Burnout and well-being in young doctors in Hong Kong: a territory-wide cross-sectional survey.

INTRODUCTION: This territory-wide study evaluated the level of burnout and health status among young doctors in Hong Kong. METHODS: All young doctors in Hong Kong, defined as residents-in-training or doctors within 10 years of their specialist registration, were invited to participate in an online cross-sectional survey. This survey used standardised questionnaires including the Copenhagen Burnout Inventory (CBI) for burnout, Patient Health Questionnaire-9 for depression, and general health questionnaires. RESULTS: In total, 514 doctors completed the survey; 284 were doctors within 10 years of their specialist registration, while 230 were residents-in-training. There were 277 women (54%); among all respondents, the mean age was 33.7 ± 6.1 years. Using a CBI subscale cut-off score of ≥50 (moderate and higher), 72.6% (n=373) of respondents reported personal burnout; 70.6% (n=363) of respondents reported work-related burnout; and 55.4% (n=285) of respondents reported client-related burnout. Furthermore, 24% (n=125) of respondents were "somewhat dissatisfied" with their present job position; 4% (n=19) of respondents were "very dissatisfied" with their present job position. The prevalence of depression among respondents was 21% (n=110). CONCLUSIONS: In this territory-wide cross-sectional survey of young doctors in Hong Kong, a high prevalence of burnout was identified among young doctors; respondents exhibited a considerable level of depression and substantial dissatisfaction with their current positions. Strategies to address these problems must be formulated to ensure the future well-being of the medical and dental workforce in Hong Kong.

Clinical and biochemical characteristics of infants with prolonged neonatal jaundice.

INTRODUCTION: Protocols for investigating neonatal prolonged jaundice vary and the yield from screening has not been assessed. International guidelines recommend establishing cholestasis before proceeding to investigate the underlying pathology. However, in most hospitals administered by the Hospital Authority, full liver function is checked at the first neonatal jaundice clinic visit. To study the diagnostic yield of this approach, we carried out a retrospective study of all infants referred for prolonged jaundice. METHODS: Attendance records from the neonatal jaundice clinic at the Tuen Mun Hospital, Hong Kong, the clinical management system, and electronic patient records were used to retrieve epidemiological, clinical, and laboratory data, and patients' clinical progress. RESULTS: During the 8-month study period from 8 July 2015 to 8 March 2016, 1164 infants were referred to the neonatal jaundice clinic for prolonged jaundice. Among them, 16 (1.4%) infants had conjugated hyperbilirubinaemia. Diagnoses included biliary atresia (n=1), cytomegalovirus (CMV) infection (n=3), neonatal hepatitis syndrome (n=2), and transient cholestasis (n=10). In total, 98 (8.42%) infants had elevated alanine transaminase levels. Diagnoses included biliary atresia (n=1), hepatic congestion related to congestive heart failure (n=1), CMV infection (n=5), neonatal hepatitis syndrome (n=16), and non-specific elevated alanine transaminase (n=75). In total, 59 infants had elevated alkaline phosphatase levels. CONCLUSIONS: A stepwise approach is recommended, in which full liver function is checked and the underlying cause of jaundice is investigated only after confirming cholestasis.

Autophagic Adaptations to Long-term Habitual Exercise in Cardiac Muscle.

Autophagy has been shown to be responsive to physical exercise. However, the effects of prolonged habitual exercise on autophagy in cardiac muscle remain unknown. The present study aimed to examine whether long-term habitual exercise alters the basal autophagic signalling in cardiac muscle. Female Sprague-Dawley rats aged 2 months were randomly assigned to control and exercise groups. Animals in exercise group were kept in cages with free access exercise wheels to perform habitual exercise for 5 months. Animals in the control group were placed in cages without exercise wheels. Ventricular muscle tissues were harvested for analysis after 5 months. Phosphorylation statuses of upstream autophagic regulatory proteins and protein expressions of downstream autophagic facts remained unchanged in the cardiac muscle of exercise animals when compared to control animals. Intriguingly, the protein abundance of microtubule-associated protein-1 light chain -3 II (LC3-II), heat shock protein 72 (HSP72) and peroxisome proliferator-activated receptor-gamma coactivator (PGC-1α) were significantly increased in cardiac muscle of exercise rats relative to control rats. 5 months of habitual exercise causes the adaptive increase in LC3-II reserve without altering autophagic flux, which probably contributes to the elevation of cellular autophagic capacity and efficiency of cardiac muscle.

