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C W Chan

Publications and source records attributed to C W Chan.

At least 37 records · Page 2Linked to original sources
PubMed2001

Traveling through the cancer trajectory: social support perceived by women with gynecologic cancer in Hong Kong.

A qualitative research design was selected to gather data on the experiences of social support for Chinese women with gynecologic cancer. Eighteen women were recruited and interviewed at an oncology unit of a teaching hospital in Hong Kong. Content analysis of the interview data showed Chinese women with gynecologic cancer placed enormous emphasis on their human relationships. Family members were especially significant to them although not all identified their family relations as satisfactory or helpful. Their social network comprised 4 major sources, including family and friends, work and colleagues, health professionals, and religion and spiritual beliefs. Each network offered significant reciprocal relations, authoritative relations, or entrusting relations. The positive appraisal of the support function was linked to the Chinese value of food, work ethics, the Confucian and religious philosophy, whereas negative aspects of support, such as the stress of maintaining relationships and inadequate information, conjoined with the Chinese suppression of emotion and the busyness of health professionals. Future studies, including social relations as a determinant, should ensure a broad and multifunctional view of social support and acknowledge the cultural influences on the perspective of support.

Adaptation, Psychological↗
PubMed2000

Quality of life in Chinese women with gynaecological cancers.

Sixty-two Hong Kong Chinese women with gynaecological cancers participated in this cross-sectional study to assess their quality of life (QOL). Chinese versions of the World Health Organisation Quality of Life Measure--abbreviated version, the Profile of Mood States, and the Sexual Relationships subscale of the Psychosocial Adjustment to Illness Scale were used. Qualitative data were collected about the meaning of QOL and the areas of life most affected by the cancer and its treatments. The overall QOL was found to be moderate (mean 92.4, SD 16.34), with the domains of psychological health and social relationships most affected. The distressed facets of life were related to pain, dependency, finances, sexuality, psychological health and spirituality. Mobility, accepting one's outlook, social support and "eating" were areas considered by these women to contribute to a better QOL. The meaning of QOL was described in terms of happiness and material resources. The overall mood score was found to be impaired (mean 43.84, SD 32.31), with relatively high scores for depression, anger and tension. Depression could explain 45% of the variance in the QOL. Despite some missing data, sexual relationships among the respondents were moderately affected, with reduced sexual desire and activity. However, the patients' relationships with their husbands were minimally affected, suggesting the men's understanding and support in the cancer trajectory of their wives. Areas of life that may need further support, such as sexual functioning and psychosocial adjustment, could be improved by the use of sex therapy or group support interventions. Limitations of the present study and suggestions for future research are discussed.

Adaptation, Psychological↗
PubMed2000

Risk factors for anastomotic leakage after low anterior resection with total mesorectal excision.

BACKGROUND: This study aims to analyze the risk factors for anastomotic leakage after low anterior resection with the technique of total mesorectal excision (TME). METHODS: From September 1993 to November 1998, 196 patients with rectal cancer from 3 to 12 cm from the anal verge were treated with low anterior resection with TME. The data were entered in a prospective manner, and the factors that might affect anastomotic leakage were analyzed. RESULTS: The mean level of anastomosis was 3.6 cm from the anal verge (range 1 to 5 cm). The leakage rate was 10.2%. Female gender (P = 0.01; 95% confidence interval [CI] 1.3 to 14.3; odds ratio 4.3) and presence of a diversion stoma (P = 0.01; 95% CI 1.4 to 14.2; odds ratio 4.5) were independent significant factors for lower anastomotic leakage. The absence of a stoma was associated with significantly increased leakage in male (P = 0.001) but not in female (P = 0.51) patients. CONCLUSIONS: With low anastomosis after low anterior resection with TME, diversion stoma construction should be performed routinely in men. In women, the need for diversion can be more selective.

Adult↗
PubMed2000

Mechanical characterization of regenerated osseous tissue during callotasis and its related biological phenomenon.

