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Biomedical subjects

G W Tang

Publications and source records attributed to G W Tang.

At least 19 recordsLinked to original sources

Continuing professional development--a surrogate for recertification?

Medical practitioners are certified as competent when they graduate from medical schools. They are certified as competent specialists after they have completed the various specialist training programmes. To maintain specialist status, the commonest requirement is mandatory continuing professional development (CPD), and in some places, continuing medical education (CME), which has been perceived by some as inadequate because it is passive, and skills and professionalism are excluded. In order to sustain the standard of medical practice and to assure quality of care, some registration organisations require that recertification be conducted not only through CPD, but written and oral examinations as well. In this manner, the criteria for quality medical care, which are evidence of professional standing, lifelong learning and self-assessment, cognitive functioning and evaluation of performance in practice, are fulfilled. CPD should involve educational activities of the medical practitioner's choice and be capable of enhancing his or her practice at any particular period of time. Well-structured, well-designed and validated CPD can be considered as a surrogate for recertification.

Certification↗

Psychosocial adjustment in gynecologic cancer survivors: a longitudinal study on risk factors for maladjustment.

OBJECTIVE: The objective was to describe the change in psychosocial state over time and to identify risk factors for maladjustment in gynecologic cancer survivors. Awareness of these issues is important for planning supportive care services for cancer patients. METHODS: A longitudinal prospective study of patients with newly diagnosed gynecologic cancer using individual patients as their own control was performed. Patients were interviewed after confirmation of the diagnosis and were reassessed at 6 and 18 months after completion of treatment and with no evidence of recurrent disease. Psychological adjustment was measured by self-rating on self-esteem, outlook on life, self-role, and femininity. Neuroticism and anxiety were assessed using a neuroticism score and the Hamilton Anxiety Scale. Depressive symptoms were questioned directly. Social adjustment was assessed by changes in working capacity or work status, leisure activity, marital relationship, and sexual activity. RESULTS: Seventy-four women participated. Adjustment problems did not occur in the majority of patients. Psychosocial adjustment was different for patients receiving different types of treatments. Improvement in feminism (P = 0.050) and neuroticism (P = 0.010) was observed for patients receiving chemotherapy and deterioration was observed in patients treated with surgery. Deterioration in neuroticism was associated with lower education level (P = 0.032). With religious belief, there was better family support and more significant improvement in social activity (P = 0.038). CONCLUSION: Most patients adapted well. Patients at risk for psychosocial maladjustment include those who are treated surgically, less educated, and without religious belief.

Adolescent↗

The profile of bone mineral density in chinese women: its changes and significance in a longitudinal study.

Bone mineral density (BMD) has been shown to be different in different ethnic groups. When lifestyle and diet evolve, there is a possibility of a change in the normal reference BMD values within an ethnic group over a period of time. As the osteoporotic risk uses the T-score as the bench mark, it is pertinent to evaluate whether such changes do occur. Two measurements, 5 years apart, of the BMD of the spine and the hip were made in a cohort of Chinese women in Hong Kong. A kernel function smoothing method, a nonparametric statistical method, was employed to present the BMD data. The greatest rate of bone loss was found to occur between 50 and 59 years of age, but this rate of loss was reduced from age 60 onwards. The BMD values obtained in these two measurements were different from the previous studies in the same population and were found to be higher at the lumbar spine and neck of femur in women over 65 years of age. Even within the cohort, there seemed to be a reduction in the BMD values of the hip in a span of 5 years, although the differences were statistically insignificant. These studies suggest that BMD values could change in a population for a variety of possible reasons. Hence, the reference BMD values might need to be evaluated at regular intervals for the T-score to be meaningful.

Absorptiometry, Photon↗

The use of the Minimum Data Set. Home Care in a case management project in Hong Kong.

130 hospital-discharged elderly patients received our comprehensive assessment by using a Chinese Minimum Data Set-Home Care (MDS-HC). Our case manager developed and implemented care plans with reference to the computer-generated Clients Assessment Protocols. Results showed that the MDS-HC was sensitive to identify elderly persons' holistic needs, and helpful in formulating all-inclusive care plans.

