Biomedical subjects

A Gaffar

Publications and source records attributed to A Gaffar.

At least 19 recordsLinked to original sources

PubMed2004

Survival data and prognostic factors seen in Pakistani patients with esophageal cancer.

BACKGROUND: Esophageal cancer is common in Pakistan. An attempt has been made for the first time to look at the survival data and prognostic factors associated with esophageal cancer in this region. PATIENTS AND METHODS: We did a retrospective review of 263 cases seen at the Aga Khan University Hospital in Karachi. Data analysis was done using the Kaplan-Meier method and the Cox proportional hazard model. RESULTS: Squamous cell carcinoma was noted in 81% of the cases, whereas adenocarcinoma was the second most common. At the time of diagnosis, early-stage disease was found in 25%, locally advanced in 41% and metastatic in 34% of all cases. Mean age at diagnosis was 56 years, with 59% males and 41% females. Survival data were available in 89 cases. Median survival was 7 months. On univariate analysis, the following factors were of prognostic significance: obstruction, histology, albumin level at diagnosis, age and platelet count. On multivariate analysis, three factors were found prognostic: presence or absence of obstruction, squamous cell carcinoma versus adenocarcinoma and platelet count. CONCLUSIONS: We found that patients with squamous cell carcinoma and absence of thrombocytopenia and obstruction had a better overall survival. However, this is a limited retrospective analysis; we therefore recommend that these prognostic factors be evaluated in larger studies.

Adenocarcinoma↗

PubMed2004

A simple approach to examine early oral microbial biofilm formation and the effects of treatments.

BACKGROUND/AIMS: A simple in vivo approach to examine early dental plaque formation in the human mouth and to determine the effects of common dietary and oral hygiene procedures on biofilm formation is reported. METHODS: A custom designed device that fits securely behind the teeth of the mandibular arch provides a surface for microbial colonization. This device is prepared with denture acrylic and can be repeatedly used by the subject, exposing a large and constant surface area for microbial accumulation. RESULTS: Large numbers of oral bacteria colonized the device by 2 h; these increased significantly by 4 h (P < 0.05). Bacterial colonization increased significantly after rinsing with a sucrose solution (P < 0.05) but remained unaffected after rinsing with water, a commercially available fluoride mouthrinse without antimicrobial agents, or brushing with a fluoride dentifrice (P > 0.05). Rinsing with mouthrinses formulated with chlorhexidine, cetylpyridinium chloride or triclosan/copolymer significantly inhibited colonization (P < 0.05). A dose-dependent inhibition was noted with chlorhexidine rinses (P < 0.05). Brushing with a triclosan/copolymer dentifrice significantly inhibited microbial colonization compared with a control (P < 0.05). CONCLUSION: This simple approach was useful for examining the effects of common dietary and oral hygiene procedures. Significant biofilm inhibitory effects were noted with formulations that demonstrated efficacy in previous clinical studies.

Actinomyces viscosus↗

PubMed2003

A rapid procedure to ascertain the antimicrobial efficacy of oral care formulations.

A rapid method examining the antimicrobial efficacy of oral care formulations with alamar blue, an oxidation-reduction dye with fluorescent end-points, is described. Significant correlations between increasing viable plate counts of the oral bacteria Actinomyces viscosus, Streptococcus sanguis, Streptococcus mutans and Actinobacillus actinomycetemcomitans and increased alamar fluorescence were noted. Metabolically active bacteria reduced alamar with the reduced dye found in the cell-free filtrate. Insignificant alamar reductions were noted in the absence of bacteria or by spent culture supernatants. The efficacy of mouthrinses with clinically proven antiplaque agents such as chlorhexidine or cetylpyridinium chloride were determined by alamar blue. In a model system with A. viscosus, triclosan dentifrices demonstrate a dose-dependent effect on bacteria. Human salivary bacteria demonstrate increasing alamar fluorescence with increasing plate counts. A clinical study examined the effects of rinsing with chlorhexidine or cetylpyridinium chloride mouthrinses in comparison with a placebo mouthrinse and water on salivary bacteria. Rinsing with chlorhexidine resulted in the least number of bacteria by alamar and plate count methods. In summary, the current study demonstrates the utility of alamar blue to examine the antimicrobial effects of oral care formulations in laboratory and clinical studies.

