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Biomedical subjects

S Bhattacharya

Publications and source records attributed to S Bhattacharya.

At least 451 records · Page 25Linked to original sources
PubMed1989

Binding property of rat and Limulus C-reactive proteins (CRP) to mercury.

The C-reactive proteins (CRP) from both rat and Limulus were found to bind mercury (Hg) in both in vivo and in vitro conditions. CRP has high-affinity binding sites for Hg as evidenced by the loss of free sulfhydryl groups, arrested mobility in polyacrylamide gel electrophoresis, and the consumption of CRP in the serum after Hg administration. The binding was tight as it could not be inhibited either by the addition of cysteine or EDTA. By using a direct titration method it was shown that binding of Hg to CRP was saturable at a molar ratio of Hg/CRP = 13.11. The possibility that CRP may act as a scavenger for Hg is discussed.

Animals↗
PubMed1989

Purification and properties of pituitary gonadotropic hormone from Indian teleosts: freshwater murrel (Channa punctatus) and carp (Catla catla).

Gonadotropic hormone (GtH) from the pituitaries of two widely different Indian teleosts, a freshwater murrel and a carp, was purified by solvent fractionation, Sephadex G-100 gel filtration, affinity chromatography on concanavalin A-Sepharose (Con A-Sepharose), and immunoaffinity chromatography. Elution profile from gel filtration showed three peaks in both cases, peak I and II were clearly separated in murrel but not in carp. Peak II demonstrated strong GtH activity in both murrel and carp but this activity could also be detected in peak I and III of carp. TSH activity was restricted to peak I in murrel and was distributed in all three peaks in carp. Chromatography on Con A-Sepharose was useful in harvesting carp glycoprotein hormones, but gave no advantage in murrel. A pure homogenous GtH from murrel and carp could be obtained by using immunoaffinity chromatography. Polyacrylamide gel electrophoresis of murrel and carp GtH showed a single discrete band. Determination of molecular weight (MW) by Sephadex G-100 gel filtration indicated that murrel and carp GtH were 42,000 and 40,000 Da, respectively. SDS-polyacrylamide gel electrophoresis of murrel and carp GtH revealed two dissimilar subunits, alpha and beta. MW of murrel and carp alpha-subunits were 18,000 and 16,000 while those of beta were 27,000 and 26,000 Da, respectively. Comparison of electrophoretic patterns of murrel and carp GtH alpha and beta with ovine LH subunits reveal distinct teleostean GtH subunits.

Animals↗
PubMed1989

Requirement of extracellular calcium in fish pituitary gonadotropin release by gonadotropin hormone-releasing hormone.

Influence of extracellular calcium on gonadotropin hormone-releasing hormone (GnRH)-stimulated gonadotropin hormone (GtH) release from a teleostean fish (Channa punctatus) pituitary was examined in vitro by preparing enzymatically dispersed pituitary cell incubation. Effect of Ca2+ on GnRH-augmented GtH release was evaluated with partially purified C. punctatus GnRH (cGnRH) and synthetic mammalian GnRH (mGnRH). Cells were dispersed by 0.3% collagenase plus 0.05% trypsin in culture medium and a high yield of viable cells were obtained. Addition of cGnRH (10 micrograms/ml) to pituitary cells in Ca2+-free medium resulted in a significant increase in GtH release, but the addition of Ca2+ (2 mM) enhanced it to about four- and threefold over cGnRH and mGnRH, respectively. Increasing concentrations of Ca2+ (0.1-2.0 mM/well) with fixed concentrations of GnRH (10 micrograms/ml) or increasing doses of GnRH (2.5 to 20 micrograms/ml) with fixed amount of Ca2+ (2 mM/well) resulted in a dose dependent increase in GtH release. EDTA or EGTA (2 mM/well) completely suppressed the Ca2+-augmenting effect of GnRH-stimulated GtH release. Addition of lanthanum (La3+, 4 mM/well), a competitive inhibitor of Ca2+, reduced 60% of the Ca2+ (2 mM/well) stimulation. Verapamil, a specific Ca2+ channel blocker, when added in increasing concentrations (1-100 microM/well) to pituitary cell incubations containing GnRH-stimulated GtH release in Ca2+-free medium could be waived by EGTA (2 mM/well), indicating availability of extracellular calcium from tissue sources. The uptake of radioactive Ca2+ by pituitary cells was greatly enhanced by GnRH while the addition of verapamil (10 microM/well) not only inhibited the GnRH-stimulated uptake, but also reduced it below the control level.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1989

Dystrophin in skeletal muscle. II. Immunoreactivity in patients with Xp21 muscular dystrophy.

