Shai Shefi

Isolation and Characterization of Pluripotent Human Spermatogonial Stem Cell-Derived Cells

Several reports have documented the derivation of pluripotent cells (multipotent germline stem cells) from spermatogonial stem cells obtained from the adult mouse testis. These spermatogonia‐derived stem cells express embryonic stem cell markers and differentiate to the three primary germ layers, as well as the germline. Data indicate that derivation may involve reprogramming of endogenous spermatogonia in culture. Here, we report the derivation of human multipotent germline stem cells (hMGSCs) from a testis biopsy. The cells express distinct markers of pluripotency, form embryoid bodies that contain derivatives of all three germ layers, maintain a normal XY karyotype, are hypomethylated at the H19 locus, and express high levels of telomerase. Teratoma assays indicate the presence of human cells 8 weeks post‐transplantation but limited teratoma formation. Thus, these data suggest the potential to derive pluripotent cells from human testis biopsies but indicate a need for novel strategies to optimize hMGSC culture conditions and reprogramming. STEM CELLS 2009;27:138–149

A Stable Isotope-Mass Spectrometric Method for Measuring Human Spermatogenesis Kinetics In Vivo

PURPOSE Currently it is thought to take 60 to 70 days to produce and ejaculate human sperm. This estimate is derived mainly from a single older, descriptive, kinetic analysis of spermatogenesis. We developed a noninvasive method to assess germ cell turnover time accurately in vivo using stable isotope labeling and gas chromatography/mass spectrometry analyses. We confirmed the postulated length of a normal cycle of spermatogenesis. MATERIALS AND METHODS A total of 11 men with normal sperm concentrations ingested (2)H(2)O daily for 3 weeks. Semen samples were collected every 2 weeks for up to 90 days. Label incorporation into sperm DNA was quantified by gas chromatography/mass spectrometry, allowing calculation of the percent of new cells present. A cycle of sperm production was determined as the lag time until labeled sperm appeared in the ejaculate. RESULTS Labeled sperm were detected after a mean +/- SD of 64 +/- 8 days (range 42 to 76). In 1 subject the time lag was 42 days but it was at least 60 in all other subjects. In most subjects plateau labeling in sperm was not attained. In 2 subjects the rise and fall of the labeling curve was steep and reached greater than 85% new cells, suggesting rapid washout of old sperm in the epididymal reservoir. CONCLUSIONS This direct kinetic assessment confirms a course of spermatogenesis that is on the shorter side of traditional estimates based on prior analyses. In addition, the variability observed in healthy men suggests that characteristics such as the epididymal reservoir effect may influence the modeling of in vivo spermatogenesis.

Definition and current evaluation of subfertile men

Male infertility affects 10% of reproductive aged couples worldwide and is treatable in many cases. In addition to other well-described etiologies, genetic causes of male infertility are now more commonly diagnosed. Using principles of evidence-based medicine, this review outlines diagnostic and treatments options to inform clinical management. In order of importance, randomized controlled clinical trials, basic scientific studies, meta-analyses, case-controlled cohort studies, best-practice policy recommendations and reviews from peer-reviewed literature were incorporated that provide organized and timely guidelines to the current management of male infertility. The strength of evidence for treatment recommendations is also classified when appropriate.

Wet heat exposure: a potentially reversible cause of low semen quality in infertile men

OBJECTIVE To evaluate the recovery of semen quality in a cohort of infertile men after known hyperthermic exposure to hot tubs, hot baths or whirlpool baths. MATERIALS AND METHODS A consecutive cohort of infertile men had a history remarkable for wet heat exposure in the forms of hot tubs, Jacuzzi or hot baths. Clinical characteristics and exposure parameters were assessed before exposure was discontinued, and semen parameters analyzed before and after discontinuation of hyperthermic exposure. A significant seminal response to withdrawal of hyperthermia was defined as >or= 200% increase in the total motile sperm count (TMC = volume x concentration x motile fraction) during follow-up after cessation of wet heat exposure. RESULTS Eleven infertile men (mean age 36.5 years, range 31-44) exposed to hyperthermia were evaluated pre and post-exposure. Five patients (45%) responded favorably to cessation of heat exposure and had a mean increase in total motile sperm counts of 491%. This increase was largely the result of a statistically significant increase in sperm motility from a mean of 12% at baseline to 34% post-intervention (p = 0.02). Among non-responders, a smoking history revealed a mean of 5.6 pack-years, compared to 0.11 pack-years among responders. The prevalence of varicoceles was similar in both cohorts. CONCLUSIONS The toxic effect of hyperthermia on semen quality may be reversible in some infertile men. We observed that the seminal response to exposure elimination varies biologically among individuals and can be profound in magnitude. Among non-responders, other risk factors that could explain a lack of response to elimination of hyperthermia should be considered.

