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Biomedical subjects

K S Reddy

Publications and source records attributed to K S Reddy.

At least 127 records · Page 7Linked to original sources
PubMed1992

Indian medical journals.

Although Indian doctors produce half the articles published from the third world, little has been written about Indian medical journals. We examined 75 of the 113 serious English-language journals published in India. Of the 22 included in the Cumulated Index Medicus only 8 were judged by Indian and foreign referees to be of international standard. A survey of Indian authors indicated that foreign journals were chosen for the best papers because of their wider circulation, better refereeing practices, and punctuality. More than 98% of medical articles from India probably go unnoticed by the international medical community.

Attitude of Health Personnel↗
PubMed1992

Myocardial systolic function in systemic lupus erythematosus: a study based on radionuclide ventriculography.

We assessed left ventricular systolic function by means of radionuclide ventriculography in 20 consecutive unselected patients with systemic lupus erythematosus. All patients had normal left ventricular systolic function (defined as ejection fraction greater than 45%) in a resting state. Regional wall motion abnormalities were, however, seen in 4 patients (20%). Of these 20 patients, 8 were able to exercise on a bicycle ergometer. These patients were subjected to exercise radionuclide ventriculography. Of these 8 patients, 3 (37.5%) had an abnormal ventriculographic response to exercise (as evidenced by a subnormal rise in ejection fraction or a fall, appearance of a new regional wall motion abnormality or worsening of a pre-existing one). This probably reflects subclinical left ventricular dysfunction unmasked by the stress of exercise. The clinical significance of these abnormalities on long-term myocardial function and their possible reversibility with remission of the disease needs to be assessed in future studies.

Adolescent↗
PubMed1992

Evaluation of post-operative stay after inpatient major surgery--a prospective study.

The present study was carried out at a single surgical unit of AIIMS, to evaluate the risk and benefit of short post-operative stay in adult population after inpatient surgery under general anaesthesia for various intra-abdominal, Genitourinary, breast and thyroid disorders including emergency procedures. The age of the patients ranged from 17-71 years. Patients with minor surgical procedures were excluded from the study. A total number of 138 patients were included in the study comprising of Test group. The patients were discharged within 5 days of the operative procedure. There was no major morbidity or mortality related to early discharge. The mean duration of postoperative length of hospital stay was 5.25 days in test group of patients as compared to 10.20 in control group of patients. In conclusion therefore, short hospitals stay following major procedures is safe and effective in reducing the cost of hospital care to the patient and hospital both.

Adult↗
PubMed1991

Structural differences in solution and crystalline forms of met-myoglobin.

For several decades X-ray diffraction studies have been the paragon of biological structure studies at atomic resolution. Diffraction provides three-dimensional structure information, which is essential to our fundamental understanding of protein function. However, since X-ray diffraction cannot be done to atomic resolution on proteins in their native solution or membrane-bound state, the possibility exists that the conformations of the protein in crystals are slightly different from the conformations in solution, and attempts to interpret details of the structure may be misleading and without physiological relevance. In this paper, we show that this concern is justified for a familiar protein, myoglobin. Performing X-ray absorption fine structure experiments on both solution and crystalline met-myoglobin (met-Mb), we find significant differences in the local environment of the iron between the two states. Specifically, the average iron-nearest neighbor atom distance in the crystalline form is 0.05 A shorter than that in the solution form, and the iron-nearest neighbor bond is more rigid in the crystalline met-Mb. Possible artifactual explanations for the differences have been ruled out.

Animals↗
PubMed1991

The vanishing twin: an explanation for discordance between chorionic villus karyotype and fetal phenotype.

