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Biomedical subjects

U Erikson

Publications and source records attributed to U Erikson.

At least 19 recordsLinked to original sources
PubMed1995

Predilection of atherosclerosis for the inner curvature in the femoral artery. A digitized angiography study.

The degree of atherosclerosis in the inner and outer curvature of the femoral artery was studied by using digitized angiography and edge-roughness calculations in 301 hyperlipidemic patients. When the two edges of the vessel were compared no significant difference was seen, but when the local curvature was taken into account, inner curves were found to be more atherosclerotic than outer curves, and both inner and outer curves were more affected than straight segments. The same pattern was encountered in subpopulations defined by clinical or blood lipid criteria. The suggested explanation is that flow disturbances such as low shear rates or separated flow, which tend to arise along the inner curvature, promote the development of atherosclerosis.

Adult↗
PubMed1995

Lowering of HDL2b by probucol partly explains the failure of the drug to affect femoral atherosclerosis in subjects with hypercholesterolemia. A Probucol Quantitative Regression Swedish Trial (PQRST) Report.

The aim of the Probucol Quantitative Regression Swedish Trial (PQRST) (n = 303) was to investigate whether probucol (0.5 g BID) added to diet and cholestyramine (8 g BID) could retard progression or induce regression of femoral atherosclerosis in hypercholesterolemic (> 6.86 mmol/L) subjects. Probucol did not induce regression over the 3-year trial period as estimated by change in lumen volume on quantitative arteriography of a 20-cm segment of the femoral artery. In this report we studied in a representative subgroup (n = 72) whether the reduction in HDL concentrations induced by probucol could explain the failure of the drug to be effective. We analyzed the effects of treatment on HDL particle size subclasses. Probucol lowered the relative level of HDL2b, comprising the largest HDL particles, by 53% and the protein concentration of HDL2b by 67%. The protein reduction in HDL was mainly confined to the apolipoprotein A-I moiety. The change in lumen volume correlated significantly with change in HDL, ie, HDL cholesterol (r = .34, P < .01), HDL2 cholesterol (r = .37, P < .01), HDL2b protein (r = .44, P < .001), and the relative HDL2b value (r = .51, P < .001). The corresponding values for relative HDL2b, distribution calculated on the active (n = 35) and placebo (n = 37) groups separately were also significant (r = .39 and .32, respectively; both P < .05). The correlation between drug-induced change in the relative HDL2b concentration and change in atherosclerosis was independent of the alteration in triglyceride concentration and could not be explained by treatment interaction.(ABSTRACT TRUNCATED AT 250 WORDS)

Apolipoprotein A-I↗
PubMed1992

Correlation between computer-assisted femoral arteriography and physiological tests in hypercholesterolaemic patients: a methodological study with special reference to clinical trials.

The validity of computer-assisted femoral arteriography, for the study of regression/progression of atherosclerosis in follow-up clinical trials, was investigated by comparison with routine physiological estimates of peripheral circulatory function. Thus, in 114 hypercholesterolaemic patients, the results of aorto-femoral arteriography were compared with those of leg segmental blood pressure measurement, oscillometry, digital pulse plethysmography, and bicycle and treadmill exercise tests. In 107 patients, 18 with symptoms of peripheral vascular disease (PVD) and 89 asymptomatic, magnification arteriograms of a 20 cm segment of the right or left superficial femoral artery were obtained. These arteriograms were digitized and the following variables were calculated: arterial lumen volume (corrected for body size), per cent stenosis, and edge roughness. The correlation between arteriographic and physiological variables was investigated with a linear regression model, taking into account the possible interaction with sex, and presence or absence of symptoms of PVD. Lumen volume correlated significantly with all five physiological variables, and per cent stenosis correlated significantly with four of the physiological variables. For the roughness measure, however a significant correlation was found only with plethysmography. By using logistic multiple regression analysis linear functions of physiological variables were constructed to detect ilio-femoral arterial occlusion. The sensitivity/specificity for detection of right-sided, left-sided, and bilateral occlusion was 0.83/0.98, 0.78/0.98, and 0.60/1.00 respectively (N = 108-111). Systolic blood pressure (ankle-arm ratio) was the single variable most closely correlated to the likelihood of arterial occlusions. It is concluded that arterial lumen volume and per cent stenosis, measured for the digitized femoral arteriogram, correlate well with physiological variables, which reflect the state of atherosclerosis both in the femoral arteries and in other arterial beds including the heart, and that routine physiological tests can be used to identify patients with arterial occlusions in the iliac and femoral arteries.

Adult↗
PubMed1992

Influence of contrast media on single nephron glomerular filtration rate in rat kidney. A comparison between diatrizoate, iohexol, ioxaglate, and iotrolan.

