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Lee PPW, Jiang LP, Wang XC, Chan KW, Tu WW, Lau YL. Severe mycobacterial infections in two pairs of Chinese siblings with interleukin-12 receptor beta1 deficiency. Eur J Pediatr 2008; 167:231-2. [PMID: 17387515 DOI: 10.1007/s00431-007-0430-2] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/16/2006] [Accepted: 01/18/2007] [Indexed: 11/25/2022]
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Wong WCW, Wun YT, Chan KW, Liu Y. Silent killer of the night: a feasibility study of an outreach well-women clinic for cervical cancer screening in female sex workers in Hong Kong. Int J Gynecol Cancer 2008; 18:110-5. [PMID: 17466035 DOI: 10.1111/j.1525-1438.2007.00970.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
The purpose of this study was to see if an outreach model could be a feasible option for early detections of preinvasive cervical cancer in women with double identities of female sex workers (FSW) and illegal migrant workers in Hong Kong who most needed cervical screening but were often deprived of such a service. High turnover rates, acceptability, and compliance for follow-ups could potentially render such a clinical model unsuccessful. A total of 245 FSW were screened at the outreach clinic from January 2004 to December 2005, which was set up in a nongovernmental organization in a red light district. A questionnaire regarding their lifestyles and demographic details was used before a gynecological history, Papanicolaou (PAP) smear, and other health checkup were conducted. Chi-square test and multinomial logistic regression were used to analyze the results. Of 235 women tests, 9.8% of them had CIN I-III, and places of origin were found to be important risk factors for abnormal PAP smears. The nonlocal workers were significantly more likely to have abnormal PAP smears (chi(2)= 10.55, P= 0.04). Among the women, 88.1% of them who had the tests returned for follow-up with poorer compliance among those with an abnormal result. We conclude that an outreach well-women clinic seems to be an acceptable option for these women and an effective way for the early detection of cervical cancer.
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Chan KW, Wu Y, Liu ZF. Solvation and electronic structures of M+Ln, with M+ = Mg+ and Ca+, L = H2O, CH3OH, and NH3, and n = 1–6. CAN J CHEM 2007. [DOI: 10.1139/v07-103] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The solvation clusters M+(L)n, with a singly charged alkaline earth cation Mg+ or Ca+ as the solute and with water, methanol, or ammonia as the solvent, are studied systematically in the size range n = 1–6, to compare the variations in the solvation interactions. For clusters with n ≤ 3, the energies and structural values are compared in details, with both the MP2 and B3LYP methods. For clusters with n ≥ 4, the solute–solvent and solvent–solvent interaction energies are calculated to explain the relative stability among various isomeric structures, and the contrast in both solvent and electron distribution among these cluster series. Thermal stabilities for these clusters are also examined by ab initio molecular dynamics simulations at finite temperature.Key words: solvation clusters, ab initio calculations, solute–solvent interactions, size-dependent effects.
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Ma S, Lee TK, Zheng BJ, Chan KW, Guan XY. CD133+ HCC cancer stem cells confer chemoresistance by preferential expression of the Akt/PKB survival pathway. Oncogene 2007; 27:1749-58. [PMID: 17891174 DOI: 10.1038/sj.onc.1210811] [Citation(s) in RCA: 610] [Impact Index Per Article: 35.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The recent discovery of cancer stem cells (CSCs) has played a pivotal role in changing our view of carcinogenesis and chemotherapy. Based on this concept, CSCs are responsible for the formation and growth of neoplastic tissue and are naturally resistant to chemotherapy, explaining why traditional chemotherapies can initially shrink a tumor but fails to eradicate it in full, allowing eventual recurrence. Recently, we identified a CSC population in hepatocellular carcinoma (HCC) characterized by their CD133 phenotype. However, the molecular mechanism by which it escapes conventional therapies remains unknown. Here, we examined the sensitivity of these cells to chemotherapeutic agents (doxorubicin and fluorouracil) and the possible mechanistic pathway by which resistance may be regulated. Purified CD133+ HCC cells isolated from human HCC cell line and xenograft mouse models survived chemotherapy in increased proportions relative to most tumor cells which lack the CD133 phenotype; the underlying mechanism of which required the preferential expression of survival proteins involved in the Akt/PKB and Bcl-2 pathway. Treatment of CD133+ HCC cells with an AKT1 inhibitor, specific to the Akt/PKB pathway, significantly reduced the expression of the survival proteins that was normally expressed endogenously. In addition, treatment of unsorted HCC cells with both anticancer drugs in vitro significantly enriched the CD133+ subpopulation. In conclusion, our results show that CD133+ HCC cells contribute to chemoresistance through preferential activation of Akt/PKB and Bcl-2 cell survival response. Targeting of this specific survival signaling pathway in CD133+ HCC CSCs may provide a novel therapeutic model for the disease.
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Sleight BS, Chan KW, Braun TM, Serrano A, Gilman AL. Infliximab for GVHD therapy in children. Bone Marrow Transplant 2007; 40:473-80. [PMID: 17618323 DOI: 10.1038/sj.bmt.1705761] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
GVHD remains a significant complication of allogeneic hematopoietic stem cell transplantation. Tumor necrosis factor-alpha (TNF-alpha) is a major mediator of GVHD pathogenesis. Infliximab inhibits the binding of TNF-alpha with its cellular receptors and has been associated with encouraging responses in adults with severe GVHD. We retrospectively evaluated the efficacy and safety of infliximab 10 mg/kg i.v. once a week for a median of eight doses (range 1-162) in 24 children with steroid-resistant GVHD. The overall response rate in 22 evaluable children was 82% (12 CR+6 PR). Among those patients with acute GVHD, both skin and gastrointestinal involvement responded well to infliximab; however long-term outcome was poor. While infliximab may be useful to acutely control GVHD manifestations, GVHD recurs commonly upon discontinuation of infliximab. Within 100 days of the final infliximab dose, 77% of patients had bacterial infections, 32% had viral infections and 13.6% had probable or proven non-candidal invasive fungal infections. Infliximab appears to be well-tolerated and to have activity in steroid-resistant GVHD. Controlled studies to assess the pharmacokinetics and most effective dosing regimen of infliximab for the treatment of GVHD are warranted.
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Leung KM, Yeoh GPS, Chan KW. Breast pathology in complications associated with polyacrylamide hydrogel (PAAG) mammoplasty. Hong Kong Med J 2007; 13:137-40. [PMID: 17406041] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/14/2023] Open
Abstract
OBJECTIVE To study the tissue pathology of breast lesions associated with hydrophilic polyacrylamide gel injection augmentation mammoplasty. DESIGN Retrospective study. SETTING Private anatomical pathology practice, Hong Kong. PATIENTS Eight patients who underwent lumpectomy of the breast due to complications of hydrophilic polyacrylamide gel injection for augmentation mammoplasty. MAIN OUTCOME MEASURES Identification of hydrophilic polyacrylamide gel in breast tissue and associated pathological changes. RESULTS We reviewed the pathological changes in breast tissue associated with hydrophilic polyacrylamide gel injection in eight cases retrieved from our archive. Microscopically, the hydrophilic polyacrylamide gel appeared as pools of pale violet gelatinous material of variable size, between the interstices of connective tissue and fat cells. The larger pools were often surrounded by cellular reactions consisting of histiocytic cells and foreign body-type multinucleated giant cells. Inflammatory reaction featuring infiltration by lymphocytes and plasma cells in the adjacent breast tissue was observed in samples from four patients, and a sample from another patient showed acute inflammation with abscess formation. There was no evidence of abnormal cellular proliferation, atypia or malignant change in the stromal connective tissue or ductal-acinic epithelial components of the breast tissue. CONCLUSIONS Hydrophilic polyacrylamide gel injection for augmentation mammoplasty can give rise to a breast lump and inflammation. Pathologically, this complication is associated with fibrosis, foreign body reaction, and inflammation.
