肠屏障功能对豚鼠胆囊胆色素结石形成的影响

目的:探讨肠屏障功能与胆色素结石形成间的相关性,及其可能的作用机制.方法:豚鼠80只随机分为对照组(CON)、成石组(PS)、肠黏膜保护组(GLN),分别给予正常饲料、胆色素结石致石饮食、添加肠黏膜保护剂谷氨酰胺的致石饮食,饲养8wk建立胆囊胆色素结石模型.检测并比较各组胆结石成石率、肠黏膜形态、肠黏膜通透性、血浆内毒素水平、胆汁β-葡萄糖醛酸酶活性.结果:成石组成石率为73.9%,与正常组相比,成石组肠黏膜通透性增加,肠黏膜细胞超微结构受损,血浆内毒素水平[由(77±43)×10-6EU/L增至(1367±525)×10-6EU/L,P<0.01]和内、外源性胆汁β-葡萄糖醛酸酶活性增高(内源性由122.1±39.5Fishman单位增至209.8±47.5Fishman单位,P<0.01,外源性由573.5±476.9Fishman单位增至2206.6±983.9Fishman单位,P<0.01).肠黏膜保护组成石率下降至44.4%,各指标均较成石组降低,内毒素水平[(156±97)×10-6EU/Lvs(1367±525)×10-6EU/L,P<0.05]、肠黏膜通透性、肠黏膜细胞受损程度均较成石组有显著性差异,而胆汁β-葡萄糖醛酸酶活性无显著差异.结论:胆色素结石与肠屏障功能异常之间具有一定的相关性.肠屏障功能异常可能通过继发细菌移位、内毒素血症、胆汁β-葡萄糖醛酸酶活性改变,在促进胆色素结石的形成中发挥一定的作用.     

肠屏障在自身免疫性肝炎发病中的作用

目的观察并分析肠屏障在自身免疫性肝炎(AIH)发病中的作用,为阐释AIH的发病机制和探索基于肠道的治疗策略提供方向。方法纳入2017年1至12月在天津医科大学总医院就诊的14例AIH患者(AIH无肝硬化组6例,AIH肝硬化组8例)和10名健康对照(健康对照组),采用ELISA法检测各组血清D-乳酸、二胺氧化酶(DAO)含量,实时荧光定量PCR检测各组回肠末端组织紧密连接蛋白[闭锁小带蛋白-1(ZO-1)、闭合蛋白(occludin)]、细胞因子[IL-2、干扰素γ、IL-4和IL-10]和TLR4的相对表达量,蛋白质印迹法检测回肠末端组织分泌型免疫球蛋白A(sIgA)的相对表达量。选取30只BALB/c小鼠分为空白组、葡聚糖硫酸钠(DSS)组、刀豆蛋白A(ConA)组、DSS+ConA组、DSS+灌菌+ConA组,每组6只,检测各组小鼠结肠组织ZO-1和闭合蛋白的相对表达量,血清转氨酶水平(ALT、AST)和肝组织学炎症活动度Knodell评分。统计学方法采用独立样本t检验和单因素方差分析。结果AIH肝硬化组和AIH无肝硬化组的血清D-乳酸和DAO水平均高于健康对照组[(1768.2±147.1)μg/L、(436.2±197.0)μg/L比(100.2±10.9)μg/L和(11.5±2.5)U/L、(5.4±0.9)U/mL比(3.5±0.9)U/mL],且AIH肝硬化组血清D-乳酸和DAO水平最高,差异均有统计学意义(t=5.512、36.010、4.088和9.443,F=396.958、46.640,P均<0.01)。AIH肝硬化组的肠黏膜ZO-1、闭合蛋白的相对表达量均低于健康对照组(0.20±0.14比1.67±0.51,0.12±0.09比0.90±0.21),AIH无肝硬化组ZO-1的相对表达量低于健康对照组(0.99±0.37比1.67±0.51),差异均有统计学意义(t=8.641、7.407、2.295,P均<0.05)。AIH肝硬化组回肠末端组织中IL-2、干扰素γ的相对表达量均高于健康对照组(1.11±0.43比0.24±0.16和3.50±1.90比0.32±0.30),肠黏膜sIgA的相对表达量低于健康对照组(0.506±0.024比1.081±0.102),差异均有统计学意义(t=4.679、3.981、5.493,P均<0.05);AIH肝硬化组和AIH无肝硬化组IL-10的相对表达量均低于健康对照组(0.30±0.20、0.42±0.24比0.84±0.23),回肠末端组织TLR4的相对表达量均高于健康对照组(8.74±5.13、6.74±3.65比0.89±0.70),差异均有统计学意义(t=3.095、4.816、3.856、3.685,P均<0.05)。DSS+ConA组肠黏膜ZO-1和闭合蛋白的相对表达量均低于ConA组(0.14±0.08比0.98±0.13和0.09±0.02比0.98±0.16),血清ALT、AST水平和Knodell评分均高于ConA组[(5496.67±618.83)U/L比(3325.00±1030.06)U/L、(8825.00±1165.35)U/L比(5433.33±1691.14)U/L和(18.00±2.00)分比(9.33±3.01)分],差异均有统计学意义(t=13.480、13.520、4.427、4.045、-2.892,P均<0.01)。DSS+灌菌+ConA组肠黏膜ZO-1和闭合蛋白的相对表达量均高于DSS+ConA组(0.46±0.08比0.14±0.08和0.53±0.15比0.09±0.02),血清ALT、AST水平均低于DSS+ConA组[(4343.33±252.16)U/L比(5496.67±618.83)U/L和(6123.33±1086.60)U/L比(8825.00±1165.35)U/L],差异均有统计学意义(t=6.928、7.122、4.228、4.153,P均<0.01)。结论AIH患者的肠道通透性增高、肠屏障被破坏,且肝硬化患者较非肝硬化患者的程度更严重。肠屏障被破环会加重ConA诱导的免疫性肝损伤,而保护和修复肠屏障则可相对减轻ConA诱导的免疫性肝损伤。     

