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Huang BT, Peng Y, Liu W, Zhang C, Huang FY, Wang PJ, Zuo ZL, Liao YB, Chai H, Huang KS, Huang DJ, Chen M. Lean mass index, body fat and survival in Chinese patients with coronary artery disease. QJM 2015; 108:641-7. [PMID: 25609701 DOI: 10.1093/qjmed/hcv013] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/03/2014] [Indexed: 01/15/2023] Open
Abstract
BACKGROUND 'Obesity paradox' was not consistently observed in Asians with coronary artery disease (CAD). AIM The study investigated the association between body composition and outcomes in Chinese patients with CAD. DESIGN Cohort study. METHOD A total of 3280 patients with angiographically validated CAD were consecutively included. Body fat (BF) percentage and lean mass index (LMI) were evaluated using the Clínica Universidad de Navarra-Body Adiposity Estimator. The rate of mortality from any cause was compared across groups classified by the quartiles of LMI. RESULTS During a median period of 24 months, 288 (8.8%) participants died. There was a close association between increasing LMI and reducing mortality rate. However, univariate analyses did not find protective effect of BF on survival. After adjusting for age, sex, diabetes, current smoking, systolic blood pressure, creatinine, white blood cell count, haemoglobin and medication, Cox regression analyses showed that the significant relation between higher quartiles (Q) of LMI and survival benefit (Q4, hazard ratio 0.58 (95% confidence interval: 0.36-0.94) vs. Q3, 0.60 (0.39-0.91) vs. Q2, 0.60 (0.41-0.88) vs. Q1, reference) remained. CONCLUSION Low LMI but not BF predicts all-cause mortality in Chinese patients with CAD.
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Luo X, Zhao Z, Chai H, Zhang C, Liao Y, Li Q, Peng Y, Liu W, Ren X, Meng Q, Chen C, Chen M, Feng Y, Huang D. Efficacy of transcatheter aortic valve implantation in patients with aortic stenosis and reduced LVEF. A systematic review. Herz 2015; 40 Suppl 2:168-80. [PMID: 25712464 DOI: 10.1007/s00059-014-4193-z] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2014] [Revised: 10/20/2014] [Accepted: 11/29/2014] [Indexed: 02/05/2023]
Abstract
BACKGROUND Transcatheter aortic valve implantation (TAVI) is safe and effective for patients with aortic stenosis (AS) who have a high operative risk. However, there is still debate on the effect of TAVI in AS patients with reduced left ventricular ejection fraction (REF). The objective of the review is to clarify the efficacy of TAVI and the impact of REF on the 30-day and midterm mortality in these patients. METHODS Studies on TAVI were searched in PubMed, Embase, and the Cochrane Library databases and were included in this review following predefined criteria. Data were extracted and pooled risk ratios (RR) were synthesized to explore the relationship between REF and 30-day plus midterm mortality. RESULTS Twenty-eight studies comprising 14,099 patients were included in the analysis of the association of REF with the prognosis of patients after TAVI. An average increase in left ventricular ejection fraction of 8-10 % was observed among these patients after TAVI. REF was not related to the 30-day mortality [RR = 1.90, 95 % confidence interval (CI) = 0.80-4.47]; however, it was related to the midterm mortality (RR = 1.49, 95 %CI = 1.14-1.93) of patients undergoing TAVI. Patients with low-flow and low-gradient AS had a higher 30-day mortality (RR = 1.54, 95 %CI = 1.11-2.13) and midterm mortality rate (RR = 1.69, 95 %CI = 1.33-2.14) compared with AS patients without these characteristics. The mortality of TAVI patients was significantly lower than that of those undergoing conservative therapy, and was similar to that of patients undergoing surgical aortic valve replacement. CONCLUSION REF was not associated with 30-day mortality, but it was associated with the midterm mortality of TAVI patients. Patients with REF could benefit from TAVI compared with conservative therapy.