In the preceding paper a sensitive Western blotting analysis system based on the use of a monoclonal antibody to dystrophin was described. Here we report the immunoreactivity on blots and on unfixed frozen sections of muscle from patients with Duchenne (DMD) and Becker (BMD) muscular dystrophy. Muscle from 3 BMD patients showed variation both in the band pattern observed on blots and in the immunocytochemical labelling of dystrophin on frozen sections. In contrast to previous reports, we were able to detect some minor dystrophin bands on blots from 6 of 9 DMD biopsy samples. Tissue sections from 8 of the 9 contained isolated fibres with dystrophin-positive labelling. We conclude that the majority of DMD patients have muscle fibres which can synthesize dystrophin in a limited manner.

Adolescent↗
PubMed1989

In vitro inhibition of goat brain acetylcholinesterase by pure and commercial anticholinesterase pesticides.

In vitro inhibition of goat cerebellar acetylcholinesterase by pure and commercial anticholinesterase pesticides clearly indicates a remarkably high inhibitory effect of commercial carbamate and organophosphate pesticides containing a lower percentage of the respective active ingredients comparable to that of the known anticholinesterase agents such as DFP and physostigmine. It may be presumed that injudicious use of commercial formulations conduce severe toxicity in the nontarget mammalian species, namely, goat, and this response of the brain acetylcholinesterase may be utilized as a reliable bioindicator of pesticidal contamination of the terrestrial environment.

Acetylcholinesterase↗
PubMed1989

Ovarian damage to Channa punctatus after chronic exposure to low concentrations of Elsan, mercury, and ammonia.

Histopathological changes were induced in the ovary by chronic nonlethal levels of Elsan (211 ppb), mercury (16.7 ppb), and ammonia (15.64 ppm). In the breeding season, treated Channa punctatus revealed a significant decrease in ovarian weight throughout the duration of the experiment. Acute changes were noted in the diameter and percentage occurrence of the different stages of oocytes. In all cases, stage I oocytes revealed no difference in diameter with respect to control although they demonstrated an increase in the percentage occurrence. For stages II and III, a remarkable decrease occurred in both the number and the diameter of these mature oocytes. The preponderance of stage I and destruction of stage II and stage III oocytes in all three treatments indicate that chemically diverse xenobiotics have equal reproductive toxicity in fish, interfering with their breeding.

Ammonia↗
PubMed1989

Documentation of the first web space angle.

We describe a new method of measuring adduction contractures of the thumb by using stent mould casts of the first web, which are sectioned sagittally to give an accurate clinical angle at their cut section. This can be recorded from ink impressions. This method has been used successfully in 65 cases and appears more accurate than other methods.

Casts, Surgical↗
PubMed1989

Hyaluronan affects extravascular water in lungs of unanesthetized rabbits.

We have determined whether changes in lung hyaluronan content affect extravascular water in lungs of unanesthetized rabbits. Three groups of experiments were performed. In group 1 (n = 12), no infusions were given; in group 2, nine pairs of rabbits received either intravenous hyaluronidase (750 U.kg-1.min-1) or an equivalent volume of saline; in group 3, nine pairs of rabbits received either hyaluronidase or saline, followed by intravenous saline infusion amounting to 24% of body weight. At the end of each experiment, one lung was analyzed for extravascular lung water by the wet-dry method. Except for group 3, in all animals the other lung was analyzed for hyaluronan content by a method that involved hydrolyzing lung hyaluronan with fungal hyaluronidase to release reducing N-acetyl glucosamine groups, which were quantified. In group 1, lung hyaluronan, which varied from 50 to 159 micrograms/g dry wt (mean 106 +/- 35 micrograms/g dry wt), significantly correlated with variation in extravascular lung water (mean 4.2 +/- 0.3 g/g dry wt). In group 2 rabbits given hyaluronidase, lung hyaluronan was 40% lower and extravascular lung water was 14.6% lower than in paired controls (P less than 0.01). In group 3, volume expansion did not affect lung water, except after hyaluronidase when lung water was 47% higher than paired controls. We conclude that in the lung the content of hyaluronan is one of the determinants of extravascular water content.

