Biomedical subjects

T K Chung

Publications and source records attributed to T K Chung.

At least 19 recordsLinked to original sources

PubMed2001

Alteration of cyclin D1 and CDK4 gene in carcinoma of uterine cervix.

Amplification and overexpression of cyclin D1 and CDK4 genes in cervical carcinoma were studied by semi-quantitative differential polymerase chain reaction assay and an immunostaining technique, respectively. Amplifications of cyclin D1 and CDK4 genes were found in 24% (27/113) and 26% (29/112) of tumors, respectively. Overexpression of cyclin D1 and CDK4 was demonstrated in 32% (21/66) and 73% (45/62) of tumors, respectively. No tumor showed CDK4 gene mutation on single strand conformational polymorphism. Sixteen percent (8/49) of the tumor specimens showed neither amplification nor overexpression. Disease stage, tumor grade and overexpression of cyclin D1 were found to be independent poor prognostic factors in cervical carcinoma.

Adult↗

PubMed2001

Screening for postnatal depression: are specific instruments mandatory?

BACKGROUND: Few studies have examined the utility of rating scales developed in non-puerperal context in detecting postnatal depression. This study evaluated the utility of the General Health Questionnaire (GHQ) and the Beck Depression Inventory (BDI) in screening for depression among recently delivered women in Hong Kong. METHODS: A prospective cohort of 145 Chinese women completed the GHQ, BDI and Edinburgh Postnatal Depression Scale (EPDS) 6 weeks after delivery. They were then assessed using the non-patient version of the Structured Clinical Interview for DSM-III-R (SCID-NP) to establish psychiatric diagnosis, against which the criterion validity of the GHQ and BDI was evaluated against this clinical diagnosis. The psychometric performance of the GHQ, BDI and EPDS in detecting postnatal depression was assessed using the receiver operating characteristic (ROC) curves. RESULTS: Both Chinese GHQ and BDI had satisfactory sensitivity and positive predictive value in detecting postnatal depression. Their receiver operating characteristic (ROC) curves were comparable to that of the EPDS. LIMITATION: The study was conducted in Chinese women using translated version of the rating scales. CONCLUSIONS: The GHQ and BDI are useful for detecting postnatal depression among recently delivered Chinese women. The results of this study suggest that rating scales developed in non-puerperal context may also be applicable for postnatal depression.

Adolescent↗

PubMed2001

Microsatellite instability in cervical carcinoma.

OBJECTIVE: To investigate the incidence of microsatellite instability (MI) in cervical carcinoma and its relationship with clinicopathological characteristics. STUDY DESIGN: A retrospective study of 100 cases of cervical carcinoma. RESULTS: MI, defined as tumor-associated alterations in at least one of five dinucleotide microsatellite markers examined, was detected in 25% of the cervical carcinomas which were observed. There was a nonsignificant trend towards MI occurrence in higher grade tumors, more advanced stage and cases with poor clinical outcome. CONCLUSION: The results suggest that microsatellite instability is present in a subset of cervical carcinoma and may be an independent prognostic factor. Further research with more samples is required.

Dinucleotide Repeats↗

PubMed2001

Rate of rise in maternal plasma corticotrophin-releasing hormone and its relation to gestational length.