Pigment gallstone formation in the cholesterol-fed guinea pig

Female Hartley guinea pigs fed a 0.5% cholesterol-supplemented diet were found to form pigmented gallstones after 6 weeks (17/23) and 12 weeks (11/11), while only 2 of 44 animals fed a trace cholesterol diet formed gallstones over a comparable period. The light brown stones consisted primarily of aggregates of fine granular crystals, morphologically similar to calcium bilirubinate crystals. The stones were soluble in 0.1 N sodium hydroxide and were found to contain a substance which co-migrated with unconjugated bilirubin during thin-layer chromatography. Despite hypercholesterolemia (202 +/- 34 vs. 59 +/- 22 mg per dl in controls, p less than 0.05) and fatty infiltration of the liver, cholesterol-fed animals had a lithogenic index of only 0.22 +/- 0.04 in gallbladder bile as compared to a lithogenic index of 0.02 +/- 0.01 in animals fed the trace cholesterol diet. Accordingly, no cholesterol monohydrate crystals were found in any animals. Hematocrits among cholesterol-fed animals (47.6 +/- 1.2%) were lower than those of controls (54.8 +/- 1.3%, p less than 0.05) probably as a result of the cholesterol-induced hemolytic anemia which has been reported by others in this species. Fasting gallbladder volume was greater in cholesterol-fed animals (2.4 +/- 0.18 ml) than in controls (1.7 +/- 0.11, p less than 0.0025), and a comparable increase in gallbladder dry tissue mass was found. There was no evidence of biliary obstruction, however, and the gallbladder contractile response to octapeptide cholecystokinin was comparable in both groups.(ABSTRACT TRUNCATED AT 250 WORDS)     

