Search PubMed⌕ Search

Biomedical subjects

A Desai

Publications and source records attributed to A Desai.

At least 91 records · Page 5Linked to original sources
PubMed1998

Production of poly-3-hydroxybutyrate from lactose and whey by Methylobacterium sp. ZP24.

Methylobacterium sp. ZP24, isolated from a local pond, is able to grow in a medium containing 12 g l-1 lactose as a sole source of carbon, giving 5.25 g l-1 biomass yield and poly-3-hydroxybutyrate (PHB) up to 59% of its dry weight in 40 h. The isolate was also able to utilize cheese whey and produce 1.1 g l-1 PHB. Addition of ammonium sulphate increased the production of PHB from whey 2.5-fold. The potential of Methylobacterium sp. ZP24 in PHB production from cheese whey is discussed.

Ammonium Sulfate↗
PubMed1998

Association of insulin resistance to electrocardiographic changes in non obese Asian Indian subjects with hypertension.

To investigate the relationship between insulin resistance and electrocardiographic changes in hypertension in the absence of confounding influences, plasma glucose and insulin responses to oral glucose were studied in 26 normotensive and 38 hypertensive subjects. Resting ECG was taken and classified into normal or abnormal using the Minnesota code. Among the 38 subjects, 16 had ECG abnormalities. All the hypertensive subjects had normal glucose tolerance. Serum insulin response of hypertensive subjects with ECG changes was 43% higher than those of hypertensive subjects without ECG changes and of normotensive subjects. The ratio AUC glucose/AUC insulin, a measure of insulin sensitivity was significantly reduced in subjects with abnormal ECG. Serum LDL cholesterol was significantly elevated and was the highest in hypertensive subjects with abnormal ECG. The ratio, Total Cholesterol/HDL Cholesterol was elevated to 5.81+/-0.47. I(125)-insulin binding to erythrocytes from 6 normotensive subjects, and 16 hypertensive subjects (8 with and 8 without ECG abnormalities) indicated 50% reduction in insulin receptor number in both the groups of hypertensive subjects compared to normotensive subjects. Multiple logistic regression analysis using mean blood pressure, serum total cholesterol, LDL cholesterol/HDL cholesterol, sex, insulin level at 60 min in OGTT, treatment, serum triglyceride, presence of family history of diabetes, CHD, hypertension and tobacco as independent variables causing ECG changes, revealed correct classification in 84% of cases. Among the variables, insulin level in OGTT contributed the most to ECG abnormalities. The data suggest that in the non obese, non diabetic Asian Indian hypertensive subjects, the presence of electrocardiographic abnormalities might be partly related to hyperinsulinemia or insulin resistance in them.

Area Under Curve↗
PubMed1997

Reliability of the quantitative angiographic measurements in the New Approaches to Coronary Intervention (NACI) registry: a comparison of clinical site and repeated angiographic core laboratory readings.

To assess the agreement of clinical site and angiographic core laboratory readings obtained in the New Approaches to Coronary Intervention (NACI) registry, we reviewed the angiographic results obtained in 787 lesions assessed both by the sites and the core laboratory, including 135 lesions analyzed twice (> or =2 months apart) by the angiographic core laboratory. Although moderate agreement was demonstrated between the clinical site and angiographic core laboratory for qualitative lesion morphology such as lesion calcium (kappa [kappa] = 0.42), only fair agreement was found between site and core laboratory estimation of lesion ulceration (kappa = 0.33); thrombus (kappa = 0.30); and eccentricity (kappa = 0.27); with poor agreement for angulation (kappa = 0.16); and proximal vessel tortuosity (kappa = 0.03). Agreement for qualitative morphology was better for repeated core laboratory readings of lesion eccentricity (kappa = 0.75); angulation (kappa = 0.72); thrombus (kappa = 0.68); proximal vessel tortuosity (kappa = 0.66); and calcification (kappa = 0.64). Quantitative angiographic measurements correlated moderately between the clinical site using the digital caliper method and the core laboratory using the automated edge-detection method, including preprocedural percentage diameter stenosis (intraclass correlation [R] = 0.50) and postprocedural percentage diameter stenosis (R = 0.63). Repeated core laboratory readings had almost perfect agreement, with R ranging from 0.88 for postprocedural percentage diameter stenosis to 0.93 for reference vessel diameter and pre- and postprocedural minimal lumen diameters. Repeated angiographic core laboratory readings provided highly consistent quantitative and qualitative morphologic results in the NACI registry, but the core laboratory readings varied substantially from those obtained at the clinical site. More standardized angiographic analytic criteria and core laboratory feedback to investigators may improve agreement between the clinical sites and the angiographic core laboratory in subsequent studies.