Impact of nuchal cord on fetal outcomes, mode of delivery, and management: a questionnaire survey of pregnant women.

OBJECTIVES: To explore pregnant women's views on the impact of nuchal cord on fetal outcomes, mode of delivery, and management. DESIGN: Questionnaire survey. SETTING: Antenatal clinic of two regional hospitals in Hong Kong. PARTICIPANTS: A questionnaire survey of all pregnant women at their first visit to the antenatal clinic of United Christian Hospital and Tseung Kwan O Hospital in Hong Kong was conducted between August and October 2012. RESULTS: Most participants (71.8%) were worried about nuchal cord, and 78.3% and 87.7% of them thought that nuchal cord could cause intrauterine death and fetal death during labour, respectively. Approximately 87.5% of participants thought that nuchal cord would reduce the chance of successful vaginal delivery and 56.4% thought that it would increase the chance of assisted vaginal delivery. Most (94.1%) participants thought that it was necessary to have an ultrasound scan at term to detect nuchal cord. In addition, 68.8% thought that it was necessary to deliver the fetus early and 72.8% thought that caesarean section must be performed in the presence of nuchal cord. Participants born in Mainland China were significantly more worried about the presence of nuchal cord than those born in Hong Kong. However, there was no difference between participants with different levels of education. CONCLUSION: Most participants were worried about the presence of nuchal cord. Many thought that nuchal cord would lead to adverse fetal outcomes, affect the mode of delivery, and require special management. These misconceptions should be addressed and proper education of women is needed.

A novel way of visualizing the ductal and aortic arches by real-time three-dimensional ultrasound with live xPlane imaging.

OBJECTIVE: To describe a novel method of visualizing the ductal and aortic arches by real-time three-dimensional echocardiography with live xPlane imaging. METHODS: Live xPlane imaging was used to display the ductal- and aortic-arch views in 107 women with singleton pregnancies, including seven cases with suspected congenital heart defects (CHDs). The three vessels and trachea (3VT) view was obtained in such an orientation that either the pulmonary artery or the aorta was parallel to the direction of the ultrasound beam. The xPlane reference line was then placed across the targeted vessel, which in a normal case would provide an image of the corresponding arch view as a dual-image display. RESULTS: Once the 3VT view had been obtained, live xPlane imaging showed the aortic and ductal arches in all 100 normal cases. In seven cases with suspected CHD, the 3VT view was abnormal in five cases and normal in the other two. However, the ductal-arch view demonstrated by live xPlane imaging was abnormal in five cases of conotruncal anomalies and normal in two cases in which conotruncal anomalies were excluded. CHDs were confirmed at autopsy following termination of pregnancy in five cases and on postnatal echocardiography in one case. The heart was found postnatally to be normal in one case of suspected CHD; in this case live xPlane imaging showed that the observed abnormal 3VT view was caused by a tortuous course of the thoracic aorta associated with an abnormal diaphragm. CONCLUSION: Live xPlane imaging is a novel and relatively simple method of visualizing the ductal- and aortic-arch views, and may potentially be a useful tool in the screening of fetal conotruncal and aortic-arch anomalies.

A study on in-line tablet coating--the influence of compaction and coating on tablet dimensional changes.

