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Biomedical subjects

S D Bhatt

Publications and source records attributed to S D Bhatt.

18 recordsLinked to original sources
PubMed1998

Mosaic trisomy 16 ascertained through amniocentesis: evaluation of 11 new cases.

Trisomy 16, once thought to result uniformly in early pregnancy loss, has been detected in chorionic villus samples (CVS) from on-going pregnancies and was initially ascribed to a second, nonviable pregnancy. Prenatally detected trisomy 16 in CVS and its resolution to disomy has led to the reexamination of the viability of trisomy 16. This study evaluates 11 cases of mosaic trisomy 16 detected through second trimester amniocentesis. In 9 of the 11 cases, amniocenteses were performed in women under the age of 35 because of abnormal levels of maternal serum alpha-fetoprotein (MSAFP) or maternal serum human chorionic gonadotropin (MShCG). The other two amniocenteses were performed for advanced maternal age. Five of the 11 pregnancies resulted in liveborn infants, and six pregnancies were electively terminated. The liveborn infants all had some combination of intrauterine growth retardation (IUGR), congenital heart defects (CHD), or minor anomalies. Two of them died neonatally because of complications of severe congenital heart defects. The three surviving children have variable growth retardation, developmental delay, congenital anomalies, and/or minor anomalies. In the terminated pregnancies, the four fetuses evaluated by ultrasound or autopsy demonstrated various congenital anomalies and/or IUGR. Cytogenetic and fluorescent in situ hybridization studies identified true mosaicism in 5 of 10 cases examined, although the abnormal cell line was never seen in more than 1% of cultured lymphocytes. Placental mosaicism was seen in all placentas examined and was associated with IUGR in four of seven cases. Maternal uniparental disomy was identified in three cases. Mosaic trisomy 16 detected through amniocentesis is not a benign finding but associated with a high risk of abnormal outcome, most commonly IUGR, CHD, developmental delay, and minor anomalies. The various outcomes may reflect the diversity of mechanisms involved in the resolution of this abnormality. As 80% of these patients were ascertained because of the presence of abnormal levels of MSAFP or MShCG, the increased use of maternal serum screening should bring more such cases to clinical attention.

Amniocentesis↗
PubMed1989

Myocardial dysfunction in diabetic rats: influence of beta-adrenoceptor blockade (propranolol).

The effects of a beta-blocker, propranolol, on the enzyme and isoenzyme activities in the heart muscle in vitro and concomitant histopathology of the component cells of the islets of Langerhans were studied in the Wistar rats after treatment with streptozotocin and isoproterenol. The biochemical data indicated that the isoproterenol induced myocardial infarction (MI) precipitates an acute diabetic response in the rat heart. The superimposition of MI in diabetes mellitus caused significant inhibition of phosphofructokinase and hexokinase in the heart muscle. The lactate dehydrogenase depicted shifting of H-type to M-type in diabetes with or without MI. The drugs, when administered in combination, brought distinctive histopathological changes in beta-cells of the pancreatic islets including degranulation, hyalinosis and a near-total destruction; however A and D cells remained more or less unaffected. The effect of propranolol in diabetes mellitus was uncertain but in MI with or without prior diabetes, the drug inversely altered the activities of all the cardiac enzymes, besides stimulating a mild recuperation of the cells of the endocrine parenchyma.

Animals↗
PubMed1986

Pituitary gland of the exotic carp, Carassius carassius Linn., with reference to the histocytology of the adenohypophysis in conjunction to male and female rhythms of reproduction.

The pituitaries of the exotic carp (Carassius carassius) are studied at the light microscopic level, for the characterization of the adenohypophysial cell-types with particular emphasis to the gonadotropic potency of the pituitary in relation to the annual reproductive patterns. The gland in the fish is of the cranioleptobasic type. Based on the classical staining methods and localization of the differential cell-types, the adenohypophysis of the fish can be subdivided into the rostral (RPD) and proximal (PPD) pars distalis and the pars intermedia (PI). The pars nervosa (PN) of the fish consists of the neurosecretory (NS) fibres which show varied accumulations of the NS material in concert with the seasonal reproductive cycle. The NS tract is constituted of AF--ve nucleus praeopticus and AF + ve nucleus lateralis tuberis. 2 tinctorially different cell-types, corresponding to corticotrops and lactotrops of other teleosts, are identifiable in the RPD of the present species. In the PPD, 3 cell-types can be distinguished with various granule-staining procedures: they represent somatotrops, thyrotrops, and gonadotrops. Further, 2 gonadotropic cells with apparently different staining properties are discernible. In the PI are dispersed besides a few agranular cells, islets of 2 kinds of cells separable with combined PAS-PbH technique. Seasonal changes in the gonadosomatic index and diameter of the testicular lobules and egg diameter as indices of gonadal maturation are found to be closely interwoven with the morphometric alterations in the basophilic cell area (BCA) chosen as criterion of gonadotropic potency of the PPD. The maximum BCA values are preceded with the time of greatest atresia of the eggs indicating the influence of the pituitary gonadotropins in the follicular resorption in the test fish.

Acclimatization↗
PubMed1980

Insulin effects in clarias batrachus L.: a combined biochemical and anatomical study.

