Nuclear-to-cytoplasmic ratios of 1PN and 2PN zygotes after fertilization of mouse oocytes.

Numerous studies have reported comparisons of the nuclear-to-cytoplasmic (NC) ratio during mitosis. However, little information is known about how the pronuclear size is regulated and determined at the end of meiosis II in mammalian zygotes. The present study aims to analyze the NC ratio of female and male pronuclei, and also to compare the size of single pronuclei using photographs that were obtained during experiments to create chimeric hermaphrodites from 2-cell oocytes.

A General Framework for Tilings, Delone Sets, Functions, and Measures and Their Interrelation.

We define a general framework that includes objects such as tilings, Delone sets, functions, and measures. We define local derivability and mutual local derivability (MLD) between any two of these objects in order to describe their interrelation. This is a generalization of the local derivability and MLD (or S-MLD) for tilings and Delone sets which are used in literature, under a mild assumption.

Detection and quantification of male-specific fetal DNA in the serum of pregnant cynomolgus monkeys (Macaca fascicularis).

Because of their developmental similarities to humans, nonhuman primates are often used as a model to study fetal development for potential clinical applications in humans. The detection of fetal DNA in maternal plasma or serum offers a source of fetal genetic material for prenatal diagnosis. However, no such data have been reported for cynomolgus monkeys (Macaca fascicularis), an important model in biomedical research.

Aggregated chromosomes transfer in human oocytes.

Germinal-vesicle (GV) transfer, spindle-chromosome complex transfer in metaphase-II oocytes and two pronuclei transfer have been evaluated as possible treatments for patients who have mitochondrial diseases. However, GV transfers often lead to heteroplasmy while the other two methods are frequently associated with aneuploidy. The present study used a new method based on the transfer of aggregated chromosomes, which occurs in human oocytes, before the metaphase spindle is established.

The redox state of recombinant human serum albumin and its optimal concentration for mouse embryo culture.

Albumin has multiple physiological functions in embryo culture, such as a chelator of heavy metals, free radical scavenger, pH and osmotic regulator, a stabilizer, growth factor carrier, a surfactant, and a nutrient. However, the commercially available human serum albumin (HSA) products may not be completely safe since they could be contaminated with viruses and prions. Recombinant human serum albumin (rHSA) has been reported to be as efficient as commercial HSA for fertilization and embryo development.

The influence of the redox state of follicular fluid albumin on the viability of aspirated human oocytes.

A number of reports have suggested that the oxidative state of human albumin in serum and in some body fluids is associated with cell damage. However there are no reports on the redox state of human follicular fluid (FF) and its influence on oocyte viability. The aim of this study was to examine the relationship between the redox state of FF and serum on oocyte viability.

Impact of dietary folate intake on depressive symptoms in young women of reproductive age.

Introduction: Folate deficiencies may be linked to depressive disorders among persons suffering from neurological and psychiatric problems. The purpose of the present study was to evaluate the impact of dietary folate intake on depressive symptoms in young Japanese women of reproductive age.

Methods: The study was conducted in Japan in 2009 with 141 Japanese women aged 18 to 28 years.

Symmetrical division of mouse oocytes during meiotic maturation can lead to the development of twin embryos that amalgamate to form a chimeric hermaphrodite.

Background: Gentle compression of mouse oocytes during meiosis-1 prevented the usual extrusion of a small polar body and resulted in the symmetrical division of the ooplasm into two cells of similar size within the zona pellucida. The purpose of our study was to determine whether such cells, equivalent to two small oocytes, were capable of embryonic development and would result in birth following transfer to the uterus.

Methods: IVF of the 2-celled oocytes was performed and the twin intra-zonal embryos were observed.

Risk factors for term small for gestational age infants in women with low prepregnancy body mass index.

Aim: The purpose of our study was to investigate the association between low maternal prepregnancy body mass index (BMI) less than 18.5 kg/m(2) and the incidence of small for gestational age (SGA) infants.

Material & Methods: This was a cross-sectional study.

Association of spindle midzone particles with polo-like kinase 1 during meiosis in mouse and human oocytes.

