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Biomedical subjects

G Friedman

Publications and source records attributed to G Friedman.

At least 145 records · Page 8Linked to original sources
PubMed1983

Infective endocarditis in Jerusalem. A comparative analysis of native and prosthetic valve endocarditis.

Thirty patients with prosthetic valve endocarditis (PVE) and 62 patients with native valve endocarditis (NVE) observed during a concurrent period of time (1970-80) were analyzed. Patients with PVE were also compared with 697 patients who underwent cardiac valve replacement in the same period, in an attempt to uncover risk factors for PVE. In the operated patients the overall incidence of endocarditis was 4.3%. There were several significant differences between the NVE and PVE groups. Atrial fibrillation was more prevalent in the PVE group (33.4 vs. 11.5%, P less than 0.05), while infection with gram-positive organisms was more prevalent in the NVE patients (79 vs. 47%, P less than 0.01). The outcome of combined medical and surgical treatment showed a much higher mortality rate (50 vs. 6.4%, P less than 0.01) in the PVE group. Staphylococcal endocarditis resulted in 16% mortality in NVE vs. 100% in the PVE group (P less than 0.01). Careful surveillance may hopefully lead to early detection, treatment and better outcome of PVE.

Adolescent↗
PubMed1982

Binding of lipoprotein lipase to the cell surface is essential for the transmembrane transport of chylomicron cholesteryl ester.

Four cell types, F1 rat heart cells, rat preadipocytes, human skin fibroblasts and bovine endothelial cells, were used to investigate whether surface binding of lipoprotein lipase was essential in the transmembrane transport of chylomicron cholesteryl ester. Exposure of F1 heart cells to colchicine resulted in decrease in endogenous surface-bound lipoprotein lipase and a concomitant fall in the uptake of chylomicron cholesteryl linoleyl ether, a nondegradable analog of cholesteryl ester. Uptake of chylomicron cholesteryl linoleyl ether was enhanced by addition of milk lipoprotein lipase and this enhancement also persisted in the presence of colchicine. The drug did not reduce surface binding to the enzyme. Milk lipoprotein lipase was bound to the cell surface of the different cell types and its fate during chase in enzyme-free medium was determined. The t 1/2 of surface-bound enzyme in endothelial cells and in F1 heart cells was about 2 h; it was 4 h in skin fibroblasts. The decrease in surface-bound lipoprotein lipase was accompanied by a parallel fall in the binding and uptake of chylomicron cholesteryl linoleyl ether by the various cell types examined. This decrease in the uptake of cholesteryl linoleyl ether occurred even though lipoprotein lipase activity in the medium was present, as evidenced by the hydrolysis of [14C]triacylglycerol. Release of surface-bound endogenous or exogenous lipoprotein lipase by heparin was accompanied by almost complete elimination of uptake of cholesteryl linoleyl ether in presence of complete hydrolysis of [14C]triacylglycerol. The present results indicate that the transmembrane transport of cholesteryl ester is catalyzed by lipoprotein lipase only when the enzyme is bound to the cell membrane.

Adipose Tissue↗
PubMed1982

Fate of milk 125I-labelled lipoprotein lipase in cells in culture. Comparison of lipoprotein lipase- and non-lipoprotein lipase-synthesizing cells.

Radioiodinated lipoprotein lipase, isolated from bovine milk (125I-labeled milk lipoprotein lipase) was shown to retain full hydrolytic activity towards its native substrate, i.e., chylomicron triacylglycerol. The 125I-labeled enzyme interacted with various cells in culture by being bound to the cellular surface, internalized and degraded. Cellular binding of the labeled enzyme occurred in the presence or absence of substrate and was related to enzyme concentration. Heparin reduced cellular binding by 50% but inhibited uptake and degradation more extensively. Cellular uptake was not affected by chloroquine or NH4Cl, but degradation of the labeled enzyme was blocked. Uptake and degradation were not inhibited by mannose 6-phosphate. The interaction between the exogenous enzyme and cells which do not synthesize lipoprotein lipase, i.e., fibroblasts and endothelial cells, resulted in a high ratio of surface binding to degradation. In heart cell cultures and preadipocyte cultures, which produce lipoprotein lipase, the ratio of enzyme catabolized to that bound was high at all time points examined. Since in the intact organism lipoprotein lipase acts at the luminal surface of vascular endothelium, it seems expedient that these cells are able to bind the enzyme, but will catabolize it only slowly. The rapid and extensive degradation of the 125I-labeled lipoprotein lipase in heart cells and preadipocytes may be related to the metabolism of the endogenously produced lipoprotein lipase.