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Chai H, Chen WZ, Zhu J, Xu Y, Lou L, Yang T, He W, Wang W. Processing of facial expressions of emotions in healthy volunteers: an exploration with event-related potentials and personality traits. Neurophysiol Clin 2012. [PMID: 23181967 DOI: 10.1016/j.neucli.2012.04.087] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
AIMS OF THE STUDY Previous studies have shown that event-related potentials (ERPs) are modulated by anxiety or psychopathic personality traits. Therefore, we hypothesized that the automatic processing of facial expressions of emotions (FEE) is also correlated with related disordered personality traits. METHODS Thirty-seven healthy volunteers underwent both an "oddball" ERP recording to facial expressions of Anger, Happiness, Sadness, and Neutral, and a test of the Dimensional Assessment of Personality Pathology (DAPP). RESULTS Mean reaction time was longer in response to anger than to other facial expressions. Facial expressions of Anger, Happiness and Sadness did not affect N1 (N170). By contrast, Happiness elicited a delayed P2, Anger elicited both a smaller N2 and a delayed P3b, and both Happiness and Anger elicited a P3b of higher amplitude. In addition, P3a latencies to Happiness were negatively correlated with DAPP Identity problems, and P3b latencies to Happiness were negatively correlated with DAPP Stimulus seeking, Callousness, Passive aggressivity, and Narcissism. CONCLUSION Our study demonstrates that Anger implicitly captures attentional resources, and Happiness triggers more facilitated processing in individuals with dissocial traits.
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Dhingra S, Ayala A, Chai H, Moreno V, Zhao B. Renal Myopericytoma: Case Report and Review of Literature. Arch Pathol Lab Med 2012; 136:563-6. [DOI: 10.5858/arpa.2011-0387-cr] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Myopericytoma arising in the visceral organs is rare and only 1 case of renal myopericytoma has been reported in the literature to date. We report the second case of myopericytoma arising in the kidney in a 40-year-old Hispanic woman who presented with pain on the left side of the abdomen and frequent urination. Abdominal computed tomography scan showed an exophytic left-sided renal mass. Partial nephrectomy was performed. The patient remains free of disease at 24 months after diagnosis. Our case is histologically distinct from the previously described case as it lacks the “hemangiopericytic/glomangiopericytoma” pattern. The tumor in our case showed the characteristic pattern of myopericytoma and an additional glomus tumorlike pattern. The tumor cells showed diffuse reactivity for vimentin, smooth muscle actin, smooth muscle myosin heavy chain, and muscle-specific actin in both morphologic patterns and strong diffuse CD34 expression in glomus tumorlike focus. This case report adds to the morphologic heterogeneity of myopericytomas.
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Chen C, Ochoa LN, Kagan A, Chai H, Liang Z, Lin PH, Yao Q. Lysophosphatidic acid causes endothelial dysfunction in porcine coronary arteries and human coronary artery endothelial cells. Atherosclerosis 2012; 222:74-83. [PMID: 22424734 DOI: 10.1016/j.atherosclerosis.2012.02.010] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/13/2011] [Revised: 01/21/2012] [Accepted: 02/06/2012] [Indexed: 12/29/2022]
Abstract
AIM The objective of this study was to determine the effects of lysophosphatidic acid (LPA) on endothelial functions and molecular alternations in both porcine coronary arteries and human coronary artery endothelial cells (HCAECs). METHODS AND RESULTS The vessel rings and HCAECs were treated with clinically relevant concentrations of LPA for different times. Vasomotor reactivity was studied with a myograph tension system. LPA (10 and 50 μM) treatment for the vessel rings significantly reduced endothelium-dependent vasorelaxation in response to bradykinin (×10(-5)M) by 32% and 49%, respectively, compared with the control (P<0.05). LPA decreased endothelial nitric oxide synthase (eNOS) mRNA and immunoreactivity levels in the vessel rings. In HCAECs, LPA reduced eNOS mRNA, phospho-eNOS and total eNOS protein levels. In addition, superoxide anion levels in LPA-treated vessel rings and HCAECs were significantly increased by lucegenin-enhanced chemiluminescence assay and dihydroethidium staining, respectively. Mitochondrial membrane potential and ATP content in LPA-treated HCAECs were substantially decreased. The mRNA levels of reactive oxygen species generating enzymes NOX4 and p40(phox) were increased, while endogenous antioxidant enzyme superoxide dismutase 1 was decreased in response to LPA treatment in HCAECs. Furthermore, exogenous antioxidant molecule selenomethionine (SeMet) effectively reversed these LPA-induced effects in both porcine coronary arteries and HCAECs. CONCLUSIONS LPA causes endothelial dysfunction by a mechanism associated with decreased eNOS expression and increased oxidative stress in porcine coronary arteries and HCAECs.
