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Biomedical subjects

K Larsson

Publications and source records attributed to K Larsson.

At least 289 records · Page 16Linked to original sources
PubMed1983

Effect of castration on hypothalamic testosterone metabolism in the male rat.

In vitro studies were performed of hypothalamic testosterone (T) metabolism 30 days after castration of adult male rats. No changes were seen in T conversion into dihydrotesterone and estrogens in the castrated rats. Plasma T levels were decreased while plasma estradiol concentrations did not differ from those of intact controls. It was suggested that the hypothalamic T metabolism probably is not androgen dependent.

Animals↗
PubMed1983

Open tibial shaft fractures.

A change in the management of open tibial shaft fractures provided an opportunity for comparative study. One series of patients was treated nearly exclusively by conservative methods and compared with another series treated by external skeletal transfixation (EST). The latter method was found to be superior. In spite of a number of pin tract infections, EST led to a significantly shorter healing time and fewer pseudarthroses. EST had no effect on the duration of hospital stay.

Adolescent↗
PubMed1982

Mechanisms of anticoagulant effects of some sulphated polysaccharides.

The anticoagulant activity of a partially reduced sulphated alginic acid, a partially reduced aminated and sulphated alginic acid and sulphated guaran have been studied. The anticoagulant activities in the APTT assay were 28, 39 and 70 IU/mg respectively. None showed any activity in anti-factor Xa assay. Studies on binding to Antithrombin III - Sepharose showed that sulphated guaran and a fraction of the aminated and sulphated alginic acid was bound, whereas no binding occurred with sulphated alginic acid. The inhibition of thrombin activity by these polysaccharides was studied in purified systems with or without added Antithrombin III, using both fibrinogen clotting and chromogenic peptide substrate assays. The two alginic acid preparations showed Antithrombin III-dependent inhibition of thrombin, whereas the sulphated guaran inhibits both by Antithrombin III-dependent and independent mechanisms.

Alginates↗
PubMed1982

Patterns of motor and seminal vesicle activities during copulation in the male rat.

The interaction between behavioral and visceral events during copulation was studied in nine intact adult male Wistar rats. The motor copulatory pattern was analyzed by an accelerometric technique and the seminal vesicle pressure (SVP) was recorded through a catheter chronically inserted into the right seminal vesicle. Mounting was associated with a small broad rise in SVP that often preceded the initiation of pelvic thrusting. Penile insertion resulted in a second sharp rise in SVP superimposed on the primary wave related to mounting. A steep rise in SVP occurred during the performance of the motor ejaculatory pattern after a variable period of intravaginal thrusting. This final rise was associated with ejaculation. Analysis of the temporal relationships ships between the SVP changes and copulatory behavior revealed that each of the three rises of SVP was related to distinct patterns of stimulation, suggesting that they were mediated by separate reflex arcs.

Animals↗
PubMed1982

Plasma progesterone levels from oestrus through day 7 after A.I. in heifers carrying embryos with normal or deviating morphology.

Twenty-five dairy heifers, 11 repeat breeder and 14 virgin heifers, were used. Blood samples were taken twice a day (9 a.m. and 3 p.m.) from day of A.I. to 7 days later when embryo collection was made. One series of blood samples were taken from 16 heifers and two and three, respectively, from 6 and 3 heifers. Analysis of progesterone was performed by radioimmunoassay. The embryos were classified in 3 groups: normal blastocysts, morphological deviators, and degenerated embryos. Analysis of variance and a discriminant analysis was performed. The discriminant analysis was made to predict embryonic morphology, using daily progesterone values as predictors. No significant relationship between embryonic morphology and progesterone levels was found. The discriminant analysis showed that 64.9 % of progesterone curves were correctly classified, with individual groups ranging from 50 % (degenerated) to 76.5 % (normal embryos). It was concluded that abnormal embryonic development occurs with normal lateal function and that normal bovine embryo does not exhibit luteotrophic activity 7 days after mating.

Journal Article↗
PubMed1982

Oxitropium bromide, ipratropium bromide and fenoterol in exercise-induced asthma.

Oxitropium bromide (Ba 253) is a new inhaled bronchodilating agent with anticholinergic properties. The effect of this compound (100 micrograms) was compared to that of ipratropium bromide (40 micrograms), the beta 2-receptor stimulant fenoterol (400 micrograms) and placebo in 8 patients with exercise-induced asthma. The drugs were administered by metered dose inhalers, after which exercise test were performed on ergometer cycles at the times of the drugs' maximal effects. Forced expiratory volume during 1 S and vital capacity were recorded basally, repeatedly during 20 min after exercise and following the inhalation of isoprenaline (160 micrograms) which was given 20 min after exercise. Fenoterol possessed a very good protective effect against exercise-induced bronchoconstriction in all patients, whereas the other drugs differed very little from placebo. Thus, only 4 patients did benefit from ipratropium bromide, 1 patient from oxitropium bromide and 2 patients from placebo. No side effect occurred. In the doses used the two anticholinergic agents ipratropium bromide and oxitropium bromide were less effective than a beta 2-adrenoreceptor stimulant like fenoterol in protecting against exercise-induced asthma.