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Yeoh GPS, Chan KW. Fine-needle aspiration cytology of the thyroid: screening or diagnostic test? Hong Kong Med J 2007; 13:169. [PMID: 17406053] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/14/2023] Open
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Lam MF, Au WY, Tse KC, Chan TM, Chan GSW, Chan KW, Lai KN. Late onset membranous nephropathy complicating donor lymphocyte infusion for leukaemia relapse after allogeneic stem cell transplantation. Am J Hematol 2007; 82:327-8. [PMID: 17177190 DOI: 10.1002/ajh.20788] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Leung KM, Chan KW, Yeoh GPS, Chan JKC, Cheung PSY. Positive non-sentinel lymph nodes in breast cancer. Hong Kong Med J 2007; 13:167-8. [PMID: 17406050] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/14/2023] Open
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Ma S, Guan XY, Beh PSL, Wong KY, Chan YP, Yuen HF, Vielkind J, Chan KW. The significance of LMO2 expression in the progression of prostate cancer. J Pathol 2007; 211:278-85. [PMID: 17167821 DOI: 10.1002/path.2109] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
LIM domain only 2 (LMO2) proteins are important regulators in determining cell fate and controlling cell growth and differentiation. This study has investigated LMO2 expression in human prostatic tissue specimens, prostate cancer cell lines, and xenografts; and has assessed the possible role and mechanism of LMO2 in prostate carcinogenesis. Immunohistochemical analysis on a tissue microarray consisting of 91 human prostate specimens, including normal, prostatic hyperplasia, high-grade prostatic intraepithelial neoplasia, and invasive carcinoma, revealed that overexpression of LMO2 was significantly associated with advanced tumour stage, as measured by Gleason score (p = 0.012), as well as with the development of distant metastasis (p = 0.018). These data were supported by quantitative real-time PCR experiments, where LMO2 mRNA levels were found to be significantly higher in prostate tumour specimen than in normal epithelium (p = 0.037). The expression of LMO2 in cell lines and xenografts representing androgen-dependent (AD) and androgen-independent (AI) prostate cancer stages was further studied. Consistent with the in vivo data, LMO2 mRNA and protein were found to be overexpressed in the more aggressive AI cells (PC3, DU145, and AI CWR22 xenografts) compared with less aggressive AD cells (LNCaP and AD CWR22 xenografts). Furthermore, stable introduction of LMO2 into LNCaP cells conferred enhanced cell motility and invasiveness in vitro, accompanied by down-regulation of E-cadherin expression. Taken together, these findings provide the first evidence to support the hypothesis that LMO2 may play an important role in prostate cancer progression, possibly via repression of E-cadherin expression.
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Leung KM, Chan KW, Yeoh GPS, Chan JKC, Cheung PSY. Clinical relevance of intra-operative sentinel lymph node examination in breast cancer management. Hong Kong Med J 2007; 13:8-11. [PMID: 17277385] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/13/2023] Open
Abstract
OBJECTIVES To determine the sensitivity, accuracy, and clinical relevance of intra-operative examination of sentinel lymph nodes in breast cancer management. DESIGN Retrospective study. SETTING Private anatomical pathology practice. PARTICIPANTS Three hundred breast cancer patients who underwent axillary sentinel lymph node biopsies for intra-operative assessment between January 2004 and March 2006. MAIN OUTCOME MEASURES Correct identification of metastatic carcinoma in sentinel lymph nodes during intra-operative examination, sparing patient a second surgery. RESULTS The intra-operative diagnosis of sentinel lymph node biopsies from 300 consecutive patients were compared with the final pathological diagnoses. The final pathology results showed metastatic carcinoma in 74 patients, of whom 63 (85%) were correctly diagnosed during frozen section examination. There was no false-positive case (positive predictive value 100%). The sensitivity for detecting macro- and micro-metastases were 95% and 50%, respectively (P<0.01). The sensitivity for detecting metastases in T1 and T2/above tumours were 72% and 90%, respectively (P<0.05). CONCLUSIONS Intra-operative examination is a reliable and sensitive method for the detection of sentinel lymph node metastasis. Eighty-five percent of the patients with metastatic disease were correctly diagnosed and spared a second operation for axillary dissection. The disadvantage of missing a positive lymph node is by far outweighed by the advantage of a single stage operation in case of a positive diagnosis. The benefit of intra-operative examination was slightly less in patients with smaller tumours.
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Leung CC, Yew WW, Law WS, Tam CM, Leung M, Chung YW, Cheung KW, Chan KW, Fu F. Smoking and tuberculosis among silicotic patients. Eur Respir J 2007; 29:745-50. [PMID: 17182648 DOI: 10.1183/09031936.00134706] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
The aim of the present study was to investigate the relationship between smoking and tuberculosis (TB) among high-risk silicotic patients in Hong Kong. A cohort of 435 silicotic patients tuberculin tested from 1995-2002 was prospectively followed-up until the end of 2005. Baseline characteristics were analysed with respect to positive tuberculin reaction (> or =10 mm) at baseline and subsequent development of TB. Smoking, alcohol use and body mass index were independent predictors of positive tuberculin reaction at baseline in multiple logistic regression analysis. Total cigarette pack-yrs did not demonstrate any significant effect. The annual incidences of TB were 1,841, 2,294 and 4,181 per 100,000 for never-, ex- and current smokers, respectively. On Cox proportional hazard analysis, current smokers have a significantly higher risk of TB than other silicotic patients (adjusted hazard ratio (95% confidence interval (CI)): 1.96 (1.14-3.35)) after controlling for age, alcohol use, tuberculin status, treatment for latent TB infection and other relevant background/disease factors. A significant dose-response relationship was also observed with the daily number of cigarettes currently smoked. Smoking cessation may reduce 32.4% (95% CI: 6.5-54.0) of the risk. Smoking increases the risk of both tuberculosis infection and subsequent development of the disease among silicotic patients.
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Panesar NS, Chan KW. Evidence for nitrite reductase activity in intact mouse Leydig tumor cells. Steroids 2006; 71:984-92. [PMID: 16952382 DOI: 10.1016/j.steroids.2006.07.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/15/2006] [Revised: 07/21/2006] [Accepted: 07/25/2006] [Indexed: 10/24/2022]
Abstract
Nitric oxide (NO) supposedly derived via L-arginine-NO synthase (NOS) pathway has been implicated in inhibiting steroidogenesis by binding the heme moiety of steroidogenic enzymes. Previously, nitrite, and to a lesser extent nitrate ions inhibited steroidogenesis via NO by hitherto unknown reduction mechanism. Recently, a putative mammalian nitrite reductase activity ascribed to complex III of mitochondrial respiratory chain complexes (MRCC) has been reported, where MRCC inhibitors reduced NO production from nitrite variably. We thus studied the effects of MRCC inhibitors on testosterone production in mouse Leydig tumor cells (MLTC-1) without (basal) or with human chorionic gonadotropin (hCG) stimulation. In stimulated MLTC-1, MRCC inhibitors decreased testosterone production, order being: complex III (antimycin A and myxothiazol) > complex I (rotenone) > complex II (thenoyltrifluoroacetone), while cAMP production increased inversely. In unstimulated MLTC-1, MRCC inhibitors in same order, increased basal testosterone production, which correlated inversely with the percentage inhibition of NO production, with one exception; while antimycin A did not inhibit NO production in the nitrite reductase study mentioned above, it increased basal testosterone production in the present study. While MLTC-1 expressed mRNA for endothelial and neuronal, but not inducible NOS, various stimulators and inhibitors of L-arginine-NOS pathway had no effect on basal testosterone production in MLTC-1 or fresh Balb/c Leydig cells. Moreover, hCG increased nitrate uptake into MLTC-1, which suggests the gonadotropin aids nitrite and nitrate ions in their steroidogenesis inhibitory activity. In conclusion, this study supports the existence of a surrogate mammalian nitrite reductase and the dormancy of L-arginine-NOS pathway in MLTC-1.
