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Biomedical subjects

D A Marshall

Publications and source records attributed to D A Marshall.

18 recordsLinked to original sources
PubMed1992

Helmets! All the pros wear them.

OBJECTIVE: To assess the outcome of a multidisciplinary community campaign to increase helmet use and determine the success of a school education and helmet distribution program. DESIGN: Survey research. SETTING: Large metropolitan area and two elementary schools. PARTICIPANTS: Five hundred representative families in a metropolitan area and students enrolled in two elementary schools. INTERVENTIONS: A 1-year-long regional media campaign and a helmet distribution program in one elementary school after 4 weeks of safety instruction. RESULTS: Evaluation of the community component 1 year after initiation of the campaign revealed a 23% awareness of the promotion. Factors associated with wearing a helmet in the community included higher income levels, higher level of education, and male sex. The school component survey revealed that 73% of the children in school A reported helmet use vs 23% in school B. This multifaceted approach to affect helmet use demonstrated variable success in our community. CONCLUSION: This campaign effort achieved its greatest success in promoting community awareness of the importance of helmet use. However, further studies need to be performed to determine the success of the school education and helmet distribution program.

Bicycling↗
PubMed1992

Early aortic valve cusp rupture in relapsing polychondritis.

Aortic regurgitation associated with relapsing polychondritis usually occurs late in the disease as a result of aortic root dilatation. A case where aortic regurgitation occurred early and was due to cusp rupture with a normal aortic root is reported. The patient required urgent aortic valve replacement within six weeks of developing a murmur despite apparent control of inflammation with immunosuppressive treatment. The possibility of cusp rupture with sudden haemodynamic deterioration should be considered in patients with relapsing polychondritis who develop aortic regurgitation.

Aortic Valve↗
PubMed1992

Double blind, placebo controlled study of metronidazole as a disease modifying agent in the treatment of rheumatoid arthritis.

Anecdotal reports suggest that metronidazole may have disease modifying activity in the treatment of rheumatoid arthritis. To assess possible beneficial effects a double blind, comparative trial of metronidazole and placebo was performed. Fifty patients with active rheumatoid arthritis were randomly allocated to receive active drug (n = 24) or placebo (n = 26) and reviewed at weeks 0, 1, 4, 8, 12, 16, and 24. Detailed assessment of drug safety, biochemical and haematological parameters, and efficacy was made at these dates. Dose regimen was 400 mg twice daily from weeks 0 to eight, increasing to 400 mg three times a day from weeks nine to 24 provided that no adverse effects were recorded. Most patients were unable to tolerate metronidazole because of side effects or lack of efficacy, with only five (21%) continuing to take the drug at 24 weeks. For those patients attaining 12 weeks of treatment an overall improvement in articular index and morning stiffness was found. No improvement in laboratory indices of disease activity was seen, however. In this study metronidazole did not have disease modifying properties and was unacceptably toxic.

Adult↗
PubMed1990

Taste responses of dogs to ethylene glycol, propylene glycol, and ethylene glycol-based antifreeze.

Although it is widely believed that ethylene glycol-based antifreeze (AF) is an attractive tastant to dogs and other animals, empirical data on this point are not available. In experiment 1, we examined the propensity of 178 adult mixed-breed dogs to approach, sniff, and lick a concentration of AF commonly used in automotive cooling systems (50%). Despite the fact that most of the dogs approached and sniffed the AF in these 5-minute tests, only 9% initiated lick responses and most of these were brief and not followed by additional licking. In experiment 2, the lick responses of five gastric-cannulated dogs to aqueous solutions of 20% sucrose, 50% ethylene glycol, 50% propylene glycol, water, and 50% AF were examined in 14-minute tests before and after periods of food and water deprivation. Under the latter conditions, 2 of the 5 dogs drank amounts of ethylene glycol that would have been lethal to uncannulated dogs. None of the five dogs drank potentially lethal amounts of AF. The preference order for these tastants was sucrose greater than water greater than ethylene glycol greater than AF = propylene glycol. Although these findings question the general belief that AF is highly palatable to most dogs, they do imply that large individual differences in responsiveness exist and that AF ingestion is likely influenced by motivational state. Furthermore, they suggest the possibility that unpleasant-tasting additives could be successfully developed to eliminate the ingestion of AF, because the initial attractiveness of AF is relatively low. Such additives would have to be stable in vehicular cooling systems and not adversely affect the functional aspects of AF performance.

