Gonadoblastoma Y locus genes expressed in germ cells of individuals with dysgenetic gonads and a Y chromosome in their karyotypes include DDX3Y and TSPY.

STUDY QUESTION: Which Y genes mapped to the 'Gonadoblastoma Y (GBY)' locus on human Y chromosome are expressed in germ cells of individuals with some Differences of Sexual Development (DSD) and a Y chromosome in their karyotype (DSD-XY groups)? SUMMARY ANSWER: The GBY candidate genes DDX3Y and TSPY are expressed in the germ cells of DSD-XY patients from distinct etiologies: patients with mixed gonadal dysgenesis (MGD) and sex chromosome mosaics (45,X0/46,XY; 46,XX/46,XY); patients with complete androgen insensitivity (CAIS), patients with complete gonadal dysgenesis (CGD; e.g. Swyer syndrome). WHAT IS KNOWN ALREADY: A GBY locus was proposed to be present on the human Y chromosome because only DSD patients with a Y chromosome in their karyotype have a high-although variable-risk (up to 55%) for germ cell tumour development. GBY was mapped to the proximal part of the short and long Y arm. TSPY located in the proximal part of the short Y arm (Yp11.1) was found to be a strong GBY candidate gene. It is expressed in the germ cells of DSD-XY patients with distinct etiologies but also in foetal and pre-meiotic male spermatogonia. However, the GBY region extends to proximal Yq11 and therefore includes probably more than one candidate gene. STUDY DESIGN, SIZE, DURATION: Protein expression of the putative GBY candidate gene in proximal Yq11, DDX3Y, is compared with that of TSPY in serial gonadal tissue sections of 40 DSD-XY individuals from the three DSD patient groups (MGD, Complete Androgen Insensitivity Syndrome [CAIS], CGD) with and without displaying malignancy. Expression of OCT3/4 in the same tissue samples marks the rate of pluripotent germ cells. PARTICIPANTS/MATERIALS, SETTING, METHOD: A total of 145 DSD individuals were analysed for the Y chromosome to select the DSD-XY subgroup. PCR multiplex assays with Y gene specific marker set score for putative microdeletions in GBY Locus. Immunohistochemical experiments with specific antisera mark expression of the GBY candidate proteins, DDX3Y, TSPY, in serial sections of the gonadal tissue samples; OCT3/4 expression analyses in parallel reveal the pluripotent germ cell fraction. MAIN RESULTS AND THE ROLE OF CHANCE: Similar DDX3Y and TSPY protein expression patterns were found in the germ cells of DSD-XY patients from each subgroup, independent of age. In CAIS patients OCT3/4 expression was often found only in a fraction of these germ cells. This suggest that GBY candidate proteins are also expressed in the non-malignant germ cells of DSD-XY individuals like in male spermatogonia. LIMITATIONS, REASONS FOR CAUTION: Variation of the expression profiles of GBY candidate genes in the germ cells of some DSD-XY individuals suggests distinct transcriptional and translational control mechanisms which are functioning during expression of these Y genes in the DSD-XY germ cells. Their proposed GBY tumour susceptibility function to transform these germ cells to pre-malignant GB/Germ Cell Neoplasia in Situ (GB/GCNIS) cells seems therefore to be limited and depending on their state of pluripotency. WIDER IMPLICATIONS OF THE FINDINGS: These experimental findings are of general importance for each individual identified in the clinic with DSD and a Y chromosome in the karyotype. To judge their risk of germ cell tumour development, OCT3/4 expression analyses on their gonadal tissue section is mandatory to reveal the fraction of germ cells still being pluripotent. Comparative expression analysis of the GBY candidate genes can be helpful to reveal the fraction of germ cells with genetically still activated Y chromosomes contributing to further development of malignancy if at high expression level. STUDY FUNDING/COMPETING INTEREST(S): This research project was supported by a grant (01GM0627) from the BMBF (Bundesministerium für Bildung und Forschung), Germany to P.H.V. and B.B. The authors have no competing interests.

Conserved Hypothalamic c-Fos Activation Pattern Induced by the mGlu5 Receptor Antagonist MPEP during Peri-pubertal Development in Mice.

