Yasushi Yumura

Expansion of Murine Spermatogonial Stem Cells Through Serial Transplantation

Abstract Mammalian male germ cells might be generally thought to have infinite proliferative potential based on their life-long production of huge numbers of sperm. However, there has been little substantial evidence that supports this assumption. In the present study, we performed serial transplantation of spermatogonial stem cells to investigate if they expand by self-renewing division following transplantation. The transgenic mouse carrying the Green fluorescent protein gene was used as the donor cell source that facilitated identification and recollection of colonized donor germ cells in the recipient testes. The established colonies of germ cells in the recipient testes were collected and transplanted to new recipients. This serial transplantation of spermatogonial stem cells repopulated the recipient testes, which were successfully performed sequentially up to four times from one recipient to the next. The incubation periods between two sequential transplantations ranged from 55 to 373 days. During these passages, the spermatogonial stem cells showed constant activity to form spermatogenic colonies in the recipient testis. They continued to increase in number for more than a year following transplantation. Colonization efficiency of spermatogonial stem cells was determined to be 4.25% by using Sl/Sld mice as recipients that propagated only undifferentiated type A spermatogonia in their testes. Based on the colonization efficiency, one colony-forming activity was assessed to equate to about 20 spermatogonial stem cells. The spermatogonial stem cells were estimated to expand over 50-fold in 100 days in this experiment.

GnRH analog, leuprorelin acetate, promotes regeneration of rat spermatogenesis after severe chemical damage

Future fertility is a major concern for cancer patients who undergo intensive chemotherapy. There has been controversy about whether hormonal treatments may have protective effects against the severe spermatogenic damage caused by chemotherapy or irradiation. Recently, it has been proposed that gonadotrophin‐releasing hormone (GnRH) analogs administered after testicular damage stimulate the recovery of spermatogenesis. In this study, we have investigated the effects of GnRH agonist, leuprorelin, on the damage to spermatogenesis induced by busulfan.

Effect of reactive oxygen species in semen on the pregnancy of infertile couples.

Objective:  We intended retrospectively to investigate whether reactive oxygen species (ROS) levels, detected in whole semen, were correlated with the actual pregnancy rate.

Successful pregnancy with sperm retrieved from the bladder after the introduction of a low-electrolyte solution for retrograde ejaculation.

OBJECTIVE To determine the safety and efficacy of the introduction of a low-electrolyte solution into the bladder before masturbation for sperm recovery in patients with retrograde ejaculation. DESIGN Two case reports. SETTING Assisted reproduction practice at a university hospital. PATIENT(S) Two men with retrograde ejaculation. INTERVENTION(S) A 0.32-mol/L glucose solution or Hams modified F-10 medium (GIBCO, Grand Island, NY) with 10% serum was introduced into the urinary bladder before masturbation. The retrieved sperm were used for IUI. MAIN OUTCOME MEASURE(S) The motility of retrieved sperm, achievement of pregnancy, and outcome of pregnancy. RESULT(S) In patient 1, the motility rate of sperm retrieved from the bladder after the introduction of Hams modified F-10 medium was higher than that after the introduction of a glucose solution. The patients wife did not become pregnant during 10 IUI cycles after treatment with Hams modified F-10 medium. However, she became pregnant during the first IUI cycle after treatment with a glucose solution and was delivered of healthy twin infants. The wife of patient 2 also became pregnant during the first IUI cycle after treatment with a glucose solution and was delivered of a healthy female infant. CONCLUSION(S) The introduction of a glucose solution appears to be a safe and simple method for sperm recovery in patients with retrograde ejaculation.

Increased neutrophil-to-lymphocyte ratio is associated with disease-specific mortality in patients with penile cancer.

BackgroundThe neutrophil-to-lymphocyte ratio (NLR), a simple marker of the systemic inflammatory response, has been demonstrated to correlate with patient outcomes for various solid malignancies. We investigated the utility of the pretreatment NLR as a prognosticator in patients who presented with penile cancer.MethodsA total of 41 patients who underwent complete blood count with differential and subsequent radical penectomy from 1988 to 2014 were analyzed. We assessed the correlation between the NLR and the prognosis of penile cancer.ResultsThe median and mean (± SD) NLRs in 41 penile cancer patients were 3.42 and 5.03 ± 4.99, respectively. Based on the area under receiver operator characteristic curve, the cut-off value of NLR was determined to be 2.82. Patients with a high NLR (≥2.82) showed a significantly poorer cancer-specific survival (p = 0.023) than those with a low NLR.ConclusionsThe pretreatment NLR may function as a biomarker that precisely predicts the prognosis in patients with penile cancer.

Onco-testicular sperm extraction (onco-TESE) for bilateral testicular tumors: two case reports

BackgroundMost patients with testicular cancer are infertile; thus, the preservation of the sperm after surgery is an important factor to consider. We report two cases of bilateral testicular cancer in patients who underwent bilateral higher orchiectomy and simultaneous testicular sperm extraction.Case presentationTwo Asian-Japanese men were referred to our hospital with bilateral testicular tumors. Both of the patients were preoperatively diagnosed with azoospermia and requested testicular sperm extraction at the time of higher orchiectomy. In one patient, sperm was successfully harvested and then frozen. In the other patient, sperm could not be retrieved from the patient’s testis. In both patients, the pathological diagnosis was seminoma. Testicular tumors often occur in patients of reproductive age. The preservation of sperm before chemotherapy or bilateral orchiectomy is necessary for patients with testicular tumors who wish to be fathers.ConclusionsOnco-testicular sperm extraction might be an option for patients with testicular cancer and azoospermia or severe oligospermia.

Inverse correlation between reactive oxygen species in unwashed semen and sperm motion parameters as measured by a computer-assisted semen analyzer.

