Lean implementations of software testing tools using XML representations of source codes

By utilizing XML representations of source programs under test, a new approach is proposed to concisely implement some prototypes for TACCLE, a software testing methodology. The conversions between a source program and its XML representation can be easily realized using existing conversion tools. In this way, the conversion tools can automatically analyze and parse the source program, so that testing tool developers only need to concentrate on the manipulation of the XML document. If appropriate XML DOM APIs are chosen, the implementations of such testing tools will be pretty lean. A detailed case study for GMPS tool, a prototype for the TACCLE methodology, is presented to illustrate the new approach. © 2008 IEEE.published_or_final_versionThis research is supported by the Jinan University Youth Foundation under Grant #51208035, Union Grant of Guangdong Province and National Natural Science Foundation of China under Grant #U0775001, and the Guangdong Province Science Foundation under Grant #7010116

A newly derived small synthetic compound alleviated ventricular fibrillation in a pig model with chronic myocardial infarction as revealed by optical mapping

published_or_final_versionThe 16th Medical Resarch Conference (MRC), The University of Hong Kong, Hong Kong, China, 22 January 2011. In Hong Kong Medical Journal, 2011, v. 17, suppl. 1, p. 13-14, abstract no. 1

A scheme to aid construction of left-hand sides of axioms in algebraic specifications for object-oriented program testing

In order to ensure reliability and quality, software systems must be tested. Testing object-oriented software is harder than testing procedure-oriented software. It involves four levels, namely the algorithmic level, class level, cluster level, and system level. We proposed a methodology TACCLE for class-and cluster- level testing. It includes an important algorithm GFT for generating fundamental equivalent pairs as class-level test cases based on axioms in a given algebraic specification for a given class. This formal methodology has many benefits. However, system analysts often find it difficult to construct axioms for algebraic specifications. In this paper, we propose a scheme to aid the construction of the left-hand sides of axioms. The scheme alleviates the difficulties of the system analysts and also helps them check the completeness, consistency, and independence of the axiom system. © 2008 IEEE.published_or_final_versionUnion Grant of Guangdong Province and National Natural Science Foundation of China (#U0775001), Guangdong Province Science Foundation (#7010116), and by a grant of the Youth Science Foundation of Jinan University (#51208035)

Discoveries from a phenanthroline-based dynamic combinatorial library: catenane from a copper(I) or copper(II) template?

We report here a DCL study of a phenanthroline-based building block focusing on catenane formation with copper templates. Two [2]catenanes have been amplified by using Cu+ as a template from the DCLs that contain no interlocked compounds in the absence of copper. In addition, an unexpected Cu2+ template effect on the [2]catenane formation was discovered. The observed Cu2+ template effect was found to originate from the in situ reduction of the divalent metal to Cu+.postprin

Nutrient supplemented serum-free medium increases cardiomyogenesis efficiency of human pluripotent stem cells.

AIM: To development of an improved p38 MAPK inhibitor-based serum-free medium for embryoid body cardiomyocyte differentiation of human pluripotent stem cells. METHODS: Human embryonic stem cells (hESC) differentiated to cardiomyocytes (CM) using a p38 MAPK inhibitor (SB203580) based serum-free medium (SB media). Nutrient supplements known to increase cell viability were added to SB medium. The ability of these supplements to improve cardiomyogenesis was evaluated by measurements of cell viability, total cell count, and the expression of cardiac markers via flow cytometry. An improved medium containing Soy hydrolysate (HySoy) and bovine serum albumin (BSA) (SupSB media) was developed and tested on 2 additional cell lines (H1 and Siu-hiPSC). Characterization of the cardiomyocytes was done by immunohistochemistry, electrophysiology and quantitative real-time reverse transcription-polymerase chain reaction. RESULTS: hESC cell line, HES-3, differentiating in SB medium for 16 d resulted in a cardiomyocyte yield of 0.07 +/- 0.03 CM/hESC. A new medium (SupSB media) was developed with the addition of HySoy and BSA to SB medium. This medium resulted in 2.6 fold increase in cardiomyocyte yield (0.21 +/- 0.08 CM/hESC). The robustness of SupSB medium was further demonstrated using two additional pluripotent cell lines (H1, hESC and Siu1, hiPSC), showing a 15 and 9 fold increase in cardiomyocyte yield respectively. The age (passage number) of the pluripotent cells did not affect the cardiomyocyte yields. Embryoid body (EB) cardiomyocytes formed in SupSB medium expressed canonical cardiac markers (sarcomeric alpha-actinin, myosin heavy chain and troponin-T) and demonstrated all three major phenotypes: nodal-, atrial- and ventricular-like. Electrophysiological characteristics (maximum diastolic potentials and action potential durations) of cardiomyocytes derived from SB and SupSB media were similar. CONCLUSION: The nutrient supplementation (HySoy and BSA) leads to increase in cell viability, cell yield and cardiac marker expression during cardiomyocyte differentiation, translating to an overall increase in cardiomyocyte yield.published_or_final_versio

Attenuation of Hind-limb Ischemia in Mice with Endothelial-like Cells Derived from Different Sources of Human Stem Cells

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Cobalt chloride pretreatment promotes cardiac differentiation of human embryonic stem cells under atmospheric oxygen level

