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Biomedical subjects

H K Ma

Publications and source records attributed to H K Ma.

At least 19 recordsLinked to original sources
PubMed2001

Parent-adolescent conflict and adolescent antisocial and prosocial behavior: a longitudinal study in a Chinese context.

This longitudinal study examined the relationships between parent-adolescent conflict and antisocial and prosocial behavior in Chinese adolescents. Results showed that father-adolescent conflict and mother-adolescent conflict were concurrently related to adolescent antisocial and prosocial behavior. Longitudinal analyses showed that parent-adolescent conflict predicted antisocial behavior but not prosocial behavior. Adolescent antisocial and prosocial behavior was also found to be related to father-adolescent conflict across time. The findings suggest that the linkage between father-adolescent conflict and adolescent social behavior is stronger than that between mother-adolescent conflict and adolescent social behavior.

Adolescent↗
PubMed2000

Parental, peer, and teacher influences on the social behavior of Hong Kong Chinese adolescents.

Intensive interviews and self-report questionnaires were used to investigate parental, peer, and teacher influences on the prosocial and antisocial behaviors of Hong Kong Chinese adolescents. Students came from 5 academically different high schools. Results indicated that perceived parental influence was positively associated with frequency of prosocial behavior and negatively associated with frequency of delinquent behavior. Students with good relationships with their parents and peers showed lower frequencies of antisocial behaviors than did students with bad relationships. Adolescents in different identity statuses (achievement, moratorium, foreclosure, diffusion; E. H. Erikson, 1968) showed different patterns of prosocial and antisocial behaviors. For example, adolescents in the identity achievement group exhibited high frequencies of prosocial behaviors and low frequencies of antisocial behaviors, but those in the identity moratorium group exhibited quite high frequencies of both prosocial and antisocial behaviors.

Adolescent↗
PubMed1998

Conceptions of success: their correlates with prosocial orientation and behaviour in Chinese adolescents.

Data from a sample of 673 Chinese adolescents lent support to the hypothesis that conceptions of success or achievement goals affect both the inclination to and the actual performance of prosocial acts. With regard to attitude, it was found that: (a) task orientation (belief that success is gaining skill or understanding) and collaboration orientation (belief that success is working productively with one or more collaborators) increased with the inclination to help others, to co-operate and share things with others, to maintain an affective relationship with others, and to behave in compliance with social norms; and (b) ego orientation (belief that success is establishing one's competence as superior) was not generally associated with the inclination to perform prosocial acts. With regard to action, it was found that task orientation and collaboration orientation, but not ego orientation, increased with the number of normative and altruistic acts in the past year. The similarity between the belief-attitude correlation and the belief-action correlation indicates the robustness of the influence of conceptions of success. Also, sex differences and grade differences in the relationship between conceptions of success and prosocial and antisocial behaviours were found. Implications of the findings are discussed.

Achievement↗
PubMed1998

Intrascleral dissemination of infectious scleritis following pterygium excision.

AIMS: To assess the clinical pictures, possible pathogenesis, management, and therapy of patients with infectious scleritis associated with multifocal scleral abscesses following pterygium excision. METHODS: The records of patients with infectious scleritis after pterygium excision who developed multifocal scleral abscesses presenting from 1988 to the end of 1995 were reviewed. Early culture of abscesses was performed, and topical, systemic antimicrobials, or both were given to all patients. Fourteen eyes were operated on in addition to antimicrobial treatment. RESULTS: The initial culture reports of scleral ulcers identified Pseudomonas species in 12 of these 18 patients, Aspergillus in one, Mycobacterium fortuitum in one, and mixed organisms in four. Subsequent abscess cultures were taken from 15 of the infected eyes, and revealed the same organism as the initial culture in 12. Associated complications included four serous retinal detachments, three choroidal detachments, two double detachments, five complicated cataracts, and four recurrences of the initial infection. Four eyes required eventual enucleation and 11 eyes regained useful vision. CONCLUSIONS: With subsequent abscess cultures proving to be the same organism as found in the initial ulcer, the abscess formation appears to represent intrascleral dissemination. Early diagnosis and appropriate, prolonged topical plus systemic antimicrobial treatment are essential to halt the progression of such severe infections.

