维生素C对烫伤休克大鼠肠内补液时肠组织氧自由基损伤的影响

目的研究维生素C对烫伤休克大鼠肠内补液时肠组织氧自由基损伤的影响。方法雄性Wistar大鼠40只,20%乌拉坦(100mg/kg)肌注麻醉后,采用沸水法(100℃,15s)造成35% TBSA Ⅲ度烫伤,行十二指肠和空肠置管。随机分为单烫组(S组)、葡萄糖-电解质溶液(GES)组、VC组和GES/VC组,每组10只,GES组和GES/VC组大鼠在烫伤后30min将GES经十二指肠置管处匀速泵入,前4h按1/2Parkland公式量和速率(2ml.1%TBSA-1.kg-1)补液,VC组和GES/VC组大鼠在伤后30min将VC(250mg/kg)单独或溶于GES中注入十二指肠。伤后4h处死大鼠,取空肠组织测定丙二醛(MDA)含量及黄嘌呤氧化酶(XOD)、髓过氧化物酶(MPO)活性,并用干湿重法测定肠组织含水率(GW)。结果与S组比较,GES组MDA含量明显增高(P<0.05),而XOD、MPO活性两组比较无显著差异;VC组和GES/VC组上述指标与S组和GES组比较均显著降低(P<0.05)。GES组GW(83.1%±2.4%)显著高于S组(78.8%±2.5%,P<0.05),且二者均明显高于VC组(72.4%±1.2%)和GES/VC组(68.9%±2.1%,P<0.05)。结论VC能减轻烫伤休克大鼠肠内补液时的缺血再灌注损伤和肠组织水肿。     

谷氨酰胺对严重烧伤小型香猪肠道免疫功能的影响

为研究烧伤后肠道分泌Ｓ－ＩｇＡ的变化，利用３０％Ⅲ度小型香猪烧伤动物模型，动态观察了早期肠道营养液中加入谷氨酰胺对肠道分泌Ｓ－ＩｇＡ的影响，结果显示：未补充谷氨酰胺的动物空肠和回肠液中Ｓ－ＩｇＡ的含量在伤后明显降低，动脉血中ＩｇＡ的含量也明显降低，而补充谷氨酰胺的动物空肠、回肠液中的Ｓ－ＩｇＡ，以及动脉血中的ＩｇＡ均明显高于未补充的动物，且与伤前无明显差别。提示早期肠道营养液中加入谷氨酰胺能明显维护肠粘膜细胞分泌Ｓ－ＩｇＡ的功能，对防治烧伤后细菌或毒素移位有重要意义。     

补锌对缺锌烫伤大鼠肠粘膜营养状态的影响

目的 :研究补锌对缺锌烫伤大鼠肠粘膜营养状态的影响。　方法 :1月龄大鼠进食低锌饲料 (含锌量为 1.6μg/g) 1周 ,造成缺锌模型 ,2 0 %深二度烫伤后分别改饲三种不同含锌量饲料 (各为 1.6 μg/g、2 4 .7μg/g和 2 86 .9μg/g) ,同时设一组大鼠烫伤前后均进食正常含锌饲料 (2 4 .7μg/g)作对照组。伤后第 8天处死并留取标本。动物处死前注射长春新碱 ,以肠腺细胞增生率 (CCPR)、粘膜湿重、空肠与回肠的DNA、蛋白质含量反映肠粘膜的营养状态。　结果 :各补锌组空肠DNA含量及CCPR均显著高于缺锌组 ,回肠也存在类似的趋势。　结论 :缺锌大鼠烫伤后补锌有利于肠粘膜营养状态的改善和损伤的修复     

