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Biomedical subjects

S Mukherjee

Publications and source records attributed to S Mukherjee.

At least 307 records · Page 17Linked to original sources

Regional cerebral blood flow in mood disorders. I. Comparison of major depressives and normal controls at rest.

We measured regional cerebral blood flow with the xenon 133 inhalation technique in 41 patients with major depressive disorder and 40 matched, normal controls during an eyes-closed, resting condition. The depressed group had a marked reduction in global cortical blood flow. To examine topographic abnormalities, traditional multivariate analyses were applied, as well as a new scaled subprofile model developed to identify abnormal functional neural networks in clinical samples. Both approaches indicated that the depressed sample had an abnormality in topographic distribution of blood flow, in addition to the global deficit. The scaled subprofile model identified the topographic abnormality as being due to flow reduction in the depressed patients in selective frontal, central, superior temporal, and anterior parietal regions. This pattern may reflect dysfunction in the parallel distributed cortical network involving frontal and temporoparietal polymodal association areas. The extent of this topographic abnormality, as revealed by the scaled subprofile model, was associated with both patient age and severity of depressive symptoms.

Adult↗

Existence of cholinephosphotransferase in mitochondria and microsomes of liver and lung of guinea pig and rat.

We reported earlier on the occurrence of cholinephosphotransferase in the mitochondria of guinea pig lung. In order to determine whether organ and/or species specificities exist in regard to the cholinephosphotransferase activity in mitochondria, we have compared the subcellular distribution of the enzyme in the liver and lungs of rats and guinea pigs. Even though the activity of the enzyme was higher in microsomes than it was in mitochondria, the mitochondrial activity was authentic in both tissues of both species. The authenticity of mitochondrial activity was established by marker enzyme studies and ultrastructural examination of mitochondrial preparations.

Animals↗

Subjective awareness of abnormal involuntary movements in chronic schizophrenic patients.

The authors examined the effects of verbal and visual feedback on subjective awareness of involuntary movements in 20 chronic schizophrenic patients. At initial evaluation only 25% of the patients were fully aware of their movement disorder. Both verbal and visual feedback resulted in significant immediate enhancement of awareness. However, assessment of awareness 2 weeks later showed a return to prefeedback baseline levels. Lack of awareness of involuntary movements was associated with a lack of awareness of psychiatric disorder, and both were associated with a longer duration of illness.

Adult↗

Acute abdominal pain in gynaecology.

Fifty female patients with acute abdominal pain were studied. High risk factors helping in clinical diagnosis were evaluated and 7(14%) cases with clear cut surgical indications were immediately operated on while 43 (86%) were kept under active observation. In doubtful cases, culdoscopy and diagnostic laparoscopy were found to be helpful in confirming the diagnosis and another 26% were operated later on. The delay in surgery did not increase the morbidity and mortality and only one patient (2%) underwent unnecessary laparotomy. Hence, it was concluded that active observation in cases of acute abdominal pain of doubtful origin is a safe and effective approach.

Abdominal Pain↗

Subcellular distribution of "peripheral type" binding sites for [3H]Ro5-4864 in guinea pig lung. Localization to the mitochondrial inner membrane.

Binding of [3H]Ro5-4864, a specific ligand for "peripheral type" benzodiazepine receptors, was determined in subcellular fractions of guinea pig lung. Even though the level of binding was predominant in the mitochondrial fraction, nuclear and cytosolic fractions also contained significantly measurable amounts of binding sites. The presence of binding sites in the microsomal fraction and in a fraction intermediate in density between the mitochondria and microsomes depended on which buffer was used to homogenize the tissue. If calcium-containing mannitol buffer was used, binding was negligible in the postmitochondrial organelles. However, in the case of sucrose buffer which did not contain any calcium, the postmitochondrial organelle fractions contained measurable amounts of binding sites. Most probably, these binding sites were of mitochondrial and nuclear origin. Furthermore, binding sites in the mitochondria were associated with the succinic dehydrogenase-enriched mitochondrial inner membrane, but not with the monoamine oxidase- and cholinephosphotransferase-enriched outer mitochondrial membrane. Furthermore, several proteolytic enzymes caused a decrease in binding of the ligand to the mitochondrial membrane only under hypotonic conditions and not under isotonic conditions, suggesting that the location of the receptors is inside the mitochondria.

Animals↗

Anomalous dominance and persistent tardive dyskinesia.