Abscess↗
PubMed1998

Tumour markers and their prognostic value in adenocarcinoma of the cervix.

Ninety-one patients with adenocarcinoma of the cervix had 4 tumour markers (TMs) assayed before treatment. Serum squamous cell carcinoma antigen (SCC) (n = 91) was raised in 25%; tissue polypeptide antigen (TPA) (n = 78) was raised in 35%; carcinoembryonic antigen (CEA) (n = 34) was raised in 26% and CA 125 (n = 64) was raised in 27% of these patients. In 47 of these 91 patients (52%), 1 or more of the markers were raised. The percentage of patients with raised TM increased with advancing stage. Univariate survival analysis showed that age, stage, raised TPA, raised CA 125, and raised TMs (any one or more) were of prognostic significance. When multivariate analysis was done and each TM was individually analysed, only age, stage and raised CA 125 were of prognostic significance. Rising SCC or TPA or CA 125 levels in serial estimations correlated well with the occurrence of recurrence. Thus, pretreatment estimation of SCC, TPA and CA 125 can be used to identify the patients who can subsequently be monitored by serial TM estimation.

Adenocarcinoma↗
PubMed1996

The relation of prosocial and antisocial behavior to personality and peer relationships of Hong Kong Chinese adolescents.

The prosocial and antisocial behaviors of 2,862 Hong Kong Chinese adolescents were investigated. The major findings were as follows: (a) boys were more antisocial than girls: (b) negative peer influences were significantly stronger in boys than in girls, whereas positive peer influences were significantly stronger in girls than in boys; (c) antisocial adolescents tended to perceive their best friend as antisocial and exerting more negative influences on them, whereas prosocial adolescents tended to perceive their best friend as prosocial and exerting more positive influences on them; (d) antisocial behavior was positively associated with psychoticism and neuroticism; and (e) academic achievement tended to have a positive relation with prosocial behavior and a negative relation with antisocial behavior.

Adolescent↗
PubMed1996

A multicentre study to investigate the prevalence of abnormal carbohydrate metabolism in Chinese pregnant women.

OBJECTIVES: To determine the prevalence of abnormal carbohydrate metabolism in Chinese pregnant women. To study the inter-relationship between maternal body habitus, maternal serum glucose and birth weight of the baby. METHODS: Multicentre observational study involving 713 pregnant Chinese women, attending antenatal clinics in Beijing, Shanghai, Guangzhou and Hong Kong. RESULTS AND CONCLUSION: The overall prevalence of abnormal glucose tolerance was 6.9%. The prevalence was 6.8%, 5.5%, 7.2% and 8.1% in Beijing, Shanghai, Guangzhou and Hong Kong, respectively. The differences among the centres did not reach statistical significance (p = 0.9). The mean ponderal index of women with abnormal glucose tolerance was significantly higher than that of women with normal glucose tolerance (15.2 vs 14.3, p < 0.01). The birth weight ratio of the babies was positively correlated with the maternal height (correlation coefficient 0.23, 95% C.I. 0.15-0.30), weight (0.32, 95% C.I. 0.25-0.39) and to a lesser extent, the fasting level of serum glucose (0.10, 95% C.I. 0.02-0.28) but not with the 2 hour level of serum glucose.

Birth Weight↗
PubMed1996

Prognostic significance of serum tumour markers in carcinoma of the cervix.

