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Biomedical subjects

L J Gooren

Publications and source records attributed to L J Gooren.

At least 73 records · Page 4Linked to original sources
PubMed1996

An epidemiological and demographic study of transsexuals in The Netherlands.

This is an epidemiological and demographic study of 1285 transsexuals in the Netherlands. The data were collected from 1975 to the end of 1992. Over 95% of the Dutch transsexuals have been treated at the study center. Between 1975 and 1984 the annual number of female-to-male transsexuals increased, stabilizing thereafter. In the male-to-female transsexuals this trend continued up to 1989, declining slightly thereafter. Over the last 5 years on average 50 (range 38-60) male-to-female transsexuals and 21 (range 14-25) female-to-male transsexuals received surgical and/or hormonal treatment yearly. The sex ratio remained stable over this period: 3 male vs. 1 female subject. The calculated prevalence of transsexualism in The Netherlands is 1:11,900 males and 1:30,400 females. Transsexuals live predominantly in urbanized areas, but those living in nonurbanized areas show an even distribution over the country. The majority of female-to-male transsexuals apply for reassignment between the ages of 20-25, seldom in middle ages. The majority of male-to-female transsexuals do so between the ages of 25-30 and middle-aged subjects are not rare. Between 77-80% of both categories receive surgical and/or hormonal treatment. Five male-to-female transsexuals regretted sex reassignment.

Adult↗
PubMed1996

Effects of insulin infusion on endothelium-derived vasoactive substances.

An association between insulin resistance and hypertension has been reported in several studies. In apparent contradiction, insulin infusion in healthy volunteers is associated with vasodilatation. Furthermore, there is evidence that some insulin effects may differ between the sexes. We performed three-step hyperinsulinaemic-euglycaemic clamp studies in six men and six women to test the hypotheses that: 1) insulin might affect the release of vasoactive substances by the endothelium, and 2): this putative effect on vasoactive substances might differ between men and women. Six other women and six men served as control subjects, receiving 154 mmol/l NaCl (saline) infusion. Plasma levels of insulin, immunoreactive endothelin, L-arginine (precursor of nitric oxide), L-citrulline (by-product of nitric oxide synthesis) and cyclic GMP (second messenger of nitric oxide) were measured during infusion of insulin or 154 mmol/l NaCl (saline), respectively. We also assessed urinary excretion of 6-keto PGF-1 alpha (a degradation product of prostacyclin reflecting prostacyclin production). Blood pressure was monitored in all subjects throughout the experiment. In women plasma levels of immunoreactive endothelin decreased from (mean +/- SD) 2.58 +/- 0.96 to 1.7 +/- 0.72 pmol/l during insulin infusion (p < 0.01), while remaining constant in female control subjects (p < 0.02). No changes in levels of endothelin were observed in men during infusion of insulin or saline. In women levels of cGMP rose and levels of L-arginine decreased significantly during insulin infusion, consistent with an increase in nitric oxide production. Excretion of 6-keto PGF-1 alpha also increased significantly in women during insulin infusion. No such effects were observed in men, or in women during infusion of saline. Blood pressure remained constant in all subjects during hyperinsulinaemia. We conclude that sex differences exist in the effects of insulin on the endothelium. Short-term hyperinsulinaemia in women is associated with a decline in levels of immunoreactive endothelin, and possibly with a rise in production of nitric oxide and prostacyclin. In contrast, levels of vasoactive substances remained constant in men during hyperinsulinaemia. Our findings may partly explain insulin's vasodilatory effects in healthy individuals. It remains to be investigated whether these effects are lost in insulin-resistant states. Our observation that there is a sex difference in insulin effects on the endothelium may help explain why the link between hyperinsulinaemia and cardiovascular disease appears to be clearer in men than in women.

6-Ketoprostaglandin F1 alpha↗
PubMed1996

Facial corrections in male to female transsexuals: a preliminary report on 16 patients.

