscular proboscis of the sanguivorous Glossiphoniid leeches Haementeria ghilianii and Haementeria officinalis. Each anterior gland is 0.8 cm to 2 cm in length, and comprises over 200 giant salivary cell bodies ranging from 150 microns to over 1000 microns in diameter, depending on the size of the animal. The salivary cells are neither electrically nor dye coupled, and there is no acinar structure or common duct, but instead each cell extends an individual ductule. The cells fire action potentials of 100-200 ms duration and 70-100 mV amplitude in response to depolarizing pulses, or at the cessation of a hyperpolarizing pulse. The impulse is abolished by procedures known to antagonize calcium currents, and persists in sodium-free solution, or when calcium is replaced with strontium or barium. Our results support the hypothesis of a purely calcium-dependent impulse. <21> UI - 85007733 AU - Luoma H AU - Seppa L AU - Koskinen M AU - Syrjanen S TI - Effect of chlorhexidine-fluoride applications without and with Sr and Zn on caries, plaque, and gingiva in rats. SO - Journal of Dental Research 1984 Oct;63(10):1193-6 AB - Molar teeth of four groups of Osborne-Mendel rats, kept on a cariogenic diet, were treated once per day for 48 days with either distilled water (solution C), a solution containing 0.05% chlorhexidine gluconate and 0.04% NaF, pH 5.8 (solution CXF), CXF plus 1000 ppm Sr (solution CXFS), or CXFS plus 1000 ppm Zn (solution CXFSZ). Caries of the hemi-sectioned lower molars was scored according to grades of severity, and the extent of the buccal plaque was estimated. Inflammatory cell infiltration, vascularity, and thickness of the oral mucosa were estimated from stained sections of the buccal oral mucosa to detect possible adverse effects of the treatments. Fissure caries lesions with involvement of the dentin were reduced by 57% (p less than 0.01) with the CXF treatment and by 68% (p less than 0.001) with the CXFS treatment. The CXFSZ treatment reduced the fissure caries least (44%, p less than 0.05), but it appreciably reduced the extent of plaque. The mucosal changes were greatest in the group receiving the CXFSZ treatment, but they were generally small and at a non-pathological level. Supplementation of the CXF solution with Sr thus appeared beneficial for caries reduction. <22> UI - 84055339 AU - Hunter M AU - Smith PA AU - Case RM TI - The dependence of fluid secretion by mandibular salivary gland and pancreas on extracellular calcium. SO - Cell Calcium 1983 Oct;4(4):307-17 AB - Acetylcholine-stimulated fluid secretion from the perfused rabbit mandibular salivary gland was inhibited in a biphasic manner when extracellular calcium concentration was reduced in the range 5 X 10(-4) - 10(-5)M. An initial rapid inhibition was followed by partial recovery to a plateau, the level of which depended upon the calcium concentration. Since no recovery was observed during substitution of calcium by strontium, recovery may depend upon an increased membrane permeability to calcium. It is concluded that acetylcholine evokes fluid secretion in this gland by enhancing calcium entry from the extracellular space, an action which can be mimicked by the calcium ionophore A23187. Changes in the electrolyte composition of saliva during calcium-depletion were such as to suggest that ductal reabsorption of sodium and chloride, and secretion of potassium are inhibited as extracellular calcium concentration is reduced. Secretin-stimulated fluid secretion from the cat pancreas was unaffected when perfusate calcium concentration was reduced to 2.5 X 10(-6)M and carbachol-stimulated amylase secretion was only slightly reduced. Since the latter is a calcium-dependent process, the source of calcium is presumably intracellular. In both glands, reducing calcium to 1 X 10(-6)M caused rapid and irreversible inhibition of fluid secretion. <23> UI - 83153670 AU - Terman BI AU - Gunter TE TI - Characterization of the submandibular gland microsomal calcium transport system. SO - Biochimica et Biophysica Acta 1983 Apr 21;730(1):151-60 AB - Calcium accumulation by submandibular gland microsomes (first described by Selinger and Naim, ((1970) Biochim. Biophys. Acta 323, 337-341) has been further characterized. Accumulation was concentration dependent, had a Km of 25 microM added calcium and a Vmax of 12 nM calcium/mg protein per min. No accumulation was observed in the presence of either the calcium ionophore A23187, or the detergent Triton X-100 (0.05). The