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Zhang Y, Chai H, Lee JJW, Lawn BR. Chipping resistance of graded zirconia ceramics for dental crowns. J Dent Res 2012; 91:311-5. [PMID: 22232142 DOI: 10.1177/0022034511434356] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
A serious drawback of veneering porcelains is a pronounced susceptibility to chipping. Glass-infiltrated dense zirconia structures can now be produced with esthetic quality, making them an attractive alternative. In this study, we examined the hypothesis that such infiltrated structures are much more chip-resistant than conventional porcelains, and at least as chip-resistant as non-infiltrated zirconia. A sharp indenter was used to produce chips in flat and anatomically correct glass-infiltrated zirconia crown materials, and critical loads were measured as a function of distance from the specimen edge (flat) or side wall (crown). Control data were obtained on zirconia specimens without infiltration and on crowns veneered with porcelains. The results confirmed that the resistance to chipping in graded zirconia is more than 4 times higher than that of porcelain-veneered zirconia and is at least as high as that of non-veneered zirconia.
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Lu DQ, Chai H, Ling XQ, Chen J, Wang JL. 2,6-Dibromo-4-(2-hy-droxy-eth-yl)phenol. Acta Crystallogr Sect E Struct Rep Online 2011; 67:o3263-4. [PMID: 22199772 PMCID: PMC3238923 DOI: 10.1107/s1600536811046538] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2011] [Accepted: 11/04/2011] [Indexed: 11/18/2022]
Abstract
The title compound, C8H8Br2O2, crystallized with two independent molecules (A and B) in the asymmetric unit. They differ in the conformation of the 2-hydroxyethyl chain with the C—C—C—O torsion angle being −68.0 (12)° in molecule A and 172.2 (9)° in molecule B. In the crystal, the A molecules are linked via pairs of O—H⋯O hydrogen bonds, forming inversion dimers, while the B molecules are linked via an O—H⋯O hydrogen bond, forming a polymeric chain propagating in [010]. In addition, there are O—H⋯O and O—H⋯Br hydrogen bonds, and Br⋯Br [3.599 (2) Å] and π–π interactions [centroid–centroid distances = 3.581 (6) and 3.931 (6) Å], leading to the formation of a two-dimensional network parallel to (001).
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Ding RQ, Tsao J, Chai H, Mochly-Rosen D, Zhou W. Therapeutic potential for protein kinase C inhibitor in vascular restenosis. J Cardiovasc Pharmacol Ther 2010; 16:160-7. [PMID: 21183728 DOI: 10.1177/1074248410382106] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Vascular restenosis, an overreaction of biological response to injury, is initialized by thrombosis and inflammation. This response is characterized by increased smooth muscle cell migration and proliferation. Available pharmacological treatments include anticoagulants, antiplatelet agents, immunosuppressants, and antiproliferation agents. Protein kinase C (PKC), a large family of serine/threonine kinases, has been shown to participate in various pathological stages of restenosis. Consequently, PKC inhibitors are expected to exert a wide range of pharmacological activities therapeutically beneficial for restenosis. In this review, the roles of PKC isozymes in platelets, leukocytes, endothelial cells, and smooth muscle cells are discussed, with emphasis given to smooth muscle cells. We will describe cellular and animal studies assessing prevention of restenosis with PKC inhibitors, particularly targeting -α, -β, -δ, and -ζ isozymes. The delivery strategy, efficacy, and safety of such PKC regulators will also be discussed.
