| 11. |
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| 12. |
- Elzanaty, Saad, et al.
(författare)
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Duration of sexual abstinence: epididymal and accessory sex gland secretions and their relationship to sperm motility.
- 2005
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Ingår i: Human Reproduction. - : Oxford University Press (OUP). - 0268-1161 .- 1460-2350. ; 20:1, s. 221-225
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: The data on the association between the abstinence period and sperm motility are conflicting. METHODS: Ejaculates from 422 men assessed for infertility were analysed according to the World Health Organization (WHO) guidelines. Seminal plasma neutral alpha-glucosidase (NAG), prostate-specific antigen (PSA), zinc and fructose were measured. Three groups were defined according to the length of sexual abstinence: G(2-3) (2-3 days), G(4-5) (4-5 days) and G(6-7) (6-7 days). RESULTS: The total percentage of progressively motile spermatozoa was significantly higher in G(4-5) compared with G(2-3) and G(6-7) (medians 55 versus 47 and 42%: P = 0.039 and P < 0.001, respectively). The percentage of spermatozoa with tail defects was significantly higher in G(6-7) compared with G(2-3) and G(4-5) (medians 14 versus 10 and 10%; P = 0.011 and P = 0.002. respectively). NAG was significantly lower in G(2-3) compared with G(4-5) and G(6-7) (medians 23 versus 34 and 34mU/ejaculate; P < 0.001 and P = 0.001, respectively). The same trend was found regarding zinc (medians 6 versus 8 and 8 mumol/ejaculate; P = 0.001 and P = 0.005, respectively). CONCLUSIONS: Within the time interval recommended by the WHO (2-7 days), the length of the abstinence period is associated with sperm characteristics and should be taken into consideration when interpreting results of semen analysis.
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| 13. |
- Elzanaty, Saad, et al.
(författare)
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Significant impact of 5 alpha-reductase type 2 polymorphisms on sperm concentration and motility
- 2006
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Ingår i: International Journal of Andrology. - : Wiley. - 0105-6263 .- 1365-2605. ; 29:3, s. 414-420
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Tidskriftsartikel (refereegranskat)abstract
- Androgens, including 5 alpha-dihydrotestosterone (DHT), are known to play a role for spermatogenesis and accessory sex gland function. The enzyme 5 alpha-reductase (SRD5A) catalyses the conversion of testosterone to DHT. Our objective was to investigate whether polymorphisms in the SRD5A2 gene influence semen parameters in the general population. DNA from 182 Swedish military conscripts was examined for the A49T, V89L, and R227Q polymorphisms in the SRD5A type 2 gene. Ejaculates were analysed according to WHO guidelines. In addition, sperm motility was assessed using computer-aided sperm analysis (CASA). Seminal markers of epididymal (neutral alpha-glucosidase), prostatic (prostate specific-antigen and zinc), and seminal vesicles function (fructose) were measured. The A49TT-allele was associated with significantly higher sperm concentration compared with the wild type A-allele (mean: 102 x 10(6)/mL vs. 57 x 10(6)/mL, p = 0.02). The V89LV-genotype was correlated with significantly higher proportion progressive motile spermatozoa compared with the L-variant (mean: 55% vs. 48%, p = 0.04). The same trend was found regarding the CASA motile spermatozoa (mean: 52% vs. 41%, p = 0.02). No association between any of the polymorphisms and biochemical markers was found. SRD5A2 gene variants were associated with sperm concentration and motility, but not with epididymal and accessory sex gland markers. This effect on sperm parameters might therefore be exerted via a direct effect of DHT on spermatogenesis.
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| 14. |
- Erenpreiss, Juris, et al.
(författare)
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Intra-individual variation in sperm chromatin structure assay parameters in men from infertile couples: clinical implications.
