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Biomedical subjects

S C Sharma

Publications and source records attributed to S C Sharma.

At least 163 records · Page 9Linked to original sources
PubMed1990

Kinetic fate of potassium embelate, a non-narcotic centrally acting analgesic after oral and intravenous administration.

The pharmacokinetics of oral and intravenous potassium embelate (20 mg/kg) was studied in rats. The results revealed that this compound follows a biexponential kinetic pattern. Absorption was complete (bioavailability 97%) and fast. The disposition half-life is 9.5 h on intravenous and 11 h on oral administration. High concentrations of the drug were found in brain between 0.25 and 2 h, which is in agreement with its pharmacological action. The kidney plays a major role in the excretion of the drug.

Administration, Oral↗
PubMed1990

Chronic muscle wasting in alcoholics--a histochemical and biochemical study.

A comparative histochemical and biochemical study of the anterior tibial muscle of 10 alcoholics suggests that neuropathy could be the cause of chronic muscle weakness and wasting. Myopathic changes did not predominate in the findings. It is concluded that the proximal muscle atrophy could also be attributed to neurogenic damage. Histochemical reactions in muscle specimens show a selective type 2 atrophy and a slight increase in the mean diameter of type 1 fibres. Biochemical investigations reveal that the activities of a number of enzymes representative of energy supplying pathways--the glycogenolysis and glycolysis--as well as acid phosphatase activity in the muscle is lowered. Oxidative enzymes are of similar activity in the alcoholics and the control group. The glycolytic enzyme activity is particularly important, being the most sensitive indicators of the onset, intensity, and course of neurogenic damage.

Adult↗
PubMed1990

Effect of pH stress on lipid composition of Saccharomyces cerevisiae.

Total lipids (% dry weight basis) of S. cerevisiae increased when pH of the growth medium was altered. Phospholipid content increased when the yeast was grown at a pH higher than its optimal (pH 6). Sterol content was not affected much. Sterol:phospholipid ratio was not affected by pH of the medium. Phosphatidylcholine content of S. cerevisiae was inversely related to pH of its growth medium. Glycolipids were more when the yeast was grown at pH 9. Fatty acids of S. cerevisiae grown at pH 3 were more saturated which makes the membranes less fluid.

Adaptation, Physiological↗
PubMed1990

Toxicity studies with potassium embelate, a new analgesic compound.

Potassium embelate, 2,5-dihydroxy, 3-undecyl-1, 4-benzoquinone, from Embelia ribes Burm. was subjected to toxicity evaluation which included subacute, chronic, reproductive toxicity testing and teratological investigations in laboratory animals (mice, rats and monkeys). The results did not indicate adverse effects suggesting that potassium embelate is a safe compound.

Abnormalities, Drug-Induced↗
PubMed1990

Locked in state. A clinicopathological study.

Two patients developed the locked-in state characterised by quadriplegia and mutism with an alert sensorium. Initially they had mild dysarthria and uncrossed hemisensory or hemimotor deficits involving the face and ipsilateral extremities. Both patients died. Rostral brainstem infarctions were found at autopsy in them. Acute onset of uncrossed hemisensory and hemimotor deficits with dysarthria may be caused by infarction of the pons which may predispose to locked-in state.

Brain↗
PubMed1989

Mercaptan and dicarboxylate inhibitors of hamster dihydroorotase.

In mammals, dihydroorotase is part of a trifunctional protein, dihydroorotate synthetase, which catalyzes the first three reactions of de novo pyrimidine biosynthesis. Dihydroorotase catalyzes the formation of a peptide-like bond between the terminal ureido nitrogen and the beta-carboxyl group of N-carbamyl-L-aspartate to yield heterocyclic L-dihydroorotate. A variety of evidence suggests that dihydroorotase may have a catalytic mechanism similar to that of a zinc protease [Christopherson, R. I., & Jones, M. E. (1980) J. Biol. Chem. 255, 3358-3370]. Tight-binding inhibitors of the zinc proteases, carboxypeptidase A, thermolysin, and angiotensin-converting enzyme have been synthesized that combine structural features of the substrates with a thiol or carboxyl group in an appropriate position to coordinate a zinc atom bound at the catalytic site. We have synthesized (4R)-2-oxo-6-thioxohexahydropyrimidine-4-carboxylate (L-6-thiodihydroorotate) and have found that this analogue is a potent competitive inhibitor of dihydroorotase with a dissociation constant (Ki) in the presence of excess Zn2+ ion of 0.17 +/- 0.02 microM at pH 7.4. The potency of inhibition by L-6-thiodihydroorotate in the presence of divalent metal ions decreases in the order Zn2+ greater than Ca2+ greater than Co2+ greater than Mn2+ greater than Ni2+; L-6-thiodihydroorotate alone is less inhibitory and has a Ki of 0.85 +/- 0.14 microM. 6-Thioorotate has a Ki of 82 +/- 8 microM which decreases to 3.8 +/- 1.4 microM in the presence of Zn2+. Zn2+ alone is a moderate inhibitor of dihydroorotase and does not enhance the potency of other inhibitors.(ABSTRACT TRUNCATED AT 250 WORDS)

Amidohydrolases↗
PubMed1989

Distribution of substance P-like immunoreactivity in the goldfish brain.

