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Biomedical subjects

C Lassvik

Publications and source records attributed to C Lassvik.

At least 19 recordsLinked to original sources
PubMed1992

Hyperhomocyst(e)inaemia: an independent risk factor for intermittent claudication.

The aim of this study was to test the question of hyperhomocyst(e)inaemia as a risk factor for intermittent claudication (IC) independent of other important risk factors for peripheral atherosclerotic disease, such as smoking, hypertension, diabetes mellitus, hypercholesterolaemia, hypertriglyceridaemia, low levels of high-density-lipoprotein (HLD) cholesterol and age. The study population was recruited from an epidemiological study in Linköping County, Sweden, where all middle-aged men (n = 15,253, 45-69 years of age) were screened for IC. Seventy-eight subjects with verified IC and 98 healthy sex- and age-matched controls were randomly selected. Plasma levels of homocyst(e)ine (including the sum of free and bound forms of homocysteine and their disulphide oxidation products, homocystine, and homocysteine-cysteine mixed disulphide) were significantly higher (16.74 +/- 5.45 mumol l-1, mean value +/- SD, P = 0.0002) in IC subjects than in controls (13.80 +/- 3.21 mumol l-1), with 23% of the claudicants above the 95th percentile for controls. Stepwise logistic regression analysis revealed that the difference in plasma homocyst(e)ine was independent of the other above-mentioned risk factors. Moreover, the elevation of plasma homocyst(e)ine in claudicants was mainly confined to subjects with serum folate levels of less than or equal to 11.0 nmol l-1. The results suggest that folic acid supplementation should be tried in IC subjects with hyperhomocyst(e)inaemia.

Aged↗
PubMed1992

Significant association between low-molecular-weight apolipoprotein(a) isoforms and intermittent claudication.

The role of lipoprotein(a) (Lp[a]) and apolipoprotein(a) (apo[a]) isoforms in symptomatic peripheral atherosclerosis was studied in 100 randomly selected middle-aged (45-69 years) men with intermittent claudication (IC) and 100 randomly selected healthy control (C) subjects. IC and C subjects were matched pairwise for sex, age, and smoking habits. Plasma Lp(a) concentrations were significantly higher in IC subjects, with a median value of 20.12 mg/dl, compared with 11.11 mg/dl in C subjects (p less than 0.0009). The elevated Lp(a) concentration was to a great extent due to a significant difference in the frequency distribution of apo(a) isoforms between IC and C subjects (p less than 0.029). Low-molecular-weight apo(a) isoforms were more prevalent in IC than C subjects. Also, IC subjects with apo(a) S2 and S3 phenotypes had higher Lp(a) concentrations than control subjects with the same phenotypes: S2:60.70 mg/dl (IC) and 48.69 mg/dl (C), p less than 0.038; and S3: 30.18 mg/dl (IC) and 12.01 mg/dl (C), p less than 0.042, so other still-unknown factors, genetic or nongenetic, may be important. Stepwise logistic regression analysis demonstrated that Lp(a) concentration contributed significantly (p less than 0.0002) to IC, independent of age, smoking, hypertension, diabetes mellitus, plasma total cholesterol, low density lipoprotein cholesterol, high density lipoprotein cholesterol, apo B, and plasma total triglycerides. Apo(a) isoforms grouped according to molecular weight were also independent of the above risk factors associated (p = 0.016) with the occurrence of IC because of their low-molecular-weight but were not independent of Lp(a) concentrations.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1990

Effect of fish oil treatment on plasma lipoproteins in type III hyperlipoproteinaemia.

Nine patients with type III hyperlipoproteinaemia and homozygosity for the apolipoprotein E2 isoform were treated with 15 g daily of MaxEPA, a fish oil preparation rich in eicosapentaenoic acid (2.7 g daily) and docosahexaenoic acid (1.8 g daily) for 16 weeks. Plasma lipoprotein and apolipoprotein concentrations were compared with those obtained during treatment with an olive oil preparation. MaxEPA treatment decreased plasma median total cholesterol, triglyceride and apolipoprotein B concentrations by 16, 53 and 19%, respectively. Plasma median very low density lipoprotein (VLDL)-cholesterol, triglyceride and apolipoprotein B concentrations were reduced by 45, 62 and 75% respectively, while the abnormal VLDL-cholesterol/triglyceride ratio remained unchanged. Individual reductions of VLDL concentrations varied considerably, for VLDL-cholesterol between 10 and 75%. In the majority of cases the abnormal late pre beta-bands on agarose electrophoresis, typical for type III hyperlipoproteinaemia normalized to pre beta-mobility on MaxEPA treatment. LDL-cholesterol and apolipoprotein B tended to increase after 8 weeks on MaxEPA but decreased again after 16 weeks. Median plasma high density lipoprotein cholesterol and apolipoprotein A-I did not change during MaxEPA treatment. It is concluded that MaxEPA have decreasing effects on plasma VLDL lipid and apolipoprotein concentrations in apolipoprotein E2 homozygous type III hyperlipoproteinaemia but that this effect is variable and unpredictable.

