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Biomedical subjects

W Wade

Publications and source records attributed to W Wade.

At least 19 recordsLinked to original sources
PubMed1999

The impact of race and fractures on mortality in a postmenopausal Medicaid population.

The purpose of this study was to model fractures and survival by age and race in a large postmenopausal Medicaid population. All Georgia Medicaid claims were abstracted for the years 1992, 1993, and 1994. Claims for postmenopausal women (> or =50 years of age) were retained, and patients with fractures were identified by International Classification of Diseases, Ninth Revision codes for fracture. A survival analysis was conducted using Kaplan-Meier estimators to evaluate the effect of fracture, age, and race on 3-year survival. A total of 159,400 white and black postmenopausal women were identified. The cohort with fracture totaled 5933 patients, with femoral fractures constituting 46% of all fractures. Discounting those with fracture before the study, the fracture incidence was approximately 1.2% in this postmenopausal female cohort. The survival analysis suggested that after age was accounted for, black postmenopausal women had a 42% increased risk of death within 3 years of fracture, compared with 13% for white women. However, postmenopausal black women were approximately 50% less likely to experience a fracture, and postmenopausal black women without fracture had better survival rates than comparable white women. Mortality crossover and the diminished likelihood of fracture mask the true nature of fracture survival in postmenopausal black women. Postmenopausal black women with fracture are at greater risk of dying than their white counterparts.

Aged↗
PubMed1997

The relationship between microbial factors and gingival crevicular fluid glycosaminoglycans in human adult periodontitis.

Counts of cultivable Porphyromonas gingivalis, assays of microbial proteases and the concentration in gingival crevicular fluid of proteoglycan metabolites were investigated at periodontitis and gingivitis sites in 16 patients with chronic adult periodontitis before and after treatment. Two periodontitis sites and two gingivitis sites were selected from each patient on the basis of a clinical examination. Gingival crevicular fluid from each site was analysed for the concentrations of the glycosaminoglycans chondroitin-4-sulphate and hyaluronan and subgingival plaque samples were analysed for cultivable P. gingivalis and microbial trypsin-like proteases assayed by benzoyl-DL-arginine-naphthylamide (BANA) hydrolysis. Significantly higher concentrations (p = 0.007) of chondroitin-4-sulphate were found at periodontitis than gingivitis sites but there was no significant difference in hyaluronan (p = 0.36) between these sites. Although the majority of periodontal sites were P. gingivalis-negative (23/32), there were significantly higher concentrations of chondroitin-4-sulphate (p = 0.05) and hyaluronan (p = 0.04) at the P. gingivalis-positive, compared to negative, periodontitis sites. At BANA-positive periodontitis sites there were also higher concentrations of chondroitin-4-sulphate (p = 0.0015) and hyaluronan (p = 0.0001) than at BANA-positive gingivitis sites. There was a significant decrease in concentrations of chondroitin-4-sulphate and hyaluronan at periodontitis sites after treatment. This study lends support to the hypothesis that P. gingivalis may be actively involved in the destruction of connective tissue components at culture-positive sites but shows that elevated concentrations of connective tissue breakdown products may occur in gingival crevicular fluid from periodontal sites where this organism is absent.

Adult↗
PubMed1997

Studies on stannous fluoride toothpaste and gel (1). Antimicrobial properties and staining potential in vitro.

Stannous fluoride (SF) in a toothpaste vehicle has the potential to provide anticaries and plaque inhibitory benefits through the fluoride and antimicrobial stannous moieties respectively. Dental staining, however, can occur by precipitation of dietary chromogens onto the tooth surface by stannous ions. These studies in vitro compare the antimicrobial profile and propensity to cause tea staining of a number of stannous fluoride formulations. The formulations used were 2 SF toothpaste products (SF1, SF2), 2 experimental SF plus stannous pyrophosphate toothpastes (SFSP1, SFSP2), a SF gel (G) and a NaF toothpaste (C). Maximum inhibitory dilution values against a range of oral bacteria were determined by agar dilution. Tea staining was measured spectrophotometrically on saliva coated clear acrylic blocks exposed to slurries of the paste or gel. All formulations showed antimicrobial activity with the order of greatest activity downwards being C, SF2, SF1, SFSP1, SFSP2 and G. Tea staining at 10 exposures was in the following descending order of optical density SFSP1, SFSP2, G. C, SF1, SF2, water control. The antimicrobial profile of G was similar to that of SF, whereas that of the other formulations were varied but similar to a detergent profile. The difference in staining suggested considerable variation in availability of stannous ions in the formulations. However, the propensity for stannous ions to stain must be balanced against the stain removal propensity of the contained detergents in the toothpaste formulations. In conclusion, the variation in antimicrobial activity and more particularly staining activity of the formulations suggest the products will vary in activity in vivo.

