In vitro induction of the pronephric duct in Xenopus explants

The earliest form of embryonic kidney, the pronephros, consists of three components: glomus, tubule and duct. Treatment of the undifferentiated animal pole ectoderm of Xenopus laevis with activin A and retinoic acid (RA) induces formation of the pronephric tubule and glomus. In this study, the rate of induction of the pronephric duct, the third component of the pronephros, was investigated in animal caps treated with activin A and RA. Immunohistochemistry using pronephric duct-specific antibody 4A6 revealed that a high proportion of the treated explants contained 4A6-positive tubular structures. Electron microscopy showed that the tubules in the explants were similar to the pronephric ducts of normal larvae, and they also expressed Gremlin and c-ret, molecular markers for pronephric ducts. These results suggest that the treatment of Xenopus ectoderm with activin A and RA induces a high rate of differentiation of pronephric ducts, in addition to the differentiation of the pronephric tubule and glomus, and that this in vitro system can serve as a simple and effective model for analysis of the mechanism of pronephros differentiation.     

Inhibition of stored Ca2+ release disrupts convergence‐related cell movements in the lateral intermediate mesoderm resulting in abnormal positioning and morphology of the pronephric anlagen in intact zebrafish embryos

Ca²⁺ is a highly versatile intra‐ and intercellular signal that has been reported to regulate a variety of different pattern‐forming processes during early development. To investigate the potential role of Ca²⁺ signaling in regulating convergence‐related cell movements, and the positioning and morphology of the pronephric anlagen, we treated zebrafish embryos from 11.5 h postfertilization (hpf; i.e. just before the pronephric anlagen are morphologically distinguishable in the lateral intermediate mesoderm; LIM) to 16 hpf, with a variety of membrane permeable pharmacological reagents known to modulate [Ca²⁺]_i. The effect of these treatments on pronephric anlagen positioning and morphology was determined in both fixed and live embryos via in situ hybridization using the pronephic‐specific probes, cdh17, pax2.1 and sim1, and confocal imaging of BODIPY FL C₅‐ceramide‐labeled embryos, respectively. We report that Ca²⁺ released from intracellular stores via inositol 1,4,5‐trisphosphate receptors plays a significant role in the positioning and morphology of the pronephric anlagen, but does not affect the fate determination of the LIM cells that form these primordia. Our data suggest that when Ca²⁺ release is inhibited, the resulting effects on the pronephric anlagen are a consequence of the disruption of normal convergence‐related movements of LIM cells toward the embryonic midline.     

Essential function of Wnt-4 for tubulogenesis in the Xenopus pronephric kidney

In the vertebrate embryo, development of the excretory system is characterized by the successive formation of three distinct kidneys: the pronephros, mesonephros, and metanephros. While tubulogenesis in the metanephric kidney is critically dependent on the signaling molecule Wnt-4, it is unknown whether Wnt signaling is equally required for the formation of renal epithelia in the other embryonic kidney forms. We therefore investigated the expression of Wnt genes during the pronephric kidney development in Xenopus. Wnt4 was found to be associated with developing pronephric tubules, but was absent from the pronephric duct. Onset of pronephric Wnt-4 expression coincided with mesenchyme-to-epithelium transformation. To investigate Wnt-4 gene function, we performed gain- and loss-of-function experiments. Misexpression of Wnt4 in the intermediate and lateral mesoderm caused abnormal morphogenesis of the pronephric tubules, but was not sufficient to initiate ectopic tubule formation. We used a morpholino antisense oligonucleotide-based gene knockdown strategy to disrupt Wnt-4 gene function. Xenopus embryos injected with antisense Wnt-4 morpholinos developed normally, but marker gene and morphological analysis revealed a complete absence of pronephric tubules. Pronephric duct development was largely unaffected, indicating that ductogenesis may occur normally in the absence of pronephric tubules. Our results show that, as in the metanephric kidney, Wnt-4 is critically required for tubulogenesis in the pronephric kidney, indicating that a common, evolutionary conserved gene regulatory network may control tubulogenesis in different vertebrate excretory organs.     

