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Biomedical subjects

J Thompson

Publications and source records attributed to J Thompson.

At least 775 records · Page 43Linked to original sources
PubMed1976

Prosthesis endocarditis: treatment of a case occurring five years after a Rastelli-Ross operation.

A severe staphylococcal septicemia originating from an unknown focus occurred in a 17-year-old patient who had undergone a Rastelli-Ross operation 5 years earlier. The clinical course was complicated by extensive bilateral pneumonia, diffuse intravascular coagulation, and glomerulonephritis. After 4 weeks of intensive conservative treatment, including a daily regimen of 16 Gm. of cloxacillin, the patient was operated upon for a rapidly progressive false aneurysm, which had resulted from dehiscence of the anastomosis between the prosthesis and ventricle. The excised prosthesis proved to be sterile. The postoperative course was uneventful. Cloxacillin treatment was continued for 6 months, initially parenterally and later orally. After discontinuation of therapy, no signs of infection have occurred. Right-sided intracardiac or intravascular prosthetic material may be particularly susceptible to infections originating from the body surface.

Aneurysm, Infected↗
PubMed1975

In vitro induction of tumour-specific immunity. I. Development of optimal conditions for induction and assay of cytotoxic lymphocytes.

A microculture system for in vitro induction of tumour-specific immunity with syngeneic spleen cells and plasma-cell tumours is described. The system generates cytoxic lymphocytes assessed by their ability to lyse 51Cr-labelled target cells in a microcytotoxicity assay. Both the inductive and effector phases are subject to many variables in material and methodology and the optimal conditions are defined in this study. Of particular importance are the responder- to stimulator-cell ratios, the presence of 2-mercaptoethanol, the day of harvest, the method of target-cell 51Cr labelling, and preincubation of the cytotoxic lymphocytes prior to assay.

Animals↗
PubMed1975

Safety and antigenicity of influenza A/Hong Kong/68-ts-1 (E) (H3N2).

Influenza A/Hong Kong/68-ts-1 [E] (H3N2) vaccine was administered intranasally to 18 seronegative children 14 to 32 months of age. Fourteen children, 78%, shed influenza A/Hong Kong virus for a mean of eight days following vaccination. Sixteen children, 89%, experienced a fourfold or greater rise in hemagglutination-inhibition antibody. Some children appeared to experience a febrile reaction to the vaccine although interpretation of this data was complicated by intercurrent illness. These findings demonstrate that influenza A ts-1 [E] replicates more readily in the young seronegative child than in the HAI negative adult. In addition, the temperature-sensitive marker of the vaccine was not genetically stable in four of the vaccinated children. Careful evaluation of any future live respiratory viral vaccines needs to be undertaken in the young seronegative child before the vaccine's safety is fully established.

Administration, Intranasal↗
PubMed1975

Effect of glucocorticosteroids on the phagocytosis and intracellular killing by peritoneal macrophages.

The effect of hydrocortisone on the phagocytosis and intracellular killing by mouse peritoneal macrophages in vitro was studied by a method making it possible to measure these processes separately. The results showed that in vivo treatment with 15 mg of hydrocortisone acetate did not significantly decrease the phagocytosis of several bacterial species such as Staphylococcus albus, Staphylococcus aureus, Escherichia coli, Salmonella typhimurium, and Pseudomonas aeruginosa. The killing indexes of normal macrophages for the various microorganisms were found to be significantly different. This may indicate that the bactericidal mechanisms are not uniform for these bacteria. The effect of hydrocortisone on the intracellular killing was also variable. For Staphylococcus albus a normal killing index was found. For the other species of bacterial and for Candida albicans some decrease was found, but this was only significant for Salmonella typhimurium. It is concluded that a decrease host resistance due to glucocorticosterioid treatment is not caused by a direct effect of these drugs on the phagocytosis and intracellular killing by mononuclear phagocytes.

Animals↗
PubMed1975

Effects of growth conditions on cyclic nucleotide phosphodiesterases of cultured fibroblasts.

Cyclic nucleotide phosphodiesterase activities of baby hamster kidney cells (BHK) grown in surface cultures were altered by modifying growth conditions. The untransformed BHK cells grown in medium containing 10% fetal calf serum showed non-linear LineweaverBurk plots for cyclic AMP phosphodiesterase activity with apparent Michaelis constants for cyclic AMP of approximately 5 and 30 muM. When these cells were placed in medium containing 1% fetal calf serum, linear kinetic plots for cyclic AMP phosphodiesterase with an apparent Km for cyclic AMP of approximately 20 muM were obtained. Modification of the apparent Km of BHK cell phosphodiesterase was detectable within 20 minutes after dillution of cells grown in 10% serum into fresh medium containing 1% serum. With the BHK cell line transformed with Rous sarcoma virus, differences in enzyme kinetics were not seen when these cells were diluted in 1% or 10% serum. In addition to the serum induced differences in the apparent Km of cyclic AMP phosphodiesterases of BHK cells, total cyclic AMP and cyclic GMP phosphodiesterase activities were also modified by growth conditions. BHK cells grown to high cell densities had three to five-fold higher total cyclic AMP activity than did the cells in less dense cultures. When the dense cell cultures were diluted into fresh medium containing 10% serum, total enzyme activities fell to levels comparable to those found in the rapidly growing cells at low cell densities. The reduction in total enzyme activity after dilution of BHK cells occurred rapidly and was influenced by cell density. A similar reduction of total enzyme activity was also seen in diluted RSV cells; however, the time course of the response differed from that seen in the untransformed cells.

