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Biomedical subjects

R Prakash

Publications and source records attributed to R Prakash.

At least 55 records · Page 3Linked to original sources
PubMed1990

Study of innervation of the pancreatic duct of Lepus europaeus, using the cholinesterase technique.

The innervation of the pancreatic duct was studied in the European Hare (Lepus europaeus) by the cholinesterase technique. The duct was accompanied by thick myelinated and thin non-myelinated nerve fibres, which subsequently formed a plexi. The plexi were associated with the fibres of the plexi of the islet of Langerhans, or with ganglia, blood vessels or neural networks. No chain of ganglia was observed on or near the duct and the ductules.

Acetylcholinesterase↗
PubMed1989

Primary mediastinal tuberculous abscess: demonstration with MR.

An unusual case of primary mediastinal tuberculous abscess is presented in whom the diagnosis was obtained on magnetic resonance (MR) and ultrasound (US) guided aspiration cytology. Mycobacterium tuberculosis was isolated from direct smear as well as from culture of the "pus". Normal spine signal with MR and normal bone scintigraphy excluded any vertebral focus of infection. MR was helpful in, defining the extent and characterising the abscess, besides excluding a vertebral focus of infection.

Abscess↗
PubMed1989

Torsional moment to failure for carbon fibre polysulphone expandable rivets as compared with stainless steel screws for carbon fibre-reinforced epoxy fracture plate fixation.

A method of securing carbon fibre-reinforced epoxy bone plates with carbon fibre polysulphone expanding rivets was investigated. Six carbon fibre-reinforced epoxy bone plates were secured to rods with carbon fibre polysulphone rivets and six were secured with standard cortical stainless steel screws. These constructions were then subjected to pure torsional load to failure. The carbon fibre expandable rivets failed at a greater torsional moment.

Biocompatible Materials↗
PubMed1989

Technetium-99m radiocolloid scintigraphy, planar and SPECT red blood cell imaging and ultrasonography in diagnosis of hepatic hemangioma.

Technetium-99m planar sulfur colloid scintigraphy, red blood cell imaging and ultrasonography were performed in eighteen patients of hepatic hemangioma to evaluate their diagnostic utility. Radiocolloid scans detected fourteen hemangiomas in 12 patients as focal hepatic defects but missed 9 lesions smaller than 2.5 cm in the other 6 patients, accounting for a 61% sensitivity. All 23 lesions were avascular or normovascular on radionuclide flow study. Serial planar red blood cell scintigraphy showed characteristic gradually increasing focal isotopic accumulation in the 14 hemangiomas which had identifiable cold areas on the radiocolloid study. One of 6 patients with normal radiocolloid scan also showed the typical increasing blood pool pattern of hemangioma, five had normal planar scans till 1 1/2 hours. SPECT red blood cell imaging in these 5 patients detected an additional seven hemangiomas. All 7 lesions were smaller than 2.5 cm. One 1.5 cm hemangioma was missed on both planar and SPECT red blood cell imaging. Region of interest ratios in SPECT transaxial images confirmed gradually increasing concentration of labeled red blood cells in the lesions. Ultrasonography detected 22 of the 23 hemangiomas. Ten were hyperechoic, average size 2.25 cm. Twelve were of mixed pattern, generally larger, average size 7.2 cm. Sonography is useful in the detection of hepatic hemangiomas as a focal mass lesion, but the variable sonographic appearance precludes a definite pathological diagnosis. Technetium-99m red blood cell imaging appears a sensitive technique in detection of hepatic hemangioma, with SPECT being especially useful in locating smaller lesions. The addition of useful in locating smaller lesions.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

Non-invasive evaluation of global ventricular functions in coronary artery disease by exercise radionuclide angiocardiography.

Rest and exercise radionuclide angiocardiographic measurement of left ventricular functions were obtained in 12 normal subjects (group I) and 42 patients with well documented coronary artery disease (group II). Additionally thirty-five patients had an exercise tread mill test. Resting left ventricular ejection fraction less than 50% provided the greatest diagnostic information. Exercise was induced by supine bicycle exercise ergometer. In group II 32 patients of coronary artery disease with normal global ventricular function at rest, new regions of dysfunction developed during exercise and global ejection fraction fell by 8 to 15 percent while in group I there was an increase in LVEF and no areas of any ventricular wall motion abnormalities were detected. Exercise radionuclide angiocardiography is a useful non invasive technique which permits accurate assessment of the presence and functional severity of coronary artery disease.