INTRODUCTION: 2-Methyl-6-(phenylethynyl)pyridine (MPEP) is a selective mGlu5 receptor (mGluR5) antagonist intensively studied as potential novel anxiolytic drug. In the adult, MPEP activates stress-related areas, including the paraventricular nucleus of the hypothalamus (PVNh). However, it is unknown if MPEP targets similar structures in the juvenile brain as well. METHODS: Here we examined by immunohistochemical methods the induction pattern of the neuronal activity marker c-Fos by MPEP at peri-pubertal stages (postnatal day P16, P24, P32 and P40) in C57BL6/N mice. RESULTS: Despite the previously reported sharply diminished hypothalamic mGluR5 expression during postnatal development, we found a highly conserved PVNh activation by MPEP together with c-Fos expression in the extended amygdala. Interestingly, MPEP also robustly activated the paraventricular nucleus of the thalamus (PVT) and suprachiasmatic nucleus (SCN), regions associated with the modulation of circadian rhythms. DISCUSSION: These results indicate a conserved activation pattern induced by MPEP in the young vs. adult brain especially in brain areas regulating stress and circadian rhythms and may be of importance regarding the effect of mGluR5 antagonists in the treatment of mood disorders during juvenile development.

Long-term Surveillance of Children with Congenital Hypothyroidism: Data from the German Registry for Congenital Hypothyroidism (AQUAPE "Hypo Dok").

BACKGROUND: The German study group for quality assurance in pediatric endocrinology and the University of Ulm have established a software ("Hypo Dok") for the documentation of longitudinal data of patients with congenital primary hypothyroidism (CH). Aim of this study was to analyse the long-term follow-up of patients with CH and to compare treatment with current guidelines. METHODS/PATIENTS: Anonymised data of 1,080 patients from 46 centres were statistically analysed. RESULTS: Newborn screening result was available at a mean age of 7.3 days. Confirmation of the diagnosis was established at 8.4 days and therapy was started at 11 days. The average screening TSH was 180.0 mIU/L. During the first 3 months mean levothyroxine (LT4) dose was 10.7 µg/kg/day or 186.0 µg/m²/day. Weight-, BMI- and height-SDS did not differ significantly from the normal population. Only 25% of the patients (n=262) underwent formal EQ/IQ-testing. Their average IQ was 98.8 ± 13.2 points. DISCUSSION: In Germany screening, confirmation and start of treatment of CH are within the recommended time frame of 14 days. Initial LT4-doses are adequate. The auxological longterm outcome of young CH patients is normal. The implementation of standardized IQ testing has to be improved in routine patient care. CONCLUSION: Longitudinal data of patients with CH was analysed and compared to current guidelines. Confirmation and start of treatment are according to the recommendations. However standardised IQ testing requires improvement.

Low androgen signaling rescues genome integrity with innate immune response by reducing fertility in humans.

Development of the gonads under complex androgen regulation is critical for germ cells specification. In this work we addressed the relationship between androgens and genomic integrity determining human fertility. We used different study groups: individuals with Differences of Sex Development (DSD), including Complete Androgen Insensitivity Syndrome (CAIS) due to mutated androgen receptor (AR), and men with idiopathic nonobstructive azoospermia. Both showed genome integrity status influenced by androgen signaling via innate immune response activation in blood and gonads. Whole proteome analysis connected low AR to interleukin-specific gene expression, while compromised genome stability and tumorigenesis were also supported by interferons. AR expression was associated with predominant DNA damage phenotype, that eliminated AR-positive Sertoli cells as the degeneration of gonads increased. Low AR contributed to resistance from the inhibition of DNA repair in primary leukocytes. Downregulation of androgen promoted apoptosis and specific innate immune response with higher susceptibility in cells carrying genomic instability.

Is the response to growth hormone in short children born small for gestational age dependent on genetic or maternal factors?

BACKGROUND/AIMS: We investigated whether genetic or maternal/environmental risk factors for being born small for gestational age (SGA), e.g. Silver-Russell syndrome, congenital heart defects, infections of mothers or smoking during pregnancy, explain the variation in the first-year growth response to GH therapy. METHODS: Secondary analysis was made of growth response in 135 short prepubertal German children (66% males) enrolled in a SGA phase III trial. Initial mean patient age was 6.8 +/- 2.6 years; mean patient height SDS -3.8 +/- 1.2, and GH treatment dose was 0.066 mg/kg body weight per day. RESULTS: Growth velocity increased by 4.5 +/- 2.0 cm/year and height SDS by 1.0 +/- 0.5 SDS. Although patient number was limited and variation was high, both growth response (cm/year) and change in height SDS did not appear to differ between subgroups which also did not differ in terms of Studentized residuals set up in the KIGS growth prediction model for SGA. Likewise, in a step-forward multivariate analysis, the variables Silver-Russell syndrome, congenital heart defects, infections of mothers and smoking were not identified as independent factors influencing growth velocity. CONCLUSION: The retrospectively analyzed genetic and maternal/environmental risk factors for SGA do not appear to explain the observed patient variance in response to GH. Larger prospective studies are needed, however, to substantiate these preliminary findings.