Genital herpes: pathogenesis and chemotherapy in the guinea pig model

Genital herpes is different from other common venereal diseases in that there is no cure. As yet the natural history of genital herpes is not well understood. There are many unanswered questions regarding the biology of the disease; the virulence of the virus strains, individual host responses, and means for prevention and control all require further investigation. The study of genital herpes has been greatly aided in recent years by the development of animal models. The clinical and pathologic features of acute and recurrent genital disease of guinea pigs inoculated with low doses of herpes simplex virus are similar to those seen in human infection. Therefore, questions not readily studied in human infection--such as latent infection in the nervous system, the natural history, prevention, and treatment of neonatal herpes, the effects of immunosuppression on herpes infection, and the efficacy and toxicity of antiviral drugs and vaccines--are amenable to study in the guinea pig model. The applications of this animal model and its relevance to human disease are herein reviewed.     

The preliminary experimental and clinical study of the relationship between the pigment gallstone and intestinal mucosal barrier

Aims:  To investigate the relations between the formation of pigment gallstone and the function of the intestinal mucosal barrier, as well as the underlying mechanism.
Methods:  Eighty guinea pigs were randomly divided into three groups in which they were respectively given normal diet, gallstone-causing diet, and gallstone-formation diet with a supplementary intestinal mucosal protection compound known as glutamine. The model of pigment gallstone was established after 8 weeks of dietary administration. Indices about the function of the intestinal mucosal barrier and bacterial translocation were measured. Clinical cases were divided into three groups: control, cholesterol gallstone, and pigment gallstone, where the levels of plasma diamine oxidase (DAO), plasma endotoxin and the excretion rates of technetium 99m-diethylene triamine pentaacetic acid (99mTC-DTPA) in the urine of each group were measured.
Results:  In the pigment gallstone group, the level of plasma DAO and endotoxin, the excretory ratio of lactulose and mannitol in urine, the bacterial translocation ratio in the celiac lymph nodes and the activities of β-glucuronidase increased comparing to the control group. The gallstone-formation rate for the intestinal mucosal protection group (GLN) decreased, and other indices, except the activity of β-glucuronidase, were all lower than that of gallstone-formation group. In the clinical experiment, the levels of plasma DAO and endotoxin, as well as the excretory rate of 99mTC-DTPA in urine were higher in the patients with gallstones than that in the control group.
Conclusions:  The formation of pigment gallstone was related to the abnormal function of the intestinal mucosal barrier. The abnormality in the function of the intestinal mucosal barrier probably induced the formation of gallstone by a bacterial translocation mechanism.     

Melatonin prevents pigment gallstone formation induced by bile duct ligation in guinea pigs

Free radical-mediated oxidative stress has been implicated in the genesis of gallstone in vitro. This study was designed to examine the oxidative stress changes during pigment gallstone formation and to investigate whether melatonin (MLT) could act as a chemopreventive agent for cholelithiasis in a guinea pig model. The common bile duct of guinea pigs was ligated with or without MLT pretreatment. Animals were studied on day 7, 9, 12, and 14 after surgery. Stone and/or sludge developed in ligated guinea pigs without MLT. Fourier transform infrared spectra of the sludge showed the presence of calcium bilirubinate, whose peak height per milligram of sludge gradually increased with time after ligation. Total antioxidant activity (TAA) in bile of guinea pigs at day 14 after ligation reduced to one third of the level in sham-operated controls (P <.001). In addition, the bile of ligated guinea pigs had increased pH (P <.001), bile salts (P <.01), and malondialdehyde (MDA) (P <.05), compared to sham controls. Pretreatment of guinea pigs with MLT at a dose of 1,000 microg/kg significantly decreased the incidence of pigment gallstone formation at day 14 after ligation, as compared to no pretreatment (0/7 vs. 8/10). MLT also reverted the ligation-induced changes in biliary bile salts, pH, MDA, and TAA to control levels. These in vivo findings support a causative role of oxidative stress in the bile duct ligation-induced pigment gallstone formation. Antioxidants may prove useful in preventing pigment gallstone formation in humans.     

