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Biomedical subjects

R Kaur

Publications and source records attributed to R Kaur.

At least 73 records · Page 4Linked to original sources
PubMed1986

Effects of anthelmintics on Haemonchus contortus (Nematoda: Trichostrongylidae).

The review summarizes and evaluates recent information about the effects of anthelmintics on Haemonchus contortus. The topic is discussed under the headings effects of drugs on the absorptive surfaces, effects of drugs on metabolism, effects of drugs on the neuromuscular system, effects of drugs on developmental stages, anthelmintic efficacy, and resistant strains. Possible future lines of work are suggested in the conclusions.

Animals↗
PubMed1983

The effects of DL-tetramisole and rafoxanide on tricarboxylic acid cycle enzymes of Haemonchus contortus, in vitro.

Various enzymes of the tricarboxylic acid cycle (TCA) viz., aconitase (E.C. 4.2.1.3), isocitrate dehydrogenase (E.C. 1.1.1.42), succinate dehydrognease (E.C. 1.3.99.1), fumarate reductase (NADH: fumarate oxido-reductase), fumarase (E.C. 4.2.1.2) and maltate dehydrogenase (E.C. 1.1.1.37) were detected in adult Haemonchus contortus (Nematoda: Trichostrongylidae), in vitro. Low activities of aconitase and isocitrate dehydrogenase suggested that the TCA cycle has a minor function and the pathway of CO2 fixation is the major pathway in the energy metabolism of the parasite. In vitro incubation in Tyrode's solution had no significant effect on TCA cycle enzymes and the worm was able to maintain normal metabolism for 12 h. The effects of D L-tetramisole and rafoxanide on various enzymes of the TCA cycle were studied in adult H. contortus. At 50 micrograms ml-1 varying degrees of inhibition of succinate dehydrogenase and fumarate reductase activities were observed. At the same concentration, the activities of other enzymes remained unaltered.

Animals↗
PubMed1980

Protein-transients during heterocyst differentiation in Anabaena circularis and Cylindrospermum sp.

The programme of protein synthesis accompanying cellular differentiation to the heterocyst following transfer of the blue-green algae Anabaena circularis and Cylindrospermum sp. (CBSC 1755) from ammonia-enriched medium to nitorgen-free medium was determined by polyacrylamide gel electrophoresis of whole proteins during successive intervals of differentiation. Besides this, total proteins and soluble amino acids were determined quantitatively. At least 4 sets of proteins can be distinguished on the basis of the time at which they are synthesized. Besides this, differentiation is distinguishable on the basis of the time at which their synthesis is turned off. The postmaturation stages revealed the synthesis of two sets in A. circularis andone in Cylindrospermum so. (CBSC 1755).

Amino Acids↗
PubMed1980

Comparison of polyethylene glycol and polyoxyethylene stearate as excipients for solid dispersion systems of griseofulvin and tolbutamide I: phase equilibria.

Phase equilibrium diagrams were constructed based on hot-stage microscopy and differential scanning calorimetry of solid dispersions of griseofulvin or tolbutamide in polyethylene glycol 2000 or polyoxyethylene 40 stearate. The solid dispersions were prepared by physical mixing, fusion, and coprecipitation from ethanol. The phase diagrams were largely independent of the method of preparation of the dispersion systems. The diagrams were of the monotectic type for polyethylene glycol 2000 with each drug and for griseofulvin with each excipient, with the monotectic species being the pure drug. Polyoxyethylene 40 stearate with tolbutamide gave eutectic systems in which liquid polyoxyethylene 40 stearate dissolved up to 20% of the tolbutamide. The phase diagrams showed greater solubility of tolbutamide in liquid polyoxyethylene 40 stearate than in polyethylene glycol 2000 but showed a similar solubility of griseofulvin in each experiment. Solid solution formation was not detected.

Excipients↗
PubMed1980

Comparison of polyethylene glycol and polyoxyethylene stearate as excipients for solid dispersion systems of griseofulvin and tolbutamide II: dissolution and solubility studies.

The effects of joining a long-chain ester group with the polyethylene glycol molecule were studied in solid dispersion systems by comparing the dissolution and solution properties of such systems prepared from polyethylene glycol 2000 with those prepared from the nontoxic, water-soluble, solid excipient polyoxyethylene 40 stearate. Solid dispersion systems of griseofulvin and tolbutamide were prepared by physical mixing, fusion, or coprecipitation from ethanol. The compacted dispersion systems dissolved by progressive erosion, releasing floccules of microcrystals. The released microcrystals of tolbutamide (3--10 micrometer) were smaller than the original drug particles (approximately 20 micrometer), but those of griseofulvin were of similar size to the original particles. In general, the rate of and extent of release of each drug were greater from polyoxyethylene 40 stearate than from polyethylene glycol 2000 dispersions. The aqueous solubility and dissolution rate of nondisintegrating disks of each pure drug increased only slightly in the presence of polyethylene glycol 2000 but increased considerably with increasing concentration of polyoxyethylene 40 stearate due to micellar solubilization. Thus, polyoxyethylene 40 stearate generally is superior to polyethylene glycol 2000 in promoting the dispersion of the drugs in solids, disintegration of the compacted solids, and solubilization of the drug during dissolution.

Chemical Precipitation↗
PubMed1979

A study of changes in the spine in weight lifters and other athletes.

The present study was undertaken in sportsmen of those groups of sports activities where weight training exercises constitute a major part of the training. Two groups consisting of 25 weight-lifters and 25 track and field athletes were studied to find out the effect of sports activities and lifting weights on the spine. 84% weight-lifters and 72% track and field athletes suffered from varying abnormalities. Incidence of backache in 25 weight-lifters was 40% and in 25 track and field athletes 48%. Radiological changes were more common in weight-lifters (84%) than in athletes (72%). Reduction in lumbar lordosis was found in three cases (12%) in both the groups. Obtuse angle deformity of vertebral margins was found in 11 cases (44%) amongst weight-lifters and six cases (24%) amongst athletes. Osteophytic formation was found in six cases (24%) in weight-lifters and four cases (16%) in athletes. Schmorl's node were noticed in five cases (20%) amongst weight-lifters and seven cases (28%) amongst athletes. The incidences of spondylosis and Schmorl's node were found only in those cases who had been doing weight training exercises for more than four years.

Adolescent↗
PubMed1975

Morphology of ovarian changes during the reproductive cycle of the fish, Mystus tengara (Ham.).

A study has been made of the morphological and histological changes of the cat fish (Mystus tengara) ovary during its reproductive cycle in natural and confined waters. This fish is oviparous and breeds once a year during the rainy season (July throught September). Factors responsible for bringing about spawning in fishes are discussed and the onset of spawning in Mystus is attributed to monsoon rains. In the ovarian cycle 7 phases have been recognised, whic are based on the gross morphological changes in the ovary, the percentage and duration of different developmental stages of oocytes, the average diameter and the gonosmatic index. They are: 1) immature virgin (November-February); 2) preparatory virgin (March-April); 3) maturing virgin (April-May); 4) pre-spawning virgin (June); 5) spawning (July-August); 6) depletion (September), and 7) recoupment (October-November). Oocyte growth has been divided into 9 stages. The ova diameter and gonosomatic index are maximum in July and minimum in November and December.

Animals↗