肠细胞凋亡在新生鼠坏死性小肠结肠炎肠损伤中动态变化

目的 动态观察新生大鼠坏死性小肠结肠炎(NEC)发病过程中肠细胞凋亡率变化及其与肠损伤关系.方法 40只新生SD大鼠随机分成对照组(C)和模型组(M).对照组8只;模型组32只,在出生48 h开始给予鼠配方奶人工喂养,100%氮气缺氧90 s,4℃冷刺激10 min,每天2次,连续3 d,建立新生大鼠NEC模型;模型组开始造模后24 h(M24)、48 h(M48)、72 h(造模结束,M72)及造模结束后24 h(M96)分别处死8只,留取肠管进行肠组织损伤评分和肠细胞凋亡率检测(流式细胞仪).组织学评分≥2确定为NEC.各组随机选取1份回盲部近端小肠标本进行肠黏膜透射电镜检查.采用SPSS 11.0统计学软件进行统计分析,α =0.05为显著性检验标准.结果 透射电镜显示模型组大鼠肠黏膜出现大量凋亡细胞,形成凋亡小体.对照组、M24、M48、M72和M96肠组织损伤评分分别为(0.08±0.15)、(1.38±0.42)、(1.46±0.69)、(1.58±0.30)分和(3.33±0.59)分,肠细胞凋亡率分别为4.8%±2.9%、12.8%±6.3%、14.9%±5.5%、17.7%±5.5%和27.6%±9.9%.肠损伤程度与肠细胞凋亡率呈显著正相关(r＜凋亡率=0.853,P＜0.01).结论 新生鼠肠细胞凋亡增加是NEC肠组织损伤起始事件;随时间延长,肠细胞凋亡增加程度进一步加重;肠细胞凋亡增加是造成新生鼠NEC肠道进行性损伤的病理基础.     

新生鼠坏死性小肠结肠炎肠组织一氧化氮和一氧化氮合酶变化

目的动态观察新生大鼠坏死性小肠结肠炎(NEC)发病过程中肠组织一氧化氮(NO)含量、一氧化氮合酶(NOS)活性变化及其与肠损伤关系,为进一步阐明NEC发病机制、寻找新的治疗方法提供实验依据。方法40只新生SD大鼠按简单随机法分成模型组(M)32只,对照组(C)8只。模型组大鼠出生48h开始鼠配方奶人工喂养,并予以3次缺氧和冷刺激建立NEC模型,缺氧冷刺激开始后24h(M24)、48h(M48)、72h(造模结束,M72)及最后一次缺氧和冷刺激后24h(M96)分别空腹断头处死8只;实验结束时处死对照组大鼠,分别留取肠管进行肠组织损伤评分、肠组织中NO含量和NOS活性检测。结果建模后,模型组出现腹泻、腹胀、萎靡、活动减少。M24、M48、M72、M96及对照组肠组织损伤评分分别为(1.25±0.56)、(1.46±0.31)、(2.79±0.40)、(3.33±0.59)和(0.08±0.15)分,肠组织NO含量分别为(2.07±0.38)、(2.88±0.32)、(3.09±0.40)、(3.98±1.15)和(0.94±0.44)μmol/gprot,总NOS活性分别为(2.21±0.42)、(2.77±0...     

