猪胃肠道黏膜二糖酶的性质

研究了猪小肠中麦芽糖酶,蔗糖酶和乳糖酶3种二糖酶的生化性质及活性分布。试验以3头“杜加”生长猪为对象,屠宰并刮取胃底部,十二指肠,空肠上段和回肠黏膜。其中空肠黏膜用于3种二糖酶生化性质的研究,包括酶的最适温度,热稳定性,最适pH ,pH稳定范围和金属离子对酶活性的影响;胃底部,十二指肠,空肠上段和回肠黏膜用于测定3种二糖酶活性以揭示其在胃扬中的分布规律。试验结果表明：麦芽糖酶,蔗糖酶和乳糖酶的最适反应温度分别为50,45和55℃,最适pH分别为6.8,6.5和6．0;乳糖酶的耐热温度（70℃）高于麦芽糖酶和蔗糖酶（50℃）;不同pH对3种二糖酶活性影响不大;金属离子Cu^2 和Fe^2 对3种二糖酶均有激活作用;而Mn^2 有抑制作用。此外,Zn^2 能抑制麦芽糖酶活性,提高蔗糖酶活性,而不影响乳糖酶活性。3种二糖酶活性在肠道中由高到低的分布为：空肠,回肠,十二指肠和胃;其中麦芽糖酶在空肠和回肠中活性相近。回肠和空肠黏膜中的麦芽糖酶活性均显著高于十二指肠和胃中的酶活性,十二指肠酶活性显著高于胃;空肠中蔗糖酶和乳糖酶活性显著高于回肠,十二指肠和胃底部。从3种二糖酶活性大小看,胃底部和十二指肠中的麦芽糖酶活性显著高于蔗糖酶和乳糖酶;空肠上段和回肠中的麦芽糖酶活性显著高于蔗糖酶活性,蔗糖酶活性又显著高于乳糖酶。上述结果表明,3种二糖酶的生化性质具有一定的差异,在胃肠道中的活性分布规律相似。     

Challenges in assessing pathogenicity based on frequency of variants in mismatch repair genes: an extreme case of a MSH2 variant and a meta-analysis

The clinical interpretation of variants in mismatch repair (MMR) genes associated with Lynch syndrome can be confusing when the functional nature of the variant is not clearly defined. We report an extreme case where a polymorphism in the MSH2 gene which had a low minor allele frequency, was misclassified as a mutation based on low evidential methods in the database and previous publications. We expanded this experience to perform a systematic meta-analysis in order to investigate other variants that have potentially been misclassified. Our results suggested that the interpretation of pathogenicity should be more cautious and emphasized the need for solid validation through multiple analyses including functional analysis for variants in MMR genes.     

A review of advanced oral drug delivery technologies facilitating the protection and absorption of protein and peptide molecules

The oral delivery of proteins and peptides is a dynamic research field despite the numerous challenges limiting their effective delivery. Successful oral delivery of proteins and peptides requires the accomplishment of three key tasks: protection of the macromolecules from degradation in the gastrointestinal tract (GIT), permeation through the intestinal barrier and absorption of molecules into the systemic circulation. Currently, no clinically useful oral formulations have been developed but several attempts have been made to overcome the challenges of low oral bioavailability resulting from poor absorption, poor permeation and enzymatic degradation of the proteins and peptides in the GIT. Present strategies attempt to provide structural protection of the proteins and peptides and improved absorption through the use of enzyme inhibitors, absorption enhancers, novel polymeric delivery systems and chemical modification. However, each of these technologies has their limitations despite showing positive results. This review attempts to discuss the physical and chemical barriers of the GIT with particular emphasis on the current approaches employed to overcome these barriers, including the evaluation of other non-parenteral routes of protein and peptide delivery. In addition, this review assimilates oral formulation strategies under development and within the clinical trial stage in relation to their benefits and drawbacks with regard to facilitating optimal protection and absorption of proteins and peptides, as well as pertinent future challenges and opportunities governing oral drug delivery.     

