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Biomedical subjects

R C Thompson

Publications and source records attributed to R C Thompson.

At least 397 records · Page 22Linked to original sources
PubMed1980

Radioactive plume from the Three Mile Island accident: xenon-133 in air at a distance of 375 kilometers.

The transit of an air mass containing radioactive gas released from the Three Mile Island reactor was recorded in Albany, New York, by measuring xenon-133. These measurements provide an evaluation of Three Mile Island effluents to distances greater than 100 kilometers. Two independent techniques identified xenon-133 in ambient air at concentrations as high as 3900 picocuries per cubic meter. The local gamma-ray whole-body dose from the passing radioactivity amounted to 0.004 millirem, or 0.004 percent of the annual dose from natural sources.

Air Pollution, Radioactive↗
PubMed1980

An ultrastructural study of the microtriches of adult Proteocephalus tidswelli (Cestoda: Proteocephalidea).

Ultrastructural observations on adult Proteocephalus tidswelli revealed a marked microtrichial polymorphism. Structural and dimensional variations of microtriches between different regions of the strobila and scolex, as well as within the same region, were observed. The authors suggest that microtriches are involved in a diversity of functions, and possible functional activities are discussed.

Animals↗
PubMed1979

Effect of BCG on the resistance of rats to infection with Fasciola hepatica.

The effects of three different doses of BCG, given at various periods before infection, on the subsequent establishment of Fasciola hepatica metacercariae were studied. Although evidence was found to suggest that rats which received BCG had mounted a cell mediated immune response, there were no significant differences in worm recovery between BCG-treated rats and controls. The significance of these results in the light of current knowledge on immunity to F. hepatica in rats is discussed.

Animals↗
PubMed1979

The anoplocephalid cestode parasites of the spectacled hare-wallaby Lagorchestes conspicillatus Gould, 1842 (Marsupialia: Macropodidae).

Progamotaenia gynandrolinearis sp. nov. is described from the small intestine of Lagorchestes conspicillatus Gould, 1842 from Barrow I., Western Australia. It is distinguished from other species by the small number of testes arranged in a single transverse row. Progamotaenia lagorchestis (Lewis, 1914) is redescribed. The name Progamotaenia thylogale sp. nov. is proposed for a second species described previously under the name P. lagorchestis. Progamotaenia zschokkei (Janicki, 1905), Progamotaenia festiva (Rudolphi, 1819) and Progamotaenia villosa (Lewis, 1914) were also found in L. conspicillatus.

Animals↗
PubMed1979

Crystallographic and kinetic investigations of the covalent complex formed by a specific tetrapeptide aldehyde and the serine protease from Streptomyces griseus.

X-ray crystallographic data show that a specific tetrapeptide aldehyde inhibitor (N-acetylprolylalanylprolylphenylalaninal) forms a stable, covalent, tetrahedral addition complex with the serine protease, SGPA, from Streptomyces griseus. Earlier proposals, based on kinetic measurements, for the covalent nature of such linkages are confirmed, and the difference electron density map of this aldehyde inhibitor indicates that a major conformational change of the histidyl-57 side chain occurs on inhibitor binding.

Aldehydes↗
PubMed1979

Metabolic activity of articular cartilage in osteoarthritis. An in vitro study.

Biochemical changes and in vitro rates of glycosaminoglycan synthesis were studied in thirty-seven samples of human articular cartilage from nineteen osteoarthritic and four normal control patients who were fifty to seventy-five years old. The samples were compared on the basis of histological grade of the arthritis, and subgroups based on the duration of disease, synovial pathological changes, joint studied, and sex were also compared. The osteoarthritic samples showed a progressive loss of glycosaminoglycans in the cartilage as the histological grade increased. In the early stages of the disease there was an increase in the chondroitin sulphate content as well as in the rate of glycosaminoglycan synthesis in several cases when the values for the osteoarthritic articular-cartilage samples were compared with those for the age-matched controls. In the late stages there was a progressive decrease in the rate of glycosaminoglycan synthesis and a relative decrease in chrondroitin sulphate synthesis compared with keratan sulphate synthesis, and these decreases were highly correlated with the histological grade.