divalent cations Sr2+ and Mn2+ inhibited accumulation competitively with Ki values of 67 microM and 200 microM, respectively. The effect of various enzyme inhibitors were tested on the microsomal calcium transport system and it was found that chlorpromazine, trifluoperazine, and DIDS all inhibited. The mitochondrial transport inhibitors ruthenium red and CCCP had no effect on transport. Experiments directed at clarifying the cellular location of the system are described. It was found that the membrane vesicles responsible for transport show different purification properties than the membrane vesicles which contain the standard enzyme markers for total and rough endoplasmic reticulum, Golgi apparatus, plasma membrane, and lysosomes. These conclusions are based upon experiments using these properties for membrane purification, density, size, and electrophoretic mobility. Three possible explanations of the results are given and it is organelles. The significance of the results in: (1) understanding the biochemical properties of the submandibular gland microsomal calcium transport system, (2) clarifying the cellular location of the system, and (3) clarifying the function of the system in salivary secretion are discussed. <24> UI - 83047777 AU - Curzon ME AU - Ashrafi MH AU - Spector PC TI - Effects of strontium administration on rat molar morphology. SO - Archives of Oral Biology 1982;27(8):667-71 AB - Strontium at concentrations of 0, 50 and 150 mg/l was given to rats during pregnancy and to the pups during a pre- and post-weaning period. Measurements were made on first and second mandibular molars to assess the morphology of tooth and fissure dimensions, and enamel and dentine thickness. A significant increase in horizontal and vertical dentine thickness was associated with a level of 50 mg Sr/l, a concentration previously found to be associated with decreased caries prevalence in rats. <25> UI - 82219634 AU - Driessens FC TI - Mineral aspects of dentistry. [Review] [771 refs] SO - Monographs in Oral Science 1982;10:1-215 <26> UI - 81210077 AU - Curzon ME AU - Spector PC TI - Effect of using different strontium salts on dental caries in the rat. SO - Caries Research 1981;15(4):296-301 <27> UI - 81126417 AU - Matsumoto S TI - [The effects of strontium upon experimental dental caries in rats (author's transl)]. [Japanese] SO - Shikwa Gakuho 1980 Jan;80(1):53-75 <28> UI - 81001690 AU - Ashrafi MH AU - Spector PC AU - Curzon ME TI - Pre- and posteruptive effects of low doses of strotium on dental caries in the rat. SO - Caries Research 1980;14(5):341-6 <29> UI - 80139843 AU - Landis CA AU - Putney JW Jr TI - Calcium and receptor regulation of radiosodium uptake by dispersed rat parotid acinar cells. SO - Journal of Physiology 1979 Dec;297(0):369-77 AB - 1. Dispersed rat parotid acinar cells were used to study the effects of secretagogues on 22Na uptake. 2. Carbachol stimulated 22Na uptake, and caused a net gain in total Na and a loss in total K. These effects were accentuated in the presence of 10(-3) M-ouabain. 3. Substance P, epinephrine and phenylephrine also stimulated 22Na uptake while isoproterenol and angiotensin II did not. 4. The 22Na uptake due to carbachol was inhibited by atropine, procaine or CoCl2; the response to Substance P was inhibited by CoCl2 only. 5. Extracellular Ca was required for stimulation of 22Na uptake by carbachol. Strontium but not Ba could substitute for Ca in supporting 22Na uptake. 6. Uptake of 22Na was stimulated by the divalent cationophore, A-23187, and Ca was required for this effect. 7. It is concluded that activation of Ca influx by muscarinic, alpha-adrenergic or peptide agonists triggers, among other effects, an increased membrane permeability to Na. <30> UI - 80008838 AU - Haddas RA AU - Landis CA AU - Putney JW Jr TI - Relationship between calcium release and potassium release in rat parotid gland. SO - Journal of Physiology 1979 Jun;291:457-65 AB - 1. A study was made of the role of Ca release in mediating the sustained phase of K release (86 Rb release) in the rat parotid gland due to receptor activation. 2. Sr could substitute for Ca in supporting the sustained phase of the 86Rb release due to carbachol. Sr was less effective than Ca, while Ba was ineffective. 3. Sr could also restore responsiveness of the transient phase to agonists in media lacking Ca. Again, Sr was less effective than Ca, and Ba was without effect. 