Search PubMed⌕ Search

Biomedical subjects

A R Volpe

Publications and source records attributed to A R Volpe.

At least 73 records · Page 4Linked to original sources
PubMed1997

Clinical efficacy of an optimized stannous fluoride dentifrice, Part 3: A 6-month plaque/gingivitis clinical study, southeast USA.

This 6-month, double-blind clinical study, also following the American Dental Association guidelines, investigated the efficacy of Colgate Optimized Stannous Fluoride (COSF) dentifrice in controlling supragingival dental plaque and gingivitis. The same dentifrice, containing 0.454% stannous fluoride, stannous chloride, polyphosphate, and citrate in a silica base was used. Adult men and women from the Atlanta, Georgia, area received an oral prophylaxis and were instructed to brush their teeth twice daily (morning and evening) for 1 minute with their assigned dentifrice, using a soft-bristled toothbrush. As in the first study, plaque and gingivitis examinations were conducted after 3 months and again after 6 months of using the dentifrices. At both the 3- and 6-month study examinations, the COSF dentifrice group exhibited statistically significant reductions in both plaque and gingivitis compared to the control dentifrice group. At the 6-month examination, the magnitude of these percent reductions exceeded 20% for all 4 parameters measured. Thus, the results of this study reflect those found in the New Jersey study, i.e., supporting the conclusion that the COSF dentifrice is efficacious for the control of supragingival plaque and gingivitis.

Adolescent↗
PubMed1997

Clinical efficacy of an optimized stannous fluoride dentifrice, Part 4: A 3-month calculus clinical study, northwest USA.

The objective of this 3-month, double-blind study was to investigate the efficacy of Colgate Optimized Stannous Fluoride (COSF) dentifrice for the control of supragingival dental calculus accumulation. After 3 months' use, the COSF dentifrice group exhibited a statistically significant 56.6% reduction in supragingival calculus formation, as compared to the control dentifrice group. The results of this study support the conclusion that the COSF dentifrice is efficacious for controlling the accumulation of supragingival calculus.

Adult↗
PubMed1997

Clinical efficacy of an optimized stannous fluoride dentifrice, Part 5: A 3-month study of extrinsic tooth staining, northeast USA.

The objective of this 3-month, double-blind clinical study was to investigate the level of tooth staining associated with the use of Colgate Optimized Stannous Fluoride (COSF) dentifrice compared to the tooth staining associated with two commercially available dentifrices. The results of this clinical study support the conclusion that the intensity and extent of extrinsic tooth stain associated with the use of the COSF dentifrice are significantly lower than that associated with Crest Gum Care Toothpaste. Further, this study provided no indication that the use of the COSF dentifrice is associated with a greater level of stain than that associated with the use of Crest Regular Toothpaste, a standard 0.243% sodium fluoride/silica dentifrice.

Adult↗
PubMed1997

Inheritable and acquired hyperalgesia associated to abnormal opioid receptor set-up seem to act as opiate addiction preventors.

Hyperalgesia is known to depend on neuroplastic changes chiefly represented by long-term potentiation. These phenomena are proved to depend on excitatory amino acids (EAAs) action at the level of NMDA receptors. This action is known to be related to nitric oxide (NO) release. We found a visceral/vascular hyperalgesia state in migraine (M) sufferers as well as an inheritable systemic hyperalgesia in healthy subjects who are first-degree consanguineous with M sufferers; this type was labelled 'third hyperalgesia'. We discovered that a hyper-increase of plasma L-citrulline, equimolar co-product in the synthesis of NO, characterizes both M sufferers and their first-degree relatives who are exempt from primary headache. A similar pattern never occurred in healthy subjects having both a personal and family history negative for primary headache. We conclude that both 'third hyperalgesia' and a pattern of NO synthase (NOS) hyperactivity seems to be inheritable and can constitute, at least in part, a ground for developing headache. Morphine, proved to be unable to relieve M attack, was given in low doses that caused pain and side-effects in M sufferers only. This outcome seemingly indicates that M sufferers are characterized by a set-up of opioid receptor subtypes different from that of healthy headache-exempts. Following a period of morphine addiction and a withdrawal period, 65.07% of a group of 63 opiate addicts developed M syndrome. All these subjects were first-degree consanguineous relatives of primary headache sufferers. Discussion topics concern the activity of morphine in NO release and the role of NO in sensory transmission of both controls and hyperalgesia sufferers. It is suggested that the inheritable couple consisting of hyperalgesia and NOS hyperactivity can play some role in setting off the pain occurring following morphine in M sufferers.

