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Biomedical subjects

M V Kumar

Publications and source records attributed to M V Kumar.

At least 55 records · Page 3Linked to original sources

Comparison of left coronary and laevo-phase pulmonary angiograms in detecting left atrial thrombi in rheumatic mitral stenosis.

We have compared the diagnostic accuracy of left coronary and laevo-phase pulmonary angiograms in detecting left atrial thrombi in 27 consecutive patients with rheumatic mitral stenosis who underwent both these procedures prior to open-heart surgery. In 10 patients, both procedures were 'positive' for thrombus, confirmed at subsequent surgery in all instances (true positive). Both procedures were negative for thrombus in 11 patients, and none of these patients showed thrombi at subsequent surgery (true negative). Left coronary angiography only was positive for thrombus in one patient in whom no thrombus was found at surgery. Laevo-phase pulmonary angiography only was positive for thrombus in five patients, two of whom had thrombus at subsequent surgery. The sensitivity, specificity and predictive accuracy of left coronary angiogram were 83.3% and 93.3% and 90.9% and that of laevo-phase pulmonary angiogram 100%, 80% and 80% respectively. Laevo-phase pulmonary angiograms showed higher sensitivity and left coronary angiograms showed higher specificity for angiographic diagnosis. However, the differences were found to be statistically insignificant. Angiography is a reliable method for detecting left atrial thrombi if both left coronary and pulmonary angiograms are performed and both procedures are positive or negative for thrombus.

Adolescent↗

Chest radiographs are unreliable in predicting thrombi in the left atrium or its appendage in rheumatic mitral stenosis.

We have assessed the diagnostic accuracy of a flat or concave left mid-cardiac border (the region of the left atrial appendage) on conventional postero-anterior chest radiographs as a predictor of the presence of thrombi in the left atrium or its appendage in 80 patients with rheumatic mitral stenosis who subsequently underwent open-heart surgery. Forty-six patients (Group I) were found to have left atrial thrombus at surgery whereas 34 patients (Group II) showed no evidence of thrombosis. Only 22 of 46 patients in Group I showed a flat or concave left mid-cardiac border (sensitivity, 48%; specificity, 53%; positive predictive value, 58%). Furthermore in Group 1, the thrombus involved the left atrial appendage in 33 patients. In this subgroup only 14 patients showed a flat or concave left mid-cardiac border (sensitivity, 42%; specificity, 49%; positive predictive value, 37%). The presence of flatness or concavity in the left mid-cardiac border on conventional posterior-anterior chest radiographs in patients with rheumatic mitral stenosis is an unreliable indicator of the presence of thrombi in the left atrium or its appendage.

Adolescent↗

Filarial elephantiasis of penis: a crippling manifestation.

Filarial involvement of penis in endemic areas is not an uncommon entity. In the late stage it may lead to crippling "ramhorn" penis. A case of filarial penis is presented which was successfully managed by split thickness free graft.

Adult↗

Left coronary angiography in the pre-operative diagnosis of thrombosis of the left atrium or its appendage in rheumatic mitral stenosis.

We studied the utility of pre-operative selective left coronary angiograms for detecting thrombosis in the left atrium or its appendage in 81 patients with rheumatic mitral stenosis, who subsequently underwent open-heart surgery. Thrombus was predicted by the angiographic demonstration of neovascularity seen as a bunch of small vessels arising from the circumflex branch of the left coronary artery coursing superiorly to the region of the left atrial appendage and terminating in a network of smaller vascular channels with a blush of contrast medium coalescing into small 'lakes'. This pooling of contrast medium was considered essential for positive angiographic diagnosis. Based on these criteria, the angiographic diagnosis of thrombus was made in 27 patients. Thrombus was found in 33 patients at surgery. Selective left coronary angiography had a sensitivity of 72.7%, specificity of 92.7% and predictive value of 88.8% for detecting thrombi in the left atrium or its appendage. Coronary angiography should be performed in all the patients with mitral stenosis who are undergoing cardiac catheterization especially if balloon mitral valvoplasty or closed mitral valvotomy are planned.

Adolescent↗

Effect of hypothyroidism on the biogenic amines of the epididymis of rat.

Concentrations of norepinephrine and dopamine in various parts of the epididymis of rats have been determined. Effects of thyroidectomy and castration (15 days) and administration of thyroxine (2 micrograms/100 g body weight) and testosterone (1 mg/rat/day) were studied. The content of these amines did not change after thyroidectomy, although orchidectomy reduced same. Administration of thyroxine to animals that had thyroid and testes removed enhanced the catecholamine content of the epididymis.

Animals↗

Epididymal histoarchitecture of goats under chronic cyproterone acetate.

Epididymis were collected from cyproterone acetate-treated Black Bengal goats. Treatment for 70 days reduced the epididymal weight. Caput epididymidis showed drastic decrease in the height of the epithelium, loss of stereocilia, the number of narrow cells and apical cells. Though the corpus showed dramatic changes after treatment, cauda epididymidis showed moderate changes.

Animals↗

Angiotensin converting enzyme in the testis and epididymis of mammals.

Angiotensin converting enzyme (ACE) activity has been reported in testis and epididymis of seven different animal species. Among all the species, the mouse testis and epididymis showed the highest converting enzyme activity followed by rat testis and epididymis. The lowest activity was detected in buffalo testis and rabbit epididymis. Most of the testicular enzyme was found concentrated in the 107,00 X g sediment while the epididymal enzyme was equally distributed between sediment and supernatant. ACE levels of different regions of the rat testis and epididymis was analyzed. The gradient of ACE was found increasing from caput to cauda. A major fraction of testicular and epididymal ACE activity was found in their respective fluid. ACE appeared only in mature rats, rabbits and mice testis and epididymis. Sexually stimulated rabbits showed significant ACE increase in the testis. In vitro characterization studies were conducted.