Aged↗

Evaluation of a new calcaneal quantitative ultrasound system and determination of normative ultrasound values in southern Chinese women.

Quantitative ultrasound (QUS) assessment at the calcaneus has been found to be a safe and reliable method for evaluating skeletal status. The present study aimed at evaluating the precision of the Sahara bone ultrasound densitometer and to determine the normative QUS data in healthy southern Chinese women. Broadband ultrasound attenuation (BUA), speed of sound (SOS) and qualitative ultrasound index (QUI) were determined. The long-term in vitro precision of the Sahara machine over 6 months was 4.6% for BUA and 0.39% for SOS. The short-term in vivo precision was 3.2 +/- 1.3% for BUA, 0.3 +/- 0.2% for SOS and 1.8 +/- 1.0% for QUI. The standardized precision for BUA, SOS and QUI was 4.4, 3.8 and 2.2 respectively. The normative data were determined in 1086 healthy subjects. Postmenopausal women had significantly lower BUA, SOS and QUI levels than the premenopausal women. Significant negative correlations were observed between QUS indices and age. Bone mineral density (BMD) assessments was performed on 349 of these subjects. BUA correlated significantly with lumbar spine BMD (r = 0.326) and femoral neck BMD (r = 0.395). Similar correlations were observed between SOS, QUI and BMD, with r values ranging between 0.446 to 0.522. Despite the fact that Chinese women have significantly lower BMD values than Caucasian women, the mean BUA values for pre- and postmenopausal Chinese women (73 +/- 18 and 59 +/- 18 dB/MHz respectively) were almost the same as those reported for Caucasian women. These normative data will be useful in the assessment of southern Chinese women with fracture risk.

Absorptiometry, Photon↗

Quantitative ultrasound and symptomatic vertebral fracture risk in Chinese women.

Quantitative ultrasound (QUS) is emerging as a simple, inexpensive and noninvasive method for assessing bone quality and assessing fracture risk. We assessed the usefulness of a contact calcaneal ultrasonometer by studying normal premenopausal women (group I, n = 53), normal postmenopausal women (group II, n = 198), and osteoporotic women without (group III, n = 141) and with vertebral fractures (group IV, n = 53). The osteoporotic subjects had a T-score of the spine or hip neck bone mineral density (BMD) <-2.5 based on the local Chinese peak young mean values. When compared with postmenopausal controls, mean broadband ultrasound attenuation (BUA), speed of sound (SOS), and quantitative ultrasound index (QUI) were 26%, 2.1% and 25% lower in women with vertebral fractures (p all <0.005). The correlation coefficients between QUS parameters and BMD of the spine and hip ranged between 0.4 and 0.5. The ability of the QUS to discriminate between patients groups was determined based on the mean value of normal premenopausal women in group I. The mean T-score for women with fractures was -2.87 +/- 1.02 for BUA, -2.54 +/- 0.79 for SOS, -3.17 +/- 0.70 for QUI, -2.65 +/- 0.86 for L2-4 BMD and -2.53 +/- 0.66 for hip neck BMD. After adjustment for age and body mass index, the odds ratio of vertebral fracture was 1.71 (95% CI 1.2-2.6) for each 1 SD reduction in BUA, 2.72 (1.3-5.3) for SOS, 2.58 (1.4-4.6) for QUI, 2.33 (1.6-3.3) for L2-4 BMD, 2.09 (1. 37-3.20) for femoral neck BMD and 1.88 (1.34-2.92) for total hip BMD. The association between the QUS parameters and vertebral fracture risk persisted even adjustment for BMD. The area under the receiver operating characteristic curve for BUA for vertebral fracture was 0. 92, for SOS, QUI, L2-4 BMD and femoral neck BMD was 0.95, and for total hip was 0.91.

Absorptiometry, Photon↗

Prevention of postoperative nausea and vomiting in gynaecological laparotomies: a comparison of tropisetron and ondansetron.

