1
|
Mukhopadhyay S, Huang HY, Lin Z, Ranieri M, Li S, Sahu S, Liu Y, Ban Y, Guidry K, Hu H, Lopez A, Sherman F, Tan YJ, Lee YT, Armstrong AP, Dolgalev I, Sahu P, Zhang T, Lu W, Gray NS, Christensen JG, Tang TT, Velcheti V, Khodadadi-Jamayran A, Wong KK, Neel BG. Genome-Wide CRISPR Screens Identify Multiple Synthetic Lethal Targets That Enhance KRASG12C Inhibitor Efficacy. Cancer Res 2023; 83:4095-4111. [PMID: 37729426 PMCID: PMC10841254 DOI: 10.1158/0008-5472.can-23-2729] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2023] [Revised: 09/16/2023] [Accepted: 09/18/2023] [Indexed: 09/22/2023]
Abstract
Non-small lung cancers (NSCLC) frequently (∼30%) harbor KRAS driver mutations, half of which are KRASG12C. KRAS-mutant NSCLC with comutated STK11 and/or KEAP1 is particularly refractory to conventional, targeted, and immune therapy. Development of KRASG12C inhibitors (G12Ci) provided a major therapeutic advance, but resistance still limits their efficacy. To identify genes whose deletion augments efficacy of the G12Cis adagrasib (MRTX-849) or adagrasib plus TNO155 (SHP2i), we performed genome-wide CRISPR/Cas9 screens on KRAS/STK11-mutant NSCLC lines. Recurrent, potentially targetable, synthetic lethal (SL) genes were identified, including serine-threonine kinases, tRNA-modifying and proteoglycan synthesis enzymes, and YAP/TAZ/TEAD pathway components. Several SL genes were confirmed by siRNA/shRNA experiments, and the YAP/TAZ/TEAD pathway was extensively validated in vitro and in mice. Mechanistic studies showed that G12Ci treatment induced gene expression of RHO paralogs and activators, increased RHOA activation, and evoked ROCK-dependent nuclear translocation of YAP. Mice and patients with acquired G12Ci- or G12Ci/SHP2i-resistant tumors showed strong overlap with SL pathways, arguing for the relevance of the screen results. These findings provide a landscape of potential targets for future combination strategies, some of which can be tested rapidly in the clinic. SIGNIFICANCE Identification of synthetic lethal genes with KRASG12C using genome-wide CRISPR/Cas9 screening and credentialing of the ability of TEAD inhibition to enhance KRASG12C efficacy provides a roadmap for combination strategies. See related commentary by Johnson and Haigis, p. 4005.
Collapse
Affiliation(s)
- Suman Mukhopadhyay
- Laura and Isaac Perlmutter Cancer Center, NYU Grossman School of Medicine, NYU Langone Health, New York, United States
| | - Hsin-Yi Huang
- Laura and Isaac Perlmutter Cancer Center, NYU Grossman School of Medicine, NYU Langone Health, New York, United States
| | - Ziyan Lin
- Applied Bioinformatics Laboratories, Office of Science and Research, New York University Grossman School of Medicine, New York, United States
| | - Michela Ranieri
- Laura and Isaac Perlmutter Cancer Center, NYU Grossman School of Medicine, NYU Langone Health, New York, United States
| | - Shuai Li
- Laura and Isaac Perlmutter Cancer Center, NYU Grossman School of Medicine, NYU Langone Health, New York, United States
| | - Soumyadip Sahu
- Laura and Isaac Perlmutter Cancer Center, NYU Grossman School of Medicine, NYU Langone Health, New York, United States
| | - Yingzhuo Liu
- Laura and Isaac Perlmutter Cancer Center, NYU Grossman School of Medicine, NYU Langone Health, New York, United States
| | - Yi Ban
- Laura and Isaac Perlmutter Cancer Center, NYU Grossman School of Medicine, NYU Langone Health, New York, United States
| | - Kayla Guidry
- Laura and Isaac Perlmutter Cancer Center, NYU Grossman School of Medicine, NYU Langone Health, New York, United States
| | - Hai Hu
- Laura and Isaac Perlmutter Cancer Center, NYU Grossman School of Medicine, NYU Langone Health, New York, United States
| | - Alfonso Lopez
- Laura and Isaac Perlmutter Cancer Center, NYU Grossman School of Medicine, NYU Langone Health, New York, United States
| | - Fiona Sherman
- Laura and Isaac Perlmutter Cancer Center, NYU Grossman School of Medicine, NYU Langone Health, New York, United States
| | - Yi Jer Tan
- Laura and Isaac Perlmutter Cancer Center, NYU Grossman School of Medicine, NYU Langone Health, New York, United States
| | - Yeuan Ting Lee
- Laura and Isaac Perlmutter Cancer Center, NYU Grossman School of Medicine, NYU Langone Health, New York, United States
| | - Amanda P. Armstrong
- Laura and Isaac Perlmutter Cancer Center, NYU Grossman School of Medicine, NYU Langone Health, New York, United States
| | - Igor Dolgalev
- Laura and Isaac Perlmutter Cancer Center, NYU Grossman School of Medicine, NYU Langone Health, New York, United States
| | - Priyanka Sahu
- Laura and Isaac Perlmutter Cancer Center, NYU Grossman School of Medicine, NYU Langone Health, New York, United States
| | - Tinghu Zhang
- Department of Chemical and Systems Biology, ChEM-H, Stanford Cancer Institute, School of Medicine, Stanford University, California, United States
| | - Wenchao Lu
- Department of Chemical and Systems Biology, ChEM-H, Stanford Cancer Institute, School of Medicine, Stanford University, California, United States
| | - Nathanael S. Gray
- Department of Chemical and Systems Biology, ChEM-H, Stanford Cancer Institute, School of Medicine, Stanford University, California, United States
| | | | - Tracy T. Tang
- Vivace Therapeutics, Inc., San Mateo, California, United States
| | - Vamsidhar Velcheti
- Laura and Isaac Perlmutter Cancer Center, NYU Grossman School of Medicine, NYU Langone Health, New York, United States
| | - Alireza Khodadadi-Jamayran
- Applied Bioinformatics Laboratories, Office of Science and Research, New York University Grossman School of Medicine, New York, United States
| | - Kwok-Kin Wong
- Laura and Isaac Perlmutter Cancer Center, NYU Grossman School of Medicine, NYU Langone Health, New York, United States
| | - Benjamin G. Neel
- Laura and Isaac Perlmutter Cancer Center, NYU Grossman School of Medicine, NYU Langone Health, New York, United States
| |
Collapse
|
2
|
Lee YT, Tan YJ, Oon CE. BZD9L1 Differentially Regulates Sirtuins in Liver-Derived Cells by Inducing Reactive Oxygen Species. Biomedicines 2023; 11:3059. [PMID: 38002059 PMCID: PMC10669747 DOI: 10.3390/biomedicines11113059] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2023] [Revised: 11/04/2023] [Accepted: 11/06/2023] [Indexed: 11/26/2023] Open
Abstract
Growing evidence has highlighted that mitochondrial dysfunction contributes to drug-induced toxicities and leads to drug attrition and post-market withdrawals. The acetylation or deacetylation of mitochondrial proteins can affect mitochondrial functions as the cells adapt to various cellular stresses and other metabolic challenges. SIRTs act as critical deacetylases in modulating mitochondrial function in response to drug toxicity, oxidative stress, reactive oxygen species (ROS), and energy metabolism. We previously showed that a recently characterised SIRT inhibitor (BZD9L1) is non-toxic in rodents in a short-term toxicity evaluation. However, the impact of BZD9L1 on mitochondrial function is unknown. This work aims to determine the effects of BZD9L1 on mitochondrial function in human normal liver and kidney-derived cell lines using the Agilent Seahorse Cell Mito Stress Test to complement our short-term toxicity evaluations in vivo. The Mito Stress assay revealed that BZD9L1 could potentially trigger oxidative stress by inducing ROS, which promotes proton leak and reduces coupling efficiency in liver-derived THLE cells. However, the same was not observed in human kidney-derived HEK293 cells. Interestingly, BZD9L1 had no impact on SIRT3 protein expression in both cell lines but affected SOD2 and its acetylated form at 72 h in THLE cells, indicating that BZD9L1 exerted its effect through SIRT3 activity rather than protein expression. In contrast, BZD9L1 reduced SIRT1 protein expression and impacted the p53 protein differently in both cell lines. Although BZD9L1 did not affect the spare respiratory capacity in vitro, these findings call for further validation of mitochondrial function through assessment of other mitochondrial parameters to evaluate the safety of BZD9L1.
Collapse
Affiliation(s)
| | | | - Chern Ein Oon
- Institute for Research in Molecular Medicine (INFORMM), Universiti Sains Malaysia, Gelugor 11800, Penang, Malaysia; (Y.T.L.); (Y.J.T.)
| |
Collapse
|
3
|
Oon CE, Subramaniam AV, Ooi LY, Yehya AHS, Lee YT, Kaur G, Sasidharan S, Qiu B, Wang X. BZD9L1 benzimidazole analogue hampers colorectal tumor progression by impeding angiogenesis. World J Gastrointest Oncol 2023; 15:810-827. [PMID: 37275453 PMCID: PMC10237024 DOI: 10.4251/wjgo.v15.i5.810] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/03/2023] [Revised: 02/17/2023] [Accepted: 04/21/2023] [Indexed: 05/12/2023] Open
Abstract
BACKGROUND The development of new vasculatures (angiogenesis) is indispensable in supplying oxygen and nutrients to fuel tumor growth. Epigenetic dysregulation in the tumor vasculature is critical to colorectal cancer (CRC) progression. Sirtuin (SIRT) enzymes are highly expressed in blood vessels. BZD9L1 benzimidazole analogue is a SIRT 1 and 2 inhibitor with reported anticancer activities in CRC. However, its role has yet to be explored in CRC tumor angiogenesis.
AIM To investigate the anti-angiogenic potential of BZD9L1 on endothelial cells (EC) in vitro, ex vivo and in HCT116 CRC xenograft in vivo models.
METHODS EA.hy926 EC were treated with half inhibitory concentration (IC50) (2.5 μM), IC50 (5.0 μM), and double IC50 (10.0 μM) of BZD9L1 and assessed for cell proliferation, adhesion and SIRT 1 and 2 protein expression. Next, 2.5 μM and 5.0 μM of BZD9L1 were employed in downstream in vitro assays, including cell cycle, cell death and sprouting in EC. The effect of BZD9L1 on cell adhesion molecules and SIRT 1 and 2 were assessed via real-time quantitative polymerase chain reaction (qPCR). The growth factors secreted by EC post-treatment were evaluated using the Quantibody Human Angiogenesis Array. Indirect co-culture with HCT116 CRC cells was performed to investigate the impact of growth factors modulated by BZD9L1-treated EC on CRC. The effect of BZD9L1 on sprouting impediment and vessel regression was determined using mouse choroids. HCT116 cells were also injected subcutaneously into nude mice and analyzed for the outcome of BZD9L1 on tumor necrosis, Ki67 protein expression indicative of proliferation, cluster of differentiation 31 (CD31) and CD34 EC markers, and SIRT 1 and 2 genes via hematoxylin and eosin, immunohistochemistry and qPCR, respectively.
