Human poliovirus receptor contributes to biliary atresia pathogenesis by exacerbating natural-killer-cell-mediated bile duct injury.

BACKGROUND AND AIMS: Natural killer (NK) cells play an important role in biliary atresia (BA) pathogenesis; human poliovirus receptor (PVR) is an important NK-cell modulator. Here, we explored the role of PVR in BA pathogenesis. METHODS: Poliovirus receptor expression and NK cell-associated genes were detected in human BA samples and a rotavirus-induced BA mouse model using quantitative PCR and immunofluorescence staining. Chemically modified small interfering RNA silenced PVR expression in the BA model, and its effects on the population and function of intrahepatic NK cells were investigated using flow cytometry (FCM). The effects of PVR overexpression and knockdown on proliferation, apoptosis and NK-cell-mediated lysis of cultured human cholangiocytes were analysed using FCM and cell viability assays. Serum PVR, high-mobility group box 1 (HMGB1), and interleukin-1beta (IL-1beta) levels were measured in a cohort of 50 patients using ELISA. RESULTS: Poliovirus receptor expression was upregulated in the biliary epithelium of BA patients and BA model and was positively correlated with the population and activation of intrahepatic NK cells. Silencing of PVR expression impaired the cytotoxicity of NK cells, reduced inflammation and protected mice from rotavirus-induced BA. Activation of the TLR3-IRF3 signalling pathway induced PVR expression in cultured cholangiocytes. PVR overexpression promoted proliferation and inhibited the apoptosis of cholangiocytes but exacerbated NK cell-mediated cholangiocyte lysis. Serum PVR levels were elevated in BA patients and were positively correlated with HMGB1 and IL-1beta levels. CONCLUSIONS: Poliovirus receptor contributes to BA pathogenesis by regulating NK cell-mediated bile duct injury; PVR has the value as a biomarker of BA.

Decreased enteric fatty acid amide hydrolase activity is associated with colonic inertia in slow transit constipation.

BACKGROUND: Constipation is one of the most common chronic digestive complaints. Gastrointestinal transit studies have divided it into three patterns: normal transit, slow transit constipation (STC), and outlet obstruction. It has been demonstrated that STC patients respond poorly to standard therapies, and the etiology of STC remains poorly understood. Animal studies have also shown that fatty acid amide hydrolase (FAAH) controls intestinal motility through its putative receptors or non-receptor-mediated pathways. However, the role of FAAH in STC has not been elaborated. METHODS: A case series was carried out on thirty-two STC patients fulfilling the Rome II criteria and on 24 controls. All of the subjects underwent a laparotomy in Shengjing Hospital. Colonic specimens were obtained and used for FAAH expression analysis, enzyme activity assay, and cannabinoid detection. RESULTS: FAAH immunoreactivity occurred in the enteric neurons and in the surface epithelial and glands. The expression level and enzyme activity of FAAH in the STC group were both significantly lower than those in the control group (P < 0.05). The amounts of anandamide, 2-arachidonylglycerol, and palmitoylethanolamide, which are negatively correlated with enzyme activity, were significantly higher in the constipation group than that in the control group. In the STC group, cannabinoid receptor type 1 immunoreactivity occurred predominantly in the submucosal and myenteric fibers that were obviously strong and wave-like in their appearance. Enteric ganglions decreased or disappeared. CONCLUSIONS: The tone of the enteric cannabinoids system is disturbed in STC, and the decreased enteric FAAH activity contributes to colonic inertia in STC.

[Epidemiologic survey on the prevalence and distribution of childhood functional constipation in the northern areas of China: a population-based study].

OBJECTIVE: Functional constipation (FC) is a common complaint in childhood but the prevalence still remains unclear, the aim of this study was to explore the prevalence of FC in childhood in the northern parts of China. METHODS: A screening program on FC in childhood was carried out in 5 northern cities (Beijing, Tianjin, Shenyang, Changchun, Harbin) of China according to symptoms under the Rome III criteria. Random clustered sampling of the inhabitants was carried out under stratification of cities, geographic zones, schools or nurseries. Sample size of each area was in proportion to the population of the area. The range of age was 4-14. All subjects under study were requested to fill in a questionnaire distributed by the teachers. The screening program was carried out immediately after a section survey was completed. All together, 20 000 questionnaires were distributed with 19 638 retrievals. According to the result of the screening, a small number of patients who met the criteria were further selected to undergo a detailed clinical examination in the hospital including laboratory examination, colonic transit time, defecography or/and barium enema, electromyologram and anorectal manometry to exclude organic disease of the colon. Simultaneously, a detailed questionnaire was requested to fill under the assistance of trained doctors or medical students. Prevalence of FC of the population was adjusted by the rate of correct diagnosis from the detailed study. RESULTS: The adjusted point prevalence of FC in 5 northern cities of China according to Rome III criteria was 4.73% with higher prevalence rate of FC seen in the Beijing area (5.02%) than in other cities (4.82%, 4.76%, 4.27%, 4.40%, with P < 0.001). Male to female ratio was 1.26:1 with majority of the FC fell in the 4 - 6 year olds (5.76%). CONCLUSION: FC appeared a common disorder in childhood in the northern parts of China which called for greater attention. Higher prevalence was noted in the age groups of 4-6.

