肠道微生态与支气管哮喘发生发展相关性的研究进展

近年来,随着对微生物生态学的理解,人们逐渐认识到微生物群落在维持人类健康方面有着重要作用。肠道为人体中最大的微生物群提供环境,当肠道微生态失衡时,不仅对肠道系统产生影响,也会影响其他器官。研究表明,在支气管哮喘的进展过程中,肠道微生物群对疾病有一定影响。本文通过对人体微生态学的研究进展、肠道微生态与支气管哮喘发病机制及肠道微生态与支气管哮喘发展的关系进行综述,旨在为支气管哮喘的预防和治疗方向提供新思路。     

感染性腹泻的微生态疗法

0 引言从微生态学观点来说,胃肠道受到外界因素的影响导致内部的微生态失调将导致腹泻.对于感染性腹泻的防治,目前仍以抗生素治疗为主.但应用抗生素治疗的弊端已愈来愈引起人们的重视,微生态制剂的兴起是治疗感染性腹泻的又一重要手段,它具有调节肠道菌群失调及改善肠道生态环境的作用,对急、慢性腹泻和抗生素引起的肠道菌群失调有良好的预防和治疗作用.微生态防治的本质是以扶植正常菌群,拮抗致病或条件致病菌,调整和恢复微生态平衡为日的的一种预防和治疗方法.1 肠道的微生态平衡正常情况下,由正常微生物群、宿主和外环境构成的生态系统是相互平衡的.从出生到死亡人体与正常菌群之间保持着和谐的共生关系.新生儿刚出生时肠道是无菌的,出生后2h 左右开     

肠道微生态变化与非酒精性脂肪性肝病研究进展

由定植于肠道的大量固有菌群、肠道上皮细胞及肠道局部粘膜免疫系统组成了肠道微生态系统。"肝-肠轴"概念的提出为从肠道微生态角度寻找非酒精性脂肪性肝病(NAFLD)的诊疗措施提供了依据。肠道微生态失衡所致的肠道菌群过度生长、肠黏膜通透性改变、免疫功能紊乱、肠源性内毒素血症、效应细胞激活及炎症因子生成等在NAFLD发生发展中发挥了不容忽视的作用。深入研究肠道菌群与NAFLD之间的关系将为NAFLD的预防和治疗提供新靶点。     

下呼吸道微生态在支气管哮喘中的研究进展

随着二代测序的不断发展,过去人们认为无菌的下呼吸道现已被证实有多种不同的微生物群落定植.同时,越来越多的研究也证明,微生态在宿主免疫系统的发生发展中起着重要的作用.呼吸道微生态紊乱可能与多种呼吸道疾病密切相关,包括肺结核、COPD及支气管哮喘(简称哮喘)等.该研究主要回顾了近年来对哮喘患者及健康人群呼吸道微生态的研究,探讨在哮喘患者中呼吸道菌群定植的改变趋势,以及呼吸道微生态的改变与哮喘发病机制之间的关系,并且对呼吸道微生态在哮喘治疗中的研究进展进行讨论.     

肠道菌群微环境与结直肠癌的关系研究进展

肠道菌群是目前研究的热点领域,现有的研究结果提示:肠道菌群可能与代谢性疾病、免疫性疾病、神经系统疾病、认知与行为失常、癌症等多种疾病相关.本文检索和分析了近10余年来有关肠道菌群及其微环境与结直肠癌(colorectal cancer,CRC)关系的研究成果,从肠道菌群及其微环境与CRC的定义、健康与CRC状态下的肠道菌群构成、肠道菌群的失调方式、肠道菌群微环境与CRC的相关性、肠道菌群微环境与CRC的病理生理机制等5个方面进行了综述,期望能够为揭示肠道菌群微环境在CRC的发生与发展病理机制中的作用,以及以肠道菌群微环境为靶向的、新的CRC预防和治疗手段的研发提供思路和线索.     

