菌群代谢产物与变态反应性疾病

近几十年来,变态反应性疾病的发病率明显上升。越来越多的研究表明,菌群异常参与变态反应性疾病的发生和发展。人体内约有1 000种细菌定植在肠道内,肠道细菌可以通过消化不同的食物而产生不同的代谢产物,从而影响机体的免疫应答反应,参与包括变态反应性疾病在内的多种免疫性疾病的发展。本文对近年来有关共生菌群的代谢产物参与调控变态反应性疾病的研究进行综述。     

肠道微生态与2型糖尿病关系的研究进展

肠道微生态是影响能量代谢的关键因素,肠道菌群参与机体代谢,其结构功能失调将影响能量平衡、糖脂代谢以及炎症反应等。研究表明,T2DM患者存在肠道菌群中度失衡,是糖代谢紊乱的重要始动因素,调整肠道菌群结构失调已作为药物干预靶点,引起了越来越多学者的关注。本文对肠道微生态变化与T2DM发生发展关系的相关研究及发展趋势进行综述。     

肠道菌群及其代谢物在心血管疾病中的研究进展

肠道菌群及其代谢物在心血管疾病中的研究引起广泛关注。肠道菌群与宿主免疫系统密切相关,通过调节免疫反应和合成生物活性分子等途径参与心血管疾病的发病过程。研究发现,肠道菌群的失衡可能与其发生、发展密切相关,其代谢产物如短链脂肪酸、氨基酸、胆固醇代谢产物等可能在心脏炎症过程中扮演关键角色。本文将对肠道微生物在心血管疾病中的潜在机制、相关性及未来研究方向作一综述,以期提供新的视角。     

氧化三甲胺致动脉粥样硬化作用及其防治的研究进展

氧化三甲胺(TMAO)是由胆碱等物质依赖于肠道菌群代谢生成的产物。近年来,国内外研究发现TMAO在动脉粥样硬化(As)发生、发展过程中起重要作用,TMAO通过介导血管内皮细胞炎症信号和基因的表达、增加血栓形成风险、上调清道夫受体和促进泡沫细胞形成、影响胆固醇转运途径及其代谢通路等方式促进As。本文对近年来相关文献报道进行总结,发现通过控制饮食、调节肠道菌群、抑制三甲胺前体代谢、抑制黄素单加氧酶活性等方式,可以降低血液循环的TMAO水平,阻止As进展。     

食物不耐受和肠易激综合征

食物不耐受是肠易激综合征常见的临床症状之一.其发生机制可能与食物刺激机体肠黏膜并造成肠道微环境紊乱有关.食物抗原、肠道有害菌群等引起肠道黏膜免疫应答,使肠黏膜长期处于低级别炎症状态,造成特异性IgG4抗体产生、肥大细胞浸润及其生物活性介质的释放等,肠内菌群代谢毒素亦可加重肠道神经内分泌功能紊乱;在多因素相互作用下发生肠...     

肠道菌群和缺血性脑卒中的研究进展

肠道菌群作为人的"第二大脑",不仅从免疫、炎症方面影响脑肠轴，而且内分泌、神经、代谢通路等都会调节脑肠轴，从而影响中枢神经系统(CNS)功能如缺血性脑卒中。同时，CNS功能的改变，亦可通过上述作用机制改变肠道菌群的丰度和多态性，影响肠道功能。近年来，越来越多的研究表明，肠道菌群失调可以参与缺血性脑卒中的发生及发展过程，本综述主要就肠道菌群与缺血性脑卒中之间关系的研究进展进行阐述。     

肠道微环境对TH17细胞分化及其功能影响的研究进展

肠道微环境是指肠道微生态环境,由大量微生物菌群组成并参与机体肠道黏膜保护、能量传递及营养代谢等生理机制,微环境发生改变时会引起肠道病理性反应。人体内肠道菌群失调会影响肠道TH17细胞的正常发育、分化及功能,从而使免疫系统的抗病能力降低,导致肠道黏膜损伤及肠道炎症反应。肠道微环境、肠道菌群、肠道TH17细胞与肠道炎症性反应相关因素之间有密切关系,但目前联系并不明确。本文就肠道微环境、肠道菌群、肠道TH17细胞与肠道炎症反应相关因素之间关系作一概述,从而探讨肠道疾病可能的发病机制,为炎症性肠道疾病治疗途径提供新的思路。     

肠道微生态与大肠癌相关性研究专家共识意见

<正>肠道微生物及其代谢产物在人体内发挥生物屏障功能,参与免疫系统成熟和免疫应答的调节,并对维持机体内多种生理代谢起到重要作用。随着国内外研究的深入,人们逐渐发现肠道菌群可能通过多种机制影响大肠癌的发生发展。为进一步揭示肠道微生态与大肠癌相关性的关键或热点问题,为今后的深入研究奠定基础,为部分临床决策提供参考,我们     

肠道菌群和心血管疾病的免疫调节

心血管疾病是人类健康的第一杀手,发病率和死亡率逐年增加。数万亿微生物寄居于人类肠道,在心血管疾病及其相关的代谢、免疫反应中发挥着至关重要的作用。先天性和适应性免疫机制都参与了心血管疾病的发生发展,菌群组分和代谢产物可调节巨噬细胞、淋巴细胞等免疫细胞的分化及功能,并通过循环系统影响机体免疫稳态。本文将通过肠道菌群及其代谢产物与免疫系统的相互作用,讨论肠道菌群与心血管疾病发展之间潜在的免疫机制,为预防和治疗心血管疾病提供新思路。     

