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Biomedical subjects

R Malik

Publications and source records attributed to R Malik.

At least 199 records · Page 11Linked to original sources
PubMed1991

Common atrioventricular canal in a foal.

A 3-week-old Thoroughbred colt was presented for weakness and cyanosis. A pansystolic regurgitant murmur and other physical findings suggested that the foal developed pulmonary oedema as a consequence of congenital heart disease. A large atrial septal defect, a high ventricular septal defect and dysplasia of the atrioventricular valves were visualised echocardiographically. A persistent common atrioventricular canal was observed at necropsy.

Journal Article↗
PubMed1991

An unusual case of plasma cell granuloma involving lung and brain.

A young male aged 20 years had resection of the upper lobe of right lung for plasma cell granuloma. Five years later he developed three lesions in the brain, one of which was resected. Brain lesion showed similar histopathological picture. A unique case of plasma cell granuloma involving more than one organ is reported.

Adult↗
PubMed1990

Congenital obstruction of the caudal vena cava in a dog.

A 16-week-old female Rottweiler was examined because of labored breathing and abdominal distention. Ascites, hepatomegaly, and pleural effusion were detected during physical and radiographic examinations. Selective angiography revealed a stenotic lesion at the junction of the caudal vena cava and the right atrium. A fibrous diaphragm with a pin-hole orifice was observed at surgery. Clinical signs of disease resolved after successful removal of the membranous obstruction.

Animals↗
PubMed1990

Transvenous pacemaker leads in the dog: an experimental study.

Tined transvenous pacing leads were inserted into nine healthy large-breed dogs as part of an experimental study evaluating an implantable defibrillator. The pacing leads were used to induce ventricular fibrillation on the day of insertion, two and four weeks after insertion and then monthly. Despite daily running exercise on and off a leash, the tined leads remained firmly anchored to the right ventricular apex for the full experimental period of up to 12 months. Apart from mechanical endocarditis of the tricuspid valve, and partial penetration of the ventricular wall in one dog, problems associated with the pacing leads were not encountered. The use of tined leads and careful technique may minimise the likelihood of transvenous lead displacement.

Animals↗
PubMed1989

Cystogastrostomy in the treatment of pancreatic pseudocyst/abscess in two dogs.

Two dogs with pancreatic pseudocyst or pancreatic abscess formation were treated by transgastric cystogastrostomy. In each case drainage of the cyst/abscess cavity into the stomach was followed by resolution of the primary lesion. One dog succumbed to an E coli bronchopneumonia after infection of the deep venous line used for total parenteral nutrition. The second dog recovered despite requiring additional surgery for biliary obstruction. Both dogs required intensive care during and after the operation.

Abscess↗
PubMed1987

Comparison of electrocardiography and thallium-201 myocardial scintigraphy for the detection of ergonovine-induced coronary artery spasm: angiographic correlation.

This study was performed to determine the sensitivity of thallium imaging vs ECG monitoring for detecting coronary artery spasm noninvasively following intravenous ergonovine administration as compared to simultaneous coronary angiography. Thirty-two patients with insignificant coronary artery disease and chest pain underwent 12-lead ECG monitoring, thallium imaging, and coronary arteriography following the administration of 0.05, 0.1, 0.2, and 0.3 mg of ergonovine given 5 minutes apart or until chest pain occurred. One minute following the last dose of ergonovine, 2.5 mCi of thallium-201 was injected intravenously, and a final ECG was recorded and repeat coronary arteriography performed. Within 10 minutes following the injection of thallium, imaging was performed in the 40-degree and 70-degree left anterior oblique and anterior projections. The ECG, thallium study, and coronary arteriogram were read blindly and results were compared. The ECG, angiogram, and thallium study were read as positive if the following occurred, respectively: greater than or equal to 1 mm ST segment elevation, depression, or T wave reversal; greater than 50% vessel narrowing,; and reversible perfusion defect. Five patients were excluded from analysis because of either catheter-induced spasm, suboptimal thallium studies, or protocol violations. Of the 27 patients included for analysis, six had chest pain, five had a positive angiogram, five had a positive thallium study, and one had a positive ECG. The sensitivity of thallium vs ECG monitoring was 80% vs 25%, and the accuracy was 92% vs 80%. We conclude that thallium imaging greatly increases the noninvasive detection of ergonovine-induced coronary spasm as compared with the ECG with no loss of accuracy.

