Biomedical subjects
N Ghosh
Publications and source records attributed to N Ghosh.
Acute phase response of rabbit to HgCl2 and CdCl2.
A variety of changes occur in the rabbit under metal stress which include the appearance of the acute phase protein, C-reactive protein in the serum and significant reduction in the serum titres of albumin and acetylcholinesterase. The phospholipid profile is positively correlated with the higher degree of tissue necrosis encountered in mercury treated rabbit. Cadmium and mercury treatments evoke a similar response pattern in rabbit differing only in the degree of change.
Purification of uridine diphosphate-galactose:glucosyl ceramide, beta 1-4 galactosyltransferase from human kidney.
A galactosyltransferase that transfers galactose from UDP-galactose to glucosylceramide was purified 440-fold to apparent homogeneity from normal human kidney "buffy coat" preparation employing detergent extraction, ultrafiltration, and Sepharose Q column chromatography. On reducing and nonreducing gels, the enzyme resolved into two bands with apparent molecular weights on the order of 60,000 and 58,000, respectively. The activity of the enzyme was also associated with these two bands following separation on polyacrylamide gels. Analytical isoelectric focusing revealed that the pI of this enzyme is approximately 4.55. Product characterization and substrate specificity studies employing chromatography, enzymatic digestion with various glycosidases, and use of a variety of glycosphingolipid substrates revealed that the major product synthesized by this enzyme was Cer1-1 beta Glc4-1Gal, and Cer1-1 beta Glc was the preferred substrate. Digestion of the 60- and 58-kDa proteins with Staphylococcus aureus (V-8) protease revealed at least six peptides having identical electrophoretic migration. This finding suggests that the two proteins may be related to each other. Western immunoblot assays revealed that the antibody against UDP-galactose:GlcCer, beta 1-4 galactosyltransferase (GalT-2) but not galactosyltransferase UDP-Gal:N-acetyl-D-glucosaminyl-glycopeptide 4-beta-D-galactosyltransferase (EC 2.4.1.38) (B-GT) immunoprecipitated (recognized) the kidney GalT-2. In contrast, antibody against B-GT did not immunoprecipitate GalT-2. Thus our data indicate that GalT-2 and B-GT are two distinct enzymes. The availability of the enzyme GalT-2 and corresponding antibody will allow functional studies in the near future.
Comparison of plasma prolactin and CEA in monitoring patients with adenocarcinoma of colon and rectum.
Plasma prolactin (PRL) and carcinoembryonic antigen (CEA) were measured by radioimmunoassay in 74 patients with adenocarcinoma of colon and rectum. The markers were correlated with disease stage, histological grade and progression/remission of disease. The circulating preoperative median PRL and CEA levels were significantly higher in colorectal cancer patients than in their respective controls. PRL was elevated in all Dukes stages and in all histological grades of the tumour whereas the rise in CEA was more pronounced in Dukes D. Out of 74 patients, 29% (21/74) developed recurrent disease and 31% (23/74) responded to the treatment. With regard to monitoring recurrence(s), the predictive value of PRL was 94% which was significantly greater than that of CEA which was only 62%. In patients who developed liver metastases PRL remained elevated whereas CEA showed more than 100-fold increase. Therefore, we feel that CEA is a better marker for monitoring patients who developed liver metastases. From our results, we suggest that PRL can be used as a better overall marker for detecting recurrence(s) in patients with colorectal adenocarcinoma.
Curative effect of methionine on certain enzymes of chick kidney cortex under lanthanum toxicity situation.
Acute single dose administration of lanthanum chloride (250 mg/kg body wt, ip) to chicks have been found to alter the levels of enzymes of the antioxidant defence system of chick renal cortex fractions. Such changes involved significant decrease in activities of glucose-6-phosphate dehydrogenase, glutathione reductase, glutathione peroxidase and catalase of kidney epithelial cells. However glutathione-S-transferase activity was not altered. Glutathione and total thiol contents were decreased while lipoperoxidative reactions in kidney-cortex was significantly enhanced. The data indicate that amelioration of lanthanum toxicity condition by methionine supplementation may be due to the methionine serving as a precursor of glutathione.
Endocrine status in stage II vs. advanced premenopausal and postmenopausal breast cancer patients.
Circulating preoperative levels of DHEA-S, androstenedione and SHBG were measured in 40 premenopausal and 49 postmenopausal breast cancer patients, and in 30 and 15 age-matched healthy controls, respectively. Moreover, the levels of LH, FSH, prolactin, estradiol, progesterone, testosterone, DHEA-S, androstenedione and SHBG of Stage II breast cancer patients were compared with advanced patients and also with controls. In premenopausal patients the levels of steroid hormones were significantly low whereas those of peptide hormones were significantly high. On the contrary, in postmenopausal patients, except DHEA-S, all other hormones were significantly elevated in comparison with controls. In premenopausal patients, DHEA-S, androstenedione, estradiol, progesterone, and testosterone decreased as stage advanced with concomitant increase of SHBG, LH, FSH and prolactin when compared with hormone levels of Stage II patients. In postmenopausal advanced breast cancer patients, when compared with Stage II patients, the levels of SHBG, LH, FSH, and prolactin increased significantly, while DHEA-S, androstenedione, estradiol, and progesterone decreased as stage advanced.