Actinomyces viscosus↗

PubMed2001

Development of an enhanced anticaries efficacy dual component dentifrice containing sodium fluoride and dicalcium phosphate dihydrate.

A dual-chamber dentifrice, which contains sodium fluoride (NaF) in one component and dicalcium phosphate dihydrate (dical) in the other, has been developed. The dentifrice is packaged in a dual-chamber tube and is formulated to deliver 1100 ppm F. A series of studies consisting of in vitro fluoride uptake, in vivo calcium labeling, intraoral remineralization-demineralization, and animal caries studies were performed to support the improved anticaries efficacy of this product in comparison to a sodium fluoride/silica dentifrice (NaF/silica). An in vitro fluoride uptake study comparing 1100 ppm F NaF/dical dentifrice to 1100 ppm F NaF/silica showed that NaF/dical delivered significantly more fluoride than NaF/silica, 3.72 +/- 0.36 micrograms/cm2 versus 2.41 +/- 0.10 micrograms/cm2. A 6-day in vivo brushing study with a 44Ca labeled NaF/dical dentifrice showed that calcium from dical penetrated demineralized enamel and was present in plaque up to 18 hrs since the last brushing. An intra-oral remineralization-demineralization study was performed to evaluate NaF/dical's ability to promote remineralization in comparison to three silica-based dentifrices containing 0, 250, and 1100 ppm F as NaF. The percent mineral changes after treatment were +20.44 +/- 17.14 for NaF/dical, +9.27 +/- 19.53 for 1100 ppm NaF/silica, -1.43 +/- 20.57 for 250 ppm NaF/silica, and -12.36 +/- 32.76 for 0 ppm F/silica. A statistical analysis showed that the dual-chamber NaF/dical dentifrice was significantly more effective than the 1100 ppm NaF/silica dentifrice at promoting remineralization. A rat caries study was performed to evaluate NaF/dical ability to prevent caries in comparison to 1100 ppm F NaF/silica, 250 ppm F NaF/silica, silica, and dical dentifrices. The mean smooth surface caries scores were 1.6 +/- 2.8 for NaF/dical, 5.5 +/- 6.2 for 1100 ppm F NaF/silica, 10.6 +/- 6.2 for 250 ppm F NaF/silica, 13.7 +/- 4.7 for 0 ppm F/silica, and 9.5 +/- 7.8 0 ppm F/dical. A statistical analysis showed that the the dual-chamber NaF/dical dentifrice was superior to all other treatments tested in preventing caries in rats. The dical dentifrice was significantly superior to the silica dentifrice in preventing caries, which indicates that dical alone exhibits anticaries efficacy. In conclusion, individual and cumulative results from the fluoride uptake, intra-oral remineralization-demineralization, and rat caries studies from the dual chamber NaF/dical dentifrice support the improved anticaries efficacy of this product.

Animals↗

PubMed2001

Recurrent oral ulcers--an overview.

Recurrent oral ulcers (ROUs) are the most common oral mucosal disease. The etiology of ROUs is complex. The factors include mechanical trauma, genetics, stress, smoking, and viral and bacterial infections. Treatment modalities depend on the differential diagnosis of ROUs and could consist of antimicrobial agents, anti-inflammatory agents, immunomodulators, or over-the-counter medications. New therapy available in the form of a coating polymer, Colgate ORABASE Soothe.N.Seal, is clinically proven to provide rapid relief and healing of ROUs.

Carboxymethylcellulose Sodium↗

PubMed2000

Present and future technologies of tooth whitening.

Dental stains can be broadly classified as intrinsic or extrinsic. Intrinsic stains are a result of defects in tooth development, fluorosis, or acquired through the use of tetracycline. Extrinsic stains are localized mainly in the pellicle and are generated by the reaction between sugars and amino acids or acquired from the retention of exogenous chromophores in the pellicle. Three clinical methods are currently used for measuring stain removal and tooth whitening in the development of new whitening technologies: Lobene Stain Index, Shade Guide Color Change, and Minolta ChromaMeter. Professional tooth whitening products rely on proven technologies--35% hydrogen peroxide for in-office power bleaching or 10% to 15% carbamide peroxide for at-home bleaching--to reduce intrinsic stain and change the inherent tooth color. Over-the-counter tooth whitening products use a combination of surfactants, abrasives, anticalculus agents, and low levels of hydrogen peroxide to reduce extrinsic stain and help maintain tooth whiteness after professional treatment. Future technologies for whitening teeth could involve the use of activating agents to enhance the performance of hydrogen peroxide and natural enzymes.

