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Biomedical subjects

R Pasternak

Publications and source records attributed to R Pasternak.

29 records · Page 2Linked to original sources
PubMed1986

Proteoglycan- and collagen-degrading enzymes from human interleukin 1-stimulated chondrocytes from several species: proteoglycanase and collagenase inhibitors as potentially new disease-modifying antiarthritic agents.

Human IL-1-stimulated chondrocytes derived from rabbit, bovine, and human articular cartilage produce proteoglycan- and collagen-degrading enzymes. These studies demonstrate that the biological activity of IL-1 is not species specific. Several thiol, carboxyalkyl, and hydroxamic acid peptide inhibitors showed differential effects. The thiols were equipotent inhibitors of both the collagen- and proteoglycan-degrading enzymes whereas the carboxyalkyls appear to inhibit solely the proteoglycan-degrading enzyme(s). The hydroxamic acid peptides, the most potent inhibitors, appear to be more active against the proteoglycan-degrading enzymes. These synthetic inhibitors of proteoglycan- and/or collagen-degrading enzymes may represent a new class of disease-modifying antiarthritic agents.

Animals↗
PubMed1986

Lack of response of rat chondrosarcoma chondrocytes to interleukin-1 to produce proteoglycan- and collagen-degrading enzymes.

Chondrocytes obtained from rat articular cartilage and Swarm rat chondrosarcoma were maintained in culture. Human interleukin-1 (IL-1) was added at confluency, and three days later the spent media was evaluated for proteoglycan- and collagen-degrading enzymes. Unlike chondrocytes from articular cartilage from several species, chondrocytes from Swarm rat chondrosarcoma did not respond to IL-1 stimulation. This lack of sensitivity to IL-1 may be a useful biochemical marker to classify various types of chondrosarcomas. However, it appears that the use of chondrosarcoma chondrocyte cultures are not useful as a source for metalloproteinases.

Animals↗
PubMed1979

Echocardiographic aortic root motion in ventricular volume overload and the effect of mitral incompetence.

Echocardiographic aortic root motion in systole was studied in 57 patients: 13 normal subjects, 4 patients with left ventricular (LV) volume overload due to anaemia, 16 patients with mitral incompetence, 13 with aortic incompetence and 11 with mitral stenosis. In normal subjects, patients with mitral stenosis and in patients with LV volume overload, in whom the increased stroke volume was ejected forwards into the ascending aorta (anaemia, aortic incompetence) the amplitude of motion of the posterior aortic wall (vp), the aortic widening fraction (AWF) and total aortic motion (TAM) were increased. In mitral incompetence, however, despite the large increase in total LV stroke index, there was a decrease in vp (P less than 0.01), AWF (P less than 0.001) and TAM (P less than 0.001), and the decrease in aortic motion for a given stroke index was related to the mitral regurgitant fraction, indicating that aortic wall movement in systole depended predominantly on forward ejection of the LV stroke volume. Reduced echocardiographic aortic root motion and widening during systole are useful echocardiographic signs of mitral regurgitation.

Anemia↗
PubMed1975

Enhanced rate of progression of coronary artery disease following aortocoronary saphenous vein bypass surgery.

To evaluate the fate of the boronary arteries after aortocoronary bypass, 40 patients underwent serial selective coronary angiographic studies 1 year apart, and the frequency of progression of coronary artery disease was estimated. Thirty-two had saphenous vein bypass surgery after the first procedure, six had Vineberg operations, and two had no interim operation. In each patient, the right, left, anterior descending and circumflex coronary arteries (including their branches) were separately evaluated. Progressive narrowing was evident in 31 of 50 (62 per cent) bypassed vessels and in only 11 to 113 (9.7 per cent) nonbypassed arteries (p less than 0.001). Coronary arteries with moderate to severe obstruction initially (50 to 99 per cent occluded) manifested progressive diseasee more frequently (33 of 70 arteries) than did arteries that were normal or mildly narrowed initially (4 of 71) (p less than 0.001. Considering only those vessels with 50 to 99 per cent obstruction initially, 27 of 35 (77 per cent) of the bypassed arteries and only 6 of 35 (17 per cent) of the nonbypassed arteries showed progression (p less than 0.001). We conclude that moderately or severely narrowed coronary arteries are more likely to show progressive narrowing than normal or mildly obstructed ones and that progression of coronary disease is greater in bypassed vessels than in nonbypassed vessels. In view of potential graft closure, the implications of these findings must be considered in selecting patients for aortocoronary bypass.

Cineangiography↗
PubMedDate not supplied

Database Conference January 27-30, 2000, Washington D.C.--Do existing databases answer clinical questions about geriatric cardiovascular disease and stroke?

EXECUTIVE SUMMARY: Most randomized, controlled trials evaluating the effectiveness of pharmaceutical, surgical, and device interventions for the prevention and treatment of cardiovascular disease have excluded patients over 75 years of age. Consequently, the use of these therapies in the older population is based on extrapolation of safety and effectiveness data obtained from younger patients. However, there are many registries and observational databases that contain large amounts of data on patients 75 years of age and older, as well as on younger patients. Although conclusions from such data are limited, it is possible to define the characteristics of patients who did well and those who did poorly. The goal of this conference was to convene the principal investigators of these databases, and others in the field of geriatric cardiology, to address questions relating to the safety and effectiveness of treatment interventions for several cardiovascular conditions in the elderly. Seven committees discussed the following topics: (I) Risk Factor Modification in the Elderly; (II) Chronic Heart Failure; (III) Chronic Coronary Artery Disease: Role of Revascularization; (IV) Acute Myocardial Infarction; (V) Valve Surgery in the Elderly; (VI) Electrophysiology, Pacemaker, and Automatic Internal Cardioverter Defibrillators Databases; (VII) Carotid Endarterectomy in the Elderly. The chairs of these committees were asked to invite principal investigators of key databases in each of these areas to discuss and prepare a written statement concerning the available safety and efficacy data regarding interventions for these conditions and to identify and prioritize areas for future study. The ultimate goal is to stimulate further collaborative outcomes research in the elderly so as to place the treatment of cardiovascular disease on a more scientific basis.

Aged↗