Wei Kong

Publication Details
Article Title: A semi-implantable multichannel telemetry system for continuous electrical, mechanical and hemodynamical recordings in animal cardiac research.

First Author: Wei Kong

All Authors: Kong W, Huang J, Rollins DL, Ideker RE, Smith WM

Journal Title: Physiological measurement

Abstract: We have developed an eight-channel telemetry system for studying experimental models of chronic cardiovascular disease. The system is an extension of a previous device that has been miniaturized, reduced in power consumption and provided with increased functionality. We added sensors for ventricular dimension, and coronary artery blood flow and arterial blood pressure that are suitable for use with the system. The telemetry system consists of a front end, a backpack and a host PC. The front end is a watertight stainless steel case with all sensor electronics sealed inside; it acquires dimension, flow, pressure and five cardiac electrograms from selected locations on the heart. The backpack includes a control unit, Bluetooth radio, and batteries. The control unit digitizes eight channels of data from the front end and forwards them to the host PC via Bluetooth link. The host PC has a receiving Bluetooth radio and Labview programs to store and display data. The whole system was successfully tested on the bench and in an animal model. This telemetry system will greatly enhance the ability to study events leading to spontaneous sudden cardiac arrest.

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Zhonghua nei ke za zhi
[A long-term outcome study of acute kidney injury after cardiac surgery].

Authors: Jiang J, Ding X, Jiang W, Xu J, Fang Y, Teng J

Abstract: To evaluate the long-term outcome of acute kidney injury (AKI) during hospitalization after cardiac surgery.1 770 patients underwent cardiac surgery in Fudan University Zhongshan Hospital from April 2009 to February 2011 were enrolled. Based on the Kidney Disease: Improving Global Outcomes (KDIGO) guideline of AKI, the patients were divided into the AKI and the non-AKI groups, and followed up for 2 years. The 2-year survival rate and incidence of the advanced chronic kidney disease (CKD) was compared between the two groups.Factors influencing the 2-year survival rate and incidence of the advanced CKD were also analyzed.Among all the patients, 715 (40.4%) of them were developed AKT. (1) The 2-year survival rate of the AKI group was lower than that of the non-AKI group (83.2% vs 93.6%;P < 0.05). Compared with the non-AKI group, AKI group had an increased risk for death with the hazard ratio of 1.710 (95%CI 1.250-2.340). COX regression analysis showed that AKI was an independent factor for death with the risk intensity just less than diabetes and chronic cardiac insufficiency. The advanced age, the preoperative history of chronic cardiac insufficiency and the time of staying in ICU also significantly increased the risk of death. (2) Compared with patients without AKI (0.2%), the incidence of the 2-year of advanced CKD was higher in patients with AKI (6.7%;P < 0.05) with an hazard ratio of 31.220 (95%CI 7.550-129.110). COX regression analysis showed that AKI was still the independent risk factor for advanced CKD after adjustment of other factors.In addition, diabetes, the time of the cardiopulmonary bypass and the time of staying in ICU were also associated with the risk for the advanced CKD.AKI is common after cardiac surgery, which was associated with a decrease in the 2-year survival rate and an increase in the incidence of advanced CKD of patients, which emphasized the importance of prevention and treatment of AKI, and close follow-up of renal function for the improvement of patient long-term prognosis.

Radiological physics and technology
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Authors: Nagamori T, Yoshida Y, Takahashi H, Oka H, Kajihama A, Nakau K, Sugimoto M, Minami-Hori M, Azuma H

Abstract: Juvenile-onset systemic sclerosis (jSSc) is a rare condition, having unique characteristic features compared to adult-onset SSc. Although cardiac involvement (CI) is known as a leading cause of mortality overall in SSc, the importance of CI in jSSc has not been emphasized. Here we present a 13-year-old female with jSSc overlapped with dermatomyositis (DM) complicated CI. She developed skin thickness and induration, Raynaud's phenomenon, digital pitting scars in fingertips, and skeletal myositis. Oral prednisolone and pulse methotrexate treatment led to the improvement of skin findings; however two weeks after the initiation she suddenly presented with muscle pain and dyspnea within a few days. Cardiac investigations then showed pericardiac effusion and diastolic dysfunction due to significant biventricular hypertrophy causing heart failure. As pericardiac effusion and exacerbation of skeletal myositis were evident, steroid pulse therapy was initiated. Unexpectedly, not only the myositis but also the CI including diastolic dysfunction was improved. She thereafter followed a favorable clinical course without reactivation of the CI or cardiac fibrosis. As a conclusion, close attention to CI must be paid in jSSc patients, especially when skeletal muscle involvement is evident and immunosuppressive therapy may be effective for CI in jSSc in cases where it occurs abruptly.

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Authors: Koshino K, Fukushima K, Fukumoto M, Sasaki K, Moriguchi T, Hori Y, Zeniya T, Nishimura Y, Kiso K, Iida H

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Rheumatology international
Lupus myocarditis: marked improvement in cardiac function after intravenous immunoglobulin therapy.

