Methotrexate in therapy of gastrointestinal diseases]

This review is not only a comprehensive synopsis of the published data on methotrexate treatment for inflammatory bowel disease and primary biliary cirrhosis but gives also an overview about acting mechanisms, pharmacologic properties and limiting toxicities of low-dose methotrexate. Methotrexate and its polyglutamate analogues are structurally related to folic acid and inhibit many enzymes in the metabolic pathway of folic acid. Long-term low-dose methotrexate treatment (7.5-25 mg) inhibits production of thymidylate, purines, and methionine and leads to intracellulary accumulation of adenosin. These actions lead to inhibition of cellular proliferation, decreased formation of antibodies and reduced productions of inflammatory medicators. Several trials have demonstrated the efficacy of low-dose methotrexate therapy for certain indications as a promising new agent in the treatment of inflammatory bowel disease and primary biliary cirrhosis. However, several serious toxicities potentially limit its use.     

Clinical use of proton pump inhibitors in gastrointestinal diseases]

The development and introduction into clinical practice of proton pump inhibitors (PPIs) have influenced the management of acid-peptic disorders dramatically. PPIs inhibit the gastric hydrogen/potassium adenosine triphosphatase selectively and irreversibly which is the final step in acid secretion. PPIs are currently the most effective form of therapy in acid-peptic diseases. All PPIs are potent, effective and generally safe, but little different in equivalent doses. PPIs undergo hepatic metabolism by cytochrome P450 (CYP) system. Polymorphism of CYP2C19 influences the pharmacokinetics and pharmacodynamics of PPIs. Doses and dosing schemes of PPIs based on CYP2C19 genotype status is expected to increase the efficacy in clinical outcome. The major indication of PPIs are acid-related diseases such as peptic ulcers and their complications, gastroesophageal reflux diseases, Zollinger-Ellison syndrome and eradication of Helicobacter pylori with antibiotics and dyspepsia. The potency and cost-effectiveness of PPIs have extended their clinical uses. However, their widespread and long-term use may limit the therapeutic benefit between efficacy and clinical problems such as acid rebound hypersecretion, enhanced oxyntic gastritis, problems with carcinoids in rodents and long-term concern for gastric cancer development. Further studies are needed to minimize the side effects and to maximize the therapeutic effects of PPIs.     

Current application of minimally invasive surgery for gastrointestinal diseases]

The advent of minimally invasive surgery (MIS) brought a major deviation in trend from conventional surgery. Since the introduction of first laparoscopic cholecystectomy in 1985, many operations for gastrointestinal diseases adopted MIS technique in a relatively short period of time. These MIS operations yielded better outcomes when compared to their open counterparts: less pain, shorter hospital stay, faster recovery, and better cosmetics. More complex surgical procedures for benign and malignant diseases of gastrointestinal tract are currently being performed by MIS technique with the improvement in equipment, instrumentation, and surgical skills. At the forefront of MIS, lies robotics. This paper briefly reviews the current status of MIS in the field of gastrointestinal diseases.     

Ghrelin与胃肠疾病关系的研究进展

Ghrelin是生长激素促分泌素受体的内源性配体,与受体结合后产生广泛的生物学效应,可刺激生长激素分泌、调节能量代谢等作用.而在消化系统中,Ghrelin具有保护胃肠黏膜、调节胃肠动力、促进胃酸分泌及控制肿瘤细胞增殖的作用,现将其与胃肠病疾病的研究进展综述如下.     

Autoimmunity in gastrointestinal diseases

This article is an update on the importance of some gastrointestinal diseases such ulcerative colitis, coeliac disease and some types of diarrhoea, in preceding an autoimmune response. A correlation with autoimmune disease without digestive symptoms, is made (rheumatoid arthritis, Hashimoto's thyroiditis, ankylosing spondylitis, and so on). Recognising such interrelations should be followed by search of extradigestive symptoms of autoimmune gastrointestinal diseases, allowing a better understanding of the immunologic phenomena involved.     

