Protective effect of resolvin D2 on inflammatory response and endoplasmic reticulum stress injury of CVB3-induced viral myocarditis mice and its mechanism / 中华微生物学和免疫学杂志

Objective:To clarify the anti-inflammatory effects and anti-endoplasmic reticulum stress effects of resolvin D2 (RvD2) in viral myocarditis mice and to explore its possible mechanism.Methods:Fifty male BALB/c mice were collected and assigned corresponding numbers. Then 40 male BALB/c mice were selected randomly with 10 mice in each group. They were set as normal control group, RvD2 control group, viral myocarditis group and RvD2 treatment group. Afterwards, mice in the RvD2 control group received continuous intraperitoneal injection of RvD2 for 7 days, while mice in the viral myocarditis group received intraperitoneal injection of Coxsackievirus B3 virus (CVB3) in the purpose of constructing an animal model of viral myocarditis. Then, mice in the RvD2 treatment group were given continuous intraperitoneal injection of RvD2 for 7 days. After these 7 days, the mice of each group were sacrificed and their cardiac tissue and serum samples were taken. The expression levels of serum inflammatory factors including IL-1β and TNF-α were detected by ELISA in each group of mice, and HE staining were used to detect the inflammatory cell infiltration in myocardial tissue of each group. Meanwhile, the expression levels of inflammation-related proteins IL-1β, TNF-α as well as endoplasmic reticulum stress-related proteins like GRP78 and Chop in the myocardial tissue in each group of mice were detected by Western blot experiment. The remaining 10 BALB/c mice were treated with intraperitoneal injection of RvD2 as well as GPR18 protein inhibitors after constructing the animal model of viral myocarditis mentioned above. In the end, the expression levels of GPR18 protein, inflammation-related proteins including IL-1β and TNF-α as well as endoplasmic reticulum stress-related proteins like GRP78 and Chop in the myocardial tissue of each group were detected by Western blot experiments.Results:Compared with the normal control group, the expression levels of inflammatory factors IL-1β and TNF-α in the serum of mice with viral myocarditis were significantly increased, and the degree of infiltration of inflammatory cells in myocardial tissue was also significantly increased. Besides, the expression levels of the inflammation-related proteins IL-1β, TNF-α as well as endoplasmic reticulum stress-related proteins including GRP78 and Chop increased largely. While compared with the viral myocarditis group, the expression levels of serum inflammatory factors IL-1β and TNF-α in the mice of the RvD2 treatment group were significantly reduced and the degree of infiltration of inflammatory cells in the cardiac tissue was significantly reduced. Also, the expression levels of inflammation-related proteins IL-1β and TNF-α as well as endoplasmic reticulum stress-related proteins GRP78 and Chop were significantly reduced. After intraperitoneal injection of RvD2 and GPR18 inhibitor, in the mice treated with viral myocarditis, the expression levels of IL-1β, TNF-α and endoplasmic reticulum stress-related proteins like GRP78 and Chop in myocardial tissue of these mice significantly increased when it came to compare with the RvD2 treatment group, while the expression levels of GPR18 protein were significantly reduced.Conclusions:RvD2 can inhibit the inflammatory response and endoplasmic reticulum stress injury in mice with viral myocarditis by binding to the membrane protein receptor GPR18, thus exerting a protective effect on heart.

Regulatory effects of PI3K/AKT2/mTOR signaling pathway on autophagy activation in cardiac tis-sues of mice with vial myocarditis / 中华微生物学和免疫学杂志

