Role of endogenous opioid peptides in protection of ischemic preconditioning in rat small intestine

This study investigated the protective effects of ischemic preconditioning on intestinal ischemic injury and the role of endogenous opioid peptides (EOP) in these effects. Ischemia-reperfusion (I/R) induced by 30-min of ischemia and 60-min of reperfusion significantly increased the levels of malondialdehyde (MDA) and lactate dehydrogenase (LDH) and resulted in serious intestinal edema (wet weight/dry weight). The ischemic preconditioning (PC) elicited by three 8-min occlusion periods interspersed with 10-min reperfusion markedly attenuated intestinal injury caused by ischemia-reperfusion. Pretreatment with morphine (300 microg x kg(-1), i.v.) 10-min before ischemia and reperfusion mimicked the protection produced by PC. Naloxone (3 mg x kg(-1), i.v.) abolished the protection of morphine-induced preconditioning and ischemic preconditioning in rat intestine. However, there were no changes between naloxone alone and control groups. Treatment with naloxone before ischemia-reperfusion had no effect on animals compared with the I/R group. In addition, we also measured the content of endogenous opioid peptides (Leu-enkephalin) in the effluent which was collected before and during preconditioning. It was shown that the release of leu-enkephalin was markedly increased during preconditioning. These results suggested that EOP might play an important role in PC in rat small intestine.     

Improved molecular diagnosis of dystrophin gene mutations using the multiplex ligation-dependent probe amplification method

Mutation detection in the DMD gene defective in Duchenne (DMD) and Becker muscular dystrophies (BMD) is complicated by the presence of 79 exons. The majority of recognized mutations are, however, copy number changes of individual exons, which traditionally have been identified by three common multiplex polymerase chain reaction (PCR) assays and/or Southern blotting. Here we report the use of the newly developed quantitative assay multiplex ligation-dependent probe amplification (MLPA) to determine the copy number of each of the 79 DMD exons in 182 males and 14 carrier females referred to our diagnostic facility on the clinical suspicion of DMD or BMD. The MLPA method confirmed all previously recognized mutations and identified an additional 28, including four point mutations. Also, the assay reliably identified 7 carrier females, which are usually not easily recognized. In our hands the method is highly reproducible, easy to handle, and has increased our mutation pick-up rate by a total of 33%.     

草原群落退化与恢复演替中的植物个体行为分析

定义植物个体小型化是在草原过度放牧条件下 ,草原植物植株变矮 ,叶片变短、变窄 ,节间缩短 ,以及根系分布浅层化等性状的集合。小型化个体的生态学属性介于环境饰变与生态型之间 ,特称之为扰动响应型。个体小型化逆转过程表现出集体行为 ;小型化个体具有维持其形状的保守性 ,变化的阶段性和突变性 ;小型化的逆过程即正常化过程 ,与演替时间有关。个体小型化是过度放牧下群落生产力衰退的重要表现 ,是对过度放牧的负反馈机制。在草原群落退化演替机理研究中 ,对个体小型化的深入认识是十分重要的环节。     

蝗虫微孢子虫对东亚飞蝗卵黄原蛋白含量的影响

采用免疫学方法,对东亚飞蝗Locusta migratoria manilensis感染蝗虫微孢子虫Nosema locustae后体内卵黄蛋白含量的变化进行了研究。结果表明,感病蝗虫与对照健虫相比,卵黄发生有严重障碍,脂肪体和卵巢中卵黄原蛋白或卵黄蛋白含量极低,导致感病雌虫丧失产卵能力。脂肪体中卵黄原蛋白含量最高峰健虫为18.7 mg/mL,而病虫只有4.7 mg/mL;血淋巴中卵黄原蛋白含量最高峰健虫为7.6 mg/mL,而病虫只有2.6 mg/mL;卵巢中卵黄蛋白含量最高峰健虫为73.4 mg/mL,而病虫只有4.9 mg/mL。     

昆虫乙酰胆碱酯酶基因研究进展

对昆虫乙酰胆碱酯酶（acetylcholinesterase, AChE,EC 3.1.1.7）的基因结构和表达等方面的研究进展进行了综述。分析了昆虫乙酰胆碱酯酶基因的结构,包括10个外显子的特征。对已经报道的昆虫AChE基因进行了系统归纳,并基于已知全序列的昆虫AChE基因,进行了昆虫AChE基因的分子进化分析。对昆虫AChE基因的结构特点及其功能,以及昆虫AChE基因的活性位点、AChE的变构与昆虫抗药性的关系进行了探讨。最后对昆虫AChE基因研究中存在的问题和前景进行了分析和展望。     

Sheets of Vertically Aligned BaTiO3 Nanotubes Reduce Cell Proliferation but Not Viability of NIH-3T3 Cells

