Yasutaka Murata

Possible antenatal and perinatal related factors in development of cystic periventricular leukomalacia

Cystic periventricular leukomalacia (cPVL), the principal ischemic brain injury in premature infants, is characterized by necrosis of the white matter in the periventricular region and the major neuropathology for spastic motor deficits in cerebral palsy or epilepsy. Recent reports strongly suggest that the brain injury associated with cPVL may have already occurred in utero. In this study we searched retrospectively for possible clinical situations related to cPVL to facilitate assessment of optimal management. A total of 201 babies born at gestational ages from 24 to 33 weeks were entered into the study (1992-1997) and examined for involvement of 18 factors in cPVL retrospectively. And psychomotor development was examined at least until 18 months of corrected age. Among 201 premature babies 35 cases were diagnosed as cPVL later developed spastic diplegia. There are 23 cases of preeclampsia, no infant suffering from cPVL. In the univariate analysis, exposure to antenatal indomethacin, cord length > or =40 cm, and a low Apgar score were significantly associated with a 2-3 risk increased of cPVL occurrence, while antenatal magnesium sulfate reduced the risk. Chorioamnionitis was positively correlated with the risk, but did not reach statistical significance. In the multivariate analysis we found the statistical significance in exposure to antenatal indomethacin, a low Apgar score, and antenatal magnesium sulfate. Our results suggested that preeclampsia and antenatal exposure of magnesium sulfate reduced the risk while antenatal exposure of indomethacin and low Apgar score associated with the occurrence of cPVL. These findings support a growing consensus that cPVL is often the result of maternal and fetal factors as well as antenatal treatment.

Effect of aspiration vacuum on the developmental competence of immature human oocytes retrieved using a 20-gauge needle

In-vitro maturation (IVM) of immature oocytes has been proposed as a potential alternative to conventional IVF treatment following ovarian stimulation. However, the effects of the oocyte retrieval conditions on subsequent development have not been well understood. This study assessed the effects of different aspiration vacuums during oocyte retrieval on the developmental competence of immature oocytes following IVM, IVF and embryo transfer, retrospectively. Immature oocytes were aspirated with 20-gauge needles with a vacuum of 180 or 300 mmHg. Immature oocytes were cultured in IVM medium for 26 h. All mature oocytes were inseminated by intracytoplasmic sperm injection (ICSI). Embryo transfer was carried out 2 or 3 days after ICSI. The percentage of cumulus-cell enclosed oocytes and of transferable embryos per retrieved oocytes in 180 mmHg (69.7% and 23.8%, respectively) were significantly higher (P < 0.01) than those in 300 mmHg (46.2% and 12.8%, respectively). The ongoing pregnancy rate per retrieval cycle in 180 mmHg (30%) was higher (P < 0.01) than that in 300 mmHg (4.3%). The data indicate that lower pressure of vacuum aspiration with a 20-gauge needle improves the developmental competence of immature oocytes following IVM, IVF and embryo transfer.

Possible involvement of aminopeptidase A in hypertension in spontaneously hypertensive rats (shrs) and change of refractoriness in response to angiotensin Ii in pregnant Shrs

Background Hypertension complicated with pregnancy is a major cause of maternal and fetal mortality, but its pathophysiology is unclear. Objective To investigate the pressor response to angiotensin II (Ang II) and the involvement of the Ang II degrading protease, aminopeptidase A, in spontaneously hypertensive rats (SHRs). Design Pregnant SHRs and Wistar–Kyoto (WKY) rats were studied. Angiotensin II (200 ng/kg per min) or saline was infused by osmotic pump from day of 15 gestation, and caesarean section was performed at day 20 of gestation. Blood pressure during pregnancy, weight of placentas and pups at caesarean section, and aminopeptidase A activity in placenta and renal cortex were measured. Results Ang II treatment induced increases in blood pressure that were greater in non-pregnant WKY rats than those in pregnant WKY rats, pregnant SHRs, and non-pregnant SHRs. Renal aminopeptidase A activity in SHRs was significantly lower than that in WKY rats. Renal aminopeptidase A activity in pregnant SHRs was significantly greater than that in non-pregnant SHRs, but there was no significant increase in pregnant WKY rats. Placental aminopeptidase A activity in SHRs was greater than that in WKY rats. Placental aminopeptidase A activity in WKY rats was increased by Ang II, but was not increased in SHRs. Weights of placentas and pups were significantly lower in SHRs than in WKY rats. Conclusions Renal aminopeptidase A may be involved in the development of hypertension and the regulation of blood pressure in SHRs. Placental aminopeptidase A may be upregulated in response to fetal stress in pregnant SHRs.

Clinical outcomes after IVF or ICSI using human blastocysts derived from oocytes containing aggregates of smooth endoplasmic reticulum

In this study the clinical and neo-natal outcomes after transfer of blastocysts derived from oocytes containing aggregates of smooth endoplasmic reticulum (SER) were compared between IVF and intracytoplasmic sperm injection (ICSI) cycles. Clinical and neo-natal outcomes of blastocysts in cycles with at least one SER metaphase II oocyte (SER + MII; SER + cycles) did not significantly differ between the two insemination methods. When SER + MII were cultured to day 5/6, fertilization, embryo cleavage and blastocyst rates were not significantly different between IVF and ICSI cycles. In vitrified-warmed blastocyst transfer cycles, the clinical pregnancy rates from SER + MII in IVF and ICSI did not significantly differ. In this study, 52 blastocysts (27 IVF and 25 ICSI) derived from SER + MII were transferred, yielding 15 newborns (5 IVF and 10 ICSI) and no malformations. Moreover, 300 blastocysts (175 IVF and 125 ICSI) derived from SER-MII were transferred, yielding 55 newborns (24 IVF and 31 ICSI cycles). Thus, blastocysts derived from SER + cycles exhibited an acceptable ongoing pregnancy rate after IVF (n = 125) or ICSI (n = 117) cycles. In conclusion, blastocysts from SER + MII in both IVF and ICSI cycles yield adequate ongoing pregnancy rates with neo-natal outcomes that do not differ from SER-MII.