Publications by authors named "Isao Tamura"

To investigate the actual status of fertility preservation techniques in oncofertility in Japan and to clarify the involvement of embryologists in this field. This survey was conducted online, targeting embryologists working at 622 facilities registered with the Japan Society of Obstetrics and Gynecology for assisted reproductive technology. The response rate was 56.

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Decidualization of the human endometrium is critical for establishing pregnancy and is entailed by differentiation of endometrial stromal cells (ESCs) into decidual cells. During decidualization, the actin cytoskeleton is dynamically reorganized for the ESCs' morphological and functional changes. Although actin dynamically alters its polymerized state upon external stimuli not only in the cytoplasm, but also in the nucleus, nuclear actin dynamics during decidualization have not been elucidated.

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Article Synopsis
  • Dose-dense paclitaxel/carboplatin (ddTC) therapy was initially thought to be more effective for treating ovarian cancer than the traditional tri-weekly TC, based on the JGOG3016 study, although later studies showed mixed results.
  • A retrospective analysis of patients treated with ddTC from 2012 to 2018 revealed high response rates (RRs) and progression-free survival (PFS) times, with front-line treatment achieving an RR of 82.9% and a median PFS of 20 months.
  • Overall, ddTC therapy showed strong effectiveness in managing advanced stages (III and IV) of ovarian cancer, providing promising outcomes for both first-line and platinum-sensitive relapse treatments.
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  • Decidualization is crucial for successful embryo implantation, and failures in this process can lead to issues like miscarriage; the extent of decidualization failure in infertile women is not well understood.
  • Researchers analyzed endometrial samples from 33 infertile women in the late-secretory phase to determine the prevalence of decidualization failure and examined key transcription factors related to the process.
  • Findings showed that 62.5% of the women experienced decidualization failure, which was linked to a history of more miscarriages, and notable differences in the expression levels of important transcription factors were observed between those with and without failures.
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Purpose: To investigate whether long noncoding RNAs (lncRNAs) are involved in the development or malignant behavior of ovarian high-grade serous carcinoma (HGSC), we attempted to identify lncRNAs specific to HGSC.

Methods: Total RNAs were isolated from HGSC, normal ovarian, and fallopian tube tissue samples and were subjected to a PCR array that can analyze 84 cancer-associated lncRNAs. The lncRNAs that were upregulated and downregulated in HGSC in comparison to multiple samples of normal ovary and fallopian tube were validated by real-time RT-PCR.

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Article Synopsis
  • Decidualization of human endometrial stromal cells (ESCs) can be induced by various stimuli, with different stimuli leading to distinct cellular responses and gene expression profiles.
  • Research indicated that stimuli involving cAMP triggered more significant changes in gene expression and cellular functions compared to those that relied solely on medroxyprogesterone acetate (MPA).
  • Findings suggest that the combination of cAMP and MPA more closely resembles natural in vivo decidualization, demonstrating differences in how various stimuli impact the endometrial cellular environment.
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Purpose: We investigated the interactions between mural granulosa cells (MGCs) and cumulus granulosa cells (CGCs) during ovulation after the LH surge.

Methods: We performed clustering, pseudotime, and interactome analyses utilizing reported single-cell RNA sequencing data of mouse ovary at 6 h after eCG-hCG injection.

Results: Clustering analysis classified granulosa cells into two distinct populations, MGCs and CGCs.

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Purpose: To test the theory that invaginated ovarian surface epithelium and endometrial implants on the ovary form ovarian endometriomas.

Methods: Adhesion sites of ovarian endometrioma on the peritoneum and consecutive ovarian endometrioma cyst wall, called non-adhesion sites, were histologically examined. DNA methylomes of the adhesion sites, non-adhesion sites, and blueberry spots were compared with those of ovary, endometrium, and peritoneum.

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Article Synopsis
  • Human endometrial stromal cells undergo a crucial differentiation called decidualization, which is essential for embryo implantation and is impacted by specific genes being upregulated or downregulated.
  • Defective decidualization can lead to serious reproductive issues such as implantation failure, miscarriage, and infertility, highlighting its significance in successful pregnancies.
  • Recent studies emphasize the role of epigenetic mechanisms, specifically histone modifications like H3K27ac and H3K4me3, in regulating gene expression during this process, suggesting potential new treatment avenues for women facing implantation challenges.
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Decidualization is a process of differentiation of human endometrial stromal cells (hESCs) accompanied by dramatic changes in cellular functions. This process is critical for embryo implantation and the establishment of pregnancy. Impairment of decidualization of hESCs leads to implantation failure, miscarriage, and unexplained infertility.

