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Biomedical subjects

R A Knight

Publications and source records attributed to R A Knight.

At least 163 records · Page 9Linked to original sources
PubMed1982

Insensitivity to interferon of NK cells from patients with systemic lupus erythematosus.

Natural cytotoxicity (NK) by fresh E-rosette-negative (ER-) cells from normal donors was increased after overnight incubation with purified IFN alpha and with supernatants containing IFN gamma. ER- cells from 61% of 23 patients with systemic lupus erythematosus did not show increased cytotoxicity after treatment with IFN alpha. Similarly, ER- cells from nine of 18 patients that were treated with IFN gamma-containing supernatants failed to show increased cytotoxicity. The patients who did not show enhanced cytotoxic responses to IFN had higher mean indices of disease activity than responding patients.

Adult↗
PubMed1982

Kinetics of specific in vitro antibody production following influenza immunization.

In vitro specific antibody responses to influenza viral antigens by peripheral blood mononuclear leucocytes following stimulation with influenza virus or pokeweed mitogen have been measured before and at time intervals after influenza immunization in 11 healthy volunteers. There was an early increase in specific antibody produced by lymphocytes stimulated with influenza virus in vitro, in all subjects immunized. The magnitude of the response varied considerably between individuals as did its duration. Virus specific antibody production by cells stimulated with pokeweed mitogen also increased after immunization in all donors. Cells from six of the 11 individuals produced specific antibody in vitro seven days after immunization without antigen or mitogen stimulation. Seven of the 11 subjects had a greater than four-fold increase in serum titre of haemagglutination inhibiting antibody. This study shows an early brisk increase in the ability of lymphocytes to respond to influenza virus in vitro following immunization consistent with a secondary immune response.

Antibodies, Viral↗
PubMed1982

Kinetics of specific anti-influenza antibody production by cultured lymphocytes from patients with systemic lupus erythematosus following influenza immunization.

Specific antibody responses to influenza viral antigens produced by cultured peripheral blood mononuclear leucocytes stimulated with influenza virus or pokeweed mitogen (PWM) have been measured in seven patients with systemic lupus erythematosus (SLE) before and at time intervals after influenza immunization. Cells from two patients stimulated with influenza virus in vitro produced high levels of specific antibody 7 days after immunization. Cells from a third patient produced small amounts of specific antibody at day 14. No antibody was produced by cells from the remaining four patients. Responses were of short duration and were not detectable 1 month after immunization. Specific anti-influenza antibody was induced by PWM only from cells of those patients who responded to virus antigen although absolute levels of antibody produced were not as high. In six patients serum haemagglutination inhibiting antibody to influenza virus was measured, and all six had a greater than four-fold increase. The disparity between in vitro antibody production by peripheral blood mononuclear leucocytes and changes in serum antibody suggests that in patients with systemic lupus erythematosus, in vitro functions of peripheral blood lymphocytes do not reflect the immune system as a whole.

Antibodies, Viral↗
PubMed1982

Activities of some enzymes of glucose metabolism in bovine liver and kidney cortex at three stages of lactation.

The activities (per g of tissue) of hexokinase, phosphofructokinase and pyruvate kinase were unchanged throughout lactation in liver and in kidney cortex. In both these tissues glucose 6-phosphatase activity decreased during late lactation. At the same time fructose diphosphatase activity increased in kidney cortex but not in liver. Activities of the pentose cycle dehydrogenases and of aspartate aminotransferase tended to increase in mid lactation. For most enzymes the activities at peak lactation were similar to those for dry, non-pregnant cows and there was no specific response of the gluconeogenic enzymes. Total hepatic contents of most enzymes tended to increase in mid lactation, but the changes were not clear cut and were the result of an increase in liver size.

Animals↗
PubMed1981

Quantitation of bacillus subtilis L-form growth parameters in batch culture.

Several methods were used to monitor the growth of a stable L-form in batch culture. The end of the exponential growth phase was determined with greatest accuracy by the amounts of deoxyribonucleic acid per milliliter of culture. Optical density and viable count data were not as reliable because the L-forms began to lyse at the end of exponential growth. Lysis was detected visually, by phase-contrast observations of wet mounts, and by release of ultraviolet-absorbing material into culture supernatant fluids.

Bacillus subtilis↗
PubMed1981

Antigen restricted hybridization between antigen primed macrophage and thymic RNA.

