糖尿病心肌病相关信号通路的研究进展

糖尿病心肌病是一种独立、特异的心肌病,与糖尿病患者发生心力衰竭和死亡率升高密切相关。其病理表现为心肌肥厚和心肌纤维化,发病机制复杂,可能涉及心肌细胞代谢障碍、心肌微血管病变、自主神经病变、胰岛素抵抗及细胞因子异常等多个方面。本文综述了糖尿病心肌病发病机制中研究较多的几条信号通路,为糖尿病心肌病的治疗提供理论依据。     

胰岛素抵抗与糖尿病脑病

胰岛素抵抗(insulin resistance,IR)指胰岛素分泌量在正常水平时刺激靶细胞对葡萄糖的利用率减弱,或维持正常生理效应时需超常量的胰岛素,其主要机制是胰岛素信号通路敏感性下降。糖尿病脑病(diabetic encephalopathy,DE)是由糖尿病引起的认知功能障碍和大脑神经生理及结构的改变,目前认为胰岛素抵抗在糖尿病脑病的发生发展中起重要作用,本文从IR与DE的关系以及IR在DE中的主要作用机制作一综述.     

口服降糖药和胰岛素对不同临床分期糖尿病视网膜病变病情进程的影响

目的:探讨降糖药物和胰岛素控制血糖对不同临床分期糖尿病视网膜病变进程的影响。方法:收集糖尿病伴有视网膜病变的患者78例。采用随机表法,将糖尿病视网膜病变患者分为药物控制血糖组和胰岛素控制组,药物治疗组38例,胰岛素治疗组40例,使血糖达到控制标准。评价干预前后患者血清C肽、糖化血红蛋白、胰岛素抵抗指数,以及糖尿病视网膜病变分级。结果:药物控制组治疗前后2 h CP、以及糖化血红蛋白测定差异无统计学意义(p0.05)。胰岛素组治疗前后,血清空腹C肽、2 h CP差异有统计学意义(p0.05);而糖化血红蛋白、胰岛素抵抗指数差异无统计学意义(p0.05)。药物组治疗前Ⅰ期、Ⅱ期、Ⅲ期、Ⅳ期、Ⅴ期、Ⅵ期病例数和治疗后相比,差异有统计学意义(p0.05),视网膜病变分级程度明显增高。胰岛素组治疗前Ⅰ期、Ⅱ期、Ⅲ期、Ⅳ期、Ⅴ期、Ⅵ期病例数和治疗后相比,差异有统计学意义(p0.05)。药物组和胰岛素组间视网膜病变分级差异无统计学意义(p0.05);治疗后差异有统计学意义(p0.05)。结论:胰岛素能够提高糖尿病患者血清C肽,降低胰岛素抵抗,和药物控制血糖相比,能够延缓糖尿病视网膜病变的进展。     

肥胖诱发胰岛素抵抗的炎性机制

肥胖可诱发一系列慢性代谢性疾病,如2型糖尿病、血脂障碍、高血压和非酒精性脂肪肝等.这些疾病构成了当今世界人类健康的极大威胁.胰岛素抵抗是这些疾病的共有特征.胰岛素抵抗的发生与慢性低度系统炎性密切相关,涉及多条炎性信号通路的激活和胰岛素信号转导的缺陷.本文综述了肥胖、炎性与胰岛素抵抗之间的本质联系,以及肥胖诱发胰岛素抵抗的炎性机制,以期为肥胖相关疾病的防治提供重要参考.     

维生素D与二型糖尿病预防的研究进展

二型糖尿病是一种危害人类健康的疾病.维生素D与二型糖尿病之间的关系为糖尿病研究的热点,越来越多的研究表明维生素D可以有效的预防二型糖尿病.本文从观察性研究、干预性研究及遗传学研究三个方面综述了维生素D与二型糖尿病之间的关系,并从维生素D对胰腺β细胞的作用、对胰岛素抵抗的作用及其对炎症反应的影响三个方面阐述了其可能的机制.     

砷引发糖尿病的研究进展

糖尿病是早已被人们认识的一种内分泌疾病,分为Ⅰ型糖尿病和Ⅱ型糖尿病.它除糖代谢紊乱外,还与遗传因素,环境因素,应激因素有关.近年来研究发现糖尿病的发病原因与环境中的砷密切相关,尤其2型糖尿病,2型糖尿病是一种缓慢进展性疾病,其发病中心环节是胰岛素抵抗和胰岛β细胞功能缺陷,尤其是胰岛素分泌第一时相的损害.砷是毒性很强的类金属元素,现已明确,砷会严重影响胰岛素的分泌以及胰岛素在周围靶器官的利用,从而诱发胰岛素抵抗.因此砷是2型糖尿病重要的危险因子之一,本文就砷元素与糖尿病的关系以及可能的机理作一综述.     