Adult↗
PubMed1997

Bradykinin and cerebral circulation: selective non-receptor interaction with histamine and serotonin through the system of nitric oxide.

Bradykinin, histamine and serotonin were the most active physiological agonists in increasing jugular levels of nitric oxide when administered into the left common carotid artery of anaesthetized rabbits. Bradykinin potentiated selectively the effects of histamine and serotonin (but not vice versa) on both nitric oxide and carotid blood flow, without involving activation of specific receptors. Since these effects were demonstrated using doses of the three agonists in the order of their physiological plasma concentrations, it was concluded that cerebral circulation in regulated, also within its autoregulatory limits, by bradykinin through selective autocoidal interactions converging on nitric oxide.

Acetylcholine↗
PubMed1997

The effect of bicarbonate/fluoride dentifrices on human plaque pH.

The acidogenic response in dental plaque after rinsing with sodium bicarbonate/fluoride dentifrice slurries was studied using three intra-oral models. In the first model, resting plaque pH was monitored in mesiobuccal plaque on upper molars and premolars in six healthy subjects after abstinence from normal oral hygiene for three days. These measurements were followed by a three-minute rinse with 10% sucrose and, following a two-minute interval, a three-minute rinse with a test dentifrice slurry. After the test dentifrice rinse, pH was monitored at regular intervals up to 60 minutes. Flow rate, pH and buffer capacity of stimulated saliva were also determined. Changes in resting pH, plaque pH minima, and maximum pH drop were calculated. A clear elevation in the resting pH was observed after bicarbonate/fluoride dentifrice rinses, and a significant increase was obtained in the pH minima. The smallest pH drop also was found after treatment with the bicarbonate/fluoride dentifrice rinse treatment (p < 0.02). A second model using telemetric partial dentures with interproximally placed micro-antimony pH electrodes was used to study the effects of rinsing with increasing concentrations of sodium bicarbonate and calcium carbonate solutions, and with a fluoride dentifrice containing sodium bicarbonate. The response to these treatments was found to be rapid, dose-dependent, and was the greatest from the sodium bicarbonate. A third model used 24 subjects to assess the effects of sodium bicarbonate/fluoride dentifrice on plaque pH before and after a glucose challenge. The use of the bicarbonate/fluoride dentifrice resulted in significantly less measurable plaque acid than the fluoride dentifrice treatment. Collectively, these results indicate bicarbonate in dentifrice to be an effective buffering agent for stabilizing the pH and neutralizing plaque acids in dental plaque.

Adult↗
PubMed1996

Vanadate as factor of cardiovascular regulation by interactions with the catecholamine and nitric oxide systems.

The effects of 1 microgram/mL of vanadium, given for 12 mo as sodium metavanadate in drinking water, on cardiovascular and biochemical indices of male rabbits were investigated. At the end of the exposure period, vanadium was more accumulated in bones and kidneys than in spleen and liver; the cardiac ventricles and the aorta contained similar amounts of this element. Blood pressure and heart rate were unchanged in the vanadate-exposed animals since the observed decrease of both cardiac inotropism and stroke volume was counteracted by an increase of peripheral vascular resistance, with reduction of arterial blood flow. The arterial levels of sodium, potassium and aldosterone were unmodified by vanadate which, however, strongly raised those of noradrenaline, adrenaline, L-DOPA, and dopamine. Vanadate caused a marked increase of the activity of monoamine oxidase in renal tubules and liver (probably in relation to the increased plasma catecholamine levels) and a reduction of that of glucose-6-phosphate dehydrogenase in the kidney. There was also evidence that vanadium reduces synthesis and/or release of nitric oxide, the endothelium-derived vasodilating factor, likely through a reduced formation from bradykinin. It was concluded that vanadium may represent an environmental factor of altered cardiovascular homeostasis.

Animals↗
PubMed1996

Interleukin-1 beta specifically stimulates nitric oxide production in the hypothalamus.

In previous experiments we have shown the role of nitric oxide (NO) in basal and interleukin-1 beta (IL-1 beta)-induced CRH and ACTH release in vitro. Now, we have studied the possible production of NO from hypothalamic cell cultures, particularly after IL-1 beta stimulation or L-NOArg inhibition, by high performance liquid chromatographic (HPLC) assay of L-citrulline production, adding further evidence for a role of NO in IL-1 beta activity in the hypothalamus.

Animals↗
PubMed1996

Nitric oxide synthase activity and non-adrenergic non-cholinergic relaxation in the rat gastric fundus.

