Search PubMed⌕ Search

Biomedical subjects

K Thompson

Publications and source records attributed to K Thompson.

At least 217 records · Page 12Linked to original sources
PubMed1979

Involving your staff in the decision-making process.

According to the authors, a growing feeling of alienation among employees is a major problem in all organizations. The technique of Goal-Directed Group Support (GDGS) is suggested to improve communications and provide job enrichment. GDGS is based on weekly or biweekly group meetings to discuss progress and problems in the work environment. The role of the manager at the meetings is to help define problems and to find solutions. While group members are responsible for identifying and analyzing a variety of alternatives, the manager's task is to determine a course of action. Once the decision has been implemented, feedback should be provided to the group. The authors have found GDGS to be an excellent tool for resolving group conflict.

Decision Making↗
PubMed1979

Comparative efficacy of ten commercial Campylobacter fetus vaccines in the pregnant guinea pig: challenge with Campylobacter fetus serotype A.

Efficacy of ten commercial Campylobacter fetus vaccines was tested in pregnant guinea pigs and compared with that of an experimental vaccine prepared from the challenge-exposure strain. If the first lot of vaccine failed to protect 50% of the guinea pigs, one or two additional lots of that vaccine were purchased and retested. Three vaccines for cattle, evaluated, as the most effective of those tested, protected 62%, 72%, and 89% of the guinea pigs from abortion; the experimental vaccine protected 98%. The two vaccines for sheep protected 50% and 61% of the guinea pigs from abortion. With the other five vaccines produced for immunizing cattle, protection was from 0% to 36%, with the exception of one lot of a vaccine that protected 74%. Blood infection was found at necropsy in only 6% of the guinea pigs given vaccines that protected 50% or more from abortion, but was found in 66% of those given vaccines that protected less than 50%. Similarly, tissue infection was found at necropsy in only 18% of the guinea pigs given vaccines that protected more than 50%, but was found in 91% of those given vaccines that protected less than 50% from abortion. Oil-emulsion adjuvants appeared to enhance protection from abortion and infection. Nodules persisted at the injection site in most of the guinea pigs immunized with vaccines containing oil-emulsion adjuvants, but rarely persisted in guinea pigs given aqueous-phase adjuvant vaccines. Comparison of efficacy of the vaccines in guinea pigs with efficacy in sheep and cattle remains to be made.

Abortion, Veterinary↗
PubMed1978

Recognition of lysozyme by lymphocyte subsets.

Extensive studies with antisera from a variety of animals have failed to detect any cross-reactivity between egg white lysozyme and its reduced, S-carboxymethylated (CM-) derivative. In contrast, a number of studies addressing the specificity of T lymphocytes have revealed that these two forms of lysozyme cross-react rather extensively at that level. Preliminary attempts to eliminate this latter cross-reactivity by further denaturation and/or chemical modification have so far proven unsuccessful. In a second line of experimentation the response to CM-lysozyme of mice which are genetically unresponsive to native lysozyme was assessed and found deficient. The implications of these findings are discussed.

Animals↗
PubMed1978

Appearance and distribution of surface proteins of the human erythrocyte membrane. An electron microscope and immunochemical labeling study.

We have used freeze-etching, before and after immunoferritin labeling, to visualize spectrin molecules and other surface proteins of the human erythrocyte membrane. After intramembrane particle aggregation was induced, spectrin molecules, identified by labeling with ferritin-conjugated antispectrin, were clustered on the cytoplasmic surface of the membrane in patches directly underlying the particle clusters. This labeling pattern confirms the involvement of spectrin in such particle aggregates, as previously inferred from indirect evidence. Ferritin-conjugated antihapten molecules, directed against external and cytoplasmic surface proteins of the erythrocyte membrane which had been covalently labeled nonspecifically with the hapten p-diazoniumphenyl-beta-D-lactoside, were similarly found in direct association with such intramembrane particle aggregates. This indicates that when spectrin and the intramembrane particles are aggregated, all the major proteins of the erythrocyte membrane are constrained to coaggregate with them. Although giving no direct information concerning the freedom of translational movement of proteins in the unperturbed erythrocyte membrane, these experiments suggest that a close dynamic association may exist between the integral and peripheral protein components of the membrane, such that immobilization of one component can restrict the lateral mobility of others.

Erythrocyte Membrane↗
PubMed1977

Seed germination in response to diurnal fluctuations of temperature.

Diurnal fluctuations in temperature may initiate or accelerate germination in certain flowering plants, and the effectiveness of the stimulus varies according to the amplitude of fluctuation and the presence or absence of light. Attempts to assess the adaptive significance of the phenomenon, however, have been limited by the scarcity of data for species of contrasted ecology. We report here an investigation of germination responses to fluctuating temperatures, conducted on seeds of herbaceous species collected from native populations near Sheffield. The results suggest that requirements for diurnal fluctuations in temperature are characteristic of the germination of species from particular types of habitat and provide mechanisms which cause seeds to germinate at times and in places favourable for seedling establishment.

Circadian Rhythm↗
PubMed1977

Phenothiazine effects on psychological and psychophysiological dysfunction in chronic schizophrenics.