糖皮质激素与脂肪代谢和胰岛素抵抗

内源性和外源性糖皮质激素过多会导致胰岛素抵抗和发展为糖尿病.糖皮质激素增加循环中葡萄糖、胰岛素和游离脂肪酸(FFA)浓度.循环中FFA增高与肥胖、胰岛素抵抗和2型糖尿病密切相关,其主要来源于脂肪细胞内甘油三酯水解.糖皮质激素刺激脂肪分解、增加FFA构成了激素导致胰岛素抵抗的重要机制之一.     

维生素D缺乏诱发糖尿病的机制

维生素D缺乏/不足近年来在全世界各年龄段人群中都非常普遍。维生素D在糖尿病发展过程中发挥着非常重要的作用。1型糖尿病患者常常具有骨健康风险,这与维生素D代谢异常关系密切。糖尿病患者并发维生素D缺乏的机制是多样的,涉及到内分泌紊乱引起的维生素D合成减少、炎症细胞因子影响、微血管病相关血流量减少等。2型糖尿病患者通常主要会出现胰岛B细胞功能、胰岛素敏感性、以及系统性的炎症反应三方面的缺陷。维生素D对胰岛素分泌有直接和间接的影响。胰岛素抵抗会引起肠激素抵抗,氧化应激,胰岛B细胞功能失调,以及基因和行为因素,都会促进肥胖个体中糖尿病发展。补充维生素D可能有利于改善胰岛素敏感性,有助于糖尿病的治疗。     

新型脂肪因子网膜素-1抗炎作用的研究进展

新型脂肪因子网膜素具有抗炎作用,网膜素-1是3个亚型中的主要亚型,其水平与身体质量指数和胰岛素抵抗指数等呈负相关,与脂联素呈正相关。肥胖、糖耐量受损和2型糖尿病患者血清网膜素-1水平显著降低,这被减肥、有氧训练及抗糖尿病药物反转。网膜素-1抑制炎症性肠病和类风湿性关节炎等的炎症反应,这与JNK和NF-κB信号通路相关。本文就网膜素的分子生物学特征、抗炎作用以及与肥胖、胰岛素抵抗和2型糖尿病的关系予以简要概述。     

Chemerin及ChemR23与糖尿病大血管病变

Chemerin是2007年新确认的一种脂肪因子,其主要功能受体为ChemR23。近期研究发现chemerin可能是联系肥胖、糖尿病及动脉粥样硬化的潜在因子,有望为糖尿病及其血管并发症的预防及治疗提供新的靶点。然而,chemerin及其受体ChemR23参与糖尿病及其大血管病变的具体机制尚不明确。本文将就目前研究中chemerin及其受体ChemR23与糖尿病及其大血管病变的关系作一综述,并从免疫及炎症反应、氧化应激、自噬、糖脂代谢和胰岛素抵抗等方面,分析chemerin分别对巨噬细胞、血管内皮细胞、脂肪细胞及骨骼肌细胞的影响,从而进一步阐述chemerin及其受体ChemR23参与糖尿病及其大血管病变的具体生物学机制。     

白蚁与动物及微生物的共生类型及其机制

综述了白蚁螱客的主要种类、共生关系及相关机制的研究进展。白蚁螱客中,已报道的动物种类达170种。在与动物的共生关系中存在偏利共生（宾主共栖和异种共栖）、互利共生和无关共生三种;在与微生物的共生关系中,存在与内生菌（原生动物、细菌、真菌和放线菌）和外生菌（蚁巢伞菌等）间的互利关系。指出了白蚁与螱客研究中存在的问题,给出了解决方案,并提出了今后可能的研究热点或方向,为白蚁的综合利用（如纤维素酶）及今后研究物种间的协同进化提供了基础资料。     

New amino-dithiaphospholanes and phosphoramidodithioites and their rhodium and iridium complexes

New sulfur derivatives of phosphoramidite ligands were synthesized and the impact of the sulfur unit on the spectroscopic properties of their rhodium and iridium complexes was investigated. The new ligands Bn₂NPSCH₂CH₂S^a(P-S^a) (Bn = benzyl, 4), Bn₂NPSCHCHS^a(CH₂)₃C^aH₂(P-S^a)(C^a-S^a) (6) and Bn₂NP(4-XC₆H₄OMe)₂ (X = S, 7a; X = O, 7b) were converted to the rhodium and iridium complexes trans-[Rh(CO)Cl(L)₂] (L = 4, 6, 7), [RhCl(COD)(L)] (L = 4, 6, 7), [IrCl(COD)(7a)] and [IrCl₂Cp∗(6)]. For comparison, some phosphoramidite complexes of these formulations also were synthesized. The new metal complexes were spectroscopically analyzed. For the carbonyl complexes, the ν_CO IR stretching frequencies were lower than for the corresponding phosphite and phosphoramidite ligands. The ¹J_PRh coupling constants for the rhodium complexes with the new ligands were also smaller than for the respective phosphoramidite and phosphite complexes. Finally, the ¹J_PSe coupling constants of the selenides of the new ligands were lower than those of the phosphoramidite ligands but higher than for PPh₃. The spectroscopic data reveal that the new thio ligands 4, 6 and 7a are more electron donating than phosphites and phosphoramidites but less electron donating than PPh₃.     

