Implantation and Decidualization in PCOS: Unraveling the Complexities of Pregnancy

Polycystic Ovary Syndrome (PCOS) is a prevalent endocrine disorder in women of reproductive age, affecting 5-15% globally with a large proportion undiagnosed. This review explores the multifaceted nature of PCOS and its impact on pregnancy, including challenges in fertility due to hormonal imbalances and insulin resistance. Despite restoring ovulation pharmacologically, women with PCOS face lower pregnancy rates and higher risks of implantation failure and miscarriage. Our review focuses on the complexities of hormonal and metabolic imbalances that impair endometrial receptivity and decidualization in PCOS. Disrupted estrogen signaling, reduced integrity of endometrial epithelial tight junctions, and insulin resistance impair the window of endometrial receptivity. Furthermore, progesterone resistance adversely affects decidualization. Our review also examines the roles of various immune cells and inflammatory processes in the endometrium, contributing to the condition's reproductive challenges. Lastly, we discuss the use of rodent models in understanding PCOS, particularly those induced by hormonal interventions, offering insights into the syndrome's impact on pregnancy and potential treatments. This comprehensive review underscores the need for advanced understanding and treatment strategies to address the reproductive complications associated with PCOS, emphasizing its intricate interplay of hormonal, metabolic, and immune factors.

ROR2 expression predicts human induced pluripotent stem cell differentiation into neural stem/progenitor cells and GABAergic neurons

Despite the development of various in vitro differentiation protocols for the efficient derivation of specific cell types, human induced pluripotent stem cell (hiPSC) lines have varing ability to differentiate into specific lineages. Therefore, surrogate markers for accurately predicting the differentiation propensity of hiPSC lines may facilitate cell-based therapeutic product development and manufacture. We attempted to identify marker genes that could predict the differentiation propensity of hiPSCs into neural stem/progenitor cells (NS/PCs). Using Spearman's rank correlation coefficients, we investigated genes in the undifferentiated state, the expression levels of which were significantly correlated with the neuronal differentiation propensity of several hiPSC lines. Among genes significantly correlated with NS/PC differentiation (P < 0.01), we identified ROR2 as a novel predictive marker. ROR2 expression in hiPSCs was negatively correlated with NS/PC differentiation tendency, regardless of the differentiation method, whereas its knockdown enhanced differentiation. ROR2 regulates NS/PC differentiation, suggesting that ROR2 is functionally essential for NS/PC differentiation. Selecting cell lines with relatively low ROR2 expression facilitated identification of hiPSCs that can differentiate into NS/PCs. Cells with ROR2 knockdown showed increased efficiency of differentiation into forebrain GABAergic neurons compared to controls. These findings suggest that ROR2 is a surrogate marker for selecting hiPSC lines appropriate for NS/PC and GABAergic neuronal differentiations.

Steroid hormone signaling: multifaceted support of testicular function

Embryonic development and adult physiology are dependent on the action of steroid hormones. In particular, the reproductive system is reliant on hormonal signaling to promote gonadal function and to ensure fertility. Here we will describe hormone receptor functions and their impacts on testicular function, focusing on a specific group of essential hormones: androgens, estrogens, progesterone, cortisol, and aldosterone. In addition to focusing on hormone receptor function and localization within the testis, we will highlight the effects of altered receptor signaling, including the consequences of reduced and excess signaling activity. These hormones act through various cellular pathways and receptor types, emphasizing the need for a multifaceted research approach to understand their critical roles in testicular function. Hormones exhibit intricate interactions with each other, as evidenced, for example, by the antagonistic effects of progesterone on mineralocorticoid receptors and cortisol's impact on androgens. In light of research findings in the field demonstrating an intricate interplay between hormones, a systems biology approach is crucial for a nuanced understanding of this complex hormonal network. This review can serve as a resource for further investigation into hormonal support of male reproductive health.

A Case of Solitary Kidney and Single-system Ectopic Ureter Draining Into the Vestibule in an Infant With Müllerian Duct Defect: Was the Bladder Missing?

We report a case of a solitary kidney and a single-system ectopic ureter draining into the vestibule in an infant with a Müllerian duct defect. Due to the absence of the upper vagina and uterus, an extremely underdeveloped bladder masqueraded as the vagina, and bladder agenesis was suspected preoperatively. Urinary continence was achieved using staged bladder surgery without augmentation or urinary diversion.

Unilateral renal agenesis and ipsilateral absence of the vas deferens in a cryptorchid infant with Klippel-Feil syndrome

We report an exceedingly rare case of Klippel-Feil syndrome (KFS), compounded by ipsilateral absence of the vas deferens, renal agenesis, and diaphragmatic hernia. Unilateral absence of the vas deferens was found incidentally during orchidopexy. To the best of our knowledge, no case of unilateral absence of the kidney and vas deferens has been reported in children with KFS.

Prenatally diagnosed giant umbilical cord resulted from patent urachus in a monochorionic diamniotic twin with selective intrauterine growth restriction

A long diffuse giant umbilical cord (GUC), caused by umbilical cord edema associated with a patent urachus, is an extremely rare anomaly. While patients with diffuse GUC appear to experience no significant complications and a good prognosis, little is known about their etiology and prenatal course. Here, we report the first case of prenatally diagnosed diffuse GUC resulted from patent urachus in a monochorionic diamniotic twin with selective intrauterine growth restriction. This case indicates that GUC is epigenetic and unrelated to multiple births.

Single-Cell RNA-Seq Reveals LRRC75A-Expressing Cell Population Involved in VEGF Secretion of Multipotent Mesenchymal Stromal/Stem Cells Under Ischemia

Human multipotent mesenchymal stromal/stem cells (MSCs) have been utilized in cell therapy for various diseases and their clinical applications are expected to increase in the future. However, the variation in MSC-based product quality due to the MSC heterogeneity has resulted in significant constraints in the clinical utility of MSCs. Therefore, we hypothesized that it might be important to identify and ensure/enrich suitable cell subpopulations for therapies using MSC-based products. In this study, we aimed to identify functional cell subpopulations to predict the efficacy of angiogenic therapy using bone marrow-derived MSCs (BM-MSCs). To assess its angiogenic potency, we observed various levels of vascular endothelial growth factor (VEGF) secretion among 11 donor-derived BM-MSC lines under in vitro ischemic culture conditions. Next, by clarifying the heterogeneity of BM-MSCs using single-cell RNA-sequencing analysis, we identified a functional cell subpopulation that contributed to the overall VEGF production in BM-MSC lines under ischemic conditions. We also found that leucine-rich repeat-containing 75A (LRRC75A) was more highly expressed in this cell subpopulation than in the others. Importantly, knockdown of LRRC75A using small interfering RNA resulted in significant inhibition of VEGF secretion in ischemic BM-MSCs, indicating that LRRC75A regulates VEGF secretion under ischemic conditions. Therefore, LRRC75A may be a useful biomarker to identify cell subpopulations that contribute to the angiogenic effects of BM-MSCs. Our work provides evidence that a strategy based on single-cell transcriptome profiles is effective for identifying functional cell subpopulations in heterogeneous MSC-based products.

