ABSTRACT
<p><b>Background</b>Ischemia preconditioning (IPC) remains the most powerful intervention of protection against myocardial ischemia/reperfusion injury (IRI), but diabetes can weaken or eliminate its cardioprotective effect and detailed mechanisms remain unclear. In this study, we aimed to explore whether changes of autophagy in the diabetic condition are attributable to the decreased cardioprotective effect of IPC.</p><p><b>Methods</b>Sixty diabetic male Sprague-Dawley rats were randomly divided into the control (C), IRI, rapamycin (R), wortmannin (W), rapamycin + IPC (R + IPC), and wortmannin + IPC (W + IPC) groups. The in vivo rat model of myocardial IRI was established by ligaturing and opening the left anterior descending coronary artery via the left thoracotomy. Durations of ischemia and reperfusion are 30 min and 120 min, respectively. Blood samples were taken at 120 min of reperfusion for measuring serum concentrations of troponin I (TnI) and creatine kinase isoenzyme MB (CK-MB) using the enzyme-linked immunosorbent assay. The infarct size was assessed by Evans blue and triphenyltetrazolium chloride staining. The expressions of LC3-II, beclin-1, phosphoinositide 3-kinase (PI3K), mammalian target of rapamycin (mTOR), and P-Akt/Akt ratio in the ischemic myocardium were assessed by Western blotting.</p><p><b>Results</b>Compared to the IRI group, infarct size (56.1% ± 6.1% vs. 75.4 ± 7.1%, P < 0.05), serum cTnI (0.61 ± 0.21 vs. 0.95 ± 0.26 ng/ml, P < 0.05), and CK-MB levels (6.70 ± 1.25 vs. 11.51 ± 2.35 ng/ml, P < 0.05) obviously decreased in the W + IPC group. Compared with the C group, myocardial expressions of LC3-II (0.46 ± 0.04 and 0.56 ± 0.04 vs. 0.36 ± 0.04, P < 0.05) and beclin-1 (0.34 ± 0.08 and 0.38 ± 0.07 vs. 0.24 ± 0.03, P < 0.05) evidently increased, and myocardial expressions of mTOR (0.26 ± 0.08 and 0.25 ± 0.07 vs. 0.38 ± 0.06, P < 0.05), PI3K (0.29 ± 0.04 and 0.30 ± 0.03 vs. 0.38 ± 0.02, P < 0.05), and P-Akt/Akt ratio (0.49 ± 0.10 and 0.48 ± 0.06 vs. 0.72 ± 0.07, P < 0.05) markedly decreased in the IRI and R groups, indicating an increased autophagy. Compared with the IRI group, myocardial expression of beclin-1 (0.26 ± 0.03 vs. 0.34 ± 0.08, P < 0.05) significantly decreased, and myocardial expressions of mTOR (0.36 ± 0.04 vs. 0.26 ± 0.08, P < 0.05), PI3K (0.37 ± 0.03 vs. 0.29 ± 0.04, P < 0.05), and P-Akt/Akt ratio (0.68 ± 0.05 vs. 0.49 ± 0.10, P < 0.05) increased obviously in the W + IPC group, indicating a decreased autophagy.</p><p><b>Conclusions</b>Increased autophagy in the diabetic myocardium is attributable to decreased cardioprotection of IPC, and autophagy inhibited by activating the PI3K-Akt-mTOR signaling pathway can result in an improved protection of IPC against diabetic myocardial IRI.</p>
ABSTRACT
<p><b>Background</b>Oxygen-glucose deprivation-nutrition resumption (OGD-NR) models on H9c2 cells are commonly used in vitro models of simulated myocardial ischemia-reperfusion injury (MIRI), but no study has assessed whether these methods for establishing in vitro models can effectively imitate the characteristics of MIRI in vivo. This experiment was designed to analyze the feasibility of six OGD-NR models of MIRI.</p><p><b>Methods</b>By searching the PubMed database using the keywords "myocardial reperfusion injury H9c2 cells," we obtained six commonly used OGD-NR in vitro models of MIRI performed on H9c2 cells from more than 400 published papers before January 30, 2017. For each model, control (C), simulated ischemia (SI), and simulated ischemia-reperfusion (SIR) groups were assigned, and cell morphology, lactate dehydrogenase (LDH) release, adenosine triphosphate (ATP) levels, reactive oxygen species (ROS), mitochondrial membrane potential (MMP), and inflammatory cytokines were examined to evaluate the characteristics of cell injury. Subsequently, a coculture system of cardiomyocyte-endothelial-macrophage was constructed. The coculture system was dealt with SI and SIR treatments to test the effect on cardiomyocytes survival.</p><p><b>Results</b>For models 1, 2, 3, 4, 5, and 6, SI treatment caused morphological damage to cells, and subsequent SIR treatment did not cause further morphological damage. In the models 1, 2, 3, 4, 5 and 6, LDH release was significantly higher in the SI groups than that in the C group (P < 0.05), and was significantly lower in the SIR groups than that in the SI groups (P < 0.05), except for no significant differences in the LDH release between C, SI and SIR groups in model 6 receiving a 3-h SI treatment. In models 1, 2, 3, 4, 5, and 6, compared with the C group, ATP levels of the SI groups significantly decreased (P < 0.05), ROS levels increased (P < 0.05), and MMP levels decreased (P < 0.05). Compared with the SI group, ATP level of the SIR groups was significantly increased (P < 0.05), and there was no significant ROS production, MMP collapse, and over inflammatory response in the SIR groups. In a coculture system of H9c2 cells-endothelial cells-macrophages, the proportion of viable H9c2 cells in the SIR groups was not reduced compared with the SI groups.</p><p><b>Conclusion</b>All the six OGD-NR models on H9c2 cells in this experiment can not imitate the characteristics of MIRI in vivo and are not suitable for MIRI-related study.</p>
