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Biomedical subjects

E Stranden

Publications and source records attributed to E Stranden.

At least 55 records · Page 3Linked to original sources
PubMed1988

Measurements of common femoral artery flow velocity in the evaluation of aortoiliac atherosclerosis. Comparisons between pulsatility index, pressures measurements and pulse-volume recordings.

Blood flow velocity in the common femoral artery was measured in 52 limbs of 45 patients with radiologic signs of aortoiliac atherosclerosis. Group A limbs had significant obstruction of the aortoilac segment; group B had not. 'Significant' implied a transobstruction pressure gradient of greater than or equal to 10 mmHg at rest or greater than or equal to 20 mmHg after intra-arterial injection of papaverine. Pulse-volume recording (PVR) and non-invasive measurement of the common femoral artery pressure (FAP) were also performed. Pulsatility index (PI) less than 3.9 and PVR amplitude less than 13 mm indicated significant obstruction, whereas PI greater than 5.4 and PVR amplitude greater than 20 mm were observed only in limbs without significant pressure gradient across the aortoiliac segment. PI 3.9-5.4 and PVR amplitude 13-20 mm were found in both groups. FAP and flow velocity during reactive hyperemia did not adequately distinguish the two groups, because of value overlap. In assessing the hemodynamic significance of aortoiliac obstruction, PI and PVR in the common femoral artery may be useful supplements to clinical examination, but measurement of the pressure gradient across the aortoiliac obstruction before and after vasodilation probably is most reliable.

Aged↗
PubMed1987

Arterial blood flow in deep venous thrombosis of the lower limbs.

Calf blood flow was measured in 19 patients with deep venous thrombosis (DVT) of the lower limb using a mercury strain gauge. The affected limb had a significantly (P less than 0.05) higher blood flow (2.9 +/- 1.4 ml/min. 100 g of tissue) then the contralateral limb (2.3 +/- 1.2 ml/min. 100 g). Blood flow velocity in the common femoral artery measured with a pulsed Doppler ultrasound flowmeter in 13 patients was also significantly (P less than 0.05) higher in the limb with DVT (6.6 +/- 2.8 cm/s) compared to the contralateral limb (5.3 +/- 3.0 cm/s). Interstitial fluid hydrostatic pressure (Pif) was measured by the "wick-in-needle" technique in the deep posterior compartment of the leg. There was a significant (P less than 0.001) increase in the limb with DVT (6.3 +/- 5.5 mmHg) compared to the contralateral limb (1.2 +/- 3.4 mmHg).

Aged↗
PubMed1987

Ketanserin in intermittent claudication: effect on walking distance, blood pressure, and cardiovascular complications.

In a 7-center Scandinavian double-blind placebo-controlled study of 179 patients with intermittent claudication, the effect of the serotonin antagonist ketanserin was evaluated on walking distance, brachial and ankle blood pressure, and symptoms. For all centers together, pain-free walking distance was significantly increased after 6 months with both ketanserin (+65%; 71 patients) and placebo (+42%; 78 patients), with no significant difference. However, there was large variability among centers. Classification of "responders" (doubling of walking distance) and patients who deteriorated (decrease of walking distance or dropout for inefficacy) showed significantly more patients responding and significantly fewer patients deteriorating with ketanserin than with placebo. Systemic blood pressure was significantly decreased by ketanserin in hypertensive, but not normotensive, patients, while ankle pressure was unaffected. The incidence and nature of side effects were equal with ketanserin and placebo, but there were more side effects causing dropout in the ketanserin group. An unexpected and possibly important observation was the occurrence of six serious cardiovascular events (myocardial infarction, cerebrovascular complications, and development of rest pain) in the placebo group but none in ketanserin-treated patients. Moreover, there were four additional similar complications in the placebo run-in period. Ketanserin appears to be beneficial in a subgroup of patients with intermittent claudication. A fortuitous finding of this study is that ketanserin might possess a protective effect against thrombovascular complications in patients with intermittent claudication.

Adult↗
PubMed1986

Radon in Norwegian dwellings and the feasibility of epidemiological studies.

The results of a pilot study on radon in Norwegian dwellings are presented together with a discussion on the feasibility of an epidemiological study on the correlation between lung cancer and radon progeny exposure in dwellings. There are large variations in the mean radon concentration in Norwegian municipalities, and the population average indoor radon concentration is high (80-100 Bq m-3). The large variations and high absolute values, together with excellent lung cancer and smoking habit data, make it feasible to conduct epidemiological studies based on representative exposure data in the Norwegian population.