PURPOSE: The purpose was to evaluate the prognostic significance of serum tumour markers and other potential prognostic factors in cervical cancer. MATERIALS AND METHODS: Five hundred and thirty-one patients with cervical cancer were studied. The pre-treatment levels of SCC (squamous cell carcinoma antigen), TPA (tissue polypeptide antigen), CEA (carcinoembryonic antigen), CA125 and hCG (human chorionic gonadotrophin) were assayed in these patients. Possible association between raised tumour markers and potential prognostic factors and their prognostic significance were sought by univariate and multivariate Cox analysis. RESULTS: SCC was raised in 65% of squamous cell carcinoma of the cervix and TPA was raised in 50%. Other markers were raised in less than 25%. No tumour markers were raised more than 30% in adenocarcinoma of the cervix. Raised SCC and TPA were related to advancing age, stage and grade of differentiation. Univariate analysis showed that age, stage, grade, raised SCC and TPA were significant prognostic factors on survival. Multivariate Cox analysis showed that stage was the most significant factor. CONCLUSION: Stage, age, grade of differentiation, raised pre-treatment levels of SCC and TPA were significant prognostic factors in cervical cancer using univariate analysis. However, only stage remains the most important independent prognostic factor in multivariate analysis. The prognostic value of these other factors in early stage disease needs further exploration.

Adenocarcinoma↗
PubMed1995

The prevalence and clinical significance of pulmonary infection due to non-tuberculous mycobacteria in Hong Kong.

An unexpected increase in positive sputum cultures of non-tuberculous mycobacteria (NTM) was noted in Hong Kong in 1990 compared to previous years, in contrast to a steady decline in the number of positive cultures of Mycobacterium tuberculosis. A retrospective case note study was therefore undertaken to ascertain the clinical importance of the rise in NTM isolates. A representative sample of 183 of the 675 patients with NTM isolates from sputum during 1990 was identified. Cases were assigned to groups according to whether there was evidence of progressive pulmonary disease due to NTM (group 1), persisting colonization without evidence of progressive disease (group 2) or transient isolation of NTM without evidence of progressive disease (group 3). Of 168 cases with adequate clinical and radiological records, 28 (16.7%) represented progressive disease due to NTM and 6 (3.6%) represented persisting colonization. The remainder were both transient and clinically insignificant. Most patients (71%) with progressive pulmonary disease due to NTM had pre-existing lung damage, and 50% had received anti-tuberculous therapy for documented M. tuberculosis previously. The commonest organism involved was the M avium complex. Eighty-six percent of patients with progressive disease and 83% of those with persisting colonization had at least one smear positive sputum specimen, whereas only 2% of patients with sputum contamination had a smear positive sputum sample (P < 0.0001). M. malmoense, M. xenopi and M. fortuitum all appear to be rare causes of significant NTM disease in Hong Kong. However, M. chelonei caused four cases of progressive disease within the study population, two of which were fatal.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1995

Oral misoprostol versus placebo for cervical dilatation before vacuum aspiration in first trimester pregnancy.

Intravaginal misoprostol has been shown to be effective for cervical priming before a surgically induced abortion. The objective was to investigate the effectiveness of oral misoprostol in cervical dilatation prior to vacuum aspiration between the 6th and 12th weeks of pregnancy. The results showed that in nulliparous patients, the median cervical dilatation in the treatment group (7.8 mm) was significantly greater than that in the placebo group (3.7 mm). In multiparous patients, the difference was also statistically significant (9.8 versus 6.0 mm). The ease of dilatation, assessed subjectively by the operating surgeons, was significantly improved in the treatment group. There was also a significant reduction in the duration of the operation and in the mean blood loss in the treatment group. The side-effects encountered in the treatment group were mild and well accepted by the women. Oral misoprostol is an effective and safe method for cervical dilatation prior to vacuum aspiration in first trimester pregnancy.

Abortion, Induced↗
PubMed1995

Pregnancies complicated by acute appendicitis.