Angioplasty, Balloon, Coronary↗
PubMed1997

A method that allows the assembly of kinetochore components onto chromosomes condensed in clarified Xenopus egg extracts.

Kinetochores are complex macromolecular structures that link mitotic chromosomes to spindle microtubules. Although a small number of kinetochore components have been identified, including the kinesins CENP-E and XKCM1 as well as cytoplasmic dynein, neither how these and other proteins are organized to produce a kinetochore nor their exact functions within this structure are understood. For this reason, we have developed an assay that allows kinetochore components to assemble onto discrete foci on in vitro-condensed chromosomes. The source of the kinetochore components is a clarified cell extract from Xenopus eggs that can be fractionated or immunodepleted of individual proteins. Kinetochore assembly in these clarified extracts requires preincubating the substrate sperm nuclei in an extract under low ATP conditions. Immunodepletion of XKCM1 from the extracts prevents the localization of kinetochore-associated XKCM1 without affecting the targeting of CENP-E and cytoplasmic dynein or the binding of monomeric tubulin to the kinetochore. Extension of this assay for the analysis of other components should help to dissect the protein-protein interactions involved in kinetochore assembly and function.

Animals↗
PubMed1997

Astressin, a novel and potent CRF antagonist, is neuroprotective in the hippocampus when administered after a seizure.

Corticotropin-releasing factor (CRF), the principle hypothalamic regulator of the adrenocortical axis, also functions as a neurotransmitter. In this latter role, CRF causes electrophysiological activation and epileptiform activity in various brain regions. That finding, coupled with the observation that CRF mRNA is induced in endangered brain regions following necrotic insults, suggests that the peptide might contribute to necrotic neuron loss. Supporting that, a number of studies have shown that CRF antagonists decrease ischemic or excitotoxic damage to neurons. In the present report, we demonstrate the considerable neuroprotective potential of a novel and potent CRF antagonist, astressin, against kainic acid-induced excitotoxic seizures. Intracerebroventricular infusion of the peptide both 30 min before and 10 min after seizures decreased damage in some hippocampal cell fields by as much as 84%, a magnitude of protection greater than reported for other CRF antagonists against other models of necrotic neuronal injury. Administration of astressin was done against both local microinfusion (0.035 microgram) or systemic infusion (10 mg/kg body weight) of the excitotoxin; furthermore, the peptide protected even if administered only 10 min following excitotoxin exposure. This fulfills a critical prerequisite for any eventual therapeutic use of CRF antagonists, namely that they need not be administered in anticipation of a neurological insult.

Analysis of Variance↗
PubMed1997

Co-existence of cerebral cysticercosis with Japanese encephalitis: a prognostic modulator.

In this study, we investigated the frequency of co-existence of cerebral cysticercosis (CC) in Japanese encephalitis (JE) cases with special emphasis on its role in predicting the final clinical outcome. Amongst the 163 confirmed cases of JE, 37.42% (61/163) had co-existent CC. This was confirmed by antibody detection in the CSF of 45 cases, CT scan of the brain in 6 cases and at autopsy in 3 cases. In 2 cases confirmation was possible by CT scan as well as at autopsy, in 4, CSF antibody levels and CT scan were suggestive of CC while in 1, CSF antibodies and autopsy were suggestive of CC The co-occurrence of Cysticercus cellulosae in the brain emerged as a prognosticator of poor outcome in JE cases (P < 0.03).

Adolescent↗
PubMed1997

Microtubule polymerization dynamics.

