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Tam MTK, Cheng YW, Chan JYS, Chan CP, Au ACK, Fan KWS, Chim TMY, Kwok WY, Fong FK, Lai A, Tan GM, Yan BP. Aveir VR real-world performance and chronic pacing threshold prediction using mapping and fixation electrical data. Europace 2024; 26:euae051. [PMID: 38457487 PMCID: PMC10923508 DOI: 10.1093/europace/euae051] [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] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2024] [Accepted: 02/14/2024] [Indexed: 03/10/2024] Open
Abstract
AIMS Aveir VR performance and predictors for its pacing threshold (PCT) in a real-world cohort were investigated. METHODS Electrical measurements at various stages of an Aveir VR implant were prospectively collected. Predictors for 3-month PCT were studied. A retrospective cohort of consecutive 139 Micra implants was used to compare the PCT evolution. High PCT was defined as ≥1.5 V, using a pulse width of 0.4 ms for Aveir and 0.24 ms for Micra. Excellent PCT was defined as ≤0.5 V at the respective pulse width. RESULTS Among the 123 consecutive Aveir VR implant attempts, 122 (99.2%) were successful. The majority were of advanced age (mean 79.7) and small body size (mean BSA 1.60). Two patients (1.6%) experienced complications, including one pericardial effusion after device reposition and one intraoperative device dislodgement. Eighty-eight patients reached a 3-month follow-up. Aveir 3-month PCT was correlated with impedance at mapping (P = 0.015), tether mode (P < 0.001), end-of-procedure (P < 0.001), and mapping PCT (P = 0.035), but not with PCTs after fixation (P > 0.05). Tether mode impedance >470 ohms had 88% sensitivity and 71% specificity in predicting excellent 3-month PCT. Although it is more common for Aveir to have high PCT at end of procedure (11.5% for Aveir and 2.2% for Micra, P = 0.004), the rate at 3 months was similar (2.3% for Aveir and 3.1% for Micra, P = 1.000). CONCLUSION Aveir VR demonstrated satisfactory performance in this high-risk cohort. Pacing thresholds tend to improve to a greater extent than Micra after implantation. The PCT after fixation, even after a waiting period, has limited predictive value for the chronic threshold. Low-mapping PCT and high intraoperative impedance predict chronic low PCT.
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Affiliation(s)
- Mark T K Tam
- Division of Cardiology, Department of Medicine and Therapeutics, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, NT, Hong Kong
| | - Yuet-Wong Cheng
- Division of Cardiology, Department of Medicine, Queen Elizabeth Hospital, 30 Gascoigne Road, KLN, Hong Kong
| | - Joseph Y S Chan
- Division of Cardiology, Department of Medicine and Therapeutics, Prince of Wales Hospital, 30-32 Ngan Shing Street, Shatin, NT, Hong Kong
| | - Chin-Pang Chan
- Division of Cardiology, Department of Medicine and Therapeutics, Prince of Wales Hospital, 30-32 Ngan Shing Street, Shatin, NT, Hong Kong
| | - Alex C K Au
- Division of Cardiology, Department of Medicine and Therapeutics, Prince of Wales Hospital, 30-32 Ngan Shing Street, Shatin, NT, Hong Kong
| | - Katie W S Fan
- Division of Cardiology, Department of Medicine and Therapeutics, Prince of Wales Hospital, 30-32 Ngan Shing Street, Shatin, NT, Hong Kong
| | - Thomas M Y Chim
- Division of Cardiology, Department of Medicine, Queen Elizabeth Hospital, 30 Gascoigne Road, KLN, Hong Kong
| | - Wan-Ying Kwok
- Division of Cardiology, Department of Medicine, Queen Elizabeth Hospital, 30 Gascoigne Road, KLN, Hong Kong
| | - Fuk-Kei Fong
- Division of Cardiology, Department of Medicine and Therapeutics, Prince of Wales Hospital, 30-32 Ngan Shing Street, Shatin, NT, Hong Kong
| | - Angel Lai
- Division of Cardiology, Department of Medicine and Therapeutics, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, NT, Hong Kong
| | - Guang-Ming Tan
- Division of Cardiology, Department of Medicine and Therapeutics, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, NT, Hong Kong
| | - Bryan P Yan
- Division of Cardiology, Department of Medicine and Therapeutics, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, NT, Hong Kong
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Tam MTK, Au ACK, Chan JYS, Chan CP, Cheung LL, Cheng YW, Yuen FSM, Yan BP. Personalized cardiac resynchronization therapy guided by real-time electrocardiographic imaging for patients with non-left bundle branch block. Heart Rhythm 2024:S1547-5271(24)00198-X. [PMID: 38369037 DOI: 10.1016/j.hrthm.2024.02.027] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/22/2023] [Revised: 02/07/2024] [Accepted: 02/12/2024] [Indexed: 02/20/2024]
Abstract
BACKGROUND Patients with heart failure and a non-left bundle branch block (non-LBBB) QRS pattern have a limited response to biventricular pacing (BVP). OBJECTIVE A personalized cardiac resynchronization therapy (CRT) implantation approach guided by real-time electrocardiographic imaging (ECGi) was studied. METHODS Twenty patients with left ventricular ejection fraction (LVEF) ≤ 35%, QRS duration ≥ 120 ms, and non-LBBB [13 (65%) with right bundle branch block and 7 (35%) with intraventricular conduction delay] were recruited. During CRT implantation, right atrial, right ventricular, coronary sinus, His-bundle, and/or left bundle leads were inserted. The total activation time (TAT) with different pacing combinations were measured in real time during implantation by ECGi. The configuration producing the shortest TAT was chosen. Clinical response was defined as ≥1 New York Heart Association class improvement. Echocardiographic response was defined as left ventricular end-systolic volume reduction ≥ 15% and/or LVEF improvement ≥ 10% at 6 months. RESULTS After ECGi-guided CRT implantation, LVEF improved from 26% ± 6% to 34% ± 11% (P < .01) and New York Heart Association class improved from 3.0 ± 0.5 to 2.0 ± 0.6 (P < .01). Both clinical and echocardiographic response rates were 70%. The ECGi approach resulted in better acute electrical resynchronization over BVP as measured by TAT reduction (40% vs 14%; P < .01). The percentage of TAT reduction was found to be a strong predictor for echocardiographic response (area under the curve for the receiver operating characteristic curve 0.91; 95% confidence interval 0.78-1.00). A strong positive correlation between percentage TAT reduction and percentage LVEF improvement (Pearson R = 0.70; P = .001) was found. CONCLUSION ECGi-guided CRT implantation in patients with non-LBBB generates superior acute electrical resynchronization compared with BVP and is associated with favorable clinical and echocardiographic outcomes.
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Affiliation(s)
- Mark T K Tam
- Division of Cardiology, Department of Medicine and Therapeutics, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong SAR, China
| | - Alex C K Au
- Division of Cardiology, Department of Medicine and Therapeutics, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong SAR, China
| | - Joseph Y S Chan
- Division of Cardiology, Department of Medicine and Therapeutics, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong SAR, China
| | - Chin-Pang Chan
- Division of Cardiology, Department of Medicine and Therapeutics, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong SAR, China
| | - Li-Li Cheung
- Division of Cardiology, Department of Medicine and Therapeutics, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong SAR, China
| | - Yuet-Wong Cheng
- Division of Cardiology, Department of Medicine, Queen Elizabeth Hospital, Hong Kong SAR, China
| | - Fiona S M Yuen
- Division of Cardiology, Department of Medicine, North District Hospital, Hong Kong SAR, China
| | - Bryan P Yan
- Division of Cardiology, Department of Medicine and Therapeutics, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong SAR, China; Heart & Vascular Institute, The Chinese University of Hong Kong, Hong Kong SAR, China.
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Lee JCY, Chiang JB, Ng PP, Chow BCK, Cheng YW, Wong CY. Utility of cardiac magnetic resonance imaging in troponin-positive chest pain with non-obstructive coronary arteries: literature review. Hong Kong Med J 2021; 27:266-275. [PMID: 34413254 DOI: 10.12809/hkmj208690] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Affiliation(s)
- J C Y Lee
- Department of Radiology and Imaging, Queen Elizabeth Hospital, Hong Kong
| | - J B Chiang
- Department of Radiology and Imaging, Queen Elizabeth Hospital, Hong Kong
| | - P P Ng
- Department of Radiology and Imaging, Queen Elizabeth Hospital, Hong Kong
| | - B C K Chow
- Department of Radiology and Imaging, Queen Elizabeth Hospital, Hong Kong
| | - Y W Cheng
- Department of Medicine, Queen Elizabeth Hospital, Hong Kong
| | - C Y Wong
- Department of Medicine, Queen Elizabeth Hospital, Hong Kong
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Ho C, Lee PH, So TC, Chiang MCS, Wong MH, Fong YH, Tsang CF, Cheng YW, Luk NH, Chui SF, Chan KC, Wong CY, Fu CL, Lee KY, Chan KT. 224 Malignancy associated pericardial effusion- do we need to drain them all? Eur Heart J 2020. [DOI: 10.1093/ehjci/ehz872.009] [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] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Abstract
On Behalf
Cardiac Team, Department of Medicine, Queen Elizabeth Hospital
Background
Management of significant pericardial effusion in cancer patients is controversial. These patients have poor prognosis, and avoiding unnecessary intervention is important. Close monitoring of symptoms and echocardiogram is often a reasonable option, but inherits risk of cardiac tamponade. Whether pericardial drainage by means of percutaneous pericardiocentesis or surgical pericardiotomy could prevent future deterioration or affect survival is unknown.
Purpose
To evaluate the benefit of elective pericardial drainage in malignancy associated pericardial effusion without echocardiographic or clinical evidence of tamponade effect.
Methods
From 1st Jul 2014 to 31st Dec 2017, all patients with new onset malignancy-associated pericardial effusion with size more than 1cm were retrospectively analyzed. Patients with clinical or echocardiographic evidence of cardiac tamponade were excluded. We compared pericardial drainage versus monitoring for short-term (30-day), mid-term (90-day) and long term (1 year) survival without need for drainage.
Results
101 patients were retrospectively analyzed. 40 (39.6%) patients underwent drainage. Overall median survival free from drainage was 4 months. There were no significant difference in short-term (30-day), mid-term (90-day) and long term (1-year) survival free from drainage or mortality between treatment and monitoring group. Size of pericardial effusion did not predict mortality or future need of drainage. Chemotherapy was associated with improved 30-day mortality (RR 0.53 CI 0.32-0.87 p = 0.025) but not survival free from drainage or longer term mortality.