Prior to coating, tablets are usually stored for a definite period to enable complete strain recovery and prevent subsequent volumetric expansion-related coating defects. In-line coating is defined as the coating of tablets immediately after compaction. In-line coating will be expected to improve manufacturing efficiencies. In this study, the possibility of in-line coating was studied by evaluating the influence of compaction and coating on tablet dimensional changes. The use of tapered dies for compaction was also evaluated. Two types of tablet coaters which presented different coating environments, namely the Supercell™ coater and pan coater, were employed for coating. The extent of tablet dimensional changes was studied in real time using optical laser sensors in a controlled environment. After compaction, tablet dimensional changes were found to be anisotropic. In contrast, coating resulted in isotropic volume expansion in both the axial and radial directions. Pan coating resulted in significantly greater tablet dimensional changes compared to Supercell™ coating. There was no significant difference in dimensional changes of tablets coated in line or after complete viscoelastic strain recovery for Supercell™ coating. However, significantly different dimensional changes were observed for pan coating. The use of tapered dies during compaction was found to result in more rapid viscoelastic strain recovery and also significantly reduced tablet dimensional changes when tablets were immediately coated after compaction using the pan coater. In conclusion, the Supercell™ coater appeared to be more suitable for in-line tablet coating, while tapered dies were beneficial in reducing tablet dimensional changes when the pan coater was employed for in-line coating.

Comparison of likelihood ratios of first-trimester nuchal translucency measurements: multiples of median, delta or mixture.

OBJECTIVE: To compare the likelihood ratios (LR) determined for a measured nuchal translucency (NT) using the multiples of the median (MoM), delta-NT and mixture model approaches. METHODS: This was a retrospective study of singleton pregnancies with known outcome screened at the 12(th) week of pregnancy between January 2006 and May 2008. NT, crown-rump length (CRL) and LR for trisomy 21 using the delta-NT approach (LRNT-delta) were extracted from The Fetal Medicine Foundation trisomy 21 risk-calculation software database. NT measurements were converted into their equivalent MoM by dividing by the expected CRL-specific median NT. LR for trisomy 21 based on the MoM (LRNT-MoM) of each case was then calculated as the ratio of the Gaussian probability density functions using published trisomy 21 risk-screening parameters. The LR using the mixture model (LRNT-mixture) was calculated as the ratio of individual composite probability densities reported for trisomy 21 and unaffected pregnancies. The intraclass correlation coefficient (ICC) was used to assess the agreement between the three different approaches while the paired t-test was used to perform pairwise comparisons. RESULTS: Of the 5907 pregnancies with known outcome, 14 had trisomy 21. The ICC between the three approaches to determining an LR was 0.947 (95% CI, 0.943-0.951; P < 0.0001). Pairwise comparison indicated that differences between LR were statistically significant (P < 0.0001). Likelihood ratios determined via the delta-NT model were in general greater than those produced by both the mixture model (z = 5.58, P < 0.0001) and the MoM approaches (z = 32.8, P < 0.0001). For a 5% false-positive rate the detection rate of trisomy 21 (DR) was 78.6% (95% CI, 57.1-99.9%) The screen positive thresholds to achieve this DR were 1 : 200 for the delta-NT approach, 1 : 220 for the mixture approach and 1 : 290 for the MoM approach. CONCLUSION: No single method of determining NT-associated LR outperformed the others in its ability to detect a trisomy 21-affected pregnancy.

Comparison of first-trimester contingent screening strategies for Down syndrome.

OBJECTIVE: To assess the relative performance of a multi-stage first-trimester screening protocol for fetal Down syndrome. METHODS: Data from 10,767 women who underwent combined ultrasound and biochemistry (BC) screening in the first trimester were reanalyzed using a contingent model approach. Amongst the 10,854 fetuses with known outcome, 32 had Down syndrome, 232 had other abnormalities and 10,590 were unaffected. Nuchal translucency (NT), BC and combined (NT-BC) gestational age-specific risks were calculated for each individual using The Fetal Medicine Foundation risk calculation algorithms (Mixture Model and Biochemistry). Individual patients were categorized as at low, high or intermediate risk according to one of the following three strategies. In 'Strategy-NT-BC' initial screening was performed using both NT and BC. In 'Strategy-BC' initial screening was undertaken using maternal serum markers followed by NT assessment in those with an intermediate risk (1 : 51 < risk

Real-time three-dimensional ultrasound with Live xPlane imaging assists first-trimester acquisition of a true midsagittal section.

