Two-year follow-up of Helicobacter pylori infection in C57BL/6 and Balb/cA mice

Helicobacter pylori infection is associated with chronic gastritis, peptic ulcer disease, gastric adenocarcinoma and MALT lymphoma. We previously found high-grade lymphoma after 13 months' H. pylori infection in C57BL/6 mice. In this study we followed H. pylori infection by three different isolates in C57BL/6 and Balb/cA mice for 23 months. Six-week-old C57BL/6 and Balb/cA mice were infected with H. pylori strains 119p (CagA+, VacA+), SS1 (CagA+, VacA+) and G50 (CagA-, VacA-). Mice were followed at 2 weeks, 10 weeks and 23 months post-inoculation (p.i.) by culture, histopathology and serology. Strain G50 was only reisolated from mice 2 weeks p.i. There was no difference in colonization between strain 119p and SS1 at 10 weeks p.i., whereas SS1 gave 100% colonization versus 119p gave 50% 23 months p.i. Interestingly, the inflammation score was higher in mice infected with strain 119p than with SS1 10-week p.i., and there were lymphoepithelial lesions in mice infected with strain 119p and G50 but not with SS1 at 23 months post-infection. Eight mice infected with strains 119p and G50 developed gastric lymphoma (grade 5 and 4). One C57BL/6 mouse infected with strain 119p developed hepatocellular carcinoma after 23 months. Immunoblot showed specific bands of 26-33 kDa against H. pylori in infected mice, and two mice infected with strain SSI reacted with antibodies to the 120 kDa CagA toxin. Conclusion: A reproducible animal model for H. pylori-induced lymphoma and possibly hepatocellular carcinoma is described. Strain diversity may lead to different outcomes of H. pylori infection.     

幽门螺杆菌感染小鼠及其抗原免疫小鼠后体液免疫应答的比较

目的：比较BALB／c小鼠感染H.pylori后以及经H.pylori UreB抗原口服免疫后的体液免疫应答的差异。方法：80只BALB／c小鼠分为感染组和免疫组，感染组灌喂H.pylori小鼠适应株；免疫组灌喂重组H.pylori UreB抗原和佐剂LTB。在试验的0，2，6和10周时每组分别取10只小鼠收集唾液及血液标本，用ELISA法检测抗UreBIgG和IgA抗体，同时采集胃组织作H.pylori感染检测。结果：感染组小鼠在灌喂H.pylori后2，6，10周，感染率均为100％，其血清中抗UreB IgG增高明显，但血清及唾液中均未见IgA的明显升高，；免疫组小鼠在初次免疫后第6，10周后，血清及唾液中抗UreB,IgG和IgA抗体的均显著升高。结论：H.yplori感染BALB／ c小鼠不能诱导其产生明显的特异性黏膜免疫应答，而重组UreB可作为良好的免疫原诱导其产生分泌型IgA抗体。     

miRNA-148a对乙型肝炎小鼠的保护作用

目的探讨miR-148a对乙型肝炎模型小鼠肝功能的影响。方法40只SPF级C57BL/6小鼠(20-25 g)随机分为对照组、模型组、miRNA-148a mimics及miRNA-148a inhibitor组,每组10只。除对照组外,其余各组小鼠均建立慢性乙型肝炎模型,利用尾静脉注射pAAV/HBV1.3表达质粒的方法构建乙型肝炎小鼠模型。待模型成功后,将miRNA-148a mimics、miRNA-148a inhibitor经尾静脉注射到乙型肝炎模型小鼠体内,3周后利用Real-time PCR检测血清中miRNA-148a表达水平、乙肝病毒的脱氧核糖核酸(HBV-DNA)水平;利用试剂盒检测肝功能相关指标天门冬氨酸氨基转移酶(AST),丙氨酸氨基转移酶(ALT)、γ-谷氨酰转肽酶(γ-GT)、总胆红素(TBIL);ELISA检测C反应蛋白(CRP)及炎症因子肿瘤坏死因子α(TNF-α)、白细胞介素6(IL-6)的水平变化。结果miRNA-148a mimics组与模型组相比,miRNA-148a表达水平明显增加,血清中HBVDNA水平降低,AST、ALT、γ-GT、TBIL及CRP水平明显降低(P<0.05),且炎症因子TNF-α和IL-6水平也明显降低(P<0.05)。miRNA-148a inhibitor能显著降低miRNA-148a的表达水平并增加小鼠血清中HBV-DNA水平,同时,AST,ALT,γ-GT,TBIL,CRP水平及炎症因子TNF-α和IL-6水平显著增加(P<0.05)。结论MiRNA-148a能够改善乙型肝炎小鼠肝功能,抑制炎症因子的表达,发挥保护肝脏的作用。     

