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Biomedical subjects

R M Lawrence

Publications and source records attributed to R M Lawrence.

At least 55 records · Page 3Linked to original sources
PubMed1978

Totally synthetic medium for susceptibility testing.

The results of disk diffusion and plate dilution susceptibility testing of Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, and Proteus mirabilis on media gelled with agar-agar or with a synthetic hydrogel were compared. Synthetic hydrogel can be combined with a totally defined synthetic amino acid medium to yield a reproducible, totally defined, synthetic solid medium without the antagonistic or booster effects of some components of agar. Such a medium could be used as a reference medium for susceptibility testing.

Agar↗
PubMed1978

Quantitative microbiology of traumatic orthopedic wounds.

Quantitative bacterial and fungal cultures carried out on 116 speciments of tissue debrided from traumatic orthopedic wounds yielded 118 bacterial and 8 fungal isolates. The organisms obtained reflected primarily the resident flora of the skin.

Aerobiosis↗
PubMed1977

Reproducible method for induction of pulmonary coccidioidomycosis in mice.

Intranasal instillation of an inoculum has been suggested as a method for establishment of experimental pulmonary infections. Because we encountered untoward variation in rates and times of death with use of this method for inducing coccidioidomycosis in mice, a simple method for direct intratracheal infection was devised. With doses of 50 or 100 arthrospores of Coccidioides immitis, mortality rates were 80%-90% from 14 to 25 days after infection by the intratracheal route and 20%-60% from 12 to 24 days after infection by the intranasal route. The procedure for intratracheal infection caused only slight morbidity, and the method resulted in consistent rates of disease.

Animals↗
PubMed1977

Comparative pharmacology of amphotericin B and amphotericin B methyl ester in the non-human primate, Macacca mulatta.

The pharmacokinetics of amphotericin B methyl ester hydrochloride (AME) and commercial deoxycholate-stabilized amphotericin B (AMB) were compared after single doses of 5 mg and 1 mg/kg of body weight, respectively, given intravenously in a period of 3 h to adult female rhesus monkeys (Macaca mulatta). By bioassay, the concentrations of AME were 12.2 to 7.2 times higher in the serum and 7.8 to 2.5 times higher in the urine during the 8 h after infusion. The decline in concentrations of the drugs in sera was consistent with a three-compartment, open pharmacokinetic model; rate constants of transfer of the drugs between the compartments and volumes of distribution were calculated. The overall rate of elimination from the central compartment (the bloodvascular space) was about four times greater for AME than for AMB. Serum urea nitrogen and creatinine concentrations were mildly and transiently increased after infusion of AME, whereas the more severe azotemia that followed infusion of AMB persisted for 5 days. AME was less toxic and achieved a greater urinary outfall than AMB. As the antifungal activity of AME is comparable to that of AMB by testing in vitro, further study is warranted.

Amphotericin B↗
PubMed1976

Comparison of amphotericin B and amphotericin B methyl ester: efficacy in murine coccidioidomycosis and toxicity.

The methyl ester of amphotericin B was compared with the parent compound, amphotericin B, in terms of therapeutic efficacy in experimental murine coccidioidomycosis and of toxicity. Infections were established by intraperitoneal or intratracheal inoculation with arthrospores. The mice were given either intraperitoneal or intravenous injections of drug for 30 days, according to several dosage schedules. At low doses, amphotericin B methyl ester was less effective therapeutically than was amphotericin B; however, at higher doses, amphotericin B was directly lethal and/or nephrotoxic, whereas the methyl ester was therapeutically effective and nontoxic. In contrast to amphotericin B, the methyl ester did not cause either azotemia or histopathologic changes in the kidneys.

Amphotericin B↗
PubMed1975

Microbial development of drug resistance: mechanisms and clinical significance.

Bacteria have demonstrated a disconcerting ability to develop resistance to antimicrobial agents nearly as quickly as new compounds become available. During the past two decades the molecular bases of several types of resistance have been elucidated. Mechanisms of resistance include the transference of genetic material either through conjugation (involving direct contact between microorganisms), or indirectly through transduction (involving bacteriophages). In addition to this "infectious" drug resistance, genetic mutations which permit the utilization of new metabolic pathways, and the production of enzymes which can inactivate the antimicrobic have been described. One particularly complex problem has been the ability of many Enterobacteriaceae to develop resistance to multiple antimicrobials simultaneously. The possible effect of such an occurrence is illustrated by the recent epidemic of multiply resistant Salmonella typhi in Mexico. Because the typhoid bacilli shared an identical resistance pattern to an epidemic Shigella dysenteriae type 1 the in vivo interspecies transmission of resistance has been postulated. Understanding the various mechanisms of resistance development should allow more rational use of antimicrobial agents.

Anti-Bacterial Agents↗
PubMedDate not supplied

Knowledge and attitudes about acquired immunodeficiency syndrome in nursing and nonnursing groups.

A study was undertaken to determine the difference in knowledge and attitudes about acquired immunodeficiency syndrome (AIDS) in nursing and nonnursing groups, and to determine the effect that knowledge acquisition would have on attitudes about AIDS. The total study population consisted of 60 registered nurses, 50 baccalaureate nursing students, 42 liberal arts college students, and 30 nonnurse adults. An AIDS knowledge and attitude assess test was developed and used in the study. Univariate descriptive methodology, descriptive correlational analysis, and a pretest-posttest design were used. Phase I showed that professional nurses with graduate degrees have the highest knowledge base and the most positive attitudes about AIDS; and that nursing students' attitudes are more similar to the attitudes of nonnursing students than of professional nurses. Phase II showed that people's attitudes about AIDS could be changed by increasing their knowledge levels, and nursing students showed more increase in knowledge and more significant changes in attitudes following education than liberal arts college students.

Acquired Immunodeficiency Syndrome↗