Search PubMed⌕ Search

Biomedical subjects

H Singh

Publications and source records attributed to H Singh.

At least 541 records · Page 30Linked to original sources

Experimental production of varicocele and its effect on testes.

Parital obstruction of left renal vein leads to production of varicocele in a fairly short period, i.e.; even within a month. Collateral venous channels play an important role in the formation and degree of varicocele. Varicocele has got a depressive effect on the spermatogenesis on the side of varicocele as well as on opposite testes. Leydig cells and interstitial tissue flourish at the expense of gonadal elements. The factors affecting the spermatogenesis are different from those of other tissues of the testes.

Animals↗

Injectable non-occlusive chemical contraception in the male-I.

A new contraceptive technique has been proposed and tested. The method uses a novel polymer which when injected into the vas deferens, lowers the pH sufficiently kill the spermatozoa passing through. The polymer itself does not degrade in the process but can be flushed out to regain fertility. Experiments carried out on rats demonstrate the efficacy of the technique so as to have non-surgical, non-occlusive and reversible male contraception.

Animals↗

Tyrosyluria in marasmus.

1. Plasma tyrosine and urinary p-hydroxyphenyl lactic acid (PHPLA) and p-hydroxyphenyl acetic acid (PHPAA) were studied in thirty patients with marasmus and twenty normal controls in the same age group. 2. In the control group conventional tyrosyluria was not observed but 30% of the group excreted high levels of PHPAA. In the group with marasmus, plasma tyrosine and urinary PHPLA and PHPAA values were signigificantly higher than the control values. However only 13.3% of the patients were considered to have conventional tyrosyluria and 52.3% were found to excrete high levels of PHPAA. 3. Administration of ascorbic acid resulted in a reduction of PHPLA excretion while it had no effect on PHPAA excretion. 4. It was inferred that (a) tyrosyluria in marasmus is due to the reduced activity of the hepatic enzyme 4-hydroxyphenyl pyruvate: oxygen oxidoreductase (hydroxylating, decarboxylating) (PHPAA-oxidase; EC 1.13.11.27) due to the deficiency of ascorbic acid and (b) high excretion of PHPAA is related to age and nutrition of the child and is unaffected by the administration of ascorbic acid. 5. It was further inferred that urinary excretion of PHPLA is a reliable index of tyrosyluria.

4-Hydroxyphenylpyruvate Dioxygenase↗

The turnover of myelin proteins in adult rat brain.

The turnover of proteins of myelin of brain was followed after an intracerebral injections of [1-14C] leucine into adult rats and compared with the turnover of proteins of total brain homogenate, microsomal and supernatant fractions. The myelin proteins were separated into three major fractions, viz., the Wolfgram, proteolipid and basic proteins as fluorescamine derivatives by a new preparative sodium-dodecylsulfate-polyacrylamide slab gel electrophoresis method. The bands were visualized, without staining, by their fluoresence under UV light. The maximal incorporation into myelin proteins was about 11% of that in the microsomal proteins. The maximum amoount ofnto myelin proteins was about 11% of that in the microsomal proteins. The incorporation of the label in myelin proteins reached a moximum about six hr after the injection, while the microsomal and supernatant and myelin proteins declined at multiphasic rates with half-lives varying from three hours to several days. Individual myelin proteins also appeared to turn over at multiphasic rates, with half-lives of 5, 20 and 90-100 days for the Wolfgram proteins, 7 and 100-120 days for the proteolipid proteins and 5 and 80-110 days for the basic proteins.

Animals↗

Unusual manifestations of mycetoma.

Five cases of mycetoma of bone involving patella, shaft of tibia, medial malleolus, calcaneum and phalanx of great toe are presented. In all the cases bones were extensively damaged with minimal or no involvement of soft tissue, a very unusual feature. Aetiopathogenesis involvement of bone substantiated by facts, is discussed.

Adult↗

A comparative study of the polypeptides of mammalian peripheral nerve myelin.

Polypeptide components of peripheral nerve myelin prepared from sciatic nerves of mouse, rat, rabbit, cat, guinea pig, monkey, dog and chicken were analyzed using a 20% polyacrylamide slab-gel electrophoresis system. Using this technique, we have demonstrated that there are at least two polypeptides present in the region of P1 protein (mol. wt. 18,000 and 16,000), and two closely moving components in the region of P2 protein (mol. wt. 13,500). A polypeptide (mol. wt. 10,500) is present in significant amounts only in mouse sciatic nerve myelin. Staining with periodic acid-Schiff reagent shows that in addition to P0 protein (mol. wt. 28,000), the major glycoprotein of peripheral nerve myelin, there are several minor glycoprotein components in both the high and low molecular weight regions.

Animals↗