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Biomedical subjects

E Andersson

Publications and source records attributed to E Andersson.

At least 109 records · Page 6Linked to original sources

Creativity in old age: a longitudinal study.

A creativity test was administered to a selected sample of 52 subjects all 70 years old and repeated in the same group 13 years later. The stimuli used were diffuse ink-blots coded for three components of creativity: fluency, flexibility and originality. The three components were also summed to form a composite creativity score. Repeated analyses showed no age-related changes in the creativity scores obtained at the two testing times. Furthermore, no gender differences nor age and gender inter-actions were found. The results of this longitudinal study indicate that, contrary to earlier findings from cross-sectional studies, creativity does not seem to decline significantly in old age.

Age Factors↗

Effects of castration on pituitary gonadotropic cells of the male three-spined stickleback, Gasterosteus aculeatus L., under long photoperiod in winter: indications for a positive feedback.

Male three-spined sticklebacks caught in winter were castrated or sham-operated and subsequently kept under long photoperiod at about 20 degrees for a month. With this treatment the sham-operated fish attained breeding condition. The gonadotropic cells of the sham-operated fish contained significantly more dilated endoplasmic reticulum and fewer granules than those of the castrated fish, indicating a higher secretory activity of the gonadotrops in the sham-operated fish. These findings suggest the existence of a physiological positive feedback within the gonadal-pituitary axis of the male stickleback when stimulated into its breeding condition by long photoperiod.

Animals↗

Characterization of gonadotropin-releasing hormone binding sites in the pituitary of the three-spined stickleback, Gasterosteus aculeatus.

Binding sites for gonadotropin-releasing hormone (GnRH) in stickleback pituitary homogenates were characterized using an iodinated, superactive analog of salmon GnRH (sGnRH), D-Arg6-Pro9-sGnRH-NEt (sGnRHa). Binding of 125I-sGnRHa reached equilibrium after 60 min incubation at 4 degrees and was a function of tissue concentration. The specificity of 125I-sGnRHa binding was demonstrated by displacement with sGnRHa, sGnRH, and Buserelin [D-Ser(t-Bu)6-Pro9-GnRH-NEt]. Both Scatchard analyses of saturation data and displacement curves revealed a single class of high-affinity binding sites (Ka = 0.71 +/- 0.03 X 10(9) M-1, Bmax = 1087 +/- 165 fmol/mg protein).

Animals↗

Splanchnic and peripheral release of 3-methylhistidine in relation to its urinary excretion in human infection.

The present investigation was undertaken in order to determine the release of 3-methylhistidine (3MH) from the splanchnic region and from the leg, and the contributions these make to the increase in urinary 3MH excretion in infection. Thirteen febrile patients with infection were investigated. After an overnight fast, hepatic vein, femoral vein, and radial artery catheterizations were performed. Splanchnic and leg blood flows were determined by dye dilution technique. Plasma 3MH was analyzed by a modified HPLC method. The release of 3MH from the leg was 0.064 +/- 0.007 mumol/min (+/- SE) and from the splanchnic region 0.012 +/- 0.013 mumol/min. These releases of 3MH constitute 27% +/- 2% and 8% +/- 6% of the individual urinary excretions, respectively. With increasing degree of catabolism, measured as individual 3MH increase above baseline excretion or as the 3MH to creatinine ratio (3MH:Cr), the relative contribution to urinary excretion from the leg was increased (individual increase, P = 0.08; 3MH:Cr, P less than 0.01). Since this contribution was not decreased in the more catabolic patients, as would have been expected if the increase in urinary 3MH originated elsewhere, it is concluded that skeletal muscle is the source, and these results thus validate the use of urinary 3MH excretion as a marker of myofibrillar protein catabolism in infected patients.

Adult↗

Exchange of 3-methylhistidine in the splanchnic region in human infection.

This investigation was undertaken to determine the splanchnic exchange of 3-methylhistidine (3MH) in infection. Hepatic vein, femoral vein, and radial artery catheterizations were performed in 12 febrile patients with infections of varying severity. Differences in arteriovenous 3MH, analyzed by high-performance liquid chromatography, were multiplied by the plasma flows, determined by a dye dilution technique. The mean splanchnic efflux was 0.062 +/- 0.180 mumol/min (mean +/- SD) with uptake occurring in five patients. The splanchnic uptake was significantly (p less than 0.001) correlated with the urinary 3MH excretion and the peripheral release from the leg. It is concluded that in human infection, splanchnic 3MH release is low and in patients with high rates of myofibrillar catabolism there may even be an uptake. The urinary 3MH excretion is still a marker of myofibrillar protein breakdown because it correlates well with the release from the leg, regardless of whether the patient has a splanchnic uptake or a release.

Chromatography, High Pressure Liquid↗

Aromatase activity in the brain of the three-spined stickleback, Gasterosteus aculeatus. III. Effects of castration under different conditions and of replacement with different androgens.

