ISSN:0267-1379    

出版商:OVID    

年代:1993

数据来源: OVID

摘要:

Great progress has been made toward the understanding of the molecular and cellular biology of the small intestine. The obtaining of complementary DNA and genomic clones for critical small intestinal proteins has provided the foundation for a detailed analysis of intestine-specific gene expression and differentiation. New insights have been provided into the regulation of intestine-specific gene expression along the horizontal axis from duodenum to ileum and along the vertical axis from crypt to villus. The expression of some intestinal proteins occurs at the level of posttranscriptional regulation. Other proteins are regulated at the level of gene transcription and the interaction between transcription factors and theircis-acting elements in the intestine-specific genes is beginning to be elucidated.

ISSN:0267-1379    

出版商:OVID    

年代:1993

数据来源: OVID

摘要:

Several important studies were performed exploring the cell biology and molecular biology of disaccharidases and monosaccharide absorption. The cloned glucose transporter was shown to be the physiologically important one. Supporting this finding, two sisters who had a missense mutation of the transporter were unable to absorb glucose. Pancreatic proteases (trypsin) were shown to be important in the cleavage of sucrase-α-dextrinase at the surface of the brush border membrane. Lactase insufficiency type 1 was correlated with messenger RNA levels indicating either a translational defect or increased catabolism of lactase messenger RNA. Sucrase-isomaltase activity was shown to correlate vertically along the crypt-villus axis with steady state messenger RNA levels but along the length of the intestine with translated product. In an important study, lipoprotein AIV was shown to produce satiety.

ISSN:0267-1379    

出版商:OVID    

年代:1993

数据来源: OVID

摘要:

This article focuses on several subtopics of intestinal circulatory physiology and pathophysiology. More than 200 recent publications were examined before a small group of papers were selected for this survey, which epitomizes the problem confronted by a reviewer searching an active field. The subtopics into which these papers were divided include 1) regulatory events, such as aging, autoregulation, adenosine, intraluminal lipid, and sensory nerves; 2) nitric oxide-related investigations, including its role in portal vein stenosis, the serum albumin nitric oxide reservoir, and a novel biosensor for it; 3) ischemia-reperfusion injury-related topics, namely the effects of intraluminal pancreatic proteases, the important functions of histidine decarboxylase and ornithine decarboxylase in injury and repair, andin vitroinvestigations of superoxide dismutase; 4) other causes of mucosal injury, such as indomethacin ulcerations, a duodenal ulcer model, and endotoxemia; and 5) diagnosis of clinical ischemia by novel approaches, including phosphorous spectroscopy, serum creatine kinase isoenzyme assay, and tonometric mucosal pH determinations. The broad subject range touched on by this review reflects the vitality of recent mesenteric circulatory research.

ISSN:0267-1379    

出版商:OVID    

年代:1993

数据来源: OVID

摘要:

Topics relating to the diagnosis and medical management of small intestinal diseases include the use of the steatocrit test to measure fecal fat content, the assessment of bile acid absorption with the selenium 75 homocholic acid-taurine test, the diagnosis of small bowel bacterial overgrowth by endoscopic aspiration and by hydrogen and carbon-14 breath tests, and the prevention of small intestinal injury induced by methotrexate and ionizing radiation. Further topics include management of jejunal varices, treatment of enterocutaneous fistulas with somatostatin, prevention of postoperative ileus with cisapride, and treatment of autoimmune enteropathy with cyclosporin A. Also addressed are the potential of cholylsarcosine for bile acid replacement, the prevention of side effects induced by nonsteroidal anti-inflammatory drugs, and the management of desmoid and carcinoid tumors.

ISSN:0267-1379    

出版商:OVID    

年代:1993

数据来源: OVID

摘要:

Vascular diseases affecting the small intestine received considerable attention in the literature this year. Computed tomography, ultrasonography, and magnetic resonance imaging are capable of replacing angiography in detecting venous thrombosis and in following the response of the thrombus to therapy. Ischemic bowel injuries are described in patients with vasculitis, blunt trauma, and cocaine use. Two large series have shed light on effective approaches to the radiologic evaluation of patients with hemorrhage from a small bowel source. Computed tomography continues to be explored as a useful technique for detecting and evaluating small bowel obstruction. Studies from the Department of Radiologic Pathology at the Armed Forces Institute of Pathology review the features of two rare, benign, intestinal, neoplastic conditions: Peutz-Jeghers syndrome and inflammatory fibroid polyps.

ISSN:0267-1379    

出版商:OVID    

年代:1993

数据来源: OVID

摘要:

This review deals with several topics of interest, including ileal pouch-anal anastomosis, human immunodeficiency virus disease, small-bowel anastomosis, bleeding from the gastrointestinal tract, and small-bowel transplantation. The results of restorative proctocolectomy without ileostomy are described. New methods for investigation of gastrointestinal bleeding are also discussed. Finally, reports on small-bowel-liver transplantation in humans are highlighted.

ISSN:0267-1379    

出版商:OVID    

年代:1993

数据来源: OVID

摘要:

During the past year, the modulation of small intestinal motility by suostances such as nitric oxide, opioids, and prostaglandins continued to be the focus of attention ofin vitrostudies. With regard to human small bowel motility, most articles dealt with investigations into the pathophysiology of various gastrointestinal disorders, or into the effects of drugs on patterns of motor activity and transit. The gradual progress occurring in these areas should eventually lead to better therapeutic regimens for a number of diseases. In contrast, technical advances have been few; results of experiments in progress using novel methodologies are awaited with interest. These include ambulatory monitoring of small bowel motility, the small intestinal barostat, strain-gauge transducers to determine propulsive forces in the small intestine, and sophisticated scintigraphic studies to assess small bowel transit and its relationship to motor activity.

ISSN:0267-1379    

出版商:OVID    

年代:1993

数据来源: OVID

摘要:

The molecular immunogenetics of celiac disease continues to be a major area of study. CertainHLA-DQgenes appear to be the main HLA susceptibility marker in the various populations studied, although interest has been shown in related genes that are involved in antigen processing. The role of γ/δ T-cell receptor positive lymphocytes in the intestinal epithelium continues to be investigated; cytotoxicity seems possible but whether this occursin vivois not known.

ISSN:0267-1379    

出版商:OVID    

年代:1993

数据来源: OVID

摘要:

The enteric nervous system is unique in that it can mediate reflex activity in the absence of input from the brain or spinal cord. This activity is made possible by the presence within the wall of the gut of many different types of neurons, an abundance of interneurons, and intrinsic sensory neurons. Recent advances have enabled enteric microcircuits to be investigated. Studies that have followed expression of the protooncogene,c-fos, have now established that some primary afferent neurons (which are cholinergic and costore calbindin and substance P) are submucosal. These cells are excited by deformation of the mucosa and project both to other submucosal ganglia and to the myenteric plexus. They may be activated by serotonin released from enterochromaffin cells. One type of myenteric neuron,2/AH, has also been postulated to be a primary afferent, although some believe it is an interneuron. The 2/AH cells project widely within the myenteric plexus and to the mucosa. Although the behaviors regulated by the enteric nervous system cannot yet be explained in terms of the activity of single cells, it should soon be possible to do so.

ISSN:0267-1379    

出版商:OVID    

年代:1993

数据来源: OVID