Sensory neuron regulation of gastrointestinal inflammation and bacterial host defence

Sensory neurons in the gastrointestinal tract have multifaceted roles in maintaining homeostasis, detecting danger and initiating protective responses. The gastrointestinal tract is innervated by three types of sensory neurons: dorsal root ganglia, nodose/jugular ganglia and intrinsic primary afferent neurons. Here, we examine how these distinct sensory neurons and their signal transducers participate in regulating gastrointestinal inflammation and host defence. Sensory neurons are equipped with molecular sensors that enable neuronal detection of diverse environmental signals including thermal and mechanical stimuli, inflammatory mediators and tissue damage. Emerging evidence shows that sensory neurons participate in host–microbe interactions. Sensory neurons are able to detect pathogenic and commensal bacteria through specific metabolites, cell‐wall components, and toxins. Here, we review recent work on the mechanisms of bacterial detection by distinct subtypes of gut‐innervating sensory neurons. Upon activation, sensory neurons communicate to the immune system to modulate tissue inflammation through antidromic signalling and efferent neural circuits. We discuss how this neuro‐immune regulation is orchestrated through transient receptor potential ion channels and sensory neuropeptides including substance P, calcitonin gene‐related peptide, vasoactive intestinal peptide and pituitary adenylate cyclase‐activating polypeptide. Recent studies also highlight a role for sensory neurons in regulating host defence against enteric bacterial pathogens including Salmonella typhimurium, Citrobacter rodentium and enterotoxigenic Escherichia coli. Understanding how sensory neurons respond to gastrointestinal flora and communicate with immune cells to regulate host defence enhances our knowledge of host physiology and may form the basis for new approaches to treat gastrointestinal diseases.     

抗线粒体抗体与原发性胆汁性胆管炎临床血清学和肝硬化指标的相关性

目的探究首次就诊的抗线粒体抗体(AMA)阳性原发性胆汁性胆管炎(PBC)患者的AMA水平及其与临床指标的相关性。方法通过北京大学人民医院信息系统,收集2013年1月至2016年12月首次检测AMA和(或)M2型抗线粒体抗体(AMA-M2)阳性的1323例患者的临床资料,其中采用间接免疫荧光法183例、免疫印迹法431例、ELISA法709例;分为未诊断PBC组(973例)和新诊断PBC组(350例,其中非肝硬化者268例,肝硬化者82例)。709例采用ELISA法的患者中,未诊断PBC组567例,新诊断PBC组142例(PBC非肝硬化组115例,PBC肝硬化组27例)。183例采用间接免疫荧光法的患者中,未诊断PBC组118例,新诊断PBC组65例;其中AMA滴度为低滴度(1∶40~1∶80)者69例(未诊断PBC组53例,新诊断PBC组16例)、中滴度(1∶160~1∶320)者95例(未诊断PBC组59例,新诊断PBC组36例)、高滴度(≥1∶640)者19例(未诊断PBC组6例,新诊断PBC组13例)。比较各组患者的AMA水平,分析其与PBC临床指标免疫球蛋白(Ig)G、IgM、血小板计数、ALT、AST、GGT、ALP、血清总蛋白、TBil、总胆固醇,以及肝硬化指标天冬氨酸转氨酶与血小板比率指数(APRI)、基于四因子的纤维化指数(Fib-4)的相关性。统计学方法采用Mann-Whitney U检验、Kruskal-Wallis检验和线性回归分析。结果采用ELISA法检测的709例患者的AMA-M2滴度中位值为53 RU/mL,新诊断PBC组的血清AMA和AMA-M2中位水平均高于未诊断PBC组(1∶320比1∶80和180 RU/mL比47 RU/mL),差异均有统计学意义(χ^2=14.111,Z=-7.531,P均<0.01)。未诊断PBC组的AMA-M2值与年龄、IgG、IgM、AST、GGT、ALP、血清总蛋白、总胆固醇水平均呈正相关,均有统计学意义(Rho值=0.114、0.108、0.337、0.089、0.197、0.086、0.121、0.073,P均<0.05);新诊断PBC组的AMA-M2值与年龄、IgM、血清总蛋白、总胆固醇水平均呈正相关,与血小板计数呈负相关,均有统计学意义(Rho值=0.218、0.483、0.230、0.161、-0.183,P均<0.05);PBC非肝硬化组的血清AMA和AMA-M2中位水平均有低于PBC肝硬化组的趋势(1∶160比1∶320和174 RU/mL比495 RU/mL),但差异均无统计学意义(P均>0.05);PBC肝硬化组者组患者的AMA-M2值与IgM水平呈正相关(r=0.38,P=0.039),但与APRI、Fib-4均无明确相关性(P均>0.05)。采用间接免疫荧光法检测的183例患者的AMA滴度中位值为1∶160;未诊断PBC组中AMA低滴度、中滴度和高滴度者的IgM中位水平逐渐升高(分别为1.2、1.7和1.8 g/L),新诊断PBC组中AMA低滴度、中滴度和高滴度者的IgM、GGT、ALP的水平均逐渐升高(中位水平分别为1.5、3.7和4.1 g/L,144、182和317 U/L,137、168和221 U/L),差异均有统计学意义(χ^2=6.260、7.081、8.030、15.226,P均<0.05)。总体中未诊断PBC组男性的血清AMA-M2中位水平低于女性(41 RU/mL比50 RU/mL),差异有统计学意义(Z=-2.945,P=0.003);新诊断PBC组男性的血清AMA-M2中位水平有低于女性的趋势(113 RU/mL比206 RU/mL),但差异无统计学意义(P=0.257)。结论血清AMA水平与诸多临床指标有一定的相关性,并可能与PBC患者的疾病严重程度相关。     

