Boonsri Chanrachakul - Academia.edu (original) (raw)

Papers by Boonsri Chanrachakul

Journal of the Medical Association of Thailand = Chotmaihet thangphaet

ABSTRACT

The 2 adrenergic receptor ( 2 -AR) and the large conductance calcium-activated 25 potassium (BK C... more The 2 adrenergic receptor ( 2 -AR) and the large conductance calcium-activated 25 potassium (BK Ca ) channel have been shown, separately, to be involved in mediating 26 uterine relaxation. Our recent studies reveal that the levels of both 2 AR and BK Ca 27 channel proteins in pregnant human myometrium decrease by approximately 50% after 28 the onset of labour. We present direct evidence in support of a structural and functional 29 association between the 2 AR and the BK Ca channel in pregnant human myometrium. 30

A considerable body of evidence exists suggesting that the 2-adrenergic receptor (2-AR) mediates ... more A considerable body of evidence exists suggesting that the 2-adrenergic receptor (2-AR) mediates uterine relaxation. However, little information exists on the localization, distri- bution, or expression of 2-ARs in the human myometrium during the nonpregnant to labor transition. We have used immunochemical methods to investigate 2-AR localization and expression in the nonpregnant, term pregnant, and term parturient uterus. Myometrial biopsies

Journal of the Medical Association of Thailand = Chotmaihet thangphaet, 2006

To compare repeated doses of sublingual with oral misoprostol in the medical management of early ... more To compare repeated doses of sublingual with oral misoprostol in the medical management of early pregnancy failure. One hundred and thirty eight women with a period of gestation less than 20 week calculated by her last menstrual period and less than 12 weeks by size were sequentially allocated to two groups to receive either 400 microg of misoprostol orally or sublingually every 4 hours until termination of pregnancy was completed. There is no difference in the mean induction to abortion interval. Fever and chill were more common in sublingual group compared with oral group. The other adverse effects were similar and included nausea, vomiting, diarrhea, abdominal pain, and headache. Sublingual misoprostol is as effective as oral route. Most adverse effects are similar in both groups except fever was more common in sublingual group.

American journal of physiology. Cell physiology, 2004

The beta(2)-adrenergic receptor (beta(2)-AR) and the large-conductance Ca(2+)-activated K(+) (BK(... more The beta(2)-adrenergic receptor (beta(2)-AR) and the large-conductance Ca(2+)-activated K(+) (BK(Ca)) channel have been shown, separately, to be involved in mediating uterine relaxation. Our recent studies reveal that the levels of both beta(2)-AR and BK(Ca) channel proteins in pregnant human myometrium decrease by approximately 50% after the onset of labor. We present direct evidence in support of a structural and functional association between the beta(2)-AR and the BK(Ca) channel in pregnant human myometrium. Localization of both proteins is predominantly plasmalemmal, with 60% of beta(2)-AR colocalizing with the BK(Ca) channel. Coimmunoprecipitation studies indicate that BK(Ca) and beta(2)-AR are structurally linked by direct protein-protein interactions. Functional correlation was confirmed by experiments of human myometrial contractility in which the BK(Ca) channel blocker, paxilline, significantly antagonized the relaxant effect of the beta(2)-AR agonist ritodrine. These nove...

The Journal of clinical endocrinology and metabolism, 2003

European journal of obstetrics, gynecology, and reproductive biology, Jan 10, 2003

To study the cesarean rate between expectant management and immediate induction in the otherwise ... more To study the cesarean rate between expectant management and immediate induction in the otherwise uncomplicated postterm pregnancy with favorable cervix. A total of 249 women with uncomplicated pregnancies at 41 weeks plus 3 days (290 days) with favorable cervix (Bishop score > or =6) were randomized to either expectant management (n=125) or immediate induction of labor (n=124). The women in the induction group were sent to labor ward for induction by artificial rupture of membranes (ARM) and/or oxytocin infusion. The women with expectant management had nonstress test (NST) and amniotic fluid index (AFI) performed once a week and twice a week after 43 weeks of gestation until spontaneous labor. The cesarean rate was not different between expectant management and immediate induction (21.6% versus 26.6%; P=0.36). Ninety-five percent of the expectant group delivered within 1 week after enrollment, and all of them delivered within 9 days after randomization. Maternal and fetal complic...