Non-breeding stickleback males were gonadectomized or sham-operated in winter. They were then exposed to a high temperature and either a short photoperiod which did not induce breeding or to a longer, stimulatory, photoperiod. In the latter experiment empty Silastic capsules or capsules filled with the aromatizable androgen, androstenedione or the non-aromatizable androgen, 11-ketoandrostenedione were implanted intraperitoneally in the operated fish. Furthermore, males that were already in breeding condition were gonadectomized or sham-operated in late spring. Brains were freeze-sectioned and punches from the nucleus preopticus-nucleus anterioris periventricularis region were incubated with [19-3H]-androstenedione. After extraction of steroids with CH2CI2, the tritium activity remaining in the water phase gives a measure of aromatization as tritiated water and formic acid are formed when [19-3H]-androstenedione is aromatized to oestrogens. The aromatase activity was higher in sham-operated than in castrated fish in all three experiments. Both androstenedione and 11-ketoandrostenedione abolished the effect of gonadectomy on aromatization.

Androgens↗

Aromatase activity in brain and pituitary of immature and mature Atlantic salmon (Salmo salar L.) parr.

Brain homogenates from Atlantic salmon parr converted tritiated androstenedione to testosterone, estrone, and 17 beta-estradiol. The formation of estrogens was markedly higher in homogenates of whole brains from mature parr males than from immature parr males. The highest estrogen synthesis was found in the telencephalon and diencephalon. In both of these parts the estrogen production was higher in mature males than in immature males. There was no difference in estrogen formation by pituitaries from immature female and immature male parr, whereas the formation of estrogens and testosterone was higher in the mature male parr.

Age Factors↗

Trunk muscle strength in athletes.

Maximal voluntary strength of the trunk muscles was measured in 57 male elite athletes (soccer players, wrestlers, tennis players, and gymnasts), 14 female elite gymnasts, and in a normal group of 87 conscripts. Mean ages in the different groups ranged from 18-22 yr. An isokinetic (constant velocity) technique was used to record maximal torque produced by trunk and hip muscles during flexion, extension, and lateral flexion over the range of motion. The constant angular velocities used were 15 deg.s-1 and 30 deg.s-1, respectively. Isometric strength was measured in a straight body position (0 deg. of flexion). The measurements were made with the subjects in a horizontal position with the pivot point at the hip and at the lumbar (L2-L3) level. All male athlete groups showed higher peak torque values than the normals. The differences were largest in hip extension and trunk flexion. The male gymnasts also showed significantly higher peak values in hip flexion as compared to all other categories. There was no difference in strength per kg body weight between female gymnasts and untrained males, except in trunk extension. The position for peak torque occurred earlier in the movements for the athletes, especially for the gymnasts in extension movements and for the tennis players in flexion movements. In isometric contractions essentially the same strength differences were present as in the slow isokinetic contractions. In lateral flexion wrestlers and tennis players showed significantly higher strength in movements toward the nondominant side. Thus, differences were present between the athletes and the normals, some of which appeared to be sport specific and related to long-term systematic training.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

Leg ulcer epidemiology in Gothenburg.

Patients with ulcers on the legs and feet due to vascular disorders in Gothenburg 1980 were selected for this retrospective survey of medical records. 1377 patients were found, of whom 61% were women. The median age of the women was 76 years and of the men 70 years. The ulcers were located on the feet only in 30% of the patients and on the medial sides of the ankles only in 17%. A total of 7074 outpatient visits were made. The total treatment time for the ulcer inpatients was 19947 days (nursing home patients excluded). The prevalence was estimated of 0.32% (0.2-0.4%) in the whole population. The number of patients with leg and foot ulcers increased with age. 4-5% of the population in the age interval over 80 years of age sought medical advice for their ulcers.

Adult↗

Enzyme action in polymer and salt solutions. I. Stability of penicillin acylase in poly(ethylene glycol) and potassium phosphate solutions in relation to water activity.

The stability of penicillin acylase (penicillin aminohydrolase, EC 3.5.1.11) was studied in poly(ethylene glycol) and potassium phosphate solutions. Enzyme stability measured as the half-life of the enzymatic activity and the transition temperature determined by differential scanning calorimetry, correlated well. The enzyme stability could not be related to the water activity as a measure of solute-solvent interaction. It seems to be related more to the concentration of the solutes and much less to the molecular weight of poly(ethylene glycol). The stabilizing effect of poly(ethylene glycol) is also discussed in terms of poly(ethylene glycol)-protein interactions.

Amidohydrolases↗

Enzyme action in polymer and salt solutions. II. Activity of penicillin acylase in poly(ethylene glycol) and potassium phosphate solutions in relation to water activity.

Increasing concentrations of poly(ethylene glycol) and potassium phosphate solutions decreased the enzymatic activity of penicillin acylase (penicillin aminohydrolase, EC 3.5.1.11). Low molecular weight poly(ethylene glycol) reduced the penicillin acylase activity more than high molecular weight poly(ethylene glycol). The decrease in enzymatic activity seemed to be related to the decrease in water activity in solutions containing poly(ethylene glycol), irrespective of the molecular weight of the polymer. The decrease in enzymatic activity in potassium phosphate solutions was lower than in poly(ethylene glycol) solutions and did not fit the water activity relationship. The decreased enzymatic activity is discussed in relation to the enzyme stability in these solutions.

Amidohydrolases↗