Feminising genitoplasty: one-stage genital reconstruction in congenital adrenal hyperplasia: 30 years' experience.

The study objective is to evaluate the results of our surgical technique for children with congenital adrenal hyperplasia and ambiguous genitalia at the University Hospital of Heidelberg, Department of Paediatric Surgery. The records of 19 patients with congenital adrenal hyperplasia treated between 1972 and 2004 were reviewed with respect to age at surgery, operative procedures and outcome. We describe the recession clitoroplasty technique currently used in our hospital and highlight the importance of short and long-term follow-up results with respect to appearance, position and size of the clitoris and quality of the vagina. One-stage recession clitoroplasty and vaginoplasty gives very satisfactory cosmetic and functional results, with few complications and a reduced need for secondary surgical interventions. The results of this study support the assumption that total correction can be achieved through a single-stage operation, performed in infancy.

Molecular basis of congenital adrenal hyperplasia due to 3 beta-hydroxysteroid dehydrogenase deficiency.

Congenital adrenal hyperplasia is the most frequent cause of adrenal insufficiency and ambiguous genitalia in newborn children. In contrast to congenital adrenal hyperplasia due to 21-hydroxylase and 11 beta-hydroxylase deficiencies, which impair steroid formation in the adrenal cortex, exclusively, classical 3 beta-hydroxysteroid dehydrogenase (3 beta-HSD) deficiency affects steroid biosynthesis in the gonads as well as in the adrenals. The structures of the highly homologous type I and II 3 beta-HSD genes have been analyzed in three male pseudohermaphrodite 3 beta-HSD deficient patients from unrelated families in order to elucidate the molecular basis of classical 3 beta-HSD deficiency from patients exhibiting various degrees of severity of salt losing. The nucleotide sequence of DNA fragments generated by selective polymerase chain reaction amplification that span the four exons, the exon-intron boundaries, as well as the 5'-flanking region of each of the two 3 beta-HSD genes have been determined in the three male patients. The five point mutations characterized were all detected in the type II 3 beta-HSD gene, which is the gene predominantly expressed in the adrenals and gonads, while no mutation was detected in the type I 3 beta-HSD gene, predominantly expressed in the placenta and peripheral tissues. The two male patients suffering from severe salt-losing 3 beta-HSD deficiency are compound heterozygotes, one bearing the frame-shift mutation 186/insC/187 and the missense mutation Y253N, while the other bears the nonsense mutation W171X and the missense mutation E142K. The influence of the detected missense mutations on enzymatic activity was assessed by in vitro expression analysis of mutant recombinant enzymes generated by site-directed mutagenesis in heterologous mammalian cells. Recombinant mutant type II 3 beta-HSD enzymes carrying Y253N or E142K substitutions exhibit no detectable activity. On the other hand, the nonsalt-losing patient is homozygous for the missense mutation A245P. This mutation decreases 3 beta-HSD activity by approximately 90%. The present findings, describing the first missense mutations in the human type II 3 beta-HSD gene, provide unique information on the structure-activity relationships of the 3 beta-HSD superfamily. Moreover, the present findings provide a molecular explanation for the enzymatic heterogeneity responsible for the severe salt-losing form to the clinically inapparent salt-wasting form of classical 3 beta-HSD deficiency.(ABSTRACT TRUNCATED AT 400 WORDS)

Analyses of Gonadoblastoma Y (GBY)-locus and of Y centromere in Turner syndrome patients.

BACKGROUND: Mosaicism with cytogenetically visible Y chromosome is found in 5-6% of Turner Syndrome (TS) patients. Additionally, occult Y-chromosome derived material is increasingly found in patients with monosomy X when using more sensitive molecular techniques. These TS patients are at risk of developing gonadoblastomas when the Y genes presumed to be involved in gonadoblastoma development (Gonadoblastoma-Y-locus; GBY) are present. AIM: To find occult Y-chromosome material in TS patients and to correlate the patient's phenotype to Y-chromosome material. METHODS: We studied 60 TS-patients for presence of the Y chromosome with focus on the Gonadoblastoma Y-locus and its extension in Yp and Yq using sensitive Y centromere and Y gene deletion PCR assays. In addition, we evaluated their individual clinical and auxological characteristics. RESULTS: We identified presence of the GBY-locus in 7 patients (11.7%) including 4 patients without evidence for a Y chromosome in their preceding standard karyotype analyses. Clinical and auxological characteristics were similar in GBY-positive and GBY-negative patients. CONCLUSIONS: Presence of the GBY locus in Turner patients with no indication of the Y chromosome in standard cytogenetic chromosome analysis can be revealed by sensitive molecular PCR assays screening for presence of the Y centromere and the GBY-candidate-genes in proximal Yp11 and Yq11, respectively.