新生鼠坏死性小肠结肠炎肠组织一氧化氮和一氧化氮合酶变化

目的 动态观察新生大鼠坏死性小肠结肠炎(NEC)发病过程中肠组织一氧化氮(NO)含量、一氧化氮合酶(NOS)活性变化及其与肠损伤关系,为进一步阐明NEC发病机制、寻找新的治疗方法提供实验依据.方法 40只新生SD大鼠按简单随机法分成模型组(M)32只,对照组(C)8只.模型组大鼠出生48 h开始鼠配方奶人工喂养,并予以3次缺氧和冷刺激建立NEC模型,缺氧冷刺激开始后24 h(M24)、48 h(M48)、72 h(造模结束,M72)及最后一次缺氧和冷刺激后24h(M96)分别空腹断头处死8只;实验结束时处死对照组大鼠,分别留取肠管进行肠组织损伤评分、肠组织中NO含量和NOS活性检测.结果 建模后,模型组出现腹泻、腹胀、萎靡、活动减少.M24、M48、M72、M96及对照组肠组织损伤评分分别为(1.25±0.56)、(1.46±0.31)、(2.79±0.40)、(3.33±0.59)和(0.08±0.15)分,肠组织NO含量分别为(2.07±0.38)、(2.88±0.32)、(3.09±0.40)、(3.98±1.15)和(0.94±0.44) μmol/gprot,总NOS活性分别为(2.21±0.42)、(2.77±0.58)、(2.95±0.32)、(3.80±1.08)和(1.49±0.25)U/mgprot,诱导型NOS活性为(1.25±0.27)、(1.94±0.46)、(2.06±0.18)、(2.86±1.07)和(0.55±0.23)U/mgprot.随缺氧和冷刺激时间延长,模型组肠组织损伤评分、肠组织中NO、总NOS、诱导型NOS的含量逐渐增加,均高于对照组(P均<0.05),肠组织NO、总NOS、诱导型NOS含量与肠组织损伤程度均呈正相关(r分别为0.865、0.743、0.807,P均<0.05).结论 NO可能是参与肠道屏障损伤过程的重要介质,在NEC肠道屏障损伤发病机制中起重要作用.     

新生鼠坏死性小肠结肠炎肠上皮细胞Bax表达与细胞凋亡的初步研究

目的探讨新生鼠坏死性小肠结肠炎（necrotizingenterocolitis,NEC）时肠上皮细胞Bax表达与凋亡相关性。方法出生当日48只清洁级SD新生鼠采用奇、偶数方法随机分为对照组和NEC模型组,每组24只。对照组由母鼠喂养。模型组与母鼠分开,通过代乳品人工喂养＋缺氧一复氧一冷刺激建立新生鼠NEC动物模型。分别于实验开始后24h、48h、72h留取大鼠回盲部近段回肠组织行免疫组织化学法检查肠上皮细胞Bax表达,原位末端标记法检测肠上皮细胞凋亡率。结果与对照组[（666．55±15．77）IOD;（4．73±0．04）％]相比,NEC模型组新生鼠肠上皮细胞Bax表达和细胞凋亡率在实验开始后24h开始升高[（1005．06±11．96）IOD;（15．04±0．24）％]（P〈0．01）,72h后达到高峰[（3340．66±68．72）IOD;（35．65±0．61）％]（P〈0．01）。NEC模型组新生鼠肠上皮细胞凋亡率与肠上皮细胞Bax表达量呈正相关（r=0．94,P〈0．01）。结论新生鼠NEC肠上皮细胞凋亡与Bax表达有明确相关性。新生鼠NEC肠上皮细胞可能通过高表达Bax导致肠上皮细胞凋亡。     

新生鼠坏死性小肠结肠炎动物模型建立及评价

目的利用新生SD大鼠建立缺氧、冷刺激、鼠乳代用品人工喂养等多因素造成的新生鼠坏死性小肠结肠炎动物模型,并对其进行评价。方法按析因设计,32只新生SD大鼠出生48h开始随机分成4组,每组动物各8只。A组采用鼠乳代用品人工喂养,并给予100%氮气缺氧90s,4℃冷刺激10min,每天2次,连续3d;B组为单纯采用鼠乳代用品人工喂养,未进行缺氧冷刺激;C组采用鼠乳喂养,给予同样的缺氧冷刺激;D组为正常对照组,采用鼠乳喂养,未进行缺氧冷刺激。HE染色后光镜下观察回盲部近端肠组织形态学改变,采用肠损伤病理评分进行评价,组织学评分≥2分确定为坏死性小肠结肠炎(NEC)。结果A、B、C组新生SD大鼠相继出现腹泻、腹胀、萎靡、活动减少,生长减慢,A组程度最为严重。A、B、C、D4组肠损伤病理评分(x-±s)分别为(3.25±0.89)分、(2.63±0.92)分、(1.13±1.36)分、(0.25±0.46)分,各组间差异均有统计学意义(H=19.30,P<0.01)。NEC发病率分别为100%、87.5%、37.5%和0。喂养方式和缺氧冷刺激为肠组织损伤病理评分值影响因素,两因素间无明显交互作用。结论新生鼠在剔除鼠乳喂养,改用鼠乳代用品人工喂养的前提下,经过连续多次的缺氧冷刺激后,诱导的新生鼠坏死性小肠结肠炎模型与人类新生儿NEC临床特征、病理改变相一致,是一种理想的新生儿坏死性小肠结肠炎动物模型。     