RESULTS BZD9L1 impeded EC proliferation, adhesion, and spheroid sprouting through the downregulation of intercellular adhesion molecule 1, vascular endothelial cadherin, integrin-alpha V, SIRT1 and SIRT2 genes. The compound also arrested the cells at G1 phase and induced apoptosis in the EC. In mouse choroids, BZD9L1 inhibited sprouting and regressed sprouting vessels compared to the negative control. Compared to the negative control, the compound also reduced the protein levels of angiogenin, basic fibroblast growth factor, platelet-derived growth factor and placental growth factor, which then inhibited HCT116 CRC spheroid invasion in co-culture. In addition, a significant reduction in CRC tumor growth was noted alongside the downregulation of human SIRT1 (hSIRT1), hSIRT2, CD31, and CD34 EC markers and murine SIRT2 gene, while the murine SIRT1 gene remained unaffected, compared to vehicle control. Histology analyses revealed that BZD9L1 at low (50 mg/kg) and high (250 mg/kg) doses reduced Ki-67 protein expression, while BZD9L1 at the high dose diminished tumor necrosis compared to vehicle control.
CONCLUSION These results highlighted the anti-angiogenic potential of BZD9L1 to reduce CRC tumor progression. Furthermore, together with previous anticancer findings, this study provides valuable insights into the potential of BZD9L1 to co-target CRC tumor vasculatures and cancer cells via SIRT1 and/or SIRT2 down-regulation to improve the therapeutic outcome.
Collapse
Affiliation(s)
- Chern Ein Oon
- Institute for Research in Molecular Medicine, Universiti Sains Malaysia, Penang 11800, Malaysia
| | - Ayappa V Subramaniam
- Institute for Research in Molecular Medicine, Universiti Sains Malaysia, Penang 11800, Malaysia
| | - Lik Yang Ooi
- Institute for Research in Molecular Medicine, Universiti Sains Malaysia, Penang 11800, Malaysia
| | - Ashwaq Hamid Salem Yehya
- Cancer Research, Eman Biodiscoveries, Kedah 08000, Malaysia
- Vatche and Tamar Division of Digestive Diseases, Department of Medicine, David Geffen School of Medicine at University of California Los Angeles, Los Angeles, CA 90095, United States
| | - Yeuan Ting Lee
- Institute for Research in Molecular Medicine, Universiti Sains Malaysia, Penang 11800, Malaysia
| | - Gurjeet Kaur
- Institute for Research in Molecular Medicine, Universiti Sains Malaysia, Penang 11800, Malaysia
| | - Sreenivasan Sasidharan
- Institute for Research in Molecular Medicine, Universiti Sains Malaysia, Penang 11800, Malaysia
| | - Beiying Qiu
- Academic Clinical Program, Duke-NUS Medical School, National University of Singapore, Singapore 169857, Singapore
- Singapore National Eye Centre, Singapore Eye Research Institute, Singapore 168751, Singapore
| | - Xiaomeng Wang
- Academic Clinical Program, Duke-NUS Medical School, National University of Singapore, Singapore 169857, Singapore
- Singapore National Eye Centre, Singapore Eye Research Institute, Singapore 169857, Singapore
| |
Collapse
|
4
|
Lee YT, Tan YJ, Oon CE. Benzimidazole and its derivatives as cancer therapeutics: The potential role from traditional to precision medicine. Acta Pharm Sin B 2023; 13:478-497. [PMID: 36873180 PMCID: PMC9978992 DOI: 10.1016/j.apsb.2022.09.010] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Revised: 08/11/2022] [Accepted: 09/08/2022] [Indexed: 11/18/2022] Open
Abstract
Cancer is the second leading cause of mortality globally which remains a continuing threat to human health today. Drug insensitivity and resistance are critical hurdles in cancer treatment; therefore, the development of new entities targeting malignant cells is considered a high priority. Targeted therapy is the cornerstone of precision medicine. The synthesis of benzimidazole has garnered the attention of medicinal chemists and biologists due to its remarkable medicinal and pharmacological properties. Benzimidazole has a heterocyclic pharmacophore, which is an essential scaffold in drug and pharmaceutical development. Multiple studies have demonstrated the bioactivities of benzimidazole and its derivatives as potential anticancer therapeutics, either through targeting specific molecules or non-gene-specific strategies. This review provides an update on the mechanism of actions of various benzimidazole derivatives and the structure‒activity relationship from conventional anticancer to precision healthcare and from bench to clinics.
Collapse
|
5
|
Lee YT, Tan YJ, Mok PY, Kaur G, Sreenivasan S, Falasca M, Oon CE. Sex-divergent expression of cytochrome P450 and SIRTUIN 1-7 proteins in toxicity evaluation of a benzimidazole-derived epigenetic modulator in mice. Toxicol Appl Pharmacol 2022; 445:116039. [PMID: 35489524 DOI: 10.1016/j.taap.2022.116039] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2022] [Revised: 04/21/2022] [Accepted: 04/22/2022] [Indexed: 10/18/2022]
Abstract
Efforts in precision medicine to combat aberrant epigenome have led to the development of epigenetic targeting drugs. We have previously reported the capability of the BZD9L1 epigenetic modulator to impede colorectal tumour growth in vitro and in vivo through sirtuin (SIRT) inhibition. Although most benzimidazole derivatives are commonly less toxic, their effects on SIRTs and cytochrome P450 (CYP) regulations have not been explored alongside toxicity assessments. SIRTs are histone deacetylases that are crucial in maintaining metabolic homeostasis, whereas CYP is essential in drug metabolism. This study aims to determine the toxicology profile of BZD9L1 through oral acute and repeated dose toxicity evaluations, along with molecular analyses of SIRT, CYP and relevant toxicity markers through western blot and quantitative polymerase chain reaction (qPCR). BZD9L1 demonstrated no sign of acute toxicity at the limit dose (2000 mg/kg). The 28-day toxicity study highlighted the tolerability of repeated dose administration without adverse effects. BZD9L1 showed a sex-divergent regulation of hepatic SIRT1-7, CYP2A5 and CYP2D proteins. Furthermore, BZD9L1 did not induce the expression of organ injury proteins or alter the gene expression of cellular function indicators in mouse liver and kidneys, hence demonstrating, at least in part, the safety of BZD9L1 in short-term evaluations. The present study cautions for personalised strategies when employing benzimidazole-derived epigenetic therapeutics.
Collapse
Affiliation(s)
- Yeuan Ting Lee
- Institute for Research in Molecular Medicine (INFORMM), Universiti Sains Malaysia, 11800 Penang, Malaysia
| | - Yi Jer Tan
- Institute for Research in Molecular Medicine (INFORMM), Universiti Sains Malaysia, 11800 Penang, Malaysia
| | - Pei Yi Mok
- Institute for Research in Molecular Medicine (INFORMM), Universiti Sains Malaysia, 11800 Penang, Malaysia
| | - Gurjeet Kaur
- Institute for Research in Molecular Medicine (INFORMM), Universiti Sains Malaysia, 11800 Penang, Malaysia
| | - Sasidharan Sreenivasan
- Institute for Research in Molecular Medicine (INFORMM), Universiti Sains Malaysia, 11800 Penang, Malaysia
| | - Marco Falasca
- Curtin Medical School, Curtin Health Innovation Research Institute (CHIRI), Curtin University, GPO Box U1987, Perth, WA 6845, Australia
| | - Chern Ein Oon
- Institute for Research in Molecular Medicine (INFORMM), Universiti Sains Malaysia, 11800 Penang, Malaysia.
| |
Collapse
|
6
|
Yu WS, Chang MH, Lee HL, Lee YT, Tsai MC, Wang CC. Recurrent umbilical varix rupture with hemoperitoneum: a case report and review of literature. BMC Gastroenterol 2022; 22:160. [PMID: 35365084 PMCID: PMC8973573 DOI: 10.1186/s12876-022-02167-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/21/2021] [Accepted: 02/15/2022] [Indexed: 11/10/2022] Open
Abstract
Background Non-traumatic hemoperitoneum was a rare event with the risk of sudden death. Spontaneous rupture of hepatocellular carcinoma is the most intuitive diagnosis when hemoperitoneum occurs in cirrhotic patients who are not regularly followed up. However, other etiologies of hemoperitoneum, such as intra-abdominal varix rupture, should be kept in mind.
Case presentation A 44-year-old man with alcoholic liver cirrhosis, Child–Pugh B was sent to our emergency department (ED) because of recurrent abdominal pain and hypovolemic shock. He had similar symptoms one month ago and was diagnosed as hepatocellular carcinoma (HCC) rupture with hemoperitoneum, therefore he underwent trans-arterial embolization (TAE). However, the follow-up magnetic resonance imaging (MRI) showed less possibility of hepatocellular carcinoma. Contrast enhanced abdominal computed tomography (CT) showed possible umbilical vein contrast agent extravasation. Exploratory laparotomy confirmed the diagnosis of rupture umbilical varix with hemoperitoneum. Conclusion Although umbilical varix rupture is a rare cause of hemoperitoneum, it should be kept in mind in cirrhotic patients with unexplained hemoperitoneum. Supplementary Information The online version contains supplementary material available at 10.1186/s12876-022-02167-3.
Collapse
Affiliation(s)
- W S Yu
- Division of Gastroenterology and Hepatology, Department of Internal Medicine, Chung Shan Medical University Hospital, Taichung, Taiwan
| | - M H Chang
- Division of Gastroenterology and Hepatology, Department of Internal Medicine, Chung Shan Medical University Hospital, Taichung, Taiwan
| | - H L Lee
- Department of Surgery, Chung Shan Medical University Hospital, Taichung, Taiwan.,School of Medicine, Chung Shan Medical University, Taichung, Taiwan
| | - Y T Lee
- Infection Control, Chung Shan Medical University Hospital, Taichung, Taiwan.,School of Medicine, Chung Shan Medical University, Taichung, Taiwan
| | - M C Tsai
- Division of Gastroenterology and Hepatology, Department of Internal Medicine, Chung Shan Medical University Hospital, Taichung, Taiwan.,School of Medicine, Chung Shan Medical University, Taichung, Taiwan
| | - C C Wang
- Division of Gastroenterology and Hepatology, Department of Internal Medicine, Chung Shan Medical University Hospital, Taichung, Taiwan. .,School of Medicine, Chung Shan Medical University, Taichung, Taiwan.
| |
Collapse
|
7
|
Wong D, Lee YT, Tang GPY, Chan SSC. Surgical treatment of pelvic organ prolapse in women aged ≥75 years in Hong Kong: a multicentre retrospective study. Hong Kong Med J 2022; 28:107-115. [PMID: 35354666 DOI: 10.12809/hkmj219271] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
INTRODUCTION Pelvic organ prolapse (POP) is common among older women. With the increasing lifespan and emphasis on quality of life worldwide, older women increasingly prefer surgical treatment for POP. We reviewed the surgical treatment of POP in older women to characterise its safety, effectiveness, and the type most often selected. METHODS This multicentre, retrospective study was conducted at four hospitals between 2013 and 2018. Included patients were aged ≥75 years and had undergone POP surgery. We compared patient demographic characteristics, POP severity, and surgical outcomes between reconstructive and obliterative surgeries; these comparisons were also made among vaginal hysterectomy plus pelvic floor repair (VHPFR), transvaginal mesh surgery (TVM), vaginal hysterectomy (VH) plus colpocleisis, and colpocleisis alone. RESULTS In total, 343 patients were included; 84.3% and 15.7% underwent reconstructive and obliterative surgeries, respectively. Overall, 246 (71.7%), 43 (12.5%), 20 (5.8%), and 34 (9.9%) patients underwent VHPFR, TVM, VH plus colpocleisis, and colpocleisis alone, respectively. Patients who were older (81.9 vs 79.6 y; P=0.001), had vault prolapse (38.9% vs 3.5%; P<0.001), and had medical co-morbidities (37% vs 4.8%; P<0.001) chose obliterative surgery more frequently than reconstructive surgery. Obliterative surgeries had shorter operative time (73.5 min vs 107 min; P<0.001) and fewer surgical complications (9.3% vs 28.0%; P=0.003). Vaginal hysterectomy plus pelvic floor repair had the highest rate of surgical complications (most were minor), while colpocleisis alone had the lowest rate (30.1% vs 8.8%; P=0.01). CONCLUSIONS Pelvic organ prolapse surgeries were safe and effective for older women. Colpocleisis may be appropriate as primary surgery for fragile older women.
