Large-conductance calcium-activated potassium (BKCa) channels play an important role in the contr... more Large-conductance calcium-activated potassium (BKCa) channels play an important role in the control of myometrial excitability. The aim of the present study was to determine the localization and protein expression of the alpha subunit of BKCa channels in the pregnant and parturient human uterus. An anti-alpha BKCa channel monoclonal antibody (anti-alpha(995-1113)) was used to localize and quantitate immunoreactive BKCa channel protein in myometrium of singleton term pregnant women undergoing either elective (n=26) or emergency Caesarean section following the onset of spontaneous labour (n=25). Data are presented as medians (interquartile range). Differences between groups were analysed using the Mann-Whitney U test. Immunohistochemistry studies localized the alpha subunit of the BKCa channel to the plasma membrane and the cytosol of myometrial cells with similar reaction end product in pregnant women who were or were not undergoing labour. Expression of this subunit, observed as a 1...
Journal of Obstetrics and Gynaecology Research, 1996
To determine the level of correlation between mother and machine detected episodes and clusters o... more To determine the level of correlation between mother and machine detected episodes and clusters of fetal movements and their association with fetal heart rate acceleration. An observational study conducted on health pregnant women between 29-40 weeks gestation who were admitted in spurious labour to the Department of Obstetrics and Gynaecology, National University Hospital, Republic of Singapore. A continuous record of fetal heart rate and fetal movement was obtained using the fetal actocardiograph. Fetal movements felt by mother were also noted. If a continuous series of fetal movements were perceived over a period of 15 secs or more it was termed clusters of fetal movement. The presence or absence of acceleration in relation to these movements were noted. There was a highly significant correlation between mother and machine in detection of clusters of fetal movements (r = 0.77, p < 0.001); for episodes of fetal movements, the correlation was weaker (r = 0.23, p < 0.05). All clusters of fetal movements perceived by the mother were recorded by the machine and were associated with fetal heart rate accelerations. Two or more accelerations within 3 minutes of the fetal movements were seen with 87.8% of clusters felt by mother compared with 66.7% detected by the machine (p = 0.01). In the 2,263 minutes of recording in 42 women, a cluster of fetal movements was felt at least every 25 minutes by the mother. Maternal perception of 1 or 2 clusters of fetal movements in 30 to 60 minutes may be as reliable as a non-stress test in reassuring good health. It would be less time consuming than the traditional count to 10 fetal movement chart and a more reliable indicator of fetal health than counting episodes of fetal movements. Thus, our study suggests that clusters rather than episodes of fetal movements should be considered for evaluating fetal health based on fetal movements.
Journal of Obstetrics and Gynaecology Research, 1997
A prospective study was undertaken to assess the amniotic fluid index (AFI) in women with spuriou... more A prospective study was undertaken to assess the amniotic fluid index (AFI) in women with spurious labour and its possible role in management. Eight hundred and ninety-three women in early labour, who had uncomplicated pregnancy, were recruited for the study. Of these, 133 were later diagnosed to have had spurious labour, while 760 were in true labour. An admission cardiotocography and determination of AFI was done for all patients at the time of their admission to the labour ward. Labour was induced within 24 hours for those women in spurious labour who had severe oligohydramnios. The incidence of severe oligohydramnios (AFI < 5) was significantly higher in the patients later diagnosed to have had spurious labour (15.7%) compared with those in true labour (2.1%). With this management protocol, the obstetric and the neonatal outcome was similar in the spurious labour and the true labour groups. The assessment of AFI could be a simple and useful screening tool to avoid adverse perinatal outcome in women who experience spurious labour.
In 27 women, uterine activity in the third stage of labour was correlated with blood loss measure... more In 27 women, uterine activity in the third stage of labour was correlated with blood loss measured quantitatively during the same period of time. Myometrial activity was reflected by total intrauterine pressures measured using a Gaeltec catheter tipped pressure transducer inserted transcervically within 5 min of delivery of the placenta. Blood loss over the same 2-hour period was collected on absorbent paper and measured in the laboratory by colorimetric measurement of the haemoglobin content. As total uterine activity in the third stage of labour decreases total blood loss increases, but there is a poor correlation of uterine activity to total blood loss over the same period of time, probably because of biological variations in myometrial activity in normal women.
British journal of hospital medicine (London, England : 2005), 2008
Recent experiences of working with maternity services in difficulty have highlighted the need for... more Recent experiences of working with maternity services in difficulty have highlighted the need for regular surveillance of clinical governance parameters, using a performance chart or 'dashboard' to monitor and assure quality and safety.
Changes in the ST waveform of the fetal ECG have been detected in 47 term deliveries with vertex ... more Changes in the ST waveform of the fetal ECG have been detected in 47 term deliveries with vertex presentations using a specially developed microprocessor-based system for on-line recording of T wave amplitude. The T wave was quantified by the T/QRS ratio. The recording included one scalp electrode for exploration and a maternal skin electrode as reference. Signal quality allowed optimal ST waveform assessment in 89% of the cases. The degree of perinatal asphyxia was judged from cord artery acid-base status and the neonatal outcome. In completely normal fetuses at term the mean T/QRS ratio was 0.148 with a standard deviation of 0.048. With this basic information we can proceed in the investigation of the T/QRS ratio as a means for fetal surveillance.