食物过敏与肠道菌群的研究进展

食物过敏(food allergy,FA)是指机体针对摄入的食物蛋白产生的一种有害的免疫反应.2007年疾病预防与控制中心(CDC)数据显示,年龄在18岁以下儿童发生食物过敏者超过3百万(3.9%),5岁以下发病率更高.本文阐述了健康的肠道菌群对促使免疫系统成熟有非常重要的作用,食物过敏与非过敏婴儿间肠道菌群组成确实不同.儿童食物过敏与肠道黏膜屏障的破坏、黏膜屏障成分的发育不成熟、肠道菌群失调、肠道菌群紊乱密切相关.益生菌(probiotics)作为肠道微生态的平衡者和肠黏膜免疫系统调节者,对防治过敏性疾病的发生可能具有适度的作用,但需要更进一步的、更多的大样本随机对照临床研究.     

肠道微生态失衡与非酒精性脂肪性肝病的关系

肠道微生态系统由定植于肠道的固有菌群、肠上皮细胞、肠黏膜免疫系统组成。非酒精性脂肪性肝病(NAFLD)是一种与胰岛素抵抗和遗传易感性相关的代谢应激性肝损伤。近年来关于肠道微生态与NAFLD发病机制关系的研究越来越多。肠道微生态失衡导致的肠道菌群过度生长、肠黏膜通透性增加、肠源性内毒素血症、炎症因子产生等在NAFLD的发生发展过程中扮演着重要的角色。深入研究肠道微生态失衡与NAFLD的关系将有助于为NAFLD的治疗及预防提供新方向。     

非酒精性脂肪性肝病肠道菌群的研究进展

非酒精性脂肪性肝病发病率不断升高且起病年龄渐趋低龄化,其发病机制至今尚未明确。在众多致病因素中,肠道菌群的改变与非酒精性脂肪性肝病的发病及进展密切相关。归纳了肠道菌群在非酒精性脂肪性肝病发生及发展中的作用机制,以及通过调节肠道菌群治疗非酒精性脂肪性肝病的方式。可见通过调节肠道菌群,恢复肠道微生态平衡,对延缓乃至阻止非酒精性脂肪性肝病的进展可能有重要的作用,成为预防及治疗该病的新方法。     

蠕虫及其来源分子对螨性哮喘免疫调控的研究进展

随着人们生活卫生水平的提高，我国寄生蠕虫的感染率显著下降，逐渐进入后寄生虫时代。但是与此同时，螨性哮喘的发病率逐年上升，造成了重大的社会经济负担。越来越多的证据表明，蠕虫感染与过敏性疾病之间存在一定的联系。本文对蠕虫及其来源分子对螨性哮喘免疫调控的研究进行综述，包括对抗原递呈细胞、B细胞、T细胞的免疫应答和细胞因子释放的直接调节作用以及蠕虫通过肠道微生物菌群的间接调节作用，为螨性哮喘的治疗提供新的思路与方向。     

艰难梭菌感染与肠道微生态的研究进展

肠道微生态包括肠道微生物及其代谢产物。肠道微生物群分布广、种类多、数量大,在人体作用机制复杂,随着生物学研究技术及分析方法的发展和应用,人们对肠道微生态的认识逐步加深。艰难梭菌感染(Clostridium difficile infection, CDI)与肠道菌群失调密切相关,互为因果,艰难梭菌感染亟待解决。本文就艰难梭菌感染的发病机制、高危因素、治疗及其与肠道微生态的相关内容研究进展进行综述,以期增加对肠道菌群与艰难梭菌的认识,提高临床诊治和预防CDI的能力。     

