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Biomedical subjects

K C Das

Publications and source records attributed to K C Das.

At least 73 records · Page 4Linked to original sources

Anorexia after adrenalectomy in gold thioglucose-treated obese mice.

The effects of adrenalectomy on food intake, weight gain, plasma glucose, and corticosterone levels were investigated in normal untreated controls and gold thioglucose-(GTG) treated hyperphagic obese mice. Adrenalectomy of normal untreated mice was followed by a transient reduction in food intake and body weight with a return, after approximately 7 days, to levels which paralleled those of untreated sham-operated mice. Plasma corticosterone levels were significantly depressed in all untreated adrenalectomized mice. Plasma glucose levels were not affected by adrenalectomy. In sharp contrast to the response of untreated adrenalectomized mice, adrenalectomy of GTG-treated hyperphagic obese mice was followed by a sudden and persistent drop in food intake (anorexia) and body weight. These mice were unable to maintain their body weight. Despite this condition, the mice did not appear to be physically debilitated until a short time (6-12 h) before their death which was preceded by a period of severe hypoglycemia. These findings indicate that the hyperphagia and weight gain of GTG-treated obese mice is dependent on adrenal hormones. The anorexia after adrenalectomy of GTG-treated hyperphagic obese mice may be the result of a direct dependence of central or peripheral structures involved in the regulation of food intake on adrenal hormones. Alternatively, these structures may be affected by the action of metabolites or hormones which arise as a consequence of adrenal insufficiency.

Adrenalectomy↗

Haemoglobin E-beta-thalassaemia; a study of eight cases in Northwest India.

Eight cases of haemoglobin E-beta.thalassaemia are described. Seven of them are natives of Punjab, a Northwest province of India, and one is a native of Rajasthan, a province adjacent to Punjab. Hb E is rarely encountered in Punjab, but beta-thalassaemia is relatively common. The interaction of Hb E with beta-thalassaemia resulted in a varying severity of phenotypic manifestations. An extraordinary feature in 3 out of 8 cases was the presence of a high percentage of Hb E (94 to 96%) and proportionately low Hb F (4 to 6%). The interacting thalassaemia in 5 patients was of beta0 type and in 3 patients of beta+ type.

Adolescent↗

Inhibition by hypophysectomy of the hyperphagia and obesity following gold thioglucose.

The effect of hypophysectomy in mice previously treated with gold thioglucose (GTG) was studied with respect to changes in food intake and development of obesity. As expected, all mice treated with GTG alone exhibited lesions in the ventromedial hypothalamus (VMH), hyperphagia and obesity. Hypophysectomy of GTG treated mice prevented the appearance of hyperphagia and obesity. Daily administration of the adrenal corticoid, cortisone, completely restored the hyperphagia and obesity in GTG treated hypophysectomized mice. The amounts of cortisone used did not appreciably affect food intake or body weights of normal, hypophysectomized or GTG treated mice. These findings indicate that the hypothalamic hyperphagia and obesity which normally follows the administration of GTG is dependent on a functional pituitary gland. Furthermore, the specific ability of an adrenal corticoid to completely restore the hyperphagia and obesity of GTG treated hypophysectomized mice in the absence of other pituitary factors, suggests that the pituitary adrenal axis serves as an important link in the regulatory mechanism for control of feeding behavior in the mouse.

Adrenal Glands↗

Effect of folate deficiency on the reproductive organs of female rhesus monkeys: a cytomorphological and cytokinetic study.

The effect of folate deficiency was studied on the cytomorphology and the kinetics of proliferation of ovarian granulosa cells, and the epithelial cells lining the uterus, cervix and vagina of six sexually mature female rhesus monkeys. The cellular kinetics were study by in vivo labeling with [3H]thymidine, followed by autoradiography of the histological sections of tissue biopsies taken at various time intervals and labeled mitosis curves. The folate-deficient monkeys showed an increased number of atresic and cystic ovarian follicles with depletion of granulosa cells. There was also a significant impairment of the proliferation kinetics of granulosa cells as indicated by decreased [3H]thymidine labeling index (L.I.), and marked prolongation of the pre- DNA-synthetic time (G1 phase); the DNA-synthetic (S phase) and postsynthetic (G2 phase) periods were only mildly prolonged. These changes may have impaired the ovarian synthesis of the steroidal hormones, estrogen and progesterone. The cervico-vaginal epithelium showed megaloblastosis, multinucleation and impairment of orderly proliferation and maturation. Less pronounced changes were also seen in the uterus. The cytomorphological and functional disturbances in the uterus, cervix and vagina may be partly secondary to those in the ovaries, and partly due to the depletion of their essential folate coenzymes.

Animals↗

Gold thioglucose-induced hypothalamic damage, hyperphagia, and obesity: dependence on the adrenal gland.

