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Biomedical subjects

S Banerjee

Publications and source records attributed to S Banerjee.

At least 379 records · Page 21Linked to original sources
PubMed1995

Family cohesion as a buffer against the effects of problem-drinking fathers on psychological distress, deviant behavior, and heavy drinking in adolescents.

In this paper we examine the degree to which family cohesion buffers the effects of fathers' problem drinking at Time 1 (T1) on adolescent distress, deviance, and heavy drinking at Time 2 (T2), one year later. Data from a representative sample of 658 families were used to test the hypotheses. Mothers, fathers (if present), and adolescent children were interviewed in the home. Fathers who were present completed self-report scales measuring problem drinking. When fathers were not available, mothers' reports on fathers' drinking were used to measure fathers' problem drinking. Results from regression analysis indicate that after controlling for the effects of race, SES, age, gender, and family structure: (1) the more cohesion in the family and the fever stressful events, the less distress, deviance, and heavy drinking shown by adolescents; (2) the fathers' problem drinking affects adolescent distress and deviance when cohesion is low; but as cohesion increases, the effects of the fathers' drinking are reduced. The findings support the hypothesis that cohesion in families buffers the effects of fathers' problem drinking on adolescents.

Adolescent↗
PubMed1995

Elevated levels of 2',5'-linked oligoadenylate-dependent ribonuclease L occur as an early event in colorectal tumorigenesis.

RNA decay in IFN-treated cells is controlled by 2'5'-linked oligoadenylate (2-5A)-dependent RNase (RNase L), a uniquely regulated endoribonuclease that requires short 5'-phosphorylated, 2-5A for its activity. Because RNase L is also implicated in the regulation of cell proliferation, we monitored its expression in colorectal adenocarcinomas and noncancerous polyps from familial adenomatous polyposis patients. Elevated levels of RNase L mRNA and activity were found in 17 of 20 tumors compared with corresponding normal mucosa. An mAb against RNase L revealed elevated amounts of this RNase in sections of the tumors, largely in the base of the villi. The occurrence of elevated levels of RNase L seems to be an early event in colorectal tumorigenesis, suggesting that control of RNA turnover is an important step in tumor progression. These data also indicate that regulating RNase L activity may be a useful strategy in treating colorectal carcinomas.

Adenocarcinoma↗
PubMed1994

Induction of chromosome aberrations in Syrian hamster renal cortical cells by various estrogens.

Estrogens, both natural and synthetic, have been implicated in carcinogenesis at different organ sites in a variety of animals, including man, for more than six decades. However, the molecular mechanism(s) involved in the carcinogenic action of estrogens still remains both controversial and elusive. Cytogenetic damage in the hamster kidney has been studied after in vivo treatment with either potent or weak estrogens for varying periods. Compared to age-matched untreated control, diethylstilbestrol (DES) treatment resulted in significant increases in the number of chromatid gaps and breaks, chromosome breaks, and endoreduplicated cells in hamster renal cortical cells. These chromosomal aberrations (CA) were cumulative with continued hormone exposure from 1.0 to 5.0 months. However, chromosome exchanges as a result of the breaks were not elevated. After 5.0 months of hormone treatment, potent estrogens such as 17 beta-estradiol and Moxestrol exhibited similar frequencies of CA in the hamster kidney to that found for DES, whereas weak estrogens such as 17 alpha-estradiol and beta-dienestrol exhibited CA frequencies that were not significantly different from untreated levels. Ethinylestradiol treatment for a similar period resulted in significant increases in chromatid gaps, although these did not evolve into increases in either chromatid or chromosome breaks, and in a rise in endoreduplicated cells. These results raise the possibility that the CA generated after estrogen treatment may be involved in renal tumorigenic processes.

Analysis of Variance↗
PubMed1994

Intradural thoracic disc herniation.

STUDY DESIGN: Patients with intradural herniation of an intervertebral disc were identified and managed surgically. OBJECTIVES: Illustrative cases of patients with intradural herniated discs at the mid-thoracic level are presented, the literature is reviewed, and the management of these patients is discussed. SUMMARY OF BACKGROUND DATA: Intradural herniation of an intervertebral disc is rare and most common at the lumbar level, but isolated cases have been reported at other levels. Cases reports of this entity have been published, but the surgical details have not been adequately addressed. METHODS: In this report, two patients with calcified intradural herniated discs at the mid-thoracic level are presented. RESULTS: Both patients had progressive paraparesis and had calcified disc material in the mid-thoracic canal. Both were treated successfully with a posterolateral extracavitary costotransversectomy and hemilaminotomy using intraoperative ultrasound and somatosensory-evoked potential monitoring. CONCLUSIONS: This entity should be suspected when a calcified disc within the spinal canal is being treated. The optimal exposure is a posterolateral extracavitary costotransversectomy with a hemilaminotomy. Alternative approaches to a typical thoracic disc would be problematic in managing these patients.

Dura Mater↗
PubMed1994

BUB/BnJ (H-2q) is a TCR deletion mutant mouse strain (TCR V beta a, KJ16-) that is susceptible to type II collagen-induced arthritis.