Hormone ontogeny in the ovine fetus: XXI. The effect of insulin-like growth factor-I on plasma fetal growth hormone, insulin and glucose concentrations.

We infused intravenously recombinant human Insulin-like Growth Factor-I (IGF-I; 1 microgram/kg/min for 120 minutes after an acute dose of 25 micrograms/kg) into chronically catheterized ovine fetuses (124-132 days gestation) to study its effect on the secretion of fetal ovine Growth Hormone (oGH). In all IGF-I infused fetuses, oGH concentrations fell during the infusion. The maximal change in the concentration of oGH (mean +/- SEM) was -54 +/- 10 ng/ml in contrast to +7 +/- 6 ng/ml in saline controls (p less than 0.005), a decrease of 33 +/- 4% (controls: +6 +/- 5%; p less than 0.005). By 60 minutes after the infusion of IGF-I was completed, the concentration of plasma oGH was comparable to control and pre-infusion values. In IGF-I infused fetuses, the mean concentration of insulin also decreased (p less than 0.02), whereas glucose levels remained unaltered. The results suggest that the lack of inhibitory feedback by the relatively low levels of circulating IGF-I is one factor in the hypersecretion of GH by the fetus.

Hormone ontogeny in the ovine fetus. XXIII. Pulsatile administration of follicle-stimulating hormone stimulates inhibin production and decreases testosterone synthesis in the ovine fetal gonad.

Inhibin, a gonadal glycoprotein with selective FSH-suppressing activity, is synthesized by the Sertoli cell of the testis and the granulosa cell of the ovary mediated by the action of FSH. It is not known whether inhibin is produced by the fetal testes and ovaries or if FSH has the capacity to stimulate inhibin production by the fetal gonad. To explore these questions, we examined the bioactive inhibin content of the gonads of 16 chronically catheterized sheep fetuses between 111 and 143 days gestational age (0.7-0.95 gestation) in an ovine pituitary bioassay. Both the fetal testes and ovary contained inhibin activity (testes, 53.5-1,240 U inhibin/g tissue; ovaries, 58.5-2,250 U/g). After pulsatile administration of oFSH (5 micrograms every 3 h) to the fetus for 5 days in 1 fetus and 10 days in 2 fetuses, 10-day gonadal inhibin content of fetal testes increased to 5,080 +/- 3,180 U/testes (n = 3) vs. 165 +/- 50 U/testes in controls (n = 8; P less than 0.02); the concentration of testicular inhibin in these features rose to a mean of 9,100 +/- 6,620 vs. 415 +/- 126 U/g tissue in controls (P less than 0.01). Ovarian inhibin content in female fetuses given ovine FSH for 10 days was 5,220 +/- 4,920 U/ovary (n = 4) compared to 40 +/- 16 U/ovary in controls (n = 4); the inhibin concentration was 41,000 +/- 30,000 U/g in ovaries of FSH-treated fetuses vs. 1,190 +/- 960 U/g in controls. The ovary of 1 female fetus contained several large follicles and the highest inhibin concentration. Unexpectedly, FSH administration was associated with a decrease in testosterone content in the fetal testes and ovaries. The testosterone content was 0.54 +/- 0.42 ng/ovary after FSH treatment (n = 4) vs. 2.11 +/- 0.68 ng/ovary in controls (n = 4; P less than 0.02). The testosterone concentration fell to 5.8 +/- 2.0 ng/g in treated female fetuses vs. 60.3 +/- 14.6 ng/g in controls (P less than 0.0005). The testosterone content in fetal testes decreased to 21.7 +/- 6.9 ng/testes in FSH-treated fetuses (n = 3) vs. 75.1 +/- 24.0 ng/testes in controls (n = 5; P less than 0.04); the testosterone concentration fell to 38.6 +/- 16.1 ng/g tissue compared to 223.0 +/- 88.7 ng/g in untreated controls (P less than 0.03). In male fetuses the concentration of plasma testosterone decreased to 15.5 +/- 2.3 ng/dl after FSH treatment, significantly lower than 39.6 +/- 4.5 ng/dl in controls (P less than 0.02).(ABSTRACT TRUNCATED AT 400 WORDS)

Hormone ontogeny in the ovine fetus. XXVII. Pulsatile and copulsatile secretion of luteinizing hormone, follicle-stimulating hormone, growth hormone, and prolactin in late gestation: a new method for the analysis of copulsatility.