Animals↗
PubMed1990

Occlusive dressings. Does dressing type influence the growth of common bacterial pathogens?

We studied the effect of different occlusive dressings and of air exposure on the growth of four pathogenic bacteria in wounds. Partial-thickness wounds on domestic pigs were inoculated with Staphylococcus aureus, Clostridium perfringens, Bacteroides fragilis, or Pseudomonas aeruginosa. Each wound was covered with three dressings (DuoDERM, Opsite, or Vigilon), or left exposed to air. Groups of wounds were sampled at 24, 48, and 72 hours. Staphylococcus aureus reached high levels beneath all of the dressings and in the air-exposed wounds. The numbers of C perfringens and B fragilis were greatly reduced in the air-exposed wounds and slightly reduced in the Opsite-covered wounds. The numbers of P aeruginosa were greatest in the Opsite- and Vigilon-covered wounds. The results indicate that occlusive dressings are not indicated in wounds that clinically appear to be grossly contaminated or that may contain anaerobic organisms.

Animals↗
PubMed1989

Infective endocarditis caused by Streptococcus agalactiae.

We report a series of five cases of infective endocarditis caused by Streptococcus agalactiae (group B streptococcus) in Glasgow over a 30 month period. There were three males and two females mean age 48.6 years (range 28-63 years). Only one patient had previous valvular heart disease. The infections were characterised by an acute presentation and an aggressive course with major arterial emboli. Despite early diagnosis and appropriate intravenous antibiotics three patients died, one after valve replacement and two before surgery could be undertaken. The remaining two patients had successful valve surgery and have recovered. S. agalactiae endocarditis is an uncommon but important condition which carries a high mortality. The infection is difficult to control with antibiotics alone and therefore early surgery may be indicated.

Adult↗
PubMed1989

Topical mupirocin treatment of impetigo is equal to oral erythromycin therapy.

Topical antimicrobial therapy has not been effective in the past against cutaneous bacterial infections. In this study, a new topical antibiotic ointment, mupirocin, was compared with oral erythromycin ethylsuccinate in the treatment of impetigo. Seventy-five patients clinically diagnosed as having impetigo and with positive cultures of Staphylococcus aureus, Streptococcus pyogenes, or both were examined in an investigator-blinded study. Patients used topical mupirocin applied three times daily or the usual oral dose of erythromycin ethylsuccinate (30 to 50 mg/kg per day). Patients' lesions were examined clinically and cultured bacteriologically on days 0, 3, and 8, and 1 week after treatment. Susceptibility testing was performed on pathogens isolated to determine antibiotic resistance. Mupirocin treatment produced similar clinical results to oral erythromycin and was superior in the eradication of S aureus, including antibiotic-resistant S aureus. These results show topical mupirocin to be a safe and effective alternative to oral antibiotic therapy in the treatment of impetigo.

Administration, Oral↗
PubMed1987

Model for studying bacterial adherence to skin wounds.

The adherence of bacterial pathogens to wounded skin is probably the first step in wound infection. This report describes the development of a bioassay to simulate the adherence of bacteria to wounds. The adherence of bacteria was examined by exposing wounds to known quantities of pathogens, washing the wounds with distilled water, and quantitating the number of adherent bacteria per cm2 of tissue. Our studies focused on the effects of naturally occurring mediators of bacterial adherence, such as wound fluid, serum, and fibronectin. Bacterial adherence was shown to be challenge dependent. Addition of wound fluid, serum, and heat-inactivated serum was shown to reduce the adherence of Pseudomonas aeruginosa to the wound surface compared with that of a saline control. Additional fibronectin treatment of the wound had no effect on the adherence of Staphylococcus aureus. The ability to identify what affects the binding of bacteria to wounded skin can lead to a better understanding of wound infection.