Collapse
Affiliation(s)
- D Wong
- Department of Obstetrics and Gynaecology, Pamela Youde Nethersole Eastern Hospital, Hong Kong
| | - Y T Lee
- Department of Obstetrics and Gynaecology, Prince of Margaret Hospital, Hong Kong
| | - G P Y Tang
- Department of Obstetrics and Gynaecology, Kwong Wah Hospital, Hong Kong
| | - S S C Chan
- Department of Obstetrics and Gynaecology, Prince of Wales Hospital, Hong Kong
| |
Collapse
|
8
|
Tan YJ, Lee YT, Mancera RL, Oon CE. BZD9L1 sirtuin inhibitor: Identification of key molecular targets and their biological functions in HCT 116 colorectal cancer cells. Life Sci 2021; 284:119747. [PMID: 34171380 DOI: 10.1016/j.lfs.2021.119747] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2020] [Revised: 05/22/2021] [Accepted: 06/11/2021] [Indexed: 02/07/2023]
Abstract
BZD9L1 was previously described as a SIRT1/2 inhibitor with anti-cancer activities in colorectal cancer (CRC), either as a standalone chemotherapy or in combination with 5-fluorouracil. BZD9L1 was reported to induce apoptosis in CRC cells; however, the network of intracellular pathways and crosstalk between molecular players mediated by BZD9L1 is not fully understood. This study aimed to uncover the mechanisms involved in BZD9L1-mediated cytotoxicity based on previous and new findings for the prediction and identification of related pathways and key molecular players. BZD9L1-regulated candidate targets (RCTs) were identified using a range of molecular, cell-based and biochemical techniques on the HCT 116 cell line. BZD9L1 regulated major cancer pathways including Notch, p53, cell cycle, NFκB, Myc/MAX, and MAPK/ERK signalling pathways. BZD9L1 also induced reactive oxygen species (ROS), regulated apoptosis-related proteins, and altered cell polarity and adhesion profiles. In silico analyses revealed that most RCTs were interconnected, and were involved in the modulation of catalytic activity, metabolism and transcription regulation, response to cytokines, and apoptosis signalling pathways. These RCTs were implicated in p53-dependent apoptosis pathway. This study provides the first assessment of possible associations of molecular players underlying the cytotoxic activity of BZD9L1, and establishes the links between RCTs and apoptosis through the p53 pathway.
Collapse
Affiliation(s)
- Yi Jer Tan
- Institute for Research in Molecular Medicine (INFORMM), Universiti Sains Malaysia, Penang 11800, Malaysia; Curtin Medical School, Curtin Health Innovation Research Institute (CHIRI) and Curtin Institute for Computation, Curtin University, GPO Box U1987, Perth, WA 6845, Australia
| | - Yeuan Ting Lee
- Institute for Research in Molecular Medicine (INFORMM), Universiti Sains Malaysia, Penang 11800, Malaysia
| | - Ricardo L Mancera
- Curtin Medical School, Curtin Health Innovation Research Institute (CHIRI) and Curtin Institute for Computation, Curtin University, GPO Box U1987, Perth, WA 6845, Australia.
| | - Chern Ein Oon
- Institute for Research in Molecular Medicine (INFORMM), Universiti Sains Malaysia, Penang 11800, Malaysia.
| |
Collapse
|
9
|
Lee YT, Tan YJ, Falasca M, Oon CE. Cancer-Associated Fibroblasts: Epigenetic Regulation and Therapeutic Intervention in Breast Cancer. Cancers (Basel) 2020; 12:cancers12102949. [PMID: 33066013 PMCID: PMC7600259 DOI: 10.3390/cancers12102949] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2020] [Revised: 09/24/2020] [Accepted: 09/30/2020] [Indexed: 02/06/2023] Open
Abstract
Simple Summary Drug resistance and insensitivity to treatments are the main challenges in breast cancer therapy. Cancer-associated fibroblasts (CAFs) are heterogeneous stromal cells with prevailing roles in cancer development and progression. Epigenetic alterations are essential in regulating CAF activation and heterogeneity. These modifications are druggable targets that can be reversed using pharmacological interventions. CAFs therefore, have a remarkable potential as a therapeutic target in breast cancer. This review provides an update on the mechanisms of epigenetic modulation in breast cancer and discusses the challenges of translating the optimism of CAF-directed therapies from bench to clinic. Abstract Breast cancer is the leading cause of cancer-related mortality in women worldwide. Cancer-associated fibroblasts (CAFs) are a heterogeneous population of cells in the solid tumour microenvironment. These cells are positively linked to breast cancer progression. Breast CAFs can be categorised into distinct subtypes according to their roles in breast carcinogenesis. Epigenetic modifications change gene expression patterns as a consequence of altered chromatin configuration and DNA accessibility to transcriptional machinery, without affecting the primary structure of DNA. Epigenetic dysregulation in breast CAFs may enhance breast cancer cell survival and ultimately lead to therapeutic resistance. A growing body of evidence has described epigenetic modulators that target histones, DNA, and miRNA as a promising approach to treat cancer. This review aims to summarise the current findings on the mechanisms involved in the epigenetic regulation in breast CAFs and discusses the potential therapeutic strategies via targeting these factors.
Collapse
Affiliation(s)
- Yeuan Ting Lee
- Institute for Research in Molecular Medicine (INFORMM), Universiti Sains Malaysia, Penang 11800, Malaysia; (Y.T.L.); (Y.J.T.)
| | - Yi Jer Tan
- Institute for Research in Molecular Medicine (INFORMM), Universiti Sains Malaysia, Penang 11800, Malaysia; (Y.T.L.); (Y.J.T.)
| | - Marco Falasca
- Metabolic Signalling Group, School of Pharmacy and Biomedical Sciences, Curtin Health Innovation Research Institute, Curtin University, Perth, WA 6102, Australia
- Correspondence: (M.F.); (C.E.O.); Tel.: +61-892-669-712 (M.F.); +60-4653-4879 (C.E.O.)
| | - Chern Ein Oon
- Institute for Research in Molecular Medicine (INFORMM), Universiti Sains Malaysia, Penang 11800, Malaysia; (Y.T.L.); (Y.J.T.)
- Correspondence: (M.F.); (C.E.O.); Tel.: +61-892-669-712 (M.F.); +60-4653-4879 (C.E.O.)
| |
Collapse
|
10
|
Tan YJ, Lee YT, Petersen SH, Kaur G, Kono K, Tan SC, Majid AMSA, Oon CE. BZD9L1 sirtuin inhibitor as a potential adjuvant for sensitization of colorectal cancer cells to 5-fluorouracil. Ther Adv Med Oncol 2019; 11:1758835919878977. [PMID: 31632470 PMCID: PMC6767736 DOI: 10.1177/1758835919878977] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2019] [Accepted: 09/06/2019] [Indexed: 02/06/2023] Open
Abstract
Background: This study aims to investigate the combination effect of a novel sirtuin
inhibitor (BZD9L1) with 5-fluorouracil (5-FU) and to determine its molecular
mechanism of action in colorectal cancer (CRC). Methods: BZD9L1 and 5-FU either as single treatment or in combination were tested
against CRC cells to evaluate synergism in cytotoxicity, senescence and
formation of micronucleus, cell cycle and apoptosis, as well as the
regulation of related molecular players. The effects of combined treatments
at different doses on stress and apoptosis, migration, invasion and cell
death mechanism were evaluated through two-dimensional and three-dimensional
cultures. In vivo studies include investigation on the
combination effects of BZD9L1 and 5-FU on colorectal tumour xenograft growth
and an evaluation of tumour proliferation and apoptosis using
immunohistochemistry. Results: Combination treatments exerted synergistic reduction on cell viability on HCT
116 cells but not on HT-29 cells. Combined treatments reduced survival,
induced cell cycle arrest, apoptosis, senescence and micronucleation in HCT
116 cells through modulation of multiple responsible molecular players and
apoptosis pathways, with no effect in epithelial mesenchymal transition
(EMT). Combination treatments regulated SIRT1 and SIRT2 protein expression
levels differently and changed SIRT2 protein localization. Combined
treatment reduced growth, migration, invasion and viability of HCT 116
spheroids through apoptosis, when compared with the single treatment. In
addition, combined treatment was found to reduce tumour growth in
vivo through reduction of tumour proliferation and necrosis
compared with the vehicle control group. This highlights the potential
therapeutic effects of BZD9L1 and 5-FU towards CRC. Conclusion: This study may pave the way for use of BZD9L1 as an adjuvant to 5-FU in
improving the therapeutic efficacy for the treatment of colorectal
cancer.
Collapse
Affiliation(s)
- Yi Jer Tan
- Institute for Research in Molecular Medicine (INFORMM), Universiti Sains Malaysia, Penang, Malaysia
| | - Yeuan Ting Lee
- Institute for Research in Molecular Medicine (INFORMM), Universiti Sains Malaysia, Penang, Malaysia
| | - Sven H Petersen
- Cancer Science Institute of Singapore, National University of Singapore, Singapore, Singapore
| | - Gurjeet Kaur
- Institute for Research in Molecular Medicine (INFORMM), Universiti Sains Malaysia, Penang, Malaysia
| | - Koji Kono
- Cancer Science Institute of Singapore, National University of Singapore, Singapore, Singapore
| | - Soo Choon Tan
- USains Biomics Laboratory Testing Services Sdn. Bhd., Universiti Sains Malaysia, Penang, Malaysia
| | - Amin M S Abdul Majid
- EMAN Testing and Research Laboratories, Department of Pharmacology, School of Pharmaceutical Sciences, Universiti Sains Malaysia, Penang, Malaysia
| | - Chern Ein Oon
- Institute for Research in Molecular Medicine (INFORMM), Universiti Sains Malaysia, Penang, 11800, Malaysia
| |
Collapse
|
11
|
Ferguson M, Bhinge R, Park J, Lee YT, Law KH. A Data Processing Pipeline for Prediction of Milling Machine Tool Condition from Raw Sensor Data. Smart Sustain Manuf Syst 2018; 2:10.1520/SSMS20180019 . [PMID: 31093603 PMCID: PMC6512847 DOI: 10.1520/ssms20180019] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
With recent advances in sensor and computing technology, it is now possible to use real-time machine learning techniques to monitor the state of manufacturing machines. However, making accurate predictions from raw sensor data is still a difficult challenge. In this work, a data processing pipeline is developed to predict the condition of a milling machine tool using raw sensor data. Acceleration and audio time series sensor data is aggregated into blocks that correspond to the individual cutting operations of the Computer Numerical Control (CNC) milling machine. Each block of data is preprocessed using well-known and computationally efficient signal processing techniques. A novel kernel function is proposed to approximate the covariance between preprocessed blocks of time series data. Several Gaussian process regression models are trained to predict tool condition, each with a different covariance kernel function. The model with the novel covariance function outperforms the models that use more common covariance functions. The trained models are expressed using the Predictive Model Markup Language (PMML), where possible, to demonstrate how the predictive model component of the pipeline can be represented in a standardized form. The tool condition model is shown to be accurate, especially when predicting the condition of lightly worn tools.
