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Biomedical subjects

K Höglund

Publications and source records attributed to K Höglund.

5 recordsLinked to original sources

Effect of statins on beta-amyloid metabolism in humans: potential importance for the development of senile plaques in Alzheimer's disease.

According to the amyloid cascade hypothesis, both familial and sporadic Alzheimer's disease (AD) is caused by the toxic effect of over-production and/or aggregation of beta-amyloid (Abeta). Recent cell and animal studies have linked the production of Abeta to high levels of cholesterol and the use of statins, compounds inhibiting the de novo synthesis of cholesterol. Epidemiological studies have also supported such linkage by showing a reduced prevalence of AD for subjects taking statins. A limited number of clinical studies have been published trying to elucidate the effect of statin treatment on amyloid precursor protein (APP) processing and metabolism of brain cholesterol in AD in humans and this review focuses on the current state of these clinical studies. The results are contradictory, but the overall interpretation suggests that statin treatment probably does not have a direct impact through lowering of cholesterol on the APP processing and Abeta production in humans. To confirm this, further clinical studies needs to be performed with extended treatment periods and where several parameters (lipid profile, lipoproteins, sterols, biomarkers related to AD and APP metabolites) are analyzed, both in the cerebrospinal fluid and plasma. The pleiotropic effects of statins should be investigated further. One approach is presented in this review.

Alzheimer Disease↗

Low intensity heart murmurs in boxer dogs: inter-observer variation and effects of stress testing.

Inter-observer variation in the detection and grading of low intensity heart murmurs in boxer dogs was investigated. Six veterinarians with different levels of experience examined 27 boxers by cardiac auscultation. The dogs were auscultated before and after exercise, and the results were compared with phonocardiographic and echocardiographic examinations performed at rest and during two different stress tests. A subvalvular aortic ridge was identified in six dogs on two-dimensional echocardiography. Using dogs with low intensity murmurs or dogs free of heart murmurs, inter-observer agreement was positively correlated to the level of experience at rest (weighted kappa [kappa] 0.14 to 0.75), while the agreement was poor after exercise (weighted kappa 0.01 to 0.36). The presence of a subvalvular aortic ridge was associated with higher aortic flow velocities (P<0.002) and higher auscultatory murmur grading (P<0.001). There was an increase in murmur duration during one kind of stress test (P<0.001) and in aortic flow velocity during the other (P=0.001).

Animals↗

Physiological reactions to fear provocation in dogs.

Fear is a common behavioral problem in dogs. In this paper, we studied the association between behavioral and physiological responses in two potentially fear-eliciting situations. The aim was to establish whether it is possible to separate dogs of the collie breed that are fearful of floors and gunshots from those that are not by studying changes in heart rate and hematocrit, plasma cortisol, progesterone, testosterone, vasopressin, and beta-endorphin concentrations. Thirteen privately owned male dogs of the collie breed were studied during a floor test, using different types of floors, and a subsequent gunshot test. Seven of the dogs were identified as being fearful of floors and six were declared as fearless. Out of the 13 dogs, seven were fearful of gunshots and six were fearless of gunshots. Since fear of floors did not always occur concomitantly with fear of gunshots, there were consequently four different groups of dogs. The heart rate increased during the floor test in all groups, but dogs that were fearful of floors had higher heart rates than dogs that were fearless of floors. Dogs that were fearful of gunshots had higher heart rates, higher hematocrit levels and higher plasma concentrations of cortisol, progesterone, vasopressin, and beta-endorphins during the gunshot test than did dogs that were found to be fearless of gunshots. Plasma cortisol and progesterone increased drastically during the gunshot test in dogs identified as being fearful of gunshots. In fearful dogs, the testosterone concentration increased after completion of the floor test and before the gunshot test started, but there were no significant differences in testosterone between the groups. Since dogs fearful of gunshots had increased levels of several physiological parameters, the results demonstrated that this fear is a serious stress for the individual, a fear which it is possible to register with physiological variables.

Adaptation, Physiological↗

A high exercise load is linked to pathological weight control behavior and eating disorders in female fitness instructors.

Demographic data, exercise habits, weight control behavior, attitudes towards body shape, eating disorder (ED) experience, and menstrual regularity among female fitness instructors were descriptively assessed. A 60-item questionnaire was sent to 295 female fitness instructors at eight fitness centers. Responders (57%) reported a mean weekly exercise load of 5.5 h week(-1) (SD 2.6), which indicates frequent training, however, less than that of athletes. Overall, 35% reported ED experience (DSM-IV criteria), with an onset at 15-17 years of age. The problems had lasted 5-7 years, and 20% of the entire group reported recovery, however, 11% still had EDs. For the entire group, it was found that a high weekly exercise load was linked to a pathological weight control behavior. Fitness instructors with an active ED exercised more than instructors who never had an ED or who had a past ED. Menstrual irregularity was more common among instructors who did not use contraceptives (14%), compared to those who did (5%). As ED experience and pathological weight control behavior were common in the studied group, the importance of guidelines regarding communication from female fitness instructors about healthy training habits to regular exercisers is discussed in the article.

Adolescent↗