All biomaterials initiate a tissue response when implanted in living tissues. Ultimately this reaction causes fibrous encapsulation and hence isolation of the material, leading to failure of the intended therapeutic effect of the implant. There has been extensive bioengineering research aimed at overcoming or delaying the onset of encapsulation. Nanotechnology has the potential to address this problem by virtue of the ability of some nanomaterials to modulate interactions with cells, thereby inducing specific biological responses to implanted foreign materials. To this effect in the present study, we have characterised the growth of fibroblasts on nano-structured sheets constituted by BaTiO₃, a material extensively used in biomedical applications. We found that sheets of vertically aligned BaTiO₃ nanotubes inhibit cell cycle progression - without impairing cell viability - of NIH-3T3 fibroblast cells. We postulate that the 3D organization of the material surface acts by increasing the availability of adhesion sites, promoting cell attachment and inhibition of cell proliferation. This finding could be of relevance for biomedical applications designed to prevent or minimize fibrous encasement by uncontrolled proliferation of fibroblastic cells with loss of material-tissue interface underpinning long-term function of implants.     

Inflammatory Serum Proteins Are Severely Altered in Metastatic Gastric Adenocarcinoma Patients from the Chinese Population

Background

Inflammation is one of the major hallmarks of cancer. This study was designed to profile a panel of inflammatory mediators in gastric adenocarcinoma (GA) and to identify their potential differences separately in metastatic and non-metastatic patient subgroups.

Methods

Serum samples from 216 GA patients and 333 healthy controls from China were analyzed for six proteins using the Luminex multiplex assay.

Results

The serum levels for all the six proteins were significantly elevated in metastatic GA compared to non-metastatic GA. Two acute phase proteins (SAA and CRP) and a CXC chemokine (GRO) were significantly elevated in metastatic GA (p <0.01) but smaller changes were observed in non-metastatic GA compared to healthy controls. OPN is moderately increased in non-metastatic GA (2.05-fold) and more severely elevated in metastatic GA (3.34-fold). Surprisingly, soluble VCAM1 and AGP were significantly lower in both non-metastatic and metastatic GA patients compared to controls. Several individual proteins were shown to possess moderate diagnostic value for non-metastatic GA (AUC = 0.786, 0.833, 0.823 for OPN, sVCAM1 and AGP, respectively) and metastatic GA (AUC = 0.931, 0.720, 0.834 and 0.737 for OPN, sVCAM1, SAA and CRP, respectively). However, protein combinations further improve the diagnostic potential for both non-metastatic GA (best AUC = 0.946) and metastatic GA (best AUC = 0.963). The protein combination with best AUC value for both comparisons is OPN+sVCAM1+AGP+SAA.

Conclusions

These results suggest that several serum proteins are directly related to the severity of gastric cancer. Overall, stronger associations are observed with metastatic than non-metastatic GA as the protein changes are greater with the metastatic status. A combination of these serum proteins may serve as non-invasive markers to assess the severity status and stage of gastric cancer.     

Low Elastin Content of Carotid Plaques Is Associated with Increased Risk of Ipsilateral Stroke

Objectives

Atherosclerotic plaques with a low content of connective tissue proteins are believed to have an increased risk of rupture and to give rise to clinical events. The aim of the present study was to investigate if the content of elastin, collagen and of the matrix metalloproteinase (MMP) −1, −3, −9 and −12 in plaques removed at surgery can be associated with the occurrence of ipsilateral symptoms.

Methods

The atherosclerotic plaques of 221 patients undergoing carotid endarterectomy were analyzed and their composition was related to the incidence of preoperative, intraoperative and postoperative neurological events.

Results

Elastin, collagen and MMP-12 contents were lower in males and diabetic patients. Elastin (P .010), MMP-3 (P .008) and MMP-9 (P < .0001) were lower, while MMP-1 (P .004) and MMP-9 (P .002) were higher in plaques of patients with preoperative symptoms, even after correction for the time between the occurrence of symptoms and surgery. Elastin and MMP-12 decreased (r = −0.17, P .009 and r = −.288, P <.0001 respectively) while MMP-1 (r = 0.17, P .012) and MMP-9 (r = .21 P <.0001) increased with age. After a mean follow-up time of 39.6 ± 16.6 months, 7.7% of patients had suffered one or multiple ipsilateral neurological events. Patients with plaque elastin levels lower than the median (52 mg/g) had increased post-operative incidence of ipsilateral stroke (P for trend 0.009 using Log Rank Chi-square test). This finding was confirmed when controlling for age, gender, hypertension, diabetes, smoking, pre-operative symptoms and statin usage in a Cox Proportional Hazard model (hazard ratio 7.38, 95% C.I. 1.50–36.31).

Conclusions

These observations support the concept that elastin may be important for plaque stability, and suggest that a low plaque content of elastin is associated with a higher risk for ipsilateral stroke.