OBJECTIVE: To assess the relationship between rate of increase in maternal plasma corticotrophin-releasing hormone and gestational length. DESIGN: A prospective observational study. SETTING: Department of Obstetrics and Gynaecology, Prince of Wales Hospital, Hong Kong. METHODS: Serial venous samples taken at four to six week intervals from 81 pregnant Chinese subjects were assayed for corticotrophin-releasing hormone concentrations. The investigators responsible for the laboratory assay were blinded to the obstetric outcome. RESULTS: A total of 380 blood samples were taken. Each subject provided three to seven samples (median = 5). Seven of the 81 subjects had preterm delivery. Maternal corticotrophin-releasing hormone levels increased exponentially as gestation advanced. A negative correlation between the rate of rise of logarithmic equivalence of corticotrophin-releasing hormone concentrations (Ln-corticotrophin releasing hormone) per week and the gestational age at delivery was demonstrated (r = -0.45, P < 0.001). The rate of increase of Ln-corticotrophin releasing hormone concentrations per week was also significantly greater for those who delivered preterm before 37 weeks compared with those with uncomplicated term deliveries (0.27 Vs 0.22, P = 0.018). CONCLUSIONS: The rate of increase in maternal plasma corticotrophin-releasing hormone is inversely proportional to gestational length. Results in a Chinese population confirm and extend results from previous caucasian populations. This study provides another piece of evidence on the close link between maternal plasma corticotrophin-releasing hormone and the timing of human parturition. As the hormone is synthesized by the placenta, it supports the suggestion that the human placenta has an important role in determining gestational length.

Adult↗

PubMed2001

Clinical and prognostic significance of human papillomavirus in a Chinese population of cervical cancers.

OBJECTIVE: To investigate the clinical and prognostic significance of human papillomavirus (HPV) in a Chinese population of cervical cancers. METHODS: We studied 121 cervical cancer tissue samples from patients treated at our hospital. Identification and typing of HPV were done by polymerase chain reaction (PCR) using consensus primers MY11 and MY09 followed by direct DNA sequencing. The results were correlated with various clinical and prognostic parameters. RESULTS: We found HPV DNA in 95 (78.5%) cases, including HPV-16 in 59 (48.8%) and HPV-18 in 14 (11.6%) cases. chi(2) analysis revealed no significant correlation between the presence of HPV DNA and age at diagnosis, clinical stage, histologic type, tumor grading, 2-year and 5-year survival rate. Of the factors evaluated, age at diagnosis and histologic type were found to have a statistically significant relationship with HPV type. The mean age of the HPV-18 group was 48.6 years compared to 57.1 years for the HPV-16 group (p = 0.045) and 58.2 years for the HPV-negative group (p = 0.04). HPV-18 was detected more often in adenocarcinomas (AC) than in squamous cell carcinomas (SCC). Conversely HPV-16 was detected significantly more often in SCC (p < 0.0001). The HPV-negative group also had a higher incidence of SCC (p = 0.007). HPV-18-positive patients seemed to have more nodal involvement than both HPV-16-positive patients (45.5 vs. 20.8%) and HPV-negative patients (45.5 vs. 18.2%); however, it did not reach statistical significance. CONCLUSIONS: These observations suggest that the presence of HPV DNA does not bear any clinical or prognostic significance in a Chinese population of cervical cancers. HPV-18 is found more often in younger patients and is associated with AC.

Adenocarcinoma↗

PubMed2000

Loss of heterozygosity at the short arm of chromosome 3 in microdissected cervical intraepithelial neoplasia.

Loss of heterozygosity (LOH) is a common genetic finding in many human neoplasms, including cervical cancer. The detection of LOH at specific loci in the precursor of cervical cancer, cervical intraepithelial neoplasia (CIN) may help in elucidating the evolution of this cancer, which has a clearly defined histological premalignant phase. However, molecular genetic investigation of CIN is difficult because many of the lesions are very small and sometimes ill defined topographically. In this study we analyzed eighteen polymorphic microsatellite repeats on chromosome 3p in CINs using a method of primer extension pre-amplification (PEP) for whole genome amplification combined with microdissection. These markers encompass chromosome region 3pter-3p12. LOH at one or more loci was detected in five (33%) out of the 15 informative cases with low grade CIN (CIN 1), while 22 (92%) out of 24 cases with high grade CIN (CIN 2 and 3) (P<0.01). The highest incidence (41%) of LOH was detected at locus D3S1038 (3p26.1-3p25.2). Frequent LOH (more than 20%) was also found at other loci including D3S1110 (3p25.3-3p25.1) (31%), D3S656 (3p25.1) (24%), D3S1076 (3p21.2-3p21.1) (29%), D3S1300 (3p21.1-3p14.2) (24%), D3S1600 (3p14.2-3p14.1) (24%), and D3S1079 (3p13) (25%). The results from this study taken together with others indicate that the genetic alterations on chromosome 3p are common in high grade of CIN and are probably early events in cervical carcinogenesis. Tumor suppressor gene(s) that play a role in cervical neoplasm may be located on the short arm of chromosome 3, likely at or near 3p26.1-25.1, 3p21.2-21.1, and 3p14.2-13.