OBJECTIVE: To determine whether real-time three-dimensional (3D) ultrasound with Live xPlane imaging, which enables the simultaneous display of two real-time high-quality image planes, can assist both operators certified by The Fetal Medicine Foundation (FMF) and non-FMF-certified operators in acquiring a true midsagittal plane in the first trimester. METHODS: Eight operators, four of them FMF certified (FMF group) and the other four not (non-FMF group), were asked to acquire a fetal image that they believed to represent the true midsagittal plane using real-time 3D ultrasound with Live xPlane imaging as guidance. Each operator was asked to obtain such an image five times from each of five patients. A total of 200 images from 40 patients were obtained and stored for subsequent analysis. All pregnancies were between 11 + 0 and 13 + 6 weeks of gestation. The angle between the falx cerebri and vertical axis (angle of deviation) was then measured by a single operator. A true midsagittal section was defined as an angle of deviation equal to 0 degrees. The angle of deviation and the time taken to acquire each image were compared between FMF and non-FMF groups. RESULTS: The median angle of deviation for each operator ranged from 1.2 degrees to 3.4 degrees. There was no significant difference in this angle between those who were FMF certified and those who were not (2.0 degrees vs. 2.2 degrees, P = 0.463). The interquartile range of the angle of deviation was also similar between the FMF- and non-FMF-certified operators. Although the time taken for image acquisition was longer among the non-FMF-certified operators (median, 45.5 s vs. 32.0 s), this difference did not reach statistical significance (P = 0.107). CONCLUSION: Live xPlane imaging can provide a tool to assist the acquisition of a true midsagittal plane and to determine how true a 'midsagittal' plane really is.

Fetoscopic laser photocoagulation in the management of twin-twin transfusion syndrome: local experience from Hong Kong.

OBJECTIVE: To review the perinatal outcome of monochorionic twin pregnancies treated by fetoscopic laser coagulation for twin-twin transfusion syndrome. DESIGN: Retrospective study. SETTING: A university teaching hospital in Hong Kong. PATIENTS: Thirty consecutive cases of fetoscopic laser coagulation of placental anastomoses for twin-twin transfusion syndrome performed in a single centre. MAIN OUTCOME MEASURES: Operative complications and perinatal survival rates. RESULTS: The median gestational age at initial presentation, laser photocoagulation, and delivery were 22 (range, 16-27) weeks, 23 (18-28) weeks, and 32 (21-37) weeks, respectively. To improve the visualisation, in three cases amnio-exchange was undertaken; the procedure was abandoned in two due to poor visualisation. The overall fetal survival rate, the double infant survival rate, and survival rate for at least one twin were 72% (43/60), 60% (18/30), and 83% (25/30), respectively. The most common peri-operative complication was bleeding from the uterine wall into the amniotic cavity, which affected three (10%) patients. CONCLUSIONS: Our results of fetoscopic laser surgery for twin-twin transfusion syndrome were similar to those in specialised centres in other countries.

Medians and correction factors for biochemical and ultrasound markers in Chinese women undergoing first-trimester screening for trisomy 21.

OBJECTIVE: To establish normative values and distribution parameters of first-trimester maternal serum free beta-human chorionic gonadotropin (beta-hCG), pregnancy-associated plasma protein-A (PAPP-A) and fetal nuchal translucency (NT) thickness in Chinese women and to examine the effects of covariates on their levels. METHODS: Maternal serum free beta-hCG, PAPP-A and fetal NT were measured in 9762 women presenting for first-trimester combined screening for Down syndrome at 11 to 14 weeks of gestation. Individuals' markers were converted to multiples of the median (MoM) using expected medians estimated by performing a weighted regression analysis. Multivariate regression analysis was performed to assess the influence of maternal weight, parity, ethnicity, chorionicity in twin pregnancies, smoking, insulin-dependent diabetes and mode of conception on individual marker MoM levels. RESULTS: Both free beta-hCG and PAPP-A median values demonstrated an exponential relationship with gestational age in days. Multivariate regression analysis indicated that free beta-hCG MoM was statistically significantly dependent on maternal weight (P < 0.0001) and chorionicity in twin pregnancy (both monochorionic and dichorionic P < 0.0001), that PAPP-A MoM was dependent on maternal weight (P < 0.0001), parity (P < 0.0001), chorionicity in twin pregnancy (both monochorionic and dichorionic P < 0.0001) and mode of conception (P = 0.002), and that fetal NT-MoM was dependent on maternal weight (P = 0.0006) and mode of conception (P = 0.012). CONCLUSION: Normative values have been generated to allow conversion of NT, free beta-hCG and PAPP-A to their MoM equivalents and correction factors have been determined to adjust for maternal and pregnancy characteristics for use in ethnic Chinese women undergoing first-trimester screening for aneuploidy.