Conclusion
Close monitoring could be a feasible strategy in cancer patients with significant pericardial effusion without tamponade effect.
Baseline characteristics Factor Drainage (n = 40) monitoring (n = 61) p-value method of drainage pericardiocentesis alone 17 NA pericardiotomy alone 13 both 10 Male 19 (47.5%) 27 (44.3%) 0.749 mean size (cm) 1.93 2.77 <0.001 mean age 60.9 63.1 0.357 on chemotherapy 27 (67.5%) 38 (62.3%) 0.593
Abstract 224 Figure. Survival free from drainage
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Affiliation(s)
- C Ho
- Queen Elizabeth Hospital, Hong Kong, Hong Kong
| | - P H Lee
- Queen Elizabeth Hospital, Hong Kong, Hong Kong
| | - T C So
- Queen Elizabeth Hospital, Hong Kong, Hong Kong
| | | | - M H Wong
- Queen Elizabeth Hospital, Hong Kong, Hong Kong
| | - Y H Fong
- Queen Elizabeth Hospital, Hong Kong, Hong Kong
| | - C F Tsang
- Queen Elizabeth Hospital, Hong Kong, Hong Kong
| | - Y W Cheng
- Queen Elizabeth Hospital, Hong Kong, Hong Kong
| | - N H Luk
- Queen Elizabeth Hospital, Hong Kong, Hong Kong
| | - S F Chui
- Queen Elizabeth Hospital, Hong Kong, Hong Kong
| | - K C Chan
- Queen Elizabeth Hospital, Hong Kong, Hong Kong
| | - C Y Wong
- Queen Elizabeth Hospital, Hong Kong, Hong Kong
| | - C L Fu
- Queen Elizabeth Hospital, Hong Kong, Hong Kong
| | - K Y Lee
- Queen Elizabeth Hospital, Hong Kong, Hong Kong
| | - K T Chan
- Queen Elizabeth Hospital, Hong Kong, Hong Kong
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Abstract
Objective To test the validity of the Hong Kong version of Appropriateness Evaluation Protocol and estimate the prevalence of inappropriate acute hospitalisations in Hong Kong. Methods A retrospective chart review of two hundred randomly selected patients admitted to the specialty of Internal Medicine and General Surgery via the Accident & Emergency department of 2 regional hospitals in 2008. Comparison between the Hong Kong version of Appropriateness Evaluation Protocol and the consensus of an expert panel on appropriateness of admissions was made. The extent of agreement between the reviewer using the protocol and the expert panel was measured. Results The kappa coefficient for agreement was 0.73 (95% confidence interval: 0.63-0.83). The prevalence of inappropriate acute hospitalisations was 29%. Conclusions The Hong Kong version of Appropriateness Evaluation Protocol is a valid tool for assessing the appropriateness of acute hospitalisations.
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Affiliation(s)
| | - YW Cheng
- Queen Elizabeth Hospital, Department of Medicine, 30 Gascoigne Road, Kowloon, Hong Kong
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Cheng YW. TCTAP C-189 Post Cardiac Arrest with New Onset LBBB: When “Nothing” Means Something. J Am Coll Cardiol 2017. [DOI: 10.1016/j.jacc.2017.03.421] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Cheng YW. TCTAP C-113 A Lesson to Learn from an Octogenarian with STEMI. J Am Coll Cardiol 2016. [DOI: 10.1016/j.jacc.2016.03.320] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Abstract
This study aimed to analyze the transcriptome profile of red lettuce and identify the genes involved in anthocyanin accumulation. Red leaf lettuce is a popular vegetable and popular due to its high anthocyanin content. However, there is limited information available about the genes involved in anthocyanin biosynthesis in this species. In this study, transcriptomes of 15-day-old seedlings and 40-day-old red lettuce leaves were analyzed using an Illuminia HiseqTM 2500 platform. A total of 10.6 GB clean data were obtained and de novo assembled into 83,333 unigenes with an N50 of 1067. After annotation against public databases, 51,850 unigene sequences were identified, among which 46,087 were annotated in the NCBI non-redundant protein database, and 41,752 were annotated in the Swiss-Prot database. A total of 9125 unigenes were mapped into 163 pathways using the Kyoto Encyclopedia of Genes and Genomes database. Thirty-four structural genes were found to cover the main steps of the anthocyanin pathway, including chalcone synthase, chalcone isomerase, flavanone 3-hydroxylase, flavonoid 3'-hydroxylase, flavonoid 3',5'-hydroxylase, dihydroflavonol 4-reductase, and anthocyanidin synthase. Seven MYB, three bHLH, and two WD40 genes, considered anthocyanin regulatory genes, were also identified. In addition, 3607 simple sequence repeat (SSR) markers were identified from 2916 unigenes. This research uncovered the transcriptomic characteristics of red leaf lettuce seedlings and mature plants. The identified candidate genes related to anthocyanin biosynthesis and the detected SSRs provide useful tools for future molecular breeding studies.
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Affiliation(s)
- Y Z Zhang
- Life Science Department, Luoyang Normal University, Luoyang, China
| | - S Z Xu
- Life Science Department, Luoyang Normal University, Luoyang, China
| | - Y W Cheng
- Life Science Department, Luoyang Normal University, Luoyang, China
| | - H Y Ya
- Life Science Department, Luoyang Normal University, Luoyang, China
| | - J M Han
- Life Science Department, Luoyang Normal University, Luoyang, China
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Zhang YZ, Cheng YW, Ya HY, Han JM, Zheng L. Identification of heat shock proteins via transcriptome profiling of tree peony leaf exposed to high temperature. Genet Mol Res 2015; 14:8431-42. [PMID: 26345770 DOI: 10.4238/2015.july.28.10] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
The tree peony leaf is an important vegetative organ that is sensitive to abiotic stress and particularly to high temperature. This sensitivity affects plant growth and restricts tree peony distribution. However, the transcriptomic information currently available on the peony leaf in public databases is limited. In this study, we sequenced the transcriptomes of peony leaves subjected to high temperature using the Illumina HiSeq TM 2000 platform. We performed de novo assembly of 93,714 unigenes (average length of 639.7 bp). By searching the public databases, 22,323 unigenes and 13,107 unigenes showed significant similarities with proteins in the NCBI non-redundant protein database and SWISS-PROT database (E-value < 1e-5), respectively. We assigned 17,340 unigenes to Gene Ontology categories, and we assigned 7618 unigenes to clusters of orthologous groups for eukaryotic complete genomes. By searching the Kyoto Encyclopedia of Genes and Genomes Pathway database, 8014 unigenes were assigned to 6 main categories, including 290 KEGG pathways. To advance research on improving thermotolerance, we identified 24 potential heat shock protein genes with complete open reading frames from the transcriptomic sequences. This is the first study to characterize the leaf transcriptome of tree peony leaf using high-throughput sequencing. The information obtained from the tree peony leaf is valuable for gene discovery, and the identified heat shock protein genes can be used to improve plant stress-tolerance.
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Affiliation(s)
- Y Z Zhang
- Life Science Department, Luoyang Normal University, Luoyang, China
| | - Y W Cheng
- Life Science Department, Luoyang Normal University, Luoyang, China
| | - H Y Ya
- Life Science Department, Luoyang Normal University, Luoyang, China
| | - J M Han
- Life Science Department, Luoyang Normal University, Luoyang, China
| | - L Zheng
- Life Science Department, Luoyang Normal University, Luoyang, China
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Abstract
Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL), which has long been believed to be highly selective in inducing apoptosis in cancer cells, has turned out to be a molecule that induces a far more diverse range of effects. The aim of this study was to investigate whether or not ERK1/2 pathway is involved in antitumor effects of TRAIL on gastric cancer cells. In addition to activate the extrinsic and intrinsic apoptotic pathway, TRAIL also triggered the activation of ERK1/2. Inhibition of ERK1/2 signaling by MEK inhibitor U0126 promoted cell death via increased activation of caspases, drop in mitochondrial membrane potential and downregulation of XIAP, cIAP2 and Mcl-1. These results indicate that TRAIL-induced rapid activation of ERK1/2 may be a survival mechanism to struggle against TRAIL assault at the early stage, and inhibition of ERK1/2 signaling can sensitize gastric cancer cells to TRAIL-induced apoptosis.
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Lin CH, Li CH, Liao PL, Tse LS, Huang WK, Cheng HW, Cheng YW. Silibinin inhibits VEGF secretion and age-related macular degeneration in a hypoxia-dependent manner through the PI-3 kinase/Akt/mTOR pathway. Br J Pharmacol 2013; 168:920-31. [PMID: 23004355 DOI: 10.1111/j.1476-5381.2012.02227.x] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2012] [Revised: 08/19/2012] [Accepted: 09/06/2012] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND AND PURPOSE Hypoxia-mediated neovascularization plays an important role in age-related macular degeneration (AMD). There are few animal models or effective treatments for AMD. Here, we investigated the effects of the flavonoid silibinin on hypoxia-induced angiogenesis in a rat AMD model. EXPERIMENTAL APPROACH Retinal pigmented epithelial (RPE) cells were subjected to hypoxia in vitro and the effects of silibinin on activation of key hypoxia-induced pathways were examined by elucidating the hypoxia-inducible factor-1 alpha (HIF-1α) protein level by Western blot. A rat model of AMD was developed by intravitreal injection of VEGF in Brown Norway rats, with or without concomitant exposure of animals to hypoxia. Animals were treated with oral silibinin starting at day 7 post-VEGF injection and AMD changes were followed by fluorescein angiography on days 14 and 28 post-injection. KEY RESULTS Silibinin pretreatment of RPE cells increased proline hydroxylase-2 expression, inhibited HIF-1α subunit accumulation, and inhibited VEGF secretion. Silibinin-induced HIF-1α and VEGF down-regulation required suppression of hypoxia-induced phosphatidylinositol 3-kinase/Akt/mammalian target of rapamycin (mTOR) pathway. In the rat model of AMD, silibinin administration prevented VEGF- and VEGF plus hypoxia-induced retinal oedema and neovascularization. CONCLUSION AND IMPLICATIONS The effects of silibinin, both in vitro and in vivo, support its potential as a therapeutic for the prevention of neovascular AMD.
