Mitochondrial DNA mutations can influence the post-implantation development of human mosaic embryos

Introduction: Several healthy euploid births have been reported following the transfer of mosaic embryos, including both euploid and aneuploid blastomeres. This has been attributed to a reduced number of aneuploid cells, as previously reported in mice, but remains poorly explored in humans. We hypothesized that mitochondrial function, one of the most critical factors for embryonic development, can influence human post-implantation embryonic development, including a decrease of aneuploid cells in mosaic embryos. Methods: To clarify the role of mitochondrial function, we biopsied multiple parts of each human embryo and observed the remaining embryos under in vitro culture as a model of post-implantation development (n = 27 embryos). Karyotyping, whole mitochondrial DNA (mtDNA) sequencing, and mtDNA copy number assays were performed on all pre- and post-culture samples. Results: The ratio of euploid embryos was significantly enhanced during in vitro culture, whereas the ratio of mosaic embryos was significantly reduced. Furthermore, post-culture euploid and culturable embryos had significantly few mtDNA mutations, although mtDNA copy numbers did not differ. Discussion: Our results indicate that aneuploid cells decrease in human embryos post-implantation, and mtDNA mutations might induce low mitochondrial function and influence the development of post-implantation embryos with not only aneuploidy but also euploidy. Analyzing the whole mtDNA mutation number may be a novel method for selecting a better mosaic embryo for transfer.

O-183 Frequent spontaneous abortion in pregnancies followed by ICSI using frozen sperm from patients with testicular germ cell tumor (TGCT)

Study question

Despite the high rate of sperm chromosome abnormalities in testicular germ cell tumor (TGCT), why is newborn aneuploidy rate in pregnancies with TGCT patient normal?

Summary answer

Miscarriage rate is higher in the pregnancy of TGCT patients than of non-TGCT cancer patients, although the pregnancy rate in ICSI was not significantly different.

What is known already

Previous reports showed higher sperm aneuploidy in TGCT patients than control males. The sperm aneuploidy rate is high before treatment, and after radical treatments peaked at 6 months after treatment and remained high until 24 months after treatment. However, in the Swedish government base study, the rate of newborn malformations including aneuploidy in all pregnancy with TGCT patients was higher than without TGCT, but not statistically significant. In only natural pregnancies, the rate was not significantly different between the two groups. The cause for discrepancy within sperm aneuploidy and newborn aneuploidy was not well clarified.

Study design, size, duration

To clarify the mechanism for the purifying selection of aneuploid sperm in conception, we examined ICSI cases with TGCT patients that did not include natural sperm competition and compared to controls with non-TGCT cancer patient, who have normal rate of aneuploid sperm. By investigating ICSI outcomes, we aimed to determine which stage of embryonic development are affected by the sperm of TGCT patients.

Participants/materials, setting, methods

Under ethical review of Yokohama city university, the 10 TGCT patients (123 oocytes) and 16 non-TGCT cancer patients (251 oocytes) who underwent ICSI with their frozen sperm from 2012 to 2021 were enrolled. Fertilization, embryo viability and embryo transfer outcomes (pregnancy and miscarriage rate) were examined between two groups underwent ICSI with cryopreserved sperm for fertility preservation. Clinical information was retrospectively collected from medical records.

Main results and the role of chance

The patients' age of sperm cryopreservation was 21-56 years old. 10 cases of TGCT were diagnosed as seminoma (3), non seminoma (6), and unknown (2). 15 cases of non-TGCT were diagnosed as malignant blood diseases (9), prostate cancer (2), bladder cancer (1), and others (3). In both groups, all patients were treated by ICSI with cryopreserved sperm obtained prior to chemotherapy. The mean age of female partners in TGCT was 33.2±3.5 years and not different with 35.8±3.4 years in non-TGCT meaning no different age factor. The fertilization rate, viable embryo rate, pregnancy rate and chemical abortion rate of TGCT vs non-TGCT group were 76.4% vs 67.7%, 64.3% vs 61.7%, 37.1% vs 21.7%, 7.1% vs 23.1%, respectively. Those developmental evaluations were not significantly different between two groups. However, spontaneous abortion rate was significantly higher 46.2% in TGCT group than 10% in non-TGCT group (p < 0.05). Further, in our follow-up, no congenital malformations in the babies born in either group (5 babies in TGCT vs 7 babies in non-TGCT group). The outcome of ICSI using sperm in TGCT patients show normal pregnancy rate but include higher spontaneous abortions rate, suggesting aneuploid embryo were negatively purifying selected under post-implantation stage.

Limitations, reasons for caution

Because ICSI with fertility-preserving frozen sperm in TGCT patient is rare even in reproduction center in general university hospital, single center analysis is still small and limited. More case reports and studies for TGCT fertility preservation are needed for more accurate evaluation.