Unilateral Fibrous Hyperplasia of the Labium Majus in Pre- and Early Pubertal Girls: A Report on 3 Cases

BACKGROUND

In recent years, certain prepubertal cases of asymmetric enlargement of the labium majus came to be recognized as a physiological condition in response to hormonal stimulation. However, there exist only scattered case reports or a few case series on this entity, with different terminology.

CASE

We present 3 cases of unilateral asymptomatic swelling of the labium majus in otherwise healthy pre- and early pubertal girls. Physical examination revealed painless, fluctuating, nontender bulging that was recognized for a few years on one side of the labium majus. Ultrasound and magnetic resonance imaging showed increased labial soft tissue without any masses. In all cases, surgical excision was performed for cosmetic request. Histopathological diagnosis was fibrous hyperplasia of the labium majus in all cases. Recurrence occurred in one of 3 cases a year after surgery.

SUMMARY AND CONCLUSION

Due to the site- and age-specific non-neoplastic physiological condition, we recommend prepubertal unilateral fibrous hyperplasia of the labium majus (PUFHLM), as the terminology accurately reflects this entity. For the differential diagnosis of genital disorders in children, recognition of PUFHLM is important to avoid unnecessary biopsy or invasive procedures. Surgical excision for cosmetic reasons should not be considered because of the benign nature of this entity and a high recurrence rate in childhood and early adolescence.

Immune Cells as Critical Regulators of Steroidogenesis in the Testis and Beyond

Steroidogenesis is an essential biological process for embryonic development, reproduction, and adult health. While specific glandular cells, such as Leydig cells in the testis, are traditionally known to be the principal players in steroid hormone production, there are other cell types that contribute to the process of steroidogenesis. In particular, immune cells are often an important component of the cellular niche that is required for the production of steroid hormones. For several decades, studies have reported that testicular macrophages and Leydig cells are intimately associated and exhibit a dependency on the other cell type for their proper development; however, the mechanisms that underlie the functional relationship between macrophages and Leydig cells are unclear. Beyond the testis, in certain instances immune cells themselves, such as certain types of lymphocytes, are capable of steroid hormone production, thus highlighting the complexity and diversity that underlie steroidogenesis. In this review we will describe how immune cells are critical regulators of steroidogenesis in the testis and in extra-glandular locations, as well as discuss how this area of research offers opportunities to uncover new insights into steroid hormone production.

Association of Lower Urinary Tract Symptoms Based on the International Prostate Symptom Score and Cardiovascular Disease

BACKGROUND

Because it is unclear whether lower urinary tract symptoms (LUTS) are associated with cardiovascular disease (CVD) in the Japanese population, we explored the association in general Japanese men aged 55-75 years.Methods and Results:The cross-sectional study included male participants who had both national health checkup data and the International Prostate Symptom Score (IPSS) in the same calendar year between 2009 and 2017. LUTS severity was evaluated by IPSS. A robust Poisson regression model was used to assess the association between LUTS severity and the composite CVD outcome [coronary artery disease (CAD), stroke, or atrial fibrillation (AF)] and each component of the composite outcome. Prevalence ratio (PR) was adjusted for conventional cardiovascular risk factors. Of 16,781 male participants (mean age, 67±5 years), mild LUTS were observed in 9,243 (55.1%); moderate, 6,445 (38.4%); and severe, 1,093 (6.5%). Compared with the mild LUTS group, moderate LUTS [PR 1.18, 95% confidence interval (CI) 1.10-1.25, P<0.001] and severe LUTS (PR 1.38, 95% CI 1.24-1.53, P<0.001) were significantly associated with a higher prevalence of CVD. LUTS severity was associated with higher prevalence of CAD and stroke, but not AF.

CONCLUSIONS

The severity of LUTS was associated with a higher prevalence of CVD, especially CAD and stroke, independent of conventional CVD risk factors.

Congenital perineal urethrocutaneous fistula without rupture in a neonate

Congenital anterior urethrocutaneous fistula (CAUF) is a rare anomaly, commonly observed in the mid-shaft or more distal position of the penis. It can be seen in the perineum in anorectal anomalies or in cases of duplicated urethra. However, isolated CAUF opening into the perineum has not been reported. Herein, we present a case of congenital anterior urethral diverticulum and possible perineal urethrocutaneous fistula of an otherwise healthy neonate.

Neurokinin 3 receptor-selective agonist, senktide, decreases core temperature in Japanese Black cattle

Heat stress disrupts reproductive function in cattle. In summer, high ambient temperature and humidity elevate core body temperature, which is considered to be detrimental to reproductive abilities in cattle. Neurokinin B (NKB) is a factor that generates pulsatile GnRH and subsequent LH secretion in mammals. Recent studies have reported that NKB-neurokinin 3 receptor (NK3R) signaling is associated with heat-defense responses in rodents. The present study aimed to clarify the role of NKB-NK3R signaling in thermoregulation in cattle. We examined the effects of an NK3R-selective agonist, senktide, on vaginal temperature as an indicator of core body temperature in winter and summer. In both seasons, continuous infusion of senktide for 4 h immediately decreased vaginal temperature, and the mean temperature change in the senktide-treated group was significantly lower than that of both vehicle- and GnRH-treated groups. Administration of GnRH induced LH elevation, but there was no significant difference in vaginal temperature change between GnRH- and vehicle-treated groups. Moreover, we investigated the effects of senktide on ovarian temperature. Senktide treatment seemed to suppress the increase in ovarian temperature from 2 h after the beginning of administration, although the difference between groups was not statistically significant. Taken together, these results suggest that senktide infusion caused a decline in the vaginal temperature of cattle, in both winter and summer seasons, and this effect was not due to the gonadotropin-releasing action of senktide. These findings provide new therapeutic options for senktide to support both heat-defense responses and GnRH/LH pulse generation.

