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Biomedical subjects

M Hammar

Publications and source records attributed to M Hammar.

At least 109 records · Page 6Linked to original sources
PubMed1990

Does physical exercise influence the frequency of postmenopausal hot flushes?

The frequency of moderate and severe hot flushes was investigated in a group of women (n = 142) who took part in organized physical exercise on a regular basis, and a control group of all women 52 and 54 years old in the city of Linköping, Sweden (n = 1,246). Only women with natural menopause and without a history of hormonal replacement treatment were statistically compared in the study. It appeared that moderate and severe vegetative symptoms with hot flushes and sweatings were only half as common among the physically active postmenopausal women (21.5%) as in the control group (43.8%). Although this could be due to a positive selection of these physically active women, it might also be due to the fact that exercise may affect the mechanisms that elicit hot flushes in peri- and postmenopausal women.

Climacteric↗
PubMed1990

Long term androgen replacement therapy does not preclude gonadotrophin-induced improvement on spermatogenesis.

A previously hypophysectomized man with azoospermia, who was on androgen replacement therapy since 11 years, was studied with regard to his intratesticular steroid conversion capacity in vitro after which he was given combined hCG/hMG therapy. Before therapy a steroid conversion pattern similar to that seen in prepubertal boys was found, i.e. a high proportion of 20 alpha-dihydroprogesterone was produced while only smaller amounts of 17 alpha-hydroxyprogesterone was produced from the substrate 3H-progesterone. After only five weeks of hCG/hMG treatment, sperm counts and serum testosterone levels increased dramatically and a child was conceived. The steroid conversion pattern simultaneously switched to the mature, adult type with a low production of 20 alpha-dihydroprogesterone and large amounts of 17 alpha-hydroxyprogesterone being produced in vitro. Thus gonadotrophin substitution therapy may still be very effective after long term androgen replacement.

Chorionic Gonadotropin↗
PubMed1989

hCG-treatment alone is insufficient for restitution of spermatogenesis in a state with arrest at the spermatogonial level.

In an infertile man with azoospermia and arrest at the spermatogonial stage, hCG treatment alone improved the spermatogenesis but not beyond the primary spermatocyte stage. During hCG treatment steroid conversion in vitro in testicular biopsy material, as well as serum testosterone concentrations increased dramatically. When hMG treatment was added, spermatogenesis was complete. Combined hCG/hMG treatment seems to be an efficient therapy in well-selected infertile men, whereas increased testosterone production induced by hCG-treatment may be insufficient for restitution of spermatogenesis.

Adult↗
PubMed1989

Testicular GnRH-receptors and direct effects of a GnRH-agonist on human testicular steroidogenesis.

GnRH-like substances have been isolated from interstitial fluid from the rat testis and have been found to exert direct, mainly inhibitory effects on steroidogenesis. In rat testis, specific GnRH receptors have been shown, but so far no GnRH-receptors have been isolated from the human testis. In this study testicular tissue from nine elderly men was incubated with either 3H-pregnenolone or 3H-progesterone and the steroid metabolic patterns were analyzed. In parallel incubations a GnRH-agonist was added to the incubate in concentrations of 10(-6) M or 10(-7) M. Furthermore, receptor studies were performed in tissue specimens from four of these untreated patients as well as in tissue specimens from five GnRH-agonist treated patients. No consistent effects were elicited by the addition of GnRH-agonist on the steroid metabolic patterns in vitro after three hours incubation. In the receptor studies the GnRH-agonist was bound to the testicular tissue, although the binding sites were of low affinity and high capacity, indicating a less specific kind of binding than classical receptor binding.

Aged↗
PubMed1989

Women's soccer injuries in relation to the menstrual cycle and oral contraceptive use.

During 1984, 86 women soccer players answered detailed questionnaires concerning contraceptive use, menstruation data, premenstrual and menstrual symptoms, and data concerning soccer activities including injuries. This prospective study showed that women soccer players were more susceptible to traumatic injuries during the premenstrual and menstrual period compared to the rest of the menstrual cycle (P less than 0.05), especially among players with premenstrual symptoms such as irritability/irascibility, swelling/discomfort in the breasts, and swelling/congestion in the abdomen. It was also found that women using contraceptive pills had a lower rate of traumatic injuries (P less than 0.05) compared to women who were not on the Pill. The results can be explained by the fact that oral contraceptives ameliorate some symptoms of the premenstrual and menstrual period which might also affect coordination and hence the risk of injury.

Adolescent↗
PubMed1988

Climacteric symptoms among women aged 60-62 in Linköping, Sweden, in 1986.

