Biomedical subjects

S K Roy

Publications and source records attributed to S K Roy.

At least 109 records · Page 6Linked to original sources

PubMed1994

Ontogeny of granulosa cells in the ovary: lineage-specific expression of transforming growth factor beta 2 and transforming growth factor beta 1.

The differentiation of ovarian somatic cells into granulosa, interstitial, and thecal lineages, and the ovarian growth factor(s) potentially associated with the cytodifferentiation of granulosa cells during the perinatal period were investigated using cell type-specific protein markers. Ovaries collected from prenatal (Days 12-15 of pregnancy) and postnatal (Days 1-30) female hamsters were processed for immunohistochemical localization of transforming growth factor (TGF) beta (TGF beta 1, beta 2, and beta 3). Plasma levels of FSH, LH, progesterone, and estradiol-17 beta were detected by RIA. Prenatal hamster ovaries contained numerous mitotic oocytes and a few somatic cells. Only a fraction of somatic cells expressed barely detectable TGF beta 2 activity. Plasma FSH levels were quite detectable on postnatal Day 1 and increased gradually to reach a peak on Day 25, whereas LH did not increase until Day 12 and reached a plateau by postnatal Day 20. On postnatal Day 1, TGF beta 2 immunoreactivity was localized only in certain cells closely apposed to primordial oocytes. On postnatal Day 4, flattened, TGF beta 2-positive cells encircled individual oocytes, forming the very first cohort of primordial follicles. By Days 7 and 8, primary and early secondary follicles with intense TGF beta 2-positive cuboidal granulosa cells appeared. Subsequently, in large preantral follicles TGF beta 2 was expressed only in mural granulosa cells. On Day 13, TGF beta 1 and beta 2 immunoreactivities appeared for the first time in the interstitial cells. TGF beta 1 was localized in cells closely apposed to follicles, but TGF beta 2 activity was restricted to scattered cell clusters. Subsequently, the entire interstitium was positive for TGF beta 1 protein. These results suggest that differentiation of somatic cells into granulosa cells is the first event in ovarian morphogenesis; once the finite number of granulosa cells is selected, the residual cells differentiate into interstitium. Whether ovarian TGF beta 2 and TGF beta 1 are physiologically important in granulosa and interstitial cell differentiation needs further evaluation.

Animals↗

PubMed1994

Molecular analysis of rRNA and cholera toxin genes carried by the new epidemic strain of toxigenic Vibrio cholerae O139 synonym Bengal.

Vibrio cholerae O139 synonym Bengal recently caused large epidemics of cholera-like disease in Bangladesh and India. We compared the restriction fragment length polymorphisms of ctxA and rRNA genes (ribotypes) in 27 isolates of V. cholerae O139 from patients in Bangladesh and India with those of 48 isolates of V. cholerae O1 from patients and 21 V. cholerae isolates from surface waters in Bangladesh, which included 2 O139 and 19 other non-O1 isolates. Ribotyping of the isolates with BglI revealed that all 29 isolates of O139 vibrios belonged to a single ribotype, suggesting a clonal nature of the infection. However, the O139 vibrios comprised two ctxA genotypes and carried three or more copies of the ctxA gene, and the chromosomal locations of these copies were unlike those of the El Tor or classical vibrios. Analysis of the restriction fragment length polymorphisms of the rRNA genes suggested that V. cholerae O139 isolates are more closely related to El Tor strains of V. cholerae O1 than were 19 other non-O1 vibrios and 33 classical V. cholerae O1 isolates that were studied. However, further studies are needed to determine whether V. cholerae O139 originated from mutations and genetic changes in a V. cholerae O1 strain or was due to the acquisition of virulence genes by a previously unknown V. cholerae non-O1 strain.

Bacterial Typing Techniques↗

PubMed1994

Antisense epidermal growth factor oligodeoxynucleotides inhibit follicle-stimulating hormone-induced in vitro DNA and progesterone synthesis in hamster preantral follicles.

