Biomedical subjects

N Ghosh

Publications and source records attributed to N Ghosh.

At least 19 recordsLinked to original sources

PubMed1996

Reversible unfolding of Escherichia coli alkaline phosphatase: active site can be reconstituted by a number of pathways.

Acid-induced and guanidine hydrochloride (GdnCl)-induced reversible unfolding of Escherichia coli alkaline phosphatase (AP) was characterized under equilibrium conditions. The protein was exposed to extreme conditions of pH 2.0 or 6 M GdnCl and was subsequently returned to normal conditions. Associated changes in the protein structure was probed by various spectroscopic methods. The changes in the functional properties were monitored by measuring enzymatic activity, capacity to renature spontaneously upon removal of the denaturant, and renaturation in presence of various site-specific and nonspecific effector molecules, in the absence and presence of beta-mercaptoethanol. Analysis of the fluorescence and CD spectra showed that the unfolding of the organized structures was much more extensive in 6 M GdnCl than at pH 2.0. Intrachain S-S bonds in each unfolded state were accessible to reduction by beta-mercaptoethanol. The effectors Zn2+ and ATP induced renaturation of active site only under reducing conditions, whereas Triton X-100 or alpha-crystallin needed the presence of some organized structure. The reconstituted protein from each denatured state without or with an effector showed different CD spectra. It is concluded that the active site domain of AP could be reconstituted independently of other structural domains in different pathways.

Alkaline Phosphatase↗

PubMed1996

Node negative breast carcinoma: hyperprolactinemia and/or overexpression of p53 as an independent predictor of poor prognosis compared to newer and established prognosticators.

The purpose of this study was to investigate a prognostic indicator that can differentiate node negative breast cancer patients (N = 39, T2N0M0) with high risk and low risk for the development of recurrence or metastases. Preoperative plasma prolactin (PRL) was estimated by radioimmunoassay. The expression of PRL, p53, nm23, and c-erbB2 was investigated by immunohistochemical (IHC) localization; cathepsin D (CD, Enzyme Linked Sorbant Assay) and estrogen- and progesterone-receptors (ER and PR, Dextran coated charcoal method) were estimated in the tumor cytosols. The follow-up period was 2-6 years. Statistical comparisons were made between each marker for relapse-free survival (RFS) and overall survival (OS). Of the 39 patients, 18 had hyperprolactinemia (PRL > 20.0 ng/ml plasma), whereas overexpression of p53 was observed in 55% (17/31) tumors. These were independently and in combination associated with a reduced RFS and OS. The rest of the investigated markers did not show promising results. Hyperprolactinemia and/or overexpression of p53 were associated with aggressiveness of the tumor, early disease relapse or metastases, and poor OS in patients with node negative breast cancer. These two markers may enhance our ability to identify node negative breast cancer patients with aggressive tumors, for whom the use of adjuvant chemo and/or endocrine therapy is unequivocally justified.

Adult↗

PubMed1996

Oxidized low density lipoprotein stimulates aortic smooth muscle cell proliferation.

We have investigated the effects of oxidized low density lipoproteins (Ox-LDL) on aortic smooth muscle cell (SMC) proliferation and the biosynthesis of glycosphingolipids. We found that Ox-LDL exerted a concentration, time, and temperature dependent alteration of cell proliferation and the biosynthesis of lactosylceramide. At low concentrations (5-10 micrograms/ml medium) Ox-LDL stimulated cell proliferation measured by an increase in the incorporation of [3H]-thymidine in cells and the synthesis of lactosylceramide, but not glucosylceramide synthesis. Oxidized LDL exerted a threefold increase in the incorporation of [3H]-galactose and [3H]-serine in lactosylceramide. The activity of lactosylceramide synthetase; UDP-galactose glucosylceramide beta 1 --> 4 galactosyltransferase (GalT-2), but not glucosylceramide synthetase (GlcT-1) was stimulated by Ox-LDL. On the other hand, LDL suppressed the activity of GalT-2 in these cells. When cells were preincubated with antibody against Ox-LDL or GalT-2 it compromised the Ox-LDL mediated stimulated in cell proliferation and GalT-2 activity. Similarly, D-PDMP an inhibitor of GalT-2 compromised the Ox-LDL mediated effects in cells. In contrast, L-PDMP further stimulated the Ox-LDL mediated cell proliferation and GalT-2 activity. However, preincubation of cells with preimmune rabbit serum IgG failed to abrogate Ox-LDL mediated stimulation in cell proliferation and GalT-2 activity. In sum, we found that Ox-LDL stimulated aortic smooth muscle cell proliferation in culture. This effect resulted from Ox-LDL mediated activation of GalT-2 that produced lactosylceramide. Lactosylceramide in turn, contributed to cell proliferation. Such correlations are supportive of the notion that GalT-2 action mediates the signal transduction of Ox-LDL contributing to cell proliferation.