By means of a simple postal questionnaire, all women aged 60, 61 and 62 (n = 2015) living in the community of Linköping, Sweden, were screened for vasomotor symptoms and local vaginal complaints. After one reminder, answers were received from 73% of the women. At the time of the survey (April 1986) all the women were post-menopausal, the median period since menopause being 11 yr. Slightly over one in four of the women (27%) were suffering from sweating and hot flushes. Ten percent (10%) of the women who were more than 15 yr post-menopausal still had moderate to severe climacteric symptoms. Vasomotor symptoms were significantly more common among oophorectomized women than among those whose ovaries were intact. Local vaginal symptoms were positively correlated with urinary problems, repeated urinary tract infections and a high risk of disturbance of sexual activity. It was concluded that climacteric symptoms often persist for more than 15 yr after the menopause.

Climacteric↗
PubMed1988

Zinc in sperm chromatin and chromatin stability in fertile men and men in barren unions.

The stability and the content of zinc of the chromatin were studied in spermatozoa from ten men with unexplained infertility, and in spermatozoa from five fertile donors. A positive relation was found between zinc in sperm nuclei (X-ray microanalysis) and the resistance of the chromatin to decondense in sodium dodecylsulfate (SDS). The infertile men had lower degree of sperm chromatin stability and lower sperm zinc content than the fertile donors. A subgroup of the infertile men, which all had minor clinical signs of prostatic inflammatory reaction, had the lowest content of zinc in the chromatin and the lowest degree of chromatin stability. A low content of nuclear zinc would impair the structural stability of the chromatin and thereby increase the vulnerability of the male genome. This mechanism may be one explanation for the reduced fertility of the men with minor inflammation of the prostate.

Chromatin↗
PubMed1988

Early effects of hCG on human testicular cyclic AMP content, protein kinase activity, in-vitro progesterone conversion and the serum concentrations of testosterone and oestradiol.

Ten infertile men underwent testicular biopsy. Cyclic AMP concentration and cAMP-dependent protein kinase activity were determined in biopsies obtained before, and at 3, 10, 20 and 30 min after an intravenous injection of hCG (1500-5000 IU). The in-vitro conversion of progesterone by testicular tissue, and the serum concentrations of testosterone and oestradiol were then studied before and at 30 min after hCG injection. Intravenous injection of hCG induced a rapid increase in cAMP concentration and in the activity of cAMP-dependent protein kinase. The kinetics of this response indicated that cAMP and cAMP-dependent protein kinase mediate hCG effects on the human testis, presumably via effects on the Leydig cells. No stimulatory effect on steroid conversion in vitro or on the serum concentrations of testosterone and oestradiol were seen after 30 min.

Adult↗
PubMed1988

Variable bioavailability of papaverine.

The plasma concentration curves of papaverine have been studied in nine healthy males and seven patients after administration of single intravenous (80 mg) and oral (80 mg) doses. The bioavailability of the drug was highly variable with a mean of 28% (range 5-99%) but reproducible within the same individual (4 of the volunteers) after a repeated (80 mg) oral dose. The calculated half-life after intravenous administration ranged between 1.2-6.6 hours (mean 3.0). The mean apparent volume of distribution was 3.1 l/kg and the mean total plasma clearance was 836 ml/min. It is concluded that papaverine shows an unacceptable inter-individual variation in the bioavailability after oral administration of 80 mg tablets.

Administration, Oral↗
PubMed1988

Low back pain during pregnancy.

All pregnant women from a well defined area (the central district of the County of Ostergötland, Sweden) attending antenatal clinics over a period of seven months were interviewed with regard to low back pain during pregnancy. Of 862 women who answered the questionnaires, about half developed some degree of low back pain. Seventy-nine women who were unable to continue their work because of severe low back pain were referred to an orthopedic surgeon for an orthoneurologic examination. The most common reason for severe low back pain was dysfunction of the sacroiliac joints. Physically strenuous work and previous low back pain were factors associated with an increased risk of developing low back pain and sacroiliac dysfunction during pregnancy.

Back Pain↗
PubMed1987

Influence of hCG treatment on the metabolism of progesterone and pregnenolone in vitro by the human undescended prepubertal testis.

Testicular biopsies were taken from 56 prepubertal and pubertal boys, aged 3-17 years, with undescended testes. The biopsies were incubated in vitro with 3H-progesterone or 3H-pregnenolone. Fifteen of the boys had been treated with human chorionic gonadotrophin (hCG) prior to operation. Nine boys were operated on within 1 week of the last injection of hCG while the others were operated on between 12 days and 2 years after hCG treatment. In non-treated prepubertal boys very small amounts of substrate were converted by means of the enzymes 3 beta-hydroxysteroid-dehydrogenase and 17 alpha-hydroxylase and virtually no testosterone was produced. Immediately after treatment with hCG there was a large increase in the conversion of substrate by 17 alpha-hydroxylase and 3 beta-hydroxysteroid-dehydrogenase. Considerable amounts of testosterone were formed, especially from pregnenolone, while smaller amounts were formed from progesterone. This suggests that testosterone production occurred primarily via the delta 5 pathway, at least beyond the 17 alpha-hydroxylase-step. Within 2 weeks of the last hCG injection, steroidogenic activity had decreased towards levels similar to those found in prepubertal testis from untreated boys. These observations indicate that hCG treatment of boys with undescended testes does not result in irreversible or even long-lasting stimulation of their steroidogenic function.