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Zhou W, Chai H, Ding R, Lam HYC. Distribution of Inflammatory Mediators in Carotid and Femoral Plaques. J Am Coll Surg 2010; 211:92-8. [DOI: 10.1016/j.jamcollsurg.2010.02.054] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2009] [Revised: 02/09/2010] [Accepted: 02/26/2010] [Indexed: 10/19/2022]
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Chen C, Jiang J, Lü JM, Chai H, Wang X, Lin PH, Yao Q. Resistin decreases expression of endothelial nitric oxide synthase through oxidative stress in human coronary artery endothelial cells. Am J Physiol Heart Circ Physiol 2010; 299:H193-201. [PMID: 20435848 DOI: 10.1152/ajpheart.00431.2009] [Citation(s) in RCA: 141] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Resistin is a newly discovered adipocyte-derived cytokine that may play an important role in insulin resistance, diabetes, adipogenesis, inflammation, and cardiovascular disease. However, it is largely unknown whether resistin impairs endothelial functions by affecting the endothelial nitric oxide synthase (eNOS) system. In this study, we determined the effect of human recombinant resistin protein on eNOS expression and regulation in human coronary artery endothelial cells (HCAECs). When cells were treated with clinically relevant concentrations of resistin (40 or 80 ng/ml) for 24 h, the levels of eNOS mRNA, protein, and activity and eNOS mRNA stability were significantly reduced. Cellular nitric oxide levels were also decreased. In addition, the cellular levels of reactive oxygen species (ROS), including superoxide anion, were significantly increased in resistin-treated HCAECs. Mitochondrial membrane potential and the activities of catalase and superoxide dismutase were reduced. Three antioxidants, seleno-L-methionine, ginsenoside Rb1, and MnTBAP (superoxide dismutase mimetic), effectively blocked resistin-induced eNOS downregulation. Meanwhile, resistin activated the mitogen-activated protein kinases p38 and c-Jun NH(2)-terminal kinase (JNK), and the specific p38 inhibitor SB-239063 effectively blocked resistin-induced ROS production and eNOS downregulation. Furthermore, immunoreactivity of resistin was increased in atherosclerotic regions of human aorta and carotid arteries. Thus resistin directly induces eNOS downregulation through overproduction of ROS and activation of p38 and JNK in HCAECs. Resistin-induced mitochondrial dysfunction and imbalance in cellular redox enzymes may be the underlying mechanisms of oxidative stress.
