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Y Lau

Publications and source records attributed to Y Lau.

At least 19 recordsLinked to original sources
PubMed2002

Breast conservation treatment in Hong Kong-early results of 203 patients: retrospective study.

OBJECTIVE: To study the clinical outcomes of patients with invasive or non-invasive breast cancer after breast conservation treatment. DESIGN: Retrospective study. SETTING: Clinical oncology department of a public hospital, Hong Kong. PATIENTS: Two hundred and three patients who received postlumpectomy radiotherapy at the Pamela Youde Nethersole Eastern Hospital between January 1994 and June 1999. INTERVENTIONS: Adjuvant radiotherapy with or without systemic adjuvant treatment. MAIN OUTCOME MEASURES: Actuarial local control rate, progression-free survival rate, disease-specific survival rate, and cosmetic score. RESULTS: The median follow-up was 3.5 years. Two of the 25 patients with carcinoma in situ only developed local recurrence; the 5-year actuarial local control rate was 91.3%. Among the 178 patients with invasive cancer, seven had a local recurrence and 12 developed distant metastases without local failure. The 5-year actuarial local control, progression-free survival, and disease-specific survival rates for patients with invasive cancer were 95.5%, 85.8%, and 95.2%, respectively. The risk of local recurrence was significantly increased for younger patients (age <40 years) and those with positive final margins. Cosmetic scores were rated good to excellent by 95.6% of patients. CONCLUSIONS: The early clinical outcomes of these patients are comparable to those in large overseas trials, which have demonstrated the equivalence of mastectomy and breast conservation treatment in terms of survival. In addition to mastectomy, with or without breast reconstruction, breast conservation treatment should be offered as an alternative to suitable Chinese women. To maximise local control, further excision or mastectomy is recommended for patients with positive final margins.

Adult↗
PubMed2001

Validation and development of quantitative flow cytometry-based fluorescence in situ hybridization for intercenter comparison of telomere length measurement.

BACKGROUND: Telomeres are highly conserved repeats at the ends of chromosomes that maintain chromosome stability and reflect the replicative potential of cells. Telomere length can be determined by Southern blot hybridization or quantitative fluorescence in situ hybridization (Q-FISH). Recently, two flow cytometry-based (Flow) FISH protocols have been published. METHODS: We compared the telomere length measured by Southern blotting and Flow FISH using standard beads to calibrate and quantify the fluorescence intensity. RESULTS: The telomeric fluorescence of cord blood and peripheral blood mononuclear cells was similar to that reported by other studies. There was a linear relationship between the telomeric fluorescence determined by Flow FISH and the telomere fragment size determined by Southern blotting (r = 0.89; P < 0.001). CONCLUSION: It is important to set up a center-specific curve and select appropriate cell lines for reference. This Q-Flow FISH protocol will facilitate the measurement of telomere length and allow more meaningful comparison of data (in standard fluorescence units or fragment size) between institutes.

Adult↗
PubMed2001

The impact of mastectomy, breast-conserving treatment and immediate breast reconstruction on the quality of life of Chinese women.

BACKGROUND: The psychosocial impact of breast surgery has been extensively studied in the Western population. There is a relative paucity of comparable data in Oriental women who are increasingly affected by cancer of the breast. The present study investigates the effects that different types of breast surgery have on the quality of life of Chinese women. METHODS: Forty-nine Chinese women with early breast cancer were interviewed at 6 months-2 years following their primary surgery (breast-conserving treatment (BCT, 17 patients), mastectomy (15 patients) and mastectomy with immediate breast reconstruction (17 patients)). Aspects of quality of life measured included general psychological well-being, body image, sexual functioning and social functioning. RESULTS: Patients who received BCT had significantly better body image scores compared to mastectomy patients. They were less worried about their appearance, had more freedom in the choice of clothing, felt less upset by the change in their body and felt more accepted by their partners. The three groups did not differ significantly in the other aspects of quality of life measured. CONCLUSIONS: Compared to mastectomy or mastectomy and immediate breast reconstruction, the most significant benefit of BCT is the preservation of a better body image.

Adult↗
PubMed2001

Diagnostic accuracy of vacuum-assisted biopsy device for image-detected breast lesions.