The effects of slow (10 min) i.v. infusions of contrast media (CM, 1,600 mg I/kg b.w.) on single nephron glomerular filtration rate (SNGFR) in the rat kidney were investigated using a micropuncture technique. Diatrizoate, iohexol, or ioxaglate did not change SNGFR, although a tendency towards a transient suppression was seen during the infusion phase. Iotrolan infusion, however, decreased SNGFR (p < 0.05) and the value still remained below the control value 25 min after the start of infusion. Iotrolan is a nonionic dimeric CM and has a lower osmotic effect in the tubules than the ionic dimeric CM and the monomeric CM when given in iodine equivalent doses. These characteristics of iotrolan have probably some influence on the depression of SNGFR after iotrolan injection.

Animals↗
PubMed1992

Complications of percutaneous pericardiocentesis under fluoroscopic guidance.

Complications in 352 cases of fluoroscopy-guided percutaneous pericardiocentesis accomplished through an indwelling catheter were reviewed following surgery and non-surgery. Thirteen major complications were found, namely 3 cardiac perforations, 2 cardiac arrhythmias, 4 cases of arterial bleeding, 2 cases of pneumothorax in children, one infection, and one major vagal reaction. No significant difference in complications was found between pericardiocenteses for pericardial effusions after cardiac surgery (n = 208) and those for effusions of non-surgical (n = 144) origin. Fluoroscopy-guided pericardiocentesis by the subxiphoid approach with placement of an indwelling catheter is a safe method for achieving pericardial drainage in both surgical and non-surgical effusions. Accidental cardiac perforation with a fine needle is a minor complication as long as the needle is directed towards the anterior diaphragmatic border of the right ventricle and drainage is achieved with a reliable indwelling catheter.

Adolescent↗
PubMed1991

Image operations in quantification of atherosclerosis from digitized angiograms.

This report describes a method of quantifying the inner volume (lumen volume) of a contrast medium-filled femoral artery from a roentgenogram by computerized image analysis. The various factors influencing the accuracy of the volume determination are analyzed and an image-processing procedure for the elimination of artifacts due to crossing arteries is described and evaluated. The presented methods have been used in a large study of 281 patients and the short-term reproducibility has been found to be 1.00.

Arteriosclerosis↗
PubMed1991

Atherosclerosis-related measures in digitized femoral arteriograms.

Atherosclerosis is reflected in the arteriogram as narrowing of the arterial lumen and irregularity of the arterial wall. We have quantified these changes in digitized femoral arteriograms from 107 hypercholesterolaemic patients and defined 10 different measures concerning arterial diameter, cross-sectional area, stenosis and edge irregularity. We examined the precision of these measures and the correlations between them. Lumen volume and mean diameter for defined arterial segments had the highest precision and may be useful for follow-up studies. The linear correlation between the mean diameter and the square root of the lumen volume was greater than 0.99, so these two measures seem to be equivalent for all practical purposes. The measured variables could be separated into 2 groups: the measures concerning arterial diameter and lumen volume and those concerning edge irregularity and localized stenosis. The measures within each group showed strong positive mutual correlations, while the correlations between measures from different groups were negative and small. It was concluded that if the results of one measure from each group, suitably those of lumen volume and edge roughness, are known, the other described measures will add no further information about the atherosclerotic process.

Arteriosclerosis↗
PubMed1990

The effect of serum lipid regulation on the development of femoral atherosclerosis in hyperlipidaemia: a non-randomized controlled study.

The development of femoral atheroma after 1 year of treatment with diet and nicotinic acid plus fenofibrate was studied in 45 asymptomatic, hyperlipidaemic, middle-aged male subjects in a non-randomized controlled study. The median serum very low density lipoprotein (VLDL) cholesterol concentration and the low density lipoprotein (LDL) cholesterol concentration were lowered by 67% and 36%, respectively, in the treatment group. The median serum high density lipoprotein (HDL) cholesterol concentration was increased by 23%. Femoral atheroma was estimated by overall atherosclerosis score (OAS). Changes in femoral atherosclerosis were estimated by intrapair comparison of angiograms. Progression was found in 24% and 40% in the treatment and control groups, respectively. Regression occurred in 29% and 0%, respectively. The OAS decrease correlated with reductions in VLDL cholesterol and systolic blood pressure.

Adult↗
PubMed1990

Changes in atheroma volume estimated from digitized femoral arteriograms.

