摘要:

Reports over the past year provide significant advances in our knowledge of the neurohumoral control of exocrine pancreatic secretion, especially related to human physiology. Major findings include those demonstrating that human pancreatic acinar cells do not respond to cholecystokinin stimulation and that a major circulating form of cholecystokinin is CCK-58. These findings establish that in humans, cholecystokinin causes pancreatic secretion via a neural circuit after interacting with neural sensory receptors in the mucosa of the intestine and that CCK-58 is the likely form of cholecystokinin that stimulates the neural pathways. Other findings demonstrate significant differences in the pancreatic secretory response in humans as a function of the type of nutrient delivered to the gut, especially the fact the elemental diets and medium-chain triglycerides cause much less stimulation of pancreatic secretion than do complex diets. Finally, convincing evidence demonstrating that pancreatic proteases cause inhibition of pancreatic secretion in humans has been presented. In addition to new insights into the neurohumoral control of pancreatic secretion, these findings provide information relevant to both the pathogenesis of pancreatic disorders and their treatment.

ISSN:0267-1379    

出版商:OVID    

年代:2003

数据来源: OVID

摘要:

Acute pancreatitis is associated with significant morbidity and a mortality rate of approximately 8%. In severe pancreatitis, necrosis at the site of inflammation and remote organ failure develop in the course of disease. Pancreatic injury is initiated by molecular events in acinar cells. Premature activation of digestive enzymes, disturbances of intracellular calcium, and activation of transcription factors such as NF-&kgr;B characterize the initial phase of acute pancreatitis. The release of proinflammatory mediators and the recruitment of immune cells expand the local disturbances to a systemic inflammatory response associated with failure of distant organs such as lungs or kidney. The use of transgenic or knockout mice together with classic models of secretagogue-induced pancreatitis has provided considerable insight into the role of individual cellular or humoral factors in different stages of experimental pancreatitis. Transfer of these findings into clinical management or novel therapeutic strategies so far has had only very limited success. This may be due to the limitation of pancreatitis models to mimic completely the human disease. Therefore, a distinction between experimental models and clinical acute pancreatitis has to be maintained. The first part of this review will therefore concentrate on the initiation of acinar cell injury in experimental pancreatitis. Novel insights covering the mechanism by which local pancreatic involvement expands into systemic inflammation described in the second part. Progress in the clinical management and treatment of acute pancreatitis in humans is the focus of the third part of this review.

ISSN:0267-1379    

出版商:OVID    

年代:2003

数据来源: OVID

摘要:

Purpose of reviewWe are beginning to better understand the causes of chronic pancreatitis. This knowledge will hopefully lead to better diagnosis and treatment and abandonment of ill-conceived treatments. This review highlights contributions that moved the field toward these goals in the past year.Recent findingsSmall steps have been made toward a better understanding of the molecular basis, particularly genetic causes, of the forms of chronic pancreatitis. Investigation of the role of stellate cells, an essential component of the fibrosis of chronic pancreatitis, has led to the finding that lovastatin inhibits stellate cell activation and could surface as a novel treatment of chronic pancreatitis. The clinical description of autoimmune pancreatitis has led to the realization that steroids are effective treatment for this form of chronic pancreatitis. Other treatments such as extracorporeal shock wave lithotripsy and endoscopic treatments have not been proved, because no controlled studies support these treatments over other treatments. The diagnosis of chronic pancreatitis may be enhanced by the new imaging technique of electronic pancreatoscopy whereby a 2.1-mm diameter scope can be advanced into the pancreatic duct through a duodenoscope. However, the data are too preliminary at this time to advocate this imaging procedure. A potential new endoscopic pancreatic function test may lead to more widespread use of function testing, but this test is not perfected and also cannot be advised for use at present.SummaryOngoing basic and clinical research this past year has further characterized the genetic, molecular, and clinical aspects of chronic pancreatitis: efforts that may translate into novel therapies, once well-designed, controlled studies have been performed.

ISSN:0267-1379    

出版商:OVID    

年代:2003

数据来源: OVID

摘要:

Purpose of reviewThis review describes significant basic science and clinical advances in the field of pancreatic neoplasms.Recent findingsSome of the genetic and molecular bases for the aggressive behavior of pancreatic cancer have been uncovered, and new targets for therapy have been identified. Various techniques for diagnosis and staging of this disease—endoscopic ultrasound, laparoscopy—continue to undergo evaluation. Surgical results show slightly improved long-term survival, and perioperative mortality rates remain low. The concept that locally invasive pancreatic cancer can be effectively downstaged and later resected has been called into question. Regional chemotherapy has shown promise, especially when combined with immunotherapy. Intraductal papillary mucinous tumors continue to be commonly encountered and their development and clinical course intensely studied. Acinar cell carcinomas are rare pancreatic neoplasms associated with postresection survival longer than ductal adenocarcinoma but shorter than endocrine carcinoma. Neoplasms metastatic to the pancreas can be resected safely and with improved survival compared with nonsurgical therapies.SummaryThe treatment of pancreatic neoplasms remains a major challenge for physicians and surgeons. Future progress requires sound scientific inquiry and continued clinical diligence.