益生菌和胃肠道疾病

在人类的胃肠道功能中,肠道微生物发挥了重要的作用.很多益生菌是从原有的肠道细菌中发现出来的,并被证实对一些胃肠道疾病具有临床功效.益生菌的作用具有种株特异性,既不是通过共同的机制发挥作用,也不是所有的益生菌都有益于健康.在抗炎作用上,他们有几种共同的功能,如通过不同的方式和其他微生物竞争拮抗,通过增强宿主细胞的防御功能...     

Probiotics and gastrointestinal diseases

There is increasing evidence indicating health benefits by consumption of foods containing microorganisms, i.e. probiotics. A number of clinical trials have been performed to evaluate the effects in the prevention and treatment of gastrointestinal diseases caused by pathogenic microorganisms or by disturbances in the normal microflora. Gastrointestinal infections caused by Helicobacter pylori, traveller's diarrhoea, rotavirus diarrhoea, antibiotic-associated diarrhoea (AAD) and Clostridium difficile-induced diarrhoea are conditions that have been studied. There are also studies performed on the preventive effect of probiotics on radiation-induced diarrhoea and diarrhoea in tube-fed patients. Inflammatory bowel disease and irritable bowel syndrome, two idiopathic conditions where alterations in the normal microflora have been implicated as responsible for initiation, are two further areas where the use of probiotics has been regarded as promising. The results from clinical studies have not been conclusive in that the effects of probiotics have been strain-dependent and different study designs have been used. Treatment of acute diarrhoea in children and prevention of AAD are the two most justified areas for the application of probiotics.     

Classification of eosinophilic gastrointestinal diseases

Diagnosis of eosinophilic gastrointestinal diseases is based on morphological evaluation with regard to localization and density of eosinophil infiltration of the mucosa and/or deeper parts of the oesophagus, stomach, and bowel in biopsy or resection specimens. As with eosinophils in any tissue, in the majority of diseases they are probably a sequel of acute inflammation and do not indicate any specific disease. Eosinophil morphology includes intact cells with bilobated nuclei and eosinophil granules in the cytoplasm and extracellular tissue following activation/degranulation. There is no fixed number of eosinophils that can be used as a cut-off criterion to define disease. Associated histopathological features observed in eosinophilic gastrointestinal disease depend on the site of manifestation and primary disease. Eosinophils are typically increased in allergy-associated colitis in adults and allergic proctocolitis in infants, eosinophilic gastroenteritis and eosinophilic oesophagitis. Their presence can also suggest a drug-induced eosinophilia or the presence of a parasitic infection. In general, eosinophils are increased in inflammatory bowel disease (IBD). They are seen in reflux oesophagitis, coeliac disease, and microscopic and infectious colitis. Eosinophils may be a feature of polyarteriitis nodosa and Churg-Strauss syndrome, and can accompany connective-tissue disease as well as malignant lymphomas and adenocarcinomas of gastrointestinal mucosa.     

Endoscopic ultrasound and upper gastrointestinal disorders

Endoscopic ultrasound (EUS) plays a vital role in management of upper gastrointestinal disorders, particularly cancer of the esophagus, pancreas, stomach, lung (via transesophageal mediastinal staging), and bile duct. Endoscopic ultrasound has also been valuable in detection of early chronic pancreatitis (CP). In cancer of the esophagus, the primary role of EUS is to determine whether disease is localized (T1-2, N0) and appropriate for surgery, locally advanced (T3-4, N1, M1a) (which may benefit from chemoradiation with or without surgery), or metastatic. Pancreatic and bile duct cancers are more complex given the controversy over portal vein resection. In centers that resect tumors invading the portal venous system, the role of EUS is limited to tissue confirmation or identification of metastases to the liver or distant lymph nodes. In centers that do not resect the portal vein invasion, EUS plays an important role in local staging. In lung cancer, EUS is emerging as an accurate, nonsurgical alternative to staging the mediastinum through EUS fine-needle aspiration. Endoscopic ultrasound has an important role in diagnosing CP because of its high degree of sensitivity. This has also led to controversy over whether EUS can overdiagnose CP. For these reasons, we recommend the use of a high threshold for EUS and that CP be diagnosed in conjunction with other standard tests (endoscopic retrograde cholangiopancreatography, pancreatic function tests).