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Biomedical subjects

B K Puri

Publications and source records attributed to B K Puri.

At least 73 records · Page 4Linked to original sources
PubMed1996

An investigation of motor function in schizophrenia using transcranial magnetic stimulation of the motor cortex.

BACKGROUND: In this first investigation of motor function in schizophrenia using transcranial magnetic stimulation (TMS), the general hypothesis tested was that this methodology could be used to investigate the disruption of corticospinal inhibitory processes suggested by cognitive and psychophysiological paradigms. METHOD: Nine drug-free DSM-IV schizophrenic patients were compared with nine age- and sex-matched normal subjects. Electromyographic (EMG) recordings were made from the thenar muscles of the dominant hand during sustained, weak voluntary contraction. TMS over a particular threshold applied to the motor cortex would elicit a compound motor evoked potential (cMEP) followed by a period of suppression of EMG. RESULTS: The latency of cMEPs following TMS was significantly shorter in the schizophrenic patients. The two groups did not differ significantly with respect to mean latency of suppression of EMG activity, or stimulus thresholds for either cMEPs or EMG suppression. CONCLUSION: These findings could be the result of a relative lack of corticospinal inhibition of motor responses; a change in the site of TMS activation; or an abnormality of peripheral nervous function in schizophrenia. Drug effects were unlikely since seven of the patients were drug-naive.

Adult↗
PubMed1996

The successful treatment of a gender dysphoric patient with pimozide.

OBJECTIVE: The case is reported of a gender dysphoric patient who responded successfully to pharmacotherapy with pimozide. CLINICAL PICTURE: An adult male patient with a borderline learning disability presented with cross-dressing and a strong wish to undergo a sex change. TREATMENT: Supportive psychotherapy and pharmacotherapy with pimozide was tried. OUTCOME: There was an excellent response to pimozide 2 mg daily, with a cessation of both cross-dressing and the wish for sex reassignment. When, after 1 year, the dose was reduced to 1 mg daily, there was a rapid return of the cross-dressing and the wish for sex reassignment. An increase in the dose again led to a remission which has been maintained since then. CONCLUSION: Pharmacotherapy with pimozide should be considered in cases of doubtful gender dysphoria.

Adult↗
PubMed1995

Elevated platelet calcium mobilization and nitric oxide synthase activity may reflect abnormalities in schizophrenic brain.

Schizophrenia has a diverse nature of clinical symptoms and a number of hypotheses have been suggested to explain its aetiological basis. In this study we have examined two aspects of membrane function, receptor-activated calcium mobilization and calcium activated nitric oxide synthase activity in schizophrenic subjects. Thrombin induces mobilization of calcium ions from intracellular stores. The platelet response of drug naive schizophrenics was found to be significantly increased over a range of thrombin concentrations (0.01 to 0.60 U/ml) compared to control subjects. Possible involvement of nitric oxide (NO) in the aetiology of schizophrenia was investigated. NO has been functionally linked to both dopaminergic and glutamatergic systems both of which are strongly implicated in the biochemical pathology of schizophrenia. Nitric oxide synthase (NOS) activity was determined in platelets of controls, schizophrenic and panic disorder subjects. Enzyme activity was found to be significantly higher in platelets of drug naive schizophrenic subjects compared to controls, drug treated schizophrenics and panic disorder subjects. It is suggested that there is an imbalance of the calcium-induced L-arginine- nitric oxide pathway in platelets of schizophrenic subjects which may be modified by neuroleptic treatment. This imbalance may be mirrored in the central nervous system in particular at the NMDA receptor. It is possible that such a disturbance in the L-arginine-nitric oxide pathway may have pathological implications in the aetiology of schizophrenia.

Adult↗
PubMed1995

Expressed emotion and a hypothetical model of relapse in schizophrenia.

A hypothetical model is proposed that connects the risk of relapse in schizophrenia and expressed emotion in relatives with genetic factors in the individual, familial schizophrenia, severity of illness, family psychopathology, age of onset of the illness, and length of family exposure to a psychotic relative.

Age of Onset↗
PubMed1995

Mortality in a hospitalized mentally handicapped population: a 10-year survey.

The mortality experiences of a hospitalized mentally handicapped population between 1981 and 1990 (inclusive) were examined. A continued trend for increasing longevity in both males and females was found, with mean ages at death now approaching those in the general population. The commonest cause of death was non-tubercular respiratory infection, from which patients were particularly at risk during the months of December to February (inclusive). Patients diagnosed as suffering from psychoses other than schizophrenia and mood disorder had an increased mortality and should be thoroughly investigated for the presence of organic pathology. Epilepsy and Down's syndrome were associated with increased risk of earlier death, although in the case of Down's syndrome there has been a marked increase in longevity.

Adult↗
PubMed1995

Doctors' holding power in practice: section 5(2) of the Mental Health Act 1983.

