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.

Operations for portal hypertension due to extrahepatic obstruction: results and 10 year follow up

Between 1976 and 1984, 136 patients with portal hypertension due to extrahepatic obstruction were operated on. Twenty two patients had emergency and 114 elective operations. The operative mortality was 9% and 1%, respectively. Altogether 117 patients (86%) were followed up for from two to 10 years: 17 rebled, none developed encephalopathy or sepsis after splenectomy, and 90% and 75% were alive at five and 10 years respectively. Unlike endoscopic sclerotherapy and treatment with propranolol, operative treatment of variceal bleeding can usually be completed during one admission and carries a low mortality and a fairly low morbidity. Operation seems to be the best form of treatment for poor patients living far from medical facilities in developing countries and may be the treatment of choice in developed countries as well.

Dose-related stimulation of feeding by systemic injections of monosodium glutamate

Monosodium glutamate (MSG) is an excitotoxin capable of both stimulating and lesioning neurons in circumventricular organs (CVOs) after systemic administration. In this study, MSG and equiosmotic concentrations of NaCl were administered subcutaneously to adult rats in order to observe the effects on food and water intake. MSG (0.5, 1, 2 and 6 g/kg), but not NaCl, stimulated feeding. The magnitude of the feeding was dose-related. After the highest dose, rats consumed 4.4 g of pelleted food. Since MSG does not cross the blood-brain barrier, we conclude that feeding was stimulated by an action of glutamate on CVOs. Doses of MSG that stimulated feeding did not alter blood glucose concentration. Neonatal MSG treatment, which is known to be more damaging to circumventricular neurons than adult treatment, greatly reduced or abolished subsequent MSG-induced stimulation of feeding in adults. Both MSG and NaCl stimulated drinking. Since the magnitude of the drinking response was similar for both solutes and was directly related to the osmotic strength of the solutions, we conclude that the drinking response after MSG was mediated by cellular dehydration.

A new allele with abnormal cyclic-AMP phosphodiesterase activity in Phycomyces

A mutant of the fungus Phycomyces blakesleeanus (Burgeff), C21 (madA7) that was isolated for its abnormal phototropism (Bergman et al. 1973) carries a secondary mutation pde-1 which is unlinked to the madA gene. The pde-1 allele causes the loss of about 80% of the cAMP phosphodiesterase activity. This allele is not essential for the photoreactions of the mycelium or the sporangiophore, and the bulk activity of the phosphodiesterase appears to play no role in the phototransduction pathway of Phycomyces.

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.