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Biomedical subjects

M S Singh

Publications and source records attributed to M S Singh.

10 recordsLinked to original sources
PubMed2001

Castration-induced hyperactivity of seminal vesicle in the catfish Clarias batrachus: a case of paradox and blockade by antiandrogen (cyproterone acetate) treatment.

Castration of the catfish Clarias batrachus in late preparatory-early prespawning phase (April-May) caused time-dependent stimulatory effect on morphology, weight, and in the concentrations of biochemical correlates, such as total proteins, fructose, hexosamines and sialic acid in the seminal vesicle (SV). The peak changes were noticed on week 4 of castration. The hyperactivity was related to augmented production of testosterone by the SV of castrates with the levels significantly high from week 3 onwards. As a result, serum testosterone level fluctuated with a significant decrease in the first and fifth weeks, a significant increase in the third week, and no significant difference in the second and fourth weeks. Serum E2 level decreased significantly throughout. Cyproterone acetate treatment (CA; 1 mg/fish daily for 21 days) from the second day of castration decreased the size and weight of the SV and the concentrations of total proteins, hexosamines, fructose and sialic acid. The antiandrogen treatment did not alter serum testosterone level but the E2 level was significantly decreased. It is concluded that the hypersecretory activity of the SV in castrates is a sequel to local synthesis and action of testosterone and the effect could be prevented by CA by blocking androgen actions.

Androgen Antagonists↗
PubMed2001

Effects of ovine LH, GH and prolactin, and testosterone on serum testosterone and estradiol-17 beta levels, and seminal vesicle and testicular activity in the catfish Clarias batrachus (L.).

Intraperitoneal administrations of testosterone (0.5 microgram/g body wt), and ovine LH (1.0 microgram/g body wt), GH (5 micrograms/g body wt) and prolactin (10 micrograms/g body wt) daily for 7 days during early prespawning phase (May) in C. batrachus produced varied effects on seminal vesicle (SVSI) and testicular (GSI) weights and biochemical correlates. Testosterone and LH treatments significantly increased serum testosterone level and concentrations of total proteins, fructose, hexosamines and sialic acid in both seminal vesicles and testis. Serum E2 levels increased significantly only after testosterone treatment. GH treatment increased significantly serum testosterone level and only the concentrations of SV hexosamines and testicular protein. Prolactin, however, significantly lowered serum testosterone level and concentrations of total protein, hexosamines in both SV and testis, and testicular fructose and sialic acid levels. The results show that the stimulating effect of LH and GH on SV and testicular activity is mediated through the increased secretion of testosterone and the inhibitory effect of prolactin by decreased testosterone secretion.

Animals↗
PubMed2000

Intense high-energy proton beams from Petawatt-laser irradiation of solids.

An intense collimated beam of high-energy protons is emitted normal to the rear surface of thin solid targets irradiated at 1 PW power and peak intensity 3x10(20) W cm(-2). Up to 48 J ( 12%) of the laser energy is transferred to 2x10(13) protons of energy >10 MeV. The energy spectrum exhibits a sharp high-energy cutoff as high as 58 MeV on the axis of the beam which decreases in energy with increasing off axis angle. Proton induced nuclear processes have been observed and used to characterize the beam.

Journal Article↗
PubMed2000

Methallibure inhibition of testicular and seminal vesicle activity in catfish, Clarias batrachus (Linn.): a study correlating changes in serum sex steroid profiles.

The administration of methallibure (2 microg/g BW, daily for 15 days) in Clarias batrachus in prespawning phase (May-June) resulted in decreased weights of seminal vesicle (SV) and testis, and reductions in the concentrations of total proteins, fructose, hexosamines, and sialic acid in SV and testis. The inhibitory changes can be attributed to impairment of steroidogenesis, serum levels of testosterone and estradiol -17beta decreased significantly. Withdrawal of methallibure treatment for 7 and 15 days resulted in gradual recovery and restoration of all the above parameters except the sialic acid levels in the SV and testis, and fructose level in the SV. The methallibure induced regressive changes in the SV and testis were discussed in the light of its GTH inhibiting property.

Animals↗
PubMed2000

Kimura's disease: a report of three cases with a brief review of literature.

Kimura's disease (KD) is an uncommon chronic inflammatory condition of unknown aetiology involving subcutaneous tissue, presenting as a tumor like lesion with a predilection for the head and neck region. Clinically it is often confused with parotid tumor with lymph node metastasis. It is difficult to diagnose before tissue biopsy. Fine needle aspiration cytology has only limited value. Unless the pathologists are aware of this entity, it might be misdiagnosed. Surgery, radiotherapy and steroid therapy have been tried but none is proved best and recurrence is common. Three cases of KD seen in our hospital and the problems encountered in them are presented.

Adult↗
PubMed1998

Precocious recrudescence of seminal vesicle and testis in catfish, Clarias batrachus (Linn.), subjected to a long photoperiod regime.

The catfish C. batrachus were exposed to a long photoperiod of 14 hr light during resting--early preparatory (December-February) phases of the reproductive cycle. At 70-day sampling, both the seminal vesicle (SV) and testis registered marked stimulatory effects in comparisons to control fish maintained under approximately 10.55 L:13.45D as shown by the increased size and weight. In both the SV and testis, concentrations of total proteins, fructose, hexosamines, and sialic acid were significantly high compared to those of the control fish indicating increased activities of the organs. Serum levels of gonadotropin-II, testosterone, and estradiol-17 beta were significantly high in the long photoperiod group. The results show that exposure to long photoperiod can stimulate early development of both the SV and testis by activating the pituitary--gonadal axis.

Animals↗
PubMed1997

Effects of administration of testosterone on seminal vesicle activity in the catfish Clarias batrachus during preparatory phase: a study correlating changes in testis and serum sex steroid levels.

In the catfish Clarias batrachus administration of testosterone (0.25, 0.5 and 1.0 microgram/g BW for 30 days) during the preparatory phase increased significantly gonadosomatic index (GSI), seminal vesicle-somatic index (SV-SI) and concentrations of proteins, fructose, hexosamines, and sialic acid in the SV and testis in a dose-dependent manner. These stimulatory effects could be correlated positively with the increase of serum testosterone level. Serum estradiol-17 beta was also significantly high in the testosterone groups.

Analysis of Variance↗