Adipose Tissue↗
PubMed1982

Hypothesis: new concepts on the pathogenesis of early prosthetic valve endocarditis.

During the years 1970-1980, 697 patients had valve replacement surgery at our institution. Thirty patients subsequently developed prosthetic valve endocarditis (P.V.E.). Reexamination of the native valves of 25 of these patients revealed histopathological evidence of thromboendocarditis in 7, 5 of whom subsequently developed early P.V.E. In 3 out of 25 matched controls in whom P.V.E. was not diagnosed clinically, similar pathological findings were found; these patients all had fever pre- or post-operatively and were treated with a short antibacterial course, but no definite clinical diagnosis was made. We suggest that there is a close relationship between subclinical thromboendocarditis on the native valve and the early development of infective endocarditis on the implanted artificial valve.

Endocarditis, Bacterial↗
PubMed1982

Epidemiology of temporal arteritis in Israel.

An effort was made to identify all cases of biopsy-proven temporal arteritis (TA) diagnosed in Israel during 1960-78. A total of 46 Jewish patients was found, none of them under 50 yr of age. The age-standardized annual incidence rate of biopsy-proven TA among Jews in Israel rose from 1.6 in 1960-64 to 8.6 in 1975-78, with an overall incidence of 4.9 new cases diagnosed annually/10(6) population greater than or equal to 50 yr. The male:female ratio was 0.95. The annual incidence was 0.2 cases/10(6) population aged 50 to 59 yr, and 11.6/10(6) population greater than or equal to 70 yr of age. We feel that apparent increase in the incidence of TA is due to increased awareness of the disease rather than to an increase in morbidity.

Age Factors↗
PubMed1981

Risk factors for coronary artery disease in patients with acute myocardial infarction. Effects of age, sex and ethnicity.

The characteristics of 200 patients with acute myocardial infarction were determined and analyzed according to age, sex and country of origin. Older patients (greater than 65 yr) were characterized by an overall low-risk profile. Women with myocardial infarction (especially less than 65 yr) were characterized by a high-risk profile, although fewer smoked cigarettes and their high density lipoprotein cholesterol levels were higher than in men. In patients of Asian-African origin, hyperlipoproteinemia of the type IIb variety was more prevalent and the plasma triglyceride levels were higher than in the other patients. The analysis has thus indicated several distinct risk patterns among the study population; in particular, plasma and lipoprotein lipid levels were found to be an important predisposing factor for coronary artery disease in young patients, in women, and in immigrants from Asian and African countries.

Age Factors↗
PubMed1980

Lipoprotein lipase activity in F1 heart cell cultures. Effect of dialyzable serum factors on enzyme stability and enzyme synthesis.

F1 heat cell cultures were grown in F-10 medium containing 20% fetal calf and horse serum and after 6-7 days showed high activity of lipoprotein lipase. When the culture medium contained 20% serum which had been dialyzed against F-10 medium, a 75% decline in lipoprotein lipase activity occurred after 3 h of incubation. Cultures incubated with 20% dialyzed serum and dialysate, obtained after 24 h dialysis of serum against F-10 medium, retained full enzyme activity. Restoration of enzyme activity, lost upon incubation with dialyzed serum, became apparent only 2 h after incubation of the cells with dialysate and dialyzed serum and was complete after 24 h. The effectiveness of the dialysate was not affected by trichloroacetic acid precipitation, ether extraction, exposure to pronase or to 80 degrees C for 10 min; it was retained after chromatography of DEAE cellulose but was lost after elution from CM cellulose colums. Addition of spermidine and spermine to culture media containing dialyzed serum did prevent partially the decline in lipoprotein lipase activity of the heart cell cultures. These polyamines were also able to stabilize lipoprotein lipase activity of heart homogenates incubated at 37 degrees C. However, these compounds were not effective in resoration of enzyme activity of cultured cells lost after exposure to dialyzed serum. It appears that positively charged low molecular weight molecules present in sera of various species are required for the stabilization and synthesis of lipoprotein lipase in heart cell cultures.

Animals↗
PubMed1980

Use of health education and attempted dietary change to modify atherosclerotic risk factors: a controlled trial.

