Biomedical subjects

Louis J G Gooren

Publications and source records attributed to Louis J G Gooren.

7 recordsLinked to original sources

PubMed2003

Oral and transdermal estrogens both lower plasma total homocysteine in male-to-female transsexuals.

Plasma total homocysteine (tHcy) levels are on average lower in women versus men, indicating an estrogenic effect. Oral estrogens (absorbed via the liver) may be hypothesized to have stronger effects on hepatic homocysteine metabolism than transdermal estrogens. We randomly assigned 30 male-to-female transsexuals (20-44 years old) to 4 months' administration of oral ethinyl estradiol (n=15) or transdermal 17beta-estradiol (n=15), both with the antiandrogen cyproterone acetate (CA). Ten other male controls were treated with CA only. At baseline and after 2 and 4 months, plasma tHcy was analyzed in conjunction with plasma folate. Oral ethinyl estradiol and transdermal 17beta-estradiol similarly reduced plasma tHcy (geometric mean 10.6 micromol/l [95% CI 8.2-13.9] to 7.5 [6.5; 8.8], and 11.3 [8.1; 16.4] to 8.4 [6.5; 11.1]; P<0.001 for both), whereas CA had no effects. No effects were found on folate levels. Thus, oral and transdermal estrogens decrease plasma tHcy to a similar degree (by geometric mean -26%), which suggests that a hepatic mechanism is unlikely to play an important role in the decline of tHcy levels.

Administration, Cutaneous↗

PubMed2003

Effects of sex steroids on components of the insulin resistance syndrome in transsexual subjects.

OBJECTIVE: Sex differences are found in most components of the insulin resistance syndrome and the associated cardiovascular risk profile. These differences are attributed to sex-specific sex steroid profiles, but the effects of sex steroids on the individual components of the insulin resistance syndrome remain incompletely understood. DESIGN: Prospective, intervention study. SUBJECTS: In 37 young (age range 16-36 years), nonobese [body mass index (BMI) < 29], transsexual subjects, effects of ethinyl oestradiol (100 micro g/day) + cyproterone acetate (100 mg/day) administration were evaluated in 20 male-to-female transsexuals and of testosterone-ester administration [250 mg intramuscularly (i.m.)/2 weeks] in 17 female-to-male transsexuals. MEASUREMENTS: We studied lipid spectrum, postheparin hepatic lipase (HL) and lipoprotein lipase (LPL) activity, blood pressure, glucose utilization (by euglycaemic hyperinsulinaemic clamp), and fat areas (by magnetic resonance imaging) at baseline and during 1-year cross-sex hormone administration. RESULTS: Oestrogens + antiandrogens increased high-density lipoprotein (HDL)-cholesterol and decreased LDL-cholesterol, and HL activity, which are considered beneficial. But this combination also increased triglycerides, blood pressure, subcutaneous fat and visceral fat, and decreased the LDL-particle size, LPL activity and insulin sensitivity, which are all considered detrimental. Testosterone reduced HDL-cholesterol and the LDL-particle size, and increased triglycerides and HL activity. An android fat distribution was induced (i.e. decreased subcutaneous and increased visceral fat). Blood pressure, total and LDL-cholesterol, LPL activity and insulin sensitivity were mainly unaffected. CONCLUSIONS: The effects of cross-sex hormone treatment - in the dosages used in this study - in healthy, nonobese, young transsexual subjects do not show unequivocally that female sex steroids, given in large amounts to male subjects, have beneficial effects on cardiovascular profile and that high dose testosterone administration to female subjects is detrimental with respect to cardiovascular risk.

Adipose Tissue↗

PubMed2002

Androgens and male behavior.

Sexual differentiation into a male or a female includes sexual differentiation of the brain. The paradigm of mammalian sexual differentiation is that in the presence of androgens (normally produced by the fetal testis) a male brain differentiation occurs, while in the absence of androgens (normal in females) a female brain differentiation follows. In the human there is a sex-dimorphism in gender identity/role, sexual orientation, sexual functioning, and in non-sexual functions, such as spatial ability, and verbal fluency. Inasmuch these properties can be studied in other mammals the effects of androgens are solidly demonstrable. In the human the evidence for androgen effects is equally plausible, evident from observations in subjects with errors in the process of sexual differentiation and in morphological studies of brain structures presumably related to these properties. But clinical observations show compellingly that other, largely unidentified, factors may modulate, or even override the effects of androgens.