Color↗

PubMed1999

Synthesis and histamine H3 receptor activity of 4-(n-alkyl)-1H-imidazoles and 4-(omega-phenylalkyl)-1H-imidazoles.

The influence of lipophilic moieties attached to a 4-1H-imidazole ring on the histamine H3 receptor activity was systematically investigated. Series of 4-(n-alkyl)-1H-imidazoles and 4-(omega-phenylalkyl)-1H-imidazoles were prepared, with an alkyl chain varying from 2-9 methylene groups and from 1-9 methylene groups, respectively. The compounds were tested for their activity on the H3 receptor under in vitro conditions. For the 4-(n-alkyl)-1H-imidazoles the activity is proportional to chain length, ranging from a pA2 value of 6.3 +/- 0.2 for 4-(n-propyl)-1H-imidazole to a pA2 value of 7.2 +/- 0.1 for 4-(n-decyl)-1H-imidazole. For the series 4-(omega-phenylalkyl)-4H-imidazoles an optimum in H3 activity was found for the pentylene spacer: 4-(omega-phenylpentyl)-1H-imidazole has a pA2 value of 7.8 +/- 0.1.

Animals↗

PubMed1999

Influence of OAS-1000 on mediators of inflammation.

OAS-1000 is a semisynthetic derivative of pseudopterosine A, isolated from sea whip (Pseudopterogorgia elizabethae), that has been shown to have topical anti-inflammatory activity. The purpose of this research was to investigate OAS-1000 for potential use as an anti-inflammatory agent for topical oral application, and to begin to investigate a mechanism of action. OAS-1000 was therefore evaluated as an inhibitor of 4 enzymes of the arachidonic acid metabolic pathways (prostaglandin G/H synthase I (PGHS-1, COX-1), prostaglandin G/H synthase II (PGHS-2, COX-2), arachidonate 5-lipoxygenase (5-LOX), and arachidonate 15-lipoxygenase (15-LOX)). It was found that OAS-1000 inhibits PGHS-1 activity with an IC-50 value of 80.3 microM, but had much less activity versus PGHS-2 enzyme and no activity versus the 15-LOX enzyme. 5-LOX activity showed some inhibition, but only at a high OAS-1000 concentrations. Additionally, OAS-1000 was tested for it's ability inhibit 1 ng/ml IL-1beta stimulated PGE2 production in a cell culture system. Inhibition of 46% was seen at an OAS-1000 concentration of 22.4 microM. Taken together, these experiments suggest that at least some of the topical anti-inflammatory activity of OAS-1000 may be attributed to inhibition of the arachidonic acid metabolites that have been shown to be important in inflammation and tissue destruction.

Animals↗

PubMed1999

The clinical effectiveness of a dentifrice containing triclosan and a copolymer for providing long-term control of breath odor measured chromatographically.

The objective of this double-blind clinical study was to investigate the effectiveness of a commercially available dentifrice containing triclosan and a copolymer (Colgate Total Toothpaste) for controlling long-term, i.e., seven-hour and overnight breath odor. In particular, a comparison was made between the level of control of breath odor provided by the test dentifrice, and that provided by a placebo dentifrice which did not contain triclosan or a copolymer. This study followed a two-treatment, two-period crossover design. Prospective subjects were provided with a supply of a commercially available fluoride dentifrice, which was used for a one-week period prior to the two seven-day treatment periods. During each treatment period, subjects were instructed to brush their teeth twice a day, morning and evening, for sixty seconds with their assigned study dentifrice, using the soft-bristled toothbrush which had been provided. On the morning following the seventh day of each treatment period, subjects reported to the clinical facility for overnight breath odor assessments. Directly following this, subjects brushed their teeth, ate and drank normally, and reported once again to the clinical facility at seven hours post-toothbrushing for another breath odor assessment. Prior to the overnight breath odor assessments, subjects refrained from brushing their teeth, rinsing their mouths or using breath mints, and from eating or drinking anything on the morning of the evaluation. Subjects refrained from the use of tobacco products, and from eating onions, garlic, or strong spices throughout the entire study. Breath odor was instrumentally evaluated by measuring the level of volatile sulfur compounds in the mouth air using a 565 Tracor gas chromatograph equipped with a flame photometric detector. Measurements were taken in duplicate, and then averaged. Levels of volatile sulfur compounds were expressed in nanograms per milliliter (ng/ml) of mouth air. The two dentifrices exhibited statistically significant differences (p < 0.05) with respect to both overnight breath odor and seven-hour post-toothbrushing breath odor. The mean overnight breath odor scores were 9.63 ng/ml for Colgate Total Toothpaste, and 12.64 ng/ml for the placebo dentifrice. For seven-hour breath odor, the mean scores were 5.62 ng/ml for Colgate Total Toothpaste, and 7.10 ng/ml for the placebo dentifrice. Thus, the results of this double-blind clinical study on 19 subjects support the conclusion that Colgate Total Toothpaste provides effective seven-hour and overnight control of breath odor.

