A novel immunoassay based on monoclonal antibodies for the detection of Helicobacter pylori antigens in human stool.

BACKGROUND AND AIM: With the Premier Platinum HpSA EIAtrade mark a new enzyme immunoassay was developed for diagnosis of H. pylori infection, using polyclonal antibodies against H. pylori antigens in human stool. Here we evaluated FemtoLab H. pyloritrade mark based on the use of monoclonal antibodies in comparison to established reference methods. METHODS: 53 consecutive patients (27male, 26 female, age: 17-85 years) undergoing routine upper gastrointestinal endoscopy were enrolled in this study. The H. pylori status was determined by 4 reference methods: Histology, rapid urease test (HUT), (13)C-urea breath test ((13)C-UBT) and serology. Patients were considered to be infected with H. pylori if at least 2 of the 4 reference tests were positive. Stool samples were aliquoted after reception and stored frozen (-20 degrees C) until tested. The FemtoLab H. pyloritrade mark (Connex GmbH, Germany) and the Premier Platinum HpSA EIAtrade mark (Meridian, Connecticut, Ohio, USA) were performed according to the manufacturers protocols. RESULTS: 26 of the 53 patients were H. pylori infected. 3 were false-negative by the FemtoLab H. pyloritrade mark and one false-positive result was obtained (sensitivity 88,5 %, specificity 96,3 %). The concordance between the 2 stool tests was 94,3 % (50/53 cases). CONCLUSION: The diagnostic quality of the novel FemtoLab H. pyloritrade mark Enzyme Immunoassay is comparable with the established Premier Platinum HpSA EIAtrade mark. The differences between positive and negative results obtained with the FemtoLab H. pyloritrade mark are greater in comparison to the Premier Platinum HpSA EIAtrade mark and therefore this test system allows a better distinction.

Stabilization of coiled-coil peptide domains by introduction of trifluoroleucine.

Substitution of leucine residues by 5,5,5-trifluoroleucine at the d-positions of the leucine zipper peptide GCN4-p1d increases the thermal stability of the coiled-coil structure. The midpoint thermal unfolding temperature of the fluorinated peptide is elevated by 13 degrees C at 30 microM peptide concentration. The modified peptide is more resistant to chaotropic denaturants, and the free energy of folding of the fluorinated peptide is 0.5-1.2 kcal/mol larger than that of the hydrogenated form. A similarly fluorinated form of the DNA-binding peptide GCN4-bZip binds to target DNA sequences with affinity and specificity identical to those of the hydrogenated form, while demonstrating enhanced thermal stability. Molecular dynamics simulation on the fluorinated GCN4-p1d peptide using the Surface Generalized Born implicit solvation model revealed that the coiled-coil binding energy is 55% more favorable upon fluorination. These results suggest that fluorination of hydrophobic substructures in peptides and proteins may provide new means of increasing protein stability, enhancing protein assembly, and strengthening receptor-ligand interactions.

Evaluation of an enzyme immunoassay for detecting Helicobacter pylori antigens in human stool samples.

BACKGROUND AND AIM: So far, the detection of Helicobacter pylori (Hp) infection by stool analysis appeared to be almost impossible. With the Premier Platinum HpSA EIA a new enzyme immunoassay was developed for diagnosis of Hp infection, using polyclonal antibodies against Hp antigens in human stool. We evaluated this new test in its diagnostic accuracy in comparison to established reference methods. METHODS: From 54 consecutive patients (29 male, 25 female, age: 19 to 85 years) undergoing routine upper gastrointestinal endoscopy antral and corpus biopsies were taken for histology and Helicobacter urease test (HUT). Endoscopy, 13C-urea breath test (13C-UBT), serology, and stool probes sampling were performed within two days. Stool samples were aliquoted after reception and stored frozen (-20 degrees C) until tested. The Premier Platinum HpSA test (Meridian, Connecticut, Ohio, USA) was performed according to the manufactures protocol. Patients were considered to be infected with Hp if two of the four reference tests were positive. RESULTS: 28 of the 54 patients were Hp-infected. Only one of these was found to be false-negative by the HpSA EIA. Two false-positive results were obtained in the noninfected group (sensitivity 96.4%, specificity 92.3%). CONCLUSION: In this group of patients investigated, the novel HpSA Enzyme Immunoassay (EIA) proved to be highly accurate for diagnosis of Hp infection. Collection and testing of stool are noninvasive and easy to perform, therefore this test will become an important tool for diagnosing Hp infection in clinical practice.