BACKGROUND: Non-palpable breast lesions present diagnostic difficulties. Ultrasound-guided fine-needle aspiration cytology (FNAC) is a common method used to obtain a diagnosis, but FNAC is frequently inconclusive or insufficiently accurate. Recently a vacuum-assisted biopsy device (Mammotome, Ethicon, Endo-surgery, USA) has been introduced. The diagnostic accuracy of this biopsy device was assessed for lesions that were visible on ultrasound. METHODS: Fifty ultrasound-guided mammotome biopsies were performed. All were small breast lesions primarily detected by ultrasound. All received FNAC as initial assessment. Mammotome biopsy was performed whenever the breast lesion was considered indeterminate or if it was considered benign and there were associated risk factors such as a family history of breast cancer. RESULTS: Of 50 mammotome biopsies 45 had benign histology. Three of 45 lesions were excised at the patients' request and were confirmed to be benign. The remaining 42 patients received an ultrasound follow up at 6 months. The lesion size remained static in 39 patients. In three patients the lesion size increased and they were excised and histology was benign. For the four malignancies diagnosed with mammotome biopsy, three patients received definitive treatment and one patient defaulted. There was one failed mammotome biopsy in the present series. CONCLUSIONS: Mammotome biopsy is an acceptable diagnostic method for small breast lesions seen on ultrasound. It reduces the need for open biopsy without compromising diagnostic accuracy.

Adult↗
PubMed2000

Interaction of hCLIM1, an enigma family protein, with alpha-actinin 2.

Enigma proteins are proteins that possess a PDZ domain at the amino terminal and one to three LIM domains at the carboxyl terminal. They are cytoplasmic proteins that are involved with the cytoskeleton and signal transduction pathway. By virtue of the two protein interacting domains, they are capable of protein-protein interactions. Here we report a study on a human Enigma protein hCLIM1, in particular. Our study describes the interaction of the human 36 kDa carboxyl terminal LIM domain protein (hCLIM1), the human homologue of CLP36 in rat, with alpha-actinin 2, the skeletal muscle isoform of alpha-actinin. hCLIM1 protein was shown to interact with alpha-actinin 2 by yeast two-hybrid screening and immunochemical analyses. Yeast two-hybrid analyses also demonstrated that the LIM domain of hCLIM1 binds to the EF-hand region of alpha-actinin 2, defining a new mode of LIM domain interactions. Immunofluorescent study demonstrates that hCLIM1 colocalizes with alpha-actinin at the Z-disks in human myocardium. Taken together, our experimental results suggest that hCLIM1is a novel cytoskeletal protein and may act as an adapter that brings other proteins to the cytoskeleton.

Actinin↗
PubMed2000

Validation of fully automatic brain SPET to MR co-registration.

Fully automatic co-registration of functional to anatomical brain images using information intrinsic to the scans has been validated in a clinical setting for positron emission tomography (PET), but not for single-photon emission tomography (SPET). In this paper we evaluate technetium-99m hexamethylpropylene amine oxime to magnetic resonance (MR) co-registration for five fully automatic methods. We attached six small fiducial markers, visible in both SPET and MR, to the skin of 13 subjects. No increase in the radius of SPET acquisition was necessary. Distortion of the fiducial marker distribution observed in the SPET and MR studies was characterised by a measure independent of registration and three subjects were excluded on the basis of excessive distortion. The location of each fiducial marker was determined in each modality to sub-pixel precision and the inter-modality distance was averaged over all markers to give a fiducial registration error (FRE). The component of FRE excluding the variability inherent in the validation method was estimated by computing the error transformation between the arrays of MR marker locations and registered SPET marker locations. When applied to the fiducial marker locations this yielded the surface registration error (SRE), and when applied to a representative set of locations within the brain it yielded the intrinsic registration error (IRE). For the best method, mean IRE was 1.2 mm, SRE 1.5 mm and FRE 2.4 mm (with corresponding maxima of 3.3, 4.3 and 5.0 mm). All methods yielded a mean IRE <3 mm. The accuracy of the most accurate fully automatic SPET to MR co-registration was comparable with that published for PET to MR. With high standards of calibration and instrumentation, intra-subject cerebral SPET to MR registration accuracy of <2 mm is attainable.

Algorithms↗
PubMed2000

Prevalence of childhood asthma, allergic rhinitis and eczema in Urumqi and Beijing.