Neutron-induced signal on the single crystal chemical vapor deposition diamond-based neutral particle analyzer

A diamond-based neutral particle analyzer (DNPA) array composed of single-crystal chemical vapor deposition (sCVD) diamond detectors was installed on the Large Helical Device (LHD) for measuring the helically trapped energetic particles. In high neutron flux experiments, the unwanted neutron-induced pulse counting rate should be estimated using the neutron diagnostics because a diamond detector is sensitive to neutrons as well as energetic neutral particles. In order to evaluate the quantitative neutron-induced pulse counting rate on the DNPA, the response functions of the sCVD diamond detector for mono-energetic neutrons were obtained using accelerator-based D-D and D-⁷Li neutron sources in Fast Neutron Laboratory (FNL). As a result of the neutron flux estimation by the Monte Carlo N-Particle code at the NPA position in the LHD and the response function obtained in the FNL experiment, the counting rate of the neutron-induced signal was predicted to be 1.1 kcps for the source neutron emission rate of S_n = 1 × 10¹⁵ n/s. In the LHD experiment, the neutron-induced signals were observed by closing the gate valve during the plasma discharges. It is found that the counting rates of the neutron-induced signals proportional to S_n reached 1.1 kcps at S_n = 1 × 10¹⁵ n/s. As a result of the quantitative estimation of the neutron-induced signals on the DNPA using other neutron measurements, it has become possible to accurately measure energetic neutral particles in the high neutron flux experiment.

Differences between primary care physicians and specialised neurotologists in the diagnosis of dizziness and vertigo in Japan

OBJECTIVE

Vertigo and dizziness are frequent symptoms in patients at out-patient services. An accurate diagnosis for vertigo or dizziness is essential for symptom relief; however, it is often challenging. This study aimed to identify differences in diagnoses between primary-care physicians and specialised neurotologists.

METHOD

In total, 217 patients were enrolled. To compare diagnoses, data was collected from the reference letters of primary-care physicians, medical questionnaires completed by patients and medical records.

RESULTS

In total, 62.2 per cent and 29.5 per cent of the patients were referred by otorhinolaryngologists and internists, respectively. The cause of vertigo or dizziness and diagnosis was missing in 47.0 per cent of the reference letters. In addition, 67.3 per cent of the diagnoses by previous physicians differed from those reported by specialised neurotologists.

CONCLUSION

To ensure patient satisfaction and high quality of life, an accurate diagnosis for vertigo or dizziness is required; therefore, methods or materials to improve the diagnostic accuracy are needed.

Variation of Gonadal Dysgenesis and Tumor Risk in Patients With 45,X/46,XY Mosaicism

OBJECTIVE

To describe the gonadal features of patients with 45,X/46,XY mosaicism, and to evaluate the prevalence of gonadal tumor in different phenotypes.

MATERIALS AND METHODS

The medical records of consecutive patients with 45,X/46,XY karyotype or its variants who had undergone gonadal biopsy or gonadectomy at a single institute between 1996 and 2017 were retrospectively reviewed.

RESULTS

Of 34 patients with 45,X/46,XY mosaicism, a unilateral dysgenetic testis and a contralateral streak gonad was detected in 20 patients (59%), bilateral streak gonads in 9 (26%), and bilateral dysgenetic testes in 5 (15%). A gonad composed of both streak and dysgenetic testicular portions was observed in 7 gonads of 6 patients. All streak gonads were removed, and bilateral gonadectomy was performed in 15 patients raised as girls. Pathologic examination revealed gonadal tumors in 6 of the 34 (18%) patients, including a gonadoblastoma in 7 gonads among 5 patients and an association of dysgerminoma with gonadoblastoma in 1 gonad. All 6 patients who developed gonadal tumor had female genitalia. Postoperative course was uneventful except 1 boy. A seminoma was developed in his soritaly scrotal testis at the age of 16 years.

CONCLUSION

The prevalence of gonadal tumor in patients with 45,X/46,XY mosaicism may vary according to the phenotype, and high in patients with female phenotype. Considering the increased risk of gonadal tumors in such patients, early investigation and individual management, including prophylactic gonadectomy, are recommended. In male patients, a close follow-up of the preserved testes is mandatory until adulthood.

Design optimization of a fast-neutron detector with scintillating fibers for triton burnup experiments at fusion experimental devices

Time-resolved triton burnup studies have been carried out to estimate the behavior of alpha particles in DD fusion experimental devices. In those studies, 14 MeV neutrons emitted through DT reactions in DD plasmas should be measured selectively in the backgrounds of DD neutrons and gamma rays. For this purpose, a scintillating-fiber (Sci-Fi) based fast-neutron detector has been adapted because of its advantages such as fast response, design flexibility in detection efficiency by changing the number of Sci-Fi, and discrimination property against 2.4 MeV neutrons produced through DD reactions and gamma rays. However, its length had conventionally been set to around 10 cm without an optimization study of its design parameters to meet the requirements as 14 MeV neutron detector. In the present study, we tested three types of Sci-Fi detectors with three different lengths and compared with the simulated results of energy deposition, through which we tried to understand the phenomena in the detection process of fast neutrons. From the results, it has been shown that, due to the self-shielding of neutrons by Sci-Fi and the attenuation of scintillation photons during the transmission process to the photomultiplier tube, the optimal length of Sci-Fi is concluded to be about 6 cm.

Development of selective cytotoxic viral vectors for concentration of undifferentiated cells in cardiomyocytes derived from human induced pluripotent stem cells

Cell-processed therapeutic products (CTPs) derived from human pluripotent stem cells (hPSCs) have innovative applications in regenerative medicine. However, undifferentiated hPSCs possess tumorigenic potential; thus, sensitive methods for the detection of residual undifferentiated hPSCs are essential for the clinical use of hPSC-derived CTPs. The detection limit of the methods currently available is 1/105 (0.001%, undifferentiated hPSCs/differentiated cells) or more, which could be insufficient for the detection of residual hPSCs when CTPs contain more than 1 × 105 cells. In this study, we developed a novel approach to overcome this challenge, using adenovirus and adeno-associated virus (AdV and AAV)-based selective cytotoxic vectors. We constructed AdV and AAV vectors that possess a suicide gene, iCaspase 9 (iCasp9), regulated by the CMV promoter, which is dormant in hPSCs, for the selective expression of iCasp9 in differentiated cells. As expected, AdV/CMV-iCasp9 and AAV/CMV-iCasp9 exhibited cytotoxicity in cardiomyocytes but not in human induced pluripotent stem cells (hiPSCs). The vectors also induced apoptosis in hiPSC-derived cardiomyocytes, and the surviving cells exhibited higher levels of hPSC marker expression. These results indicate that the AdV- and AAV-based cytotoxic vectors concentrate cells expressing the undifferentiated cell markers in hiPSC-derived products and are promising biological tools for verifying the quality of CTPs.