抗结核药品对肠道菌群的改变及其对机体的影响

肠道菌群的结构和代谢产物与人体互相作用,维持肠道屏障稳态,促进全身营养代谢与免疫平衡,参与多种系统及组织、器官的病理生理过程,在结核感染、发病、治疗及转归过程中发挥重要作用,但是抗结核药品对肠道菌群的影响研究刚刚起步。作者综述肠道菌群在肠道屏障稳态中的作用,进而梳理和总结抗结核药品对肠道菌群影响的研究成果,并最终扩展至相关临床问题,讨论肠道菌群改变对机体的广泛影响。     

Studies on the mechanism of action of the bipyridine milrinone on the heart

Summary Milrinone is a positive inotropic and vasodilator agent when tested in experimental animals and in human heart-failure patients. It is generally believed that milrinone acts by inhibiting phosphodiesterase IV, thus increasing cyclic AMP, [Ca^{+ +}]_i and cardiac contractile force and relaxation. Maximal force produced by milrinone is greater when single-dose response curves are compared to cumulative dose-response curves. In vitro, milrinone produces a tachyphylaxis, the extent of which is both dose- and time-dependent. Recovery of tachyphylaxis is both dose- and time-dependent and is not influenced by inhibitors of protein or RNA synthesis. There is a specific cross-tachyphylaxis between milrinone and amrinone, theophylline, papaverine, and Bay K8644. This tachyphylaxis may explain the low maximal contractile response of the cumulative dose-response observed in isolated tissues. Milrinone increased cyclic AMP in dog and guinea pig cardiac muscle. As previously shown by Endoh et al. [17], milrinone in low doses produced a biphasic effect on cyclic AMP. The early increase (first 60–70 s) in cyclic AMP shows a good correlation with contractile force changes. If cyclic AMP is determined at maximal contractile force this correlation was poor. Here we also present instances where the increase in cyclic AMP after milrinone (determined at maximal effect) does not correlate with the contractile response. The cross-tachyphylaxis of milrinone with Bay K8644 suggests that milrinone has an action on the sarcolemmal Ca⁺⁺ channels. Bay K8644 suppresses the positive inotropic effect of catecholamines by 50%, but not the cyclic AMP response. The inotropic effect of milrinone, in contrast to norepinephrine is highly sensitive to [Ca⁺⁺]₀, stimulation rate, and [K⁺]₀. In this respect milrinone behaves more like Bay K8644. We postulate that the main inotropic action of milrinone is due to a sarcolemmal effect. The early cyclic AMP production described could be in the sarcolemmal compartment and this may explain some of the similarities of milrinone’s actions with those of Bay K8644. The tachyphylaxis observed with the inotropic effect of milrinone does not extend to the decreases in relaxation time. This and other findings to be discussed suggest that the positive inotropic and reduction in relaxation time by milrinone depend on different mechanisms, possibly through differential compartmentalization of cyclic AMP.     

锌对心肌保护作用机理的探讨

应用电镜、电子示踪技术和立体计量测试法，从形态学上观察异丙基肾上腺素对心肌膜系统的影响及锌的保护作用，同时应用标准玻璃微电极技术和微机实时分析方法，研究异丙基肾上腺素致心肌损伤及锌对心肌保护作用的机理。实验结果表明：异丙基肾上腺素可引起心肌细胞膜系统损伤，此时心肌细胞的去极化和复极化过程均发生改变；经锌前处理后，心肌损伤程度明显减轻，心肌细胞的复极化过程得到明显改善。锌对心肌的保护作用，主要是通过阻断心肌细胞膜慢通道、减少平台期钙离子内流、防止细胞内钙超载来实现。     

Study on the Compression Effect of Clothing on the Physiological Response of the Athlete

The study aimed to analyze whether the high compression of unique, tight-fitting sportswear influences the clothing physiology comfort of the athlete. Three specific sportswear with different compression were tested on four subjects while they were running on a treadmill with increasing intensity. The compression effect of the sportswear on the body of the test persons, the temperature distribution of the subjects, and the intensity of their perspiration during running were determined. The results indicate that the compression effect exerted by the garments significantly influences the clothing physiology comfort of the athlete; a higher compression load leads to more intense sweating and higher skin temperature.     

丙硫咪唑对囊尾蚴糖原作用的观察

猪囊尾蚴于体外经驱虫药丙硫味唑在0,20,50,100μg/ml和96小时作用后,进行了组织化学观察。对照组囊尾蚴的糖原分布在头颈部和外囊壁上,颈部区糖原分布较均匀,外囊壁糖原较多。实验各组头颈部糖原均有减少,而外囊壁糖原无显著变化。     

Comments on the effect of variations in the size of the heart on the magnitude of ECG potentials

Utilizing a mathematical model of the inhomogeneous torso, the effect of variations in the size of the heart on the amplitude of the surface potential is studied. The results show that incases of congestive heart failure, low potentials may result in spite of the cardiomegaly. This can be explained by the increased lung conductivity due to edema.