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Biomedical subjects

M Thompson

Publications and source records attributed to M Thompson.

At least 307 records · Page 17Linked to original sources
PubMed1986

VP7 serotype-specific glycoprotein of OSU porcine rotavirus: coding assignment and gene sequence.

With a reassortant from a cross of human rotavirus DS-1 (serotype 2) and OSU (serotype 5) it was determined that the OSU major neutralization glycoprotein antigen (VP7) was encoded by gene segment 9. A full-sized cloned cDNA copy of the OSU gene 9 was produced and sequenced. Hybridization of such labelled cDNA with the corresponding segment of a reassortant DS-1 X OSU virus confirmed the coding assignment. Comparison of the deduced amino acid sequence of the VP7 of OSU with those previously determined for five other rotavirus strains, representing four distinct serotypes, revealed some hydrophilic regions that exhibited significant homology and other hydrophilic domains with greater amino acid divergence. In one of the latter hydrophilic domains each of the five serotypes had a distinct amino acid substitution at residue 146, suggesting that it may be involved in serotype specificity.

Amino Acid Sequence↗
PubMed1986

Trimethyltin-induced alterations in brain amino acids, amines and amine metabolites: relationship to hyperammonemia.

An investigation of several neurochemical consequences of exposure of the rat to 3/4 of the estimated single injection LD50 quantity of trimethyltin chloride (TMT) indicated that a significant elevation in the levels of glutamine (Gln) and 5-hydroxyindole acetic acid (5-HIAA) occurred at post-dosing day 7 in each examined region of the brain; elevated Gln persisted in the hippocampus through day 14 and returned to control levels at day 28. At post-dosing day 7, levels of glutamate were decreased in the hippocampus, while levels of GABA were decreased in hippocampus and frontal cortex, but not in corpus striatum; hippocampal glutamate and GABA returned to control levels by post-dosing day 14. Decreased levels of taurine (Tau) occurred on day 7 in both hippocampus and frontal cortex; hippocampal Tau remained below control levels through post-dosing day 28. Levels of other amino acids and of amines and amine metabolites were not altered by TMT in the 7 to 28 day post-dosing interval. At day 7, TMT treatment did not alter brain regional activities of glutamine synthetase; however, plasma ammonia was elevated 100% above the control value. Alterations in several serum enzymes (esp., alkaline phosphatase and aspartate aminotransferase) revealed several other peripheral consequences of TMT exposure which persist through post-dosing day 28. The more prominent and wide-spread neurochemical alterations resulting from TMT exposure appear to reflect consequences of hyperammonemia resulting from a peripheral effect of the organotin compound.

Amino Acids↗
PubMed1985

Expression of proto-oncogenes in normal and papovavirus-transformed or -infected rat fibroblasts.

Dot blot hybridization was used to determine the transcript levels of 10 cellular oncogenes in Fischer rat fibroblasts transformed or infected in tissue culture by polyoma virus or SV40. The level of these messages was compared to that determined for nontransformed, noninfected control cells. The analysis includes the oncogenes myc, sis, mos, erbB, erbA, Ha-ras, Ki-ras, src, fps, and abl. For all the oncogenes tested, except for mos, detectable expression was observed in all cell lines studied including the normal control cells; when normal and transformed or infected cells were compared, no significant difference in transcript level was found for any of the oncogenes except one. A slight elevation of sis message was observed for some transformants. The results of this study apply to six polyoma and seven SV40 transformants which were chosen with the purpose of analyzing transformants displaying a variety of properties. Thus, the polyoma-transformed cell lines varied in their expression of the transformed phenotype as judged by anchorage-independent growth and cell morphology, in their coding capacity for and expression of early gene products, and included two classes of rat fibroblasts transformed by ts-a mutants: those with a temperature-insensitive transformed phenotype, and those with a temperature-sensitive phenotype, A-type and N-type, respectively. Concerning the latter two types, no differences in oncogene expression were observed between cells grown at low and those grown at high temperatures, or between the two groups of cells at either temperature.

Animals↗
PubMed1985

An approach to NMR studies of the metabolism of internal organs using surface coils.

This communication describes a surgical preparation of experimental animals to permit NMR spectroscopic studies of the metabolism of internal organs. In the procedure developed, the layer of protective muscle directly above the organ is removed, but the skin is left intact. NMR studies of the metabolism of the organ can then be carried out using surface coils placed externally over the herniated area. Modified probe and stack designs for use with the surgically modified animals in a conventional NMR spectrometer are described. Phosphorus-31 NMR spectra of liver and kidney of the modified animals have been obtained, and data corresponding to the hepatic response to a load of fructose are presented.

Adenine Nucleotides↗
PubMed1985

Activated eosinophils in familial eosinophilic gastroenteritis.