Appendicitis is one of the most common acute abdominal conditions that requires operation during pregnancy. The maternal and fetal complications occurring in such situations are well known. However, the diagnostic and therapeutic challenges of acute appendicitis complicating pregnancy persist in current surgical practice. Thirty-eight obstetric cases who had an appendicetomy performed during pregnancy between 1986 and 1993, were reviewed. In 31 cases, acute appendicitis was proven at laparatomy, and by subsequent histopathology. In the confirmed cases, seven occurred in the first trimester, 12 in the second trimester, eight in the third trimester and four in the immediate postpartum period. Two miscarriages occurred in the first trimester group, and two late abortions and two preterm (26 and 28 weeks) deliveries occurred in the second trimester group. In the third trimester/postpartum group, all babies survived, but four patients had Caesarean sections with the appendicetomy and the incidence of perforated/gangrenous appendices was highest. Perinatal outcome was worst, with the highest fetal wastage rate if the acute appendicitis occurred in the second trimester, although maternal morbidity appeared to be the same across different gestational periods.

Abortion, Spontaneous↗
PubMed1995

Reducing the induction to abortion interval in termination of second trimester pregnancies: a comparison of mifepristone with laminaria tent.

OBJECTIVE: To determine whether mifepristone (RU486) is more effective than laminaria tent in shortening the induction-abortion interval in termination of second trimester pregnancies with gemeprost. DESIGN: Prospective randomised comparative trial. SETTING: Department of Obstetrics and Gynaecology in a University teaching hospital. SUBJECTS: Sixty-two women undergoing termination of pregnancy in the second trimester. INTERVENTIONS: The women were allocated at random to one of the two treatment groups. The first group received 600 mg of mifepristone 36 h before administration of gemeprost. In the second group, a medium-sized laminaria tent was inserted 12 h before gemeprost. The pregnancies in both groups were terminated with vaginal gemeprost, 1 mg every 3 h up to a maximum of 5 mg/day. MAIN OUTCOME MEASURES: Induction-abortion intervals, amount of gemeprost required, and incidence of side effects. RESULTS: The median induction-abortion interval in the mifepristone group (7.5 h) was significantly shorter than that in the laminaria tent group (11 h) and significantly fewer gemeprost pessaries were required. There was no significant difference in the amount of narcotic analgesics required or the incidence of side effects between the two groups. CONCLUSIONS: Mifepristone is more effective than laminaria tent in shortening the induction-abortion interval in termination of second trimester pregnancies.

Abortifacient Agents, Nonsteroidal↗
PubMed1994

Vaginal template implant for cervical carcinoma with vaginal stenosis or inadvertent diagnosis after hysterectomy.

PURPOSE: For cervical carcinoma patients with poor geometry for conventional intracavitary radiotherapy, a simple vaginal template for interstitial implantation as a substitute was used. This template has also been used to treat patients who had hysterectomy done without knowledge of an early tumor in the cervix, and for patients with recurrent disease. This is a report of the treatment results. METHODS AND MATERIAL: A total of 21 patients were treated over from July 1987 to June 1991 with this vaginal template implant forming part of the treatment, 12 of these were performed for vaginal stenosis. The applicator consists of a front piece and an end piece. Holes were drilled in the front piece to guide the implantation of the cervix or vaginal vault. The diameter of applicators varied from 2 cm to 3.5 cm. Depending on the diameter of the applicators, six to eight needles on the periphery, or eight peripheral plus one central needle were used. The activity of the needles were around 8 mCi with a total length of 5.5 cm. The end piece was locked onto the front piece by a bayonet-type locking device. The purpose of the end piece was two-fold: to make up the length of the whole applicator to fit the vagina and to keep the implanted needles in place without being extruded. The implantation was performed under general anesthesia. RESULTS: One of the twelve patients treated with the vaginal template implant for vaginal stenosis had relapsed centrally but subsequently died of intercurrent disease. Two other patients died of intercurrent disease at 26.2 and 41.9 months, respectively, without evidence of relapse. Nine other patients had been followed with no evidence of local relapse for 23.7 to 54.6 months. CONCLUSION: This vaginal template implantation is a satisfactory means of treating patients with vaginal stenosis and those who had hysterectomy done without knowledge of an early tumor in cervix.