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Petropoulos D, Worth LL, Mullen CA, Lockhart S, Choroszy M, Chan KW. Interferon-α after autologous stem cell transplantation in pediatric patients with advanced Hodgkin's lymphoma. Bone Marrow Transplant 2006; 38:345-9. [PMID: 16915224 DOI: 10.1038/sj.bmt.1705458] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Thirteen children with refractory or recurrent Hodgkin's lymphoma (HL) received high-dose chemotherapy and autologous hematopoietic stem cell transplant (ASCT). After hematologic recovery, 10 patients were given interferon-alpha (IFN-alpha) as adjuvant therapy, starting at a dose of 0.5 x 10(6) U/m2 subcutaneously, three times a week. The dose was escalated as tolerated. Patients were treated for a median of 12 (4-24) months. Transient myelosuppression was the most common toxicity and led to temporary treatment interruption in five patients. The IFN-alpha dose was increased in nine patients, to a median final dose of 3.5 x 10(6) U/m2/week. With a median follow-up of 67 (range 25-114) months, nine of the 10 patients are alive and in continuous remission. One patient relapsed. Three patients were not treated with IFN-alpha initially, two because of rapidly progressive disease. One patient received IFN-alpha for treatment of relapse after transplant, and is alive in remission 10 years later. IFN-alpha has activity in children with advanced HL, and prolonged, low-dose treatment given after ASCT can be tolerated. Its therapeutic effect as a post-transplant adjuvant warrants further investigation.
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Chan GSW, Tse KC, Lam MF, Chan KW. Thrombotic microangiopathy in an allograft kidney: a diagnostic challenge. Histopathology 2006; 48:775-6. [PMID: 16681703 DOI: 10.1111/j.1365-2559.2006.02338.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Panesar NS, Chan KW, Li CY, Rogers MS. Status of anti-thyroid peroxidase during normal pregnancy and in patients with hyperemesis gravidarum. Thyroid 2006; 16:481-4. [PMID: 16756470 DOI: 10.1089/thy.2006.16.481] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Autoimmune thyroid diseases (AITD) comprising Hashimoto's thyroiditis, primary myxedema, and Graves' disease are associated with autoantibodies directed against thyroglobulin and thyroid peroxidase (anti-TPO). Anti-TPO occur in 10% of pregnant women, half of whom reportedly develop postpartum thyroid dysfunction. We recently published data on the thyroid function reference ranges in pregnant Chinese but the AITD status of our cohort was unknown. In view of this missing information we have measured anti-TPO in specimens from our cohort stored at -80 degrees C, and compared these to those of patients with hyperemesis gravidarum (HG) and nonpregnant controls. After eliminating 3 outliers from 47 nonpregnant controls, the anti-TPO concentration range was 2.2-14.7 kIU/L (n = 44). In 282 pregnant control subjects, the anti-TPO levels were less than 14.7 kIU/L (upper limit of nonpregnant controls) in 189 (67%); between 14.7-55 kIU/L in 82 (29.1%); and greater than 55 kIU/L in 11 (3.9%). The percentage of women with anti-TPO greater than 14.7 kIU/L during the first, second, and third trimesters were 47% (30/64), 39% (49/126), and 16% (15/92), respectively. Anti-TPO level was significantly higher in pregnant controls compared to nonpregnant controls and patients with HG. With reference to other studies in which anti-TPO levels greater than 60 kIU/L were considered pathologic, we conclude that more than 96% of our pregnant controls were without AITD and the data on thyroid function reference ranges we previously reported remain valid.
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Feng HC, Tsao SW, Ngan HYS, Kwan HS, Shih SM, Xue WC, Chiu PM, Chan KW, Cheung ANY. Differential Gene Expression Identified in Complete Hydatidiform Mole by Combining Suppression Subtractive Hybridization and cDNA Microarray. Placenta 2006; 27:521-6. [PMID: 16026829 DOI: 10.1016/j.placenta.2005.05.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/24/2005] [Revised: 05/09/2005] [Accepted: 05/10/2005] [Indexed: 11/21/2022]
Abstract
Complete hydatidiform mole (CHM) is a type of gestational trophoblastic disease with pure paternal chromosome contribution and unpredictable malignant potential. As an attempt to assess the molecular pathogenesis of CHM, suppression subtractive hybridization (SSH) combined with cDNA microarray was used to compare the gene expression pattern of CHM compared with normal first-trimester placenta of similar gestational ages. cDNA microarray analysis using tissue-specific chips constructed with subtracted cDNA libraries identified 13 differentially expressed gene transcripts. Quantitative real-time polymerase chain reaction (PCR) confirmed up-regulation of human chorionic gonadotropin beta subunit (CGB) (P=0.0008) and KIAA1200 (P=0.0005), a G-protein regulator, as well as down-regulation of osteopontin (SPP1) (P<0.0001) in 14 genotyped CHM when compared with 15 normal placentas. These candidate genes may contribute toward understanding the mechanism involved with the development and progression of CHM.
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Chan KW, Lee PY, Lam AKY, Law S, Wong J, Srivastava G. Clinical relevance of Fas expression in oesophageal squamous cell carcinoma. J Clin Pathol 2006; 59:101-4. [PMID: 16394289 PMCID: PMC1860271 DOI: 10.1136/jcp.2005.027508] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
AIMS To determine the extent of Fas expression in oesophageal squamous cell carcinomas (ESCCs) from Chinese patients and to correlate Fas expression with clinicopathological prognostic parameters. METHODS Clinicopathological data were collected from 58 patients with ESCC who underwent oesophagectomy and had no prior radiotherapy or chemotherapy. Immunostaining was performed on the primary tumours. Expression of Fas was correlated with patients' demographics, tumour characteristics and stage, R category of surgery, and patients' survival. RESULTS The actuarial survival rates of all patients at two and five years after surgery were 48% and 14%, respectively. Fas expression was detected in 89.7% of ESCCs. Higher Fas expression recorded on a four point scale correlated with better tumour differentiation (p < 0.01), but not with other patient or tumour variables. Importantly, higher Fas expression was associated with better survival (p = 0.0317). CONCLUSIONS These findings suggest that Fas activated apoptosis is important in the pathogenesis of ESCC. This molecular pathway may be a potential therapeutic target for ESCC.