Collapse
Affiliation(s)
- M Ferguson
- Stanford University, Civil and Environmental Engineering, Stanford, CA, USA
| | - R Bhinge
- Infinite Uptime, Inc. Berkeley, CA, USA
| | - J Park
- Korea Advanced Institute of Science and Technology, Industrial and Systems Engineering, Daejeon, South Korea
| | - Y T Lee
- National Institute of Standards and Technology, Systems Integration Division, Gaithersburg, MD, USA
| | - K H Law
- Stanford University, Civil and Environmental Engineering, Stanford, CA, USA
| |
Collapse
|
12
|
Ziegler AD, Echaubard P, Lee YT, Chuah CJ, Wilcox BA, Grundy-Warr C, Sithithaworn P, Petney TN, Laithevewat L, Ong X, Andrews RH, Ismail T, Sripa B, Khuntikeo N, Poonpon K, Tungtang P, Tuamsuk K. Untangling the Complexity of Liver Fluke Infection and Cholangiocarcinoma in NE Thailand Through Transdisciplinary Learning. Ecohealth 2016; 13:316-327. [PMID: 26822781 DOI: 10.1007/s10393-015-1087-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/19/2015] [Revised: 10/22/2015] [Accepted: 11/19/2015] [Indexed: 06/05/2023]
Abstract
This study demonstrates how a transdisciplinary learning approach provided new insights for explaining persistent Opisthorchis viverrini infection in northern Thailand, as well as elucidating problems of focusing solely on the parasite as a means of addressing high prevalence of cholangiocarcinoma. Researchers from diverse backgrounds collaborated to design an investigative homestay program for 72 Singaporean and Thai university students in five northeast Thai villages. The students explored how liver fluke infection and potential cholangiocarcinoma development are influenced by local landscape dynamics, aquatic ecology, livelihoods, food culture and health education. Qualitative fieldwork was guided daily by the researchers in a collaborative, co-learning process that led to viewing this health issue as a complex system, influenced by interlinked multidimensional factors. Our transdisciplinary experience has led us to believe that an incomplete understanding of these linkages may reduce the efficacy of interventions. Further, viewing liver fluke infection and cholangiocarcinoma as the same issue is inadvisable. Although O. viverrini infection is an established risk factor for the development of cholangiocarcinoma, multiple factors are known to influence the likelihood of acquiring either. Understanding the importance of the current livelihood transition, landscape modification and the resulting mismatch between local cultures and new socio-ecological settings on cholangiocarcinoma initiation and liver fluke transmission is of critical importance as it may help readjust our view of the respective role of O. viverrini and other socioeconomic risk factors in cholangiocarcinoma etiology and refine intervention strategies. As demonstrated in this study, transdisciplinary approaches have the potential to yield more nuanced perspectives to complex diseases than research that focuses on specific aspects of their epidemiology. They may therefore be valuable when designing effective solutions to context-sensitive diseases such as liver fluke infection and cholangiocarcinoma.
Collapse
Affiliation(s)
- A D Ziegler
- Department of Geography, Faculty of Arts and Social Sciences, National University of Singapore, AS2-04-21, 1 Arts Link, Singapore, 117570, Singapore.
| | - P Echaubard
- Tropical Disease Research Laboratory, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand
- Global Health Asia, Faculty of Public Health, Mahidol University, Bangkok, Thailand
- Department of Biology, Laurentian University, Sudbury, ON, Canada
| | - Y T Lee
- Department of Geography, Faculty of Arts and Social Sciences, National University of Singapore, AS2-04-21, 1 Arts Link, Singapore, 117570, Singapore
| | - C J Chuah
- Department of Geography, Faculty of Arts and Social Sciences, National University of Singapore, AS2-04-21, 1 Arts Link, Singapore, 117570, Singapore
| | - B A Wilcox
- Global Health Asia, Faculty of Public Health, Mahidol University, Bangkok, Thailand
| | - C Grundy-Warr
- Department of Geography, Faculty of Arts and Social Sciences, National University of Singapore, AS2-04-21, 1 Arts Link, Singapore, 117570, Singapore
| | - P Sithithaworn
- Tropical Disease Research Laboratory, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand
- Department of Parasitology, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand
- Liver Fluke and Cholangiocarcinoma Research Center, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand
| | - T N Petney
- Department of Ecology and Parasitology, Karlsruhe Institute of Technology, Kornblumenstrasse 13, Karlsruhe, Germany
- Cholangiocarcinoma Screening and Care Program (CASCAP), Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand
| | - L Laithevewat
- Office of Prevention and Control 8, Udonthani Province, Thailand
| | - X Ong
- Department of Geography, Faculty of Arts and Social Sciences, National University of Singapore, AS2-04-21, 1 Arts Link, Singapore, 117570, Singapore
| | - R H Andrews
- Department of Parasitology, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand
- Liver Fluke and Cholangiocarcinoma Research Center, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand
- Cholangiocarcinoma Screening and Care Program (CASCAP), Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand
| | - T Ismail
- Department of Geography, Faculty of Arts and Social Sciences, National University of Singapore, AS2-04-21, 1 Arts Link, Singapore, 117570, Singapore
| | - B Sripa
- Tropical Disease Research Laboratory, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand
| | - N Khuntikeo
- Cholangiocarcinoma Screening and Care Program (CASCAP), Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand
| | - K Poonpon
- Department of English Language, Faculty of Humanities and Social Sciences, Khon Kaen University, Khon Kaen, Thailand
| | - P Tungtang
- Department of English Language, Faculty of Humanities and Social Sciences, Khon Kaen University, Khon Kaen, Thailand
| | - K Tuamsuk
- Department of English Language, Faculty of Humanities and Social Sciences, Khon Kaen University, Khon Kaen, Thailand
| |
Collapse
|
13
|
Chen PC, Chien KL, Su TC, Jeng JS, Hsu HC, Lee YT. Carotid Atherosclerosis Progression and Risk of Cardiovascular Events in a Community in Taiwan. Eur J Public Health 2015. [DOI: 10.1093/eurpub/ckv175.109] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
|
14
|
Lee KH, Lee YT, Chen TC, Yeh CC, Chen JY, Liu LY, Chi CH. Effects of sheng hua tang on uterine involution and ovarian activity in postpartum dairy cows. Asian-Australas J Anim Sci 2014; 26:1247-54. [PMID: 25049906 PMCID: PMC4093405 DOI: 10.5713/ajas.2013.13042] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/15/2013] [Revised: 05/16/2013] [Accepted: 04/08/2013] [Indexed: 11/27/2022]
Abstract
The effects of Sheng Hua Tang (SHT) on uterine involution and ovarian activity were investigated in postpartum dairy cows. SHT (70 g) was given to dairy cows (n = 10) to evaluate its effects for five days from the first postpartum day. Postpartum cows fed with a basal diet without SHT were used as the control group (n = 10). Ultrasounds and blood tests were recorded for four weeks from postpartum day seven with a 3-d interval. The results showed that the areas and diameters of endometria were significantly (p<0.01) reduced in the group that received SHT compared to the control group on the seventh postpartum day. The group that received SHT had an intrauterine fluid volume mean of 1.2±0.6 cm(3), which was significantly lower than that of the control group, 2.3±0.8 cm(3) (p<0.01) on the 13th postpartum day. In addition, the uterine tension score was a mean of 1.0±0.0 in the group that received SHT, which was also significantly lower than that of the control group, 1.5±0.5 (p<0.01) on the 19th postpartum day. Taken together, the Chinese herbal medicine remedy, SHT, promoted uterine involution and ovarian activity in postpartum dairy cows.
Collapse
Affiliation(s)
- K H Lee
- Department of Veterinary Medicine, National Taiwan University, Taipei, 10617, Taiwan
| | - Y T Lee
- Department of Veterinary Medicine, National Taiwan University, Taipei, 10617, Taiwan
| | - T C Chen
- Department of Veterinary Medicine, National Taiwan University, Taipei, 10617, Taiwan
| | - C C Yeh
- Department of Veterinary Medicine, National Taiwan University, Taipei, 10617, Taiwan
| | - J Y Chen
- Department of Veterinary Medicine, National Taiwan University, Taipei, 10617, Taiwan
| | - L Y Liu
- Department of Veterinary Medicine, National Taiwan University, Taipei, 10617, Taiwan
| | - C H Chi
- Department of Veterinary Medicine, National Taiwan University, Taipei, 10617, Taiwan
| |
Collapse
|
15
|
Yang HS, Chen IC, Lee YT, Lee KC, Chuang YC, Chang CY, Wei J. Cardiac transplantation and concomitant coronary artery bypass grafting: our experiences in 11 cases. Transplant Proc 2014; 46:900-2. [PMID: 24767376 DOI: 10.1016/j.transproceed.2013.11.127] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2013] [Accepted: 11/07/2013] [Indexed: 11/19/2022]
Abstract
INTRODUCTION The shortage of donor hearts for transplantation could be alleviated by including the hearts of older donors. Previous literature revealed similar early and medium-term survival outcomes compared with those of younger donors. This study presents our experience with patients who underwent orthotopic heart transplantation and concomitant coronary artery bypass grafting at our institution. METHODS We present our experience with 11 patients with end-stage cardiomyopathy (8 men and 3 women) undergoing orthotopic heart transplantation and concomitant coronary artery bypass grafting from September 2002 to November 2011 at our institute. RESULTS All 11 donor organs would otherwise have been rejected, depriving potential recipients of organ transplantation. Two patients received concurrent 2-coronary-artery bypass, and the other 9 patients received concurrent single-coronary-artery bypass during orthotopic heart transplantation. All patients had an uneventful postoperative course, with follow-up completed 3 to 128 months after cardiac transplantation and concomitant coronary artery bypass grafting surgery. CONCLUSIONS Our experiences suggest that donor hearts requiring coronary artery bypass grafting, which form a small but significant donor subgroup, can be used effectively and safely when matched to the recipients' age and medical condition.
Collapse
Affiliation(s)
- H S Yang
- Heart Center, Cheng-Hsin General Hospital, Taipei, Taiwan, R.O.C
| | - I C Chen
- Heart Center, Cheng-Hsin General Hospital, Taipei, Taiwan, R.O.C
| | - Y T Lee
- Heart Center, Cheng-Hsin General Hospital, Taipei, Taiwan, R.O.C
| | - K C Lee
- Heart Center, Cheng-Hsin General Hospital, Taipei, Taiwan, R.O.C
| | - Y C Chuang
- Heart Center, Cheng-Hsin General Hospital, Taipei, Taiwan, R.O.C
| | - C Y Chang
- Heart Center, Cheng-Hsin General Hospital, Taipei, Taiwan, R.O.C
| | - J Wei
- Heart Center, Cheng-Hsin General Hospital, Taipei, Taiwan, R.O.C.
| |
Collapse
|
16
|
Wei J, Sue SH, Lee YT, Chang CY. Combined heart transplantation and total replacement of thoracic aorta in Marfan's syndrome with recurrent aortic dissection: a case report. Transplant Proc 2012; 44:1174-5. [PMID: 22564657 DOI: 10.1016/j.transproceed.2012.02.013] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
It is extremely rare for a patient to need simultaneous heart transplantation (HTx) and replacement of the thoracic aorta. A 23-year-old woman with Marfan's syndrome underwent Bentall's operation and replacement of the ascending aorta (AsA) due to a type A aortic dissection (AD) in August 2001. In March 2005, she began to experience dyspnea on exertion and was found to have a huge pseudoaneurysm at the aortic root, which had caused dehiscence of the aortic conduit. In July 2009, she suffered acute chest pain followed by hypotension and cold sweating. The computed tomography (CT) scan showed a recurrent dissection with a long intimal tear extending from the arch to the mid-portion of the descending thoracic aorta (DTA). Due to technical difficulties in the repair of the aortic root, she was placed on the HTx waiting list. The next day, she received a donor heart and underwent combined HTx and total replacement of the thoracic aorta. Explantation of the heart improved the exposure of the DTA. With the use of a vascular ring connector (Vasoring), the operation was successfully performed without need for a blood transfusion. The patient was still well at 2 years after the operation. Simultaneous replacement of the heart and the whole segment of the thoracic aorta is technically possible in Marfan patients who are complicated with aortic dissection.