To analyze the secretion patterns of LH, FSH, GH, and PRL in the late gestational sheep fetus in vivo, we measured simultaneous plasma levels of these hormones during a period of frequent sampling under basal conditions (samples every 15 min for 5 h) in 17 chronically catheterized sheep fetuses. To calculate mean plasma levels and areas under the curve, we analyzed hormone pulses and coincident pulse patterns to assess interactions between the release of these pituitary hormones. Mean plasma levels for all fetuses were: LH, 0.8 +/- 0.2 ng/ml (mean +/- SEM); FSH, 4.6 +/- 0.7 ng/ml; GH, 136.6 +/- 16.5 ng/ml; and PRL, 40.5 +/- 10.3 ng/ml. Pulse analysis detected 20 LH pulses during 5100 min of total sampling time, which gave a mean interpulse interval of 255.0 min. For GH, 37 pulses were detected; the mean interpulse interval was 129.7 min. Twenty PRL pulses yielded a mean interpulse interval of 225.0 min. FSH pulses could not be analyzed due to the long half-life of this hormone, but hormone level fluctuations were screened for maxima. A new method was developed to detect an interaction between hormone pulses. The probability of the simultaneous occurrence of hormone pulses was calculated and compared with the rate of coincidences found in the experiments. Analysis of copulsatile release of LH, GH, and PRL revealed 11 GH pulses coinciding with the LH pulses (P = 0.0020). An interaction between the pulsatile release of LH and GH can, therefore, be assumed. There was also a significant interaction between GH and PRL. Seven PRL pulses preceded the GH pulses by 15 min (P = 0.0014). In contrast, no significant copulsatile release could be observed between LH and PRL; 95.5% of LH pulses were accompanied by a maximum FSH level, suggesting an interaction between LH and FSH secretion. In summary, we show that LH, GH, and PRL (and possibly FSH) are secreted in a pulsatile fashion in the ovine fetus. Furthermore, the pulsatile releases of LH, FSH, and GH as well as GH and PRL are temporarily coupled, as demonstrated by a significant number of coincident pulses between LH/GH and GH/PRL and a high number of FSH hormone maxima concomitant with LH pulses.

Regulation of growth hormone (GH) secretion by GH-releasing factor, somatostatin, and insulin-like growth factor I in ovine fetal and neonatal pituitary cells in vitro.

Serum GH concentrations in the ovine fetus are much higher than those in the neonate, and the maximal GH response induced by GRF is 5-fold greater in the fetus than in the neonate. To clarify these in vivo observations further, we studied the effects of GRF, somatostatin (SRIF), and insulin-like growth factor I (IGF-I) on primary cultures of fetal and neonatal ovine pituitary cells. GH secretion from fetal ovine pituitary cells increased from 148 +/- 34 to 950 +/- 130 ng/10(5) cells.3 h in response to 1 nM GRF, whereas GH secretion from neonatal pituitary cells rose from 113 +/- 26 to 1221 +/- 129 ng/10(5) cells.3 h, a significantly greater response (P less than 0.001). This greater GRF-induced GH response in neonatal than fetal cells differs from the response in vivo and suggests that the increased in vivo response in the fetus is not due to inherently increased sensitivity of pituitary cells to GRF. SRIF (10 nM) decreased maximal GRF-induced GH secretion by 37 +/- 3% in fetal cells compared with 59 +/- 8% in neonatal cells (P less than 0.01). This may explain in part the decreased in vivo sensitivity to SRIF in the ovine fetus compared to that in the neonatal lamb. In fetal pituitary cells, 10 nM GRF increased ovine (o) GH mRNA from 100 +/- 14% to 145 +/- 40%, SRIF decreased oGH mRNA to 84 +/- 3%, and GRF and SRIF in combination increased fetal oGH mRNA to 126 +/- 24%. Values in neonatal pituitary cell cultures were similar (control, 100 +/- 17%; GRF, 132 +/- 6%, SRIF, 85 +/- 15%; GRF plus SRIF, 105 +/- 26%). Pretreating fetal cells with 100 nM IGF-I for 3 days reduced GRF-stimulated GH secretion from 1049 +/- 38 to 232 +/- 8 ng/10(5) cells.3 h (P less than 0.001). Similarly, IGF-I pretreatment of neonatal cells reduced GRF-stimulated GH secretion from 810 +/- 18 to 419 +/- 16 ng/10(5) cells.3 h (P less than 0.001). The mean secreted IGF-I was 0.58 U/ml (36 nM) in culture medium from neonatal cells and was unchanged by incubation for 3 days with 5 micrograms/ml hGH. Secreted IGF-I in medium from fetal cells was 0.87 U/ml (54 nM) without GH and 0.81 U/ml (51 nM) after incubation with human GH. IGF-I mRNA was present in neonatal pituitary and brain.(ABSTRACT TRUNCATED AT 400 WORDS)

Hormone ontogeny in the ovine fetus and neonatal lamb. XX. Effect of age, breeding season, and twinning on the growth hormone (GH) response to GH-releasing factor: evidence for a homeostatic role of fetal GH.