PURPOSE: The need for facial corrective surgery to facilitate passing as a member of the other sex occurs in a relatively low percentage of male-to-female transsexuals. The aim of this study was to explore criteria and techniques for facial corrections in male-to-female transsexuals because little is known on objective measures for meaningful facial alterations in the female direction. PATIENTS AND METHODS: In the period 1992 to 1994, 16 male-to-female transsexual patients were eligible for bony facial corrections. Several techniques were used to feminize the masculine appearance: mandibular angle reduction, genioplasty, bimaxillary osteotomy, and zygoma onlay and zygoma sandwich osteotomies. RESULTS: Subjectively good results were obtained. Improvement in quality of life was not objectively assessed. CONCLUSIONS: Facial corrective surgery seems to be promising in selected cases of male-to-female transsexualism. Further research is recommended on quantification of the differences in male and female faces for optimal indications and design of this type of surgery. The psychosocial aspects of the facial surgery and long-term stability of the surgical result also need to be further investigated.

Adult↗
PubMed1996

Oral estrogen treatment induces a decrease in expression of sialyl Lewis x on alpha 1-acid glycoprotein in females and male-to-female transsexuals.

The effect of estrogen on the glycosylation of alpha 1-acid glycoprotein was studied in women using oral contraceptives and in male-to-female transsexuals receiving oral or transdermal estrogen treatment. Oral estrogen treatment induced an increase in degree of branching and a decrease in fucosylation and sialyl Lewis x expression on alpha 1-acid glycoprotein compared to individuals receiving no estrogens or transdermal estrogen treatment. The effect on the glycosylation of alpha 1-acid glycoprotein was less in the male-to-female transsexuals receiving oral estrogens in combination with cyproterone acetate, a blocker of the androgen receptor with progestagen-like effects. This was of comparable magnitude as in women using oral contraceptives containing both estrogen and progestagen. We conclude that oral estrogens have an identical effect on the hepatic glycosylation of alpha 1-acid glycoprotein in both males and females and that progestagen reduces this effect. These results show that oral estrogens induce an effect on the glycosylation of alpha 1-acid glycoprotein opposite to that induced by inflammation. Oral estrogens can therefore modulate the glycosylation dependent inflammatory actions of alpha 1-acid glycoprotein, while this is not the case with transdermal estrogens. In all likelihood, estrogen receptors on the hepatocyte must play a significant role in the observed effect.

Administration, Oral↗
PubMed1995

A sex difference in the human brain and its relation to transsexuality.

Transsexuals have the strong feeling, often from childhood onwards, of having been born the wrong sex. The possible psychogenic or biological aetiology of transsexuality has been the subject of debate for many years. Here we show that the volume of the central subdivision of the bed nucleus of the stria terminals (BSTc), a brain area that is essential for sexual behaviour, is larger in men than in women. A female-sized BSTc was found in male-to-female transsexuals. The size of the BSTc was not influenced by sex hormones in adulthood and was independent of sexual orientation. Our study is the first to show a female brain structure in genetically male transsexuals and supports the hypothesis that gender identity develops as a result of an interaction between the developing brain and sex hormones.

Acquired Immunodeficiency Syndrome↗
PubMed1995

Gender differences in behaviour: activating effects of cross-sex hormones.

The relative contribution of organizing and activating effects of sex hormones to the establishment of gender differences in behaviour is still unclear. In a group of 35 female-to-male transsexuals and a group of 15 male-to-female transsexuals a large battery of tests on aggression, sexual motivation and cognitive functioning was administered twice: shortly before and three months after the start of cross-sex hormone treatment. The administration of androgens to females was clearly associated with an increase in aggression proneness, sexual arousability and spatial ability performance. In contrast, it had a deteriorating effect on verbal fluency tasks. The effects of cross-sex hormones were just as pronounced in the male-to-female group upon androgen deprivation: anger and aggression proneness, sexual arousability and spatial ability decreased, whereas verbal fluency improved. This study offers evidence that cross-sex hormones directly and quickly affect gender specific behaviours. If sex-specific organising effects of sex hormones do exist in the human, they do not prevent these effects of androgen administration to females and androgen deprivation of males to become manifest.