Whether FSH-induced follicular DNA synthesis in the hamster involves epidermal growth factor (EGF) message induction and translation was evaluated using antisense EGF oligodeoxynucleotides. The 15 base pair antisense oligomers synthesized according to mouse EGF cDNA sequence downstream from the 5'-ATG start site hybridized with a 4.4-kilobase message of mouse submaxillary glands and with 4.0 kilobases of mRNA of hamster submaxillary glands, kidney, and ovaries. Preantral follicles at stages 1-7 were enzymatically and mechanically isolated from adult, cyclic hamsters on day 4:0900 h (day 1 = estrus), and follicles at stages 1-5 were isolated from hamsters hypophysectomized for 10 days. Follicles were preexposed to either antisense or sense EGF thio-oligomers for 1, 12, or 24 h and then cultured for an additional 24 h in the absence or presence of ovine-FSH (100 ng/ml) or recombinant murine EGF (50 ng/ml), and 1 microCi/ml [3H]thymidine. Follicular [3H]thymidine incorporation and EGF and steroid (progesterone, androstenedione, and 17 beta-estradiol) production were monitored to assess the molecular mechanism of FSH regulation of follicular development. Antisense oligomers significantly inhibited FSH-induced follicular DNA synthesis and progesterone but not androgen or estrogen production with a latency of 24 h. The oligomer inhibition of FSH action was effectively reversed by exogenous EGF. Antisense oligomers significantly inhibited follicular EGF synthesis in vitro. These results suggest that EGF message is expressed in the hamster ovary, and one of the molecular mechanisms of FSH regulation of hamster preantral folliculogenesis involves EGF mRNA induction and translation.(ABSTRACT TRUNCATED AT 250 WORDS)

Amino Acid Sequence↗

PubMed1994

Sporotrichosis in north-west India.

Twelve culture proven patients of sporotrichosis were seen over a period of 4 1/2 yr in the north-western region of this country. Most of the patients (75%) were from Himachal Pradesh, with slight female preponderance. The right upper limb was commonly (58.3%) involved; gardeners and housewives being the common sufferers. Localised lymphocutaneous variety was the commonest presentation (91.7%), except in one patient, where after initial involvement of the face, the lesion extended to the right upper limb and trunk. All but one patient responded to oral potassium iodide therapy; this patient with mixed infection of Sporothrix schenckii and Cladosporium species, required in addition, amphotericin B therapy.

Amphotericin B↗

PubMed1993

Separation of interleukins by a preparative chromatofocusing-like method.

A chromatofocusing-like method used in the large-scale separation of deamidated from amidated recombinant human interleukin-1 alpha (amino acids 117-271), derived from Escherichia coli, is described. Two major protein species having isoelectric points (pI) of approximately 5.3 and 5.1 were separated by high-performance liquid chromatography using a sulfopropyl strong cation-exchange column. Unlike standard chromatofocusing technique, this method does not use carrier ampholytes during gradient separation of proteins, nor does it employ increased ionic strength for protein elution, the usual method for performing standard ion-exchange chromatography. N-Terminal sequence analysis of the protein with a pI of 5.3 revealed an Asn residue at position 32 as predicted by the cDNA sequence. The pI 5.1 species showed an Asp residue at the same position as a result of deamidation of Asn. This method was also used in the large-scale separation of N-Met from des-Met recombinant human interleukin-1 beta.

Chromatography↗

PubMed1993

Serum and tissue trace elements in colorectal cancer.

Serum copper, zinc, and Cu/Zn ratio were measured using atomic absorption spectrophotometry in 30 patients with colorectal cancer and compared with 30 healthy control subjects. In the patients with colorectal cancer, the tissue copper and zinc levels were also measured in paired histologically normal and malignant colorectal tissue samples obtained at surgery. The mean serum copper levels were higher in patients with colorectal cancer (165.99 vs. 98.84 micrograms/dl) (P < 0.001). The mean serum zinc levels were lowered only in advanced (Dukes stages C and D) colorectal cancer compared to controls (89.94 vs. 115.08 mu/dl) (P < 0.001). However, the Cu/Zn ratio progressively increased with the advancing stage of malignancy (1.86 vs. 0.86) (P < 0.001). The cancerous colorectal tissue showed a higher concentration of both copper (2.78 vs. 1.79 micrograms/g) (P < 0.001) and zinc (27.16 vs. 18.98 micrograms/g) (P < 0.01) compared to non-cancerous colorectal tissue. The exact mechanism responsible for the alterations in trace element levels in patients with colorectal cancer is largely unclear and requires further evaluation. However, the serum copper level and the Cu/Zn ratio are of value in estimating the extent of the carcinoma as well as in determining the prognosis of these patients.

