摘要:

&NA;Current Opinion in Gastroenterology 1993,9:887‐888

ISSN:0267-1379    

出版商:OVID    

年代:1993

数据来源: OVID

摘要:

&NA;This review of the past year's literature focuses on progress in the elucidation of the pathways and mechanisms controlling gastric exocrine (ie, acid and pepsin) and endocrine (ie, gastrin, histamine, somatostatin, and prostaglandin) secretion at the central, peripheral, and intracellular levels by neural, hormonal, and paracrine agents. The use of selective receptor antagonists (eg, bombesin/gastrin‐releasing peptide antagonists, vasoactive intestinal peptide antagonists, gastrin antagonists, cholecystokinin‐A antagonists, and muscarinic antagonists), antisera (eg, somatostatin antiserum and secretin anti‐serum), inhibitors (eg, indomethacin,NG‐nitro‐L‐arginine methyl ester, and omeprazole) and toxins (eg, capsaicin) have furthered our understanding of the potential physiologic role for bombesin/gastrin‐releasing peptide, vasoactive intestinal peptide, gastrin, cholecystokinin, acetylcholine, prostaglandin, nitric oxide, hydrochloric acid, and sensory neurons in the regulation of gastric secretion. The increased use of molecular biologic techniques has provided new insights into the function of receptors (eg, gastrin, histamine, acetylcholine, somatostatin, and neuropeptide Y) and the transduction pathways to which they are coupled. Much progress has been made in our understanding of gastric physiology; much more, however, remains to be learned.Current Opinion in Gastroenterology 1993,9:889‐901

ISSN:0267-1379    

出版商:OVID    

年代:1993

数据来源: OVID

摘要:

&NA;Studies in the past year have clarified several aspects of gastroduodenal defense. An explanation for the mucus layer's ability to allow free passage of secreted acid while acting as a barrier to luminal acid has been suggested. Further insights have been gained into the role of surface‐active phospholipids in defense and the regulation and actions of mucosal bicarbonate. Microcirculatory mechanisms of defense and injury, including the complex roles of nitric oxide, sensory afferent nerves, mast cells, and neutrophils, and the coupling of blood flow to acid secretion have been further elucidated. Other elements of the mucosal immune system, such as macrophages, plasma cells, and cytokines, have been found to modulate both defense and injury. Finally, progress has been made in better understanding the actions of a number of growth factors in mucosal defense and repair.Current Opinion in Gastroenterology 1993,9:902‐908

ISSN:0267-1379    

出版商:OVID    

年代:1993

数据来源: OVID

摘要:

&NA;Peptic ulcer therapy directed againstHelicobacter pylorihas become increasingly accepted, but traditional and alternative therapies are still valid and valuable. Reinfection rates afterH. pylorieradication seem low enough (in industrialized countries) to expect continued remission for most subjects. Eradication has been achieved with a myriad of regimens; regimens with success rates less than 90% probably should not be chosen as first‐line therapy. Courses of antibiotics that are too short may be detrimental. Anti‐acid treatment is beneficial to maintain remission and patients may be able to control their own doses. A novel study has used oxygen‐derived free radical scavengers to treat acute duodenal ulcer and maintain remission. Some patient groups, notably cirrhotics, are especially resistant to therapy. A wide variety of efficacious treatment and maintenance options currently exist and are responsible for the continued decline in surgery as definitive therapy for all but complicated ulcers.Current Opinion in Gastroenterology 1993,9:909‐916

ISSN:0267-1379    

出版商:OVID    

年代:1993

数据来源: OVID

摘要:

&NA;Percutaneous endoscopic gastrostomy feeding has continued to gain popularity with a 12‐fold increase in its use in the United Kingdom in the past 4 years. There is now a large body of literature detailing the outcome and complications of percutaneous endoscopic gastronomy feeding. A recent randomized controlled study comparing percutaneous endoscopic gastrostomy feeding with nasogastric feeding in patients requiring long‐term nutritional support indicates that percutaneous endoscopic gastrostomy feeding is superior in improving nutritional status and is better tolerated. Portal hypertensive gastropathy is being increasingly recognized as a cause of upper gastrointestinal hemorrhage. Recent studies have highlighted the role of variceal sclerotherapy and the anatomic pattern of the blood supply to the stomach as factors that promote the development of portal hypertensive gastropathy. &bgr;‐Blockers decrease the incidence of bleeding from portal hypertensive gastropathy and should be used in most patients both prophylactically and after variceal sclerotherapy. Further evidence has accumulated indicating that endoscopic injection of ulcers with visible vessels decreases the risk of rebleeding. Endoscopic therapy is also beneficial for the treatment of Dieulafoy's lesions. A steady flow of publications continues to point to endosonography as a powerful tool in the diagnosis and staging of upper gastrointestinal malignancy, and for the detection of residual tumor tissue after therapy.Current Opinion in Gastroenterology 1993,9:917‐921