A method for creating reversible ureteric obstruction in the primate

A technique has been developed for the establishment of a state of reversible, ureteric obstruction in the primate. Ten adult males had baseline ^99mTc-DTPA renogram studies. A randomly selected ureter was totally occluded and obstruction confirmed on renogram. The occlusion was reversed and subsequent renograms confirmed recovery of activity in the obstructed kidneys of the eight animals who survived the reversal procedure. Seven were alive on conclusion of the study. Prevention of ureteric strictures was achieved with an intra-ureteric silastic tube. Autopsies demonstrated patency of every previously occluded ureter. This is the first study to be reported in primates, and the second overall, in which complete ureteric obstruction and its successful reversal has been confirmed on renogram using this surgical method. The technique is suitable for the study of the effect of reversible ureteric obstruction on renal function.     

老年男性脑卒中患者排尿功能障碍的尿动力学评估

目的:存在阻塞性尿路疾患的老年男性在发生脑血管意外后,是否可通过早期症状或排尿症状类型(梗阻性还是刺激性)来预判排尿功能障碍的病因。方法:选择57例脑卒中后主诉排尿障碍的老年男性患者,所有患者均有继发于良性前列腺增生(BPH)的膀胱出口梗阻(BOO)症状。采集病史并行体检,57位患者均实行尿动力学检查,检查结果行A-G图分析并分类为:有梗阻,无梗阻及可疑梗阻。结果:患者平均年龄70岁(54-87),按排尿障碍的主诉类型分组(纯刺激症状42%,纯梗阻症状34%,两者混合24%),其中51例(89%)在脑卒中发生后即出现排尿症状,47(82%)例患者出现逼尿肌反射亢进(DH),在三组患者中无显著统计学差异。压力流率分析显示,36(63%)位患者有出口梗阻,无梗阻14(24%)例,可疑梗阻7(13%)例。在3组患者中亦无显著统计学差异。结论:所有老年男性患者呈现的症状不能预测膀胱出口梗阻或逼尿肌反射亢进的尿动力学结果。中风发生后排尿功能障碍症状的发生率明显升高,表明由脑血管意外引起的排尿功能障碍合并前期具有膀胱出口梗阻疾病时,可能会使后者的症状恶化,反之亦然。     

The application of cryosurgery in the treatment of lung cancer

Lung cancer is the commonest cause of cancer death, with a very poor survival rate. By the time of diagnosis, most cases are at an advanced stage and about 30% present with symptoms caused by central endobronchial obstruction. Endobronchial cryosurgery is an effective technique, which can be used to relieve tracheobronchial obstruction caused by lung cancer. This report describes the technique, using a nitrous oxide cooled cryoprobe, inserted through a bronchoscope, to remove the obstruction and reopen the airway. In this study, 476 consecutive patients (mean age 68.3 years, M:F ratio 1.9:1) with obstructive tracheobronchial tumours underwent a mean of 2.4 cryosurgical treatments. Their TNM staging was, stage II 6.7%, IIIa 21.0%, IIIb 23.9%, IV 48.4%. Improvement in symptom quantification was found with 76.4, 69.0, 59.2, and 42.6% of symptomatic patients for haemoptysis, cough, dyspnoea, and chest pain, respectively. Mean values for respiratory function improved from 1.38 to 1.41 litres for FEV1 and 1.91 to 2.04 litres for FVC (p 相似文献   

双歧杆菌三联活菌胶囊在术后早期炎性肠梗阻治疗中的应用

目的探究双歧杆菌三联活菌胶囊辅助治疗术后早期炎性肠梗阻的临床效果。方法收集兰州大学第一医院2014年9月至2016年9月收治的术后早期炎性肠梗阻患者56例为研究对象,随机分为对照组和干预组,每组28例,对照组予以常规治疗,干预组在对照组治疗基础上加用双歧杆菌三联活菌胶囊。收集整理两组患者临床数据并分析比较临床治疗效果。结果两组患者治疗总有效率差异无统计学意义(P0.05)。干预组患者腹胀消失时间、肛门排气时间、肠鸣音恢复时间均较对照组短(P0.05);两组患者治疗前后降钙素原下降及淋巴细胞绝对值增加差异均有统计学意义(P0.05),且干预组治疗前后降钙素原降低及淋巴细胞绝对值增加幅度与对照组相比差异均有统计学意义(P0.05)。结论双歧杆菌三联活菌胶囊用于术后早期炎性肠梗阻的治疗,可缩短治疗时间,促进肠道免疫功能恢复,且使用安全,值得临床推广。     