Adult↗

PubMed1993

Maternal nutritional status as a determinant of child health.

To determine the relationship between the nutritional status of the mother and that of the child, 339 children aged 3-36 months and their mothers in two urban hospitals and a community out-patient clinic, were studied. The weight and height of both children and their mothers were measured, and body mass indices (BMI) of the mothers were calculated. Socio-economic status, maternal educational level, and dietary information were recorded in a predesigned questionnaire. The child's nutritional status, as indicated by weight for age (as a percentage of NCHS median), was associated with the body mass index of the mother (P < 0.001), socio-economic status of the family (P < 0.001), and breastfeeding status of the child (P < 0.005) in a multivariate analysis after adjusting for several prognostic factors. The results indicate that maternal nutritional status is a proximate determinant of a child's nutritional status and should be considered in programmes aiming at improving child health.

Bangladesh↗

PubMed1993

Persistent diarrhoea: management in algorithmic approach using a low-cost rice-based diet in severely malnourished Bangladeshi children.

Easy and successful dietary management of persistent diarrhoea has been a long desired goal. Finding an efficient diet which is economically feasible, and easy to prepare in poor homes of developing countries, has not been easy. A dietary algorithm was followed to test the clinical efficacy of an inexpensive and easy to prepare diet made up with rice powder, egg white, glucose, and soya oil. We studied a cohort of 100 severely malnourished children aged between 3 and 36 months with persistent diarrhoea in Dhaka Shisu (children's) Hospital, Bangladesh, during 1990. Initially on a milk-based diet, 26 children (26 per cent) improved while on a subsequent rice-based diet; 65 (88 per cent) of the remaining 74 children improved within a week, with a mean recovery period of 4 days. Patients who did not improve with the rice-based diet were weaned earlier than those who improved. Nine patients failed to improve on the rice-based diet. They were given a soya formula, and only two improved. The remaining seven patients finally improved when a comminuted chicken diet was given. Eight patients died in the hospital with secondary infections of septicaemia and bronchopneumonia. This study offers a simple and effective algorithm on the management of persistent diarrhoea and also demonstrates the success of a rice-based diet, showing promising and feasible means of management of persistent diarrhoea in patients with severe malnutrition.

Algorithms↗

PubMed1993

Epidermal growth factor and transforming growth factor-beta modulation of follicle-stimulating hormone-induced deoxyribonucleic acid synthesis in hamster preantral and early antral follicles.

The interactions of epidermal growth factor (EGF) and transforming growth factor-beta (TGF-beta) in modulating FSH-induced follicular DNA synthesis were studied in isolated intact preantral (stages 1-6) and early antral (stage 7) ovarian follicles from adult hamsters. Follicles were exposed in vitro for 24 h to FSH (100 ng), EGF (50 ng), TGF-beta 1 (1-10 ng), or TGF-beta 2 (1-10 ng), either alone or in combination. The rate of DNA synthesis was assessed by measuring the incorporation of [3H]thymidine into follicular DNA. Both EGF and FSH significantly stimulated follicular DNA synthesis compared with that in controls. Both isoforms of TGF-beta significantly increased follicular [3H]thymidine incorporation in a dose-dependent manner; the effect was greater for small preantral follicles, such as those of stages 1-4. Interestingly, TGF-beta significantly inhibited EGF-induced follicular DNA synthesis, but the rates of DNA synthesis for most of the stages were still higher than that of the control follicles. Specificity of the TGF-beta action on follicular DNA synthesis was evident from the ability of isoform-specific anti-TGF-beta antibodies to neutralize the effect. These antibodies also reversed the TGF-beta inhibition of EGF-induced DNA synthesis. Surprisingly, although TGF-beta attenuated EGF-induced DNA synthesis, it synergized with FSH to stimulate follicular DNA synthesis. Interestingly, FSH-induced DNA synthesis remained unaffected by the anti-TGF-beta antibodies, indicating that TGF-beta may not mediate FSH action on follicular DNA synthesis. These studies suggest that a critical interaction of EGF and TGF-beta modulates granulosa cell proliferation during folliculogenesis in the hamster.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1993

Transforming growth factor-beta potentiation of follicle-stimulating hormone-induced deoxyribonucleic acid synthesis in hamster preantral follicles is mediated by a latent induction of epidermal growth factor.

