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Biomedical subjects

M W Pang

Publications and source records attributed to M W Pang.

18 recordsLinked to original sources
PubMed2006

Tension-free vaginal tape sling procedure for the treatment of stress urinary incontinence in Hong Kong women with and without pelvic organ prolapse: 1-year outcome study.

OBJECTIVE: To assess the outcome of patients who underwent a tension-free vaginal tape sling procedure alone versus patients who underwent concomitant pelvic floor surgery. DESIGN: Retrospective cohort study. SETTING: Urogynaecology unit of a university teaching hospital, Hong Kong. PATIENTS: Patients diagnosed with moderate-to-severe urodynamic stress incontinence and underwent a tension-free vaginal tape sling procedure from September 1999 to August 2004. MAIN OUTCOME MEASURES: Objective cure rate of stress urinary incontinence 1 year following tension-free vaginal tape sling procedure was assessed. Patients were considered objectively cured if no stress urinary incontinence was evident on urodynamic studies at 1-year follow-up. Subjective cure rates at 4 months and 1 year after tension-free vaginal tape sling procedure were also assessed. Other outcome measures included intra-operative and perioperative complication rates, and the rate of de-novo detrusor overactivity at 1 year. RESULTS: Of 302 patients recruited, 250 (82.8%) completed 1-year follow-up. There were 157 (62.8%) patients who had a tension-free vaginal tape sling alone, and 93 (37.2%) had tension-free vaginal tape sling and concomitant pelvic floor surgery for pelvic organ prolapse. All patients had urodynamic studies before and 1 year following surgery. The objective cure rate was 87.3% for patients with tension-free vaginal tape sling alone, and 80.6% for tension-free vaginal tape sling with concomitant procedures (Chi squared test, P>0.05). The subjective cure rates for tension-free vaginal tape sling alone and tension-free vaginal tape sling plus concomitant procedures were 89.2% and 86.0% at 4 months, and 93.0% and 94.6% at 1 year, respectively (Chi squared test, P>0.05). The most common complication was postoperative urinary retention (15.2%), followed by de-novo detrusor overactivity at 1 year (10%), and bladder perforation (8%). CONCLUSION: The tension-free vaginal tape sling procedure alone or in combination with pelvic floor surgery are equally effective for the treatment of female stress urinary incontinence.

Aged↗
PubMed2005

17beta-estradiol suppresses proliferation of fibroblasts derived from cardinal ligaments in patients with or without pelvic organ prolapse.

BACKGROUND: Estrogen replacement therapy (ERT) has been used in the treatment of pelvic organ prolapse (POP) but clinical results are inconclusive. The purpose of this study was to investigate the effect of 17beta-estradiol (E(2)) on the proliferation of fibroblasts derived from cardinal ligaments in women with or without POP. METHODS: Fibroblasts were derived from seven patients with POP and seven age-matched controls. The growth rate of POP fibroblasts was compared with that of control by 3-(4,5,-dimethyl thiazolyl-2)-2,5-diphenyl tetrazolium bromide (MTT) assay. Four cell strains from each patient and control group were treated with different concentrations of E2 (10(-4), 10(-8), 10(-9) and 10(-10) mol/l). The effect of E2 on cell proliferation was then measured by MTT assay. RESULTS: The overall growth rate of POP fibroblasts was significantly slower than that of controls under normal culture conditions. Addition of E2 suppressed cell proliferation of all the fibroblasts, especially in POP fibroblasts. POP fibroblasts showed a significantly lower proliferative rate than that of controls at all E2 concentrations, with the most prominent inhibitory effect at physiological concentration (10.83 34.41% versus 81.56 48.10% at 10(-8) mol/l). CONCLUSIONS: Our results suggest that decreased fibroblast turnover may contribute to the development of POP; and ERT may not be an effective POP treatment.

Cell Proliferation↗
PubMed2005

Cervical length at 18-22 weeks of gestation for prediction of spontaneous preterm delivery in Hong Kong Chinese women.

