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Biomedical subjects

S Chatterjee

Publications and source records attributed to S Chatterjee.

At least 595 records · Page 33Linked to original sources
PubMedDate not supplied

Gender and performance in athletics.

A comparison of women's and men's performance in swimming, running, and skating is made based on available world record data. The ratio of women's to men's record times is analyzed as a time series, and the asymptotic value of this ratio is discussed in the context of a model. "Rate of improvement curves" are defined over time and by event in a given sport and are compared across gender. The relationship of record time to event distance is estimated and also analyzed across event and gender boundaries. We make three conclusions: 1. The rate of improvement for women has been extraordinary and is larger for longer distance vents. 2. Law-like relations emerge for record times and event lengths. These relations have interesting physical interpretations when examined for various sports. 3. The male physiology is more suited to anaerobic strength events while, given increased access and participation, women can be expected to be more on a par with men in some long-distance aerobic events.

Cross-Sectional Studies↗
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Cephradine in the treatment of infective endocarditis.

Ten patients with a mean age of 34.1 years with infective endocarditis (55% of cases due to Staphylococcus aureus) were treated with cephradine. The peak serum levels of cephradine (8-42 microgram/ml) were 3- to 17-fold higher than the minimum inhibitory concentrations of cephradine against pathogenic strains of S aureus (1.2-4 microgram/ml). Patients treated with cephradine became afebrile in 2 to 13 days of therapy, and their white blood cell count returned to a normal level in 3 to 30 days. Cephradine therapy was well tolerated without any incidence of phlebitis. The drug could be administered by three different routes. Cephradine is a useful cephalosporin for treatment of nonenterococcal gram-positive endocarditis in young heroin addicts.

Adult↗
PubMedDate not supplied

Lactosylceramide mediates shear-induced endothelial superoxide production and intercellular adhesion molecule-1 expression.

Laminar shear stress activates NADPH oxidase in vascular endothelial cells (ECs), and the generated superoxide radicals (O2(-.) are known to be involved in intercellular adhesion molecule (ICAM)-1 expression. In this study, the role of a glycosphingolipid (GSL), lactosylceramide (LacCer), as a second messenger in the shear-induced O2(-.) generation and ICAM-1 expression was examined. It is known that glucosylceramide synthase (GlcT-1) catalyzes the synthesis of glucosylceramide (GlcCer) from ceramide, and subsequently lactosylceramide synthase (GalT-2) synthesizes LacCer from GlcCer. We observed that exposing cultured human umbilical vein ECs (HUVECs) to fluid shear stress (20 dyn/cm(2) for 30 min) activated GalT-2. Shear stress also increased EC O2(-.) generation, that peaked at 30 min, and surface ICAM-1 protein expression at 6 h post-shear. EC preincubation with the antioxidant N-acetylcysteine (NAC; 20 mM for 2 h) completely abolished the shear-induced O2(-.) production and significantly inhibited ICAM-1 expression. EC preincubation with D-1-phenyl-2-decanoylamino-3-morpholino-1-propanol (D-PDMP), an inhibitor of the GSL glycosyltransferases GlcT-1 and GalT-2, abrogated the shear-induced activation of GalT-2. D-PDMP also abolished the shear-induced O2(-.) production and ICAM-1 expression. We conclude that laminar shear stress activates GalT-2 to produce LacCer. In turn, LacCer activates NADPH oxidase, which produces O2(-.), and O2(-.) mediates the shear-induced increase in ICAM-1 expression. Thus, LacCer may play an important role in hemodynamic force-induced pathological conditions, such as atherosclerosis and ischemia/reperfusion injury.

Antigens, CD↗
PubMedDate not supplied

Semen characteristics of tobacco users in India.

Qualitative analysis of semen samples have been compared between 79 different types of tobacco addicts (smokers, chewers, and multiple addicts) with 21 nonaddicts (never consumed any form of tobacco). The percentage of motile sperm and total sperm count of the tobacco chewers are significantly low (p < .05). The frequency of abnormal sperm is also significantly high (p < .001) for smoking and multiple addict groups. Differential effects of smoking and chewing tobacco on sperm characteristics are discussed.

Adult↗
PubMedDate not supplied

Free radical-induced liquefaction of ejaculated human semen: a new dimension in semen biochemistry.

Even though the aminopeptidase and amylase are the major liquefying factors in the liquefaction process of the ejaculated semen-coagulum, the exact nature of "switching on" phenomena has not been elucidated yet. Monitoring the rate of production of the asborbyl radical, an indirect method for oxyradical-stress measurement, this prima facie study reports the involvement of oxygen radical in the liquefaction process of coagulated semen.

Dehydroascorbic Acid↗
PubMedDate not supplied

Superoxide anion radical mediated dissection of rat sperm: an in vitro study.

Sperm is highly sensitive to superoxide radical surge in the granuloma interior. To investigate possibility of a superoxide radical bomb, the role of an oxyradical on the spermatozoon was studied in vitro using potassium superoxide, a potent superoxide radical producer. Results confirm that the superoxide radical has a unique site-specific scissoring power.

Animals↗
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Free radical mediated sperm-load management in the vagina of rats.

The postcoitus phagocytic engulfment of spermatozoa following disintegration of a sperm cell has not been well understood until now. By monitoring the free radical status of the vagina in accordance with the various stages of the estrous cycle and the sperm-cutting power of vaginal flushing, a positive correlation has been detected that favors the superoxide theory of the sperm-cutting technique in vivo. This finding is also consistent with the previous experience of free radical bombing of spermatozoa in spermatic granuloma.