The mechanisms of transforming growth factor-beta (TGF-beta) potentiation of FSH action on follicular DNA synthesis in the hamster were investigated by use of TGF-beta (beta 1 and beta 2) and a potent epidermal growth factor (EGF)-specific polyclonal antibody. Preantral follicles at stages 1-6 and early antral follicles at stage 7 were enzymatically and mechanically isolated from adult golden hamsters on proestrus. Follicles were incubated in Dulbecco's modified Eagle's medium with ITS+ (6.25 micrograms insulin, 6.25 micrograms transferrin, 6.25 micrograms selenium, 1.25 mg BSA, and 5.35 micrograms linoleic acid/ml) hydrocortisone, and 1 microCi/ml [3H]thymidine. Follicles were exposed for 24 h to FSH (100 ng/ml), TGF-beta 1, and TGF-beta 2 (1 and 10 ng/ml), EGF antibody (50 microliters/ml), and TGF-alpha (50 ng/ml) under various experimental conditions. Both TGF-beta 1 and TGF-beta 2 significantly potentiated FSH-induced follicular DNA synthesis; however, the effect was drastically attenuated by EGF antibody. EGF antibody also inhibited FSH-induced follicular [3H]thymidine incorporation. TGF-beta 2 potentiation of FSH action was also significantly inhibited by a second dose of TGF-beta 2 when added 6 h after the beginning of culture; however, follicles at different stages responded differently to the second dose of TGF-beta 2. For example, when the second dose of TGF-beta 2 was added 14 h after the first dose, only the large preantral follicles at stages 4-6 were affected. Interestingly, the second dose of TGF-beta 2 also inhibited TGF-beta 2-induced DNA synthesis.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1993

Biliary bile acids in cholelithiasis and carcinoma of the gall bladder.

The role of biliary deoxycholate as an endogenous carcinogen and the possible association between cholelithiasis and the subsequent development of carcinoma of the gall bladder is unclear. This paper describes biliary bile acid analysis performed on three groups of patients, 10 with cholelithiasis, 10 with carcinoma of the gall bladder and 10 control patients. This is the first report of bile acid changes in carcinoma of the gall bladder. In these 30 patients the total bile acids concentration was highly variable (11.44-53.68 mg/ml). The mean ratio of primary to secondary bile acids was 3.5:1. This ratio was, however, significantly higher in cholelithiasis than in the control group (5.34:1; P < 0.001); patients with carcinoma of the gall bladder had significantly higher secondary bile acids (1:1; P < 0.001). This is due to a marked increase in the secondary bile acids and indicates that raised biliary deoxycholate concentrations are present in patients with carcinoma of the gall bladder and therefore may well be a factor in carcinogenesis.

Bile Acids and Salts↗

PubMed1993

Uterocutaneous fistula.

Fistulous communications of the uterus are relatively unknown. We report in this paper the first case to our knowledge of uterocutaneous fistula which developed following a septic abortion induced by introduction of Laminaria tent into the uterus.

Abortion, Septic↗

PubMed1993

Lipoxygenase activity in rat embryos and its potential for xenobiotic oxidation.

This paper reports dioxygenase activity in rat embryos and demonstrates for the first time the ability of rat embryo lipoxygenase (LO) to oxidize xenobiotics in vitro. Significant dioxygenase activity towards linoleic acid was found in cytosol isolated from rat embryos in different developmental stages on day 9 and 10 of gestation. All four xenobiotics tested were oxidized at significant rate by the LO in the presence of linoleic acid. Both dioxygenase activity and benzidine oxidation were inhibited by the known inhibitors of LO, i.e. nordihydroguaiaretic acid and eicosatriynoic acid. These findings suggest that LO may be an important pathway for xenobiotic metabolism in the rat embryo.