微生态制剂对坏死性小肠结肠炎大鼠肠上皮细胞凋亡和增殖的影响

目的研究复方嗜酸乳杆菌对坏死性小肠结肠炎大鼠肠上皮细胞凋亡及增殖细胞核抗原(PCNA)表达的影响,为应用复方嗜酸乳杆菌防治新生儿坏死性小肠结肠炎(NEC)提供参考。方法36只出生48 h新生SD大鼠,采用随机数字表法分为正常组、模型组、干预组,每组12只。采用缺氧加冷刺激3 d建立NEC模型,干预组在建模同时给予复方嗜酸乳杆菌;于模型建立后禁食12 h处死所有大鼠,剖取其肠组织采用原位末端标记法(terminal-deoxynucleoitidyl transferase mediated nick end labeling,TUNEL)测定细胞凋亡情况,采用实时荧光定量PCR检测大鼠肠组织中PCNA基因表达情况。结果1.大鼠肠组织细胞凋亡的检测结果:模型组、正常组、干预组凋亡指数分别为(88.33±2.77)%、(4.75±0.75)%、(44.41±4.81)%,各组间两两比较差异均有统计学意义(均P<0.05)。2.大鼠肠组织中PCNA基因表达结果:模型组、正常组、干预组PCNA基因mRNA表达水平分别为(9.28±3.26)×10^-4、(15.35±1.91)×10^-4、(12.09±3.06)×10^-4,各组间两两比较差异均有统计学意义(均P<0.05)。结论NEC时新生大鼠肠上皮细胞凋亡增加,PCNA表达减少;复方嗜酸乳杆菌能减少细胞凋亡,促进肠上皮细胞增殖,可能有助于降低新生大鼠发生NEC的风险及严重程度。     

谷氨酰胺对新生鼠坏死性小肠结肠炎的影响

目的探讨谷氨酰胺(glutamine,Gln)对新生鼠坏死性小肠结肠炎(necrotizing enterocoli-tis,NEC)肠黏膜修复的影响。方法新生1日龄Wistar大鼠30只随机分为三组,A组为正常对照组;B组为NEC模型组;C组为NEC模型后灌胃给Gln组(2·0g/kg·d)。建立NEC模型,连续3天给予新生鼠100%二氧化碳5min,然后再给予100%氧气5min,放回母鼠身边喂养,第4天断头处死新生鼠,取肠道组织待检。分别取近回盲段2~3cm肠道组织固定、包埋、切片。HE染色光镜下作病理学检查,应用免疫组化技术检测肠黏膜增殖细胞核抗原(PCNA)表达情况,原位末端标记(TUNEL)法检测肠黏膜细胞凋亡的变化。结果B组HE染色切片见肠壁有不同程度的损伤,病理评分的中位积分为3分;C组有的肠黏膜正常,有的轻度肠上皮细胞脱落,有的绒毛轻度坏死,病理评分的中位积分为1分。B组PCNA数量均低于A组及C组(P<0·01)。B组的肠黏膜细胞凋亡的数量高于A组及C组(P<0·01)。结论NEC时,新生鼠肠黏膜受损,增殖减慢,细胞凋亡的数量增加;补充Gln可促进NEC新生鼠肠黏膜隐窝细胞增殖,减少肠黏膜细胞凋亡数量,使肠黏膜修复加快。     