$Research paper thumbnail of Lidocaine versus plain saline for pain relief in fractional curettage: a randomized controlled trial$

To compare the efficiency of lidocaine with that of plain saline for paracervical pain relief dur... more To compare the efficiency of lidocaine with that of plain saline for paracervical pain relief during fractional curettage. This double-blind, randomized, controlled trial included 140 women who underwent fractional curettage. Seventy women were allocated to the lidocaine group and 70 to the plain saline group. The main outcome measure was the intensity of pain measured by visual analog scale during and after the procedure. The intensity of pain was significantly lower in the lidocaine group than in the plain saline group over the course of the procedure (P = .02), especially during fractional curettage. There were no serious adverse effects in this study. Lidocaine is more effective than plain saline for paracervical pain relief during fractional curettage. The anesthetic mechanisms of lidocaine are mechanical distention of tissue and peripheral nerve block.

Reviews, 1996

Cervical priming before first-trimester surgical abortion is recommended in certain groups of wom... more Cervical priming before first-trimester surgical abortion is recommended in certain groups of women. Nitric oxide (NO) donors induce cervical ripening without uterine contractions, but the efficacy and side effects are of concern. To evaluate efficacy, side effects and complications of NO donors for cervical ripening before first-trimester surgical abortion. We searched the Cochrane Controlled Trials Register, MEDLINE, EMBASE and Popline. We also searched reference lists of retrieved papers. We contacted experts in the field for information on both published and unpublished trials. Randomised controlled trials comparing NO donors alone or in combination with other methods for cervical ripening in first-trimester surgical abortion. Two reviewers independently selected and extracted the data onto a data extraction form. We processed the data using Review Manager (RevMan5) software. We included eight studies involving 718 participants. There were no serious complications (infection requiring antibiotic treatment, blood transfusion, complications requiring unintended operation, cervical injury, uterine perforation, death or serious morbidity) in the trials included.NO donors were ineffective in cervical ripening comparing with placebo or no treatment. The cumulative force required to dilate the cervix to 8 mm (mean difference -4.29, 95% CI -9.92, 1.35), baseline cervical dilatation before the procedure (mean difference 0.21, 95% CI -0.12, 0.53), headache (RR 1.73, 95% CI 0.86, 3.46), abdominal pain (RR 0.87, 95% CI 0.51, 1.50) or patient satisfaction (RR 0.95, 95% CI 0.84, 1.07) were not different. More nausea and vomiting occurred in the women who received a NO donor (RR 2.62, 95% CI 1.07, 6.75).NO donors were inferior to prostaglandins for cervical ripening. The cumulative force required to dilate the cervix to 8-9 mm was higher (mean difference 13.12, 95% CI 9.72, 16.52) and baseline cervical dilatation was less (mean difference -0.73, 95% CI -1.01, -0. 45) in the NO donor group. Side effects including headache (RR 5.13, 95% CI 3.29, 8.00), palpitation (RR 3.43, 95% CI 1.64, 7.15), dizziness (RR 3.29, 95% CI 1.46, 7.41) and intraoperative blood loss (mean difference 33.59 ml, 95% CI 24.50, 42.67) were also higher. However, abdominal pain (RR 0.33, 95% CI 0.25, 0.44) and vaginal bleeding (RR 0.14, 95% CI 0.07, 0.27) was less in the NO donor group. Patient satisfaction was not different.One trial compared a NO donor with a NO donor plus prostaglandin. The cumulative force required to dilate the cervix to 8 mm was higher (mean difference 14.50, 95% CI 0.50, 28.50) in the NO donor group. There was no difference in headache (RR 0.88, 95% CI 0.38, 2.00), abdominal pain (RR 0.14, 95% CI 0.02, 1.07) or intraoperative blood loss (mean difference -50, 95% CI -164.19, 64.19). NO donors are inferior to prostaglandins for first-trimester cervical ripening, and associated with more side effects. NO donors are comparable to placebo and no treatment for cervical ripening.