The polymerization dynamics of microtubules are central to their biological functions. Polymerization dynamics allow microtubules to adopt spatial arrangements that can change rapidly in response to cellular needs and, in some cases, to perform mechanical work. Microtubules utilize the energy of GTP hydrolysis to fuel a unique polymerization mechanism termed dynamic instability. In this review, we first describe progress toward understanding the mechanism of dynamic instability of pure tubulin and then discuss the function and regulation of microtubule dynamic instability in living cells.

Animals↗
PubMed1997

Cardioprotection with dexrazoxane for doxorubicin-containing therapy in advanced breast cancer.

PURPOSE: To determine the cardioprotective effect of dexrazoxane (DZR) used in a doxorubicin-based combination therapy in advanced breast cancer. PATIENTS AND METHODS: Between November 1988 and January 1991, 534 patients with advanced breast cancer were randomized to two multicenter, double-blind studies (088001 and 088006). Patients received fluorouracil, doxorubicin, and cyclophosphamide (FAC) with either DZR (DZR-to-doxorubicin ratio, 10:1) or placebo (PLA) every 3 weeks and were monitored with serial multiplegated acquisition (MUGA) scans. RESULTS: The hazards ratio (HR) of PLA to DZR for a cardiac event, which was predefined ejection fraction changes or congestive heart failure (CHF), was 2.63 (95% confidence interval [CI], 1.61 to 4.27; P < .001) for 088001 and 2.00 (95% CI, 1.01 to 3.96; P = .038) for 088006. The objective response rates for 088001 were 46.8% for DZR and 60.5% for PLA, a difference of 14% (95% CI, -25% to -2%; P = .019), and for 088006 were 53.7% for DZR and 49.3% for PLA, a difference of 4% (95% CI, -13% to 22%; P = .63). Time to progression and survival were not significantly different between treatment arms in either study. Toxicities on the DZR arms included lower granulocyte and platelet counts at nadir (P = .009 and P = .004, respectively) and more pain on injection (P = .001), with no difference in the rates of fever, infection, or hemorrhage. CONCLUSION: DZR had a significant cardioprotective effect as measured by noninvasive testing and clinical CHF. One of the two studies (088001) showed a lower response rate with DZR, but time to progression and survival were not significantly different. DZR is the first agent shown to reduce cardiotoxicity from doxorubicin.

Aged↗
PubMed1997

Correlation of tumor necrosis factor levels in the serum and cerebrospinal fluid with clinical outcome in Japanese encephalitis patients.

To investigate the prognostic role of tumour necrosis factor (TNF) in Japanese encephalitis virus (JEV) infection, we measured the immunoreactive forms of TNF concentrations in the serum and cerebrospinal fluid (CSF) of 47 laboratory-confirmed cases of JE. It was observed that TNF levels were elevated (> 15 pgm/ml) in all the 47 serum samples (range 19.4-923.8 pg/ml), while in 46/47 CSF samples TNF was elevated (range 10.8-376 pg/ml). The mean (SD) TNF levels in the serum of fatal cases was 234.34 pg/ml (304.40) as compared to the mean of 85.31 pg/ml (SD 153.92) in nonfatal cases. Similar observations were also made with respect to the TNF levels in the CSF; the mean of fatal cases was 69.39 pg/ ml (SD 39.00) in contrast to the mean of 62.41 pg/ml (SD 75.25) of nonfatal cases. The increase in TNF levels did not show any correlation to the duration of illness. It was further observed that the mortality rate increased with increasing concentrations of TNF in the serum and CSF. Correlation of laboratory parameters to final outcome revealed that TNF concentrations above 50 pg/ ml in serum correlated significantly (P = .05) with a fatal outcome, whilst high levels of JEV-IgM antibodies (> 500 units) in the CSF correlated with a nonfatal outcome (P = .03). These results suggest that TNF can be used as a possible prognosticator of a fatal outcome in JEV infection.

Adolescent↗
PubMed1996

XKCM1: a Xenopus kinesin-related protein that regulates microtubule dynamics during mitotic spindle assembly.

