Search PubMed⌕ Search

Biomedical subjects

A Husain

Publications and source records attributed to A Husain.

At least 127 records · Page 7Linked to original sources
PubMed1986

Schinus molle: a new source of natural fungitoxicant.

The oil of Schinus molle exhibited the maximum fungitoxic activity during the screening of some essential oils against some common storage and animal pathogenic fungi. It showed absolute toxicity against animal pathogens and mild activity against storage fungi. The effective concentrations of the oil varied from 200 to 900 ppm. The toxicity of the oil persisted up to 80 degrees C and 90 days of storage but declined when autoclaved. It withstood heavy inoculum density. The oil exhibited a narrow range of activity and was found to be more effective than Multifungin, an antifungal drug. The oil was characterized by its various physicochemical properties. It was found to comprise 50 constituents. It appeared that some changes in the oil constituents during storage affected its fungitoxic potency.

Antifungal Agents↗
PubMed1986

Characterization of receptors for angiotensin-induced drinking and blood pressure responses in conscious rats using angiotensin analogs extended at the N-terminal.

Angiotensin II analogs with N-terminal extensions were synthesized to examine their effects on the brain and vascular angiotensin II (Ang II) receptors of the rat. Ang II, Crinia-Ang II, Thr.Ala.Gly-Ang II and Val. Ser.Leu.Thr.Ala.Gly-Ang II were all found to elicit drinking and raise blood pressure when given into the cerebrospinal fluid (CSF), and elevate blood pressure when given intravenously. When given intracerebroventricularly, the order of potency of the peptides in eliciting blood pressure and drinking responses was: Ang II (100%) = Crinia-Ang II (100%) greater than Thr.Ala.Gly-Ang II (10% blood pressure, 15% drinking) greater than Val.Ser.Leu.Thr.Ala.Gly-Ang II (5%). The order of pressor potency did not change when the Ang II analogs were given intravenously, but compared with the central effects, there was a marked difference in the relative potencies of the peptides. The potencies were: Ang II (100%) greater than Crinia-Ang II (80%) greater than Thr.Ala.Gly-Ang II (60%) greater than Val.Ser.Leu.Thr.Ala.Gly-Ang II (20%). Blood pressure and drinking responses produced by all of these peptides were markedly attenuated by the Ang II receptor antagonist, [Sar1,Thr8] Ang II. These findings indicate a difference in the Ang II receptors present in the brain and the periphery. However, no differences were noted between the central Ang II receptors mediating the pressor responses and the central Ang II receptors stimulating drinking behavior.

Angiotensins↗
PubMed1986

Monoiodinated angiotensin II is a potent, full agonist analog of angiotensin II.

Mono 125I-angiotensin II (Ang II) has been used extensively as a radioligand to identify Ang II receptors whereas its receptor binding properties are well characterized, its biological activity has been less well studied. To examine this issue, nonradioisotopic monoiodo-Ang II was prepared and compared to Ang II. Monoiodo-Ang II was found to be a potent, full agonist in in vivo bioassays and a more potent (2.5-fold) pressor agent than the native hormone Ang II in the pithed rat. In eliciting dipsogenic responses monoiodo-Ang II was equipotent to Ang II, but was less potent (2.7-fold) than Ang II in contracting rat aortic strips. These results suggest that the well characterized binding affinity of monoiodo-Ang II is representative of its biological activity (40-250% of the activity of Ang II). The variation in relative peptide potency is consistent with the hypothesis of a heterogeneity of Ang II receptors. Most importantly, the similar efficacies between Ang II and monoiodo-Ang II indicate that the monoiodinated Ang II is a suitable ligand for the study of Ang II receptors.

Angiotensin II↗
PubMed1985

Presence of cyclopiazonic acid in kodo millet (Paspalum scrobiculatum) causing 'kodua poisoning' in man and its production by associated fungi.

Cyclopiazonic acid was isolated and identified from a sample of kodo millet seed that caused symptoms of 'kodua poisoning' in man. The extract of the toxic grain when injected intraperitoneally into mice produced symptoms of depression and complete loss of mobility. The seed was infected by Aspergillus flavus and A. tamarii and both fungi produced cyclopiazonic acid. This is the first report of the association of a mycotoxin with kodua poisoning and of A. tamarii with mycotoxicoses.

Animals↗
PubMed1985

Analysis of the calcium-dependent interaction of calmodulin with bovine serum albumin.