Anti-Infective Agents, Local↗
PubMed1996

A 6-month home-usage trial of 0.1% and 0.2% delmopinol mouthwashes (I). Effects on plaque, gingivitis, supragingival calculus and tooth staining.

Delmopinol is a morpholinoethanol derivative which, in mouthrinses used in the absence of normal oral hygiene, has been shown effective in the inhibition of plaque and gingivitis. The aim of this study was to determine the adjunctive oral hygiene benefits and safety of delmopinol rinses when used alongside normal toothcleaning. This 6-month home use study was a placebo-controlled, double-blind, randomised parallel design evaluating 0.1% and 0.2% delmopinol rinses and structured to conform with the ADA Council of Dental Therapeutics guidelines. A total of 450 dentate male and female subjects were recruited who had no relevant medical or pharmacotherapy histories determined from a full medical examination, including haematological and biochemical tests. Subjects had moderate levels of plaque and gingivitis. At baseline, 3 and 6 months subjects were scored for plaque, gingivitis, tooth stain and supragingival calculus, with plaque sampled for microbiological analysis. Additionally, oral mucosal examinations were performed and subjects questioned for adverse symptoms. Baseline special tests were repeated at the end of the study. After baseline examinations, the subjects received a professional prophylaxis, provided with the allocated mouthwash and instructed to use 10-ml volumes for 60 s 2 x daily and where appropriate after toothbrushing and meals. Demographic features of the 3 groups were similar and losses to trial were small. Adverse signs and symptoms included transitory numbness of the tongue, tooth and tongue staining, taste disturbance and rarely mucosal soreness and erosion. All local side-effects were less commonly reported at 6 compared to 3 months and only 6 subjects were withdrawn because of adverse event. No systemic effects attributable to the agent were observed and no significant shifts in haematological or biochemical parameters occurred. All groups showed considerable improvements in oral hygiene and gingival health with some significant differences in favour of 0.2% delmopinol compared to placebo for gingivitis and more particularly plaque. Staining was also significantly increased in the delmopinol groups but not calculus. In the present study, a considerable Hawthorne effect occurred, which must in part explain why only a modestly significant effect was achieved.

Adult↗
PubMed1995

Interaction of beta-amyloid peptides with integrins in a human nerve cell line.

beta-Amyloid accumulates as extracellular aggregates in Alzheimer's-afflicted brain tissue, but it also is secreted by healthy tissue, for reasons not yet established. One possibility is that beta-amyloid, which contains a sequence (RHDS) homologous to the cell-binding domain of fibronectin, may modulate integrin function, a possibility supported by previous data from non-neuronal cells (Ghiso et al., Biochem. J., 288 (1992) 1053-1059). The current work shows that functional interaction with beta-amyloid peptides is also supported by integrins in neuronal cells. Experiments used the SH-SY5Y human neuroblastoma cell line, which was shown to contain integrins that mediated cell adhesion to substratum-bound fibronectin. Adhesion to fibronectin was partially blocked by synthetic beta-amyloid peptides containing the RHDS sequence. beta-Amyloid sequences adsorbed to substratum themselves were found to mediate cell adhesion, although less effectively than fibronectin. Anti-integrin blocked the peptide-mediated adhesion, at doses commensurate with those blocking fibronectin-mediated adhesion. The data support the hypothesis that beta-amyloid peptides could physiologically, and perhaps pathogenically, modulate the activity of neuronal integrins, important cell surface receptors known to control protein kinase activities, Ca2+ levels, gene expression and organization of the cytoskeleton.

Amyloid beta-Peptides↗
PubMed1995

Detection of acute infection/inflammation with Tc-99m labeled intact polyvalent human IgG.

