Search PubMed⌕ Search

Biomedical subjects

J A Patterson

Publications and source records attributed to J A Patterson.

At least 55 records · Page 3Linked to original sources
PubMed1984

Characterization of immature T cell subpopulations in neonatal blood.

A series of monoclonal antibodies directed against T cell differentiation antigens was used to identify circulating T cells in normal human neonates. Twenty-five cord blood samples, taken after cesarean or vaginal delivery, and 16 venous blood samples from normal adult controls were examined using monoclonal antibodies in an indirect immunofluorescence technique. The percentage of circulating OKT3 positive (pan-T cell) cells was significantly lower in the neonatal blood (52.8%) compared with the adult controls (74.9%) (P less than .001). Of the cord mononuclear cells, 58% showed reactivity with OKT10 (common thymocyte antigen) compared with only 7% in adult controls (P less than .001). The helper:suppressor T cell ratio was lower in cord blood (1:2) as compared with 1:3 for adult blood (P less than .005) as observed in these studies. These figures reflect the presence of a significant population (25%) of immature T cells in cord blood that expresses simultaneously both helper (OKT4) and suppressor (OKT8) phenotypes. Twenty-four percent of the T cells in cord blood also expressed OKT6 antigen (cortical thymocyte), a feature not found in adult blood. Double-labeling studies characterized a previously undescribed blood T cell phenotype, which was simultaneously OKT6 and OKT3 (pan-T cell) positive; of the cells reactive with OKT3, 43% also were positive with OKT6. This study reveals the presence of immature populations of T cells in normal human neonatal blood exhibiting phenotypes characteristic of normal developing thymocytes and a previously undescribed cell phenotype.

Adult↗
PubMed1984

Pulmonary venoocclusive disease in pregnancy.

A 23-year-old woman in her 27th week of gestation presented with clinical findings of progressive pulmonary hypertension. After cardiac catheterization she went into labor and was delivered by cesarean section. She died shortly thereafter from right heart failure. Pulmonary venoocclusive disease was found at autopsy. Hemodynamic changes during pregnancy, labor, delivery, and the postpartum period may have contributed to her deterioration and death. This is the first description of pulmonary venoocclusive disease in pregnancy.

Adult↗
PubMed1983

Biogenic amines in cephalopod retina.

Biochemical and ultrastructural studies by previous workers have suggested dopamine as a candidate neurotransmitter for the centrifugal neurons present in the cephalopod retina. We have examined the retina in 3 species of cephalopod mollusc and find strong green bands of glyoxylic acid-induced fluorescence in the synaptic plexus region. These results, together with data obtained from our Golgi impregnations, help to confirm previous speculations that the centrifugal neurons are dopaminergic.

Animals↗
PubMed1983

Thymopoietin-like substance in human skin.

A heterologous antithymopoietin (anti-TP) antibody was used to determine whether a TP-like molecule is present in the epidermis, since such factors have been postulated to play a part in known T cell-epidermal cell interaction. Examination of cytocentrifuge smears of freshly separated human epidermal cells stained by indirect immunofluorescence revealed that 8-14% of these cells possessed cytoplasmic reactivity with the anti-TP antibody. Similarly, 2-5% of human epidermal cells, maintained in tissue culture for 2-8 weeks, showed cytoplasmic staining with the anti-TP antibody. Double-labeling immunofluorescence studies, with the anti-TP antibody and a monoclonal antibody specifically reactive with Langerhans cells (OKT6), demonstrated that cells possessing this TP-like substance were not Langerhans cells. In situ studies of 4-microns frozen sections of normal human skin indicated that the cell population which possesses the TP-like substance is the basal layer of keratincoytes in the epidermis.

Fluorescent Antibody Technique↗
PubMed1983

Effects of diaryliodonium chemicals on rumen fermentation in vitro and in vivo.

In vitro fermentation studies demonstrated that diaryliodonium chemicals were inhibitors of amino acid utilization. Only small differences were found in comparative effectiveness of different analogs and salt forms of chemicals tested. Protection against degradation and(or) uptake was greatest for valine, methionine, isoleucine, leucine and phenylalanine. Although changes were not as large, animals fed 4,4'-dimethyldiphenyliodonium chloride for 112 d had higher ruminal concentrations of amino acids and lower concentrations of ammonia. Decreased production of acetate in conjunction with increased production of propionate and butyrate resulted in improved fermentation efficiencies. Fermentative shifts in vivo were not as large as those observed in vitro and additional investigations are needed to determine whether feeding diaryliodonium chemicals increases the transfer of energy in digested carbohydrates to volatile fatty acids.

Amino Acids↗
PubMed1983

Effects of diaryliodonium chemicals on nitrogen utilization in growing steers.

Diaryliodonium chemicals increased nitrogen (N) absorption, utilization of absorbed N and N retention in growing steers. Fifty parts per million of the chemicals (diphenyliodonium chloride, diphenyliodonium bromide, 4,4'-difluorodiphenyliodonium chloride or 4,4'-dimethyldiphenyliodonium chloride) in the diet appeared sufficient to promote significant (P less than .05 or .10) improvements in N utilization. Diet digestibility was either not affected or improved slightly. We suggest that diaryliodonium chemicals improve N utilization by adjusting the ruminal degradation of dietary protein to yield more amino-N and less ammonia-N.