宏基因组学与动物病原微生物检测

宏基因组学（ metagenome）是直接从土壤、海水、人及动物胃肠道、口腔、呼吸道、皮肤等环境中获取样品DNA,利用载体将其克隆到替代宿主细胞中构建宏基因文库,以高通量检测为主要技术来研究特定环境中全部微生物的基因组及筛选活性物质和基因的新兴学科。利用宏基因组学技术不仅能够有效地检测特定环境的微生物群落结构,扩展了微生物资源的利用空间,发展了新兴的高通量检测技术,丰富了生物信息学内容。基于宏基因组学研究方法在环境微生物研究中的优势,对近年来相关领域、方法及其在人及动物病原微生物研究中的应用进行综述,以期将此方法用于实验动物病原微生物的调查分析及动物疫情、生物安全的监测。     

Radiobiology of the acute radiation syndrome

Acute radiation syndrome or acute radiation sickness is classically subdivided into three subsyndromes: the hematopoietic, gastrointestinal and neurovascular syndrome but many other tissues can be damaged. The time course and severity of clinical signs and symptoms are a function of the overall body volume irradiated, the inhomogeneity of dose exposure, the particle type, the absorbed dose and the dose rate. Classical pathophysiology explain the failure of each of these organs and the timing of appearance of their signs and symptoms due to radiation-induced cytocidal effects of a great number of parenchymal cells of hierarchically organized tissues. Contemporaneously, many other radiation-induced effects has been described and all of them may lead to tissue injury with their corresponding signs and symptoms that can be expressed after short or long period of time. Radiation-induced multi-organ involvement is thought to be due to radiation-induced systemic inflammatory response mediated by released pro-inflammatory cytokines.     

胃肠道间质瘤的分子分型及靶向治疗

胃肠道间质瘤（gastrointestinal stromal tumors,GISTs）是消化道常见的间叶肿瘤,不同于消化道真正的平滑肌瘤、神经源性肿瘤,其发生主要与Kit基因和血小板衍生生长因子受体α（platelet-derived growth factor receptor alpha,PDGFRα）基因突变有关。KIT靶点的发现使得胃肠道间质瘤治疗进入新治疗模式。伊马替尼与舒尼替尼,均为酪氨酸激酶抑制剂,分别被批准为进展期GISTs治疗的第一线及第二线靶向治疗药物。本文就GISTs的分子生物学分型以及分子靶向药物治疗进展作一概述。     

Innate lymphoid cells and gastrointestinal disease

Innate lymphoid cells (ILCs) are a group of innate immune cells, which constitute the first line of defense in the immune system, together with skin and mucous membrane. ILCs also play an important role in maintaining the homeostasis of the body, particularly in the complex and diverse environment of the intestine. ILCs respond to different microenvironments, maintaining homeostasis directly or indirectly through cytokines. As a result, ILCs, with complex and pleiotropic characteristics, are associated with many gastrointestinal diseases. Their ability of transition among those subgroups makes them function as both promoting and inhibiting cells, thus affecting homeostasis and disease progressing to either alleviation or deterioration. With these special characteristics, ILCs theoretically can be used in the new generation of immunotherapy as an alternative and supplement to current tumor therapy. Our review summarizes the characteristics of ILCs with respect to category, function, and the relationship with intestinal homeostasis and gastrointestinal diseases. In addition, potential tumor immunotherapies involving ILCs are also discussed to shed light on the perspectives of immunotherapy.     