Intact polyvalent human immune globulin (IgG) labeled with Tc-99m by a mild chemical method was investigated with animals infected with either S. aureus or E. coli in the thigh muscle. Focal infection was clearly visualized by Tc-99m IgG scintigraphy within 1 h postinjection. Tc-99m IgG appeared to be concentrated in the liver, spleen, kidneys and urinary bladder. It cleared rapidly via the kidneys resulting minimal of tissue background activity and high infection-to-normal organ ratios. At 24 h postinjection, the ratios of infectious lesion to blood, normal muscle and bone averaged 10:1, 23:1, and 24:1 for S. aureus infection vs 4:1, 9:1 and 9:1 for E. coli infection, respectively. Tc-99m labeled IgG also concentrated in terpentine-induced aseptic inflammatory lesion with a target-to-blood ratio of 4:1, bone 6:1 and normal muscle about 10:1. These findings suggest potential value of Tc-99m IgG as an imaging agent for the early detection of focal infection and inflammation.

Animals↗
PubMed1995

The effect of oxidising mouthrinses compared with chlorhexidine on salivary bacterial counts and plaque regrowth.

For various clinical indications, oxidising agents have been used in dentistry for many years. Little is known, however, of their antibacterial activity and their ability to inhibit plaque formation. In this study, 2 mouthrinses containing peroxyborate (Bocasan) and peroxycarbonate (Kavosan) were compared alongside a negative control saline rinse and a positive control chlorhexidine rinse (Corsodyl) for their ability to inhibit plaque reformation. Employing a randomised four replicate 4 x 4 latin square cross over design and, whilst omitting all other oral hygiene, plaque was measured by area and index after rinsing for 4 days. In a second study, in vivo antibacterial effects of the rinses were assessed by measuring salivary bacterial counts following single rinses with the preparations at various time intervals over 7 h. Plaque inhibition by chlorhexidine was significantly greater than the other rinses. All rinses were significantly better than the saline rinse at inhibiting plaque. For plaque area, the peroxycarbonate rinse was significantly better than the peroxyborate rinse at inhibiting plaque. Salivary bacterial count reductions were significantly greater compared to saline with chlorhexidine at all time intervals up to 7 h. Whilst both peroxyborate and peroxycarbonate rinses produced greater reductions in bacterial counts than saline up to 3 h, at no time interval were the differences significant. The findings of these studies would suggest oxidising mouthrinses may inhibit plaque formation not by a direct antibacterial effect, but by some other mechanism. The magnitude of plaque reductions obtained with the peroxyborate and more so peroxycarbonate rinses would suggest a need for further study of these preparations when used as adjuncts to normal toothbrushing.

Analysis of Variance↗
PubMed1995

An approach to efficacy screening of mouthrinses: studies on a group of French products (I). Staining and antimicrobial properties in vitro.

There is a large and increasing number of oral hygiene products available to the general public. As such, it is difficult to demonstrate efficacy for all in long-term home-use studies. The aim of this project was to determine whether screening studies could position the activity and efficacy of a number of antiseptic mouthrinses, available in France, by comparison with an established product. This study reports the experiments in vitro. The products under test were, 4 containing chlorhexidine (Eludril, Hibident, Parodex and Prexidine) with Hibident considered the positive control, one containing cetylpyridinium chloride (Alodont) and one containing hexetidine (Hextril). The 1st study determined the antibacterial profile of the chlorhexidine products against a panel of oral bacteria using an agar dilution method. The 2nd study recorded, by optical density, the propensity of all products to induce tea staining on clear acrylic specimens. The maximum inhibitory dilution (MID) of the chlorhexidine products against the test organisms, once adjusted for initial concentration differences, were essentially similar. One exception was Eludril which had an increased MID against Capnocytophaga sputigena, an organism normally less sensitive to chlorhexidine. Hibident and Prexidine produced expected levels of tea staining; that produced by Parodex was lower than the expected. Staining by Eludril was little different than water controls suggesting markedly reduced availability of chlorhexidine in this product.(ABSTRACT TRUNCATED AT 250 WORDS)

Acrylic Resins↗
PubMed1995

An approach to efficacy screening of mouthrinses: studies on a group of French products (II). Inhibition of salivary bacteria and plaque in vivo.