Adult↗
PubMed1995

Effects of gonadal androgens and oestrogens on adrenal androgen levels.

OBJECTIVE: The physiological role of adrenal androgens in humans remains unclear. Furthermore, there are few data on the relation between sex steroids and adrenal androgen production. We have assessed the effects of sex steroid hormone administration on adrenal androgen levels, by studying a large group of transsexual patients. DESIGN: A non-randomized intervention. SETTING: A university teaching hospital. PATIENTS: Thirty-one male-to-female and 22 female-to-male transsexual patients. MEASUREMENTS: Plasma levels of adrenal androgens were measured in a group of male-to-female and female-to-male transsexual patients both before and during cross-gender hormone treatment. This treatment involves administration of testosterone esters to women and of ethinyloestradiol and cyproterone acetate to men. RESULTS: High dose sex steroid administration had marked effects on adrenal androgens levels, which decreased by 27-48% in males treated with ethinyloestradiol and increased by 23-70% in females treated with testosterone. CONCLUSION: We conclude that administration of high doses of testosterone and oestradiol exert opposing effects on adrenal androgen production.

Adolescent↗
PubMed1995

Biomedical concepts of homosexuality: folk belief in a white coat.

Biological and medical tradition teaches that sexuality exists for the sole purpose of reproduction. Within this tradition homosexuality has no biological significance. It is conceived as a pathological condition wherein a homosexual has the internal or external characteristics of the opposite sex. The initial search for cross-sex physical characteristics in homosexuals (e.g., wide hips in males, wide shoulders in females) failed. The search then focussed on so-called sex hormones. It was hypothesized that homosexuals had an excess of hormones of the opposite sex. The researchers are now hypothesizing that homosexuals have a cross-sex brain organization. To date, no evidence for such cross-sex differentiation has been credibly demonstrated. This paper describes the results of unsuccessful attempts to replicate studies which are based on the assumption that homosexuals have a cross-sexed brain organization due to perinatal hormonal factors.

Adolescent↗
PubMed1995

Brain research, gender and sexual orientation.

Recent brain research has revealed structural differences in the hypothalamus in relation to biological sex and sexual orientation. Differences in size and cell number of various nuclei in the hypothalamus for homosexual versus heterosexual men have recently been reported in two studies. We have found that a cluster of cells in the preoptic area of the human hypothalamus contains about twice as many cells in young adult men as in women. We have called this cluster the sexually dimorphic nucleus (SDN). The magnitude of the difference is the SDN depends on age. In other human research, two other hypothalamic nuclei (interstitial nuclei of the anterior hypothalamus [INAH] 2 and 3) and part of the bed nucleus of the stria terminalis (BST) have been reported to be sexually dimorphic in the human. Sexual differentiation to the human brain takes place much later than originally claimed. At birth the SDN contains only some 20% of the cells found at 2 to 4 years of age. The cell number rapidly increases in boys and girls at the same rate until 2 to 4 years of age. After that age period, a decrease in cell number takes place in girls, but not in boys. This causes the sexual differentiation of the SDN. This postnatal period of hypothalamic differentiation indicates that, in addition to genetic factors, a multitude of environmental and psychosocial factors may have profound influence on the sexual differentiation of the brain. No difference in SDN cell number was observed between homosexual and heterosexual men. This finding refutes Dörner's hypothesis that homosexual males have a "female" hypothalamus. However, in a sample of brains of homosexual men we did find that an area of the hypothalamus called the suprachiasmatic nucleus (SCN) contains twice as many cells as the SCN of a heterosexual group. A recent report by LeVay claims that another nucleus, INAH-3, is more than twice as large in heterosexual as in homosexual men, whereas Allen and Gorski found that the anterior commissure was larger in homosexual men than in heterosexual men or women. Preliminary research on male-to-female transsexuals is also discussed. The functional implications of these findings in determining adult sexual orientation are as yet far from clear.

Adolescent↗
PubMed1994

Serum testosterone level is the major determinant of the male-female differences in serum levels of high-density lipoprotein (HDL) cholesterol and HDL2 cholesterol.