5,8,11,14-Eicosatetraynoic Acid↗

PubMed1993

Isolation and long-term culture of human preantral follicles.

OBJECTIVE: To isolate intact preantral follicles from the human ovary for in vitro studies. PROCEDURE: Premenopausal human ovary was digested by a mixture of collagenase and deoxyribonuclease (DNase) for 1 hour at 37 degrees C and for 36 hour at 4 degrees C. Intact preantral follicles at classes 1 and 2 were isolated and cultured for up to 120 hours in a serum-free Dulbecco's modified Eagle's medium (GIBCO, Grand Island, NY) with ITS+ (insulin, transferrin, selenium, linoleic acid, and bovine serum albumin; Collaborative Research, Bedford, MA) with or without FSH. Follicular DNA synthesis was measured by [3H]thymidine incorporation, whereas steroidogenic capacity was assessed by P, androstenedione (A), and 17 beta-E2 RIA. The morphology of long-term cultured follicles was studied by routine histologic procedure. RESULTS: A large number of intact, preantral follicles was efficiently dissociated from a portion of ovary. Morphologically, follicles were healthy and did not have any thecal layer. Follicle-stimulating hormone, in vitro, induced follicular DNA synthesis by 24 hours and antrum formation in class 2 follicles after 120 hours. Both class 1 and 2 follicles were able to produce a small basal amount of P and A, but they did not produce any measurable E2. However, both classes synthesized increasing amounts of P, A, and E2 after FSH exposure. CONCLUSION: This is a first report of a successful enzymatic isolation of human preantral follicles and their long-term culture in vitro. The growth and differentiation of preantral follicles by FSH clearly indicate the importance of FSH in human follicular development. These results provide an opportunity for quantitative studies on factors regulating folliculogenesis in the human and a novel future direction for human IVF.

Adolescent↗

PubMed1992

Cell-type-specific localization of transforming growth factor-beta 2 and transforming growth factor-beta 1 in the hamster ovary: differential regulation by follicle-stimulating hormone and luteinizing hormone.

Cell-type-specific localization and gonadotropin regulation of transforming growth factor-beta 1 (TGF-beta 1) and transforming growth factor-beta 2 (TGF-beta 2) in the hamster ovary were evaluated immunohistochemically under three conditions: (1) during the estrous cycle (Day 1 = estrus; Day 4 = proestrus); (2) after the blockade of periovulatory gonadotropin surges by phenobarbital, and (3) after FSH and/or LH treatment of long-term hypophysectomized hamsters. Ovarian TGF-beta 1 activity was primarily localized in theca and interstitial cells. The activity increased moderately but significantly after the preovulatory LH surge and reached a peak at 0900 h, Day 2 h; oocytes showed considerable activity. TGF-beta 1 immunoreactivity subsequently fell to low levels in theca-interstitial cells through 0900 h, Day 4. Significant TGF-beta 2 immunoreactivity appeared after the surge, mainly in the granulosa cells of both preantral and antral follicles; a few interstitial cells surrounding preantral follicles showed discrete staining. TGF-beta 2 immunoreactivity in granulosa cells and in interstitial cells next to preantral follicles reached a peak at 0900 h, Day 1, and persisted up to 0900 h, Day 2; oocytes showed no staining. Phenobarbital treatment blocked the appearance of TGF-beta 1 and TGF-beta 2 immunoreactivities at 1600 h, Day 4; however, a rebound in immunoreactivities was observed with the onset of the surge after a 1-day delay. Replacement of LH to long-term hypophysectomized hamsters resulted in a marked increase in TGF-beta 1 immunoreactivity in the interstitial cells, but FSH, although it induced follicular development, did not influence ovarian TGF-beta 1 activity. Treatment with FSH, however, induced a massive increase in TGF-beta 2 immunoreactivity in the granulosa cells of newly developed antral and preantral follicles but not in the interstitial cells; LH, on the other hand, had no significant effect on TGF-beta 2 activity. Treatment with FSH and LH combined resulted in a dramatic increase in TGF-beta 2 immunoreactivity in granulosa and interstitial cells and in TGF-beta 1 in theca and interstitial cells comparable to their peak activity in intact animals. Western analyses substantiated the presence of TGF-beta 1 and TGF-beta 2 in the hamster ovary and the specificity of immunolocalization. These studies, therefore, provide critical evidence that TGF-beta 1 and TGF-beta 2 in the hamster ovary are expressed in specific cell types and that their expression is differentially regulated by LH and FSH, respectively.