In a randomized, double-blind study, the antiemetic efficacy of a single bolus of tropisetron 5 mg (group T, 37 patients), ondansetron 4 mg (group O, 39 patients) or saline (group C, 45 patients) given at induction was compared in a homogeneous group of 121 patients undergoing gynaecological laparotomy and receiving postoperative patient-controlled intravenous morphine for 24 to 48 hours. Fewer group T and group O patients developed severe nausea compared to group C (P < 0.01, log rank test in Kaplan-Meier analysis). Group T patients also had lower nausea scores than group O at 8 to 16h (P < 0.05). The overall incidences of severe nausea in groups T, O, and C were 5.4%, 17.9%, and 44.4% respectively (P < 0.001, group T vs group C; P < 0.05 group O vs group C). In conclusion, the 5-hydroxytryptamine 3 receptor antagonists tropisetron and ondansetron were superior to placebo in preventing PONV.

Antiemetics↗

Plasma melatonin profile and hormonal interactions in the menstrual cycles of anovulatory infertile women treated with gonadotropins.

The patterns of plasma melatonin, gonadotropins, sex steroids and prolactin were studied in anovulatory infertile females undergoing ovulation induction with hMG/hCG. Melatonin levels were found to fluctuate during the menstrual cycle of these subjects with a nadir at mid-cycle and peak occurring at the early follicular/late luteal phases of the cycle (p < 0.05). Melatonin correlated negatively with estradiol during the follicular phase (r=-0.5180, p < 0.05) and positively with LH (5 + 0.6321, p < 0.05) in the luteal phase, respectively. Correlational analyses by partial and multiple correlations suggest that the effects of estradiol and LH on melatonin in the follicular phase are interdependent whereas the effect of LH on melatonin in the luteal phase is independent of the effects of other hormones. The results suggest that hormonal interactions and phases of the cycle are important variables contributing to the fluctuations in melatonin levels during the menstrual cycle.

Adult↗

Levonorgestrel intrauterine device in the treatment of menorrhagia in Chinese women: efficacy versus acceptability.

Ten Chinese women who had menorrhagia without organic cause and suffered from anaemia were treated with levonorgestrel intrauterine device for a total of 129 woman-months. There was a 54%, 87% and 95% reduction in menstrual blood loss at the first, third and sixth month of treatment when compared with the pretreatment cycle. These percentages of reduction were statistically significant, with p values of 0.004, 0.03 and 0.008, respectively. There was a median increase in menstrual cycle length of 12 days in nine months. Fifteen percent of the menstrual cycles were longer than 60 days. The total bleeding days increased by 4 days at the third menstrual cycles, but reduced to a median of 6 days at 6 months. Seventy-six percent of the menstrual bleeding was in the form of spotting. These Chinese women accepted such menstrual alterations. There was no hormonal side effects. All women preferred the device to hysterectomy. Levonorgestrel intrauterine device appeared to be an effective and acceptable treatment for menorrhagia in perimenopausal Chinese women.

Adult↗

The climacteric of Chinese factory workers.

Chinese factory workers (427) mainly of Fujian origin were found to have few climacteric symptoms. Of these, 65% and 50% reported having no circulatory and nervosity symptoms, respectively. Only 18% of women experienced hot flushes. The climacteric symptoms were more pronounced at the perimenopausal period (P < 0.001) when these women experienced more irregular menstruation. Low socio-economic status and educational level did not have adverse effects on the symptom reporting. High parity and employment may be positive factors in this period of change of life. A majority of women (74%) felt that the climacteric and menopause is a natural process which caused them no concern. Of those who were still menstruating 80% did not anticipate that they would have problems with the climacteric and menopause. These women's different climacteric pattern could be related to their introspective abilities to cope adequately or in an impersonal manner.

Adult↗

Psychosocial study on Hong Kong Chinese with gynecological cancer.

Psychosocial support and adjustment to cancer in 115 Chinese patients with gynecological malignancies were studied by interviews using semi-structured and structured questionnaires before commencement of treatment. Ninety per cent of patients had emotional support with 72% coming from family members, while 77% of the patients said that they were clearly informed of their diagnosis. The majority of our patients (63%) did not wish to see a counsellor. Psychological outcome of the patients was good, with less than 21% having expression of anxiety or depression. Social adjustment was less favorable; 42% of women had a reduction in leisure activity. The majority of married couples maintained a good marital relationship even though 78% had reduction or cessation of their sexual activity. Good emotional support was associated with fewer neurotic symptoms. Though there was no statistical significance demonstrated, the good psychosocial support and the favorable psychological outcome in this group of patients indicated the likelihood of a positive relationship between the two.