We isolated a cDNA clone encoding a kinesin-related protein, which we named XKCM1. Antibodies to XKCM1 stain mitotic centromeres and spindle poles. Immunodepletion and antibody addition experiments in an in vitro spindle assembly assay show that XKCM1 is required for both establishment and maintenance of mitotic spindles. The structures that form in the absence of XKCM1 contain abnormally long microtubules. This long microtubule defect can be rescued by the addition of purified XKCM1 protein. Analysis of microtubule dynamics in a clarified mitotic extract reveals that loss of XKCM1 function causes a 4-fold suppression in the catastrophe frequency. XKCM1 thus exhibits a novel activity for a kinesin-related protein by promoting microtubule depolymerization during mitotic spindle assembly.

Amino Acid Sequence↗
PubMed1996

Nonspecific protease-catalyzed hydrolysis/synthesis of a mixture of peptides: product diversity and ligand amplification by a molecular trap.

We sought to develop a peptide library in solution and dynamically screen this library for peptides that would bind to macromolecules of interest. Peptide diversity was achieved in an initial stock solution of peptides by using proteases under conditions in which both hydrolysis and synthesis occurred. As an example, a simple reaction containing YGG, FL and thermolysin resulted in the synthesis of YGGFL as well as many other undefined products. When low molecular weight products of a reaction containing VA, AL, and thermolysin were subsequently exposed to dipeptidase, 7 out of 9 potential dipeptides were observed. Incubation of protease with an hydrolysate of albumin and a radiolabeled peptide resulted in the radiolabel participating in reactions other than simple hydrolysis and, after 24 h, the specific activity of radiolabel was shown by high performance liquid chromatography to disperse to a level that would be necessary in the event of maximum theoretical diversity. When a binding macromolecule was exposed to this system, ligand production was amplified relative to reactions run in the absence of binding macromolecule. This protease-based peptide scrambling and binding system was utilized for the discovery of novel peptides that bind to fibrinogen.

Chromatography, High Pressure Liquid↗
PubMed1996

Genetic map of diploid wheat, Triticum monococcum L., and its comparison with maps of Hordeum vulgare L.

A genetic map of diploid wheat, Triticum monococcum L., involving 335 markers, including RFLP DNA markers, isozymes, seed storage proteins, rRNA, and morphological loci, is reported. T. monococcum and barley linkage groups are remarkably conserved. They differ by a reciprocal translocation involving the long arms of chromosomes 4 and 5, and paracentric inversions in the long arm of chromosomes 1 and 4; the latter is in a segment of chromosome arm 4L translocated to 5L in T. monococcum. The order of the markers in the inverted segments in the T. monococcum genome is the same as in the B and D genomes of T. aestivum L. The T. monococcum map differs from the barley maps in the distribution of recombination within chromosomes. The major 5S rRNA loci were mapped on the short arms of T. monococcum chromosomes 1 and 5 and the long arms of barley chromosomes 2 and 3. Since these chromosome arms are colinear, the major 5S rRNA loci must be subjected to positional changes in the evolving Triticeae genome that do not perturb chromosome colinearity. The positional changes of the major 5S rRNA loci in Triticeae genomes are analogous to those of the 18S-5.8S-26S rRNA loci.

Chromosome Mapping↗
PubMed1996

Cryptococcal infections of the central nervous system: an analysis of predisposing factors, laboratory findings and outcome in patients from South India with special reference to HIV infection.

The incidence of cryptococcosis in patients with AIDS is significant. Predisposing factors, laboratory findings and outcome were assessed in 60 patients with cryptococcal infections of the central nervous system over a 17.5-year period (Jan. 1978-June 1995). Predisposing factors for cryptococcal infection were identified in 36 patients, with HIV infection being the commonest (18). Cryptococcal cultures were positive in all patients. India ink staining was positive in 48 patients and cryptococcal antigen was detected in 35 of 36 patients tested. Comparison of clinical and laboratory parameters between HIV-positive and HIV-negative patients showed that CSF cell response was poorer, culture of cryptococci from non-neural sites was more frequent and mortality was higher in the HIV-positive group. Although not statistically significant, concurrent systemic infections, especially tuberculosis, were more frequent in the HIV-positive group.

AIDS-Related Opportunistic Infections↗