Spironolactone Regulates HCN Protein Expression Through Micro-RNA-1 in Rats With Myocardial Infarction.

Emerging evidence has shown that aldosterone blockers reduced the incidence of ventricular arrhythmias in patients with myocardial infarction (MI). However, the mechanism remains unknown. In this study, we investigated the mechanism by which spironolactone, a classic aldosterone blocker, regulates hyperpolarization-activated cyclic nucleotide-gated channel (HCN) protein expression in ischemic rat myocardium after MI. Eighteen rats surviving 24 hours after MI were randomly assigned into 3 groups: MI, spironolactone, and spironolactone + antagomir-1. Six sham-operated rats had a suture loosely tied around the left coronary artery, without ligation. The border zone of the myocardial infarct was collected from each rat at 1 week after MI. HCN2 and HCN4 protein and messenger RNA (mRNA) level were measured in addition to miRNA-1 levels. Spironolactone significantly increased miRNA-1 levels and downregulated HCN2 and HCN4 protein and mRNA levels. miRNA-1 suppression with antagomir-1 increased HCN2 and HCN4 protein levels; however, HCN2 and HCN4 mRNA levels were not affected. These results suggested that spironolactone could increase miRNA-1 expression in ischemic rat myocardium after MI and that the upregulation of miRNA-1 expression partially contributed to the posttranscriptional repression of HCN protein expression, which may contribute to the effect of spironolactone to reduce the incidence of MI-associated ventricular arrhythmias.

[Methods for the assessment of organic compounds biodegradability: A review].

There are plenty of methods used for the assessment of organic compounds biodegradability, but lack of comprehensive literatures in systematically introducing the assessment methods and guiding the choice of the methods. This paper briefly introduced the indicative parameters in assessing organic compounds biodegradability and the assessment methods of aerobic and anaerobic biodegradation, with the focus on the principles and criteria in the choice of the assessment methods, and analyzed in detail the reasons for the differences in the biodegradation rates of organic compounds when different test methods were adopted. Taking the standards established by the Organization for Economic Co-operation and Development (OECD) as an example, the process of choosing and applying the assessment methods was introduced, the systematic method-choosing route was integrated, and the advantages of the OECD standard methods were pointed out.

[Environmental behavior and ecological effect of polydimethylsiloxane: a review].

Polydimethylsiloxane (PDMS) is widely used in industrial products, medical and health care products, and personal care products. In the treatment process of sewage, PDMS can be hardly biodegraded but enter the environment mainly through the discharge of excess sludge, and only a small amount of PDMS adsorbed on the suspended solids or sludge particle surface is discharged into water body and sediment with treated sewage. There is no enough evidence to verify that PDMS can vertically migrate in sediment. The degradation of PDMS in sediment is very slow, but PDMS can be degraded in different types of soils. PDMS has less risk to aquatic ecosystem, and no apparent acute toxicity to benthos. In soil environment, PDMS and its degradation products have no significant effects on the soil microorganisms, soil animals, and crops. Though a few studies indicated that PDMS and its degradation products have relatively low ecological toxicity in various environments, it is still very important to clarify the potential threat of PDMS to the environment because of the increasingly large number of PDMS being produced and used.

Effects of auricular acupuncture on the memory and the expression of ChAT and GFAP in model rats with Alzheimer's disease / 中国针灸

<p><b>OBJECTIVE</b>To observe the effects of auricular acupuncture on the learning and memory abilities of model rats with Alzheimer's disease (AD), and investigate its mechanism.</p><p><b>METHODS</b>Thirty SD rats were randomly divided into a control group, a model group and an auricular acupuncture group, 10 rats in each group. The model rats with AD were established by multiple injections with Okadaic Acid into the CA1 region of hippocampus. In the control group, the same quantity injection with Dimethyl Sulfoxide (DMSO) was applied on experimental rats. The auricular acupoints of "Nao" (brain) and "Shen" (kidney) were used for treating in the auricular acupuncture group, in contrast, the auricular region were not treated in the model and the control groups. The learning and memory capabilities of the rats were assessed with Morris Water Maze behavioral test, and the expressions of choline acetyltransferase (ChAT) and glial fibrillary acidic protein (GFAP) were examined by immunohistochemistry.</p><p><b>RESULTS</b>Comparing with the model group, the treated AD rats with auricular acupuncture was showed that the average escape latency was obviously shortened in the place navigation test (P<0.01), the movement time in plateform quadrant was obviously prolonged in the spatial probe test (P<0.05), and the number of traversing platform obviously increased (P<0.01) after the platform was taken away. The expression of ChAT increased in the hippocampus and cortex (P<0.01, P<0.05), but the expression of GFAP obviously decreased in the CA1 region of hippocampus (P<0.01).</p><p><b>CONCLUSION</b>Auricular acupuncture can improve the learning and memory capability of the model rats with AD. Its mechanism might be related with decreasing cholinergic neuron damage and reducing the abnormal activation and hyperplasia of astrocyte.</p>

[Relative factors of recent discovered atrial fibrillation following isolated coronary artery bypass grafting].

OBJECTIVE: To identify the relative factors of recent discovered atrial fibrillation (AF) following isolated coronary artery bypass grafting (CABG). METHODS: Classified the 649 cases undergoing isolated CABG from January 2005 to December 2006 to two groups according to whether AF appeared after operation. Collected the peri-operative data and operative strategy, then analyzed with single-factor analysis and Logistic regression. RESULTS: The incidence of AF was 8.0% (52 cases), and 84.6% (44 cases) recovered sinus-rhythm leaving hospital. Age, standard European system for cardiac operative risk evaluation (EuroSCORE), ratio of high-operative-risk, left atrium diameter and ratio of left coronary artery dominance were higher in AF group than in non-AF group. Age, eject fraction, left atrium diameter, operative risk evaluation, left coronary artery dominance and anastomosis on right coronary artery were the relative factors of recent discovered AF following isolated CABG. But off-pump operation, prescription of adrenergic beta-antagonists pre-operatively and degree of coronary artery stenosis had no influence to AF. CONCLUSIONS: AF following CABG is a result of common influence by many factors. EuroSCORE might forecast partially the incidence of AF following CABG. Improve the myocardial protection and reduce the surgical damage during operative progress maybe the mostly approach to decrease the incidence of AF following CABG.