谷氨酰胺对新生鼠坏死性小肠结肠炎的影响

目的 探讨谷氨酰胺(glutamine,Gln)对新生鼠坏死性小肠结肠炎(necrotizing enterocolitis,NEC)肠黏膜修复的影响.方法 新生1日龄Wistar大鼠30只随机分为三组,A组为正常对照组;B组为NEC模型组;C组为NEC模型后灌胃给Gln组(2.0 g/kg·d).建立NEC模型,连续3天给予新生鼠100%二氧化碳5 min,然后再给予100%氧气5 min,放回母鼠身边喂养,第4天断头处死新生鼠,取肠道组织待检.分别取近回盲段2～3 cm肠道组织固定、包埋、切片.HE染色光镜下作病理学检查,应用免疫组化技术检测肠黏膜增殖细胞核抗原(PCNA)表达情况,原位末端标记(TUNEL)法检测肠黏膜细胞凋亡的变化.结果 B组HE染色切片见肠壁有不同程度的损伤,病理评分的中位积分为3分;C组有的肠黏膜正常,有的轻度肠上皮细胞脱落,有的绒毛轻度坏死,病理评分的中位积分为1分.B组PCNA数量均低于A组及C组(P＜0.01).B组的肠黏膜细胞凋亡的数量高于A组及C组(P＜0.01).结论 NEC时,新生鼠肠黏膜受损,增殖减慢,细胞凋亡的数量增加;补充Gln可促进NEC新生鼠肠黏膜隐窝细胞增殖,减少肠黏膜细胞凋亡数量,使肠黏膜修复加快.     

谷氨酰胺和表皮生长因子对新生鼠坏死性小肠结肠炎的影响

目的探讨谷氨酰胺(Gln)和表皮生长因子(EGF)对新生鼠坏死性小肠结肠炎(NEC)肠黏膜修复的影响。方法新生1日龄Wistar大鼠40只随机分为4组,A组(正常对照组),B组(NEC模型组),C组(NEC Gln),D组(NEC EGF Gln)。建立NEC模型,4 d后分别取近回盲段2~3 cm肠道组织固定、包埋、切片。HE染色光镜下作病理学检查,应用免疫组织化学技术检测肠黏膜增殖细胞核抗原(PCNA)的表达,TUNEL法检测肠黏膜细胞凋亡。结果B组HE染色切片见肠黏膜损伤,病理评分的中位积分为3分;C、D组损伤程度较轻,病理评分的中位积分为1分。B组PCNA阳性细胞数低于A组(P<0.01);C、D组PCNA阳性细胞数高于B组(P<0.01);且D组PCNA阳性细胞数高于C组(P<0.05)。B组肠黏膜细胞凋亡数高于A组(P<0.01);C、D组肠黏膜细胞凋亡数低于B组(P<0.01);且D组肠黏膜细胞凋亡数低于C组(P<0.05)。结论NEC新生鼠肠黏膜受损,增殖减慢,细胞凋亡数增加;补充Gln和EGF可促进NEC新生鼠肠黏膜隐窝细胞的增殖,减少肠黏膜细胞的凋亡,加快肠黏膜修复。     

新生鼠坏死性小肠结肠炎动物模型建立及评价

目的 利用新生SD大鼠建立缺氧、冷刺激、鼠乳代用品人工喂养等多因素造成的新生鼠坏死性小肠结肠炎动物模型,并对其进行评价.方法 按析因设计,32只新生SD大鼠出生48 h开始随机分成4组,每组动物各8只.A组采用鼠乳代用品人工喂养,并给予100%氮气缺氧90 s,4 ℃冷刺激10 min,每天2次,连续3 d;B组为单纯采用鼠乳代用品人工喂养,未进行缺氧冷刺激;C组采用鼠乳喂养,给予同样的缺氧冷刺激;D组为正常对照组,采用鼠乳喂养,未进行缺氧冷刺激.HE染色后光镜下观察回盲部近端肠组织形态学改变,采用肠损伤病理评分进行评价,组织学评分≥2分确定为坏死性小肠结肠炎(NEC).结果 A、B、C组新生SD大鼠相继出现腹泻、腹胀、萎靡、活动减少,生长减慢,A组程度最为严重.A、B、C、D 4组肠损伤病理评分(±s)分别为(3.25±0.89)分、(2.63±0.92)分、(1.13±1.36)分、(0.25±0.46)分,各组间差异均有统计学意义(H=19.30,P＜0.01).NEC发病率分别为100%、87.5%、37.5%和0.喂养方式和缺氧冷刺激为肠组织损伤病理评分值影响因素,两因素间无明显交互作用.结论 新生鼠在剔除鼠乳喂养,改用鼠乳代用品人工喂养的前提下,经过连续多次的缺氧冷刺激后,诱导的新生鼠坏死性小肠结肠炎模型与人类新生儿NEC临床特征、病理改变相一致,是一种理想的新生儿坏死性小肠结肠炎动物模型.     