Antigen primed macrophage and thymic RNAs hybridize in an antigen restricted fashion. Thymic RNA complementary to the antigen-stimulated macrophage RNA can be obtained from mice inoculated with antigen three days earlier. The ratio of thymic and macrophage RNAs for the optimal hybridization was 50 : 1. The optimal incubation time for hybridization was 32 hours at 60 degrees C. Hybrid RNAs were insensitive to various kinds of RNase. The 31p Fourier transform nuclear magnetic resonance spectra identified hybrid RNA molecules form single stranded RNS's.

Animals↗
PubMed1981

Generation of suppressor cells in the autologous mixed lymphocyte reaction.

When challenged with HLA-A, B and DR incompatible cells, T cells which have been primed in an autologous mixed lymphocyte response (AMLR) show an accelerated (day 2) component of their proliferative response, as well as the expected primary-style response at day 5. This early response of AMLR-primed cells to allogeneic stimulation, like the response to rechallenge with autologous cells, is abolished by treatment of the primary culture with BUdR and light. These results suggest that priming in the AMLR is not solely to MHC-private specificities, and that an antigenic element common to autologous and allogeneic cells is recognized. The AMLR also generates cells with suppressor activities. AMLR-primed cells suppress the proliferative responses of fresh T cells from the same donor to autologous or allogeneic stimulation. Limiting numbers of suppressor cells are more effective suppressors of the autologous, than of the allogeneic response. Suppressor activity is reduced but not abolished by treatment with mitomycin C. AMLR-primed cells also suppress pokeweed mitogen-induced antibody production by fresh peripheral blood lymphocytes. In some experiments, specific antigen-induced antibody production is also suppressed.

Antibodies, Viral↗
PubMed1980

Efficacy of albendazole for prevention of fascioliasis in sheep.

Daily doses of albendazole administered as a premix in the feed for 35 days were effective in preventing Fasciola hepatica infections in 17 sheep in three groups: 5 mg/kg/day (6 sheep) was 100% effective; 3 mg/kg/day (5 sheep) was 98% effective; and 1 mg/kg/day (6 sheep) was 42% effective. Infective cysts were given daily for 5 days during the first week of treatment, treatment was continued an additional 28 days, and sheep were necropsied 14 weeks after final cyst inoculation. There were no visible lesions in any livers of sheep given albendazole at the rate of 5 mg/kg/day or in three of five livers of sheep dosed at the rate of 3 mg/kg/day. Sheep treated with albendazole had a mean weight gain of 2.7 kg, 4.0 kg, and 4.0 kg greater than the controls for the dosages of 1, 3, and 5 mg/kg/day, respectively. Determination of bile duct damage by measurement of serum gamma-glutamyl transpeptidase activity at 9 weeks after final cyst inoculation revealed increases of 3.0X, 1.0X, and 1.1X for the dosages of 1, 3, and 5 mg/kg/day, respectively, and 2.3X for the control, as compared with 7 weeks after final cyst inoculation.

Administration, Oral↗
PubMed1980

The validity of the Whitaker Index of Schizophrenic Thinking.

The Whitaker Index of Schizophrenic Thinking was designed to address an important clinical and research problem--the objective assessment of thought disorder. The present study assessed this test's convergent and discriminant validity and its diagnostic discriminating power (N = 56). We found that the WIST has limited clinical utility as a specific measure of disordered thought and as a diagnostic tool, but that it might still have certain important research applications.

Adolescent↗
PubMed1980

Separation of spontaneous-killing effector populations by target preference.

Three populations active in human spontaneous cytotoxicity have been identified. Two of these are E-rosette positive, and differ in their adherence to nylon wool. The third is E-rosette negative. The E-rosette positive fraction which does not adhere to nylon consistently does not lyse a breast-cancer-derived target, MDA-157. When tested simultaneously on 4 other tumour target cells lines--Raji, Chang, K562 and Molt 4--however, all three populations are cytolytic. The MDA-157 target is consistently lysed by a nylon-adherent T-cell fraction, irrespective of whether the E rosettes are formed under optimal or the limiting conditions giving only "high-affinity" T cells. The observation that a given effector fraction can lyse one target but not another, whereas other fractions are cytolytic on both, implies that different targets may differentiate effector populations differing in their lytic mechanism.

Animals↗