Case Reports in Radiology, 2012

Congenital high airway obstruction syndrome is a rare but life-threatening condition. Therefore, ... more Congenital high airway obstruction syndrome is a rare but life-threatening condition. Therefore, prenatal diagnosis is important. The obstruction can be due to laryngeal/tracheal atresia or external compression. While a differential diagnosis with congenital cystic adenomatoid malformation (CCAM) type III may be difficult, it is still possible with ultrasonography. In this study, we report a case of bilateral echogenic lungs with hydrops fetalis. After the prenatal diagnosis of laryngeal atresia, the couple opted to have an elective termination of pregnancy performed at 20 weeks of gestation. The diagnosis was confirmed by a complete pathological examination.

Reproduction, 2003

Large-conductance calcium-activated potassium (BK Ca ) channels play an important role in the con... more Large-conductance calcium-activated potassium (BK Ca ) 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 ␣ subunit of BK Ca channels in the pregnant and parturient human uterus. An anti-␣ BK Ca channel monoclonal antibody (anti-␣ 995−1113 ) was used to localize and quantitate immunoreactive BK Ca 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 ␣ subunit of the BK Ca 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 125 kDa band in western blots, was significantly higher in pregnant women who were not undergoing labour (30.6% (20.3, 43.9)) than in those who were undergoing labour (15.7% (11.3, 22.4); P < 0.01). Reduced BK Ca ␣ subunit expression in pregnant women during labour may underlie the initiation of uterine contractility during parturition.

Obstetrics & Gynecology, 2000

To estimate the adverse effects of glyceryl trinitrate compared with prostaglandin (PG) E2 vagina... more To estimate the adverse effects of glyceryl trinitrate compared with prostaglandin (PG) E2 vaginal tablet for cervical ripening in term pregnancy. One hundred ten women with term pregnancies referred for induction of labor with Bishop scores of 6 or less were randomly assigned to receive a 500-microg glyceryl trinitrate tablet vaginally (n = 54) or a 3-mg PGE2 tablet vaginally (n = 56), every 6 hours for maximum of two doses. Subjects were sent to the labor ward for amniotomy or oxytocin if their Bishop scores were more than 6 or their cervices were not ripe 24 hours after treatment. Adverse effects, changes in the Bishop scores, progress, and outcomes of labor were assessed. Glyceryl trinitrate was associated with fewer episodes of uterine tachysystole (0% versus 9%; P =.02). The median Bishop score after 12 hours was lower in women given glyceryl trinitrate compared with those given PGE2. Adverse effects, including headache and palpitations, were more frequent with glyceryl trinitrate than with PGE2. The cesarean rate was not significantly different between groups. Cervical ripening with glyceryl trinitrate resulted in fewer episodes of tachysystole, but there were significantly more minor side effects. It can be used for cervical ripening at term, but it was not as effective as PGE2.

Journal of Obstetrics and Gynaecology Research, 2012

To construct a normal value for inhibin-A concentrations at 14-20 weeks of gestation for a Thai p... more To construct a normal value for inhibin-A concentrations at 14-20 weeks of gestation for a Thai population. Inhibin-A concentrations from pregnant women without Down&amp;amp;amp;amp;amp;#39;s syndrome at 14-20(+6) weeks of gestation were measured. Maternal serum inhibin-A levels were analyzed according to the gestational age. Serum specimens from 727 Thai women were analyzed. Inhibin-A levels decreased from 14 to 17(+4) weeks and then gradually rose thereafter, giving a U-shape pattern. The data of inhibin-A concentration at 14-20 weeks of gestation for normal Thai pregnant women fitted well with quadratic regression.