Gonadal function and testicular histology in males with Prader-Willi syndrome

CONTEXT

Cryptorchidism is common in Prader-Willi syndrome (PWS) males, but the testicular histology in childhood remains uncertain. The association between testicular histology and long-term gonadal function in PWS males is also unknown.

OBJECTIVES

To evaluate the relationship between testicular histology in childhood and long-term gonadal function in PWS males.

PATIENTS AND METHODS

Forty men with PWS were assessed longitudinally at our institute over the past 24 years. Clinical examinations and blood tests for LH, FSH and testosterone levels were compared with normal reference values. Tissue specimens were collected during orchiopexy and analyzed based on Nistal categories.

RESULTS

Of nine testes available for pathological assessments, two showed favourable histology (Nistal I) and seven showed unfavourable histology (Nistal II or III). Of five postpubertal males with histology available, four reached puberty spontaneously, but only one reached Tanner stage 5. In a male with favourable histology, LH and FSH were high, but testosterone was normal, though below the average of the reference range. In three males with unfavourable histology, LH was normal, but FSH was highly elevated, and testosterone was at the lower limit of normal. One patient took hCG treatment to induce puberty; this patient showed favourable histology, but LH, FSH and testosterone were not elevated in adolescence.

CONCLUSIONS

Testicular histology of PWS men in childhood varies from normal to Sertoli Cell-Only Syndrome. Regardless of the testicular histology in childhood, hypogonadism in PWS adults arises as a consequence of primary testicular dysfunction with highly elevated FSH and insufficient testosterone levels.

Administration of Thrombomodulin (CD141) Could Improve Cardiac Allograft Survival in Mice

Thrombomodulin (TM) is a promising natural anti-coagulant therapeutic protein that is effective in the treatment of disseminated intravascular coagulation. However, the mechanisms by which TM on micro-vessels enable the regulation of intimal hyperplasia remain elusive. We investigated the graft-protective effects of TM in a fully major histocompatibility complex-mismatched murine cardiac allograft transplantation model. CBA recipients transplanted with a C57BL/6 heart received intraperitoneal administration of 0.2, 2.0, and 20.0 μg/day of TM for 8 days. Histological staining was conducted to assess the degree of inflammation and infiltration in the transplanted cardiac grafts. Untreated CBA recipients rejected C57BL/6 cardiac grafts acutely (median survival time [MST] was 7 days). CBA recipients exposed to the above dosages had significantly prolonged allograft survival (MSTs were 16, 21, and 37.5 days, respectively). Histologic assessments from TM-exposed recipients 2 weeks after grafting showed that the myocardium and vessel structure in their allografts were clearly preserved, and that the infiltration of inflammatory cells around coronary arteries was suppressed. TM can induce the prolongation of fully major histocompatibility complex-mismatched cardiac allograft by exerting graft protective effects within the myocardium and coronary arteries.

Tumorigenicity-associated characteristics of human iPS cell lines

Human induced pluripotent stem cells (hiPSCs) represent promising raw materials of human cell-based therapeutic products (hCTPs). As undifferentiated hiPSCs exhibit intrinsic tumorigenicity properties that enable them to form teratomas, hCTPs containing residual undifferentiated hiPSCs may cause tumor formation following transplantation. We first established quantitative and sensitive tumorigenicity testing of hiPSCs dissociated into single cells using NOD/Shi-scid IL2Rγnull (NOG) mice by inhibiting apoptosis of hiPSCs with a Rho kinase inhibitor. To examine different features in tumorigenicity of various hiPSCs, 10 commonly available hiPSC lines were subjected to in vivo tumorigenicity testing. Transplanted hiPSC lines showed remarkable variation in tumor incidence, formation latency, and volumes. Most of the tumors formed were classified as immature teratomas. However, no signs of malignancies, such as carcinoma and sarcoma, were recognized in the tumors. Characteristics associated tumorigenicity of hiPSCs were investigated with microarray analysis, karyotype analysis, and whole exome sequencing. Gene expression profiling and pathway analysis supported different features of hiPSC lines in tumorigenicity. hiPSC lines showed chromosomal abnormalities in some lines and 61-77 variants of cancer-related genes carrying effective nonsynonymous mutations, which were confirmed in the COSMIC databases. In this study, the chromosomal abnormalities and cancer-related gene mutations observed in hiPSC lines did not lead to the malignancy of tumors derived from hiPSCs. Our results suggest that the potential tumorigenicity risk of hCTPs containing residual undifferentiated hiPSCs is dependent on not only amounts of undifferentiated hiPSCs but also features of the cell lines used as raw materials, a finding that should be considered from the perspective of quality of hCTPs used.

Acquired undescended testis and possibly associated testicular torsion in children with cerebral palsy or neuromuscular disease

INTRODUCTION

Torsion of an undescended testis (UDT) associated with cerebral palsy (CP) and neuromuscular disease (NMD) is an uncommon condition that is not well recognized by primary care physicians or healthcare providers.

OBJECTIVE

The objective of this study was to highlight the clinical importance of torsion of a UDT in children with CP and NMD.

MATERIALS AND METHODS

Eleven children with testicular torsion of a UDT operated on at the study institute between 1991 and 2015 were identified. The records of seven children (63.6%) associated with CP or NMD were retrospectively reviewed. Clinical findings of testicular torsion were assessed along with the treatment outcome and testicular salvageability.

RESULTS

All seven children were not identified with a UDT by public health checkup for infant and young children. No children with CP or NMD had torsion of a descended testis during the present study period. Median age at surgery was 15 years (range, 1-20 years). The testis location was at the external inguinal ring in five patients, in the inguinal canal in one, and in the superficial inguinal pouch in one. Of the contralateral testes, four were a UDT, one was a retractile testis, and two were descended testes. Orchiectomy was performed in six patients (85.7%). In the remaining patients, the testis was preserved but became atrophic.

DISCUSSION

This study demonstrated that children with CP or NMD may be affected with torsion of a UDT with peak at around puberty with the poor salvage rate, even if the testes appear descended in infancy and young children. Shortcomings of this study were the retrospective design and a small series of children undergoing surgery for torsion of a UDT.