Aged↗
PubMed1978

The enhancement of tetrathyridial proliferation of Mesocestoides corti in mice by B.C.G.

The effects of different doses of B.C.G. given at various periods before infection, on the development of tetrathyridia of Mesocestoides corti was studied. B.C.G. administration was found to exert a complex influence upon M. corti infection in mice. Either enhancement or inhibition of parasite proliferation may occur, depending upon dosage level and the time interval between B.C.G. administration and parasite challenge.

Animals↗
PubMed1978

A complete dislocation of the thumb metacarpal.

Multiple dislocations of a single finger are rare. We report a patient with complete dislocation of the thumb metacarpal, a condition not reported previously. A 9 year follow-up shows the patient to have a normal-appearing, strong, and painless hand.

Adult↗
PubMed1977

Proofreading of the codon-anticodon interaction on ribosomes.

The fidelity of protein synthesis is substantially greater than the specificity of codon-anticodon recognition that would be expected from the known energetics of base-pairing in solution. To test the suggestion that the specificity of recognition may be increased by "kinetic proofreading" associated with GTP hydrolysis [J. J. Hopfield (1974) Proc. Natl. Acad. Sci. USA 71, 4135-4139], we have studied the interaction of ternary complexes of polypeptide elongation factor Tu, aminoacyl-tRNA, and GTP with poly(U)-programed ribosomes. With most noncognate ternary complexes, including two that pair correctly with the 5' and 3' bases of UUU, rejection occurred without GTP hydrolysis, presumably by the reverse of the initial binding reaction. However, with complexes containing Leu- or Ile-tRNAs, which may pair correctly with the 3' and middle bases, GTP hydrolysis was stimulated though the aa-tRNA was not retained on the ribosome. These results demonstrate the existence of a GTP-dependent proofreading step in aminoacyl-tRNA recognition on ribosomes. They also suggest that the 5' base of the codon is more prone than the middle base to errors that can be corrected by proofreading.

Anticodon↗
PubMed1977

Extracellular labeling of nascent polypeptides traversing the membrane of Escherichia coli.

To provide direct evidence for the hypothesis that secreted proteins may traverse membranes as growing chains, we labeled spheroplasts of Escherichia coli with a reagent (acetyl[35S]methionyl methylphosphate sulfone) that reacts with amino groups but does not cross the membrane. After fractionation, about 6% of the label in the membrane-polysome fraction was found to be attached to the polysomes. This attachment was via peptidyl-tRNA, as shown by several tests: release of most of the label from purified polysomes at low Mg2+; subsequent loss of about 25,000 daltons on cleavage by dilute alkali; release by puromycin; and release, accompanied by a marked increase in average molecular weight, on peptide chain completion. Moreover, a significant fraction of the completed chains was identified serologically and by molecular weight as a major periplasmic protein, alkaline phosphatase [orthophosphoric-monoester phosphohydrolase (alkaline optimum); EC 3.1.3.1]. This work provides direct evidence that: (i) secreted proteins thread through the membrane as growing peptide chains; and (ii) membrane-associated polysomes in bacteria are functionally attached to membrane and not merely trapped on disruption of the cell.

Alkaline Phosphatase↗
PubMed1977

Total hip replacement in disseminated neoplastic disease.

Between 1972 and 1975, 11 total hip replacements were performed on ten patients with advanced neoplastic disease. Eight of ten patients survived more than one year after total hip replacement. Eight of 11 hips were rated as having excellent or good functional results six months postoperatively. We suggest that total hip arthroplasty be considered an appropriate procedure in the operative management of patients with advanced neoplastic disease involving the hip.

Adult↗