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Biomedical subjects

A Ghosh

Publications and source records attributed to A Ghosh.

At least 289 records · Page 16Linked to original sources
PubMed1991

Changes in plasma gangliosides in relation to tumor growth modified by vitamin A.

Treatment of Swiss male mice with vitamin A at a dose of 100 IU/mouse could inhibit the growth of Ehrlich ascites tumor in these mice almost by 50%, whereas a dose of 250 IU/mouse enhanced the growth of same tumor by 60%. The inhibitory and enhancing effects of vitamin A on tumor growth were reflected in the change in concentration of gangliosides of plasma. However, changes were quite different in those two cases. Out of six gangliosides detected in the plasma of tumor-bearing mice only three were observed to be related to the tumor growth regulatory effect of vitamin A.

Animals↗
PubMed1991

Inhibition of clastogenic effects of cesium chloride in mice in vivo by chlorophyllin.

The antagonistic effect of chlorophyllin was tested in reducing the clastogenic action of cesium chloride (CsCl) in vivo on mice bone marrow cells. CsCl induced chromosomal aberration in frequencies directly proportional to the dose administered. Chlorophyllin, when given alone, was not clastogenic even at a concentration of 1.5 mg/kg body wt. of the animal. Simultaneous administration of chlorophyllin and CsCl reduced chromosomal aberrations significantly at 24 h. Exposure to the same dose of chlorophyllin 2 h before exposure to CsCl also decreased clastogenic effects but to a lesser extent. These findings are of importance in view of the uptake of radioactive Cs by green plants after nuclear fallout.

Animals↗
PubMed1991

Mosaic partial trisomy 17q2.

Examination of an infant born after prenatal diagnosis of mosaic partial trisomy 17q2 showed the unique phenotypic features of this chromosomal abnormality, that is, frontal bossing, large mouth, brachyrhizomelia, and hexadactyly. Amniocentesis was performed because of polyhydramnios and ultrasound diagnosis of fetal craniofacial dysmorphology and rhizomelic shortening of the limbs. Chromosomal mosaicism was restricted to fetal tissue and amniotic fluid cells. The placental chromosomal complement was normal, suggesting that the abnormality developed after differentiation of embryonic and trophoblastic cells. This emphasises the usefulness of cytogenetic evaluation of placental, fetal, and amniotic fluid cells in delineating the pathogenesis of congenital abnormalities.

Abnormalities, Multiple↗
PubMed1991

Effect of lignocaine on blood lipid in relation to partition coefficient and biological activity.

To correlate lipophilicity of lignocaine with changes in lipid composition of blood as a result of in vitro incubation with the drug, phosphorus content and fatty acid compositions of blood lipids before and after lignocaine treatment have been compared with those of a standard phospholipid, lecithin, under similar conditions of drug treatment. The change in fatty acid constituents has been correlated with the biological activity (both therapeutic and toxic) of lignocaine.

Animals↗
PubMed1991

Stimulation of thrombopoiesis in mice bearing experimental tumors.

Significant increase (p less than 0.05) in circulating platelet counts was observed in a wide spectrum of experimental tumors in mice. The mechanism of this abnormality was investigated in strain A mice bearing a transplantable ascites tumor, Sarcoma 180 (S 180). Thrombocytosis observed in the tumor hosts was not due to prolonged platelet surviva], as 51Cr platelet half-life was normal. On the other hand, stimulation of thrombopoiesis, expressed in terms of platelet 75Selenomethionine (75SeM) incorporation, appeared to be the primary reason for elevated platelet counts in the tumor-bearers. Evaluation of thrombopoietic activity in the femoral marrow and spleen by measuring organ uptake of 75SeM and megakaryocyte counts indicated that tumor-induced stimulation in thrombopoiesis may be attributed to enhancement in splenic activity. Pretreatment of normal mice with tumor ascites or tumor cell-conditioned medium resulted in enhancement in thrombopoiesis. The findings suggest the production of some factor(s) by the tumor cells which probably mediate the stimulation of platelet production in tumor hosts.

Animals↗
PubMed1990

Effect of plasma gangliosides on the growth of Ehrlich ascites tumor.

Total plasma gangliosides of Ehrlich ascites tumor-bearing mice enhanced tumor growth when adoptively transferred with the same tumor cells in mice. However, individual gangliosides acted differently. Out of 6 gangliosides separated from plasma, 2 components enhanced tumor growth, whereas the remaining 4 inhibited tumor growth. Neither of the 2 enhancing components in various combinations with the 4 inhibitory components could restore the enhancing effect. The enhancing effect was restored only when both the enhancing components were mixed with the remaining 4 ganglioside components, i.e., with full/complete reconstitution.

Animals↗
PubMed1990

Requirement for subplate neurons in the formation of thalamocortical connections.