An air-driven ultracentrifuge has been used to investigate the calcium-dependent association between calmodulin and bovine serum albumin. Procedures were described which allowed the interaction to be analyzed to yield the equilibrium constant. At low ionic strength (25 mM Tris-HCl, pH 7.5, pCa 6.68, 9 degrees C) the equilibrium constant for the interaction was estimated to be 2.1 X 10(4) M-1, while at high ionic strength (25 mM Tris-HCl, pH 7.5, 150 mM KCl, pCa 6.68, 9 degrees C) the value was 4.5 X 10(3) M-1. Under similar conditions, calmodulin was also found to interact with beta-lactoglobulin A and gelatin, but no detectable association was observed with ovalbumin.

Animals↗
PubMed1985

Antihepatotoxic principles of Phyllanthus niruri herbs.

Among phyllanthin, hypophyllanthin, triacontanal and tricontanol isolated from a hexane extract of Phyllanthus niruri, phyllanthin and hypophyllanthin protected against carbon tetrachloride- and galactosamine-induced cytotoxicity in primary cultured rat hepatocytes, while triacontanal was protective only against galactosamine-induced toxicity.

Animals↗
PubMed1985

Fibrosing peritonitis in a drug abuser.

We report a case of fatal fibrosing peritonitis in a 28-year-old drug abuser. The extensive fibrosis, which was limited to the abdominal cavity, contained birefringent material. Silica was identified by spectrophotometric analysis. Silica is a component of talc (magnesium silicate) used as a drug filler. Relatively small amounts are known to induce fibrosis. The manner of introduction of this material into the peritoneal cavity is hypothetical and includes accidental direct peritoneal contamination during subcutaneous injections, a method used by drug abusers.

Adult↗
PubMed1985

The interaction of calmodulin with erythrocyte membrane proteins.

The method of sedimentation equilibrium in an air-driven ultracentrifuge (Airfuge) has been employed to investigate the interaction of 125I-calmodulin with the cytoskeletal components of the human red cell membrane. The results indicate significant calcium-dependent calmodulin binding activity in the low and high ionic strength extracts of the human erythrocyte membrane. The interaction of 125I-calmodulin with the low ionic strength extract proteins is analysed quantitatively. Further purification of the high ionic strength extract comprising mainly band 2.1 and band 4.1 results in the elution of calmodulin binding activity in a purified fraction of band 4.1.

Blood Proteins↗
PubMed1984

The interaction of calmodulin with human and avian spectrin.

An air-driven ultracentrifuge was used to investigate the calcium-dependent interaction of 125I-calmodulin with human and avian spectrins. The equilibrium constants (Ka) for the interaction between calmodulin and human spectrin dimer and tetramer under non-denaturing conditions were estimated to be 4.6 X 10(4) M-1 and 7.3 X 10(4) M-1, respectively. The denaturation of human spectrin by urea (5 M) increased the Ka for calmodulin to 4.6 X 10(5) M-1. The value of Ka for the interaction of calmodulin with avian spectrin dimer under non-denaturing conditions was 5.1 X 10(5) M-1. A bifunctional reagent cross-linked both avian spectrin and human spectrin to calmodulin in a calcium-dependent manner.

Adenosine Triphosphatases↗
PubMed1984

Rat brain angiotensin II receptors: effects of intracerebroventricular angiotensin II infusion.

Angiotensin II (Ang II) was infused into a lateral cerebral ventricle of male Sprague-Dawley rats and its effects on blood pressure, water balance and specific [125I]Ang II binding to brain and adrenal tissues were studied. The infusion was maintained at a rate of 500 ng/microliter/h for 6 days using subcutaneously implanted osmotic minipumps. A control group was infused intracerebroventricularly (i.c.v.) with 0.9% saline at a rate of 1 microliter/h for 6 days. Angiotensin II treated rats showed a four-fold increase in water intake and urine volume and a moderate increase in blood pressure; these effects were not observed in rats given saline i.c.v. There was no significant difference in [125I]Ang II binding site density or binding affinity in either the hypothalamus-thalamus-septum-midbrain (HTSM) or the brainstem between Ang II-treated and saline-treated groups. In addition, [125I]Ang II binding sites in the adrenals were also unaffected by i.c.v. infusion of Ang II. The results suggest that brain Ang II receptors are unresponsive to increased Ang II levels in cerebrospinal fluid.

