Although sufficient androgen receptor (AR) function is crucial for normal male sexual differentiation, single-point mutations in the AR gene are infrequent in the two most common male congenital malformations, hypospadias and cryptorchidism. Because polymorphic CAG and GGN segments regulate AR function, we investigated whether there was any association between these polymorphisms and mentioned malformations. Genotyping was performed by direct sequencing of DNA from patients diagnosed with hypospadias (n = 51) and cryptorchidism (n = 23) and controls (n = 210). The subjects with hypospadias were divided into subgroups of glanular, penile, and penoscrotal hypospadias. Median GGN lengths were significantly higher (24 vs. 23) among both subjects with cryptorchidism, compared with controls (P = 0.001), and those with penile hypospadias, compared with either controls (P = 0.003) or glanular and penoscrotal hypospadias combined (P = 0.018). The frequency of cases with GGN 24 or more vs. GGN = 23, differed significantly among those with cryptorchidism (65/35%), compared with controls (31/54%) (P = 0.012), and among subjects with penile hypospadias (69/31%), compared with either controls (P = 0.035) or glanular or penoscrotal hypospadias combined (32/55%) (P = 0.056). There were no significant differences in CAG lengths between the cases and controls. Our findings indicate an association between GGN length and the risk of cryptorchidism and penile hypospadias, both conditions considered consequences of low androgenicity.
It has been proposed that hypospadias, cryptorchidism and testicular cancer, as well as decreasing sperm quality are symptoms of an underlying entity called testicular dysgenesis syndrome (TDS). We wanted to study the risk factors for hypospadias and compare them with those of the other conditions belonging to TDS. A large case-control study was undertaken on data on all live-born boys registered in the Medical Birth Registry of Norway during the period 1967-1998 (n = 961 396; hypospadias cases = 2382). Logistic regression analysis was used to study the association between potential risk factors and hypospadias, estimated by odds ratio (OR). The risk factors for hypospadias were divided into four categories: (i) maternal characteristics, e.g. low parity [p(trend) < 0.001], hypertension (OR = 1.49) and bleeding (OR = 1.39) during index pregnancy, and (pre)eclampsia (OR = 1.84); (ii) complications during delivery, e.g. retained placenta (OR = 1.67) or Caesarean section (OR = 1.36); (iii) characteristics of the newborn, e.g. low birth weight [p(trend) < 0.001], small for gestational age (OR = 2.16), and presence of congenital malformations other than hypospadias (OR = 2.72), e.g. inguinal hernia (OR = 5.65); (iv) prevalence among relatives of hypospadias cases, e.g. brother with hypospadias (OR = 20.81). The novel finding of retained placenta as a risk factor indicates that early malfunction of placenta could be a causative factor for hypospadias. When comparing with previously published risk factors for hypospadias, cryptorchidism and testicular cancer, we found that the following risk factors were common to all three conditions: low parity, low birth weight, low gestational age, inguinal hernia, bleeding during pregnancy and Caesarean section. In conclusion, our results support the notion that the conditions of TDS share risk factors.
Polymorphisms in ERbeta may have modulating effects on human spermatogenesis. The phenotype of TDS seems to be, at least partly, determined by the genotype.
There is still controversy as to how body mass index (BMI) affects male reproduction. We investigated how BMI is associated with semen quality and reproductive hormones in 166 men, including 38 severely obese men. Standard semen analysis and sperm DNA integrity analysis were performed, and blood samples were analysed for reproductive hormones. Adjusted for age and time of abstinence, BMI was negatively associated with sperm concentration (B = -0.088, P = 0.009), total sperm count (B = -0.223, P = 0.001), progressive sperm motility (B = -0.675, P = 0.007), normal sperm morphology (B = -0.078, P = 0.001), and percentage of vital spermatozoa (B = -0.006, P = 0.027). A negative relationship was observed between BMI and total testosterone (B = -0.378, P < 0.001), sex hormone binding globulin (B = -0.572, P < 0.001), inhibin B (B = -3.120, P < 0.001) and anti-Müllerian hormone (AMH) (B = -0.009, P < 0.001). Our findings suggest that high BMI is negatively associated with semen characteristics and serum levels of AMH.
The purpose of this study is to provide insight into shortterm professionalization of teachers regarding teaching socioscientific issues (SSI). The study aimed to capture the development of science teachers' pedagogical content
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