Chikara Endo

Induction of the acrosome reaction in human spermatozoa by human zona pellucida and effect of cervical mucus on zona-induced acrosome reaction

OBJECTIVES To investigate the induction of the acrosome reaction in human spermatozoa by the zona pellucida (ZP), cumulus oophorus, and cervical mucus (CM), and to examine the effect of cumulus oophorus and CM on the zona-induced acrosome reaction. DESIGN, PATIENTS, MAIN OUTCOME MEASURES: The acrosome status of spermatozoa from healthy donors that were cultured with salt-stored human ZP, cumulus oophorus, and/or cervical mucus was assessed using fluoresceinated pisum sativum agglutinin. RESULTS The acrosome reaction rate after sperm attachment to the zona for 6 hours was 35.7% +/- 17.7%, which was higher than controls (2.8% +/- 1.9%). The acrosome reaction was not observed after passage through cumulus oophorus or CM; however, the acrosome reaction rate of spermatozoa passed through CM after the attachment to zona was 51.6% +/- 6.8%, a higher value in comparison with spermatozoa that had not passed through CM (25.6% +/- 9.4%). CONCLUSION These data indicate that human ZP are capable of inducing the acrosome reaction in human spermatozoa; however, cumulus oophorus and CM are unable to do so. The data further provide evidence that CM promotes the zona-induced acrosome reaction in human spermatozoa.

The slope of fetal heart rate deceleration is predictive of fetal condition during repeated umbilical cord compression in sheep

The relationship between components of fetal heart rate deceleration and fetal arterial blood gas values or plasma catecholamine concentrations was investigated by repeated complete umbilical cord compression in chronically instrumented fetal lamb. Fetal arterial pH and bicarbonate levels decreased, while plasma norepinephrine and epinephrine concentrations increased more than tenfold. The slope of the descending limb of the fetal heart rate deceleration curve decreased and correlated strongly with fetal arterial pH, bicarbonate, and logarithmic plasma norepinephrine and epinephrine concentrations. Fetal arterial pH and bicarbonate levels were significantly lower in the group with lower fetal heart rate deceleration slope, and a greater plasma catecholamine concentration in this group suggested a redistribution of blood flow to vital organs. Therefore, during repeated umbilical cord compression, the fetal acid-base and hormonal state was predicted by the fetal heart rate deceleration slope. This relationship may be applicable to human fetuses in the diagnosis of fetal distress caused by umbilical cord compression during labor.

The influence of prostaglandins on the contractile response to electrical field stimulation in rabbit myometrial and cervical smooth muscles

Indomethacin (10 microM) significantly reduced the contractile responses to electrical field stimulation (EFS) in the non-pregnant myometrium (5-50 Hz by an average of 25.7%) and the pregnant myometrium (30-50 Hz by an average of 16.5%). On the other hand, it significantly increased the contractile responses of the cervix in non-pregnant (2.5-30 Hz by an average of 21.5%) and pregnant (2.5-10 Hz by an average of 12.5%) muscular strips. Prostaglandin (PG) E2 (0.1-1000 nM) strongly and PGI2 (0.1-1000 nM) slightly and dose-dependently inhibited the contractile response to EFS of the non-pregnant cervical muscle, but not of the myometrium. In the pregnant uterus, the contractile responses of the cervical muscle were similar to those of the non-pregnant cervix, while the response of the myometrium was increased significantly and dose-dependently by the application of PGE2 or PGI2.PGF2 alpha (1000 nM) significantly increased the contractile response of the myometrium but not cervical muscle to EFS in the pregnant rabbits. In non-pregnant muscles, the contractile responses of the myometrium and cervical smooth muscle to EFS were not influenced by the treatment with PGF2 alpha.PGE2 (0.1-1000 nM) also inhibited the contractile response to direct muscle stimulation, but the inhibition was significantly less than that of the response to indirect stimulation. PGI2 slightly inhibited the contractile responses to both indirect and direct stimulation. These findings indicate that PGE2, PGI2 and PGF2 alpha increase the contractile response of pregnant myometrium to EFS.(ABSTRACT TRUNCATED AT 250 WORDS)

A Method of Measuring Dipalmitoylphosphatidylcholine (DPPC) by High-Performance Liquid Chromatography (HPLC) : Effect of Dexamethasone on DPPC Secretion in Fetal Rat Alveolar Type II Cell Culture

Objectives: To establish a method by which to measure dipalmitoylphosphati‐dylcholine (DPPC), which is the most prevalent phospholipid in lung surfactant, by high‐performance liquid chromatography (HPLC), and to measure DPPC secretion in type‐II alveolar cell culture to determine whether glucocorticoid has a direct accerelating effect.

Space-time block coded amplify-and-forward cooperative relay without channel state information at relay station

In this paper, we propose a space-time block coded (STBC) amplify-and-forward cooperative (STBC-Co-AF) relay which requires no knowledge of CSI at relay station (RS). In STBC-Co-AF relay, the source node transmits 2-block signal to both RS and the destination node in the first time slot and then, RS transmits amplified STBC-coded signal to the destination node in the second time slot. The destination node performs a series of frequency-domain equalization (FDE), diversity combining, and STBC decoding by viewing the concatenation of the channels between the source node-RS link and between the RS-destination node link as an equivalent channel. We evaluate, by computer simulation, the average bit error rate (BER) performance when using STBC-Co-AF relay and show that the STBC-Co-AF relay can achieves the BER performance superior to Co-AF relay.

STBC AF relay for unmanned aircraft system

If a large scale disaster similar to the Great East Japan Earthquake 2011 happens, some areas may be isolated from the communications network. Recently, unmanned aircraft system (UAS) based wireless relay communication has been attracting much attention since it is able to quickly re-establish the connection between isolated areas and the network. However, the channel between ground station (GS) and unmanned aircraft (UA) is unreliable due to UA’s swing motion and as consequence, the relay communication quality degrades. In this paper, we introduce space-time block coded (STBC) amplify-and-forward (AF) relay for UAS based wireless relay communication to improve relay communication quality. A group of UAs forms single frequency network (SFN) to perform STBC-AF cooperative relay. In STBC-AF relay, only conjugate operation, block exchange and amplifying are required at UAs. Therefore, STBC-AF relay improves the relay communication quality while alleviating the complexity problem at UAs. It is shown by computer simulation that STBC-AF relay can achieve better throughput performance than conventional AF relay.