Type II collagen-induced arthritis (CIA) in mice is an animal model of autoimmune inflammatory arthritis. Arthritis is induced in susceptible strains of mice (H-2q and H-2r) after immunization with heterologous or autologous type II collagen in CFA. Induction of CIA is T cell dependent and a restricted usage of TCR V beta genes has been found in the arthritic joints and lymph nodes of mice with CIA. However, genes within the MHC are not the only determinants of susceptibility to CIA as SWR/j, AU/ssJ (both H-2q) and RIIIS/J(H-2r) mice are resistant to the induction of CIA. These strains of mice are TCR V beta chain genes deletion mutants (TCR V beta a and TCR V beta c haplotypes) and it was hypothesized that these mice are resistant to CIA because of the absence of a particular set of V beta TCR genes that are genomically deleted in these strains of mice. We now show that BUB/BnJ mice (H-2q) are T cell subsets deficient because of the genomic deletion of TCR V beta 5, 8, 9, 11, 12, and 13 sub-families. Our data demonstrate that despite the deficiency in T cell subsets from genomic deletion of TCR V beta genes, BUB mice are highly susceptible to the development of CIA. These results indicate that genomic deletion of certain TCR V beta genes alone is not in itself sufficient to confer resistance to CIA. These results further suggest that other unknown gene(s) must also contribute to the induction of CIA.

Animals↗
PubMed1994

Sperm nuclear chromatin transformations in somatic cell-free extracts.

HeLa cell extracts induced decondensation of lysolecithin permeabilized Xenopus, pig, and human sperm chromatin; decondensation began almost immediately on incubation in the extract and was completed within 10-20 min. The average enlargements of human and pig sperm nuclei were 15-fold and 3-fold, respectively. The structural organization of pig and human sperm chromatin was significantly different. Decondensation was differentially inhibited by Mg++ and polyamines; inhibition was least for Xenopus and most for pig sperm nuclei. The nuclear membrane was disintegrated on chromatin dispersion, whereas the nuclei which failed to decondense exhibited distinct nuclear envelopes. The decondensing factors were stable at 65 degrees C for 15 min. The dispersed chromatin was remodelled to somatic nucleosomal structures within 60 min. The remodelled chromatin could be recondensed to chromosome-like structures, when incubated further in extracts from mitosis arrested HeLa cells.

Animals↗
PubMed1994

2'-(3 alpha-Benzyloxy-24-norcholan-23-yl)-2',4',4'-trimethyl-4',5'- dihydrooxazoline-N-oxyl as a potential spin probe for model membranes.

A new steroidal doxyl (4,4-dimethyloxazolidine-N-oxyl) nitroxide (SDN) viz. 2'-(3 alpha-benzyloxy-24-norcholan-2'-yl)-2',4',4'-trimethyl-4',5'- dihydrooxazoline-N-oxyl has been synthesized. This is expected to have higher mobility over other spin labels reported earlier. The localization of this spin probe in lipid bilayers has been determined using 1H NMR and 31P NMR techniques. The alterations induced by drugs in the membrane characteristics such as phase transition and permeability have been investigated using electron paramagnetic resonance (EPR) techniques. The results show the applicability of SDN as a potential spin probe in the study of biomembranes.

Cell Membrane Permeability↗
PubMed1994

Histopathology of kidney of Channa punctatus exposed to chronic nonlethal level of Elsan, mercury, and ammonia.

Histopathological changes in the head and trunk kidneys of Channa punctatus induced by chronic nonlethal levels of Elsan (211 ppb), mercuric chloride (16.7 ppb), and aqueous ammonia (15.64 ppm) were studied on 7, 28, 63, and 90 days of exposure. The pathology of the head kidney was characterized by degeneration and dispersion of interrenal and chromaffin tissue and necrosis in the haemopoietic elements. Kidney lesions were observed throughout the entire experimental period in fish exposed to Elsan and mercuric chloride. In contrast, the lesion induced by exposure to aqueous ammonia began to heal during the first phase of treatment. Marked abnormalities in trunk kidney histology were also found. Renal lesions consisted of minimal to mild multifocal, acute tubular epithelial degeneration, karyolysis, and dilation or shrinkage of Bowman's capsule and glomerulus. Elsan treatment resulted in a highly significant decrease in the dimension of Bowman's capsule and glomerulus at all days of sampling, except on Day 28. The response of the fish trunk kidney tissue to mercuric chloride was similar to that observed with Elsan exposure in terms of the alteration in the mean dimensions of Bowman's capsule and glomerulus. The response to ammonia was significant reduction in the size of Bowman's capsule and glomerulus throughout the experimental period except at Day 28. Little dilation of Bowman's capsule and a significant dilation of glomerulus were found at Day 28 of ammonia exposure. This study demonstrated that a chronic nonlethal exposure to Elsan, mercuric chloride affect both endocrine and excretory parts of the kidney while ammonia specifically damages the excretory part of the kidney of C. punctatus.

Ammonia↗
PubMed1994

Advances in microbial biotechnology of bile acids.