The ovine GH (oGH) response to GRF (1-44 amide) was evaluated in 74 chronically catheterized fetal and neonatal lambs. After a 1-h control period, GRF was administered iv, and the oGH response was studied during the next 60 min. The following variables were analyzed: GRF dose, fetal or neonatal age, breeding season, and singleton or multiple pregnancy. One and 10 micrograms/kg GRF elicited a similar oGH response, which was greater (P less than 0.001) than the response to 0.1 microgram/kg GRF. GRF-stimulated oGH release was strikingly age dependent. The mean peak incremental oGH response in fetuses of 89-122 days gestation (294 +/- 55 ng/ml) was higher (P less than 0.05) than that in fetuses of 127-145 days gestation (136 +/- 19 ng/ml); the fetal response was much greater (P less than 0.005) than the mean peak increment in neonatal lambs (46 +/- 7 ng/ml). A remarkable difference in basal and GRF-induced oGH secretion was observed in both fetuses and lambs of ewes bred in the normal breeding season (on-season) and those bred out of season (off-season). In the neonatal lamb, the mean basal oGH concentration was higher (P less than 0.005) in the on-season (12 +/- 2 ng/ml) than in the off-season (7 +/- 0.5 ng/ml) neonatal lambs, as was the mean peak incremental oGH response to GRF (70 +/- 12 vs. 33 +/- 7 ng/ml; P less than 0.01). In contrast, in singleton, late gestational fetuses (127-145 days), the mean basal oGH concentration was lower (P less than 0.03) in the on-season (74 +/- 9 ng/ml) than in the off-season (124 +/- 18 ng/ml) fetuses, as was the mean peak incremental oGH response to GRF (136 +/- 9 vs. 292 +/- 41 ng/ml; P less than 0.005). Further, compared to the on-season, late gestational singletons, on-season twin fetuses had higher (P less than 0.0001) basal oGH levels (199 +/- 19 ng/ml) and peak incremental oGH responses (248 +/- 11 ng/ml). Moreover, off-season twin fetuses had the highest basal GH concentrations and the most striking increment in GH concentration after GRF treatment of any of the groups. The strikingly age-dependent pattern of the GRF-induced oGH response in fetal and neonatal lambs is compatible with the concept that the inhibitory influences or their effects on the somatotrope increase gradually during late gestation and sharply at birth.(ABSTRACT TRUNCATED AT 400 WORDS)

Basal inhibin B and the testosterone response to human chorionic gonadotropin correlate in prepubertal boys.

During childhood, the quiescent phase of testicular activity, the hCG stimulation test is widely used to evaluate testicular function. Inhibin B, a gonadal peptide regulating FSH secretion, is an established marker of Sertoli cell function and spermatogenesis in adults. In contrast to the other hormones of the hypothalamo-pituitary-gonadal axis, inhibin B is also secreted in detectable amounts during childhood. The aim of this study was to determine whether basal inhibin B levels are able to predict prepubertal testicular function, so as to avoid a stimulation test. Inhibin B and testosterone before and after hCG stimulation were measured in 54 male children with various testicular disorders by an immunoassay specific for inhibin B. Basal inhibin B was compared to the testosterone increase after hCG. Inhibin B and the hCG-induced testosterone increment correlated strongly (r = 0.84; P<0.0001). Patients with anorchia were clearly distinguishable from those with abdominal testes, having undetectable (inhibin B, <15 pg/mL) respective normal inhibin B levels for age. Inhibin B and the testosterone response to hCG were low in boys with testicular damage (delayed diagnosis of cryptorchidism; after testicular torsion) and in patients with gonadal dysgenesis, but were normal or increased in children with androgen insensitivity syndrome. We conclude that basal inhibin B predicts the testosterone response to hCG in boys and therefore gives reliable information about both the presence and function of the testes. The diagnostic procedure in cryptorchidism may be reduced to a single inhibin B measurement. Furthermore, inhibin B levels show specific alterations in patients with sexual ambiguity, adding a valuable diagnostic tool to the complex differential diagnosis of male pseudohermaphroditism.

Growth retardation in Turner syndrome: aneuploidy, rather than specific gene loss, may explain growth failure.