PCT及CRP在急性肠梗阻大鼠血清中的表达水平及其临床意义

目的:探讨降钙素原(Procalcitonin,PCT)及C反应蛋白(C-reactive protein,CRP)在急性肠梗阻大鼠血清中的水平及其临床意义。方法:将83只Wistar大鼠分为对照组(n=13)、假手术组(n=35)和急性肠梗阻组(n=35)。对照组大鼠采集标本后处死,肠梗阻组行开腹手术结扎回肠末端,假手术组仅行开腹手术。检测8 h、24 h、48 h、72 h及96 h血清PCT及CRP水平,观察急性肠梗阻大鼠回肠组织的病理学改变情况。结果:假手术组PCT与CRP水平在术后24 h内显著升高,48 h至96 h逐渐下降;各时间点PCT水平明显高于对照组,而CRP水平在实验结束时已恢复至正常水平。肠梗阻组PCT和CRP水平在各时间点均明显高于对照组,并逐渐增加,到实验结束时达到高峰;肠梗阻组PCT和CRP水平在48 h-96 h均显著高于假手术组,差异具有统计学意义(P0.05)。组织病理学检查显示,对照组大鼠肠壁粘膜结构正常,假手术组可见轻度病理改变,肠梗阻组大鼠回肠组织可见粘膜结构明显破坏,绒毛坏死,严重水肿和炎症细胞浸润。结论:血浆PCT和CRP水平能够反映肠梗阻的状态和肠粘膜受损程度。     

The probiotic bacterium Lactobacillus plantarum species 299 reduces intestinal permeability in experimental biliary obstruction

AIMS: Extrahepatic biliary obstruction is associated with the failure of intestinal barrier function, allowing bacteria and other substances from the intestine to enter the circulation and initiate a systemic inflammatory response, causing impairment of organ function. Probiotic bacteria have been shown to have beneficial effects on intestinal barrier function in other conditions, but their effects have never been studied in biliary obstruction. Methods and Results: This study examined the effects of enteral administration of Lactobacillus plantarum species 299 (LP299) in oatmeal fibre compared with sterile oatmeal fibre in water or water alone in an animal model of biliary obstruction. Administration of LP299 was associated with reduced intestinal permeability compared with sterile oatmeal alone (0.262 +/- 0.105%vs 0.537 +/- 0.037%, P=0.019, percentage excretion of (14)Carbon), but there was no evidence of reduced endotoxin exposure or blunting of the systemic inflammatory response. Animals receiving sterile oatmeal fibre alone also failed to develop the hyperpermeability after biliary obstruction seen in animals receiving water only (0.512+/- 0.05%vs 0.788 +/- 0.18%), suggesting that oatmeal itself may have some beneficial effects on intestinal barrier function. Conclusion: Enteral administration of the probiotic bacterium LP299 reduces intestinal hyperpermeability associated with experimental biliary obstruction. Significance and Impact of the Study: This study provides insight to direct further work into the modulation of intestinal barrier function by probiotic bacteria.     

肠镜下置入支架治疗左半结肠癌性梗阻的临床疗效分析

目的:探讨肠镜下置入支架治疗左半结肠癌性梗阻的应用价值。方法:对我院54例左半结肠癌性梗阻的患者行肠镜下支架置入术,恢复肠道通畅性。结果:24例患者永久性植入结肠内支架以姑息的治疗,30例患者暂时植入结肠支架,并行肠道准备,择期外科手术。术后患者无死亡,无相关并发症的发生,均痊愈出院。结论:肠镜下置入支架在治疗左半结肠癌性梗阻中有临床应用价值,既可作为姑息疗法,也可作为术前准备的一部分。     

