Biomedical subjects

V M Reddy

Publications and source records attributed to V M Reddy.

130 records · Page 8Linked to original sources

PubMed1984

Gel electrophoretic profiles of proteinases in dark-germinated flax seeds.

The proteinases present in dark-germinated flax seeds (Linum usitatissimum) were studied as a function of germination at 25 degrees C. A majority of activity was present in basic proteinases with an acidic pH optimum and a temperature optimum of 45 degrees C in the digestion of hemoglobin. Electrophoresis in a sodium dodecyl sulfate-polyacrylamide mixture which had been polymerized with gelatin was used to separate proteins in extracts of seedlings. Subsequent activation of proteinases with Triton X-100 and resultant digestion of gelatin proved to be very reproducible and afforded detection and good quantification of various proteinase zones. An ethylenediaminetetraacetate-sensitive proteinase zone, P4 (about 60,000 daltons), appeared at day 3 after imbibition and attained maximum activity at day 4. This correlates with a rapid loss in vivo of the glyoxysomal enzyme, isocitrate lyase (EC 4.1.3.1). Ethylenediaminetetraacetate also slowed the loss of isocitrate lyase activity in extracts of 4-day seedlings in a dose-dependent manner. The addition of leupeptin, alpha-tolylsulfonyl fluoride, Pepstatin A, p-chloromercuribenzoate, or 1,10-phenanthroline prior to, during, or after exchange of Triton X-100 for sodium dodecyl sulfate had almost no inhibitory effect upon proteinases in 4-day seedlings.

Journal Article↗

PubMedDate not supplied

Tetralogy of Fallot with major aortopulmonary collaterals: early total repair.

Tetralogy of Fallot with pulmonary atresia and major aortopulmonary collaterals is a complex lesion distinguished by marked heterogeneity of pulmonary blood supply. Over the past two decades, investigators have developed various approaches to the management of this anomaly generally based on the concept of staged unifocalization of pulmonary blood supply. Although such approaches may represent an improvement on the natural history of this lesion, they remain inadequate for a substantial portion of patients born with tetralogy of Fallot and major aortopulmonary collaterals. Since 1992, our approach has been to perform one-stage complete unifocalization through a midline approach in all but a few extremely complicated patients. We aim to repair these patients early in infancy, with an emphasis on native tissue-tissue reconstruction, in order to optimize prospects for survival with a good functional outcome in as many patients as possible. In this review, we present our philosophy and our experience with unifocalization and repair in 72 patients.

Adolescent↗

PubMedDate not supplied

Intravenous digital subtraction angiography in the pre-operative evaluation of coarctation of the thoracic aorta.

Many authors have previously advocated the use of intravenous digital subtraction angiography (IV-DSA) in the pre-operative evaluation of coarctation of aorta with excellent results and good surgical correlation. We have studied 20 patients with coarctation of aorta by IV-DSA and compared the angiographic findings with those seen at surgery in nine patients. The IV-DSA examinations were performed by utilizing small-volume (25 ml), bolus injections of an ionic, iodinated water soluble contrast medium delivered in the mid-right atrium. Good quality diagnostic arterial images were obtained in 14 patients (70 per cent). Associated cardiac decompensation and inability to profile the coarct segment due to overlap by surrounding dilated blood vessels were responsible for the unsuccessful examinations. Whereas most IV-DSA findings were confirmed at surgery, the calibre and length of the coarct segment at IV-DSA were found to be unreliable predictors of the actual severity of the coarctation. The IV-DSA images failed to detect a localized diaphragm at the coarct site in two patients. Even though IV-DSA is useful for the diagnosis of aortic coarctation, the surgeon must be aware of its pitfalls in assessing the calibre and length of the coarct segment.

Adolescent↗

PubMedDate not supplied

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↗