Volumetric (3D) imaging reduces inter- and intraobserver variation of fetal biometry measurements.

OBJECTIVE: To compare the inter- and intraobserver variation of fetal biometric measurements utilizing two-dimensional (2D) and three-dimensional (3D) ultrasound imaging. METHODS: This prospective study, utilizing three pairs of doctors trained in sonography, evaluated singleton pregnancies in the mid-trimester. Measurements of the biparietal diameter (BPD), head circumference (HC), abdominal circumference (AC) and femur length (FL) were taken in duplicate by each doctor using 2D imaging and then again using 3D volume datasets. Each set of paired doctors evaluated 12 patients. Inter- and intraobserver variation were calculated as the SD of the difference between paired measurements performed by the doctor pairs and by the individual doctors, respectively. Bland-Altman plots were used to visually compare measurement bias and agreement by 2D and 3D methods. RESULTS: Inter- and intraobserver variation for 2D and 3D ultrasound were small. The intraobserver variation of HC, AC and FL was significantly lower for 3D compared with 2D ultrasound. Interobserver variation was not significantly different when measured with 2D and 3D ultrasound, with the exception of FL, which was lower when measured with 3D ultrasound. The Bland-Altman plots showed that in 95% of the measurements, the percentage difference between 2D and 3D ultrasound techniques was within 5.3%, 4.6%, 9.6% and 9.6% for BPD, HC, AC and FL, respectively. CONCLUSIONS: 2D and 3D fetal biometric measurements are reproducible. The use of 3D ultrasound significantly reduces intraobserver variation for HC, AC and FL and reduces interobserver variation for FL.

Which ultrasound or biochemical markers are independent predictors of small-for-gestational age?

OBJECTIVES: To investigate which ultrasound or biochemical markers in both the first and the second trimesters are the best predictors for fetal growth and small-for-gestational age (SGA). METHODS: This was a prospective study of 619 Chinese women with a singleton pregnancy. At 11 to 13 + 6 weeks, fetal crown-rump length (CRL), placental volume (PlaV), uterine artery pulsatility index (UtA-PI), and the maternal serum levels of pregnancy-associated plasma protein-A (PAPP-A) and free beta-human chorionic gonadotropin (beta-hCG) were measured. Fetal biparietal diameter, femur length, abdominal and head circumference, PlaV and UtA-PI were then measured at 18-22 weeks. All markers were transformed to gestational age-specific Z-scores or multiples of the median (MoM). Birth weights were also transformed to Z-scores using the individualized gestational age-related optimal weight based on a locally derived nomogram. The relationship between all markers and the customized birth weight were examined, and their predictive powers for SGA were examined by regression analysis. RESULTS: Univariate analysis revealed that all markers except free beta-hCG correlated with birth weight Z-score. After multiple linear regression analysis, only PlaV, UtA-PI and CRL in the first trimester, and PlaV and UtA-PI in the second trimester, stood out as independent markers. Logistic regression analysis showed that PlaV was the only independent first-trimester predictor of SGA, and in the second trimester both PlaV and UtA-PI were independent predictors. The sensitivity of these first- and second-trimester markers in predicting SGA were 41% and 45%, respectively, at a false-positive rate of 20%. Combining them did not significantly improve prediction of SGA. CONCLUSIONS: Among the various known ultrasound and biochemical markers, only the first-trimester PlaV and the second-trimester PlaV plus UtA-PI are independent predictors for SGA.

First-trimester fetal nasal bone length in an ethnic Chinese population.

