I-SceI meganuclease-mediated transgenesis in Xenopus.

Several experimental approaches have been described to generate transgenic frogs. Here, we report on the application of a novel method in Xenopus, making use of I-SceI meganuclease. The characteristic feature of this endonuclease is that it has an extended recognition site of 18 bp, which is expected to exist only once in 7 x 10(10) bp of random DNA sequences. Various reporter constructs flanked by two I-SceI recognition sites were injected together with the I-SceI meganuclease into one-cell stage Xenopus embryos. We observed an overall transgenesis frequency of 10% or more under optimized condition. The injected genes were integrated into the genome and transmitted to F1 offspring. Southern blot analysis showed that between one and eight copies of the transgene were integrated. Meganuclease-aided transgenesis, thus, provides a simple and highly efficient tool for transgenesis in Xenopus.     

2-methoxyestradiol induces apoptosis and cell cycle arrest in human chondrosarcoma cells.

2-Methoxyestradiol (2ME) is an endogenous metabolite with estrogen receptor-independent anti-tumor activity. The current study seeks to determine the mechanism of anti-tumor activity of 2ME on human chondrosarcoma. 2ME caused a time- and dose-dependent cytotoxity in chondrosarcoma cells, while primary chondrocytes were minimally affected. Cells accumulated in G0/G1 phase in response to 2ME and DAPI stain indicated an induction of apoptosis. Bax, Cytochrome C, and Caspase-3 protein expression were increased, while p53 expression was decreased. A higher Bax/Bcl-2 ratio followed 2ME treatment. 2ME has a potentially promising role as a systemic therapy of chondrosarcoma when the mechanism of action is better delineated.     

Validation of the medical outcomes study family and marital functioning measures in SLE patients in Singapore.

OBJECTIVE: To validate the Medical Outcomes Study Family and Marital Functioning Measures (FMM and MFM) in a multi-ethnic, urban Asian population in Singapore. METHODS: English speaking Chinese, Malay or Indian SLE patients (n=120) completed a self-administered questionnaire containing the FFM and MFM at baseline, after 2 weeks and after 6 months. Lupus activity, disease-related damage and quality of life were assessed using the British Isles Lupus Assessment Group (BILAG), Systemic Lupus International Collaborating Clinics/American College of Rheumatology (SLICC/ACR) Damage Index and SF-36 Health Survey respectively. Scale psychometric properties were assessed through factor analysis, Cronbach's alpha, quantifying test-retest differences and known-groups construct validity. RESULTS: Factor analysis of scores obtained at baseline and after 6 months identified 3 factors corresponding to the FFM (1 factor) and the MFM (2 factors). Both scales showed acceptable internal consistency, with Cronbach's alpha of 0.95 for the FFM and 0.70 for the MFM. Mean (s.d.) test-retest differences were -0.31 (3.82) points for the FFM and -0.70 (4.26) points for the MFM. Eleven out of 13 a priori hypotheses relating both the FFM and MFM to demographic, disease and quality of life variables were confirmed, supporting the construct validity of these scales. CONCLUSION: The FFM and MFM are valid and reliable measures of family and marital functioning in a multi-ethnic cohort of Asian SLE patients in Singapore.     

The influence of positive peritoneal cytology on survival in patients with pancreatic adenocarcinoma

The American Joint Committee on Cancer (AJCC) staging system for pancreatic adenocarcinoma classifies positive peritoneal cytology as stage IV disease. Data are limited with respect to the prevalence of positive peritoneal cytology and its influence on survival in patients with resectable, locally advanced, and metastatic disease. Four hundred sixty-two patients underwent staging laparoscopy for pancreatic adenocarcinoma between January 1995 and December 2005. Kaplan-Meier survival comparisons were performed to evaluate the significance of positive peritoneal cytology on overall survival (OS) in resected patients and patients with locally advanced and metastatic disease. Of the 462 patients, 47% (217/462) underwent a pancreatic resection. The 21% (95/462) with locally advanced disease and 32% (150/462) with metastatic disease did not undergo resection. Peritoneal cytology was positive in 17% (77/462), and was associated with stage of disease (metastatic, 37%; locally advanced, 11%; resected, 5%; P=0.01). Positive cytology was not associated with OS in patients with metastatic disease or locally advanced disease, but was in resected patients (median, 16 months vs. 8 months; P<0.001). Node-positive disease was present in 8 of 10 patients resected with positive cytology (2 years OS, 12% positive cytology vs. 23% negative; P=0.006). In this study, patients who underwent resection in the presence of positive peritoneal cytology and absence of other identifiable metastatic disease had a similar survival as other patients with stage IV disease. Presented at the Forty-Seventh Annual Meeting of The Society for Surgery of the Alimentary Tract, Los Angeles, California, May 20–24, 2006 (poster presentation).     

The Rheumatology Attitudes Index and its helplessness subscale are valid and reliable measures of learned helplessness in Asian patients with systemic lupus erythematosus.

OBJECTIVE: To assess the internal consistency, reliability, and construct validity of the Rheumatology Attitudes Index (RAI) and its subscales in a cohort of Asian patients with systemic lupus erythematosus (SLE). METHODS: English speaking ethnic Chinese, Malay, or Indian patients with SLE (n = 120) seen at a rheumatology unit completed a questionnaire containing the RAI twice within a 2 week period. Lupus activity was assessed using the British Isles Lupus Activity Group (BILAG) score, disease related damage using the Systemic Lupus International Collaborating Clinics/American College of Rheumatology (SLICC/ACR) damage index, and quality of life using the Medical Outcome Survey Short Form 36 Health Survey (SF-36). Factor analysis and Cronbach's alpha were used to study the psychometric properties of the RAI. The magnitude of test-retest differences was assessed using the method of Bland and Altman. Relationships between the RAI, its helplessness (HS) and internality (IS) subscales, and BILAG, SLICC/ACR damage index and SF-36 scores were studied using Spearman's rank correlation. RESULTS: Factor analysis (n = 105) identified 2 factors corresponding to the HS and IS subscales of the RAI. All scales showed acceptable internal consistency, with Cronbach's alpha of 0.64 for the HS, 0.77 for the IS, and 0.74 for the RAI. Mean (SD) test-retest differences were 0.85 (3.96) points for the HS (n = 86), 0.81 (4.44) points for the IS (n = 85), and 1.46 (7.88) points for the RAI (n = 74). Six of 10 hypotheses relating the RAI and HS to demographic, disease, and quality of life variables were confirmed, supporting the construct validity of these scales. CONCLUSION: The RAI and its helplessness subscale are valid and reliable measures of learned helplessness in a multiethnic cohort of Asian patients with SLE in Singapore.