4. Carbachol stimulated release of 45Ca from parotid gland slices. The amount of Ca released (about 0.2 micromole/g) was much greater than the estimated Ca influx for the same period. 5. Release of 45Ca by carbachol prevented release due to a subsequent exposure to substance P. 6. Release of 45Ca due to substance P was significantly increased if muscarinic receptors were activated during tissue labelling. 7. These results support an earlier hypothesis whereby different agonists (such as carbachol and substance P) stimulate the release of Ca from a common pool and the release of this Ca mediates the transient phase of the K release response. <31> UI - 79211054 AU - Meyerowitz C AU - Spector PC AU - Curzon ME TI - Pre- or post-eruptive effects of strontium alone or in combination with fluoride on dental caries in the rat. SO - Caries Research 1979;13(4):203-10 <32> UI - 79115274 AU - Feiglin B AU - Reade PC TI - The distribution of [14C] leucine and 85Sr labeled microspheres from rat incisor root canals. SO - Oral Surgery, Oral Medicine, Oral Pathology 1979 Mar;47(3):277-81 AB - The distribution of [14C] leucine and 85Sr labeled tracer microspheres from rat incisor pulp canals was investigated in an effort to establish the potential for passage of substances from within the root canal to the systemic circulation. Following introduction of the tracer materials into the pulp canals, the radioactivity in the lungs, spleen, kidney, liver, heart, blood, skeletal muscle, adrenal glands, salivary glands, and submandibular lymph nodes was determined. At all of the time intervals studied the incorporation of [14C] leucine into the adrenal gland was significantly greater than the [14C] leucine incorporation into the other organs. High levels of 85Sr labeled microspheres were detected in the ipsilateral submandibular glands and submandibular lymph nodes and in the lungs. <33> UI - 79068183 AU - Olson BL AU - McDonald JL Jr AU - Stookey GK TI - The effect of strontium and fluoride upon in vitro plaque and rat caries. SO - Journal of Dental Research 1978 Sep-Oct;57(9-10):903 <34> UI - 91072307 AU - Baud CA AU - Bang S AU - Very JM IN - Institut de Morphologie, Ecole de Medecine, Geneve, Switzerland. TI - Minor elements in bone mineral and their effects on its solubility. SO - Journal de Biologie Buccale 1977 Sep;5(3):195-202 AB - Mineral substance deposited in bone tissue when either strontium or fluoride are present, is both qualitatively and quantitatively different from that deposited in their absence. The presence of these ions causes not only heteroionic substitutions in the crystalline lattice of the apatite phase, but also important modifications of the percentage of crystalline mineral, of crystal size and perfection, and of quantity of mineral per unit volume. These modifications affect the in vitro and in vivo demineralization of bone tissue. <35> UI - 78083279 AU - Limanowska H TI - [Microscopic picture of dental periapical tissues in teeth with root canals filled with paste containing zinc oxide eugenol or the same paste with addition of strontium chloride]. [Polish] SO - Czasopismo Stomatologiczne 1977 Dec;30(12):1013-8 <36> UI - 78046403 AU - Joseph M AU - Gedalia I AU - Fuks A TI - Effect of strontium and fluoride administration on caries resistance of hamster molars. SO - Journal of Dental Research 1977 Aug;56(8):924 <37> UI - 77023913 AU - Losee FL AU - Adkins BL AU - Curzon ME TI - Effect of water solids on dental caries in the rat. SO - Caries Research 1976;10(5):332-6 <38> UI - 77008935 AU - Deleze J AU - Loewenstein WR TI - Permeability of a cell junction during intracellular injection of divalent cations. SO - Journal of Membrane Biology 1976 AUG 27;28(1):71-86 AB - Divalent cations are microinjected into Chironomus salivary gland cells while the cell-to-cell passage of fluorescein (330 dalton) and electrical coupling are monitored. Injections of Ca and Mg that substantially depolarize the cells produce block or marked slowing fluorescein passage, accompanied by electrical uncoupling. Injections of Ca, Mg or Sr that cause little depolarization, and presumably smaller elevation of divalent cation concentration in the cytoplasm, produce block or marked slowing of fluorescein passage with little or no detectable electrical uncoupling. This partial uncoupling may reflect total closure of a fraction of the channels in junctional membrane or partial closure of all channels. <39> UI - 76111724 AU - Palmer HE AU - Karagianes MT TI - Use of 85Sr as an indicator of bone mineral replacement in