Collapse
Affiliation(s)
- J Wei
- Heart Centre, Cheng-Hsin General Hospital, Taipei, Taiwan, R.O.C.
| | | | | | | |
Collapse
|
17
|
You JH, Kim DH, Lee DU, Yoo KH, Park CY, Park KW, Jang SJ, Lee YT, Kim TW. Effect of temperature on optical and electronic properties of InGaP/InGaAIP multiple quantum wells. J Nanosci Nanotechnol 2012; 12:5843-5846. [PMID: 22966667 DOI: 10.1166/jnn.2012.6246] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
The optical and electronic properties in an InGaP/InGaAIP multiple quantum well (MQW) grown by using molecular-beam epitaxy utilizing the digital alloy technique were investigated through temperature-dependent photoluminescence (PL) measurements and numerical calculations. The high-resolution transmission electron microscopy images showed that the sample clearly displayed the InGaP wells and the InGaAIP barriers and separate confinement heterostructure layers. The PL measurements at various temperatures were performed to investigate the interband transitions of the InGaP/InGaAIP MQW. The electronic subband energies and the wavefunctions in the InGaP/InGaAIP MQW at several temperatures were determined by using a finite element method employing the standard 8-band k x p Lagrangian. The numerical results for optical interband transition energies from the ground state electron subband to the ground state heavy-hole subband of the InGaP/InGaAIP MQW at various temperatures were in reasonable agreement with the excitonic transition energies observed in the PL measurements.
Collapse
Affiliation(s)
- J H You
- Department of Electronics and Computer Engineering, Hanyang University, Seoul 133-791, Korea
| | | | | | | | | | | | | | | | | |
Collapse
|
18
|
Wei YJ, Tsai KS, Lin LC, Lee YT, Chi CW, Chang MC, Tsai TH, Hung SC. Catechin stimulates osteogenesis by enhancing PP2A activity in human mesenchymal stem cells. Osteoporos Int 2011; 22:1469-79. [PMID: 20683709 DOI: 10.1007/s00198-010-1352-9] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/19/2010] [Accepted: 06/14/2010] [Indexed: 01/03/2023]
Abstract
SUMMARY Using human mesenchymal stem cells, we identified catechin from a panel of herbal ingredients and Chinese traditional compounds with the strongest osteogenic effects. Catechin increased alkaline phosphatase activity, calcium deposition, and mRNA expression of Runx2 and osteocalcin. We further clarified the signaling pathway that catechin mediated to stimulate osteogenesis. INTRODUCTION Human mesenchymal stem cells (hMSCs), useful as a species specific cell culture system for studying cell lineage differentiation, were examined as a tool to identify novel herbal ingredients and Chinese traditional compounds for enhancing osteogenesis. METHODS Immortalized and primary hMSCs were induced in osteogenic induction medium in the presence of a variety of herbal ingredients and Chinese traditional compounds and osteogenic differentiation was evaluated by histochemical assays and quantitative RT-PCR. RESULTS Using immortalized hMSCs, we first identified catechin, 18β-glycyrrhetinic acid, baishao, and danggui with osteogenic properties, which enhanced calcium deposition at the dose without significant cytotoxic effects. Primary hMSCs were then applied for confirming the osteogenic effects of catechin, which increased alkaline phosphatase activity, calcium deposition, and mRNA expression of Runx2 and osteocalcin. We further found the extracellular signal-regulated kinase (ERK) pathway was downregulated upon stimulation with catechin. Catechin increased the level and activity of protein phosphatases 2A (PP2A) that dephosphorylates ERK kinase (MEK) and ERK. Further, PP2A inhibitor, okadaic acid, abolished the effect of catechin-mediated inactivation of ERK and stimulation of osteogenesis. The blocking effect of okadaic acid on osteogenesis was further reversed by PD98059, a specific inhibitor of MEK. Co-immunoprecipitation revealed the association of PP2A to both MEK and ERK. CONCLUSIONS These studies propose catechin enhanced osteogenesis by increasing the PP2A level that inhibits the MEK and ERK signaling in hMSCs. These results prove the concept of using hMSCs as a convenient tool for rapid and consistent screening of the osteogenic herbal ingredients and traditional Chinese compounds.
Collapse
Affiliation(s)
- Y J Wei
- Laboratory of Pharmacokinetics, Institute of Traditional Medicine, National Yang-Ming University, 155, Sec 2, Li-Nong Street, Taipei 112, Taiwan
| | | | | | | | | | | | | | | |
Collapse
|
19
|
Reid WV, Chen D, Goldfarb L, Hackmann H, Lee YT, Mokhele K, Ostrom E, Raivio K, Rockström J, Schellnhuber HJ, Whyte A. Earth System Science for Global Sustainability: Grand Challenges. Science 2010; 330:916-7. [PMID: 21071651 DOI: 10.1126/science.1196263] [Citation(s) in RCA: 83] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Affiliation(s)
- W V Reid
- David and Lucile Packard Foundation, Los Altos, CA 94022, USA.
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
20
|
Noh SJ, Lee YT, Byrnes C, Miller JL. A transcriptome-based examination of blood group expression. Transfus Clin Biol 2010; 17:120-5. [PMID: 20685146 DOI: 10.1016/j.tracli.2010.06.010] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2010] [Accepted: 06/08/2010] [Indexed: 11/27/2022]
Abstract
Over the last two decades, red cell biologists witnessed a vast expansion of genetic-based information pertaining to blood group antigens and their carrier molecules. Genetic progress has led to a better comprehension of the associated antigens. To assist with studies concerning the integrated regulation and function of blood groups, transcript levels for each of the 36 associated genes were studied. Profiles using mRNA from directly sampled reticulocytes and cultured primary erythroblasts are summarized in this report. Transcriptome profiles suggest a highly regulated pattern of blood group gene expression during erythroid differentiation and ontogeny. Approximately one-third of the blood group carrier genes are transcribed in an erythroid-specific fashion. Low-level and indistinct expression was noted for most of the carbohydrate-associated genes. Methods are now being developed to further explore and manipulate expression of the blood group genes at all stages of human erythropoiesis.
Collapse
Affiliation(s)
- S-J Noh
- Molecular Medicine Branch, National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), National Institutes of Health (NIH), 31 Center Drive, Bethesda, Building 10, Room 9N311, MD 20892, USA
| | | | | | | |
Collapse
|
21
|
Lee YT, Hwang S, Lee SG, Kim KW, Choi NK, Park GC, Yu YD, Yoo JW, Kim WS, Shim TS. Living-donor liver transplantation in patients with concurrent active tuberculosis at transplantation. Int J Tuberc Lung Dis 2010; 14:1039-1044. [PMID: 20626950] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/29/2023] Open
Abstract
SETTING Although active tuberculosis (TB) is a contraindication for liver transplantation (LT), LT may be the only possible treatment option in patients with irreversible liver failure and concurrent TB. OBJECTIVES To assess the outcome of LT in patients with concurrent TB and liver failure. METHODS We retrospectively evaluated the clinical outcomes of nine LT recipients with concurrent TB in Korea, an intermediate TB burden country. RESULTS The primary causes of living-donor LT (LDLT) in nine patients were anti-tuberculosis drug-induced fulminant hepatic failure (n = 4) and end-stage liver disease (n = 5). The sites of active TB were the lungs (n = 5), lymph nodes (n = 3) and pleura (n = 1). After LDLT, most patients were treated with less hepatotoxic drugs, including fluoroquinolones, ethambutol and cycloserine; none was treated with pyrazinamide. One patient experienced acute rejection, probably attributable to an interaction between rifampicin and cyclosporine. All nine patients, including one taking rifabutin, successfully completed anti-tuberculosis treatment and have been followed up for a median of 926 days after LDLT, without relapse of TB. CONCLUSION When properly managed, the prognosis of LDLT recipients with concurrently active TB at transplantation is very favourable. The current protocol, which considers active TB an absolute contraindication for LT, should be modified or relaxed, particularly for patients with LDLT.
Collapse
Affiliation(s)
- Y T Lee
- Division of Pulmonary and Critical Care Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea
| | | | | | | | | | | | | | | | | | | |
Collapse
|
22
|
Lee YT, Lai LH, Sung JJY, Ko FWS, Hui DSC. Endoscopic ultrasonography-guided fine-needle aspiration in the management of mediastinal diseases: local experience of a novel investigation. Hong Kong Med J 2010; 16:121-125. [PMID: 20354246] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/29/2023] Open
Abstract
OBJECTIVE To study the efficacy and safety of endoscopic ultrasonography-guided fine-needle aspiration in the management of mediastinal diseases in Hong Kong. DESIGN Retrospective review of prospectively collected data. SETTING University teaching hospital, Hong Kong. PATIENTS A total of 125 consecutive patients with various mediastinal and pulmonary lesions that underwent trans-oesophageal endoscopic ultrasonography-guided fine-needle aspiration from July 1998 to June 2007. MAIN OUTCOME MEASURES The diagnostic accuracy and safety of the procedure and its influence in patient management. RESULTS Malignancy was confirmed in 62 (50%) of the patients and excluded in 42 (34%). The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of endoscopic ultrasonography-guided fine-needle aspiration in diagnosing mediastinal malignancies were 75% (95% confidence interval, 64-83%), 100% (90-100%), 100% (93-100%), 67% (54-78%), and 83%, respectively. Eighty-six (69%) of the patients had their initial plan of invasive investigations changed. Only one (0.8%) patient developed a septic complication in a mediastinal cyst after puncturing, and was treated surgically. CONCLUSIONS Trans-oesophageal endoscopic ultrasonography-guided fine-needle aspiration is a minimally invasive, effective, and safe method of diagnosing malignant mediastinal disease. It may reduce the need for other invasive investigations.
Collapse
Affiliation(s)
- Y T Lee
- Department of Medicine and Therapeutics, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, Hong Kong
| | | | | | | | | |
Collapse
|
23
|
Song YM, Choi ES, Yu JS, Lee YT. Light-extraction enhancement of red AlGaInP light-emitting diodes with antireflective subwavelength structures. Opt Express 2009; 17:20991-20997. [PMID: 19997337 DOI: 10.1364/oe.17.020991] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
We demonstrate the enhancement of light extraction in 633 nm AlGaInP light-emitting diodes (LEDs) with antireflective subwavelength structures (SWS). From the contour plots by the rigorous coupled wave analysis method, it is found that the reduction of the internal reflection strongly depends on the period of SWS. The Ag nanoparticles formed by thermal dewetting were used as an etch mask for dry etch process to fabricate antireflective SWS on the LED surface. The tapered pillars on the GaP were fabricated, on average, with distances below 200 nm, satisfying the required antireflection condition at the emission wavelength. The improvement in light output power by approximately 26.4% was achieved for the fabricated AlGaInP LEDs with SWS compared to the conventional LEDs due to a strongly reduced Fresnel internal reflection at the GaP/air interface. The improved directionality in the far-field pattern was also obtained due to the directional light extraction enhancement.