Two siblings with eosinophilic gastroenteritis who presented with severe iron deficiency anemia and hypoalbuminemia associated with varying degrees of mucosal damage are described. Using a monoclonal antibody to the secreted form of eosinophil cationic protein, we demonstrated activated degranulating eosinophils in the gastrointestinal mucosa that correlated with the degree of histologic damage. This finding suggests that eosinophils may have a primary role in the tissue damage in this condition. Oral disodium cromoglycate (Nalcrom) failed to alter the clinical, radiologic, and histologic abnormalities. Prednisolone, however, was beneficial in 1 case but did not completely reverse the abnormalities.

Adolescent↗
PubMed1985

Personal assessment of stress factors for college students.

During a four-year period, an instrument to identify stress was developed from items suggested by students from a search of related literature, and from a jury of experts. The 100-item instrument, including four subcategories, was administered to more than 1,200 students at 23 colleges. Means were computed to the total test, subcategories, and individual items according to frequency and intensity. Responses of men and women were sufficiently different to warrant establishing separate means; women scored higher than men. The degree of stress reported by women decreased with each grade level, but peaked in the sophomore year for men and declined thereafter. Academic factors were cited most frequently as a source of stress, while Relationships and Home and Community factors ranked high in stress intensity. The instrument provides a valuable tool to assist students identify factors that could be targeted for stress management. The instrument also could be used as a tool for further stress management research.

Adolescent↗
PubMed1985

Production of neutralizing monoclonal antibodies to Escherichia coli heat-stable enterotoxin.

In an effort to develop new approaches to the study and control of infectious diarrhea, we prepared murine monoclonal antibodies to the Escherichia coli heat-stable enterotoxin (STa). The toxin was purified from E. coli culture media and conjugated to bovine serum albumin. The STa-bovine serum albumin conjugate was used to immunize BALB/c mice, and the immune spleen cells from these mice were fused with SP2/0 myeloma cells. Resultant hybridomas were screened in an enzyme-linked immunosorbent assay protocol against 500 ng of STa-bovine serum albumin bound to microtiter wells as the solid-phase antigen. Five stable clones were selected and grown further in ascites fluid, which demonstrated anti-STa activity at dilutions of up to 1:500,000 in the enzyme-linked immunosorbent assay for heat-stable enterotoxin. In a competitive enzyme-linked immunosorbent assay format, the antibodies recognized several human and porcine strains of STa to various extents, but did not recognize E. coli heat-labile toxin, cholera toxin, or staphylococcal enterotoxin B. The antibodies were all able to bind lactoperoxidase-labeled [125I]STa, and antibody 20B3 was also able to dissociate [125I]STa bound to toxin receptors on rat jejunal villous cells. Preincubation of STa with antibodies 20B3 or 20F5 led to a concentration-dependent neutralization of toxin activity in a suckling mouse intestinal secretion assay. These antibodies are likely to provide new tools for the continued study of STa structure-function relationships and may lead to improved diagnosis and treatment of E. coli-induced infectious diarrhea.

Animals↗
PubMed1985

Association of MHC antigens with susceptibility to and severity of rheumatoid arthritis in multicase families.

A study of HLA association with rheumatoid arthritis (RA) in multicase families has been performed in north east England. Two hundred and nineteen individuals from 13 families were assessed for the presence of RA, and all were HLA typed. Thirty-nine were found to have classical or definite RA by American Rheumatism Association (ARA) criteria. Thirty-five (90%) of these possess HLA-DR4, confirming the previously reported association of RA with DR4. A further 19 individuals were found to have probable RA or gave a convincing history of previous inflammatory polyarthritis. Thirteen (68%) of these possess HLA-DR4, and this is not significantly different from non-affected family members of whom 63% possess DR4. These results suggest that HLA-DR4 is associated only with the more severe forms of RA. Homozygosity for HLA-DR4 was not associated with either earlier onset or more severe disease when compared with heterozygous DR4. Possession of the haplotype most commonly inherited with the RA in individual families was not associated with earlier onset but may be associated with more severe disease. The severity of RA appears to be influenced by the major histocompatibility complex (MHC) in these families.

Adult↗
PubMed1985

Use of essential amino acid/dextrose solutions in the nutritional management of patients with acute renal failure.

A review of the literature on the effectiveness of essential amino acid and hypertonic dextrose in the nutritional management of patients with acute renal failure is evaluated critically. Earlier case reports and studies published indicated that the administration of these solutions could lead to lower blood urea nitrogen concentrations, positive nitrogen balance, and various other clinical and metabolic improvements. Recent studies, however, show that various combinations of essential and nonessential amino acids can provide similar results. Some investigators have suggested increasing the concentration of branched-chain amino acids in these solutions to decrease protein catabolism in muscle. Unfortunately, patients with complications such as sepsis, burns, and shock may not benefit from any of these therapies. Further research is needed to elucidate fully the optimal composition of these solutions in severely stressed hypercatabolic patients with this disorder.

Acute Kidney Injury↗