Biomedical subjects
S Chatterjee
Publications and source records attributed to S Chatterjee.
Harvard step test as a measure of physical fitness in adolescent boys.
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Systemic sarcoidosis involving the breast.
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Ammonia-induced change in the hepatic glutathione level of an air-breathing freshwater teleost Channa punctatus (Bloch).
Exposure to ammonia (NH4OH) for 48 h resulted in greater than 50% depletion of the hepatic glutathione pool in Channa punctatus (Bloch). Removal of fish to ammonia free ambience induced a rapid and excessive resynthesis of glutathione within 24 h. This level, however, decreased within 5 days of return to ammonia-free fresh water. It is concluded that ammonia stress in a freshwater air-breathing teleost is counteracted by the glutathione system of detoxication of xenobiotics and resynthesis of glutathione is induced by short-term exposure to ammonia followed by transfer to ammonia-free water.
Localization of urinary lactosylceramide in cytoplasmic vesicles of renal tubular cells in homozygous familial hypercholesterolemia.
An average 15-fold increase in lactosylceramide (LacCer) in the sediment of receptor-negative, familial hypercholesterolemic (FH) homozygotes has been reported [Chatterjee, S., Sekerke, C.S. & Kwiterovich, P.O., Jr. (1982) J. Lipid Res. 23, 513-522]. We report here the abnormal urinary excretion of significant numbers of renal tubular cells in eight FH homozygotes. The mean activity of gamma-glutamyltransferase, a marker for renal tubular cells, was twice as high in urinary sediment of FH homozygotes as in normals. Membrane-enclosed cytoplasmic vesicles that stained strongly positive with a fluorescein-labeled antibody against LacCer were found in the renal tubular cells of all homozygotes except two who had undergone a portacaval shunt. These two had normal urinary levels of LacCer, and the cytoplasmic vesicles were vacuolated. In the other six, most of the fluorescent antibody label was intracellular and perinuclear. The cytoplasmic vesicles stained strongly with polychromatic Papanicolaou stain, periodic acid/Schiff reagent, and oil red O. Electron microscopy revealed perinuclear membrane-enclosed lipid and free lipid droplets. When two FH homozygotes, who excreted increased LacCer, underwent plasma exchange, the cytoplasmic vesicles became empty, and the urinary LacCer level decreased into the normal range. We conclude that the increased urinary excretion of LacCer in FH homozygotes occurs in renal tubular cells and that the intracellular locatin of LacCer is within cytoplasmic vesicles. The presence of LacCer within these vesicles can be modulated by treatment with plasma exchange.
Immunomodulatory role of thyroid hormones: in vivo effect of thyroid hormones on the blastogenic response of lymphoid tissues.
In an attempt to find out the mechanism of immunomodulation by thyroid hormones (T3 and T4), their in vivo effect on the blastogenic response of lymphocytes from various lymphoid tissues of hormone-treated and thyroidectomized rats were studied. The blastogenic response of lymphocytes from thymus, peripheral blood and mesenteric lymph nodes to pokeweed mitogen (PWM) was found to be increased significantly following T3 or T4 administration for 15 days or 30 days. However, the response to phytohaemagglutinin (PHA) increased only after 1 month of T3 or T4 administration. The blastogenic response of spleen cells to both PHA and PWM was, on the other hand, found to be depressed following 15 days of hormone administration. Thyroidectomy invariably induced significant depression in the blastogenic response to both PHA and PWM in lymphocytes of all the lymphoid tissues. Thyroid hormone (T3) administration was found to restore the blastogenic response of the lymphocytes of thyroidectomized animals.
Systemic and neuro-sarcoidosis in a child.
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Terbutaline in the management of acute intrapartum fetal acidosis.
A beta 2-mimetic agent, terbutaline, was used before full cervical dilatation in 10 of 18 cases of fetal distress evidenced by fetal scalp blood pH (FSB-pH) less than 7.25. A reduction in uterine activity with an improvement in the fetal heart rate trace was seen in all the cases. In addition, a significant improvement in FSB-pH, when compared with umbilical artery pH (p less than 0.05), was noted whereas there was no significant change in the untreated cases. An Apgar score of less than or equal to 6 at five minutes occurred in two of eight untreated patients but not in any treated patients.
