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Biomedical subjects

U Ravnskov

Publications and source records attributed to U Ravnskov.

At least 19 recordsLinked to original sources
PubMed1992

Cholesterol lowering trials in coronary heart disease: frequency of citation and outcome.

OBJECTIVE: To see if the claim that lowering cholesterol values prevents coronary heart disease is true or if it is based on citation of supportive trials only. DESIGN: Comparison of frequency of citation with outcome of all controlled cholesterol lowering trials using coronary heart disease or death, or both, as end point. SUBJECTS: 22 controlled cholesterol lowering trials. RESULTS: Trials considered by their directors as supportive of the contention were cited almost six times more often than others, according to Science Citation Index. Apart from trials discontinued because of alleged side effects of treatment, unsupportive trials were not cited after 1970, although their number almost equalled the number considered supportive. In three supportive reviews the outcome of the selected trials was more favourable than the outcome of the excluded and ignored trials. In the 22 controlled cholesterol lowering trials studied total and coronary heart disease mortality was not changed significantly either overall or in any subgroup. A statistically significant 0.32% reduction in non-fatal coronary heart disease seemed to be due to bias as event frequencies were unrelated to trial length and to mean net reduction in cholesterol value; individual changes in cholesterol values were unsystematically or not related to outcome; and after correction for a small but significant increase in non-medical deaths in the intervention groups total mortality remained unchanged (odds ratio 1.02). CONCLUSIONS: Lowering serum cholesterol concentrations does not reduce mortality and is unlikely to prevent coronary heart disease. Claims of the opposite are based on preferential citation of supportive trials.

Choice Behavior↗
PubMed1979

Glomerulonephritis and exposure to organic solvents. A case-control study.

Fifty patients with biopsy-proven glomerulonephritis and 100 sex- and age-matched controls (50 patients each with non-glomerular renal disease or acute appendicitis) were asked by questionnaire and a telephone interview whether they had been exposed to organic solvents. The questioning and the evaluation of the exposure, if any, was made without knowing the diagnosis of the interviewee. Fifty per cent of the patients with glomerulonephritis reported more than slight exposure, but only 20% of the controls. Exposure to organic solvents may often play a role in the causation of glomerulonephritis.

Adolescent↗
PubMed1979

Porcine nephropathy induced by long-term ingestion of ochratoxin A.

Nine pigs were fed crystalline ochratoxin A in their feed at a concentration of about 1 mg/kg. Three pigs and their controls were killed after 3 months and 6 pigs and controls were killed after 2 years. A decrease of the ratio TmPAH/CIn, increased urinary glucose excretion and decreased ability to concentrate urine, occurred within a few weeks and aggravated slightly during the 2-year period. Changes in renal structure, characterized by degeneration and atrophy of proximal tubules, interstitial fibrosis and hyalinization of glomeruli, were progressive during time of exposure, but terminal renal failure was not reached. The kidney, liver, muscular and adipose tissue contained 3 to 27 microgram ochratoxin A/kg after 3 months of exposure. No further accumulation of ochratoxin A residue was found after 2 years of exposure.

Animals↗
PubMed1978

Exposure to organic solvents--a missing link in poststreptococcal glomerulonephritis?

Fifteen patients with evidence of acute poststreptococcal glomerulonephritis were asked about their contact with vapours of organic solvents. Six patients reported brief exposure shortly before the onset of glomerulonephritis, 4 fairly long exposure, and 5 none or insignificant. At the latest followup, 3 of 4 patients who were still exposed to such solvents had proteinuria and a low glomerular filtration rate (GFR), and 2 were hypertensive. Of the 11 patients who had never been or were no longer exposed, the GFR was insignificantly decreased in 2, none had proteinuria and none were hypertensive. Fifteen age-and sex-matched controls, who had been infected with group A beta-hemolytic streptococci, T type 12, had not been exposed, or the exposure was insignificant and not related to the streptococcal infection. Exposure to organic solvents or other nephrotoxic agents may be the condition which determines the outcome of an infection with nephritogenic streptococci.

Adolescent↗
PubMed1977

Treatment of glomerulonephritis with drainage of the thoracic duct and plasmapheresis.