Environmental Exposure↗
PubMed1986

Transcapillary forces in subcutaneous tissue of lower limbs with deep venous thrombosis.

Starling forces (interstitial fluid pressure, plasma- and interstitial fluid colloid osmotic pressures) were measured in the subcutaneous tissue of legs in 22 patients with deep venous thrombosis (DVT). For comparison, measurements were obtained in the contralateral leg and in healthy controls as well. Interstitial fluid pressure (Pif) was measured with the 'wick-in-needle' technique and we found a significantly higher pressure in limbs with DVT compared to contralateral limbs and controls. Interstitial fluid was collected from subcutaneous tissue with the 'wick technique'. Colloid osmotic pressure was measured in wick interstitial fluid (COPif) and plasma (COPpl) with an osmometer. A significant reduction of COPif was found in limbs with DVT compared to the contralateral side and controls. The COPpl was also significantly reduced in patients compared to controls. Saphenous vein pressure (Pv) measured at the ankle was significantly increased in the thrombosed limb compared to the contralateral. We conclude that the main cause of subcutaneous oedema in DVT of the lower limbs is increased transcapillary filtration caused by a rise in Pv. This leads to a fall in COPif and rise in Pif which act as oedema-preventing mechanisms.

Aged↗
PubMed1986

Human gastric blood circulation evaluated by endoscopic laser Doppler flowmetry.

Endoscopic laser Doppler flowmetry was used to study gastric blood circulation in 34 healthy subjects. This paper presents the results of methodological studies and blood flux measurements in different parts of the stomach. In the recorded curve the flux level was easy to define, even though fluctuations synchronous with heart beat, respiration, and peristalsis were visible. The temporal and spatial variations of recorded values were within acceptable limits. Angulation between the measuring probe and mucosa and moderate pressure of the probe against the gastric wall did not seem to influence the recorded values significantly. When the blood circulation was examined in different parts of the stomach, the values along the lesser curvature were significantly lower than the values along the greater curvature (p less than 0.01).

Adult↗
PubMed1986

The femoral arterial flow velocity pattern in patients with aortoiliac atherosclerosis. Studies with a pulsed Doppler ultrasound flowmeter.

The femoral arterial flow velocity pattern in 164 limbs with aortoiliac atherosclerosis was analyzed preoperatively, using a pulsed wave Doppler ultrasound flowmeter. Following aortoiliac reconstruction, 32 limbs were studied. The highest (Va), the lowest (Vb) and the time average of the mean velocities (V mean) were obtained, and pulsatility index (PI = Va-Vb/V mean) was calculated. The aortoiliac obstruction was radiologically graded as reduction in cross-sectional area (less than 25%, 25-50%, greater than 50%) or complete occlusion. With increasing grade of stenosis, progressive reduction of PI (from 7.6 to 2.1) was observed. PI differed according to degree of obstruction. In 30 extremities with clinical improvement after vascular reconstruction, PI showed significant postoperative rise (from 2.7 to 6.9). In the two limbs without clinical benefit of surgery, PI was largely unaffected. A monophasic, flattened curve of femoral arterial flow velocity and reduced PI may indicate aortoiliac atherosclerosis. Normalization of PI and biphasic curve following aortoiliac reconstruction suggest successful treatment.

Aged↗
PubMed1985

Sources of exposure to technologically enhanced natural radiation.

The paper presents a review of sources of enhanced natural radiation and their relative importance. Only sources that have been caused by some human technological activity are discussed, even though higher doses may be received by truly natural sources, such as radium rich ground. The distinction between "natural" and "technologically enhanced" sources and the justification of the different sources are discussed.

Coal↗
PubMed1985

Radon exhalation from the ground; method of measurements and preliminary results.

The paper will present a method for measurements of radon exhalation from the ground. The method is based on a combination of activated charcoal and TLD. This method is superior to the traditional charcoal method, because it yields a mean value for the exhalation rate during the whole in-growth time. Furthermore, by using the activated charcoal/TLD method, the decay time is not critical, because the TLD is irradiated from absorbed radon during the decay time. In this way, the method is usable for remote measurements by mail. The method has been tested in areas with "normal" ground and in areas where high indoor radon concentrations previously have been measured. Exhalation measurements were performed near to houses where the indoor radon concentrations were known, and in most cases there was a strong correlation between exhalation rate and indoor radon concentrations. The method thus seems to be usable for classification of building ground.