[Preliminary study on diagnostic standard of functional constipation in children from five cities in North China].

OBJECTIVE: To explore the symptomatic criteria for diagnosis in children with functional constipation(FC) in North China. METHODS: A screening program for FC in children was carried out in 5 northern cities (Beijing, Tianjin, Shenyang, Changchun, Harbin) of China according to symptoms using Rome III( criteria. Random clustered sampling of the inhabitants was carried out under stratification of city, region and school or kindergarten. Sample size of each area was in proportion to the population of the area. The range of age was 4-14. All the subjects were requested to fill in a questionnaire distributed by the teacher. The screening program was carried out immediately after a plot survey. A total of 20,000 questionnaires were distributed and 19,638 retrieved. According to the result of the screening, a small number of patients who fulfilled the criteria were further selected to undergo detail clinical examinations in the hospital including laboratory examination, colonic transit time, defecography or/and barium enema, electromyogram and anorectal manometry to exclude organic disease of the colon. A detailed questionnaire was filled in with the assistance from a trained doctor or a medical student. Potential risk factors and the relative symptoms were explored by comparing frequencies between FC group and non-FC group using χ2 and Logistic analysis. RESULTS: Eighteen symptoms (defecation less than 3 times per week, dry hard sausage-shape stool, difficulty in defecation, abdominal pain, nausea and vomiting, etc) could exist in control group, but FC group had a higher frequency. The difference was statistically significant. Multivariable stepwise logistic regression analysis showed that defecation less than 3 times per week, hard sausage-shape feces, difficulty in defecation, and the need for laxative were associated with FC. The absence of other symptoms had no influence on diagnosis of FC. The sensitivity, specificity and diagnostic accuracy of symptomatic standard diagnostic test based on Rome III( criteria in FC children showed that ≥2 items had the best diagnostic accuracy but moderate sensitivity and specificity. CONCLUSION: The symptomatic criteria for FC diagnosis in children are suggested as follows: (1) defecation frequency less than 3 times per week; (2) dry, hard, sausage-shape stool in most defecation; (3) difficulty in most defecation; (4) use of medication or digital evacuation. FC can be considered when 2 of the above 4 criteria are met and the symptoms last at least 2 months.

[Quantitative analysis of sensory neurons innervating the muscle levator ani in rats with anorectal malformation].

OBJECTIVE: To quantitatively observe the sensory neurons innervating the levator ani muscle and explore the cause of poor post-operative anorectal function in patients with anorectal malformation (ARM). METHODS: Combining the microsurgery and microinjection techniques, we investigated the deficiency of sensory neurons of the spinal cord in fetal rats with anorectal malformation by injecting the retrograde tracer fluorogold (FG) into the muscle levator ani. Sixty 11 days pregnant female rats were fed with ethylenethiourea (ETU) so as to cause ARM in the fetuses. When the female rats were 20 days pregnant they underwent hysterectomy and the male fetal rats were taken out. Fluorogold (FG), a tracer, was injected into their levator ani muscles. Then the fetal rats were put back into the uteri. Twenty-four hours later hysterectomy was performed for the second time to take out and kill the live fetuses that had undergone FG injection. Their lumbo-sacral spinal cords were taken out, fixed and made into serial longitudinal sections. Digital camera system and fluorescent microscopy were used to observe the FG-labeled sensory neurons. Fifteen normal female rats were used as controls. RESULTS: The FG-labeled sensory neurons innervating levator ani muscle were located mainly in the posterior root ganglia of the 5 th segment of lumber and the 1 st sacral cord. The number of FG-labeled sensory neurons in the normal control fetuses, fetuses without defect of the ETU-fed female rats, fetuses with low type imperforate anus, and fetuses with high type imperforate anus were 11 804 +/- 2362, 10 429 +/- 708, 2886 +/- 705, and 1026 +/- 425 respectively, the latter 2 number being significantly fewer than that in the fetuses without defects (P < 0.05) and that in the normal controls (P < 0.05). CONCLUSION: Defective sensory neurons innervating the levator ani muscle co-exists with the alimentary tract anomaly in rat fetuses with ARM. The defective development of sensory neurons is an important factor likely to contribute to poor post-operative anorectal function despite surgical correction of the ARM.