Immunohistochemistry and in situ hybridization of the androgen receptor in the developing human prostate

 As it is suggested that the androgen receptor mechanism is required for prostatic development, we attempted to determine the appearance, expression and distribution of the androgen receptor in embryonic, infantile and pubertal human prostate. Using mono- and polyclonal antibodies and a digoxigenin-labeled 713 bp riboprobe, the androgen receptor expression in paraffin sections of fetal, infantile, and pubertal prostates was studied at the protein and RNA level. Under highly standardized conditions, application of the polyclonal antibodies resulted in a weak cytoplasmic and nuclear labeling of the epithelium of fetal glands. No immunoreaction was obtained with monoclonal antibodies. Applying the polyclonal antibody to pubertal and adult specimens, immunoreactivity of the androgen receptor was positive in nuclei of adluminal and basal epithelial cells, in interstitial and vascular smooth muscle cells and vascular endothelium, whereas ganglionic cells and enteroendocrine cells were negative. In situ hybridization with the digoxigenin-labeled riboprobe gave clear positive results already in epithelium of very young fetal specimens. A semiquantitative visual evaluation of in situ hybridizations showed that intermediate intensity of expression was increased in pubertal and adult specimens, whereas strong expression was reduced in prostatic epithelium. Conclusions: The essential findings are: (1) an early expression of androgen receptor mRNA in the fetal prostate; (2) no immunoreaction of monoclonal antibodies against the androgen receptor in the same specimens, (3) a decrease of androgen receptor mRNA expression, but increase in immunoreactivity of the androgen receptor protein with the onset of glandular maturation during puberty. Accepted: 29 September 1997     

Deciding on Gender in Children with Intersex Conditions

Biologic factors such as genetic and hormonal influences contribute to gender identity, gender role behavior, and sexual orientation in humans, but this relationship is considerably modified by psychologic, social, and cultural factors. The recognition of biologically determined conditions leading to incongruity of genetically determined sex, somatic phenotype, and gender identity has led to growing interest in gender role development and gender identity in individuals with intersex conditions. Sex assignment of children with ambiguous genitalia remains a difficult decision for the families involved and subject to controversial discussion among professionals and self-help groups. Although systematic empirical data on outcomes of functioning and health-related quality of life are sparse, anecdotal evidence from case series and individual patients about their experiences in healthcare suggests traumatic experiences in some. This article reviews the earlier 'optimal gender policy' as well as the more recent 'full consent policy' and reviews published data on both surgical and psychosocial outcomes. The professional debate on deciding on sex assignment in children with intersex conditions is embedded in a much wider public discourse on gender as a social construction. Given that the empirical basis of our knowledge of the causes, treatment options, long-term outcomes, and patient preferences is insufficient, we suggest preliminary recommendations based on clinical experience, study of the literature, and interviews with affected individuals.     

Störungen der Geschlechtsentwicklung

Disorders of sex development (DSD) were previously termed “intersexuality”. They comprise inborn errors of genetic control of the sexual determination of the gonads and of hormonal control of sexual differentiation of the genitalia. Among the endocrine mechanisms the presence or absence of normal androgen biosynthesis and androgen action plays a central role. Disorders of sex development can be part of overriding syndromes. In Germany the incidence is approximately 1 in 4,500 newborns. Clinically, disorders of sex development are mostly diagnosed at birth because of ambiguities of the external genitalia. However, they can be present in cases of primary amenorrhoea, virilization of a girl at pubertal age or even in cases of an abdominal tumor (dysgerminoma). Disorders of sex development can be associated with developmental and functional disorders of the kidneys and the adrenal glands.     

Novel insertion frameshift mutation of the LH receptor gene: problematic clinical distinction of Leydig cell hypoplasia from enzyme defects primarily affecting testosterone biosynthesis

Leydig cell hypoplasia (LCH) is a rare autosomal recessive condition that interferes with normal development of male external genitalia in 46,XY individuals and is caused by inactivating mutations of the LH receptor gene. The clinical and biochemical diagnostic parameters of LCH are not always specific and may therefore show significant overlap with other causes of insufficient testicular steroid biosynthesis. We have studied a 46,XY newborn with completely female external genitalia and palpable testes. Due to an increased basal serum ratio of androstenedione/testosterone, 17 beta-hydroxysteroid dehydrogenase type 3 (17 beta-HSD 3) deficiency was initially suspected. DNA analysis of the corresponding HSD17B3 gene, however, showed no abnormalities in the entire coding region. In contrast, direct sequencing of the LH receptor gene revealed a novel homozygous single nucleotide insertion in exon 11 (codon A589fs) producing a frame shift in the open reading frame predicting for premature termination of translation 17 amino acids downstream. From the genetic perspective, this mutation represents the first frame shift mutation in the LH receptor gene ever reported to date. From the clinical standpoint, LCH should always be considered in the differential diagnosis as steroid profiles may not be informative. Therefore, molecular genetic analysis should be warranted for androgen biosynthesis defects in all cases.     