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Chiu PM, Feng HC, Benbrook DM, Ngan HYS, Khoo US, Xue WC, Tsao SW, Chan KW, Cheung ANY. Effect of all-trans retinoic acid on tissue dynamics of choriocarcinoma cell lines: an organotypic model. J Clin Pathol 2006; 59:845-50. [PMID: 16461808 PMCID: PMC1860458 DOI: 10.1136/jcp.2005.025833] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
BACKGROUND All-trans retinoic acid (ATRA) is a natural vitamin A derivative that has a profound effect on the regulation of cell growth, differentiation and death. AIM To investigate the tissue dynamic and cellular invasion effects of ATRA in choriocarcinoma (CCA), an aggressive trophoblastic tumour, by using a three-dimensional organotypic culture model system and cell invasion assay, respectively. METHODS An organotypic culture model of two CCA cell lines, JAR and JEG, was established. The effects of 1 microM ATRA on proliferation, differentiation and apoptosis on this CCA model were assessed by morphological assessment of the mitotic and apoptotic figures as well as by Ki-67 and caspase-related M30 cytoDeath antibody immunohistochemistry and the terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end labelling (TUNEL) assay. The effect of ATRA on p53 and its regulated protein product, WAF1/Cip1, was also evaluated with DO7 and p21(WAF1) antibodies, respectively. Moreover, the effect of ATRA on cellular (CCA) invasion was also investigated with Cell Invasion Kit on the JEG cell line. RESULTS ATRA was found to induce marked apoptosis in organotypic cultures of both cell lines, as evidenced by increased M30-positive cells (p<0.0001) and increased TUNEL-positive cells (p<0.0001) in treated cultures; to decrease proliferation, as evidenced by decreased Ki-67-positive cells (p<0.0001); and to decrease p53-DO7 immunoreactivity (p<0.0001) and increase p21(WAF1) (p<0.0001) immunoreactivity. 1.5 microM ATRA was found to effectively inhibit JEG cell invasion in the cell invasion assay. CONCLUSION ATRA treatment was found to inhibit invasion and proliferation and enhance apoptosis, probably by the activation of caspases and induction of differentiation. ATRA and synthetic retinoids may be alternative agents for the treatment of CCA.
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Petropoulos D, Worth LL, Mullen CA, Madden R, Mahajan A, Choroszy M, Ha CS, Champlin RC, Chan KW. Total body irradiation, fludarabine, melphalan, and allogeneic hematopoietic stem cell transplantation for advanced pediatric hematologic malignancies. Bone Marrow Transplant 2006; 37:463-7. [PMID: 16435013 DOI: 10.1038/sj.bmt.1705278] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
We evaluated the efficacy and toxicity of adding 9 Gy of total body irradiation (TBI), in three single daily fractions of 3 Gy, to the reduced intensity regimen of fludarabine 30 mg/m2 i.v. x 4 days and melphalan 140 mg/m2 i.v. x 1 day in advanced pediatric hematologic malignancies. Twenty-two acute lymphoblastic leukemia (ALL), six acute myeloid leukemia (AML), and one non-Hodgkin lymphoma patients were transplanted. Of these, 13 were beyond second remission, and five had prior hematopoietic stem cell transplant (HSCT). Twenty-one donors were unrelated, of which 19 were from cord blood (CB) units. Three of the eight related donors were genotypically disparate. Oral mucositis and diarrhea were the most common toxicities. Twenty-seven patients achieved neutrophil engraftment (median 16 days), and 23 had platelet engraftment (median 42 days). One patient had primary graft failure. Seven patients died of non-relapse causes in the first 100 days. With a median follow-up of 52 months, seven of 22 ALL, five of six AML, and one of one lymphoma patients are alive and in remission. The regimen of TBI, fludarabine, and melphalan allows the engraftment of allogeneic hematopoietic stem cells (including mismatched CB). It was fairly well tolerated in pediatric patients, even for second transplants. Its efficacy requires further evaluation.
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Abstract
AIMS Our goal was to define the spectrum of glomerular diseases in allograft kidneys and to correlate them with clinical parameters. METHODS Eight hundred ninety-one renal graft biopsies and 43 graft nephrectomies from 1980 to 2004 were obtained from 442 allografts transplanted to 425 patients. RESULTS Glomerular diseases were diagnosed in 33% of kidney grafts. Indications for biopsy were baseline assessment (23 biopsies, 2.5%); renal dysfunction (790 biopsies, 88.7%); proteinuria (154 biopsies, 17.3%); hematuria (11 biopsies, 1.2%); and study protocol (four biopsies, 0.4%). The median time to take a biopsy was less than 8 months posttransplant. The mean time posttransplant when the biopsy diagnosis was made was 70 months for IgA nephropathy (IgAN); 66 months for transplant glomerulopathy (TG); 65 months for focal segmental glomerulosclerosis (FSG); 55 months for mesangiocapillary glomerulonephritis (MCGN); 45 months for membranous glomerulonephritis (GN); 49 months for mesangial proliferative GN; and 101 months for diabetic nephropathy. Recurrent glomerular disease was documented in 31 (7.0%) grafts. Specific glomerular diseases were diagnosed by biopsies in 106 (89.1%) of 119 proteinuric allografts. CONCLUSIONS Glomerulopathy was common in allografted kidneys. IgAN, TG, FSG, mesangial proliferative GN, and membranous GN were the majority. A higher proportion of grafts from donors related to the recipients than from unrelated donors showed IgAN (P < .05), suggesting that genetic factors might play a role in the pathogenesis of IgAN. Recurrence of glomerulopathy underlying ESRD was frequent for IgAN, FSG, and MCGN, but this was rarely seen in membranous GN.
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Chan KW, Chan GSW. Glomerular Pathology of Allograft Kidneys. Int J Organ Transplant Med 2005. [DOI: 10.1016/s1561-5413(09)60208-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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Lui SL, Chan KW, Tsang R, Yung S, Lai KN, Chan TM. Effect of Rapamycin on Renal Ischemia Reperfusion Injury. Int J Organ Transplant Med 2005. [DOI: 10.1016/s1561-5413(09)60183-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
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74
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Tang SCW, Lai FMM, Lui YH, Tang CSO, Kung NNS, Ho YW, Chan KW, Leung JCK, Lai KN. Lamivudine in Hepatitis B-associated Membranous Nephropathy. Int J Organ Transplant Med 2005. [DOI: 10.1016/s1561-5413(09)60200-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
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75
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Xue WC, Feng HC, Chan KYK, Chiu PM, Ngan HYS, Khoo US, Tsao SW, Chan KW, Cheung ANY. Id helix-loop-helix proteins are differentially expressed in gestational trophoblastic disease. Histopathology 2005; 47:303-9. [PMID: 16115231 DOI: 10.1111/j.1365-2559.2005.02190.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
AIMS To assess the expression of Id proteins in trophoblastic tissues and to correlate this with clinical parameters, proliferative and apoptotic indices as well as to related oncogene expression. METHODS AND RESULTS Immunohistochemistry for Id1, Id2, Id3 and Id4 was performed on 83 trophoblastic tissues including 17 normal first-trimester placentas, seven term placentas, 47 hydatidiform moles (HM), and 12 spontaneous miscarriages. The four Id proteins were predominantly expressed in the villous and implantation site intermediate trophoblast. Expression of Id1 in HM was significantly higher than that in normal placenta (P = 0.0006) and spontaneous miscarriage (P = 0.0001) but did not correlate with subsequent development of gestational trophoblastic neoplasia (GTN). Id1 expression correlated with the proliferation index as assessed by MCM7 (P = 0.003) and Ki67 (P = 0.017) and with the apoptotic activity assessed by TUNEL (P = 0.001) and M30 CytoDeath antibody (P = 0.013). Moreover, the expression of Id1 correlated with the expression of p53 (P = 0.004), p21(WAF1) (/CIP1) (P = 0.003) but not with p16 (P = 0.107). CONCLUSIONS Id proteins may play a role in the regulation of proliferative and apoptotic activity in trophoblastic tissue and are potentially useful in differentiating molar and non-molar gestation, but are not helpful in predicting GTN.
