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Biomedical subjects

M L Barnett

Publications and source records attributed to M L Barnett.

At least 19 recordsLinked to original sources
PubMed1996

A pilot trial of oral type II collagen in the treatment of juvenile rheumatoid arthritis.

OBJECTIVE: To evaluate the efficacy of oral chicken type II collagen (CCII) in the treatment of juvenile rheumatoid arthritis (JRA). METHODS: Ten patients with active JRA were treated with CCII for 12 weeks. Efficacy parameters, which included swollen and tender joint count and score, grip strength, 50-foot walking time, duration of morning stiffness, and patient and physician global scores of disease severity, were assessed monthly. RESULTS: All patients completed the full course of therapy. Eight patients had reductions in both swollen and tender joint counts after 3 months of CCII. The mean changes from baseline in swollen and tender joint counts for the 8 responders at the end of the study were -61% and -54%, respectively. Mean values for other efficacy parameters also showed improvement from baseline. There were no adverse events that were considered to be treatment related. CONCLUSION: Oral CCII may be a safe and effective therapy for JRA, and its use in this disease warrants further investigation.

Administration, Oral↗
PubMed1996

Assessing pre-procedural subgingival irrigation and rinsing with an antiseptic mouthrinse to reduce bacteremia.

In this controlled clinical study, the authors examined the effect of subgingival irrigation and rinsing with an antiseptic mouthrinse before ultrasonic scaling of a quadrant containing inflamed gingivae. The results showed that pre-procedural subgingival irrigation and rinsing can significantly reduce the level of bacteremia associated with ultrasonic scaling. These results support the American Heart Association's recommendation of adjunctive subgingival irrigation prior to invasive procedures in patients at risk of developing bacterial endocarditis.

Adult↗
PubMed1995

Ethical issues in sponsored clinical research.

In recent years, the relationship between industry and academic investigators has been strengthened and has become increasingly complex, creating a variety of situations which have the potential of leading to ethical compromises. Two categories of behavior have been the primary concern of those dealing with ethical issues in science, namely, scientific misconduct and conflict of interest. This paper presents an overview of emerging ethical concerns as well as institutional responses designed to manage the new relationships.

Biomedical Research↗
PubMed1993

Characterization of interleukin-8 receptors in human neutrophil membranes: regulation by guanine nucleotides.

Interleukin-8 (IL-8) is a polymorphonuclear leukocyte (PMN) chemoattractant and activator which mediates its effects through specific cell-surface receptors. Indirect evidence indicates that guanine nucleotide regulatory proteins (G proteins) are necessary for transmembrane signaling. The present study characterizes IL-8 receptors in isolated PMN membrane fractions and shows direct regulation of these receptors by guanine nucleotides. The binding of [125I]IL-8 to subcellular fractions of PMNs showed specific binding in a low-density membrane fraction containing alkaline phosphatase, but not in primary or secondary granules. The binding of [125I]IL-8 was rapid and reversible. The equilibrium dissociation constant (Kd) of the receptor ranged from 5.0-12.4 nM and there were 1.58-5.90 . 10(10) receptors/mg protein. The dose-response curves for the competitive binding of three different forms of IL-8 to the receptor labeled by [125I]IL-8 corresponded with their ability to produce chemotaxis and granule exocytosis in PMNs. Treatment of membranes with the nonhydrolyzable analogs of GTP, GMP-PNP and GTP gamma S, inhibited the binding of [125I]IL-8. GMP-PNP decreased the affinity of the IL-8 receptor by approx. 2-fold without altering the total receptor number. These findings demonstrate that IL-8 receptors in PMN membranes are of high affinity and are convertible to a low-affinity state in the presence of guanine nucleotides, suggesting a direct role for G proteins in transmembrane signaling by this cytokine.

Binding Sites↗
PubMed1993

Efficacy of meclofenamate sodium (Meclomen) in the treatment of rapidly progressive periodontitis.

This 6-month, double-blind, controlled clinical trial determined the efficacy of the non-steroidal anti-inflammatory drug, meclofenamate sodium (Meclomen), as an adjunct to scaling and root planing in the treatment of rapidly progressive periodontitis (RPP). 22 subjects (7 male, 15 female) aged 36.5 +/- 7.88 years with RPP and disease-active sites as determined by pretreatment bone scan had standardized radiographs at baseline and 6 months, and clinical measurements at baseline, 3 and 6 months. Following full-mouth scaling and root planing, subjects were randomly assigned to either a placebo, 50 or 100 mg meclofenamate sodium bid group. Bone change over the 6-month period as assessed by subtraction radiography was the primary efficacy determinant. Specialized software was used to isolate the lesion from the subtraction image and to measure bone change along the root surface. ANOVA using the subject as the unit of analysis revealed a significant dose response (p < 0.001) with the placebo group having a mean bone loss of 0.42 +/- 0.06 mm and the low and high dose groups having mean bone gains of 0.07 +/- 0.05 and 0.20 +/- 0.07 mm, respectively. These findings indicate that meclofenamate sodium may be a useful adjunct in the treatment of rapidly progressive periodontitis.

Adolescent↗
PubMed1993

Reduction of viable bacteria in dental aerosols by preprocedural rinsing with an antiseptic mouthrinse.