OBJECTIVE: To assess the prevalence of asthma and other allergies in children in Urumqi and Beijing, compared with that in Hong Kong. METHODS: A total of 7754 primary school students were randomly selected to participate in the study. Data were collected in 1995-96 using the International Study of Asthma and Allergies in Childhood (ISAAC) protocol for 6- and 7-year-olds. The study design and data quality assurance in all aspects followed the protocol, including the double entry of data. RESULTS: The questionnaire response rate was high (98.9%). Beijing children reported significantly more asthma than those living in Urumqi in three categories: wheezing or whistling in the chest in the past year (6.0%, 95% confidence interval (CI): 5.1-6.9% vs 2.9%, 2.3-3.5%, P < 0.001), sleeping disturbed due to wheezing (1.3%, 0.9-1.7% vs 0.6%, 0.3-0.9%, P < 0. 03) and having experienced asthma ever (10.7%, 9.6-11.8% vs 7.6%, 6. 6-8.6%, P < 0.001). The prevalence of allergic rhinitis (30.0% vs 31. 1% estimated as 12-month nasal symptoms in Beijing and Urumqi, respectively) and eczema (2.8% vs 2.0% recorded as 12-month itchy rash) in the two cities were not significantly different. A similar study was also performed in Hong Kong in 1995 using the same ISAAC protocol. The children in Urumqi and Beijing had fewer (P < 0.05) allergic symptoms compared to those living in Hong Kong (n = 3618). The 12-month prevalence of wheezing, nasal symptoms and itchy rash found in Hong Kong were 9.2% (95% CI: 8.2-10.2%), 35.1% (33.5-36.7%) and 4.2% (3.5-4.9%), respectively. CONCLUSION: : Urumqi, Beijing and Hong Kong represent communities at different stages of westernization and the results from these three cities reflect a worldwide trend for an increasing prevalence of allergies along with westernization. These three cities could assist in identifying risk factors involved in the increase in asthma, allergic rhinitis and eczema.

Asthma↗
PubMed2000

Expression of a candidate gene for the gonadoblastoma locus in gonadoblastoma and testicular seminoma.

The gonadoblastoma locus on the Y chromosome (GBY) predisposes the dysgenetic gonads of XY females to develop in situ tumors. It has been mapped to a critical interval on the short arm and adjacent centromeric region on the Y chromosome. Currently there are five functional genes identified on the GBY critical region, thereby providing likely candidates for this cancer predisposition locus. To evaluate the candidacy of one of these five genes, testis-specific protein Y-encoded (TSPY), as the gene for GBY, expression patterns of TSPY in four gonadoblastoma from three patients were analyzed by immunohistochemistry using a TSPY specific antibody. Results from this study showed that TSPY was preferentially expressed in tumor germ cells of all gonadoblastoma specimens. Additional study on two cases of testicular seminoma demonstrated that TSPY was also abundantly expressed in all stages of these germ cell tumors. The present observations suggest that TSPY may either be involved in the oncogenesis of or be a useful marker for both types of germ cell tumors.

Cell Cycle Proteins↗
PubMed2000

Experience of neoadjuvant chemotherapy for breast cancer at a public hospital: retrospective study.

OBJECTIVE: To review local experience of neoadjuvant chemotherapy in breast cancer. DESIGN: Retrospective study. SETTING: Public hospital, Hong Kong. PATIENTS: Seventeen patients who presented from August 1988 through April 1997 with locally advanced breast cancer, which was treated with neoadjuvant chemotherapy. RESULTS: The clinical response rate was 71% and two of the 12 patients who responded to chemotherapy achieved complete remission. Three patients had their tumours downstaged sufficiently to allow them to undergo breast conservation surgery after neoadjuvant chemotherapy. None of these three patients has so far had a local recurrence of disease. CONCLUSION: Neoadjuvant chemotherapy can achieve a high objective response rate in patients with locally advanced breast cancer and thus enables breast conservation surgery to be performed on patients who are initially not suitable for this procedure.

Adult↗
PubMed1998

Migration of vascular smooth muscle cells is enhanced in cultures derived from spontaneously hypertensive rat.