We examined handedness and cerebral hemispheric asymmetries on computed tomography (CT) scan in a sample of schizophrenic patients who were rated also for the presence or absence of persistent tardive dyskinesia (TD). Patients with TD showed a more standard dominance pattern, with dextral hand preference and normal occipital asymmetry. Anomalous dominance was associated with a marked underrepresentation of TD. Stepwise discriminant analyses indicated that the statistical prediction of TD was enhanced by the inclusion of dominance measures. Schizophrenic patients with strong standard dominance patterns may be more susceptible to developing TD, or conversely, anomalous dominance may confer protection against TD.

Adult↗

Treatment of tardive dyskinesia with bromocriptine. A test of the receptor modification strategy.

Pathophysiologic theories postulate that tardive dyskinesia arises from the development of chemical denervation supersensitivity of dopamine receptors produced by chronic long-term neuroleptic treatment. To test a dopamine receptor modification strategy, 16 patients with tardive dyskinesia were assigned to treatment with a neuroleptic plus bromocriptine (a dopamine agonist) or placebo for 10 weeks in a rising-dose design. Patients were evaluated weekly during the 10-week treatment period and for 8 weeks after medication withdrawal. No significant treatment effect was found in tardive dyskinesia response in the overall sample. When patients were classified by tardive dyskinesia subtype, patients with choreoathetoid symptoms exhibited only slight improvement with active treatment, which persisted after drug withdrawal; patients with dystonic symptoms showed moderate improvement that was drug and dose dependent. The sustained administration of substantial doses of a dopamine agonist did not produce significant adverse effects, including behavioral toxic effects. These results, although not statistically significant, are of clinical and heuristic interest.

Adolescent↗

Cardiolipin-fluorescent (M1) antimitochondrial antibody and cholestatic hepatitis in secondary syphilis.

A 27-year-old black male with secondary syphilis and cholestatic jaundice is presented. The liver biopsy was believed to be most consistent with large bile duct obstruction, but both the ultrasound and endoscopic retrograde cholangiography were normal. Prior to treatment with penicillin, his serum was positive for antimitochondrial antibody. After treatment, the antibody was no longer detectable and the jaundice gradually resolved. The patient's pretreatment serum was, after further analysis, found to be positive for the antibody to the M1 antimitochondrial antigen subtype, which is identical to cardiolipin, the antigen in both the VDRL and Wasserman tests. A review of hepatic involvement in secondary syphilis is presented.

Adult↗

The neuropsychology of schizophrenic speech.

Recent interest in the biological basis of schizophrenia has led to a reexamination of many symptomatic aspects of the disorder in terms of brain-behavioral models. Schizophrenic speech disturbances have traditionally been described in terms of a model of acquired aphasia. We review some of the limitations of this model and provide an alternative model for the study of some characteristics of schizophrenic speech based on neuropsychological theories of frontal lobe dysfunction in schizophrenia. The emphasis is placed on the study of productive errors noted in schizophrenic speech, most notably verbal perseverations. In a study of errors observed during a sample of 15 schizophrenics performance on a confrontation naming test, we were able to reliably identify and classify hierarchic categories of verbal perseverations occurring at both semantic and phonemic levels. These perseverations constituted 20% of the total errors. We argue that these perseverations represent a special case of executive dysfunction resulting from a disturbance of language monitoring mechanisms. We examine the implications of these findings for a hypothesis of schizophrenic speech disturbances in terms of frontal lobe dysfunction and the developmental neuropathological processes involved in the illness.

Adult↗

Persistent tardive dyskinesia and neuroleptic effects on glucose tolerance.

The relations of persistent tardive dyskinesia (TD) to glucose tolerance and family history of type 2 diabetes mellitus (FH-NIDDM) were examined in 22 schizophrenic patients. All patients underwent a standard oral glucose tolerance test (GTT) while receiving haloperidol, and 15 patients also underwent a GTT when drug free. Fasting blood glucose (FBS) was significantly higher in the TD group than in the non-TD group in the medicated condition, but not in the drug-free state. TD and non-TD groups did not differ significantly in postload glucose levels either in the drug-free or in the medicated condition. However, relative to the drug-free state, haloperidol-treated TD patients showed decreased glucose tolerance while non-TD patients showed increased glucose tolerance. Seven (32%) of the 22 patients had an FH-NIDDM. A positive FH-NIDDM was significantly associated with the presence of TD and with higher drug-free FBS. A possible role of melatonin in mediating the TD-augmenting effects of FH-NIDDM and the neuroleptic-induced decrease in glucose tolerance has been proposed.

