DNA sperm damage correlates with nuclear ultrastructural sperm defects in teratozoospermic men.

Sperm morphology has consistently been the best indicator of male fertility. Transmission electron microscopy currently provides the most information on the subcellular details of sperm structure. Recently, assessment of sperm DNA damage has been employed to assess fertility potential. The purpose of this work was to link sperm DNA damage, evaluated by an intercalated fluorescent dye, with the structural characteristics of sperm. Conventional semen analysis was performed on samples from men undergoing fertility evaluation. Thirty men were evaluated and assigned to three subgroups based on strict criteria for sperm morphology: normal morphology (>14% normal forms), intermediate morphology (5-14% normal forms), and poor morphology (<5% normal forms). By quantifying acridine orange-positive cells and ultrastructural sperm defects, we found that the poor morphology pattern group showed a positive association between sperm carrying damaged DNA and the percentage of sperm nucleus with vacuoles (P = 0.01). No statistically significant correlations were established in other ultrastructural characteristics of sperm, including immature chromatin, lytic changes, or abnormal sperm tails. These results suggest that zones without chromatin in the sperm nucleus reflect underlying chromosomal or DNA defects in severe teratozoospermic men. This association should be considered in the evaluation of male fertility.

Toll receptor 4 Asp299Gly polymorphism and its association with preterm birth and premature rupture of membranes in a South American population.

Preterm birth (PTB) is a worldwide health problem and remains the leading cause of perinatal morbidity and mortality. Systemic and local intrauterine infections have been implicated in the pathogenesis of preterm labor and delivery. Common pathways between PTB, premature rupture of ovular membranes (PROM) and altered molecular routes of inflammation have been proposed. There is evidence to support a genetic component in these conditions. Lipopolysaccharide (LPS), a component of the cell wall of Gram-negative bacteria, is thought to play a key role in eliciting an inflammatory response. LPS is recognized by proteins of the innate immune system, including Toll-like receptor 4 (TLR4). Individuals from some European countries carrying the variant alleles resulting in an amino acid substitution (Asp299Gly) are at increased risk of Gram-negative infections and premature birth. The objective of this study was to determine if preterm newborns have different allele frequency of the Asp299Gly TLR4 variant from healthy term neonates in Uruguay. The impact of PROM was also examined. There was an increase in the risk for fetuses carrying the Asp299Gly substitution in TLR4 of being severely premature (<33 weeks) and to present PROM at the same time.