Animals↗
PubMed1989

X chromosome restriction fragment length polymorphisms in five racial groups: rare variant detected with the RC8 (DXS9) probe in the Marathi population, India.

Restriction fragment length polymorphisms were investigated in five racial groups using the X chromosome probes DXS9 and DXS7. The allele frequencies of these polymorphisms showed significant differences and both DNA fragments were found to be highly polymorphic in the populations of south and southeast Asia. In the Marathi population of India, a rare allele B*3 (3 kilobases; kb) and an altered 7-kb fragment instead of the 6.6-kb constant band were found with DXS9. This is the first time that the rare B*3 allele is found in a non-European population.

Asian People↗
PubMed1989

Measurement of lung microvascular pressure in the intact anesthetized rabbit by the micropuncture technique.

We have developed a micropuncture technique for the measurement of microvascular pressure in the intact lung of rabbit. We anesthetized 16 rabbits (halothane, 0.8%) and mechanically ventilated them through a tracheotomy. Then, we exposed the right lung by rib resection over the right anterior chest. We measured pulmonary artery, left atrial, and systemic pressures by direct catheterization and cardiac output by the thermodilution technique. For micropuncture, we stabilized the lung on a shelf and stopped ventilation for 3-4 minutes at an airway pressure of 7 cm H2O. We injected pancuronium intravenously to paralyze the diaphragm and intercostal muscles. Of the total pulmonary vascular pressure drop, 52% occurred in the microvascular segment between arterioles and venules of 20 micron diameter, 28% occurred in the arterial segment, and 20% occurred in the venous segment. We conclude that in the intact lung of rabbit, the major pressure drop occurs in the microvascular segment.

Anesthesia↗
PubMed1989

Homologous radioimmunoassay and radioreceptorassay of gonadotropic hormone for an Indian carp Catla catla.

A homologous radioimmunoassay (RIA) for Indian carp (C. catla) gonadotropin (GtH) was developed by using purified Catla GtH and its specific antiserum. In Ouchterlony agar diffusion, antisera raised against purified Catla GtH (cGtH), showed clear crossreaction. Catla-anti GtH (anti-cGtH) did not cross-reacted with Catla TSH enriched fraction. Immunocrossreaction was further confirmed with competitive binding inhibition studies where displacement of radiolabelled cGtH was precisely linear against increasing concentrations of cGtH, hence this was later used as standard curve for RIA. Competitive binding inhibition was also observed with purified murrel GtH, silver carp GtH and Cyprinus GtH, using varied doses. Both murrel and silver carp GtH showed clear parallelism with cGtH, while Cyprinus GtH inhibition slope was less steeper. Mammalian GtHs (hCG, oLH, oFSH), bTSH and bPRL had no crossreaction with anti-cGtH. Radioreceptorassay (RRA) for cGtH was developed by preparing plasma membranes from Catla oocytes. Binding of 125I-cGtH to oocyte plasma membranes showed saturability with high affinity (Ka = 0.11 X 10(13)M-1) and low capacity (17 fmol/mg protein). Displacement of 125I-cGtH in receptorassay by cold cGtH was linear and therefore served as standard curve. The interassay and intrassay variability in RIA was 7.9% and 3% while that of RRA was 5% and 3% respectively. Sensitivity of RIA was in the picogram level whereas it was in nanogram level by RRA. Determination of carp pituitary and serum GtH content by RIA and RRA showed the consistency, precision and validity of these assays. Although RRA was comparatively less sensitive than RIA, it was convenient, quick and less expensive.

Animals↗
PubMed1989

Impact of nonlethal levels of Metacid-50 and carbaryl on thyroid function and cholinergic system of Channa punctatus.