Polo-like kinase 1 (Plk1) has been reported to localize to the spindle midzone during meiosis in mouse oocytes. However, it has not been reported in human oocytes. In this study, the interaction of the meiotic structures and chromosome segregation in mouse and human oocytes were studied by time-lapse differential interference contrast microscopy.

Experience of sexual violence among sexually experienced Japanese teenage girls and influencing factors.

The aim of the present study was to identify influencing factors for sexual violence in sexually experienced teenage girls. Eighty sexually experienced teenage girls aged between 14 and 19 attending obstetrics and gynecology clinics in suburban Tokyo were selected as subjects. After completing a simple questionnaire on sexual behavior and lifestyle the subjects were interviewed using a semistructured interview technique.

Dietary folate intake, use of folate supplements, lifestyle factors, and serum folate levels among pregnant women in Tokyo, Japan.

Aim: The aim of this study was to determine the folate status of pregnant women and how it is affected by dietary folate, use of folate supplements, and lifestyle factors (smoking and drinking habits).

Methods: This cross-sectional study involved 537 healthy, pregnant women attending an obstetric clinic in a Tokyo suburb. Morning blood samples were taken to determine serum folate levels.

Dietary folate intake during pregnancy and birth weight in Japan.

Background: Inadequate folate status has been associated with many negative reproductive outcomes, such as neural tube defects (NTD), low birth weight and placental abruption.

Aim Of The Study: The objectives of this study were to evaluate the levels of dietary folate intake during pregnancy in Japanese women and the subsequent birth weight of their babies.

Methods: A longitudinal prospective study was conducted with 197 women with a singleton pregnancy in 2005.

Damage of embryo development caused by peroxidized mineral oil and its association with albumin in culture.

Objectives: To examine the effect of free radicals from peroxidized oil and the role of albumin on the passage of radicals.

Design: Prospective study.

Setting: Clinical IVF laboratory and university department.

Risk factors for small for gestational age.

Background: The purpose of the paper was to determine the risk factors for small-for-gestational-age (SGA) infants at full term, in Japan.

Methods: The study was conducted at four hospitals and clinics in the Tokyo metropolitan area. A retrospective review of 2972 mothers and their infants born from singleton pregnancies at any time during the years 2002 and 2003 was conducted.

A phase of chromosome aggregation during meiosis in human oocytes.

A higher rate of chromosomal abnormality occurs in human oocytes compared with other animal oocytes. In this study, chromosome movement has been successfully observed during first and second meiosis using a time-lapse culture system and a differential interference contrast inverted microscope. In human oocytes, a specific sequence of early maturation changes was observed.

Lipofuscin bodies in human oocytes as an indicator of oocyte quality.

Refractile bodies are one of the main morphological abnormalities that can be observed in the cytoplasm of human oocytes. In the present studies the characteristics of refractile bodies and the relationship between the size of these structures and developmental competence of the affected oocytes and resulting embryos were examined. The refractile bodies were found to have yellow autofluorescence which was consistent with the typical autofluorescence of lipofuscin.

Peroxidation of mineral oil used in droplet culture is detrimental to fertilization and embryo development.

Unexpected deterioration of human embryos led us to an investigation of possible toxic factors in the oil covering culture medium. Elevated levels of peroxidation in the oil by oxygen exposure or unfavorable storage were found to be the main causes of toxicity.

Restricting weight gain during pregnancy in Japan: a controversial factor in reducing perinatal complications.

Objective: To evaluate the effectiveness of restricting weight gain during pregnancy to reduce perinatal complications.

Study Design: The study was conducted in the Tokyo metropolitan area, and reviewed 3071 mothers and their infants born from singleton pregnancies retrospectively. To examine the influence of increased maternal weight gain on perinatal complications, we performed five-category stratification for weight gain: less than 8.

Timed IVM followed by ICSI in a patient with immature ovarian oocytes.

A complete failure of meiotic maturation occasionally occurs following human chorionic gonadotrophin administration during IVF-intracytoplasmic sperm injection (ICSI) cycles. ICSI on day 1 is commonly used to allow maturation in culture. However, if the oocytes become mature in the evening soon after their recovery but ICSI is delayed until the next day, then subsequent ageing of matured oocytes may be unfavourable for fertilization and development.