Complement components in kidney allograft recipients: relationship to cytomegalovirus infection.
Serum complement profiles of 19 renal transplant recipients were studied serially before and after renal transplantation to determine if there is any relationship between cytomegalovirus (CMV) infection and alteration in the serum complement (C) levels. Most patients had low serum C3 and C4 levels before transplantation, but afterwards these levels increased in some patients. Clq was elevated before and after transplantation. Factor B was low before transplantation, but after surgery, its level approached normal in patients without cytomegalovirus viremia, whereas in those with viremia, Factor B level became even more depressed. Circulating Factor B fragments were found in the sera of five out of seven patients with active cytomegalovirus infection, which suggests activation of the alternative pathway possibly related to active CMV infection.
Comparison of cytosol estrogen receptor status in ovarian carcinoma using different radiolabeled ligands and methods.
It is not uncommon to find more than one class of steroid hormone receptors present in a given tissue specimen. In this study we compared methods with different ligands and incubation conditions. Samples were also assayed using the dextran-coated charcoal as well as sucrose gradient. The purpose of this paper is to show the need for a standardization of technique if we are to draw meaningful conclusions from the values obtained by different workers. Whereas normal ovaries and benign ovarian lesions lacked estrogen receptors, the presence of estrogen receptor was confirmed in malignant ovarian lesions.
A glutamic acid producing Streptomyces sp.
Following the bioautographic technique, a strain of Streptomyces sp. has been isolated producing L-glutamic acid. The strain in able to grow and produce glutamate in mineral salt medium, but supplementation with yeast extract improved the yield.
Survival and mutation of Chinese hamster cells after ultraviolet irradiation and caffeine treatment.
UV-irradiated Chinese hamster cells on post-irradiation treatment with caffeine in growth medium for 24 h gave rise to biphasic UV-survival curves. At caffeine concentrations between 0.001 and 0.1 mM, control and caffeine-grown cells had similar survival curves initially from 0 to 30 J/m2. At fluences greater than 30 J/m2, there was effectively only little further killing of caffeine-grown cells beyond that observed at 30 J/m2. At concentrations of caffeine greater than 0.5 mM, there was a gradual sensitization in the early part of the survival curve with increasing caffeine concentrations; but at fluences greater than 30 J/m2, the slopes in the survival curves decreased very much. It has been proposed that the initial sensitization observed at low UV fluences is due to the suppression of post-replication repair by caffeine. After high fluences of UV exposures in these excision-deficient cells, in the presence of caffeine, the possibility of an induced 'SOS'-like repair process has been suggested. This suggestion was supported by the observation that caffeine increased the yield of the UV-induced 8-azaguanine-resistant mutants only for the cell population exposed to UV fluences greater than 30 J/m2.
Interferon inhibits Sendai virus-induced cell fusion: an effect on cell membrane fluidity.
Interferon can affect several cellular functions, in addition to its antiviral activity. We report here that pretreatment of human cells with homologous interferon significantly inhibits cell fusion induced by Sendai virus and that this refractory state is accompanied by a decrease in cell plasma membrane fluidity. Multinucleate cell formation induced by beta-propiolactone-inactivated Sendai virus in human fibroblast cells (a system in which fusion results from an interaction of the viral glycoprotein with the cell membrane) was inhibited by more than 90% after addition of human interferon for 18-24 hr. This inhibition could be neutralized by antiserum to interferon. Furthermore, inhibitor studies with cycloheximide and actinomycin D clearly indicated that synthesis of protein and RNA is necessary to establish the resistant state. To determine whether the inhibition of Sendai virus-induced cell fusion resulted from interferon-induced changes at the cell plasma membrane, experiments were carried out using the fluorescence probe 1,6-diphenyl-1,3,5-hexatriene, which is capable of sensing molecular motions in the hydrocarbon core of the bilayer structure. A significant decrease in the membrane fluidity of interferon-treated cells was observed. It is likely, therefore, that the inhibitory effect on Sendai virus-induced cell fusion observed in interferon-treated cells results from an increased rigidity of the target cell membrane.
Treatment with anti-Ia and antiblast/monocyte monoclonal antibodies can prolong skin allograft survival in nonhuman primates.