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Wong KK, Chan KW, Kwok TK, Mak KH. Volar fixation of dorsally displaced distal radial fracture using locking compression plate. J Orthop Surg (Hong Kong) 2005; 13:153-7. [PMID: 16131677 DOI: 10.1177/230949900501300208] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
PURPOSE To evaluate the functional and radiological results of treating unstable fractures of the dorsal distal radius with a volar locking plate. METHODS Dorsally displaced distal radial fractures in 30 patients (11 men and 19 women; mean age, 58.6 years) were fixed by volar locking compression plate and followed up for a minimum of one year. RESULTS At final functional assessment, 24 patients achieved excellent and 5 achieved good outcomes, with one patient exhibiting fair results. Radiological scores demonstrated 22 excellent and 8 good outcomes. No nonunion or infection occurred. CONCLUSION Volar locking compression plating is a safe and effective treatment for unstable fractures of the dorsal distal radius.
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Duzovali O, Choroszy MS, Chan KW. Hyponatremia as the presenting feature of cerebral toxoplasmosis. Bone Marrow Transplant 2005; 35:1221-2. [PMID: 15880132 DOI: 10.1038/sj.bmt.1704989] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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78
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Lam DST, Lee TL, Chan KW, Ho HK, Lau YL. Primary immunodeficiency in Hong Kong and the use of genetic analysis for diagnosis. Hong Kong Med J 2005; 11:90-6. [PMID: 15815061] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/02/2023] Open
Abstract
OBJECTIVES To review the management of primary immunodeficiency and discuss recent advances in genetic analysis. DESIGN Retrospective study. SETTING University teaching hospital, Hong Kong. PATIENTS Children diagnosed with primary immunodeficiency and followed up in the immunology clinic during the period 1988 to 2003. MAIN OUTCOME MEASURES Demographic data, co-morbidities and treatment of patients, outcome and complications; identification of disease by genetic mutations. RESULTS Medical records of a total of 117 patients (72 male, 45 female) diagnosed with primary immunodeficiency in the Department of Paediatrics and Adolescent Medicine, Queen Mary Hospital, Hong Kong during the past 15 years (1988-2003) were reviewed. All patients were followed up in the immunology clinic. Some patients had been referred from the private sector or other hospitals for immunological workup. Six categories of primary immunodeficiency were identified: predominantly humoral defect (n=50), predominantly cellular defect (n=22), combined humoral and cellular defect (n=5), phagocytic defect (n=18), complement disorders (n=4), and others (n=18). Although infection was the underlying cause of most co-morbidities and mortality, autoimmune (n=7) and allergic (n=23) manifestations were common. In addition, three patients developed lymphoma. Recent advances in the genetic diagnosis of several types of primary immunodeficiency were also reviewed: X-linked Wiskott-Aldrich syndrome, X-linked chronic granulomatous disease, X-linked agammaglobulinaemia, X-linked lymphoproliferative syndrome, leukocyte adhesion disease type I, and X-linked hyperimmunoglobulin M syndrome. This provides an invaluable means of understanding the molecular basis of primary immunodeficiency and has important clinical applications. CONCLUSIONS Co-morbidities like autoimmune disease and allergic disease are common in patients with primary immunodeficiency and should be carefully evaluated. Likewise, a diagnosis of primary immunodeficiency should be considered when evaluating patients with these conditions. Rapid progress in the field of molecular genetics will enable definite and early diagnosis, and more importantly, potential curative therapy to be administered.
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Pulsipher MA, Levine JE, Hayashi RJ, Chan KW, Anderson P, Duerst R, Osunkwo I, Fisher V, Horn B, Grupp SA. Safety and efficacy of allogeneic PBSC collection in normal pediatric donors: The Pediatric Blood and Marrow Transplant Consortium Experience (PBMTC) 1996–2003. Bone Marrow Transplant 2004; 35:361-7. [PMID: 15608659 DOI: 10.1038/sj.bmt.1704743] [Citation(s) in RCA: 83] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The use of peripheral blood stem cells (PBSC) for allogeneic transplants in adults has greatly increased. This trend is reflected in pediatrics, where healthy children increasingly are donating PBSC or donor lymphocyte infusion (DLI) via apheresis for use by ill siblings. There is a potential concern that the risks of PBSC collection may differ for pediatric donors. However, no large studies have assessed safety issues in this population. To address this need, we reviewed 218 (213 PBSC, five DLI) collections in 201 normal pediatric donors (8 months to 17 years, median 11.8 years) at 22 institutions in the Pediatric Blood and Marrow Transplant Consortium. Donors received a median of 4 days of growth factor, and mean collection yield was 9.1 x 10(6) CD34+ cells/kg recipient weight. Younger age, days of apheresis, and male gender predicted increased yield of CD34+ cells/kg donor weight. Growth factor-induced pain was mild and reported in less than 15% of patients. Most donors <20 kg (23/25, 92%) required PRBC priming of the apheresis machine. This experience with over 200 collections demonstrates that PBSC collection is safe in normal pediatric donors and desired CD34 cell yields are easily achieved. Younger children utilize more medical resources and children <20 kg usually require a single blood product exposure.
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Chan GSW, Lam MF, Au WY, Tse KC, Chan TM, Lai KN, Chan KW. IgA nephropathy complicating graft-versus-host disease, another nephropathy causing nephrotic syndrome after bone marrow transplantation. Histopathology 2004; 45:648-51. [PMID: 15569061 DOI: 10.1111/j.1365-2559.2004.01958.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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81
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Panesar NS, Chan KW. Low temperature blocks the stimulatory effect of human chorionic gonadotropin on steroidogenic acute regulatory protein mRNA and testosterone production but not cyclic adenosine monophosphate in mouse Leydig tumor cells. Metabolism 2004; 53:955-8. [PMID: 15281000 DOI: 10.1016/j.metabol.2004.03.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Low temperatures slow down metabolism, partly because the kinetic energy of molecules is reduced and enzymes may be structurally impaired. We now report that relative to its maximal activity at 37 degrees C, adenylate cyclase (AC) still retained 25% functionality (determined as cyclic adenosine monophosphate [cAMP] production) at 4 degrees C in mouse Leydig tumor cells (MLTC-1) in response to 50 IU/L human chorionic gonadotropin (hCG), whereas steroidogenic acute regulatory (StAR) protein mRNA and testosterone production were completely impaired. The incubation of MLTC-1 with the phosphodiesterase inhibitor (3-isobutyl-1-methylxanthine; IBMX) resulted in significantly increased intracellular cAMP concentration at all 3 temperatures, but this had no impact on testosterone production. AC, cAMP, and phosphodiesterase form an important intracellular second-messenger mechanism in many organisms, some that inhabit very low temperature niches. The cold-resistance of AC and phosphodiesterase may thus have evolved to cope with adverse conditions. Although hibernation may lead to decreased steroid hormone production, it is also likely that cold-mediated decreased steroid hormone production induces hibernation.
