Chinoketides A and B, Two New Antimicrobial Polyketides from the Endophytes of Distylium chinense with the "Black-Box" Co-culture Method

Meng-Meng Lv,Ming-Hui Tan,Li-Wen Lu,Rong-Hua Zhang,Zhi-Yong Guo,Cheng-Xiong Liu,Jin Yang,Kun Zou,Peter Proksch 한국생약학회 2018 Natural Product Sciences Vol.24 No.3

Two new polyketides, chinoketides A and B (1 - 2) with a known compound xylarphthalide A (3), were isolated from the solid medium of the endophytes from the leaves of the relic plant Distylium chinense with the "black-box" co-culture method, and the structures of two new compounds were elucidated by NMR, MS and CD spectra. And the absolute configurations of chinoketides A (1) and B (2) were determined as 2R,3R,8S and 5R,6S by calculating their ECD spectra to compare with the experimental CD spectra. Finally, the antimicrobial activities were evaluated to Erwinia carotovora sub sp. Carotovora (Jones) Bersey et al, and the results showed that compounds 1 - 3 displayed the antimicrobial activities with MIC value at 20.5, 30.4 and 10.2 mg/mL.

Men’s Health Index: A Pragmatic Approach to Stratifying and Optimizing Men’s Health

Hui Meng Tan,Wei Phin Tan,Jun Hoe Wong,Christopher Chee Kong Ho,Chin Hai Teo,Chirk Jenn Ng 대한비뇨의학회 2014 Investigative and Clinical Urology Vol.55 No.11

Purpose: The proposed Men’s Health Index (MHI) aims to provide a practical and systematicframework for comprehensively assessing and stratifying older men with theintention of optimising their health and functional status. Materials and Methods: A literature search was conducted using PubMed from 1980to 2012. We specifically looked for instruments which: assess men’s health, frailty andfitness; predict life expectancy, mortality and morbidities. The instruments were assessedby the researchers who then agreed on the tools to be included in the MHI. Whenthere was disagreements, the researchers discussed and reached a consensus guidedby the principle that the MHI could be used in the primary care setting targetting menaged 55-65 years. Results: The instruments chosen include the Charlson’s Combined Comorbidity-AgeIndex; the International Index of Erectile Function-5; the International ProstateSymptom Score; the Androgen Deficiency in Aging Male; the Survey of Health, Ageingand Retirement in Europe Frailty Instrument; the Sitting-Rising Test; the SeniorFitness Test; the Fitness Assessment Score; and the Depression Anxiety StressScale-21. A pilot test on eight men was carried out and showed that the men’s healthindex is viable. Conclusions: The concept of assessing, stratifying, and optimizing men’s health shouldbe incorporated into routine health care, and this can be implemented by using the MHI. This index is particularly useful to primary care physicians who are in a strategic positionto engage men at the peri-retirement age in a conversation about their life goalsbased on their current and predicted health status.

Atypical Ductal Hyperplasia of the Breast on Core Needle Biopsy: Risk of Malignant Upgrade on Surgical Excision

Tiffany Sin Hui Bong,Jun Kiat Thaddaeus Tan,Juliana Teng Swan Ho,Puay Hoon Tan,Wing Sze Lau,Tuan Meng Tan,Jill Su Lin Wong,Veronique Kiak Mien Tan,Benita Kiat Tee Tan,Preetha Madhukumar,Wei Sean Yong 한국유방암학회 2022 Journal of breast cancer Vol.25 No.1

