| 1. |
|
|
| 2. |
|
|
| 3. |
- Giwercman, YL, et al.
(författare)
-
Response to treatment in patients with partial androgen insensitivity due to mutations in the DNA-binding domain of the androgen receptor
- 2000
-
Ingår i: Hormone research. - : S. Karger AG. - 0301-0163. ; 53:2, s. 83-88
-
Tidskriftsartikel (refereegranskat)abstract
- The androgen insensitivity syndrome is a disorder caused by deficient function of the androgen receptor, characterized by varying degrees of undermasculinization in karyotypic males. We have identified four mutations in the androgen receptor gene, in the region encoding the DNA-binding domain of the protein. Two mutations, R607X and R615G, were found in patients with complete insensitivity to androgens, whereas the other two, S578T and A596T, were found in patients with partial insensitivity. The functional consequences of the three missense mutations were assayed in vitro after transient expression of the receptors in COS cells. All mutants showed normal androgen binding but abnormal abilities to stimulate transcription of an androgen-responsive reporter gene. R615G abolished transactivation whereas S578T and A596T were partially malfunctional. The function of A596T, but not of S578T, was normalized at high androgen concentrations in vitro, reflecting the in vivo situation. Thus, patients with specific mutations in the DNA-binding domain of the androgen receptor may benefit from androgen treatment.
|
|
| 4. |
- Aschim, EL, et al.
(författare)
-
Linkage between cryptorchidism, hypospadias, and GGN repeat length in the androgen receptor gene
- 2004
-
Ingår i: Journal of Clinical Endocrinology and Metabolism. - : The Endocrine Society. - 1945-7197 .- 0021-972X. ; 89:10, s. 5105-5109
-
Tidskriftsartikel (refereegranskat)abstract
- 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.
|
|
| 5. |
|
|
| 6. |
- Bonde, J P, et al.
(författare)
-
Sperm count and chromatin structure in men exposed to inorganic lead: lowest adverse effect levels
- 2002
-
Ingår i: Occupational and Environmental Medicine. - 1470-7926. ; 59:4, s. 234-234
-
Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVES: To obtain knowledge on male reproductive toxicity of inorganic lead at current European exposure levels and to establish lowest adverse effect levels, if any. METHODS: A cross sectional survey of the semen of 503 men employed by 10 companies was conducted in the United Kingdom, Italy, and Belgium. The mean blood lead concentration was 31.0 microg/dl (range 4.6-64.5) in 362 workers exposed to lead and 4.4 microg/dl (range below the detection limit of 19.8) in 141 reference workers. Semen volume and sperm concentration were determined in a fresh semen sample according to an agreed protocol subject to quality assurance. The sperm chromatin structure assay (SCSA) was performed at a centralised laboratory. Extraneous determinants including centre, period of sexual abstinence, and age were taken into account in the statistical analysis. If appropriate, possible thresholds were examined by iterative threshold slope linear regression. RESULTS: The median sperm concentration was reduced by 49% in men with blood lead concentration above 50 microg/dl. There was no indication of a linear trend of lower sperm concentration with increasing blood lead values, but threshold slope least square regression identified a blood lead concentration of 44 microg/dl (beta=-0.037, F=4.35, p=0.038) as a likely threshold. Abnormal sperm chromatin structure was not related to blood lead concentration, but some indications of deterioration of sperm chromatin was found in men with the highest concentrations of lead within spermatozoa. Biological monitoring data did not indicate long term effects of lead on semen quantity or sperm chromatin. CONCLUSION: Adverse effects of lead on sperm concentration and susceptibility to acid induced denaturation of sperm chromatin are unlikely at blood lead concentrations below 45 microg/dl. Effects of low level exposure to lead on other measures of testicular function cannot be ruled out.
|
|
| 7. |
- Richthoff, Jonas, et al.
(författare)
-
Serum Levels of 2,2,4,4,5,5 -Hexachlorobiphenyl (CB-153) in Relation to Markers of Reproductive Function in Young Males from the General Swedish Population.
- 2003
-
Ingår i: Environmental Health Perspectives. - : Environmental Health Perspectives. - 1552-9924 .- 0091-6765. ; 111:4, s. 409-413
-
Tidskriftsartikel (refereegranskat)abstract
- A time-related deterioration in male reproductive function caused by exposure to endocrine disrupters, including persistent organochlorines (POCs), has been hypothesized. In animal studies, POCs were found to have adverse effects on male reproductive function. However, little is known about the impact of POC exposure on reproductive parameters in men. In a study of 305 young Swedish men 18-21 years old from the general population, we correlated lipid-adjusted serum levels of 2,2´,4,4´,5,5´-hexachlorobiphenyl (CB-153)--an index substance for POC exposure--to markers of male reproductive function: testis size assessed by ultrasound, sperm concentration, total sperm count, sperm motility assessed manually and with a computer-aided sperm analyzer (CASA), and serum levels of follicle-stimulating hormone, inhibin B, testosterone, sexual hormone-binding globulin (SHBG), luteinizing hormone, and estradiol. We found weak but statistically significant, negative correlations between CB-153 levels and both the testosterone:SHBG ratio (r = -0.25, p < 0.001)--a measure of the biologically active free testosterone fraction--and CASA sperm motility (r = -0.13, p = 0.02). No statistically significant association with other seminal, hormonal, or clinical markers of male reproductive function was found. In previous studies of more highly POC-exposed groups of adult men, the correlation between POC exposure, including CB-153, and free testosterone levels was not statistically significant. The present study gives some tentative support for weak negative effects of CB-153 exposure on sperm motility and free testosterone levels in young men, but further semen studies on more highly exposed groups may give more firm conclusions on the hazard for male reproductive function from dietary POC exposure. Key words: dioxin, male reproduction, PCB, reproductive hormones, semen quality, sperm concentration, sperm motility.
|
|
| 8. |
|
|
| 9. |
|
|