Two monoclonal antibodies, one directed against human Ia antigens and the other reactive to both monocytes and blast cells, were evaluated for prolonging skin graft survival in Rhesus monkeys. Various doses of the antibodies were given intravenously until the skin graft was rejected. Compared with a graft survival of five days for untreated control monkeys, five animals receiving anti-Ia had grafts surviving from 13 to 19 days and six animals treated with antiblast/monocyte antibody had grafts surviving from 15 to 22 days. No adverse side effects were seen with treatment with antiblast/monocyte antibodies. However, the dose of anti-Ia antibody was critical in that four monkeys died of anaphylaxis when injected with amounts exceeding 200 microliters of ascites with a titer of 1:10(5).
The role of lymphocytes in infections due to Epstein-Barr virus and cytomegalovirus.
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Effect of monensin on Mason-Pfizer monkey virus glycoprotein synthesis.
The effect of the monovalent carboxylic ionophore monensin on the biosynthesis, intracellular transport, and surface expression of the glycoproteins of Mason-Pfizer monkey virus was examined. Cells treated with monensin at concentrations of 10(-7) or 10(-6) M continued to synthesize virus particles, which from electron microscopic studies appeared to bud normally from the plasma membrane of the cells. However, the particles released had an altered buoyant density in sucrose gradients and were noninfectious. These noninfectious virions had a normal complement of non-glycosylated polypeptides but showed a significantly reduced amount of glycosylated proteins. The gp70 and gp20 polypeptides appeared to be completely absent, and a heterogeneous, higher-molecular-weight protein was observed on the virions instead. Studies on intracellular protein synthesis indicated that the precursor (Pr86env) to gp70 and gp20 is synthesized normally but is not cleaved to the mature proteins. Immunofluorescence studies showed, however, that the uncleaved molecule is expressed on the cell surface. In this system, therefore, Mason-Pfizer monkey virus glycoprotein migration appears to occur in the presence of monensin, whereas the cleavage and insertion of the glycoproteins into virions are inhibited.
Catabolite repression in Streptomyces venezuelae. Induction of beta-galactosidase, chloramphenicol production, and intracellular cyclic adenosine 3',5'-monophosphate concentrations.
Chloramphenicol production was studied in cultures of Streptomyces venezuelae growing in a simple buffered medium with ammonia as the nitrogen source and glucose, lactose, or a glucose-lactose mixture as the sole source of carbon. With each carbon source the antibiotic was formed during growth. In the glucose-lactose medium, the production pattern was biphasic; a marked decrease in the rate of synthesis was associated with depletion of glucose from the medium and a corresponding diauxie pause in growth. Cells of S. venezuelae contained an inducible beta-galactosidase. Induction by lactose was suppressed by glucose. Measurement of the concentration of intracellular adenosine 3',5'-cyclic monophosphate during growth of cultures with glucose or a glucose-lactose mixture as the source of carbon showed no appreciable changes coinciding with depletion of glucose or the onset of chloramphenicol biosynthesis. It is concluded that the cyclic nucleotide does not mediate selective nutrient utilization or control antibiotic biosynthesis in this organism.
Glucose suppression of beta-glucosidase activity in a chloramphenicol-producing strain of Streptomyces venezuelae.
beta-Glucosidase activity was induced in Streptomyces venezuelae during growth on cellobiose, gentiobiose, salicin, methyl beta-glucoside, and p-nitrophenyl beta-D-glucopyranoside. Activity in cell extracts was separated by DEAE-cellulose chromatography into two fractions differing in substrate preference. One component showed higher activity with, and was more strongly induced by, cellobiose; the other showed greater activity and inducibility with salicin. Addition of glucose to cultures severely depressed induction of beta-glucosidase activity by cellobiose but not by salicin. Acetate and several amino acids inhibited induction by either substrate. The action of glucose was not reversed by cyclic AMP. Cultures of S. venezuelae using glucose, cellobiose, or a mixture of the two saccharides as their carbon source produced chloramphenicol during growth. In contrast with its effect on the induction of cellobiose activity, glucose did not suppress chloramphenicol production, indicating that the control mechanisms that establish carbon source preferences are not linked to those that regulate antibiotic biosynthesis in this organism.