Astrocytes and Synaptosomes Transport and Metabolize Lactate and Acetate Differently

Astrocytes transport the monocarboxylate acetate, but synaptosomes do not. The reason for this is unknown, because both preparations express monocarboxylate transporters (MCT). The transport and metabolism of lactate, another monocarboxylate, was examined in these two preparations, and the results were compared to those for acetate. Lactate transport is more rapid in astrocytes than in synaptosomes, but of lower affinity (Kms of 17 and 4 mM, respectively). Lactate (0.2 mM) is metabolized to CO2 more rapidly in synaptosomes than in astrocytes (rates of 0.37 and 0.07 nmol x mg protein(-1) x min(-1), respectively). The reason for this is unclear, but cellular differences in lactate dehydrogenase isotype expression may be involved. Acetate is metabolized to CO2 more rapidly in astrocytes than in synaptosomes (rates of 0.43 and 0.02 nmol x mg protein(-1) x min(-1), respectively). This is likely due to cellular differences in the expression of monocarboxylate transporter subtypes.     

Rapporteur report: Basics and technology and metrology and standards

The first and second sessions of the Workshop focussed on the basics of ultrasound and infrasound, their applications in both industry and medicine, and metrology and protection standards for ultrasound applications.     

Relative and combined effects of ethanol and protein deficiency on strontium and barium bone content and fecal and urinary excretion

To elucidate accumulation of minerals in human iliac arteries with aging, the content of minerals was analyzed by inductively coupled plasma atomic emission spectrometry. Bilateral common, internal, and external iliac arteries of 16 men and 8 women, ranging ages from 65 to 93 yr, were examined. It was found that an extremely high accumulation of calcium and phosphorus occurred in the common iliac artery at old age, being higher than that of the internal and external iliac arteries. It should be noted that the accumulation of calcium and phosphorus is the highest in the common iliac artery among the human arteries examined to date. Regarding sexual differences, the content of calcium and phosphorus in the common and internal iliac arteries was higher in women than in men, whereas their content in the external iliac artery was lower in women than in men.     

Chemokines and cytokines: axis and allies in asthma and allergy

Allergic asthma can be precipitated by many factors. For the atopic person, fungus, pollen, dust mites, cockroach antigens, and diesel exhaust are all agents that may trigger an allergic attack. Cytokines and chemokines are integral mediators of fungal asthma. From the earliest time points, they recruit and activate the cells required for the clearance of fungus as well as being critical factors involved in the immunopathology of this disease. In the final analysis, it is clear that these mediators can act to the benefit or the detriment of the host.     

人血管能抑素基因的克隆、表达及其表达产物的纯化和生物活性测定

以人胎盘脐带组织为材料,提取组织总RNA,用netRTPCR方法合成人血管能抑素cDNA基因,将该cDNA克隆进pSP72载体获得重组质粒pSP72C, DNA序列分析结果与预期序列一致。用BamHⅠ和NdeⅠ双酶切,切下pSP72C上的血管能抑素cDNA,插入pET3c载体的相应位点获得重组表达质粒pETC, 转化E. coli BL21(DE3), SDSPAGE分析显示：在IPTG诱导下,血管能抑素基因获得了高效表达,表达量约占菌体总蛋白的 27.9 %,主要以包涵体形式存在。包涵体经过洗涤、裂解、蛋白复性以及Sephadex G75凝胶过滤层析等步骤后,获得了纯度达91.4 %的人血管能抑素。CAM实验证明10 μg纯化蛋白就能显著抑制鸡胚新生血管生成。     

Oxidation and nitration of ribonuclease and lysozyme by peroxynitrite and myeloperoxidase

In spite of the many studies on protein modifications by reactive species, knowledge about the products resulting from the oxidation of protein-aromatic residues, including protein-derived radicals and their stable products, remains limited. Here, we compared the oxidative modifications promoted by peroxynitrite and myeloperoxidase/hydrogen peroxide/nitrite in two model proteins, ribonuclease (6Tyr) and lysozyme (3Tyr/6Trp). The formation of protein-derived radicals and products was higher at pH 5.4 and 7.4 for myeloperoxidase and peroxynitrite, respectively. The main product was 3-nitro-Tyr for both proteins and oxidants. Lysozyme rendered similar yields of nitro-Trp, particularly when oxidized by peroxynitrite. Hydroxylated and dimerized products of Trp and Tyr were also produced, but in lower yields. Localization of the main modified residues indicates that peroxynitrite decomposes to radicals within the proteins behaving less specifically than myeloperoxidase. Nitrogen dioxide is emphasized as an important protein modifier.