Effect of microgravity on mammalian embryo development evaluated at the International Space Station.

Mammalian embryos differentiate into the inner cell mass (ICM) and trophectoderm at the 8-16 cell stage. The ICM forms a single cluster that develops into a single fetus. However, the factors that determine differentiation and single cluster formation are unknown. Here we investigated whether embryos could develop normally without gravity. As the embryos cannot be handled by an untrained astronaut, a new device was developed for this purpose. Using this device, two-cell frozen mouse embryos launched to the International Space Station were thawed and cultured by the astronauts under microgravity for 4 days. The embryos cultured under microgravity conditions developed into blastocysts with normal cell numbers, ICM, trophectoderm, and gene expression profiles similar to those cultured under artificial-1 g control on the International Space Station and ground-1 g control, which clearly demonstrated that gravity had no significant effect on the blastocyst formation and initial differentiation of mammalian embryos.

Time-lapse observation of mouse preimplantation embryos using a simple closed glass capillary method.

Time-lapse observation is a popular method for analyzing mammalian preimplantation embryos, but it often requires expensive equipment and skilled techniques. We previously developed a simply and costly embryo-culture system in a sealed tube that does not require a CO2 incubator. In the present study, we developed a new time-lapse observation system using our previous culture method and a glass capillary. Zygotes were placed in a glass capillary and sunk in oil for observation under a stereomicroscope. Warming the capillary using a thermoplate enabled most of the zygotes to develop into blastocysts and produce healthy offspring. This time-lapse observation system captured images every 30 min for up to 5 days, which confirmed that the developmental speed and quality of the embryos were not affected, even with fluorescence. Overall, this new system is a simple time-lapse observation method for preimplantation embryos that does not require dedicated machines and advanced techniques.

Aberrant histone methylation in mouse early preimplantation embryos derived from round spermatid injection.

Round spermatid injection (ROSI) is the last resort and recourse for men with nonobstructive azoospermia to become biological fathers of their children. However, the ROSI-derived offspring rate is lower than intracytoplasmic sperm injection (ICSI) in mice (20% vs. 60%). This low success rate has hindered the spread of ROSI in ART (Assisted Reproductive Technology). However, the cause of the ROSI-zygote-derived low offspring rate is currently unknown. In the previous studies, we reported that H3K9me3 and H3K27me3 exhibited ectopic localizations in male pronuclei (mPN) of ROSI-zygotes, suggesting that the carried over histone to zygotes conveys epigenetic information. In this study, we analyzed other histone modifications to explore unknown abnormalities. H3K36me3 showed an increased methylation state compared to ICSI-derived embryos but not for H3K4me3. Abnormal H3K36me3 was corrected until 2-cell stage embryos, suggesting a long window of reprogramming ability in ROSI-embryos. Treatment with TSA of ROSI-zygotes, which was reported to be capable of correcting ectopic DNA methylation in ROSI-zygotes, caused abnormalities of H3K36me3 in male and female PN (fPN) of the zygotes. In contrast, round spermatid TSA treatment before ROSI, which was reported to improve the preimplantation development of ROSI-zygotes, showed beneficial effects without toxicity in fPN. Therefore, the results suggest that TSA has some negative effects, but overall, it is effective in the correction of epigenetic abnormalities in ROSI-zygotes. When attempting to correct epigenetic abnormalities, attention should be paid to epigenomes not only in male but also in female pronuclei.

Successful Production of Offspring Derived from Phospholipase C Zeta-Deficient Sperm by Additional Artificial Activation.