OBJECTIVE: To assess the value of a single cervical length measurement by transvaginal sonography (TVS) at the time of mid-trimester anomaly scan for predicting spontaneous preterm delivery (SPD) among Chinese women. METHODS: A prospective observational study was carried out involving 2880 subjects with singleton pregnancies and confirmed gestational age. Cervical length was measured at 18-22 weeks of gestation. RESULTS: The incidence of SPD < 34 weeks and < 37 weeks were 0.7% and 3.7%, respectively. Women with SPD < 34 weeks and SPD < 37 weeks had shorter median cervical lengths (32.6 mm and 36.2 mm, respectively) than those with term deliveries (37.6 mm) (P = 0.006 and 0.025, respectively). The predictive performance of cervical length was better for SPD < 34 weeks compared with < 37 weeks. A cervical length < or = 27 mm, which corresponded to the 4th centile, occurred in 36.8%, 62.5% and 100% of those with SPD < 34, < 30 and < 26 weeks, respectively. The positive likelihood ratio (LR) of a cervical length < or = 27 mm in predicting SPD < 34 weeks was 9.8. Using logistic regression, both short cervix and funneling were independent predictors for SPD < 34 weeks of gestation. The coexistence of funneling and a cervical length < or = 27 mm gave a positive predictive value (PPV) and LR of SPD < 34 weeks of 14.7% and 26.0, respectively. CONCLUSIONS: Mid-trimester cervical length is predictive of SPD in Chinese women. However, given the low PPV of a short cervical length, its clinical utility is still limited in low-risk populations.

Adult↗
PubMed2005

The impact of urinary incontinence on quality of life among women in Hong Kong.

OBJECTIVE: To determine the prevalence of female urinary incontinence in Hong Kong and its impact on quality of life. DESIGN AND SETTING: Territory-wide telephone survey in Hong Kong. PARTICIPANTS: Hong Kong women aged 10 to 90 years accessed by fixed residential telephone lines between June 2001 and July 2002. MAIN OUTCOME MEASURES: The prevalence of urinary symptoms was assessed using telephone interview. The urinary symptoms investigated were as listed in a validated Chinese version of Urogenital Distress Inventory Short Form (UDI-6). The impact on quality of life was quantified using a validated Chinese version of Incontinence Impact Questionnaire Short Form (IIQ-7). RESULTS: There were 749 valid respondents (response rate, 24.4%). Urinary symptoms were reported by 52% of women (95% confidence interval, 48.9-56.0%), of whom 12% believed it impaired their quality of life. Stress urinary incontinence was reported by 34% (95% confidence interval, 28.7-38.9%). Social (5.1%; 95% confidence interval, 2.8-7.4%) and emotional (5.6%; 95% confidence interval, 3.3-7.9%) factors were the quality-of-life areas most impacted by urinary incontinence. CONCLUSIONS: Urinary symptoms are common among Hong Kong women. Quality of life is consequently impaired in 12% of affected women.

Adolescent↗
PubMed2004

Retained products of gestation in miscarriage: an evaluation of transvaginal ultrasound criteria for diagnosing an "empty uterus".

OBJECTIVE: The purpose of this study was to compare clinical outcomes of conservative management versus surgical evacuation of retained products of gestation after misoprostol treatment for first trimester spontaneous miscarriage using less restrictive transvaginal ultrasound criteria for diagnosing "empty uterus," which were managed conservatively. STUDY DESIGN: This was a prospective, randomized, controlled trial. RESULTS: Forty-six patients who had sonographic features previously regarded as significant retained products of gestation after misoprostol treatment, ie, homogenous intrauterine dimension of more than 11 cm 2 in combined transverse and sagittal plane, or those with heterogeneous intrauterine contents were consented to randomization. The short-term complication rates of those managed conservatively were significantly higher than surgical evacuation ([9/24] 37.5% vs [0/21] 0%, P < .05). CONCLUSION: Our previously reported transvaginal ultrasound criteria of homogenous intrauterine dimension of less than 11 cm 2 in combined transverse and sagittal planes for defining "empty uterus," which requires no further treatment, cannot be "relaxed" without incurring additional complications.

