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Biomedical subjects

A S Gupta

Publications and source records attributed to A S Gupta.

At least 19 recordsLinked to original sources
PubMed1986

Possible role of collagen in transverse myelitis and chymopapain-induced paraplegia.

We studied the effect of nucleus pulposus (NP) on platelet aggregation. Our in vitro experiments showed that NP extract produced platelet aggregation and the addition of collagenase to the NP extract abolished this response. It was further shown that chymopapain did not affect the activity of the extract. We assume that collagen is the active platelet aggregant in the NP extract. Intravascular release of collagen may cause platelet aggregation, vascular obstruction, ischemia, and cord necrosis in a patient with acute transverse myelitis. Intradiskal chymopapain is known to cause transverse myelitis and it is possible that collagen released during the action of the enzyme initiates a similar chain of events.

Cartilage↗
PubMed1979

A second look at Steinach's second procedure: testiculoepididymal occlusion in man and dog.

After advocating vas occlusion as a biological method for rejuvenating aging males, Steinach had suggested that the effect might be more pronounced if the obstruction were placed proximal to the epididymis. This Steinach II procedure has now been studied in 15 dogs and five men. Occlusion was performed at the level of the vasa efferentia, avoiding any vascular trauma. Radiological visualization confirmed a perfect block. There were no untoward reactions, such as orchitis or hydrocele. In dogs, widespread degeneration in the seminiferous tubules was evident, and the total Leydig cell volume showed an increase from 0.7 to 1.0 ml/testis. The changes, however, were not significantly different from conventional vasectomy. In men, there were considerable preexisting senile changes, and the total Leydig cell volume was already as high as 2.8 ml/testis. These changes obscured any possible effect of Steinach II operation.

Animals↗
PubMed1978

Structural changes in the human vas deferens after tantalum clip occlusion and conventional vasectomy.

In 15 human subjects, the vasa deferentia were occluded by applying two tantalum clips on one side and by conventional vasectomy with silk ligatures on the other. After 2 weeks, the occluded segments were recovered for histopathologic examination of serial sections. Obstructing the seminal tract did not, as such, produce any significant change in the vas: the distal and proximal segments appeared to be essentially similar and normal. At the actual site of occlusion, however, tantalum clips produced marked flattening of the tube, complete loss of lining epithelium, distortion of the muscular lamellae, and areas of hemorrhage. The lumen was converted into a narrow slit. Under the ligatures, the damage was largely confined to denudation of the mucosal epithelium. The mucosa of the intersegment left unexcised between two clips showed hyalinization, invasion by macrophages, and degeneration of the epithelium. The changes under the clips suggest that, although clip occlusion may offer several advantages, sterility cannot be reversed merely by removing the clips. The mechanisms of these changes, different in the case of clips and ligatures, are discussed and some possible long-term consequences are considered.

Epididymis↗
PubMed1977

Vas occlusion by tantalum clips and its comparison with conventional vasectomy in man: reliability, reversibility, and complications.

Occlusion of the vas deferens has been carried out by applying tantalum clips in 60 men. Another 50 men were vasectomized conventionally and served as controls. Vasography showed that two clips were required on each vas to bring about perfect and firm occlusion. The incidence of postoperative infection and other complications was much lower in the clip-occluded cases. Under a long-term follow-up, 10% of the conventionally vasectomized men were dissatisfied with the operation as compared with 2% of the clip-occluded group. Both groups became azoospermic within 3 months and the failure rate was zero. Removal of the clips not only was difficult but left the vas compressed and leaking. The method cannot, therefore, be considered reversible by itself. However, recanalization could easily be achieved by end-to-end anastomosis after excision of the small clipped segment or by side-to-side anastomosis without any excision. This, damage to the neuromuscular apparatus of the vas may be minimized. Male sterilization by clip occlusion has the advantages of minimal surgical intervention, shorter operative time, safety from postoperative infection, and easier recanalization if desired.

Evaluation Studies as Topic↗
PubMed1977

Seminal fructose and acid phosphatase in vasectomised men.

Seminal fructose and acid phosphatase levels have been determined in 30 vasectomised and 30 nonvasectomised healthy adults, both the groups being closely matched for age (32 to 45 years). The fructose and acid phosphatase values in the vasectomised men, 3 to 6 months after the operation, were 316 +/- 36 mg% and 2,098 +/- 112 K.A. units/ml, respectively, while in the control group they were 251 +/- 28 mg% and 1,932 +/- 92 K.A. units/ml. The differences are statistically significant (P less than 0.001) and the possible implications of the post-vasectomy rise in these androgen dependent seminal constituents are discussed.

Acid Phosphatase↗
PubMed1975

Surgical sterilization by vasectomy and its effects on the structure and function of the testis in man.

The early and late effects of vasectomy have been investigated in 40 men. Besides histopathological examination, the volume of the testis and its total content of testosterone-screting Leydig cells have been measured. The volume of the testis showed a wide normal variation (5-3-23-3 ml) but was not significantly changed by vasectomy. One month after vasectomy widespread degeneration of the germinal epithelium, thickening of the basement membrane and some intertubular fibrosis were observed. Spermatogenesis had ceased. However, cases examined 2-31/2 years later showed an essentially normal structure with active spermatogenesis. This indicates that regeneration does occur spontaneously, even without recanalization. Whether the sperms formed are functionally normal remains uncertain. The normal total Leydig cell volume was 2-2 plus or minus 0-4 ml/testis in young adults and showed a modest increase after vasectomy, rising to 2-5 plus or minus 0-5 ml after 1 month and 2-6 plus or minus 0-5 ml after 2-31/2 years. The findings have been discussed in the light of Steinach's (1927) original hypothesis that vasectomy can rejuvenate ageing males by improving the endocrine function of the testis.

Adult↗