Oxidative origin of sperm DNA fragmentation in the adult varicocele

ABSTRACT Purpose: Sperm DNA fragmentation is a major cellular mechanism underlying varicocele-related male infertility. However, the type of DNA fragmentation - whether oxidative or of another nature - remains unknown. Thus, the aim of this study was to evaluate single- and double-stranded sperm DNA fragmentation, and oxidative-induced sperm DNA damage in men with varicocele. Materials and Methods: A cross-sectional study was performed, including 94 normozoospermic adults, of which 39 men without varicocele (controls) and 55 men with varicocele grades II or III, uni- or bilaterally. All men collected semen by masturbation. After semen analysis, the remaining volume was used for evaluation of three types of sperm DNA damage: (i) total DNA fragmentation, using an alkaline comet assay, (ii) double-stranded DNA fragmentation, using a neutral comet assay, and (iii) oxidative DNA damage, using an alkaline comet assay associated with the DNA glycosylase formamidopyrimidine enzyme. In each assay, percentage of sperm with any degree of DNA fragmentation, and with high DNA fragmentation were compared between the groups using an unpaired Student's t test or a Mann-Whitney test. Results: The varicocele group presented a higher rate of sperm with fragmented DNA (both any and high DNA fragmentation), considering single-stranded DNA fragmentation, double-stranded DNA fragmentation, or a combination of both, as well as oxidative- induced DNA fragmentation. Conclusions: Patients with varicocele have an increase in sperm DNA fragmentation levels, particularly in oxidative stress-induced sperm DNA damage.

Evaluation of a Multiplex PCR Kit Used for Detecting Y Chromosome Microdeletions / 대한진단검사의학회지

BACKGROUND: In addition to Klinefelter's syndrome, microdeletion of Yq is the most common genetic cause of male infertility; 15% of azoospermic or 5-10% of oligozoospermic males have Yq deletions. We evaluated a Yq microdeletion kit (LG Life Sciences, Korea) for identifying microdeletions in the azoospermic factor (AZF) regions of the Yq. METHODS: The kit was designed to amplify 3 regions of the AZF gene (AZFa, AZFb, and AZFc) using 15 sequence-tagged sites. We evaluated the preclinical performance of the kit. For clinical validation, 58 patients including 25 idiopathic azoospermic or oligozoospermic patients were examined. RESULTS: We observed clear bands on electrophoresis of DNA, up to a DNA concentration of 3.12 ng/microliter; the known microdeletion regions of all 6 reference cell-lines (Coriell, USA) were accurately detected and no false positive/negative results showed with normal female (n=11) and fertile male (n=15) specimens. This kit could identify the same microdeletions in the common regions, similar to another commercial kit. Among the 58 male infertile patients, 7 (12.1%) had microdeletions of the Yq. Among the idiopathic azoospermic (n=22) and oligozoospermic (n=3) patients, 3 (12.0%) had microdeletions. Further, 2 of 21 varicocele patients (9.5%), 1 of 4 patients with testicular failure, and 1 patient with a 45,X/46,XY mosaic had microdeletions. CONCLUSIONS: The kit was effective for detecting microdeletions of the Yq. We identified microdeletions in 12% of the infertile patients. This Y chromosome microdeletion detection kit is useful for screening Yq microdeletions in infertile patients.

Seguimiento telefónico de pacientes con malformaciones del tracto genitourinario en sus primeros dos años de vidas / Telephonic follow-up of patients with genitourinary malformations in their first two years of life

Las malformaciones del tracto genitourinario (MTG) son una causa importante de morbilidad en la población pediátrica pudiendo llevar a los pacientes a falla renal severa o incluso a la muerte y dejando como posible discapacidad impotencia e infertilidad en el adulto. Es de vital importancia hacer un seguimiento a estos pacientes para determinar las complicaciones, pronóstico y posibles discapacidades secundarias a estas patologías congénitas. Por esta razón se realizó una encuesta telefónica de seguimiento a 40 pacientes con diagnóstico de MTG en la ciudad de Bogotá. Después de analizar múltiples variables se encontró que en nuestro medio, la mortalidad directamente relacionada con el defecto urogenital fue baja comparada con otros estudios y se relacionó directamente con malformaciones mayores. El 22 por cien de los pacientes que sobrevive requiere al menos una cirugía en los primeros dos años de vida, con buenos resultados. También se encontró que los pacientes son valorados en su mayoría de forma interdisciplinaria por más de un especialista. Para complementar estos resultados es necesario un sistema de seguimiento más exhaustivo que busque evaluar estos pacientes a más largo plazo para evaluar discapacidad en la adolescencia y edad adulta

Single nucleotide polymorphisms of the heat shock protein 90 gene in varicocele-associated infertility

PURPOSE: Varicoceles are associated with impaired testicular function and male infertility, but the molecular mechanisms by which fertility is affected have not been satisfactorily explained. Spermatogenesis might be affected by increased scrotal temperature, such as that caused by varicocele. HSP90 is a molecular chaperone expressed in germ cells and is related to spermatogenesis, motility, and both heat and oxidative stress. Possible correlations between coding single region nucleotide polymorphisms (cSNPs) in the HSP90 gene in patients with varicocele associated with infertility were analyzed, and polymorphisms in these exons were characterized through DNA sequencing. MATERIALS AND METHODS: PCR-SSCP and DNA sequencing were used to search for mutations in 18 infertile patients with varicocele, 11 patients with idiopathic infertility and 12 fertile men. DNA was extracted from leucocytes for PCR amplification and SSCP analysis. DNA from samples with an altered band pattern in the SSCP was then sequenced to search for polymorphisms. RESULTS: Three silent polymorphisms that do not lead to amino acid substitutions were identified. CONCLUSION: Mutations in the HSP90 gene do not appear to be a common cause of male factor infertility. The low incidence of gene variation, or SNPs, in infertile men demonstrates that this gene is highly conserved and thus confirms its key role in spermatogenesis and response to heat stress.