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Affiliation(s)
- C H Lin
- School of Pharmacy, College of Pharmacy, Taipei Medical University, Taipei, Taiwan
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Amburgey K, Lawlor MW, Del Gaudio D, Cheng YW, Fitzpatrick C, Minor A, Li X, Aughton D, Das S, Beggs AH, Dowling JJ. Large duplication in MTM1 associated with myotubular myopathy. Neuromuscul Disord 2012; 23:214-8. [PMID: 23273872 DOI: 10.1016/j.nmd.2012.11.010] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2012] [Revised: 10/23/2012] [Accepted: 11/23/2012] [Indexed: 11/26/2022]
Abstract
Myotubular myopathy is a subtype of centronuclear myopathy with X-linked inheritance and distinctive clinical and pathologic features. Most boys with myotubular myopathy have MTM1 mutations. In remaining individuals, it is not clear if disease is due to an undetected alteration in MTM1 or mutation of another gene. We describe a boy with myotubular myopathy but without mutation in MTM1 by conventional sequencing. Array-CGH analysis of MTM1 uncovered a large MTM1 duplication. This finding suggests that at least some unresolved cases of myotubular myopathy are due to duplications in MTM1, and that array-CGH should be considered when MTM1 sequencing is unrevealing.
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Affiliation(s)
- K Amburgey
- Department of Pediatrics, University of Michigan, Ann Arbor, MI, USA
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Cheng YW, Sparks TN, Laros Jr RK, Nicholson JM, Caughey AB. Suspected macrosomia: will induction of labour modify the risk of caesarean delivery? BJOG 2012. [DOI: 10.1111/j.1471-0528.2012.03327.x] [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: 11/30/2022]
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Abstract
OBJECTIVE To compare the annual incidence rates of caesarean delivery between induction of labour and expectant management in the setting of macrosomia. DESIGN This is a retrospective cohort study. SETTING Deliveries in the USA in 2003. POPULATION Singleton births of macrosomic neonates to low-risk nulliparous women at 39 weeks of gestation and beyond. METHODS Women who had induction of labour at 39 weeks of gestation with a neonatal birthweight of 4000 ± 125 g (3875-4125 g) were compared with women who delivered (either induced or spontaneous labour) at 40, 41 or 42 weeks (i.e. expectant management), assuming an intrauterine fetal weight gain of 200 g per additional week of gestation. Similar comparisons were made at 40 and 41 weeks of gestation. Chi-square test and multivariable logistic regression analysis were used for statistical comparison. MAIN OUTCOME MEASURES Method of delivery, 5-minute Apgar scores, neonatal injury. RESULTS There were 132,112 women meeting the study criteria. In women whose labours were induced at 39 weeks and who delivered a neonate with a birthweight of 4000 ± 125 g, the frequency of caesarean was lower compared with women who delivered at a later gestational age (35.2% versus 40.9%; adjusted OR 1.25, 95% CI 1.17-1.33). This trend was maintained at both 40 weeks (36.1% versus 42.6%; adjusted OR 1.31, 95% CI 1.23-1.40) and 41 weeks (38.9% versus 41.8%; adjusted OR 1.16, 95% CI 1.06-1.28) of gestation. CONCLUSIONS In the setting of known birthweight, it appears that induction of labour may reduce the risk of caesarean delivery. Future research should concentrate on clinical and radiological methods to better estimate birthweight to facilitate improved clinical care. These findings deserve examination in a large, prospective, randomised trial.
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Affiliation(s)
- Y W Cheng
- Division of Maternal-Fetal Medicine, Department of Obstetrics, Gynecology and Reproductive Sciences, University of California, San Francisco, CA 94143-0132, USA.
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Cheng YW, Kaimal AJ, Bruckner TA, Halloran DR, Hallaron DR, Caughey AB. Perinatal morbidity associated with late preterm deliveries compared with deliveries between 37 and 40 weeks of gestation. BJOG 2011; 118:1446-54. [PMID: 21883872 PMCID: PMC3403292 DOI: 10.1111/j.1471-0528.2011.03045.x] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.8] [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] [Indexed: 11/29/2022]
Abstract
OBJECTIVE To estimate the risk of short-term complications in neonates born between 34 and 36 weeks of gestation. DESIGN This is a retrospective cohort study. SETTING Deliveries in 2005 in the USA. POPULATION Singleton live births between 34 and 40 weeks of gestation. METHODS Gestational age was subgrouped into 34, 35, 36 and 37-40 completed weeks of gestation. Statistical comparisons were performed using chi-square test and multivariable logistic regression models, with 37-40 weeks of gestation designated as referent. MAIN OUTCOME MEASURES Perinatal morbidities, including 5-minute Apgar scores, hyaline membrane disease, neonatal sepsis/antibiotics use, and admission to the intensive care unit. RESULTS In all, 175,112 neonates were born between 34 and 36 weeks in 2005. Compared with neonates born between 37 and 40 weeks, neonates born at 34 weeks had higher odds of 5-minute Apgar <7 (adjusted odds ratio [aOR] 5.51, 95% CI 5.16-5.88), hyaline membrane disease (aOR 10.2, 95% CI 9.44-10.9), mechanical ventilation use >6 hours (aOR 9.78, 95% CI 8.99-10.6) and antibiotic use (aOR 9.00, 95% CI 8.43-9.60). Neonates born at 35 weeks were similarly at risk of morbidity, with higher odds of 5-minute Apgar <7 (aOR 3.42, 95% CI 3.23-3.63), surfactant use (aOR 3.74, 95% CI 3.21-4.22), ventilation use >6 hours (aOR 5.53, 95% CI 5.11-5.99) and neonatal intensive-care unit admission (aOR 11.3, 95% CI 11.0-11.7). Neonates born at 36 weeks remain at higher risk of morbidity compared with deliveries at 37-40 weeks of gestation. CONCLUSIONS Although the risk of undesirable neonatal outcomes decreases with increasing gestational age, the risk of neonatal complications in late preterm births remains higher compared with infants delivered at 37-40 weeks of gestation.
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Affiliation(s)
- Y W Cheng
- Division of Maternal-Fetal Medicine, Department of Obstetrics, Gynecology and Reproductive Sciences, University of California, San Francisco, 94143-0132, USA.
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Esakoff TF, Sparks TN, Kaimal AJ, Kim LH, Feldstein VA, Goldstein RB, Cheng YW, Caughey AB. Diagnosis and morbidity of placenta accreta. Ultrasound Obstet Gynecol 2011; 37:324-327. [PMID: 20812377 DOI: 10.1002/uog.8827] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 08/25/2010] [Indexed: 05/29/2023]
Abstract
OBJECTIVE To examine the diagnostic precision of ultrasound examination for placenta accreta in women with placenta previa and to compare the morbidity associated with accreta to that of previa alone. METHODS This was a retrospective cohort study of all women with previa with/without accreta examined at the University of California, San Francisco (UCSF) between 2002 and 2008. The sensitivity, specificity, negative predictive value (NPV) and positive predictive value (PPV) of ultrasound examination for the diagnosis of accreta were calculated and compared with results from similar studies in the literature. Univariable analysis was used to compare clinical outcomes. RESULTS The PPV of an ultrasound diagnosis of accreta was 68% and NPV was 98%. Ultrasound had a sensitivity of 89.5%. Compared with previa alone, accreta had an odds ratio (OR) of 89.6 (95% CI, 19.44-412.95) for estimated blood loss > 2 L, an OR of 29.6 (95% CI, 8.20-107.00) for transfusion and an OR of 8.52 (95% CI, 2.58-28.11) for length of hospital stay > 4 days. CONCLUSION Placenta accreta is associated with greater morbidity than is placenta previa alone. Ultrasound examination is a good diagnostic test for accreta in women with placenta previa. This is consistent with most other studies in the literature.
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Affiliation(s)
- T F Esakoff
- Department of Obstetrics and Gynecology, Cedars Sinai Medical Center, Los Angeles, CA 90048, USA.
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Cheng YW, Li KC, Sung FC. Medical waste generation in selected clinical facilities in Taiwan. Waste Manag 2010; 30:1690-1695. [PMID: 20427173 DOI: 10.1016/j.wasman.2010.04.006] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/29/2010] [Revised: 03/28/2010] [Accepted: 04/06/2010] [Indexed: 05/29/2023]
Abstract
This study investigated the type and amount of medical waste generated from small clinical facilities in Taiwan. We sampled 200 small medical establishments, with few or no patient beds, to survey the wastes generated and disposed. The surveyed medical facilities consisted of four groups including private clinics, medical laboratories, blood centers and public clinics. Private clinics providing surgical, dental, obstetrical, and dialysis services were included in this survey because they may generate higher amounts of infectious waste than other specialties. The overall mean general waste production rate was 3.97 kg/bed/day (or 0.075 kg/patient/day) at all the surveyed facilities, higher than that obtained from larger hospitals in Taiwan, which ranged from 2.41 to 3.26 kg/bed/day. The highest amount of infectious wastes generated among the four groups of facilities were from blood centers (3.14 kg/bed/day), followed by private clinics, medical laboratories and public clinics (1.91, 1.07, and 0.053 kg/bed/day, respectively). The overall average was 2.08 kg/bed/day. This study suggests that the waste generated at small medical facilities ranged widely.
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Affiliation(s)
- Y W Cheng
- General Education Center, St. John's University, 499 Tam King Road, Section 4, Taipei 25135, Taiwan.
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Cheng YW, Sung FC, Yang Y, Lo YH, Chung YT, Li KC. Medical waste production at hospitals and associated factors. Waste Manag 2009; 29:440-4. [PMID: 18359619 PMCID: PMC7133359 DOI: 10.1016/j.wasman.2008.01.014] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/15/2007] [Revised: 12/24/2007] [Accepted: 01/17/2008] [Indexed: 05/03/2023]
Abstract
This study was conducted to evaluate the quantities of medical waste generated and the factors associated with the generation rate at medical establishments in Taiwan. Data on medical waste generation at 150 health care establishments were collected for analysis in 2003. General medical waste and infectious waste production at these establishments were examined statistically with the potential associated factors. These factors included the types of hospital and clinic, reimbursement payment by National Health Insurance, total number of beds, bed occupancy, number of infectious disease beds and outpatients per day. The average waste generation rates ranged from 2.41 to 3.26kg/bed/day for general medical wastes, and 0.19-0.88kg/bed/day for infectious wastes. The total average quantity of infectious wastes generated was the highest from medical centers, or 3.8 times higher than that from regional hospitals (267.8 vs. 70.3Tons/yr). The multivariate regression analysis was able to explain 92% of infectious wastes and 64% of general medical wastes, with the amount of insurance reimbursement and number of beds as significant prediction factors. This study suggests that large hospitals are the major source of medical waste in Taiwan. The fractions of medical waste treated as infectious at all levels of healthcare establishments are much greater than that recommended by the USCDC guidelines.