Adult↗
PubMed1990

Detrusor pressure in cystometry compared to physiological filling in patients with a reflex urinary bladder after spinal cord injury.

The maximum detrusor pressure and the duration of detrusor contractions in 10-50 ml/min fill cystometry were compared to the corresponding measurements during 12 hours of physiological filling, in 18 patients with a reflex urinary bladder after spinal cord injury. In four consecutive cystometries with 10 min intervals the intraindividual variation of the maximum detrusor pressure and the duration of detrusor contractions were similar to the variation during physiological filling. The mean pressure values in cystometries of each patient correlated well with the mean values in registration during physiological filling. In cystometry, there was no significant difference between mean values in 50 ml/min filling compared to 10 ml/min filling nor between mean values in first and second cystometries compared to third and fourth cystometries. Thus, mean values from a series of 10 ml/min or 50 ml/min fill cystometries appear to be as useful as registrations during physiological filling to describe the mean maximum detrusor pressure and the mean duration of contractions in a patient with a spinal reflex bladder.

Adult↗
PubMed1989

Continuous monitoring of detrusor pressure in patients with a reflex urinary bladder after spinal cord injury.

In spinal cord injury, the detrusor pressure, as a parameter of urinary bladder dysfunction, is related to incontinence and renal complications. In order to determine the intraindividual variation of maximum pressure and duration of detrusor contractions, in patients with a spinal reflex bladder, the detrusor pressure was registered during 24 hours of physiological filling in 16 patients. Between the bladder contractions the detrusor pressure was low in all patients, indicating high bladder complicance. During contractions the maximum detrusor pressure and its duration varied both inter- and intraindividually. In individual patients, however, mean values during the initial 12 hours correlated with mean values during the final 12 hours. Thus, mean values of a series of contractions appear to be characteristic of each patient and useful in describing the voiding pressure in spinal reflex bladder.

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

Changes in skin perfusion after sympathetic block with guanethidine. Laser Doppler flowmetry in human volunteers.

Total forearm blood flow and skin microcirculation have been measured by occlusion plethysmography and by laser Doppler flowmetry (skin blood cell flux) before and after the induction of regional sympathetic block with Guanethidine. Total forearm blood flow more than doubled while the skin blood cell flux increased by 50% comparing simultaneous flows of blocked and control arms. The increase lasted for 3 days during which period the flux pattern registered by the laser Doppler flowmeter in the blocked extremities showed regular variations oscillating around the mean flux in an almost sinus wave fashion. In non-blocked arms the flux pattern registered by the laser Doppler flowmeter was highly irregular. We conclude that regional sympathetic block with Guanethidine results in an increased skin microcirculation in healthy human volunteers and that the increase lasts for 3 days. No valid conclusions can be made from this study concerning the nutritive benefit of the microcirculatory change.

Adult↗
PubMed1987

Does peroperative external pneumatic leg muscle compression prevent post-operative venous thrombosis in neurosurgery?

Post-operative deep venous thrombosis (DVT) is a frequent and potentially life-threatening complication in neurosurgery. In this field of surgery, with its special demands for exact haemostasis, prophylaxis against deep venous thrombosis with anticoagulant drugs has been utilized only reluctantly. Postoperative pneumatic muscle compression (EPC) has been shown to be effective, although there are several practical considerations involved with this method which limit its clinical applicability. In the present study per-operative EPC was evaluated and was found to provide good protection against DVT in patients with increased risk from this complication. This method has the advantage of being effective, safe, inexpensive and readily practicable.

Adult↗
PubMed1987

Cold sensitivity after replantation in relation to arterial circulation and vasoregulation.