Thyrotoxicity of the chlorides of cadmium and mercury in rabbit.
Exposure to heavy metals such as cadmium and mercury is of immediate environmental concern. The present study was aimed at establishing a direct relationship between heavy metal poisoning and thyroid dysfunction. Cadmium and mercury treatment at LD50 levels resulted in severe thyrotoxicosis in the rabbit. Within 24 h of intramuscular administration of cadmium chloride 15 mg.kg-1 body weight (bw) and mercury chloride 20 mg.kg-1 bw, thyroid peroxidase activity increased significantly over the control with a concomitant rise in the triiodothyronine (T3) titre. On the other hand, there was a remarkable fall in the thyroxine (T4) level, and the T3/T4 ratio was high as compared with the control. Evidence indicates that acute heavy metal lethality will induce immediate hyperthyroidism. It is suggested that T3-toxicosis may be produced by a preferential synthesis of T3 and/or preferential deiodination of T4 to T3. Measurement of T3 and T4 levels may thus be utilized as a reliable indicator of heavy metal lethality.
Estrogen and progesterone receptor status of primary breast cancer: relationship with the pattern of first metastasis and survival.
Estrogen (ER) and progesterone receptor (PR) contents in primary tumors from 127 advanced breast cancer patients were measured by DCC method. The patients were followed for 2 years and the prognostic value of the receptor levels was evaluated and compared with other tumor and patient characteristics. No relation was found between receptor levels and tumor, first relapse site as well as short-term survival (2 years) which might be due to the advanced stage of disease at diagnosis.
Hepatic lesions caused by excretory and secretory products of Ascaris lumbricoides in golden hamster.
OBJECTIVE: To ascertain the role of excretory and secretory (ES) products of Ascaris lumbricoides in liver damage. METHODS: The ES products of A lumbricoides were collected in vitro and their SDS-PAGE analysis was done. Feeding and subcutaneous injection of ES products were done in hamsters. Estimation of serum proteins, alkaline phosphatase and alanine aminotransferase and histology of liver were carried out. Control animal experiments were done concurrently. RESULTS: The ES products of A lumbricoides contained several proteins ranging in molecular weight from 14 to 205 Kd. Prolonged feeding of ES products caused elevation of ALT and amyloid deposition in the liver, whereas short term feeding or subcutaneous challenge caused focal cell necrosis and granuloma formation in the liver. CONCLUSION: ES products of A lumbricoides can produce liver damage.
Impact of chromium on lipoperoxidative processes and subsequent operation of the glutathione cycle in rat renal system.
Oral administration of K2Cr2O7 to male albino rats at an acute dose of 1500 mg/kg body wt/day for 3 days brought about sharp decrease in the activities of glucose-6-phosphate dehydrogenase and glutathione reductase of kidney epithelial cells. The scavenging system of kidney epithelium is also affected as evident by the highly significant fall in the activities of glutathione peroxidase, superoxide dismutase and catalase which ultimately leads to the increase in lipid peroxidation value in kidney cortical homogenate. However, glutathione-s-transferase activity in cytosol and glutathione and total thiol content in cortical homogenate were not altered. Chronic oral administration of K2Cr2O7 (300 mg/kg body wt/day) for 30 days to rats lead to elevation in the activities of glutathione peroxidase, glutathione reductase, glutathione-s-transferase, superoxide dismutase and catalase with no change in glucose-6-phosphate dehydrogenase activity in epithelial cells. This might lead to the increase in glutathione and total thiol status and decrease in lipid peroxidation value in whole homogenate system.
Endocrine function in premenopausal and postmenopausal advanced breast cancer patients treated with CMF or tamoxifen.
The effect of CMF (cyclophosphamide, methotrexate and 5-fluorouracil) or tamoxifen treatment on endocrine function was investigated in premenopausal and postmenopausal breast cancer patients. CMF therapy resulted in ovarian failure but pituitary and adrenal functions were unaffected in premenopausal patients. Although amenorrhea was achieved within two to five months in older patients, younger patients required large cumulative doses of cytotoxic drugs to exhibit ovarian dysfunction. CMF therapy had no effect on hormonal levels in postmenopausal patients indicating that in this group therapeutic response is not mediated via the endocrine system. On the other hand, tamoxifen therapy in postmenopausal patients resulted in hyperestrogenemia.
Acetylcholinesterase characteristics of termite queen exposed to anticholinesterase compounds.
