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Biomedical subjects

B K Puri

Publications and source records attributed to B K Puri.

At least 91 records · Page 5Linked to original sources
PubMed1986

Spectrophotometric determination of copper in environmental samples by solid-liquid extraction of its 9, 10-phenanthrenequinone monoximate complex into molten naphthalene.

A fairly selective and sensitive spectrophotometric method has been developed for determination of copper after extraction of its 9, 10-phenanthrenequinone monoximate complex into molten naphthalene in the pH range of 6.1-8.4. At room temperature, the solid naphthalene containing the metal complex is separated by filtration, dissolved in dimethylformamide (DMF) and the absorbance measured at 470 nm against the reagent blank. Beer's law is obeyed in the concentration range, 0.0-9.6 micrograms of copper in 10ml of DMF. The molar absorptivity and sensitivity are 6.30 X 10(4) 1 mol-1 cm-1 and 0.001 micrograms cm-2, respectively. The interference of various ions has been studied and the method has been applied for the determination of copper in various standard reference materials, beers, wines, human hair and environmental samples.

Copper↗
PubMed1977

Mast cell response during the early phase of tuberculosis: an electron-microscopic study.

Guinea pig lungs were infected with Mycobacterium tuberculosis by intratracheal route and examined under electron microscope to investigate the morphological alterations of the organisms, if any, and the response of the host tissue. The bacilli showed no changes in their morphology, while the host tissues revealed several cells containing many electron-dense intracytoplasmic granules. These cells were predominantly seen during the 1st week of infection. The electron-dense bodies of these cells may be the ones observed by earlier workers and suggested to be the altered forms of tubercle bacilli. The present investigation, however, revealed them to be the granules of the mast cells. These cells were observed to respond to tuberculous infection during the first few days by appearing in large numbers crowded with intracytoplasmic granules and soon disintegrating as the result of subsequent degranulation. The above observation is presented and its significance discussed.

Animals↗
PubMedDate not supplied

The potential role of fatty acids in attention-deficit/hyperactivity disorder.

As currently defined, attention-deficit/hyperactivity disorder (ADHD) encompasses a broad constellation of behavioural and learning problems and its definition and diagnosis remain controversial. The aetiology of ADHD is acknowledged to be both complex and multifactorial. The proposal considered here is that at least some features of ADHD may reflect an underlying abnormality of fatty acid metabolism. Clinical and biochemical evidence is discussed which suggests that a functional deficiency of certain long-chain polyunsaturated fatty acids could contribute to many of the features associated with this condition. The implications in terms of fatty acid treatment proposals are also discussed; such a form of treatment is relatively safe compared to existing pharmacological interventions, although further studies are still needed in order to evaluate its potential efficacy in the management of ADHD symptoms.

Attention Deficit Disorder with Hyperactivity↗
PubMedDate not supplied

Evaluation of a FLAIR sequence designed to reduce CSF and blood flow artifacts by use of k-space reordered by inversion time at each slice position (KRISP) in high grade gliomas of the brain.

The objective of this study was to compare conventional and KRISP (k-space reordered by inversion time at each slice position) fluid-attenuated inversion recovery (FLAIR) sequences in high grade gliomas for artifact control, conspicuity of intracranial structures, and lesions as well as sensitivity to contrast enhancement. Artifacts were lower with the KRISP FLAIR sequence, and the conspicuity of all assessed structures and lesions was better. The degree of contrast enhancement was similar with T1-weighted and KRISP FLAIR sequences.

Adult↗
PubMedDate not supplied

Social drift in forensic psychiatric inpatients with schizophrenia.

The highest social class before admission of 27 forensic psychiatric inpatients in a regional secure unit who suffered from schizophrenia was found to be significantly lower than that of their fathers. This is the first report of social drift in this group of patients.

Adult↗
PubMedDate not supplied

Eicosapentaenoic acid treatment in schizophrenia associated with symptom remission, normalisation of blood fatty acids, reduced neuronal membrane phospholipid turnover and structural brain changes.

The administration of the omega-3 fatty acid eicosapentaenoic acid (EPA) to a drug-naive patient with schizophrenia, untreated with conventional antipsychotic medication, led to a dramatic and sustained clinical improvement in both positive and negative symptoms. This was accompanied by a correction in erythrocyte membranes of abnormalities in both n-3 and n-6 highly unsaturated fatty acids and with reduced neuronal membrane phospholipid turnover, as evidenced by serial 31-phosphorus cerebral magnetic resonance spectroscopy. Using recently developed techniques of image segmentation, subvoxel registration and quantitation, analysis of serial high-resolution 3D cerebral MRI scans showed that, in the year before EPA treatment, cerebral atrophy was taking place and that this atrophy was reversed by six months of EPA treatment. These results demonstrate that EPA can reverse both the phospholipid abnormalities previously described in schizophrenia and cerebral atrophy. They provide strong further evidence in support of the membrane phospholipid model of schizophrenia.

