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1.  Management of patients with implantable cardioverter defibrillators at emergency departments 
Emergency Medicine Journal : EMJ  2007;24(2):106-109.
With rapid improvements in technology and accumulation of clinical evidence, the implantable cardioverter defibrillator (ICD) has become a standard treatment for either primary or secondary prevention of sudden cardiac death. However, no analysis based on the perspective of emergency department has been reported, and managing patients with ICD remains a challenge to the emergency department doctors.
This study reviewed the emergency department visits of patients who received ICD implantation in a single university hospital from 1995 to 2004. The baseline demographic and laboratory data were compared between groups with the non‐parametric method of the Mann–Whitney U test for continuous data and the χ2 test for categorical data; p<0.05 was considered significant.
81 patients (56 men and 25 women) were included in this study. 43% of patients had at least one emergency department visit during the follow‐up period, and a total of 86 emergency department visits were recorded. The most frequent aetiology of emergency department visits was ICD discharge (37 episodes; 43.1%) and the most frequent presenting symptom was electric shock sensation (25 episodes; 29.1%). Only 11 (12.8%) emergency department visits were because of non‐cardiac aetiologies. Patients with emergency department visits had significant lower left ventricular ejection fraction (mean (SD) 41.5 (19.8) v 55.2 (18.4) ejection fraction units; p = 0.005) and more use of warfarin (8.6% v 0%; p<0.05). Although most emergency department visits were device or arrhythmia related, the acute coronary syndrome and congestive heart failure still accounted for 27.9% of hospital returns in combination.
Defibrillator discharge, acute coronary syndrome and heart failure constitute most aetiologies of emergency department visits of patients with ICD. The risk factors include lower left ventricular ejection fraction and use of warfarin.
PMCID: PMC2658183  PMID: 17251615
2.  Optical assessment of the cardiac rhythm of contracting cardiomyocytes in vitro and a pulsating heart in vivo for pharmacological screening 
Biomedical Optics Express  2014;5(5):1616-1625.
Our quest in the pathogenesis and therapies targeting human heart diseases requires assessment of the contractile dynamics of cardiac models of varied complexity, such as isolated cardiomyocytes and the heart of a model animal. It is hence beneficial to have an integral means that can interrogate both cardiomyocytes in vitro and a heart in vivo. Herein we report an application of dual-beam optical reflectometry to determine noninvasively the rhythm of two representative cardiac models–chick embryonic cardiomyocytes and the heart of zebrafish. We probed self-beating cardiomyocytes and revealed the temporally varying contractile frequency with a short-time Fourier transform. Our unique dual-beam setup uniquely records the atrial and ventricular pulsations of zebrafish simultaneously. To minimize the cross talk between signals associated with atrial and ventricular chambers, we particularly modulated the two probe beams at distinct frequencies and extracted the signals specific to individual cardiac chambers with phase-sensitive detection. With this setup, we determined the atrio-ventricular interval, a parameter that is manifested by the electrical conduction from the atrium to the ventricle. To demonstrate pharmacological applications, we characterized zebrafish treated with various cardioactive and cardiotoxic drugs, and identified abnormal cardiac rhythms and atrioventricular (AV) blocks of varied degree. In light of its potential capability to assess cardiac models both in vitro and in vivo and to screen drugs with cardioactivity or toxicity, we expect this approach to have broad applications ranging from cardiopharmacology to developmental biology.
PMCID: PMC4026895  PMID: 24877019
(170.0170) Medical optics and biotechnology; (170.2655) Functional monitoring and imaging
3.  Baicalein Protects Against Doxorubicin-Induced Cardiotoxicity by Attenuation of Mitochondrial Oxidant Injury and JNK Activation 
Journal of cellular biochemistry  2011;112(10):2873-2881.
