Indications and techniques for lower intestinal endoscopy.

The search for inflammatory and neoplastic lesions are the main indications for colonoscopy. A high rate of detection of polyps has become a quality criterion that depends on skilled handling of the colonoscope, on expertise and concentration during the examination, on excellent bowel preparation, and on a high standard of technical equipment. The diagnostic benefits outweigh the risk of bleeding, perforation and infection in almost all situations. Contraindications are signs of perforated intestine or imminent perforation due to deep ulcerations, necroses, or fulminant colitis. The patient's comorbidity must be considered to assess the physical stress of bowel preparation, colonoscopy and sedation. Informed consent is necessary and must be documented in all cases. It is advisable to explain planned therapeutic manoeuvres before the examination, since all non-invasive polyps must be removed completely. Total colonoscopy is possible in 95-99% of cases, but technical efforts are under way to solve the problem of looping and fixed colon angulations. Optimising optical imaging is another main focus of industrial development. The combination of narrow-band imaging, zoom magnification, and high-definition processor technology is currently the most promising tool for identifying small and flat lesions in the colon.

Myelin basic protein-specific T lymphocyte repertoire in multiple sclerosis. Complexity of the response and dominance of nested epitopes due to recruitment of multiple T cell clones.

The human T cell response to the myelin basic protein (MBP) has been studied with respect to T cell receptor (TCR) usage, HLA class II restriction elements, and epitope specificity using a total of 215 long-term MBP-specific T cell lines (TCL) isolated from the peripheral blood of 13 patients with multiple sclerosis (MS) and 10 healthy donors. In most donors, the anti-MBP response was exceedingly heterogeneous. Using a panel of overlapping synthetic peptides spanning the entire length of human MBP, at least 26 epitopes recognized by human TCL could be distinguished. The MBP domain most commonly recognized was sequence 80-105 (31% of MS TCL, and 24% of control TCL). Sequence 29-48 was recognized more frequently by control-derived TCL (24%) than by TCL from MS patients (5%). The MBP epitopes were recognized in the context of DRB1 *0101, DRB5*0101, DRB1*1501, DRB1*0301, DRB1*0401, DRB1*1402, and DRB3*0102, as demonstrated using a panel of DR gene-transfected L cells. The TCR gene usage was also heterogeneous. V beta 5.2, a peptide of which is currently being used in a clinical trial for treatment of MS patients, was expressed by only one of our TCL. However, within this complex pattern of MBP-specific T cell responses, a minority of MS patients were found to exhibit a more restricted response with respect to their TCL epitope specificity. In these patients 75-87% of the TCL responded to a single, patient-specific cluster of immunodominant T cell epitopes located within a small (20-amino acid) domain of MBP. These nested clusters of immunodominant epitopes were noted within the amino acids 80-105, 108-131, and 131-153. The T cell response to the immunodominant epitopes was not monoclonal, but heterogeneous, with respect to fine specificity, TCR usage, and even HLA restriction. In one patient (H.K.), this restricted epitope profile remained stable for > 2 yr. The TCR beta chain sequences of TCL specific for the immunodominant region of HK are consistent with an oligoclonal response against the epitopes of this region (80-105). Further, two pairs of identical sequences were established from TCL generated from this patient at different times (June 1990 and June 1991), suggesting that some TCL specific for the immunodominant region persisted in the peripheral repertoire. The possible role of persistent immunodominant epitope clusters in the pathogenesis of MS remains to be established.

Can an endocytoscope system (ECS) predict histology in neoplastic lesions?