Collapse
Affiliation(s)
- Y M Song
- Department of Information and Communications, Gwangju Institute of Science and Technology, 1 Oryong-dong, Buk-gu, Gwangju 500-712, Republic of Korea
| | | | | | | |
Collapse
|
24
|
Song YM, Jeong BK, Na BH, Chang KS, Yu JS, Lee YT. High-speed characteristics of vertical cavity surface emitting lasers and resonant-cavity-enhanced photodetectors based on intracavity-contacted structure. Appl Opt 2009; 48:F11-F17. [PMID: 19724307 DOI: 10.1364/ao.48.000f11] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
We fabricated vertical cavity surface emitting lasers (VCSELs) and resonant-cavity-enhanced photodetectors (RCE-PDs) with GaAs/AlGaAs distributed Bragg reflectors (DBRs), operating at lambda approximately 980 nm, based on an intracavity-contacted structure. The top-DBR mesa diameter of the VCSELs was optimized to 18 microm in terms of slope efficiency, differential series resistance, and 3 dB bandwidth. For VCSELs with an oxide aperture of 4.5 microm and a top-DBR mesa diameter of 18 microm, the threshold current was about 1.2 mA, exhibiting maximum output power of approximately 3.49 mW (at 20 degrees C) with good uniformity. The effect of the overetching in the outermost layer of RCE-PDs on the device performance was also investigated. For RCE-PDs based on the VCSEL structure, a peak responsivity of 0.44 A/W (at lambda approximately 979.7 nm) with a spectral width of approximately 3 nm and a dark current of 68 pA under a bias voltage of -5 V at 20 degrees C was obtained. The maximum 3 dB bandwidths of approximately 11.5 GHz with a modulation current efficiency factor of 5.6 GHz/mA(1/2) at -7 mA and 9 GHz at -7 V were achieved for VCSELs and RCE-PDs, respectively.
Collapse
Affiliation(s)
- Y M Song
- Department of Information and Communications, Gwangju Institute of Science and Technology, Gwangju 500-712, South Korea
| | | | | | | | | | | |
Collapse
|
25
|
Chang CH, Chang SR, Lin JS, Lee YT, Yeh SR, Chen H. A CMOS neuroelectronic interface based on two-dimensional transistor arrays with monolithically-integrated circuitry. Biosens Bioelectron 2009; 24:1757-64. [PMID: 18951013 DOI: 10.1016/j.bios.2008.09.007] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2008] [Revised: 09/03/2008] [Accepted: 09/04/2008] [Indexed: 11/17/2022]
Abstract
The ability to monitor and to elicit neural activity with a high spatiotemporal resolution has grown essential for studying the functionality of neuronal networks. Although a variety of microelectrode arrays (MEAs) has been proposed, very few MEAs are integrated with signal-processing circuitry. As a result, the maximum number of electrodes is limited by routing complexity, and the signal-to-noise ratio is degraded by parasitics and noise interference. This paper presents a single-chip neuroelectronic interface integrating oxide-semiconductor field-effect transistors (OSFETs) with signal-processing circuitry. After the chip was fabricated with the standard complementary-metal-oxide-semiconductor (CMOS) process, polygates of specific transistors were etched at die-level to form OSFETs, while metal layers were retained to connect the OSFETs into two-dimensional arrays. The complete removal of polygates was confirmed by high-resolution image scanners, and the reliability of OSFETs was examined by measuring their electrical characteristics. Through a gate oxide of only 7nm thick, each OSFET can record and stimulate neural activity extracellularly by capacitive coupling. The capability of the full chip in neural recording and stimulation was further experimented using the well-characterised escape circuit of the crayfish. Experimental results indicate that the OSFET-based neuroelectronic interface can be used to study neuronal networks as faithfully as conventional electrophysiological tools. Moreover, the proposed simple, die-level fabrication process of the OSFETs underpins the development of various field-effect biosensors on a large scale with on-chip circuitry.
Collapse
Affiliation(s)
- C H Chang
- Institute of Electronics Engineering, National Tsing Hua University, HsinChu, Taiwan
| | | | | | | | | | | |
Collapse
|
26
|
Chiu PWY, Chan KF, Lee YT, Sung JJY, Lau JYW, Ng EKW. Endoscopic submucosal dissection used for treating early neoplasia of the foregut using a combination of knives. Surg Endosc 2008; 22:777-83. [PMID: 17704882 DOI: 10.1007/s00464-007-9479-2] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
BACKGROUND Endoscopic submucosal dissection (ESD) has emerged as a novel technique for achieving en bloc resection for early esophageal or gastric carcinoma limited to the mucosa. The authors report their experience with a combination of various devices to treat early neoplasia of the foregut using the ESD technique. METHODS In this prospective case series, ESD was performed for early esophageal or gastric carcinoma limited to the mucosa. These lesions were staged by endoscopic ultrasonography before resection. Magnifying endoscopy and chromoendoscopy were used to locate the tumor and define the margin. The resection was accomplished with submucosal dissection using the insulated tip knife, the hook knife, and the triangular tip knife. The resected specimen was examined systematically for the lateral and deep margins. RESULTS From January 2004 to March 2006, ESD was performed to manage 30 cases of early gastric or esophageal carcinoma. For 29 of these patients, R0 resection was successfully achieved. The mean operating time was 84.6 min. One patient experienced reactionary hemorrhage 12 h after resection, which was controlled endoscopically. There was no perforation. Most of the circumferential mucosal incisions were performed using the insulated tip knife (76.6%), whereas submucosal dissection was accomplished with a combination of various knives. One of the specimens showed involvement of the lateral margin, whereas another patient had two areas of new early gastric cancer 6 months after the initial procedure. These patients received salvage laparoscopically assisted gastrectomy. CONCLUSIONS Endoscopic submucosal dissection to manage early neoplasia of the foregut can be achieved safely and effectively with a combination of knives.
Collapse
Affiliation(s)
- P W Y Chiu
- Institute of Digestive Disease, Department of Surgery, The Chinese University of Hong Kong, 30-32, Ngan Shing Street, Shatin, N.T., Hong Kong.
| | | | | | | | | | | |
Collapse
|
27
|
Affiliation(s)
- P W Chiu
- Institute of Digestive Disease, The Chinese University of Hong Kong, Hong Kong
| | | | | |
Collapse
|
28
|
Affiliation(s)
- Y T Lee
- Department of Medicine and Therapeutics, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong
| | | | | | | |
Collapse
|
29
|
Affiliation(s)
- Y T Lee
- Institute of Digestive Diseases, Prince of Wales Hospital, Chinese University of Hong Kong, Shatin, N.T., Hong Kong SAR, China
| | | | | | | |
Collapse
|
30
|
Affiliation(s)
- Y Q Guan
- School of Mechanical and Aerospace Engineering, Nanyang Technological University, Singapore
| | | | | | | | | |
Collapse
|
31
|
Jeung JU, Kim BR, Cho YC, Han SS, Moon HP, Lee YT, Jena KK. A novel gene, Pi40(t), linked to the DNA markers derived from NBS-LRR motifs confers broad spectrum of blast resistance in rice. Theor Appl Genet 2007; 115:1163-77. [PMID: 17909744 DOI: 10.1007/s00122-007-0642-x] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/20/2007] [Accepted: 08/31/2007] [Indexed: 05/06/2023]
Abstract
Rice blast disease caused by Magnaporthe grisea is a continuous threat to stable rice production worldwide. In a modernized agricultural system, the development of varieties with broad-spectrum and durable resistance to blast disease is essential for increased rice production and sustainability. In this study, a new gene is identified in the introgression line IR65482-4-136-2-2 that has inherited the resistance gene from an EE genome wild Oryza species, O. australiensis (Acc. 100882). Genetic and molecular analysis localized a major resistance gene, Pi40(t), on the short arm of chromosome 6, where four blast resistance genes (Piz, Piz-5, Piz-t, and Pi9) were also identified, flanked by the markers S2539 and RM3330. Through e-Landing, 14 BAC/PAC clones within the 1.81-Mb equivalent virtual contig were identified on Rice Pseudomolecule3. Highly stringent primer sets designed for 6 NBS-LRR motifs located within PAC clone P0649C11 facilitated high-resolution mapping of the new resistance gene, Pi40(t). Following association analysis and detailed haplotyping approaches, a DNA marker, 9871.T7E2b, was identified to be linked to the Pi40(t) gene at the 70 Kb chromosomal region, and differentiated the Pi40(t) gene from the LTH monogenic differential lines possessing genes Piz, Piz-5, Piz-t, and Pi-9. Pi40(t) was validated using the most virulent isolates of Korea as well as the Philippines, suggesting a broad spectrum for the resistance gene. Marker-assisted selection (MAS) and pathotyping of BC progenies having two japonica cultivar genetic backgrounds further supported the potential of the resistance gene in rice breeding. Our study based on new gene identification strategies provides insight into novel genetic resources for blast resistance as well as future studies on cloning and functional analysis of a blast resistance gene useful for rice improvement.
Collapse
Affiliation(s)
- J U Jeung
- Plant Breeding, Genetics, and Biotechnology Division, International Rice Research Institute, Los Baños, Laguna, Philippines
| | | | | | | | | | | | | |
Collapse
|
32
|
Abstract
The ab initio/Rice-Ramsperger-Kassel-Marcus (RRKM) approach has been applied to investigate the photodissociation mechanism of 1,3,5-triazine at different wavelengths of the absorbed photon. Reaction pathways leading to various decomposition products have been mapped out at the G3(MP2,CC)//B3LYP level, and then the RRKM and microcanonical variational transition state theories have been applied to compute rate constants for individual reaction steps. Relative product yields (branching ratios) for the dissociation products have been calculated using the steady-state approach. The results show that, after being excited by 275, 248, or 193 nm photons, the triazine molecule isomerizes to an opened-ring structure on the first singlet excited-state potential energy surface (PES), which is followed by relaxation into the ground electronic state via internal conversion. On the contrary, excitation by 285 and 295 nm photons cannot initiate the ring-opening reaction on the excited-state PES, and the molecule relaxes into the energized ring isomer in the ground electronic state. The dissociation reaction starting from the ring isomer is calculated to have branching ratios of various reaction channels significantly different from those for the reaction initiating from the opened-ring structure. The existence of two distinct mechanisms of 1,3,5-triazine photodissociation can explain the inconsistency in the translational energy distributions of HCN moieties at different wavelengths observed experimentally.