肠饲谷氨酰胺对严重烧伤小型香猪肠道葡萄糖代谢的影响

采用小型香猪30%TBSA 烧伤模型,动态观察了烧伤后肠道补充谷氨酰胺对肠道葡萄糖代谢的影响。结果显示:伤后第1天,不补充谷氨酰胺组肠道葡萄糖的消耗量明显减少,而补充谷氨酰胺组则出现少量的净释放。为0.11μmol·min~(-1)·kg~(-1)。伤后第4天,两组均出现净释放,补充谷氨酰胺的动物明显高于不补充谷氨酰胺的动物;伤后7、10天,两组仍维持葡萄糖的净释放。提示严重烧伤后肠道补充谷氨酰胺能明显减少肠道对葡萄糖的利用,增加肠道葡萄糖的生成能力。     

肠道微生态对放射治疗的影响与相关机制

微生态是由定植于人类上皮屏障的共生菌和其他微生物组成的。共生的微生态对人类的生存和健康发挥着重要作用。微生态还参与了肿瘤的发生、发展和扩散过程。新近研究有力证实了微生态尤其是肠道微生态在抗肿瘤反应中和毒性反应的调节中发挥重要作用。肠道微生态影响着治疗所致的免疫原性细胞死亡诱导的免疫反应。本文中我们将聚焦于肠道微生态对放射治疗所致的机体免疫反应及毒性反应的调节作用及具体机制。     

The effect of immune sera from hamsters immunized with sandfly gut and whole body extract antigens on the fecundity and mortality of Phlebotomus duboscqi (Diptera: Psychodidae)

Phlebotomus duboscqi were fed on hamsters previously immunized with different concentrations of homogenized crude sandfly gut antigen and supernatant obtained from whole body extract. The humoral response in the rodents was quantified at different times post-immunization by the enzyme-linked immunosorbent assay. Sandflies were fed on either immunized or saline control hamsters and the effect of the blood meals on sandfly feeding, survival and fecundity was investigated. The humoral response in immunized hamsters as measured by the presence of P. duboscqi-specific IgG antibodies was significantly greater (P < 0.05) as compared to the controls. This difference was noted in sera collected on 15 and 25 days post-immunization. Sandflies fed on immunized hamsters had a significantly higher mortality (P < 0.05) and decreased egg production (P < 0.05) than those fed on unimmunized control hamsters.     

How to adapt an intestinal microbiota transplantation programme to reduce the risk of invasive multidrug-resistant infection

BackgroundVulnerable patients with intestinal colonization of multidrug-resistant organisms (MDROs) are recognized to be at increased risk of invasive MDRO-driven infection. Intestinal microbiota transplantation (IMT, also called faecal microbiota transplant) is the transfer of healthy screened donor stool to an affected recipient, and recent interest has focused on its impact on the reduction of invasive MDRO infection.ObjectivesTo describe how to establish a clinical IMT pathway for patients at risk of MDRO invasive infection, with special considerations for optimizing administration and assessment of endpoints.SourcesExpert guidelines and peer-reviewed clinical studies are encompassed and discussed.ContentIMT is offered to patients with MDROs detected on rectal or stool screening and either at risk of MDRO invasive infection due to altered immune status or those with recurrent MDRO-mediated invasive disease and considered at risk of further disease. Donor screening should include pathogens with theoretical or demonstrated risk of transmission (including MDROs themselves and SARS-CoV-2) and take into consideration the relative immunosuppressed state of potential recipients. Delivery of IMT is timed for when the patient is free from active infection, but no additional antibiotics are indicated. If administered when future immunosuppression is to take place, IMT is aligned at least 2 weeks beforehand to ensure sufficient time for engraftment. Patients are followed up in terms of adverse effects from IMT and clinicians are advised to discuss with the IMT multidisciplinary team on choice of antibiotics if needed to take into consideration the impact upon the intestinal microbiome. Prevention of invasive disease is the primary measure of success, rather than using intestinal decolonization as a binary outcome. Repeat IMT is considered case by case.ImplicationsFuture research areas should include randomized studies that consider clinical outcomes and cost-effectiveness, and better understanding of mechanisms to identify markers of treatment success and functional microbiome components that could be used therapeutically.     