The mechanical characteristics of the regenerated osseous tissue and osteoblastic activities during callotasis were studied using Chinese mountain goat as the animal model. Open osteotomy of the left tibiae was done in 24 goats. Distraction started 6 days after the operation with the rate of 1 mm per day for 4 weeks. The bone regeneration was monitored with serial X-ray films. The tension generated during distraction was measured with the strain gauges mounted on the distraction apparatus. The osteoblastic activities were monitored by measuring plasma bone specific alkaline phosphatase activity. The results showed that the average lengthening was 22.9 +/- 2.8 mm in each animal. The newly formed osseous tissue becomes stiffer during the course of distraction lengthening. The continuous evolution of the tensile behaviour of the newly formed osseous tissue correlates with the plasma bone specific alkaline phosphatase activities. The radiological appearance of a physis like structure took place at 12 mm lengthening. Its appearance corresponds to the changes in the tensile behaviour as well as the biological activities of the osteoblasts and may serve as a useful radiological marker in monitoring the process of callotasis in clinical practice.

Alkaline Phosphatase↗
PubMed2000

Concanavalin A induced apoptosis in murine macrophage PU5-1.8 cells through clustering of mitochondria and release of cytochrome c.

Concanavalin A (ConA), normally a mitogen of T-lymphocytes, was found to be a cell cycle-independent apoptosis-inducing agent in cultured murine macrophage PU5-1.8 cells. This assertion is based on the following observations: (1) ConA increased the number of cells with hypodiploid DNA in a dose dependent manner as revealed by flow cytometry; (2) ConA elicited DNA fragmentation and the cytotoxicity of ConA was suppressed by alpha-D-methylmannoside which blocks the lectin site of ConA; (3) ConA was able to release cytochrome c (cyto c) into the cytosol of PU5-1.8 cells. When isolated mitochondria were incubated with ConA, release of cyto c was observed too. Interestingly, clustering of mitochondria was found in the cytosol under a confocal microscope after ConA treatment. When cells were incubated with ConA-FITC and subsequently with mitotracker red (a probe for mitochondria), co-localization of fluorescence signals was observed. These results suggest that ConA was delivered to the mitochondria, induced mitochondrial clustering and released cyto c. Our results also show that introduction of exogenous cyto c electroporationally into ConA-untreated cells elicited DNA fragmentation. On the other hand, introduction of specific antibody against cyto c into PU5-1.8 cells suppressed the ConA-mediated cell death. Taken together, our results indicate that ConA induced apoptosis in PU5-1.8 cells through mitochondrial clustering and release of cyto c and the release of cyto c was sufficient to elicit apoptosis in PU5-1.8 cells.

Animals↗
PubMed2000

Painful leg and missing pulses: a case report.

Popliteal artery entrapment syndrome (PAES) is a rare but potentially limb threatening anatomical anomaly occurring predominantly in young adults. We report a case of a 14 year old boy who presented with limb threatening ischaemia requiring urgent surgery. The pathology, presentation, and management are discussed.

Acute Disease↗
PubMed2000

Results of revision total knee arthroplasty.

BACKGROUND/AIM OF STUDY: The results of primary total knee arthroplasties have improved over the years but some still fail, requiring revision. Revision total knee arthroplasty is technically more difficult and has not enjoyed the same success rates as the index operation. The aim of this retrospective study was to review the results of revision total knee arthroplasties carried out at our centre. This is the first study in Singapore on revision total knee arthroplasty. METHODS: A retrospective study where 17 patients (18 knees) had been followed up since their revision operations were clinically assessed. Based on the Knee Society Clinical Scoring System, they were assigned separate knee and function scores (each having a maximum possible 100). RESULTS: The mean knee score was 76 (range 35-93), which rates as good. Of the 18 knees, 67% had excellent or good knee scores. By comparison, the mean function score was 56 (range 0-90) which rates as poor and 33% had excellent or good function scores. CONCLUSION: Revision total knee arthroplasty achieves good and excellent results in spite of technical difficulties often associated with the revision operation. The difference in mean knee and function scores emphasises that many other factors such as physical strength and stamina affect function. Nevertheless, 15 patients were able to walk out of their house and around their neighbourhood for varying distances. This satisfied their expectations and the poor mean function score may reflect different expectations of patients overseas from whence this scoring system originated.