3',5'-Cyclic-AMP Phosphodiesterases↗
PubMed1974

A case of cholera in Texas, 1973.

The first naturally acquired case of cholera reported in the United States since 1911 occurred in a 51-year-old resident of Port Lavaca, Texas. Extensive epidemiologic investigation of the patient's contacts and environment did not identify a cholera carrier of elucidate a pathway of transmission, but several avenues of investigation suggested possible means by which the patient may have acquired his infection. No secondary spread resulted from this case, and its occurrence did not endanger the community at large.

Cholera↗
PubMed1974

Specific electron donor-energized transport of alpha-aminoisobutyric acid and K+ into intact cells of a marine pseudomonad.

The transport of alpha-aminoisobutyric acid and K(+) into K(+)-depleted cells of a marine pseudomonad (ATCC 19855) was stimulated strongly by ethanol, reduced nicotinamide adenine dinucleotide (NADH), and ascorbate-reduced N, N, N', N'-tetramethyl-p-phenylenediamine. In the presence of the quinone inhibitor 2-heptyl-4-hydroxyquinoline-N-oxide, only ascorbate-reduced N, N, N', N'-tetramethyl-p-phenylenediamine was active. Primary and secondary, but not tertiary, alcohols from ethanol to n-amyl alcohol stimulated both alpha-aminoisobutyric acid and K(+) transport and were oxidized by the cells. Malate and succinate, which were oxidized rapidly by the cells, had little or no capacity to energize the transport of alpha-aminoisobutyric acid into K(+)-depleted cells but were partially effective in promoting K(+) uptake. Ethanol stimulated the transport of alpha-aminoisobutyric acid into K(+)-preloaded cells. The transport of both alpha-aminoisobutyric acid and K(+) was inhibited 20% by iodoacetate, 85% by N-ethylmaleimide, and 90 to 100% by both NaCN and p-chloromercuribenzoate. The addition of Na(3)Fe(CN)(6) permitted the ethanol-induced transport of alpha-aminoisobutyric acid into K(+)-preloaded cells in the presence of NaCN, but little or no uptake of alpha-aminoisobutyric acid or of K(+) into K(+)-depleted cells under the same conditions. The transport of alpha-aminoisobutyric acid into K(+)-depleted cells required both K(+) and an electron donor. The oxidation of NADH and ethanol by K(+)-depleted cells was stimulated strongly by K(+). Parallels between these studies and those with membrane vesicles show that results with membrane vesicles of the marine pseudomonad have physiological significance for the intact cells. The results support the conclusion that the energy for the active transport of both alpha-aminoisobutyric acid and K(+) into cells of this organism is provided by electron flow through a region of the respiratory chain lying between cytochrome c and O(2).

Alcohols↗
PubMed1974

Potassium transport and the relationship between intracellular potassium concentration and amino acid uptake by cells of a marine pseudomonad.

Transport of K(+) by K(+)-depleted cells of marine pseudomonad B-16 (ATCC 19855) exhibited saturation kinetics. Rb(+) inhibited both K(+) transport and the K(+)-dependent transport of alpha-aminoisobutyric acid (AIB) into K(+)-depleted cells of the organism in proportion to the concentration of Rb(+) in the suspending medium. Inhibition of the K(+)-dependent uptake of AIB into K(+)-depleted cells by Rb(+) could be overcome by increasing the concentration of K(+) in the medium. When AIB and K(+) were added simultaneously to a suspension of K(+)-depleted cells, the uptake of K(+) occurred immediately and rapidly, whereas the accumulation of AIB occurred only after a lag. The initial uptake rate of AIB was directly proportional to the intracellular K(+) concentration. The intracellular concentration of K(+) and AIB at their steady-state levels increased to a maximum as the Na(+) concentration in the suspending medium was increased. At Na(+) concentrations between 0.2 and 0.3 M, the molar ratio of K(+) to AIB at their intracellular steady-state concentrations was constant at 1.6. At external Na(+) concentrations less than 0.2 M, the cells maintained a relatively higher K(+) intracellular steady-state level than AIB.

Amino Acids↗