Wider implications of the findings

In TGCT patients, chromosome aberrations and DNA fragmentation of sperm may not be apparent in natural pregnancies with normal sperm competition, but may become apparent as spontaneous abortions when ICSI were performed, suggesting PGT-A can predict and avoid the hidden risk of repeated pregnancy loss in ICSI to TGCT patients.

Trial registration number

not applicable

Fertility preservation immediately after therapeutic abortion results in multiple normal follicular growth with the absence of mature oocytes due to early luteinization: a case report and literature review

Cancer therapy has priority over fertility preservation. The time available for fertility preservation in patients with cancer is often very limited and depends on the condition of the underlying disease. This case report presents the results of two rounds of controlled ovarian stimulations (COSs) performed after an induced abortion. The patient had mixed phenotype acute leukemia diagnosed during early pregnancy and underwent a surgical abortion, followed by ovarian stimulation using urinary follicle-stimulating hormone (uFSH) and gonadotropin-releasing hormone (GnRH) agonists. Oocyte retrieval was subsequently performed for oocyte cryopreservation. Despite good hormonal and ultrasonic follicular growth, no oocytes were obtained. During a second COS performed at a low human chorionic gonadotropin (hCG) level (less than 100 IU/L), several mature oocytes were obtained, suggesting that higher hCG levels during COS induce the absence of mature oocytes during normal follicular growth. It is recommended to start COS post-abortion after confirming a low hCG level while considering the timing of cancer treatment.

Impact of red blood cell distribution width and mean platelet volume in patients with ST-segment elevation myocardial infarction

The complete blood cell count is one of the most frequently ordered laboratory tests, and many parameters, including red blood cell distribution width (RDW) and mean platelet volume (MPV), are available. The purpose of this study was to investigate the usefulness of the combination of RDW and MPV in patients with ST-segment elevation myocardial infarction (STEMI). Patients with STEMI who underwent primary percutaneous coronary intervention were retrospectively enrolled (n = 229). The association between RDW as well as MPV and cardiovascular events was investigated. The median age was 67 years, and males made up 85% of the sample. Median RDW was 13.6%, and median MPV was 8.2 fL. During a median follow-up period of 528 days (IQR 331.5-920.5), 41 patients died or experienced major adverse cardiac and cerebrovascular events (MACCEs). Patients with RDW ≧ 13.7% had more deaths or MACCEs with marginal significance (p = 0.0799). Patients with MPV ≧ 8.3 fL had significantly more deaths or MACCEs (p = 0.0283). Patients with RDW ≧ 13.7% and MPV ≧ 8.3 fL had significantly more deaths or MACCEs (p = 0.0185). MPV was significantly associated with death or adverse events in patients with STEMI who were treated with primary PCI. RDW had only a weak association with death or adverse events. The results of the combination of MPV and RDW were similar to those of MPV.

Osteoid osteoma in mandibular condyle

A 21-year-old Japanese woman presented with trismus and spontaneous pain (especially at night) around the left temporomandibular joint. Radiographic examination showed a subcortical sclerosed nodule measuring approximately 8 mm in diameter on the infero-lateral aspect of the left mandibular condyle. Amputation of the condyle was performed under general anesthesia. The patient has been in good condition 8 years postoperatively. The histopathology of the specimen consisted of actively proliferating osteoblasts mixed with an interlacing network of woven bone and osteoid trabeculae. Histopathological diagnosis was osteoid osteoma.

[Preliminary clinical applications of asymmetric screen-film systems in chest radiography]

The physical imaging properties of asymmetric systems and a conventional system were evaluated by measuring characteristic curves, resolution properties and noise Wiener spectra. The potential clinical application of asymmetric screen-film systems was studied by evaluating the visibility of the anatomical structures and various types of abnormalities in comparison with those of a conventional screen-film system. The asymmetric systems showed a wider dynamic range than the conventional system. The resolution properties of asymmetric systems depend on the combination of front and back screens used. Chest radiographs obtained with asymmetric systems improved the visibility of the mediastinal area. The visibility of the lung field in the asymmetric systems was slightly inferior to that with the conventional system when the same tube potential was used. However, the image quality and visibility of various abnormalities showed greater improvement with the asymmetric systems when a lower tube potential was applied. We conclude that the selection of radiographic techniques and combination of screens are important for the clinical use of asymmetric systems.

[Case of sialolithiasis with severe fatty change of the submandibular salivary gland]

We encountered a 57-year-old female with sialolithiasis associated with severe fatty change in the submandibular salivary gland. The submandibular salivary gland was removed under general anesthesia, and the postoperative course was uneventful. Histopathological changes observed in submandibular salivary glands with sialoliths are mainly inflammatory cell infiltration or connective tissue infiltration. On the other hand, increase in fat cells with age has been reported, but these age-related fatty changes are not severe. It was considered that the cause of the fatty change in this case was related to anoxia, which increased with long-term stasis of the duct system that was brought on by the development of the sialolith.