幽门螺杆菌感染对人牙龈组织细胞凋亡的影响

目的:观察正常牙龈组织中幽门螺杆菌(Hp)的感染情况及其对人牙龈组织细胞凋亡的影响。方法:采用聚合酶链式反应(PCR)检测30例健康牙龈组织中Hp感染情况,应用脱氧核糖核苷酸末端转移酶介导的原位缺口末端标记(TUNEL)法检测牙龈组织中的细胞凋亡指数,分析Hp对牙龈组织的毒性作用。结果:PCR检测的30名患者,Hp阳性率为40%。在TUNEL结果中,可见Hp阳性组有大量棕色凋亡细胞,部分细胞核固缩成团或核膜周围边集成环状。而正常对照组中阳性凋亡细胞较Hp感染组明显偏低,2组细胞凋亡指数差异有统计学意义。结论:Hp感染可能是引起牙龈组织细胞凋亡的因素之一。     

汉坦病毒感染C57BL/6小鼠组织中特异性抗原的检测

目的通过检测汉坦病毒感染C57BL/6小鼠组织中特异性病毒抗原,以建立汉坦病毒感染动物的评价体系。方法将汉坦病毒陈株按照原病毒液、10-1、10-2三个滴度经肌肉注射感染C57BL/6小鼠,在感染后的第3、6、9、12、15天,分别取小鼠的心、肝、脾、肺、肾、脑等组织研磨后制成病毒悬液,以ELISA法检测各组织中的病毒特异性抗原。结果 C57BL/6小鼠感染汉坦病毒后短期内在其肝脏和脾脏可以检测到特异性抗原,随着时间的延长,这些抗原逐步消失。结论上述结果为建立汉坦病毒感染动物的评价体系提供了一种参考。     

非酒精性脂肪性肝病与幽门螺杆菌感染的相关性

非酒精性脂肪性肝病(non-alcoholic fatty liver disease,NAFLD)本质上是一种肝代谢性疾病,其发病机制复杂,目前尚未完全明确.目前各项资料显示幽门螺杆菌感染(Helicobacter pylori,Hp)与NAFLD的发生和发展有密切的关系,但也有研究得出了相反的结论.对于存在争议的部分至今尚未解决,但如证实Hp感染可作为NAFLD的一种独立危险因素存在,则对NAFLD发病预测以及治疗提供帮助,因此研究两者相关性的工作仍然具有临床意义.     

Abnormality in the cerebellar folial pattern of C57BL/6J mice

The characteristic folial pattern of the mouse cerebellum is formed during postnatal development. We observed this process in C57BL/6J (B6) mice in detail, and found an abnormal folial pattern in a specific region (lobules VIII and IX of the vermis) in a substantial number of B6 mice. The frequency of this abnormality increased during postnatal development and reached 55% in the adult. Thus, the present study showed an abnormality in the cerebellar folial pattern of B6 mice, a mouse widely used in knockout studies, and called for caution in the phenotypic analysis of knockout mice of the B6 genetic background.     

幽门螺杆菌感染在肝硬化、肝癌高动力循环及胃黏膜病变中的作用

目的：为探讨幽门螺杆菌感染在肝硬化、肝硬化并发肝癌患者高动力循环及胃黏膜病变中的作用.方法：应用快速尿素酶试验、14C-尿素呼气试验、鲎血试验定量法、免疫印迹试验、亚硝酸盐比色法及ELISA法检测肝硬化、肝硬化并发肝癌患者胃黏膜标本HP感染;胃黏膜组织、外周血IL-1、IL-8、TNF-α、内毒素、一氧化氮（NO）、内皮素（ET）及VacA和CagA抗体水平;应用彩色多普勒超声检测门静脉系统血流量参数.结果：肝硬化患者HP感染率77.1%,VacA和CagA抗体同时阳性率为60.4%;VacA和CagA抗体阳性HP感染的肝硬化患者胃黏膜组织、外周血IL-1、IL-8、TNF-α、内毒素、NO及ET水平明显高于VacA和CagA抗体阴性HP感染的肝硬化患者（P＜0.05,P＜0.01）,VacA和CagA抗体阳性HP感染的肝硬化患者其脾静脉血流量（SVF）与肠系膜上静脉血流量（SMVF）之和显著大于、门静脉血流量（PVF）显著小于VacA和CagA抗体阴性HP感染的肝硬化患者SVF与SMVF之和及PVF.结论：产毒素幽门螺杆菌感染在肝硬化、肝癌高动力循环及其胃黏膜病变中具有重要作用.     