Aged↗
PubMed1999

A new multigene family encoding calcium-dependent calmodulin-binding membrane proteins of Paramecium tetraurelia.

Ca2+/calmodulin (CaM) regulates various physiological processes in a wide variety of organisms, metazoa and protists alike. To better understand Ca2+/CaM-dependent processes, particularly those with membrane-associated components, we studied Ca2+/CaM-binding membrane proteins in Paramecium tetraurelia, a unicellular model system. A CaM-binding protein, PCM1 (Paramecium CaM-binding membrane-bound protein), from a detergent-solubilized ciliary membrane fraction was identified and purified through Ca2+-dependent CaM-affinity chromatography. PCM1 has an apparent molecular mass of approx. 65kDa. It binds radiolabeled CaM in blot overlay assays and binds to CaM-affinity columns, both only in the presence of 10 microM or higher Ca2+. Three peptide sequences from PCM1 were obtained, and polymerase chain reaction (PCR) and Southern hybridization experiments were designed accordingly, leading to a partial cDNA clone for PCM1 and the discovery of three homologs: PCM2, PCM3 and PCM4. Amino acid sequences predicted by the full-length coding sequence for PCM3 and partial genes for PCM1, PCM2 and PCM4 are very similar (approx. 85% amino-acid identities). Their sequences indicate that they are hitherto novel proteins with beta/gamma-crystallin domains, cysteine-rich regions and potential CaM-binding domains. These protein motifs are suggested to mediate protein-protein interaction important for Ca2+/CaM signal transduction event(s) through the PCM family of proteins.

Amino Acid Sequence↗
PubMed1999

Prospective evaluation of selective defunctioning stoma for low anterior resection with total mesorectal excision.

Low anterior resection with total mesorectal excision for rectal carcinoma is associated with a high anastomotic leakage rate, and the effectiveness of a defunctioning stoma in preventing anastomotic leakage remains controversial. In this study a policy of selective defunctioning stoma for stapled colorectal anastomosis after low anterior resection with total mesorectal excision in 148 consecutive patients was evaluated prospectively. A defunctioning stoma was performed in 61 patients (41%) considered at high risk of anastomotic leakage. Clinical leakage occurred in 2 patients (3.3%) with a stoma and 11 patients (12.6%) without a stoma (p = 0.047). Among those without a stoma, the leakage rate among male patients (20.9%) was significantly higher than that for female patients (4. 5%) (p = 0.022). Leakage subsided with conservative treatment in the two patients with a stoma, but seven patients without a stoma developed peritonitis requiring laparotomy. No deaths resulted from leakage, and there was one hospital death (0.6%) in the whole group. Median hospital stay was similar with and without a stoma (13.0 vs. 12.0 days) (p = 0.290). Closure of the stoma was associated with no mortality, a morbidity rate of 8.7%, and a median hospital stay of 6. 0 days. In conclusion, a defunctioning stoma is effective in preventing clinical anastomotic leakage after low anterior resection with total mesorectal excision. The relatively high incidence of leakage in the low risk group indicates the difficulty of predicting anastomotic leakage and hence the need for more liberal use of a defunctioning stoma especially in male patients.

Adult↗
PubMed1999

Computerized analysis of lesions in US images of the breast.