豚鼠镰刀菌性角膜炎模型的建立

目的探讨豚鼠镰刀菌性角膜炎模型的建立方法,为真菌性角膜炎的临床和基础研究提供理想的动物模型。方法采用角膜划痕法和角膜基质注射法以不同浓度茄病镰刀菌孢子悬液感染豚鼠,建立镰刀菌性角膜炎模型,观察感染症状,进行组织病理学和病原学检查,判断最适感染方式和接种浓度。结果划痕法感染角膜病变较轻,易自愈,感染率较低;基质注射法感染病变较重,且较持久,感染率较高。随着接种孢子悬液浓度的增加感染率增高。结论利用角膜基质注射法接种较高浓度的孢子悬液成功地建立了豚鼠镰刀菌性角膜炎模型,为真菌性角膜炎的进一步研究奠定了基础。     

Effect of age and sensitivity to cholecystokinin on gallstone formation in the guinea pig

The purpose of this study was to evaluate the effect of age and the role of cholecystokinin therapy on gallstone formation in guinea pigs. Guinea pigs (31 1-mo-old, 31 1-yr-old, and 23 3-yr-old) were placed on a cholelithogenic diet for 2 wk while another 10 guinea pigs of each age group remained on regular chow. Half of each group received a daily injection of cholecystokinin (0.5 nmol/kg). After 2 wk, guinea pigs were killed and the gallbladders were examined for gallstones. The concentrations of bile constituents were determined. The prevalence of gallstones was: 1-mo-old, control 0 out of 16, cholecystokinin 1 out of 15; 1-yr-old, control 3 out of 14, cholecystokinin 5 out of 16; 3-yr-old, control 10 out of 11, cholecystokinin 3 out of 8. Gallstone formation was significantly greater in 3-yr-old controls than in the two younger control groups, and cholecystokinin treatment significantly reduced the incidence of gallstones to near the level seen in younger guinea pigs. In the two younger age groups (but not in the 3-yr-old group), the cholelithogenic diet significantly reduced the concentration of bile salts in bile below that of guinea pigs on a normal diet. The cholelithogenic diet and treatment with cholecystokinin did not alter the relative compositions of bile lipids from that of guinea pigs on a normal diet in any of the three ages studied. In the second experiment we measured gallbladder emptying in response to exogenous infusion of cholecystokinin-8 (100 fmol/kg/h-100 nmol/kg/h) in the same three age groups of guinea pigs in vivo that had been maintained on regular chow. There was no difference in cholecystokinin sensitivity between the two younger age groups, but both were significantly more sensitive to cholecystokinin than the 3-yr-old guinea pigs in rate of gallbladder emptying in the dose range 1 pmol/kg/h-1 nmol/kg/h. We conclude that a major factor in the increased incidence of gallstone formation in the aged guinea pig gallstone model is decreased gallbladder emptying due to decreased gallbladder sensitivity to cholecystokinin.     

Role of substance P in increased airway hypersensitivity following induced stress in a guinea pig asthma model.

Stress is one of the important factors influencing bronchial asthma, but many questions still remain unanswered. To clarify this point we examined airway hypersensitivity before and after electric shock stress and the role of substance P in an animal model of asthma. We determined airway hypersensitivity to histamine and the substance P levels in serum, bronchoalveolar lavage fluid, and bronchial tissue before and after electric shock stress in biphasic asthma-responsive guinea pigs which had been sensitized using ovalbumin. The cell components in bronchoalveolar lavage fluid were also examined. Airway hypersensitivity to histamine (4.9-156 micrograms/ml) was significantly increased (p < 0.01) by electric shock stress. The substance P level was also significantly increased in plasma and bronchoalveolar lavage fluid, but it was significantly decreased in bronchial tissue. The number of eosinophils in bronchoalveolar lavage fluid increased significantly after electric shock stress. These findings demonstrated that airway hypersensitivity to histamine was increased by stress and suggested that substance P, as well as eosinophils, contribute to the pathogenesis of hypersensitivity.     

Control of guinea pig intestinal electrolyte secretion by a delta-opiate receptor.