Adult↗
PubMed1982

Sympathoadrenal reactivity in exercise-induced asthma.

The possibility that sympathoadrenal activity is altered in asthma was examined in eight patients with a history of exercise-induced asthma (EIA), eight matched patients with nonexercise induced asthma (NEIA), and eight matched healthy control subjects. No medication was allowed for at least one week before examination. In a pretrial exercise test diagnosis of EIA was confirmed and each individual's work capacity (Vo2 max) was determined. The trial consisted of an orthostatic test and a standardized exercise test at 80 to 90 percent of VO2 max on a treadmill. The trial exercise test caused a decrease in FEV1 in EIA patients only, whereas measurements of Sgaw revealed a significant but less pronounced postexercise bronchoconstriction in NEIA-patients as well. Basal plasma catecholamine levels were similar in all groups. Noradrenaline and adrenaline levels were approximately doubled by the orthostatic test and increased approximately ten-fold following exercise, with no differences between the groups. Plasma cAMP levels were approximately doubled by the exercise test. In the EIA patients there was an inverse correlation between increases in plasma cAMP and decreases in Sgaw. Our study does not support earlier claims that exaggerated catecholamine response to exercise causes postexercise bronchoconstriction by alpha-adrenoceptor stimulation in EIA. Differences in study results appear to have methodologic explanations.

Adolescent↗
PubMed1982

Influence of labetalol, propranolol and practolol in patients with asthma.

The acute effect of non-selective beta-blockade alone (propranolol) or in combination with alpha-blockade (labetalol) and beta 1-selective blockade (practolol) on the airways was studied in 14 asthmatic patients. Severe bronchoconstriction was not seen in any patient after placebo (saline) or practolol (10 mg i.v.) while pronounced bronchoconstriction was seen in three patients after labetalol (20 mg i.v.) and in six patients after propranolol (5 mg i.v.). The effects of 2 weeks of oral medication with labetalol (200 mg x 2) and placebo were studied in the same patients. Four patients had symptoms of asthma during the labetalol period while none had asthmatic symptoms during the placebo period. The results suggest that coexistent alpha-adrenoceptor blockade fails to prevent asthmatic symptoms caused by beta-blockade.

Adolescent↗
PubMed1981

Reorganization and orientation of regenerating nerve fibres, perineurium, and epineurium in preformed mesothelial tubes - an experimental study on the sciatic nerve of rats.

Regeneration of severed peripheral nerves is unfortunately often incomplete, due to loss of nerve fibers and neuroma formation. A new approach is presented with the intention of improving the conditions for nerve repair. In the first of the two stages, a pseudosynovial tube is formed around a silicone rubber rod, surrounded by a stainless steel spiral, which was placed in the backs of rats. This tube, in the second stage, is used as a free "tube graft" to bridge gaps of about 10-12 mm lengths in the severed sciatic nerve. The tube was kept open by the metal spiral. Regenerating nerve fibers with their sprouts grew into the initially open space in the tube. A new nerve trunk was formed, comprised of closely packed myelinated and unmyelinated axons, organized into fascicles. Demonstration by electron microscopy and by EMG recording of reinnervation of foot muscles supported successful long-term results. The fascicles were delimited by perineurial and epineurial sheaths and, furthermore, showed signs of maturation. It was also demonstrated that the nerve-fiber regeneration ceased after a few weeks if there was no distal nerve inserted into the tube. The importance of optimizing the interaction between local factors and regenerating nerve fibers for reestablishment of functionally valuable motor units is discussed.

Animals↗
PubMed1981

Creatine kinase in tibial shaft fractures. Serum creatine kinase levels in patients with tibial shaft fractures.

The creatine kinase (CK) activity of the serum of 33 male and 24 female patients with tibial shaft fractures has been assayed. In 40 of the 57 patients the CK level surpassed the maximal normal limit of 1.7 mukat/l. Patients with fractures due to direct violence had significantly higher levels than those with fractures due to indirect violence. When the fracture was displaced the CK level was more often abnormal than when there was no displacement. Patients with extensive swelling of the injured leg had significantly higher levels than patients with minor or no swelling. CK determinations could be used to quantify muscle injury.

Adolescent↗
PubMed1981

Aqueous lipid phases of relevance to intestinal fat digestion and absorption.

The phase behavior of monoglyceride/water systems, with oleic and linoleic acid as the dominating fatty acid residues, was investigated. Increased solubilization of triglycerides (oil) or oleic acid in the cubic liquid-crystalline phase formed by monoglyceride and water resulted in the formation of a reversed hexagonal liquid-crystalline phase followed by an L2-phase. The liquid-crystalline phases have different dispersion properties compared to each other in dilute micellar bile salt solutions. The cubic phase is found to be easily dispersed. The relevance of aqueous lipid phases other than micellar is discussed in relation to intestinal lipid digestion and absorption.

Bile Acids and Salts↗