Adult↗

PubMed1999

Treating hypersensitivity with fluoride varnish.

Dentinal hypersensitivity results when stimulation causes the fluid in open dentinal tubules to undergo pressure changes, which activates mechanoreceptor nerves and results in pain. Treatment with fluoride varnish forms a protective layer of calcium fluoride that prevents this fluid flow, thereby reducing dentinal sensitivity.

Calcium Fluoride↗

PubMed1998

Cariostatic effects of a xylitol/NaF dentifrice in vivo.

Xylitol has been shown to reduce plaque acids, but its topical cariostatic effect has been equivocal. The purpose of the studies reported here was to optimise the xylitol/NaF combination in dentifrices for an improved anticaries activity. In the first study, the combination of 10 per cent xylitol with 1100 ppm F (NaF), 1100 ppm F (NaF), and placebo dentifrices were tested in a rat caries model to assess the cariostatic effect. The combination was significantly more effective than fluoride by itself (P = 0.05). The xylitol/NaF combination provided significantly more remineralisation of dentine than fluoride by itself. Collectively, results of these investigations confirm the improved anticaries effectiveness of the xylitol/NaF combination in a variety of animal and intra-oral models. A three-year clinical study confirmed these findings.

Acids↗

PubMed1998

Treating hypersensitivity with fluoride varnishes.

Administration, Topical↗

PubMed1997

Clearance of sodium lauryl sulphate from the oral cavity.

Sodium lauryl sulphate (SLS) is used in toothpaste and mouth rinses as an emulsifying and surface cleaning agent. SLS has been implicated in an increased incidence of oral irritation in subjects predisposed to recurrent aphthous stomatitis (RAU). Hence, the purpose of this study was to determine the levels of SLS found in the oral cavity following rinsing with an SLS containing mouth rinse and brushing with a SLS containing dentifrice. An analytical method to separate SLS from saliva and other complex systems was developed. The method used high performance liquid chromatography (HPLC) and detection performed using conductivity measurements. Standard curves with known concentrations showed a detection limit of less than 0.4 ug SLS/ml of fluid. 2 clinical studies were conducted to determine the amount of SLS retained in the mouth by a healthy population after rinsing or brushing with commercially available products. The results showed, after rinsing, that 96% of the available SLS from the rinse was recovered in the collected samples within 2 min. Similarly, after brushing, 86% of the SLS contained within the toothpaste was recovered from the collected samples within the first 10 min. These results showed that the amount of SLS retained in the oral cavity was minimal and the contact time between SLS and the oral cavity was very short. A 2nd study was conducted to measure the amount of SLS retained in the mouth by a population susceptible to RAU. After rinsing, 97% of the available SLS was recovered within the first 2 min. Following brushing, 89% of the SLS in the dentifrice was recovered within the first 10 min. These results were comparable to those determined by the study involving the healthy population.

Adult↗

PubMed1997

Chemical agents for the control of plaque and plaque microflora: an overview.