Alleles↗

PubMed2000

Misoprostol's effect on uterine arterial blood flow and fetal heart rate in early pregnancy.

OBJECTIVE: To determine whether a single oral dose of misoprostol is associated with change in Doppler resistance indices (RIs) of the uterine artery in early pregnancy. METHODS: Forty pregnant women seeking legal termination of pregnancy at 7-15 completed gestational weeks were each given a single oral dose of 200 microg misoprostol. Resistance indices (A/B ratio) and pulsatility index (PI) of the uterine arteries (UA) and fetal heart rate (FHR) were assessed by Doppler ultrasound before and 1 hour after administration of misoprostol. RESULTS: Doppler RIs (UA-A/B and UA-PI) of the right and left uterine arteries increased significantly 1 hour after misoprostol administration. The right UA-A/B increased from 7.16 +/- 1.09 (mean +/- SEM) to 10.26 +/- 0.67 (P < .001), and the left UA-A/B increased from 7.40 +/- 0.72 to 9.21 +/- 0.82 (P = .04). The right UA-PI increased from 2.38 +/- 0.11 to 2.90 +/- 0.12 (P < .001), and the left UA-PI increased from 2.38 +/- 0.17 to 2.70 +/- 0.18 (P = .03). No significant changes in FHR were noted 1 hour after misoprostol administration. None of the fetuses died during that time. CONCLUSION: Doppler RIs of the uterine arteries increased significantly after single oral doses of misoprostol during the first trimester, implying a reduction in arterial blood flow. Those changes were not associated with fetal death, possibly explaining congenital abnormalities associated with misoprostol in early pregnancy.

Abortifacient Agents, Nonsteroidal↗

PubMed2000

Analysis of mid-trimester corticotrophin-releasing hormone and alpha-fetoprotein concentrations for predicting pre-eclampsia.

The aims of this study were firstly to examine if corticotrophin-releasing hormone (CRH) concentrations in maternal plasma were significantly elevated in Chinese pregnancies complicated by pre-eclampsia, secondly to assess if this elevation could be detected in the mid-trimester before onset of clinical signs of the disease, and thirdly to evaluate the performance of using maternal CRH and/or alpha-fetoprotein (AFP) concentrations in the mid-trimester for prediction of pre-eclampsia. The first part of this study was tested in a cohort of 39 subjects. The CRH concentrations were significantly elevated in pregnant women complicated by pre-eclampsia. The second and third parts of the study involved a different cohort of 1021 subjects. Both CRH and AFP concentrations in the mid-trimester were significantly elevated in those who subsequently developed pre-eclampsia. However, when used for prediction of pre-eclampsia, neither the CRH nor AFP concentrations alone in the mid-trimester had strong predictive value. Although the combination of both tests improved the detection rate compared to the use of CRH alone, the small increase in the likelihood ratio from 1.9 to 2.6 did not suggest that the combination would be of great clinical value.

Adult↗

PubMed2000

Overexpression of p53 and HER-2/neu and c-myc in primary fallopian tube carcinoma.

Primary fallopian tube carcinoma is a rare form of female cancer and the genetic basis of its carcinogenesis remains unclear. Eighteen cases of primary fallopian tube adenocarcinoma were studied. Immunohistochemical staining for p53, HER-2/neu and c-myc genes were performed. Overexpression of p53 was detected in 12 cases (67%), HER-2/neu in 16 cases (89%), and c-myc in 11 cases (61%). The potential relevance of overexpression of the three genes with clinicopathological features was examined, but no significant correlation was found. The high incidence of p53, HER-2/neu and c-myc overexpression in fallopian tube adenocarcinoma suggests these genes may play a role in its tumorigenesis.

