PubMed Health⌕ Search

Biomedical subjects

D Chakraborty

Publications and source records attributed to D Chakraborty.

At least 91 records · Page 5Linked to original sources
PubMed1993

Feigning schizophrenic disorders on the MMPI-2: detection of coached simulators.

The Minnesota Multiphasic Personality Inventory (MMPI) and, more recently, its revised version (the MMPI-2) have represented the "gold standard" in the psychometric assessment of malingering and other response styles. In this study, we provide a stringent test of the MMPI-2 validity indices and their ability to detect feigned schizophrenia in four groups of simulators (n = 72). Simulators were randomly assigned to one of four conditions: (a) coached on symptoms of schizophrenia, (b) coached on strategies for the detection of fakers, (c) coached on both symptoms and strategies, or (d) uncoached. Simulators were compared to subjects responding under an honest condition (n = 13) and a comparison group of schizophrenic inpatients (n = 37). We found knowledge of strategies alone allowed many simulators (i.e., one third or more, depending on the validity indices) to elude detection. In contrast, knowledge of the disorder appeared less useful to simulators in avoiding detection. Coaching on both strategies and symptoms was not as effective as strategies alone. Consistent with previous studies, uncoached simulators were detected with moderately high levels of accuracy.

Adult↗
PubMed1993

Effect of cimetidine on adenohypophysis of male albino mice under certain experimental condition.

Effect of 75 mg/kg of body weight of cimetidine administered intraperitoneally daily for 14 days to two groups of experimental animals (one of the experimental group was having intact testis and another group was bilaterally orchidectomized) was observed on cell population & cell volume of gonadotrophs and lactotrophs in pituitary gland, as it has not been studied earlier. In the experimental group of intact testis, there was significant reduction in the cell population of FSH cells in the cephalomedian area (P < 0.001) and in the lateral lobe (P < 0.01); the volume of both FSH and LH cells was also significantly reduced. In group 4 and group 5 there was significant increase in the population of lactotrophs and also in the volume of LH cells, FSH cells & lactotrophs. The change in the gonadotrophs in group 2 was due to increased production of testosterone from hypertrophied Leydig cells of testis rather then it's direct effect on adenohypophysis; in group 4 and group 5 the changes were due to lack of testosterone as in those cases bilaterally orchidectomy already done.

Animals↗
PubMed1993

Effect of phenobarbitone on pituitary gland of male albino mice.

The effects of phenobarbitone on gonadotrophs and lactotrophs of pituitary gland were studied in male albino mice which were administered phenobarbitone 50 mg/kg body weight intraperitoneally (ip) daily for 14 days. A group of control mice were administered saline ip. In the experimental group, there was significant reduction in the average cell population of FSH cells in the cephalomedian area (P < 0.001) and in the lateral lobe (P < 0.01). The average volume of both FSH and LH cells was also significantly reduced (P < 0.001). The changes in the gonadotrophs of the experimental group could be attributed to the negative feedback action of testosterone which is being secreted from hypertrophied Leydig cells of testis.

Animals↗
PubMed1989

Indirect determination of tungstate in rat tissues by atomic absorption spectrometry.

An indirect method is described for the determination of tungsten as tungstate in tissue samples by atomic absorption spectrometry (AAS). Tungstate forms a stable ion-association complex [Fe(dipy)3]2+WO4(2-) (dipy = 2,2'-dipyridyl) in acidic solution, which can be extracted into chloroform with an efficiency of higher than 98%. The extract can be analysed for iron (and hence indirectly for WO4(2-] by flame AAS after stripping back into 60% perchloric acid. The calibration graph is linear up to 19 p.p.m. of WO4(2-) and the limit of detection is 0.17 p.p.m. Many foreign ions do not interfere and the method has been applied successfully to the determination of tungstate in rattus norvegicus tissue samples.