Animals↗

PubMed1996

Objective evaluation of psychological abnormality in irritable bowel syndrome.

BACKGROUND: Irritable bowel syndrome (IBS) is frequently regarded as a psychological disorder. Data on objective evaluation of psychological abnormalities among IBS patients and control subjects are scanty in our country. We therefore objectively studied patients with IBS. METHODS: 42 patients satisfying the Manning's criteria and Munich workers' for diagnosis of IBS underwent psychological evaluation using the following tests: a) Eyesenck personality questionnaire. b) State and trait anxiety inventory according to Speilberger's method. c) Hamilton depression rating scale for detection of depression. d) Whitely index of hypochondriasis and discriminant function by Pilowsky's illness behavior questionnaire. RESULTS: Neuroticism was detected in 76% of IBS patients compared to 9% in control population (p < 0.01). State and trait anxiety scores were 44.5 +/- 17.1 and 49.0 +/- 15.3 respectively in IBS patients; these were higher than those in controls (35.5 +/- 7.5 and 41.2 +/- 6.1 respectively; p < 0.01). Severe depression was observed in 26% of IBS patients and 6% of control subjects (p < 0.05). Significantly higher hypochondriasis score was observed in IBS patients as compared to controls (p < 0.001). CONCLUSION: Neuroticism, hypochondriasis and depression were significantly more prevalent in IBS patients attending a clinic, compared to control population.

Adult↗

PubMed1995

Prognostic value of insulin-like growth factor-1 receptors in patients with colon/rectal cancer: correlation with plasma prolactin.

Prognostic value of IGF-1 receptors (IGF-1R) was evaluated and compared with circulating prolactin (PRL) in 59 patients with Dukes B or C colon/rectal cancer. IGF-1R was estimated by radioligand binding assay and PRL was estimated by immunoradiometric assay. Eighty-five percent (50/59) of patients had IGF-1R- tumours while IGF-1R positivity was observed in only 15% (9/59) of patients. None of the clinicopathological parameters showed any association with IGF-1R status. No significant difference was observed in overall survival period between patients with IGF-1R+ tumours and those with IGF-1R- tumours. However, a significant difference in overall survival time was observed between patients with PRL < 20.0 and > 20.0 ng/ml plasma (X2 = 4.70, df = 1, P < 0.05). In bivariate analysis, patients with IGF-1R- tumours and concomitant hyperprolactinemia had unfavourable prognosis compared to their counterpart (X2 = 4.21, df = 1, P < 0.05). We conclude that there was a trend of better overall survival in patients with IGF-1R+ tumours, and PRL < 20.0 ng/ml plasma when compared to patients with IGF-1R- tumours, and PRL > 20.0 ng/ml plasma. Further, IGF-1R negativity in conjunction with hyperprolactinemia could be used as an indicator of unfavourable prognosis in patients with Dukes B or C colon/rectal cancer.

Adult↗

PubMed1994

Plasma prolactin in patients with colorectal cancer. Value in follow-up and as a prognosticator.

