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Biomedical subjects

B M Marshall

Publications and source records attributed to B M Marshall.

17 recordsLinked to original sources
PubMed1999

Release of bacteria during the purge cycles of steam-jacketed sterilizers.

The design of the steam-jacketed sterilizer includes an exterior air-gap fixture through which purged chamber aerosols potentially could escape into the ambient environment. Studies of the purge cycle in two sterilizer models tested the potential release of a genetically marked Enterococcus faecalis, together with Bacillus stearothermophilus spores introduced as exposed cultures. Direct plate counts, broth enrichment and polymerase chain reaction analysis were used to confirm any released organisms trapped in an all-glass impinger. From the retrieval of both bacterial strains, an estimated 10(3) organisms can be released from uncontained bacterial loads of 10(11) E. faecalis and 10(7) B. stearothermophilus, even from properly functioning autoclaves. The release of an opportunistic pathogen from sterilizer purge exhausts emphasises the importance of proper sterilizer location, ventilation, containment of heavily contaminated loads, and adequate sterilizer maintenance.

Air Microbiology↗
PubMed1994

Tn5 Insertion Mutants of Pseudomonas fluorescens Defective in Adhesion to Soil and Seeds.

Tn5 insertion mutants of a soil isolate, Pseudomonas fluorescens Pf0-1, were selected for decreased ability to adhere to quartz sand in a column assay. Three adhesion-deficient mutants that differed in the location of the Tn5 insertion in the chromosome were isolated and compared with the wild-type strain. One mutant, Pf0-5, was described previously as an adhesion-defective, nonmobile, flagellumless mutant (M. F. DeFlaun, A. S. Tanzer, A. L. McAteer, B. Marshall, and S. B. Levy, Appl. Environ. Microbiol. 56:112-119, 1990). Another insertion mutant, Pf0-10, was also missing flagella and the 34-kDa outer membrane protein that was absent in Pf0-5 but present in the wild-type strain. The third mutant (Pf0-15) had increased amounts of this 34-kDa outer membrane protein and more flagella than the wild-type strain. These mutants also displayed decreased ability to adhere to sterile and natural (live) soil and to a variety of plant seeds. In kinetics studies, the wild-type strain showed an initial rapid binding to seeds followed by a later slow phase of binding. The mutant strains were defective in the initial stages of attachment but did show the later slow binding. The findings indicate that the same mutations that affect binding to sand and soil also affect adhesion to plant seeds.

Journal Article↗
PubMed1992

Postpartum rupture of a subcapsular hematoma of the liver.

We report a case of postpartum rupture of a subcapsular hematoma of the liver. The etiology, pathology, diagnosis and treatment of this condition are discussed. We emphasize the modern concepts in treatment of hepatic hemorrhage. This knowledge and an awareness of the possible diagnosis will help to decrease the high morbidity and mortality rates associated with this disorder.

Acute Kidney Injury↗
PubMed1992

Ethical issues in assisted reproduction.

Since the birth of Louise Brown in 1978, no other area in clinical practice and medical research has held the public interest to the same extent as the assisted reproductive technologies. This has led to the formation of committees of enquiry, guidelines from professional bodies, the passage of legislation, and the formation of legislative bodies. The ethical issues which arise in the clinical practice of assisted reproduction, the donation of gametes and embryos, and their cryopreservation, surrogacy, and human embryo research are reviewed.

Ethics↗