Affect↗

PubMed2002

The effect of beta-adrenergic blockade after encoding on memory of an emotional event.

RATIONALE: Animal and human studies lend support to the hypothesis that enhanced memory associated with emotional experiences involves activation of the beta-adrenergic system. Evidence for the role of noradrenaline in emotional memory in humans has been gathered from experimental studies where blockade of the beta-adrenergic system with a beta-blocker selectively impaired long-term memory for an emotionally arousing story (a slide show), when the beta-blocker was given before subjects were confronted with the emotional stimuli. OBJECTIVE: The purpose of this study was to test whether effective beta-adrenergic blockade occurring only after the stage of encoding has a similar impairing effect on memory. METHODS: In a double blind experimental design, 60 healthy adult subjects received randomly one tablet of either propranolol (Inderal, 40 mg) or placebo. Drugs were administered just before the slide show begun and (in view of its pharmacokinetics) propranolol reaches peak levels 1 h after drug intake. Physiological arousal was monitored by heart rate and blood pressure. Half of the beta-blocker and placebo groups watched either a neutral or an arousal version of an 11-slide presentation. Memory performance was tested with a surprise free recall and recognition test 1 week later. RESULTS: Memory performance, specifically for the second phase in which emotional elements were introduced, was better in subjects who viewed the arousal version than subjects who saw the neutral version of the slide show. However, no effect of the beta-blocker condition was found. CONCLUSION: This experiment does not support a role for noradrenaline in the post-encoding phase and on the later processes of consolidation and retrieval. Although it remains possible that with a different dosage or timing protocol a post-treatment effect of noradrenaline in humans can be found, this experiment could not find support for it.

Adrenergic beta-Antagonists↗

PubMed2002

Diagnostic approach to the aging male.

Quality of life has become a major issue in health care, particularly in old age. The aging process runs its own course but certain elements potentially lend themselves to intervention. The urologist has excellent opportunities to counsel aging men on general aspects of health and to offer screening for common ailments of old age. It is relevant to distinguish between the process of aging itself and diseases occurring in old age. The latter should be diagnosed and adequately treated. Risk factors for these age-related diseases should be identified and addressed. Several questionnaires have been developed that are helpful. Apart from urological disease, cardiovascular disease, diabetes mellitus and osteoporosis are common conditions. There are now tests available that allow screening. Of great importance is the need to raise awareness in aging men of the possibilities modern medicine offers to improve quality of life, and to encourage these men to utilize them for their benefit.

Body Composition↗

PubMed2002

Organizing and activating effects of sex hormones in homosexual transsexuals.

The cause of transsexualism remains unclear. The hypothesis that atypical prenatal hormone exposure could be a factor in the development of transsexualism was examined by establishing whether an atypical pattern of cognitive functioning was present in homosexual transsexuals. Possible activating effects of sex hormones as a result of cross-sex hormone treatment were also studied. Female-to-male and male-to-female transsexuals were compared with female and male controls with respect to spatial ability before and after treatment. The data were consistent with an organizing effect, but there was no evidence of an activating effect. Homosexual transsexuals, who prior to hormone treatment scored in the direction of the opposite sex, may have reached a ceiling in performance and therefore do not benefit from activating hormonal effects.

Adolescent↗

PubMed2002

Psychological consequences.

Sex assignment of children born with ambiguous genitalia is a difficult and responsible decision based on limited empirical evidence regarding future development of gender identity/role, sexual orientation, and sexual functioning. Sex of assignment and rearing has appeared to be a prognosticator of future gender identity, usually better than the other criteria of sex (chromosomes, gonadal tissue, prenatal and postnatal hormonal profiles). The decision to assign a sex is guided by the prognosis of the "optimal" sex for the newborn, of which the elements are an overall sex-appropriate appearance with a stable gender identity; good sexual function, preferably combined with reproductive function if attainable; minimal medical procedures; and a reasonably happy life given the limitations. The limited follow-up studies indicate that this is a reasonable policy, although a limited number of subjects will experience gender dysphoria later in life and will cross over to the other sex. This is more often the case in subjects assigned to the female sex with considerable prenatal or postnatal androgen exposure. Children in this predicament must receive guidance well into adulthood. It may be difficult to engage in sexual relations when the anatomy of the genitalia (often operated upon) is not fully normal.

Androgens↗