Biomedical subjects

C Kjellström

Publications and source records attributed to C Kjellström.

22 records · Page 2Linked to original sources

PubMed1993

Decreased synapse-to-neuron ratio in rat locus ceruleus following chronic ethanol feeding.

Effects of chronic ethanol exposure on the synapse-to-neuron ratio of rat locus ceruleus were investigated. Male Sprague-Dawley rats were given an ethanol-containing liquid diet for 4 months starting at an age of 5 weeks. Littermates, given isocaloric amounts of an ethanol-free diet, served as control. The animals were perfusion fixed using a mixture of glutaraldehyde and paraformaldehyde. Synapse-to-neuron ratio was estimated by the double disector method and calculated from (Ns/A) x (Nsec -1) / (Nn/A) where Ns/A is the number of synapses per unit area estimated in a disector with a height of on section and Nsec -1 is height of the disector, i.e., the number of sections, used for estimating the number of neurons per area (Nn/A). The mean estimated synapse-to-neuron ratio was 2046 +/- 544 (SD) in ethanol-fed rats and 4291 +/- 1171 (SD) in control rats. The difference is statistically significant (p < 0.05). The finding may be of relevance for understanding the development of abuse, tolerance, drug dependence, and abstinence reactions.

Alcoholism↗

PubMed1992

Tricuspid valve insufficiency as a complication of endomyocardial biopsy.

The purpose of this study was to investigate the occurrence of major tricuspid insufficiency caused by endomyocardial biopsy in heart transplant recipients. Endomyocardial biopsy was used for the detection of rejection and Doppler echocardiography was performed at regular intervals. Six of 96 heart transplant patients (6.3%) had sudden appearance of large tricuspid regurgitation, all of which were directly related to a preceding biopsy. Chordal tissue was identified histologically in biopsy samples of all six patients. All patients developed symptoms of right ventricular failure which was confirmed by right heart catheterization. Three patients subsequently underwent valvuloplasty for ruptured chordae tendineae of either of the three leaflets. Two of these three patients were free from symptoms during follow-up, but the third patient developed moderate tricuspid regurgitation and clinical symptoms. It is concluded that endomyocardial biopsy, although it is the most useful tool for detection of rejection, should be used with caution with regard to anatomical structures and the risk of damage to the tricuspid valve must not be neglected. It is also concluded that valvuloplasty of the tricuspid valve can be successfully performed in a transplanted heart.

Adolescent↗

PubMed1991

The metabolism of ethyl esters of fatty acids in adipose tissue of rats chronically exposed to ethanol.

The concentration of ethyl esters of fatty acids as well as the activity of the enzyme synthesizing these esters (fatty acid ethyl ester synthase) were determined in adipose tissue of rats ingesting ethanol (9-16 g/kg body weight/day) for different periods of time. After 10 and 17 weeks of ethanol exposure about 300 nmol of ethyl esters of oleic, palmitic, stearic, and linoleic acids were found per gram adipose tissue. The ethyl esters disappeared after 1 week of abstinence. Closer analyses, using radioactive ethanol, revealed a half-life of the esters of less than 24 hr. The bulk of the esters was found in a membrane preparation of isolated adipocytes. Hormone-sensitive lipase hydrolyzed emulsified ethyl oleate as efficiently as that of trioleoylglycerol, but in mixed ethyl oleate/trioleoyl glycerol particles the hydrolysis of ethyl oleate was slower, suggesting a decreased accessibility. Synthase activity was found in adipose tissue from rats not exposed to ethanol. It doubled after 10 and 17 weeks of ethanol and decreased with a half-life of at least a week after abstinence. It was concluded that ethyl esters of fatty acids are formed in rat adipose tissue as previously shown in other tissues. They seem to be stored mainly in membranous parts of the adipocytes. Synthase activity is induced by ethanol. The elevated activity has a longer half-life, and may be useful as an indicator of alcohol abuse.

Acyltransferases↗

PubMed1989

Laser Doppler flowmetry in experimental mesenteric vascular occlusion.

The performance of the laser Doppler-signal (measuring blood flow) and the direct current-signal (measuring the amount of backscattered light) were studied in isolated segments of feline small intestine during arterial or venous occlusion. Following total arterial or venous occlusion, the LD-signal rapidly fell to 16% and 29% of control values, respectively. The DC-signal decreased significantly (to 78% of control, p less than 0.001) in response to venous occlusion but did not change significantly following arterial occlusion. After total venous occlusion, the amount of backscattered light was sometimes insufficient to allow flow measurement, probably due to high light absorption in the congested tissue. After ligation of the vascular stalk, the LD-signal soon decreased to 10-15% of control but did not reach the baseline until 4-6 hours. It is suggested that this residual LD-signal is caused by activity in the muscularis layer in the early phase of intestinal infarction.

Animals↗