OBJECTIVES: To determine reference ranges of fetal nasal bone length (NBL) in a Chinese population and to assess the value of NBL measurement in screening for chromosomal defects in the first trimester. METHODS: In this prospective study the fetal profile was examined and the fetal NBL and crown-rump length (CRL) were measured in Chinese women presenting with singleton pregnancies for first-trimester screening for aneuploidy between January 2004 and June 2007. Screening was performed on the basis of nuchal translucency (NT) measurement and maternal serum free beta-human chorionic gonadotropin and pregnancy-associated plasma protein-A levels. RESULTS: NBL was measured in 7543 fetuses, of which 7517 were euploid. The best fit equation for median NBL in euploid fetuses in relation to CRL was: NBL (mm) = 0.4593 + (0.0186 x CRL(mm)). The NBL for gestational age (GA, in days) was given by the equation NBL(mm) = 0.2392 + (0.0027 x GA). There was no correlation between log(10)(NBL multiples of the median (MoM)) and log(10)(NT MoM) in unaffected pregnancies (r = - 0.009; P = 0.43). Only two of the 11 cases with trisomy 21 had an NBL outside the 5(th) or 95(th) centiles of the reference range for euploid fetuses. CONCLUSION: Reference ranges for NBL in a Chinese population suitable for screening for aneuploidy between 11 and 13 + 6 weeks' gestation have been derived. The NBL in Chinese fetuses is similar to that of other ethnic groups. However, unlike the determination of presence vs. absence of the nasal bone, NBL measurement is unlikely to further improve screening for aneuploidy.

Trends in maternal obesity and associated risks of adverse pregnancy outcomes in a population of Chinese women.

OBJECTIVE: To assess the effect of increasing body mass index (BMI) on pregnancy outcome in a population of Chinese women. DESIGN: A retrospective study. SETTING: A university teaching hospital. POPULATION: Women delivering singleton babies between 1995 and 2005 who sought antenatal care before 20 weeks of gestation. METHODS: A total of 29,303 women were categorised into six BMI groups according to WHO's classification. Univariate, multivariate and logistic regression analysis were performed to compare obstetric and perinatal outcomes between BMI groups. MAIN OUTCOME MEASURES: Incidences of caesarean delivery, pre-eclampsia, gestational diabetes, preterm delivery, small for gestational age (SGA) and large for gestational age (LGA), perinatal death, and the respective odd ratios in reference to the normal group with BMI > or = 18.5 kg/m(2) and <23 kg/m(2). RESULTS: The median BMI increased with increasing maternal age, parity, gestation at the first visit, but decreased with year of delivery (P < 0.001). Concerning the obstetric outcomes, increasing BMI was associated with increasing incidence of caesarean section, pre-eclampsia, gestational diabetes, preterm delivery, LGA, as well as SGA according to customised growth standards (P < 0.001). The odds ratios for most of these adverse outcomes are higher than those reported in Caucasian population. Increasing BMI was not associated with the rate of stillbirth, neonatal death or shoulder dystocia. CONCLUSION: Increasing BMI is associated with increased risks of adverse obstetric outcomes. The impacts of high BMI on pre-eclampsia, gestational diabetes and preterm delivery in Chinese women might be stronger than that in Caucasian. Hence, it may be appropriate to use a lower BMI cutoff for defining overweight in Chinese.

How true is a 'true' midsagittal section?

OBJECTIVES: To study the deviation of presumed midsagittal sections of the fetal head from the true image plane, to compare whether certification (by The Fetal Medicine Foundation (FMF), UK) has an effect on the degree of this deviation, and to investigate the impact of imperfect midsagittal sections on nuchal translucency thickness (NT) measurement. METHODS: Eight sonographers, four of them FMF-certified (Group A) and the other four not (Group B), were asked to obtain image sections which they believed to represent true midsagittal sections of the fetal head and neck in five patients each. Three-dimensional volume datasets were acquired for subsequent analysis. The angle between the falx cerebri and the vertical axis was measured and the effect of this angle on NT measurement was assessed. RESULTS: The mean angle of deviation was significantly lower among those who were FMF-certified (5.7 degrees vs. 14.7 degrees, P < 0.001). The 1.8% underestimation of NT by Group A was not statistically significant (P = 0.76), while in Group B the NT could not be measured when the angle of deviation was 14.7 degrees. CONCLUSIONS: FMF-certified operators obtain a better midsagittal section compared with non-certified operators. The minor deviation from the true midsagittal section by certified operators has no significant effect on the value of NT measurement. This study could provide a model for operator training and auditing.