The effect of mammalian insulin was studied in a freshwater fish, Clarias batrachus, at both high and low ambient temperatures. The hormone produced a significant but delayed, yet recoverable, lowering of blood glucose, a concurrent decrease in liver glycogen, and an increase in the glycogen content of muscles. The decrease in brain glycogen occurred during advanced hypoglycemia. Hypoglycemic seizures developed intermittently in most of the fishes whose plasma glucose and brain glycogen levels had been considerably depleted. Necrobiotic changes in the pancreatic islets, including degranulation and atrophy, and necrosis of B cells, were seen in the treated fish. In some cases damage to A cells and the acinar tissue was also observed. With the restitution of normal glucose and glycogen values, the islet cells also seemed to have recuperated. Changes in glycemia, glycogen, and the islets were more pronounced in the fishes held at 24 degrees C than in those at 10 degrees C, indicating that the ambient temperature plays an important role in blood glucose homeostasis as well as insulin.

Animals↗
PubMed1976

Histopathology of the endocrine pancreas of a fresh-water fish, Clarias Batrachus L. VII. Effects of hydrocortisone and thyroxine administration.

Hydrocortisone treatment caused a hyperglycaemic state in Clarias batrachus within an hour. The blood glucose values remained significantly increased for 6 days. An initial increase in liver glycogen was followed by a decrease below the normal value. The muscle and brain glycogen levels remained unaffected. A mild degranulation of B cells was seen in the early hours and a conspicuous vacuolation and necrosis of both A and B cells appeared 72-96 h after treatment. Administration of thyroxine resulted in hyperglycaemia within 15 h but a distinct hypoglycaemic condition was seen 4 days after the treatment. Considerable drain in the liver glycogen deposits was noticed between 24 and 72 h while the muscle glycogen showed an increase. The brain glycogen did not change noticeably. Islets of the fishes autopsied between 72 and 96 h contained severely damaged B cells. The A cells remained unaffected. It is suggested that, in addition to several other hormones, hydrocortisone and thyroxine play an important role in carbohydrate metabolism and blood sugar homoeostasis in C. batrachus.

Animals↗
PubMed1975

Histopathology of the endocrine pancreas of a fresh-water fish, Clarias batrachus (L.). V. Effect of epinephrine administration.

Intramuscular administration of epinephrine in 2 mg/kg and 5 mg/kg body weight doses to Clarias batrachus caused significant hyperglycemia between 12 and 18 h after treatment. The hormone produced a small decrease in the liver glycogen, but induced a notable fall in the glycogen of muscles and a transient increase in the brain glycogen. Light-microscopical examination of the pancreatic islets revealed degranulation and vacuolization of the beta-cells accompanied by acute necrosis. Damage to the alpha-cells was also noticed in hyperglycemic fish. The changes in the cellular configuration of the islets, blood glucose and on the tissue glycogen contents were dose-dependent. It is suggested that epinephrine alters the carbohydrate metabolism through the alpha-cells of the islets.

Animals↗
PubMed1975

Cellular composition of the islets of langerhans in the himalayan toad, Bufo melanostictus (Schneider): a light microscopical study.

The pancreatic islet tissue of Bufo melanostictus, investigated by differential staining techniques, is generally condensed in the anterior and middle regions, and contains distinguishable islets of various size, shape and or irregular configuration. Histologically, 3 distinct cell types have been identified: B, A1 and A2. Various tinctorial characteristics of B cells reveal that they correspond to the insulin producing B-cells of other vertebrates. The A cells are a few in number, some of which definitely show positive argyrophilia (= A1). A few isolated A- and B-cells are found scattered in the exocrine tissue. A conspicuous feature of several B-cells in some specimens of Bufo melanostictus is the presence of vacuoles of varying size.

Animals↗
PubMed1975

Histopathology of the endocrine pancreas of a fresh-water fish, Clarias batrachus (L.) IX: Effect of the new antidiabetic drug, glibenclamide (HB 419).

Oral administration of glibenclamide, the new antidiabetic drug, caused hypoglycemia in Clarias batrachus. The effect was maximal at 15 hours, when some fish had practically no sugar in their plasma. The hypoglycemic effect was insignificant in partially-pancreatectomized fish, indicating that the drug potentiated the effect of insulin in such animals. In fasting normal fish, the drug provoked an increase in the liver glycogen contents while in the diabetic animals, a reverse condition occurred. Significant beta-cell degranulation and vacuolisation was noted in the Langerhans' islets, the effect being synchronous with hypoglycemia. In a few cases, the alpha-cells had also undergone degenerative changes. No significant side effects and discerneable toxicity was observed in the treated-fish. It is stipulated that the drug is endowed with the beta cytotropic property.

Animals↗
PubMedDate not supplied

Effects of some drugs on islet function in catfish.

Blood glucose variations and concomitant bioptical cytopathological changes in the pancreatic islets following treatment with certain drugs were studied in the catfish. Glucose loading produced a dose-related hyperglycemia, maximum within 3 hr, while alloxan caused a biphasic rise in glucose level without induction of permanent diabetes. Streptozotocin elicited a monophasic hyperglycemic state at a lower dose and biphasic response at higher doses. Glybenclamide produced hypoglycemia in normal and sham-operated fish; the depancreatized animals were unresponsive to this treatment. In all the cases, normoglycemic values were restituted within 4 days of the treatment. The beta-cells of the islets underwent varying histopathological changes with signs of regenerative activity. A depletion in heavy metal (zinc) in these cells was also evident after treatment with streptozotocin.

Alloxan↗