Purpose This study identified factors predicting malignant upgrade for atypical ductal hyperplasia (ADH) diagnosed on core-needle biopsy (CNB) and developed a nomogram to facilitate evidence-based decision making. Methods This retrospective analysis included women diagnosed with ADH at the National Cancer Centre Singapore (NCCS) in 2010–2015. Cox proportional hazards regression was used to identify clinical, radiological, and histological factors associated with malignant upgrade. A nomogram was constructed using variables with the strongest associations in multivariate analysis. Multivariable logistic regression coefficients were used to estimate the predicted probability of upgrade for each factor combination. Results Between 2010 and 2015, 238,122 women underwent mammographic screening under the National Breast Cancer Screening Program. Among 29,564 women recalled, 5,971 CNBs were performed. Of these, 2,876 underwent CNBs at NCCS, with 88 patients (90 lesions) diagnosed with ADH and 26 lesions upgraded to breast malignancy on excision biopsy. In univariate analysis, factors associated with malignant upgrade were the presence of a mass on ultrasound (p = 0.018) or mammography (p = 0.026), microcalcifications (p = 0.047), diffuse microcalcification distribution (p = 0.034), mammographic parenchymal density (p = 0.008). and ≥ 3 separate ADH foci found on biopsy (p = 0.024). Mammographic parenchymal density (hazard ratio [HR], 0.04; 95% confidence interval [CI], 0.005–0.35; p = 0.014), presence of a mass on ultrasound (HR, 10.50; 95% CI, 9.21–25.2; p = 0.010), and number of ADH foci (HR, 1.877; 95% CI, 1.831–1.920; p = 0.002) remained significant in multivariate analysis and were included in the nomogram. Conclusion Our model provided good discrimination of breast cancer risk prediction (C-statistic of 0.81; 95% CI, 0.74–0.88) and selected for a subset of women at low risk (2.1%) of malignant upgrade, who may avoid surgical excision following a CNB diagnosis of ADH.

A novel design method for improving collapse resistances of multi-story steel frames with unequal spans using steel braces

Zheng Tan,Wei-hui Zhong,Bao Meng,Shi-chao Duan,Hong-chen Wang3,Xing-You Yao,Yu-hui Zheng 국제구조공학회 2023 Steel and Composite Structures, An International J Vol.47 No.2

The bearing capacities resisted by the two-bay beams of multi-story planar frames with unequal spans under column removal scenarios differ considerably owing to the asymmetric stress on the left and right beams connected to the failed column and cause the potential for beams with larger span-to-depth ratios to be unable to exert effectively, which is disadvantageous for resisting the vertical load in unequal-span frame structures. To address this problem, the structural measure of adding braces to the weak bays of multi-story unequal-span frames was proposed, with the objective of achieving a coordinated stress state in two-bay beams with unequal spans, thereby improving the collapse resistance of unequal-span frame structures. Before conducting the numerical simulation, the modeling methods were verified by previous experimental results of two multi-story planar frames with and without steel braces. Thereafter, the effects of the tensile and compressive braces on the collapse behavior of the frame structures were elucidated. Then, based on the mechanical action laws of the braces throughout the collapse process, a detailed design method for improving the collapse resistance of unequal-span frame structures was proposed. Finally, the proposed design method was verified by using sufficient example models, and the results demonstrated that the design method has good application prospects and high practical value.

Collapse-resistant performance of a single-story frame assembly and multi-story sub-frame under an internal column-removal scenario

Wei-hui Zhong,Zheng Tan,Li-Min Tian,Bao Meng,Yu-hui Zheng,Shi-chao Daun 국제구조공학회 2021 Steel and Composite Structures, An International J Vol.41 No.5

To elucidate the differences in the collapse behavior between a single-story beam-column assembly and multi-story frame, two 1/3-scale two-bay composite frames, including a single-story composite beam–column assembly and a three-story composite sub-frame, were designed and quasi-statically tested. The load–displacement responses, failure modes, and internal force development of the two frames were analyzed and compared in detail. Furthermore, the resistance mechanisms of the two specimens were explored, and the respective contributions of different load-resisting mechanisms to the total resistances were quantitatively separated to gain deeper insights. The experimental tests indicated that Vierendeel action was present in the two-dimensional multi-story frames, which led to an uneven internal force distribution among the three stories. The collapse resistance of TSDWA-3S in the flexural stage was not significantly increased by the structural redundancy provided by the additional story, as compared to that of TSDWA-1S. Although the development of the load response was similar in the two specimens at flexural stage, the collapse mechanisms of the multi-story composite frame were much more complicated than those of the single-story beam–column assembly, and the combined action between stories was critical in determining the internal force redistribution and rebalancing of the remaining structure.

