Chronic viral hepatitis may have immunologic manifestations, and such features may reflect genetic predispositions. The aim of this study was to assess associations between immune manifestations and HLA-DR antigens.

Whereas severe portal hypertensive gastropathy and gastric antral vascular ectasia (GAVE) have been separately defined in patients with cirrhosis, there is much confusion in the literature because they are both characterized by red spots at endoscopy. This prospective study compared clinical, biochemical, and pathological features of these syndromes.

T cell-mediated immune reactions could be crucial for hepatocellular damage in viral chronic hepatitis. The aims of this study were to compare the expression of activation and cell adhesion molecules on peripheral blood and intrahepatic lymphocytes from chronic hepatitis C and to analyze the intrahepatic expression of vascular adhesion molecules in viral chronic hepatitis.

Glucagonlike peptide (GLP) 1, a peptide of 30 amino acids with 50% sequence homology to glucagon, results from expression of the glucagon gene in the L cells of the distal intestinal mucosa. It is secreted early in response to mixed meals by mechanisms involving the presence of unabsorbed nutrients in the gut lumen or the absorptive process itself, but other mechanisms may also be involved. GLP-1 has two important actions. First, it stimulates insulin secretion and inhibits glucagon secretion and thereby inhibits hepatic glucose production and lowers blood glucose levels. It may have effects on glucose clearance independent of its pancreatic effects. It acts on recently cloned G protein-coupled specific receptors and seems to increase insulin secretion via cyclic adenosine monophosphate-dependent increases in intracellular calcium. It has been suggested that activation of the beta cells by GLP-1 is a prerequisite for glucose-induced insulin secretion. Second, it also potently inhibits gastrointestinal secretion and motility and is likely to act as an "ileal brake," possibly after activation of cerebral receptors. Therefore, GLP-1 physiologically seems to signal nutritional abundancy and enhance deposition of nutrients. Because of these effects, however, the peptide can completely normalize blood glucose levels in type 2 diabetics and is therefore of considerable pharmaceutical interest.

For evaluating primary colonic and rectal malignancies, CT and MRI are often complementary imaging methods which are useful in assessing patients suspected of having extensive disease and in deciding whether a patient will benefit from preoperative radiation. CT is also helpful in designing radiation ports and in detecting complications related to the neoplasm such as perforation with abscess formation. MRI offers excellent tissue resolution which aids in distinguishing between localized colorectal disease and disease which invades muscle. Also, MRI can add information with coronal views for determining whether a sphincter-saving procedure can be performed, and may be of benefit for assessing the subtle extent of tumour into muscle and bone. However, CT and MRI lack the ability to assess depth of neoplastic involvement within bowel wall. This limitation is the major factor which, combined with the inability to diagnose metastatic tumour foci in normal-sized nodes and microinvasion of perirectal fat, prevents optimal tumour staging. Because of the low accuracy for assessing early cancer stages, neither CT nor MRI are recommended for routine use in preoperative staging. CT and MRI have a premier role in the assessment of recurrent colorectal neoplasm, with CT providing a slightly better overall evaluation due to volume imaging, easy image reconstructions in different planes, and availability of excellent oral and intravenous contrast agents. Cross-sectional imaging is the only method to evaluate fully patients with total AP resection, particularly male patients. Neither CT nor MRI can determine with certainty that a soft tissue density in the surgical bed following total AP resection represents recurrent tumour unless a clear mass is present which has increased in size over time. However, both methods surpass colonoscopy for detecting early mass-like tumour recurrence at the anastomotic site due to its extrinsic component. Cross-sectional imaging plays a prominent role in assessing inflammatory disease of the colon. Clinical history, laboratory data and extent of involvement are used together with results from radiographic examinations to reach a specific diagnosis. CT is preferred over MRI in the assessment of extent of inflammatory disease in and beyond the bowel wall. An additional benefit of CT over MRI is the fact that patients with abscesses or large fluid collection can undergo drainage while still in the CT scanner. CT and MRI can aid in the distinction between ulcerative colitis with minimal wall-thickening and Crohn's disease with marked wall-thickening combined with skip lesions and fistula and/or abscess formation.(ABSTRACT TRUNCATED AT 400 WORDS)