During mammalian fertilization, repetitive rises of intracellular calcium called calcium oscillations are required for full activation of oocytes. Therefore, oocytes such as round spermatid injected or somatic cell nuclear transferred require additional artificial activation which mimics the calcium oscillations. It is well recognized that sperm specific phospholipase C (PLCζ) is a strong candidate as the sperm factor which can induce calcium oscillations and, at least in mammals, the genetic mutation of PLCζ in human causes male infertility due to the lack of calcium oscillations in the oocytes. Recent studies showed that the sperm lacking PLCζ (Plcz1-/-) still could induce rise(s) of intracellular calcium in the oocytes after IVF but not intracytoplasmic sperm injection (ICSI). In the ICSI oocytes, no pronuclear formation or development to the two-cell stage was observed. However, it is still unclear whether additional activation treatment can rescue the low developmental ability of Plcz1-/--sperm-derived oocytes after ICSI. In this study, we examined whether oocytes injected with a Plcz1-/- sperm can develop to term by additional artificial activation. In oocytes injected a Plcz1-/- sperm and Plcz1-/- and eCS (another candidate of the sperm factor) double knockout sperm (Plcz1-/-eCS-/-), the rates of pronuclear formation were very low (2.0 ± 2.3% and 6.1 ± 3.7%, respectively) compared to control (92.1 ± 2.6%). However, these rates were dramatically improved by additional procedures of PLCζ-mRNA injection or SrCl2 treatment (Plcz1-/- sperm + PLCζ mRNA, Plcz1-/- sperm + SrCl2 and Plcz1-/-eCS-/- sperm + PLCζ mRNA; 64.2 ± 10.8%, 89.2 ± 2.4% and 72.6 ± 5.4%, respectively). Most of the oocytes were developed to the two-cell stage. After embryo transfer, healthy pups were obtained in all these groups (Plcz1-/- sperm + PLCζ mRNA:10.0 ± 2.8%, Plcz1-/- sperm + SrCl2:4.0 ± 4.3% and Plcz1-/-eCS-/- sperm + PLCζ mRNA: 10.0 ± 5.7%). The rate in Plcz1-/- sperm + SrCl2 group was significantly lower than that in control (26.0 ± 2.4%). Taken together, our present results show that additional activation treatment such as SrCl2 and PLCζ mRNA can fully support to develop to term even in oocyte injected Plcz1-/- sperm. In addition, PLCζ-induced oocyte activation is more suitable for successful development to term compared to that such as phenomenon induced by SrCl2. These findings will contribute to improvement for male-dependent human infertility and reproductive technologies in other mammalian species.

Development of a new device for manipulating frozen mouse 2-cell embryos on the International Space Station.

Whether mammalian embryos develop normally under microgravity remains to be determined. However, embryos are too small to be handled by inexperienced astronauts who orbit Earth on the International Space Station (ISS). Here we describe the development of a new device that allows astronauts to thaw and culture frozen mouse 2-cell embryos on the ISS without directly contacting the embryos. First, we developed several new devices using a hollow fiber tube that allows thawing embryo without practice and observations of embryonic development. The recovery rate of embryos was over 90%, and its developmental rate to the blastocyst were over 80%. However, the general vitrification method requires liquid nitrogen, which is not available on the ISS. Therefore, we developed another new device, Embryo Thawing and Culturing unit (ETC) employing a high osmolarity vitrification method, which preserves frozen embryos at -80°C for several months. Embryos flushed out of the ETC during thawing and washing were protected using a mesh sheet. Although the recovery rate of embryos after thawing were not high (24%-78%) and embryonic development in ETC could not be observed, thawed embryos formed blastocysts after 4 days of culture (29%-100%) without direct contact. Thus, this ETC could be used for untrained astronauts to thaw and culture frozen embryos on the ISS. In addition, this ETC will be an important advance in fields such as clinical infertility and animal biotechnology when recovery rate of embryos were improved nearly 100%.

Paternally inherited H3K27me3 affects chromatin accessibility in mouse embryos produced by round spermatid injection.

Round spermatid injection (ROSI) results in a lower birth rate than intracytoplasmic sperm injection, which has hampered its clinical application. Inefficient development of ROSI embryos has been attributed to epigenetic abnormalities. However, the chromatin-based mechanism that underpins the low birth rate in ROSI remains to be determined. Here, we show that a repressive histone mark, H3K27me3, persists from mouse round spermatids into zygotes in ROSI and that round spermatid-derived H3K27me3 is associated with less accessible chromatin and impaired gene expression in ROSI embryos. These loci are initially marked by H3K27me3 but undergo histone modification remodelling in spermiogenesis, resulting in reduced H3K27me3 in normal spermatozoa. Therefore, the absence of epigenetic remodelling, presumably mediated by histone turnover during spermiogenesis, leads to dysregulation of chromatin accessibility and transcription in ROSI embryos. Thus, our results unveil a molecular logic, in which chromatin states in round spermatids impinge on chromatin accessibility and transcription in ROSI embryos, highlighting the importance of epigenetic remodelling during spermiogenesis in successful reproduction.

Successful treatment with proton beam therapy for a solitary sternal metastasis of breast cancer: a case report.