低位胆道恶性梗阻性黄疸术前胆红素异常的处理策略探讨(附134例报告)

目的:探讨低位胆道恶性梗阻性黄疸患者术前胆红素异常的处理策略,以提高该类患者的临床疗效。方法:回顾性分析西京医院肝胆外科2008年1月1日-2017年12月31日收治的符合研究条件的134例低位胆道恶性梗阻性黄疸(术前总胆红素≥171μmol/L)患者,按胆红素水平分为中、重度黄疸组,分析和比较两组术前黄疸的处理方法、术后肝功能、并发症情况等。结果:两组患者胆道引流后总胆红素水平均明显低于引流前,而肝功能Child-Pugh分级比较差异均无统计学意义(P0.05);两组行术前胆道引流患者与未行胆道引流患者的围手术期情况比较均无统计学差异(P0.05);两组行术前胆道引流患者与未行胆道引流患者的手术并发症的发生情况比较均无统计学差异(P0.05)。结论:对于低位胆道恶性梗阻性黄疸患者,无论中度黄疸还是重度黄疸,原则上术前不必行胆道引流。对于伴有脏器功能不全、急性炎症或其他暂不宜手术的患者,可先行胆道引流处理,限期手术。若行术前胆道引流,采用PTCD方式,更为简单安全有效。     

The absence of a triphasic renovascular response by the multicalyceal kidney of the primate in reaction to acute,complete, unilateral,ureteric obstruction

The early renovascular response by the ipsilateral kidney to acute, total, unilateral, ureteric obstruction was investigated in the adult male chacma baboon (Papio ursinus). Complete occlusion was effected by ligating the ureter at the brim of the bony pelvis (“N” = 10). Sham studies were enacted using the same method but the ureter was not obstructed (“N” = 11). Haemodynamic reactions were monitored for 12 hours. Compared with the sham-occluded set, the renal pelvic pressures in the obstructed group were significantly increased (P < 0.05) from the second hour of the inquiry. However, there were no significant differences in renal blood flow, either between or within the respective cohorts. In this study, the renovascular response to acute ureteric occlusion was similar to that displayed by the multicalyceal kidney of other species under identical conditions. This reaction was fundamentally different to that exhibited by the unicalyceal kidney under similar circumstances.     

Unmodified calcium concentrations in tumour necrosis factor receptor subtype-mediated apoptotic cell death

Partial bladder outlet obstruction of the rabbit bladder results in a rapid increase in mass characterized by remodeling of the bladder wall.In this study we investigated the effect of partial outlet obstruction on microvessel density and distribution in the bladder wall immunohistochemically using CD31 as a marker for vascular endothelium, and on blood flow using a fluorescent microsphere technique. Transverse sections of bladder wall were examined after 0 (unobstructed), 1, 3, 5, 7, and 14 days of obstruction. The microvasculature of obstructed rabbit bladder mucosa and detrusor smooth muscle apparently increased relative to augmentation of these compartments, while new vessels appeared in the thickening serosa. These vascular changes correlated with results showing that, at 1 week after obstruction, blood flow (ml/min/g tissue) to the mucosa and detrusor was unchanged.Thickening of the serosa, apparent after 1 day of obstruction, began before its vascularization. Then, 1 week post-obstruction, there was significant microvessel formation in the transition region between the detrusor smooth muscle and the increasing serosa; after 2 weeks, the entire serosa was vascularized. The vascularization of the muscle-serosal transition region and then the remaining serosa apparently precedes fibroblast differentiation, providing blood supply and thus metabolic support for this process.All obstructed rabbit bladders in this study were in a state of compensated function based on their weights. Our working hypothesis is that blood flow per unit tissue mass is normal in compensated obstructed bladders, thus allowing for normal contractile function and cellular metabolism. The results of this study indicate the presence of an augmented microvasculature in compensated obstructed rabbit bladders that provides adequate blood perfusion for normal function.     