BACKGROUND: Preoperative plasma prolactin and carcinoembryonic antigen (CEA) levels were assessed to monitor disease recurrence and to identify low-risk and high-risk patients with Dukes B or C colorectal cancer. METHODS: Prolactin and CEA were estimated by radioimmunoassay method. Blood samples were collected preoperatively and sequentially thereafter from patients with colorectal cancer (N = 114); the samples were compared with samples from age-matched healthy control subjects (smokers and nonsmokers, N = 45). For rest of the analysis, patients with Dukes A disease (N = 7) were not included because of the small number. In monitoring recurrences, the criteria for positive test for the two markers was a continual increase in the marker level after an initial decrease or persistent high level of the marker. These were the indicators of relapse or no response to treatment. To determine the efficacy of the preoperative markers, the patients were grouped according to disease status at the end of 3 years, i.e., patients who had response to the treatment modalities (N = 52) and patients who later had progressive disease (N = 55). To determine the prognostic significance of preoperative marker levels, the patients were divided according to the cutoff levels (upper normal limits); for prolactin the cutoff level was 20.0 ng/ml plasma, and for CEA it was 5.0 ng/ml plasma. RESULTS: Both of the markers were significantly high in patients with colorectal cancer compared with the markers of their respective control subjects (P < 0.0001). In monitoring disease course, the predictive power of prolactin was 100%, whereas that of CEA was 66%. Prolactin showed a lead time of 2-3 months. Preoperative prolactin levels were significantly higher in patients who later had progressive disease (P < 0.001) than in patients who had response to the treatments. However, such an intergroup variation was not observed for CEA. Patients with preoperative levels of prolactin greater than 20.0 ng/ml had shorter overall survival times than did those with prolactin levels less than 20.0 ng/ml plasma; such a trend was not observed for patients with CEA levels less than 5.0 ng/ml and those with CEA levels greater than 5.0 ng/ml plasma. CONCLUSION: Prolactin is a better overall marker than is CEA in patients with Dukes B or C colorectal cancer. The authors recommend the use of plasma prolactin levels to help identify low-risk and high-risk patient subgroups so that high-risk patients may be followed up more intensely and treated accordingly. Hyperprolactinemic patients with Dukes B or C disease have shortened survival time.

Adult↗

PubMed1994

Interrelationship of prolactin and its receptor in carcinoma of colon and rectum: a preliminary report.

The prolactin receptors (PRLR) were correlated with circulating prolactin and various clinicopathologic parameters to investigate its prognostic value in patients with colorectal cancer. The prolactin (by radioimmunoassay) and its receptors (by radioligand method) were estimated in a total of 71 male patients with colorectal cancer enrolled at the Gujarat Cancer and Research Institute, Ahmedabad. The patients were followed for a period of 3 years. We have observed that 51% colorectal tumors were PRLR+. Significant correlation was not observed between presence/absence of PRLR and clinicopathologic variables. Dukes' D patients were lost to follow-up after 2-3 months; therefore, the results of prognostic significance were analysed only in patients with Dukes' A, B, and C (N = 64). Statistically significant difference in overall survival was not observed when the patients were subgrouped according to the presence/absence of PRLR and according to the cutoff level (i.e., 2%). PRLR+ hyperprolactinemic (Prolactin > 20.0 ng/ml plasma) patients had better overall survival than that of patients with PRLR- hyperprolactinemia, although the difference was statistically nonsignificant. However, PRLR- hyperprolactinemia patients had a more unfavourable prognosis than that of their counterparts. A similar trend was observed in patients with Dukes' B and C disease. Our preliminary study suggests an unequivocal finding, that PRLR- with concomitant hyperprolactinemia probably characterises a subgroup of patients with aggressive colorectal cancer.

Adult↗

PubMed1994

Prolactin: its role in advanced tongue cancer.

Serum prolactin was measured pretherapeutically and sequentially thereafter using immunoradiometric assay method in 37 male patients with advanced tongue cancer and compared with 23 healthy, age-matched controls. Prolactin levels were correlated with age, various clinicopathologic parameters, overall survival, and patients with response and those with progressive disease. Patients with advanced tongue cancer had higher prolactin levels than controls (P < 0.02), but intergroup variation in prolactin was not observed when considering the age, site of the lesion, disease stage, histologic grade, and keratin. Of the patients, 30% had hyperprolactinemia (prolactin > 15.0 ng/ml). To assess the prognostic significance of pretherapeutic prolactin level, the patients were divided according to the cutoff level of prolactin (15.0 ng/ml). Hyperprolactinemic patients had more unfavourable prognosis than patients with prolactin < 15.0 ng/ml (X2 = 2.91, df = 1, P < 0.0037). In monitoring disease course, patients who responded to treatments had decreased prolactin levels at the end of 18 months as compared to their pretherapeutic levels (P < 0.01). In patients who subsequently developed progressive disease within 18 months, prolactin levels reduced initially at response, whereas with disease progression, prolactin levels increased significantly (P < 0.05). The positive and negative predictive value of prolactin was 100%. Immunohistochemical localization confirmed the ectopic production of prolactin by tongue tumors. In conclusion, our data indicate that hyperprolactinemia may be an independent predictor of short-term prognosis; circulating prolactin may be used as a marker for monitoring disease course in patients with advanced tongue cancer, and prolactin is produced ectopically by tongue tumors.

Adult↗

PubMed1994

Tumor markers in patients with advanced breast cancer as prognosticators: a preliminary study.

