Shape of the first mitotic spindles impacts multinucleation in human embryos.

During human embryonic development, early cleavage-stage embryos are more susceptible to errors. Studies have shown that many problems occur during the first mitosis, such as direct cleavage, chromosome segregation errors, and multinucleation. However, the mechanisms whereby these errors occur during the first mitosis in human embryos remain unknown.

An approach for live imaging of first cleavage in mouse embryos using fluorescent chemical probes for DNA, microtubules, and microfilaments.

Purpose: Dynamic morphological changes in the chromosome and cytoskeleton occur in mammals and humans during early embryonic development, and abnormalities such as embryonic chromosomal aneuploidy occur when development does not proceed normally. Visualization of the intracellular organelles and cytoskeleton allows elucidation of the development of early mammalian embryos. The behavior of the DNA and cytoskeleton in early mammalian embryos has conventionally been observed by injecting target molecule mRNAs, incorporating a fluorescent substance-expressing gene, into embryos.

Consistency between chromosomal status analysis of biopsied human blastocyst trophectoderm cells and whole blastocyst cells.

Purpose: This study investigated the consistency between results of preimplantation genetic testing for aneuploidy performed on trophectoderm (TE) cells and remaining blastocyst cells.

Methods: TE biopsy was performed on 29 surplus cryopreserved human blastocysts. Biopsy samples and remaining blastocysts were processed using the VeriSeq PGS kit, and chromosomal statuses were compared by next-generation sequencing.

Cell-free DNA in spent culture medium effectively reflects the chromosomal status of embryos following culturing beyond implantation compared to trophectoderm biopsy.

This prospective study evaluated the accuracy of non-invasive preimplantation genetic testing for aneuploidy (niPGT-A) using cell-free DNA in spent culture medium, as well as that of preimplantation genetic testing for aneuploidy (PGT-A) using trophectoderm (TE) biopsy after culturing beyond implantation. Twenty frozen blastocysts donated by 12 patients who underwent IVF at our institution were investigated. Of these, 10 were frozen on day 5 and 10 on day 6.

Live visualisation of electrolytes during mouse embryonic development using electrolyte indicators.

Studies have shown that some electrolytes, including Na+ and K+, play important roles in embryonic development. However, these studies evaluated these electrolytes by using inhibitors or knockout mice, with no mention on the changes in the intracellular electrolyte concentrations during embryogenesis. In this study, we used the electrolyte indicators CoroNa Green AM and ION Potassium Green-2 AM to directly visualise intracellular concentrations of Na+ and K+, respectively, at each embryonic developmental stage in mouse embryos.

Human frozen-thawed blastocyst morphokinetics observed using time-lapse cinematography reflects the number of trophectoderm cells.

Recent studies reported morphokinetic indices for optimal selection of embryos in assisted reproductive technology (ART). The morphokinetics in blastocyst stage include the collapse and re-expansion rates after thawing. However, evaluation methods using these morphokinetics have not been established, mainly because the underlying molecular mechanisms remain unclarified.

Evaluation of drug-induced hematotoxicity using novel in vitro monkey CFU-GM and BFU-E colony assays.

In order to evaluate drug-induced hematotoxicity in monkey cells in vitro, colony-forming unit-granulocyte, macrophage (CFU-GM), and burst-forming unit-erythroid (BFU-E) colony assays were established using mononuclear cells in the bone marrow collected from male cynomolgus monkeys. Furthermore, the effects of doxorubicin, chloramphenicol, and linezolid on CFU-GM and BFU-E colony formation were investigated using established monkey CFU-GM and BFU-E colony assays in comparison with those on human CFU-GM and BFU-E colonies acquired from human umbilical cord blood cells. Bone marrow mononuclear cells were collected from the ischial or iliac bone of male cynomolgus monkeys.

The location of "8"-shaped hatching influences inner cell mass formation in mouse blastocysts.

The hatching of a blastocyst where the blastocyst portions on the inside and the outside of the zona pellucida feature a figure-of-eight shape is termed "8"-shaped hatching; this type of hatching has been reported to affect the proper presentation of the inner cell mass (ICM) in both human and mouse embryos. Here, our aim was to investigate the factors that affect ICM presentation during "8"-shaped hatching. We performed IVF by using B6D2F1 female mice and ICR male mice, and used the 104 captured blastocysts.

Wide application of a novel topoisomerase I inhibitor-based drug conjugation technology.

To establish a novel and widely applicable payload-linker technology for antibody-drug conjugates (ADCs), we have focused our research on applying exatecan mesylate (DX-8951f), a potent topoisomerase I inhibitor, which exhibits extensive antitumor activity as well as significant myelotoxicity, as the payload part. Through this study, we discovered a promising exatecan derivative (DX-8951 derivative, DXd), that has the characteristics of low membrane permeability and shows considerably less myelotoxicity than that shown by exatecan mesylate in an in vitro human colony forming unit-granulocyte macrophage assay. DXd was further used for drug conjugation by using commercially or clinically useful monoclonal antibodies to evaluate the potency of the ADC.

Effect of body-weight loading onto the articular cartilage on the occurrence of quinolone-induced chondrotoxicity in juvenile rats.

The effect of body-weight loading onto the articular cartilage on the occurrence of chondrotoxicity was investigated in male juvenile Sprague-Dawley rats given ofloxacin (OFLX) orally once at 900 mg/kg. Just after dosing of OFLX, hindlimb unloading was performed for 0, 2, 4, or 8 h by a tail-suspension method. Animals were sacrificed at 8h post-dose, and then the distal femoral articular cartilage was subjected to a histological examination and an investigation for gene expression of tumor necrosis factor receptor superfamily, member 12a (Tnfrsf12a); prostaglandin-endoperoxide synthase 2 (Ptgs2); plasminogen activator, urokinase receptor (Plaur); and matrix metalloproteinase 3 (Mmp3) by qRT-PCR analysis.

Tienilic acid enhances hyperbilirubinemia in Eisai hyperbilirubinuria rats through hepatic multidrug resistance-associated protein 3 and heme oxygenase-1 induction.

We demonstrated that tienilic acid, a diuretic drug withdrawn from the market because of hepatic failure, enhanced hyperbilirubinemia in Eisai hyperbilirubinuria rats (EHBR) with a defect of canalicular multidrug resistance-associated protein 2 (Mrp2). In contrast, no remarkable changes were noted in Sprague-Dawley (SD) rats, the parent strain for EHBR. To investigate a mechanism underlying this enhanced hyperbilirubinemia, we focused on comprehensive effects of tienilic acid on clinicopathological aspects and expression of hepatic transporters.