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Biomedical subjects

U Kujala

Publications and source records attributed to U Kujala.

27 records · Page 2Linked to original sources

Effects of a long acting somatostatin analog on pituitary, adrenal, and testicular function during rest and acute exercise: unexpected stimulation of testosterone secretion.

The purpose of this study was to delineate the possible endocrine effects of exercise-induced GH secretion. Twelve healthy adult males were studied during short (20 min) and subsequent prolonged (2 h) physical exercise and recovery period (2 h), both after injection of a long acting somatostatin analog [Sandostatin (ST); 0.1 or 0.05 mg, sc] and after a control saline injection. Additional subjects were studied during rest with similar injections of ST (0.1 mg) and saline (n = 7) or using a lower ST dose (0.01 mg; n = 6). Several venous blood samples were taken during the trials and analyzed for selected hormones, monitoring pituitary, testicular, and adrenal functions. ST injection blocked the serum GH response to short term maximal bicycle ergometer exercise, but not to the following prolonged bicycle exercise. No relationship of the exercise-associated GH increase to the concomitant endocrine responses of the adrenals and testes was observed. Unexpectedly, the higher ST doses (0.1 and 0.05 mg) increased the mean levels of serum testosterone by 18-25% in both exercise (P = 0.0017) and rest trials (P < 0.0001), respectively. ST did not affect the levels of LH, FSH, or cortisol. ST slightly increased serum sex hormone-binding globulin (3%; P = 0.021) and albumin (4%; P = 0.017) concentrations, but not that of free testosterone. Because the testosterone response to somatostatin was fast and without a simultaneous increase in LH, it was consistent with a direct testicular response. The explanation for this novel ST effect remains obscure, but it may be due to modulation of some paracrine mechanisms inhibiting testicular steroidogenesis.

Adrenal Glands↗

Stress fracture of the medial malleolus.

We studied eight patients who had a stress fracture of the medial malleolus. The main symptom was localized pain on the medial side of the ankle. The initial radiographs revealed the lesion for only three patients; for the other patients, the diagnosis was made with the use of isotope scans and was confirmed with computerized tomography scans, magnetic resonance images, or subsequent plain radiographs. One vertical fracture was treated initially with compression with AO screws. On the basis of our experience with stress fractures in other bones, drilling was performed to enhance the formation of bone in two patients who had delayed healing and who had had symptoms for eight and twelve months. The fractures healed four and five months after the drilling. The five patients who were managed non-operatively had to avoid running and jumping for at least three months (average, four months) so that healing could take place. All five of these fractures healed within five months.

Adolescent↗

Response of the trunk muscles to training assessed by magnetic resonance imaging and muscle strength.

A group of 12 sedentary medical students (1 man and 11 women aged 21-27 years) participated in a strength training programme for the trunk muscles lasting 18 weeks. The maximal isometric flexion and extension forces of the trunk muscles were measured before the training and at 18 weeks by dynamometer. The cross-sectional area of the back muscles, i.e. erector spinae, multifidus and psoas muscles, was measured from magnetic resonance images (spin echo sequence TR/TE 1500/80, slice thickness 10 mm) obtained at the L4-L5 disc level before the training, at 11 and 18 weeks. During training, no significant change in the body mass or body fat content was found. Muscle forces or muscle cross-sectional area were not related to body mass. There was a significant increase in both trunk muscle cross-sectional area (psoas muscle P < 0.001 and back muscles P < 0.01) and trunk muscle forces (flexion and extension forces P < 0.01) during the training but no direct association between the muscle cross-sectional area and strength of the flexors and extensors was detected before or after the training.

Adipose Tissue↗

Motor ability and personality with reference to soccer injuries.

Thirty-seven male soccer players performed a series of motor ability tests and answered the Sixteen Personality Factor Questionnaire (the 16PF). A past-injury examination and interview was performed by a physician and occurrence of injuries was followed up prospectively for one year. Stepwise regression analyses revealed significant associations between past injuries and long reaction time as well as personality factors N (astute) and H (shy). We conclude that both weakness of motor abilities, especially long reaction time, and a specific personality type may predispose a player to soccer injuries.

Adolescent↗

Pyruvate dehydrogenase activity in Streptococcus mutans.

Streptococcus mutans NCTC 10449 and Escherichia coli K-12 strain 37 were grown under aerobic and anaerobic conditions. In cell extracts of both strains, pyruvate dehydrogenase activity dependent on thiamine pyrophosphate, coenzyme A, and NAD was shown. The enzyme was induced by pyruvate in the growth medium, and there was higher activity in aerobically grown cells than in anaerobically grown cells. Acetyl phosphate was a potent inhibitor of the activity. This inhibition was partly overcome by inorganic phosphate.

Ferricyanides↗

Injury profile in ice hockey from the 1970s through the 1990s in Finland.

The aim of this study was to investigate the incidence, types, and mechanisms of injury in Finnish ice hockey players at the highest competition level in different decades. Several teams were observed prospectively during the seasons between 1976 and 1979, and in the 1988 to 1989 and 1992 to 1993 seasons. An injury was defined as any sudden trauma requiring examination and treatment by a physician. The inclusion criteria were the same during the entire study. A total of 641 injuries were recorded. The injury rate per game increased significantly from 54 per 1000 player-hours in the 1970s to 83 per 1000 player-hours in the 1990s. The injury profile in the 1980s and 1990s differed from that in the 1970s. Per 1000 player-years, the rate of contusions as well as of sprains or strains increased significantly with each decade. Checking and unintentional collision with an opponent were common mechanisms of injury throughout the study, and the rate of injury by these mechanisms has continually increased. In conclusion, we suggest that there has been an increase in rough body contact between players, causing an alarming increase in the rate of ice hockey injuries.

Athletic Injuries↗