Point-of-care testing for sensitive cardiac troponin Ⅰ in early diagnosis of acute myocardial infarction / 中华急诊医学杂志

Objective To evaluate the diagnostic performance of a point-of-care testing for sensitive cardiac troponin Ⅰ (POCT-cTnI) in early diagnosis of chest pain patients who had a high pretest probability of acute myocardial infarction (AMI).Methods Total of 127 patients with new-onset chest pain at the emergency department were enrolled.Blood samples were drawn for the routine blood test,and determined POCT-cTnI and central laboratory testing for high sensitive cardiac troponin T (CLT-hscTnT) at admission,three and then at six hours after admission.All patients were divided into AMI group and non-AMI group according to the final diagnosis,which was adjudicated independently by two physicians who reviewed all available medical records for the 90-day follow-up period,and they were unaware of the results of the investigational assays of cardiac troponins.The receiver operating characteristic (ROC) curves were constructed to assess and compare the diagnostic performance of AMI of two cardiac troponin assays.The comparison of areas under the ROC curves (AUC) was performed by DeLong test,and the sensitivity,specificity,negative predictive values (NPV) and positive predictive values (PPV) for the target markers were calculated by applying a maker-specific cutoff value.Results The final diagnosis of AMI was made in 40 of 127 patients (31.5 ％).The diagnostic accuracy of the two assays oBtained at presentation,as quantified by AUC,was no statistically differences (AUC for POCT-cTnⅠ,0.901,95％ CI,0.901 to 0.947;and for CLT-hscTnT,0.907,95％ CI,0.842 to 0.951;Z =0.235,P =0.745).The AUC for POCT-cTnI at 3 hours after admission was significantly higher than that on admission (0.931 vs.0.858;Z =-2.038,P =0.042),while there was on further improvement at 6 hours after admission (0.931 vs.0.949;Z =-1.435,P =0.151).With use of POCT-cTnI (cutoff value 0.023 ng/mL,which was the 99th percentile upper reference limit) on adimission,the clinical sensitivity was 77.5％,and the specificity was 94.2％.A single sample of POCT-cTnI at 3 hours after admission improved the diagnostic accuracy,with a sensitivity of 96.4％,a specificity of 92.0％,and a NPV of 98.6％,a PPV of 81.8％.While,with use of CLT-hscTnT (cutoff value 0.014 ng/mL,was the 99th percentile upper reference limit) at 3 hours after admission,the NPV reached to 100％.Conclusions The use of a POCT-cTnI assay in chest pain patients can identify and exclude the AMI rapidly and exactly at three hours after admission,and the diagnostic performance is equivalent to CLT-hscTnT.

Analysis of clinical characteristic of 158 inpatients with dengue fever in Guangzhou area during the 2014 epidemic / 中华危重病急救医学

ObjectiveTo investigate the clinical characteristics of the inpatients suffering from dengue fever in order to provide references for better diagnosis and treatment.Methods The clinical data of 158 dengue fever patients admitted to the First Affiliated Hospital of Sun Yat-Sen University from July 23rd to October 31st, 2014 during the 2014 epidemic in Guangzhou area were retrospectively analyzed, including general clinical manifestations, conventional examinations, pathogenesis, and prognosis.Results The mean age of the 158 patients was (56±20) years, with half of them over 60 years old (79 cases). Among them, 94 (59.49%) were male.① The common manifestations included fever (100%), headache (70.89%), myalgia/bone soreness (62.03%), and skin rash (54.43%). Bleeding and plasma leakage were found in 25.95% and 14.56% of the patients respectively.② Laboratory examination:leucopenia (75.32%) and thrombocytopenia (77.85%) were found, and alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were elevated in 57.59% and 77.85% of the patients respectively. However, elevation of blood hematocrit was rare (1.27%).③ It was found that in the acute phase (0 - 5 days of the onset), serum dengue virus antibody IgM (DF-IgM) was positive in 63.54% of the patients (61/96), and 92.62% (113/122) of patients were dengue virus RNA (DENA-RNA) positive.④ The rate of comorbidity in this study was 55.06% (87/158), including hypertension (27.22%) and type 2 diabetes (15.82%), which were the two most common co-morbidities.⑤ All the patients were given supportive therapy to prevent complications. They were also isolated for more than 5 days after onset, and at least for 24 hours after subsidence of fever in addition.⑥ The criteria for the diagnosis of severe dengue were fulfilled in 18 patients (11.39%). One patient died of massive hemorrhage from gastro-intestinal tract, and 1 patient voluntarily left hospital with untreated multiple organ dysfunction syndrome (MODS). Another 2 patients of dengue fever died from primary cardio-cerebrovascular disease, and the remaining 154 patients (97.47%) fully recovered with supportive therapy and complication prevention measures.Conclusions The clinical manifestations of inpatients with dengue fever in this study were typical, and they manifested a higher incidence of severe illness. DENA-RNA could be a sensitive indicator for early pathogenic diagnosis. With symptomatic and supportive therapy, most patients had a good outcome. However, early diagnosis and clinical interventions of severe dengue still need further studies.

Research of Adaptive Protection of Preconditioning with Hydrogen Peroxide in Bone Marrow Mesenchymal Cells Against Apoptosis / 中山大学学报(医学科学版)

[Objective] To investigate the effects of preconditioning with low concentration of hydrogen peroxide (H2O2) on oxidative stress-induced BMSC apoptosis.[Methods] In vitro separation,purification,culture,and amplification of bone marrow mesenchymal stem cells were performed.BMSC were insulted with 0,50,100,200,300,400,500 μmol/L H2O2 and the effect of different consentration of H2O2 on BMSC was detected by Flow cytometry (FCM).And then cells were preconditioned with different consentraion of H2O2.(FCM) was used to determine the protective role of H2O2 preconditioning on BMSC apoptosis,BMSC chromatin distribution changes were observed by Hoechst33324;BMSC Caspase-3 and Bcl-2 gene changes were detected by RT-PCR.[Results] Analysis of BMSC apoptosis by flow cytometry showed that H2O2 induced BMSC apoptosis in a dose-dependent manner,and pretreatment of the cells with low concentration of H2O2 prevented subsequent stimulation with high H2O2.RT-PCR results showed that preconditioning with low concentration of H2O2 reduced the BMSC Caspase-3 gene expression but increased Bcl-2 gene expression.[Conclusion] Preconditioning with low concentration of H2O2 has an adaptive role in BMSC,and its mechanism may be related to inhibit abnormal gene expression of Caspase-3 and increase the gene expression of Bcl-2.