BACKGROUND AND STUDY AIMS: An endocytoscope system (ECS) has recently been developed with the possibility of super-high magnification of gastrointestinal mucosa, thus allowing in vivo imaging of living cells. The aim of the present study was to assess the potential of ECS in the prediction of histology in both normal gastrointestinal mucosa and neoplastic lesions. PATIENTS AND METHODS: In total, 76 patients (57 men, 19 women; age range 37-86 years) with neoplastic lesions in the esophagus, stomach, or colon were enrolled into the study and underwent esophagogastroduodenoscopy or colonoscopy. After staining with 1% methylene blue, the mucosa was examined with the ECS probe (x 450 and x 1100 magnification), and video sequences were recorded on video disk. Biopsies from the examined areas were taken for histology and served as the gold standard. The endocytoscope video sequences were evaluated by two blinded pathologists. Finally the results were compared with those resulting from the evaluation of an experienced endoscopist who was aware of the macroscopic endoscopic pictures and the endocytoscope image results. RESULTS: A total of 25 patients with esophageal lesions, 28 patients with colonic lesions, and 23 patients with gastric lesions were examined. The sensitivity and specificity for the evaluation of the blinded pathologists was 81% and 100%, respectively, in the esophagus, 56% and 89% in the stomach, and 79% and 90% in the colon. If an endoscopist evaluated the endocytoscopic pictures in combination with the macroscopic endoscopic images sensitivity and specificity increased significantly. CONCLUSIONS: First experiences with ECS show good sensitivity rates even by blinded assessment for esophageal and colonic lesions. Sensitivity for neoplastic lesions in the stomach is lower because of gastric mucous secretion. Combining the endoscopic and cytoscopic appearance of the lesion may further enhance the diagnostic value of the method.

[Meningitis caused by Streptococcus suis]. / Bakterielle Meningitis durch Streptococcus suis.

HISTORY AND ADMISSION FINDINGS: A 42-year-old man was admitted to hospital because of headache and fever for two days and showing signs of meningism. As a butcher he had had frequent cuts on his hands and forearms. INVESTIGATIONS AND DIAGNOSIS: Analysis of the cerebrospinal fluid revealed an elevated leukocyte count (81% segmented neutrophils). Large numbers of Gram-positive bacteria were found in both cerebrospinal fluid and blood culture, which were subsequently identified as Streptococcus suis (S. suis) by biochemical methods. The hypothesis of bacterial meningitis was thus confirmed. TREATMENT AND CLINICAL COURSE: The patient was treated with ampicillin, initially combined with ceftriaxone. Hearing impairment and vestibular dysfunction - a frequent complication after infection with S. suis - were observed as sequelae, indicating involvement of the vestibulocochlear nerve. CONCLUSION: Infections caused by S. suis are rare in Europe but must be taken into account if an occupational exposition to pigs is established.

[Abdominal ultrasound after endoscopic or percutaneous stenting and drainage]. / Abdomineller Ultraschall zum Therapiemonitoring nach endoskopischer oder perkutaner Stent- und Drainageimplantation.

Stents and prostheses in the hepatobiliary system are visible by ultrasound examination and can be checked for their function. The reappearance of mechanical cholestasis, stent dislocation or formation of sludge on the stent tip is signs of stent dysfunction. Graduation of the biliary obstruction can help to find the best time for changing the stent. After intervention hematoma, abscess, intraabdominal fluid or gas may occur and can be diagnosed by ultrasound. Tumor stenosis in the gastrointestinal tract can be treated by self expandable metallic stents. Ultrasound helps to localize the stent in the correct position and to observe the reduction of occlusive ileus. Percutaneous and gastrointestinal drainage of pancreatic cysts, necrosis and abscesses are often controlled by ultrasound to evaluate size, echogenicity and localized pain. Many procedures and interventions in gastroenterology can be monitored by an experienced ultrasound examiner in an effective and inexpensive manner.

[Colorectal carcinoma in Cronkhite-Canada syndrome]. / Kolorektales Karzinom bei Cronkhite-Canada-Syndrom.

We report a 63-year-old lady with Cronkhite-Canada syndrome, who developed colorectal cancer. A hemicolectomy was performed, and the tumor specimen was prepared for DNA-analysis and immunohistochemical screening. We found a mutation of p53 gene without APC- and ras-gene alteration and expression of erbB2-protooncogen. The polyps in non-hereditary Cronkhite-Canada-syndrom are neither adenomatous nor hyperplastic, but patients often develop colorectal cancers. The steps of mutation do not follow the adenoma-carcinoma sequence, first described by Vogelstein 1988. This and previous observations suggest that carcinogenesis in Cronkhite-Canada syndrome follows another independent sequence.