The purpose of this investigation was to determine if nutrition education regarding atherosclerotic risk factors and dietary changes that might reduce these factors, taught in an elementary school setting, would cause children to alter their diets in a way that would produce a significant reduction in risk factor values as compared to a control group. Serum cholesterol, blood pressure, height, weight, and skinfold thickness were the evaluated variables. Sixty-eight children who had been enrolled in the intervention program had complete data at the termination of the 3-year study. The major control group consisted of 23 children from a different school. Additional control groups were formed to provide information regarding general population changes in the risk factors during the time span of the study and to investigate values of children who did not complete the entire program. The results showed no major significant changes for these variables as compared to the control group or the preintervention values of the intervention population. As expected, the population had an initially relatively low risk. Tracking of these variables over 3 years showed results similar to those of other investigations that did not include intervention. It is concluded that, although the education proved effective by cognitive testing, the methodology used in this study was ineffective in reducing significantly the above risk factors of the population investigated.

Arteriosclerosis↗
PubMed1980

Clindamycin unresponsive anaerobic osteomyelitis treated with oral metronidazole.

A diabetic patient with peripheral neuropathy and a foot ulcer developed osteomyelitis of the foot. Antibiotic therapy of the aerobes isolated from the ulcer resulted in no clinical improvement. Intravenous clindamycin therapy of the anaerobe isolated (Bacteroides fragilis) was associated with an incomplete and temporary response, but there was a dramatic response to oral metronidazole with healing of the ulcer and osteomyelitis. One year later there were no signs of recurrence.

Administration, Oral↗
PubMed1979

Lipoprotein lipase of cultured mesenchymal rat heart cells. IV. Modulation of enzyme activity by VLDL added to the culture medium.

Lipoprotein lipase activity was studied in rat heart cell cultures grown in the presence of 20% fetal calf and horse serum and a medium concentration of triacylglycerol of 0.03 mg/ml. After 6--8 days, when the enzyme activity had reached high levels, the cells were incubated for 24 h in a medium containing 20% serum derived from fasted or fed rats. No change in enzyme activity occurred in the presence of fasted rat serum, but a 50% fall was observed with fed rat serium. When the complete culture medium was supplemented with rat plasma VLDL (0.075--0.75 mg triacylglycerol) a pronounced decrease in lipoprotein lipase activity occurred after 3--5 h of incubation. Similar extent of enzyme fall was observed also in the presence of triacylglycerol-rich lipoproteins isolated from rat plasma after feeding of safflower oil or lard, even though the fatty acid composition of the triacylgylcerol varied markedly. As the addition of VLDL to the culture medium resulted in a lesser fall of heparin releasable than residual activity it seems that there was no direct inhibition of surface bound enzyme activity and that the transport of the enzyme to the cell surface was not affected. These data indicate that addition of VLDL to the culture medium resulted in a fall in enzyme synthesis, while total protein synthesis as determined by incorporation of [3H]leucine, remained unchanged. This inhibition could be reproduced by increasing free fatty acid concentration of the medium, however addition of excess albumin to VLDL-containing medium did not prevent the fall in enzyme activity. The present results obtained with cultured rat hearts cells suggest that in vivo plasma levels of triacylglycerol-rich lipoproteins could modulate the lipoproteins could modulate the lipoprotein lipase activity of the heart.

Animals↗
PubMed1979

[Value and results of computer tomography in diseases of the pancreas (author's transl)].

In a joint study carried out by the radiological university clinics of Bonn, Hamburg, Cologne, Leuven and Munich, 483 computer tomographs of the pancreas were evaluated. A correct histological diagnosis, or one confirmed at surgery, was obtained in 74.5% of 168 cases; in a further 9% an abnormality was seen in the pancreas or in its immediate vicinity, but was wrongly interpreted. The computer tomographic criteria of inflammatory processes and of tumours of the pancreas are given, and the not uncommon difficulties in distinguishing between these are discussed.

Acute Disease↗
PubMed1979

Co-existing aortic stenosis and secondary hypertrophic cardiomyopathy manifested by an hourglass left ventricle. Successful treatment with verapamil.

A patient with moderate aortic stenosis had severe hypertrophy and a typical hourglass appearance of the left ventricle. His effort-induced angina and dyspnea responded to treatment with verapamil. We suggest that the aortic stenosis resulted in secondary hypertrophic cardiomyopathy which may be treated by calcium antagonists.

Aortic Valve Stenosis↗