ISSN:0267-1379    

出版商:OVID    

年代:1993

数据来源: OVID

摘要:

&NA;Significant advances were reported in several areas of gastroduodenal motility during the past 12 months. The complexity and multifactorial control of gastric emptying rate was highlighted. It seems that simultaneous analysis of the spatial and temporal characteristics of gastro‐pyloro‐duodenal contractions is important in fully understanding the mechanisms of regulation of gastric emptying. Cholecystokinin may play an important role in the afferent sensory pathway to inhibit gastric emptying by neurohormonal feedback from the duodenum. Very little progress was made in elucidating the etiology of dyspepsia. However, it seems that cisapride may be effective in relieving symptoms of dyspepsia at least in some patients. Erythromycin remains a potential gastro‐prokinetic agent. However, like other prokinetic agents, it may not be effective in all patients with gastric stasis and the patients may become refractory after long‐term use. The method of monitoring gastric function by cutaneous electrogastrogram is noninvasive and convenient, but the information it can provide is very limited. This raises serious questions about its potential as a diagnostic tool. Finally, absence of nitric oxide synthase in the enteric nerves of the pyloric circular muscle may be a factor in infantile hypertrophic pyloric stenosis.Current Opinion in Gastroenterology 1993,9:922‐929

ISSN:0267-1379    

出版商:OVID    

年代:1993

数据来源: OVID

摘要:

&NA;Gastric cancer remains one of the most common causes of cancer mortality worldwide, despite a decline in incidence in Western countries. An important recent finding has been the recognition of an association betweenHelicobacter pyloriand gastric cancer. The mechanisms, however, by whichH. pyloriinfection and other environmental factors influence gastric tumorigenesis remain to be elucidated. The recent identification of growth factors and their receptors has provided insights into the regulation of cell growth, proliferation, and differentiation. Furthermore, studies of the effects and interactions of growth factors, oncogenes, and tumor suppressor genes on biological behavior of human gastric cancers are in progress and may aid in therapeutic decision‐making. Fortuitously, molecular analysis requires small amounts of tumor tissue, which can be obtained from endoscopic biopsies. Regarding the treatment of gastric cancer, promising data on the use of neoadjuvant chemotherapy to increase surgical resectability have been obtained. However, locoregional failure continues to be the major obstacle and the addition of adjuvant intraperitoneal chemotherapy is specifically aimed at this problem. Novel therapeutic approaches are clearly needed in the management of advanced disease in view of the relatively poor results thus far with available compounds.Current Opinion in Gastroenterology 1993,9:930‐937

ISSN:0267-1379    

出版商:OVID    

年代:1993

数据来源: OVID

摘要:

&NA;Although there is no single focus to the work presented here, it is all relevant to the pediatric patient and draws attention to new developments in the field. First, the ongoing evolution of our understanding ofHelicobacter pylori‐associated disease is discussed, followed by an update on the effects of several systemic diseases on gastroduodenal function. New work is presented that further elucidates the development of the stomach and the duodenum and enhances our understanding of gastroduodenal motor function. Finally, the use of tube feedings and complications of omeprazole in the pediatric population are reviewed.Current Opinion in Gastroenterology 1993,9:938‐942

ISSN:0267-1379    

出版商:OVID    

年代:1993

数据来源: OVID

摘要:

&NA;Current Opinion in Gastroenterology 1993,9:943‐945

ISSN:0267-1379    

出版商:OVID    

年代:1993

数据来源: OVID

摘要:

&NA;The human mucosal immune system seems to be structurally mature, having all the necessary cellular components to generate an immune response at birth. In the absence of dietary antigens and bacterial flora, there are no secondary follicles in the Peyer's patches and virtually no immunoglobulin A plasma cells in the lamina propria at birth. Reactive follicle centers develop soon after birth but it may take about 2 years for mucosal immunoglobulin A plasma cell density to reach adult levels. T cells are present in epithelium and lamina propria at birth, albeit in fewer numbers than later in life. Functional studies on mucosal immunity in the neonate are limited for clinical and ethical reasons. Salivary antibodies have been studied, but it is not clear whether reactivity in saliva reflects mucosal responses at other sites. Deficiencies in the ability of peripheral blood T cells of the neonate to produce interleukin‐4 and interferon‐&ggr; may also occur in the intestine. The available data are contradictory and it is still not known whether it is better to try to prevent immunologic sensitization of the neonate by avoiding potential allergens (eg, cow's milk, gluten), or whether early exposure (as occurs when premature infants are given formula feeds) might tolerize the infant. It is also unclear whether events in the neonate have any role in the subsequent development of life‐long diseases such as celiac disease or inflammatory bowel disease.Current Opinion in Gastroenterology 1993,9:946‐952

ISSN:0267-1379    

出版商:OVID    

年代:1993

数据来源: OVID