1. In the presence of atropine (1 microM) and guanethidine (5 microM), electrical field stimulation (EFS, 120 mA, 1 ms, 0.5-16.0 Hz, trains of 2 min) induced frequency-dependent relaxations of 5-hydroxytryptamine (3 microM)-precontracted longitudinal muscle strips from the rat gastric fundus. 2. L-Citrulline concentrations were measured in the incubation medium of precontracted strips before and after EFS to investigate nitric-oxide (NO) synthase activity and its possible relation to non-adrenergic non-cholinergic (NANC) relaxation. 3. Basal NO synthase activity was reflected by the finding of prestimulation levels of L-citrulline of approximately 30 nM. These levels were unaffected by tetrodotoxin (3 microM) and NG-nitro-D-arginine methyl ester (D-NAME, 100 microM), slightly reduced by a calcium-free medium and halved by NG-nitro-L-arginine methyl ester (L-NAME, 100 microM). 4. EFS evoked significant, frequency-dependent increases in bath levels of L-citrulline at all frequencies tested. The increases evoked by 16-Hz EFS were abolished by tetrodotoxin (3 microM), a calcium-free medium and L-NAME (100 microM) but not by D-NAME (100 microM). 5. L-NAME (0.1 microM-1.0 mM) produced significant reduction of 4-Hz EFS-induced L-citrulline production (100% inhibition at 10 microM), but had less marked effects on basal production (approximately 50% reduction at 100 microM) and 4-Hz EFS-induced NANC relaxation (approximately 50% reduction at 1 mM). 6. L-Arginine (1 mM), but not D-arginine (1 mM), increased basal L-citrulline levels and reversed the inhibitory effect of L-NAME (10 microM). 7. These findings represent clear biochemical evidence of both basal and EFS-stimulated NO synthase activity in the rat gastric fundus.

Animals↗
PubMed1996

The effects of antimicrobial mouthrinses on de novo plaque formation at sites with healthy and inflamed gingivae.

The objective of the present investigation was to evaluate to what extent mouthrinses containing triclosan and chlorhexidine may modify the amount of de novo plaque that forms on tooth surfaces adjacent to healthy and inflamed gingival units. 10 volunteers were recruited. On day 0, gingival crevicular fluid (GCF) was obtained at predetermined sites and gingivitis (GI) was assessed. A careful oral prophylaxis was given to each of the volunteers who subsequently abstained from all mechanical plaque control measures for the following 18 days. During the first 4 days (rinse phase I), they rinsed with either 0.12% chlorhexidine, 0.06% triclosan or placebo solution. Clinical examinations (GCF, GI) were repeated and the amount of plaque formed determined on days 4, 7 and 14. On day 14, the participants received a new professional tooth cleaning after which rinse phase II was initiated. During this 2nd phase, the participants rinsed for 4 days with the same mouthwash preparation and in the same manner as during rinse phase I. The examinations were repeated on day 18. Each participant received a comprehensive oral prophylaxisis and was instructed to perform meticulous mechanical plaque control during the following 4 weeks. A 2nd experimental period was then initiated. A total of 3 experimental periods were repeated until all subjects had rinsed with the 3 different mouthwash preparations. The results demonstrated (i) that significantly more plaque formed at sites with gingivitis than at surfaces adjacent to healthy gingival units and (ii) pre-existing gingivitis significantly increased the amount of de novo plaque that formed in subjects who rinsed with mouthwash preparations containing chlorhexidine and triclosan.

Adult↗
PubMed1996

Comparison of the clinical anticaries efficacy of an 1100 NaF silica-based dentifrice containing triclosan and a copolymer to an 1100 NaF silica-based dentifrice without those additional agents: a study on adults in California.