Comparison of continuous subcutaneous insulin infusion (CSII) and multiple daily injections (MDI) in paediatric Type 1 diabetes: a multicentre matched‐pair cohort analysis over 3 years

Aims To conduct a multicentre, matched‐pair cohort analysis comparing glycaemic control and adverse events of continuous subcutaneous insulin infusion (CSII) with multiple daily injections (MDI) in paediatric patients. Methods Using standardized computer‐based prospective documentation, HbA_1c, insulin dose, body mass index–standard deviation score (BMI–SDS), rate of hypoglycaemia, rate of diabetic ketoacidosis (DKA) and intensity of care were analysed in 434 matched pairs during a follow‐up period of 3 years after initiation of MDI or CSII. Results HbA_1c was significantly lower in the CSII group during the first year of new regimen (CSII 7.5 ± 0.05 vs. MDI 7.7 ± 0.06; P < 0.05), but rose to the same level as in the MDI group during year 3. Insulin requirement remained significantly lower in the CSII group. The BMI–SDS increased in both study groups, with no significant difference. The rate of severe hypoglycaemia decreased significantly after the change of regimen (CSII 17.87 ± 2.85 vs. MDI 25.14 ± 3.79; P < 0.05) and during year 3 of the regimen, particularly when compared with baseline (?21% vs. ?16%). The rate of DKA was lower at baseline in the CSII group and remained significantly lower over all 3 years. Intensity of care was the same in both subsets. Conclusions Employing a large cohort, this matched‐pair analysis has demonstrated over a 3‐year study period that CSII is a safe form of intensive insulin therapy with similar glycaemic effects, but with significantly reduced rates of hypoglycaemia and DKA and a lower insulin requirement when compared with MDI.     

Homozygous disruption of P450 side-chain cleavage (CYP11A1) is associated with prematurity, complete 46,XY sex reversal, and severe adrenal failure

Disruption of the P450 side-chain cleavage cytochrome (P450scc) enzyme due to deleterious mutations of the CYP11A1 gene is thought to be incompatible with fetal survival because of impaired progesterone production by the fetoplacental unit. We present a 46,XY patient with a homozygous disruption of CYP11A1. The child was born prematurely with complete sex reversal and severe adrenal insufficiency. Laboratory data showed diminished or absent steroidogenesis in all pathways. Molecular genetic analysis of the CYP11A1 gene revealed a homozygous single nucleotide deletion leading to a premature termination at codon position 288. This mutation will delete highly conserved regions of the P450scc enzyme and thus is predicted to lead to a nonfunctional protein. Both healthy parents were heterozygous for this mutation. Our report demonstrates that severe disruption of P450scc can be compatible with survival in rare instances. Furthermore, defects in this enzyme are inherited in an autosomal-recessive fashion, and heterozygote carriers can be healthy and fertile. The possibility of P450scc-independent pathways of steroid synthesis in addition to the current concept of luteoplacental shift of progesterone synthesis in humans has to be questioned.     

Analyzing the functional and structural consequences of two point mutations (P94L and A368D) in the CYP11B1 gene causing congenital adrenal hyperplasia resulting from 11-hydroxylase deficiency

CONTEXT: Congenital adrenal hyperplasia is a group of autosomal recessive inherited disorders of steroidogenesis. The deficiency of steroid 11-hydroxylase (CYP11B1) resulting from mutations in the CYP11B1 gene is the second most frequent cause. OBJECTIVE: We studied the functional and structural consequences of two CYP11B1 missense mutations, which were detected in a 1.8-yr-old boy with acne and precocious pseudopuberty, to prove their clinical relevance and study their impact on CYP11B1 function. RESULTS: The in vitro expression studies in COS-7 cells revealed an almost complete absence of CYP11B1 activity for the P94L mutant to 0.05% for the conversion of 11-deoxycortisol to cortisol. The A368D mutant severely reduced the CYP11B1 enzymatic activity to 1.17%. Intracellular localization studies by immunofluorescence revealed that the mutants were correctly localized. Introducing these mutations in a three-dimensional model structure of the CYP11B1 protein provides a possible explanation for the effects measured in vitro. We hypothesize that the A368D mutation interferes with structures important for substrate specificity and heme iron binding, thus explaining its major functional impact. However, according to structural analysis, we would expect only a minor effect of the P94L mutant on 11-hydroxylase activity, which contrasts with the observed major effect of this mutation both in vitro and in vivo. CONCLUSION: Analyzing the in vitro enzyme function is a complementary procedure to genotyping and a valuable tool for understanding the clinical phenotype of 11-hydroxylase deficiency. This is the basis for accurate genetic counseling, prenatal diagnosis, and treatment. Moreover, the combination of in vitro enzyme function and molecular modeling provides valuable insights in cytochrome P450 structural-functional relationships, although one must be aware of the limitations of in silico-based methods.