Collapse
Affiliation(s)
- Y A Dyakov
- Institute of Atomic and Molecular Sciences, Academia Sinica, P.O. Box 23-166, Taipei 10764, Taiwan.
| | | | | | | | | |
Collapse
|
33
|
Chien KL, Hsu HC, Chen WJ, Chen MF, Su TC, Lee YT. Familial aggregation of metabolic syndrome among the Chinese: report from the Chin-Shan community family study. Diabetes Res Clin Pract 2007; 76:418-24. [PMID: 17097184 DOI: 10.1016/j.diabres.2006.09.026] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/30/2006] [Accepted: 09/20/2006] [Indexed: 01/08/2023]
Abstract
Genetic study on metabolic syndrome is a great challenge, due to its complex traits and the pleiotropic manifestation of atherosclerosis. Familial aggregation and recurrence risk ratio can provide the insight of possible genetic mechanism. The Chin-Shan community family study was based on adolescent probands and their relatives (1356 subjects) who were recruited from one junior high school in the community. Structured questionnaires and biochemical measures were obtained in standard procedures. Definition of metabolic syndrome was followed using the criteria defined by the third adult treatment panel, with a modification of the criteria for adolescent and Asian population. Grandmothers had the highest frequencies (70%) in metabolic syndrome and various atherosclerotic risks. Three factors were found and thus explained 68% of the overall variance. Estimated heritability was the highest in LDL and cholesterol factor (0.36 and 0.40), then blood pressure/obesity factor (0.27), and insulin resistance/dyslipidemia (0.27). Recurrence risk ratio among siblings was 2.95 (95% confidence interval [CI]: 1.39-6.26). The adjusted odds ratio (OR) of proband's metabolic syndrome status was 1.99 (95% CI: 1.08-3.66). The adjusted odds ratios for the three factors for predicting metabolic syndrome were all significant, with highest risk in blood pressure/obesity factor (OR: 1.27, CI: 1.22-1.33), then insulin resistance/dyslipidemia (OR: 1.29, CI: 1.16-1.23). This study demonstrated clearly familial aggregation and recurrence risk ratio of metabolic syndrome and components among the general ethnic Chinese population in Taiwan.
Collapse
Affiliation(s)
- K L Chien
- Institute of Preventive Medicine, School of Public Health, National Taiwan University, Taipei, Taiwan
| | | | | | | | | | | |
Collapse
|
34
|
Burke DT, Al-Adawi S, Lee YT, Audette J. Martial arts as sport and therapy. J Sports Med Phys Fitness 2007; 47:96-102. [PMID: 17369805] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
The term Martial Arts is often used as general phrase to describe many of the combat arts, which have developed in eastern cultures over the past millennium. This paper reviews the Martial Arts from the original context of a trio of life skills. This trio includes the healing arts such as acupuncture, the self-exploration arts such as yoga, and the vital life skills such as meditation. As Martial Arts suggests the waging of combat, the origins of the most common combat arts are reviewed, with an overview of the difference between the hard and the soft styles. The arts developed not only in the eastern, but also in all parts of the world, with references of these types of combats arts in the writings of the ancient Egyptians and Greeks. In modern times, the combat arts are performed for both exercise and sport. A review of the injuries that occur, and the health benefits that might be expected are discussed. A review of the medical literature that demonstrates some of these health benefits is included, with Tai Chi Chuan as the most studied of these. The health benefits discussed include strengthen and self-efficacy of the elderly, reduced falls, increased exercise capacity, and benefits to the immune system and autonomic nervous system. The paper emphasized the breadth of the Martial Arts and the import of these to the sports and health community.
Collapse
Affiliation(s)
- D T Burke
- Department of Physical Medicine and Rehabilitation, Spaulding Rehabilitation Hospital, Harvard Medical School, Boston, MA 02114, USA.
| | | | | | | |
Collapse
|
35
|
Guan YQ, Cai YY, Lee YT, Opas M. An automatic method for identifying appropriate gradient magnitude for 3D boundary detection of confocal image stacks. J Microsc 2006; 223:66-72. [PMID: 16872433 DOI: 10.1111/j.1365-2818.2006.01600.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Gradients play an important role in 2D image processing. Many edge detection algorithms are gradient-based. We are interested in 3D boundary detection which can be considered as an extension of 2D edge detection in 3D space. In this paper, an algorithm to automatically and quantitatively measure the suitability of gradient magnitudes in detection of 3D boundary points of confocal image stacks is presented. A Measurement Function is defined to evaluate the suitability of each gradient magnitude chosen to be the threshold for 3D boundary detection. The application of Gauss's Divergence Theorem provides a solution to calculate the Measurement Function numerically. The gradient magnitude at which the maximum of the Measurement Function is achieved can be utilized as the most appropriate threshold for gradient-based boundary detection and other operations like volume visualization.
Collapse
Affiliation(s)
- Y Q Guan
- School of Mechanical and Aerospace Engineering, Nanyang Technological University, Singapore, Singapore.
| | | | | | | |
Collapse
|
36
|
Abstract
BACKGROUND AND STUDY AIMS Although colonoscopy is a well-established procedure, various technical difficulties may cause failure. This report describes experience with cap-assisted colonoscopy (CAC), a technique in which a mucosectomy cap is attached to the end of colonoscope in order to improve the success rate. PATIENTS AND METHODS From January 2003 to May 2005, CAC was used in consecutive patients with difficult colonoscopy procedures, which were defined firstly as failure to pass through the sigmoid colon after 20 min of examination, or secondly as failure to reach the cecum at the end of the procedure. Patients with prior colonic surgery, poor bowel preparation, distal colonic stricture, or obstructing tumors were excluded. The results with the CAC method were reviewed retrospectively. RESULTS A total of 100 patients met the criteria for difficult colonoscopy during the study period. When CAC was used to repeat the procedure, cecal and terminal ileal intubation could then be achieved in 94 and 70 patients, respectively. In the remaining six patients in whom cecal intubation failed, one failure was due to a tumor obstruction at the splenic flexure. CONCLUSIONS CAC can be used as a rescue method to improve the success rate of colonoscopy when failure is encountered.
Collapse
Affiliation(s)
- Y T Lee
- Institute of Digestive Diseases, Chinese University of Hong Kong, Shatin, Hong Kong
| | | | | | | | | |
Collapse
|
37
|
Chen PC, Chien KL, Su TC, Hsu HC, Sung FC, Lee YT. Metabolic Syndrome as a Predictor of Stroke in Taiwan. Am J Epidemiol 2006. [DOI: 10.1093/aje/163.suppl_11.s6-a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
|
38
|
Abstract
The ab initio/Rice-Ramsperger-Kassel-Marcus (RRKM) approach has been applied to investigate the photodissociation mechanism of the azulene cation at different values of the photon energy. Reaction pathways leading to various decomposition products have been mapped out at the G3(MP2,CC)//B3LYP level and then the RRKM and microcanonical variational transition state theories have been applied to compute rate constants for individual reaction steps. Relative product yields (branching ratios) for the dissociation products have been calculated using the steady-state approach. The results show that a photoexcited azulene cation can readily isomerize to a naphthalene cation. The major dissociation channels are elimination of atomic hydrogen, an H2 molecule, and acetylene. The branching ratio of the H elimination channel decreases with an increase of the photon energy. The branching ratio of the acetylene elimination as well as that of the H2 elimination rise as the photon energy increases. The main C8H6+ fragment at all photon energies considered is a pentalene cation, and its yield decreases slightly with increasing excitation energy, whereas the branching ratios of the other C8H6+ fragments, phenylacetylene and benzocyclobutadiene cations, grow.
Collapse
Affiliation(s)
- Yu A Dyakov
- Institute of Atomic and Molecular Sciences, Academia Sinica, P.O. Box 23-166, Taipei 10764, Taiwan
| | | | | | | | | |
Collapse
|
39
|
Lee YT, Ng EKW, Hung LCT, Chung SCS, Ching JYL, Chan WY, Chu WC, Sung JJ. Accuracy of endoscopic ultrasonography in diagnosing ascites and predicting peritoneal metastases in gastric cancer patients. Gut 2005; 54:1541-5. [PMID: 15955787 PMCID: PMC1774738 DOI: 10.1136/gut.2004.055772] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
BACKGROUND Preoperative diagnosis of peritoneal metastases (PM) is difficult in patients with gastric cancer (GC). AIMS To assess the accuracy of endoscopic ultrasonography (EUS) in diagnosing ascites and its predictability for the presence of PM in GC patients. SUBJECTS Consecutive patients with newly diagnosed GC from 1998 to 2004 were studied. METHODS All patients underwent EUS, ultrasound (US), and computed tomography (CT) scan for preoperative staging and the presence of ascites. The results were compared with operative findings. The diagnosis of PM was confirmed by histopathology or peritoneal fluid cytology. RESULTS A total of 301 patients were recruited and in 250 patients the presence of ascites (n = 93) and PM (n = 71) were confirmed. EUS was more sensitive (87.1%) than combined US and CT scan examinations (16.1%) and operative findings (laparoscopy or laparotomy) (40.9%) in diagnosing ascites. Sensitivity, specificity, positive and negative predictive values, and accuracy for predicting the presence of PM were 73%, 84%, 64%, 89%, and 81% by EUS; 18%, 99%, 87%, 75%, and 76% by combining US and CT scan; and 77%, 94%, 83%, 91%, and 89% by operative findings, respectively. In multivariate logistic regression analysis, EUS detected ascites was the only significant independent predictor for the presence of PM (p<0.001; odds ratio 4.7 (95% confidence interval 2.0-11.2)). CONCLUSION EUS is a sensitive method for diagnosing ascites which is an important predictive factor for the presence of PM in GC patients.
Collapse
Affiliation(s)
- Y T Lee
- Department of Medicine and Therapeutics, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin NT, Hong Kong, China.
| | | | | | | | | | | | | | | |
Collapse
|
40
|
Abstract
The ab initio/Rice-Ramsperger-Kassel-Marcus (RRKM) approach has been applied to investigate the photodissociation mechanism of azulene at 6.4 eV (the laser wavelength of 193 nm) upon absorption of one UV photon followed by internal conversion into the ground electronic state. Reaction pathways leading to various decomposition products have been mapped out at the G3(MP2,CC)//B3LYP level and then the RRKM and microcanonical variational transition state theories have been applied to compute rate constants for individual reaction steps. Relative product yields (branching ratios) for the dissociation products have been calculated using the steady-state approach. The results show that photoexcited azulene can readily isomerize to naphthalene and the major dissociation channel is elimination of an H-atom from naphthalene. The branching ratio of this channel decreases with an increase of the photon energy. Acetylene elimination is the second probable reaction channel and its branching ratio rises as the photon energy increases. The main C8H6 fragments at 193 nm are phenylacetylene and pentalene and the yield of the latter grows fast with the increasing excitation energy.
Collapse
Affiliation(s)
- Yu A Dyakov
- Institute of Atomic and Molecular Sciences, Academia Sinica, P.O. Box 23-166, Taipei 10764, Taiwan
| | | | | | | | | |
Collapse
|
41
|
Lee YT, Lee CM, Lin CS, Sheu SH, Kuo WK, Tsai CW, Huang LC, Huang HC, Wang JS, Tseng WK. A double-blind comparison of the efficacy and tolerability of telmisartan 40-80 mg vs. losartan 50-100 mg in Taiwanese hypertensive patients. Int J Clin Pract 2005:40-5. [PMID: 15617458 DOI: 10.1111/j.1742-1241.2004.00409.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
Abstract
A multicentre, randomised, double-blind, double-dummy, parallel-group, dose-titration study was conducted to determine the efficacy and tolerability of telmisartan 40-80 mg once daily compared with losartan 50-100 mg once daily in 180 Taiwanese patients with mild-to-moderate essential hypertension. After an initial 2-week placebo run-in phase, patients were randomised in a double-blind, double-dummy fashion to receive either telmisartan 40 mg or losartan 50 mg. If blood pressure control (diastolic blood pressure [DBP] <90 mmHg or > or = 10 mmHg reduction in DBP) was achieved after 4 weeks, the dose was maintained for the second 4 weeks of the active treatment phase; if not, the dose was doubled to telmisartan 80 mg or losartan 100 mg, respectively, for the second 4 weeks of double-blind treatment. Telmisartan 40-80 mg (n = 86) was as effective as losartan 50-100 mg (n = 90) in reducing trough seated DBP (11.1 vs. 8.7 mmHg, p = 0.144), and was significantly more effective than losartan in reducing trough seated systolic blood pressure (SBP) (22.1 vs. 16.5 mmHg, p = 0.032) and standing SBP (21.0 vs. 16.3 mmHg, p = 0.033). Significantly fewer patients treated with telmisartan than those treated with losartan required uptitration after 4 weeks' treatment (32.6% vs. 61.5%, p = 0.001). Both telmisartan and losartan were well tolerated.