Cold intolerance is a common problem after injuries to the hand. To elucidate the mechanism of this cold sensitivity, eight patients with successful replantations of amputations of the thumb or index finger were studied one and half years later. In six patients the Doppler signal from the anastomosed arteries was normal and in two patients signs of mild stenosis were found. All patients had normal or slightly reduced basal finger systolic pressure in the replanted finger. Six had signs of marked vasospasm. Alpha-receptor blockade had no effect on the cold-induced decrease in finger systolic pressure in the replanted finger. It is concluded that cold intolerance after hand injuries results from a defect in vasoregulation and is not caused by organic insufficiency of the circulation.

Adult↗
PubMed1987

Effects of the platelet inhibitor ticlopidine on exercise tolerance in stable angina pectoris.

Coronary blood flow might be reduced by platelet aggregates or by vasospasm induced by platelet-produced thromboxane A2. Therefore the effects of the platelet inhibitor ticlopidine (500 mg daily) on platelet function and on exercise tolerance were investigated in a double-blind placebo-controlled study in 38 middle-aged men with stable incapacitating angina pectoris. Before and after 4 and 8 weeks of treatment, exercise tests were performed in warm and cold environments. The in vitro platelet reactivity to ADP was determined at rest and the plasma levels of beta-thromboglobulin (BTG) and platelet factor 4 (PF4) were measured before and immediately after exercise. There were no signs of increased platelet activity at rest or after exercise as judged by the levels of BTG and PF4. Despite a potent inhibition of platelet reactivity to ADP in vitro during ticlopidine treatment, the exercise tolerance was reduced in exercise tests in both warm and cold environments and in daily life. Therefore platelet activity does not seem to play any significant role in exercise tolerance in the stable phase of angina pectoris.

Adult↗
PubMed1986

Duplex scanning in presumably normal persons of different ages.

Ultrasonic duplex scanning was used for flow velocity measurement in the extracranial carotid vessels in 92 presumably healthy volunteers aged 20-82 and in 14 patients aged 23-72 with normal carotid vessels on angiography. Velocities were examined as a function of age, diameter, blood pressure, side, or position in the vessel. The peak systolic velocities and late diastolic velocities in the CCA showed an age-dependent decrease (p less than 0.001), and the same was true of the peak systolic velocity in the proximal ICA on the right side (p less than 0.05) and the late diastolic velocity in the right (p less than 0.01) and left (p less than 0.001) proximal ICA. The change in velocity was inversely correlated to diameter and blood pressure. The systolic and late diastolic velocities were significantly (p less than 0.05 and 0.001 respectively) faster in the left CCA at low position than in the right, and, conversely, in the right ICA (p less than 0.05) than in the left. At CCA high position faster diastolic velocities were noted than at CCA low, on both sides. All age-dependent quotients comprised a peak systolic velocity in the CCA, whereas the quotient between the late distolic velocities in ICA and high did not show age dependency. Reproducibility of peak systolic and late diastolic velocities in the CCA, ICA, and ECA, expressed as the mean percentage difference, varied between 6.4 +/- 4.6% and 12.7 +/- 6.4%.

Adult↗
PubMed1986

Intercrural differences of arterial blood-pressure and blood-flow in new-born infants.

Intercrural systolic blood-pressure differences did not exceed 10 mmHg in 22 healthy infants who were term, pre-term or small for their gestational age (three); as measured simultaneously in both legs with 3-cm wide thigh cuffs and mercury-in-silastic strain gauges around the calves. In 13 infants with indwelling umbilical artery catheter and normal angiographic findings in both legs, blood-pressure differences were similarly low in a majority of the infants, but in three of these intercrural differences of 15-20 mmHg were found. Resting and submaximal arterial leg blood-flow, measured with venous occlusion plethysmography, showed larger intercrural differences than blood-pressure, and did not add further information. The results indicate that simultaneous systolic blood-pressure measurements in the legs, with strain gauge plethysmography, is a simple and risk-free noninvasive method, suitable, for example, for diagnosing thromboembolism in infants. An indwelling umbilical artery catheter seems to interfere very little with the arterial circulation in the catheterized leg.

Birth Weight↗
PubMed1986

Ramp-function work test suitable for automatic computation.

Heart rate (HR) response to step-function and ramp-function (20 W/min) work tests was compared in 12 healthy subjects. For a given power output (P), HR was substantially lower in the ramp tests. The HR difference increased with power output and increasing difference in work time between the test types. The HR difference can be explained in terms of a drift component (which accounts for 1/3 of the difference) and a lag component (2/3). As a consequence of the HR differences, P for a given HR is higher in ramp tests. Work capacity expressed, for example as P170, can be determined in ramp tests, and the result can be translated to step-function P170. The precision in this translation is markedly improved if a steady-state period is incorporated into the ramp test.