When properly performed, CT of the abdomen can provide valuable information about mural diseases of the alimentary tract. It can demonstrate the digestive origin of an abdominal mass, categorize a given lesion on the basis of its specific CT appearance and any associated CT findings, assess the extramural spread of gastrointestinal lesion, guide various interventional procedures (biopsy, drainage) and follow a patient's response to therapy.

Dynamic rectal examination (DRE), first described in 1952, is becoming more widely used in the dynamic evaluation of pelvic floor and anorectal motility disorders. It is a minimally invasive investigation which is well tolerated by patients and provides information about the anosphincteric, puborectal and levator muscle in addition to insight in rectal function and structure. DRE is the only investigation of anorectal function that can give detailed anatomical information such as the presence of a rectocele, an enterocele and an intussusception. DRE should be performed in a quiet environment with a minimum number of investigators present. Any technique which attempts to study the defecatory mechanism must be a compromise since the patient is aware of being studied. In order to defecate on command the radiologist must make the patient comfortable before starting the investigative procedures to avoid any possible psychological inhibition. We have not encountered any failures in this regard. The relative value of the radiological findings with respect to symptoms and complaints is insufficiently known. This has been the main incentive to design carefully and carry out a large prospective critical evaluation of various aspects of DRE in particular the correlation with objective findings and symptoms. Moreover an assessment has been made of its overall clinical utility (Wiersma, 1994). It is very likely that DRE is both investigator- and technique-dependent. To ensure that the study is as physiological as possible the contrast medium used to fill the rectum needs to be semi-solid and malleable equivalent in consistency to a normal faecal bolus. For proper anatomical studies in females vaginal opacification is mandatory. The acceptance of vaginal contrast was good. Only 4% of the female patients preferred not to have the vaginal application of contrast. The technique of DRE when performed with small bowel and vaginal opacification provides a sensitive and objective method of detecting enteroceles. A substantial number of female patients related the onset of their complaints to hysterectomy. In female patients with constipation there was a significantly higher incidence of enteroceles in patients with a hysterectomy compared to the group of females without hysterectomy. Because of these findings a series of pre- and postoperative DREs in hysterectomy patients are on their way in our institute. Unlike a rectocele which is usually most obvious during defecation, enteroceles are sometimes appreciated only with repeated straining after evacuation.(ABSTRACT TRUNCATED AT 400 WORDS)

The morphological spectrum of colonic disease is wide. Various treatment modalities may influence the macroscopic aspect of colonic lesions and render a pathological differential diagnosis occasionally difficult or impossible. Before starting therapy in patients suspected of having colonic disease, a physician should undertake a thorough radiological and endoscopic evaluation of the extent and severity of disease activity in the large bowel (Ruderman and Farmer, 1987). DCBE and colonoscopy are complementary imaging modalities, each test has its own intrinsic advantages and merits (Lichtenstein and Rothstein, 1991). DCBE remains the cornerstone in the detection of fistulas, strictures, perforations and estimating depth of ulcerations. Colonoscopy and biopsy remain the most sensitive imaging modalities to identify mucosal involvement (Dijkstra, 1992). The main clinically relevant discrepancies between colonoscopy and DCBE consist of inflammatory lesions without distortion of the mucosal relief and inflammation in the form of small, superficial erosions and ulcers (Dijkstra, 1992).

There are clinical data suggesting that the intubation method (enteroclysis) is the most accurate form of examining the small bowel. The diagnostic accuracy of small bowel enema is generally found superior to that of the tubeless method. Despite the growing interest in small bowel enema this procedure has not yet become the prevailing method in Western countries. However, due to further developments in sonde or push enteroscopy in which 300 cm of the small bowel can be visualized, it is of utmost importance to perform state of the art radiological small bowel enteroclysis investigation, otherwise the bright lights from enteroscopy will rapidly illuminate the dark corners of the small intestine, leaving no place for radiology.