With regard to brain acetylcholinesterase and acetylcholine and serum triiodothyronine (T3) and thyroxine (T4) profiles, a biphasic response pattern was elicited in Channa punctatus chronically exposed to nonlethal doses of locally used pesticides, namely, Metacid-50 and Carbaryl. Data revealed that these xenobiotics caused significant inhibition of brain acetylcholinesterase activity and a decrease in thyroxine level accompanied by a concurrent increase in acetylcholine accumulation and T3 level. It is surmised that Metacid-50 and Carbaryl influence both neural and hormonal functions.

Acetylcholine↗
PubMed1989

Beneficial effects of ACE inhibitors in severe mitral stenosis.

There are several reports of beneficial effects of ACE inhibitors in both primary and secondary pulmonary hypertension. However the effect of ACE inhibitors in mitral stenosis is not documented. The authors report three patients with severe mitral stenosis in whom surgery was delayed. They had initial symptomatic improvement with diuretics and sodium restriction, but had recurrence of their symptoms while on treatment. Enalapril not only relieved their symptoms in particular exertional dyspnoea and haemoptysis but prevented recurrence and improved their effort tolerance without causing excessive fall of blood pressure or impairment of renal function.

Adult↗
PubMed1989

Influence of industrial pollutants on thyroid function in Channa punctatus (Bloch).

A 30 day exposure of C. punctatus to sublethal levels of phenol, ammonia, mercuric chloride, cadmium chloride and a mixture of the four resulted in an overall activation of guaiacol peroxidase and depression of iodide peroxidase (IPOD) activity and blood T4 titre. Interestingly enough, in case of 15 day ammonia and 1 day mercury exposures, an increase of IPOD activity was accompanied by a decrease in T4 titre. In general, phenol, mercury, cadmium and the mixture of pollutants were found to inhibit LP activity by 56% to 85% while ammonia inhibited lysosomal protease (LP) activity by 70%. Alterations in acid phosphatase (AP) activity indicate changes in the lysosomal membrane characteristics caused by these toxicants. Considering the concomitant alterations in IPOD, T4, LP and AP it is surmised that thyroid function in C. punctatus is influenced by the pollutants by two pathways, one via IPOD pathway affecting T4 synthesis and the other via lysosomal pathway affecting T4 release.

Ammonia↗
PubMed1989

Effect of piracetam, a nootropic agent, on rat brain monoamines and prostaglandins.

Piracetam is the prototype of a new class of psychotropic drugs, the nootropic agents, which are claimed to selectively improve the higher telencephalic integrative activities. The effect of piracetam on rat brain monoamines and prostaglandins (PGs) was assessed so as to garner information on its mode of action. Two doses of the drug were used, a lower dose (20 mg/kg ip) and a higher dose (100 mg/kg, ip), the latter being known to exert a facilitatory effect on learning and memory. Piracetam produced a dose-related effect on rat brain serotonin (5HT) and noradrenaline (NA), with the lower dose inducing a decrease in 5HT levels and an increase in NA concentrations. The higher dose of piracetam produced the opposite effect. Dopamine (DA) levels were not significantly affected. The lower dose of the drug attenuated 5HT turnover and augmented that of NA, whereas the higher dose of piracetam produced the reverse effects, in clorgyline treated rats. The lower dose of piracetam produced a slight and statistically insignificant increase in rat brain PGE2 and PGF2 alpha. However, the higher dose of the drug produced marked increase in the levels of both the PGs. The observed biochemical effects may provide a basis for the nootropic effect of piracetam. However, they may also be due to the GA-BA-mimetic action of the drug, particularly those observed with the lower dose of piracetam.

Animals↗
PubMed1989

Appearance of C-reactive protein (CRP) in serum and liver cytosol of cadmium-treated rats.

The possibility of stimulation of C-reactive protein (CRP) due to inflammation and necrosis caused by cadmium was investigated. Cadmium injection (less than 3 mg/kg body weight) in white rat was found to be associated with the appearance of CRP in liver cytosol after 8 hr and in serum after 18 hr of injection. Although, no definite dose-response relationship was found, yet CRP level was elevated drastically, varying from 1-4 mg/g wet weight liver and 0.3-0.7 mg/ml serum. CRP-positive serum from Cd-treated rats precipitated with normal rat serum on agarose-covered slides in the presence of 1 mM CaCl2. Evidences for raised level of CRP indicates acute tissue damage in the animal.

Animals↗