Association Between Antibiotic Exposure During Pregnancy and Postpartum Depressive Symptoms: The Japan Environment and Children's Study.

Postpartum depressive symptoms (PDS) are a common mental health condition among women after delivery. Although various causative factors have been reported, PDS remains a challenging condition to predict and prevent. The disruption of the gut microbiota due to antibiotic exposure has been reported to affect psychiatric conditions.

Medaka (Oryzias latipes) for use in evaluating developmental effects of endocrine active chemicals with special reference to gonadal intersex (testis-ova).

Japanese medaka (Oryzias latipes) has been widely used for the evaluation of the toxicity of endocrine active chemicals (EACs) and other chemicals as well as for monitoring the adverse effects of effluent discharges in relation to sexual development and function. It is useful for these evaluations for many reasons including the following: 1) it has a short life cycle facilitating studies extending over long phases of development and over multigenerations, 2) it is easy to rear, 3) male and female phenotypes can easily be distinguished on the basis of secondary sex characteristics, and 4) a genetic marker (DMY) is available for identifying the true genotypic sex. Several biomarkers have been found to be useful for identifying the effects of exposure to estrogenic and androgenic chemicals in medaka and they include increased levels of hepatic vitellogenin (VTG) and testis-ova induction in males for exposure to estrogenic chemicals, and decreased levels of hepatic VTG in females and an altered morphology of dorsal and anal fins and formation of papillae for androgenic chemicals.