根除儿童口腔幽门螺杆菌预防胃内幽门螺杆菌感染的多中心研究

目的:探讨根除儿童口腔幽门螺杆菌（Hp）预防胃内Hp感染的可能性。方法:采用多中心前瞻随机研究,选取口腔Hp阳性但胃内Hp阴性的幼儿园儿童共计427例,随机分为使用“无幽梅”牙膏组与普通牙膏组,分别接受“无幽梅”牙膏和普通牙膏。疗程结束后,再次检测口腔Hp,将口腔Hp阳性及阴性患者各分为一组,1年后行C13呼气试验检查,分析两组患者胃内Hp感染情况。口腔Hp检测方法采用特异度及敏感度双高的套式PCR方法。结果:随访1年,口腔Hp阴性组胃内Hp感染率为0.51%,口腔Hp阳性组胃内Hp感染率为6.51%,两组统计差异具有显著性（P<0.01）。结论:儿童根除口腔Hp可以降低胃内Hp感染的发生。     

Pathogenicity of Helicobacter pylori infection

Numerous Helicobacter pylori virulence factors, including various enzymes (urease, catalase, lipase, phospholipase and proteases), vacuolating cytotoxin (a product of expression of the vacA gene), and the immunogenic protein CagA, encoded by the cagA gene localised in the H. pylori pathogenicity island, are involved in the pathomechanism of infection caused by these organisms. This review presents the current state of knowledge concerning the molecular mechanisms and epidemiology of H. pylori infection, based on the published literature and recent unpublished observations.     

荷EL4肿瘤小鼠模型的建立及美法仑抑瘤作用免疫机制的探讨

目的:建立荷小鼠淋巴瘤EL4的野生型C57BL/6小鼠及其裸鼠模型,探讨美法仑(melphalan)抑瘤作用的免疫机制。方法:给正常野生型C57BL/6小鼠皮下接种小鼠淋巴瘤EL4细胞,建立荷EL4肿瘤的小鼠模型。于野生型C57BL/6小鼠皮下接种瘤细胞后12d,经腹腔给荷瘤小鼠单次注射不同剂量的美法仑,找出美法仑可发挥最大的抑瘤作用,并能致使肿瘤消退、不再复发的最小使用剂量。然后再给野生型C57BL/6小鼠及其裸鼠(遗传背景相同)皮下同时接种小鼠淋巴瘤EL4细胞建立两种荷瘤小鼠模型。同样于接种瘤细胞后12d,经腹腔给两种荷瘤小鼠模型均注射可使野生型C57BL/6小鼠肿瘤消退、不再复发的最低剂量的美法仑,以正常野生型C57BL/6小鼠为对照,观察在T淋巴细胞缺陷的裸鼠体内美法仑的抑瘤作用。结果:注射7.5mg/kg美法仑治疗后,免疫功能正常的野生型C57BL/6荷瘤小鼠的肿瘤消退;而荷瘤C57BL/6裸鼠的肿瘤仍继续生长。结论:单一剂量的美法仑对荷淋巴瘤EL4小鼠具有明显的治疗作用,其作用的发挥需要T淋巴细胞的参与,可能与T细胞的杀伤作用有关。     

巨细胞病毒感染C57BL/6小鼠诱导NK细胞免疫应答的模型研究

目的:研究小鼠巨细胞病毒(murine cytomegalovirus,MCMV)感染C57BL/6小鼠诱导自然杀伤(natural killer,NK)细胞免疫应答的最佳剂量和最佳时间。方法:分别根据剂量和时间效应进行分组,剂量效应：无特定病原体( specific pathogen free,SPF)级8周龄C57...     