One 'erroneous' diagnosis occurred in 200 first-trimester chorionic villus samples (CVS) analysed. In direct preparations following 24 h incubation as well as in long-term cultures, a 46,XX karyotype was observed in the villi (28 and 25 cells, respectively). At 20 weeks of gestation, labour was induced because of fetal death in utero. An autopsy performed on the fetus revealed a male phenotype. Placenta and fetal tissues were not submitted for cytogenetic studies. The discordant CVS karyotype (46,XX), in view of the male fetal phenotype, prompted further cytogenetic and molecular studies. Chromosome marker studies on the parents' blood and chorionic villi confirmed both maternal and paternal inheritance of chromosomes in the CVS. DNA studies on formalin-fixed skin using a Y-specific probe, DYZ1, confirmed the presence of a Y chromosome in the fetus. The most likely cause of the discrepant CVS karyotype is the presence of an undetected degenerating dizygotic twin.

Adult↗
PubMed1991

Active site conformation in myoglobin as determined by X-ray absorption spectroscopy.

X-ray absorption fine structure experiments were performed to study structural and dynamic aspects of the active site of various forms of myoglobin. The structures determined for deoxyMb, MbCO, and MbO2 are consistent with the structure established by X-ray absorption fine structure experiment and X-ray crystallography. The first shell of ferrous MbNO determined contains 5 nitrogens located at 2.02 A and a short NO bond length of 1.76 A. This study focuses on the change of the XAFS Debye-Waller factor with temperature, which is a measure of thermal and static disorder. It was found that the changes of Debye-Waller factor with temperature for the Mb proteins, except deoxyMb, are consistent with a simple Einstein model, in which a single frequency was assumed for the bond stretching modes. In contrast, the temperature dependence of deoxyMb cannot be fitted to the Einstein model and a large disorder was found at low temperatures, which indicates the existence of conformational substates of the active site.

Animals↗
PubMed1991

A review of fallopian tube carcinoma over 20 years (1971-90) in Pondicherry.

Nine cases of tubal carcinoma were found in a period of 20 years in JIPMER Hospital among approximately 9,000 gynaecological malignancies. Most patients were diagnosed as malignant ovarian tumour, but two cases presented unusually, one as Meig's syndrome and another as acute hemoperitoneum. This often stressed symptom of amber discharge or hydrops tubae profluens could not be elicited in any patient. All the patients underwent surgical treatment and radiotherapy or chemotherapy. The period of follow up ranged from two months to four and half years.

Adult↗
PubMed1990

A role for the metal binding domain in determining the DNA sequence selectivity of Fe-bleomycin.

Previous studies of Fe-bleomycin-mediated DNA cleavage have established that the bithiazole moiety + C-terminal substituent of bleomycin are required for DNA binding, while the metal binding domain is responsible for O2 activation. Although recent studies have indicated that the metal binding domain also participates in DNA unwinding, and in determining the sequence and strand selectivity of DNA cleavage, no study has defined the structural domain that bears primary responsibility for the observed pattern of bleomycin-mediated DNA degradation. Presently, by the use of four synthetic analogs of bleomycin demethyl A2 having the functional domains connected by rigid spacers of varying lengths, the source of DNA cleavage specificity has been determined. When the four analogs cleaved 242- and 127-base pair 5'-32P-end-labeled DNA restriction fragments containing isolated Fe-bleomycin cleavage sites, all four produced cleavage at the same preferred sites. Because the (oligo)glycine spacers altered the distance between the domains by as much as 14 A, the identical cleavage patterns argue that the primary determinant of sequence specificity for these analogs is the metal binding domain.

Base Sequence↗
PubMed1990

The significance of trisomy 7 mosaicism in chorionic villus cultures.

Two cases of mosaic trisomy 7 confined to the cultured cells and not found in direct preparation were detected from 200 consecutive first-trimester chorionic villus samples (CVS) analysed. The mosaicism was similar in the two cases, but the pregnancy outcome was different. In both cases, the direct metaphases from the CVS were 46,XY. Culture metaphases were mos46,XY/47,XY, +7; the trisomy 7 was seen in 34 per cent of cells from case 1 and 53 per cent from case 2. A sonogram at 15 1/2 weeks revealed fetal death in utero in case 1, and the patient declined amniocentesis. The fetal tissue failed to grow in culture, but the placental cultured cells were 47,XY, +7 in 28 (100 per cent) cells analysed. In the second case, all the amniotic fluid cells were 46,XY and the pregnancy resulted in a normal male with a 46,XY karyotype in the cord blood and foreskin fibroblast cultures. The term placenta was mosaic with 13/163 (8 per cent) trisomy 7 cells. Extensive cytogenetic studies on the placenta for the first time confirmed trisomy 7 mosaicism confined to the villus cultures.