Abortifacient Agents, Nonsteroidal↗
PubMed2004

A validation study of ultrasonic foetal weight estimation models for Hong Kong Chinese singleton pregnancies.

OBJECTIVE: To validate the published regression models for ultrasonic foetal weight estimation in Hong Kong Chinese singleton pregnancies. DESIGN: Prospective cohort study. SETTING: Regional hospital, Hong Kong. PARTICIPANTS: One hundred and fourteen Hong Kong Chinese women with singleton pregnancy at term (37-42 weeks). MAIN OUTCOME MEASURES: The birth weight of the neonate was used to validate the ultrasonic foetal weight estimation models. The ultrasound used to collect the data was performed within 2 days prior to delivery. RESULTS: Foetal weight estimation models published by Hadlock and Woo have a high intraclass correlation coefficient of 0.86. Woo's regression model has the least mean difference (0.2 g; 95% limits of agreement, -569.4 to 569.8 g) and Hadlock 3 has the smallest limits of agreement (-114.6 g; 95% limits of agreement, -663.4 to 434.2 g) among the models tested. CONCLUSIONS: Woo's regression model of foetal weight estimation gave the least mean difference and the actual birth weight for our local population were within the acceptable limits of agreement.

Cohort Studies↗
PubMed2003

One-year urodynamic outcome and quality of life in patients with concomitant tension-free vaginal tape during pelvic floor reconstruction surgery for genitourinary prolapse and urodynamic stress incontinence.

The aim of the study was to examine the 1-year urodynamic outcome and quality of life in patients who have had concomitant tension-free vaginal tape insertion during pelvic floor reconstruction surgery. The medical notes of a retrospective cohort of 45 patients who had undergone tension-free vaginal tape together with pelvic floor reconstruction surgery were reviewed. The operative information, the results of the urodynamic studies and the change in the quality-of-life scores 1 year after surgery were examined. The quality of life was assessed with both general and disease-specific quality-of-life questionnaires (General Health Questionnaire (GHQ-12), Urogenital Distress Inventory (UDI-6), Incontinence Impact Questionnaire (IIQ-7)). Patient satisfaction was assessed with the validated Chinese version of the Client Satisfaction Questionnaire (CSQ). Forty-five patients underwent tension-free vaginal tape insertion together with pelvic floor reconstruction surgery. The overall objective cure rate was 43%. There was a significant improvement in the disease specific quality-of-life assessment (UDI-6 score 38.3-15.5; P<0.01) and (IIQ-7 score 15.0-4.0; P<0.01). The patients who had a concomitant cystocele repair had a worse objective cure rate than patients without concomitant cystocele repair (38% vs 67%; P=0.19).

Aged↗
PubMed2003

Customizing fetal biometric charts.

OBJECTIVE: To study the effects of maternal and pregnancy characteristics on fetal biometric size using longitudinal ultrasound measurements and to construct customized models for fetal biometric size charts. METHODS: A cohort of 533 healthy pregnant women with normal singleton pregnancies were recruited for regular ultrasound examination for fetal biometry between 24 and 40 weeks' gestation. Multilevel modeling was used to construct models of fetal head size, femur length and abdominal circumference. Variables of maternal and pregnancy characteristics including booking weight and height, age, parity and fetal sex were included in the construction of the customized fetal biometric size charts. RESULTS: Increased fetal head size and abdominal circumference were significantly associated with extremes of maternal age. Maternal height had a statistically significant influence on biparietal diameter. Maternal booking weight had an influence on fetal abdominal circumference and femur length. Fetal sex was found to have a statistically significant influence on the final regression models of biparietal diameter, head circumference and femur length. Parity had an influence on fetal head circumference and abdominal circumference. CONCLUSIONS: Maternal and pregnancy characteristics have a significant influence on in-utero fetal biometry. We produced models to construct customized fetal biometric size charts. Further validation studies are necessary to evaluate the clinical usefulness of such customized fetal biometric size charts.

Adult↗
PubMed2002

An unusual case of a vesicovaginal stone.