应用荧光定量PCR法检测病理组织中幽门螺旋杆菌感染

目的探讨荧光定量PCR方法检测病理组织中幽门螺旋杆菌（Hp）的效果,为临床Hp感染诊断提供快速有效的检测方法。方法应用荧光定量PCR法及苯胺蓝染色法分别对106例临床送检胃窦黏膜组织标本进行幽门螺旋杆菌检测,对检测结果进行对比分析。结果在106例胃窦标本中,荧光定量PCR法检测阳性例数68例,阳性率为64．2％,苯胺蓝染色法检测阳性例数46例,阳性率为43．4％。两种方法检测阳性率比较有显著性差异（P〈0．05）。结论荧光定量PCR技术用于检测病理组织中幽门螺旋杆菌,具有灵敏度高、特异性强的特点,对确诊胃镜活检标本中幽门螺旋杆菌感染具有重要应用价值。     

幽门螺杆菌中国菌株IS605插入靶基因的获得及分析

目的 获得幽门螺杆菌插入因子IS605的插入靶位点并分析其插入特征。方法采用酶切、Southem blot、LAPCR体外克隆、连接、测序的方法获得不同菌株IS605的靶基因及拷贝数，并对插入位点进行分析。结果中国菌株G40A、G61B各两个拷贝的IS605分别插入在幽门螺杆菌功能未明的基因中；IS605插入位点的左侧（ORFA侧）富含“AT”。结论IS605的插入位点具有区域特异性的倾向性；LAPCR体外克隆法是研究原核生物已知基因的周边基因及其拷贝数的较好方法。     

Diversity of Helicobacter pylori vacA gene and cytotoxin production

Objective: To determine the frequency of different alleles of the vacA gene among the strains of Helicobacter pylori isolated from children and adults, and to compare vacuolating cytotoxin production with different combinations of vacA alleles.
Methods: H. pylori strains were isolated from the gastric biopsy samples of 100 patients with duodenal ulcer (32) and chronic gastritis (68). Bacterial DNA was extracted and the vacA alleles typed using PCR. Cytotoxin activity was assessed by an Intestine 407 cell vacuolation assay.
Results: Alleles s1 and s2 of vacA were identified in 72% and 28% of the tested strains, respectively. Of the 72 type s1 strains, 71 were classified as type s1a and only one as s1b. The predominant sequence observed in the vacA middle region was the m2 type (65%). Combinations of vacA genotypes s1a m1, s1a m2 and s2 m2 were found in 35%, 36% and 28% of strains, respectively. Vacuolating cytotoxin was produced by vacA s1a m1 strains isolated from patients with duodenal ulcer (84.6%) and chronic gastritis (68.2%). Subtype s1a m2 strains expressed vacuolating cytotoxin less frequently in both duodenal ulcer (47.1%) and chronic gastritis (21.1%) patients (   p <0.01  ). Antibodies to VacA (89 kDa) were found in 71.9% of patients with duodenal ulcer and in 42.6% of patients with chronic gastritis.
Conclusions: Most H. pylori vacA s1 m1 strains are toxic, whereas s2 m2 forms are essentially non-toxic.     

Bimodal effect of amphetamine on motor behaviors in C57BL/6 mice

Amphetamine-induced motor behaviors, i.e., locomotor and stereotypic activities, were simultaneously characterized in C57BL/6 mice, a strain commonly used for genetic studies. Our findings show relatively high levels of focused activities in drug-naive C57BL/6 mice, confirming the lively nature of this mouse strain. Acute amphetamine induced a dose-dependent, bimodal response: locomotion predominated at lower doses of amphetamine and was gradually displaced by stereotypic behavior as dose and time increased. The sum total of both behavioral activities increased with amphetamine dose, supporting the notion that amphetamine-induced locomotion and stereotypy form a continuum. These data provide a basis for using C57BL/6 mice as a strain to study the molecular and cellular mechanisms underlying psychostimulant effects, drug addiction and psychotic disorders.     

Five month persistence of Helicobacter pylori infection in guinea pigs

Seven Dunkin-Hartley guinea pigs were infected with the Sydney strain of H. pylori (SS1). Gastric histopathology was evaluated and serum antibody response to H. pylori cell-surface proteins was analysed by enzyme immunoassay (EIA) and immunoblot. Tissue and faecal samples from five control animals were analysed for the presence of naturally occurring Helicobacter spp. infection by culture and Helicobacter genus-specific PCR. The H. pylori infection persisted for 5 months, in most animals accompanied by a histologically severe antral gastritis, exhibiting focal degeneration and necrosis of gastric crypt epithelium. Increased numbers of mitotic figures were observed in the gastric epithelium, indicating a regenerative process. Infected animals displayed specific antibodies towards H. pylori cell-surface proteins in immunoblot, whereas EIA was of dubious value creating false-positive results. Serum complement C3 and cholesterol levels appeared to be elevated in infected animals. Helicobacter spp. infection was not detected in the control animals. The persistent infection, accompanied by severe gastritis and a prominent serum antibody response, and the apparent absence of a natural Helicobacter spp. infection makes the guinea pig model useful in H. pylori research.     