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Affiliation(s)
- Y W Cheng
- General Education Center, St. John's University, 499 Tam King Road, Section 4, Taipei 25135, Taiwan, ROC.
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Abstract
This is the first detailed characterization of the airborne bacterial profiles in indoor environments. Two restaurants were selected for this study. Fifteen genera of bacteria were isolated from each restaurant and identified by three different bacterial identification systems including MIDI, Biolog and Riboprinter. The dominant bacteria of both restaurants were Gram-positive bacteria in which Micrococcus and Bacillus species were the most abundant. Most bacteria identified were representative species of skin and respiratory tract of human, and soil. Although the bacterial levels in these two restaurants were below the limit of the Hong Kong Indoor Air Quality Objective (HKIAQO) Level 1 standard (i.e., < 500 cfu/m3), the majority of these bacteria were opportunistic pathogens. These results suggested that the identity of airborne bacteria should also be included in the IAQ to ensure there is a safety guideline for the public.
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Affiliation(s)
- P L Chan
- Department of Biology, The Chinese University of Hong Kong, Shatin, NT, Hong Kong SAR, China.
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Abstract
PURPOSE To review the diagnosis and management of gestational diabetes. EPIDEMIOLOGY In the United States, approximately 2 to 5% of all pregnant women have gestational diabetes. Those women with a family history of type 2 diabetes mellitus, Asian or native American race, Latina ethnicity or obesity are at higher risk for developing gestational diabetes. CONCLUSION Women with gestational diabetes who are treated appropriately can achieve good outcomes in the majority of pregnancies. Frequent blood glucose monitoring, nutrition counseling and frequent physician contact allow for individualized care to achieve optimal outcomes. Such treatment includes diet, exercise and insulin. The use of oral hypoglycemic agents is controversial and there is some concern about worse maternal and neonatal outcomes as compared to treatment with insulin. Evolving technologies promise to provide more therapeutic options.
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Affiliation(s)
- Y W Cheng
- Department of Obstetrics and Gynecology, University of California, San Francisco, CA 94143, USA
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Sham CO, Cheng YW, Ho KW, Lai PH, Lo LW, Wan HL, Wong CY, Yeung YN, Yuen SH, Wong AY, Wong AYC. Do-not-resuscitate decision: the attitudes of medical and non-medical students. J Med Ethics 2007; 33:261-5. [PMID: 17470500 PMCID: PMC2598130 DOI: 10.1136/jme.2005.014423] [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] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
OBJECTIVES To study the attitudes of both medical and non-medical students towards the do-not-resuscitate (DNR) decision in a university in Hong Kong, and the factors affecting their attitudes. METHODS A questionnaire-based survey conducted in the campus of a university in Hong Kong. Preferences and priorities of participants on cardiopulmonary resuscitation in various situations and case scenarios, experience of death and dying, prior knowledge of DNR and basic demographic data were evaluated. RESULTS A total of 766 students participated in the study. There were statistically significant differences in their DNR decisions in various situations between medical and non-medical students, clinical and preclinical students, and between students who had previously experienced death and dying and those who had not. A prior knowledge of DNR significantly affected DNR decision, although 66.4% of non-medical students and 18.7% of medical students had never heard of DNR. 74% of participants from both medical and non-medical fields considered the patient's own wish as the most important factor that the healthcare team should consider when making DNR decisions. Family wishes might not be decisive on the choice of DNR. CONCLUSIONS Students in medical and non-medical fields held different views on DNR. A majority of participants considered the patient's own wish as most important in DNR decisions. Family wishes were considered less important than the patient's own wishes.
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Affiliation(s)
- C O Sham
- University of Hong Kong, Hong Kong.
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23
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Cheng YW, Chan RCY, Wong PK. Disinfection of Legionella pneumophila by photocatalytic oxidation. Water Res 2007; 41:842-52. [PMID: 17224169 DOI: 10.1016/j.watres.2006.11.033] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/21/2006] [Revised: 11/18/2006] [Accepted: 11/21/2006] [Indexed: 05/13/2023]
Abstract
Photocatalytic oxidation (PCO) was proven to be efficacious in the inactivation of Legionella pneumophila serogroup 1 Strains 977, 1009, 1014 and ATCC 33153. The local (Strains 997, 1009 and 1014) and ATCC (Strain 33153) strains showed sensitivity differences towards PCO. The inactivation mechanisms of PCO were investigated by transmission and scanning electron microscopy by which PCO was found to disintegrate the cells eventually. Before the disintegration, there was lipid peroxidation of outer and cytoplasmic membrane causing holes formation and leading to the entry of OH into the cells to oxidize the intracellular components. Fatty acid profile analysis found that the amount of saturated, 16-carbon branched-chain fatty acid, which is predominant in Legionella, decreased in the surviving populations from PCO. A relationship between the amount of this fatty acid and the PCO sensitivity of the tested strains was also observed. Mineralization of cells by PCO was proven by total organic carbon analysis.
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Affiliation(s)
- Y W Cheng
- Department of Biology, The Chinese University of Hong Kong, Shatin, NT, Hong Kong SAR, China
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Abstract
BACKGROUND Cervical lymphadenopathy is a typical feature in some children with Kawasaki disease, but whether its presence or absence delays diagnosis, thereby increasing the risk of coronary artery abnormalities, has remained uncertain. AIM : The aim of this study is to review the clinical features of Kawasaki disease with particular reference to investigating the relationship of cervical lymphadenopathy to the development of coronary artery lesions. METHODS Demographic and clinical data from all the patients entered into the Hong Kong Kawasaki disease registry during 1994 to 2000 were reviewed. The presenting clinical features, echocardiographically monitored coronary artery lesions and influence of cervical lymphadenopathy (> or = 1 nodes > or = 1.5 cm diameter) on clinical onset-to-diagnosis time and response to immunoglobulin therapy are reported. RESULTS We studied 696 patients (99% Chinese, male/female ratio 1.7:1). Their distribution was inversely related to age. Twenty-four percent of the patients presented with cervical lymphadenopathy, the relative incidence of which was directly related to age. Five percent of patients had demonstrable coronary artery aneurysms at 8 weeks after disease onset. A slightly higher percentage of patients with absence of lymphadenopathy had late diagnosis. No significant positive or negative overall association between cervical lymphadenopathy and coronary artery lesions was observed. Time to resolution of fever after immunoglobulin administration did not differ between those with and without cervical lymphadenopathy. CONCLUSIONS Cervical lymphadenopathy was present in only 24% of the patients with Kawasaki disease, correlating directly with age. Its absence may delay the timing of diagnosis. There was, however, no overall association between lymphadenopathy and coronary lesions.
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Affiliation(s)
- Rita Y T Sung
- Department of Paediatrics, Prince of Wales Hospital, The Chinese University of Hong Kong, Shatin.
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Ng YM, Sung RYT, So LY, Fong NC, Ho MHK, Cheng YW, Lee SH, Mak WC, Wong DML, Yam MC, Kwok KL, Chiu WK. Kawasaki disease in Hong Kong, 1994 to 2000. Hong Kong Med J 2005; 11:331-5. [PMID: 16219951] [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: 05/04/2023] Open
Abstract
OBJECTIVE To describe the epidemiology, clinical characteristics, and management of Kawasaki disease in children in Hong Kong. DESIGN Retrospective survey of medical records from July 1994 to June 1997, and prospective data collection from July 1997 to June 2000. SETTING Hospitals with a paediatric unit in Hong Kong. PATIENTS Patients diagnosed with Kawasaki disease between July 1994 and June 2000 in public hospitals in Hong Kong. MAIN OUTCOME MEASURES Incidence of Kawasaki disease and coronary artery aneurysm rates. RESULTS A total of 696 cases of Kawasaki disease were reported. There were 435 (62.5%) boys and 261 (37.5%) girls giving a male to female ratio of 1.7:1. The age ranged from 1 month to 15 years 5 months with a median of 1.7 years. Infants (<1 year) constituted the largest group of patients (223, 32.0%) and overall, 638 (91.7%) were younger than 5 years. Skin rash, conjunctivitis, and oral signs were among the principal clinical features present in over 80% of cases. Prominent cervical lymph nodes larger than 1.5 cm were less commonly found (24%). Coronary artery aneurysms or ectasia were present in 15.7% (109/696), 8.5% (59/696), and 5.0% (35/696) of patients at 2, 4, and 8 weeks, respectively. The incidence of Kawasaki disease per 100,000 children under 5 years was significantly higher in the prospective study period than in the retrospective period (39 vs 26, P<0.001). CONCLUSION The incidence of Kawasaki disease is high in Hong Kong and is 39 per 100,000 children below 5 years of age. The coronary artery aneurysm prevalence is 5%. Intravenous gamma-globulin and high-dose aspirin is the mainstay of treatment.
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Affiliation(s)
- Y M Ng
- Department of Paediatrics, Queen Elizabeth Hospital, Kowloon, Hong Kong.
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Cheng YW, Kang JJ, Shih YL, Lo YL, Wang CF. Cholesterol-3-beta, 5-alpha, 6-beta-triol induced genotoxicity through reactive oxygen species formation. Food Chem Toxicol 2005; 43:617-22. [PMID: 15721210 DOI: 10.1016/j.fct.2005.01.007] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.2] [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: 10/10/2004] [Revised: 01/04/2005] [Accepted: 01/09/2005] [Indexed: 12/20/2022]
Abstract
The mutagenicity of oxysterols, cholesterol-3beta,5alpha,6beta-triol (alpha-Triol), 7-keto-cholesterol (7-Keto) and cholesterol-5alpha,6alpha-epoxide (alpha-Epox) were examined by the Ames method and chromosome aberration test in this study. Only alpha-Triol concentration-dependently caused an increase of bacterial revertants in the absence of metabolic activating enzymes (S9), but not 7-keto and alpha-Epox. The mutagenic effect of alpha-Triol was reduced by the addition of S9. On the other hand, although alpha-Triol significantly induced chromosome aberration in CHO-K1 cells with and without S9. However, the addition of S9 reduced the degree of abnormal structure chromosome compared to without S9 mix. Catalase and superoxide dismutase (SOD) inhibited alpha-Triol induced increase of revertants in Salmonella typhimurium and chromosome aberration frequency in CHO cells, suggesting that reactive oxygen species (ROS) might be involved in the genotoxic effect of alpha-Triol. Treatment with alpha-Triol increased the ROS production in CHO cells, which could be attenuated by catalase and SOD. Results in this study suggested, for the first time that alpha-Triol, causes genotoxic effect in an ROS-dependent manner.