Anti-collapse performance analysis of unequal span steel–concrete composite substructures

Bao Meng,Liangde Li,Wei-hui Zhong,Zheng Tan,Yu-hui Zheng 국제구조공학회 2021 Steel and Composite Structures, An International J Vol.39 No.4

In the study, three 1:3-scale unequal span steel–concrete composite substructures with top-seat angle and double web angle connection were designed and identified as specimens GTSDWA-0.6, GTSDWA-1.0, and GTSDWA-1.4. Pseudo-static tests and refined numerical model analysis were conducted to examine the anti-progressive collapse performance of a semi-rigid steel–concrete composite substructure. The results indicated that the failure modes of the three specimens revealed that the fracture occurred in the root of the long leg of the top/seat angle in tension at the connection. With increases in the span ratio of the left and right composite beams, the bearing capacities of the composite substructures decreased, and the corresponding displacement increased. With respect to GTSDWA-0.6 and GTSDWA-1.4, the resistance due to the short composite beam corresponded to 62% and 60%, respectively, and the total resistance provided by the short composite beam exceeded that of the long composite beam. With respect to GTSDWA-1.0, the resistance due to the left and right composite beams was similar. All three specimens underwent the flexure mechanism and flexure–axial mixed mechanism stages. They resisted the external load mainly via the flexure mechanism. Moreover, the addition of stiffeners on both sides of the top and seat angles is advantageous in terms of improving the collapse resistance and ductility of unequal span composite substructures.

Long-Term Trends in Ischemic Stroke Incidence and Risk Factors: Perspectives from an Asian Stroke Registry

Benjamin Y.Q. Tan,Joshua T.C. Tan,Dawn Cheah,Huili Zheng,Pin Pin Pek,Deidre A. De Silva,Aftab Ahmad,Bernard P.L. Chan,Hui Meng Chang,Keng He Kong,Sherry H. Young,Kok Foo Tang,Tian Ming Tu,Leonard Leon 대한뇌졸중학회 2020 Journal of stroke Vol.22 No.3

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Fluorescence-in-situ-hybridization in the Surveillance of Urothelial Cancers: Can Use of Cystoscopy or Ureteroscopy be Deferred?

Ho, Christopher Chee Kong,Tan, Wei Phin,Pathmanathan, Rajadurai,Tan, Wei Keith,Tan, Hui Meng Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.7

Background: Fluorescence in situ hybridization (FISH) testing may be useful to screen for bladder carcinoma or dysplasia by detecting aneuploidy chromosomes 3, 7, 17 and deletion of the chromosome 9p21 locus in urine specimens. This study aimed to assess the sensitivity, specificity, positive and negative predictive value of FISH in a multi-ethnic population in Asia. Materials and Methods: Patients with haematuria and/or past history of urothelial cancer on follow-up had their voided urine tested with FISH. Patients then underwent cystoscopy/ureteroscopy and any lesions seen were biopsied. The histopathological reports of the bladder or ureteroscopic mucosal biopsies were then compared with the FISH test results. Results: Two hundred sixty patients were recruited. The sensitivity and specificity of the FISH test was 89.2% and 83.4% respectively. The positive (PPV) and negative predictive values (NPV) were 47.1% and 97.9%. By excluding patients who had positive deletion of chromosome 9, the overall results of the screening test improved: sensitivity 84.6%; specificity 96.4%; PPV 75.9% and NPV 97.9%. Conclusions: UroVysion FISH has a high specificity of detecting urothelial cancer or dysplasia when deletion of chromosome 9 is excluded. Negative UroVysion FISH-tests may allow us to conserve health resources and minimize trauma by deferring cystoscopic or ureteroscopic examination.