To evaluate the effects of treatment in patients with cardiovascular risk factors, valid and reproducible methods for assessing changes in atheroma volume are required. We postulated that these changes could be accurately estimated by repeat measurement of the lumen volume of the artery to be studied. With a computer-based technique, the lumen volume of a 20 cm segment of the femoral artery was measured in arteriograms from 107 patients with hypercholesterolemia. Films were digitized with use of a high-resolution scanner, cross-sectional areas were calculated with a slice thickness of 150 microns and the lumen volume was obtained by their integration. The validity of the method was demonstrated in model experiments. An automatic algorithm to correct for changes due to patient positioning was developed and validated in a model experiment. With repeat measurement 10 min and 11 to 13 months apart the coefficients of variation were 2.9 per cent (N = 107) and 6.1 per cent (N = 29), respectively.

Algorithms↗
PubMed1990

Arterial segmental vasoconstriction in hypercholesterolaemic patients.

Regular, wave-like constriction in medium-sized arteries, arterial segmental vasoconstriction (ASV), has been observed at arteriography and described by many authors. We found ASV in arteriograms of the superficial femoral artery in 13 of 107 hypercholesterolaemic patients, enrolled in the Probucol Quantitative Regression Swedish Trial (PQRST). The arteriograms were digitized and studied with a quantitative computer-assisted technique. The frequency of ASV was higher than has been reported earlier in clinical materials, possibly because of an increased vasoreactivity in hypercholesterolaemia, as recently observed experimentally. The ASV patients were, on average, younger, had lower blood pressure and less atherosclerosis, than the non-ASV patients. ASV was not found in any of the 19 patients in the material who either had symptoms of peripheral vascular disease or arteriographically verified arterial occlusions. No significant correlations with smoking habits or serum cholesterol levels were found. A computer-based index of ASV and measurement of ASV wavelength are discussed.

Adult↗
PubMed1989

Prevalence of femoral atherosclerosis in asymptomatic men with hyperlipoproteinaemia.

Sixty-two male subjects with primary hyperlipoproteinaemia of type IIA (n = 18), type IIB (n = 18) or type IV (n = 24) underwent femoral arteriography to investigate the degree of atherosclerosis. All except two were free from symptoms of peripheral arterial disease. The presence of atheroma was determined according to a standardized consensus procedure based on visual interpretation. Atherosclerosis were graded by means of a scoring system, whereby an overall atherosclerosis score (OAS) was calculated for each patient, based on four consecutive segments of the femoral artery. Thirteen type IIA (72%), 14 type IIB (78%) and 18 type IV (75%) patients had femoral atherosclerosis, and the mean OAS in the patients with hyperlipoproteinaemia of these types were 0.58, 0.75 and 0.49, respectively, all with a standard error of the mean about 0.05. The atherosclerosis score increased the more distal the arterial segment, being most prevalent in the lower inferior segment. The OAS was higher in patients of above median age, in those with systolic or diastolic blood pressure above the median and in smokers. Multiple stepwise regression analysis showed that low density lipoproteins cholesterol was highly significantly related to OAS among smokers. In conclusion, femoral atherosclerosis is a prevalent finding in asymptomatic subjects with hyperlipoproteinaemia and could serve as a basis for intervention studies.

Adult↗
PubMed1988

Development of femoral atherosclerosis in hypercholesterolemic patients during treatment with cholestyramine and probucol/placebo: Probucol Quantitative Regression Swedish Trial (PQRST): a status report.

The Probucol Quantitative Regression Swedish Trial is being performed to investigate the effects of probucol on atherosclerosis in the femoral artery. Probucol is combined with cholestyramine and dietary management in hypercholesterolemic patients, and the effects of atheroma developing in the femoral artery will be followed by a quantitative angiographic technique. A randomly selected control group is also being managed by dietary therapy and cholestyramine, but receives placebo instead of probucol. The treatment time in this double-blind trial is 3 years, and femoral angiography is performed yearly. Detailed lipoprotein and apolipoprotein analysis are performed at monthly intervals. The basic study design is described here, and some results from the open prerandomization phase of the study are presented.

Arteriosclerosis↗
PubMed1988

Probucol Quantitative Regression Swedish Trial: new angiographic technique to measure atheroma volume of the femoral artery.

The Probucol Quantitative Regression Swedish Trial is studying the development of atherosclerosis in hyperlipidemic patients through the use of digitized femoral arteriographic examinations. In a 20-cm segment of the femoral artery, cross-sectional areas are calculated using an algorithm that was introduced by Hilal and Crawford. Changes in atheroma volume are measured in repeat arteriographic examinations. This report describes the radiologic technique, the scanning procedure and the image analysis.

Arteriosclerosis↗
PubMed1988

Effects of intravenous contrast media on cortical and medullary blood flow in the rat kidney.