Our previous study demonstrated the direct involvement of the HIF-1α subunit in the promotion of cardiac differentiation of murine embryonic stem cells (ESCs). We report the use of cobalt chloride to induce HIF-1α stabilization in human ESCs to promote cardiac differentiation. Treatment of undifferentiated hES2 human ESCs with 50μM cobalt chloride markedly increased protein levels of the HIF-1α subunit, and was associated with increased expression of early cardiac specific transcription factors and cardiotrophic factors including NK2.5, vascular endothelial growth factor, and cardiotrophin-1. When pretreated cells were subjected to cardiac differentiation, a notable increase in the occurrence of beating embryoid bodies and sarcomeric actinin-positive cells was observed, along with increased expression of the cardiac-specific markers, MHC-A, MHC-B, and MLC2V. Electrophysiological study revealed increased atrial-and nodal-like cells in the cobalt chloride-pretreated group. Confocal calcium imaging analysis indicated that the maximum upstroke and decay velocities were significantly increased in both noncaffeine and caffeine-induced calcium transient in cardiomyocytes derived from the cobalt chloride-pretreated cells, suggesting these cells were functionally more mature. In conclusion, our study demonstrated that cobalt chloride pretreatment of hES2 human ESCs promotes cardiac differentiation and the maturation of calcium homeostasis of cardiomyocytes derived from ESCs. © 2011 Mary Ann Liebert, Inc.published_or_final_versio

Role of Circulating Fibroblast Growth Factor 21 Measurement in Primary Prevention of Coronary Heart Disease Among Chinese Patients With Type 2 Diabetes Mellitus

BACKGROUND: Fibroblast growth factor 21 (FGF21) has demonstrated beneficial effects on lipid and carbohydrate metabolism. In cross-sectional studies, an association of raised circulating FGF21 levels with coronary heart disease (CHD) was found in some but not all studies. Here we investigated prospectively whether baseline serum FGF21 levels could predict incident CHD in subjects with type 2 diabetes mellitus and no known cardiovascular diseases. METHODS AND RESULTS: Baseline serum FGF21 levels were measured in 3528 Chinese subjects with type 2 diabetes mellitus recruited from the Hong Kong West Diabetes Registry. The role of baseline serum FGF21 levels in predicting incident CHD over a median follow-up of 3.8 years was analyzed using Cox regression analysis. Among 3528 recruited subjects without known cardiovascular diseases, 147 (4.2%) developed CHD over a mean follow-up of 4 years. Baseline serum log-transformed FGF21 levels were significantly higher in those who had incident CHD than those who did not (222.7 pg/mL [92.8-438.4] versus 151.1 pg/mL [75.6-274.6]; P<0.001). On multivariable Cox regression analysis, baseline serum FGF21 levels, using an optimal cutoff of 206.22 pg/mL derived from our study, independently predicted incident CHD (hazard ratio, 1.55; 95% CI, 1.10-2.19; P=0.013) and significantly improved net reclassification index and integrated discrimination improvement after adjustment for conventional cardiovascular risk factors. CONCLUSIONS: We have demonstrated, for the first time, that serum FGF21 level is an independent predictor of incident CHD and might be usefully utilized as a biomarker for identifying type 2 diabetes mellitus subjects with raised CHD risk, for primary prevention.published_or_final_versio

Predictors common to cardiovascular and cancer outcomes in a population-based 13-year prospective study in Hong Kong

Oral PresentationINTRODUCTION: Cardiovascular diseases (CVD) and cancer are the two leading causes of death in Hong Kong. Obesity is becoming increasingly prevalent in the local population and has been reported to be associated with CVD and some forms of cancer in the western world. In this study, we attempted to identify the aetiological factors linking obesity to both CVD and cancer among Hong Kong Chinese. METHODS: Subjects were recruited from the Hong Kong Cardiovascular Risk Factor Prevalence Study (CRISPS) …published_or_final_versionThe 16th Medical Research Conference, The University of Hong Kong, Hong Kong, 22 January 2011. In Hong Kong Medical Journal, 2011, v. 17 suppl. 1, p. 56, abstract no. 9

Identification and Expression Profiling of MicroRNAs in the Brain, Liver and Gonads of Marine Medaka (Oryzias melastigma) and in Response to Hypoxia

The marine medaka (Oryzias melastigma) has been increasingly used as a fish model for detecting environmental stresses and chemical contaminants in the marine environment. Recent mammalian studies have shown that environmental stresses can alter the expression profiles of microRNAs (miRNAs), leading to transgenerational effects. Here, we use high-throughput Illumina RNA sequencing (RNA-Seq) for miRNA transcriptome analysis of brain, liver, and gonads from sexually mature male and female marine medaka. A total of 128,883,806 filtered sequence reads were generated from six small RNA libraries, identifying a total of 2,125,663 non-redundant sequences. These sequences were aligned and annotated to known animal miRNAs (miRBase) using the BLAST method. A total of 223 distinct miRNA types were identified, with the greatest number expressed in brain tissue. Our data suggested that 55 miRNA types from 34 families are common to all tested tissues, while some of the miRNAs are tissue-enriched or sex-enriched. Quantitative real-time PCR analysis further demonstrated that let-7a, miR-122, and miR-9-3p were downregulated in hypoxic female medaka, while miR-2184 was specifically upregulated in the testis of hypoxic male fish. This is the first study to identify miRNAs in O. melastigma using small RNA deep sequencing technology. Because miRNA expression is highly conserved between marine medaka and other vertebrates, marine medaka may serve as a good model for studies on the functional roles of miRNAs in hypoxia stress response and signaling in marine fish.published_or_final_versio