- 2006
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Ingår i: Human Reproduction. - : Oxford University Press (OUP). - 0268-1161 .- 1460-2350. ; 21:2006 May 9, s. 2061-2064
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Sperm DNA integrity is an important factor in the prognosis of male fertility. In this study, we investigated intra-individual variation of sperm chromatin structure assay (SCSA) parameters in infertility patients undergoing assisted reproductive techniques (ARTs). METHODS: Retrospective study of 282 consecutive patients referred for ART [intrauterine insemination (IUI), IVF or ICSI] with repeated (between 2 and 5) SCSA measurements. RESULTS: Mean coefficient of variation (CV) of DNA Fragmentation Index (DFI) for repeated SCSA measurements was 29%. A high proportion [37%; 95% confidence interval (CI): 27%, 49%] of patients with DFI > 30% in the first test had DFI < 30% in the second test. Also, a considerable proportion (27%; 95% CI : 16%, 40%) of patients with 21-30% DFI values in the first test had DFI > 30% in the second test. CONCLUSIONS: Intra-individual variability in DFI is significant, therefore repeated SCSA measurements are recommended. The biological mechanisms behind these variations remain to be elucidated.
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| 15. |
- Erenpreiss, Juris, et al.
(författare)
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Sperm DNA damage in men from infertile couples
- 2008
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Ingår i: Asian Journal of Andrology. - : Medknow. - 1008-682X .- 1745-7262. ; 10:5, s. 786-790
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Tidskriftsartikel (refereegranskat)abstract
- Aim: To investigate the prevalence of high levels of sperm DNA damage among men from infertile couples with both normal and abnormal standard semen parameters. Methods: A total of 350 men from infertile couples were assessed. Standard semen analysis and sperm chromatin structure assay (SCSA) were carried out. Results: Ninety-seven men (28% of the whole study group) had a DNA fragmentation index (DFI) > 20%, and 43 men (12%) had a DFI > 30%. In the group of men with abnormal semen parameters (n = 224), 35% had a DFI > 20%, and 16% had a DFI > 30%, whereas these numbers were 15% and 5%, respectively, in the group of men with normal semen parameters (n = 126). Men with low sperm motility and abnormal morphology had significantly higher odds ratios (ORs) for having a DFI > 20% (4.0 for motility and 1.9 for morphology) and DFI > 30% (6.2 for motility and 2.8 for morphology) compared with men with normal sperm motility and morphology. Conclusion: In almost one-third of unselected men from infertile couples, the DFI exceeded the level of 20% above which, according to previous studies, the in vivo fertility is reduced. A significant proportion of men with otherwise normal semen parameters also had high sperm DNA damage levels. Thus, the SCSA test could add to explaining causes of infertility in cases where semen analysis has not shown any deviation from the norm. We also recommend running the SCSA test to choose the appropriate assisted reproductive technique (ART).
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| 16. |
- Erenpreiss, Juris, et al.
(författare)
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The impact of androgen receptor polymorphism and parental ethnicity on semen quality in young men from Latvia
- 2008
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Ingår i: International Journal of Andrology. - : Wiley. - 0105-6263 .- 1365-2605. ; 31:5, s. 477-482
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Tidskriftsartikel (refereegranskat)abstract
- Recent studies on young men from the general population have demonstrated geographic and ethnic differences in semen quality. The aim of this study was to investigate whether reported ethnic differences in semen quality might be associated with the maternally derived CAG and GGN polymorphisms in the androgen receptor gene or paternal ethnicity. In total 114 military conscripts from Latvia were included in the study. Information on maternal and parental ethnicity was collected by questionnaires. CAG and GGN repeats were analysed by direct sequencing of leukocyte DNA. Men with Latvian mothers (n = 83) had marginally shorter CAG repeat length (21.6 +/- 2.9) as compared with those with non-Latvian mothers (22.9 +/- 3.2, n = 31), not reaching statistical significance (p = 0.053). Sperm concentration did not differ significantly between these two groups (76 +/- 59 and 70 +/- 52, p = 0.9 respectively). In contrast, significantly higher sperm concentration and total sperm count were found in men with Latvian fathers (n = 77) as compared with men with non-Latvian fathers (n = 37) (80 +/- 61 vs. 62 +/- 48, p = 0.035, for sperm concentration and 225.7 +/- 209 vs. 158.4 +/- 134.4, p = 0.002, for total sperm count respectively). CAG repeat length did not correlate with any semen parameters in the whole population. However, GGN repeat length correlated with semen volume: men with GGN > 23 presented with higher semen volume (3.2 +/- 2.1) as compared with men with GGN = 23 (2.6 +/- 1.3, p = 0.04) or GGN < 23 (2.0 +/- 1.2, p = 0.006). We conclude that GGN repeat length has an impact on semen volume, whereas differences in sperm numbers are associated with the paternal ethnicity.