Recent years have seen much work in the development of dentifrices containing the antimicrobial agent triclosan, a broad spectrum antibacterial agent manufactured for use in oral products by the Ciba-Geigy Corporation. Studies have shown that the incorporation of this agent into dental products, in combination with a PVM/MA copolymer (the non-proprietary designation for a polyvinylmethyl ether/maleic acid copolymer), can provide several important dental therapeutic benefits, including an antigingivitis effect. Much research on the therapeutic benefits of such dentifrices has been reported in the literature. The present study is a component of a large-scale program of clinical research to investigate the anticaries effectiveness of fluoride dentifrices containing 0.3% triclosan and 2.0% PVM/MA copolymer. The study included two treatment groups, each consisting of adults living within a 50 mile radius of Loma Linda, California, who were assigned to the use of one of the following sodium fluoride (NaF) dentifrices: 1) a dentifrice containing 0.3% triclosan and 2.0% PVM/MA copolymer in a 0.243% NaF/silica (1100 ppm F) base; or 2) a dentifrice containing 0.243% NaF/silica (1100 ppm F). Conducted in accordance with the guidelines for caries clinical studies published by the Council on Dental Therapeutics of the American Dental Association, the study employed clinical diagnostic criteria as described in the August, 1987 National Institute of Dental Research (NIH/NIDR) publication. Dental radiographs were not employed. Principal comparisons of the dentifrices tested were implemented through the construction of 90% confidence intervals for the ratio of mean 3-year caries increments, using Fieller's theorem. Of those subjects who met the initial inclusion/exclusion criteria for this study, 1,542 were available for the 36-month examination. DFS (resp., DFT) increments over this period were 2.07 (0.63) for the triclosan/copolymer dentifrice, and 2.16 (0.68) for the dentifrice without those additives. The confidence interval calculations for both incremental DFS and DFT support the conclusion that a dentifrice containing 0.3% triclosan and 2.0% PVM/MA copolymer in a 0.243% NaF/silica (1100 ppm F) base provides a level of anticaries efficacy which is "at least as good as" that provided by a dentifrice containing 1100 NaF/silica without those additive agents. As such, the results of this clinical study clearly indicate that the addition of triclosan and a copolymer to a 1100 NaF/silica dentifrice does not compromise its anticaries efficacy.

Adult↗
PubMed1996

Comparison of the clinical anticaries efficacy of a 1500 NaF silica-based dentifrice containing triclosan and a copolymer to a 1500 NaF silica-based dentifrice without those additional agents: a study on adults in Israel.

Recent years have seen much work in the development of dentifrices containing the antimicrobial agent triclosan, a broad spectrum antibacterial agent manufactured for use in oral products by the Ciba-Geigy Corporation. Studies have shown that the incorporation of this agent into dental products, in combination with a PVM/MA copolymer (the non-proprietary designation for a polyvinylmethyl ether/maleic acid copolymer), can provide several important dental therapeutic benefits, including an antigingivitis effect. A considerable amount of the research on the therapeutic benefits of such dentifrices has been reported in the literature. The present study is a component of a large-scale program of clinical research to investigate the anticaries effectiveness of fluoride dentifrices containing 0.3% triclosan and 2.0% PVM/MA copolymer. The study included two treatment groups, each consisting of adults living near the Kiryat Gat area in Israel, who were assigned to the use of one of the following sodium fluoride (NaF) dentifrices: 1) a dentifrice containing 0.3% triclosan and 2.0% PVM/MA copolymer in a 0.331% NaF/silica (1500 ppm F) base; or 2) a dentifrice containing 0.331% NaF/silica (1500 ppm F). Conducted in accordance with the guidelines for caries clinical studies published by the Council on Dental Therapeutics of the American Dental Association, the study employed clinical diagnostic criteria as described in the August, 1987 National Institute of Dental Research (NIH/NIDR) publication. Dental radiographs were not employed. Principal comparisons of the dentifrices tested were implemented through the construction of 90% confidence intervals for the ratio of mean 3-year caries increments using Fieller's Theorem. Of those subjects who met the initial inclusion/exclusion criteria for this study, 1,296 were available for the 36-month examination. DFS (resp., DFT) increments over this period were 5.21 (1.30) for the triclosan/copolymer dentifrice, and 5.23 (1.39) for the dentifrice without those additives. The confidence interval calculations for both incremental DFS and DFT support the conclusion that a dentifrice containing 0.3% triclosan and 2.0% PVM/MA copolymer in a 0.331% NaF/silica (1500 ppm F) base provides a level of anticaries efficacy which is "at least as good as" that provided by a dentifrice containing 1500 NaF/silica, without those additive agents. As such, the results of this clinical study clearly indicate that the addition of triclosan and a copolymer to a 1500 NaF/silica dentifrice does not compromise its anticaries efficacy.

Adult↗
PubMed1995

Microbial alterations in supragingival dental plaque in response to a triclosan-containing dentifrice.