胰岛素瘤的解剖分布特点分析

目的胰岛素瘤是最常见的胰腺神经内分泌肿瘤，因其临床表现多样，导致诊断困难。影像学诊断尤其是超声内镜(EUS)在胰岛素瘤的诊断中起着重要作用，拥有较高的敏感性和特异性。本研究拟通过明确胰岛素瘤的解剖分布特点，以期有助于提高影像学的诊断准确率和降低漏诊率，尤其是在教育和培训实践中对于EUS的学习者更具有指导价值。 方法回顾性分析解放军总医院第一医学中心病案资料数据库1993年1月至2019年11月经外科手术、病理确诊为胰岛素瘤的患者的临床资料，检索方法采取搜索术后病理诊断为"胰岛素瘤"的病例，通过查阅病例的方法，提取出胰岛素瘤的大小和解剖分布等数据，进一步分析其特点。 结果共检索到确诊为胰岛素瘤的患者116例，其中，男45例、女71例，年龄13～76岁，平均年龄(44.4±14.85)岁。胰岛素瘤单发110例(94.8%)、多发6例(5.2%)。位置分布：头颈部46例(39.7%)，单发45例、多发1例；体尾部68例(58.6%)，单发65例、多发3例；全胰腺多发2例(1.7%)。病变大小特点：最大径0.4～3.4 cm，平均大小(1.53±0.58)cm。≤1 cm 29例、>1 cm而≤1.5 cm41例、>1.5 cm而≤2.0 cm28例，≤3 cm 15例，>3 cm 3例。年龄与肿瘤的大小相关，≤44岁患者肿瘤平均大小为(1.36±0.51)cm、>44岁患者肿瘤平均大小为(1.70±0.60)cm，P<0.05。头颈部的肿瘤大于体尾部的肿瘤，头颈部肿瘤平均大小(1.66±0.63)cm，体尾部(1.42±0.52)cm，P<0.05。 结论胰岛素瘤在胰腺体尾部较头颈部更好发；绝大多数单发，但可以全胰腺多发；多数小于1.5 cm，肿瘤的大小与患者年龄和肿瘤的解剖分布相关。     

Pathogenesis of carcinoma of the papilla of Vater

Most adenomas and carcinomas of the small intestine and extrahepatic bile ducts arise in the region of the papilla of Vater. In familial adenomatous polyposis (FAP) it is the main location for carcinomas after proctocolectomy. In many cases symptoms due to stenosis lead to diagnosis at an early tumor stage. In about 80%, curative intended resection is possible. Operability is the most relevant prognostic factor. Most ampullary carcinomas resp. carcinomas of the papilla of Vater develop from adenomatous or flat dysplastic precursor lesions. They can be sited in the ampulloduodenal part of the papilla of Vater, which is lined by intestinal mucosa. They also can develop in deeper parts of the ampulla, which are lined by pancreaticobiliary duct mucosa. Intestinal-type adenocarcinoma and pancreaticobiliary-type adenocarcinoma represent the main histological types of ampullary carcinoma. Furthermore, there exist unusual types and undifferentiated carcinomas. Many carcinomas of intestinal type express the immunohistochemical marker profile of intestinal mucosa (keratin 7?, keratin 20+, MUC2+). Carcinomas of pancreaticobiliary type usually show the immunohistochemical profile of pancreaticobiliary duct mucosa (keratin 7+, keratin 20?, MUC2?). Even poorly differentiated carcinomas, as well as unusual histological types, may conserve the marker profile of the mucosa they developed from. These findings underline the concept of histogenetically different carcinomas of the papilla of Vater which develop either from intestinal- or from pancreaticobiliary-type mucosa of the papilla of Vater. Molecular alterations in ampullary carcinomas are similar to those of colorectal as well as pancreatic carcinomas, although they appear at different frequencies. In future studies, molecular alterations in ampullary carcinomas should be correlated closely with the different histologic tumor types. Consequently, the histologic classification should reflect the histogenesis of ampullary tumors from the two different types of papillary mucosa.     