Animals↗

PubMed1992

Impact of zinc supplementation on intestinal permeability in Bangladeshi children with acute diarrhoea and persistent diarrhoea syndrome.

Zinc has been shown to enhance intestinal mucosal repair in patients suffering from acrodermatitis enteropathica; but the impact on mucosal integrity during acute (AD) or persistent (PD) diarrhoea is unknown. One hundred eleven children with AD and 190 with PD aged between 3 and 24 months received, randomly and blind to the investigators, either an elemental zinc supplement of 5 mg/kg body wt/day or placebo in multivitamin syrup for 2 weeks while intestinal permeability and, biochemical and anthropometric markers were serially monitored. The permeability test was administered as an oral dose of 5 g lactulose/l g mannitol in a 20-ml solution followed by a 5-h urine collection. The ratio of the urinary probe sugars was correlated to clinical, biochemical, and microbiological parameters. At presentation, lactulose excretion was increased and mannitol excretion decreased in both AD and PD as compared with age-matched asymptomatic children. The lactulose/mannitol ratio (L/M) was higher in subjects with mucosal invasive pathogens (rotavirus and enteropathogenic Escherichia coli) compared with children excreting Vibrio cholera and enterotoxigenic E. coli. Two-week zinc supplementation significantly reduced lactulose excretion in both AD and PD, whereas the change in mannitol excretion and L/M was similar between study groups in both studies. Changes in lactulose excretion were significantly influenced by zinc supplementation in children with E. coli, Shigella sp., and Campylobacter jejuni stool isolates. The greatest reduction in total lactulose excretion was seen in supplemented children who on presentation were lighter (wt/age less than 80%), thinner (wt/ht less than 85%), and undernourished [middle upper arm circumference (MUAC) less than 12.5 cm] or with hypozincaemia (less than 14 mumol/L).(ABSTRACT TRUNCATED AT 250 WORDS)

Acrodermatitis↗

PubMed1992

Persistent diarrhoea: factors affecting absorption and clinical prognosis during management with a rice-based diet.

Twenty-six persistent diarrhoea patients aged 4 to 18 months were treated with a diet prepared with rice powder, soya oil, glucose, egg white and water. Absorption of macronutrients was estimated in a 72 h balance study and clinical response was examined during one week of dietary treatment. Nutrient absorption was compared with that of 25 healthy age-matched controls treated with the same diet. Twenty-one patients (81%) recovered from diarrhoea within seven days. Absorption of nutrients was significantly reduced among the persistent diarrhoea patients. More malnourished patients had a significantly reduced absorption of nutrients except carbohydrate and an increased severity and longer duration of diarrhoea. Total gut transit time had significant association with nutrient absorption in the persistent diarrhoea patients. The period of recovery negatively correlated with coefficient of absorption and positively with initial stool weight. Failure to recover was associated with severity of diarrhoea and systemic infection. The study indicates that nutrient absorption is significantly reduced in patients with persistent diarrhoea and nutritional status, and that initial purging rate and intestinal hurry are significantly related to the prognosis and nutrient absorption.

Arm↗

PubMed1992

Effect of Vibrio cholerae-L-asparaginase on surface structure of splenic lymphocytes.

The surface ultrastructure of splenic lymphocytes and rosetting properties of lymphocytes of Swiss mice were studied under scanning electron microscope following transplantation of Dalton's lymphoma and ascites fibrosarcoma tumour cells and administration of Vibrio cholerae-L-asparaginase. The results were compared to those obtained with the standard Escherichia coli-L-asparaginase. The surface structure of the lymphocytes (T cells) following L-asparaginase administration was not so different from that of normal lymphocytes. V. cholerae-L-asparaginase did not cause higher number of rosette formation in T cells as compared to the normal group. The study thus revealed that V. cholerae-L-asparaginase did not have a significant stimulatory or non-immunosuppressive effect on the lymphocyte functions.

Animals↗