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Biomedical subjects

B Singh

Publications and source records attributed to B Singh.

At least 829 records · Page 46Linked to original sources
PubMed1981

Mapping of evoked responses from different areas of hypothalamus on stimulation of spermatic nerve in monkeys.

Stainless steel pedestal was implanted on the skull of 12 adult anesthetized rhesus monkeys, according to the predetermined stereotaxic coordinates of hypothalamus. For recording, conscious monkey was made to sit on its chair in a shielded cage to minimize interfering artifacts. Spermatic nerves were stimulated with concentric needle electrodes inserted into undissected portion of the spermatic cord and evoked responses were recorded from a number of hypothalamic areas. Responses with initial negative and positive phases appeared in the anteromedial and posterior hypothalamic regions respectively. The middle medial portions of hypothalamus showed non-conductive local activity, while the lateral regions at the same anteroposterior co-ordinates gave responses, which showed a positive negative response more on a pattern of primary sensory motor cortex. The results indicate smaller latency zones in medial part and longer latency in anterior and posterior parts, and suggest that hypothalamic excitation occurs via periventricular fiber system.

Animals↗
PubMed1981

Cell-mediated immune response in anaplasmosis in cattle.

The cell-mediated immune response (CMIR) was demonstrated during experimental Anaplasma marginale infection in cattle, in vivo by the intradermic skin test and in vitro by the leucocyte migration inhibition test (LMIT). The skin test showed a delayed hypersensitivity reaction which reached its maximum after 48-72 hours. Histopathological examination of the skin biopsies revealed excessive infiltration by mononuclear cells and accumulation of oedematous fluid in the deeper dermal layers. For LMIT, the particulate antigen was used and the inhibition of leucocyte migration was significant in vaccinated and carrier animals as compared to controls.

Anaplasmosis↗
PubMed1981

A mercuric iodide detector unit implantable and externally powered for use in radionuclide tracer studies in small animals.

A small externally powered implantable gamma-radiation detector unit (35 X 12 mm diameter containing a mercuric iodide detector (HgI2), charge amplifier, radiotransmitter and an inductive power supply has been constructed. Since the total weight of the device is 5 g, it is suitable for implantation in laboratory animals such as rats or hamsters. A comparison between the implanted HgI2 detector unit and a conventional stationary 2 X 2 inch NaI(TI) detector has been performed by simultaneous measurements of the 133Xe clearance from a depot. Using 125I-iothalamate a kidney function study of an unrestrained hamster is shown as an example of measurements in the unrestrained animal.

Animals↗
PubMed1980

Disaster: the helper's perspective.

The responses to disaster and death vary enormously, but there is much to suggest that they are not confined to those who are directly affected. The helpers, too, may be "victims" of the disaster, and it is important that their psychological needs are perceived and met. There is an indication that, if this is done, considerable psychological morbidity may be prevented.

Disasters↗
PubMed1980

Inhibitory effect of glucose and adenosine 3',5'-monophosphate on the synthesis of inducible N-acetylglucosamine catabolic enzymes in yeast.

Glucose can block the utilization of N-acetylglucosamine in Saccharomyces cerevisiae, a facultative aerobe, but not in Candida albicans, an obligatory aerobe. Furthermore, glucose represses the synthesis of the enzymes of the N-acetylglucosamine catabolic pathway in S. cerevisiae, but not in C. albicans. The results suggest that catabolite repression is present in S. cerevisiae, but not in C. albicans. Cyclic AMP added to S. cerevisiae cells maintained in a glucose medium cannot bring about their release from catabolite repression. On the contrary, the synthesis of inducible enzymes of N-acetylglucosamine pathway was inhibited by cyclic AMP in both the yeasts. This seems to indicate that cyclic AMP can penetrate into the yeast cells. Furthermore, cyclic AMP inhibits protein synthesis, suggesting that protein synthesis in yeast is under cyclic AMP control.

Acetylglucosamine↗
PubMed1980

Purification and some properties of inducible N-acetylglucosamine kinase from Candida albicans.

N-Acetylglucosamine kinase (ATP:2-acetamido-2-deoxy-D-glucose 6-phosphotransferase, EC 2.7.1.59) catalyzes the first reaction in the inducible N-acetylglucosamine catabolic pathway of Candida albicans, an obligatory aerobic yeast. As a part of continuing biochemical studies concerning the regulation of gene expression in a simple eukaryote, N-acetylglucosamine kinase has been purified and characterized biochemically. The enzyme has been purified about 300-fold from the crude extract and its molecular weight of 75 000 has been determined by Sephadex G-100 gel filtration. Isolation and analysis procedures are described. The kinase reaction is optimal within a pH range of 7--8. The enzyme is strictly specific for GlcNAc as phosphate acceptor; ATP is the phosphoryl group donor for the kinase reaction and to a lesser extent dATP and CTP. Km values for GlcNAc and ATP are 1.33 mM and 1.82 mM, respectively. The enzyme required Mg2+, which may be replaced by other bivalent metal ions such as Mn2+, Ca2+, Ba2+ and Co2+ for a lesser degree of effectiveness. The purified enzyme is extremely sensitive to thermal denaturation and becomes completely inactive by heating at 65% C for 2 min. The enzyme is also inactivated by sulphydryl reagents such as p-chloromercuribenzene sulfonic acid and N-ethylmaleimide.

Candida albicans↗
PubMed1980

Extramammary cystosarcoma phyllodes with bilateral breast involvement.

A 30-year-old woman presented with breast masses. One of the breast masses was clinically suggestive of cystosarcoma phyllodes. Excision of the breast masses revealed bilateral cystosarcoma phyllodes. A few weeks later another lump appeared in the left groin, and this on excision was found to be cystosarcoma phyllodes at an aberrant site. We consider it a unique clinical presentation of cystosarcoma phyllodes.

Adult↗
PubMed1980

Inducible N-acetyglucosamine-binding protein in yeasts.

Addition of N-acetylglucosamine (GlcNAc) to the medium elicits an immediate synthesis of a specific GlcNAc-binding protein in yeasts. Synthesis of this protein requires the continuous presence of GlcNAc as the inducer and is inhibited completely by the inhibitors of ribonucleic acid and protein syntheses. Furthermore, this protein has been partially purified from GlcNAc-grown Candida albicans cells and is quite distinct from the other induced enzymes of the GlcNAc catabolic pathway. A good correlation between the level of GlcNAc-binding protein and GlcNAc uptake capacity of the cells during induction was observed. Some of the sugars, e.g., N-acetylmannosamine, N-acetylgalactosamine, and glucose, had a similar competitive effect on the binding of GlcNAc as well as on its uptake. Furthermore, both the binding and uptake activities were sensitive to sulfhydryl reagents.

Acetylglucosamine↗