Radiation Monitoring↗
PubMed1985

The radiological impact of mining in a Th-rich Norwegian area.

The radiological impact of former mining activities in the Fen area in southern Norway has been assessed. The area is known to have enhanced concentrations of Th. A recent epidemiological study suggested a significant increment of lung cancer among the former miners, and the doses to the miners have been assessed. The main contributor to the effective dose equivalent in one of the mines was inhaled 220Rn progeny. Water in drilled wells and in nearby lakes has been analysed for 220Rn and Ra. Uranium and Th analyses were performed on mine and lake water. The mining activity does not seem to have contaminated drinking water significantly. The tailings from Nb production has enriched Ra and Th concentrations. The tailings and the possible use of waste rock from the mining are probably the most important environmental results of the mining activities.

Air Pollutants, Radioactive↗
PubMed1985

Cancer incidence among workers exposed to radon and thoron daughters at a niobium mine.

The aim of this study was to investigate the incidence of cancer among 318 male employees of a niobium mining company which was only operated between 1951 and 1965. Many of the workers, especially underground miners, were exposed to the daughters of radon and thoron and also to thorium. The accumulated doses to the workers from short-lived radon and thoron daughters in the mine atmosphere were assessed to be relatively low; up to 300 working-level months. During the follow-up period 1953-1981, 24 new cases of cancer were observed compared to an expected number of 22.8. Twelve cases of lung cancer had occurred versus 3.0 expected. Among the 77 miners, 9 cases of lung cancer were observed against 0.8 expected. Associations between the occurrence of lung cancer and exposure to alpha radiation and smoking were found. For the radon and thoron daughter exposure, about 50 excess cases per million person-years at risk per working-level month were observed.

Adult↗
PubMed1984

Rectal temperature monitoring during neodymion-YAG laser irradiation for prostatic carcinoma.

Neodymion-YAG laser irradiation is a new and promising method for curative treatment of localized prostatic carcinoma. The laser light energy is transformed into heat within the tissue, and there is a risk of unintended damage to neighbouring organs. In seven patients the temperature in the rectal mucosa was monitored during the laser irradiation of the prostatic capsule. The temperatures did not increase to dangerous levels. According to a standardized irradiation procedure based on experiences gained in this study 47 patients have been treated without complications.

Aged↗
PubMed1984

Dynamic recording of vasoconstrictor response to increased vascular transmural pressure. A study in patients with lower limb atherosclerosis.

Ultrasound Doppler flowmetry during local exposure to subatmospheric pressure (limb negative pressure exposure--LNPE) was used to study the effect of increased transmural pressure on femoral artery blood flow. Twelve healthy controls and patients with lower limb atherosclerosis--before (n = 11) and after (n = 18) femoropopliteal reconstruction were included in the study. One minute after onset of LNPE blood flow in the common femoral artery was reduced by 46% in controls, which implies increased arterial tone at increased transmural pressure (veno-arteriolar vasoconstrictor response). In patients with lower limb atherosclerosis the average blood flow during LNPE was not different from blood flow at rest. In 3 patients with pain at rest blood flow increased 25% during exposure, indicating reduced arterial tone. This finding is consistent with the clinical experience that patients with ischemic pain find relief by lowering their legs. Following femoropopliteal reconstruction the vasoconstrictor response was absent during the first days; but appeared approximately one week postoperatively. Thus impaired arteriolar regulatory mechanisms may be one causative factor for the initial formation of local edema frequently observed after arterial reconstruction.

Adult↗
PubMed1983

Assessment of the radiological impact of using fly ash in cement.

The radiological consequences of using fly ash as a component of cement are discussed. Measurements of the activity concentrations of the fly ash and cement are reported together with measurements of emanation coefficients and exhalation rates. The radon-exhalation rate was found to be significantly lower in concrete containing fly ash than in ordinary concrete. Dose calculations suggest that fly ash will contribute to a reduction in effective dose equivalent due to the reduced radon-exhalation rate.

Air Pollution, Radioactive↗