The effect of slow intravenous infusion of contrast medium (CM) (1600 mg I/kg body weight) on cortical blood flow (BF) and medullary BF in rat kidneys was investigated by laser-Doppler flowmetry on either renal cortex or exposed renal papillas (inner medulla). The effect on cortical BF was evaluated after infusion of either ioxaglate, iohexol, or ioxithalamate. Mannitol and Ringer's solution were used as control substances. The effect on medullary BF was examined after infusion of either ioxaglate, iohexol, iopamidol, ioxithalamate, or mannitol. BF was measured continuously during a 30-minute control period and a 60-minute experimental period, starting with the CM infusion. Cortical BF was unchanged in the ioxaglate group and significantly increased in the iohexol, ioxithalamate, and mannitol groups (P less than .05). Medullary BF was moderately increased in the ioxaglate group (P less than .05) but moderately decreased in the groups that received iohexol, iopamidol, ioxithalamate, or mannitol (P less than .05). The reduction in medullary BF following infusion of the ratio 3.0 nonionic CM and of the ratio 1.5 ionic CM might be one contributory mechanism to the pathogenesis of CM nephropathy, especially in the presence of microangiopathy in the kidney.

Animals↗
PubMed1985

Qualitative and quantitative evaluation of the exercise electrocardiogram in assessing the degree of coronary heart disease.

Exercise-induced changes in the ST segments of the electrocardiogram were compared with the results of coronary arteriography in 73 consecutive patients referred for preoperative evaluation of coronary artery disease. Eighteen patients had single-, 25 double-, and 30 triple-vessel disease. Thirteen were taking digitalis alone, 28 were taking beta blockers alone, 21 had beta blockers and digitalis and 11 had no cardiac drugs. Exercise induced elevation of the ST segment in 11 patients, all with a predominant lesion in the left anterior descending coronary artery. ST depression with an upsloping ST segment was observed in patients with one-, two-, and three-vessel disease and it was the most common type of ST change in patients with single-vessel disease. Horizontal ST depression was most common in two-vessel disease and downsloping ST segment in three-vessel disease. There was a good correlation between the number of stenosed vessels and ST changes caused by exercise, expressed as the sum of ST segment displacements in twelve leads recorded immediately after the end of exercise (sigma/ST/) or as ST depression per unit increase in heart rate during exercise ("m" (ST/HR]. The latter was obtained by linear regression of ST displacement and heart rate measured at three or four different workloads in the lead with the greatest displacement of the ST segment. The mean values of sigma/ST/ were 0.58 +- 0.030 mV in single-vessel, 0.97 +- 0.41 mV in double-vessel and 1.58 +- 0. 46 mV in triple-vessel disease. The mean values of "m" (ST/HR) were 0.0024 +- 0.0013 mV X min-1 X beat-1 in single-vessel, 0.0042 +- 0.0012 in double-vessel, and 0.0078 +- 0.0033 in triple-vessel disease. These differences were highly significant (p less than 0.01 - 0.001) and there was only minimal overlap between the single- and triple-vessel groups. Digitalis caused a slight (statistically nonsignificant) increase in sigma/ST/ but not in "m" (ST/HR).

Adrenergic beta-Antagonists↗
PubMed1984

Value of chest radiography in adult respiratory distress syndrome.

In a prospective investigation of 19 patients with traumatic (n = 11) and septic (n = 8) shock at risk of developing the adult respiratory distress syndrome (ARDS), serial chest films were monitored. Eight patients developed ARDS, 2 following traumatic shock and 6 following septic shock. Only 2 of these 8 patients exhibited radiographic abnormalities consisting in bilateral widespread infiltrates of the alveolar type. In the 2 patients ARDS had already developed before artificial ventilation with positive end expiratory pressure (PEEP) was instituted. In the other 6 patients, in whom ventilator treatment with PEEP was initiated prophylactically or early in the disease, the chest films remained virtually normal despite development of a marked pulmonary insufficiency. It is concluded that early ventilator treatment with PEEP counteracts the classical radiographic abnormalities of ARDS, probably by reducing alveolar oedema and atelectasis. Thus, presently, with use of early or prophylactic ventilator treatment with PEEP as a therapeutic measure against ARDS chest radiography may be of limited value in the diagnosis. However, it should be essential for early recognition of therapy requiring complications.

Adolescent↗
PubMed1983

Catheter pericardiocentesis in the postoperative period.

Catheter pericardiocentesis was performed under fluoroscopy in 52 cases. Differentiated localized injection of contrast medium was of value for inserting the needle to a suitable site in the pericardial sac. The catheter tip could be positioned in different fluid filled compartments.

Adult↗