Barium and endoscopy both have advantages. Endoscopy not only gives you direct visualization but also the ability to biopsy tissue. It does not give you the ability to determine the exact anatomy or the gross appearance of a lesion. Barium on the other hand gives you a dynamic examination which is particularly useful for the assessment of swallowing disorders and oesophageal motility. When the pharynx and oesophagus are not of prime concern and cost is not a problem then endoscopy is the examination of choice. It has been shown that dyspeptic patients who have had both examinations have a definite preference for endoscopy (Stevenson et al, 1991). As endoscopy requires minimal physical effort, it is also a preferable examination for the unwell patient.

Oropharyngeal dysphagia is usually either a secondary manifestation of neuromuscular disease or a primary abnormality related to structural aberrations of the oropharynx. In either case, a focused history is essential in defining the malfunction and distinguishing oropharyngeal dysphagia from globus, xerostomia, or oesophageal dysphagia. The functional evaluation of the oropharyngeal swallow is best accomplished by a videofluoroscopic swallowing study which is used to assess efficacy of functional elements within the swallow: nasopharyngeal closure, UOS opening, airway protection, tongue loading, tongue pulsion and pharyngeal clearance. Both diagnosis and therapy of oropharyngeal dysphagia are based on this functional assessment.

ES is certainly the most accurate technique presently available for visualizing small lesions in the pancreas and (distal) bile duct. However, this technique can at present not be utilized for improving the earlier diagnosis of pancreatic carcinoma but is of great help in the preoperative localization of pancreatic endocrine tumours. ES makes significant contributions to the preoperative loco-regional staging of pancreatic, ampullary and distal biliary malignancies, but it has distinct limitations in large masses and more remote areas (superior mesenteric vein) and in the differentiation between malignant and inflammatory lesions.

Almost 15 years after its introduction endosonography is an important technique in a wide range of gastrointestinal diseases. Two types of dedicated echoendoscopes are commercially available each with their own advantages. Thinner instruments with higher resolutions, that will go through a normal endoscope are currently in development. With these probes differentiation between T1 and T in situ will be possible in the near future. Characterization of 'submucosal' lesions in the upper gastrointestinal tract is a field in which ES is the most reliable technique for determining the origin of these lesions. Also submucosal vessels are easily visualized and ES is acquiring an important role in the investigation of portal hypertension. ES is the most accurate staging technique for oesophageal and gastric carcinoma as well as for gastric lymphoma. T- and N-staging results are superior to CT scanning, although ES is not very reliable in individual lymph nodes. Therefore a lot of effort is put into obtaining cytological samples from lesions outside the gastrointestinal tract. It is now possible to get cytological proof of mediastinal lymph nodes through ES-guided fine needle aspiration biopsy. It seems that low grade malignant gastric lymphomas show a typical picture on ES, which may help in selecting treatment. The future will bring us higher resolution images and three-dimensional reconstruction is already being investigated. This last technique will probably become a standard preoperative investigation in oesophageal carcinoma before the century is over.

Dietary fats have an impact on health and disease. A pancreatic exocrine protein, pancreatic triglyceride lipase, is essential for the efficient digestion of dietary fats. This enzyme requires another pancreatic exocrine protein, colipase, for full activity in the gut lumen. In addition to its importance in fat digestion, pancreatic triglyceride lipase has potential applications in medical therapy, medical diagnostics, and industry. This potential stimulated interest in lipases; radiograph during the last few years, studies applying the technologies of molecular biology and radiograph crystallography greatly increased our knowledge about pancreatic triglyceride lipase and colipase protein structure, enzyme mechanism, and gene structure. This review focuses on these recent advances and discusses models for the kinetic properties of pancreatic triglyceride lipase and for the interaction of pancreatic triglyceride lipase with colipase.