This presentation provides an overview of the technologies available for the chemical control of plaque. It is generally accepted that the formation of dental plaque at the interfaces of tooth/gingiva is one of the major causes of gingival inflammation and dental caries. Several therapeutic approaches have been used to control dental plaque and supragingival infections. These include fluoride preparations such as stannous fluoride, oxygenating agents, anti-attachment agents, and cationic and non-cationic antibacterial agents. Among the fluoride preparations, stable stannous fluoride pastes and gels have been shown to reduce supragingival plaque, gingivitis, hypersensitivity and caries. The effect of the oxygenating agents on the supragingival plaque has been equivocal, but recent data indicate that a stable agent which provides sustained active oxygen release is effective in controlling plaque. A polymer, PVPA, which reduced attachment of bacteria to teeth was shown to significantly reduce plaque formation in humans. A new generation of antibacterials includes non-ionics such as triclosan, which in combination with a special polymer delivery system, has been shown to reduce plaque, gingivitis, supragingival calculus and dental caries in long-term studies conducted around the world. Unlike the first generation of agents, the triclosan/copolymer/sodium fluoride system is effective in long-term clinicals and does not cause staining of teeth, increase in calculus, or disturbance in the oral microbial ecology.

Anti-Infective Agents, Local↗

PubMed1997

In vivo detection of calcium from dicalcium phosphate dihydrate dentifrices in demineralized human enamel and plaque.

A series of studies was conducted to clarify the role of DCPD in improving the effects of fluoride in the mouth. We performed plaque fluid studies to see if the use of DCPD dentifrices increases the levels of free Ca2+ ions and the DSenamel in plaque fluid. The results of these studies showed that plaque fluid was undersaturated with respect to DCPD; therefore, DCPD would dissolve in the mouth. The Ca2+ activity in plaque fluid measured 12 hours post-treatment was significantly elevated with the use of DCPD dentifrices in comparison with silica dentifrices. The use of DCPD dentifrices also increased the DSenamel of plaque fluid in comparison with a NaF/silica dentifrice. To determine whether Ca from DCPD could be detected in demineralized enamel and whole plaque after in vivo usage of a DCPD/ fluoride dentifrice, we conducted a 44Ca labeling study. Secondary Ion Mass Spectrometry (SIMS) was used to detect and measure changes in 44Ca levels in enamel before and after 6 days of in vivo treatment with a 44DCPD/fluoride dentifrice. The results showed that 44Ca from DCPD was incorporated into enamel and detected in plaque 18 hours post-treatment. The findings from these studies show that brushing with a DCPD dentifrice introduces additional, exogenous Ca into the oral environment, which fosters improved remineralization of teeth in combination with fluoride.

Calcium↗

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

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

Some effects of mouthrinses containing salifluor on de novo plaque formation and developing gingivitis.

Three clinical trials were carried out to evaluate the effects of mouthrinses containing 5n-octanoyl-3'-trifluormethylsalicylanilide (salifluor) on plaque and gingivitis. Each trial was performed as a double-blind, randomised and cross-over designed study (studies 1, 2 and 3). In each study, 10 young individuals with healthy gingiva abolished all means of mechanical plaque control during the course of the experimental period including 6 x 4 days (study 1), 3 x 18 days (study 2) and 3 x 14 days (study 3). They rinsed, 2 x daily, with various mouthwash preparations for 4 days (study 1), for the last 4 days of a 18 day period (study 2) or for 14 days (study 3). 6 (control, vehicle control, 0.08%, 0.12% and 0.2% salifluor and 0.12% chlorhexidine), 3 (control, 0.12% salifluor and 0.12% chlorhexidine) and 3 (control, 0.12% salifluor and 0.12% chlorhexidine) mouthwash preparations were tested in studies 1, 2 and 3, respectively. The findings of study 1 indicated that (i) mouthrinses containing salifluor were significantly more effective than control rinses and that (ii) the salifluor mouthrinses were equally effective as the 0.12% chlorhexidine mouthrinse, in retarding 4-day de novo plaque formation. The findings of study 2 indicated that (i) the mouthrinse containing 0.12% salifluor retarded de novo plaque formation to the same extent as the 0.12% chlorhexidine mouthrinse at healthy as well as at inflamed sites but that (ii) the anti-plaque effects of the salifluor and chlorhexidine mouthrinses were significantly smaller at sites with inflamed than with healthy gingiva. In study 3, it was observed that there was no significant difference between the 0.12% salifluor and 0.12% chlorhexidine mouthrinses in retarding de novo plaque formation and the development of gingivitis during a 14-day period of no mechanical plaque control. Thus, the results of the 3 clinical trials demonstrated the potential of salifluor as an effective anti-plaque and anti-inflammatory agent.

Adult↗