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Biomedical subjects

T Hansson

Publications and source records attributed to T Hansson.

At least 145 records · Page 8Linked to original sources
PubMed1983

Changes in bone mineral content of the axial skeleton in relation to aging and the menopause. Results from a longitudinal population study of women in Gothenburg, Sweden.

Patterns of bone loss in the axial skeleton have been studied in a sample of Swedish women participating in a longitudinal population study which was started in 1968. In 1976, the mineral content of the lumbar spine (predominantly trabecular bone) was measured in vivo in 130 women by dual photon absorptiometry. Premenopausal or recently postmenopausal women were compared with women of identical age who had been postmenopausal for a long time. The first group was found to have significantly higher values of bone mineral content. Five years later, in 1981, the same women were re-examined with identical techniques. A slight decrease in bone mineral content with age was found in postmenopausal women. The findings were mostly in agreement with those of the first cross-sectional study, with bigger differences in bone mineral content between women of different menstrual status than between women of different age. In addition, the lower values in women with early menopause compared to those with late menopause remained in spite of increasing age.

Aged↗
PubMed1983

The amount of bone mineral and Schmorl's nodes in lumbar vertebrae.

The bone mineral areal content and the ultimate compressive strength were determined in 109 lumbar vertebrae from 36 subjects. The bone mineral areal content was related to the number, shape, and localization of the Schmorl's nodes detected in the x-rayed and sectioned vertebral bodies. One type of node, irregular in shape and localization, occurred only in the vertebrae with low bone mineral areal content values and thus in vertebrae with relatively low compressive strength. A second type of Schmorl's nodes, regular in shape and localization, did not reflect any general weakness of the vertebral bodies.

Adult↗
PubMed1983

Postural and time-dependent effects on body height and scoliosis angle in adolescent idiopathic scoliosis.

Changes in body height and scoliosis angle under the influence of gravity were studied in 40 patients with adolescent scoliosis. The average decrease in body height was 1% during a day. There were no significant changes in the mean angles of the scoliosis curves during the day. The patients were grouped according to age, standing and sitting heights, weight and skeletal maturation. A decrease in the scoliosis angles occurred in younger, more skeletally immature and lighter individuals, while an increase occurred in older, more skeletally mature and heavier individuals. The difference between the scoliosis angles measured from standing and supine views was also analyzed. The correction of the scoliosis angle in the supine position was on average 19%. No correlation was found between the change in angle and any of the growth factors studied. There was also no correlation between the change in angle and the degree of curvature.

Adolescent↗
PubMed1982

Androgenic regulation of hepatic metabolism of 4-androstene-3,17-dione in the rainbow trout, Salmo gairdnerII.

The metabolism of 4-androstene-3,17-dione by liver microsomes from the juvenile rainbow trout, Salmo gairdnerii, was studied in vitro. Administration of testosterone, 11 -oxotestosterone, dihydrotestosterone or 17 alpha-methyltestosterone to juvenile fish significantly increased mean hepatic 17-hydroxysteroid oxidoreductase (17-HSOR) activity. Androgen treatment tended to increase the total cytochrome P-450 content significantly in liver microsomes from 11-oxotestosterone-treated fish. On the other hand, androgen treatment decreased mean hepatic 6 beta-hydroxylase activity but did not affect 16-hydroxylase or 5 alpha-reductase activity. The suppressive effect of simultaneous administration of testosterone and oestradiol-17 beta on 6 beta-hydroxylase activity was more pronounced than when these steroids were administered separately. Furthermore, oestradiol-17 beta diminished the effect of testosterone on 17-HSOR activity. Testosterone treatment of hypophysectomized fish caused a significant increase in 17-HSOR activity when compared with activity in untreated hypophysectomized fish, indicating that this effect of testosterone is mainly direct and independent of the pituitary gland. The results indicate that androgens as well as oestradiol-17 beta play a role in the control of sexual differences in hepatic steroid metabolism in trout.

17-Hydroxysteroid Dehydrogenases↗
PubMed1982

Effects of oestradiol-17 beta and hypophysectomy on hepatic mixed function oxidases in rainbow trout.

The effects of oestradiol-17 beta and/or hypophysectomy on the metabolism of benzo (a) pyrene (BP), paranitroanisole (PNA), ethylmorphine (EM) and 7-ethoxycoumarin by liver microsomes from juvenile rainbow trout, Salmo gairdnerii, were studied. Administration of oestradiol-17 beta caused significant decrease in the liver microsomal metabolism of BP, PNA and EM while hypophysectomy had no effect. The suppressive effect of oestradiol-17 beta on the mixed function oxidases was as pronounced in hypophysectomized as in sham-operated fish, indicating that this effect of oestradiol-17 beta is mainly direct and independent of the pituitary gland. Administration of oestradiol-17 beta caused a significant increase in the apparent Km values of the PNA-O-demethylase whereas no alteration was seen in the apparent Vmax values of the enzyme. The results indicate that oestradiol-17 beta may play a role in the regulation of hepatic mixed function oxidases in rainbow trout.