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Melatonin is a promising reagent that can improve assisted reproductive technology (ART) outcomes in infertility patients. However, melatonin is not effective for all infertile patients, and it remains unclear for which patients melatonin would be effective. This study examined the effects of melatonin on ART outcomes and examined its mechanisms.

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We previously reported that CCAAT/enhancer-binding protein beta (C/EBPβ) is the pioneer factor inducing transcription enhancer mark H3K27 acetylation (H3K27ac) in the promoter and enhancer regions of genes encoding insulin-like growth factor-binding protein-1 (IGFBP-1) and prolactin (PRL) and that this contributes to decidualization of human endometrial stromal cells (ESCs). Peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α; PPARGC1A) is a transcriptional coactivator known to regulate H3K27ac. However, although PGC-1α is expressed in ESCs, the potential role of PGC-1α in mediating decidualization is unclear.

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Human endometrial stromal cells (ESCs) differentiate into decidual cells by the action of progesterone, which is essential for implantation and maintenance of pregnancy. We previously reported that glucose uptake by human ESCs increases during decidualization and that glucose is indispensable for decidualization. Although glucose transporter 1 (GLUT1) is upregulated during decidualization, it remains unclear whether it is involved in glucose uptake.

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The ovulatory luteinizing hormone (LH) surge induces rapid changes of gene expression and cellular functions in granulosa cells (GCs) undergoing luteinization. However, it remains unclear how the changes in genome-wide gene expression are regulated. H3K4me3 histone modifications are involved in the rapid alteration of gene expression.

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Women usually experience body weight gain with aging, which can put them at risk for many chronic diseases. Previous studies indicated that melatonin treatment attenuates body weight gain and abdominal fat deposition in several male animals. However, it is unclear whether melatonin affects female animals in the same way.

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We previously reported that H3K27 acetylation (H3K27ac) increases throughout the genome during decidualization of human endometrial stromal cells (ESCs). However, its mechanisms have not been clarified. We also reported that C/EBPβ acts as a pioneer factor initiating chromatin remodeling by increasing H3K27ac of IGFBP-1 and PRL promoters.

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Purpose: To identify the upstream regulators (URs) involved in the onset and pathogenesis of ovarian endometrioma.

Methods: Recently, a method called Significance-based Modules Integrating the Transcriptome and Epigenome (SMITE) that uses transcriptome data in combination with publicly available data for identifying URs of cellular processes has been developed. Here, we used SMITE with transcriptome data from ovarian endometrioma stromal cells (ovESCs) and eutopic endometrium stromal cells (euESCs) in combination with publicly available gene regulatory network data.

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Article Synopsis
  • - The study aimed to find long non-coding RNAs (lncRNAs) that are expressed unusually in ovarian high-grade serous carcinoma (HGSC) by analyzing RNA from various ovarian cell types.
  • - Using a PCR array, researchers pinpointed ten lncRNAs with altered expressions in HGSC cell lines—six were upregulated and four downregulated—and tested their effects on cell activities like proliferation, migration, and apoptosis.
  • - They discovered that overexpressing certain lncRNAs (MEG3 and POU5F1P5) inhibited cell migration, and the same four downregulated lncRNAs were also found to be low in actual HGSC tissue samples, indicating their potential significance in ovarian cancer.
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We previously reported that the transcription factor Wilms tumor 1 () regulates the expression of insulin-like growth factor-binding protein-1 () and prolactin () during decidualization of human endometrial stromal cells (ESCs). However, other roles of WT1 in decidualization remain to be fully clarified. Here, we investigated how WT1 regulates the physiological functions of human ESCs during decidualization.

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Background: Endometriosis is considered to be the most intractable cause of female infertility. Administering any type of treatment for endometriosis before in vitro fertilization and embryo transfer (IVF-ET) is an important strategy for improving the IVF-ET outcomes for infertile women with endometriosis. In fact, treatment with a gonadotropin-releasing hormone (GnRH) agonist just before IVF-ET has been reported to improve the clinical outcome in endometriosis patients.

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The aim of this study is to reveal the morphological property about the loose bodies (LBs) of temporomandibular joint (TMJ) by scanning electron microscope (SEM). We obtained specimens from two female cases of released loose body by surgical operation. These specimens were fixed by soaking in a mixture of 5% glutaraldehyde or 4% formaldehyde for one week.

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