CONCLUSION

Pediatric urologists need to educate primary care physicians and healthcare providers in the recognition of acquired UDTs and possibly associated testicular torsion in children with CP and NMD. Genital examination should be continued regularly until adolescence in these children to detect acquired UDT. These children should be referred to pediatric urologists to promote surgery as soon as the diagnosis of acquired UDT is carried out. It is believed that it is perhaps the best approach to prevent loss of the testis in children with CP and NMD.

Identification of a Gene Encoding Slow Skeletal Muscle Troponin T as a Novel Marker for Immortalization of Retinal Pigment Epithelial Cells

Human pluripotent stem cells (hPSCs) are leading candidate raw materials for cell-based therapeutic products (CTPs). In the development of hPSC-derived CTPs, it is imperative to ensure that they do not form tumors after transplantation for safety reasons. Because cellular immortalization is a landmark of malignant transformation and a common feature of cancer cells, we aimed to develop an in vitro assay for detecting immortalized cells in CTPs. We employed retinal pigment epithelial (RPE) cells as a model of hPSC-derived products and identified a gene encoding slow skeletal muscle troponin T (TNNT1) as a novel marker of immortalized RPE cells by comprehensive microarray analysis. TNNT1 mRNA was commonly upregulated in immortalized RPE cells and human induced pluripotent stem cells (hiPSCs), which have self-renewal ability. Additionally, we demonstrated that TNNT1 mRNA expression is higher in several cancer tissues than in normal tissues. Furthermore, stable expression of TNNT1 in ARPE-19 cells affected actin filament organization and enhanced their migration ability. Finally, we established a simple and rapid qRT-PCR assay targeting TNNT1 transcripts that detected as low as 3% of ARPE-19 cells contained in normal primary RPE cells. Purified hiPSC-derived RPE cells showed TNNT1 expression levels below the detection limit determined with primary RPE cells. Our qRT-PCR method is expected to greatly contribute to process validation and quality control of CTPs.

Chemical etching of silicon carbide in pure water by using platinum catalyst

Chemical etching of SiC was found to proceed in pure water with the assistance of a Pt catalyst. A 4H-SiC (0001) wafer was placed and slid on a polishing pad in pure water, on which a thin Pt film was deposited to give a catalytic nature. Etching of the wafer surface was observed to remove protrusions preferentially by interacting with the Pt film more frequently, thus flattening the surface. In the case of an on-axis wafer, a crystallographically ordered surface was obtained with a straight step-and-terrace structure, the height of which corresponds to that of an atomic bilayer of Si and C. The etching rate depended upon the electrochemical potential of Pt. The vicinal surface was observed at the potential at which the Pt surface was bare. The primary etching mechanism was hydrolysis with the assistance of a Pt catalyst. This method can, therefore, be used as an environmentally friendly and sustainable technology.

[A CASE OF PARATESTICULAR FIBROUS HAMARTOMA OF INFANCY]

Fibrous hamartoma of infancy (FHI) is a rare, benign soft tissue tumor arising from subcutaneous tissue in children during the first two years of life. The tumor is commonly found in the axilla, shoulder and upper arm. Paratesticular FHI is extremely rare. To date, only a case of paratesticular FHI has been reported in Japan. We present a case of paratesticular FHI in an 11-month-old boy who eventually needed orchiectomy due to local recurrence one month after the excision of the tumor. Ten months postoperatively, there was no sign of recurrence.

Long-term Follow-up of Median Raphe Cysts and Parameatal Urethral Cysts in Male Children

OBJECTIVE

To clarify the long-term outcome of median raphe cysts (MRCs) and parameatal urethral cysts (PUCs) in males, the clinical, anatomical, and histological findings of these cysts are described, along with treatment and follow-up.

MATERIALS AND METHODS

Forty-six children diagnosed with PUCs and 23 children with MRCs at our institute during the past 14 years were retrospectively reviewed. The indications for surgery were symptoms or family preference. Telephone interviews of the parents or patients were conducted to ascertain the current condition of the cyst at a median age of 12.2 years. Fifty-nine children (85.5%) agreed to the telephone interview.

RESULTS

Median age at first presentation was 41 months; 81% of children were asymptomatic. The main symptoms were voiding symptoms with PUCs and pain of the ruptured cyst in MRCs. A total of 41 (59%) children underwent complete excision at a median age of 58 months. No recurrences were encountered with surgery in all children. Of 28 children managed nonoperatively, 22 agreed to an interview. All children (95.5%), except for 1, remained free of symptoms. Six cysts showed spontaneous resolution at a median age of 24 months, and 15 improved or stabilized. No one was concerned about the genital appearance and opted for surgical intervention.

CONCLUSION

Complete excision of the cyst is a durable procedure without recurrences in childhood. In the nonoperative management, several cysts may continue to be free of symptoms during childhood, and some cysts may resolve spontaneously during the first 2 years.

Development of array-type atmospheric-pressure RF plasma generator with electric on-off control for high-throughput numerically controlled processes

An array-type atmospheric-pressure radio-frequency (RF) plasma generator is proposed for high-precision and high-throughput numerically controlled (NC) processes. We propose the use of a metal-oxide-semiconductor field-effect transistor (MOSFET) circuit for direct RF switching to achieve plasma on-off control. We confirmed that this type of circuit works correctly using a MOSFET with a small parasitic capacitance between its source and gate. We examined the design method for the distance between adjacent electrodes, which corresponds to the parasitic capacitance between adjacent electrodes and is very important in the individual on-off control of each electrode. We developed a prototype array-type plasma generator apparatus with 19 electrodes and the same number of MOSFET circuits; we then confirmed that each electrode could control its plasma on-off state individually. We also demonstrated that the thickness uniformity of the surface Si layer of a silicon-on-insulator wafer could be processed to less than 1 nm peak to valley by the NC sacrificial oxidation method using the apparatus.

Optimal screening interval for men with low baseline prostate-specific antigen levels (≤1.0 ng/mL) in a prostate cancer screening program

PURPOSE

To optimize the rescreening schedule for men with low baseline prostate-specific antigen (PSA) levels, we evaluated men with baseline PSA levels of ≤1.0 ng/mL in PSA-based population screening.

METHODS

We enrolled 8086 men aged 55-69 years with baseline PSA levels of ≤1.0 ng/mL, who were screened annually. The relationships of baseline PSA and age with the cumulative risks and clinicopathological features of screening-detected cancer were investigated.