Animals↗
PubMed1986

Small nuclear ribonucleoprotein antigens are absent from 10S translation inhibitory ribonucleoprotein but present in cytoplasmic messenger ribonucleoprotein and polysomes.

A cytoplasmic 10S ribonucleoprotein particle (iRNP), which is isolated from chick embryonic muscle, is a potent inhibitor of mRNA translation in vitro and contains a 4S translation inhibitory RNA species (iRNA). The iRNP particle shows similarity in size to the small nuclear ribonucleoprotein (snRNP) particles. Certain autoimmune disease patients contain antibodies directed against snRNP antigenic determinants. The possibility that iRNP may be related to the small nuclear particles was tested by immunoreactivity with monospecific autoimmune antibodies to six antigenic determinants (Sm, RNP, PM-1, SS-A (Ro), SS-B (La), and Scl-70). By Ouchterlony immunodiffusion assays, the cytoplasmic 10S iRNP did not show any immunoreactivity. Also, a more sensitive hemagglutination inhibition assay for detecting Sm and RNP antigens failed to show reactivity with the 10S iRNP. Thus, the 10S iRNP particles are distinct from the similarly sized snRNP. However, free and polysomal messenger ribonucleoprotein (mRNP) particles and polysomes also isolated from chick embryonic muscle and analyzed by Ouchterlony immunodiffusion and hemagglutination inhibition for the presence of the antigenic determinants showed reactivity to Sm and RNP autoantibodies, but were not antigenic for the other four antibodies. Some of the Sm antigenic peptides of mRNP particles and polysomes were identical to those purified from calf thymus nuclear extract, as judged by Western blot analysis. The association of Sm with free and polysomal mRNP and polysomes suggests that Sm may be involved in some cytoplasmic aspects of mRNA metabolism, in addition to a nuclear function in mRNA processing.

Animals↗
PubMed1983

Hyperthermia with implanted electrodes: in vitro and in vivo correlations.

Hyperthermia as a treatment for cancer has elicited much recent interest. However, major difficulties persist both in the technology for heating deep-seated tumors, and in thermal dosimetry. We have investigated a heating technique for deep-seated neoplasms that employs an internal implanted electrode and an external electrode to apply radiofrequency current to a tumor mass. The internal electrode consists of an array of stainless steel needles or wires which define a Faraday cage within the tumor, while the external electrode consists of a variety of electrical conductors at the skin surface. Phantom measurements have closely reproduced calculated temperature distributions. The temperature profiles within the volume enclosed by the internal electrode show relatively homogenous heating. Temperature measurements in a rat tumor model have demonstrated that significant heating within such an internal electrode array is easily obtained. The heating may extend some centimeters outside the electrode. Using a dog model we have shown that with such a treatment technique the temperature profiles obtained are reproducible both spatially and temporally. A case report of a clinical application is presented. A 5 cm bronchogenic carcinoma was easily heated without significant heating of the surrounding normal lung, and without apparent toxicity. Such a technique may be applicable to a variety of operable but unresectable neoplasms. The reproducibility and relative homogeneity of heating suggest possible usefulness in combined modality trials.

Adenocarcinoma↗
PubMed1982

Association of cap binding protein-related polypeptides with cytoplasmic RNP particles of chick embryonic muscle.

Cap binding protein (CBP)-related polypeptides were identified in different cytoplasmic RNP particles of embryonic chick muscles using monoclonal antibody to purified CBP. A single immunoreactive peptide (Mr 78 000) was present in preparations of both free mRNP particles and a novel 10 S translation inhibitory RNP particle. In contrast, proteins isolated from these particles showed two new low-Mr immunoreactive peptides (Mr 43 000 and Mr 29 000). No CBP related protein could be detected in polysomal mRNP, although an immunoreactive Mr 43 000 CBP-related protein was present in polysomes. The relevance of the association of different CBP-related polypeptides with cytoplasmic RNP particles and polysomes are discussed.

Animals↗