Adenocarcinoma↗

PubMed2000

p53 polymorphism and human papillomavirus infection in Hong Kong women with cervical cancer.

In this study we investigated the involvement of p53 polymorphism at codon 72, the infection and typing of human papillomavirus (HPV) and the correlation of p53 polymorphism with HPV type and other clinicopathologic characteristics in 72 Hong Kong women with cervical cancer. We developed a simple and nonradioactive method for determining polymorphism at codon 72 of the p53 gene. The homozygous p53 arginine allele (Arg/Arg) was detected in 22 (31%), the homozygous p53 proline allele (Pro/Pro) in 14 (19%) and the heterozygous allele (Arg/Pro) in 36 (50%) cases, respectively. Using the consensus primers MY11 and MY09, HPV infection was detected in 55 of 72 (76%) cases. The prevalent types were HPV-16 (55%), HPV-18 (16%) and HPV-58 (9%). The number of HPV-positive cases with Arg/Arg, Pro/Pro and Arg/Pro were 17 (31%), 12 (22%) and 26 (47%), respectively. The p53 polymorphism at codon 72 was not significantly correlated with any of the HPV types (p > 0.05). No striking overrepresentation of homozygous arginine-72 p53 was observed in HPV-associated cervical cancer. The results in this study did not show that any p53 polymorphic form has a prognostic significance for cervical cancer.

Codon↗

PubMed2000

Identifying women at risk of postnatal depression: prospective longitudinal study.

OBJECTIVE: To identify psychosocial risk factors for postnatal depression among Hong Kong Chinese women. DESIGN: Prospective longitudinal study involving self-report questionnaires and face-to-face interviews. SETTING: University teaching hospital, Hong Kong. PARTICIPANTS: Two hundred and twenty consecutive Chinese women who were admitted to the postnatal ward of the Department of Obstetrics and Gynaecology from 6 November 1996 to 18 January 1997. MAIN OUTCOME MEASURES: Psychiatric diagnoses were established using the clinician-administered Structured Clinical Interview for the Diagnostic and Statistical Manual of Mental Disorders. Psychosocial risk factors were ascertained by conducting face-to-face interviews and using psychometric rating scales. RESULTS: Of the 330 women who delivered during the study period, 220 (66.7%) agreed to participate in the study. The 220 participants had a mean age of 29 years (range, 16-42 years). Postnatal depression was associated with depression during pregnancy, elevated depression score at delivery, and prolonged postnatal 'blues'. Other correlates of postnatal depression were temporary housing accommodation, financial difficulties, two or more induced abortions, past psychiatric disorders (including depression), and an elevated neuroticism score. Postnatal depression was more likely if the spouse was disappointed with the gender of the newborn. CONCLUSION: Some risk factors are similar to those found in the West, whereas others (spouse disappointment and history of abortion) may be unique to the local population. To help identify women who are at particularly high risk of developing postnatal depression, obstetricians and midwives in Hong Kong should consider codifying the identified risk factors into a check-list.

Adolescent↗

PubMed1999

Allelic loss on chromosome 1 is associated with tumor progression of cervical carcinoma.