Subject(s)
Humans , Apoptosis , Glucose , Metabolism , Myocardial Reperfusion Injury , Myocytes, Cardiac , Physiology , Oxygen , MetabolismABSTRACT
<p><b>OBJECTIVE</b>UEscope is a new angulated videolaryngoscope (VL). This review aimed to describe the features of UEscope and provide clinical evidences regarding the efficacy and safety of this video device in adult tracheal intubation and its roles in airway management teaching.</p><p><b>DATA SOURCES</b>The Wan Fang Data, CNKI, PubMed, Embase, Cochrane Library, and Google Scholar were searched for relevant English and Chinese articles published up to January 15, 2017, using the following keywords: "HC video laryngoscope", "UE videolaryngoscope", "video laryngoscope", and "videolaryngoscopy".</p><p><b>STUDY SELECTION</b>Human case reports, case series, observable studies, and randomized controlled clinical trials were included in our search. The results of these studies and their reference lists were cross-referenced to identify a common theme.</p><p><b>RESULTS</b>UEscope features the low-profile portable design, intermediate blade curvatures, all-angle adjustable monitor, effective anti-fog mechanisms, and built-in video recording function. During the past 5 years, there have been a number of clinical studies assessing the application and roles of UEscope in airway management and education. As compared with direct laryngoscope, UEscope improves laryngeal visualization, decreases intubation time (IT), and increases intubation success rate in adult patients with normal and difficult airways. These findings are somewhat different from the previous results regarding the other angulated VLs; they can provide an improved laryngeal view, but no conclusive benefits with regard to IT and intubation success rate. Furthermore, UEscope has extensively been used for intubation teaching and shown a number of advantages.</p><p><b>CONCLUSIONS</b>UEscope can be used as a primary intubation tool and may provide more benefits than other VLs in patients with normal and difficult airways. However, more studies with large sample are still needed to address some open questions about clinical performance of this new VL.</p>
ABSTRACT
<p><b>OBJECTIVE</b>To study single nucleotide polymorphism (SNP) of all the coding region in ABCA1 gene in 112 patients with coronary heart diseases.</p><p><b>METHODS</b>With polymerase chain reaction-single-strand conformation polymorphism (PCR-SSCP) combining argentation and glue retrieval, DNA sequencing, and restriction fragment length polymorphism (RFLP), the SNP of the 50 exons in all the coding regions of ABCA1 gene was detected in 112 patients with established diagnosis of coronary heart disease.</p><p><b>RESULTS</b>In the Chinese population with coronary heart disease, besides the SNP variation at R219K and M883I as widely reported, a new single base variation at A1092G in exon 7 was detected, which led to a conversion of the amino-side residue to M223V. This variation was confirmed to represent a novel SNP by RFLP in 108 normal subjects.</p><p><b>CONCLUSIONS</b>The Chinese population with coronary heart disease has not only the reported SNP changes at the sites R219K and M883I, but also changes at the new SNP site of M233V, which is discovered for the first time in M233V of ABCA1 gene. This variation may increase the risks for coronary heart diseases, and its exact function awaits examination in further epidemiologic survey.</p>
Subject(s)
Adult , Aged , Female , Humans , Male , Middle Aged , ATP Binding Cassette Transporter 1 , ATP-Binding Cassette Transporters , Genetics , Base Sequence , Coronary Disease , Genetics , Molecular Sequence Data , Open Reading Frames , Genetics , Point Mutation , Polymerase Chain Reaction , Polymorphism, Restriction Fragment Length , Polymorphism, Single Nucleotide , Polymorphism, Single-Stranded Conformational , Sequence Analysis, DNAABSTRACT
<p><b>OBJECTIVE</b>To identify ATP-binding cassette transporter A1 (ABCA1) gene polymorphism in Chinese patients with coronary artery disease (CAD).</p><p><b>METHODS</b>Single Nucleotide Polymorphisms in the ABCA1 gene were detected by polymerase chain reaction (PCR)-single strand conformation polymorphism (SSCP)-DNA sequence and restriction-fragment length polymorphism (RFLP) method in 112 patients with CAD.</p><p><b>RESULTS</b>A novel polymorphism in the ABCA1 gene was found in two patients: M233V which exists in exon7 of ABCA1 gene and it's cDNA location is A1092G and converse 233 amino acid from Methionine to Valeric. We further collected the blood samples from 16 family members of one proband and M233V polymorphism was found in 5 out 16 family members.</p><p><b>CONCLUSION</b>M233V is a novel polymorphism in the ATP-binding cassette transporter A1 gene and this AG genotype had family proneness.</p>