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Biomedical subjects

S Naik

Publications and source records attributed to S Naik.

At least 127 records · Page 7Linked to original sources
PubMed1987

Polymorphonuclear leukocyte functions in patients with acute rheumatic fever and rheumatic heart disease.

Polymorphonuclear (PMN) cell function was assessed in 30 children with active rheumatic fever (ARF) (Group I), 30 cases with active rheumatic heart disease (RHD) (Group II), 28 cases of ARF and RHD in remission (Group III) and 34 adults with quiescent RHD along with their age matched controls. All the groups showed normal spontaneous and chemotactic movement. Phagocytosis of yeast particles was significantly reduced in groups II (P less than 0.0005), III (P less than 0.025) and IV (P less than 0.005). The opsonic activity of disease sera was low in all 4 groups (P less than 0.0005). The intracellular metabolic activity was moderately elevated in Group III. Phagocytosis and opsonic activity were thus persistently low in all the groups including the remission and quiescent group.

Adolescent↗
PubMed1987

Cold reactive lymphocytotoxic antibodies in patients with tuberculoid and lepromatous leprosy.

Fifty-seven sera from leprosy patients and 33 sera from age- and sex-matched hospital controls were tested for the presence of cold-reacting lymphocytotoxic antibodies (LCAs) at 15 degrees C against a panel of 30 HLA-typed normal lymphocytes. Eighteen of 57 (31.6%) leprosy sera and 22 of 33 (67%) control sera showed reactivity, but the strength of reactivity of the patients' sera was significantly more than that of the control group (p less than 0.01 by Wilcoxon rank sum test). Within the leprosy group, there was no significant difference in the reactivity of 30 tuberculoid and 27 lepromatous sera. The occurrence of LCAs was independent of the sex or the HBsAg status of the serum donor. LCA activity was not correlated with treatment status, bacillary load, or reaction state.

Antilymphocyte Serum↗
PubMed1986

Attachment and long term survival of adult rat hepatocytes in primary monolayer cultures: comparison of different substrata and tissue culture media formulations.

Long-term monolayer cultures of adult rat hepatocytes were tested for their ability to glucuronize phenol red and to maintain initial levels of cell proteins, glucose consumption, and lactic acid production. Lactate dehydrogenase leakage served as an index of culture status because a high value indicates cell death. Three tissue culture (TC) media formulations were the main variables introduced to determine ideal conditions for cell survival in vitro. Investigations of long-term cultures were preceded by studies of hepatocyte attachment to polystyrene surfaces. This attachment was influenced by the amount of substrate deposited and the number of cells seeded, but not by the uniformity of the substrate coating. A statistical analysis of our data revealed that in the absence of fetal bovine serum (FBS), air dried collagen (ADC) and Biomatrix (BMX) were superior to saline precipitated collagen and fibronectin as attachment substrates. In the presence of 10% FBS, all of the substrates performed equally. Chee's Medium (CEM) proved to be the best for preserving cell proteins over a time course of 28 d and Williams' E medium also performed adequately up to 14 d. The glucuronization of phenol red was at 50% of initial values at Day 7 in CEM-ADC hepatocytes in contrast to 30% for cells in Williams' E medium and 5% for cells grown in Waymouth's. At 14 d glucuronization was still present at 40% of original values in CEM-ADC cells but had ceased in the other two media. When BMX was used, none of the TC media supported glucuronization levels comparable to ADC cells.

Animals↗
PubMed1986

Neurological complications of acute haemorrhagic conjunctivitis.

Forty four cases of the neurological complications of acute haemorrhagic conjunctivitis (AHC) seen in India during 1981 epidemic are reported. The disease predominantly affected adult males. The preceding attack of AHC, a latent period, prodromal symptoms of fever, myalgia and root pains followed by acute onset of lower motor neurone paralysis of limbs and/or cranial nerves formed the classical picture of neurological involvement. The recovery was poor and nearly half of the patients remained severely handicapped. Electrophysiological studies showed early appearance of widespread fibrillations and fasciculations, large polyphasic potentials of increased amplitude and reduced interference pattern. Nerve conduction studies were normal in most of the cases. Cerebrospinal fluid (CSF) examination revealed lymphocytic pleocytosis and rise in protein content. Significant antibody titres against enterovirus type 70 (EV 70) were demonstrated in the serum and the CSF. HLA studies showed low occurrence of A2 and B15 HLA antigens. Muscle biopsies revealed neurogenic atrophy and sural nerve biopsies were histologically unremarkable. The similarities of this disease with poliomyelitis and its pathogenesis are discussed.

Adolescent↗
PubMed1985

A novel mass spectrometric procedure for the rapid determination of the types of carbohydrate chains present in glycoproteins: application to alpha-galactosidase I from Vicia faba seeds.