Nine patients with various types of severe glomerulonephritis were treated with drainage of the thoracic duct (n=8) and/or plasmapheresis (n=6) without the use of pharmacological immunosuppression. In most of the patients treatment produced a prompt temporary regression of albuminuria and creatininemia. In one patient renal function was substantially improved 8 months after the last period of treatment, in 2 patients the progress of the uremia was probably retarded. In the remaining 6 patients treatment had no obvious effect on the course of the illness. Drainage of the thoracic duct and plasmapheresis may be of benefit in the treatment of glomerulonephritis, but their proper utilization requires further studies.

Adolescent↗
PubMed1976

alpha1-Microglobulin, a new low molecular weight plasma protein.

A new low molecular weight protein was purified from the urine of uraemic patients. The protein was found to be glycoprotein with a molecular weight of 31 500, determined by SDS-polyacrylamide gel electrophoresis, and a carbohydrate content of 19%. It was electrophoretically heterogenous and migrated in the slow alpha1-region. The mean serum level in 20 apparently healthy individuals was 32+/-10 mg/1. The serum level was normal in 5 patients with severe reduction of plasma protein synthesis caused by cirrhosis of the liver but elevated in patients with a decreased glomerular filtration rate. The mean urinary excretion in 5 healthy individuals was 1.3 mg/24 h. Increased excretion was seen in 10 patients with varying degrees of uraemia.

Amino Acids↗
PubMed1976

Low molecular weight proteinuria and slight hyperlipoproteinemia in three mentally retarded brothers.

Mental retardation in combination with proteinuria and a slight hyperlipoproteinemia was found in three brothers. The increased urinary protein excretion was dominated by albumin and the low molecular weight proteins retinol-binding protein (RBP) and beta2-microglobulin, indicating the presence of proximal tubular dysfunction. However, there was no glucosuria, phosphaturia or amino aciduria and the renal concentrating and acidification capacities were normal. A kidney biopsy in one of the patients revealed morphologic evidence of glomerular damage but a normal tubular structure. A mild hyper-beta-lipoproteinemia was found in the patients but not in their healthy siblings. The cause of this syndrome, hitherto not described, is unknown.

Adolescent↗
PubMed1976

Renal handling of Zn-alpha2-glycoprotein as compared with that of albumin and the retinol-binding protein.

An unusual electrophoretic pattern of the urine from a patient with malignant lymphoma was observed. One of the major proteins, identified Zn-alpha2-glycoprotein (Zn-alpha2), was isolated from the urine and partly characterized. The Stokes radius was found to be 3.24 nm and the molecular weight, determined by sodium dodecyl sulfate polyacrylamide electrophoresis, 42,000. The plasma level in healthy individuals was 39 +/- 7 (SD) mg/liter. In 12 of 25 healthy individuals, Zn-alpha2 was measurable in the urine and was found to be 1.0 +/- 1.1 mg/liter. In 23 patients with chronic glomerulonephritis (CGN), in 9 with proximal tubular dysfunction (PTD), in 23 with various renal diseases (VRD), and in 10 with malignant lymphoma, the plasma level and the urinary excretion were compared with those of albumin (mol wt 67,000) and of the retinol-binding protein (RBP, mol wt 21,000). A close correlation was found between the urine-to-plasma (U/P) ratios of Zn-alpha2 and albumin in the patients with CGN, whereas in the PTD patients the U/P ratios of Zn-alpha2 and RBP were correlated. No significant renal arteriovenous difference in Zn-alpha2 could be demonstrated. The Zn-alpha2 excretion was increased also in two patients with malignant lymphoma and proteinuria of a tubular pattern. The plasma Zn-alpha2 varied inversely with the glomerular filtration rate in the patients with renal disease, but was normal in those with malignant lymphoma. The results are consistent with the assumption of a sieving coefficient of Zn-alpha2, substantially exceeding that of albumin, but notably lower than that of smaller low-molecular-weight proteins. An increased excretion of Zn-alpha2 may be due to increased glomerular permeability as well as to defective proximal tubular reabsorption.

Adult↗