The etiology of short stature (SST) in Turner syndrome (TS) is still a subject of speculation. A variety of hypotheses have been put forward, from SST as a result of increased intrauterine tissue pressure after fetal lymphedema to haploinsufficiency of a specific growth gene(s). These hypotheses have various statistical-auxological implications on the growth distribution in TS. Empirical research has provided no clear evidence for any of these theories, but the well known correlation between patients' and midparental height (MPH) could be established. The influence of undetected mosaic status has often been cited as a major problem in the investigation of growth in TS. However, an assessment of mosaic status (simultaneous analysis of karyotype and phenotype) and its effect on growth with inclusion of MPH has been not yet carried out for a large sample. The aim of this study was to evaluate growth and its complex relationship to mosaic status and MPH in TS. In a mixed cross-sectional and longitudinal study we retrospectively analyzed the auxological and clinical data of 447 patients with a pure loss of X-chromosomal material (n = 381 with 45,X0; n = 66 mosaics). The 447 patients were selected from a series of 609 consecutive patients with TS. To assess the effect of mosaic status on growth, we computed a bifactorial analysis of variance (phenotype, karyotype), including MPH as a covariate. In line with the mosaic hypothesis, we found a correlation between individual loss of X-chromosomal material and phenotypical expressivity. In contrast, no correlation was found with respect to growth. With respect to MPH, we found growth retardation (GR) even in those patients with "normal" height above the third percentile (-2 or more SD score). The interindividual variance of GR in TS (comparable to growth variance in the normal population) seems to be unrelated to other TS-specific factors (e.g. mosaic status or single gene loss). Instead, both interindividual variance and the global growth shift distribution are best explained by the presence of an unspecific aneuploidic effect. Furthermore, consideration of patient height in relation to MPH should lead to a better understanding of the nature of GR in TS than the commonly used, strictly qualitative definition of SST.

Adult height after GH therapy in 188 Ullrich-Turner syndrome patients: results of the German IGLU Follow-up Study 2001.

OBJECTIVES: We aimed to evaluate the factors influencing true adult height (HT) after long-term (from 1987 to 2000) GH treatment in Ullrich-Turner syndrome (UTS) based on modalities conceived in the 1980s. DESIGN: Out of 347 near-adult (>16 Years) patients from 96 German centres, whose longitudinal growth was documented within KIGS (Pharmacia International Growth Database), 188 (45, X=59%; bone age >15 Years) were available for further anthropometric measurements. RESULTS: At a median GH dose of 0.88 (10th/90th percentiles: 0.47/1.06) IU/kg per week, a gain of 6.0 (-1.3/+13) cm above the projected adult height was recorded. Variables were recorded at GH start, after 1 Year GH, puberty onset, and last visit on GH therapy. At these visits, the median ages were 11.7, 12.7, 14.2, 16.6 and 18.7 Years; and median heights, 0.4, 1.1, 1.7, 1.7 and 1.3 SDS (UTS) respectively. Height gain (DeltaHT) after GH discontinuation was 1.5 cm. Total DeltaHT correlated (P<0.001) negatively with bone age and HT SDS at GH start, but positively with DeltaHT after the first Year, DeltaHT at puberty onset, and GH duration. Final HT correlated (P<0.001) positively with HT at GH start, first-Year DeltaHT, and HT at puberty onset. Body mass index increased slightly (P<0.05), with values at start and adult follow-up correlating highly (R=0.70, P<0.001). No major side effects of GH occurred. CONCLUSIONS: GH dosages conceived in the 1980s are safe but too low for most UTS patients. HT gain and height are determined by age and HT at GH start. Height gain during the first Year on GH is indicative of overall height gain. After spontaneous or induced puberty, little gain in height occurs.

Male pseudohermaphroditism caused by nonsalt-losing congenital adrenal hyperplasia due to 3 beta-hydroxysteroid dehydrogenase (3 beta-HSD) deficiency.

We observed a boy with ambiguous genitalia and normal testes. Steroid analyses performed during newborn age surprisingly were inconclusive basally and after hCG stimulation, but showed an insufficient testosterone response. Possibly during the early postnatal period the 3 beta-HSD activity in peripheral tissues may have been sufficient to substitute for the deficient 3 beta-HSD activity in the adrenal and gonads. In contrast at 11 and 22 months basal as well as ACTH stimulated levels of 17OHPreg, DHEA and testosterone were typical for a 3 beta-HSD defect.

Transport of insulin-like growth factor-I across endothelial cell monolayers and its binding to the subendothelial matrix.