This study investigated the correlation between sperm motion parameters obtained by a computer-assisted semen analyzer and levels of reactive oxygen species in unwashed semen. In total, 847 patients, except for azoospermic patients were investigated. At the time of each patient′s first consultation, semen parameters were measured using SMAS™ or CellSoft 3000™, and production of reactive oxygen species was measured using a computer-driven LKB Wallac Luminometer 1251 Analyzer. The patients were divided into two groups: reactive oxygen species - positive and negative. The semen parameters within each group were measured using one of the two computer-assisted semen analyzer systems and then compared. Correlations between reactive oxygen species levels and sperm motion parameters in semen from the reactive oxygen species - positive group were also investigated. Reactive oxygen species were detected in semen samples of 282 cases (33.3%). Sperm concentration (P < 0.01; P < 0.01), motility (P < 0.01; P < 0.05), and progressive motility (P < 0.01; P < 0.01) were markedly lower in the reactive oxygen species - positive group than in the reactive oxygen species - negative group. Among the sperm motion parameters in the reactive oxygen species - positive group, sperm concentration (P < 0.01; P < 0.01), motility (P < 0.05; P < 0.01), mALH (P < 0.05; P < 0.01), and progressive motility (P < 0.05; P < 0.01) also showed inverse correlations with the logarithmic transformed reactive oxygen species levels. Therefore, this study demonstrated that excessive reactive oxygen species in semen damage sperm concentration, motility, and other sperm motion parameters.

An evaluation to define the role of repeat transurethral resection in a treatment algorithm for non-muscle-invasive bladder cancer.

Objective: Repeat transurethral resection (ReTUR) is an effective treatment for non-muscle-invasive bladder cancer (NMIBC) to prevent disease recurrence or progression. It also has an important role in stratifying patients according to histopathological results. Therefore, the end point of ReTUR should be considered in a treatment algorithm. We evaluated positive ReTUR to define its role in a treatment algorithm for NMIBC. Materials and Methods: A second TUR was performed in 111 patients between July 2006 and February 2010. A third TUR was performed in 31 patients with T1/a/is tumors at the second TUR. The incidence of residual disease was calculated according to the NMIBC risk levels proposed by the International Bladder Cancer Group. We used ReTUR as a general term to indicate second and third TURs. Results: Residual disease at the second TUR was detected in 51% of the patients; it was observed in 17%, 45%, and 65% patients in the low-, intermediate-, and high-risk disease groups, respectively (P = 0.01). Residual disease at the third TUR was detected in 48% patients; it was observed in 18% and 65% patients in the intermediate- and high-risk disease groups, respectively (P = 0.06). Conclusion: The incidence of residual disease correlated with the risk levels for NMIBC. In the intermediate-risk disease group, nearly complete resection was accomplished after the third TUR. However, in the high-risk disease group, a high incidence of residual disease was identified even after the third TUR. Our results provide important data that may be useful in establishing an end point in a treatment algorithm for NMIBC.

Lack of an Association between Neutrophil-to-Lymphocyte Ratio and PSA Failure of Prostate Cancer Patients Who Underwent Radical Prostatectomy

Introduction. The neutrophil-to-lymphocyte ratio (NLR), which can be easily calculated from routine complete blood counts of the peripheral blood, has been suggested to serve as a prognostic factor for some solid malignancies. In the present study, we aimed to determine the relationship between NLR in prostate cancer patients undergoing radical prostatectomy (RP) and their prognosis. Materials and Methods. We assessed NLR in 73 men (patients) who received RP for their prostate cancer. We also performed immunohistochemistry for CD8 and CD66b in a separate set of RP specimens. Results. The median NLR in the 73 patients was 1.85. There were no significant correlations of NLR with tumor grade (p = 0.834), pathological T stage (p = 0.082), lymph node metastasis (p = 0.062), or resection margin status (p = 0.772). Based on the area under the receiver operator characteristic curve (AUROC) to predict biochemical recurrence after RP, potential NLR cut-off point was determined to be 2.88 or 3.88. However, both of these cut-off points did not precisely predict the prognosis. There were no statistically significant differences in the number of CD66b-positive neutrophils or CD8-positive lymphocytes between stromal tissues adjacent to cancer glands and stromal tissues away from cancer glands and between different grades or stages of tumors. Conclusions. There was no association between NLR and biochemical failure after prostatectomy.

Effects of extracellular ions on the reactivation of human spermatozoa preserved in electrolyte-free solution

It has previously been reported that human spermatozoa preserved in an electrolyte‐free solution can survive for several weeks at 4 °C. However, the motility of spermatozoa after preservation cannot be restored when incubated at 37 °C, unless reactivated by extracellular alkalisation. Under weak acidic conditions, the reactivation is induced by ≥10 mmol l–1 Na+ and inhibited by a Na+‐H+ antiporter inhibitor. The addition of ≥0.1 mmol l–1 K+ also induces the reactivation. In the present study, the reactivation was induced by ≥0.1 mmol l–1 Rb+ or ≥1 mmol l–1 Cs+ at an acidic pH. The maximum motility rate with K+, Rb+ or Cs+ was obtained at 10–20 mmol l–1 and inhibited by 10−5–10−2 mol l−1 ouabain in a dose‐dependent manner, while ouabain had no effect on the Na+‐induced reactivation. The addition of K+ further increased sperm motility reactivated by Na+, which was also inhibited by ouabain. The addition of Ca2+ did not induce the reactivation or increase sperm motility reactivated by Na+ or K+. It was concluded that activation of the ouabain‐sensitive Na+‐K+‐ATPase and Na+‐H+ exchange mechanism has an important role in sperm motility.