dogs after disuse demineralization. SO - Aviation Space & Environmental Medicine 1976 Jan;47(1):17-9 AB - The left front legs of two beagle dogs were immobilized for 2 months; the right front legs of each were used as weight-bearing controls. Bone mineral replacement after immobilization was studied by giving intravenous injections of 85Sr. (Stroutium-85). After allowing the radioisotope to disappear from the soft tissues, measurements were made on only that remaining in the bone. The 85Sr uptake in the bone of the leg which had been immobilized was up to 400% higher than that in the control leg. This increased 85Sr uptake probably resulted from only a few percent loss in bone mineral during immobilization and suggests that losses of less than 1% can be detected and located. The sensitivity, simplicity and minimal radiation dose associated with this technique indicates potential application for use in human bedrest and space-flight studies. <40> UI - 76069879 AU - Herbison RJ AU - Handelman SL TI - Effect of trace elements on dissolution of hydroxyapatite by cariogenic streptococci. SO - Journal of Dental Research 1975 Nov-Dec;54(6):1107-14 AB - The effect of low levels of strontium, boron, lithium, molybdenum, and fluorine, alone and in combination, on hydroxyapatite solubility, bacterial growth, and acid production in five antigenic types of Streptococcus mutans was investigated. Pour plates containing synthetic hydroxyapatite were used to compare dissolution of hydroxyapatite. The colonies of the five antigenic types of S mutans produced zones of dissolution that were measured. Acid production and growth were studied in broth culture media. The results show that low levels of strontium and fluorine can significantly reduce demineralization of synthetic hydroxyapatite by S mutans in vitro. <41> UI - 76069907 AU - Gedalia I AU - Anaise J AU - Laufer E TI - Effect of prenatal, preeruptive, and posteruptive strontium administration on dental caries in hamster molars. SO - Journal of Dental Research 1975 Nov-Dec;54(6):1240 <42> UI - 76017965 AU - Hunt CE AU - Navia JM TI - Pre-eruptive effects of Mo, B, Sr and F on dental caries in the rat. SO - Archives of Oral Biology 1975 Aug;20(8):497-501 <43> UI - 75145036 AU - Satir P AU - Gilula NB TI - The fine structure of membranes and intercellular communication in insects. [Review] [106 refs] SO - Annual Review of Entomology 1973;18:143-66 <44> UI - 74027193 AU - Alm A AU - Bill A TI - The effect of stimulation of the cervical sympathetic chain on retinal oxygen tension and on uveal, retinal and cerebral blood flow in cats. SO - Acta Physiologica Scandinavica 1973 May;88(1):84-94 <45> UI - 73244899 AU - Mechin JC AU - Toury C TI - [Action of cariogenic diet on fixation and retention of skeleton and teeth strontium in rats]. [French] SO - Revue d Odonto-Stomatologie 1973 Jan-Feb;20(1):55-9 <46> UI - 72098447 AU - Grippaudo G AU - Cattabriga M AU - Valfre' F TI - [Effect of the trace elements molybdenium, venadium and strontium on experimental caries]. [Italian] SO - Annali di Stomatologia 1971 Jul-Aug;20(7):223-36 <47> UI - 71258090 AU - Meyer MW TI - Evaluation of blood flow in the submandibular gland of the dog by fractional uptake of ionic and particle tracers. SO - Proceedings of the Society for Experimental Biology & Medicine 1971 Jul;137(3):1054-9 <48> UI - 71032787 AU - Gabovich RD AU - Stepanenko GA TI - [Experimental studies of the anti-caries effect of fluorine-containing reagents of molybdenum and strontium]. [Russian] SO - Gigiena i Sanitariia 1970 Jun;35(6):82-4 <49> UI - 70208387 AU - Dreizen S AU - Levy BM AU - Niedermeier W AU - Griggs JH TI - Comparative concentrations of selected trace metals in human and marmoset saliva. SO - Archives of Oral Biology 1970 Mar;15(3):179-88 <50> UI - 70239602 AU - Brues AM AU - Auerbach H AU - Grube DD AU - DeRoche GM TI - Retention of radiostrontium in soft tissues. ANL-7635. SO - ANL Reports 1969 Dec;:119-20 <51> UI - 69155908 AU - D'arca Simonetti A AU - Lanzola E AU - Melchiorri C AU - Pastore A TI - [Determination of strontium 90 in the deciduous teeth]. [Italian] SO - Annali di Stomatologia 1969 Jan;18(1):23-38 <52> UI - 68407007 AU - Furchner JE AU - Drake GA TI - Lack of effect of pilocarpine nitrate on the excretion of strontium-85 by mice. LA-3848-MS. SO - La Reports 1968 Jan 15;:89 <53> UI - 68357512 AU - Losee FL AU - Adkins BL TI - Anti-cariogenic effect of minerals in food and water. SO - Nature 1968 Aug 10;219(154):630-1