BACKGROUND: Breast cancer infrequently metastasizes to the sternum as solitary metastasis. We experienced successful treatment with proton beam therapy for a case of sternal metastasis of breast cancer. This case demonstrates for the first time the role of proton therapy in the treatment of oligometastatic sternal metastasis with limited tolerance of normal tissue due to previous photon irradiation. CASE PRESENTATION: A 40-year-old Japanese female presented with lumpiness in her left breast. The patient was diagnosed with breast cancer (cT1N0M0, cStage IA) and underwent partial mastectomy with axillary lymph node dissection. After the mastectomy, the patient received radiation therapy with 50 Gy in 25 fractions for initial irradiation of the left breast. After the initial irradiation of 50 Gy, the patient received 10 Gy in five fractions of a sequential boost for the tumor bed to a total dose of 60 Gy. Although the patient was administered tamoxifen after radiation therapy, solitary sternal metastasis occurred 6 months after radiation therapy. She refused chemotherapy and requested proton beam therapy for her sternal metastasis. The daily proton beam therapy fractions were 2.5 relative biological effectiveness, receiving a total dose of 70 Gy relative biological effectiveness. An acute side effect of grade 2 dermatitis according to the National Cancer Institute Common Terminology Criteria for Adverse Events version 4.0. occurred during proton beam therapy, but there was no acute or late complication of more than grade 3. At 3 years after proton beam therapy, the patient remains in complete remission without surgery or chemotherapy. DISCUSSION AND CONCLUSION: Proton beam therapy for solitary sternal metastasis of breast cancer is considered to be a therapeutic option.

A long-term survival case with proton beam therapy for advanced sphenoid sinus cancer with hypopituitarism.

Sphenoid sinus malignancies are rare diseases. Secondary hypopituitarism associated with sphenoid sinus malignancy is not well known. A 41-year-old male complained of right ptosis. Neurological findings revealed right oculomotor, trochlear and glossopharyngeal nerve palsy. Imaging diagnosis suggested a tumor that had spread bilaterally from the sphenoid sinus to the ethmoid sinus, nasopharynx and posterior pharyngeal space. Biopsy revealed squamous cell carcinoma (SCC). Based on these findings, a clinical diagnosis of SCC of the sphenoid sinus was made. Removal of the tumor without damaging nearby organs would have been difficult because the tumor extended to the bilateral optic nerves, optic chiasma and internal carotid artery, and surgeons, therefore, recommended proton beam therapy (PBT). Before PBT, the hypopituitarism occurred in the patient and we administered hydrocortisone and levothyroxine. During treating for hypopituitarism, we performed PBT with nedaplatin and 5-fluorouracil. The daily PBT fractions were 2.2 relative biological effectiveness (RBE) for the tumor received total dose of 81.4 Gy RBE. The acute side effect of grade 2 dermatitis according to the National Cancer Institute Common Terminology Criteria for Adverse Events version 4.0. Occurred after PBT. The patient needs to take hydrocortisone and levothyroxine, but he remains in complete remission 8 years after treatment without surgery or chemotherapy. Visual function is gradually declining, but there is no evidence of severe radiation-induced optic neuropathy.

Long-term survival after definitive proton beam therapy for oligorecurrent esophageal squamous cell carcinoma: a case report.

BACKGROUND: Radical esophagectomy for esophageal squamous cell carcinoma has improved survival, but the rate of recurrence is high. Patients of recurrent esophageal squamous cell carcinoma after failure of chemotherapy have a poor prognosis. We herein report the achievement of long-term survival after definitive proton beam therapy for oligorecurrent esophageal squamous cell carcinoma after failure of chemotherapy. CASE PRESENTATION: A 60-year-old Japanese man was diagnosed as having squamous cell carcinoma of the lower thoracic esophagus (cT2N0M0, stage IIA). He underwent two courses of neoadjuvant chemotherapy with cisplatin and 5-fluorouracil, and esophagectomy with three-field lymphadenectomy was performed. Microscopic findings after resection showed two lymph node metastases (ypT2N1M0, stage IIB). Five months after resection, a computed tomography scan revealed a solitary liver metastasis in the S4 area. He underwent three courses of chemotherapy with cisplatin and 5-fluorouracil; however, positron emission tomography revealed two lymph node metastases. Surgeons recommended second-line chemotherapy, but the patient refused chemotherapy and requested proton beam therapy. We performed proton beam therapy without chemotherapy for the liver metastasis and lymph node metastases, with total doses of 79.2 and 60 Gy relative biological effectiveness, respectively, according to the tumor location. An acute side effect of grade 1 dermatitis occurred after proton beam therapy, but there was no acute or late complication of more than grade 2. The patient remains in complete remission 5 years after treatment without surgery or chemotherapy. DISCUSSION AND CONCLUSIONS: Proton beam therapy exerted a curative effect on oligorecurrent esophageal squamous cell carcinoma. This is the first report on the achievement of long-term survival after definitive proton beam therapy for oligorecurrent esophageal squamous cell carcinoma.