Immunohistochemical methods were used to study the distribution of SP-like immunoreactivity (SPLI) in the brain of the common goldfish (Carassius auratus). SPLI cell bodies and fibers were seen in distant areas and nuclei throughout the brain. In the telencephalon, SPL1 was found in the area dorsalis telencephali pars centralis and pars lateralis, areas that have been compared to the basal ganglia of land vertebrates. In the diencephalon, SPLI somata were seen in the hypothalamus. Four primary visual centers contained SPLI fibers: the nucleus of the posterior commissure, the area pretectalis, the nucleus dorsolateralis thalami and the optic tectum; the origin of these fibers could not be determined. SPLI cell bodies were seen in the oculomotor nucleus; the possibility that this may be the Edinger-Westphal nucleus is discussed. A high density of immunoreactive fibers was seen in the tractus retroflexus and the interpeduncular nucleus, though the habenula showed a few SP-like immunopositive fibers. In the hindbrain, SPLI cell bodies and fibers were seen in the nuclei ambiguus and commissuralis of Cajal and in the dorsal motornucleus of the vagus nuclei; even though these nuclei are known to belong to the visceral and sensory motor columns, the exact role SP plays in processing this information is at present unknown.

Animals↗
PubMed1989

Simultaneous spectrophotometric analysis of a ternary mixture of pharmaceuticals--assay for meclozine hydrochloride, pyridoxine hydrochloride and caffeine.

Based on an extension of Vierordt's method and in continuation of earlier work, the simultaneous analysis of a ternary mixture of meclozine hydrochloride, pyridoxine hydrochloride and caffeine is discussed. Using 0.01 M methanolic sodium hydroxide as the solvent, the absorbance of the solution of the mixture is recorded at 230, 273 and 307 nm. The concentration of each component is determined by the solution of three simultaneous equations.

Caffeine↗
PubMed1989

Strontium-90 eye application.

Details of the Strontium-90 Eye Application including equipment, irradiation technique, radiation safety and data are presented.

Brachytherapy↗
PubMed1989

Procedures for interstitial radioactive gold grains.

Detailed implantation procedures and safety guidelines for use of interstitial radioactive gold grains are presented. These guidelines have been found to be of practical value for personnel involved with the implant to ensure compliance with regulations but are not necessarily the only procedures which could be utilized. Topics covered include: Description of Grains and Implantation, Management and Planning of Au-198, Source Logging, Source Transportation, Source Accounting During and After Implant, Room Monitoring, Recording, Dosimetry Films, Nursing Procedures, Levels in Patients Containing Radioactivity, and Patient Discharge of Radioactive Patients.

Brachytherapy↗
PubMed1989

Characterization of a goldfish antigen during development and regeneration of the visual system.

Normal, regenerating, and developing optic nerves of the goldfish were studied utilizing a monoclonal antibody (mAb) 1E1T which has specificity for Müller cells in the retina, radial glial cells in the tectum, and non-neuronal cells in the optic nerve. Sections of the normal optic nerve revealed longitudinally oriented chains of non-neuronal cells, that were 4-8 cells long. The number of chains in the normal nerve was very few. In addition, short acellular septa, probably the connective tissue septa, were also labeled with mAb 1E1T. Sections of crushed optic nerves showed an increase in the antigen recognized by mAb 1E1T within the septa and new septa were now visualized. Furthermore, the existing septa were longer and extended the length of the optic nerve. The formation and elongation of the septa occurred as early as 3 day postcrush. Between 3 and 11 d postcrush, there was heavy labeling of the septa and a large accumulation of non-neuronal cells at the crush site. At 3 months postcrush, the accumulation of non-neuronal cells labeled by mAb 1E1T were no longer visible but heavy labeling of the septa was still apparent.

Animals↗
PubMed1989

Simultaneous spectrophotometric determination of mefenamic acid and paracetamol in pharmaceutical preparations.

A spectrophotometric procedure for the simultaneous determination of mefenamic acid and paracetamol in a mixture is described. Using 0.01 M methanolic hydrochloric acid as solvent, the absorbance of the mixture is measured at 248, 279 and 351 nm. The concentration of each component can be calculated by solving two equations using two wavelengths, either 248 and 279 nm or 248 and 351 nm.

Acetaminophen↗