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Affiliation(s)
- Y W Cheng
- School of Pharmacy, Taipei Medical University, No. 250, Wu-Shing Street, Taipei 101, Taiwan.
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27
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Tsai YY, Tsai YY, Cheng YW, Lee H, Tseng SH, Tsai CH, Tsai FJ. No association of p53 codon 72 and p21 codon 31 polymorphisms in Taiwan Chinese patients with pterygium. Br J Ophthalmol 2004; 88:975-6. [PMID: 15205257 PMCID: PMC1772236 DOI: 10.1136/bjo.2003.040428] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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Cheng YW, Chiou HL, Sheu GT, Hsieh LL, Chen JT, Chen CY, Su JM, Lee H. The association of human papillomavirus 16/18 infection with lung cancer among nonsmoking Taiwanese women. Cancer Res 2001; 61:2799-803. [PMID: 11306446] [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: 02/19/2023]
Abstract
Lung cancer is the leading cause of cancer death in Taiwanese women since 1982. High lung cancer mortality ratio of male:female in Taiwan (2:1) was observed, although less than 10% of female lung cancer patients are smokers. Until now, the etiological factor remains unknown. We hypothesize that high-risk human papillomavirus (HPV) 16/18 may be associated with lung cancer development based on high prevalence of p53 negative immunostainings in female lung tumors compared with that of male lung tumors. In this study, 141 lung cancer patients and 60 noncancer control subjects were enrolled to examine whether HPV 16/18 DNA existed in lung tumor and normal tissues by nested PCR and in situ hybridization (ISH), respectively. The concordant detection of HPV 16 and 18 DNA between nested PCR and ISH method was 73 and 85.5%, respectively. Our data showed that 77 (54.6%) of 141 lung tumors had HPV 16/18 DNA compared with 16 (26.7%; P = 0.0005) of 60 noncancer control subjects. In addition, ISH data showed that HPV 16/18 DNA was uniformly located in lung tumor cells, but not in the adjacent nontumor cells. When study subjects were stratified by gender, age, and smoking status, nonsmoking female lung cancer patients who were older than 60 years old had significantly high prevalence of HPV 16/18 infection. The odds ratio of HPV 16/18 infection of nonsmoking female lung cancer patients is much higher at 10.12 (95% confidence interval, 3.88-26.38) compared with 1.98 (95% confidence interval, 0.84-4.76) of nonsmoking male lung cancer patients. This result strongly suggests that HPV infection is associated with lung cancer development of nonsmoking female lung cancer patients. The high prevalence of HPV 16/18 infection may explain to a certain extent why Taiwanese women nonsmokers had a higher lung cancer mortality rate.
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Affiliation(s)
- Y W Cheng
- Institute of Medicine, Chung Shan Medical and Dental College, Taichung, Taiwan, Republic of China
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29
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Hsiao G, Teng CM, Sheu JR, Cheng YW, Lam KK, Lee YM, Wu TS, Yen MH. Cinnamophilin as a novel antiperoxidative cytoprotectant and free radical scavenger. Biochim Biophys Acta 2001; 1525:77-88. [PMID: 11342256 DOI: 10.1016/s0304-4165(00)00173-2] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The antioxidant properties of cinnamophilin were evaluated by studying its ability to react with relevant reactive oxygen species, and its protective effect on cultured cells and biomacromolecules under oxidative stress. Cinnamophilin concentration-dependently suppressed non-enzymatic iron-induced lipid peroxidation in rat brain homogenates with an IC50 value of 8.0+/-0.7 microM and iron ion/ADP/ascorbate-initiated rat liver mitochondrial lipid peroxidation with an IC50 value of 17.7+/-0.2 microM. It also exerted an inhibitory activity on NADPH-dependent microsomal lipid peroxidation with an IC50 value of 3.4+/-0.1 microM without affecting microsomal electron transport of NADPH-cytochrome P-450 reductase. Both 1,1-diphenyl-2-picrylhydrazyl and 2,2'-azo-bis(2-amidinopropane) dihydrochloride-derived peroxyl radical tests demonstrated that cinnamophilin possessed marked free radical scavenging capacity. Cinnamophilin significantly protected cultured rat aortic smooth muscle cells (A7r5) against alloxan/iron ion/H2O2-induced damage resulting in cytoplasmic membranous disturbance and mitochondrial potential decay. By the way, cinnamophilin inhibited copper-catalyzed oxidation of human low-density lipoprotein, as measured by fluorescence intensity and thiobarbituric acid-reactive substance formation in a concentration-dependent manner. On the other hand, it was reactive toward superoxide anions generated by the xanthine/xanthine oxidase system and the aortic segment from aged spontaneously hypertensive rat. Furthermore, cinnamophilin exerted a divergent effect on the respiratory burst of human neutrophil by different stimulators. Our results show that cinnamophilin acts as a novel antioxidant and cytoprotectant against oxidative damage.
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Affiliation(s)
- G Hsiao
- Department of Pharmacology, Taipei Medical Univeristy, Taiwan
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Hu CM, Cheng HW, Cheng YW, Kan JJ. Mechanisms underlying the induction of vasorelaxation in rat thoracic aorta by sanguinarine. Jpn J Pharmacol 2001; 85:47-53. [PMID: 11243574 DOI: 10.1254/jjp.85.47] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
In the present study, the effect of sanguinarine (SANG) on smooth muscle was investigated in thoracic aorta isolated from rats. SANG dose-dependently relaxed the phenylephrine (PE, 3 microM)-precontracted aorta; and the concentrations to produce 50% relaxation were 3.18 +/- 0.37 and 3.42 +/- 1.14 microM, respectively, in intact and denuded aorta. These results suggest that the relaxing effect of SANG was endothelium-independent. The total contraction induced by PE was inhibited in aorta pretreated with SANG at microM concentration. Both phasic and tonic contractions induced by PE were inhibited by SANG independently, which were further supported by the fact that inositol 1,4,5-trisphosphate (IP3) formation and 45Ca2+ influx induced by 3 microM PE in denuded aorta were inhibited by SANG concentration-dependently. In addition, the vasocontraction induced by high-K+ was also inhibited by SANG, however, at higher concentrations. The inhibitory effects of SANG were reversed by dithiothreitol, a thiol reducing agent, implying that the oxidation of critical sulfhydryl groups on key molecules that regulate the smooth muscle contraction were involved. These data suggested that the inhibitory effects of SANG on PE-induced vasocontraction might involve the inhibition of IP3 formation and blockade of calcium channel.
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Affiliation(s)
- C M Hu
- Institute of Pharmaceutical Sciences, Taipei Medical University, Taiwan
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Cheng YW, Hsieh LL, Lin PP, Chen CP, Chen CY, Lin TS, Su JM, Lee H. Gender difference in DNA adduct levels among nonsmoking lung cancer patients. Environ Mol Mutagen 2001; 37:304-310. [PMID: 11424180 DOI: 10.1002/em.1037] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Lung cancer is the leading cause of cancer mortality in Taiwanese women. Cigarette smoking cannot explain the high lung cancer mortality in this population because less than 10% of women in Taiwan are smokers. Therefore, environmental factors other than smoking may play an important role in lung cancer development in female nonsmokers. The purpose of this study was to elucidate the role of environmental carcinogen exposure in lung cancer development in Taiwanese female nonsmokers, based on DNA adduct formation. We collected nontumorous lung tissues resected from 62 nonsmoking lung cancer patients and 20 noncancer controls to investigate whether differences in susceptibility to DNA adduct formation exist between men and women. (32)P-postlabeling and ELISA (enzyme-linked immunosorbent assay) with polyclonal antibody against BPDE (7,8-dihydroxy-anti-9,10-epoxy-7,8,9,10-tetrahydrobenzo[a]pyrene)-DNA adduct were used to evaluate DNA adduct levels in lung tissues of study subjects. Our data showed that the DNA adduct levels of lung cancer patients determined by both assays were significantly higher than those of noncancer controls (P = 0.0001 for (32)P-postlabeling; P = 0.01 for ELISA). Moreover, DNA adduct levels in females were markedly greater than those in males (P = 0.014 for (32)P-postlabeling; P = 0.001 for ELISA). The difference in DNA adduct levels could not be explained by genetic polymorphisms of cytochrome P-4501A1 (CYP1A1) or glutathione S-transferase (GSTM1), as determined by polymerase chain reaction and restriction fragment length polymorphism. These results demonstrate that lung cancer patients have a higher susceptibility to DNA damage than that of noncancer controls. In addition, differences in susceptibility to DNA damage derived from environmental carcinogen exposure were observed between male and female nonsmokers. In conclusion, high susceptibility to DNA damage in females may partially explain the high mortality rate of lung cancer in nonsmoking Taiwanese women.
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Affiliation(s)
- Y W Cheng
- Institute of Medicine and Toxicology, Chung Shan Medical and Dental College, Taichung, Taiwan, Republic of China
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32
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Abstract
The dissection of RNA editing mechanisms in PHYSARUM: mitochondria has been hindered by the absence of a soluble in vitro system. Based on our studies in isolated mitochondria, insertion of non-encoded nucleotides into PHYSARUM: mitochondrial RNAs is closely linked to transcription. Here we have fractionated mitochondrial lysates, enriching for run-on RNA synthesis, and find that editing activity co-fractionates with pre-formed transcription elongation complexes. The establishment of this soluble transcription-editing system allows access to the components of the editing machinery and permits manipulation of transcription and editing substrates. Thus, the availability of this system provides, for the first time, a means of investigating roles for cis-acting elements, trans-acting factors and nucleotide requirements for the insertion of non-encoded nucleotides into PHYSARUM: mitochondrial RNAs. This methodology should also be broadly applicable to the study of RNA processing and editing mechanisms in a wide range of mitochondrial systems.