Two double-blind controlled clinical studies were conducted to determine the efficacy of preprocedural rinsing with Cool Mint Listerine Antiseptic mouthrinse on the level of viable bacteria recovered from dental aerosols when generated immediately after and 40 minutes after rinsing. Eighteen healthy subjects participated in each study. In the first study, following a 24-hour no-oral-hygiene period, subjects received a 10-minute ultrasonic scaling of a randomly chosen half mouth, rinsed with either Cool Mint Listerine or a control, and received an ultrasonic scaling of the remaining half mouth. During each scaling period, aerosolized bacteria were collected on a sterile filter using a modified air-sampling device. The filters were overlaid on culture media, incubated aerobically, and colonies were counted. The second study followed the same basic design except that ultrasonic scaling was done for 5 minutes, and the post-rinsing sampling was performed following a 40-minute simulated dental treatment period. Rinsing with Cool Mint Listerine resulted in a 92.1% reduction in viable bacteria in aerosols generated immediately after rinsing and a 91.3% reduction in aerosols generated 40 minutes after rinsing. These reductions were significantly greater than control (P = 0.0001). These studies suggest that preprocedural rinsing with Cool Mint Listerine Antiseptic may potentially reduce the risk of cross contamination in the dental operatory.

Adult↗
PubMed1993

Antiseptic mouthrinse-induced microbial cell surface alterations.

This study determined the effect of an essential oil-containing mouthrinse, Listerine Antiseptic, on microbial cell surface morphology using scanning electron microscopy. Twenty-four hour cultures of C. albicans, A. viscosus, S. sanguis, F. nucleatum, and A. actinomycetemcomitans were harvested and washed in buffer. Triplicate samples were overlaid on poly-L-lysine coated coverslips, immersed in either Listerine or buffer for 30 seconds, fixed in glutaraldehyde followed by post-fixing in 1% osmium tetroxide, dehydrated, and embedded in Peldri II. Exposure of the microorganisms to Listerine Antiseptic for 30 seconds resulted in distinct morphological alterations of cell surfaces suggestive of loss of cell surface integrity. The extent of alteration varied among the structurally different species; cell surface roughening was mild in S. sanguis but extensive in the other microorganisms which developed distinct surface blebs and other abnormalities after the 30-second exposure. These results suggest that a brief exposure to Listerine produces significant morphological changes which may be associated with cell death and may help explain the alteration of surface-associated activities demonstrated in previous studies.

Actinomyces viscosus↗
PubMed1992

Phase II evaluation of piroxantrone in renal cell carcinoma. A Southwest Oncology Group Study.

The Southwest Oncology Group (SWOG) studied the response rate and toxicity of piroxantrone (150 mg/m2 q 21 days) in patients with advanced metastatic renal cell carcinoma. Among 32 eligible patients, there were no partial nor complete responses. There were two mixed responses. Significant white cell toxicity, anemia, nausea, and vomiting were observed. Mild or moderate degrees of fever, malaise, and stomatitis occurred. No significant cardiac toxicity was noted. Piroxantrone does not have significant activity as a single agent in advanced renal cell carcinoma.

Adult↗
PubMed1992

ADA dental product evaluation: case history.

The ADA Acceptance Programs entail a rigorous evaluation of products and offer clear benefits to manufacturers, dental professionals, and consumers alike. This paper outlines the implications of the ADA product-evaluation programs for each of these three constituencies and concludes that while there may be an occasional downside from the manufacturer's standpoint, their net effect is to provide assurances that products are safe, efficacious, and promoted properly.

American Dental Association↗
PubMed1992

Efficacy of preprocedural rinsing with an antiseptic in reducing viable bacteria in dental aerosols.

This double-blind, controlled, cross-over, clinical study evaluated the effect of preprocedural rinsing with an antiseptic mouthrinse on the level of recoverable viable bacteria in an aerosol generated during a typical dental procedure. Eighteen subjects participated. Following 24 hours of abstention from all oral hygiene procedures, subjects received a 10-minute ultrasonic scaling of a randomly selected one-half of their mouth which served as the unrinsed control. They were then randomly assigned either antiseptic mouthwash or a control rinse and rinsed with 20 ml for 30 seconds, after which the remaining half mouth (experimental side) was scaled ultrasonically for 10 minutes. During each 10-minute scaling period aerosolized bacteria were collected on a sterile filter using a modified vacuum air-sampling device. Microbes captured on the sterile filter were quantitated by overlaying the filters onto trypticase soy agar, incubating the filters aerobically at 37 degrees C for 24 to 72 hours, and counting the resulting colony forming units (CFU). Preliminary experiments had confirmed that neither the collection method nor residual antiseptic mouthwash in the aerosol adversely affected the number of viable bacteria recovered from the filter. Rinsing with the antiseptic mouthwash produced a 94.1% reduction in recoverable CFUs compared to the non-rinsed control, while the control rinse produced a 33.9% reduction. The difference between the mouthwash and control was statistically significant (P < .001). This study indicates that preprocedural rinsing with an antiseptic mouthwash can significantly reduce the microbial content of aerosols generated during ultrasonic scaling and may have potential in-office use as part of an infection control regimen.

Adult↗