Adult↗
PubMed1987

Loss of polyneuronal innervation and establishment of a topographical map in the glutaeus muscle of Bufo marinus during generation of secondary muscle cells.

The development of synaptic connections to the toad (Bufo marinus) glutaeus magnus from segmental nerves 8 (N8) and 9 (N9) was determined in the postmetamorphic period. Three different-size toads were studied: small (0.3-2.0 g), medium-size (5-15 g) and large (greater than 20 g). The number of cells in the glutaeus increased about 9-fold during development; this involved the appearance and subsequent maturation of secondary fibres throughout the muscle. The glutaeus in small toads, which consisted almost entirely of primary fibres, was innervated to a similar extent by N8 and N9 as assessed by tetanic contraction measurements. During late development there was a progressive increase in the percentage of the muscle innervated by N9 and a decrease in the percentage innervated by N8. This change in the segmental innervation was accompanied by changes in the innervation of the ventral glutaeus as assessed by intracellular recording. In small toads this surface of the muscle was innervated predominantly by N8, with N9 frequently appearing as a low-efficacy terminal on dually innervated fibres. With further development there was a progressive reduction in the percentage of dually innervated fibres and a concomitant decrease in the percentage innervation of the entire ventral glutaeus by N8. These results suggest that the topographical projection is established by the initial distribution of N9 terminals on the primary fibres of the muscle. The multiple innervation of newly generated fibres and the on-going process of terminal elimination results in N9 terminals, many of which were initially weak, preserving their position in the muscle. This occurs at the expense of N8 terminals, whose relative incidence declines during development. The competitive advantage of N9 motoneurones may be due to their greater capacity to lay down axon collaterals and preferentially innervate newly generated fibres; alternatively N9 terminals may displace N8 terminals, which were initially more efficacious, from dually innervated fibres. Secondary muscle fibres generated throughout the muscle are thus incorporated into an increasingly precise topographical map.

Animals↗
PubMed1987

Evaluation of high-dose versus standard FAC chemotherapy for advanced breast cancer in protected environment units: a prospective randomized study.

Fifty-nine evaluable patients under 65 years of age with measurable metastatic breast cancer and without prior chemotherapy were randomly assigned to treatment with fluorouracil, Adriamycin (Adria Laboratories, Columbus, OH), and cyclophosphamide (FAC) at standard or high doses (100% to 260% higher than standard FAC) following a dose escalation schedule. Patients randomized to the high-dose FAC received the first three cycles of therapy within a protected environment. Subsequent cycles for this group were administered at standard doses of FAC in an ambulatory setting, the same as for the control group. After reaching 450 mg/m2 of Adriamycin, patients in both groups continued treatment with cyclophosphamide, methotrexate, and fluorouracil until there was disease progression. Analysis of pretreatment patient characteristics showed an even distribution for most known pretreatment factors, although the control group had slightly (but nonsignificantly) more favorable prognostic characteristics. Fourteen patients (24%) achieved a complete remission (CR) and 32 (54%) achieved a partial remission (PR), for an overall major response rate of 78%. There were no differences in overall, CR, or PR rates between the high-dose FAC and control groups. The median response durations were 11 and 10 months for the protected environment and control groups, respectively, and the median survival was 20 months for both groups. Hematologic, gastrointestinal (GI), and infection-related complications were significantly more frequent and severe in the group treated with high-dose chemotherapy. Stomatitis, diarrhea, and skin toxicity were dose-limiting. However, there were no treatment-related deaths. High-dose induction combination chemotherapy with the agents used in this study failed to increase the response rate or survival duration, and resulted in a substantial increase in toxicity.

Adult↗