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Biomedical subjects

S Chatterjee

Publications and source records attributed to S Chatterjee.

At least 343 records · Page 19Linked to original sources
PubMed1991

The herpes simplex virus 1 segment inversion site is specifically cleaved by a virus-induced nuclear endonuclease.

Nuclear extracts from several tissue culture cell lines (human, primate, and murine) contain an endonuclease that specifically cleaves sequences at the herpes simplex virus 1 (HSV-1) segment inversion site. Mapping studies identified the preferential site of cleavage as a set of tandemly repeated dodecamers, the DR2 repeats. Endonuclease levels vary according to the proliferative state of the cell; little or no activity is detectable in extracts from quiescent cells, whereas high levels are expressed in dividing cells. Also, infection of density-arrested BSC-1 cells with HSV-1 induces a substantial increase (at least 35-fold) in endonucleolytic activity, which is first detectable at about 1 hr after infection at 32 degrees C. The elevated levels of enzyme activity then persist throughout the viral life cycle. In addition to the HSV-1 DR2 repeats, certain other G+C-rich sequences with an asymmetric distribution of purines and pyrimidines on the DNA strands and with appropriate sequences and lengths are substrates for the nuclease. These data indicate that target site recognition by the enzyme is conformation specific rather than sequence specific.

Animals↗
PubMed1991

Suppressive effect of quinalphos on the activity of accessory sex glands and plasma concentrations of gonadotrophins and testosterone in rats.

Biochemical estimation of prostatic acid phosphatase and fructose content in accessory sex glands, along with radioimmunoassay of plasma gonadotrophins (FSH and LH) and testosterone were performed in Wistar rats following treatment with quinalphos, an organophosphorus insecticide, for 13 and 26 days. Prostatic acid phosphatase activity and fructose content of the accessory sex glands, and plasma levels of testosterone and FSH were significantly lower in all rats treated with quinalphos. However, the degree of inhibition was more extensive in the 26 day-treatment group who, in addition also exhibited a significant reduction in relative weights of the testes and accessory sex organs, and plasma levels of LH. All these adverse effects of quinalphos were prevented when exogenous HCG was administered in concomitant with the insecticide for 26 days. These results suggest that quinalphos may exert a suppressive effect on the functional activity of accessory sex glands by decreasing testicular testosterone production following inhibition of pituitary gonadotrophins release.

Animals↗
PubMed1991

Apical expression of herpes simplex virus type 2 glycoproteins in human neuroblastoma cells.

The expression of herpes simplex virus type 2 (HSV-2) glycoproteins on the surface of human neuroblastoma cells has been investigated using Millipore Millicell culture plate inserts. Utilizing a modified radioimmunoassay, we learned that glycoproteins B, C, D, E, and I were expressed predominantly on the apical membrane domain of the infected neuroblastoma cells. The unidirectional transport of HSV-2 glycoproteins was substantiated by the analysis of extracellular glycoproteins released from neuroblastoma cells. The results suggest that the evaluated HSV-2 glycoproteins were transported primarily to the apical plasma membrane domain of human neuroblastoma cells.

Cell Membrane↗
PubMed1991

Evaluation of a test based on baculovirus-expressed glycoprotein G for detection of herpes simplex virus type-specific antibodies.

An immunoblot assay for discrimination of antibodies to herpes simplex virus (HSV) types 1 and 2 was devised using extracts of recombinant-baculovirus-infected insect cells expressing HSV-1 or -2 glycoprotein G (gG1 or gG2). The assay was evaluated by comparing its results with those obtained by using an immunodot assay based on gG immunopurified from HSV-1- and HSV-2-infected cells. Each of 110 human serum specimens was tested blindly and independently three times. At a serum dilution of 1:20, the maximum specificities were 96% and 100% and the maximum sensitivities were 100% and 92% for gG1 and gG2, respectively. Reproducibility was 99% among readers and 95% among individually tested samples of each specimen. Results obtained in two laboratories from a different set of 15 serum specimens were in complete agreement, indicating the assay is accurate and reproducible. The ease of antigen production should allow the test to become widely available.

Animals↗
PubMed1991

Carbohydrate tolerance and serum lipids in acromegaly before and during treatment with high dose octreotide.