BACKGROUND: Alterations in chromosome 1 are common in human malignancies. The frequency of loss of heterozygosity (LOH) on chromosome 1 in cervical carcinoma and its clinical significance are not clearly understood. METHODS: LOH on chromosome 1 was studied in 100 cervical carcinomas by the polymerase chain reaction (PCR) using 29 highly polymorphic microsatellite markers spaced approximately 10 centimorgans apart. Loci with high frequencies of LOH were identified and the findings were correlated with clinicopathologic characteristics. RESULTS: LOH on chromosome 1 at 1 or more loci was detected in 93% of tumors. The frequencies of LOH at locus D1S2829 (1p31), D1S2663 (1p36.3), and D1S2725 (1q25) exceeded 30%, and 12 other loci exhibited frequencies of LOH of 20-30%. Advanced stage tumors had a significantly higher percentage of informative microsatellite markers with LOH than early stage tumors. Of the 29 microsatellite markers studied, 4 loci had a significantly higher frequency of LOH in Stage III and IV tumors than in earlier stage tumors. CONCLUSIONS: Frequent aberrations on chromosome 1 in cervical carcinoma suggest that inactivation of tumor suppressor genes is important in cervical tumorigenesis. Higher frequencies of LOH in Stage III and IV tumors suggest that chromosome 1 changes are late events in cervical carcinoma. The findings of this study are consistent with earlier reports that suggest that tumor suppressor genes are present at 1p36.3 and 1p31. To the authors' knowledge, the high frequency of LOH mapped to 1q25 has not been reported previously. Its significance awaits further clarification.

Adenocarcinoma↗

PubMed1999

Methylation of p16INK4A in primary gynecologic malignancy.

The p16INK4A gene mapped on band p21 of chromosome 9 can be inactivated via multiple mechanisms including homozygous deletion, point mutation and promoter hypermethylation in various human tumors. A polymerase chain reaction (PCR) based analysis was performed to examine methylation of the p16INK4A gene promoter in 196 primary gynecologic malignancies including 98 cervical, 49 endometrial and 49 ovarian carcinomas. Methylation of p16INK4A was detected in 31% of cervical, 20% of endometrial, and 4% of ovarian carcinomas, respectively. The incidence of p16INK4A methylation in patients with cervical and endometrial carcinomas at advanced stages (stages III-IV) was statistically higher than those at early stages (stages I-II). There were also significant differences in the incidence of p16INK4A methylation in both cancers between the patients who had died of their disease or were alive with evidence of disease, and those without evidence of disease. The results indicate that methylation of the p16INK4A gene is present in a proportion of primary gynecologic malignancies and this alteration may be associated with poor outcome in cervical and endometrial carcinomas.

Adult↗

PubMed1999

Spontaneous abortion: a randomized, controlled trial comparing surgical evacuation with conservative management using misoprostol.

OBJECTIVE: To compare the efficacy of surgical evacuation of the uterus with medical evacuation using misoprostol in cases of spontaneous abortion. DESIGN: A prospective, randomized, controlled trial. SETTING: A university teaching hospital. PATIENT(S): Six hundred thirty-five women who aborted spontaneously and who consented to pretreatment randomization. INTERVENTION(S): Routine surgical evacuation or medical evacuation of the uterus using misoprostol. MAIN OUTCOME MEASURE(S): Immediate, short-term (2-3 weeks), and medium-term (6 months) medical complications. RESULT(S): There was a significantly lower incidence of immediate and short-term complications in the group treated with misoprostol compared with the surgically treated group. There were also fewer major complications in the 6 months after treatment in the medically treated group. Approximately 50% of the medically treated group subsequently required surgical evacuation, and these subjects required significantly more analgesia. CONCLUSION(S): Treatment with misoprostol can reduce the demand for surgical evacuation in cases of spontaneous abortion, and its use is associated with fewer medical complications.

Abortifacient Agents, Nonsteroidal↗

PubMed1999

Abducens nerve palsy complicating pregnancy: a case report.

We report a case presented at 38 weeks gestation with abducens nerve palsy. No specific pathology was found. After reviewing all the previously reported cases, hypertension is found to be a common factor in all cases presenting in late pregnancy. The clinical course is benign and all resolved after delivery.

Abducens Nerve↗

PubMed1999

Patient-related barriers to cancer pain management in a palliative care setting in Hong Kong.