Objective To study the phosphorylation of AKT2 protein and autophagy activation in cardiac tissues of mice infected with coxsackievirus B3 (CVB3) for further analyzing the regulatory mecha-nism of PI3K/AKT2/mTOR signaling pathway on autophagy activation in viral myocarditis. Methods Thir-ty BALB/c mice were randomly divided into three groups (n=10): control group, myocarditis group and AKT activator-treated group. Those in the latter two groups were intraperitoneally injected with CVB3 to es-tablish the mouse model of acute viral myocarditis. Daily intraperitoneal injection of 0.04 mg/g of Akt acti-vator (SC79) was given to each mouse in the AKT activator-treated group 24 hours after CVB3 infection for 7 consecutive days,while the mice in the other two groups were given the same dose of normal saline. HE staining was used to observe the infiltration of inflammatory cells and tissue necrosis. Expression of CVB3 and inflammatory cytokines such as IL-1β and IL-6 in cardiac tissues at mRNA level was detected by q-PCR. Brain natriuretic peptide(BNP) and cardiac troponin I(cTnI) were measured by ELISA to evaluate myocardial injury. Changes in the expression of autophagy-related protein LC3 and Beclin1 at protein level as well as PI3K/AKT2/mTOR pathway were analyzed by Western blot assay. Results Compared with the con-trol group,massive inflammatory cell infiltration was observed in cardiac specimens of mice with myocarditis, but no obvious tissue necrosis was detected. Moreover,expression of CVB3 and inflammatory factors in car-diac tissues at mRNA level,levels of BNP and cTnI in blood,LC3Ⅱto LC3Ⅰratio as well as Beclin1 pro-tein level in cardiac tissues were significantly increased after CVB3 infection(P<0.05),whereas the activi-ty of PI3K/AKT2/mTOR signaling pathway was decreased. AKT activator not only down-regulated the LC3Ⅱ to LC3Ⅰratio and the expression of Beclin1 protein, but also enhanced the activation of PI3K/AKT2/mTOR signaling pathway in cardiac tissues of mice with myocarditis (P<0.05). Conclusion Enhanced autophagy and suppressed PI3K/AKT2/mTOR signaling pathway are observed in cardiac tissues of mice with myocarditis,indicating that the activation of autophagy may be regulated by PI3K/AKT2/mTOR signaling pathway.

Clinical analysis of scrub typhus-associated hemophagocytic syndrome / 中华儿科杂志

<p><b>OBJECTIVE</b>To analyze the clinical manifestations and intervention against fulminant scrub typhus-associated hemophagocytic syndrome.</p><p><b>METHOD</b>The medical records for the onset time of hemophagocytic syndrome, the clinical course, the chest radiographic findings, laboratory data, antibiotic therapy, clinical outcome and its prognosis were retrospectively reviewed.</p><p><b>RESULT</b>(1) Four patients were diagnosed as scrub typhus based on clinical manifestations only, while 15 patients met the criteria of laboratory diagnosis. All 19 patients with scrub typhus had hemophagocytic syndrome. Eschar lesion was identified in 12 patients, 7 patients were described as an ulcer. A seasonal pattern (78.9% from June through September in 15 patients) was observed. Clinical misdiagnosis was common (all 19 cases). There were 9 patients with admitting diagnosis of scrub typhus, 10 patients were not diagnosed as scrub typhus after admission. In 5 cases within 3 days after admission diagnosis was corrected as scrub typhus. Until discharge from the hospital, 5 cases were not diagnosed with scrub typhus. In this study, the length of time from the illness onset (beginning of fever) to the occurrence of clinical symptoms was (9 ± 4) days. (2) All 19 patients had changed AST levels (149 ± 37) U/L, albumin levels (23 ± 4) g/L, C-reactive protein levels (103 ± 51) mg/L, and platelet count (48 ± 41) × 10⁹/L; bone marrow aspiration revealed in 16 patients marked hemophagocytosis. Weil-Felix agglutination test revealed positive results in 6 of 15 cases. Diagnostic IFA results were positive for 14 patients; 19 patients had interstitial pneumonitis and 17 patients had pleural effusion. (3) Five cases with failure to diagnose the disease had ineffective antibiotics treatment (imipenem or β-lactam-based regimens). These patients did not receive appropriate treatment with antibiotics against scrub typhus. Fourteen patients with admitting diagnosis of scrub typhus were successfully treated with appropriate antibiotics, 8 cases with chloramphenicol, 3 cases with azithromycin, and in 3 patients (2 cases of azithromycin and one case of erythromycin), therapy was then switched to chloramphenicol. Four patients were treated with methylprednisolone and 10 patients with dexamethasone. (4) During their hospitalization, the clinical course in five cases with failure to diagnose the disease rapidly developed and progressed to the life-threatening MODS, four of five cases died. However, the course in 14 patients were relieved and did not progress to MODS.</p><p><b>CONCLUSION</b>The diagnosis of scrub typhus was frequently delayed, the early course of scrub typhus could be associated with hemophagocytic syndrome. Serious complications of MODS generally occur without antibiotic treatment. Scrub typhus-associated hemophagocytic syndrome should be taken into consideration among patients with acute systemic febrile illness, significant increases in levels of CRP, hypoalbuminemia, thrombocytopenia, splenomegaly, pneumonitis with pleural effusion, especially those with suspected exposure history. It was not easily recognized without careful observation and was present for a few days in each patient.</p>