Adult↗
PubMed1989

Lymphocyte subsets in acute rheumatic fever and rheumatic heart disease.

Lymphocyte subsets in 53 patients with acute rheumatic fever and 78 patients with chronic rheumatic heart disease were compared with 20 normal control subjects and 39 patients suffering from uncomplicated streptococcal pharyngitis to obtain information about the pathogenesis of the disease. Twenty patients with rheumatic fever were followed for 24 weeks to evaluate changes occurring over the course of the disease. Total leukocyte and lymphocyte counts were increased in patients with rheumatic fever and to a lesser extent in those with rheumatic heart disease, when compared with controls. The difference between the two groups was significant. Patients with acute rheumatic fever had an increased number of B cells and a smaller increase in total T and T-helper-inducer (CD-4) cells. The proportion of B cells increased, while that of T-suppressor-cytotoxic (CD-8) cells fell. An increased number and proportion of B cells was also seen in patients with rheumatic heart disease. Total T and T-helper lymphocyte percentages and numbers were significantly higher in patients with rheumatic fever compared with those of patients with rheumatic heart disease. Follow-up studies at 6, 12, and 24 weeks revealed no significant differences from the entry point studies, although there was a trend toward reduction in the degree of derangement from normal values. Patients with uncomplicated streptococcal pharyngitis, however, did not show perturbations in the T-cell and T-subset counts. Our study suggests that the immunoregulatory defect in acute rheumatic fever is characterized by a relative reduction of suppressor T cells with an absolute increase in helper T cells and B cells, resulting in an increased cellular as well as humoral immune response.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Disease↗
PubMed1989

HLA-DR/DQ antigens and reactivity to B cell alloantigen D8/17 in Indian patients with rheumatic heart disease.

D8/17, a B cell alloantigen, and its occurrence with DR/DQ antigens was examined in 54 patients with rheumatic heart disease and matched North Indian controls. Thirty-four patients (62.9%) carried D8/17 as compared with a frequency of 12.5% in controls (chi 2 by Yates', 18.75; p less than 0.0001). A marginally increased frequency of human leukocyte antigen (HLA)-DR3 (44.2% vs. 28.8%) and a significantly reduced frequency of HLA-DR2 (21.1% vs. 46.6%; p less than 0.005) was observed in patients as compared with controls. However, the most significant positive association was observed with HLA-DQw2 (63.4% in patients and 31.5% in controls; chi 2 by Yates', 9.85; p less than 0.005). The DQw2 association was significant only in the D8/17-positive patients. These observations suggest that the disease susceptibility gene in rheumatic heart disease may be nearer to the HLA-DQ locus than to the HLA-DR.

Antigens, Differentiation, B-Lymphocyte↗
PubMed1988

Replication kinetics of X chromosomes in fibroblasts and lymphocytes.

The kinetics of replication for early and late replicating X chromosomes in karyotypically normal fibroblasts and lymphocytes was studied using terminal bromodeoxyuridine (BrdU) treatment followed by Hoechst/light/Giemsa staining. Although the order of band appearance differs between the two tissues, the programme (order and interval between band appearances) for early replicating bands (dark R-bands) is identical in the two homologues. This is probably also the case for later replicating bands (dark G-bands) though the criteria for determining mean band appearance times are less reliable for these bands when terminal BrdU treatment is used. This means that the late X has a delayed start but thereafter proceeds at the same pace as its early counterpart.

Bromodeoxyuridine↗