RATIONALE AND OBJECTIVES: Breast sonography is not routinely used to distinguish benign from malignant solid masses because of considerable overlap in their sonographic appearances. The purpose of this study was to investigate the computerized analyses of breast lesions in ultrasonographic (US) images in order to ultimately aid in the task of discriminating between malignant and benign lesions. MATERIALS AND METHODS: Features related to lesion margin, shape, homogeneity (texture), and posterior acoustic attenuation pattern in US images of the breast were extracted and calculated. The study database contained 184 digitized US images from 58 patients with 78 lesions. Benign lesions were confirmed at biopsy or cyst aspiration or with image interpretation alone; malignant lesions were confirmed at biopsy. Performance of the various individual features and output from linear discriminant analysis in distinguishing benign from malignant lesions was studied by using receiver operating characteristic (ROC) analysis. RESULTS: At ROC analysis, the feature characterizing the margin yielded Az values (area under the ROC curve) of 0.85 and 0.75 in distinguishing between benign and malignant lesions for the entire database and for an "equivocal" database, respectively. The equivocal database contained lesions that had been proved to be benign or malignant at cyst aspiration or biopsy. Linear discriminant analysis round-robin runs yielded Az values of 0.94 and 0.87 in distinguishing benign from malignant lesions for the entire database and for the equivocal database, respectively. CONCLUSION: Computerized analysis of US images has the potential to increase the specificity of breast sonography.

Adult↗
PubMed1999

Managing caregiver tasks among family caregivers of cancer patients in Hong Kong.

Twenty-nine family caregivers of terminally ill cancer patients in Hong Kong were asked about their perceived difficulty in managing caregiver tasks. Results showed that the level of difficulty in handling the three main aspects of tasks, that is the direct care, intrapersonal tasks, and interpersonal ties, were similar (chi2 = 0.71, P > 0.05). The individual tasks identified as extremely difficult included compensation for personal time (31%), updating knowledge of reimbursement mechanism (20.7%), and emotionally accepting the likelihood of a progressive downward course of illness (17.2%). Mann-Whitney tests indicated that caregivers who had a shorter duration of caregiving experience perceived significantly greater difficulty in direct care (P < 0.05), intrapersonal tasks (P < 0.05), and overall tasks (P < 0.05). These findings indicate the need for the provision of counselling and educational support for these caregivers.

Adaptation, Psychological↗
PubMed1999

Stress associated with tasks for family caregivers of patients with cancer in Hong Kong.

Family caregivers share the strain of cancer and are at risk of physical and psychological symptoms in relation to caregiver stress. This study investigated the relationships between perceived difficulty in managing caregiver tasks and the experience of stress symptoms among 26 family caregivers of terminally ill patients with cancer in Hong Kong. The findings revealed that more stress symptoms were experienced by caregivers who had reported increased difficulty in managing caregiver tasks (rs = 0.64; p < 0.001). Wilcoxon signed-ranks test indicated that psychological stress symptoms, rather than physical symptoms, overwhelmed most of the caregivers (z = -2.15; p < 0.05). There were significantly more negative responses to stress by caregivers who had a shorter duration of experience in providing care. In addition, caregivers who had less education were at higher risk of developing stress (p < 0.01). These findings indicate the need for the provision of support to facilitate the emotional and physical adaptation of caregivers at risk for health problems.

Adult↗
PubMed1999

Enlargement of remaining patella after partial patellectomy in rabbits.

PURPOSE: The purpose was to study the radiographic patellar tendon calcification and evaluate the histology of the healing interface between the patellar tendon and the remaining patella after partial patellectomy. METHODS: We removed the distal one-third of the patella in 24 rabbits. Specimens were harvested at 8, 12, and 24 wk postoperatively (N = 8 each). RESULTS: Histological observation demonstrated that healing interfaces between the patellar tendon and patella were structurally connected by scar tissue. The radiographic patellar tendon calcification next to the healing interface was in fact trabecular bone outgrowth histologically, resulting in an enlargement of the remaining patellar in length from 0.93+/-0.28 mm at week 8, 1.26+/-0.33 mm at week 12, to 2.5+/-1.12 mm at week 24. Metaplasia of the scar tissue observed next to the healing interface of the remaining patellar articular cartilage and the outgrowth of trabecular bone from the remaining patella with healing over time may increase the articular surface of the remaining patella after partial patellectomy. CONCLUSIONS: The remaining patella might be enlarged in length after partial patellectomy because of trabecular bone outgrowth and metaplasia with healing over time. Its theoretical advantages are an increased patellofemoral contact area and a diminished patellofemoral contact pressure following surgery.

Animals↗
PubMed1997

Waddell's nonorganic signs and Minnesota Multiphasic Personality Inventory profiles in patients with chronic low back pain.