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| 17. |
- Giwercman, Aleksander, et al.
(författare)
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Androgen receptor gene CAG repeat length as a modifier of the association between persistent organohalogen pollutant exposure markers and semen characteristics
- 2007
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Ingår i: Pharmacogenetics & Genomics. - : Ovid Technologies (Wolters Kluwer Health). - 1744-6872. ; 17:6, s. 391-401
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Tidskriftsartikel (refereegranskat)abstract
- Objectives Exposure to persistent organohalogen pollutants was suggested to impair male reproductive function. A gene-environment interaction has been proposed. No genes modifying the effect of persistent organohalogen pollutants on reproductive organs have yet been identified. We aimed to investigate whether the CAG and GGN polymorphisms in the androgen receptor gene modify the effect of persistent organohalogen pollutant exposure on human sperm characteristics. Methods Semen and blood from 680 men [mean (SD) age 34 (10) years] from Greenland, Sweden, Warsaw (Poland) and Kharkiv (Ukraine) were collected. Persistent organohalogen pollutant exposure was assessed by measuring serum levels of 2,2,4,4,5,5'-hexachlorobiphenyl (CB-153) and dichlorodiphenyl dichloroethene (p,p'-DDE). Semen characteristics (volume, sperm concentration, total count proportion of progressively motile and morphology) and DNA fragmentation index (DFI) were determined. CAG and GGN repeat lengths were determined by direct sequencing of leukocyte DNA. Results A statistically significant interaction was found between the CB-153 group and CAG repeat category in relation to sperm concentration and total sperm count (P=0.03 and 0.01, respectively). For p,p'-DDE, in the European cohorts a significant interaction was found in relation to DFI (P=0.01). For CAG<20, sperm concentration and total sperm count were 35 and 42% lower, respectively, when the group with CB-153 exposure above median was compared with that below the median. DF1 was 40% higher in the high p,p'-DDE exposure group for CAG < 21. Conclusions This study indicated that the androgen receptor CAG repeat length might modify the susceptibility of an individual to the adverse effects of persistent organohalogen pollutant exposure on semen quality. Other studies regarding this matter are warranted.
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| 18. |
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| 19. |
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| 20. |
- Giwercman, Aleksander, et al.
(författare)
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Influence of endocrine disruptors on human male fertility
- 2007
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Ingår i: Reproductive BioMedicine Online. - 1472-6491. ; 15:6, s. 633-642
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Tidskriftsartikel (refereegranskat)abstract
- It has been suggested that during the past five decades human sperm counts have declined and the incidence of testicular cancer, hypospadias and cryptorchidism has increased. Furthermore, geographical differences, with respect to these markers of male reproductive function, have been reported. According to a recent hypothesis, all these abnormalities of the male genital system do have a common cause, namely exposure to endocrine disruptors affecting the male in early fetal life. Reduced sperm production as well as congenital abnormalities of male genitalia can be evoked in laboratory animals by exposing them to chemicals with endocrine-disrupting effect, and in humans similar effects have been seen following accidental exposures to very high concentrations of these environmental toxicants. However, the evidence for association between levels of exposure found in the general population and serious adverse effects on male reproduction, including fertility, is still lacking. A recent European Union-supported study, on the effect of persistent organohalogen pollutants on human reproduction, failed to show any correlation between post-natal exposure levels and fertility. Future studies will reveal whether prenatal exposure does more strongly affect male fertility and whether genetic predisposition regulates the susceptibility of an individual to the adverse effects of endocrine disruptors.
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