RESULTS

Among the 8086 participants, 28 (0.35 %) and 18 (0.22 %) were diagnosed with prostate cancer and cancer with a Gleason score (GS) of ≥7 during the observation period, respectively. The cumulative probabilities of prostate cancer at 12 years were 0.42, 1.0, 3.4, and 4.3 % in men with baseline PSA levels of 0.0-0.4, 0.5-0.6, 0.7-0.8, and 0.9-1.0 ng/mL, respectively. Those with GS of ≥7 had cumulative probabilities of 0.42, 0.73, 2.8, and 1.9 %, respectively. The cumulative probabilities of prostate cancer were significantly lower when baseline PSA levels were 0.0-0.6 ng/mL compared with 0.7-1.0 ng/mL. Prostate cancer with a GS of ≥7 was not detected during the first 10 years of screening when baseline PSA levels were 0.0-0.6 ng/mL and was not detected during the first 2 years when baseline PSA levels were 0.7-1.0 ng/mL.

CONCLUSIONS

Our study demonstrated that men with baseline PSA levels of 0.0-0.6 ng/mL might benefit from longer screening intervals than those recommended in the guidelines of the Japanese Urological Association. Further investigation is needed to confirm the optimal screening interval for men with low baseline PSA levels.

Usefulness of selective renal artery embolization for urinary fistula following partial nephrectomy: Two case reports

The present study reported two cases in which selective artery embolization were identified to assist in resolving urinary fistulae following partial nephrectomies. The first case involved a 51-year-old male who received a mini-incision partial nephrectomy with renorrhaphy. Following the operation, urine continued to discharge from the retroperitoneal drain. Selective renal artery embolization of the upper calyx at post-operation day 20 was highly effective and urine output from the drain stopped immediately. Case 2 involved a 66-year-old male, who also suffered from a urinary fistula following a partial nephrectomy. Selective renal artery embolization performed at post-operation day 21 was again effective. In each case, the upper calyx was separated from the renal pelvis. These cases demonstrated that suturing of the collecting system and renal parenchyma may result in the separation of the urine pathway, and that selective renal artery embolization appears to be a highly effective treatment in such cases.

Utilizing an Umbilical Ligament for Complex Ureteroneocystostomy

INTRODUCTION

To overcome the tension of anastomosis between ureter and bladder for complex ureteroneocystostomy in children, we describe a novel technique utilizing an ipsilateral umbilical ligament (occluded umbilical artery) to fix the bladder.

TECHNICAL CONSIDERATIONS

From July 1991 to December 2013, 18 patients (13 girls, 5 boys) underwent our technique for complex ureteroneocystostomy. Median age at surgery was 61 months. The main indications for surgery were ectopic ureter in 9 patients, primary obstructive megaureter in 3, and persistent vesicoureteral reflux after surgery in 2. The ipsilateral umbilical ligament was ligated. A new hiatus was created craniolateral to the original hiatus. The submucosal tunnel was created trans-trigonally. The umbilical ligament was sutured to the whole bladder muscle at the hiatus. Ureteroneocystostomy was then performed. Mean duration of postoperative follow-up was 62.6 months. Seventeen patients underwent unilateral ureteroneocystostomy with our technique. One patient underwent bilateral ureteroneocystostomy with our technique on one side. Vesicoureteral reflux was not shown in 92.3% of patients and no signs of obstruction developed in any patients. No complications were encountered with our procedure.

CONCLUSIONS

Utilizing an umbilical ligament for ureteroneocystostomy to fix the bladder is an excellent option when the distal ureter creates tension in uretero-bladder anastomosis. This method seems to be applicable in many cases of complex ureteroneocystostomy in children.

Holmium Laser Enucleation of the Prostate With Percutaneous Nephrostomy Into the Transplanted Kidney in Patient With Severe Benign Prostatic Hyperplasia With Vesicoureteral Reflux - A Case Report

A 66-year-old male, who had received renal transplantation 10 years before, was admitted to our hospital with urinary retention. The prostate volume was 169.2 ml. Furthermore, grade 5 vesicoureteral reflux (VUR) was shown in the cystography. Holmium laser enucleation of prostate (HoLEP) was performed, and percutaneous nephrostomy to the transplanted kidney was performed simultaneously to prevent from severe perioperative infection. After that, renal graft function improved and no urinary retention reoccurred, although surgical repair against VUR was necessary 10 months after HoLEP. We conclude that surgical treatment for BPH after kidney transplantation should be strongly considered with care for infections.

Highly sensitive droplet digital PCR method for detection of residual undifferentiated cells in cardiomyocytes derived from human pluripotent stem cells

Human pluripotent stem cells (hPSCs), such as human embryonic stem cells (hESCs) and human induced pluripotent stem cells (hiPSCs), are leading candidate cells as raw materials for cell therapy products, because of their capacity for pluripotent differentiation and unlimited self-renewal. hPSC-derived products have already entered the scope of clinical application. However, the assessment and control of their tumorigenicity remains to be a critical challenge. Sensitive detection of the pluripotent cellular impurities is necessary for the safety and quality control of the hPSC-derived products. In the present study, we established a sensitive assay for detection of the residual undifferentiated hiPSCs in cardiomyocytes, using droplet digital PCR (ddPCR). The ddPCR method with a probe and primers for LIN28 significantly detected as low as 0.001% undifferentiated hiPSCs in primary cardiomyocytes, which is equivalent to the ratio of a single hiPSC to 1 × 10⁵ cardiomyocytes. The ddPCR also showed that LIN28 expression is extremely low in human tissues including liver, heart, pancreas, kidney, spinal cord, corneal epithelium and lung. These results suggest that the ddPCR method targeting LIN28 transcripts is highly sensitive and useful for the quality assessment of various cell therapy products derived from hPSCs.

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A highly sensitive in vitro assay for detection of residual undifferentiated hiPSCs in hiPSC-derived cell therapy products.

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LIN28 mRNA is highly sensitive marker of residual undifferentiated hiPSCs in hiPSC-derived cardiomyocytes.

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The ddPCR assay using LIN28 as a target is able to detect 0.001% undifferentiated hiPSCs in primary cardiomyocytes.