Journal of Obstetrics and Gynaecology Research, 1999

To evaluate the relationship between the status of serum vitamin A, E and hemoglobinopathies amon... more To evaluate the relationship between the status of serum vitamin A, E and hemoglobinopathies among Thai pregnant women. This was a cross-sectional study in which serum vitamin A and E were assessed in 323 pregnant women with normal hemoglobin and 73 with hemoglobinopathies (47 with hemoglobin E and 26 with thalassemia) during the first trimester. There were no significant differences in the mean serum vitamin A, E concentrations and vitamin E/cholesterol ratio between pregnant women with normal hemoglobin and hemoglobinopathies, while confounding variables that might affect serum vitamin levels i.e. maternal age, gravida, BMI, gestational age, hematocrit, hemoglobin, mean corpuscular hemoglobin concentration and blood group were not different. The results of this study suggest that antenatal care in terms of micronutrients-vitamin A, E in Thai pregnant women with hemoglobinopathies should not be different from normal pregnant women.

Journal of Obstetrics and Gynaecology Research, 2000

To study the effectiveness and complications of 600 micrograms of intravaginal misoprostol for te... more To study the effectiveness and complications of 600 micrograms of intravaginal misoprostol for terminating second trimester pregnancies. One hundred and seventy-two patients undergoing termination of pregnancy between March 1997 and April 1999 were studied. Each patient received 600 micrograms of intravaginal misoprostol every 12 hours until abortion occurred. The mean induction to abortion time was 24.1 +/- 21.6 hours. The percentage of women aborting within 24 and 48 hours was 68.6 and 89.5 respectively. There was no significant difference in the mean induction to abortion time and the percentage of women aborted within 48 hours between nulliparous and multiparous women. The mean amount of misoprostol used was 1405.5 +/- 1084.6 micrograms. Incomplete abortion occurred in 23.3% of women. The most common complication was temperature of more than 38 degrees C occurred in 41% followed by diarrhoea (20%), nausea and vomiting (15%). Six hundred micrograms of vaginal misoprostol is effective, but whether the 48 hours abortion rate can be improved with a large dose or shortened the time interval between doses, requires further study.

Journal of Obstetrics & Gynaecology, 2003

ABSTRACT Recent evidence has shown that large-conductance calcium-activated potassium (BKCa) chan... more ABSTRACT Recent evidence has shown that large-conductance calcium-activated potassium (BKCa) channels are involved in mediating uterine relaxation. The objective of this study was to determine the localisation and protein expression of the α subunit of BKCa channels in the myometrium of term pregnant women with and without labour. Myometrial biopsies obtained from singleton term pregnant women undergoing either (1) elective caesarean section (n = 26) or (2) emergency caesarean section after spontaneous labour (n = 25) were used for immunohistochemistry, immunofluorescence and Western blotting. Anti-α BKCa channel monoclonal antibody was used to localise and quantify BKCa channel protein. Myometrial BKCa channel levels were normalised to rat brain which was used as an internal standard. Data were presented as mean ± SEM. Differences between groups were analysed by two-tailed unpaired t-test. A P value < 0.05 was considered to be statistically significant. Immunohistochemistry and immunofluorescence revealed positive staining at the plasma membrane and in the cytosol of the myometrial cells with similar intensity between both groups of women. Western blotting demonstrated a 125 kDa band corresponding to the α subunit of the BKCa channel. The protein expression of the α subunit BKCa channel in myometrium was significantly higher in pregnant women without labour (32.9 ± 3.4%) than those with labour (20.3 ± 3.4%; P < 0.05).