Carbohydrate tolerance and serum lipids were studied in 14 patients with acromegaly before and in response to treatment with high dose somatostatin analogue (octreotide) over a 14-week period. Patients were assessed with respect to growth hormone (GH) profile, IGF1, HbA1, fasting lipids, and the GH, glucose, and insulin response to a standard 75 g oral glucose tolerance test (OGTT) before and during therapy. Prior to treatment mean fasting serum insulin levels were 11.7 +/- 2.8 (+/- SE) mU I-1 with a mean insulin response to OGTT of 49.8 +/- 10.8 mU I-1. Twelve of the 14 patients responded to octreotide with a reduction in mean 24-h serum GH (32.9 +/- 9.3 to 4.3 +/- 0.9 mU I-1), suppression of GH at 60 min during OGTT (3.0 +/- 0.8 mU I-1) and normalization of serum IGF1 (71 +/- 7 to 27 +/- 3 (normal 9-48 nmol I-1)). In this group the fasting insulin levels fell to 2.2 +/- 0.7 mU I-1 (p less than 0.01), and mean insulin response during OGTT was reduced (46.6 +/- 15.0 to 12.3 +/- 2.3 mU I-1) (p less than 0.01). Despite the reduction in insulin secretion there was no significant deterioration in fasting blood glucose (4.8 +/- 0.2 vs 4.6 +/- 0.4 mmol I-1), HbA1 (7.2 +/- 0.3 vs 6.8 +/- 0.3%) or mean blood glucose response to OGTT (7.9 +/- 0.7 vs 8.2 +/- 0.5 mmol I-1). Fasting triglycerides were reduced with treatment from 1.5 +/- 0.2 to 1.1 +/- 0.1 mmol I-1 (p = 0.04) in the responsive group, but serum cholesterol levels were not significantly altered (5.3 +/- 0.3 vs 5.2 +/- 0.3 mmol I-1).

Acromegaly↗
PubMed1991

Intracellular maturation and sorting of two herpes simplex virus type 1 glycoproteins. Immunogold staining of ultrathin cryosections.

Simultaneous immunocytochemical triple staining of ultrathin cryosections of herpes simplex virus type 1-infected cells was carried out using monoclonal antibodies specific for glycoprotein C, glycoprotein D and alpha + beta tubulin. The viral glycoproteins were identified in the cytoplasm, in the Golgi sacs, on the plasma membrane and on the surface of intra- and extracellular virus particles, but not on the nuclear membrane. The glycoproteins identified in the cytoplasm outside the Golgi region were not always confined to the membranes of vesicles, but were often located in close proximity to the tubulin-labelled structures. The glycoproteins C and D were usually codistributed in the cytoplasm, and both accumulated in the Golgi sacs in the same membrane domains. As the glycoproteins occur in close proximity to the microtubular structures, we speculate that these might be directly involved in the intracellular transport of viral glycoproteins.

Freezing↗
PubMed1991

Inhibition of human immunodeficiency virus type 1-induced cell fusion by recombinant human interferons.

Pretreatment of HeLa T4 cells with recombinant alpha, beta, or gamma interferon (IFN) was found to significantly inhibit syncytium formation induced by the human immunodeficiency virus type 1 (HIV-1) envelope glycoprotein. All three IFNs were found to be potent inhibitors of fusion in a system in which Spodoptera frugiperda cells, infected with a baculovirus recombinant expressing the HIV-1 envelope protein, were cocultivated with HeLa T4 cells. In addition, these IFNs were also found to block HeLa T4 cell fusion induced by the HIV-1 envelope proteins expressed from a vaccinia virus recombinant. Furthermore, the IFNs inhibited cell fusion between HIV-1 envelope glycoprotein-expressing cells and either immortalized or fresh CD4+ lymphocytes pretreated with the IFNs. These results suggest that further testing of human IFNs for therapy of HIV-1 infection will be of interest.

Animals↗
PubMed1991

No character displacement for reproductive isolation between Drosophila bipectinata and Drosophila malerkotliana.

To test whether character displacement for reproductive isolation between Drosophila bipectinata and Drosophila malerkotliana exists, the degree of sexual isolation was measured between their sympatric and allopatric populations. Although the isolation indices vary in different crosses, the average isolation index for sympatric populations is very close to that for allopatric populations. This shows no difference in the degree of sexual isolation between sympatric and allopatric populations of D. bipectinata and D. malerkotliana. Thus there is no evidence for the existence of character displacement for sexual isolation between these two closely related sympatric species.

Animals↗
PubMed1991

Maximal aerobic capacity of Bengali girl athletes of different sports activities.

The maximal aerobic capacity (VO2max) and related cardiorespiratory parameters were determined on 67 Bengalee (Indian) girl athletes having nine different sports activities. VO2max was determined with a bicycle ergometer. The highest value for VO2maxl.min-1 was obtained by javelin throwers (1.95), being followed by pentathletes (1.92) and long-distance runners (1.90), whereas the lowest value was achieved by handballers (1.45). When VO2max was expressed in ml.kg-1.min-1, the long-distance runners registered the highest mean value (43.0), which was significantly higher than that of basketballers (34.9), handball players (36.2), badminton players (34.4), and swimmers (36.0). For this measurement, the sprinters (40.0), pentathletes (40.3), javelin throwers (40.0), and jumpers (39.4) did not differ significantly with each other, but each of the groups was significantly superior to basketballers, handballers, badminton players, and swimmers. No significant difference was also found amongst the latter groups. VO2maxl.min-1 was found to be significantly correlated with all the physical characteristics. It was predicted on the basis of age, height, weight, and body surface area using stepwise regression method.

Adolescent↗
PubMed1991

Pulmonary function studies in healthy school boys of West Bengal.