The effects of opioids on transepithelial potential difference and short-circuit current across guinea pig ileum stripped of one muscle layer were measured in vitro in Ussing chambers. Opioid peptides such as [DAla2, DLeu5]enkephalin and [DAla2, DMet5]enkephalin, which are primarily agonists at delta-opiate receptors, were able to reduce transepithelial potential difference and short-circuit current at concentrations as low as 1 nM. The narcotic drug etorphine was also very potent in reducing short-circuit current, but fentanyl and morphine, which are primarily agonists at mu-opiate receptors, were almost completely ineffective. Ketocyclazocine was relatively ineffective, and beta-endorphin had intermediate potency. All opioid effects could be reversed by the opiate antagonist naloxone. Somatostatin also reduced short-circuit current, but its effect was not reduced by naloxone. Chloride flux measurements indicated that the effect of etorphine on short-circuit current is associated with an enhancement of active Cl- absorption. The relative effects of opioids in this system suggest that their actions are being mediated by a specific delta-opiate receptor. In contrast, opioid effects on guinea pig intestinal smooth muscle seem to be primarily mediated by a mu-opiate receptor.     

Role of myosin light chain kinase in intestinal epithelial barrier defects in a rat model of bowel obstruction

Background

Previous studies have reported seasonal variation in peptic ulcer disease (PUD), but few large-scale, population-based studies have been conducted.

Methods

To verify whether a seasonal variation in cases of PUD (either compicated or not complicated) requiring acute hospitalization exists, we assessed the database of hospital admissions of the region Emilia Romagna (RER), Italy, obtained from the Center for Health Statistics, between January 1998 and December 2005. Admissions were categorized by sex, age (<65, 65-74, ≥ 75 yrs), site of PUD lesion (stomach or duodenum), main complication (hemorrhage or perforation), and final outcome (intended as fatal outcome: in-hospital death; nonfatal outcome: patient discharged alive). Temporal patterns in PUD admissions were assessed in two ways, considering a) total counts per single month and season, and b) prevalence proportion, such as the monthly prevalence of PUD admissions divided by the monthly prevalence of total hospital admissions, to assess if the temporal patterns in the raw data might be the consequence of seasonal and annual variations in hospital admissions per se in the region. For statistical analysis, the χ2 test for goodness of fit and inferential chronobiologic method (Cosinor and partial Fourier series) were used.

Results

Of the total sample of PUD patients (26,848 [16,795 males, age 65 ± 16 yrs; 10,053 females, age 72 ± 15 yrs, p < 0.001)], 7,151 were <65 yrs of age, 8,849 between 65 and 74 yrs of age, and 10,848 ≥ 75 yrs of age. There were more cases of duodenal (DU). (89.8%) than gastric ulcer (GU) (3.6%), and there were 1,290 (4.8%) fatal events. Data by season showed a statistically difference with the lowest proportion of PUD hospital admissions in summer (23.3%) (p < 0.001), for total cases and rather all subgroups. Chronobiological analysis identified three major peaks of PUD hospitalizations (September-October, January-February, and April-May) for the whole sample (p = 0.035), and several subgroups, with nadir in July. Finally, analysis of the monthly prevalence proportions yielded a significant (p = 0.025) biphasic pattern with a main peak in August-September-October, and a secondary one in January-February.

Conclusions

A seasonal variation in PUD hospitalization, characterized by three peaks of higher incidence (Autumn, Winter, and Spring) is observed. When data corrected by monthly admission proportions are analyzed, late summer-autumn and winter are confirmed as higher risk periods. The underlying pathophysiologic mechanisms are unknown, and need further studies. In subjects at higher risk, certain periods of the year could deserve an appropriate pharmacological protection to reduce the risk of PUD hospitalization.     