Adult↗
PubMedDate not supplied

Preconcentration of bismuth(III) and copper(II) by solid-phase extraction and subsequent determination by differential pulse polarography.

A differential pulse polarographic method is proposed for the trace determination of bismuth and copper from large volumes of aqueous samples after adsorption of their 1-(2-thiazolylazo)-2-naphthol complexes onto microcrystalline naphthalene in the pH ranges of 7.2-9.0 and 4.0-7.8, respectively. Bismuth and copper are desorbed from microcrystalline naphthalene with 9 mL 1M HCl. Well-defined peaks are obtained at Ep = -0.09 and -0.20 V versus a saturated calomel electrode, in an HCl-isoquinoline medium as the supporting electrolyte, for bismuth and copper, respectively. Bismuth is reduced reversibly with a 3-electron change, whereas copper is reduced irreversibly under these conditions. The detection limits are 55 ng/mL for bismuth and 91 ng/mL for copper. Linearity is maintained in the concentration ranges of 0.18-13.5 and 0.30-17.3 microg/mL for bismuth and copper, respectively, with corresponding correlation coefficients of 0.9996 and 0.9885. The relative standard deviations are 1.0% for bismuth at 2.0 microg/mL and 1.4% for copper at 5.0 microg/mL. Various parameters were optimized to develop conditions for the determination of these metal ions in various samples.

Adsorption↗
PubMedDate not supplied

The niacin skin flush test in schizophrenia: a replication study.

The aim of this study was to confirm a recent report that the non-invasive niacin skin flush test can be used to demonstrate impaired arachidonic acid-related signal transduction in schizophrenia. The response to topical aqueous methyl nicotinate solution was recorded at five-minute intervals over 20 minutes in 21 patients with schizophrenia, and in 20 age- and sex-matched normal individuals with no personal or family psychiatric history. The response was significantly lower in the patients with schizophrenia. At a concentration of 0.001 M, at the 15-minute timepoint, only two out of the 21 patients with schizophrenia showed a response, compared with 15 out of 20 of the controls (p < 0.00002), giving a sensitivity of the niacin skin test of 90% and a specificity of 75%. Our results are therefore consistent with the previous published report and suggest that this test may be useful clinically in the diagnosis of schizophrenia.

Administration, Topical↗
PubMedDate not supplied

Column preconcentration of trace manganese with the ion pair of 2-nitroso-1-naphthol-4-sulfonic acid tetradecyldimethylbenzyl-ammonium chloride supported on naphthalene and determination by derivative spectrophotometry.

A column preconcentration method has been developed for the determination of trace amounts of manganese by preconcentration on 2-nitroso-1-naphthol-4-sulfonic acid (nitroso-S)-tetradecyldimethylbenzylammonium (TDBA) naphthalene as an adsorbent using a simple funnel tipped glass tube. Manganese reacts with nitroso-S to form a water soluble brown colored chelate anion. The chelate anion forms a water insoluble Mn-Nitroso-S-TDBA ion pair on naphthalene packed in a column in the pH range 9.6-10.5 at a flow rate of 1-2 ml/min. The solid mass consisting of manganese complex and naphthalene is dissolved in 5 ml of dimethylformamide (DMF) and the metal determined by second derivative spectrophotometry. The calibration curve is linear in the concentration range 0.25-35.0 micrograms of Mn in 5 ml of the final DMF solution. Eight replicate determinations of 25 micrograms of standard manganese solution give a mean peak height of 4.0 with a correlation coefficient of 0.9995 and relative standard deviation of +/- 1.1%. The sensitivity was calculated to be 0.502(d2 A/d lambda 2)/microgram ml-1 from the slope of the calibration curve. The detection limit was 0.020 microgram ml-1 for manganese at the minimum instrumental settings (signal to noise ratio = 2). Various parameters effecting the method such as the effect of pH, volume of aqueous phase and interference of a number of metal ions on the determination of manganese have been evaluated to optimize the conditions for its determination in standard alloys and biological samples.

Adsorption↗