The Journal of Clinical Endocrinology & Metabolism, 2003

A considerable body of evidence exists suggesting that the beta(2)-adrenergic receptor (beta(2)-A... more A considerable body of evidence exists suggesting that the beta(2)-adrenergic receptor (beta(2)-AR) mediates uterine relaxation. However, little information exists on the localization, distribution, or expression of beta(2)-ARs in the human myometrium during the nonpregnant to labor transition. We have used immunochemical methods to investigate beta(2)-AR localization and expression in the nonpregnant, term pregnant, and term parturient uterus. Myometrial biopsies were obtained from 1) nonpregnant, menstruating women undergoing hysterectomy; 2) singleton term pregnant women undergoing elective cesarean section before the onset of labor; or 3) singleton term pregnant women undergoing emergency cesarean section after spontaneous labor. Tissues were processed for immunohistochemistry, immunofluorescence, and Western blotting and a primary polyclonal antibody specific to the human beta(2)-AR to identify immunoreactive myometrial beta(2)-AR. Protein levels were subsequently quantified by densitometry relative to rat brain protein. Immunohistochemistry and immunofluorescence demonstrated the presence of beta(2)-AR predominantly at the plasma membrane and also in the cytosol of myometrial cells. A 2-fold decrease in protein levels of the beta(2)-AR was apparent in the myometrium of labor compared with that of nonpregnant and pregnant nonlaboring women (P &amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.05). These results demonstrate that down-regulation of beta(2)-AR protein with labor may constitute a contributory mechanism by which uterine quiescence is removed at term.

International Journal of Gynecology & Obstetrics, 2010

To evaluate the efficacy of isosorbide mononitrate (IMN) for cervical ripening prior to first tri... more To evaluate the efficacy of isosorbide mononitrate (IMN) for cervical ripening prior to first trimester surgical termination of pregnancy. A prospective, double-blind, randomized, placebo-controlled trial. Women scheduled for surgical termination of a nonviable fetus before 12 weeks of gestation from October 2008 to June 2009 were enrolled and randomly assigned to receive either 20 mg vaginally of IMN (n=24) or a placebo (n=24) 4 hours before suction evacuation. Cervical dilation before evacuation was assessed with 10-mm Hegar dilators followed by smaller sizes that were measured until the instrument passed freely through the internal os. Cervical dilation, adverse effects, termination complications, and patient satisfaction were the main outcomes. Mean cervical dilation was not significantly different between the IMN and placebo groups (6.29+/-0.99 mm vs 5.71+/-1.04 mm; P=0.05). Mean operative time did not differ between the groups (16+/-0.07 min vs 18+/-0.06 min; P=0.55), nor did patient satisfaction measured by visual analogue scale (7.04+/-1.68 vs 6.54+/-1.22; P=0.24). IMN was comparable to placebo in terms of efficacy and patient satisfaction for cervical priming prior to first-trimester termination of pregnancy.

International Journal of Gynecology & Obstetrics, 2002

Objectives: To assess the adverse effects of isosorbide mononitrate (IMN) compared with misoprost... more Objectives: To assess the adverse effects of isosorbide mononitrate (IMN) compared with misoprostol for cervical ripening at term. Methods: One hundred and seven women with term pregnancies referred for induction of labor with Bishop scores of 6 or less were randomly allocated to receive either a 40-mg IMN tablet vaginally (ns55) or 50 mg misoprostol vaginally (ns52) every 6 h for a maximum of three doses. They were sent to the labor ward for amniotomy or oxytocin if either their Bishop scores were more than 6 or their cervices were not ripe 24 h after the treatment. Adverse effects, progress, and outcomes of labor were assessed. Results: Isosorbide mononitrate was associated with fewer adverse effects especially uterine tachysystole (0 vs. 19.2%, P-0.01) and hyperstimulation (0 vs. 15.4%, P-0.01). The time from start of medication to vaginal delivery in IMN group was significantly longer (25.6"6.1 vs. 14"6.9 h, P-0.01). Oxytocin was needed in 51 women (92%) of the isosorbide mononitrate group and six women (11%) of the misoprostol group (P-0.001). The cesarean rate was not significantly different between the groups, but the major indications were different: dystocia (45%) in the IMN group vs. persistent non-reassuring fetal heart rate pattern (56%) in the misoprostol group. Conclusions: Cervical ripening with IMN resulted in fewer adverse effects, but was less effective than misoprostol. ᮊ