Vaccine-induced cytokine responses in a guinea pig model of pulmonary tuberculosis

Guinea pigs exposed to very small numbers of virulent tubercle bacilli by the respiratory route develop a disease which mimics many of the important features of the pathogenesis of human tuberculosis (TB), including the expression of strong protective immunity following vaccination with BCG. In order to elucidate the precise immunological mechanisms of vaccine-induced resistance in this model, both mRNA and protein assays for several guinea pig cytokines and chemokines have been developed. The coordinated expression of cytokine and chemokine mRNA and protein was examined in various leukocyte populations and in inflammatory cells and fluid collected following the induction of tuberculous pleurisy in BCG-vaccinated guinea pigs. Real-time RT-PCR assays revealed that the mRNA levels for IFNgamma, TNFalpha, and IL-8 rose over the first few days of TB pleuritis and then declined over the 9 days of the study. Injection of anti-TGFbeta on day 8 following pleurisy induction resulted in significant changes in cytokine mRNA levels and PPD-induced proliferation in pleural effusion lymphocytes taken 24h later. BCG vaccination induced significantly higher levels of bioactive TNFalpha protein in the supernatants of alveolar, peritoneal and splenic cells from BCG-vaccinated guinea pigs cultured in the presence of attenuated or virulent mycobacteria. In sharp contrast, following virulent challenge, all three cell types from BCG-vaccinated guinea pigs produced significantly less TNFalpha. Thus, BCG vaccination appears to modulate the potentially harmful effects of TNFalpha in this model of pulmonary TB. Levels of mRNA for IL-12p40 were upregulated by exposure of infected and uninfected macrophages to recombinant guinea pig (rgp)TNFalpha. The intracellular survival of mycobacteria was enhanced when endogeous TNFalpha activity was neutralized with anti-rgpTNFalpha antiserum. rgp RANTES (CCL5) upregulated mRNA levels for TNFalpha, IL-1beta, MCP-1 (CCL2), and IL-8 (CXCL8) in alveolar and peritoneal macrophages. These results illustrate the profound effects of prior vaccination with BCG on the cytokine and chemokine responses of distinct cell populations in the guinea pig following exposure to attenuated and virulent strains of M. tuberculosis.     

Role of airway epithelial barrier dysfunction in pathogenesis of asthma

Bronchial asthma is characterized by persistent cough, increased sputum, and repeated wheezing. The pathophysiology underlying these symptoms is the hyper-responsiveness of the airway along with chronic airway inflammation. Repeated injury, repair, and regeneration of the airway epithelium following exposure to environmental factors and inflammation results in histological changes and functional abnormalities in the airway mucosal epithelium; such changes are believed to have a significant association with the pathophysiology of asthma. Damage to the barrier functions of the airway epithelium enhances mucosal permeability of foreign substances in the airway epithelium of patients with asthma. Thus, epithelial barrier fragility is closely involved in releasing epithelial cytokines (e.g., TSLP, IL-25, and IL-33) because of the activation of airway epithelial cells, dendritic cells, and innate group 2 innate lymphoid cells (ILC2). Functional abnormalities of the airway epithelial cells along with the activation of dendritic cells, Th2 cells, and ILC2 form a single immunopathological unit that is considered to cause allergic airway inflammation. Here we use the latest published literature to discuss the potential pathological mechanisms regarding the onset and progressive severity of asthma with regard to the disruption of the airway epithelial function.     

Role of the intestinal barrier in inflammatory bowel disease

A critical function of the intestinal mucosa is to form a barrier that separates luminal contents from the interstitium. The single layer of intestinal epithelial cells （IECs） serves as a dynamic interface between the host and its environment. Cell polarity and structural properties of the epithelium is complex and is important in the development of epithelial barrier function. Epithelial cells associate with each other via a series of intercellular junctions. The apical most intercellular junctional complex referred to as the Apical Junction Complex （AJC） is important in not only cell-cell recognition, but also in the regulation of paracellular movement of fluid and solutes. Defects in the intestinal epithelial barrier function have been observed in a number of intestinal disorders such as inflammatory bowel disease （IBD）. It is now becoming evident that an aberrant epithelial barrier function plays a central role in the pathophysiology of IBD. Thus, a better understanding of the intestinal epithelial barrier structure and function in healthy and disease states such as IBD will foster new ideas for the development of therapies for such chronic disorders.     