Animals↗
PubMed1983

Effects of 4,4'-dimethyldiphenyliodonium chloride on performance of growing cattle.

Two 112-d studies were conducted to evaluate effects of the deaminase inhibitor, 4,4'-dimethyldiphenyliodonium chloride, on performance of growing cattle. With diets containing low levels of crude protein (i.e., 11%), 25 ppm of chemical in the diet increased (P less than .05) gain and improved (P less than .05) feed efficiency. Feed intake was not affected. Higher levels of chemical (50 and 100 ppm) produced equivalent responses. With a higher level of dietary crude protein (i.e., 14%) gain and feed efficiency were not improved and some decreases in feed intake were observed. Performance responses resulting from adjustments in ruminal nitrogen transactions to provide more alpha-amino-N depend upon whether the animal needs additional amino acids for maintenance and production. Our data demonstrated that the supply of amino acids can be increased either by adjustment of ruminal nitrogen transactions with a chemical agent or by increasing concentration of dietary protein.

Animals↗
PubMed1983

Recognition of immature T-cell phenotypes in neonatal blood using monoclonal antibodies.

The monoclonal antibody reactivity of cord blood mononuclear cells to six monoclonal reagents, OKT3, OKT4, OKT6, OKT8, OKT10, and OKT11, was evaluated using an indirect immunofluorescence technique. An immature population of cells was found; 24% of T cells in cord blood expressed OKT6 and 58% expressed OKT10. A previously undescribed phenotype, OKT3+/OKT6+, was discovered using double-labeling studies. In addition, the OKT4+:OKT8+ ratio in cord blood was 1:2, compared with 1:3 in the normal adult controls tested in this study. This is explained by the presence of a population of OKT4+/OKT8+ cells circulating in the neonate. Double-labeling studies of the cord blood samples demonstrated that all of the OKT3+ cells were simultaneously OKT11+ and that 17% of the cells were OKT11+ only. This is in accordance with the findings in normal adult peripheral T cells. Therefore, circulating neonatal T cells express an immature phenotype more characteristic of thymocytes and an altered OKT4+:OKT8+ ratio as compared with adult controls. We also describe a new phenotype OKT3+/OKT6+ present on the cord mononuclear cells.

Adult↗
PubMed1982

Kaposi's sarcoma following chemotherapy for testicular cancer in a homosexual man: demonstration of cytomegalovirus RNA in sarcoma cells.

A 35-year-old white Jewish homosexual man who had undergone surgery and chemotherapy for an embryonal carcinoma of the testis subsequently developed Kaposi's sarcoma. The neoplasm involved the skin as well as visceral tissues. Tissue derived from a biopsy specimen of one of the skin lesions was used in the in situ hybridization technique for the detection of genetic material. Cytomegalovirus messenger RNA was identified in the neoplastic Kaposi cells in the skin. The significance of this finding is discussed.

Cytomegalovirus↗
PubMed1982

Changes in Viability, Cell Composition, and Enzyme Levels During Starvation of Continuously Cultured (Ammonia-Limited) Selenomonas ruminantium.

Under nitrogen (ammonia)-limited continuous culture conditions, the ruminal anaerobe Selenomonas ruminantium was grown at various dilution rates (D). The proportion of the population that was viable increased with D, being 91% at D = 0.5 h. Washed cell suspensions were subjected to long-term nutrient starvation at 39 degrees C. All populations exhibited logarithmic linear declines in viability that were related to the growth rate. Cells grown at D = 0.05, 0.20, and 0.50 lost about 50% viability after 8.1, 4.6, and 3.6 h, respectively. The linear rates of decline in total cell numbers were dramatically less and constant regardless of dilution rate. All major cell constituents declined during starvation, with the rates of decline being greatest with RNA, followed by DNA, carbohydrate, cell dry weight, and protein. The rates of RNA loss increased with cells grown at higher D values, whereas the opposite was observed for rates of carbohydrate losses. The majority of the degraded RNA was not catabolized but was excreted into the suspending buffer. At all D values, S. ruminantium produced mainly lactate and lesser amounts of acetate, propionate, and succinate during growth. With starvation, only small amounts of acetate were produced. Addition of glucose, vitamins, or both to the suspending buffer or starvation in the spent culture medium resulted in greater losses of viability than in buffer alone. Examination of extracts made from starving cells indicated that fructose diphosphate aldolase and lactate dehydrogenase activities remained relatively constant. Both urease and glutamate dehydrogenase activities declined gradually during starvation, whereas glutamine synthetase activity increased slightly. The data indicate that nitrogen (ammonia)-limited S. ruminantium cells have limited survival capacity, but this capacity is greater than that found previously with energy (glucose)-limited cells. Apparently no one cellular constituent serves as a catabolic substrate for endogenous metabolism. Relative to losses in viability, cellular enzymes are stable, indicating that nonviable cells maintain potential metabolic activity and that generalized, nonspecific enzyme degradation is not a major factor contributing to viability loss.

Journal Article↗