Neonatal intestinal obstruction from solitary intestinal fibromatosis

 Solitary intestinal fibromatosis (SIF) is a very rare condition, with only 13 cases reported. We present a new case of SIF causing neonatal intestinal obstruction and review the literature on this condition. SIF appears to be a condition of infancy and carries a very good prognosis after segmental resection. Accepted: 20 March 2000     

Using porcine small intestinal submucosa in intestinal regeneration

Small intestinal submucosa (SIS) is an unusual tissue that promotes constructive tissue remodeling when applied as a xenogeneic material. The aim of our experimental study was to assess its effectiveness in intestinal regeneration. Twenty white New Zealand rabbits were anesthetized and underwent celiotomy. A 6-cm antimesenteric incision was created at the jejunal segment. An elliptical SIS graft measuring 6 cm long and 2 cm wide was sutured to the jejunal defect as a patch graft. Thirteen living rabbits were divided into groups of three and the grafts were harvested at postoperative weeks 2, 4, and 6. The obtained specimens were evaluated for gross and histologic appearance. In morphometric examination, in the 2, 4, and 6 weeks groups, the diameters of grafted intestines were larger than preoperatively by 50%, 25%, and 25% respectively; also the grafts had contracted to 0%, 25%, and 50% of their original sizes respectively. At the end of 2 weeks, the grafts were intact without evidence of epithelial regeneration. By 4 weeks, intestinal tissue regeneration was started, and epithelial coverage of the grafts was detected. The grafts were covered with a complete intestinal mucosa at 6 weeks. Remarkable regeneration marked fibroplasia, angiogenesis, and mild mononuclear cell infiltration had also occurred throughout the grafts at 6 weeks. Porcine SIS appeared an effective biodegradable scaffold, facilitating regeneration of intestinal tissue. These results suggest that SIS may be useful to increase the mucosal surface of intestine and may provide a new substance for short gut syndrome in the future.     

The effect of intestinal plication on intestinal transit time in rats

Short bowel syndrome (SBS) can occur after extensive intestinal resections. In SBS, the aim of surgical techniques is to prolong intestinal transit time (ITT) and to increase the absorptive surface. This experimental study was conducted to research the effect of extramucosal intestinal plication on ITT in rats. Thirty Sprague-Dawley rats were divided into three groups. In the control group, barium solution was administrated by gavage. Forty-five minutes later, the rats were sacrificed, and the total length of their small bowels (SBs) and the distance of the barium in the SBs were measured. The ratio of the distance of the barium to the length of the SB was calculated, and the ITT was found for normal rats. Intestinal plication (made with three seromuscular sutures at the same level: one on the antimesenteric side, and two on the lateral sides of the bowel) and laparotomy and bowel manipulation were carried out in the study and sham groups, respectively, and ITT was measured by the same method after 1 week. A one-way ANOVA test was used to compare the groups in terms of body weight, total length of the SB, distance of the barium in the SB, and the ratio of this distance to the length of the SB. The rats were statistically homogeneous in terms of body weight and total length of the SB ( p >0.05). The distances of the barium in the small bowel in the control, sham, and study groups were 73.4±8.5 cm, 77.5±6.8 cm, and 56.3±3.6 cm, respectively. The distances of barium in the SB in the study group were statistically shorter than in the other groups ( p <0.05). The ratios of the distance of the barium to the length of the SB in the control, sham, and study groups were 65.8±7.3, 66.4±4.5, and 49.9±3.8, respectively. In the study group, this ratio was also statistically lower than in the other groups ( p <0.05). Extramucosal intestinal plication retarded ITT significantly in the study group compared with the other groups. This technique does not entail any risk of morbidity and mortality; therefore, it can be used in the treatment of SBS.Presented at XX Annual Meeting of Turkish Association of Pediatric Surgeons, 15–19 October 2002, Mersin, Turkey.     