Octreotide in intestinal lymphangiectasia: lack of a clinical response and failure to alter lymphatic function in a guinea pig model.

Intestinal lymphangiectasia, which can be classified as primary or secondary, is an unusual cause of protein-losing enteropathy. The main clinical features include edema, fat malabsorption, lymphopenia and hypoalbuminemia. Clinical management generally includes a low-fat diet and supplementation with medium chain triglycerides. A small number of recent reports advocate the use of octreotide in intestinal lymphangiectasia. It is unclear why octreotide was used in these studies; although octreotide can alter splanchnic blood flow and intestinal motility, its actions on lymphatic function has never been investigated. A case of a patient with intestinal lymphangiectasia who required a shunt procedure after failing medium chain triglycerides and octreotide therapy is presented. During the management of this case, all existing literature on intestinal lymphangiectasia and all the known actions of octreotide were reviewed. Because some of the case reports suggested that octreotide may improve the clinical course of intestinal lymphangiectasia by altering lymphatic function, a series of experiments were undertaken to assess this. In an established guinea pig model, the role of octreotide in lymphatic function was examined. In this model system, the mesenteric lymphatic vessels responded to 5-hydroxytryptamine with a decrease in constriction frequency, while histamine administration markedly increased lymphatic constriction frequency. Octreotide failed to produce any change in lymphatic function when a wide range of concentrations were applied to the mesenteric lymphatic vessel preparation. In conclusion, in this case, octreotide failed to induce a clinical response and laboratory studies showed that octreotide did not alter lymphatic function. Thus, the mechanisms by which octreotide induced clinical responses in the cases reported elsewhere in the literature remain unclear, but the present study suggests that it does not appear to act via increasing lymphatic pumping.     

Role of intestinal flora imbalance in pathogenesis of pouchitis

Objective: To discuss the role of intestinal flora imbalance in the pathogenesis of pouchitis. Methods: The puochitis rat model was established and the faeces sample and the mucous membrane sample were collected regularly, in which the bacterial nucleic acids were extracted for quantitative analysis of the intestinal flora in the samples through using the real-time quantitative PCR technique and high energy sequencing technology. Results: The disorder phenomenon of the intestinal flora appeared at the 7th day of the experiment, and the pouchitis was presented at the 21 th day of the experiment. At the 31 th day of the experiment, compared to control group and non-pouchitis group, the quantity of Bifidobacterium and the Lactobacillusof the pouchitis model rats in the mucous membrane sample and the faeces sample were significantly decreased(P0.05), and the Bacteroidetes, Faecalibacterium prausnitzii and 桛 Clostridium leptum subgroup in the mucous membrane of pouchitis were significantly decreased(P0.05). The Clostridium coccoides group was the main flora in the mucous membrane of pouchitis, the bacterial diversity of non-puochitis group and control group was significantly higher than that of the puochitis group(P0.05). Conclusions: The intestinal flora imbalance is one of the factors that cause the incidence of the pouhitis; this study provides a clue of the pathogenesis and treatment direction of the intestinal inflammatory disease.     

Radioimmunoassay of vasoactive intestinal peptide immunoreactivity in guinea pig respiratory tract

Although vasoactive intestinal peptide (VIP) has been suggested to be the neurotransmitter of non-adrenergic and non-cholinergic (NANC) inhibitory nerves, its physiological functions and movements in the airway are obscure. In this study, VIP immunoreactivity in the respiratory tract from guinea pigs was measured as a preliminary experiment to elucidate its functions. VIP immunoreactivity was measured by radioimmunoassay. The rate of VIP disappearance during extraction was 52.5 +/- 17.4 (mean +/- SD)%. The dose-response curve of tissue extract almost paralleled the standard curve of authentic VIP. VIP immunoreactivity of tracheas was 939.9 +/- 262.1 pg/g wet weight and that of extrapulmonary bronchi was 858.0 +/- 241.1 pg/g wet weight. Although VIP immunoreactivity of lung extracts was not detectable in 14 samples out of 23, the value of 9 samples was 111.7 +/- 61.5 pg/g wet weight. These results suggest that there may be more VIP immunoreactivity present in tracheas and extrapulmonary bronchi than in lungs.     