The establishment of normal standards of dynamic pulmonary function measurements in the form of prediction equations will serve as a remedial measure of different aspects of obstructive pulmonary diseases, especially in children. With a view to achieving the target, dynamic pulmonary function measurements were undertaken on 328 healthy school-going children of West Bengal having age ranging between 9 and 18 years. All the spirometric measurements except PEFR were taken with the help of a 9 l closed-circuit type expirograph following the methods and techniques of American Thoracic Society. PEFR was measured by Wright Peak Flow Meter. Prediction equations were derived on the basis of age and height for all the pulmonary function measurements except FEV1% and FET. The prediction equations for FVC, FEV1, MVVF, and PEFR were reliable, but relative variability of predicted FEF25-75% and FEF75-85% was very large. A comparative study of FVC, FEV1, and PEFR values of our subjects, standardized for age and height, was much closer to the boys of Delhi in FVC but higher than South Indian boys in FEV1, North and South Indian boys in PEFR. In an attempt to compare FVC and FEV1 values of our subjects with foreign populations, it is revealed that boys of our study were much lower than American (White), European, and Jordanian boys but comparable with those of Chinese and Libyan boys.

Adolescent↗
PubMed1991

Alkylating agent hypersensitivity in poly(adenosine diphosphate-ribose) polymerase deficient cell lines.

Starting with the V79 cell line, two poly(ADP-ribose) polymerase deficient mutants, designated ADPRT 54 and ADPRT 351, had been shown to be hypersensitive to x- and UV-irradiation and to topoisomerase I inhibitors but to be resistant to topoisomerase II inhibitors (Chatterjee, S.; Cheng, M. F.; Berger, N. A. Hypersensitivity to clinically useful alkylating agents and radiation in poly(ADP-ribose) polymerase-deficient cell lines. Cancer Commun. 2:401-407;1990). We now report that these mutants were hypersensitive to a series of different alkylating agents, including alkylsufonates, alkylnitrosoureas, and nitrosoguanidine. In addition, they were hypersensitive to the UV-mimetic agent 4-nitroquinoline-1-oxide. Our findings provide strong evidence that poly(ADP-ribose) polymerase was involved in the repair of alkylating agent induced DNA damage as well as in the damage induced by UV- and x-irradiation and radiomimetic agents. The poly(ADP-ribose) polymerase deficient cell lines showed a marked decrease in the shoulder region of their survival curves, suggesting that poly(ADP-ribose) polymerase was involved in the repair of alkylating agent induced sublethal damage.

4-Nitroquinoline-1-oxide↗
PubMed1991

Butalactin, a new butanolide antibiotic. Taxonomy, fermentation, isolation and biological activity.

Butalactin, [2-(4',5'-epoxy-hex-2'(E)-en)oyl-2-hydroxy-3-hydroxymethyl-2, 3-(Z)-butanolide] is a new antibiotic produced by Streptomyces sp. HIL Y-86,36923. Taxonomically, the producing organism most closely resembles Streptomyces corchorusii. The strain also produces cineromycin B. Though butalactin is structurally related to 'signal molecules' such as A-factor, the anthracycline inducing factors and the virginiae butanolides, it does not show inducing activity for antibiotic production or aerial mycelium formation in the indicator strain. Butalactin possesses a weak antibiotic activity against Gram-positive and Gram-negative bacteria.

4-Butyrolactone↗
PubMed1991

Recurrent outbreaks of Japanese encephalitis in Nagaland (1985-1989)--a seroepidemiological study.

Recurrent epidemics of encephalitis in Nagaland, a North-Eastern State of India, following its first appearance in 1985, were investigated both epidemiologically and virologically. Although, no viral agent could be isolated from any of the clinical samples and mosquitoes, detection of JE specific IgM antibodies in many of the CSF and acute blood samples, together with presence of HI and CF antibodies to JE antigen in a number of acute and convalescent sera established the etiologic role of JE virus in this region. A total number of 83 clinically diagnosed cases could only be investigated virologically between 1985-89, where evidence of JE could be established in 34 (40.9 per cent) and flavivirus (including JE in majority) in 17 (21.5 per cent) cases. A limited serological survey among the close contacts of the victims in 1985 revealed JE antibody in 26.6 per cent of them. Analysis of the epidemiological and serological findings of different years revealed that while the outbreaks of 1985, 1987 and 1988 were due to JE infection, the episodes of 1986 and 1989, on the other hand, had chiefly features of high and prolonged fever with limited number of CNS involvement of undetermined origin, where the possibility of malarial infection has been a suspect apart from JE etiology.

Adolescent↗
PubMed1991

Effects of chlorpromazine on growth and development of Dictyostelium discoideum.

Chlorpromazine (5 x 10(-3) M) administered to Dictyostelium discoideum cells inhibited its growth and morphogenesis. Cells treated with chlorpromazine were found to have distorted morphology. At lower doses of chlorpromazine the development was delayed. Early developmental events such as cell streaming, cell aggregations, development of EDTA stable cell contacts, cAMP-chemotaxis etc, were inhibited. Chlorpromazine was also found to inhibit spore formation. Culturing D. discoideum cells on chlorpromazine agar, in supernatant taken from the chlorpromazine treated cells, or co-culturing of chlorpromazine-treated and control cells, inhibited the development of normal Dictyostelium cells. Chlorpromazine-treated cells showed a higher cAMP-dependent extracellular phosphodiesterase activity.

Animals↗