Adult↗
PubMed1989

Glycogen in the muscles of rats poisoned by metal ions.

Glycogen was determined in the skeletal muscles of rat after exposure to several salts of mercury, cadmium, zinc, copper, molybdenum, lead, cobalt and manganese. Treatment with these metals depleted muscle glycogen except in the case of copper and zinc. The causes and significance of the changes involved are discussed.

Animals↗
PubMed1988

Abnormal resting regional cerebral blood flow patterns and their correlates in schizophrenia.

Regional cerebral blood flow (CBF) was measured under resting conditions in 108 right-handed schizophrenic inpatients and a matched group of normal controls with the xenon 133 inhalation technique. Forty-six patients were free of all medication for two weeks. There were no significant differences in CBF to the two hemispheres. The patients showed a comparatively reduced anteroposterior (AP) gradient for CBF. Though there were no differences in frontal flow, the patients had higher flow to several postcentral brain regions, bilaterally. Cerebral blood flow in the patients correlated inversely with age and positively with carbon dioxide level. Women had higher flow than men. Duration of the illness was the only significant predictor of the reduced AP gradient in patients. Higher left temporal and right parietal flow were found to be the best discriminators between patients and controls. Mean hemispheric flow to both hemispheres and several brain regions correlated with the total score and the item, unusual thought content, of the Brief Psychiatric Rating Scale. There were no differences in regional CBF between medicated and unmedicated patients.

Adult↗
PubMed1988

Carbon fibre reinforced epoxy implants for bridging large osteoperiosteal gaps.

An experimental study was undertaken to evaluate the suitability or otherwise of carbon fibre reinforced epoxy (CFRE) implants for bridging large osteoperiosteal gaps, devoid of periosteum. Using the basic principles of composite mechanics and simple design criteria, CFRE implants were designed and developed. These implants were put in simulated osteoperiosteal gaps in the ulna of healthy mature rabbits. Ten wk postoperative results clearly demonstrated that implants made of CFRE induced callus bone formation (in the form of woven bone) which totally encapsulated the implant thereby providing reunion of the two bone segments. Further follow-up showed formation of lamellar bones and formation in the pores of the implant. Radiological and scanning electron microscopical evidence is presented.

Animals↗
PubMed1988

Acute effect of decaffeinated coffee on heart rate, blood pressure, and exercise performance in healthy subjects.

The effect of decaffeinated coffee on the cardiovascular exercise performance in nine healthy volunteers was evaluated in a double-blind randomized fashion. The heart rate, blood pressure, and duration of exercise were unchanged, and no arrhythmias or ischemic changes were seen on the electrocardiogram after drinking decaffeinated coffee. It was concluded that decaffeinated coffee has no discernible, acute, adverse cardiovascular effects.

Adult↗
PubMed1987

Sonography in complicated hepatic amoebic abscess.

Ultrasound examination was conducted on 150 patients with hepatic amoebic abscesses. Twenty of 150 patients were found to have various complications such as direct thoracic involvement, peritoneal rupture, subphrenic collection, obstructive jaundice and ascites. Ultrasound examination of the liver is not only useful in demonstrating the abscess cavity but it also depicts the complications extremely well.

Ascites↗
PubMed1987

Prevalence of mitral valve prolapse in hypertension.

Mitral valve prolapse was found in one of 133 patients with hypertension (0.75 percent) studied by two-dimensional echocardiography. This rarity may be related to the presence of hypertrophied papillary muscles that probably pull the chordae tendinae and mitral valve leaflets away from the left atrium in systole, thus preventing their eversion and prolapse.

Adult↗
PubMed1986

Collagen in the liver of metal fed rats.

Collagen content in the liver of rats exposed to several environmentally significant metals viz. Hg, Cd, Pb, Mo, Cu, Cr, Mn, Co and Zn have been determined. All these elements except Co, Zn and Mn enhanced the collagen contents in the liver. Mechanisms elucidating the phenomenon of collagenosis have also been discussed.

Administration, Oral↗