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Chim CS, Wong SSY, Lam CCK, Chan KW. Concurrent hyperreactive malarial splenomegaly and quartan malarial nephropathy - Plasmodium malariae revisited. Haematologica 2004; 89:ECR21. [PMID: 15257958] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/30/2023] Open
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83
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Chu WCW, Lam WWM, Chan KW, Yeung CK, Lee KH, Sihoe JDY. Dynamic gadolinium-enhanced magnetic resonance urography for assessing drainage in dilated pelvicalyceal systems with moderate renal function: preliminary results and comparison with diuresis renography. BJU Int 2004; 93:830-4. [PMID: 15049999 DOI: 10.1111/j.1464-410x.2003.04725.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
OBJECTIVE To evaluate the use of dynamic gadolinium diethylenetriaminepenta-acetic acid (DTPA)-enhanced magnetic resonance urography (Gd-MRU) for assessing kidneys with markedly dilated pelvicalyceal systems and impaired function. PATIENTS AND METHODS Eight children (mean age 30 months, sd 25) were assessed, diagnosed as having gross unilateral hydronephrosis with a mean (sd) anteroposterior renal pelvic diameter of 36 (7) mm and reduced (30-40%) renal function. Dynamic Gd-MRU was performed after the patients were pre-loaded with intravenous fluid and diuretics, and comprised a dynamic T1-weighted sequence after Gd-DTPA (0.1 mmol/kg body weight) was administered, with a time-intensity curve of each kidney produced. Drainage was diagnosed by a clearly declining time-intensity curve and direct visualization of contrast medium within the ureter in several frames. High-grade or complete obstruction was diagnosed when drainage of contrast medium could not be detected. Gd-MRU results were compared with diuresis radionuclide (mercapto-acetyltriglycine, MAG3) renography within the same week. Unobstructive units detected by Gd-MRU were treated conservatively with a close follow-up by ultrasonography and radionuclide studies. RESULTS Diuresis MAG3 renography showed drainage in three dilated units and poor washout in five; in contrast, Gd-MRU showed drainage in seven dilated systems (three showed poor washout by MAG3), and obstruction in the remaining case. The unobstructed units detected by MRU under conservative treatment thus showed no further deterioration of renal function or progressive hydronephrosis in the subsequent follow-up (mean 18 months, range 15-23). CONCLUSION These preliminary results suggest that dynamic Gd-MRU is a useful noninvasive imaging method in distinguishing obstructive from unobstructive dilated systems, particularly in patients with hydronephrosis and reduced renal function.
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Chim CS, Li FK, Chan KW. Cast nephropathy in multiple myeloma. Haematologica 2004; 89:EIM08. [PMID: 15075111] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/29/2023] Open
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85
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Shen L, Liang ACT, Au WY, Lu L, Chen YW, Wong KY, Tang JCO, Chan KW, Beh SL, Kwong YL, Liang RHS, Srivastava G. BCL10 mutations are irrelevant to its aberrant nuclear localization in nasal NK/T-cell lymphoma. Leukemia 2004; 17:2240-2. [PMID: 14523480 DOI: 10.1038/sj.leu.2403128] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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86
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Lam MF, Tse KC, Chan KW, Au WY. Acute renal tubular necrosis due to grass carp ingestion in a myeloma patient after allogeneic stem cell transplantation. Bone Marrow Transplant 2004; 33:669-70. [PMID: 14730340 DOI: 10.1038/sj.bmt.1704403] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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87
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Li SSL, Lam CW, So YC, Wong CH, Yiu SF, Ho D, Chan KW, Chan KT. The use of a distal occlusion balloon protection device in acute coronary syndrome. Int J Cardiol 2003; 92:281-4. [PMID: 14659866 DOI: 10.1016/s0167-5273(03)00097-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
We report our early experience in using the PercuSurge GuardWire Plus system as a distal protection device in patients with acute coronary syndrome and acute myocardial infarction. Forty-three patients received percutaneous coronary intervention with the GuardWire Plus system. Thirteen had unstable angina, five had non-Q myocardial infarction and 25 had ST segment elevation myocardial infarction. Forty-one target lesions were in native coronary vessels and two were in saphenous vein grafts. Total occlusion occurred in 18 patients. The mean occlusion time by the distal protective balloon was 262.8 +/- 114.1 s. Preoperatively, TIMI 0 flow was present in 18, TIMI II flow in two and TIMI III flow in 23 patients. Post-operatively, TIMI II and TIMI III flow were established in two and 41 patients, respectively. All procedures were successful and the GuardWire Plus system was successfully deployed in all but two patients. There was no procedure-related major adverse clinical event. There was no major adverse clinical event at 30 days. There was no device-related complication. We believe that the GuardWire Plus system is safe and feasible in patients with acute coronary syndrome and acute myocardial infarction.
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But B, Chan CW, Chan F, Chan KW, Cheng AWF, Cheung P, Choi KL, Chow CB, Chow FCC, Eastman C, Fok TF, Fung LM, Gomes C, Huen KF, Ip TP, Kung AWC, Lam KSL, Lam YY, Lao T, Lee CY, Lee KF, Leung J, Leung NK, Li D, Li J, Lo KW, Lo L, Ng KL, Siu SC, Tam S, Tan KCB, Tiu SC, Tse HY, Tse W, Wong G, Wong S, Wong W, Yeung VTF, Young R, Yu CM, Yu R. Consensus statement on iodine deficiency disorders in Hong Kong. Hong Kong Med J 2003; 9:446-53. [PMID: 14660812] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/27/2023] Open
Abstract
This article reviews the available data on the study of iodine deficiency disorders in Hong Kong and to discuss the approach towards preventing such disorders in Hong Kong. The importance of iodine and iodine deficiency disorders is described, and the available data on the dietary iodine intake and urinary iodine concentration in different populations of Hong Kong are summarised and discussed. Dietary iodine insufficiency among pregnant women in Hong Kong is associated with maternal goitrogenesis and hypothyroxinaemia as well as neonatal hypothyroidism. Borderline iodine deficiency exists in the expectant mothers in Hong Kong. Women of reproductive age, and pregnant and lactating women should be made aware and educated to have an adequate iodine intake, such as iodised salt, as an interim measure. A steering group involving all stakeholders should be formed to advise on the strategy of ensuring adequate iodine intake, including universal iodisation of salt in Hong Kong. Continuous surveillance of iodine status in the Hong Kong population is necessary.
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Guan Y, Zheng BJ, He YQ, Liu XL, Zhuang ZX, Cheung CL, Luo SW, Li PH, Zhang LJ, Guan YJ, Butt KM, Wong KL, Chan KW, Lim W, Shortridge KF, Yuen KY, Peiris JSM, Poon LLM. Isolation and characterization of viruses related to the SARS coronavirus from animals in southern China. Science 2003; 302:276-8. [PMID: 12958366 DOI: 10.1126/science.1087139] [Citation(s) in RCA: 1549] [Impact Index Per Article: 73.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
A novel coronavirus (SCoV) is the etiological agent of severe acute respiratory syndrome (SARS). SCoV-like viruses were isolated from Himalayan palm civets found in a live-animal market in Guangdong, China. Evidence of virus infection was also detected in other animals (including a raccoon dog, Nyctereutes procyonoides) and in humans working at the same market. All the animal isolates retain a 29-nucleotide sequence that is not found in most human isolates. The detection of SCoV-like viruses in small, live wild mammals in a retail market indicates a route of interspecies transmission, although the natural reservoir is not known.
