Myocardial ischemia and reperfusion (I/R) is a common problem in clinic and there is no satisfactory method for prevention or treatment of I/R injury so far. Chronic intermittent hypobaric hypoxia (CIHH), similar to the concept of ischemia preconditioning (IPC)or altitude hypoxia adaptation (AHA), has been recognized to confer a protective effect on heart against I/R injury with a longer protective effect than IPC and a less adverse effect than AHA. It has been proved that CIHH increases myocardial tolerance to ischemia or hypoxia, reserving cardiac function and preventing arrhythmia during I/R. Multiple mechanisms or pathway underlying the cardiac protection of CIHH have been proposed, such as induction of heat-shock protein, enhancement of myocardial antioxidation capacity, increase of coronary flow and myocardial capillary angiogenesis, activation of adenosine triphosphate (ATP)-sensitive potassium channels, inhibition of mitochondrial permeability transition pores, and activation of protein kinase C (PKC) and induced nitric oxide synthase (iNOS). In addition, CIHH has been found having many beneficial effects on the body, such as promotion of health, increase of oxygen utilization, and prevention or treatment for some diseases. The beneficial effects of CIHH and potential mechanisms are reviewed mainly based on the researches performed by our group.
Adenosine Triphosphate ; metabolism ; Antioxidants ; metabolism ; Heart ; physiopathology ; Heat-Shock Proteins ; metabolism ; Humans ; Hypoxia ; Myocardial Ischemia ; physiopathology ; Myocardium ; pathology ; Nitric Oxide Synthase Type II ; Potassium Channels ; metabolism ; Protein Kinase C ; metabolism ; Reperfusion Injury ; physiopathology

OBJECTIVETo research the bacteriostatic effects of Qingkailing Injection Extract (QKLIE) and combination therapy of Qingkailing Injection (QKLI) and antibiotics on bacteria carrying New Delhi metallo-3-lactamase 1 (NDM-1) blaNDM-1 resistance gene, and to determine their minimal inhibitory concentrations (MIC).

METHODSThe antimicrobial experiments of QKLIE (Radix Isatidis, baicalin, gardenia, honeysuckle) and combination therapy of QKLI and antibiotics were performed by using the agar dilution method and K-B method. The MIC was determined from each extract.

RESULTSThere were different degrees of inhibitory effects on resistant bacteria carrying blaNDM-1 by extracts from main components of QKLI. Of them, the inhibitory effect of baicalin was the best and the MIC of the resistant bacteria was 0.015 g/mL to WD, 0.020 g/mL to WX, 0. 005 g/mL to WJ, and more than 0.020 g/mL to pGEX-4T-NDM-1/DH5alpha (GST-NDM-1), respectively. The MIC value of each extract was sequenced from high to low as baicalin, honeysuckle, gardenia, and Radix Isatidis. Furthermore, combination therapy of QKLI and antibiotics greatly enhanced the antimicrobial activity of each antibiotics when used alone, showing very obvious antibacterial effects on multidrug resistant bacteria carrying blaNDM-1 gene. Of them, the optimal effects were obtained when combined with penicillins (penicillin G, mezlocillin, piperacillin/ tazobactam, ampicillin/sulbactam), with the antibacterial effects improved by 10 folds. The antibacterial effects of other kinds of antibiotics were improved to some extent. Conclusions QKLIE and combination therapy of QKLI and antibiotics showed better bacteriostatic effects on resistant bacteria carrying blaNDM-1 gene. This study provided theoretical bases for drug development, medication and treatment for super-resistant bacteria carrying blaNDM-1.

Anti-Bacterial Agents ; pharmacology ; Bacteria ; drug effects ; genetics ; Drug Resistance, Multiple, Bacterial ; drug effects ; genetics ; Drug Therapy, Combination ; Drugs, Chinese Herbal ; pharmacology ; beta-Lactamases ; genetics