STUDY DESIGN: An analysis of clinical data gathered at an orthopedic outpatient clinic is presented. OBJECTIVE: To examine the relationship between Waddell scores and the Minnesota Multiphasic Personality Inventory response patterns. SUMMARY OF BACKGROUND DATA: Waddell's study of nonorganic signs of low back pain showed consistent correlations with Minnesota Multiphasic Personality Inventory scales 1 to 3. METHODS: A Waddell score was obtained from 507 consecutive patients with chronic low back pain to whom an Minnesota Multiphasic Personality Inventory also was administered. The sample was divided into those patients with a high Waddell score (high waddell score = 3 to 5) and those with a low Waddell score (low waddell score = 0 to 2); men and women were scored separately. RESULTS: Among male patients, statistically significant differences were found between the high Waddell score and low Waddell score groups on Minnesota Multiphasic Personality Inventory scales, 1, 3, and 8, but among females, differences were statistically significant only on scale 8. CONCLUSIONS: Correlations between the Waddell score and the first three scales of the Minnesota Multiphasic Personality Inventory were not fully replicated. The difference between the high Waddell and low Waddell groups on scale 8, however, was significant for men and women.

Adult↗
PubMed1997

Studies of the renal action of melatonin: evidence that the effects are mediated by 37 kDa receptors of the Mel1a subtype localized primarily to the basolateral membrane of the proximal tubule.

The pineal hormone melatonin controls circadian behavior of a variety of organs in different species, including humans. However, the precise mechanism (or mechanisms) by which this occurs remains largely unknown. At the cellular level its effects are believed to be mediated via interaction with specific melatonin receptors (MR), which have previously been cloned from human brain (Mel1a) and retina (Mel1b). At the tissue level, MR have been investigated primarily through empirical definition of specific binding sites, but so far there has been little success in biochemical or molecular characterization of native MR. In the kidney, there is strong circumstantial evidence that melatonin affects diurnal variations in renal function, but relatively little is known about the overall glomerular vs. tubular contributions to these effects. The strategy behind the present study was to use a panel of peptide-specific antibodies to identify MR proteins in various tissues, and from a determination of the intrarenal distribution of MR, gain insight into the mechanism by which melatonin might regulate kidney function. We used two peptide-specific antibodies directed against different regions of Mel1a to identify MR. Our results show that the native Mel1a receptor is a 37 kilodalton (kDa) protein in human and rat brain. Further, immunofluorescent studies carried out in guinea pig kidney have revealed that anti-Mel1a antibody is also localized to the basolateral membrane (BLM) of the renal cortical epithelium, especially the early proximal tubule. Immunoblotting of purified BLM fractions from guinea pig renal cortex and small intestine using the two different peptide-specific antibodies reveals the presence of a single peptide-blockable band at 37 kDa. These same BLM fractions also demonstrate the presence of high-affinity 2-[125I]iodomelatonin (125I-MEL) binding sites, with the pharmacological specificity of binding expected of the Mel1a receptor subtype, inhibited by guanosine 5'-O-(3'-thiotriphosphate) (GTPgammaS) and pertussis toxin. We conclude that functional MR in guinea pig kidney and small intestine are of the Mel1a subtype, and are expressed as 37 kDa proteins localized to the BLM and coupled to a pertussis toxin-sensitive G-protein (Gi). This localization strongly suggests that the proximal tubule plays a significant role in mediating the renal action of melatonin.

Animals↗
PubMed1997

Bamboo skewer perforation of the bowel: computed tomography appearances.

A 25-year-old Chinese woman presented with a painful left-lower-quadrant abdominal mass. Computed tomography (CT) demonstrated a dense forked foreign body within an extraluminal mass. A 2.5 cm bamboo skewer surrounded by inflamed omentum was found at laparotomy. Different CT densities of bamboo skewers were obtained when exposed to air, water and 2% Gastrografin in an in vitro experiment. Awareness of the possible variations in appearances of wooden foreign bodies in and around the bowel may aid their CT diagnoses.

Abdominal Muscles↗