Search PubMed⌕ Search

Biomedical subjects

T Larsen

Publications and source records attributed to T Larsen.

At least 145 records · Page 8Linked to original sources
PubMed1985

Differences in reactivity of confluent and nonconfluent cultures of human endothelial cells toward thrombin-stimulated platelets or heparinized salt solution.

This study examined whether nonconfluent endothelial cell cultures reacted differently than confluent ones toward thrombin-stimulated platelets or a heparinized salt solution. The adherence to the endothelial cell cultures of 51Cr-labeled human platelets stimulated at different thrombin concentrations was studied. There was significantly higher adherence of stimulated platelets to nonconfluent cultures compared with confluent ones. This was confirmed by scanning electron microscopy, which also revealed a tendency for the platelets to adhere at the cell periphery. Electron microscopy also showed that thrombin-stimulated platelets induced endothelial cell contraction. Part of the peripheral endothelial cell surface toward the bottom of the culture dish was inverted, facing the lumen of the dish. This phenomenon was particularly seen in nonconfluent cultures. When 51Cr-labeled endothelial cultures were incubated with a mildly injurious fluid as heparinized sodium acetate and 20% serum, at 20 degrees C for 30 min, the nonconfluent cultures showed significantly more cell detachment and release of 51Cr than the confluent ones. We conclude that under the conditions of the present experiments there are differences in the reactivity of confluent and nonconfluent endothelial cell cultures. These differences probably reflect biological dissimilarities. In experiments where properties of cultured endothelium are studied, care should be taken that the degree of confluency is standardized.

Blood Platelets↗
PubMed1985

Transperineal fine needle biopsy of gynecological tumors guided by transrectal ultrasound: a new method.

Six patients had transperineal fine needle biopsy of a pelvic mass performed guided by transrectal ultrasound. Five patients following treatment for gynecological cancer with inconclusive gynecological palpation had a transrectal ultrasound examination performed because abdominal ultrasound did not disclose abnormality. One patient with low back pain had a pelvic mass disclosed with abdominal ultrasound and was referred to transrectal ultrasound for biopsy. In all cases a pelvic lesion was visualized with transrectal ultrasound and transperineal fine needle biopsy was performed. In five cases sufficient material for cytological as well as histological evaluation was obtained showing malignant disease. In one case only necrotic tissue was obtained and subsequent operation disclosed inflammatory changes. It is concluded that transrectal ultrasound combined with transperineal biopsy is a valuable diagnostic tool in the follow-up of patients treated for gynecological cancer.

Adenocarcinoma↗
PubMed1984

Injury to human endothelial cells in culture under conditions simulating the use of vein grafts for vascular surgery.

In order to evaluate the effects of various vein graft preparation media at various temperatures, the 51Cr release from cultured human endothelial cells, and the percentage of loosened cells were determined after incubation of the cells with the media. Scanning electron microscopy (SEM) was carried out to visualize any injuring effect of the media. Incubation was performed with either heparinized sodium acetate (HS), HS with 20% human serum added (HSS), or with cell culture medium with human serum, at either 4, 20 or 37 degrees C. Incubation with HS resulted in considerable injury, measured both by 51Cr release and percentage of cell detachment. By SEM cell membrane blisters and ruptures were observed. Increasing the temperature aggravated the harmful effects of HS. HSS hampered these hazardous effects significantly, but a slight increase in 51Cr release was observed when increasing the temperature. When incubated with culture medium, both 51Cr release and percentage of loosened cells were low, even at room or body temperature. From the results of the present study it may be suggested that in order to preserve the venous endothelial lining, simple solutions like HS should be avoided for irrigation and store solution of vein grafts in surgery. As we found increased percentage of loosened endothelial cells when incubation was performed with HSS or culture medium at 4 degrees C, profound cooling probably has no beneficial effect when the endothelial cells are offered an acceptable fluid.

Acetates↗
PubMed1983

Collateral arterial capacity following acute iliac occlusion in the rat.

The development of collateral circulation after ligation of the left iliac artery was studied in 46 rats by means of microsphere distribution in muscles of both lower limbs. The radioactive microspheres were injected into the aortic root in the hyperemic phase after 5 min of cuff-induced ischemia of the lower extremities. The hyperemic response to cuff-induced ischemia as well as microsphere distribution between both lower limbs in control animals were studied separately in 23 rats. The largest hyperemic response occurred 15-30 s after cuff-induced ischemia. After iliac artery ligation, flow in the thigh increased from 43% of control value 20 min after ligation to 70% after 26 days of recovery. Flow in calf muscles increased correspondingly from 4% to 33%. This study quantifies the capacity of collateral formation following acute iliac artery occlusion.

Animals↗
PubMed1982

A multicentre placebo-controlled trial comparing the efficacy of mianserin and chlordiazepoxide in general practice patients with primary anxiety.

In a double-blind multicentre trial in general practice, 144 patients with primary anxiety received daily treatment with mianserin or chlordiazepoxide, 30-60 mg, or placebo. There were no statistically significant differences in efficacy between the three treatments in the 106 patients who completed the 6-week trial. However, there was a substantial trend in favour of mianserin (P = 0.1), but not chlordiazepoxide, over placebo as assessed by the difference in overall improvement on the Hamilton Anxiety Scale. This trend may be clinically significant since more patients dropped out from the placebo group because of lack of effect or deterioration than did from the active treatment groups, particularly during the latter part of the trial. Side effects occurred to a similarly low extent with all treatments, except that mianserin caused more weight gain and, initially, more drowsiness than placebo, while placebo produced more nausea and vomiting. Taken together with the evidence from previous trials in patients with anxiety, these results support the notion that mianserin has anxiolytic properties.

Adolescent↗
PubMed1981

Adipose tissue perfusion and fatty acid release in exercising rats.

Arterial concentrations of free fatty acids (FFA), glycerol and lactate were measured in male Wistar rats before, during and after 30 minutes exercise on a treadmill. The arterial concentration of glycerol increased 120% and lactate 340% during exercise, but fell immediately upon its termination. The arterial concentration of FFA increased only 20% during the exercise, but was followed by a sharp rise in the recovery period. Maximum FFA concentration was found after 6 minutes of recovery, reaching 70% above the preexercise level, whereafter plasma FFA fell. Using radioactivity labelled microspheres it was found that the fraction of cardiac output reaching adipose tissue after 10 min of exercise was reduced by 30-90% in relation to the resting value. After 3 min recovery, however, the fractional distribution to the same tissue was in average 300% above the value measured 3 min before termination of exercise. It is concluded that the increase in plasma FFA observed during the early recovery period is caused by increased FFA release from adipose tissue, as a consequence of increased adipose tissue perfusion in the recovery period.

Adipose Tissue↗