Animals↗
PubMed1986

Masera's organ responds to odorants.

Electroolfactogram (EOG) recordings from the rat septal olfactory organ (SO) provide the first demonstration of its broad-range chemosensitivity, and clearly establish this structure as a functioning component of the mammalian intranasal chemosensory system. SO sensitivity to lower concentrations of at least one common test odorant (pentyl acetate) exceeds that at sites located on the septal portion of the main olfactory neuroepithelium. Signals from the SO, as first proposed, thus could have an alerting function and provide information relevant to odor stimulus assessment.

Animals↗
PubMed1986

Povidone-iodine in polyethylene oxide hydrogel dressing. Effect on multiplication of Staphylococcus aureus in partial-thickness wounds.

We studied the ability of a polyethylene oxide hydrogel dressing (Vigilon) containing povidone-iodine to prevent Staphylococcus aureus proliferation in partial-thickness wounds. We previously reported that a single application of povidone-iodine on wounds challenged with 2 X 10(6) S aureus was not effective in reducing the number of S aureus after 24 hours. It was therefore hypothesized that povidone-iodine might be effective if it was available continuously and applied to wounds containing a smaller number of bacteria. To test this hypothesis, we made multiple partial-thickness wounds (5 X 7 X 0.3 mm) on six domestic pigs. We then inoculated the wounds by scrubbing them with either a low concentration (log 3.5) or a high concentration (log 7) of S aureus suspension. The wounds were either treated with Vigilon or Vigilon containing povidone-iodine or left air exposed. Wounds from each of these treatment groups were cultured by the scrub technique for S aureus with a 0.5% sodium thiosulfate-polysorbate (Tween) 80 solution 5 minutes, 30 minutes, 24 hours, or 48 hours later. A significant reduction in the number of S aureus recovered from wounds treated with Vigilon containing povidone-iodine was seen with the group inoculated with a low bacterial concentration after 24 hours; but no reductions were observed when wounds were inoculated with the higher bacterial concentration of log 7. We found Vigilon containing povidone-iodine to be an effective inhibitor of S aureus in wounds over a 24-hour period when the organism was present in low numbers.

Animals↗
PubMed1985

Rat trigeminal, olfactory and taste responses after capsaicin desensitization.

Experiment 1 showed that capsaicin injections severely reduced or eliminated nasal trigeminal responses to 3 odorants. Experiments 2 and 3 investigated whether desensitized animals could behaviorally detect and discriminate odors. Capsaicin treated animals had no measurable deficits in locating buried food, in odor aversion learning, or in operant odor detection and discrimination. Experiment 4 examined whether behavioral responsiveness to salty, sour and bitter tastes was affected by desensitization. Capsaicin injections did not affect responsiveness to salty or sour, but may have raised rejection thresholds for bitter. Broadly, the present results suggest that substance P-containing fibers mediate trigeminal responsiveness to odorants and irritants but that the loss of this responsiveness does not appreciably affect smell or taste, per se.

Animals↗
PubMed1985

Occlusive wound dressings to prevent bacterial invasion and wound infection.

This study was designed to examine the possibility that some occlusive dressings are barriers to wound penetration by pathogenic bacteria. Two common skin pathogens, the nonmotile, Staphylococcus aureus, and the motile, Pseudomonas aeruginosa, were used to challenge dressings placed on partial-thickness wounds in swine. S. aureus was recovered from 100% of air-exposed wounds (log, 5.5 +/- 1.1) and from 50% of Op-Site-treated and Vigilon-treated wounds (log, 6.1 +/- 1.1). S. aureus was not isolated from DuoDERM-covered wounds. P. aeruginosa was recovered from 100% of air-exposed wounds (log, 5.1 +/- 0.5) and 100% of Op-Site-covered and Vigilon-covered wounds (log, 5.8 +/- 1.8). P. aeruginosa was not recovered from DuoDERM-covered wounds. These studies lend support to the idea that dressings may protect wounds from invasion by pathogenic bacteria and demonstrate the need to evaluate their bacterial barrier properties in situ.

Animals↗