Changes in metabolic parameters and adverse kidney and cardiovascular events during glomerulonephritis and renal vasculitis treatment in patients with and without diabetes mellitus

( Cynthia C. Lim ),( Jason C. J. Choo ),( Hui Zhuan Tan ),( Irene Y. J. Mok ),( Yok Mooi Chin ),( Choong Meng Chan ),( Keng Thye Woo ) 대한신장학회 2021 Kidney Research and Clinical Practice Vol.40 No.2

Background: Cardiovascular disease causes significant morbidity and mortality in patients with glomerulonephritis, which is increasingly diagnosed in older individuals who may have diabetes mellitus (DM). We evaluated the impact of DM on metabolic profile, renal and cardiovascular outcomes during treatment and follow-up of individuals with glomerulonephritis. Methods: We performed a retrospective cohort study of 601 consecutive adults with biopsy-proven glomerulonephritis for factors associated with kidney failure, hospitalization for cardiovascular events, and death. Biopsies with isolated diabetic nephropathy were excluded. Results: The median patient age was 49.8 years (36.7-60.9 years) with estimated glomerular filtration rate of 56.7 mL/min/1.73㎡ (27.7-93.2 mL/min/1.73㎡). DM was present in 25.4%. The most frequent diagnoses were minimal change disease (MCD) or focal segmental glomerulosclerosis (FSGS) (29.5%), lupus nephritis (21.3%), immunoglobulin A (IgA) nephropathy (19.1%), and membranous nephropathy (12.1%). The median follow-up was 38.8 months (interquartile range [IQR], 26.8-55.8 months). Among 511 individuals with lupus nephritis, anti-neutrophil cytoplasmic antibody-associated vasculitis, MCD/FSGS, membranous nephropathy, and IgA nephropathy, 52 (10.2%) developed kidney failure at a median 16.4 months (IQR, 2.3-32.2 months), while 29 (5.7%) had cardiovascular-related hospitalizations at 12.9 months (IQR, 4.8-31.8 months) and 31 (6.1%) died at 13.5 months (IQR, 2.5-42.9 months) after diagnosis. Cox regression analysis found that baseline DM was independently associated with kidney failure (adjusted hazard ratio [HR], 2.07; 95% confidence interval [CI], 1.06-4.05, p = 0.03) and cardiovascular-related hospitalization (adjusted HR, 2.69; 95% CI, 1.21-5.98, p = 0.02) but not with mortality. Conclusion: DM was strongly associated with kidney failure and hospitalization for cardiovascular events in patients with biopsy-proven glomerulonephritis.

Comparison of Ligasure Versus Conventional Surgery for Curative Gastric Cancer Resection: a Meta-Analysis

Hu, Tian-Peng,He, Xiang-Hui,Meng, Zhao-Wei,Jia, Qiang,Tan, Jian,Li, Xue Asian Pacific Journal of Cancer Prevention 2016 Asian Pacific journal of cancer prevention Vol.17 No.4

Background: The LigaSure vessel sealing system has been proposed to save operation time and reduce intraoperative blood loss for various surgeries. However, its usage for gastric cancer is still controversial. The aim of the present meta-analysis was to compare the effectiveness of LigaSure with conventional surgery in gastrectomy. Materials and Methods: Sources were retrieved from the Cochrane Library, MEDLINE, EMBASE, SCOPUS and Google Scholar until February, 2015. All randomized controlled trials comparing LigaSure with conventional surgery in curative gastric cancer resection were selected. After data extraction, statistics were performed by Review Manager 5.1 software. Results: Three eligible randomized controlled trials were evaluated, with a total of 335 patients. The quality of the included trials was good, yet some methodological and clinical heterogeneity existed. There were no significant differences between the LigaSure and conventional groups in operative time (weighted mean difference [WMD], -22.95 minutes; 95% confidence interval [CI], [-59.75, 13.85]; P = 0.22), blood loss (WMD, -45.8 ml; 95% CI, [-134.5, 42.90]; P = 0.31), nor the incidence of surgical complications (odds ratio, 1.18; 95% CI, [0.68, 2.05]; P = 0.54). But there was a longer duration of hospital stay in LigaSure group (WMD, 1.41 days; 95% CI, [0.14, 2.68]; P = 0.03). Conclusions: All available randomized evidence has been summarized. LigaSure does not confer significant advantage over conventional surgery for curative gastric cancer resection. The usefulness of the device may be limited in gastrectomy. But, more trials are needed for further assessment of the LigaSure system for gastric cancer.