Adolescent↗
PubMed1987

Influence of continuous luteinizing hormone-releasing hormone agonist treatment on steroidogenic enzymes in the human testis.

Nine elderly men with prostatic carcinoma underwent treatment with a LHRH-agonist (Zoladex, ICI) for 3-6 months. At the end of the treatment period the patients underwent subcapsular orchidectomy. Testicular tissue was incubated with different tritiated testosterone precursors. Conversion mediated by several testicular steroidogenic enzymes was compared between Zoladex-treated patients and nineteen non-treated patients who underwent orchidectomy because of prostatic carcinoma. Serum concentrations of LH, FSH and testosterone were determined before and during treatment in the treated patients. The LHRH agonist treatment induced significantly decreased conversion mediated by the enzymes 3 beta-hydroxysteroid dehydrogenase, 17 alpha-hydroxylase and C17-20 lyase. Conversion mediated by 17 beta-ketosteroid reductase was also decreased although not as dramatically as the other enzymes, while conversion mediated by 20 alpha-dehydrogenase was increased. Serum concentrations of testosterone decreased to castration levels. Serum gonadotrophins decreased but remained within normal levels suggesting that "desensitization" at the pituitary level was not the only mechanism of action of the LHRH-agonist.

Aged↗
PubMed1987

Calcium and magnesium status in pregnant women. A comparison between treatment with calcium and vitamin C in pregnant women with leg cramps.

60 pregnant women underwent a double blind trial with calcium or ascorbic acid (1 g twice daily) as treatment for leg cramps. There was no significant difference between the two treatment groups with respect to clinical improvement. In 14 out of 60 patients the symptoms were totally abolished and in another 27 patients the symptoms were significantly decreased by the treatment (irrespective of drug used). In 17 patients the symptoms were unaffected while only two patients experienced an increase in frequency of their leg cramps during therapy. Serum total and ionized calcium concentrations, serum total magnesium and albumin concentrations were determined and were not significantly changed throughout therapy in any of the groups. No biochemical differences were found between the different treatment regimens or between those patients relieved or not relieved of their symptoms. Serum magnesium concentrations were at or just below the lower normal limit (for non pregnant women) in treated women and pregnant controls.

Adult↗
PubMed1986

Gonadotrophin induced effects on human testicular morphology.

Ten infertile men were treated with gonadotrophic hormones. The effects on serum hormone concentrations, sperm counts, in vitro conversion of progesterone in testicular biopsies and on testicular morphology, were studied. Gonadotrophin treatment increased serum testosterone concentrations and sperm counts in some patients. In the patients where the in vitro conversion of progesterone in testicular tissue was changed, the Leydig cells also increased in size. In some patients the thickness of the lamina propria decreased during therapy, and a thick lamina propria should not exclude a patient from gonadotrophin therapy. Gonadotrophin therapy may be beneficial in patients with understimulated progesterone conversion in vitro, even in cases without spermatogenesis, provided spermatogonia are present. No harmful effects of hCG/hMG treatment were observed.

Adult↗
PubMed1986

Effects of oestradiol-17 beta and ethinyl oestradiol on human testicular steroidogenesis in vitro.

The inhibition of human testicular testosterone production in vitro by oestrogen was studied by measuring effects of oestradiol-17 beta and ethinyl oestradiol on the 3 beta-hydroxysteroid dehydrogenase/isomerase and the delta 4-pathway of testosterone synthesis. Progesterone, 17 alpha-hydroxyprogesterone, androstenedione and testosterone concentrations of incubation media were all depressed after oestrogen addition. To minimize differences in substrate amounts between incubations, 3H-labelled pregnenolone, progesterone, 17 alpha-hydroxyprogesterone or androstenedione was added to the incubation media. The conversion of pregnenolone, progesterone and 17 alpha-hydroxyprogesterone was inhibited by oestrogen. It is concluded that oestrogen inhibits 3 beta-hydroxysteroid dehydrogenase/isomerase, 17 alpha-hydroxylase and C17-20-lyase enzyme activities of human testicular tissue in vitro while 17 beta-ketosteroid reductase activity is unaffected.

17-alpha-Hydroxyprogesterone↗