Paradoxical sleep deprivation and performance of an active avoidance task: Impairment in C57BR mice and no effect in C57BL/6 mice

Post trial instrumental Paradoxical Sleep (PS) deprivation (by the conventional water tank method) for 10 to 24 hours influenced a time dependent improvement of active avoidance in a Y maze only in the C57BR (BR) strain of mice. Similarily treated C57BL/6 (B6) mice exhibited no change in acquisition performance. Instrumental PS deprivation prior to learning was without effect on the performance of the two strains of mice: that is, an artificial PS increase after training did not change behavior. Pharmacological PS deprivation was also effected by drugs which either primarily influence the aminergic system (αmethyl-DOPA, chlorimipramine, αmethyl-p-tyrosine and d-methamphetamine) or inhibit protein synthesis (cycloheximide, chloramphenicol and thiamphenicol). We obtained similar results to those observed following instrumental PS deprivation: only those drugs which suppressed PS for more than 6 hours impaired the delayed improvement phenomenon in BR mice, but they had no effect on acquisition in B6 mice with the exception of cycloheximide and α-methyl-tyrosine. From these results Paradoxical Sleep is apparently not directly implicated in the basic processing of memory, but if any, rather in a time dependent improvement of performance, which may be considered as a mechanism for an aspect of memory processing which requires a sufficient duration of time. The quality of vigilance is discussed.     

Detection of Helicobacter pylori infection in symptomatic Bulgarian adults

This study assessed the prevalence of Helicobacter pylori in symptomatic Bulgarian adults by means of culture, Gram's stain and an in-house rapid urease test (RUT), and also assessed the H. pylori density by culture. In total, 1441 non-treated and 270 treated patients were evaluated. Most non-treated patients with ulcers (87.7%), gastric malignancy (79.2%) and other gastroduodenal diseases (73.4%) were H. pylori-positive. Among non-treated and treated patients, 75.3% and 54.8%, respectively, of elderly patients, and 78.3% and 56.1%, respectively, of other adults were H. pylori-positive. Two (0.1%) non-treated adults were Helicobacter heilmannii-positive. The accuracy of direct Gram's stain and the in-house RUT were 74.8% and 64.2% in non-treated patients, and 73.7% and 63.0% in treated patients, respectively. Culture was highly accurate (>95%) in both groups. Older age decreased the sensitivity of the RUT in non-treated patients by 10.7% and that of all tests in treated patients by 6.9-8.1%. Incubation for 11 days was required for the growth of 2% and 4% of the strains from treated patients on selective and non-selective medium, respectively. There were no differences in isolation rates between positive fresh (74.2%) and frozen (75.2%) specimens. In non-treated adults, a high H. pylori density (growth in all quadrants of the plates) was more common (43.1%) in ulcer patients than in other patients (25.4%). In conclusion, H. pylori infection was common in Bulgarian patients, and at a high density in >40% of ulcer patients, while H. heilmannii infection was uncommon. Culture provided a highly accurate diagnostic approach. Stomach biopsies from non-treated patients can be frozen for several days. The benefit of reporting H. pylori density, as determined by culture, requires further evaluation.     

Non-invasive techniques for the diagnosis of Helicobacter pylori infection

Helicobacter pylori infection can be diagnosed by invasive techniques requiring endoscopy and biopsy (histologic examination, culture, polymerase chain reaction), and non-invasive techniques (serology, urea breath test, urine or blood, detection of H. pylori antigen in stool specimen). However, recent studies have demonstrated that a strategy of 'testing and treating' for H. pylori in uninvestigated, young (<50 years), dyspeptic patients in primary care is safe and reduces the need for endoscopy. Indeed, a number of clinical guidelines recommend non-invasive testing in dyspeptic patients followed by treatment of H. pylori in primary care based on clinical and economic analyses. Several non-invasive tests are currently available on the market. The choice depends on the clinical circumstances, the likelihood ratio of positive and negative tests, the cost-effectiveness of the testing strategy, and, finally, the availability of the tests. Nevertheless, two non-invasive tests are commonly used: the urea breath test, and the stool antigen test.