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Poon CM, Chan KW, Lee DWH, Chan KC, Ko CW, Cheung HY, Lee KW. Two-port versus four-port laparoscopic cholecystectomy. Surg Endosc 2003; 17:1624-7. [PMID: 12874694 DOI: 10.1007/s00464-002-8718-9] [Citation(s) in RCA: 72] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2002] [Accepted: 10/01/2002] [Indexed: 10/26/2022]
Abstract
BACKGROUND Two-port laparoscopic cholecystectomy has been reported to be safe and feasible. However, whether it offers any additional advantages remains controversial. This study reports a randomized trial that compared the clinical outcomes of two-port laparoscopic cholecystectomy versus conventional four-port laparoscopic cholecystectomy. METHODS One hundred and twenty consecutive patients who underwent elective laparoscopic cholecystectomy were randomized to receive either the two-port or the four-port technique. All patients were blinded to the type of operation they underwent. Four surgical tapes were applied to standard four-port sites in both groups at the end of the operation. All dressings were kept intact until the first follow-up 1 week after surgery. Postoperative pain at the four sites was assessed on the first day after surgery using a 10-cm unscaled visual analog scale (VAS). Other outcome measures included analgesia requirements, length and difficulty of the operation, postoperative stay, and patient satisfaction score on surgery and scars. RESULTS Demographic data were comparable for both groups. Patients in the two-port group had shorter mean operative time (54.6 +/- 24.7 min vs 66.9 +/- 33.1 min for the four-post group; p = 0.03) and less pain at individual subcostal port sites [mean score using 10-cm unscaled VAS: 1.5 vs 2.8 ( p = 0.01) at the midsubcostal port site and 1.3 vs 2.3 ( p = 0.02) at the lateral subcostal port site]. Overall pain score, analgesia requirements, hospital stay, and patient satisfaction score on surgery and scars were similar between the two groups. CONCLUSION Two-port laparoscopic cholecystectomy resulted in less individual port-site pain and similar clinical outcomes but fewer surgical scars compared to four-port laparoscopic cholecystectomy. Thus, it can be recommended as a routine procedure in elective laparoscopic cholecystectomy.
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Chan KL, Ng SP, Chan KW, Wo YH, Tam PKH. Pathogenesis of neonatal necrotizing enterocolitis: a study of the role of intraluminal pressure, age and bacterial concentration. Pediatr Surg Int 2003; 19:573-7. [PMID: 14551717 DOI: 10.1007/s00383-003-0979-4] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 11/06/2002] [Indexed: 10/26/2022]
Abstract
The pathogenesis of neonatal necrotizing enterocolitis (NEC) is unknown. Intestinal dilatation and preferred occurrence of NEC at sites of bacterial overgrowth (colon and ileum) are common findings. The study attempted to produce NEC with increasing intraluminal pressures and bacterial concentrations in two different aged groups of rats. First, 10-cm terminal ileum segments were isolated with intact vascular pedicles in 1-and 3-month-old rats, and a dose of 10(11) E. coli in 1 ml was injected into each segment. Intraluminal pressure was sustained for 1 h at 150, 100, 50 and 0 cmH(2)0, respectively, in four experimental groups ( n=6). The isolated loop was then returned to the abdominal cavity and assessed grossly for NEC after 24 h. Histological examination was performed by a pathologist (KWC) who was blinded to the procedures. Second, the procedure was repeated with doses of 10(8), 10(5) and 0 bacteria/ml ( n=6) at intraluminal pressure of 100 cmH(2)0 in 1-month-old rats. Third, in another experimental group, oxygenation of the pedicled loop was assessed by oximetry as the intraluminal pressure increased and the findings were correlated with aortic blood pressure. The blood pressures (mean+/-SD) for 3- and 1-month-old rats were 110+/-6 and 72+/-4 mmHg, respectively. Hypoxia (<50% oxygen saturation) of the bowel was detected when the intraluminal pressure exceeded the mean blood pressure. The relative incidences of NEC in the bowel with intraluminal pressure above and below mean blood pressure were 100% (6/6) vs. 4% (1/24; P<0.05) in 3-month-old rats, and 100% (12/12) vs. 11% (2/18; P<0.05) in 1-month-old rats. There was no occurrence of NEC in bowel injected with 10(5) E. coli/ml and less at 100 cm intraluminal pressure. Increased intraluminal pressure results in bowel hypoxia and in the presence of adequate bacterial concentration predisposes to the development of NEC. Young age is associated with a lower threshold for increased intraluminal pressure leading to NEC.
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Eberly JH, Chan KW, Law CK. Control of entanglement and the high-entanglement limit. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2003; 361:1519-1526. [PMID: 12869326 DOI: 10.1098/rsta.2003.1218] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
We examine two-particle entanglement and ways in which it might be coherently controlled. Control is desirable for successful implementation of quantum computing. As one result, we find that reaching very high entanglement may be feasible experimentally.
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Chan CSY, Wun YT, Cheung A, Dickinson JA, Chan KW, Lee HC, Yung YM. Communication skill of general practitioners: any room for improvement? How much can it be improved? MEDICAL EDUCATION 2003; 37:514-526. [PMID: 12787374 DOI: 10.1046/j.1365-2923.2003.01533.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
OBJECTIVE To measure any changes in the communication skills of primary care physicians before and after a part-time Diploma course in Family Medicine. SUBJECTS 79 Hong Kong Chinese doctors (46 of whom were local graduates, with an average of 7 years in general practice). METHODS Over the 10-month course in 2000-01, participants had 11 2.5-hour lecture/demonstrations in communication skills, 2 sessions of role play practice in groups of 20, self-analysis of a videotaped interview and skills evaluation. A before-after design measured scores in videotaped simulated patient interviews (rated by a research assistant using a structured observation guide, after standardisation by a psychologist) and scores in Objective Structured Clinical Examinations (OSCE) (rated by experienced family physician examiners with standardised checklists). RESULTS There were wide variations in baseline skills, with scores ranging between 24-78 (out of 100) for video and 18-68 for OSCE, which were related to prior training and inversely associated with years after graduation. Significant improvements occurred in both video (from 53 to 61) and OSCE (from 46 to 56) post-course (P < 0.001). The group in the lowest quartile improved from 36 to 54 for video and from 29 to 48 for OSCE, while those in the second lowest quartile improved from 50 to 61 for video and from 44 to 56 for OSCE (F = 12.2, P < 0.001). Doctors who graduated more than 20 years ago made as much improvement as more recent graduates. CONCLUSIONS Communication skills can be effectively taught to, and improved among experienced Chinese doctors by a combination of large-class teaching and medium-sized group practice with feedback, and without intensive individual supervision.
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Tam VKK, Kung WH, Li R, Chan KW. Renal parenchymal malacoplakia: a rare cause of ARF with a review of recent literature. Am J Kidney Dis 2003; 41:E13-7. [PMID: 12776305 DOI: 10.1016/s0272-6386(03)00367-6] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Renal parenchymal malacoplakia is a rare cause of acute renal failure. Traditionally, it was associated with a high mortality rate and commonly resulted in renal failure requiring renal replacement therapy. The authors report on a 70-year-old woman who presented with acute renal failure caused by renal parenchymal malacoplakia. Her renal function recovered after levofloxacin treatment. All cases reported in the English-language literature since 1990, when fluoroquinolone was first used to treat malacoplakia, were reviewed. Although some patients still had renal failure, with renal biopsy and fluoroquinolone treatment, the patient mortality rate from renal parenchymal malacoplakia is remarkably low.