Demonstration of the mechanism of action of biguanides

Summary Palmitic acid oxidation in rat diaphragm homogenate is depressed by biguanide concentrations that are still incapable of inhibiting oxidative phosphorylation. Glucose oxidation is not directly effected by the same biguanide concentrations: however, the inhibitory effect of palmitic acid on glucose oxidation is partly removed by biguanides. Inhibition of fatty acid oxidation, which accounts for most of the metabolic effects caused by these drugs, can be regarded as the fundamental mechanism of action of biguanides. There is some evidence suggesting that these drugs might interact with carnitine, thus preventing long-chain fatty acids from being transported across the mitochondrial membrane to the site of oxidation. Traduzione a cura degli AA.     

Lack of correlation of degree of villous atrophy with severity of clinical presentation of coeliac disease

BACKGROUND AND AIM: Both the clinical presentation and the degree of mucosal damage in coeliac disease vary greatly. In view of conflicting information as to whether the mode of presentation correlates with the degree of villous atrophy, we reviewed a large cohort of patients with coeliac disease. PATIENTS AND METHODS: We correlated mode of presentation (classical, diarrhoea predominant or atypical/silent) with histology of duodenal biopsies and examined their trends over time. RESULTS: The cohort consisted of 499 adults, mean age 44.1 years, 68% females. The majority had silent coeliac disease (56%) and total villous atrophy (65%). There was no correlation of mode of presentation with the degree of villous atrophy (p=0.25). Sixty-eight percent of females and 58% of males had a severe villous atrophy (p=0.052). There was a significant trend over time for a greater proportion of patients presenting as atypical/silent coeliac disease and having partial villous atrophy, though the majority still had total villous atrophy. CONCLUSIONS: Among our patients the degree of villous atrophy in duodenal biopsies did not correlate with the mode of presentation, indicating that factors other than the degree of villous atrophy must account for diarrhoea in coeliac disease.     

血吸虫童虫生长发育及其机制的研究进展

血吸虫童虫是宿主免疫系统攻击的重要靶标,包括皮肤型、肺型和肝门型童虫。宿主分子对童虫生长发育具有重要作用。童虫生长发育机制包括免疫调节、信号转导、性别发育及凋亡等。肌动蛋白、组织蛋白酶、烯醇化酶和葡萄糖基转移酶等分子为血吸虫童虫生长发育的重要分子。本文对血吸虫童虫生长发育及其机制的研究进展做一综述。     

124例耐多药结核分枝杆菌基因突变特征分析

目的对临床分离的耐多药结核分枝杆菌相关基因的突变特征进行分析。方法对124例耐多药结核分枝杆菌以及50株敏感株的耐药相关基因(包括异烟肼inh A、kat G、oxyR-ahp C间隔区以及利福平rpo B)进行序列测定,分析其基因突变情况。结果异烟肼耐药inh A基因突变率为14.5%;kat G基因突变率为70.2%(87/124),主要位于315位;oxyR-ahp C间隔区突变率为15.3%;inh A、kat G两种基因同时突变率75.0%,三种基因同时突变率为89.5%。利福平rpo B基因突变的检出率高达95.2%,突变主要发生在531、526、516位点。结论我省耐多药菌异烟肼耐药相关基因最常见突变为kat G 315、inh A C-T(-15)、axyR-ahp C间隔区(-10)C-T,利福平为rpo B531、526、516。结合MDR-TB耐药相关基因的特征分析,可以建立一种快速、准确、特异的适合于我省的检测结核菌耐多药性的新方法。     

氯硝柳胺悬浮剂的毒性评价

目的评价氯硝柳胺悬浮剂的毒性，为现场大规模应用灭螺提供依据。方法按照中华人民共和国国家标准GB 15670-1995《农药登记毒理学试验方法》和鱼类毒性试验方法进行。结果经口、经皮肤的LDso雌、雄性大鼠均>5 000 mg/kg，经呼吸道的LCso雌、雄性大鼠均>5 000mg/m3，该药经口、经皮肤、经呼吸道毒性均属微毒类药物；兔眼用药后，观察期内无不良反应，对眼无刺激性；皮肤用药后对皮肤无刺激性。与氯硝柳胺原药、氯硝柳胺乙醇胺盐原药和氯硝柳胺乙醇胺盐可湿性粉剂相比，氯硝柳胺悬浮剂对鱼急性毒性最低。结论氯硝柳胺悬浮剂属微毒类药物，对鱼的毒性低于其乙醇胺盐可湿性粉剂，适合于现场应用。     