Impact of cross-linker on alginate matrix integrity and drug release.

Sodium alginate, a biopolymer, was employed in the formulation of matrix tablets. They cracked or laminated at acidic pH, compromising their dissolution performance. Improved mechanical strength and reduced barrier permeability of calcium alginate gel provided the rationale for cross-linking the alginate matrix to sustain drug release. Studies had suggested that the incorporation of soluble calcium salts in alginate matrix tablets could sustain drug release at near-neutral pH due to in situ cross-linking. However, results from the present study showed otherwise when gastrointestinal pH conditions were simulated. Significant reduction in drug release rate was only observed when an external calcium source was utilized at low concentration. High calcium ion concentrations caused matrix disintegration. In contrast, matrices pre-coated by calcium alginate could sustain drug release at pH 1.2 followed by pH 6.8 for over 12h. The presence of cross-linked barrier impeded matrix lamination and preserved matrix structure, contributing to at least three-fold reduction in drug release at pH 1.2. Zero order release as well as delayed burst release could be achieved by employing appropriate grade of alginate and cross-linking conditions.

Drying efficiency and particle movement in coating--impact on particle agglomeration and yield.

The purpose of this study was to determine the influences of drying efficiency and particle movement on the degree of agglomeration and yield of pellets coated under different conditions. Thermodynamic conditions were varied using different inlet air temperatures and airflow rates, fluid dynamics were varied using different airflow patterns and air velocities, and two sizes of pellets were coated at different airflow rates and partition gaps. Agglomeration was minimized when all the moisture introduced into the system was removed by the drying air. Excessively dry conditions led to increased loss of yield due to spray-drying effect and attrition. Fluid dynamics were still important even with adequate drying, as the degree of agglomeration was relatively higher in the non-swirling airflow of Wurster coating than in the swirling airflow of precision coating. Increasing air velocities increased pellet velocities, resulting in lower degrees of agglomeration. Hence, agglomeration due to fluid dynamics was attributed to differences in pellet velocities, pellet proximity and pellet trajectories within the partition column. Smaller pellets agglomerated primarily from inadequate drying and not due to inadequate opportunities for particle movement. Larger pellets were more affected by the partition gap due to restriction of their movement through the partition gap. Hence, both thermodynamics and fluid dynamics were found to be important in minimizing agglomeration and ensuring quality coated products.

Side-effect and vital sign profile of nifedipine as a tocolytic for preterm labour.

OBJECTIVE: To examine the side-effect and vital sign profile of nifedipine used as a tocolytic. DESIGN: Retrospective audit. SETTING: Tertiary care university hospital, Hong Kong. PATIENTS: Women presenting with preterm labour (before 34 weeks of gestation) between March 2001 and September 2004. MAIN OUTCOME MEASURES: Maternal heart rate, blood pressure, and foetal heart rate were monitored regularly. A four-point Likert scale multiple-choice questionnaire was used to assess the perceived degree of flushing, headache, nausea, dizziness, and shortness of breath. All assessments were performed at predefined intervals from the onset of treatment. Repeated measures analysis of variance was performed to identify any time-dependent association with nifedipine treatment. RESULTS: In all, 212 episodes of preterm labour were treated with nifedipine in 203 women. In 120 episodes, preterm labour was suppressed for more than 48 hours. Treatment was discontinued in three women because of profound hypotension (<90/60 mm Hg), and in one because of severe flushing. Only one patient developed maternal tachycardia (>or=140 beats per minute), and in two foetal tachycardia (>or=180 beats per minute) was encountered. Moderate headache was experienced in nine women, flushing in nine, dizziness in four, nausea in three, and shortness of breath in one. Repeated measures analysis of variance with time of measurement revealed a significant reduction in maternal blood pressure and increase in maternal heart rate that plateaued after 1 hour of therapy. The foetal heart rate returned to baseline values 3 hours after commencing therapy. CONCLUSION: In general, use of nifedipine as the first-line tocolytic was safe. However, severe maternal hypotension can occur and close monitoring of vital signs is warranted.