腹腔镜手术治疗粘连性肠梗阻的疗效及安全性研究

目的：探讨腹腔镜粘连松解术治疗粘连性肠梗阻（AIO）的疗效，减少再梗阻率。方法：将120 例AIO 患者随机分为两组，每 组60 例，开腹组实施开腹手术，腹腔镜组实施腹腔镜粘连松解术，观察两组术后恢复及并发症发生情况，对再梗阻危险因素进行 Logistic 回归分析。结果：腹腔镜组术中失血量（73.48± 9.32）mL，少于开腹组的（207.45± 33.21）mL（P<0.05）；腹腔镜组手术、术后 镇痛、下床活动、肠恢复蠕动、肛门恢复排气、拔除尿管及住院时间分别为（69.15± 10.13）min、（14.67± 7.23）h、（27.14± 7.04）h、 （3.11± 0.96）d、（3.24± 1.02）d、（3.37± 1.23）d、（7.95± 3.05）d，均短于开腹组的（83.84± 9.24）min、（27.38± 8.02）h、（36.23± 5.87） h、（4.05± 1.35）d、（4.35± 1.74）d、（5.02± 2.13）d、（10.35± 3.71）d（P<0.05)；腹腔镜组并发症发生率、再梗阻率分别为10.00%、 10.00%，均低于开腹组的33.33%、40.00%（P<0.05)；多因素Logistic 回归分析显示开腹手术、手术时间≥ 60 min 是再梗阻发生的独 立危险因素。结论：腹腔镜手术治疗AIO 疗效优于开腹手术，而且并发症与再梗阻率低。     

奥曲肽治疗急性粘连性肠梗阻疗效观察

目的:探讨生长抑素对腹部手术后急性粘连性肠梗阻的治疗作用。方法:70例急性粘连性肠梗阻患者随机分为观察组与对照组各35例。对照组予胃肠减压、灌肠、补液及抗感染治疗等常规治疗;观察组在此基础上加用奥曲肽(生长抑素类似物)0.1 mg皮下注射,每8h一次,治疗72 h。观察两组患者腹痛评分、腹痛缓解时间、胃肠减压量、肛门恢复排气时间、立卧位腹部平片、临床缓解情况。结果:观察组34例(97.1%)临床缓解,明显高于对照组的28例(80.0%)(P<0.05)。与对照组相比,观察组在治疗第1、2天后腹痛评分明显下降(均为P<0.01),腹痛缓解时间显著缩短(P<0.01),治疗第1、2、3天的胃肠减压量均显著减少(均为P<0.01),恢复排气时间也明显缩短(P<0.01)。结论:急性粘连性肠梗阻在常规治疗基础上加用生长抑素,可明显改善临床症状,提高疗效。     

微循环阻力指数在心血管疾病中的应用

随着医疗水平的发展,心血管疾病的诊断和治疗越来越规范和细致,不仅需要对心脏大血管进行评估,对微循环的评估也是十分重要。微循环阻力指数(index of microcirculatory resistance,IMR)是2003年由Fearon医生提出的一种操作方便、能真实反映微循环阻力的冠状动脉功能学定量评价指标。IMR的可重复性好,且不受冠状动脉狭窄影响,在预测围手术期心梗、PCI术后微血管阻塞、ST段抬高性心肌梗死患者PCI预后,评价PCI辅助治疗手段的有效性,阐明应激性心肌病的发病机制以及评价心血管药物的应用等方面具有重要意义。本文就IMR的特点及临床应用做一综述。     

Effect of neighbour visibility on nest attendance patterns of Barn Swallows Hirundo rustica in loose colonies

To assess the benefits of nesting at a site hidden from neighbours in a loosely colonial species, the Barn Swallow Hirundo rustica, we carried out two field experiments, obstruction removal and mirror placement, both replicating a situation in which a nest is made visible from another nest. Under manipulated conditions in both experiments, females increased the length of time they stayed at their nests during the egg‐laying and late incubation stages, while males extended their duration of stay during the egg‐laying and early nestling stages in mirror placement experiments only. The results suggest that Barn Swallows conceal their nests to reduce fitness costs imposed by neighbours nesting in view and that hiding the nest can reduce the amount of time spent guarding the nest during certain stages of the breeding period.