We report a case of an unusual vesicovaginal stone. The dumb-bell-shaped stone created a ball valve effect in the fistula, therefore giving rise to only mild urinary leakage despite the large size of the fistula.

Calculi↗
PubMed2001

Incomplete miscarriage: a randomized controlled trial comparing oral with vaginal misoprostol for medical evacuation.

BACKGROUND: A prospective randomized controlled trial was conducted to compare the efficacy and side-effects of vaginal versus oral misoprostol in the medical management of incomplete miscarriage. METHODS: Two hundred and one patients who miscarried consented to randomization using computer-generated randomization model prior to treatment. A total of 800 microg of misoprostol was given either vaginally or orally to the randomized subjects. A second dose was repeated 4 h later if the product of conception had not been passed. RESULTS: The incidence of complete uterine evacuation following vaginal and oral misoprostol was similar [(58/95) 61.1% versus (67/103) 64.4%]. There was a significantly decreased incidence of diarrhoea [(12/95) 13.6% versus (62/103) 65.3%, P < 0.01] with the use of vaginal misoprostol. CONCLUSIONS: Vaginal misoprostol was as effective as oral misoprostol in medical uterine evacuation in patients with incomplete miscarriage. There was also a reduction in the incidence of diarrhoea with the use of vaginal misoprostol.

Abortion, Incomplete↗
PubMed2000

Development of a customised birthweight standard for ethnic Chinese subjects.

A model to establish customised birthweight standards for the Chinese population was developed, using data from a cohort of 1564 Chinese women with normal singleton pregnancies. Multiple regression analysis was performed using maternal height, weight, parity, gestation at delivery and fetal sex as independent (predictor) variables. From this, a customised ideal birthweight for each baby can be estimated, and the normality of the actual birthweight can be evaluated according to this, rather than from population standards. The results of this study show that birthweights are strongly influenced by maternal characteristics, confirming conclusions from similar studies in other ethnic populations. The overall mean birthweight at 280 days of gestation was 3252 g, which was smaller than that of the Caucasian population. Birthweight increased with maternal height (5.1 g/cm), maternal booking weight (10.2 g/kg) and gestation at delivery (18.3 g/day from 280 days). Babies from women who had two previous deliveries weighed 145.2 g more than the nulliparous. Male babies were 84.8 g heavier than females. Adjustment using these results produces a customised ideal birthweight for each baby. When compared with population based standards, customised birthweight standards identified significantly fewer small for gestational age (SGA - birthweight below 10th centile, McNemar Chi square = 19.1, p < 0.01) and fewer large for gestational age (LGA - birthweight above 90th centile, McNemar Chi square = 23.7, p < 0.01) cases.

Asian People↗
PubMed1998

Acute effects of a surgical menopause on serum concentrations of lipoprotein(a).

OBJECTIVE: The aim of this study was to investigate acute changes in serum concentrations of lipoprotein(a) and other atherogenic lipids and lipoproteins after a surgical menopause. METHODS: A total of 100 premenopausal Chinese women who were booked for hysterectomy for benign gynecological disorders were recruited. They study group comprised 40 subjects undergoing hysterectomy as well as bilateral oophorectomy. The control group consisted of 60 subjects undergoing hysterectomy with conservation of the ovaries. Complete data were available from 30 of the 40 subjects in the study group and from 44 of the 60 controls. Serum concentrations of lipoprotein(a) and other atherogenic lipids and lipoproteins were measured before surgery and these measurements were repeated 3 days, 8 weeks and 6 months postoperatively. Those study patients who received hormone replacement therapy and control patients who became menopausal, according to biochemical criteria, during the study period were excluded from analysis. RESULTS: Three days after surgery, there was a significant increase in the mean lipoprotein(a) concentration in the control group from 19.1 to 23.0 mg/dl (p < 0.01), but there was no significant change in the study group. There were no significant changes from baseline in the mean lipoprotein(a) concentration in either group 8 weeks or 6 months after surgery. There was a significant increase in the mean concentration of total cholesterol in the study group 8 weeks after surgery from 5.08 to 5.45 mmol/l (p < 0.01), in low density lipoprotein cholesterol from 3.22 to 3.49 mmol/l (p < 0.01), and in apolipoprotein B from 95.6 to 103.0 mg/dl (p < 0.05). However, the mean concentrations 6 months after surgery were not significantly different from baseline levels. The mean concentrations of high density lipoprotein cholesterol, apolipoprotein A-1 and triglycerides also did not differ significantly from baseline in the study group, either 8 weeks or 6 months after surgery. CONCLUSIONS: These results suggest that any increase in concentrations of lipoprotein(a), and other atherogenic lipids and lipoproteins which occur after the menopause, develops relatively slowly. The changes in concentrations which occurred within 8 weeks of surgery were probably an acute-phase reaction after surgery rather than a response to a decreasing estradiol concentration.