Adaptation, Psychological↗

Further acceptability evaluation of RU486 and ONO 802 as abortifacient agents in a Chinese population.

Of 144 consecutive women who requested early induced abortion, 99 (68.7%) and 45 (31.3%) women chose RU486 combined with ONO 802 (medical method) and suction evacuation (surgical method), respectively. Logistic regression analysis of covariates showed that age and marital status were significantly correlated with the acceptability and hence the choice of the medical method. There were also more working women in this medical group. Previous experience of induced abortion had no influence on the current choice of the abortion method. This group of women appeared to have a tendency of treating their disease with medication rather than with surgery if the condition would allow. They expressed fear about surgery. The long induction-abortion interval of three days will have to be tolerated, but the duration of bleeding should be minimised in order to improve the acceptability of the drug. RU486 is an alternative abortion method which should be made widely available.

Abortifacient Agents, Nonsteroidal↗

Lymphocyte subsets and serum immunoglobulins in patients with premature ovarian failure before and after oestrogen replacement.

We have previously demonstrated that in patients with oestrogen deficiency, there was a significant reduction in the ratio of CD4+ to CD8+ lymphocytes. To test our hypothesis that oestrogen deficiency was the cause of the changes in lymphocyte subsets, we have studied the lymphocyte subsets and serum immunoglobulin levels in 35 patients with idiopathic premature ovarian failure before and after oestrogen replacement therapy. Before oestrogen replacement the lymphocyte subsets in peripheral blood were enumerated with indirect immunofluorescence techniques using monoclonal antibodies. The serum immunoglobulins (Ig) G, A and M were measured with nephelometry. After oestrogen replacement therapy, the tests were repeated around day 7-11 of the 2nd, 4th and 24th month. There was no significant change in any of these parameters by the 2nd or 4th months. After 2 years of oestrogen replacement, there was a significant decrease in the percentage of CD8+ cells, a significant increase in the CD4:CD8 ratio and a significant increase in the mean serum IgG concentration. There was no significant change in the other parameters. Our results support the hypothesis that oestrogen deficiency is the cause for the changes in the lymphocyte subsets.

Adult↗

The value of transabdominal pelvic ultrasonography in monitoring of ovulation induction with gonadotropins.

Seventy-five patients with a total of 306 human menopausal gonadotropin treatment cycles over the period 1984-1989 were analysed retrospectively to evaluate the value of transabdominal pelvic ultrasonography in prevention of complications arising from ovulation induction with human menopausal gonadotropins. There were 60 pregnancies giving a pregnancy rate of 19.6% per cycle. There was positive correlation between the number of follicles > or = 14 mm in mean diameter and the incidence and degree of hyperstimulation (p < 0.005) as well as the incidence of multiple pregnancies (p < 0.01). Ultrasonography is a useful adjunct for monitoring in such a program.

Adult↗

Retinoic acid can be produced from excentric cleavage of beta-carotene in human intestinal mucosa.

The hypothesis that retinoic acid (RA) is produced from the excentric cleavage of beta-carotene was tested in human intestinal homogenates in vitro. Significant amounts of RA were identified by HPLC and derivatization after incubation of intestinal mucosal homogenates with retinal, beta-carotene, or beta-apocarotenals at 37 degrees C for 60 min. RA formation was inhibited, in a dose-dependent fashion, when retinal was incubated in the presence of 0.1-3.0 mM citral (3,7-dimethyl-2,6-octadienal) under identical experimental conditions. The formation of RA from both beta-carotene and beta-apocarotenals was dose and time dependent and RA was the major metabolite of both beta-apo-8'-carotenal and beta-apo-12'-carotenal after the incubation. However, citral (0.1 to 4 mM) did not inhibit the formation of beta-apocarotenals and RA from 2 microM beta-carotene (P greater than 0.05), which proves the existence of an excentric cleavage mechanism for beta-carotene conversion into retinoids. Furthermore, RA formation from both beta-apo-8'-carotenal and beta-apo-12'-carotenal in human intestinal homogenate occurred in the presence of citral, which demonstrates that RA can be produced from excentric cleavage of beta-carotene via a series of beta-apocarotenals as intermediates.