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Chai H, Luo AZ, Weerasinghe P, Brown RE. Sorafenib downregulates ERK/Akt and STAT3 survival pathways and induces apoptosis in a human neuroblastoma cell line. INTERNATIONAL JOURNAL OF CLINICAL AND EXPERIMENTAL PATHOLOGY 2010; 3:408-415. [PMID: 20490331 PMCID: PMC2872747] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 03/29/2010] [Accepted: 04/15/2010] [Indexed: 05/29/2023]
Abstract
Neuroblastoma is a common solid tumor in children and its tumorigenicity is enhanced by the expression of survival pathways such as Akt and signal transducer and activator of transcription 3 (STAT3). Sorafenib is a multikinase inhibitor that also inhibits STAT3 signaling and induces apoptosis. In this study, we will examine the efficacy of sorafenib on a human neuroblastoma cell line (SK-N-AS) and also investigate its possible mechanisms. After cells reached 50-60% confluence, they were treated with various concentrations of sorafenib (0, 0.1, 1, 5, 10 and 20 microM) for different periods of time. The cell viability and apoptosis were determined by MTS colorimetric assay and TUNEL, respectively. Phosphorylation of Akt1/2/3 (p-Akt1/2/3), extracellular signal-regulated kinase 1/2 (p-ERK1/2), STAT3 (p-STAT3), and AMP-activated protein kinase alpha subunit (p-AMPKalpha) were determined with Western blot. The results indicate that as early as 2 hours post-treatment, cell viability was significantly decreased at 10 microM concentration. In 24 hours or longer treatment groups, sorafenib at 5 microM and above significantly decreased cell viability. TUNEL assay showed a significant increased of apoptosis in 5 and 20 microM treatment groups 24 hours after treatment. Western blots showed a decrease of p-ERK1/2, p-Akt1/2/3, p-STAT3, and p-AMPKalpha expression levels in various sorafenib treatment groups. Our results indicate that sorafenib significantly decreased cell viability and increased apoptosis in human neuroblastoma cell line in association with down-regulation of p-ERK1/2, p-Akt, p-STAT3 survival pathways. These data suggested potential clinical application of sorafenib in the treatment of neuroblastoma.
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Abstract
One failure mode of all-ceramic restorations is radial cracking at the cementation surface, from occlusally induced flexure of the stiffer ceramic layer(s) on the softer dentin underlayer. We hypothesize that such failure may be substantially mitigated by an appropriate grading of elastic modulus through the ceramic thickness. In this study, we fabricated graded structures by infiltrating glass into zirconia plates, with resulting diminished modulus in the outer surfaces. The plates were then bonded to a polymeric base and subjected to flexure by contact loading until fracture. Comparison of infiltrated specimens with non-infiltrated controls showed a significant increase in the fracture loads, by a factor of nearly 2. Finite element analysis revealed the cause of increase in the load-bearing capacity to be diminished tensile stresses within the lower-modulus graded zone, corresponding to an increase in material strength. The results confirmed that suitably graded structures can be highly beneficial in the design of next-generation all-ceramic restorations.
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Ding Q, Chai H, Mahmood N, Zhou W. Resistin Promotes Vascular Smooth Muscle Cell Migration via Matrix Metalloproteinases. J Surg Res 2010. [DOI: 10.1016/j.jss.2009.11.356] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Wang J, Lu D, Zhao H, Jiang B, Wang J, Ling X, Chai H, Ouyang P. Discrimination and classification of tobacco wastes by identification and quantification of polyphenols with LC-MS/MS. JOURNAL OF THE SERBIAN CHEMICAL SOCIETY 2010. [DOI: 10.2298/jsc091109055w] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
The chemical composition of polyphenols in tobacco waste was identified by HPLC-PAD-ESI/MS/MS and the contents of chlorogenic acids and rutin in 10 varieties of tobacco wastes were determined by HPLC-UV. The relationships between the contents of active polyphenols and the varieties of tobacco wastes were interpreted by hierarchical cluster analysis (HCA) and principal component analysis (PCA). The results showed that 15 polyphenols were identified in a methanolic extract of dried tobacco waste. The tobacco wastes were characterized by high levels of chlorogenic acids (3-CQA, 5-CQA, and 4-CQA) and rutin; their ranges in the 10 tobacco varieties were 0.116-0.196, 0.686-1.781, 0.094- 0.192, and 0.413-0.998 %, respectively. According to multivariate statistics models, two active compound variables can be considered important for the discrimination of the varieties of tobacco wastes: chlorogenic acids and rutin. Consequently, samples of 10 tobacco varieties were characterized into three groups by HCA based on the PCA pattern. In conclusion, tobacco waste could be used as a new pharmaceutical material for the production of natural chlorogenic acids and rutin in the ethnopharmacological industry.
