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Biomedical subjects

G Ruhn

Publications and source records attributed to G Ruhn.

At least 19 recordsLinked to original sources
PubMed1990

The enterochromaffin cells in the mouse gastrointestinal tract after streptozotocin treatment.

Effects of 5 weeks streptozotocin treatment on the mouse gastrointestinal tract were studied with special emphasis on enterochromaffin (EC) cells. In the streptozotocin-treated animals the frequency of EC cells was reduced in the antral area and in the small intestine, but increased in the colon. The length of the intestinal tract and the mucosal thickness were increased in these animals. Possible mechanisms underlying these abnormalities of the EC cell system are discussed.

Animals↗
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↗
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↗
PubMed1984

Assessment of lung water content by roentgen videodensitometry.

In 17 anesthetized and mechanically ventilated pigs, different degrees of lung injury were induced by iv infusion of oleic acid (mean dose 0.1 ml/kg). The change in radiologic density of the chest was measured by a videodensitometer before and 4 h after oleic acid infusion. The lungs were then removed for determination of the wet/dry weight ratio (WW/DW). The change in radiologic density was significantly correlated to WW/DW (r = .87) and to the changes in end-inspiratory pressure (r = .80), mean pulmonary arterial pressure (r = .77) and venous admixture (r = .79), but not to changes in the oncotic-hydrostatic pressure gradient of the lungs (r = .46). Roentgen videodensitometry appears to be a useful method for assessing changes in extravascular lung water content.

Absorptiometry, Photon↗
PubMed1983

Measurement of regional lung blood flow by videodensitometry.

The pulmonary blood flow in patients with embolism, emphysema or a tumour of the lung was measured by videodensitometry in 27 lungs from 17 patients. The results suggest that the relative regional and total lung blood flow can easily be estimated. It is also easy to demonstrate abnormalities in the distribution of the lung blood flow. The mean transit time in the normal lung is considered to be 1.5 to 4 seconds.

Absorptiometry, Photon↗
PubMed1982

Computerized quantitation of atherosclerosis in an experimental model. Arteriography and microdensitometry.

Model investigations for computerized quantitation of atherosclerotic plaques by a combination of arteriography and microdensitometry were performed. The correlation between real and densitometrically determined plaque volumes was high (r = 0.987) in examinations of randomly distributed plaques. The results indicate that this method can be useful in the clinical examination of patients with atherosclerosis.

Angiography↗
PubMed1981

Regional renal function measured by videodensitometry.

The videodensitometric method was applied for the determination of regional renal blood flow and filtration fraction using 2 contrast agents, where Thorotrast represented an intravascular indicator and Angiografin will be distributed in the intravascular and interstitial space and, in addition being freely filtrable in the glomeruli. The contrast density was continuously monitored from the light intensity on a TV-screen, where the region to be analyzed could be outlined by a light pen. The passage time of Angiografin analyzed from the videodensitometric curve was compared to that of 125I-labelled Angiografin as analyzed in the venous effluent. The two methods yielded almost identical values. Knowing the volume of distribution of the agents, the regional blood flow could be calculated and was found to be the same for the two contrast agents used. The curves for Thorotrast showed a rapid passage with a rapid declination towards the base-line. For Angiografin the curves ended in an almost horizontal plateau reflecting the fraction of the Angiografin filtered and remaining into the tubular system. The height of the plateau was then used for the determination of the filtration fraction. The figure obtained was compared to that obtained by conventional clearance techniques, and was found to yield similar values. It is concluded that the videodensitometric method allows for evaluation of the functional characteristics of the kidney in addition to the anatomical information given by the conventional angiography performed in parallel to the videodensitometric measurements.

Animals↗
PubMed1980

Videodensitometry and thermodilution for measuring left ventricular function.

In animal experiments contrast medium and physiologic saline were found to be equivalent as indicator substances in thermodilution. The ejection fraction is determined with approximately the same accuracy with thermodilution as with videodensitometry. The cardiac output, on the other hand, is smaller when determined with videodensitometry than with thermodilution. The results indicate that thermodilution gives too high values.

Animals↗
PubMed1980

Coronary by-pass operation--graft and left ventricular function.

Of 121 patients surviving a by-pass operation 114 have been folowed up hitherto. At first follow-up - usually one year after operation - the angina pectoris was relieved in 87% of the patients and in 85% at least one vein by-pass was patent. A high correlation was found between subjective result and graft patency. Advanced arterial changes at preoperative coronary angiography did not prevent good result after surgery. In about half of the patients whose pain was relieved, the left ventricular ejection fraction was increased postoperatively. However, in many patients, who were subjectively improved, the ejection fraction was unchanged or even decreased.

Adult↗
PubMed1978

Left ventricular function evaluated by videodensitometry in patients with coronary heart disease.

The ejection fraction of the left ventricle was determined by videodensitometry in 121 patients with angina pectoris. The mean value was 31 per cent. This estimation, which is easily performed by the method described, gives important and accurate information on the left ventricular function which, added to other parameters, should increase the reliability of the clinical evaluation of the patient.

Angina Pectoris↗
PubMed1977

Measurements of total and regional renal blood flow by videodensitometry.

Videodensitometry has made it possible to determine not only total but also regional blood flow within the kidney. In animal experiments good agreement was found between the measurements by videodensitometry and isotope technique, taking vein samples, using 125I-labelled Angiografin. The blood flow in 21 human kidney has been determined by both videodensitometry and Xe wash-out method. The correlation was fairly good.

Adult↗
PubMed1976

Videodensitometry in the diagnosis of aortic incompetence.

The videodensitometer has been used in a group of 20 patients with aortic incompetence and incompetence combined with stenosis. The method appears effective in the preoperative evaluation of the valvular and ventricular function of the patient. It gives objective and probably more accurate information of the regurgitation fraction and the ejection fraction than the commonly used semiquantitative methods. The method is simple to use and needs no technical changes in the roentgen equipment.

Absorptiometry, Photon↗
PubMedDate not supplied

Videodensitometry in rats with pulmonary damage due to microembolism.

Serial pulmonary angiography with videodensitometry was performed in 18 rats with pulmonary damage caused by administration of a fibrinolysis inhibitor, tranexamic acid (200 mg/kg body weight injected intraperitoneally) and bovine thrombin (500 NIH/kg body weight injected into the right femoral vein). The mean transit time (MTT) was calculated from videodensitometry, the observed area of interest consisting of approximately one-third of the right lung, including both central and peripheral parts. The impact of the pulmonary damage was analysed by morphologic methods and correlated to MTT. Although a pressure rise presumably occurred in the pulmonary circulation, no change in MTT was found after induction of pulmonary damage, indicating opening of actual and potential anastomoses between pulmonary arterioles and venules to serve as by-pass portions and as a safety-valve mechanism for the capillary bed and the right heart, respectively. Another explanation to unchanged MTT may be opening of resting capillary beds. Two rats with very severe pulmonary damage showed prolonged MTT. These rats may have suffered from cardiac failure.

Absorptiometry, Photon↗
PubMedDate not supplied

Anatomic variations of the human semicircular canals. A radioanatomic investigation.

The anatomic variations of the semicircular canals were investigated in a series of 95 plastic temporal bone preparations. The results showed a wider range of variability than has been assumed previously. An intraindividual correlation was found between the sizes of the superior and lateral semicircular canals. Observations indicate why a semicircular canal is not invariably delineated on one tomographic plane despite correct positioning for its optimum reproduction.

Humans↗