A retrospective study was performed on 69 breast cancer patients (stage II, N = 18; advanced disease, N = 51) in order to assess the prognostic value of circulating prolactin (PRL), CEA, CA 15-3, insulin-like growth factor-1 (IGF-1), and epidermal growth factor (EGF) by RIA/IRMA. These markers were compared with short-term prognosis (two years). Significant difference was observed only for PRL ( < 20.0 ng/ml vs. > 20.0 ng/ml), which provide an independent predictor of short-term prognosis in advanced breast cancer.

Biomarkers, Tumor↗

PubMed1994

Can plasma prolactin predict tamoxifen resistance in patients with advanced breast cancer?

The antiestrogen tamoxifen (TAM) is an effective therapy for advanced breast cancer. However, its use is limited by the eventual development of acquired TAM resistance in many patients. There is now strong evidence to suggest that prolactin plays an important role in advanced breast cancer. We have measured plasma prolactin (PRL) and estrogen-receptor (ER) and progesterone-receptor (PR) in post-menopausal patients with breast cancer (Stage III, n = 44). The blood samples were collected pre-operatively and sequentially thereafter for a minimum period of 3 years or until the death of the patients. The ER and PR were estimated in breast tumor samples by dextran-coated charcoal (DCC) method. The patients were treated with surgery and radiotherapy followed by TAM (10 mg, 1 BD). Based on the response to treatments, the patients were divided into two groups: (1) TAM sensitive (n = 19) and (2) TAM resistant (n = 25). In the TAM sensitive group, patients responded to the treatment and did not develop progressive disease within a period of 3 years. On the contrary, in the group of TAM resistant, patients developed progressive disease within a period of 3 years. The development of progressive disease clearly indicated TAM resistance. Plasma PRL correlated well with the disease progression. This study clearly demonstrated that plasma prolactin accurately indicated the response and development of resistance to TAM in patients with advanced breast cancer.

Breast Neoplasms↗

PubMed1994

Levels of circulating peptide and steroid hormones in men with lung cancer.

Levels of circulating peptide (FSH, LH, prolactin, ACTH, calcitonin, gastrin and insulin-like growth factor-1 [IGF-1]) and steroid (estradiol, progesterone, DHEA-S and testosterone) hormones were estimated by radioimmunoassay (RIA) and immunoradiometric assay (IRMA) in male patients with lung cancer (n = 37) pre-therapeutically and compared with 25 age matched healthy controls. In this retrospective study, FSH, LH, prolactin, ACTH, calcitonin, gastrin and IGF-1 were significantly higher with concomitant lower levels of DHEA-S and testosterone, while the difference was statistically non-significant for estradiol and progesterone in patients with lung cancer when compared with controls. Early stage patients (Stage II) exhibited higher levels of gastrin as compared to advanced stage patients (Stages III and IV). It is suggested that hormonal imbalance might play an important role in the development and progression in male patients with lung cancer.

Adrenocorticotropic Hormone↗

PubMed1993

Correlation of steroid receptors in synchronous tissues with survival in breast cancer patients.

Estrogen and progesterone receptors (ER and PR) were estimated in 129 synchronous (primary and metastatic lymph node) breast cancer tissues, of which 40% were premenopausal and 60% were postmenopausal. ER and PR accordance was seen in 68% and 70% patients, and ER and PR discordance was seen in 32% and 30%, respectively. The mean level of ER in patients having ER accordance was higher in responders than in nonresponders. In patients having steroid receptors in accordance, there was a trend towards gain of receptors (type II) in responders, and loss of receptors (type I) in nonresponders. In ER discordant cases 48% were of type I while in PR discordant cases 46% were of type I. In postmenopausal patients, survival was lower in patients showing accordance than in those showing discordance. In nonresponders showing loss of receptors in lymph node, the survival was shorter than in those who showed gain of receptors in lymph node. No such trend was seen in premenopausal patients. Our study suggests that in postmenopausal patients, survival was better related to ER accordance than ER discordance and PR accordance or discordance. However, a larger patient series is needed for confirmation.

Adult↗

PubMed1993

Amelia.

Explore the source record for details and available documents.

Adult↗

PubMed1993

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.

Acetylcholinesterase↗

PubMed1992

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.

Blotting, Western↗

PubMed1992

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.

Adenocarcinoma↗

PubMed1992

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.

Animals↗

PubMed1992

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.

Androstenedione↗