ISSN:0267-1379    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

The development of colorectal neoplasms can be characterized by an ordered series of events that are referred to as thedysplasia-carcinoma sequence. These histologic changes occur as a result of genetic alterations in proto-oncogenes and tumor-suppressor genes. This review emphasizes important studies characterizing the role of four genes, APC, Cox-2, DCC/Smad4, and the mismatch repair genes, in colorectal carcinogenesis.

ISSN:0267-1379    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

Chemoprevention is defined as nutritional or pharmaceutical interventions designed to prevent or delay cellular transformation. Over the last year, the great excitement and interest in the mechanism, epidemiology, and preclinical and clinical chemopreventive effects in the lower intestine of nonsteroidal anti-inflammatory drugs continues and is reflected in the large number of publications on this topic. Investigators from Japan and the United States published preclinical studies of a number of new compounds derived from citrus products and Asian foods and spices with potential clinical promise. Disappointment in the lack of efficacy of epidemiologically predicted micronutrient chemopreventives continues with the publication of an additional clinical trial. This disappointment is tempered by a potentially important observation suggesting that pharmacologic approaches of measuring an individual’s food intake and assessing individual variation in disposition, bioavailability, and metabolism of micronutrients might allow for more accurate and individualized nutritional chemopreventive approaches in the future.

ISSN:0267-1379    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

Converging evidence from investigations of the peripheral and central aspects of bidirectional brain-gut interactions is beginning to shape a pathophysiological model of irritable bowel syndrome (IBS) and related functional gastrointestinal (GI) disorders. This neurobiological model includes alterations in autonomic, neuroendocrine, and pain modulatory mechanisms. The frequent association of IBS and other functional GI disorders with co-morbid affective disorders and temporal association of symptom exacerbation with psychosocial or physical stressors are consistent with alterations in the neurobiological mechanisms underlying the central stress response. Renewed interest in drug development for IBS has resulted in development of instruments for the better assessment of the impact of global symptoms on quality of life and in the development of candidate compounds undergoing clinical evaluation.

ISSN:0267-1379    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

Peristalsis is the main postprandial propulsive activity of the gut. It is mediated by neurons of the enteric nervous system, which form an integrated circuit composed of sensory neurons, modulatory interneurons, and motor neurons to the circular and longitudinal muscle layers. Work outlined in this review has identified, by anatomic, physiologic, and pharmacologic techniques, the myenteric neurons and neurotransmitters involved in the regulation of this reflex. Of particular note are studies identifying the role of 5-hydroxytryptamine4(5-HT4) receptors in the initiation of the peristaltic reflex and the development of selective 5-HT4agonists as potential therapeutic agents.

ISSN:0267-1379    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

Evidence is mounting that interstitial cells of Cajal may function as pacemaker cells and have a role in NO-mediated neurotransmission. Several colonic motor disorders may be associated with abnormal ICC function.

ISSN:0267-1379    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

Advances have been made in understanding specialized aspects of acquired mucosal immunity and the importance of cross-talk between host innate and acquired immune responses in host mucosal defense. These advances include elucidation of a molecular basis for the coordinated trafficking and retention of lymphocytes in intestinal sites, new insights into the possible extrathymic origin of mucosal T cells in the intestine, and the description of ligands that may be the targets of intraepithelial T-cell recognition. The past year has witnessed the characterization of an array of regulated epithelial cell mediators and responses important for host mucosal defense against enteric microbial pathogens and firmly establishes epithelial cells as an integral component of the mucosal immune network. Animal models continued to further understanding of intestinal inflammatory disease, and studies on tissue transglutaminase have generated significant new insights into the immunopathogenesis of human celiac disease.

ISSN:0267-1379    

出版商:OVID    

年代:1999

数据来源: OVID

ISSN:0267-1379    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

EnterotoxigenicEscherichia coli, Vibrio choleraeO1,Campylobacter jejuni, Salmonellaspecies, andShigellaspecies are major causes of morbidity and death in diarrheal disease. More recently recognized pathogens areV. choleraeO139 and enterohemorrhagicE. coli. In addition to this, several presumptive virulence factors have been identified in diarrheagenicE. coliand in other species. To confirm these as virulence factors we need good diagnostic tools and good epidemiological studies. These are of vital importance to create vaccines for diarrheal diseases.

ISSN:0267-1379    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

Viral gastroenteritis is a major worldwide public health problem. The number of identified pathogens continues to increase, and characterization of the viral structures and functions must be inexorably pursued. Investigators have made considerable progress toward understanding the mechanisms of virus-cell interactions, host responses, and pathogenesis, but the application of this knowledge to improve disease treatment and prevention awaits further key discoveries. Despite deficiencies in knowledge of many aspects of these important issues, a vaccine for the most important pathogen, rotavirus, has been submitted to the US Food and Drug Administration for approval.

ISSN:0267-1379    

出版商:OVID    

年代:1999

数据来源: OVID