Cultured human umbilical vein endothelial cells (HUVEC) were used as a model to study transendothelial IGF-I transport, and its deposition into the extracellular matrix (ECM). Specific binding of (125)I-IGF-I to HUVEC monolayers was demonstrated, which was inhibited by aIR-3, a specific antibody directed against the IGF-I receptor. ECM-associated (125)I-IGF-I was approximately 10% of cell-bound IGF-I at 22 degrees C, and increased 4.5-fold at 37 degrees C, indicating that endothelial metabolism is required for the transport. However, neither monensin and cytochalasin B, both of which block endocytosis, nor aIR-3 did inhibit transport of (125)I-IGF-I into the ECM. In order to characterize IGF-I binding to the subendothelial ECM, HUVEC were removed nonenzymatically by treatment with Triton X-100 and ammonia. Specific, saturable binding of (125)I-IGF-I to the isolated ECM was observed, which was protease-sensitive. Antibodies directed against vitronectin inhibited IGF-I binding to the matrix by 35%, while antibodies directed against other ECM proteins had no significant influence on IGF-I binding. Using radioimmunoassays the IGF binding protein-2 was detected in the ECM, while IGFBP-1 and IGFBP-3 were below the detection limits. In order to evaluate functional aspects of IGF-I binding to the matrix, HUVEC were incubated under serum-free conditions in the absence and presence of IGF-I. Under serum-free conditions 48% of cells rounded up and started to detach after 2 hours incubation, while only 23% of the cells started to detach in the presence of IGF-I. These data indicate that IGF-I is transported via a paracellular route across endothelial cells, and becomes bound to the subendothelial ECM. Vitronection seems to be involved in binding of IGF-I to the ECM. ECM-associated IGF-I might play a role in endothelial cell survival and stability.

Metabolites of the L-arginine-NO pathway in patients with left-to-right shunt.

OBJECTIVES: The endogenous production of metabolites of the L-arginine-NO pathway has been found to be altered in patients with left-to-right shunt and pulmonary hypertension. The objective of this study was to analyze the influence of age and of the magnitude of the left-to-right shunt on plasma levels of L-arginine, cyclic guanosine monophosphate (cGMP), nitrite and nitrate in children and young adults presenting with left-to-right shunt. METHODS: Twenty-nine patients with ventricular septal defect (n=18), atrial septal defect (n=6) and atrioventricular canal (n=5) were assigned to group I when the ratio of pulmonary to systemic blood flow (Qp/Qs) was less than 1.5 (n=10) and to group II when Qp/Qs > or = 1.5 (n=19). At cardiac catheterization blood samples were taken from the pulmonary vein or left ventricle. In 33 controls peripheral venous blood was obtained. cGMP levels were determined by radioimmunoassay, L-arginine, nitrite and nitrate by high performance liquid chromatography (HPLC). RESULTS: L-arginine plasma levels were lower in group II than in controls (51.7 [23.3-82.2] versus 60.5 [32.4-85.9] pmol/l; p < 0.05 by KRUSKAL-WALLIS). Age did not influence the L-arginine plasma levels (p = 0.30). cGMP levels depended on age (p<0.01) and mean pulmonary artery pressure (p <0.01) but not on high pulmonary blood flow (p=0.85; ANOVA). Plasma nitrite and nitrate were not different in both groups and when compared with controls (nitrite: 26.0 [23.5-31.0] micromol/l; nitrate: 26.8 [24.0-32.0] micromol/l). CONCLUSIONS: Age and pulmonary artery pressure exert important effects on plasma cGMP. Measurement of nitrite and nitrate in plasma alone may not reflect the endogenous NO production. Future studies should evaluate the role of plasma levels of L-arginine in patients with high pulmonary blood flow undergoing repair of their defect.

Diagnosis and management of juvenile hyperthyroidism in Germany: a retrospective multicenter study.

This retrospective multicenter study was designed to survey the management of childhood and adolescent hyperthyroidism in six pediatric endocrinological units in Germany. Fifty-six patients aged between 1.1 and 17.0 yr (median 10.5 yr) were enrolled. Data were collected retrospectively from the patients' records by a trained pediatric endocrinologist using standardized questionnaires. After the diagnosis of hyperthyroidism was established on the basis of clinical and biological findings, treatment with antithyroid drugs (carbimazole, methimazole, thiamazole, propylthiouracil) was started in all patients. In 55/56 of the patients treated with antithyroid drugs, euthyroidism was achieved (98%). However, 26 patients (47%) were still hyperthyroid after discontinuation of the medication. Eight children with continued hyperthyroidism ultimately underwent subtotal thyroidectomy 13-136 (median 28) months after the initial diagnosis. Management principles of the participating centers were heterogeneous. As a consequence, prospective multicenter studies are urgently needed to establish clear standards for the diagnosis and therapy of childhood hyperthyroidism.