Animals↗

Androgen dependence of testicular and epididymal angiotensin converting enzyme.

Treatment with cadmium chloride (CdCl2) and cyproterone acetate (CA) depressed angiotensin converting enzyme (ACE) activity significantly in testes and epididymal regions of the adult rats compared to the corresponding untreated controls. Exogenous testosterone to CA-treated rats significantly increased the enzyme activity both in the testes and epididymis, the effect in the latter being very significant comparable to CA-treated and untreated controls. Testosterone failed to induce ACE activity in the testes and caput epididymis of 30 day-old immature rats, but the enzyme activity was detected in corpus and cauda epididymis. Our findings indicate that ACE activity in the testicular complex is possibly linked with androgen and is concerned with spermatogenesis and sperm maturation.

Animals↗

Angiotensin converting enzyme in semen and its possible role in capacitation.

Angiotensin Converting Enzyme (ACE) is present in the testis, epididymis and semen. But no physiological role has been assigned to ACE. The present study is to indicate possible role of ACE in capacitation. Semen was incubated in minimum capacitation in vitro. Epinephrine and serotonin were added to note the effect of biogenic amines. The leakage of ACE was very high in capacitated spermatozoa compared to spermatozoa in saline. Presence of amines in the saline induced ACE leakage. These results indicate that ACE may be involved in the capacitation.

Animals↗

Changes in angiotensin converting enzyme in testes and epididymis of rat due to serotonin administration.

Effect of exogenous serotonin and blockade of its endogenous production on Angiotensin Converting Enzyme (ACE) in testes and epididymis was studied. Serotonin (30 mg/kg) and p-chlorophenylalanine (100 mg/kg) were injected for 4 and 3 days respectively. Serotonin reduced the weights of testes, seminal vesicle and ventral prostate whereas epididymal weight increased due to fluid accumulation. ACE was significantly reduced in tissue and fluid fractions of testes and epididymis of serotonin treated rats. pCPA had no effect on ACE levels. Serotonin seems to have direct effect on epididymis also.

Angiotensin-Converting Enzyme Inhibitors↗

Percutaneous transluminal angioplasty with cutting balloon and stenting for isolated bilateral aorto-coronary ostial stenosis in a young female.

Coronary artery disease involving both coronary ostia (left main and right coronary) is extremely rare in a premenopausal female, without pre-existing coronary risk factors. We report a case of tight bilateral coronary ostial disease which presented in unusual clinical circumstances in a young female, which was successfully revascularized by single-stage aorto-ostial cutting balloon angioplasty and stenting.

Adult↗

Efficacy of pre-operative levo-phase pulmonary angiograms in detecting left atrial thrombi.

We have studied the efficacy of levo-phase pulmonary angiograms in detecting thrombosis of the left atrium or its appendage in 33 patients with rheumatic mitral stenosis who subsequently underwent open-heart surgery. Left atrial thrombi had been suspected in all these patients due to the presence of atrial fibrillation and/or history of systemic embolization. The angiographic criteria for the presence of thrombus included mobile or persistent fixed filling defects of constant size in the contrast shadow of the left atrium or its appendage, partial or complete non-visualization of the left atrial appendage, irregular outline of the left atrium or its appendage and an atrial chamber which appeared smaller than the atrial shadow. 19 patients showed one or more angiographic features of thrombosis. All the patients subsequently underwent open-heart surgery for mitral valve disease, and thrombi were found in 17 patients. The angiogram was false positive in three patients, and false negative in one patient. The angiographic diagnosis of left atrial thrombosis by levo-phase pulmonary angiography has a sensitivity of 94%, specificity of 81.3%, and predictive value of 84.2%. Non-visualization of left atrial appendage as the only feature of thrombus formation was seen in five patients, and thrombi were subsequently formed at surgery in four patients (80%). Levo-phase pulmonary angiograms are safe and reasonably accurate for preoperatively detection of left atrial thrombi, and should be performed in all the patients of mitral stenosis if left atrial thrombi are clinically suspected.

Adolescent↗

Modulation of androgen receptor transcriptional activity by the estrogen receptor.

Estrogen/androgen receptor interactions in naturally occurring physiological systems and the effect of their respective steroid hormones on transcriptional activity remain undefined. In an attempt to delineate further the nature of the interaction between these two steroid hormone receptors we have examined the effect of cotransfection of androgen (AR) and estrogen receptor (ER) cDNAs on the expression of the mouse mammary tumor virus long terminal repeat region (MMTV-LTR) linked to the chloramphenicol-acetyltransferase (CAT) reporter gene. In QT6 cells, which contain neither AR nor ER, cotransfection of AR cDNA with the MMTV-LTR-CAT reporter, resulted in transactivation only in the presence of dihydrotestosterone (DHT). Treatment with 10(-8) M each of estradiol-17 beta (E2), dexamethasone, or progesterone did not enhance CAT activity, whereas treatment with the androgens DHT and mibolerone resulted in 87% and 89% CAT activity. Transfection of increasing concentrations of ER cDNA in the presence of 100 ng of AR cDNA and 10(-8) M each of DHT and E2 showed a dose-dependent decrease in CAT activity as compared to the response with DHT alone. Cotransfection of AR and ER cDNA in the presence of 10(-8) M DHT and increasing concentrations of E2 resulted in a dose-dependent decrease in CAT activity. When cells were treated with increasing concentrations of DHT with 10(-8) M E2 no significant increase in CAT activity was observed. In GC cells, which contain endogenous ER but no AR, cotransfection of AR cDNA and treatment with E2 and DHT, also reduced DHT-induced CAT activity.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