Adolescent↗
PubMed1985

Prospective evaluation of the accuracy of duplex scanning with spectral analysis in carotid artery disease.

Prospective evaluation of duplex scanning of the carotid vessels was performed over a 2-year period in 125 consecutive patients (249 vessels) with transient ischaemic attacks or minor stroke. Defining disease as a stenosis of greater than 15% reduction of the vessel diameter, with subgroups of 16-49% stenosis, 50-99% stenosis and occlusion, the sensitivity obtained was 96%, specificity 93% and accuracy 94%. With the use of linear multiregression analyses further subgrouping into 50-75% and 76-99% stenosis was performed. The best predictive variables were, in decreasing order, peak systolic velocity, late diastolic velocity and the difference between peak systolic and late diastolic velocity in the internal carotid artery. The additional periorbital Doppler examination caused a slight improvement in determination coefficient and diagnostic accuracy.

Adult↗
PubMed1985

Duplex scanning and periorbital pulsed Doppler in the diagnosis of external carotid artery disease: analysis of causes of error.

The external carotid arteries (ECA) were examined by duplex scanning in 123 consecutive patients with transient ischaemic attacks (TIA) and minor stroke. Two occlusions and five out of six high grade stenosis were correctly classified, yielding a sensitivity of 88% defining disease as stenosis greater than 50. Specificity was 94% and accuracy was 93%. Nine low grade stenosis (less than 50%) and six normal vessels were judged as high grade stenosis. A possible cause of this overestimation was a compensatory flow increase in the ECA caused by an occlusion or high grade stenosis in the internal carotid arteries (ICA), either on the same side or bilaterally. This was supported by the finding of a significantly (P less than 0.05) higher retrograde flow velocity in the ipsilateral supratrochlear arteries (STA) in patients with high ECA flow velocity, as compared to those with normal ECA flow. Thus in the evaluation of a possible ECA stenosis, the condition of the ICA should be considered in order to avoid overestimation of ECA lesions. The additional examination of flow direction and velocity in STA gives an indication as to whether or not an ECA stenosis might be present.

Adult↗
PubMed1979

Effects of various environmental temperatures on effort angina.

Eleven patients with effort angina and a history of cold intolerance performed short-term bicycle exercise tests at various room temperatures, 20, 10, 0 and -10 degrees C, and a few patients also at -30 degrees C. A significant reduction of maximal working capability (expressed as maximal work load, MWL), limited by moderately severe angina, was found at -10 degrees C (7% +/- 1, SEM, P less than 0.05) compared with normal room temperature. At 0 and 10 degrees C changes of MWL were small and not significant, and at -30 degrees C no further decrease of MWL was seen. About half of the patients, however, showed a tendency toward a decrease in MWL with decreasing environmental temperature, and and the decrease in MWL correlated significantly with an increase in rate pressure product (RPP) during exercise at both 0 and -10 degrees C. Thus, the decrease in working capability on exposure to cold could be explained by an increase in heart work. Warming up effects of exercise, counteracting the cold-induced increase in peripheral vascular resistance, were indicated by a diminishing difference in systolic blood pressure between a cold and normal environment with increasing work time.

Angina Pectoris↗
PubMed1978

Reproducibility of work performance at serial exercises in patients with angina pectoris.

The reproducibility of serial upright exercises in patients with ischaemic heart disease was tested. Five short term exercises (4--8 min) with continuous load increase and with 30 min rest intervals between tests were used. No tendency to change was found concerning work time to appearance of angina (APT), maximal working time (MWT) or time for disappearance of angina after exercise (DPT). The coefficient of variation was low for APT and MWT but considerably higher for DPT, being 9, 5 and 27%, respectively. MWT was considered as the end-point of choice. The ST depression at MWT showed no tendency to change and the variation was moderate (14%), while at APT and DPT the variation was high (52%), but, likewise, with no tendency to change. The maximal heart rate increased slightly and significantly (P less than 0.001), while the maximal blood pressure was constant throughout tests, thus the maximal rate pressure product tended to increase. This indicates a slight improvement of the myocardial performance at serial exercises, which, however, does not affect the reproducibility of the anginal reaction.

Angina Pectoris↗