A fast atom bombardment mass spectrometric protocol has been developed to determine the type of oligosaccharide chain present in glycoproteins. The procedure is based on acetolysis of the intact glycoconjugate, extraction of the peracetylated carbohydrate fragments and analysis by fast atom bombardment mass spectrometry. The molecular ions present in the FAB spectra uniquely define the composition of the oligosaccharides with respect to hexose, aminohexose and sialic acid content. High mannose oligosaccharides yield a series of peracetylated hexose oligomers whereas complex-type oligosaccharides afford a series of N-acetyl-lactosamine containing species. Fucosylation is usually not detected but sialylated oligosaccharides are readily identified and the type of sialic acid is also defined. The method has been tested on three glycoproteins of known structure - fetuin, ribonuclease B and erythrocyte Band 3 - and on a glycoprotein of unknown structure - alpha-galactosidase I, an enzyme lectin from Vicia faba. The latter is shown to contain high mannose carbohydrate chains.

Anion Exchange Protein 1, Erythrocyte↗
PubMed1983

Role of macrophage-processed antigen in a Plasmodium berghei model.

The present study demonstrates that malarial parasite could be processed by macrophages in vitro to release 'super antigens'. These super antigens obtained from the peritoneal macrophages were more protective than those processed by the splenic adherent cells. BCG-stimulated macrophages were also able to process the antigens efficiently and these antigens were even superior to those obtained from the unstimulated macrophages. These modified antigens were potent inducers of DFPS to malarial antigens. It is thus concluded that parasite antigens, processed in vitro, carry specific immunogenic potential and are able to protect the recipients to parasite challenge.

Animals↗
PubMed1983

Cross reactivity in the HLA region.

Cross-reactivity in the HLA region was studied by adsorbing each of 33 monospecific HLA antisera individually with known platelets from 90 different donors. The residual cytotoxicity following adsorption in each combination of platelet sample and antiserum was assessed against known homologous target lymphocytes. This study has confirmed a majority of the previously known cross-reactive pattern and has revealed new patterns. A more significant observation is that allelic cross-reactivity of broad antigens such as A9, A10 and Bw16, was somewhat narrowed to a given split of these antigens in several instances; e.g., cross-adsorption of A1 antiserum by Aw24, and not Aw23; of A2 antiserum by A26, and not A25; and of B5 antiserum by Bw39, and not Bw38.

Adsorption↗
PubMed1983

Cytotoxicity of a non-HLA serum towards lymphocytes from blood group B, Lewis negative and ABH secretor individuals.

Seven serum samples from a multiparous Hispanic woman (Cano) were found to be lymphocytotoxic against 2% of the cell donors in a large multiethnic cell panel. The reactivity of these sera segregated independently of the HLA region. The lymphocytotoxicity of Cano sera appeared associated with the simultaneous presence of red cell antigen B, Le (a-b-), and ABH secretor status. It could be adsorbed out by red cells from Cano-reactors, but not by those from Cano-non-reactors. Cano sera are clearly detecting a non-HLA antigen on lymphocytes. The exact relationship between this new immunogenetic system (Cano) and the ABO, Lewis and Secretor systems remains to be elucidated.

ABO Blood-Group System↗
PubMed1980

Flurbiprofen in the treatment of primary dysmenorrhoea.

1 In a double-blind crossover study, flurbiprofen produced marked relief of pain which was significantly more than with aspirin and placebo in patients suffering from primary dysmenorrhoea. In contrast, there was no significant difference between the relief of pain obtained with aspirin and placebo. 2 The clinician's overall assessment of efficacy also indicated that flurbiprofen produced better response as compared to aspirin and placebo in these patients with dysmenorrhoea. 3 Both flurbiprofen and aspirin did not produce any apparent adverse effects on blood loss during the menstrual period. 4 In conclusion, the analgesic effect of flurbiprofen seen in this trial establishes the therapeutic usefulness of the drug in the treatment of primary dysmenorrhoea.

Adolescent↗
PubMed1979

Cation transport across the guinea-pig placenta perfused in situ.

1. The guinea-pig placenta perfused in situ via the umbilical circulation has been used to measure unidirectional fluxes of Na from mother to fetus, and in the reverse direction, with 24Na and 22Na. There was no significant difference between the two fluxes, each being 22 mumole.min-1. 2. Ouabain 10(-5) M in the perfusion fluid had no detectable effect on radioisotopic movements of Na in either direction. 3. Unidirectional fluxes of 42K in both directions were approximately equal at 1.7 mumole.min-1 mother fetus and 1.8 mumole.min-1 in the reverse direction, despite a K concentration of 3.4 mM on the maternal side and 5.0 mM on the fetal side of the placenta. 4. Extraction of 42K and 86Rb from the perfusion fluid was inhibited by 43% by 10(-5) M-ouabain in the fluid. This effect was largely due to a reduction of isotope uptake by the placental tissue. 5. The relative permeabilities of the placenta, mother to fetus, were Rb approximately K (3.2) greater than Na (1.0) greater than Li (0.55). 6. Under the experimental conditions, the electrical potential difference between perfusion fluid and maternal blood was 6 mV (fetus negative). It was shifted towards the positive by a low Na fluid. 7. The results suggest the presence of a dominant Na-K pump (active component towards mother) sited at the maternal-facing membrane of the syncytiotrophoblast together with a subsidiary pump oriented in the opposite direction and probably sited together with a subsidiary pump oriented in the opposite direction and probably sited at the fetal-facing membrane of the syncytiotrophoblast. 8. A high proportion of Na movement particularly towards the fetus is probably passive, occurring through water-filled spaces, whilst K movement is more dependent on active transport.

Animals↗