Search PubMed⌕ Search

Biomedical subjects

R Sinha

Publications and source records attributed to R Sinha.

At least 145 records · Page 8Linked to original sources
PubMed1993

Significance of selenium-labeled proteins for selenium's chemopreventive functions.

A 58 kDa selenium-labeled protein purified from mouse mammary epithelial cells (MMEC) was used to examine whether selenium modulates protein synthesis or is just a marker for cellular selenium status. The protein was isolated using Sephadex G150 gel filtration and DEAE-Sephadex A50 ion-exchange chromatography. It was further analysed using 2-dimensional polyacrylamide gel electrophoresis (2D-PAGE) and was found as a single spot with a pI of 4.6. The immunoreactivity with anti-58 kDa antiserum and the 75Se signal co-localized on a single 58 kDa protein band on both 1D- and 2D-PAGE. Partial amino acid analysis of the peptide showed homology with the thiol protein disulfide oxidoreductase (TPDO). Varying the selenium concentration in culture medium did not affect the protein content or the immunoreactivity of the 58 kDa protein. Additionally, selenium did not seem to regulate the activity of TPDO in TM6 cells. The glutathione peroxidase activity of TM6 cells, taken as the internal positive control, was enhanced with the increase in selenium concentration in the medium. The results suggest that selenium is attached to the 58 kDa protein, but does not regulate either its protein synthesis or its functional activity. We conclude that selenium labeling of the 58 kDa protein reflects the cellular selenium status but probably is not involved in its chemopreventive ability.

Amino Acid Sequence↗
PubMed1993

Simple reaction time event-related potentials: effects of alcohol and sleep deprivation.

The effects of two levels of alcohol intoxication and 30 hr of sleep deprivation on visual event-related potential (ERP) waveforms concomitant to simple reaction time (RT) were examined in 54 normal male subjects. In a previous study, we reported that alcohol and sleep deprivation each increased RT. At a 0.05 breath alcohol concentration (BAC), the combined treatments produced an additive increase in RT, whereas at a 0.08 BAC the combined treatments produced no increase beyond that seen with each alone. In this study we present the ERP findings. Sleep deprivation alone increased the latency of a 150 msec negative component (N1) of the ERP. Alcohol increased the latency of a 250 msec negative component (N2), but only in the absence of sleep deprivation. Furthermore, this increased latency of N2 was correlated with RT measures. These results suggested that sleep deprivation slowed initial stimulus detection, whereas alcohol slowed later processing and response activation.

Adult↗
PubMed1993

Importance of bone marrow culture for diagnosis of Kala azar.

Kala azar was diagnosed in 45 clinically suspected cases following bone marrow smear examination and in vitro culture of the aspirate. Bone marrow aspiration smear examination revealed amastigotes in 27 cases (60%). In vitro culture of the aspirate demonstrated leishmania parasites in 44 cases (97.8%). A total of 18 cases (40%) were negative for amastigotes in smear examinations but parasites could be demonstrated by culturing the same aspirates. The in vitro culture of bone marrow is necessary to diagnose Kala azar and is strongly recommended to be performed along with the bone marrow smear examination.

Adolescent↗
PubMed1993

Hypertension care in general practice: an opinion survey.

An opinion survey was conducted among 60 general practitioners from different parts of West Bengal with 6 prefixed questions covering some practical issues of hypertension. Fifty-eight doctors responded. In the opinion of the majority, 160 mm of Hg (systolic) and 90 mm of Hg (diastolic) are the cut off pressure to diagnose hypertension. Forty-eight per cent of the practitioners opined that a period of observation is necessary before antihypertensives were started. Eighty-seven per cent of the practitioners would start their patients on antihypertensive drugs well before the blood pressure reached 160/104 mm of Hg. High diastolic pressure was thought to be dangerous by 50% doctors and both high systolic and diastolic pressures were thought to be dangerous by 43% doctors. Fifty-two per cent practitioners opined that 140/90 mm of Hg should be the target blood pressure after treatment. Most of them (63%) opined that antihypertensive treatment should be continued life long. Practitioner's opinion were analysed in the light of current international literatures on basic therapeutic approaches to hypertension with emphasis on certain issues of controversy.

Antihypertensive Agents↗
PubMed1992

Long-term test-retest reliability of event-related potentials in normals and alcoholics.

The long-term test-retest reliability of event-related potentials (ERP) measures was examined in a group of 44 controls and 71 chronic alcoholics, retested after an average of 14 months. Correlational analyses revealed moderately significant test-retest correlations for visual and auditory target N1, N2, and P3 amplitudes, with significant correlations for N1, N2 and P3 latencies. Controls and alcoholics produced similar test-retest correlations for visual and auditory ERP measures. Men and women produced equally stable ERP measures over time. Overall N1 and P3 amplitudes were most reliable in both groups followed by N2 amplitude, N1 and N2 latency, and P3 latency. The stability of ERP measures found in this study over a 14-month period in both normals and chronic alcoholics supports the use of ERPs in the study of normal and disordered cognitive functioning.

Adult↗
PubMed1992

Humoral antibody response in Leishmania tropica infection.