The neurons of layer 4 in the adult cerebral cortex receive their major ascending inputs from the thalamus. In development, however, thalamic axons arrive at the appropriate cortical area long before their target layer 4 neurons have migrated into the cortical plate. The axons accumulate and wait in the zone below the cortical plate, the subplate, for several weeks before invading the cortical plate. The subplate is a transient zone that contains the first postmitotic neurons of the telencephalon. These neurons mature well before other cortical neurons, and disappear by cell death after the thalamic axons have grown into the overlying cortical plate. The close proximity of growing thalamocortical axons and subplate neurons suggests that they might be involved in interactions important for normal thalamocortical development. Here we show that early in development the deletion of subplate neurons located beneath visual cortex prevents axons from the lateral geniculate nucleus of the thalamus from recognizing and innervating visual cortex, their normal target. In the absence of subplate neurons, lateral geniculate nucleus axons continue to grow in the white matter past visual cortex despite the presence of their target layer 4 neurons. Thus the transient subplate neurons are necessary for appropriate cortical target selection by thalamocortical axons.

Animals↗
PubMed1990

Neural influence on the action of insulin in the adrenomedullary catecholamine content in the pigeon.

Insulin-induced (4 IU/100 g b.wt.) changes of adrenomedullary catecholamines (CA) were investigated in unilaterally splanchnic denervated pigeons 0.5, 4, 12, 24, 72, 144 and 216 h after injection. Insulin caused depletion of more norepinephrine (NE) from the denervated glands 0.5 h after treatment. This indicates that the splanchnic nerve prevents early phase of insulin-induced depletion of NE. Accelerated resynthesis of NE exceeding the control value was more in the innervated glands 24 h after administration. Insulin brought about augmented synthesis of epinephrine (E) surpassing the control value in the innervated glands 72 h after treatment. The findings point out that the splanchnic nerve stimulates resynthesis of NE and synthesis of E induced by insulin.

Adrenal Glands↗
PubMed1990

Simultaneous pulsed Doppler velocimetry of fetal aorta and inferior vena cava. Diagnosis of fetal congenital heart block; two case reports.

A simple technique for the diagnosis of fetal congenital heart block by simultaneous Doppler blood-flow velocimetry of the fetal abdominal aorta and inferior vena cava is described. Furthermore, a simple method of monitoring the fetal atrial reactivity during the antenatal period; and simultaneous recording of atrial and ventricular rates during labour are also described. These simple techniques can be applied for the diagnosis and monitoring of the fetus in other types of cardiac arrhythmias.

Adult↗
PubMed1990

Clastogenic effects of cesium chloride on mouse bone marrow cells in vivo.

Clastogenic effects of cesium chloride (CsCl) on mouse bone marrow cells in vivo following oral administration were studied after 24 h. The incidence of chromosome aberrations increased linearly with increasing concentrations of the chemical from 1/20th to 1/5th of the LD50. The frequency of cell division was also enhanced by the lower doses but higher doses were mitostatic. This report is the first on the clastogenicity of cesium on animals.

Administration, Oral↗
PubMed1990

Recombinant interleukin-2 (rIL-2) with flavone acetic acid (FAA) in advanced malignant melanoma: a phase II study.

Recombinant interleukin 2 (rIL-2) and flavone acetic acid (FAA) were used to treat 34 patients with progressing metastatic melanoma. Five patients had solely non-visceral disease and the median number of organ sites involved was two. Five doses of rIL-2 were given, the first dose intrasplenically via a femoral artery catheter with a further dose 4 h later i.v. and the other doses i.v. on alternate days. The rIL-2 dose was 11 x 10(6) Cetus units m-2; the day before rIL-2, FAA (4.8 G m-2) was given as a 6 h i.v. infusion, in order to enhance further killer cell activity. A total of three courses at 21-day intervals was planned and 74 courses in all were given. Despite the high dose of rIL-2 and the potential overlapping toxicity affecting blood pressure with the addition of FAA, side-effects were generally mild. There were only five episodes of grade 4 toxicity: one of ventricular tachycardia and four other episodes of transient biochemical or haematological disturbance. Grade 3 hypotension or hypertension occurred on 22 courses but again was transient. No patient required intensive care facilities. Five patients had tumour response, one being complete. Responses occurred in pulmonary and hepatic metastases, but mainly in non-visceral sites. Eleven patients remain alive at 6-17 months and in five there is no relapse or progression of disease. Despite the impressive results in animal tumour models, the addition of FAA to rIL-2 in the present study has not markedly improved results over rIL-2 alone.

Adjuvants, Immunologic↗
PubMed1990

Effect of stress on the catecholamine content of the adrenal gland of intact and bursectomized chicks.

1. Bursa-intact and bursectomized chicks were exposed to cold-wet immobilization (CWI) stress for 1.5 min. The catecholamines (CA) from the adrenal gland were measured spectrofluorometrically 5, 15, 30 and 60 min after stress. 2. In bursa-intact chicks, the CWI stress caused decrease of both norepinephrine and epinephrine from the adrenal glands 5 min after stress. Resynthesis of epinephrine exceeded the control value 30 and 60 min after stress. 3. In bursectomized chicks, the CWI stress brought about a decrease of norepinephrine 15 and 30 min and of epinephrine 30 and 60 min after stress. 4. The findings suggest that bursa facilitates early (5 min) release of CA and also helps in quick resynthesis of epinephrine during stress.

Adrenal Glands↗