We studied prospectively the effect of exogenous testosterone (testosterone undecanoate [TU] 160 mg/d orally) on lipoprotein profiles in eight hypogonadal males and 10 females (female-to-male transsexuals). Testosterone administration to androgen-deficient men and to eugonadal women produced similar serum levels of testosterone (7.67 +/- 5.47 nmol/L v 8.45 +/- 3.81 nmol/L) and 5 alpha-dihydrotestosterone (DHT) (3.27 +/- 3.52 nmol/L v 3.97 +/- 2.35 nmol/L) in the two groups, while serum estradiol levels were three to four times higher in the females (90 +/- 24 pmol/Lv 376 +/- 315 pmol/L). After testosterone treatment serum high-density lipoprotein (HDL) cholesterol levels decreased from 1.41 +/- 0.27 mmol/L to 1.27 +/- 0.22 mmol/L after 3 months and 1.17 +/- 0.23 mmol/L after 6 months (P < .01) in female-to-male transsexuals and from 1.31 +/- 0.39 mmol/L to 1.09 +/- 0.31 mmol/L after 3 months and 1.10 +/- 0.32 mmol/L (P < .05) after 6 months in hypogonadal males. In particular, serum HDL2 cholesterol levels decreased from 0.71 +/- 0.44 mmol/L to 0.45 +/- 0.20 mmol/L after 3 months and 0.49 +/- 0.39 mmol/L after 6 months (P < .01) in female-to-male transsexuals and from 0.52 +/- 0.12 mmol/L to 0.38 +/- 0.18 mmol/L after 3 months and 0.34 +/- 0.19 mmol/L after 6 months (P < .05) in hypogonadal males. Serum apolipoprotein (apo) A1 levels decreased concomitantly. In both sexes, serum levels of HDL cholesterol and HDL2 cholesterol decreased by approximately 15% and 35%, respectively, whereas serum levels of total cholesterol, triglycerides, low-density lipoprotein (LDL) cholesterol, apo A2, and apo B were not affected.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

Activating effects of androgens on cognitive performance: causal evidence in a group of female-to-male transsexuals.

It is still unclear whether sex differences in cognitive functioning are mainly due to perinatal organizing effects of sex hormones on the brain, or to activating effects in adulthood. In a group of 22 female-to-male transsexuals a battery of visuospatial and verbal ability tests was administered twice: shortly before and 3 months after the start of androgen treatment. The administering of androgens was clearly associated with an increase in spatial ability performance. In contrast, it had a deteriorating effect on verbal fluency tasks. This study offers preliminary evidence that androgens directly and quickly affect cognitive performance in females.

Adolescent↗
PubMed1994

Testosterone administration increases adrenal response to adrenocorticotrophin.

OBJECTIVE: Various studies have demonstrated coexistence of ovarian and adrenal hyperandrogenism in women. This study was designed to determine whether testosterone can increase the response of the adrenal gland to stimulation by adrenocorticotrophin (ACTH). DESIGN: Non-randomized intervention in a university teaching hospital. PATIENTS: Twenty androgen-treated female-to-male transsexual patients (10 ovariectomized and 10 non-ovariectomized) and 10 normal female controls. MEASUREMENTS: ACTH stimulation tests were performed in all subjects. Baseline values and the increase above baseline values after ACTH stimulation were assessed for cortisol and the adrenal androgens androstenedione, dehydroepiandrosterone and dehydroepiandrosterone-sulphate. RESULTS: Increases in levels of cortisol, androstenedione and dehydroepiandrosterone after administration of ACTH were greater in testosterone-treated transsexual patients than controls. CONCLUSION: We conclude that testosterone increases the response of the adrenal gland to stimulation by ACTH.

Adrenal Cortex↗
PubMed1994

Induction of insulin resistance by androgens and estrogens.