Bax deficiency extends the survival of Ku70 knockout mice that develop lung and heart diseases

Ku70 (Lupus Ku autoantigen p70) is essential in nonhomologous end joining DNA double-strand break repair, and ku70^−/− mice age prematurely because of increased genomic instability and DNA damage responses. Previously, we found that Ku70 also inhibits Bax, a key mediator of apoptosis. We hypothesized that Bax-mediated apoptosis would be enhanced in the absence of Ku70 and contribute to premature death observed in ku70^−/− mice. Here, we show that ku70^−/−bax^+/− and ku70^−/−bax^−/− mice have better survival, especially in females, than ku70^−/− mice, even though Bax deficiency did not decrease the incidence of lymphoma observed in a Ku70-null background. Moreover, we found that ku70^−/− mice develop lung diseases, like emphysema and pulmonary arterial (PA) occlusion, by 3 months of age. These lung abnormalities can trigger secondary health problems such as heart failure that may account for the poor survival of ku70^−/− mice. Importantly, Bax deficiency appeared to delay the development of emphysema. This study suggests that enhanced Bax activity exacerbates the negative impact of Ku70 deletion. Furthermore, the underlying mechanisms of emphysema and pulmonary hypertension due to PA occlusion are not well understood, and therefore ku70^−/− and Bax-deficient ku70^−/− mice may be useful models to study these diseases.

Feeder-free and serum-free production of hepatocytes, cholangiocytes, and their proliferating progenitors from human pluripotent stem cells: application to liver-specific functional and cytotoxic assays

We have established a serum- and feeder-free culture system for the efficient differentiation of multifunctional hepatocytes from human embryonic stem (ES) cells and three entirely different induced pluripotent stem (iPS) cells (including vector/transgene-free iPS cells generated using Sendai virus vector) without cell sorting and gene manipulation. The differentiation-inducing protocol consisted of a first stage; endoderm induction, second stage; hepatic initiation, and third stage; hepatic maturation. At the end of differentiation culture, hepatocytes induced from human pluripotent stem cells expressed hepatocyte-specific proteins, such as α-fetoprotein, albumin, α1 antitrypsin and cytochrome P450 (CYP3A4), at similar or higher levels compared with three control human hepatocyte or hepatic cell lines. These human iPS/ES cell-derived hepatocytes also showed mature hepatocyte functions: indocyanine green dye uptake (≈ 30%), storage of glycogen (>80%) and metabolic activity of CYP3A4. Furthermore, they produced a highly sensitive hepatotoxicity assay system for D-galactosamine as determined by the extracellular release of hepatocyte-specific enzymes. Hepatoprotective prostaglandin E1 attenuated this toxicity. Interestingly, bile duct-specific enzymes were also detected after drug treatment, suggesting the presence of bile-duct epithelial cells (cholangiocytes) in our culture system. Electron microscopic studies confirmed the existence of cholangiocytes, and an immunostaining study proved the presence of bipotential hepatoblasts with high potential for proliferation. Differentiated cells were transferrable onto new dishes, on which small-sized proliferating cells with hepatocyte markers emerged and expanded. Thus, our differentiation culture system provides mature functional hepatocytes, cholangiocytes, and their progenitors with proliferative potential from a wide variety of human pluripotent stem cells.

MULTI-SITE AEROSOL MONITORING USING MINI STEP SAMPLER

We developed mini step samplers with low manufacturing and running costs for application in multi-site air-pollution monitoring. The miniaturization of the sampler was achieved by reducing the suction nozzle size. We tested the samplers with suction nozzle diameters of 2 and 4 mm through simultaneous exposure in the same site. Elemental concentrations of aerosol collected by these samplers were consistent within ±20% during comparison and the sample uniformity did not differ significantly. Sampling with small suction nozzle did not adversely affect aerosol collection. Aerosol samples were collected simultaneously at two sites in our laboratory and in the hall outside for 3 days and analyzed subsequently by PIXE. The time variation of elemental concentrations was high during daytime and low at night time and also during the weekend. Elemental concentrations in the hall were always higher than those in the laboratory. In our laboratory, we change shoes at the entrance and therefore, elemental concentrations inside the lab are lower than in the hall. In a second field experiment, we carried out simultaneous multi-site aerosol sampling during two periods in correlation with meteorological data (wind direction and velocity). It was observed that elemental concentrations of some soil origin elements changed periodically. On the other hand, the concentration of Cu and Zn showed irregular concentration spikes whose pattern showed a variation with the sites. Analysis using the data of wind directions showed that Cu had been transported to the sites from northeasterly direction and that the concentration of Zn was influenced by two big factories nearby. In conclusion, it has been demonstrated that the multi-site sampling system combined with meteorological data is well suited to identify sources of pollution.

AN ATTEMPT TO DETERMINE POSITIONS OF AEROSOL SOURCE BY THE PIXE ANALYSIS

Aerosols were continuously collected for 2 or 3 hours during the periods of 4-27 August 1997 and of 23 March-2 April 1998 at a suburb of Sendai City (east 10 km from Sendai), and meteorological data such as wind directions, wind velocities, etc were measured at the same time. The collected aerosol samples were analyzed by the particle-induced X-ray emission (PIXE) method. Fourteen elements (S, Cl, K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, Hg and Pb) were contained in these samples. The elemental concentrations increased in the daytime and decreased at night. It coincided with the time variation of people movement. The concentrations of Mn, Fe, Zn and Pb elements depended strongly on the direction of wind and their distributions for wind directions reflected to the position of aerosol sources. This result suggests that the position of aerosol source can be determined by measuring aerosols and wind directions at the many positions.

Preparation of Thin Polycarbonate Film and Its Application to PIXE Analysis of Anionic Elements in Water Samples

A polycarbonate film of thin and uniform thickness was prepared. A casting solution for film-formation was made up by diluting a solution of poly (bisphenol A carbonate) in chloroform by a factor of two to three with benzene. A uniform film was created by dropping 0.2-0.3 cm3 of the casting solution slowly on a water surface within an aperture (20 mm diameter) of Mylar target frame floating on 50 wt% sucrose aqueous solution. Films of 0.14-0.27 mg/cm2 thickness thus prepared offer a good combination of mechanical strength and low continuum backgrounds. To test PIXE analysis of anionic species in water, targets containing SO 42-, Cr 2 O 72-, AsO 43-, and Ga 3+-internal standard were prepared by depositing 100 μl of the test solutions onto the polycarbonate film, and irradiated in vacuum by 3 MeV proton beams. The difference between the nominal and the analyzed concentrations seldom exceeded ± 15 % in the range from 10 to 2000 ppb.