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Chen C, Chai H, Wang X, Lin PH, Yao Q. Corrigendum to: Chlamydia heat shock protein 60 decreases expression of endothelial nitric oxide synthase in human and porcine coronary artery endothelial cells. Cardiovasc Res 2009. [DOI: 10.1093/cvr/cvp316] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Song ZY, Li YH, Chai H, Li HK, Yao Q, Zhong L, Jing T, Ran BL, Tong SF, Liu JP. [Prognostic impact of heart block during transcatheter closure of ventricular septal defect]. ZHONGHUA XIN XUE GUAN BING ZA ZHI 2009; 37:990-993. [PMID: 20137322] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
OBJECTIVE To investigate the prognostic impact of heart block during the transcatheter closure of ventricular septal defect (VSD). METHODS Forty three patients developed complete left or right bundle branch block (CLBBB, CRBBB), incomplete left or right bundle branch block (ILBBB, IRBBB), and atrioventricular block (AVB) during and within 1 week post procedure were followuped at 1, 6, 12, 24, 36, 48 and 60 months post procedure. Electrocardiogram, dynamic electrocardiogram and transthoracic echocardiography were made. RESULTS Bundle branch block and atrioventricular block were detected in 26 patients (CLBBB n = 4, CRBBB n = 5, ILBBB n = 2, IRBBB n = 10 and third-degree AVB n = 5) during the transcatheter closure of VSD, and in 17 patients (CLBBB n = 5, CRBBB n = 2, first-degree AVB n = 3, second-degree I-type AVB n = 1 and third-degree AVB n = 6) within 1 week post procedure. Heart block disappeared in 33 patients (76.7%) before discharge, in 37 patients (86.1%) at 1 month and in 41 patients (95.4%) at 6 months post procedure. CLBBB or CRBBB was seen in two cases at 24 months after closure. There was no heart failure and serious cardiac dilatation during follow up. CONCLUSION The heart block occurred during the periprocedure period of transcatheter closure of VSD was a benign phenomenon without prognostic importance.
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Bismuth J, Chai H, Lin PH, Yao Q, Chen C. Lactosylceramide causes endothelial dysfunction in porcine coronary arteries and human coronary artery endothelial cells. Med Sci Monit 2009; 15:BR270-BR274. [PMID: 19721395 PMCID: PMC2927961] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/28/2023] Open
Abstract
BACKGROUND Lactosylceramide (LacCer) is a member of the glycosphingolipid family, which has been implicated in the atherogenic process. The goal of this study was to determine the effects and molecular mechanisms of LacCer on endothelial functions in porcine coronary arteries and human coronary endothelial cells (HCAECs). MATERIAL/METHODS The vessel rings and HCAECs were treated with different concentrations of LacCer for 24 hours. Vasomotor function was studied using a myograph tension system in response to thromboxane A2 analog U46619, bradykinin and sodium nitroprusside (SNP). Superoxide anion production was determined using lucigenin-enhanced chemiluminescence. The expression of endothelial nitric oxide synthase (eNOS), NADPH oxidase subunit NOX4 and catalase was determined by real-time PCR. RESULTS LacCer (0.1, 1 and 10 microM) significantly decreased endothelium-dependent vasorelaxation (bradykinin) in porcine coronary artery rings in a concentration-dependent manner compared with untreated controls (P<0.05). High concentration of LacCer (10 microM) also reduced endothelium-independent vasorelaxation (SNP). However, LacCer did not affect vessel contraction (U46619). Antioxidant selenomethionine (SeMet) effectively reversed LacCer-induced endothelial dysfunction in the vessel rings. Furthermore, LacCer significantly increased superoxide anion production in the vessel rings in a concentration-dependent manner compared with untreated controls (P<0.05). In response to LacCer treatment, NOX4 mRNA levels were significantly increased, while the expression of catalase and eNOS was significantly decreased in HCAECs compared with controls (P<0.05). CONCLUSIONS LacCer causes endothelial dysfunction with potential mechanisms of the down-regulation of eNOS and increase of oxidative stress due to the activation of NADPH oxidase and inhibition of internal antioxidant catalase. This study suggests that LacCer may represent a risk factor to the vascular system and antioxidant SeMet may have clinical applications for prevention of vascular disease.