Adult↗

A host-encoded DNA-binding protein promotes termination of plasmid replication at a sequence-specific replication terminus.

We have purified approximately 6600-fold an approximately 40-kDa protein (Ter protein) encoded by Escherichia coli that specifically binds to two sites at the 216-base-pair replication terminus (tau) of the plasmid R6K. Chemical footprinting experiments have shown that the Ter protein binds to two 14- to 16-base-pair sequences that exist as inverted repeats in the tau fragment. Site-directed mutagenesis of one of the terminus sequences (tau R) resulted in a mutant tau R that failed to bind to the Ter protein. The same mutant terminus also failed to terminate DNA replication in vivo. These experiments strongly suggest that the interaction of the Ter protein with tau sequences plays an essential role in the termination of DNA replication, specifically at tau.

Base Sequence↗

Attenuation of reserpine-induced catalepsy by melatonin and the role of the opioid system.

Several reports have indicated that melatonin influences motor activity in animals and humans. Melatonin has been reported to attenuate the rigidity and tremor of Parkinson's disease. Some of the behavioral effects (e.g., analgesic and anticonvulsant properties) of melatonin have been reported to be mediated through interactions with the endogenous opioid peptides. We investigated the effect of melatonin on reserpine-induced catalepsy in the rat and, additionally, examined whether this effect is modified by opioid peptides. Melatonin was found to attenuate markedly the duration of reserpine-induced catalepsy. These effects were potentiated by administration of the opiate agonist nalbuphine hydrochloride, while naloxone partially reversed the catalepsy reducing effect of melatonin. These findings suggest that the motor effects of melatonin may involve critical interactions with opioid peptides, and support the postulated reciprocal interactions between melatonin and opioid peptides that previously have been demonstrated for the analgesic and anticonvulsant properties of melatonin.

Animals↗

Effects of centrophenoxine on cholinephosphotransferase activity in maternal and fetal guinea pig lung.

Cholinephosphotransferase activities of guinea pig lung mitochondria and microsomes are inhibited by centrophenoxine and one of its metabolites, p-chlorophenoxyacetate. 2-Dimethylaminoethanol, the second metabolite of centrophenoxine, has no inhibitory effect on the enzyme activity. The inhibition of enzyme activity by centrophenoxine is noncompetitive. Intravenous injection of centrophenoxine and p-chlorophenoxyacetate to pregnant animals causes inhibition of cholinephosphotransferase activity in adult lung but not in fetal lung. However, direct administration of centrophenoxine to the fetus after laparotomy causes inhibition of both subcellular enzyme activity in fetal lung. It is suggested that the drug injected to the pregnant animals does not reach the fetal lung or is metabolized. Furthermore, while centrophenoxine injection does not change the total phosphatidylcholine content of adult lung, the acyl group composition of phosphatidylcholine was modulated.

Animals↗

Changes in lipid composition and some biologically important enzyme activities in the microsomal membranes of developing toad ovary in different seasons.

The microsomal membranes isolated by sucrose density gradient centrifugation from developing toad ovary have been found to differ significantly in lipid composition and various enzyme activities in different seasons. All the enzymes studied, viz. Na+, K(+)-ATPase, delta 5-3 beta-hydroxysteroid dehydrogenase (delta 5-3 beta HSD) and prostaglandin synthetase, exhibited maximum activity during the breeding season (July-September) at all stages of development (a,b,c & d). The activities of Na+, K(+)-ATPase and delta 5-3 beta HSD increased with development while that of prostaglandin synthetase followed the reverse order. The total phospholipid, cholesterol and fatty acid contents also varied with season and development. The increase in Na+, K(+)-ATPase and delta 5-3 beta HSD activities in the microsomal membranes of toad ovary at breeding season is accompanied with concomitant increase in phospholipid and unsaturated fatty acid contents at different stages in this season, thereby suggesting some correlation between them.

3-Hydroxysteroid Dehydrogenases↗

Comparative pharmacokinetic and pharmacodynamic study of four different brands of propranolol in normal volunteers.

The pharmacokinetic and pharmacodynamic studies of four different brands of propranolol (Inderal, Ciplar, Corbeta and Propal) were carried out after single and multiple dosing on six normal adult healthy volunteers in a randomized crossover fashion to determine any inter-brand variations in bioavailability and pharmacodynamic effects. No significant difference was observed in any of the pharmacokinetic and pharmacodynamic parameters of four different brands of propranolol studied.

Adult↗