A small epidemic of Leishmania tropica infection was detected in Rajasthan, India. Most cases were in the 21-25 years age group and were possibly related to outdoor activity. Nearly one third of the patients had more than five lesions, the maximum number of lesions being confined to the face, neck and extremities. As determined by ELISA, 90% cases had leishmania antibodies with an OD range of 0.8-1.1. The serum of 60% of patients was positive by CIEP against L. tropica promastigote soluble antigen. By immunofluorescence, 96% persons were positive when L. tropica promastigotes were used as the substrate. The prevalence of infection with L. tropica appears to be much higher than that reported earlier.

Adolescent↗
PubMed1992

Detection of leishmania antigen in kala azar patients using monoclonal antibodies.

Twenty-one monoclonal antibodies were produced against promastigote antigens of Leishmania donovani. Five monoclonal antibodies (Hyb.17, 6, 5, 4 and 2) identifying molecules associated with various L. donovani antigenic determinants ranging from 42-116 kDa were selected as 'capture antibodies' and compared with specific anti-leishmania antisera for detection of circulating leishmania antigens in kala azar patients' sera in a competitive-enzyme-linked immunosorbent assay system (ELISA). The anti-leishmania antisera could detect circulating antigen in 30% of kala azar cases while out of the five monoclonals, Hyb.17 could effectively detect circulating leishmania antigen in 85.4%. The efficacy of Hyb.6 was however low (31.7%). The antigens recognized by these monoclonal antibodies in the western blot assay could possibly represent the ones circulating in sera of patients suffering from kala azar. A cocktail of these monoclonal antibodies may be more useful than the conventional polyclonal antisera in detection of circulating antigen for clinical diagnosis of kala azar.

Animals↗
PubMed1991

Use of in vitro method to assess different brands of anti-leishmanial drugs.

Reports in the literature indicate the use of animal models for testing newer anti-leishmanial drugs in vivo. However, in certain established cell lines and macrophages in vitro models have the advantage over the in vivo system of simplicity and speed with which the results can be obtained. A simple in vitro system using peritoneal exudate macrophages of BALB/c mice infected with Leishmania donovani promastigotes has been tested for its use in determining the efficacy of several new drugs. Two well-established drugs, amphotericin B and sodium stibogluconate, as expected, could kill the intracellular parasites effectively. Two relatively new drugs not routinely used against leishmania, rifampicin and metronidazole at concentrations of 20 micrograms/ml and 10 micrograms/ml, respectively, were also able to kill the intracellular leishmania parasites effectively. Critical factors for drug testing in vitro have been elucidated: the most important being the temperature of incubation after infection.

Animals↗
PubMed1990

Quantification of tremor with a digitizing tablet.

Handwriting and drawing are commonly employed in the clinical assessment of tremor. These tasks have been quantified heretofore by subjective rating schemes, which are incapable of providing precise measures of the amplitude and frequency of tremor. A commercially-available digitizing tablet and personal computer can be interfaced so as to reliably record any pathologic tremor that is induced by writing or drawing. Numerical differentiation and spectral analysis can be used to conveniently quantify the amplitude and frequency of tremor. However, digitizing tablets lack sufficient sensitivity to measure physiologic tremor.

Handwriting↗
PubMed1990

Post-testicular antifertility effects of Abrus precatorius seed extract in albino rats.

Oral administration of a 50% ethanol extract of Abrus precatorius seeds (250 mg/kg) in albino rats for 30 and 60 days induced an absolute infertility in males which was reversible. Suppression of sperm motility in the cauda epididymis was the most pronounced effect of the treatment. Such treatment may affect the oxidative/energy metabolism of the cauda epididymis. Histological and histocytometric observations in testis and parareproductive tissues appeared normal while the protein, sialic acid, acid phosphatase and succinic dehydrogenase levels were significantly depleted.

Acid Phosphatase↗
PubMed1990

Immediate closed reduction of cervical spine dislocations using traction.

Cervical facet dislocations may be reduced rapidly and effectively using axial traction with weights applied at over the traditional 45-pound limit. Fifty-three sequential patients with cervical facet dislocations were reviewed. Thirty-nine patients required more than 50 pounds of traction to achieve rapid reduction. Sixty-eight percent of the entire series showed significant improvement in neurologic function. There were no cases of significant loss of function. A cadaver study confirmed that the cranial tongs could support over 100 pounds of traction. Careful application of up to 100 pounds seems to be associated with a low risk of neurologic compromise or tong failure, but results in effective reduction of dislocations.

Aged↗
PubMed1990

Relationships between neuropsychological test performance and event-related potentials in alcoholic and nonalcoholic samples.

Are event-related potentials and nonconcurrently measured neuropsychological test performance correlated? Sober male and female middle-aged alcoholics and peer controls were administered an "oddball" event-related potential (ERP) task and several hours later, a battery of neuropsychological (NP) tests. Alcoholics performed significantly poorer than controls on NP tests. Male alcoholics had significantly altered ERP responses (N1, NdA, and P3 amplitudes) but female alcoholics did not differ on any ERP variables from controls. A number of significant correlations between ERP and NP measures were present. The most consistent findings were positive correlations between perceptual-motor (PM) tests and the P3 amplitude at Pz in both male and female alcoholics and in male alcoholics, a negative correlation between PM tests and P3 latency at Pz, findings similar to those seen in Parkinson patients. Significant correlations were most numerous in family history positive alcoholics. The results lead to two conclusions: first, Grant's postulation that sober alcoholics may manifest an intermediate duration organic mental disorder is supported; second, given the lack of ERP differences in the females, ERP measures should not be considered as being causally related to NP performance.

Adult↗