Authors: Suri V, Varma S, Joshi K, Malhotra P, Kumari S, Jain S

Abstract: Intravenous immunoglobulin (IVIg) is emerging as the mainstay in the treatment of many autoimmune diseases, including systemic lupus erythematosus. IVIg has been found to be beneficial in myocarditis due to dermatomyositis/polymyositis, Kawasaki disease, and viral myocarditis in children. We report an 18-year-old man of active lupus with worsening cardiac systolic function who did not respond to pulse methylprednisolone and cyclophosphamide, but subsequently showed an improvement in his cardiac function after IVIg administration.

Hypertension (Dallas, Tex. : 1979)
Impact of new-onset diabetes mellitus on cardiac outcomes in the Valsartan Antihypertensive Long-term Use Evaluation (VALUE) trial population.

Authors: Aksnes TA, Kjeldsen SE, Rostrup M, Omvik P, Hua TA, Julius S

Abstract: There has been a lot of interest about new-onset diabetes mellitus in recent hypertension trials, but the implications of diabetes development on cardiac outcomes have not been known. In the Valsartan Antihypertensive Long-Term Use Evaluation trial, 15 245 high-risk patients were followed for an average of 4.2 years. At baseline, 5250 patients were diabetic by the 1999 World Health Organization criteria, and among the 9995 nondiabetic patients, 1298 patients developed diabetes during follow-up. We have investigated the influence of diabetes development on outcomes in the Valsartan Antihypertensive Long-Term Use Evaluation trial. The patients with diabetes at baseline and new-onset diabetes were compared with patients who did not develop diabetes by a Cox regression model with adjustment for prespecified covariates (age, diabetes status, left ventricular hypertrophy, baseline coronary heart disease, and randomized study treatment). Patients with diabetes at baseline had the highest cardiac morbidity defined as myocardial infarction and heart failure with a hazard ratio of 2.20 (95% CI: 1.95 to 2.49). The patients with new-onset diabetes had significantly higher cardiac morbidity, especially more congestive heart failure, than those without diabetes, with a hazard ratio of 1.43 (95% CI: 1.16 to 1.77). This indicates that patients who develop diabetes during antihypertensive treatment have cardiac morbidity intermediate between diabetic subjects and those subjects who never had diabetes and that it is of importance to find these patients at risk of diabetes development and optimize lifestyle and medical treatment.

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Authors: Liu X, Zhang Q, Yang ZG, Shi K, Xu HY, Xie LJ, Jiang L, Diao KY, Guo YK

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Archives of biochemistry and biophysics
Troponin T isoforms alter the tolerance of transgenic mouse cardiac muscle to acidosis.

Authors: Nosek TM, Brotto MA, Jin JP

Abstract: Troponin T (TnT) is an essential protein in the Ca2+ regulatory system of striated of muscle. Three fiber type-specific TnT genes have evolved in higher vertebrates to encode cardiac, slow and fast skeletal muscle TnT isoforms. To understand the functional significance of TnT isoforms, we studied the effects of acidosis on the contractility of transgenic mouse cardiac muscle that expresses fast skeletal muscle TnT. Contractility analysis of intact cardiac muscle strips showed that while no differences were detected at physiological pH, the transgenic cardiac muscle had significantly greater decreases in +dF/dtmax at acidic pH than that of the wild-type control. Contractility of skinned cardiac muscles demonstrated that the presence of fast TnT resulted in significantly larger decreases in force and Ca2+ sensitivity at acidic pH than that of the wild-type control. The effect of TnT isoforms on the tolerance of muscle to acidosis may explain the higher tolerance of embryonic versus adult cardiac muscles. The results are consistent with the hypothesis that charge differences in TnT isoforms contribute to the contractility of muscle. The data further support a hypothesis that slow TnT is similar to the cardiac, but not fast, and TnT may contribute to the higher tolerance of slow muscles to stress conditions. Therefore, TnT isoform diversity may contribute to the compatibility of muscle thin filaments to cellular environments in different fiber types, during development and functional adaptation.

Journal of molecular and cellular cardiology
Cardiac repolarization is prolonged in CD4C/HIV transgenic mice.

Authors: Brouillette J, Grandy SA, Jolicoeur P, Fiset C

Abstract: Pharmacological agents used to treat patients with AIDS have been associated with QT prolongation and result in delayed repolarization. New evidence suggests that delayed repolarization can occur independently of pharmacological therapy. However, the effect of HIV on ventricular repolarization has not been investigated. Therefore, the objective of this study was to characterize cardiac repolarization in a mouse model of human HIV disease. All experiments were conducted on HIV transgenic mice (CD4C/HIV). These mice express the human HIV gene nef in cells of immune system and develop a severe AIDS-like disease that is similar to that observed in humans. ECG was recorded in conscious free moving mice and patch-clamp techniques were used to record action potentials and K+ current densities in single ventricular myocytes. Results showed that the QT interval and action potential duration were significantly prolonged in CD4C/HIV mice compared to wild-type littermates. This delay in repolarization was associated with a significant reduction in outward K+ currents. Echocardiography showed that cardiac structure and function were similar in CD4C/HIV and littermate control mice. This suggests that the changes in ventricular repolarization were not the result of heart failure or cardiac hypertrophy. Overall, this study shows that repolarization was delayed in CD4C/HIV mice and that this phenotype occurred in the absence of any pharmacological intervention. Thus, it appears that HIV may be responsible for the delayed ventricular repolarization phenotype observed in CD4C/HIV mice.

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