[Newly developed method of computed tomography scanning to obtain three-dimensional graphics for supporting pulmonary resection]

To acquire the pulmonary artery (PA) and pulmonary vein (PV) image separately, we scanned PA phase while X-ray source moved caudal direction, followed by continuous scan of PV phase by moving back reverse direction. We assessed some scanning conditions to shorten scanning time and determined the starting time for scanning to obtain the maximum intensity difference of radio-opaque contrast between PA and PV phase. Additional infusion of normal saline was followed after contrast medium administration. Finally, scanning could be finished almost 10 seconds with only 20 ml contrast medium for establish three-dimensional (3D) images of pulmonary vessels, and the residual contrast medium could be used for consecutive usual preoperative computed tomography (CT). Twenty-three patients who underwent lung resection were assessed their preoperative 3D-CT images using 5-point scale; 5 and 4 as good, 3 as fair, 2 and 1 as poor. As a result, 18 (78.3%) and 1 (4.3%) were categorized as good and poor, respectively. We successfully decreased the frequency of CT and contrast agent dose for 3D-CT in patients being scheduled for lung resection by the new methods reported herein. Additionally, the workload of building up 3D-CT images by medical workers was also reduced.

Early senescence is not an inevitable fate of human-induced pluripotent stem-derived cells

Human-induced pluripotent stem cells (hiPSCs) are expected to become a powerful tool for regenerative medicine. Their efficacy in the use of clinical purposes is currently under intensive verification. It was reported that hiPSC-derived hemangioblasts had severely limited expansion capability due to an induction of early senescence: hiPSC-derived vascular endothelial cells (VECs) senesced after one passage and hiPSC-derived hematopoietic progenitor cells (HPCs) showed substantially decreased colony-forming activities. Here we show that early senescence is not an inevitable fate of hiPSC-derived cells. Applying our unique feeder-free culture methods for the differentiations of human embryonic stem cells (hESCs), we successfully generated VECs and HPCs from three lines of hiPSCs that were established by using a retrovirus vector system. All hiPS-derived VECs could be subcultured by 2:1∼3:1 dilutions up to 10∼20 passages, after which the cells underwent senescence. Among the three lines of hiPSCs, two lines generated HPCs that bore comparable granulocyte colony-forming units to those of hESCs. Moreover, one line effectively reproduced HPCs within the sac-like structures, the fields of in vitro hematopoiesis, as in the case of hESCs. Surprisingly, release of neutrophils into culture supernatant persisted even longer (∼60 days) than the case of hESCs (∼40 days). Thus, the problem of early senescence can be overcome by selecting appropriate lines of hiPSCs and applying proper differentiation methods to them.

The anti-apoptotic function of human αA-crystallin is directly related to its chaperone activity

αA-crystallin is a molecular chaperone and an antiapoptotic protein. This study investigated the mechanism of inhibition of apoptosis by human αA-crystallin and determined if the chaperone activity of αA-crystallin is required for the antiapoptotic function. αA-crystallin inhibited chemical-induced apoptosis in Chinese hamster ovary (CHO) cells and HeLa cells by inhibiting activation of caspase-3 and -9. In CHO cells, it inhibited apoptosis induced by the overexpression of human proapoptotic proteins, Bim and Bax. αA-crystallin inhibited doxorubicin-mediated activation of human procaspase-3 in CHO cells and it activated the PI3K/Akt cell survival pathway by promoting the phosphorylation of PDK1, Akt and phosphatase tensin homologue in HeLa cells. The phosphoinositide 3 kinase (PI3K) activity was increased by αA-crystallin overexpression but the protein content was unaltered. Downregulation of PI3K by the expression of a dominant-negative mutant or inhibition by LY294002 abrogated the ability of αA-crystallin to phosphorylate Akt. These antiapoptotic functions of αA-crystallin were enhanced in a mutant protein (R21A) that shows increased chaperone activity than the wild-type (Wt) protein. Interestingly, a mutant protein (R49A) that shows decreased chaperone activity was far weaker than the Wt protein in its antiapoptotic functions. Together, our study results show that αA-crystallin inhibits apoptosis by enhancing PI3K activity and inactivating phosphatase tensin homologue and that the antiapoptotic function is directly related to its chaperone activity.

145 EFFECT OF TRANSFER OF CATTLE ELONGATING EMBRYO TO A REPEAT BREEDER COW ON PREGNANCY RATE AND INCIDENCE OF A RETURN TO ESTRUS

In cattle, a low pregnancy rate directly affects calf and milk production and brings about economic loss to livestock producers. The number of repeat breeder cows in herds decreases the overall pregnancy rate. Therefore, many studies have focused on improving the cows’ reproductive performance. On the other hand, it has been demonstrated that the major embryonic loss occurs in the first or second week of pregnancy, after which mother cows recognize the presence of their embryos via a signal protein secreted by the embryos, interferon-τ. Therefore, to bypass the period with a high incidence of pregnancy loss in cattle, we used elongating embryos for embryo transfer (ET) to repeat breeder cows. Elongating embryos on Day 14 postoestrus were used for the present study because embryos of this stage have the ability to produce interferon-τ and embryos of later stages are easily damaged when they are collected from the uterus by flushing. In this study, Japanese Black cows were superovulated and inseminated when they showed standing oestrus. Elongating embryos were collected by nonsurgical uterine flushing. Collected embryos that had evident embryonic discs and intact trophectoderms were used for ET. These embryos were transferred, using plastic catheters or ET guns to ipsilateral uterine horns, to the corpus luteum of synchronized crossbred (Japanese Black × Holstein-Friesian) recipient cows. Recipient cows were divided into 2 groups according to the previous reproductive history of each cow: reproductively normal cows that were pregnant with fewer than 3 times of AI or regular ET (using Day 7 embryos) after every parturition (n = 33) and repeat breeder (RB) cows (n = 42). Elongating embryos were transfer on Day 14 after oestrus, and all cows were monitored for signs of standing oestrus twice a day until Day 80. Pregnancy was diagnosed with ultrasonography every 10 days from Day 30 to 80 postoestrus. The data were analysed by Fisher’s exact test. The pregnancy rate of reproductively normal cows was 54.5%. However, in repeat breeder cows, the pregnancy rate was significantly decreased (2.4%; P < 0.01). When the repeat breeder cows did not become pregnant, transfer of the elongating embryos was repeated another 5 times continuously and the incidence of a return of oestrus was monitored daily. At the first ET period, the average interestrus interval in nonpregnant repeat breeder cows was 50 ± 7.2 days. As the ET period proceeded, the interestrus intervals were gradually decreased, and at a sixth ET period, it approximated the normal oestrus cycle length (22.8 ± 0.8). These results indicated that although transfer of elongating embryos could bypass the critical period of high incidence of embryo loss, it did not improve the pregnancy rate of repeat breeder cows. Moreover, it suggests that the uterine environment of repeat breeder cows was gradually deteriorating in a time-dependent manner.