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Biomedical subjects

V Ranga

Publications and source records attributed to V Ranga.

33 records · Page 2Linked to original sources
PubMed1978

Effect of histamine and methacholine on guinea pig tracheal permeability to HRP.

The effects of histamine, methacholine, and ether on the permeability of the respiratory mucosa to macromolecules were investigated employing a radioimmunoassay and histochemical techniques to monitor movement of horseradish peroxidase (HRP) from airway lumen to blood. We found that 0.08% of the dose of HRP instilled into guinea pig tracheas was present in the blood volume at 10 min, and plasma HRP levels increased at a rate of 0.0036% instilled dose/min thereafter. After inhalation challenge, significant increases in plasma rates of accumulation of HRP were recorded for the histamine, methacholine, and ether groups, whereas no change in rate was noted for the control (Tyrode's) group. Electron micrographs of tracheal sections showed HRP penetration into the intercellular spaces of the epithelium after histamine, methacoline, or ether exposure but no penetration in the Tyrode's group. We conclude that, like ether, histamine and methacholine increase tracheobronchial permeability and this effect is most likely mediated by a functional change in the epithelial tight junction.

Aerosols↗
PubMed1978

Structure and function of small airways in health and disease.

During the last two decades, great strides have been made in our understanding of the functional aspects of airflow in the periphery of the lung. It seems that the small airways are the important site of obstruction in a variety of chronic respiratory disorders associated with airflow obstruction. This review deals with the anatomic and functional aspects of small airways in normal and diseased lungs. In particular, the basis of obstruction or narrowing that is not dependent on intrinsic airway lesion is reviewed. The variety of pathologic changes in small airways observed in these diseases are outlined along with physiologic tests that are currently used to detect dysfunction at a stage long before they produce symptoms or alter standard tests of lung function.

Aging↗
PubMed1977

Pulmonary resection.

Seventy-seven patients who had elective pulmonary resections were enrolled in a prospective double-blind study to assess the role of prophylactic antibiotics in preventing postoperative infections. Criteria for infection were strictly defined. A five-day course of a cephalosporin (2 gm/day in divided doses) was compared to an identical placebo. There were 17 infections in the 34 patients in the placebo group (50%), compared to only eight infections in the 43 patients in the antibiotic group (19%) (P = .005). When infections unrelated to thoracotomy and minor infections were excluded, the advantage of prophylactic antibiotics proved even more evident. Fourteen thoracic infections occurred in the placebo group (41%) compared to only two thoracic infections (4.7%) in the antibiotic group (P = .0002). No relationship of infection rate to the extent of pulmonary resection was found. A history of smoking, the presence or absence of chronic bronchitis, spirometric abnormalities, and obesity were all analyzed; none was related to the development of infection. We conclude that the routine use of perioperative antibiotics is indicated to prevent postoperative infections in pulmonary resection.

Abscess↗
PubMed1975

Aminoacetonitrile (AAN)prevents connective proliferation in rat liver induced by tetrachlorcarbon. Continuous concomitant administration of AAN.

A total dose of 10 g/kg body weight of aminoacetonitrile distributed almost evenly over 35 days prevents formation of connective bands and damage of hepatocytes in the liver of rats submitted to CCl4 inhalations at a partial pressure of 1/6 atm, eight times within the same interaval. Control animals exhibited the usual pattern of CCl4 injury.

Acetonitriles↗
PubMedDate not supplied

Experimental study on the effects of +Gz. Acceleration under gestational conditions. I. Ultrastructural myocardial lesions.

In the course of a complex experimental study concerning the effects of highly positive acceleration on gestation and development of the neonate, investigations were carried out of ultrastuctural myocardial lesions in the pregnant rat exposed to prolonged gravitational stress (+ 2G). The experimental animals presented various disseminated and partly irreversible myocardial lesions whose pathogeny is discussed.

Animals↗
PubMedDate not supplied

Morphological aspects of the rat kidney preserved by cold storage. I. Glomerular morphometric changes.

The absolute density of glomeruli in the microscopic field was determined in the rat kidney preserved by cold storage for 24, 48, 72 and 96 hrs in two different media: Sacks (hyperosmolar electrolytic solution of intracellular type) and Plasmagel (gelatin solution 4%). Progressive, statistically significant (p less than 0.01) decrease of glomerular density at 24 and 48 hrs was followed by return to initial values at 96 hrs. Decrease of the glomerular density was greater with Plasmagel.

Animals↗
PubMedDate not supplied

Bilateral trunkal vagotomy (BTV) regarded as a pathogenic process. An experimental study.

Experimentally, bilateral trunkal vagotomy (BTV) generated some early acute modifications represented during the first 14 days by blood stasis, partial thrombosis, inflammatory infiltrates and necrobiosis of the gastric mucosa. The vascular lesions are the first to occur, the tissular ones being secondary. Later on, two and three months after surgery, chronic inflammation and metaplasia of the intestinal type have been detected as well.

Animals↗
PubMedDate not supplied

Experimental study of myocardial bridges.

Myocardial bridges were reproduced in dogs by transfer of a fragment of the left ventricular wall above the upper portion of the anterior interventricular artery. The viability of this bridge was shown by coronarography, anatomic, histologic and electron microscopic studies, illustrating the vascular patency and the integrity of blood vessels and neighbouring myocardium in the cases postoperatively heparinized. The experimental model efficiency was also proved by ECG examinations revealing ischemic distresses induced by compression of the bridge against the underlying artery.

Animals↗