肠道共生细菌和肠上皮屏障间关系的研究进展

人类出生后,其胃肠道黏膜表面与肠道共生细菌和致病性病原体密切接触.肠道上皮屏障作为抵御细菌入侵的第一道防线,通过模式识别受体产生对致病性病原体杀伤性免疫应答,而对共生细菌产生保护性应答.肠上皮细胞在对共生细菌形成免疫耐受,维持肠道免疫稳态中发挥重要作用.共生细菌能协助肠道上皮抵御病原体侵袭,并调节肠道免疫发育和免疫功能.在共生细菌和宿主肠道之间形成免疫平衡,否则易引起肠道炎症疾病.该文从共生细菌对宿主肠道的作用、肠上皮屏障对共生细菌形成免疫耐受机制以及肠道上皮屏障对共生细菌识别平衡破坏引起的疾病等多方面对共生细菌和肠上皮屏障之间关系作一综述.     

Management of intestinal failure

Intestinal failure (IF) occurs when the body is unable to sustain its energy and fluid requirements without support, due to loss of functional small bowel. Prolonged IF is seen after large intestinal resection and described as short bowel syndrome (SBS). The hallmark of the management is parental nutrition (PN), which is costly and may be associated with the well-recognized problems of parental nutrition associated liver disease (PNALD) and line related sepsis. Cessation of PN at the earliest possible stage is desirable but for this enteral autonomy has to be achieved first. Intestinal adaptation occurs when the remaining gut goes through morphological changes increasing its absorptive capacity. Factors such as intraluminal nutrients, gastrointestinal secretions and hormones facilitate adaptation. Enteral feeds are a potent stimulant to adaptation, and should be started as soon as the clinical situation permits. Some drugs are thought to increase intestinal adaptation. These include glutamine, growth hormone and glucagon like peptide-2, but there is a paucity of pediatric data to guide their use. In some cases surgical bowel lengthening procedures can be performed to increase the absorptive surface area. An isolated liver transplantation may be required if the liver has sustained irreversible damage but intestinal autonomy seems achievable. When prolonged PN is either unsustainable or associated with unacceptable side effects, small bowel transplantation should be considered as a treatment option.     

一种新型肠黏膜保护剂--肠三叶因子

肠三叶因子属于三叶肽家族,是一类较新的对肠黏膜有保护作用的因子.它在肠杯状细胞大量合成,能抵抗蛋白酶的消化,且在保护肠道黏膜的完整性、促进肠黏膜损伤后的重建与修复及在肠黏液细胞的抗凋亡中有重要的作用.迄今,很多炎性肠病中都缺少有效的治疗方法,肠三叶因子的研究为肠道疾病的治疗开辟了治疗新途径.该文对肠三叶因子的结构、分布、对肠黏膜保护和修复作用可能的分子机制和调节因素作一综述.     

肠道共生细菌和肠上皮屏障间关系的研究进展

人类出生后,其胃肠道黏膜表面与肠道共生细菌和致病性病原体密切接触.肠道上皮屏障作为抵御细菌入侵的第一道防线,通过模式识别受体产生对致病性病原体杀伤性免疫应答,而对共生细菌产生保护性应答.肠上皮细胞在对共生细菌形成免疫耐受,维持肠道免疫稳态中发挥重要作用.共生细菌能协助肠道上皮抵御病原体侵袭,并调节肠道免疫发育和免疫功能.在共生细菌和宿主肠道之间形成免疫平衡,否则易引起肠道炎症疾病.该文从共生细菌对宿主肠道的作用、肠上皮屏障对共生细菌形成免疫耐受机制以及肠道上皮屏障对共生细菌识别平衡破坏引起的疾病等多方面对共生细菌和肠上皮屏障之间关系作一综述.     

Mechanisms of intestinal adaptation

The control of intestinal adaptation is complex and involves different mechanisms at different sites. The principal basic stimuli to adaptive growth are the presence of food in the gut lumen, endogenous secretions, and circulating hormones and peptides. Lesser factors include neural and vascular influences. Much effort has been devoted to the search for a systemic tropic factor responsible for the direct stimulation of mucosal cell proliferation. Conclusive proof is lacking, but evidence suggests that enteroglucagon or other gut-glucagon peptide fragments may be the elusive enterotropic substance. Attention has recently turned from the study of the phenomenon of intestinal adaptation itself, now well defined, to the possible intracellular mechanisms responsible for enhanced cell division. Offprint requests to: R. C. N. Williamson