Animals↗
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The impact of cisplat based chemotherapy on advanced ovarian cancer.

Cisplatinum based chemotherapy has become the standard treatment for ovarian cancers due to its proved superiority over non-cisplat based regimes. However, the therapeutic impact of cisplat based regimes compared to cheaper non-cisplatinum based regimes is questionable when multiple variables such as residual disease, histologic type, grade are introduced. This report is a study of 110 Stage III ovarian cancer patients from 1985-89, with cisplat (n = 69) and non cisplat (n = 41) based chemotherapy. The results of both regimes with reference to the multiple variable factors are presented. We conclude that cisplat based regimes appear to be superior to non-cisplat based regimes except probably in poorly differentiated ovarian tumors where the results were similar with either regimen.

Antineoplastic Combined Chemotherapy Protocols↗
PubMedDate not supplied

Increased dermal elastic fibers in the tight skin mouse.

OBJECTIVE: The tight skin (Tsk-1) mouse has been proposed as a model for systemic sclerosis on the basis of increased accumulation of collagen and glycosaminoglycans in the skin, and by the presence of serum autoantibodies. The genetic basis of the mutation has been identified as a genomic duplication within the fibrillin-1 (Fbn-1) gene that results in a larger than normal Fbn-1 transcript, but the mechanism that leads to dermal fibrosis is unclear Fibrillin molecules associate into a polymer that is coated with elastin molecules to form elastic fibers. To further evaluate the Tsk-1 mouse model of scleroderma, we have studied elastic fibers in the skin of these mice. METHODS: Skin sections obtained from C57BL/6-TSK+ (Tsk-1) and C57BL6-pa/+ (control) mice were stained with Masson's trichrome for evaluation of collagen and Gomori's aldehyde fuchsin stain for elastic tissue. Computer assisted image analysis was performed to quantify differences in histologic sections. RESULTS: Tsk-1 mice had a highly significant increase in the percentage of elastic fibers (19.6%) in the dermis compared to control mice (7.9%) [p < 0.001]. This correlates with the findings in the skin of systemic sclerosis patients where increased elastic fibers have been observed. In addition, an increased level of dermal collagen staining was also observed in the Tsk-1 dermis (82.9%) compared with the level in normal sections (73.7%) [p < 0.01]. CONCLUSION: These data support the use of the Tsk-1 mouse as a model for the connective tissue abnormalities of human scleroderma.

Animals↗
PubMedDate not supplied

How reliable are models for malaria vaccine development? Lessons from irradiated sporozoite immunizations.

Models occupy a key position in the development of anti-parasitic vaccines, yet their relevance has been seldom addressed. It is customary to admit that malaria vaccine development requires easy-to-handle, laboratory models. Animal models involving predominantly inbred rodents and primates as parasite hosts are currently the basic tools for the study of host-parasite interactions. Literature however indicates that the induction of host protection is more difficult in natural host-parasite pairs than in experimental models of parasite infection. Moreover different models delineate a wide range of host-pathogen relationship profiles providing a mosaic of contradictory informations, yet there is little incentive to delineate their relevance or to exploit recent advances to develop improved model systems. In this context the analysis of natural host-parasite interactions between Plasmodium berghei and its mammalian host and reservoir, the tree rat Grammomys surdaster could ge of relevance in the study of host-parasite interactions.

Animals↗
PubMedDate not supplied

Effect of quinalphos on testicular steroidogenesis in rats.

The effect of quinalphos (250 micrograms/kg i.p.) an organophosphorus insecticide treatment for 13 and 26-days on the testicular steroidogenic enzymes viz. 3 beta-Hydroxysteroid Dehydrogenase and 17 beta-Hydroxysteroid Dehydrogenase, as well as cholesterol content and histology of the testes of the Wistar strain rats was studied. The time duration of 13 days is approximately equivalent to one cycle of the seminiferous epithelium in Wistar strain rats. Treatment of quinalphos for 13 days failed to produce any effect on the relative weights of the testes and accessory sex glands. However, significant inhibition of 3 beta-HSD activity and increased cholesterol level in testis were observed. The rats treated for 26 days similarly showed a highly significant inhibition of the activity of both 3 beta-HSD and 17 beta-HSD. The relative weights of the testes and accessory sex glands were also significantly reduced. Histological examination of the testis revealed that quinalphos treatment produced detrimental changes in the seminiferous epithelium. Treatment with quinalphos for 13-days produced no toxic effect with the exception of a significant increase in serum alkaline phosphatase. However, after 26-days of treatment toxicity was significantly increased as reflected on serum transaminases, phosphatases and blood urea levels of rat. Present study indicated that quinalphos impairs testicular functions in rats.

17-Hydroxysteroid Dehydrogenases↗
PubMedDate not supplied

Effect of aldrin on accessory sex glands and plasma testosterone levels in rats.

The effects of aldrin, an organochlorine insecticide, on accessory sex glands and plasma testosterone levels in rats were studied. The aldrin was administered i.p. for 13 days and 26 days at a dose of 150 micrograms/kg. Relative weights of prostate, seminal vesicles and coagulating glands were significantly decreased in the treated rats compared to those in controls. In addition, there was a significant fall in acid phosphatase activity in prostate and fructose content in accessory sex glands was also observed in treated animals. Plasma testosterone values showed a decrease with the duration of treatment. HCG supplementation with aldrin treatment prevented all those untoward effects of aldrin in experimental rats.

Acid Phosphatase↗