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Affiliation(s)
- Y W Cheng
- Center for RNA Molecular Biology, Department of Molecular Biology and Microbiology, Case Western Reserve University School of Medicine, 10900 Euclid Avenue, Cleveland, OH 44106, USA
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Abstract
Lung cancer is a leading cause of mortality in Taiwan. We hypothesised that high susceptibility to DNA damage in the target organ acts as a risk biomarker for the development of lung cancer. To verify this hypothesis, the aromatic/hydrophobic DNA adduct levels of non-tumorous adjacent lung tissues from 73 primary lung cancer patients and 33 non-cancer controls were evaluated by 32P-postlabelling assay. Wilcoxon rank sum test showed that DNA adduct levels in lung cancer patients (49.58+/-33.39 adducts/10(8) nucleotides) were significantly higher than those in non-cancer controls (18.00+/-15.33 adducts/10(8) nucleotides, P<0.001). The DNA adduct levels among lung cancer and non-cancer samples were not influenced by smoking behaviour and cigarette consumption. Our data also showed that the polymorphisms of cytochrome P4501A1 (CYP1A1) Msp1, glutathione S-transferase M1 (GSTM1) and the combination of both genetic polymorphisms were not related to the DNA adduct levels. Interestingly, positive association between CYP1A1 protein expression and DNA adduct levels was found when CYP1A1 protein expression in lung specimens from lung cancer patients was examined by immunohistochemistry. Multivariate linear regression analysis indicated that the DNA adduct level was not associated with gender, smoking behaviour, or genetic polymorphisms of CYP1A1 and GSTM1. Moreover, multivariate logistic regression analysis showed that persons with high DNA adduct levels (>48.66 adducts/10(8) nucleotides) had an approximately 25-fold risk of lung cancer compared with persons with low DNA adduct levels (</=48.66 adducts/10(8) nucleotides). In conclusion, DNA adduct levels in lung tissue may be a more reliable lung cancer susceptibility biomarker than DNA adduct levels in leucocytes. In addition, higher susceptibility to DNA damage in lung cancer patients may partly play a role in the development of lung cancer.
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Affiliation(s)
- Y W Cheng
- Institute of Medicine & Toxicology, Chung Shan Medical & Dental College, Department of Thoracic Surgery, No. 110, Sec. 1, Chien-Kuo N. Rd., 40203, ROC, Taichung, Taiwan
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Chen JT, Ho WL, Cheng YW, Lee H. Detection of p53 mutations in sputum smears precedes diagnosis of non-small cell lung carcinoma. Anticancer Res 2000; 20:2687-90. [PMID: 10953344] [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: 02/17/2023]
Abstract
Little progress has been made in reducing lung cancer mortality by applying conventional methods to early diagnosis and screening. Recent advances in molecular oncology, however, have provided tools which may be of use in this area. p53 gene mutation is the most common gene alteration in the development of lung cancer. Conventional cytologic analysis of sputum is an insensitive test for the diagnosis of lung cancer. In this study, we attempted to establish a polymerase chain reaction (PCR)-based assay for assessing the possibility of early detection of p53 mutation in archival Papanicolaou-stained cytologic sputum smears. Ten sputum smear slides were collected prior to clinical diagnosis from 10 lung cancer patients who had been confirmed to have p53 mutations in surgically resected lung tumors. We successfully obtained sufficient amounts of RNA from each sputum smear specimen for amplification of PCR and direct sequencing. Only one patient was found to have p53 mutation at codon 286; the other nine patients had wild type p53 genes. This result supports the possibility that detection of p53 mutations in cytologic sputum smears is an available strategy for the early diagnosis of lung cancer.
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Affiliation(s)
- J T Chen
- Department of Pathology, Veterans General Hospital-Taichung, Taiwan, ROC
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35
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Liao JW, Kang JJ, Liu SH, Jeng CR, Cheng YW, Hu CM, Tsai SF, Wang SC, Pang VF. Effects of cartap on isolated mouse phrenic nerve diaphragm and its related mechanism. Toxicol Sci 2000; 55:453-9. [PMID: 10828278 DOI: 10.1093/toxsci/55.2.453] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [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: 11/15/2022] Open
Abstract
Cartap, a nereistoxin analogue pesticide, is reported to have no irritation to eyes in rabbits. However, we have demonstrated recently that cartap could actually cause acute death in rabbits via ocular exposure. Our preliminary study with isolated mouse phrenic nerve diaphragms has shown that instead of neuromuscular blockade, cartap caused muscular contracture. The objective of the study was to examine the effect of cartap on the neuromuscular junction in more detail and to investigate its possible underlying mechanism with isolated mouse phrenic nerve diaphragms and sarcoplasmic reticulum (SR) vesicles. Cartap or nereistoxin at various concentrations was added in the organ bath with isolated mouse phrenic nerve diaphragm and both nerve- and muscle-evoked twitches were recorded. Instead of blocking the neuromuscular transmission as nereistoxin did, cartap caused contracture in stimulated or quiescent isolated mouse phrenic nerve diaphragm. Both the cartap-induced muscular contracture force and the time interval to initiate the contracture were dose-dependent. The contracture induced by cartap was not affected by the pretreatment of the diaphragm with the acetylcholine receptor blocker alpha-bungarotoxin; the Na(+) channel blocker tetrodotoxin; or various Ca(2+) channel blockers, NiCl(2), verapamil, and nifedipine. On the contrary, the contracture was significantly inhibited when the diaphragm was pretreated with ryanodine or EGTA containing Ca(2+)-free Krebs solution or in combination. This suggested that both internal and extracellular Ca(2+) might participate in cartap-induced skeletal muscle contracture. Moreover, cartap inhibited the [(3)H]-ryanodine binding to the Ca(2+) release channel of SR in a dose-dependent manner. Additionally, cartap could induce a significant reduction in Ca(2+)-ATPase activity of SR vesicles at a relatively high dose. The results suggested that cartap might cause the influx of extracellular Ca(2+) and the release of internal Ca(2+), with subsequent induction of muscular contracture in the isolated mouse phrenic nerve diaphragm. Based on these findings, we propose that the acute death of rabbits following ocular exposure to cartap might have resulted from respiratory failure secondary to diaphragm contracture.
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Affiliation(s)
- J W Liao
- Department of Veterinary Medicine, National Taiwan University, Taipei, Taiwan, ROC
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36
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Abstract
MDM2 is one of the downstream target genes for transcriptional activation by the product of the p53 tumor-suppressor gene. Transactivation of MDM2 gene expression is represented by the presence of a functional p53 protein. We hypothesized that MDM2 mRNA expression may be a more suitable prognostic factor than p53 or MDM2 protein expression and p53 gene mutations. In this study, expression of MDM2 mRNA, p53 protein, and MDM2 protein and mutations of the p53 gene were assessed in 81 lung tumor tissue specimens using RT-PCR, immunohistochemistry, and direct sequencing among exons 5-8, respectively. By immunohistochemistry, 33 and 42 of 81 patients with p53 (40.7%) and MDM2 (51.5%) protein expression were found in lung tumor specimens, respectively. The p53 direct sequencing data indicated that 13 of 81 patients (16.0%) had p53 mutations. However, Kaplan-Meier analysis showed that p53 protein and MDM2 protein expression and p53 mutation were not useful as prognostic factors. Interestingly, the survival of patients with MDM2 mRNA expression was longer than that of patients without MDM2 mRNA expression, though MDM2 mRNA expression was not associated with clinicopathological parameters, including tumor grade, tumor stage, tumor type, and TNM values. Moreover, Cox regression analysis showed that MDM2 mRNA expression was a significantly independent favorable prognostic factor in non-small-cell lung cancer (NSCLC) patients. Thus, measuring MDM2 mRNA expression using RT-PCR may be a simple, useful approach for predicting the survival of NSCLC patients.
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Affiliation(s)
- J L Ko
- Institute of Toxicology, Chung Shan Medical and Dental College, Taichung, Republic of China
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37
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Hu CM, Cheng HW, Cheng YW, Kang JJ. Induction of skeletal muscle contracture and calcium release from isolated sarcoplasmic reticulum vesicles by sanguinarine. Br J Pharmacol 2000; 130:299-306. [PMID: 10807666 PMCID: PMC1572056 DOI: 10.1038/sj.bjp.0703279] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/1999] [Revised: 02/01/2000] [Accepted: 02/09/2000] [Indexed: 12/14/2022] Open
Abstract
The benzophenanthrine alkaloid, sanguinarine, was studied for its effects on isolated mouse phrenic-nerve diaphragm preparations. Sanguinarine induced direct, dose-dependent effects on muscle contractility. Sanguinarine-induced contracture was partially inhibited when the extracellular Ca(2+) was removed or when the diaphragm was pretreated with nifedipine. Depletion of sarcoplasmic reticulum (SR) internal calcium stores completely blocked the contracture. Sanguinarine induced Ca(2+) release from the actively loaded SR vesicles was blocked by ruthenium red and dithiothreitol (DTT), consistent with the ryanodine receptor (RyR) as the site of sanguinarine action. Sanguinarine altered [(3)H]-ryanodine binding to the RyR of isolated SR vesicles, potentiating [(3)H]-ryanodine binding at lower concentrations and inhibiting binding at higher concentrations. All of these effects were reversed by DTT, suggesting that sanguinarine-induced Ca(2+) release from SR occurs through oxidation of critical SH groups of the RyR SR calcium release channel.
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Affiliation(s)
- C M Hu
- Institute of Pharmaceutical Sciences, Taipei Medical College, Taipei, Taiwan, R.O.C
| | - H W Cheng
- Institute of Pharmaceutical Sciences, Taipei Medical College, Taipei, Taiwan, R.O.C
| | - Y W Cheng
- Institute of Toxicology, College of Medicine, National Taiwan University, Taipei, Taiwan, R.O.C
| | - J J Kang
- Institute of Toxicology, College of Medicine, National Taiwan University, Taipei, Taiwan, R.O.C
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38
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Cheng YW, Kang JJ. Inhibition of agonist-induced vasocontraction and impairment of endothelium-dependent vasorelaxation by extract of motorcycle exhaust particles in vitro. J Toxicol Environ Health A 1999; 57:75-87. [PMID: 10344225 DOI: 10.1080/009841099157791] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The in vitro effects of motorcycle exhaust particulate extract (MEPE) on blood vessels were studied in thoracic aorta isolated from Wistar rat. The MEPE relaxed the phenylephrine-precontracted aorta with an EC50 value of 0.05 +/- 0.004 mg/ml. This relaxing effect of MEPE persisted in endothelium-denuded aorta, suggesting that the relaxation induced by MEPE is endothelium-independent. The phenylephrine-induced vasocontraction and inositol 1,4,5-triphosphate formation were inhibited concentration dependently in aorta pretreated with MEPE. However, the high-K+-induced vasocontraction and the Ca2+ sensitivity of the contractile proteins were not significantly affected by MEPE. In addition to the inhibitory effects on agonist-induced contraction, the vasorelaxing effects both of acetylcholine and of sodium nitroprusside were impaired by MEPE. The inhibitory effects of MEPE on acetylcholine and sodium nitroprusside, but not phenylephrine, were reversed by cotreatment with superoxide dismutase. These results showed that the MEPE, added in vitro, inhibited the phenylephrine-induced, but not depolarization-induced, vasocontraction of aorta. The MEPE also impaired the vasorelaxation induced by acetylcholine in a superoxide anion-dependent manner.