A total of 325 subjects were entered into a double-blind, stratified 2-treatment clinical study that examined the effects of a dentifrice containing 0.3% triclosan, 2% Gantrez copolymer and 0.243% sodium fluoride on supragingival dental plaque and gingivitis. A subset of 159 subjects including 72 men and 87 women participated in the microbiological component of this study, which was designed to detect shifts in supragingival bacterial species in response to triclosan. Subjects were divided into two groups: one performed normal oral hygiene with the triclosan/copolymer dentifrice and a control group used a placebo dentifrice without triclosan. At baseline, 3 and 6 months during treatment and at 6, 12, 18 and 24 weeks post-treatment, supragingival dental plaque was collected from the buccal and lingual surfaces of the 4 first molar teeth and assayed for: 1) bacterial morphotypes by phase-contrast microscopy; 2) select bacterial groups and bacterial species by culture; and 3) target periodontal pathogens including Actinobacillus actinomycetemcomitans, Bacteroides forsythus, Porphyromonas gingivalis and Prevotella intermedia by immunofluorescence microscopy. There were few statistically significant differences between treatment groups in any of the 90 microbiological parameters measured at the 7 different time points. The control group demonstrated significantly higher levels of cultivable Neisseria and higher proportions at the 3-month treatment period of P. gingivalis-infected subjects and mean cells. After 6 months of treatment, the triclosan group demonstrated higher levels of fusiforms. Analysis of triclosan resistance data failed to detect a shift towards increased proportions of bacteria resistant to triclosan, and both treatment groups demonstrated triclosan-resistant strains, predominantly Veillonella dispar. This study confirms the microbiological safety of triclosan-containing dentifrices and suggests that continued use can be associated with beneficial alterations in the bacterial composition of supragingival dental plaque.

Actinomyces↗
PubMed1995

The effect of triclosan on developing gingivitis.

The aim of the study was to examine whether triclosan has an effect on developing gingival inflammation. 10 volunteers, with clinically healthy gingivae were enrolled. The study was performed as a 2-week, double-blind, cross-over, experimental gingivitis trial. Between each plaque accumulation period, there was a wash-out phase of 4 weeks. A baseline examination was performed which included assessment of plaque and gingivitis. The volunteers were asked to refrain from mechanical oral hygiene measures for 2 weeks. During this period, they rinsed 2x daily with one of the randomly assigned mouthrinse preparations. Solution A (period A): 0.06% triclosan+ 2%tween 80. Solution B (period B): 0.06% triclosan+ 0.25% sodium lauryl sulphate. Re-examinations were performed on days 4, 7, 11 and 14. The mean plaque score increased during period A to 2.2 (day 4), 2.8 (day 7), 3.1 (day 11) and 3.1 (day 14). The corresponding scores for period B were significantly lower; 1.2 (day 4), 1.8 (day 7), 2.0 (day 11) and 2.2 (day 14). The mean gingivitis scores at baseline were 0.17 (periods A and B). The mean gingivitis scores increased to 0.45 (day 4), 0.69 (day 7), 0.83 (day 11) and 0.96 (day 14) when the subjects rinsed with solution A and 0.42 (day 4), 0.64 (day 7), 0.78 (day 11) and 0.92 (day 14) in period B. There were no statistically significant differences between periods A and B with respect to gingivitis. Thus, although significantly more plaque formed during period A than period B, no differences could be found between the gingivitis scores in the 2 periods.

Adult↗
PubMed1995

Comparison of the anticaries efficacy of dentifrices containing fluoride as sodium fluoride or sodium monofluorophosphate.

The dominance of the marketplace by dentifrices containing fluoride as sodium monofluorophosphate and sodium fluoride has given rise to great academic and commercial interest regarding the comparison of those two fluoride species. Since the 1970's, several comparative clinical trials have been conducted to investigate the relative anticaries efficacy of dentifrices containing these two agents, generally giving rise to equivocal results. Recently, attention has been turned to investigative efforts which employ information derived from the collective body of relevant comparative clinical studies available in the literature to establish an omnibus conclusion concerning this issue. Beginning with the sign test of Beiswanger & Stookey (1989), and continuing through the meta-analyses of Johnson (1993) and Proskin (1993), this line of research remains vital today. The recent publication of two studies (Marks et al, 1994; Stephen et al, 1994) previously documented in the literature only in abstract form (Conti et al, 1993; Stephen et al, 1993) has given rise to the need for the present meta-analytic reconsideration of the available data. As in the previous meta-analyses, the quantitative results obtained depended on the studies which provided data for the calculations. However, as also indicated in previously-documented meta-analyses, the clinical interpretation of the results, which was based on the guidelines published by the American Dental Association (Council on Dental Therapeutics, 1988), did not vary according to study selection.(ABSTRACT TRUNCATED AT 250 WORDS)

American Dental Association↗