Acyclic Monoterpenes↗

Characterization of beta-apo-13-carotenone and beta-apo-14'-carotenal as enzymatic products of the excentric cleavage of beta-carotene.

Two new products from the incubation of beta-carotene with intestinal mucosa homogenates of human, monkey, ferret, and rat were isolated using high-performance liquid chromatography (HPLC). Identification by comparing retention times in HPLC, by monitoring ultraviolet/visible spectra, by reduction to corresponding alcohol, by oxime formation, and by mass spectrometry demonstrated that they are beta-apo-13-carotenone and beta-apo-14'-carotenal. These compounds were not found in incubations done without intestinal homogenates or with disulfiram as an inhibitor. Under standard incubation conditions, these products increased linearly for 60 min and up to a protein concentration of 1.5 mg/mL and increased along with increasing concentrations of beta-carotene. Therefore, they are enzymatic cleavage products from beta-carotene. The formation of the beta-apo-13-carotenone and beta-apo-14'-carotenal provides direct evidence for an enzymatic excentric cleavage mechanism.

Animals↗

Enzymatic conversion of beta-carotene into beta-apo-carotenals and retinoids by human, monkey, ferret, and rat tissues.

Whether the conversion of beta-carotene into retinoids involves an enzymatic excentric cleavage mechanism was examined in vitro with homogenates prepared from human, monkey, ferret, and rat tissue. Using high-performance liquid chromatography, significant amounts of beta-apo-12'-, -10'-, and -8'-carotenals, retinal, and retinoic acid were found after incubation of intestinal homogenates of the four different species with beta-carotene in the presence of NAD+ and dithiothreitol. No beta-apo-carotenals or retinoids were detected in control incubations done without tissue homogenates. The production of beta-apo-carotenals was linear for 30 min and up to tissue protein concentrations of 1.5 mg/ml. The rate of formation of beta-apo-carotenals from 2 microM beta-carotene was about 7- to 14-fold higher than the rate of retinoid formation in intestinal homogenates, and the rate of beta-apo-carotenal production was fivefold greater in primate intestine vs rat or ferret intestine (P less than 0.05). The amounts of beta-apo-carotenals and retinoids formed were markedly reduced when NAD+ was replaced by NADH, or when dithiothreitol and cofactors were deleted from the incubation mixture. Both beta-apo-carotenal and retinoid production from beta-carotene were inhibited completely by adding disulfiram, an inhibitor of sulfhydryl-containing enzymes. Incubation of beta-carotene with liver, kidney, lung, and fat homogenates from each species also resulted in the appearance of beta-apo-carotenals and retinoids. The identification of three unknown compounds which might be excentric cleavage products is ongoing. These data support the existence of an excentric cleavage mechanism for beta-carotene conversion.

Animals↗

A pilot study of acceptability of RU486 and ONO 802 in a Chinese population.

RU486 and ONO 802 in combination have been shown to be effective in early termination of pregnancy. Anecdotal information suggests that Chinese women have been using herbs to induce abortion, believing that such medication and means of abortion is less harmful to the body than surgery. Hence, a medical means of abortion using RU486 and ONO 802 may be the method of choice for some Chinese women. A pilot study involving 42 Chinese women in Hong Kong was conducted to explore the reasons for acceptance or refusal of RU486 and ONO 802 as abortifacient agents. It was found that more single women chose the medical method for abortion, the main reasons being fear of trauma to the body due to surgery and the feeling of having undergone menstrual regulation rather than having had an abortion with the medical method. Those who refused the treatment were worried about the efficacy and side effects of the new drugs and the long induction-abortion interval. There were 3 failures in the medical group of 23 women. All these 23 women were gland they had chosen the medical abortion method. Twenty-one out of the 23 women said they would choose the same abortion method again. The practice of the use of Chinese herbs was not more common in this group of women as compared to women who did not choose this method of abortion.

Abortifacient Agents, Nonsteroidal↗