ISSN:0267-1379    

出版商:OVID    

年代:2003

数据来源: OVID

摘要:

A part of living in a new and exciting era for the biologic sciences and medicine, novel high throughput tools allow exploration of the human genome in an unprecedented manner. This “information revolution” is fueled by the study of genome-wide expression profiles for complex biologic and pathophysiologic conditions using DNA arrays, as well as the development and use of robust bioinformatic algorithms. Meticulous translational experiments are becoming possible because of the development of efficient DNA printing technology for producing high-density microarrays. Therefore, there is no doubt that microarray experiments, combined with bioinformatics, will advance the understanding of the pathobiology of pancreatic cancer, assist in the diagnoses and prognoses of this disease, and develop novel therapies. In this article, the most recent advances in the application of microarray technology to pancreatic cancer research are reviewed, and areas for further development are identified.

ISSN:0267-1379    

出版商:OVID    

年代:2003

数据来源: OVID

ISSN:0267-1379    

出版商:OVID    

年代:2003

数据来源: OVID

摘要:

Purpose of reviewThis review summarizes the important studies, published since April 2002, on the role of endoscopic ultrasonography for staging of esophageal cancer.Recent findingsThe loco-regional staging accuracy for esophageal cancer by endoscopic ultrasonography is superior to other currently available imaging modalities such as helical computed tomography. Endoscopic ultrasonographic staging accuracy is further enhanced by the ability to obtain guided fine needle aspiration specimens for cytology from any suspicious celiac lymph nodes. In addition to the initial staging of esophageal cancer, endoscopic ultrasonography–based measurement of reduction of tumor cross-sectional area appears to be a reliable predictor of pathologic response to initial neoadjuvant therapy. Recently published studies on the outcomes of endoscopic ultrasonography support its utility in the staging of esophageal cancer, particularly in guiding different treatment options for different stages of loco-regional involvement.SummaryOverall, endoscopic ultrasonography for staging of patients with esophageal cancer seems to be a cost-effective intervention.

ISSN:0267-1379    

出版商:OVID    

年代:2003

数据来源: OVID

摘要:

Portal hypertensive gastropathy is a relatively recently described entity that is an important cause of bleeding in portal hypertension. This article focuses on the endoscopic diagnosis of portal hypertensive gastropathy, including a review of different proposed scoring systems, and briefly examines the epidemiology, pathogenesis, and treatment of portal hypertensive gastropathy.

ISSN:0267-1379    

出版商:OVID    

年代:2003

数据来源: OVID

摘要:

Great strides have been made in the endoscopic and radiologic therapy of esophageal varices in the past few years. With the advent of variceal band ligation and transjugular intrahepatic portosystemic shunt, almost every acute variceal bleed can be controlled. In addition, over the past decade great strides have been made in the noninvasive imaging and pressure measurement of esophageal varices. Yet, the mortality rate from variceal bleeding has not changed significantly and the pharmacologic therapy of esophageal varices and the prophylaxis of the initial variceal bleed has lagged behind these other interventional advances. These authors believe that progress in these areas has been slow because the pathophysiology and hemodynamics of esophageal varices are not well understood. It is through progress in the areas of endoluminal ultrasound imaging of esophageal varices and noninvasive pressure measurement that progress has finally been made in the area of the pathophysiology of variceal bleeding. In this update, two novel ideas regarding the pathophysiology of variceal bleeding are described. The first regards increased variceal pressure during peristaltic contraction. The second describes increased variceal pressure with increasing intraabdominal pressure. These new observations suggest a new pathophysiology in the cause of variceal bleeding and imply new methods to prevent and treat variceal bleeding. This update and review of esophageal varices is given in five sections: new developments in the pathophysiology of esophageal variceal bleeding, screening for esophageal varices, prediction of variceal bleeding, treatment of esophageal varices and new modalities to evaluate esophageal varices.

ISSN:0267-1379    

出版商:OVID    

年代:2003

数据来源: OVID

摘要:

Duodenoscope assisted cholangiopancreatoscopy allows direct visualization of the pancreatic duct and bile duct. There are several circumstances where direct ductal visualization might be helpful in clarifying a diagnosis or providing targeted treatment. Duodenoscope assisted cholangiopancreatoscopy is currently employed for a variety of indications including: indeterminate ductal strictures and filling defects, marginal chronic pancreatitis, treatment of large intraductal stones, localization of intraductal papillary mucinous tumors, and localization and treatment of hemobilia. There have however been no randomized controlled trials evaluating the diagnostic or therapeutic functions of duodenoscope assisted cholangiopancreatoscopy. This article reviews recent descriptive studies that attempt to clarify the clinical role of this technology.

ISSN:0267-1379    

出版商:OVID    

年代:2003

数据来源: OVID