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Vilariño-Güell C, Chai H, Keeling BH, Young JE, Rajput A, Lynch T, Aasly JO, Uitti RJ, Wszolek ZK, Farrer MJ, Lin SC. MEIS1 p.R272H in familial restless legs syndrome. Neurology 2009; 73:243-5. [PMID: 19620614 DOI: 10.1212/wnl.0b013e3181ae7c79] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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Chai H, Aghaie K, Zhou W. Soluble CD40 ligand induces human coronary artery smooth muscle cells proliferation and migration. Surgery 2009; 146:5-11. [DOI: 10.1016/j.surg.2009.04.004] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2008] [Accepted: 04/06/2009] [Indexed: 10/20/2022]
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Chen C, Chai H, Wang X, Lin PH, Yao Q. Chlamydia heat shock protein 60 decreases expression of endothelial nitric oxide synthase in human and porcine coronary artery endothelial cells. Cardiovasc Res 2009; 83:768-77. [PMID: 19443423 DOI: 10.1093/cvr/cvp150] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
AIMS Clinically, Chlamydia pneumoniae infection and its heat shock protein 60 (cHSP60) may contribute to atherogenesis; however, its underlying mechanisms are largely unknown. The objective of this study was to determine whether cHSP60 could cause endothelial dysfunction in human coronary artery endothelial cells (HCAECs) and porcine coronary arteries. METHODS AND RESULTS When HCAECs were treated with recombinant cHSP60, endothelial nitric oxide synthase (eNOS) mRNA and protein levels, enzyme activities, cellular NO levels, mRNA stability, and promoter activities were significantly decreased. Superoxide anion production was significantly increased due to the inhibition of mitochondrial membrane potential and catalase and superoxide dismutase (SOD) activities as well as activation of NADPH oxidase. Antioxidant seleno-l-methionine (SeMet) or SOD mimetic MnTBAP effectively blocked cHSP60-induced eNOS downregulation. In addition, cHSP60 activated mitogen-activated protein kinases (MAPKs) including p38, c-Jun-N-terminal kinase/stress-activated protein kinase, and extracellular signal-regulated kinases. Specific chemical inhibitors or their dominant-negative mutant forms of these MAPKs effectively blocked cHSP60-induced eNOS downregulation. cHSP60-induced eNOS downregulation and oxidative stress were also demonstrated in porcine coronary artery rings in vitro. Functionally, endothelium-dependent vasorelaxation was significantly reduced in cHSP60-treated vessels. CONCLUSION cHSP60 directly induces eNOS downregulation through oxidative stress and MAPK activation in both HCAECs and porcine coronary arteries, thereby causing endothelial dysfunction.
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Lee J.W, Kwon JY, Chai H, Lucas P, Thompson V, Lawn B. Fracture Modes in Human Teeth. J Dent Res 2009; 88:224-8. [DOI: 10.1177/0022034508330055] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
The structural integrity of teeth under stress is vital to functional longevity. We tested the hypothesis that this integrity is limited by fracture of the enamel. Experiments were conducted on molar teeth, with a metal rod loaded onto individual cusps. Fracture during testing was tracked with a video camera. Two longitudinal modes of cracking were observed: median cracking from the contact zone, and margin cracking along side walls. Median cracks initiated from plastic damage at the contact site, at first growing slowly and then accelerating to the tooth margin. Margin cracks appeared to originate from the cemento-enamel junction, and traversed the tooth wall adjacent to the loaded cusp from the gingival to the occlusal surface. All cracks remained confined within the enamel shell up to about 550 N. At higher loads, additional crack modes—such as enamel chipping and delamination—began to manifest themselves, leading to more comprehensive failure of the tooth structure.