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Affiliation(s)
- Y W Cheng
- Institute of Toxicology, College of Medicine, National Taiwan University, Taipei, Republic of China
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39
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Kuo CY, Cheng YW, Chen CY, Lee H. Correlation between the amounts of polycyclic aromatic hydrocarbons and mutagenicity of airborne particulate samples from Taichung City, Taiwan. Environ Res 1998; 78:43-49. [PMID: 9630444 DOI: 10.1006/enrs.1998.3838] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Taichung is the largest city in the central part of Taiwan, and its air pollution problems are similar to those in other large cities around the world. To evaluate the potential of the air pollution and identify major pollutant sources in this city, 181 airborne particulate samples were collected biweekly from seven locations around Taichung over an entire year. The mutagenicity of acetone extracts of the air samples was evaluated using the Salmonella/microsomal test with Salmonella typhimurium TA98 in the presence and absence of S9 mixtures. The air samples from September 1994 showed the highest direct and indirect mutagenicity among the 12 months, whereas those from October and June had the lowest direct and indirect mutagenicity, respectively. To elucidate the correlation between mutagenicity and polycyclic aromatic hydrocarbons (PAHs), high-performance liquid chromatography was used to determine the amount of each of 10 PAHs in the air samples. Among the 10 PAHs, the monthly average amount of B[g,h,i]P in the samples was the highest, followed by B[a]FA, B[a]P, and B[k]FA. Linear regression analysis showed a positive correlation between monthly average total amounts of PAHs and indirect mutagenicity. The monthly average amount of B[g,h,i]P was correlated more with indirect mutagenicity than with other PAHs. B[g,h,i]P is an indicator PAH emitted from both diesel and gasoline engine exhaust. Thus, we suggest that mobile air pollutant sources in Taichung City may be more significant than stationary ones. Moreover, B[g,h,i]P seems to act as a mutagenicity indicator compound in air samples from Taichung City.
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Affiliation(s)
- C Y Kuo
- Institute of Toxicology, Chung Shan Medical and Dental College, Taichung, Taiwan, Republic of China
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40
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Cheng YW, Kang JJ. Emodin-induced muscle contraction of mouse diaphragm and the involvement of Ca2+ influx and Ca2+ release from sarcoplasmic reticulum. Br J Pharmacol 1998; 123:815-20. [PMID: 9535008 PMCID: PMC1565233 DOI: 10.1038/sj.bjp.0701677] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
1. The effects on skeletal muscle of emodin, an anthraquinone, were studied in the mouse isolated diaphragm and sarcoplasmic reticulum (SR) membrane vesicles. 2. Emodin dose-dependently caused muscle contracture, simultaneously depressing twitch amplitude. Neither tubocurarine nor tetrodotoxin blocked the contraction suggesting that it was caused myogenically. 3. The contraction induced by emodin persisted in a Ca2+ free medium with a slight reduction in the maximal force of contraction. The contraction induced by emodin in the Ca2+ free medium was completely blocked when the internal Ca2+ pool of the muscle was depleted by ryanodine. These data suggest that the contraction caused by emodin is due to the release of Ca2+ from the intracellular ryanodine-sensitive pool. 4. In contrast to the effect seen in the Ca2+ free medium, emodin induced a small but consisted contraction in the ryanodine-treated muscle in Krebs medium. The contraction was blocked in the presence of dithiothreitol and was partially blocked by nifedipine, suggesting that oxidation of a sulphhydryl group on the external site of dihydropyridine receptor is involved. 5. Emodin dose-dependently increased Ca2+ release from actively loaded SR vesicles and this effect was blocked by ruthenium red, a specific Ca2+ release channel blocker, and the thiol reducing agent, DTT, suggesting that emodin induced Ca2+ release through oxidation of the critical SH of the ryanodine receptor. 6. [3H]-ryanodine binding was dose-dependently potentiated by emodin in a biphasic manner. The degree of potentiation of ryanodine binding by emodin increased dose-dependently at concentrations up to 10 microM but decreased at higher concentrations of 10-100 microM. 7. These data suggest that muscle contraction induced by emodin is due to Ca2+ release from the SR of skeletal muscle, as a result of oxidation of the ryanodine receptor and influx of extracellular Ca2+ through voltage-dependent Ca2+ channels of the plasma membrane.
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Affiliation(s)
- Y W Cheng
- Institute of Toxicology, College of Medicine, National Taiwan University, Taipei, ROC
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41
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Abstract
The effects of boldine [(S)-2,9-dihydroxyl-1,10-dimethoxy-aporphine], a major alkaloid in the leaves and bark of Boldo (Peumus boldus Mol.), on neuromuscular transmission were studied using a muscle phrenic-nerve diaphragm preparation. Boldine at concentrations lower than 200 microM preferentially inhibited, after an initial period of twitch augmentation, the nerve-evoked twitches of the mouse diaphragm and left the muscle-evoked twitches unaffected. The twitch inhibition could be restored by neostigmine or washout with Krebs solution. The twitches evoked indirectly and directly were both augmented initially, suggesting that the twitch augmentation induced by boldine was myogenic. Boldine inhibited the acetylcholine-induced contraction of denervated diaphragm dose-dependently with an IC50 value of 13.5 microM. At 50 microM, boldine specifically inhibited the amplitude of the miniature end plate potential. In addition, boldine was similar to d-tubocurarine in its action to reverse the neuromuscular blocking action of alpha-bungarotoxin. These results showed that the neuromuscular blockade by boldine on isolated mouse phrenic-nerve diaphragm might be due to its direct interaction with the postsynaptic nicotinic acetylcholine receptor.
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Affiliation(s)
- J J Kang
- Institute of Toxicology, College of Medicine, National Taiwan University, Taipei
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42
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Abstract
The effects of boldine [(S)-2,9-dihydroxy-1,10-dimethoxyaporphine], a major alkaloid in the leaves and bark of boldo (Peumus boldus Mol.), on skeletal muscle were studied using mouse diaphragm and isolated sarcoplasmic reticulum membrane vesicles. Boldine, at 10-200 microM, has little effect on the muscle-evoked twitches; however, the ryanodine-induced contracture was potentiated dose-dependently. At higher concentrations of 300 microM, boldine by itself induced muscle contracture of two phases, which were caused by the influx of extracellular Ca2+ and induction of Ca2+ release from the internal Ca2+ storage site, the sarcoplasmic reticulum, respectively. When tested with isolated sarcoplasmic reticulum membrane vesicles, boldine dose-dependently induced Ca2+ release from actively loaded sarcoplasmic reticulum vesicles isolated from skeletal muscle of rabbit or rat which was inhibited by ruthenium red, suggesting that the release was through the Ca2+ release channel, also known as the ryanodine receptor. Boldine also dose-dependently increased apparent [3H]-ryanodine binding with the EC50 value of 50 microM. In conclusion, we have shown that boldine could sensitize the ryanodine receptor and induce Ca2+ release from the internal Ca2+ storage site of skeletal muscle.
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Affiliation(s)
- J J Kang
- Institute of Toxicology, College of Medicine, National Taiwan University, Taipei, R.O.C
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43
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Kang JJ, Liu SH, Chen IL, Cheng YW, Lin-Shiau SY. Comparative studies on the induction of muscle contracture in mouse diaphragm and Ca2+ release from sarcoplasmic reticulum vesicles by organotin compounds. Pharmacol Toxicol 1998; 82:23-7. [PMID: 9527642 DOI: 10.1111/j.1600-0773.1998.tb01393.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Effects of organotins, including triethyltin and tributyltin, on skeletal muscle were studied with diaphragm and isolated sarcoplasmic reticulum membrane vesicles. Triethyltin induced muscle contracture in mouse diaphragm while tributyltin had comparatively less potency and efficacy in inducing the muscle contracture. The contracture induced by tributyltin was inhibited when the diaphragm was pretreated with low Ca2+ medium or caffeine while the contracture induced by triethyltin persisted in the Ca2+-free medium but was inhibited by pretreatment of caffeine. Pretreatment of dithiothreitol blocked the contracture induced by tributyltin but not that by triethyltin. Triethyltin dose-dependently induced Ca2+ release from sarcoplasmic reticulum vesicles and inhibited the Ca2+-ATPase activity. These results suggested that triethyltin induced contracture in mouse diaphragm was mainly by induction of Ca2+ release and inhibition of Ca2+ uptake of the internal Ca2+ storage site the sarcoplasmic reticulum, while the tributyltin induced contracture might be due to enhancement of extracellular Ca2+ influx which further induce the release of internal Ca2+ through the Ca2+-induced Ca2+ release mechanism.
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Affiliation(s)
- J J Kang
- Institute of Toxicology, College of Medicine, National Taiwan University, Section 1, Taipei
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44
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Abstract
The effect of xanthone on smooth muscle was studied in thoracic aorta isolated from rats. Xanthone relaxed the norepinephrine-induced contraction of rat thoracic aorta. This relaxing effect of xanthone persisted in endothelium-denuded aorta suggesting that the relaxation induced by xanthone is endothelium-independent. The norepinephrine and high-K+-induced vasoconstriction was inhibited dose dependently in aorta pretreated with xanthone with IC50 values of 60.26 +/- 8.43 and 82.9 +/- 13.21 microM, respectively. The inositol 1,4,5-trisphosphate formation induced by norepinephrine (3 microM) in rat aorta was not affected by xanthone (10-100 microM), suggesting that the vasorelaxant effect of xanthone was not exerted on the receptor. Xanthone concentration dependently inhibited the 45Ca2+ influx induced by either norepinephrine or high-K+, suggesting that xanthone might act as a blocker of both receptor-operated and voltage-dependent Ca2+ channels. Furthermore, xanthone caused an increase in the level of intracellular cyclic adenosine 3',5'-monophosphate (cAMP), but not cyclic guanosine 3',5'-monophosphate (cGMP) content. These data suggested that the mechanism of xanthone-induced vasorelaxation might involve the increase of intracellular cyclic adenosine 3',5'-monophosphate (cAMP) content and block of Ca2+ channels.