Section 5(2) of the Mental Health Act 1983 (England and Wales) is a commonly used short term power of detention often implemented by junior medical staff, which has no statutory right of appeal. There is little published analysis of its use in clinical practice. A detailed case note study of its use in a psychiatric service with a large catchment area is presented. Fifty-seven per cent of the patients detained under s.5(2) were female. Affective psychosis was over-represented in detained females, while schizophrenia and paranoid states were over-represented in males. Eight per cent of s.5(2) detentions were initiated via the nurses' holding power, s.5(4). None of these patients were subsequently regraded to s.2 or 3, which may be accounted for by the finding that personality disorder and alcohol dependence were more commonly diagnosed in this subgroup. Of s.5(2) detainees, none of those with a non-psychotic disorder were regraded to s.2 or 3. Three patients had not accepted in-patient admission prior to implementation of s.5(2). Moreover, 38 per cent of all s.5(2) detentions took place within 24 hours of admission. Patients with a psychotic disorder were more likely to be detained within 24 hours of admission. Doubts regarding the validity of consent to voluntary admission in these patients are raised.

Commitment of Persons with Psychiatric Disorders↗
PubMed1995

Characteristics of fire-setters. A study and proposed multiaxial psychiatric classification.

BACKGROUND: The study set out to review the relationship between mental disorder and fire-setting. METHOD: Sociodemographic, psychiatric, and medical data were retrospectively obtained from case notes of a group of 36 fire-setters referred to the North West Thames Forensic Psychiatry Service over a four-year period. RESULTS: Of the sample, 28% were female and one-third had no mental illness; 28% had a previous medical history of possible relevance. Psychoactive substance abuse was common. There was a significant disturbance of interpersonal relationships. Eighty-five per cent lived alone, and 44% of the female fire-setters had a history of sexual abuse. CONCLUSION: On the basis of this study, a multiaxial classification system of fire-setting is proposed.

Adolescent↗
PubMed1994

Differential-pulse polarographic determination of zinc and manganese in various pharmaceutical and biological samples after adsorption of their morpholine-4-carbodithioates on microcrystalline naphthalene.

A highly selective, sensitive, rapid and economical differential-pulse polarographic method was developed for the simultaneous determination of trace amounts of zinc and manganese in various standard alloys and pharmaceutical, biological and environmental samples after adsorption of their morpholine-4-carbodithioates on microcrystalline naphthalene in the pH range 4.1-9.0 for manganese and 6.5-10.2 for zinc. After filtration, the metal complexes are shaken with 10 ml of 1 mol l-1 HCl and determined simultaneously using a differential-pulse polarograph. There is no need to remove naphthalene from the solution. Dissolved oxygen is removed by adding a few millilitres of 4% NaBH4 solution. The detection limits are 0.06 ppm for Mn and 0.1 ppm for Zn (signal-to-noise ratio = 2). Linearity is maintained in the concentration ranges 0.06-10 ppm for Mn and 0.1-12 ppm for Zn with a correlation factor of 0.9997 and relative standard deviations of 0.95 and 0.81%, respectively. The characterization of the electroactive process included an examination of the degree of reversibility. Various parameters such as the effect of pH, volume of aqueous phase and interference of a number of metal ions on the determination of manganese and zinc were studied in detail to optimize the conditions for their simultaneous determination (based on the large difference in their Ep values) in various biological, pharmaceutical and environmental samples.

Humans↗
PubMed1994

SPECT in adult mosaic Down's syndrome with early dementia.

A 52-year-old patient with mosaic Down's syndrome exhibiting clinical features of early dementia who underwent high resolution SPECT neuroimaging is reported. While a CT scan of the brain showed no abnormality, cranial SPECT confirmed the presence of marked cortical blood flow deficits.

Alzheimer Disease↗
PubMed1994

Cerebral hemiatrophy and schizophrenia.

BACKGROUND: Neuroimaging of a treatment-resistant patient with schizophrenia revealed the existence of cerebral hemiatrophy. The association of schizophrenia with cerebral hemiatrophy has not previously been reported. RESULTS: Neuroimaging with X-ray computerised tomography showed marked reduction in the volume of the left cerebral hemisphere with secondary enlargement of the left lateral fissure and cortical sulci. High resolution cranial single-photon emission computerised tomography showed a functional deficit of the regional cerebral blood flow in the left lateral parietal and left temporal lobes. CONCLUSIONS: Cerebral hemiatrophy may belong to the lengthening list of neurodevelopmental cerebral anomalies associated with schizophrenia.

Adult↗
PubMed1990

Isolation and partial characterization of a plasma membrane-enriched fraction of Blastomyces dermatitidis.

The isolation and characterization of a plasma membrane-enriched fraction is reported from the pathogenic fungus Blastomyces dermatitidis employing a simplified and inexpensive procedure. The yeast cells, suspended in an osmotic stabilizer buffer, were subjected to gentle mechanical disruption followed by a three-step differential centrifugation to obtain a 40,000 x g sediment. This fraction showed 2.7- and 3.3-fold relative enrichment of the plasma membrane marker enzymes Mg2(+)-ATPase and 5'-nucleotidase, respectively, with modest cross-contamination of other intracellular membranes. The fraction comprised approximately 49% protein, 31% carbohydrate, 11% phospholipids and 9% sterol with sterol to phospholipid molar ratio of 1.1. Transmission electron microscopy of the plasma membrane-enriched fraction showed homogeneous vesicles with a tripartite unit membrane of 115 A thickness.

5'-Nucleotidase↗