承气活血通腑汤联合穴位贴敷治疗粘连性肠梗阻的疗效及对胃肠功能和血清炎性因子的影响

目的:探讨承气活血通腑汤联合穴位贴敷治疗粘连性肠梗阻的疗效及对胃肠功能和血清炎性因子的影响。方法:选取2018年2月到2020年7月期间于我院接受诊治的粘连性肠梗阻患者60例。分组方法采用随机数字表法,将入选患者分为对照组(n=30,常规治疗)、研究组(n=30,对照组的基础上给予承气活血通腑汤联合穴位贴敷治疗),对比两组疗效、胃肠功能、炎性因子、住院时间、住院费用、临床症状评分。结果:研究组的临床总有效率较对照组高(P<0.05)。两组治疗12d后血清降钙素原(PCT)、C反应蛋白(CRP)水平较治疗前降低,且研究组较对照组低(P<0.05)。两组治疗12d后腹部胀痛、排便排气、恶心呕吐、口苦口干评分较治疗前降低,且研究组较对照组低(P<0.05)。研究组胃管拔除时间、恢复正常饮食时间均短于对照组(P<0.05)。研究组住院时间短于对照组,住院费用少于对照组(P<0.05)。结论:承气活血通腑汤联合穴位贴敷治疗粘连性肠梗阻的疗效确切,可改善患者临床症状和胃肠功能,促进患者早日恢复,减少住院费用,降低机体炎性因子水平。     

胃复春片联合兰索拉唑肠溶片对慢性萎缩性胃炎患者血清胃肠激素、炎症因子及免疫功能的影响

摘要 目的：胃复春片联合兰索拉唑肠溶片对慢性萎缩性胃炎（CAG）患者血清胃肠激素、炎症因子及免疫功能的影响。方法：选取62例CAG患者,根据门诊挂号奇偶性分为对照组（n=31,兰索拉唑肠溶片治疗）和研究组（n=31,胃复春片联合兰索拉唑肠溶片治疗）。比较两组患者疗效、胃肠激素[胃泌素(GAS)、胃动素(MTL)]、炎症因子[超敏C反应蛋白（hs-CRP）、肿瘤坏死因子-α（TNF-α）、白介素-6（IL-6）]、免疫功能及不良反应。结果：研究组治疗2个月后的总有效率为87.10%（27/31）,高于对照组的64.52%（20/31）,差异有统计学意义（P<0.05）。治疗2个月后,研究组hs-CRP、TNF-α、IL-6、GAS、CD8P低于对照组,MTL、CD4P、CD4⁺/CD8⁺高于对照组（P<0.05）。两组不良反应发生率对比未见明显差异（P>0.05）。结论：胃复春片联合兰索拉唑肠溶片治疗CAG疗效确切,可有效改善机体胃肠激素、炎症因子水平及免疫功能,且安全可靠,具有一定应用价值。     

鼻饲中药抗休克合剂治疗重症烧伤休克期患者的疗效及对胃肠道复苏的影响

摘要 目的：探讨中药抗休克合剂经鼻饲给药法治疗重症烧伤休克期患者的疗效及对胃肠道复苏的影响。方法：选取上海中医药大学附属第七人民医院2017年10月至2020年9月期间收治的重症烧伤休克患者共计60例,将其按照随机数字表法分为对照组和实验组,每组各30例。对照组患者进行常规抗休克治疗,实验组在常规抗休克的基础上经鼻饲法给予中药抗休克合剂治疗。观察并记录两组患者复苏前、复苏后1 d、2 d、3 d的动脉血乳酸、内毒素水平,心率、尿量及补液量,腹胀缓解肠鸣音恢复时间、肛门排气时间,消化道不良反应、消化道出血发生率及有无继发全身性感染情况。结果：两组患者经治疗后血清内毒素和动脉血乳酸水平均呈不同趋势下降,复苏后1 d、2 d两组患者实验室指标虽有降低,但两组组间比较差异不显著（P＞0.05）,实验组患者复苏后3 d血清内毒素和动脉血乳酸值下降显著,且明显优于对照组,差异有统计学意义（P＜0.05）。实验组复苏后1 d、2 d补液量均较对照组更低（P<0.05）;实验组复苏后1 d、2 d尿量与对照组比较无统计学差异（P>0.05）,而复苏后3 d尿量较对照组更多（P<0.05）;实验组复苏后1 d、2 d、3 d心率均优于对照组（P<0.05）。实验组腹胀缓解肠鸣音恢复时间、肛门排气时间和消化不良反应、消化道出血、继发全身性感染发生率均低于对照组(P＜0.05)。结论：经鼻饲法给予中药抗休克合剂配合西医常规抗休克治疗,可发挥中医药特色,治疗重症烧伤休克期患者临床疗效明确,有助于胃肠道复苏,降低并发症及感染机率,具有一定的临床价值。