This study examined the effects of phenothiazine treatment on attentional-perceptual, cognitive, and psychophysiological dysfunction in chronic schizophrenics. Under double-blind conditions, 20 patients receiving chlorpromazine and 20 receiving placebo for eight weeks were tested by performance measures, clinically rated, and monitored for skin resistance and heart rate on four occasions. Phenothiazine effects on measures of attention-perception and on psychophysiological response were demonstrable, but not on tests and ratings of cognitive dysfunction. The direction of effects was toward normalization of function. Drug treatment tended to improve ability to sustain set, to increase efficiency of selective attention, and to increase rate of information processing. Autonomic reactivity was reduced and a deactivation effect suggested. Clinical improvement was correlated with reduction in attentional dysfunction. The results are discussed in terms of their implications for hypothesized behavioral mechanisms of drug action, primary "behavioral site" of drug action, therapeutic response measurement, and functional theories of schizophrenic psychopathology.

Adolescent↗
PubMed1977

Surface differentiation antigens of human mammary epithelial cells carried on the human milk fat globule.

Rabbit antibodies against components of the human milk fat globule bind specifically to normal human breast epithelial cells and cell lines derived from breast carcinomas, as well as to the outer surface of the human milk fat globule. Variation in indirect immunofluorescence staining in both intensity per cell and percentage of cells stained is observed for the different brest cell lines. Cells derived from other epithelial and other ectodermal tissues, fetal fibroblasts, cells of the blood buffy coat, and even fibroblasts of the breast itself do not bind the antibodies. This suggests that these antibodies are detecting cell-type-specific antigens. These normal breast epithelial cell antigens are on the cell surface and their expression is stable in long-term cultured cell lines, even after much chromosomal variation in a given line. By affinity chromatography, three distinct antigenic components can be isolated from the milk fat globule, one of which contains carbohydrate. These differentiation antigens of the human breast epithelial cell are not only useful as specific cell-type markers, but also can provide a tool to study the role of the cell surface in normal and neoplastic mammary development.

Animals↗
PubMed1977

Serum prolactin and oestradiol levels at different stages of puberty.

Serum prolactin and oestradiol levels were measured in 183 children who were staged for pubertal development. Mean serum prolactin levels are higher in girls than in boys at stage 3 of pubertal development. In girls prolactin levels rise at stage 2, and are higher after menarche; in boys there is no change in prolactin levels. In this study serum oestradiol correlates with prolactin in the girls, but not in the boys.

Adolescent↗
PubMed1976

The r.b.e. of different energy neutrons as measured by the heamatopoietic spleen-colony technique.

The spleen-colony technique has been used for determining the relative biological effectiveness (r.b.e.) for several energies of neutron radiation. Donor mice were exposed for fission and accelerator-generated neutrons at a variety of doses and energies. Immediately after exposure, donor bone-marrow was removed from the hind legs, and standard amounts were injected intravenously into lethally X-irradiated recipients. After 7 days the recipients spleens were evaluated for surface colonies. Dose-response curves were obtained for each type of radiation and the Do was determined. The neutron r.b.e. values from the Do compared with 250kVp X-rays were: reactor 1.58, 252Cf 1:59, and accelerator varied from 2.85 at 1.0 Mev to 0.85 at 13.4 MeV.

Animals↗
PubMed1976

Immunologic methods for the identification of cell types. I. Specific antibodies that distinguish between mammary gland epithelial cells and fibroblasts.

Antibodies were produced against intact mouse mammary epithelial cells and cleared fat pad fibroblasts; after appropriate absorption, two specific antibody preparations were obtained. The antimammary epithelial cell preparation did not appear to be strain- or species-specific. The antimammary fibroblast preparation recognized both mammary and fetal fibroblasts. These findings suggested that each cell type possessed distinct immunogenic components. These components were characteristic of each cell type and could be used to identify the respective cells by an immunofluorescence technique. Characterization of the antigenic component of mouse mammary epithelial cells demonstrated that this antigen was released during enzymatic cell dissociation and was regenerated underin vitro culture.

Animals↗
PubMed1974

Hapten-sandwich labeling. I. A general procedure for simultaneous labeling of multiple cell surface antigens for fluorescence and electron microscopy.

A hapten-sandwich procedure has been developed for specific labeling of cell surface antigens for fluorescence or electron microscopy. Haptens are azo-coupled to immunoglobulins specific for a cell surface antigen; the hapten-modified cell-bound antibodies can then be visualized by adding fluorescent antihapten antibody, or by adding antihapten antibody followed by hapten-modified markers for electron microscopy. Virus or high molecular weight protein markers are lightly cross-linked before conjugation with hapten to prevent their disruption. Such stable hapten-modified markers, and the accessibility of many different purified anti-azophenyl-hapten antibodies, make it feasible to distinguish more than one membrane antigen in a given labeling experiment. When mouse lymphoid cell populations are labeled with separate markers for Ig and for thymus-associated antigens, many cells exhibit the Ig marker exclusively or the thymic marker predominantly, and some cells are completely free of label.

Animals↗