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Affiliation(s)
- Y W Cheng
- Institute of Toxicology, College of Medicine, National Taiwan University, Taipei
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Ueng TH, Kang JJ, Wang HW, Cheng YW, Chiang LY. Suppression of microsomal cytochrome P450-dependent monooxygenases and mitochondrial oxidative phosphorylation by fullerenol, a polyhydroxylated fullerene C60. Toxicol Lett 1997; 93:29-37. [PMID: 9381480 DOI: 10.1016/s0378-4274(97)00071-4] [Citation(s) in RCA: 96] [Impact Index Per Article: 3.6] [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: 02/05/2023]
Abstract
The acute toxicity of fullerenol-1 was determined using mice pretreated intraperitoneally (i.p.) with polyhydroxylated C60 derivatives. The LD50 value of fullerenol-1 was estimated to be 1.2 g/kg. Pretreatments with 0.5 and 1.0 g/kg fullerenol-1 decreased cytochromes P450 and b5 contents, and NADPH-cytochrome P450 reductase, benzo[a]pyrene hydroxylase, 7-ethoxycoumarin O-deethylase, aniline hydroxylase, and erythromycin N-demethylase activities in liver microsomes. Pretreatments with 0.01 and 0.1 g/kg fullerenol-1 had no effect on these monooxygenases. Additions of fullerenol-1 to mouse liver microsomes suppressed monooxygenases activities toward benzo[a]pyrene, 7-ethoxycoumarin, aniline, and erythromycin with IC50 values of 42, 94, 102 and 349 microM, respectively. Fullerenol-1 exhibited noncompetitive and mixed-type of inhibition in benzo[a]pyrene hydroxylation and 7-ethoxycoumarin O-deethylation, respectively. Additions of fullerenol-1 to rat liver mitochondria resulted in a dose-dependent inhibition of ADP-induced uncoupling and markedly inhibited mitochondrial Mg2+ -ATPase activity with an IC50 value of 7.1 microM. These results demonstrate that fullerenol-1 can suppress the levels of the microsomal enzymes in vivo and decrease the activities of P450-dependent monooxygenase and mitochondrial oxidative phosphorylation in vitro.
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Affiliation(s)
- T H Ueng
- Institute of Toxicology, College of Medicine, National Taiwan University, Taipei, ROC.
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46
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Abstract
In the present study, the effect of polycyclic aromatic hydrocarbons (PAHs) on isolated rat aorta was investigated. Acenaphthylene and naphthalene dose-dependently relaxed the phenylephrine-induced contraction of rat aorta with 50% vasorelaxation at 40.8+/-19.83 and 118.75+/-9.83 microM, respectively. The vasorelaxation effect was diminished in the denuded (endothelium removed) aorta suggesting that the relaxation effect of PAHs was endothelium dependent. By comparing PAHs with different ring structures, we have found that acenaphthylene has the highest potency to induce vasorelaxation. Pretreatment with the nitric oxide synthase inhibitor, L-N(G)-nitroarginine methyl ester, and the guanylate cyclase inhibitor, methylene blue, prevents the vasorelaxation induced by PAHs. These results indicate that the vasorelaxation effect of PAHs is mediated by activation of nitric oxide synthase of endothelium.
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Affiliation(s)
- J J Kang
- Institute of Toxicology, College of Medicine, National Taiwan University, Taipei, ROC.
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47
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Abstract
A direct peripheral myopathy has been found in organotin intoxication and suggested to be a significant factor in the development of muscle weakness following exposure. In this study, by using the isolated sarcoplasmic reticulum membrane vesicles, we have shown that triphenyltin dose-dependently induced Ca2+ release from the actively and passively loaded sarcoplasmic reticulum vesicles. Triphenyltin induced Ca2+ release in ruthenium red-sensitive and insensitive ways with EC50 values of 75 and 270 microM, respectively. The Ca2+-ATPase activity and Ca2+ uptake of sarcoplasmic reticulum were also inhibited by triphenyltin. Triphenyltin exerted dual effects on the apparent [3H]ryanodine binding. Triphenyltin (0.5-10 microM) dose-dependently potentiated the [3H]ryanodine binding; however, the [3H]ryanodine binding decreased as the concentration of triphenyltin increased. The dissociation of bound [3H]ryanodine was facilitated by triphenyltin. The present study suggested that the internal Ca2+ store of skeletal muscle could be depleted by triphenyltin through the inhibition of the Ca2+ uptake and the induction of Ca2+ release by acting on the Ca2+-ATPase and Ca2+ release channel, also known as the ryanodine receptor, of sarcoplasmic reticulum, respectively. These results could partly explain the development of muscle weakness in organotin intoxication; however, their relevance to the development of peripheral myopathy requires further examination.
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Affiliation(s)
- J J Kang
- Institute of Toxicology, College of Medicine, National Taiwan University, Taipei.
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48
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Kang JJ, Cheng YW, Ko FN, Kuo ML, Lin CN, Teng CM. Induction of calcium release from sarcoplasmic reticulum of skeletal muscle by xanthone and norathyriol. Br J Pharmacol 1996; 118:1736-42. [PMID: 8842439 PMCID: PMC1909844 DOI: 10.1111/j.1476-5381.1996.tb15599.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [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: 02/02/2023] Open
Abstract
1. Effects of xanthone and its derivative, 1,3,6,7-tetrahydroxyxanthone (norathyriol), on Ca2+ release and ryanodine binding were studied in isolated sarcoplasmic reticulum (SR) vesicles from rabbit skeletal muscle. 2. Both xanthone and norathyriol dose-dependently induced Ca2+ release from the actively loaded SR vesicles which was blocked by ruthenium red, a specific Ca2+ release inhibitor, and Mg2+. 3. Xanthone and norathyriol also dose-dependently increased apparent [3H]-ryanodine binding. Norathyriol, but not xanthone, produced a synergistic effect on binding activation when added concurrently with caffeine. 4. In the presence of Mg2+, which inhibits ryanodine binding, both caffeine and norathyriol, but not xanthone, could restore the binding to the level observed in the absence of Mg2+. 5. Xanthone activated the Ca(2+)-ATPase activity of isolated SR vesicles dose-dependently reaching 70% activation at 300 microM. 6. When tested in mouse diaphragm, norathyriol potentiated the muscle contraction followed by twitch depression and contracture in either a Ca(2+) -free bathing solution or one containing 2.5 mM Ca2+. These norathyriol-induced effects on muscle were inhibited by pretreatment with ruthenium red or ryanodine. 7. These data suggest that xanthone and norathyriol can induce Ca2+ release from the SR of skeletal muscle through a direct interaction with the Ca2+ release channel, also known as the ryanodine receptor.
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Affiliation(s)
- J J Kang
- Institute of Toxicology, College of Medicine, National Taiwan University, Taipei, R.O.C
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49
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Wang LY, Lin JT, Cheng YW, Chou SJ, Chen CJ. Seroepidemiology of Helicobacter pylori among adolescents in Taiwan. Zhonghua Min Guo Wei Sheng Wu Ji Mian Yi Xue Za Zhi 1996; 29:10-7. [PMID: 10592783] [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] [Subscribe] [Scholar Register] [Indexed: 02/14/2023]
Abstract
Helicobacter pylori has been documented to be associated with chronic type B gastritis, peptic ulcer and gastric cancer. In order to examine the seroprevalence and risk factors for Helicobacter pylori infection in Taiwan, a total of 871 adolescents were selected randomly from junior high school children in 20 study precincts and townships. Serum samples collected were tested for IgG antibodies against Helicobacter pylori by enzyme-linked immunosorbent assay using commercial kits. The overall seropositive rate was 21.1% showing no gender difference. There was a striking geographical variation in seroprevalence of Helicobacter pylori infection ranging from 4.6% to 37.1% in 20 precincts and townships. The seroprevalence was highest in the north (25.4%), medium in central Taiwan (21.9%), and lowest in the south (18.7%). The higher the age-adjusted mortality from gastric cancer in a given study area, the higher the seroprevalence of Helicobacter pylori in the area. Metropolitan and aboriginal areas had higher seroprevalences than urban and rural areas, but the difference was not statistically significant. The seroprevalence was higher for those who had no sibling (29.4%) or had a sibship size of > or = 6 (31.1%) than for those with a sibship size of 1-5 (20.0%), but the difference was not statistically significant either.
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Affiliation(s)
- L Y Wang
- Institute of Biomedical Sciences, Academia Sinica, Taiper, Taiwan, ROC
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50
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Kang JJ, Chen YC, Kuo WC, Chen T, Cheng YW, Kuo ML, Ueng TH. Modulation of microsomal cytochrome P450 by Scutellariae Radix and Gentianae scabrae Radix in rat liver. Am J Chin Med 1996; 24:19-29. [PMID: 8739178 DOI: 10.1142/s0192415x96000049] [Citation(s) in RCA: 13] [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] [Indexed: 02/01/2023]
Abstract
The present study has determined the effects of Scutellariae Radix (Huangqin) and Gentianae scabrae Radix (Longdan) on liver microsomal cytochrome P450 (P450)-dependent mono-oxygenases using rats pretreated with crude extracts of medicinal herbs. Scutellariae Radix resulted in a 53% decrease of pentoxyresorufin O-dealkylase activity in liver microsomes. In contrast, Gentianae scabrae Radix caused a 50% increase of benzo(a)pyrene hydroxylase activity. Immunoblotting analysis of liver microsomes revealed that Scutellariae Radix induced and suppressed the levels of P450 1A and 2B proteins, respectively. Scutellariae and Gentianae scabrae Radixes had no effects on microsomal aniline hydroxylase activity and P450 2E1 protein.
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Affiliation(s)
- J J Kang
- Institute of Toxicology, College of Medicine, National Taiwan University, Taipei, Taiwan
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