The cardiotoxicity of doxorubicin limits its clinical use in the treatment of a variety of malignancies. Previous studies suggest that doxorubicin-associated cardiotoxicity is mediated by reactive oxygen species (ROS)-induced apoptosis. We therefore investigated if baicalein, a natural antioxidant component of Scutellaria baicalensis, could attenuate ROS generation and cell death induced by doxorubicin. Using an established chick cardiomyocyte model, doxorubicin (10 μM) increased cell death in a concentration- and time-dependent manner. ROS generation was increased in a dose-response fashion and associated with loss of mitochondrial membrane potential. Doxorubicin also augmented DNA fragmentation and increased the phosphorylation of ROS-sensitive pro-apoptotic kinase c-Jun N-terminal kinase (JNK). Adjunct treatment of baicalein (25 μM) and doxorubicin for 24 h significantly reduced both ROS generation (587 ± 89 a.u. vs. 932 a.u. ± 121 a.u., P < 0.01) and cell death (30.6 ± 5.1% vs. 46.8 ± 8.3%, P < 0.01). The dissipated mitochondrial potential and increased DNA fragmentation were also ameliorated. Along with the reduction of ROS and apoptosis, baicalein attenuated phosphorylation of JNK induced by doxorubicin (1.7 ± 0.3 vs. 3.0 ± 0.4 fold, P < 0.05). Co-treatment of cardiomyocytes with doxorubicin and JNK inhibitor SP600125 (10 μM; 24 h) reduced JNK phosphorylation and enhanced cell survival, suggesting that the baicalein protection against doxorubicin cardiotoxicity was mediated by JNK activation. Importantly, concurrent baicalein treatment did not interfere with the anti-proliferative effects of doxorubicin in human breast cancer MCF-7 cells. In conclusion, baicalein adjunct treatment confers anti-apoptotic protection against doxorubicin-induced cardiotoxicity without compromising its anti-cancer efficacy.
PMCID: PMC3178681  PMID: 21618589
4.  Comparative effects of flavonoids on oxidant scavenging and ischemia-reperfusion injury in cardiomyocytes 
European journal of pharmacology  2007;566(1-3):58-66.
Since flavonoids scavenge reactive oxygen species, they may potentially protect against ischemia/reperfusion injury. This study compared the scavenging capacity of specific flavonoids towards different reactive oxygen species. Whether the differential oxidant scavenging capacity correlated with their protective efficacy in ischemia/reperfusion injury of cardiomyocytes was determined. The free radical scavenging capacity of five flavonoids (wogonin, baicalin, baicalein, catechin and procyanidin B2) was analyzed using electron spin resonance spectrometry for 3 radicals: 1,1-diphenyl-2picrylhydrazyl (DPPH), superoxide and hydroxyl radical. A well-established chick cardiomyocyte model of ischemia (1 h)/reperfusion (3 h) was used to evaluate flavonoid-induced protection against ischemia/reperfusion injury in chronic treatment (pretreated 72 h and treated through ischemia/reperfusion) and acute treatment protocols (during ischemia/reperfusion or only at reperfusion). The cell viability was assessed by propidium iodide. The DPPH scavenging was most significant with catechin, followed by procyanidin B2, baicalein, baicalin, and wogonin. The superoxide scavenging was, similarly, most significant with catechin, followed by baicalein, procyanidin B2, and baicalin. For hydroxyl radical, only baicalein showed a significant scavenging capacity (> 50% reduction in ESR signal). For the cardiomyocyte studies, all flavonoids but wogonin showed protection against ischemia/reperfusion injury in the chronic treatment protocol. When flavonoids were administered only during ischemia/reperfusion, baicalein, procyanidin B2, and catechin significantly reduced cell death. If flavonoids were administered just at reperfusion, only baicalein and procyanidin B2 had protective effects, and the efficacy was less. Flavonoids possess specific but differential radical scavenging capacity, which, in conjunction with the timing of treatment, affects their protective efficacy in cardiomyocytes exposed to ischemia/reperfusion.
PMCID: PMC2657475  PMID: 17475241
Flavonoids; Reperfusion injury; Scavenging capacity; Superoxide; Hydroxyl radical
5.  Carotid Artery Intima-Media Thickness, Carotid Plaque and Coronary Heart Disease and Stroke in Chinese 
PLoS ONE  2008;3(10):e3435.