The recent advances in microbial biotechnology of production of bile acid metabolites helped to identify a number of neutral and acidic steroidal compounds useful as drugs and drug intermediates on a scale which would not have been possible by classical chemical transformations. Microbial transformations viz., hydroxylation, dehydroxylation, reduction of the carbonyl moieties, epimerization, side-chain metabolism, introduction of carbon-carbon double bonds into the steroid nucleus, deconjugation of bile acid conjugates carried out by various microorganisms for production of useful metabolites with special reference to newer techniques including cell immobilization and transposon mutagenesis for selective transformations are reviewed. The different pathways of microbial degradation of bile acids leading to the formation of various products are discussed. A compilation of the metabolites formed by various microorganisms from the bile acids or their conjugates and reported during the period 1979-1992 is also provided.

Journal Article↗
PubMed1994

Influence of certain essential oils on carcinogen-metabolizing enzymes and acid-soluble sulfhydryls in mouse liver.

The influence of essential oils from naturally occurring plant dietary items such as cardamom, celery seed, cumin seed, coriander, ginger, nutmeg, and zanthoxylum on the activities of hepatic carcinogen-metabolizing enzymes (cytochrome P450, aryl hydrocarbon hydroxylase, and glutathione S-transferase) and acid-soluble sulfhydryl level was investigated in Swiss albino mice. Each oil was fed by gavage at 10 microliters/day for 14 days, and then the animals were sacrificed and their hepatic enzyme activities and sulfhydryl levels were evaluated. Only nutmeg and zanthoxylum oils induced cytochrome P450 level significantly (p < 0.05), whereas cardamom oil caused a significant reduction in its activity (p < 0.05). Furthermore, aryl hydrocarbon hydroxylase activity was significantly elevated only by treatment with ginger oil (p < 0.01), whereas nutmeg oil caused a significant reduction in its activity (p < 0.01). The remaining oils did not significantly alter the level of cytochrome P450 and aryl hydrocarbon hydroxylase activity. Glutathione S-transferase activity was significantly elevated in all experimental groups (p < 0.1-p < 0.001) compared with controls. The acid-soluble sulfhydryl was significantly elevated only by the essential oils of cardamom (p < 0.05), nutmeg (p < 0.05), and zanthoxylum (p < 0.01). Our observations suggest that intake of essential oils affects the host enzymes associated with activation and detoxication of xenobiotic compounds, including chemical carcinogens and mutagens.

Animals↗
PubMed1994

Age- and lobe-specific responses of the brown Norway rat prostate to androgen.

We examined the effects of age and of increasing concentrations of testosterone on the wet weight, protein content, cell number, and cell size of the ventral, dorsal, and lateral lobes of the Brown Norway rat prostate. Young (3 mo of age) and aged (15, 17, and 21 mo of age) rats received implants of increasing sizes of testosterone-filled Silastic capsules for 3 mo. Wet weights of the prostate were the same in untreated young (6-mo-old) and aged (18-24-mo-old) rats. Testosterone administration resulted in serum testosterone concentrations ranging from physiologic to superphysiologic. Dose-dependent increases in wet weights and protein contents were seen in the ventral, dorsal, and lateral prostatic lobes of both young and aged rats. For each given dose of testosterone, including doses that resulted in serum testosterone concentrations within the physiologic range, the weights and protein contents of the dorsal and lateral lobes were greater in old (24-mo-old) than in young (6-mo-old) rats, indicating an effect of age in these lobes. In contrast, ventral prostate weights and protein contents increased equivalently in young and aged rats with increasing testosterone concentration. DNA content, a measure of cell number, increased significantly in the dorsal and lateral lobes as a function of testosterone dose and age, but in the ventral lobe did not differ with testosterone dose or age. Quantitative morphologic analyses showed significant hypertrophy of epithelial cells throughout each of the three lobes in both young and aged rats treated with testosterone. Taken together, these results indicate that the prostate of Brown Norway rats shows age and lobe-specific responses to androgen with respect to wet weight, protein content, cell number, and cell morphology.

Aging↗
PubMed1994

Chemopreventive action by an extract from Ocimum sanctum on mouse skin papillomagenesis and its enhancement of skin glutathione S-transferase activity and acid soluble sulfydryl level.

We report the chemopreventive property of an ethanolic extract of the leaves of Ocimum sanctum (a traditional medicinal plant) on 7,12-dimethylbenz[a]anthracene induced skin papillomagenesis in male Swiss albino mice. A significant reduction in the values of tumor incidence, average number of tumors per tumor bearing mice and the cumulative number of papillomas was observed in mice treated topically with the leaf extract of O. sanctum at either the peri-initiational, post-initiational stages or continuously at peri- and post-initiational stages of papillomagenesis as compared to the corresponding control group. Topical application of Ocimum leaf extract for 15 days resulted in significant 2-fold elevation of reduced glutathione content in the skin of mice (p < 0.05). Similarly, glutathione S-transferase activity was also observed to be significantly elevated by 25% compared with the control group (p < 0.05) following Ocimum extract treatment.

9,10-Dimethyl-1,2-benzanthracene↗