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Lui SL, Tsang R, Wong D, Chan KW, Chan TM, Fung PCW, Lai KN. Effect of mycophenolate mofetil on severity of nephritis and nitric oxide production in lupus-prone MRL/lpr mice. Lupus 2003; 11:411-8. [PMID: 12195781 DOI: 10.1191/0961203302lu214oa] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Mycophenolate mofetil (MMF), an immunosuppressive drug commonly used in organ transplantation, is increasingly being used to treat autoimmune diseases including systemic lupus erythematosus (SLE). Excessive production of nitric oxide (NO) by inducible nitric oxide synthase (iNOS) has been implicated in the pathogenesis of lupus nephritis. We evaluated the effect of MMF on the severity of nephritis and the production of NO in lupus-prone MRL/lpr mice. Eight-week-old female MRL/lpr mice (n = 20) were treated with MMF (100 mg/kg/day) by oral gavage for 12 weeks. Control mice (n = 20) received vehicle on the same schedule. The mice were killed after 12 weeks of treatment. Treatment with MMF significantly decreased the amount of proteinuria, prolonged survival and reduced the histological severity of glomerulonephritis. Urinary nitrite/nitrate excretion in the MMF-treated mice was significantly reduced during the first 8 weeks of treatment. However, by the end of the 12 weeks' treatment period, there was no significant difference between vehicle and MMF-treated mice in terms of urinary nitrite/nitrate excretion, intra-renal production of NO, expression of iNOS protein and induction of iNOS mRNA. We conclude that MMF is effective in attenuating the severity of nephritis in MRL/lpr mice. The beneficial effects of MMF on lupus nephritis during the early phase of the disease might be partly attributed to the inhibition of NO production. The inhibitory effect of MMF on NO production diminishes as the disease progresses. MMF probably has additional, as yet undefined mode of actions to fully account for its beneficial effects on lupus nephritis.
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Abstract
Urinary tract infection is a common complication after renal transplantation. The etiologies are diverse and the bacterial agents may sometimes be acquired during the hospital stay. We report a patient who developed Burkholderia cepacia urinary tract infection after renal transplantation. The bacteria showed in vivo resistance to all of the available antibiotics. A graft nephrectomy was eventually required to clear the infection. The consequence of some fastidious infection may be catastrophic and early recognition and treatment is necessary to optimize the treatment.
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Chan SWW, Datta NN, Thomas TMM, Chan KW. Intracranial chloroma in hypereosinophilic myelofibrosis. SURGICAL NEUROLOGY 2003; 59:55-7. [PMID: 12633964 DOI: 10.1016/s0090-3019(02)00941-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
BACKGROUND Chloroma, also called granulocytic sarcoma, is a localized extramedullary tumor composed of leukemic myeloid cells. It is a rare tumor that can occur in various locations. The association of chloroma with leukemic disease or myeloproliferative disorders is limited to isolated case reports. CASE DESCRIPTION We report a case of intracranial chloroma in an elderly man with myelofibrosis and progressive hypereosinophilia. The presence of leukemic cells within his pleural aspirate suggested an incipient acute leukemic state. CONCLUSION We report the first case of intracranial chloroma associated with hypereosinophilia developing in the course of myelofibrosis. The significance of hypereosinophilia in predicting the likelihood of development of central nervous system chloroma and acute leukemia in a patient with myelofibrosis needs further evaluation.
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Chan KL, Chan JKY, Peh WCG, Chan KW, Tam PKH. Endotoxemia associated with intussusception and its diagnostic and surgical interventions. Pediatr Surg Int 2002; 18:685-8. [PMID: 12598964 DOI: 10.1007/s00383-002-0755-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 06/07/2001] [Indexed: 11/24/2022]
Abstract
To determine if and when intussusception results in endotoxemia and to evaluate whether diagnostic and surgical interventions of intussusception aggravate endotoxemia, intussusception was created in seven pigs during general anesthesia (ileocolic n = 3, ileo-ileocolic n = 2, ileocolic with silicone ring as leadpoint n = 1, ileoileal with silicone ring n = 1). After a period of observation and before progression to bowel gangrene, a diagnostic ultrasound study with a saline enema was undertaken, followed by a laparotomy and resection of the intussusception with a primary bowel anastomosis. Serial blood samples were obtained before and at regular intervals after: (1) formation of the intussusception; (2) the enema; and (3) resection for endotoxin measurement by limulus amebocyte lysate assay. The mean level of endotoxin increased from a pre-intussusception value of 0.750 EU/ml (range: 0.215-1.281) to a post-intussusception maximum of 1.482 EU/ml (0.997-2.882, P = 0.009), peaking mostly at 2 h after the intussusception. The mean pre-saline-enema level was 1.547 EU/ml (0.869-2.677) while the post-enema level was 1.41 EU/ml (0.84-2.468, P = 0.655). The mean pre-resection level was 1.470 EU/ml (0.784-2.468) while the post-resection maximum was (2.130 EU/ml) (0.850-4.381, P = 0.09). It is concluded that: (1) even in the absence of bowel gangrene intussusception results in significant endotoxemia within 2 h of its formation; (2) gentle saline enemas are not associated with endotoxemia; and (3) surgical resection results in a further upward surge of endotoxemia. These findings provide a scientific basis for improved understanding and management of intussusception.
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Chan KL, Ho JCY, Chan KW, Tam PKH. A study of gut immunity to enteral endotoxin in rats of different ages: a possible cause for necrotizing enterocolitis. J Pediatr Surg 2002; 37:1435-40. [PMID: 12378449 DOI: 10.1053/jpsu.2002.35407] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
PURPOSE Immature gut immunity can be a predisposing factor for necrotizing enterocolitis (NEC). The gut active immunity and innate defense to the Escherichia coli endotoxin lipopolysaccharide (LPS) in immature and mature rats were studied. METHODS LPS, started at a dose of 10 mg/kg, was instilled into the stomachs of fetal, newborn, 1-month and 3-month-old rats. Boost doses and normal saline control instillations were given on day 14. Rats that died after instillation had detailed postmortem examinations. For survivors, a group of 6 immunized and 6 controls were killed on day 7 for the collection of serum, spleens, mesenteric lymph nodes, and small intestines. Lymphocytes (10(6)) prepared from each tissue sample of individual group were cultured for 5 days. Serum and supernatant were analyzed for IgA and anti-E coli IgA levels. RESULTS All control rats survived. The doses of LPS given were 10, 5, 2.5, and 1.25 mg/kg. All fetal rats died after LPS instillation. Half-lethal dose for newborns was 2.5 mg/kg. One-month and 3-month-old rats survived all doses of LPS. The cause of death was endotoxemia. The serum IgA and total supernatant anti- E coli IgA levels of rats of all ages studied showed no significant difference. CONCLUSION The poor innate gut defense, not so much the active immunity, may provide an explanation for the susceptibility of the premature babies and newborn infants to the development of NEC.
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Au WY, Chan KW, Lam CCK, Young K. A post-menopausal woman with anuria and uterus bulk: the spectrum of estrogen-induced TTP/HUS. Am J Hematol 2002; 71:59-60. [PMID: 12221679 DOI: 10.1002/ajh.10162] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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