A regional profile of AChE activity was noted in the Indian termite queen Odontotermes redemanni with the head recording the higher and body the lower range of activity. The enzyme characteristics such as substrate and temperature optima were more or less similar while pH requirement for optimum AChE activity varied from 7.0 to 7.6 In vitro inhibition of head and body AChE was studied using pure and commercial anticholinesterase compounds. Interestingly, the commercial formulations like Metacid-50 and Carbaryl are potent enough at 1 x 10(-8) M to produce 50% in vitro inhibition of AChE of head and body regions within 15 min of preincubation. A 20 min of preincubation (t0.5) was necessary to record 50% in vitro inhibition of AChE with known and pure anticholinesterase compounds such as DFP (3.5 x 10(-10) M) and physostigmine (3.6 x 10(-10) M). It is surmised that (a) the response of the head and body AChE to the commercial formulations of the insecticides may be used as a reliable and sensitive bioindicator of pesticidal contamination of the terrestrial environment and (b) termite control may be successfully done with the application of organophosphate or carbamate compounds.
Purification of neutral sphingomyelinase from human urine.
Explore the source record for details and available documents.
Inhibition of human fetal brain acetylcholinesterase: marker effect of neurotoxicity.
Human fetal brains were obtained after medical termination of pregnancy at 8-10 wk from informed patients. A definite regionalization of AChE was found in the brain of the fetus, with cerebellum recording the highest and cerebral hemisphere the lowest activity. Optimum conditions for the cerebellar AChE activity were determined with respect to molarity of the buffer, pH, temperature, and concentrations of substrate (acetylthiocholine iodide), activators (NaCl, MgCl2), and thiol indicator (dithiobisnitrobenzoic acid). In vitro inhibition of cerebellar AChE with two commercial pesticides, Metacid-50 (O,O-dimethyl p-nitrophenyl phosphorothioate) and carbaryl (N-methyl naphthyl-1-carbamate), were compared with pure anticholinesterase agents, diisopropylfluorophosphate (DFP) and physostigmine (eserine). In general, organophosphates are more neurotoxic than carbamate compounds, as evidenced by higher degree of AChE inhibition by DFP and Metacid-50 as compared to eserine and carbaryl. Assays were also done with psychotropic drugs by employing the procedure of in vitro AChE inhibition kinetics, and it was found that psychotropic drugs are less potent than organophosphate and carbamate compounds. Results indicate that pure and commercial organophosphates and carbamates and psychotropic drugs are all able to significantly alter the AChE activity. Thus exposure of the mother to these environmental toxicants may adversely affect the fetal neural functions.
Chicken erythrocyte membrane: lipid profile and enzymatic activity under lanthanum chloride and neodymium chloride administration.
Acute single dose (ip) administration of two rare earth elements like lanthanum chloride (250 mg/kg body wt) and neodymium chloride (200 mg/kg body wt) to chicks have been found to reduce the activity of certain erythrocyte membrane bound enzymes, viz. acetylcholinesterase, NADH dehydrogenase, Mg(2+)-ATPase, p-nitrophenyl phosphatase. Erythrocyte membrane bound glycosidases e.g. beta-D-glucosidase, beta-D-galactosidase and beta-D-glucuronidase were also reduced. Other components such as cholesterol and phospholipid residues were reduced but their ratio (cholesterol/phospholipid) remaining unchanged. Membrane sulfhydryl groups were also significantly inhibited by these rare earth elements.
Antioxidant protection mechanism of chick hepatic mitochondria exposed to lanthanum chloride & neodymium chloride treatment.
Acute lanthanum chloride (250 mg/kg body wt) and neodymium chloride (200 mg/kg body wt) administrations resulted in significant enhancement of glutathione level in chick hepatic mitochondria. However, glutathione-s-transferase activity was depressed. There was no alteration in the activity of glutathione reductase. Activity of glucose-6-phosphate dehydrogenase was not altered under lanthanum and neodymium treatment. There was a significant enhancement of intramitochondrial glutathione peroxidase and superoxide dismutase. Lipid peroxidation remains the same as control group of animals.
Plasma prolactin as an indicator of disease progression in advanced breast cancer.
Serial plasma prolactin levels were measured in 144 breast cancer patients (premenopausal [PR-M], N = 64; postmenopausal [PO-M], N = 80) and compared with respective controls. Patients with breast cancer were grouped into those who (1) developed distant metastasis, (2) developed local recurrence, (3) stable disease, and (4) responded to the various therapeutic modalities at the end of 2 years. The authors' analysis showed excellent correlation between serial plasma prolactin changes and the response to therapy or progression of disease in patients with advanced breast carcinoma.
Glycosphingolipids in patients with the Rett syndrome.
We have pursued two blind studies on the plasma glycosphingolipids in patients with the Rett syndrome (RS), other disorders and normal individuals from Baltimore, USA, Vienna, Austria, and Rostock, East Germany. We found the presence of an unusual glycosphingolipid in 70% of patients with RS. Approximately 10% of the plasma from patients with other developmental disorders also contained this glycosphingolipid. However, this glycosphingolipid was absent from the plasma of normal individuals and lipid storage disorders. Further work in this area will be necessary to associate the relevance of this finding to RS.