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Biomedical subjects

M Simon

Publications and source records attributed to M Simon.

At least 829 records · Page 46Linked to original sources
PubMed1967

Enterotoxin B: serological assay in cultures by passive hemagglutination.

Bis-diazotized benzidine hemagglutination with Formalinized sheep erythrocytes was adapted to the rapid and specific detection of enterotoxin B in staphylococcal culture fluids. There was complete agreement between hemagglutination inhibition (HI) and gel diffusion in detecting 8 enterotoxin B-positive cultures from a total of 68 staphylococcal cultures tested. The sensitivity of HI equals or exceeds that of gel diffusion. Also, results can be obtained in several hours, even with extremely low concentrations of enterotoxin, whereas it may require 24 hr to 1 week to obtain comparable results with gel diffusion. Problems associated with the presence of potent hemagglutinins for sheep erythrocytes in several staphylococcal culture fluids are discussed.

Amines↗
PubMedDate not supplied

Review--animal waste used as livestock feed: dangers to human health.

Foodborne illness remains a common and serious problem, despite efforts to improve slaughterhouse inspection and food preparation practices. A potential contributor to this problem that has heretofore escaped serious public health scrutiny is the feeding of animal excrement to livestock, a common practice in some parts of the United States. In 1994, 18% of poultry producers in Arkansas collectively fed more than 1,000 tons of poultry litter to cattle, and the procedure is also common in some other geographic areas as a means of eliminating a portion of the 1.6 million tons of livestock wastes produced in the United States annually. While heat processing reliably kills bacterial pathogens, its use is limited by expense and other factors. Deep-stacking and ensiling are commonly used by farmers to process animal wastes, but the maximal temperatures achieved in stacked poultry litter are typically in the range of 43 to 60 degrees C (110 to 140 degrees F), below the inactivation temperatures of pathogenic salmonella and Escherichia coli species, and far below the USDA's recommended cooking temperatures of 71 to 77 degrees C (160 to 170 degrees F) for potentially manure-tainted meat products. In addition to the spread of potential pathogens, using animal wastes as feed presents the possibility that antibiotic-resistant bacteria may spread from one animal to another and that antibiotics or other chemicals may be passed between animals. Few research reports have addressed the safety of this practice, and those studies that have been published have generally been in controlled and artificial environments, rather than in on-farm conditions. Further microbiological studies are recommended to assess the extent of risk.

Abattoirs↗
PubMedDate not supplied

The glycerol kinase (GUT1) gene of Saccharomyces cerevisiae: cloning and characterization.

The GUT1 gene of Saccharomyces cerevisiae, encoding glycerol kinase, was cloned and sequenced. The cloned genomic DNA fragment contains an open reading frame potentially coding for a protein of 709 amino acids with homology to bacterial glycerol kinases (40.8% identity over 502 amino acids, and 42.1% identity over 496 amino acids, in comparison to the smaller E. coli and B. subtilis enzymes). Disruption of GUT1 showed that the gene is required for growth on glycerol, but not on glucose or ethanol media. No glycerol kinase activity was detected in the disruption mutant. According to enzyme activity and transcript analysis, synthesis of glycerol kinase is repressed by glucose, and derepression is ADR1-dependent.

Amino Acid Sequence↗