Adult↗
PubMed1994

Cardiac blood flow studies in fetuses with haemoglobin Bart's disease.

Blood flow across the atrioventricular valves and outflow tracts was measured in 55 normal fetuses and 32 fetuses with haemoglobin (Hb) Bart's disease between 18 and 26 weeks of gestation. The mean velocities remained unchanged in both normal and affected fetuses over the gestations studied. The volume flow across both atrioventricular valves and outflow tracts increased as the gestation advanced in both normal and affected fetuses, but was significantly higher in affected than in normal fetuses. The same magnitude of increased flow was found in both hydropic and non-hydropic fetuses with Hb Bart's disease. These findings suggest that fetuses with severe and long-standing anaemia have a remarkable cardiac compensatory mechanism for the maintenance of tissue oxygenation. In response to anaemia and circulatory loading, the cardiac chambers and outflow tracts enlarge proportionately up to twice the normal values. Because of this response and the operation of the Frank-Starling mechanism, the heart is able to maintain a normal mean velocity of propulsion and the net output is increased to two to three times that in normal fetuses. Hydropic changes in these anaemic fetuses appear unrelated to cardiac failure as cardiac failure is not observed at the time that hydropic changes develop.

Blood Flow Velocity↗
PubMed1994

The prognostic value of TPA and SCC in squamous cell carcinoma of the cervix.

Three hundred two patients with squamous cell carcinoma of the cervix had pretreatment measurement of serum levels of tissue polypeptide antigen (TPA) and squamous cell carcinoma antigen (SCC) to assess their prognostic value. Both markers were of prognostic significance in relation to stage, recurrence, and poor survival. The addition of TPA to SCC did not increase the percentage of patients with elevated pretreatment tumor marker level nor improve the prognostic significance. One hundred thirty-five of these patients also had serial assay of both markers during follow-up. Rise from normal or persistently elevated markers after treatment was associated with recurrence. The median lead time to recurrence was 2 months for SCC and 2.5 months for TPA. The addition of TPA to SCC in serial monitoring increased the sensitivity of detection of recurrence but decreased its specificity. The cost of assay of two markers over one may not justify the slight improvement in sensitivity of detection of recurrence. For squamous cell carcinoma of the cervix, SCC is a better tumor marker than TPA.

Adult↗
PubMed1994

Detection of heterozygous XY complete hydatidiform mole by chromosome in situ hybridization.

Complete hydatidiform mole has a substantial risk of developing persistent gestational trophoblastic disease (PTD). Whether heterozygous complete moles, arising from dispermy, have a higher risk of such progression than their homozygous counterparts is controversial. In this study, the frequency of heterozygous XY complete mole in 93 consecutive cases of histologically proven complete moles managed in Hong Kong was assessed by the technique of chromosome in situ hybridization (CISH) using DNA probes specific for the short arm of the Y chromosome. The incidence of Y-chromosome positive complete mole in the groups of patients with spontaneous remissions and the group with PTD with or without metastasis was also compared. The presence of Y chromosome was identified in 6 of the 93 cases (6.5%), and this incidence fell within the range reported in the world literature. Of these 93 patients, 5 patients defaulted follow-up, while 10 patients developed PTD, with evidence of metastasis in 2 of them. The presence of Y chromosome was also assessed in another 15 patients with documented metastatic PTD. It was found that CISH signals for Y chromosome were identified in 5.1% (4/78) of complete moles with spontaneous remission and 8% (2/25) with PTD with or without metastasis (P > 0.05). Y chromosome was detected in 5.9% (1/17) of the complete moles that developed metastasis and in 5.8% (5/86) of the complete moles that either developed spontaneous remission or developed nonmetastatic PTD (P > 0.05). There is no correlation between the presence of Y chromosome and development of persistent gestational trophoblastic disease.

Female↗