Hyperinsulinemia is a common finding in hyperandrogenic women, during pregnancy, and in women using oral contraceptives. To test whether sex hormone treatment can induce insulin resistance in healthy subjects, we studied the effects of administration of testosterone to 13 female to male and of ethinyl estradiol to 18 male to female transsexuals. Utilization and production of glucose and levels of sex steroids were measured during a three-step hyperinsulinemic-euglycemic clamp before and after 4 months of hormone administration. Females were treated with im injections of testosterone esters (250 mg/2 weeks); males were treated with ethinyl estradiol alone (0.1 mg/day, orally) or a combination of ethinyl estradiol and cyproterone acetate (100 mg/day, orally). Similar insulin levels were achieved at each of the three steps of the clamp studies before and during hormone administration. During step 1 of each clamp, with insulin levels in the physiological range, glucose utilization decreased from 3.5 +/- 1.2 to 2.6 +/- 0.9 mmol/kg lean body mass (LBM).h in women treated with testosterone esters (P < 0.001) and from 3.2 +/- 0.7 to 2.5 +/- 0.5 mmol/kg lean body mass.h in men treated with ethinyl estradiol (P < 0.001). The effects of sex steroids during steps 2 and 3 of the clamp at higher (supraphysiological) insulin levels were less clear. Endogenous glucose production (measured by isotope dilution with tritiated glucose) was not affected by hormone administration, indicating that the observed changes in glucose requirement were determined by a diminished peripheral glucose uptake. We conclude that sex hormone administration, i.e. testosterone treatment in females and ethinyl estradiol treatment in males, can induce insulin resistance in healthy subjects.

Adolescent↗
PubMed1993

Influence of sex hormones on plasma endothelin levels.

OBJECTIVE: To determine whether a sex-associated difference in endothelin levels exists and to assess whether this difference is mediated by sex hormones. DESIGN: Initial survey in healthy persons, followed by a nonrandomized intervention. SETTING: A university teaching hospital. PATIENTS: Twenty-three healthy men, 29 healthy women, 20 pregnant women, and 12 male-to-female and 13 female-to-male transsexual patients. MEASUREMENTS: Plasma levels of endothelin were first assessed in healthy men, healthy women, and pregnant women; subsequently, endothelin levels were determined in male-to-female and female-to-male transsexual patients both before and during cross-gender hormone treatment. This treatment involves administration of testosterone esters to women and of ethynylestradiol and cyproterone acetate to men. RESULTS: Endothelin levels were higher in men than in women (5.9 +/- 1.2 compared with 4.17 +/- 0.67 pg/mL; P < 0.01). Endothelin levels were lower in pregnant women than in age- and sex-matched nonpregnant controls (2.19 +/- 0.73 compared with 4.17 +/- 0.67 pg/mL; P < 0.01). In 12 male-to-female transsexuals treated with estradiol and the progestational agent cyproterone acetate, endothelin levels decreased from 8.1 +/- 3.0 to 5.1 +/- 2.0 pg/mL (P < 0.01). In 13 female-to-male transsexuals treated with testosterone, endothelin levels increased from 6.2 +/- 1.1 to 7.8 +/- 1.2 pg/mL (P < 0.01). CONCLUSION: Sex hormones may modulate plasma endothelin levels, with male hormones raising levels and female hormones lowering them. This finding may be important in explaining sex-associated differences in susceptibility to atherosclerotic cardiovascular disease.

Adolescent↗
PubMed1993

The prevalence of transsexualism in The Netherlands.

The prevalence of transsexualism in the Netherlands was estimated by counting all the subjects who were diagnosed as transsexuals by psychiatrists or psychologists and were subsequently hormonally treated and generally underwent sex-reassignment surgery. At the end of 1990, 713 Dutch-born transsexuals received treatment (507 men, 206 women). This amounts to a prevalence of 1:11,900 for male-to-female transsexualism and 1:30,400 for female-to-male transsexualism (population age 15 and above in both groups). The sex ratio was about 2.5 men to 1 woman. The most important reason for this relatively high prevalence seems to be the benevolent climate for the treatment of transsexualism in the Netherlands.

Adolescent↗