Migration of vascular smooth muscle cells (SMC) constitutes a common step in neointimal formation which occurs in several vascular diseases. Whether the migratory response of SMC derived from hypertensive animals is different to that of controls may provide a clue to the link between hypertension and atherosclerosis. We examined the migratory responses of SMC from cell cultures and ring explants (thin aortic ring segment) and compared these responses between normotensive and hypertensive rats at two different ages. Both scrape-wound assay and transwell chambers from cultured aortic SMC as well as aortic ring explant cell outgrowth models were employed. The aortae were obtained from male spontaneously hypertensive rats (SHR) and their normotensive counterpart the Wistar-Kyoto rat (WKY) at 5 and 20 weeks of age. Migration was induced by fetal bovine serum or platelet-derived growth factor (PDGF) and migrated cells were counted at different times following stimulation. We found that SMC migration exhibited a high sensitivity to serum (range of ED50: 2.2-3.6%), migration of SMC from 20-week-old SHR exceeded (by 46%, P<0.025) that of SMC from age-matched WKY and the difference became significant as early as 8 h after stimulation by serum. Chemotaxis induced by PDGF (2 h) exhibited similar differences. An elevated migratory response in SHR-SMC was also found in cells derived from 5-week-old rats in whom the blood pressure was normal. In younger animals, cell outgrowth from SHR aortic ring explants also accumulated more cells compared with WKY without a higher growth rate, thus suggesting that SHR-SMC have a higher migratory response ex vivo. In conclusion, aortic SMC migration appeared to be enhanced in various preparations from SHR. This difference also existed in young animals before the elevation of blood pressure occurred and might contribute partly to the role of hypertension as a risk factor for atherosclerosis.

Aging↗
PubMed1998

Mammogram screening of Chinese women in Kwong Wah Hospital, Hong Kong.

The incidence of primary carcinoma of the breast in Hong Kong has been rising. A screening team including radiologists, breast surgeons, cytopathologists, a full-time gynaecologist and mammographers was set up at Kwong Wah Hospital. The screening method includes a clinical breast examination (CBE) and two-view mammography. The target age group is 40-70. A total of 13,033 women were screened from March 1993 to March 1995 and 8504 mammograms were performed. A double reading system was used, with an experienced mammographer as the first reader. The films were then read by radiologists and were reported. All abnormal films and normal films with palpable masses or clinical symptoms were reviewed in a weekly meeting. A total of 113 biopsies were performed including 86 stereotactic-guided fine needle aspirations (FNA) and 27 stereotactic-guided hook-wire biopsies. Four FNA showed malignant cells and another five showed suspicious cells. Eleven hook-wire biopsies showed carcinoma. The benign to malignant ratio of the hook-wire biopsies was 16:11 (< 1.5). The total number of carcinomas disclosed was 42, and 16 of these were not palpable. Four palpable tumours were not detected by mammography. The overall carcinoma of the breast detection rate was 4.94/1000, with a rate of 4.61/1000 for the 40-49-year age group and a rate of 6.46/1000 for the over 50 years of age group. The incidence of ductal carcinoma in situ plus T1 tumours was 2.82/1000.

Adult↗
PubMed1998

The potential impact of breast cancer screening in Hong Kong.

BACKGROUND: Breast cancer is the second most common cancer and cause of death in women from Hong Kong. The Well Women Clinic at Kwong Wah Hospital offers breast cancer screening (physical examination and mammography) for women over 40 years of age. METHODS: Results of screening over a 2-year period revealed an overall malignancy detection rate of 2.6 per 1000 screens with a strong selection bias for symptomatic women. RESULTS: Screening only slightly increased the proportion of stage I cancers detected; of the malignancies detected, a significant percentage were in situ cancers with doubtful effects on breast cancer mortality. Teamwork and communication were useful in keeping a low referral rate to the surgical clinic of 6.1%, as well as a low biopsy rate for mammographic abnormalities. CONCLUSIONS: A re-evaluation of the real risk of breast cancer in young women together with the lack of proven value from screening has suggested a need for reconsideration of offering screening to women 40 years and over in Hong Kong.

Adult↗
PubMed1998

Treatment of metastatic bone pain with tin-117m Stannic diethylenetriaminepentaacetic acid: a phase I/II clinical study.