Large-conductance calcium-activated potassium (BKCa) channels play an important role in the contr... more Large-conductance calcium-activated potassium (BKCa) channels play an important role in the control of myometrial excitability. The aim of the present study was to determine the localization and protein expression of the alpha subunit of BKCa channels in the pregnant and parturient human uterus. An anti-alpha BKCa channel monoclonal antibody (anti-alpha(995-1113)) was used to localize and quantitate immunoreactive BKCa channel protein in myometrium of singleton term pregnant women undergoing either elective (n=26) or emergency Caesarean section following the onset of spontaneous labour (n=25). Data are presented as medians (interquartile range). Differences between groups were analysed using the Mann-Whitney U test. Immunohistochemistry studies localized the alpha subunit of the BKCa channel to the plasma membrane and the cytosol of myometrial cells with similar reaction end product in pregnant women who were or were not undergoing labour. Expression of this subunit, observed as a 1...
Journal of Obstetrics and Gynaecology Research, 1996
To determine the level of correlation between mother and machine detected episodes and clusters o... more To determine the level of correlation between mother and machine detected episodes and clusters of fetal movements and their association with fetal heart rate acceleration. An observational study conducted on health pregnant women between 29-40 weeks gestation who were admitted in spurious labour to the Department of Obstetrics and Gynaecology, National University Hospital, Republic of Singapore. A continuous record of fetal heart rate and fetal movement was obtained using the fetal actocardiograph. Fetal movements felt by mother were also noted. If a continuous series of fetal movements were perceived over a period of 15 secs or more it was termed clusters of fetal movement. The presence or absence of acceleration in relation to these movements were noted. There was a highly significant correlation between mother and machine in detection of clusters of fetal movements (r = 0.77, p < 0.001); for episodes of fetal movements, the correlation was weaker (r = 0.23, p < 0.05). All clusters of fetal movements perceived by the mother were recorded by the machine and were associated with fetal heart rate accelerations. Two or more accelerations within 3 minutes of the fetal movements were seen with 87.8% of clusters felt by mother compared with 66.7% detected by the machine (p = 0.01). In the 2,263 minutes of recording in 42 women, a cluster of fetal movements was felt at least every 25 minutes by the mother. Maternal perception of 1 or 2 clusters of fetal movements in 30 to 60 minutes may be as reliable as a non-stress test in reassuring good health. It would be less time consuming than the traditional count to 10 fetal movement chart and a more reliable indicator of fetal health than counting episodes of fetal movements. Thus, our study suggests that clusters rather than episodes of fetal movements should be considered for evaluating fetal health based on fetal movements.
Journal of Obstetrics and Gynaecology Research, 1997
A prospective study was undertaken to assess the amniotic fluid index (AFI) in women with spuriou... more A prospective study was undertaken to assess the amniotic fluid index (AFI) in women with spurious labour and its possible role in management. Eight hundred and ninety-three women in early labour, who had uncomplicated pregnancy, were recruited for the study. Of these, 133 were later diagnosed to have had spurious labour, while 760 were in true labour. An admission cardiotocography and determination of AFI was done for all patients at the time of their admission to the labour ward. Labour was induced within 24 hours for those women in spurious labour who had severe oligohydramnios. The incidence of severe oligohydramnios (AFI < 5) was significantly higher in the patients later diagnosed to have had spurious labour (15.7%) compared with those in true labour (2.1%). With this management protocol, the obstetric and the neonatal outcome was similar in the spurious labour and the true labour groups. The assessment of AFI could be a simple and useful screening tool to avoid adverse perinatal outcome in women who experience spurious labour.
In 27 women, uterine activity in the third stage of labour was correlated with blood loss measure... more In 27 women, uterine activity in the third stage of labour was correlated with blood loss measured quantitatively during the same period of time. Myometrial activity was reflected by total intrauterine pressures measured using a Gaeltec catheter tipped pressure transducer inserted transcervically within 5 min of delivery of the placenta. Blood loss over the same 2-hour period was collected on absorbent paper and measured in the laboratory by colorimetric measurement of the haemoglobin content. As total uterine activity in the third stage of labour decreases total blood loss increases, but there is a poor correlation of uterine activity to total blood loss over the same period of time, probably because of biological variations in myometrial activity in normal women.
British journal of hospital medicine (London, England : 2005), 2008
Recent experiences of working with maternity services in difficulty have highlighted the need for... more Recent experiences of working with maternity services in difficulty have highlighted the need for regular surveillance of clinical governance parameters, using a performance chart or 'dashboard' to monitor and assure quality and safety.
Changes in the ST waveform of the fetal ECG have been detected in 47 term deliveries with vertex ... more Changes in the ST waveform of the fetal ECG have been detected in 47 term deliveries with vertex presentations using a specially developed microprocessor-based system for on-line recording of T wave amplitude. The T wave was quantified by the T/QRS ratio. The recording included one scalp electrode for exploration and a maternal skin electrode as reference. Signal quality allowed optimal ST waveform assessment in 89% of the cases. The degree of perinatal asphyxia was judged from cord artery acid-base status and the neonatal outcome. In completely normal fetuses at term the mean T/QRS ratio was 0.148 with a standard deviation of 0.048. With this basic information we can proceed in the investigation of the T/QRS ratio as a means for fetal surveillance.
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