Biomedical subjects
Publications and source records attributed to P Roy.
Echocardiography revealed a persistent large segment of dyskinesis of the posterolateral wall in a patient with clinical an enzyme evidence of acute myocardial infarction but without diagnostic electrocardiographic changes. A left ventricular angiogram confirmed the echocardiographic findings.
Echocardiography revealed idiopathic hypertrophic subaortic stenosis in a patient previously operated on for calcific aortic valve disease. The echocardiography in addition showed symmetric left ventricular hypertrophy and unusual localization of the septal hypertrophy to the apical half of the septum.
Rupture of an aortic aneurysm into the inferior vena cava is a rare complication; it represents 3 p. 100 of all ruptured aneurysms. The authors report a case with a typical clinical history and 3 main symptoms : lumbar pain, a pulsatile expansile mass, a continuous abdominal murmur giving rise to a thrill. The diagnosis was confirmed before operation by angiography which showed a fistula. A technical detail is emphasised: clamping of the inferior vena cava opening the aneurysm to reduce the risk of embolism into the right side of the heart during operation.
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From March 1963 to March 1974, 227 patients with carotid stenosis underwent unilateral or bilateral carotid endarterectomy at l'Hôpital de l'Enfant-Jésus in Québec. Survival during the first 7 years after operation was analysed by life-table methods based on full intervals. The observed probability of death in this group was significantly higher than the probability expected in the general population, by 6.8% in the 1st year and 3.9% in the 2nd year. In the next 3 years the differences were much smaller (0.5, 0.9 and 1.4%). The major causes of death were myocardial infarction and stroke. Women fared somewhat better than men after the 1st year of follow-up. Unexpectedly, patients who underwent unilateral endarterectomy had lower survival rates in each of the first 5 years after operation than patients who underwent staged bilateral operations, whether survival was measured from the date of the first or the second operation.
A 10-year-old girl had arterial hypertension, generalized neurofibromatosis, coarctation of the abdominal aorta and multiple stenoses at the origin of each renal artery. After resection of the stenotic areas and reimplantation of the renal arteries in the aorta, her arterial pressure decreased substantially. However, hypertension recurred and radiologic follow-up 4 1/2 years later showed distinct progression of the coarctation and renewed stenosis of all renal arteries at their origin. The stenotic areas showed eccentric intimal proliferation, frequently bulging into the lumen, with small nodular aggregates of smooth muscle cells and proliferation of fibrous tissue containing spindle-shaped nuclei in a palisading pattern. Hypertension associated with neurofibromatotic vascular disease has been described in 47 other patients in the literature. These patients have been young (mean age, 14 years) and predominantly male. In contrast to fibromuscular dysplasia, in which 95% of all stenoses are found in the distal two thirds of the renal arteries, in vascular neurofibromatosis more than 50% of the stenoses are found at the origin.
In 11 patients with severe angina pectoris a new beta-blocking drug, atenolol (Tenormin; I.C.I.66082), was found in a double-blind randomized trial to reduce significantly the frequency of anginal attacks (P less than 0-001) and the amount of trinitrin consumed (P less than 0-03) in comparison with practolol and placebo. There was no significant improvement in the patients' ability to exercise on the bicycle ergometer.
The association of an RNA-dependent RNA polymerase activity with virions of pike fry rhabdovirus has been demonstrated by both in vitro and in vivo studies. The temperature optimum for the in vitro assay is around 20 C, although enzyme activity can be observed at 4 C. Preparations of pike fry virus possess a glycoprotein, a membrane protein, a nucleoprotein, an L protein, and a phosphoprotein, as well as an RNA of about 3.8 times 10-6 mol wt. A protein kinase activity has been found associated with virus preparations. In vitro RNA product analyses indicate that the virus-associated enzyme functions principally as a transcriptase synthesizing viral-complementary, heteropolymeric RNA.
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Complete transcripts of the genome of vesicular stomatitis virus Indiana strain have been used to hybridize to virion RNA to determine if there is RNA sequence homology among these viruses. Cellular RNA from cells infected by each of these viruses has also been used for hybridization with the homologous or heterologous virion RNA. The results indicate that there is little exact sequence homology among these viruses.
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The initiation of RNA transcription by the virion-bound RNA transcriptase of vesicular stomatitis virus has been examined. Multiple initiation sequences have been observed, two of which have been characterized (pppApCpGp... and pppGpCp...) suggestive of a transcription process which can start at different sites along the template RNA. By the use of sequential labeling techniques and exonucleases, it has been determined that there is a 5' to 3' direction of product RNA synthesis.
The wild-type strain of vesicular stomatitis virus (VSV) contains in its complete virion (VSV-1, B particles) a minus strand RNA. The principle defective particle of the wild-type strain (VSV-111, T particles) contains a shorter minus strand, homologous to part of the VSV-1 genome. Neither virion contains any detectable complementary (plus) strand RNA. In contrast, a preparation of a heat-resistant (HR) strain of VSV containing defective virions was found to contain both plus (21%) and minus strand RNA, present in several distinct size classes. It was found that the RNA in the HR virion preparation was at least 94% single-stranded and principally (96%) in ribonucleoprotein complexes. On extraction the plus and minus strand RNA species partially annealed to give a population of double- and multistranded RNA species. A small amount of RNA polymerase activity was associated with the HR defective virus preparation.
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A procedure has been developed for the sequential removal and purification of the glycoprotein and membrane protein of vesicular stomatitis virus (VSV). Neither of these proteins exhibited transcriptase activity. All of the activity was recovered in the ribonucleic acid (RNA)-ribonucleoprotein complex of VSV, which also has four other minor proteins associated with it. During transcription of 41% of the RNA of a virus preparation, no dissociation of the ribonucleoprotein from the viral RNA was observed.