Adult↗
PubMed1997

Endometrial hyperplasia and the risk of endometrial carcinoma.

OBJECTIVES: To determine the incidence of endometrial carcinoma in endometrial hyperplasia and try to identify those patients at greatest risk. METHODS: We conducted a retrospective study of 116 patients who had simple, complex or mixed (simple with focal complex) endometrial hyperplasia with or without atypia, from January 1991 to December 1994. RESULTS: Twenty-nine patients had endometrial hyperplasia with atypia and 87 without atypia. Incidence of endometrial carcinoma was 27.6% in those with atypia; and 3.4% in those without atypia. All were stage I (A or B) adenocarcinomas. Polycystic Ovary Disease and subfertility were found significantly in the cases with cytological atypia; however, they were not significant in the cases with carcinoma. No significant historical differences that could predict carcinoma were found.

Adenocarcinoma↗
PubMed1996

Comparison of various interpositional materials in the prevention of transphyseal bone bridge formation.

Various interpositional materials, except muscle, have been used to prevent transphyseal bone bridge formation after resection of the damaged physeal plate. In this animal model, muscle was used as an interpositional material, and its effectiveness was compared with that of 3 known materials (fat, physeal allograft, and iliac apophyseal autograft). Five experiments were done on the distal femoral physis of 40 skeletally immature 3-month-old New Zealand white rabbits. The rabbits were divided into 5 groups, each containing 8 rabbits. A standard defect was created in the lateral distal physis of the left femur in all the rabbits. In Group A, there was no interpositional material. Vastus lateralis muscle, groin fat, physeal allograft, and iliac apophyseal autograft were inserted into the femoral defect in Groups B, C, D, and E, respectively. The right femur served as a sham control for the animals. The animals were sacrificed at 12 weeks after surgery. The results of limb length discrepancy and angular deformity of the groups with interpositional material were compared with those of Group A (experimental control). Muscle, fat, and iliac apophyseal autografts had less severe limb length discrepancy and angular deformity. These differences were statistically significant, whereas the differences between allograft and experimental control were statistically insignificant.

Adipose Tissue↗
PubMed1985

Correlation of steroid receptors with histologic differentiation in mammary carcinoma. A Singapore experience.

Cancer of the breast is the most common tumor in females in Singapore, with the rate of 20.7 per 100,000 per year (1977 estimate), which is predicted to increase to 29.8 per 100,000 women per year by 1995. A detailed histopathologic review of 50 primary breast cancer tumors analyzed for estrogen receptor (ER) level was carried out and a variety of morphologic features correlated with ER results to identify any factors that will improve the management and prognosis for breast cancer. Cytosol was incubated with 3H-estradiol in the presence and absence of cold diethylstilbestrol, and bound and free hormone were separated by Dextran-coated charcoal method. Tumors binding more than 5 fmol/mg cytosol protein were classified as ER-positive. Progesterone receptor (PR) level was analyzed in some specimens with the use of a similar method. Most of the patients were Chinese (90%). Three patients were Malays, one was Indian, and one was European in this series. Results indicated that there was strong correlation between ER level, age, and histologic grade of the tumors. No correlation existed between absence or presence of lymph node metastases and ER. Although there was a trend for ER-positive tumors to have a low-grade lymphocytic infiltration, the difference was not statistically significant.

Adult↗