Previous studies from our laboratory suggested that adrenal hormones may participate, directly or indirectly, in the hypothalamic mechanism involved in the regulation of food intake. In the present studies, the effect of adrenalectomy on the development of gold thioglucose (GTG)-induced hyperphagia and obesity in mice was investigated. As expected, damage to the ventromedial hypothalamus by GTG was followed by hyperphagia and obesity. Ablation of the adrenal glands after the administration of GTG prevented the onset and development of hyperphagia and obesity. The administration of cortisone completely restored the hyperphagia and weight gain of GTG-treated adrenalectomized mice. The administration of desoxycorticosterone not only failed to restore the hyperphagia and obesity in these mice but, rather, led to a suppression of food intake, weight loss, and death. It is concluded that 1) GTG-induced hypothalamic hyperphagia and obesity are dependent on adrenal glucocorticoids, and 2) the ability of adrenal glucocorticoids to restore hyperphagia and obesity in hypothalamic lesioned adrenalectomized mice indicates that adrenal glucocorticoids can act on compounds outside of the ventromedial hypothalamus involved in the control of food intake.

Adrenal Glands↗

Hemostatic abnormalities following Echis carinatus (saw-scaled viper) envenomation in the rhesus monkey.

Hemostatic abnormalities following lethal and sublethal doses of Echis carinatus venom were studied in a subhuman primate model. The observations suggest the occurrence of disseminated intravascular coagulation of varying magnitude within a few hours of envenomation. A procoagulant effect of the venom of Echis carinatus is likely to be the major cause of the disturbance in the hemostatic mechanism.

Animals↗

In vitro DNA synthesis by bone marrow cells and PHA-stimulated lymphocytes. Suppression by nonradioactive thymidine of the incorporation of 3H-deoxyuridine into DNA: enhancement of incorporation when inadequate vitamin B12 or folate is corrected.

Previous studies demonstrated that excess deoxyuridine (dU) added to short-term bone marrow and PHA-stimulated lymphocyte cultures, blocks the incorporation of radioactive thymidine into DNA via the salvage pathway. In the current study, we investigated the effects of added thymidine (TdR) in varying concentrations (10(-6) to 1 mumol) on the incorporation of 3H-dU into thymine-DNA, i.e. we executed 'thymidine suppression tests.' Increasing concentrations of exogenous TdR caused progressive inhibition of 3H-dU incorporation into DNA, and decreasing 3H-dU incorporation was parallelled by increasing incorporation of added 14C-TdR. These findings demonstrate reciprocity of the salvage and the de novo pathways of thymine-DNA synthesis, presumably mediated by thymidine-triphosphate (dTTP), the common end product of both pathways, via feedback inhibition. In patients with folate and/or vitamin B12 deficiency, the addition of appropriate vitamins to marrow and lymphocyte cultures enhanced the incorporation of 3H-dU into DNA. As predicted, this was not observed in normal subjects. The enhancing effect of these vitamins on in vitro incorporation of 3H-dU into DNA by deficient cell systems was similar to their correcting effect on abnormal dU suppression. These findings support the theoretical concept that the dU suppression test defines biochemical megaloblastosis due to deficiency of folate and vitamin B12.

Bone Marrow↗

Derangement of DNA synthesis in erythroleukaemia. Normal deoxyuridine suppression and impaired thymidine incorporation in bone marrow culture.

Deoxyuridine (dU) suppression test (i.e. ability of exogenous dU to suppress the incorporation of subsequently added 3H-thymidine into DNA) and the incorporation of 3H-thymidine (3H-TdR) alone without dU were studied in bone marrow cultures from 10 patients with erythroleukaemia, 10 patients with vitamin B12/folate-deficient megaloblastic anaemia and 10 haematologically normal subjects. Despite morphological resemblance between megaloblastosis in erythroleukaemia and nutritional megaloblastosis, the dU suppression values in erythroleukaemia were within normal range in contrast to abnormal dU suppression in vitamin B12/folate-deficient megaloblastic bone marrows. The incorporation of 3H-thymidine alone was significantly lower in erythroleukaemia than in normal or vitamin B12/folate-deficient megaloblastic bone marrows. Autoradiographic studies showed that 3H-TdR labelling indices as well as mean grain count (MGC) of basophilic and polychromatic erythroblasts were significantly lower in erythroleukaemia than in normal or vitamin B12/folate-deficient bone marrows. The reduced incorporation of 3H-TdR in erythroleukaemia erythroblasts was probably not due to deficiency of the salvage pathway enzyme, thymidine kinase, since MTX (10(-5) M) which blocks the de novo pathway of thymine-DNA synthesis, enhanced the incorporation of 3H-TdR into erythroblasts in erythroleukaemia as well as in normal bone marrows. A high intracellular pool of thymidine-triphosphate (dTTP) due to defective DNA synthesis may allosterically inhibit thymidine kinase and 3H-TdR incorporation.

Adolescent↗

Sea-blue histiocytes in idiopathic thrombocytopenic purpura. The first report from the Indian subcontinent.

Sea-blue histiocytes are described in the bone marrow of a 15-year-old male patient suffering from idiopathic thrombocytopenic purpura. Cytochemically the storage material in these cells appeared to be glycophospholipid. Lipid analysis of blood leucocytes and nucleated cells of bone marrow showed a significant increase in the phospholipids, triglycerides and cholesterol as compared to age-matched controls. Serum lipid analysis showed a mild increase of phospholipids as compared to age-matched controls.

Adolescent↗