Role of Transrectal Ultrasonography in the Evaluation of Azoospermic Men With Low-Volume Ejaculate

Objective. The purpose of this prospective study was to evaluate the incidence of distal ejaculatory system defects with transrectal ultrasonography (TRUS) among patients evaluated for azoospermia. Methods. Forty‐two patients with low‐volume ejaculate and azoospermia were evaluated by physical examination, serum follicle‐stimulating hormone and luteinizing hormone level determination, karyotyping, selective screening for cystic fibrosis mutations, and TRUS. Results. On physical examination, in 29 patients (69%), either 1 (12 patients) or both (17 patients) of the vasa deferentia could not be palpated. In the group of 17 patients with bilateral involvement of the vasa deferentia, the ultrasonographic imaging universally showed bilateral absence or hypoplasia of the seminal vesicles with bilateral agenesis of the vasa deferentia and nonvisualization of both ejaculatory ducts. In the patients with a unilateral abnormality on physical examination, the ultrasonographic imaging showed absence of the ipsilateral seminal vesicle in 7 patients and the hypoplastic seminal vesicle in 5. In the group of 13 patients with normal physical examination findings, a variety of obstructive causes were diagnosed by TRUS examination. Conclusions. According to this study, TRUS appears to be a sensitive method for evaluating the anatomy of the distal ejaculatory system. Its safety and low costs make it a good alternative to the other invasive and expensive methods.

PSA levels of 4.0 - 10 ng/ml and negative digital rectal examination: antibiotic therapy versus immediate prostate biopsy

PURPOSE The management of mildly elevated (4.0-10.0 ng/ml) prostate specific antigen (PSA) is uncertain. Immediate prostate biopsy, antibiotic treatment, or short term monitoring PSA level for 1-3 months is still in controversy. MATERIALS AND METHODS We conducted a retrospective chart review of patients in a large community practice (2003 - 2007) who had PSA levels between 4.0-10 ng/mL without any further evidence of infection. Data was gathered regarding patients age, whether standard antibiotic therapy (10-14 days of ofloxacin or ciprofloxacin) had been administered before the second PSA measurement, results of a second PSA test performed at 1- to 2-month intervals, whether a prostate biopsy was performed and its result. RESULTS One-hundred and thirty-five men met the study inclusion criteria with 65 (48.1%) having received antibiotics (group 1); the PSA levels decreased in 39 (60%) of which, sixteen underwent a biopsy which demonstrated prostate cancer in 4 (25%). Twenty-six (40%) patients of group 1 exhibited no decrease in PSA levels; seventeen of them underwent a biopsy that demonstrated cancer in 2 (12%). The other 70 (51.9%) patients were not treated with antibiotics (group 2); the PSA levels decreased in 42 (60%) of which, thirteen underwent a biopsy which demonstrated prostate cancer in 4 (31%). In the other 28 (40%) patients of group 2 there was no demonstrated decrease in PSA, nineteen of these subjects underwent a biopsy that demonstrated cancer in 8 (42%). CONCLUSIONS There appears to be no advantage for administration of antibacterial therapy with initial PSA levels between 4-10 ng/mL without overt evidence of inflammation.

Male infertility associated with adult dominant polycystic kidney disease: a case series

IntroductionAlthough described earlier, the association of male infertility with adult dominant polycystic kidney disease (ADPKD) is quite rare and unfamiliar to some of the multidisciplinary team members caring for affected men.Materials and methodsInfertile men diagnosed to have ADPKD were evaluated by clinical characteristics including testis volume, as well as serum hormone levels, semen analysis, and transrectal ultrasonography (TRUS) because of low volume ejaculate.ResultsSemen analysis revealed low-normal volume, normal pH, and azoospermia/virtual azoospermia. Serum hormones were within the normal range. Transrectal ultrasonography demonstrated cystic dilatation of the seminal vesicles in all three men.ConclusionPatients should be referred for andrological evaluation of a presentation similar to obstructive azoospermia. Their potential to achieve paternity by surgical sperm retrieval combined with assisted reproductive technology is another example of cooperation between andrologists and gynecologists.