Animals↗
PubMed1981

In-vitro metabolism of 4-androstene-3,17-dione by hepatic microsomes from the rainbow trout (Salmo gairdnerii): effects of hypophysectomy and oestradiol-17 beta.

The metabolism of 4-androstene-3,17-dione by liver microsomes from juvenile rainbow trout, Salmo gairdnerii, was studied in vitro. Hypophysectomy of the fish significantly increased mean hepatic 17-hydroxysteroid oxidoreductase activity when compared with that from sham-operated fish but none of the other enzyme activities investigated were affected. Administration of oestradiol-17 beta resulted in a significant decrease in mean hepatic 6 beta-hydroxylase activity and total cytochrome P-450 content but had no effect on the 16-hydroxylase or on the reductive metabolism of androstenedione. The effect of oestradiol-17 beta on hepatic 6 beta-hydroxylase activity was as pronounced after hypophysectomy as after sham-operation indicating that these effects of oestradiol-17 beta are mainly direct and independent of the pituitary gland. The results indicate that hypophysial hormone(s) as well as oestradiol-17 betal play a role in the regulation of hepatic steroid metabolism in trout.

17-Hydroxysteroid Dehydrogenases↗
PubMed1981

Bone mineral content in relation to age and menopause in middle-aged women. A study of bone density in lumbar vertebrae by dual photon absorptiometry in a population sample of women.

As one phase of a comprehensive population study of women, bone density was determined in the third lumbar vertebra by dual photon absorptiometric technique. The method involves the use of two radionuclides, which both emit gamma radiation but with different energies (241Am with 59.6 keV and 137Cs with 662 keV). Women in three age strata were studied: 46, 54 and 62 years. The bone mineral content was higher in premenopausal or recently postmenopausal 54-year-old women than in women of the same age who had been postmenopausal for a long time (p less than 0.02). A similar trend was found for women aged 62. The differences could not be explained by differences in other factors studied, such as body height, body weight, smoking habits, numbers of pregnancies or physical inactivity. No significant differences were found when women with similar menstrual status in different age-groups were compared. In the ages studied, hormonal factors seem to be more important than the age per se for the development of oeteoporosis.

Aging↗
PubMed1979

Resurfacing arthroplasty of the hip. Biomechanical, morphological, and clinical aspects based on the results of a preliminary clinical study.

As an alternative in total hip replacement the so called resurfacing arthroplasty of the hip is gaining wider acceptance. The procedure can be said to be a modernisation of the original Smith-Pedersen operation and is suggested in young people with degenerative hip disease, congenital hip dysplasia or Perthes' disease. The advantages are that the femoral head and neck are retained and thus no femoral stem prosthesis is necessary. The greatest disadvantage is that in case of socket loosening a secondary operation might not remain as successful as could the initial operation with a socket which is not as large as those recommended for the resurfacing procedure. In this presentation a preliminary report of a one-year material is presented together with a presentation of advantages, disadvantages, and the biomechanical appraisal of resurfacing of the hip. Fifteen patients with 17 hips have been operated and followed-up and by using the Merle d'Aubigné evaluation there was an improvement of some 3--4 points in pain, walking, and total motion. Patient opinion indicated 80% satisfaction. The management of two serious complications is also described.

Adult↗
PubMed1979

Age at menopause and its relation to osteoporosis.

As one phase of a comprehensive population study of women, bone density was determined in the third lumbar vertebra by dual photon absorptiometric technique. The method involves the use of two radionuclides, which both emit gamma radiation but with different energies (241Am with 59.6 keV and 137Cs with 662 keV). Women in three age strata were studied: 46, 54 and 62 yr. All women aged 46 were still menstruating, while the age strata 54 and 62 were subdivided into two groups: those who still menstruated or had been postmenopausal for a short time and those who had been postmenopausal for many years. The bone mineral content was higher in premenopausal or recently postmenopausal 54-yr-old women than in women of the same age who had been postmenopausal for a long time (P less than 0.01). A similar trend was found for women aged 62 (P less than 0.10). The differences could not be explained by differences in other factors studied, such as body weight, body height, smoking habits or physical activity. No significant differences were found when women with similar menopausal status in different age groups were compared.

Adult↗
PubMed1979

Sagittal splitting of the mandibular ramus. Electromyography and radiologic follow-up study of temporomandibular joint function in 44 patients.

A follow-up study was performed on 44 patients operated with sagittal splitting of the mandibular ramus for correction of a mandibular protrusion. The study included clinical examination, electromyography and masticatory efficiency test as well as radiography of the temporomandibular joint. The maximum opening capacity and protrusion of the mandible decreased one to three years after the operation. The activity of the temporal muscle decreased in rest position after the operation. Masticatory efficiency was unchanged. The position of the condyle in the fossa was unchanged postoperatively, while a posterior and superior condylar movement occurred during the fixation period. Normalization of the condylar position tended to occur one year after the operation. In 37 of 86 condyles, a double contour was seen on the postesuperior margin of the condyle one year after the operation. Possible mechanism behind the development of the new condylar bone layer is discussed.

Electromyography↗