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Wang X, Chai H, Lin PH, Yao Q, Chen C. Roles and mechanisms of human immunodeficiency virus protease inhibitor ritonavir and other anti-human immunodeficiency virus drugs in endothelial dysfunction of porcine pulmonary arteries and human pulmonary artery endothelial cells. THE AMERICAN JOURNAL OF PATHOLOGY 2009; 174:771-81. [PMID: 19218343 DOI: 10.2353/ajpath.2009.080157] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The objective of this study was to determine the effects of highly active antiretroviral therapy (HAART) drugs on pulmonary endothelial function. Porcine pulmonary arteries or human pulmonary arterial endothelial cells (HPAECs) were incubated with eight HAART drugs [ritonavir, indinavir, lopinavir, zidovudine (AZT), abacavir, stavudine, didanosine (ddI), and lamivudine] individually or in combination [three HAART drugs (3-plex; indinavir, stavudine, and ddI)] at their clinical plasma concentrations for 24 hours. Endothelium-dependent vasorelaxation in response to bradykinin was reduced significantly by the ritonavir in a concentration-dependent manner. Five other HAART drugs (indinavir, lamivudine, abacavir, AZT, and ddI) and the 3-plex significantly also impaired endothelium-dependent vasorelaxation in response to bradykinin. Five HAART drugs (ritonavir, indinavir, lamivudine, abacavir, and AZT) significantly decreased endothelial nitric oxide synthase (eNOS) expression and increased superoxide anion levels in both vessels and HPAECs. Furthermore, both ritonavir and AZT substantially activated ERK2 in HPAECs. Additionally, the antioxidants ginsenoside Rb1 and ginkgolide A effectively reversed HAART drug-induced vasomotor dysfunction and eNOS down-regulation. Inhibition of ERK1/2 also partially blocked ritonavir- and AZT-induced down-regulation of eNOS and vasomotor dysfunction. Thus, HAART drugs significantly impair endothelial functions of porcine pulmonary arteries and HPAECs, which may be mediated by eNOS down-regulation, oxidative stress, and ERK1/2 activation. These findings suggest that HAART drugs may contribute to the high incidence of pulmonary artery hypertension in human immunodeficiency virus-infected patients.
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Chai H, Aghaie K, Zhou W. 119. Soluble CD40 Ligand Induces Human Coronary Artery Smooth Muscle Cells Proliferation and Migration. J Surg Res 2009. [DOI: 10.1016/j.jss.2008.11.147] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Chai H, Brown RE. Field effect in cancer-an update. ANNALS OF CLINICAL AND LABORATORY SCIENCE 2009; 39:331-337. [PMID: 19880759] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
The concept "field effect in cancer" originated in 1953 from the histopathological observations of Slaughter and colleagues [1] regarding the occurrence of multiple primary oral squamous cell carcinomas and their local recurrences. The development of modern molecular technologies has extended the field effect concept by exploring the molecular abnormalities in tissues that appear histologically normal. To date, such field effect biomarkers have been reported in several sites and organs, eg, head and neck, colon and rectum, prostate, breast, lung, esophagus, stomach, and skin. Two popular hypotheses have been proposed. One hypothesis implicates genetic alterations that occur in a stepwise fashion (initiation, promotion, and progression); a clone gains growth advantage and acquires more genetic alterations, which eventually result in cancer. A second hypothesis focuses on epigenetic alterations, which include hypermethylation of the DNA promoter of certain tumor suppressor genes, leading to down-regulation of these genes. In this update, we discuss in detail the evidence that supports these two hypotheses. In addition, we attempt to provide a comprehensive overview of the field effect in carcinogenesis and its possible mechanisms in various organs. Moreover, we discuss the potential utilization of field effect biomarkers in cancer prevention, surgical considerations, and clinical prognosis.
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