Collapse
Affiliation(s)
- Y T Lee
- Department of Internal Medicine, National Taiwan University Hospital, Taipei, Taiwan.
| | | | | | | | | | | | | | | | | | | |
Collapse
|
42
|
Affiliation(s)
- Y T Lee
- Department of Medicine and Therapeutics, Prince of Wales Hospital, Chinese University of Hong Kong, Shatin, N.T., Hong Kong SAR, China.
| | | |
Collapse
|
43
|
Affiliation(s)
- Y T Lee
- Department of Medicine and Therapeutics, Prince of Wales Hospital, Chinese University of Hong Kong, Shatin, Hong Kong, China.
| |
Collapse
|
44
|
Ng WH, Chan YL, Sung JY, Lee YT, Lee SF, Chung SSC. Comparison of breath-hold 2D phase-contrast with non breath-hold cine phase-contrast MRA in the assessment of azygos venous blood flow in portal hypertension. Magn Reson Mater Phy 2004; 16:211-7. [PMID: 15022053 DOI: 10.1007/s10334-003-0026-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/07/2003] [Accepted: 10/23/2003] [Indexed: 11/28/2022]
Abstract
Azygos venous blood flow as an index of blood flow through the gastroesophageal collaterals and varices is of value in the prediction of gastrointestinal bleeding. Measurement of azygos venous blood flow has been achieved by non breath-hold (NBH) cine phase-contrast magnetic resonance imaging. The objective of this study was to compare the faster breath-hold (BH) phase-contrast technique with the standard (NBH) cine phase-contrast technique in the measurement of azygos blood flow. Thirty-two cirrhotic patients with esophageal varices were examined by magnetic resonance imaging using a BH technique and a NBH cine phase-contrast technique to measure the flow velocity, flow volume and calibre of the azygos vein at the mid-right atrial level. The flow values were obtained on the velocity image of the phase-contrast study. Values obtained from the two methods were evaluated statistically for the strength and significance of correlation by the Pearson test. Measurement by the BH method performed at full-inspiration as well as end-expiration was also obtained in 15 healthy volunteers. The breath-hold phase-contrast method has significant but weak correlation with non BH cine phase-contrast method in the measurement of azygos venous blood flow volume (r = 0.55, p < 0.01) and flow velocity (r = 0.43, p = 0.01). However, the calibre of the azygos vein gave a strong correlation in these two methods (0.82). In the subgroup of patients whose azygos blood flow velocity was greater than 7.4 cm/s, the correlation of azygos blood flow volume is strong (r = 0.80, p < 0.01). The azygos vein calibre remains highly correlated between the BH and NBH method, in both high flow velocity (r = 0.73) and low flow velocity (r = 0.83) groups. Breath-hold sequence leads to higher values for flow velocity and flow volume in the cirrhotic patients and also the control group. In patients with portal hypertension, BH 2D phase-contrast (PC) magnetic resonance angiography (MRA) could give a comparable estimation of the calibre of the azygos vein as the NBH 2D cine PC MRA but not for azygos flow volume. In patients with high azygos flow velocity, the strong correlation in flow volume between the BH and NBH method suggests that the BH method may be a time-saving alternative to the NBH method.
Collapse
Affiliation(s)
- W H Ng
- Department of Diagnostic Radiology and Organ Imaging, Prince of Wales Hospital, Shatin, Hong Kong SAR, China.
| | | | | | | | | | | |
Collapse
|
45
|
Leong RWL, Lee YT, Ching JYL, Sung JJY. Quality of life in Chinese patients with inflammatory bowel disease: validation of the Chinese translation of the Inflammatory Bowel Disease Questionnaire. Aliment Pharmacol Ther 2003; 17:711-8. [PMID: 12641521 DOI: 10.1046/j.1365-2036.2003.01489.x] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
BACKGROUND Health-related quality of life is an important outcome measure in inflammatory bowel disease. The Inflammatory Bowel Disease Questionnaire is a quality of life questionnaire that has not been validated previously in Chinese patients with inflammatory bowel disease. AIM To develop and validate a Chinese translation of the Inflammatory Bowel Disease Questionnaire, specifically determining its construct validity, discriminant ability, reliability and sensitivity to change. METHODS We developed a Chinese version of the Inflammatory Bowel Disease Questionnaire. Chinese patients with Crohn's disease and ulcerative colitis completed the Chinese Inflammatory Bowel Disease Questionnaire and visual analogue scales measuring systemic, social, bowel and emotional well-being. Patients also completed a validated Chinese SF-36 generic quality of life questionnaire, the Crohn's disease activity index or the clinical activity index for ulcerative colitis. RESULTS One hundred and thirty-five patients (59 with Crohn's disease and 76 with ulcerative colitis) were enrolled, 99 of whom also completed the Chinese Inflammatory Bowel Disease Questionnaire for a second time. The Chinese Inflammatory Bowel Disease Questionnaire correlated well with the SF-36 for all four domains (Spearman: r = 0.55-0.80), the Crohn's disease activity index (r = -0.62-0.72) and the clinical activity index for ulcerative colitis (r = -0.44-0.68), as well as with the visual analogue scales. The Chinese Inflammatory Bowel Disease Questionnaire accurately distinguished between active and inactive disease. Test-re-test reliability showed excellent intra-class correlation (0.76-0.92; all P < 0.001). The Chinese Inflammatory Bowel Disease Questionnaire was also sensitive to changes in disease activity (P < 0.05). CONCLUSION The Chinese Inflammatory Bowel Disease Questionnaire is a valid and reliable test that correlates well with the patients' subjective well-being and clinical disease activity.
Collapse
Affiliation(s)
- R W L Leong
- Department of Medicine and Therapeutics, Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, Hong Kong, China
| | | | | | | |
Collapse
|
46
|
Chang W, Ma M, Hwang C, Chen W, Lin F, Lee Y. Crit Care 2003; 7:P068. [DOI: 10.1186/cc1957] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
|
47
|
Sung FC, Lee YT, Lin CC, Lin RS, Su YC, Su TC. #82 Hypertension among primary school children with glucosuria and/or proteinuria. Ann Epidemiol 2002. [DOI: 10.1016/s1047-2797(02)00370-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
|
48
|
Hung LCT, Lee YT, Yu SCH, Leung WK, Sung JJY. A middle-aged woman with recurrent haemetemesis. Lancet 2002; 360:778. [PMID: 12241837 DOI: 10.1016/s0140-6736(02)09900-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Affiliation(s)
- L C T Hung
- Department of Medicine and Therapeutics, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong SAR, China.
| | | | | | | | | |
Collapse
|
49
|
Lee YT, Chan FKL, Ching JYL, Lai CW, Leung VKS, Chung SCS, Sung JJY. Diagnosis of gastroesophageal varices and portal collateral venous abnormalities by endosonography in cirrhotic patients. Endoscopy 2002; 34:391-8. [PMID: 11972271 DOI: 10.1055/s-2002-25286] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
BACKGROUND AND STUDY AIMS The role of endosonography (EUS) in the management of portal hypertension is not well defined. We aimed to study the use of a new generation video-echo endoscope in the diagnosis of gastroesophageal varices (GEV) and extraluminal venous abnormalities in cirrhotic patients. PATIENTS AND METHODS Cirrhotic patients were studied by echo endoscopy to assess esophageal varices endoscopically, and gastric varices and extraluminal venous abnormalities sonographically. The results were compared with esophagogastroduodenoscopy (EGD) examination. Dyspeptic patients served as controls. RESULTS A total of 52 cirrhotic and 166 dyspeptic patients were studied. EUS identified esophageal varices (EV) endoscopically in 28 patients (53.8 %), which showed a good correlation with EGD findings (r = 0.855, P < 0.001). The red color sign and portal hypertensive gastropathy were diagnosed in six and seven patients, respectively, by both methods. EUS detected gastric varices sonographically in 16 patients (30.8 %), compared with detection in nine patients by EGD. Extraluminal venous abnormalities were detected in 48 cirrhotic patients (92 %) and in only nine dyspeptic patients (5.4 %) (P < 0.001). The size of extraluminal adventitial venous dilatation was significantly correlated with the severity of GEV and cirrhosis (P < 0.001). Perforating veins were identified in all patients with GEV. CONCLUSION The new generation video-echo endoscope could be used as a single investigation in assessing both the intraluminal GEV and extraluminal venous abnormalities in cirrhotic patients. It may improve the management of patients with portal hypertension.
Collapse
Affiliation(s)
- Y T Lee
- Department of Medicine and Therapeutics, Prince of Wales Hospital, Chinese University of Hong Kong, Shatin, China.
| | | | | | | | | | | | | |
Collapse
|
50
|
Kaiser RI, Le TN, Nguyen TL, Mebel AM, Balucani N, Lee YT, Stahl F, Schleyer PR, Schaefer HF. A combined crossed molecular beam and ab initio investigation of C2 and C3 elementary reactions with unsaturated hydrocarbons--pathways to hydrogen deficient hydrocarbon radicals in combustion flames. Faraday Discuss 2002:51-66; discussion 121-43. [PMID: 11878006 DOI: 10.1039/b101967h] [Citation(s) in RCA: 83] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Crossed molecular beam experiments on dicarbon and tricarbon reactions with unsaturated hydrocarbons acetylene, methylacetylene, and ethylene were performed to investigate the dynamics of channels leading to hydrogen-deficient hydrocarbon radicals. In the light of the results of new ab initio calculations, the experimental data suggest that these reactions are governed by an initial addition of C2/C3 to the pi molecular orbitals forming highly unsaturated cyclic structures. These intermediates are connected via various transition states and are suggested to ring open to chain isomers which decompose predominantly by displacement of atomic hydrogen, forming C4H, C5H, HCCCCCH2, HCCCCCCH3, H2CCCCH and H2CCCCCH. The C2(1 sigma g+) + C2H4 reaction has no entrance barrier and the channel leading to the H2CCCCH product is strongly exothermic. This is in strong contrast with the C3(1 sigma g+) + C2H4 reaction as this is characterized by a 26.4 kJ mol-1 threshold to form a HCCCCCH2 isomer. Analogous to the behavior with ethylene, preliminary results on the reactions of C2 and C3 with C2H2 and CH3CCH showed the H-displacement channels of these systems to share many similarities such as the absence/presence of an entrance barrier and the reaction mechanism. The explicit identification of the C2/C3 vs. hydrogen displacement demonstrates that hydrogen-deficient hydrocarbon radicals can be formed easily in environments like those of combustion processes. Our work is a first step towards a systematic database of the intermediates and the reaction products which are involved in this important class of reactions. These findings should be included in future models of PAH and soot formation in combustion flames.
Collapse
Affiliation(s)
- R I Kaiser
- Department of Chemistry, University of York, York, UK YO10 5DD
| | | | | | | | | | | | | | | | | |
Collapse
|