Adrenal Glands↗
PubMed1984

Preparation and one-step purification of mono-125I-angiotensin II for radioligand binding assays.

A one-step purification of mono-125I-angiotensin II prepared by the chloramine T procedure is described. The purification is effected on a cellulose cation exchange column with isocratic elution by 50 mM sodium acetate, pH 5.0. The purity of the mono-125I-angiotensin II was determined by thin layer chromatography, high pressure liquid chromatography, enzymatic digestion, radioreceptor assay, and radioimmunoassay. Preparation and purification of mono-125I-angiotensin II by this procedure offers significant advantages over existing methods for its preparation in terms of purity, simplicity, efficiency, and cost.

Adrenal Glands↗
PubMed1984

Production of fumigaclavine A by Aspergillus tamarii Kita.

Aspergillus tamarii Kita. isolated from seeds of Paspalum scrobiculatum L. is found to produce ergot alkaloids in submerged culture. The culture filtrate and mycelium are observed to contain 0.125 mg/mL and 1.2 mg/g (dry weight) total alkaloids consisting of 86.5 and 91.3% fumigaclavine A, respectively. The identification of the compound was confirmed by high-performance liquid chromatography, ultraviolet, infrared, and mass spectrophotometry analyses. This is the first report of the production of ergot alkaloid by this fungus. The possible role of fumigaclavine A as a mycotoxin is discussed.

Aspergillus↗
PubMed1984

Restricted dietary sodium intake alters peripheral but not central angiotensin II receptors.

Male Sprague-Dawley rats were maintained on either a normal or low-sodium diet for 5 weeks to examine whether dietary sodium restriction alters angiotensin II (Ang II) receptors. The receptor sites in the hypothalamus-thalamus-septum (H-T-S) region of the brain, the adrenal glands and bladder visceral smooth muscle were measured by saturation isotherm binding assays using 125I-Ang II. Compared to control rats, the low-sodium diet group showed a smaller weight gain, reduced water intake, elevated hematocrit, and decreased urinary sodium concentration. In addition, sodium-depleted rats had a 10-fold elevation in plasma renin activity. However, neither binding affinity of 125I-Ang II to the brain H-T-S region nor its density was significantly different between the two groups. In contrast, both the 125I-Ang II binding density and dissociation constant in the adrenal gland were significantly elevated, while the binding density of 125-I-Ang II in the bladder smooth muscle was significantly decreased in the sodium-restricted group. These results suggest that dietary sodium depletion does not alter Ang II receptors in the rat brain areas wherein Ang II exerts the majority of its central actions.

Adrenal Glands↗
PubMed1984

A comparative study of filicidal and abusive mothers.

It is generally believed that some abusive parents if untreated eventually kill their children and "the murder of a child is the final chapter in his history of maltreatment." Yet only few authors have investigated the homicide of abused children. In this paper the authors report on a study of 8 filicidal and 52 abusive mothers referred to them by courts for pre-trial psychiatric evaluation. They found that there were significant differences between the two groups in that all (100%) of the filicidal women suffered from a major psychiatric illness before and at the time of committing the murder of their child while only 4 (7.7%) abusive mothers had a major psychiatric illness (x2 = 24.41, df = 1, p less than .001). They conclude from this study that the filicidal mothers are different from abusive mothers and that the risk of fatality as a complication of child abuse increases significantly when the mental illness is present in the mother. They point to the implications of their findings for child protection and intervention procedures and suggest that one should act very vigorously and take the child into protective custody when the mother is found to have a major psychiatric illness.

Adolescent↗
PubMed1984

Biochemical and immunological properties of dog brain isorenin.

A neutral protease with angiotensin I-forming activity which could readily be separated from acid proteases and plasma and renal renin was obtained from extracts of dog brain. This enzyme has an apparent mol wt of 40,000 by Sephadex chromatography. On chromatofocusing, it displays isoelectric points of 7.92, 7.73, and 7.42, and thus, it is a basic protein, in contrast to either renal or plasma renin which are acidic proteins. This brain enzyme does not react with antibodies specific for dog kidney renin. Since the brain enzyme forms angiotensin I from renin substrate at neutral pH, yet can be separated from and has isoelectric points different from renal renin, it is an isoenzyme of the kidney counterpart. The majority of the renin-like activity of dog brain is due to this isoenzyme.

Animals↗