Control of gastric emptying by gastric tone

During ingestion of food, the stomach relaxes to accommodate the meal and, subsequently, a progressive gastric contraction parallels gastric emptying. Intestinal nutrients trigger feedback relaxatory mechanisms that regulate gastric tone and, hence, the nutrient load delivered into the small intestine. This regulation of gastric tone is mediated, at least in part, via the vagus. Defective gastric tone is associated with impaired gastric emptying, as seen in patients with postsurgical gastroparesis. However, increased intragastric pressure, corresponding with defective gastric accommodation, induces abdominal symptoms, but does not alter the gastric emptying pattern. These data indicate that gastric emptying is controlled by complementary mechanisms: gastric tone exerts an emptying force, but gastric outlet resistance is also an important regulator.     

胃起搏对胃动力紊乱犬胃排空及胃肌电活动的影响

目的　研究胃起搏对胃动力紊乱犬胃排空及胃电参数的影响。方法　采用双侧迷走神经干切断术联合应用胰高血糖素建立胃动力紊乱犬模型 ;采用 4导联胃肠电系统微机分析仪记录胃肠浆膜肌电活动 ;99mTc 植酸钠标记的半固体试餐 ,单光子计算机断层显像技术 (SPECT)检测胃半排空时间(GEt1/ 2 ) ;采用适宜起搏参数从胃体、胃窦在腹部投影部位输入起搏信号驱动胃电节律。结果　迷走神经干切断术后犬的GEt1/ 2 为 (79.4 2± 1.91)min ,较术前 (5 6 .35± 2 .99)min明显延迟 (P <0 .0 0 1) ,但行胃起搏治疗后GEt1/ 2 为 (6 4 .94± 1.75 )min ,较治疗前明显加快 (P <0 .0 0 1) ;胃起搏治疗前迷走神经干切断犬餐后的胃电频率为 (0 .0 81± 0 .0 0 7)Hz、胃电幅度为 (2 .32± 0 .35 )mV、慢波的传播速度为 (4 .0 6± 0 .4 0 )cm/s ,均较正常对照犬显著降低 [(0 .0 90± 0 .0 0 6 )Hz ,(4 .2 5± 0 .12 )mV ,(6 .92± 0 .2 4 )cm/s,(P <0 .0 5 ) ],治疗后其餐后胃电频率 (0 .0 92± 0 .0 0 5 )Hz、胃电幅度 (3.97± 0 .19)mV和慢波的传播速度 (5 .5 7± 0 .4 8)cm/s均明显高于治疗前 (P <0 .0 5 )。结论　采用适宜起搏参数输入起搏信号可完全触发胃电慢波 ,改善胃电参数 ,纠正药物导致的异常胃电节律 ,加速胃排空 ,恢     

胃微生态与胃癌的研究进展

胃微生态平衡是人体健康的重要前提,幽门螺杆菌(Helicobacter pylori,Hp)是目前已发现的与胃癌相关的关键病原体之一,普遍存在于人胃黏膜上皮。Hp感染可引起胃内其他菌群的改变,还可引起长期慢性的胃黏膜损伤,导致一系列胃黏膜上皮恶性进展和胃癌的发生。本文就胃微生态与Hp感染的关系、Hp感染在胃癌发生中的作用、胃内其他菌群在胃癌发生中的作用及微生态制剂在胃癌治疗的作用进行综述。进一步揭示Hp感染对胃微生态平衡的影响,胃微生态平衡和Hp感染在胃癌发生发展中的作用及微生态制剂在胃癌治疗中的意义。     

The electrophoretic pattern of normal human gastric juice and of the gastric juice of patients with gastric ulcer and gastric cancer

This study reports the electrophoretic pattern of the proteins in human gastric juice of control patients and patients with gastric ulcer and gastric carcinoma. Autodigestion was prevented by intragastric neutralization. The statistical limits of normal are defined and the changes found in the gastric juice of gastric ulcer and gastric patients with gastric carcinoma described.     

The role of gastric microbiota in gastric cancer

ABSTRACT

Gastric cancer represents one of the leading causes of cancer deaths worldwide. Helicobacter pylori (H. pylori) infection is the strongest risk factor associated with gastric cancer. Due to new molecular techniques allowing greater identification of stomach microbes, investigators are beginning to examine the role that bacteria other than H. pylori play in gastric cancer development. Recently, researchers have investigated how the composition of the gastric microbiota varies among individuals with various stages of gastric disease. Specific microbes residing in the stomach have been preferentially associated with gastric cancer patients compared to individuals with a healthy gastric mucosa. Studies conducted on the insulin-gastrin (INS-GAS) transgenic mouse model have provided additional insight into the association between the gastric microbiota and gastric cancer. The purpose of this article is to review the current state of literature on the relationship between the gastric microbiota and gastric cancer based on clinical studies performed to date.     

From gastric inflammation to gastric cancer

The majority of gastric adenocarcinomas are related to chronic inflammation induced by Helicobacter pylori infection. For intestinal-type gastric cancer, a multistep process of mucosal alterations leading from gastritis via glandular atrophy, intestinal metaplasia and dysplasia to invasive carcinoma is well recognized. Ongoing clinical studies focus on a 'point of no return'. It is defined as a situation when certain alterations are no longer reversible by H. pylori eradication and progression to gastric cancer may continue. H. pylori affects the mucosal as well as the systemic immune response by secretion of cytokines and the recruitment of distinct inflammatory cells. The immune response is characterized by a balance between a Th1-dominated response and the recruitment of antigen-specific regulatory T cells that allow the bacteria to persist in human gastric mucosa. Besides immune-mediated effects, H. pylori induces cellular alterations as well as genetic alterations in genes that are essential for the epigenetic integrity and mucosal homeostasis. These genetic alterations during gastric cancer development are in focus of intensive research and should ultimately allow the identification of risk factors involved in gastric carcinogenesis. The detection of individuals at high risk for gastric cancer would help to design appropriate strategies for prevention and surveillance.     

Diagnosis of gastric adenoma versus early gastric cancer by Bromodeoxyuridine immunohistochemistry from gastric biopsy specimen

Differentiation between gastric adenomas and type IIa early gastric cancer by macroscopic and histologic examinations is often difficult. This study has shown that there are differences in the distribution of S-phase cells in these two types of tumour, and these differences can be exploited to differentiate between them. The distribution of S-phase cells was assessed by Bromodeoxyuridine (BrdU) immunohistochemistry using an in vitro BrdU-labelling method. Biopsy specimens were obtained from 27 lesions (12 adenomas and 15 type IIa early gastric cancers), and the distributions of BrdU-labelled cells in the tumour thickness as well as in the superficial layer of the tumour were determined. Significant difference was seen in the labelling of the two tumour types with regard to both these parameters. Using the criteria of BrdU immunohistochemisty, the accuracy of differentiation between gastric adenomas and cancers was 88.9%. Therefore, it is concluded in this study that in vitro BrdU labelling is a useful method of diagnosing gastric adenomas and cancers.     

Serological assessment of gastric mucosal atrophy in gastric cancer

Background  

Non-invasive tools for gastric cancer screening and diagnosis are lacking. Serological testing with the detection of pepsinogen 1 (PG1), pepsinogen 2 (PG2) and gastrin 17 (G17) offers the possibility to detect preneoplastic gastric mucosal conditions. Aim of this study was to assess the performance of these serological tests in the presence of gastric neoplasia.