Search

Background: Coronary artery bypass graft (CABG) surgery with cardiopulmonary bypass (CPB) promotes immunosuppression, which predisposes patients to infectious complications. We investigated the role of interleukin (IL)-19 in the functions of CD4+ T cells in patients undergoing CABG with CPB. Methods: Blood samples were withdrawn from 42 patients undergoing elective CABG with CPB. Serum levels of IL-19 were analyzed by enzyme-linked immunosorbent assay (ELISA). The CD4+/CD25+ T-cell population was determined with flow cytometry. Isolated CD4+ T cells were cultured and assayed for proliferation and cytokine production under phorbol myristate acetate/ionomycin stimulation. Cytokine production and Foxp3 mRNA expression in CD4+ T cells from healthy volunteers with or without IL-19 treatment were determined with ELISA and real-time polymerase chain reaction, respectively. Results: Proliferation percentages were 162%, 48%, 34%, and 39%, and interferon (IFN)-γ production was 1.22 ng/mL, 0.56 ng/mL, 0.33 ng/mL, and 0.35 ng/mL in the CD4+ T cells of patients before CPB and at 24 hours, 48 hours, and 96 hours, respectively, after CPB. Serum levels of IL-19 were higher but negatively correlated with CD4+ T-cell proliferation and IFN-γ production. The populations of CD4+/CD25+ T cells and expression of Foxp3 mRNA in T cells were higher and were positively correlated with IL-19 levels after CPB. Treatment with IL-19 reduced T-cell proliferation and IFN-γ production, increased Foxp3 mRNA expression, and induced the regulatory activity of CD4+ T cells. Conclusions: Interleukin-19 reduces T-cell responses and promotes the regulatory activity of CD4+ T cells. Induced IL-19 in patients undergoing CABG with CPB contributes to cell-mediated immunosuppression. [ABSTRACT FROM AUTHOR]

Abstract: Heatstroke is a form of excessive hyperthermia associated with a systemic inflammatory response that leads to multi-organ dysfunction in which central nervous system disorders predominate. Herein we determined to ascertain whether heat-induced multi-organ dysfunction in rats could be attenuated by granulocyte-colony stimulating factor (G-CSF) preconditioning. Anesthetized rats were divided into 2 major groups and given vehicle solution (isotonic saline, 0.3ml, subcutaneously) or G-CSF (50–200μg/kg body weight in 0.3ml normal saline, subcutaneously) daily and consecutively for 5days before the start of thermal experiments. They were exposed to an ambient temperature of 43°C for 68min to induce heatstroke. G-CSF preconditioning significantly prolonged the survival time in heatstroke rats in a dose-related way (82–98min vs 127–243min). The non-preconditioning heatstroke animals showed hyperthermia, arterial hypotension, increased serum levels of systemic inflammatory response molecules, increased hypothalamic apoptotic cell numbers as well as neuronal damage scores, and increased serum levels of renal and hepatic dysfunction indicators. These heatstroke syndromes could be significantly reduced by G-CSF preconditioning. Thus our results revealed a potential for G-CSF used as a prophylactic agent for heatstroke in rats. [Copyright &y& Elsevier]

• The effectiveness of using IF-EMD in extracting high-frequency SSVEP has been demonstrated. • The superiority of IF-EMD in avoidance of mode mixing was testified. • A real-time BCI cursor system using SSVEP higher than 40 Hz was established. • The feasibility of extracting high-frequency SSVEP using dry EEG electrode with an impedance matching circuit was confirmed. Steady-state visual evoked potential (SSVEP) has been regarded as an efficient way to design a brain computer interface (BCI). Most SSVEP-based BCIs utilize visual stimuli with flashing frequencies lower than 30 Hz, owing to their better signal-to-noise ratio (SNR). However, the practical applications of low-frequency SSVEP-based BCI are limited, because low-frequency SSVEP usually incur uncomfortable visual experience and the risk of photosensitive epilepsy. In contrast, SSVEP-based BCIs using higher stimulation frequencies (>40 Hz) can induce flicker fusion effect for better visualization. In this study, we studied the feasibility of using iterative filtering - empirical mode decomposition (IF-EMD) to implement a BCI cursor system. EEG signals were recorded from dry EEG electrodes with impedance matching circuits. Three stimulation frequencies, designed at 47, 50, and 53 Hz, were chosen to induce high-frequency SSVEPs, in order to control the leftward, forward and rightward movements of the BCI cursor. Ten subjects were recruited, and each subject was requested to complete a control experiment and an application experiment. In the control experiment, subjects were requested to gaze at each flickering target for thirty seconds. In the application experiment, subjects were instructed to move a cursor to reach three targets on a PC screen. The mean accuracy (Acc), command transfer interval (CTI), and information transfer rate (ITR) in the control experiment were 90.7 ± 2.9%, 1.14 ± 0.07 s, and 54.94 ± 5.41 bits/min, respectively. In the application experiment, the mean execution time and CTI were 30.0 ± 4.69 s and 1.50 ± 0.31 s, respectively. [ABSTRACT FROM AUTHOR]

