Sperm DNA damage measured by sperm chromatin structure assay in men with a history of undescended testes

Revalidation of DNA Fragmentation Analyses for Human Sperm-Measurement Principles, Comparative Standards, Calibration Curve, Required Sensitivity, and Eligibility Criteria for Test Sperm

(1) Background: Double-strand breaks (DSBs) in a single nucleus are usually measured using the sperm chromatin structure assay (SCSA), sperm chromatin dispersion (SCD) test, and comet assay (CA). Mono-dimensional single-cell pulsed-field gel electrophoresis (1D-SCPFGE) and angle-modulated two- dimensional single-cell pulsed-field gel electrophoresis (2D-SCPFGE) were developed to observe DNA fragmentation in separated motile sperm. (2) Methods: Comparative standards, calibration curves, required sensitivity levels, and eligibility criteria for test sperm were set up to validate the measurement principles of these tests. (3) Results: The conventional methods overlooked the interference of nucleoproteins in their measurements. In-gel proteolysis improves the measurement accuracies of 1D- and 2D-SCPFGE. Naked DNA is suitable for comparative standards and test specimens. Moreover, several dysfunctions that might induce DNA damage are observed in the separated motile sperm. Overall, the discussion highlights the need to revisit the conventional univariable analyses based on the SCSA, SCD test, and CA. (4) Conclusions: Human infertility is a complex syndrome, and the aim of quality control in intracytoplasmic sperm injection is to identify the underlying dysfunctions remaining in the separated motile sperm that render them ineligible for injection. Multivariable analyses with special consideration to confounding factors are necessary in future cohort studies.

Angle modulated two-dimensional single cell pulsed-field gel electrophoresis for detecting early symptoms of DNA fragmentation in human sperm nuclei

We here developed a novel angle-modulated two-dimensional single cell pulsed-field gel electrophoresis (2D-SCPFGE). Variations in current-application-time and rotation angle generated different alignments of DNA fibers and segments. After the first run, the specimen was turned by 150° (2D-SCPFGE-0-150) to detect naturally occurring the earliest stage of DNA fragmentation or 75° (2D-SCPFGE-0-75) to analyze artificially induced cleavage. The former revealed that a part of long chain fibers remained at the origin and long segments were still tangled in the bundle of elongated fibers after the first run. The latter visualized the dose-dependent cleavage of DNA by EcoR1. Multicycle 2D-SCPFGE was useful for generating 2D-alignments of single nuclear DNA fibers, which is the first step for visualization of single-strand breaks on stretched fibers. To date, many articles have accepted the pathogenetic significances of DNA fragmentation in human sperm for male infertility and congenital anomaly. It is necessary to perform multivariate analyses of not only earliest-stage DNA fragmentation but also other types of damage, including single-strand breaks, in sequential DNA fibers. 2D-SCPFGE is the fundamental tool for understanding single nuclear DNA damages.

Fertility in males after childhood, adolescent, and adult inguinal operations

BACKGROUND/PURPOSE

Inguinal hernia repair and orchidopexy are among the most common operations in boys. The impact on future fertility has not been conclusively defined. This study evaluates sperm quality after previous inguinal surgery.

METHODS

Spermiograms of men with a desire to conceive children were analyzed. History of previous inguinal surgery (hernia repair, orchidopexy, varicocele ligation) was correlated with sperm quality. Other influential factors (age, BMI, chronic medication, tobacco use) were also tested.

RESULTS

A total of 333 patients were included. Overall, 12.6% of the subjects had undergone previous inguinal surgery. Of these, 17 (43%) were inguinal hernia repairs, 8 (20%) orchidopexies, and 6 (15%) varicocele ligations, while 9 (22%) could not give an exact history. Abnormal spermiograms were found in 60% (n = 24) of those with previous inguinal surgery versus 48% in controls (p = 0.16). On multivariate analysis, pathologic spermiogram parameters were associated with previous inguinal surgery, orchidopexy, use of chronic medication, and smoking, but NOT with inguinal hernia or varicocele repair alone.

CONCLUSIONS

Previous inguinal hernia or varicocele repair does not seem to impact negatively on quality of sperm later in life. Orchidopexy, smoking, and use of chronic medication, however, were all associated with pathologic sperm quality parameters.

TYPE OF STUDY

Prospective comparative study.

LEVEL OF EVIDENCE

Level II.