CD4+CD25+调节性T细胞在慢性乙型肝炎患者免疫发病机制中的作用

目的:探探讨CD4~ CD25~ 调节性T细胞(regulatory T Cell,Treg)在慢性乙型肝炎(chronic hepatitis B,CHB)患者免疫发病机制中的作用以及其可能在治疗中的应用前景.方法:收集未经抗病毒治疗的CHB患者34例和健康对照18例外周血单个核细胞(peripheral blood mononuclear cell,PBMC)标本,以三色/四色流式分析法对PBMC中CD4~ CD25~ Treg的频率及表面分子表达进行分析,并同时通过磁珠分选去除CHB患者PBMC中的CD4~ CD25~ Treg,分别以MHC-肽-五聚体法和酶联斑点计数法(enzyme-linked immunospot assay,Elispot)检测HBV core18-27抗原肽刺激的对HBV特异性的CTL(cytotoxic T lymphocyte)频率的升高以及IFN-γ的分泌.结果:CHB患者外周血中CD4~ CD25~ CD45RO~ CTLA4~ T细胞群以及CD4~ CD127~(lo)CD25~(hi-int)T细胞群所占CD4~ T细胞群的比例与健康对照相比均明显上升(3.78%±1.87%.4.40%±2.11%vs 1.58%±0.76%,2.11%±1.26%;t=4.86,t=5.96;P<0.01)去除CHB患者中CD4~ CD25~ Treg后,特异性CTL的频率以及其分泌IFN-γ的频数与未去除组比出现显著上调(0.94%±0.38%,26±13 vs 0.20%±0.18%,119±30;t=5.25,t= 9.886;P<0.01).结论:CHB患者循环中增多的Treg可能参与抑制抗HBV的免疫应答抑制,去除Treg以及联合病毒抗原肽刺激的进一步研究可能为CHB的免疫治疗提供新的思路.     

Clinical and economic outcomes of a multidisciplinary team approach in a lower extremity amputation prevention programme for diabetic foot ulcer care in an Asian population: A case‐control study

Present guidelines recommend a multidisciplinary team (MDT) approach to diabetic foot ulcer (DFU) care, but relevant data from Asia are lacking. We aim to evaluate the clinical and economic outcomes of an MDT approach in a lower extremity amputation prevention programme (LEAPP) for DFU care in an Asian population. We performed a case‐control study of 84 patients with DFU between January 2017 and October 2017 (retrospective control) vs 117 patients with DFU between December 2017 and July 2018 (prospective LEAPP cohort). Comparing the clinical outcomes between the retrospective cohort and the LEAPP cohort, there was a significant decrease in mean time from referral to index clinic visit (38.6 vs 9.5 days, P < .001), increase in outpatient podiatry follow‐up (33% vs 76%, P < .001), decrease in 1‐year minor amputation rate (14% vs 3%, P = .007), and decrease in 1‐year major amputation rate (9% vs 3%, P = .05). Simulation of cost avoidance demonstrated an annualised cost avoidance of USD $1.86m (SGD $2.5m) for patients within the LEAPP cohort. In conclusion, similar to the data from Western societies, an MDT approach in an Asian population, via a LEAPP for patients with DFU, demonstrated a significant reduction in minor and major amputation rates, with annualised cost avoidance of USD $1.86m.     

微创Juvara联合Akin截骨术治疗重度母外翻的临床疗效研究

目的 探讨微创Juvara联合Akin截骨术治疗重度母外翻的临床疗效。 方法　选取2016年8月~ 2018年8月佛山市中医院骨八科治疗的重度母外翻患者45例（50足）,均采用微创Juvara联合Akin截骨术。术前、术后3个月、6个月、12个月均通过X线片测量母外翻角、跖骨间角、跖骨远端关节角、跖趾关节远端固定角、趾骨间角,参照美国足踝外科协会（AOFAS）评分和Olerud-Molander主观功能（OMA）评分标准进行测评。 结果　45例患者术后均获随访,随访时间12 ~ 17个月,平均（14.20 ± 1.55）个月,无复发病例。上述指标及评分方面,术前与术后3个月、6个月、12个月相比,差异均具有显著性意义（P<0.01）;术后3个月、6个月和12个月两两比较,差异均无显著性意义（P>0.01）。 结论 微创Juvara联合Akin截骨术治疗重度母外翻疗效确切,手术切口小,安全性高,值得临床推广应用。     

基于Sihler’s技术的踝和足背皮神经的整体分布模式研究

目的 揭示踝及足背皮神经的整体分布模式,为皮瓣移植感觉重建提供形态学指导。 方法 成年尸体24具,紧贴肌表面摘取含皮下脂肪的踝及足背皮肤,用改良的Sihler’s染色法显示并观察皮神经整体分布模式。 结果 在Sihler’s染色的标本中,肉眼可见隐神经支配踝前区（40.01±7.6）%、踝后区（30±6.7）%、以及部分足背内侧缘。腓浅神经支配踝前区（60.03±6.8）%,其足背内侧皮神经支配足背内侧区、第1、2趾背及第3趾背内侧半;95.83%的足背中间皮神经分布到第3趾背外侧半、第4、5趾背。腓肠神经支配踝后区（70±5.3）%,其足背外侧皮神经支配足背外侧缘皮肤。腓深神经分布到第1、2趾背相对面。初级神经支密度以踝前区最高,次级及以下神经支密度和总的神经支密度均以足背内侧区最高。 结论 在踝或足背的皮瓣移植中,建议把踝前区或足背内侧区设计为利于感觉重建的首选供区或感觉需求较高的受区。