Immunologic characteristics of intestinal lymphoid cells of the guinea pig

Populations of lymphoid cells from the gastrointestinal tract of guinea pigs were compared with splenic cells for both morphologic and functional characteristics. Gastrointestinal lymphoid cells were isolated from mesenteric lymph nodes, Peyer's patches, and also for the epithelium and lamina propria of the small intestinal mucosa. Isolated intraepithelial and lamina propria lymphocyte populations contained (a) T cells, B cells, and macrophages; (b) T cells that proliferated to phytohemagglutinin and concanavalin A; and (c) B cells that proliferated to bacterial lipopolysaccharide. Using inbred guinea pigs, the intraepithelial and lamina propria lymphocytes were shown to contain T cells capable of proliferating to alloantigens in mixed leukocyte culture, and also cells capable of stimulating alloreactive T cells. These studies demonstrate the presence of immunologically reactive T cells and B cells in isolated small intestinal mucosal lymphoid cells from guinea pigs.     

Phosphocitrate blocks calcification-induced articular joint degeneration in a guinea pig model

OBJECTIVE: Calcium deposition occurs frequently in osteoarthritic (OA) joints. However, evidence for a causal role of calcification in cartilage degeneration is inferential. The present study was undertaken to examine the role of calcification in OA disease progression and to evaluate a formulation of phosphocitrate (PC) as a potential therapeutic agent. METHODS: We have identified a guinea pig OA model in which meniscal calcification appears to correlate with aging and disease progression. We synthesized a new formulation of PC, [CaNa(PC)2(H2O)](n) (CaNaPC), which is a potent antimineralization agent and a specific inhibitor of crystal-induced biologic effects. After weekly treatment of guinea pigs with experimental OA with CaNaPC for 3 months, we examined calcification in menisci and cartilage degeneration. As a control, we examined whether similar CaNaPC treatment had any therapeutic effect in a hemi-meniscectomy model in which there is no known crystal involvement. RESULTS: Meniscal calcification correlated with cartilage degeneration in this animal model. PC treatment led to significant reduction of calcium deposits and arrested OA disease progression. Similar treatment had no effect in the hemi-meniscectomy model. CONCLUSION: CaNaPC diminishes mineralization in a cutaneous calcergy model and a model of OA in which intraarticular mineralization is a prominent feature. In the OA guinea pig model, inhibition of calcification is accompanied by diminished cartilage degeneration. CaNaPC has no therapeutic effect in the hemi-meniscectomy model. We conclude that pathologic calcification may initiate or amplify processes leading to cartilage degeneration and that CaNaPC may interrupt such a pathway.     

Effect of montelukast in a guinea pig model of cough variant asthma

Cough variant asthma is known as a major cause of chronic cough. Fundamental features of cough variant asthma are prolonged non-productive cough responding to bronchodilator therapy, no history of wheezing or dyspnea attack, normal cough sensitivity and slightly increased bronchial responsiveness. Recently, we reported the animal model of cough variant asthma. The aim of this study was to clarify the involvement of cysteinyl leukotrienes (cysLTs) in this model by using a specific leukotriene receptor antagonist, montelukast. Cough number and specific airway resistance (sRaw) were measured during the antigen inhalation (1.5 min) and following 18.5 min, which was carried out 72 h after the first antigen inhalation in actively sensitized guinea pigs, and then total cell number and cell differentials in bronchoalveolar lavage fluid (BALF) were measured. Montelukast significantly reduced the antigen re-inhalation-induced cough, increase in sRaw, and increase in total cell number in BALF. In conclusion, cysLTs may play an important part in antigen-induced cough associated with bronchoconstriction and airway inflammation in cough variant asthma.