The physical characteristics of Sn-117m combined with the biodistribution of the compound tin-117m (Stannic, 4+) diethylenetriaminepentaacetic acid (Sn-117m DTPA) suggest that it should be an excellent agent for the palliation of pain from bony metastases. Prior work has established the dosimetry and the safety for the material in human beings. The presence of low-energy conversion electrons should result in the relative sparing of the bone marrow while delivering a high radiation dose to sites of bony metastatic disease. Forty-seven patients with painful bone metastases from various malignancies were treated with Sn-117m DTPA. The patients were assigned to five different dose levels ranging from 2.64 to 10.58 MBq (71-286 microCi) per kg of body weight. Follow-up included review of pain diaries, performance scores, analgesic requirements, blood chemistries, and hematological assessment. Three patients received a second treatment. There was an overall response rate for relief of pain of 75% (range, 60-83%) in the 40 treatments that could be evaluated. No correlation was apparent in this limited series between response rate and the five dose levels used. The relief was complete in 12 patients (30%). The time to onset of pain relief was 19 +/- 15 days with doses < or = 5.29 MBq/kg and 5 +/- 3 days with doses > or = 6.61 MBq/kg. Myelotoxicity was minimal, with only one patient having a marginal grade 3 WBC toxicity. On the basis of our data, Sn-117m DTPA should be an effective and safe radiopharmaceutical for palliation of painful bony metastases. A large-scale trial is warranted to evaluate it in comparison to other similar agents.

Bone Marrow↗
PubMed1996

Antimicrobial susceptibility of clinical isolates of Acinetobacter baumannii.

The in-vitro activity of 18 antimicrobial agents alone or in combination against 248 clinical isolates of Acinetobacter baumannii from Taiwan were tested by agar dilution. The MIC90S of ampicillin, amoxicillin, piperacillin, cefuroxime, cefotaxime, ceftriaxone, gentamicin, and amikacin were at least 128 mu g/ml. Ceftazidime, cefepime, sulbactam, clavulanic acid, and tazobactam presented moderate activity with MIC90S of 32, 16, 16, 32, and 32 mu g/ml, respectively. The increased activity of ampicillin/sulbactam, amoxicillin/clavulanic acid, and piperacillin/tazobactam was due to the intrinsic effect of sulbactam, clavulanic acid, and tazobactam, respectively. Imipenem, meropenem, and ciprofloxacin were the most active antimicrobial agents with MIC90S of 1, 1, and 0.5 mu g/ml, respectively. Nineteen isolates (7.7%) were resistant to all aminoglycosides and beta-lactam antibiotics, except carbapenems and ciprofloxacin. We are concerned about the multidrug resistance of A. baumannii in this study.

Acinetobacter↗
PubMed1996

Immediate breast reconstruction in Chinese women using the transverse rectus abdominis myocutaneous (TRAM) flap.

BACKGROUND: Total mastectomy remains the mainstay of operative treatment for breast cancer mainly because it is preferred by surgeons. The techniques and benefits of reconstructing the amputated breast have been well documented in the medical literature but there have been very few reports on this issue in Chinese women. Immediate breast reconstruction using the transverse rectus abdominis myocutaneous (TRAM) flap in Chinese women suffering from early breast cancer who require mastectomy is summarized. METHODS: Since September 1991, the option of immediate breast reconstruction was offered to all patients less than 60 years of age suffering from early cancer (Tis, T1 or T2) who were not suitable for breast-conserving treatment or who preferred to have a mastectomy. The single-pedicled TRAM flap was used. RESULTS: From September 1991 to September 1994, 27 reconstructions were performed. Partial flap loss occurred in four patients (15%), fat necrosis in three patients (11%) and abdominal bulging in one patient (4%). Operations performed by two teams simultaneously reduced operating time by 1.5 h without increasing the risk of complications. Twenty-one patients (78%) were satisfied or very satisfied with the outcome of reconstruction. CONCLUSIONS: The TRAM flap is a satisfactory method of breast reconstruction in Chinese women. A two-team approach can be employed safely to shorten operative time. Overall patient satisfaction was high.

Adult↗
PubMed1996

Stereotactic fine needle aspiration in the management of mammographic abnormalities detected in breast screening.

BACKGROUND: Fine needle aspiration (FNA) is used routinely in the management of palpable breast lumps; with the implementation of the stereotactic technique its use has been extended to the investigation of mammographic abnormalities. The advent of breast screening means that many mammographic abnormalities will be detected; because routine open biopsy is impractical and undesirable, stereotactic fine needle aspiration becomes the method of choice for investigation. METHOD: Within a 28 month interval, 81 Chinese women underwent stereotactic FNA in Kwong Wah Hospital, Hong Kong. RESULTS: Fifty-one women (62.9%) had a benign cytology result and no further investigations were required. Inconclusive results were obtained in 18.6% of the aspirates. Open biopsy was required in 16 women (19.8%). CONCLUSION: Stereotactic FNA is very useful in the exclusion of malignancy and the avoidance of open biopsy in asymptomatic women who have mammographic abnormalities.

Adult↗