The aim of this study was to determine the value of screening studies to assess the efficacy of antiseptic mouthrinse products relative to proven products. The products tested were 6 antiseptic mouthrinses available in France. 4 contained chlorhexidine (Eludril, Hibident, Parodex and Prexidine) with Hibident considered the positive control. 1 product contained cetylpyridinium chloride (Alodont) and 1 hexetidine (Hextril). Saline was used as the negative control. The 1st study assessed the persistence of action of the products by recording salivary bacterial counts before and up to 7 h after single rinses. The 2nd study measured the inhibition of plaque regrowth, from a zero baseline, in the absence of tooth-brushing over a 4-day period. Both studies used blind randomised crossover designs balanced for residual effects. Salivary bacterial count reductions with time were highly significantly greater for Parodex to 5 h and Hibident and Prexidine to 7 h; There were no significant differences between the latter three chlorhexidine rinses except at 3 h, when decrements were significantly less with Parodex. Despite a mean trend in favour, Alodont, Eludril and Hextril were not significantly different from saline. Plaque inhibition by area and index was highly significantly different between products. Hibident, Parodex and Prexidine showed similar plaque inhibition and were significantly more effective than all other rinses. Eludril and Hextril were significantly more effective than saline but Alodont was not. Taken with the associated study in vitro and published reports on the same or similar products, it is apparent that efficacy of a product cannot be assumed merely because it contains a known active plaque inhibitor.(ABSTRACT TRUNCATED AT 250 WORDS)

Anti-Infective Agents, Local↗
PubMed1994

Beta/A4-evoked degeneration of differentiated SH-SY5Y human neuroblastoma cells.

beta/A4 peptides are known to induce neurodegeneration in cultures of rat brain cells and rat neural cell lines (Yankner et al: Science 250:279-282, 1990; Behl et al: Biochem Biophys Res Commun 186:944-950, 1992). The current data show that these peptides induce similar neurodegeneration in SH-SY5Y neuroblastoma cells, extending characterization of beta/A4 toxicity to a human nerve cell line. Human SH-SY5Y cells respond to aggregated beta/A4 with changes in cell shape, membrane blebbing, antigenic modification, loss of attachment to the substrate, and cell death. beta/A4 peptides require aggregation for maximum toxic effects, as cellular degeneration is evoked by aggregated beta/A4 1-42 and 4-41 cysteine but not by monomeric beta/A4 1-40. Aged (pre-aggregated) beta/A4 1-40 also evoked neurodegeneration. Antigenic changes comprise upregulation of Alzheimer's-type tau epitopes, recognized by the PHF-1 and Alz-50 monoclonals. These particular changes in tau support the connectivity between this in vitro model and mechanisms leading to neurodegeneration in Alzheimer's disease. A significant feature of the SH-SY5Y response is that cells must be differentiated before they become sensitive to the degeneration evoked by beta/A4. Signaling pathways leading to beta/A4-evoked neurodegeneration thus are under experimental control, becoming complete only when proliferating cells withdraw from the cell cycle and develop a postmitotic phenotype.

Alzheimer Disease↗
PubMed1994

The magnitude and duration of the effects of some mouthrinse products on salivary bacterial counts.

The persistence of action or substantivity of an antimicrobial agent in the mouth relates to the plaque inhibitory action of that compound. Substantivity can be assessed by measuring the magnitude and duration of the fall in salivary bacteria following single rinses with antimicrobials. This was a randomised single-blind, cross-over study measuring the effects of single 60-s rinses of 5 mouthwash products on salivary bacterial counts in 14 healthy human volunteers. Effects over a 7-h period were compared with a chlorhexidine rinse product (positive control) and saline (negative control). All but one rinse, containing cetylpyridinium chloride (CPC), significantly reduced bacterial counts compared to saline up to 5-7 h. No rinse produced the magnitude or duration of effect noted for chlorhexidine and decrements from baseline, with one exception, were highly significantly lower than with the chlorhexidine product. Comparing the 2 CPC rinses, the findings suggest that the activity of one product was vitiated by some other ingredient. The triclosan/copolymer, the essential oil/phenolic and one CPC products exhibited similar persistence. In those cases where information is available, these data are consistent with comparative plaque inhibitory findings for the products or their active ingredients. Again, it is concluded that the method is a useful screening and comparison test for the potential plaque inhibitory activity of antimicrobial oral hygiene products.

Adult↗
PubMed1993

A 6-month home usage trial of a 1% chlorhexidine toothpaste (1). Effects on plaque, gingivitis, calculus and toothstaining.