Clinical characteristics of lipid aspiration pneumonia in 16 children / 中华儿科杂志

<p><b>OBJECTIVE</b>To investigate clinical characteristics and changes of pulmonary imaging of mineral oil aspiration pneumonia in children.</p><p><b>METHOD</b>The clinical features, CT findings, and effects of corticosteroid therapy were analyzed in 16 children with mineral oil aspiration pneumonia, who were hospitalized in our hospital from January 2003 to July 2013.</p><p><b>RESULT</b>All patients with mineral oil aspiration pneumonia had a history of mineral oil administration.Four patients had no clinical manifestations. Ten cases presented fever, and 8 of the 10 patients had fever in 4-8 h after taking mineral oil, and the temperature was between 39-40 °C. There were wheezing in 2 cases, shortness of breath in 6 cases, cyanosis in 1 case, dyspnea in 3 cases, and moaning in 2 cases, chest pain in 1 case, headache and abnormal EEG in 1 case.Six patients had rales in lungs. Peripheral blood white cells increased in 10 cases, and C- reactive protein elevated in 7 patients. Chest CT examination showed abnormal findings in 6 children, and the earliest CT was performed within 2 h after the accident. The rest 10 children got chest X-ray, and 9 of 10 children had abnormal findings. The earliest X-ray was done within 3 h after the accident. And the remaining 1 of 10 children showed no significant changes in the first chest X-ray 2-3 h after the accident until 3 days. All of the patients received corticosteroid and antibiotic treatments, 4 cases underwent bronchoalveolar lavage, 3 patients were given albumin, 6 cases received intravenous immunoglobulin. Three cases delayed in treatment with hormone because of misdiagnosis, and 2 of them had clearly secondary infections. Twelve patients recovered completely from oil aspiration pneumonia after 8 days to 5.5 months.</p><p><b>CONCLUSION</b>Oil aspiration pneumonia in children occurs in almost all cases after mineral oil aspiration. Pulmonary opacities can be found by chest CT in most patients within 24 hours after mineral oil aspiration. Corticosteroids therapy was effective for patients with exogenous lipid pneumonia, which may inhibit the inflammatory response and possible pulmonary fibrosis.</p>

Effects of Ivabradine on the expression of inflammatory cytokines in a murine model of coxsackievir-us B3-induced viral myocarditis / 中华微生物学和免疫学杂志

in mice with coxsackievirus B3 (CVB3)-induced viral myocarditis through a comparative study with Carve-dilol.Methods 150 BALB/c male mice were divided into four groups including control group (n=30), myocarditis group (n=40), Ivabradine treatment group (n=40) and Carvedilol treatment group (n=40). Viral myocarditis was induced by intraperitoneal injection of CVB 3 in experimental mice , while mice in the control group were injected with PBS accordingly .The mice in four groups were respectively administered with PBS, PBS, Ivabradine and Carvedilol after 24 h of infection for 14 consecutive days .Heart specimens were collected from 8 mice of each group on days 4, 7 and 14 after measuring their heart rates .The patho-logical changes in heart tissues were observed through hematoxylin e-osin staining .Semi-quantitative RT-PCR and ELISA were performed to detect the expressions of MCP -1, IL-6 and TNF-αat mRNA and protein lev-els.CVB3 RNA was quantified by semi-quantitative RT -PCR as well .Results Compared with myocarditis group, the histopathological damages in myocardium were significantly alleviated in both Ivabradine group and Carvedilol group on days 7 and 14.The expressions of MCP-1,IL-6 and TNF -αat mRNA level were up-regulated in mice treated with Ivabradine and Carvedilol as compared with those in control group .Compared with myocarditis group , the expressions of TNF-αon day4 and IL-6 on day 7 at mRNA level were reduced in Ivabradine and Carvedilol treatment groups .MCP-1 expression at mRNA level was only down-regulated in Iv-abradine group on day 7.Concluison Ivabradine treatment could alleviate histopathological damages in my -ocardium of mice with CVB3-induced viral myocarditis , which was similar to the effects of carvedilol treat-ment.The treatment effects might be associated with the down-regulation of expressions of IL-6, TNF-αand MCP-1 at mRNA and protein levels .