This article reviews a study of pain management and its barriers in Hong Kong. Using an interview technique, several measures were used to understand the level of concern in patients about pain, the patients' hesitancy in reporting pain, use of analgesics, and adequacy of medication for pain. A total of nine barriers were identified, which include "addiction," "tolerance," "side effects," "physician distraction," "good patient," "fear of injection," "time interval," "fatalism," and "disease progression." Thirty-nine interviews were carried out. The interviewees were all cancer patients with pain in a palliative setting in Hong Kong. When the findings in Taiwan and the United States were compared, it was found that the cancer patients in Hong Kong had a higher level of concern toward the patient-related barriers. It was also found that the level of concern was generally higher in the group with hesitancy in reporting pain and using analgesics. Last of all, this project also identified the educational needs of patients and health care workers in Hong Kong.

Adult↗

PubMed1999

Elevated mid-trimester maternal corticotrophin-releasing hormone levels in pregnancies that delivered before 34 weeks.

OBJECTIVE: To test whether maternal corticotrophin-releasing hormone levels are elevated in the mid- trimester for those women who subsequently had spontaneous preterm delivery and to assess the clinical utility of the measurement in the prediction of preterm delivery. DESIGN: A prospective observational study. SETTING: Department of Obstetrics and Gynaecology, Prince of Wales Hospital, Hong Kong. POPULATION: 1047 low risk pregnant women recruited at 15-20 weeks of gestation. METHODS: Venous samples were assayed for levels of corticotrophin-releasing hormone. The investigators responsible for the laboratory assay were blinded to the obstetric outcome. MAIN OUTCOME MEASURES: Incidence of preterm, term and post-term pregnancies. RESULTS: Those who were delivered spontaneously at a preterm gestational age (before 34 weeks) had significantly higher corticotrophin-releasing hormone levels in the mid-trimester, compared with those who were delivered at term or post-term. There was a trend towards lower corticotrophin-releasing hormone levels with more advanced gestational age at delivery. When the measurement of corticotrophin- releasing hormone was used to predict delivery before 34 weeks, the best cut off was 1.9 MoM, which produced a sensitivity of 72.7% and specificity of 78.4%. This translated to a positive predictive value of 3.6%, negative predictive value of 99.6% and relative risk of 9.4 when the background prevalence of spontaneous preterm delivery before 34 weeks was 1.1%. The likelihood ratio was 3.4. CONCLUSIONS: Mid-trimester maternal corticotrophin-releasing hormone levels are elevated in pregnancies destined to deliver preterm before 34 weeks. When used alone in a low risk population, the measurement has a low predictive power for preterm delivery. However, the likelihood ratio of 3 4 implies that in high risk populations the test may be considerably more valuable.

Adult↗

PubMed1999

Threatened abortion: prediction of viability based on signs and symptoms.

OBJECTIVE: To examine the relationship between signs and symptoms associated with threatened abortion and viability of the pregnancy. DESIGN: A prospective observational study SETTING: A university teaching hospital PARTICIPANTS: One thousand consecutive women presenting with a threatened abortion. INTERVENTION: A structured history and an examination were performed as initial clinical assessment. These were followed by transvaginal sonography to determine the status of the pregnancy. MAIN OUTCOMES: The relationship between individual signs and symptoms and the status of the pregnancy was determined. Logistic regression was performed to determine which signs or symptoms were independent predictors of spontaneous abortion. RESULTS: A history of having passed a tissue mass, the presence of products of conception in the vagina and an open cervix were the only sign or symptom associated with a greater than 90% chance that the pregnancy was non-viable. Logistic regression of signs and symptoms at presentation indicated that maternal age greater than 35 years, a history of passing clots vaginally, vaginal bleeding similar to normal menstruation, increasing vaginal bleeding and discrepancy of 4 or more weeks between the uterine size on examination and that which would have been expected by menstrual dates were significant predictors of nonviable pregnancy. A history of vomiting was predictive of a viable pregnancy. CONCLUSION: The clinical assessment of threatened abortion is unreliable in most cases and should be superseded by ready access to sonographic assessment.

Abortion, Threatened↗