Optimised CO2-containing medium for in vitro culture and transportation of mouse preimplantation embryos without CO2 incubator.

Conventional in vitro culture and manipulation of mouse embryos require a CO2 incubator, which not only increases the cost of performing experiments but also hampers the transport of embryos to the other laboratories. In this study, we established and tested a new CO2 incubator-free embryo culture system and transported embryos using this system. Using an Anaero pouch, which is a CO2 gas-generating agent, to increase the CO2 partial pressure of CZB medium to 4%-5%, 2-cell embryos were cultured to the blastocyst stage in a sealed tube without a CO2 incubator at 37°C. Further, the developmental rate to blastocyst and full-term development after embryo transfer were comparable with those of usual culture method using a CO2 incubator (blastocyst rate: 97% versus 95%, respectively; offspring rate: 30% versus 35%, respectively). Furthermore, using a thermal bottle, embryos were reliably cultured using this system for up to 2 days at room temperature, and live offspring were obtained from embryos transported in this simple and very low-cost manner without reducing the offspring rate (thermal bottle: 26.2% versus CO2 incubator: 34.3%). This study demonstrates that CO2 incubators are not essential for embryo culture and transportation and that this system provides a useful, low-cost alternative for mouse embryo culture and manipulation.

Evaluating the long-term effect of space radiation on the reproductive normality of mammalian sperm preserved on the International Space Station.

Space radiation may cause DNA damage to cells and concern for the inheritance of mutations in offspring after deep space exploration. However, there is no way to study the long-term effects of space radiation using biological materials. Here, we developed a method to evaluate the biological effect of space radiation and examined the reproductive potential of mouse freeze-dried spermatozoa stored on the International Space Station (ISS) for the longest period in biological research. The space radiation did not affect sperm DNA or fertility after preservation on ISS, and many genetically normal offspring were obtained without reducing the success rate compared to the ground-preserved control. The results of ground x-ray experiments showed that sperm can be stored for more than 200 years in space. These results suggest that the effect of deep space radiation on mammalian reproduction can be evaluated using spermatozoa, even without being monitored by astronauts in Gateway.

Actual use of and satisfaction associated with rollators and "shopping carts" among frail elderly Japanese people using day-service facilities.

Purpose This study aimed at clarifying the actual use of and satisfaction with rollators and "shopping carts" (wheeled walkers with storage) among frail elderly people, who were certified by a long-term care insurance system as users of facilities that provide day-service nursing care and rehabilitation. Methods We identified 1247 frail elderly people who used day-service facilities, and evaluated their actual use of, and satisfaction with, rollators and shopping carts. Results Forty-four (3.5%) individuals used rollators, and 53 (4.3%) used shopping carts. The shopping cart group contained more individuals who were certified as care level 1 (26.4%), than the rollator group (20.5%), and 52.8% of the shopping cart group was certified as care levels 1-3. The scores for "repairs and services" and "follow-up" from the Quebec User Evaluation of Satisfaction with assistive Technology second version (QUEST 2.0) survey were significantly higher in the rollator group than in the shopping cart group. Conclusions The QUEST 2.0 scores revealed that shopping cart users exhibit insufficient "repairs and services" and "follow-up" scores. As frail elderly people with poor care status accounted for >50% of the shopping cart group, these individuals urgently need walking aids that are tailored to their care status. Implications for Rehabilitation We conclude that walking aid fitting must be tailored to each persons care status, and suggest that a system should be established to allow occupational or physical therapists to provide this fitting Moreover, our analysis of the QUEST2.0 service scores revealed that repairs, services, and follow-up are insufficient to meet the needs of shopping cart users.