关于肠黏膜屏障功能衰竭临床分期标准的初步探讨

目的:初步建立肠黏膜屏障功能衰竭(IBF)的临床分期标准。方法:选取消化系统恶性肿瘤、肝硬化、炎性肠病等患者共50例作为病例组,选取25例健康志愿者作为对照组,均口服双糖探针后检测样本尿液中乳果糖/甘露醇(L/M)含量以评价肠道通透性,同时采集其新鲜粪便行菌群分析,记录其临床指标及实验室指标,分析病例组与对照组的临床表现、肠道通透性、肠菌群及免疫指标间的关系。结果:与对照组(0.02938±0.00725)相比,病例组尿L/M比值(0.06694±0.02343)显著增高,差异有统计学意义(t=9.874,P<0.01)。不同程度菌群失调患者肠道通透性差异无显著性(F=2.285,P=0.113)。随着患者腹胀及腹泻程度的增高,肠道通透性增高及中重度菌群失调的比例也增加。病例组C反应蛋白[(47.8±33.5)mg/Lvs(3.2±2.6)mg/L]、血浆内毒素[(5.806±4.219)EU/mLvs(0.018±0.056)EU/mL]及血清白细胞介素-6(22.19±8.45)pg/mLvs(6.24±0.13)pg/mL]水平较之对照组均有显著升高(均P<0.01)。结论:根据患者的临床症状、肠黏膜通透性、肠菌群状态及免疫指标间的关系,可初步建立IBF的临床分期标准。     

In Vitro and In Vivo (Rabbit,Guinea Pig,Mouse) Properties of a Novel Resorbable Polymer and Allogenic Bone Composite for Guided Bone Regeneration and Orthopedic Implants

Introduction

Currently, there is no bone fixation material that could be fully replaced by the competent recipient bone. The creeping substitution of the bone graft by the recipient bone is the result of its unique potential related to the presence of bone morphogenetic proteins (BMPs). However, the size of the human bone limits the use of allogenic implants for surgical (orthopedic) fixation.The aim of this project was to develop a novel composite material for guided bone regeneration, consisting of human bone powder obtained from a tissue bank and a resorbable polymer (13 wt% of bone powder in a medical poly-l-lactide polymer). Such a biomaterial could possess osteoinductive properties and be used to manufacture bone fixation implants of different shapes and sizes.

Induction of non-painful and painful intestinal sensations by hypertonic saline: a new human experimental model.

BACKGROUND AND AIMS: To develop a pain model for chemical stimulation of the human gut. METHODS: In a double-blind experimental study 10 subjects with a previously performed sigmoidostomy were randomised to receive injections with either isotonic or hypertonic saline in the colonic mucosa. In the hypertonic experimental arm, 0.1 ml of 0.9%, 2%, 4%, and 6% and 0.2 ml of 2% and 4% saline were given. In the placebo arm, six 0.9% saline injections of the same quantities were given. In a separate experiment 0.8 ml 4% saline was infused into the mucosa by a pump over a period of 2min. The pain intensity was rated on a 0-10 visual analogue scale with 5 as the pain threshold. RESULTS: The hypertonic saline injections resulted in local as well as referred non-painful and painful sensations in 9 out of the 10 subjects. The evoked sensations were mostly described as a smarting sensation with an intensity of median 1 (range 0-5.6) for 0.1 ml 2% saline to median 2.9 (range 0-6.2) for 0.2 ml 4% saline. Seven subjects reported referred sensations to the abdominal skin. Continuous infusion of 4% saline resulted in a consistent sensory response in all subjects, with a median intensity of 4.1 (range 2.1-8.1). This sensory intensity was reproducible in 70% in a retest experiment after median 7 weeks. In the placebo arm a total of 70 isotonic saline injections only resulted in inconsistent, short-lasting non-painful sensations in three subjects. CONCLUSION: The model represents a safe method for direct chemical activation of the sensory endings in the human gut. The model may be used for pharmacological screening of analgesics and for basic investigations in patients suffering from gastrointestinal diseases.