Our aim was to prospectively investigate the association between carotid artery intima-media thickness (IMT) as well as carotid plaque and incidence of coronary heart disease (CHD) and stroke in Chinese, among whom data are limited.
Methods and Findings
We conducted a community-based cohort study composed of 2190 participants free of cardiovascular disease at baseline in one community. During a median 10.5-year follow up, we documented 68 new cases of coronary heart disease and 94 cases of stroke. The multivariate relative risks (RRs) associated with a change of 1 standard deviation of maximal common carotid IMT were 1.38 (95% confidence interval [CI], 1.12–1.70) for CHD and 1.47 (95% CI, 1.28–1.69) for stroke. The corresponding RRs with internal carotid IMT were 1.47 (95% CI, 1.21–1.79) for CHD and 1.52 (95% CI, 1.31–1.76) for stroke. Carotid plaque measured by the degree of diameter stenosis was also significantly associated with increased risk of CHD (p for trend<0.0001) and stroke (p for trend<0.0001). However, these associations were largely attenuated when adjusting for IMT measurements.
This prospective study indicates a significant association between carotid IMT and incidence of CHD and stroke in Chinese adults. These measurements may be useful for cardiovascular risk assessment and stratification in Chinese.
PMCID: PMC2562458  PMID: 18927612
6.  Scutellaria baicalensis decreases ritonavir-induced nausea 
Protease inhibitors, particularly ritonavir, causes significant gastrointestinal disturbances such as nausea, even at low doses. This ritonavir-induced nausea could be related to its oxidative stress in the gut. Alleviation of drug-induced nausea is important in effectively increasing patients' compliance and improving their quality of life. Conventional anti-emetic drugs can only partially abate the symptoms in these patients, and their cost has also been a concern. Rats respond to nausea-producing emetic stimuli by increasing consumption of non-nutritive substances like kaolin or clay, a phenomenon known as pica. In this study, we used this rat pica model to evaluate the effects of Scutellaria baicalensis, a commonly used oriental herbal medicine, on ritonavir-induced nausea.
Rats treated with 20 mg/kg ritonavir significant caused increases of kaolin consumption at 24 to 48 hr (P < 0.01). Pretreatment with 0.3 and 3 mg/kg Scutellaria baicalensis extract significantly decreased ritonavir-induced kaolin intake in a dose-related manner (P < 0.01). Compared to vehicle treatment, the extract completely prevented ritonavir-induced kaolin consumption at dose 3 mg/kg. The area under the curves (AUC) for kaolin intake from time 0 to 120 hr for vehicle only, ritonavir only, SbE 0.3 mg/kg plus ritonavir, and SbE 3 mg/kg plus ritonavir were 27.3 g•hr, 146.7 g•hr, 123.2 g•hr, and 32.7 g•hr, respectively. The reduction in area under the curves of kaolin intake from time 0 to 120 hr between ritonavir only and SbE 0.3 mg/kg plus ritonavir, ritonavir only and SbE 3 mg/kg plus ritonavir were 16.0% and 77.7%, respectively.
Scutellaria baicalensis significantly attenuated ritonavir-induced pica, and demonstrated a potential in treating ritonavir-induced nausea.
PMCID: PMC1352373  PMID: 16368007
7.  SARS Exposure and Emergency Department Workers 
Emerging Infectious Diseases  2004;10(6):1117-1119.
Of 193 emergency department workers exposed to severe acute respiratory syndrome (SARS), 9 (4.7%) were infected. Pneumonia developed in six workers, and assays showed anti-SARS immunoglobulin (Ig) M and IgG. The other three workers were IgM-positive and had lower IgG titers; in two, mild illness developed, and one remained asymptomatic.
PMCID: PMC3323160  PMID: 15207066
SARS; serologic responses; emergency department workers

Results 1-7 (7)