Research and development has been aimed towards the development of toothpastes for oral hygiene and gingival health benefits. The most effective antiplaque agent to date, chlorhexidine, is difficult to formulate into active toothpaste products. Despite some encouraging findings for experimental chlorhexidine toothpastes, there are to date no commercially available products. Based on positive findings from an experimental gingivitis study, this investigation evaluated 2 chlorhexidine toothpastes, one with fluoride, as adjuncts to oral hygiene. The study was a double-blind controlled, parallel, balanced group design, extending over 6 months. A total of 297 volunteers commenced the study after screening for a minimum acceptance level of gingivitis. At baseline, 6, 12 and 24 weeks, stain, gingival, bleeding and plaque indices were recorded, together with a calculus index at 6, 12 and 24 weeks. After a baseline prophylaxis, volunteers used the allocated product 2 x per day, with no other oral hygiene instructions given. Plaque, gingival and bleeding scores improved in all 3 groups, but to an overall significantly greater extent in the active groups. However, staining and calculus indices were significantly increased in the active compared to the control group. If the local side-effects of chlorhexidine are considered to be acceptable, these chlorhexidine toothpastes could be recommended for the same clinical applications as other chlorhexidine products. The apparent compatibility of fluoride with chlorhexidine in the one product may be pertinent to caries prevention.

Adolescent↗
PubMed1991

Staining and antimicrobial properties in vitro of some chlorhexidine formulations.

Dietary staining studies have proved useful determinants of chlorhixidine activity in mouthrinse products, and results correlate with plaque inhibitory effects. This investigation compared the staining and antimicrobial action in vitro of two known and similarly effective, commercially available chlorhexidine mouthrinses with a reformulated 0.1% chlordexidine preparation. After adjustment for original concentration the 0.2%, 0.12% and reformulated 0.1% products had essentially similar, minimum inhibitory-dilution values against standard test organisms. The 0.1% preparation was more effective against Capnocytophaga ochracea, suggesting additional antimicrobial activity derived from an ingredient other than chlorhexidine. The staining in vitro of tooth and acrylic specimens was equivalent with the 0.2% and 0.12% products. By comparison with equivalent concentrations of the diluted 0.2% preparation, the 0.1% formulation produced less staining, particularly when diluted. The data suggest that the 0.1% formulation, when used in diluted form as recommended by the manufacturer, may have slightly reduced plaque-inhibitory effects by comparison to the 0.2% or 0.12% products. However, the results raise the question whether chlorhexidine solutions could be formulated to reduce side effects, in particular, tooth staining at the expense of some loss of antiplaque activity.

Acrylic Resins↗
PubMed1990

The use of antimicrobial acrylic strips in the nonsurgical management of chronic periodontitis.

Evidence to date has demonstrated the potential value of acrylic strips to deliver antimicrobial compounds into periodontal pockets. The present study was designed to evaluate further the therapeutic effect of antimicrobial acrylic strips in the management of chronic periodontitis. A total of 101 pockets in 69 patients were randomly treated with (1) chlorhexidine strips, (2) metronidazole strips, (3) tetracycline strips, (4) root planing, and (5) combined root planing and metronidazole strips. Immediately before and after treatment clinical measurements of disease were recorded over a three-month period. For all treatment groups significant improvements in clinical parameters were seen compared to control untreated sites but the most effective treatment was combined root planing and metronidazole and the least effective chlorhexidine. Although not significant, combined root planing and metronidazole also appeared to produce some adjunctive effects on clinical parameters compared to root planing alone. Antimicrobial acrylic strips appear useful treatments for chronic periodontitis, but should be used primarily as an adjunct to conventional root planing.

Acrylic Resins↗
PubMed1989

Spinal fractures complicating ankylosing spondylitis.

Individuals with ankylosing spondylitis (AS) are at increased risk for developing fractures of the spine, especially in the cervical region. This tendency is related to the ossification of spinal ligaments and osteopenic changes in the spinal vertebrae. We reviewed our clinical experience of SCI occurring due to AS, and the literature regarding the natural history of these fractures. A significant number of individuals are not aware of their increased risk for spinal fracture and sustain spinal fractures without realizing it. Difficulties in diagnosis and inappropriate management of spinal fractures in these individuals have often resulted in severe neurologic sequelae and a mortality rate approximately twice that observed with similar fractures in a normal spine. The need for better patient education emphasizing the significance of even minor trauma, and a thorough evaluation of AS patients with a history of trauma is stressed.

Cervical Vertebrae↗