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- 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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- Lundwall, Åke
(författare)
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A locus on chromosome 20 encompassing genes that are highly expressed in the epididymis
- 2007
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Ingår i: Asian Journal of Andrology. - : Medknow. - 1008-682X .- 1745-7262. ; 9:4, s. 540-544
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Forskningsöversikt (refereegranskat)abstract
- During liquefaction of the ejaculate, the semen coagulum proteins semenogelin I (SEMG1) and semenogelin II (SEMG2) are degraded to low molecular mass fragments by kallikrein-related peptidase 3 (KLK3), also known as prostate-specific antigen. Semenogelin molecules initiate their own destruction by chelating Zn2+ that normally would completely inhibit the proteolytic activity of KLK3. In a similar way, semenogelins might regulate the activity of kallikrein-related peptidases in the epididymis, something that might be of importance for the maturation of spermatozoa or generation of anti-bacterial peptides. Studies on the evolution of semen coagulum proteins have revealed that most of them carry an exon that displays a rapid and unusual evolution. As a consequence, homologous proteins in rodents and primates show almost no conservation in primary structure. Further studies on their evolution suggest that the progenitor of the semen coagulum proteins probably was a protease inhibitor that might have displayed antimicrobial activity. The semenogelin locus on chromosome 20 contains at least 17 homologous genes encoding probable protease inhibitors with homology to semen coagulum proteins. All of these are highly expressed in the epididymis where they, similar to the semenogelins, could affect the maturation of spermatozoa or display antibacterial properties.
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- Koonjaenak, Seri, et al.
(författare)
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Seasonal variation in semen quality of swamp buffalo bulls (Bubalus bubalis) in Thailand
- 2007
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Ingår i: Asian Journal of Andrology. - : Nature Publishing Group: Open Access Hybrid Model Option A / Wiley-Blackwell. - 1008-682X .- 1745-7262. ; 9:1, s. 92-101
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Tidskriftsartikel (refereegranskat)abstract
- Aim: To test the hypothesis that season affects the semen quality of swamp buffalo (Bubalus bubalis) bulls used for artificial insemination (AI) under tropical conditions in Thailand, as it does in Bos taurus and Bos indicus. Methods: Clinical and andrological examinations, and monitoring of semen production and quality were carried out on five mature, healthy swamp buffalo Al bulls in Thailand from July 2004 to the end of June 2005. Sperm output, motility, morphology and plasma membrane integrity (PMI) were compared between three seasons of the year (rainy, i.e. July-October; winter, i.e. November-February; and summer, i.e. March-June) with distinct ambient temperature and humidity. Results: All bulls were diagnosed as clinically healthy and with good libido throughout the study. Ejaculate volume, pH, sperm concentration, total sperm number and initial sperm motility did not differ between seasons, whereas PMI and the relative proportion of morphologically normal spermatozoa were highest in summer and lowest in winter (P less than 0.05). Buffalo age, week of collection and season influenced sperm morphology (P less than 0.05-0.001). Among morphological abnormalities, only proportions of tail defects were affected by season, being highest in the rainy season and lowest in summer (P less than 0.001). In conclusion, climatic changes did not seem to largely affect semen sperm output or viability. Although the proportions of PMI and tail abnormalities were affected by season, they were always below what is considered unacceptable for Al bull sires. Conclusion: Seasonal changes did not appear to cause deleterious changes in sperm quality in swamp buffalo AI-sires in tropical Thailand.
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- Axelsson, Jonatan, et al.
(författare)
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Gene-environment interaction and male reproductive function.
- 2010
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Ingår i: Asian Journal of Andrology. - : Medknow. - 1008-682X .- 1745-7262. ; 12, s. 298-307
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Tidskriftsartikel (refereegranskat)abstract
- As genetic factors can hardly explain the changes taking place during short time spans, environmental and lifestyle-related factors have been suggested as the causes of time-related deterioration of male reproductive function. However, considering the strong heterogeneity of male fecundity between and within populations, genetic variants might be important determinants of the individual susceptibility to the adverse effects of environment or lifestyle. Although the possible mechanisms of such interplay in relation to the reproductive system are largely unknown, some recent studies have indicated that specific genotypes may confer a larger risk of male reproductive disorders following certain exposures. This paper presents a critical review of animal and human evidence on how genes may modify environmental effects on male reproductive function. Some examples have been found that support this mechanism, but the number of studies is still limited. This type of interaction studies may improve our understanding of normal physiology and help us to identify the risk factors to male reproductive malfunction. We also shortly discuss other aspects of gene-environment interaction specifically associated with the issue of reproduction, namely environmental and lifestyle factors as the cause of sperm DNA damage. It remains to be investigated to what extent such genetic changes, by natural conception or through the use of assisted reproductive techniques, are transmitted to the next generation, thereby causing increased morbidity in the offspring.
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