Assessment of quality of life of parents of children with juvenile chronic arthritis

The aim of the study was to assess the quality of life (QOL) and the psychological status of parents of children with juvenile chronic arthritis (JCA). The QOL, anxiety and depression of the parents of 28 children with JCA were evaluated and compared to those of the parents of 28 healthy children. Mothers of JCA children and mothers of healthy children reported similar QOL. The reported anxiety and depression levels were similar for mothers and fathers in both groups. The parents of children with pauciarticular-type JCA reported lower QOL and higher levels of anxiety and depression than the parents of children with other types, namely polyarticular and systemic JCA. These findings may be explained by the fact that the pauciarticular patients had shorter disease duration and were less frequently seen in the outpatient clinic. The QOL of mothers of children with JCA was found to be slightly impaired in the group of children with pauciarticular JCA. Future larger studies are needed to confirm these results, as the number of subjects in the three groups was rather low. Received: 26 September 2001 / Accepted: 8 February 2002     

Numerical Simulation of the Effect of Rate of Change of Glucose on Measurement Error of Continuous Glucose Monitors

Background

A 5-day in-patient study designed to assess the accuracy of the FreeStyle Navigator® Continuous Glucose Monitoring System revealed that the level of accuracy of the continuous sensor measurements was dependent on the rate of glucose change. When the absolute rate of change was less than 1 mg•dl⁻¹•min⁻¹ (75% of the time), the median absolute relative difference (ARD) was 8.5%, with 85% of all points falling within the A zone of the Clarke error grid. When the absolute rate of change was greater than 2 mg•dl⁻¹•min⁻¹ (8% of the time), the median ARD was 17.5%, with 59% of all points falling within the Clarke A zone.

Method

Numerical simulations were performed to investigate effects of the rate of change of glucose on sensor measurement error. This approach enabled physiologically relevant distributions of glucose values to be reordered to explore the effect of different glucose rate-of-change distributions on apparent sensor accuracy.

Results

The physiological lag between blood and interstitial fluid glucose levels is sufficient to account for the observed difference in sensor accuracy between periods of stable glucose and periods of rapidly changing glucose.

Conclusions

The role of physiological lag on the apparent decrease in sensor accuracy at high glucose rates of change has implications for clinical study design, regulatory review of continuous glucose sensors, and development of performance standards for this new technology. This work demonstrates the difficulty in comparing accuracy measures between different clinical studies and highlights the need for studies to include both relevant glucose distributions and relevant glucose rate-of-change distributions.     

Study of constancy of hydrogen-consuming flora of human colon

The constancy of the hydrogen consuming flora of the human colon was studied in 15 healthy subjects via two measurements obtained 18 to 36 months apart. Hydrogen disappearance rate and the major products of H₂-consuming bacteria, methane and sulfide, were measured during incubation of fecal homogenates with excess hydrogen and sulfate. In 11/15, the hydrogen consumption rate and the predominant hydrogen-consuming pathway (methanogenesis, sulfate reduction, or neither) remained constant. However, major shifts in these pathways were observed in four subjects, with two losing and two gaining the ability to produce methane. Methanogenesis was associated with the highest hydrogen consumption rate. This study demonstrates that clinically unrecognizable, major alterations of the colonic flora occur in healthy subjects. Understanding of the factors responsible for these alterations might allow for therapeutic manipulation of the colonic flora.Supported in part by the Department of Veterans Affairs and NIDDKD RO1 DK 13309-25.