Abstract: The present study was performed to assess the prophylactic effect of baicalin, a flavonoid compound, in an animal model of heatstroke. Anesthetized rats, immediately before the start of heat stress, were divided into two major groups and given the following: vehicle solution (1mL per kg body weight) or baicalin (10–40mg per kg body weight) intravenously. They were exposed to ambient temperature of 43°C to induce heatstroke. Another group of rats was exposed to room temperature (24°C) and used as normothermic controls. Their physiologic and biochemical parameters were continuously monitored. When the vehicle-pretreated rats underwent heat stress, their survival time values were found to be 20–28min. Pretreatment with intravenous doses of baicalin significantly improved survival during heatstroke (65–248min). As compared to those of normothermic controls, all vehicle-pretreated heatstroke animals displayed higher levels of core temperature, intracranial pressure, and nitric oxide metabolite (NO2 −), glutamate, glycerol, lactate/pyruvate ratio, and dihydroxybenzoic acid (DHBA) in hypothalamus. In addition, both serum and hypothalamic levels of interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α) as well as plasma levels of creatinine, serum urea nitrogen, glutamic oxaloacetic transaminase, glutamic pyruvic transaminase and alkaline phosphatase were elevated after heatstroke onset. In contrast, all vehicle-pretreated heatstroke animals had lower levels of mean arterial pressure, cerebral perfusion pressure, cerebral blood flow, and brain PO2. Administration of baicalin before the start of heat exposure significantly reduced the hyperthermia, intracranial hypertension, and the increased levels of NO2 −, glutamate, glycerol, lactate/pyruvate ratio, and DHBA in the hypothalamus that occurred during heatstroke. The heatstroke-induced increased levels of IL-1β and TNF-α in both the serum and hypothalamus, and renal and hepatic dysfunction were suppressed by baicalin pretreatment. In contrast, both the serum and hypothalamic levels of IL-10 were significantly elevated by baicalin during heatstroke. We successfully demonstrated that baicalin can be used as a prophylactic agent for heatstroke. In particular, baicalin may protect against cerebrovascular dysfunction and brain inflammation in heatstroke. [Copyright &y& Elsevier]

Summary Mitogen-activated protein kinase cascades are important signaling modules that convert environmental stimuli into cellular responses. We show that MPK3, MPK4, and MPK6 are rapidly activated after cold treatment. The mpk3 and mpk6 mutants display increased expression of CBF genes and enhanced freezing tolerance, whereas constitutive activation of the MKK4/5-MPK3/6 cascade in plants causes reduced expression of CBF genes and hypersensitivity to freezing, suggesting that the MKK4/5-MPK3/6 cascade negatively regulates the cold response. MPK3 and MPK6 can phosphorylate ICE1, a basic-helix-loop-helix transcription factor that regulates the expression of CBF genes, and the phosphorylation promotes the degradation of ICE1. Interestingly, the MEKK1-MKK2-MPK4 pathway constitutively suppresses MPK3 and MPK6 activities and has a positive role in the cold response. Furthermore, the MAPKKK YDA and two calcium/calmodulin-regulated receptor-like kinases, CRLK1 and CRLK2, negatively modulate the cold activation of MPK3/6. Our results uncover important roles of MAPK cascades in the regulation of plant cold response. [ABSTRACT FROM AUTHOR]