[Value of diagnostic procedures in fiberoptic bronchoscopy of pulmonary infections]. / Stellenwert diagnostischer Verfahren bei der Fiberbronchoskopie pulmonaler Infektionen.

Fibreoptic bronchoscopy has become an important means of diagnosing infections of the lower respiratory tract, since it a method with few complications, whereas, on the other hand, the conventional non-invasive methods are hardly reliable in respect of diagnostic relevance. Frequent oropharyngeal contamination severely limits the significant assessment of the pathogenicity of cultured microorganisms. The protected specimen brush (PSB) or quantitative cultures of bronchoalveolar lavage (BAL) might be useful in solving this problem. These methods were studied in two prospective trials comprising 123 patients with suspected bronchopulmonary infection and 54 control patients. Both methods were found to be disappointing in respect of sensitivity; moreover, quantitative cultivation did not yield any differences with regard to specificity.

[Developments in surgery of pulmonary metastases]. / Entwicklungen in der pulmonalen Metastasenchirurgie.

Two groups of patients between 1977-1986 and 1987-1989 underwent surgery for pulmonary metastases. The most frequent primary sites were the kidney and the colon-rectum. While metastases from testicular cancer have become rare indications, metastases from breast cancer are increasing. Our results show that more metastatic lesions are usually found at operation than indicated by CT scan. The discrepancy amounts to 18% in presumably solitary metastases and increases to 50% if three or more lesions were identified preoperatively. Therefore, bilateral exploration is advocated. Lesions of the posterior lower lobes are more satisfactorily approached by a bilateral transverse incision and sternotomy. The mortality was 1% in the former and 0% in the more recent group of patients.

Gastric function in hypopituitarism: a biochemical study.

The specific trophic effects of gastrointestinal hormones on gastric function are now recognized. In addition, pituitary, thyroid and adrenal hormones play an important role in maintaining over all gastric function. The majority of studies regarding hormonal effects on the stomach, however, have been carried out only in experimental animals. This paper reports a patient with gastric atrophy and hypopituitarism. Following therapy of the hypopituitarism with cortisone acetate, sodium levothyroxine and testosterone, the following observations were made: serum gastrin increased 137%; mucosal DNA synthesis and content and gastric acid secretion all increased. These data indicate in this one patient the role of these hormones in gastric function.

Pancreatic acinar cell metabolism and function.

This review outlines progress made during the past 11 years in research related to pancreatic acinar cell metabolism and function. We have reviewed information gained at the cellular level concerning structural and functional relationships, and effects of fasting and feeding, as well as the action of gastrointestinal hormones and cholinergic agonists on acinar cells. In toto, this information outlines a significant role for gastrointestinal hormones as mediators of secretion, synthesis, and control of trophism. This information provides a basis for more sophisticated inquiries as to the mechanisms of injury of alcohol and drugs. The information may prove helpful in developing diagnostic modalities for pancreatic disease, as well as understanding the processes involved in neoplastic transformation.

Eosinophilic ascites. A case report and review of the literature.

Hypereosinophilic syndrome is a multisystem disease with progressive valvular dysfunction as a prominent feature. Ascites has not been recognized as a part of this syndrome. This paper presents a patient with hypereosinophilic syndrome who initially developed ascites and was recognized to have cardiac disease. The differential diagnosis of eosinophilic ascites is discussed.

Fine structure of pancreatic adenocarcinoma induced in rats by 7,12-dimethylbenz(a)anthracene.

We induced pancreatic adenocarcinomas in Long-Evans rats by placing crystals, 2-3 mg, of 7,12-dimethylbenz[a]anthracene (DMBA) in a 2- to 3-mm incision in the "head" of the pancreas approximately 1 cm from the duodenum. The incisions were closed with one or two silk sutures. The animals were killed 4-10 months after DMBA implantation, and nodules were removed and routinely prepared for light and/or electron microscopic study. Histologic organization varied from normal, through areas of tubule-like structures, to sheets of pleomorphic tumor cells. Electron microscopic study of tumor cells revealed large electron-lucent nuclei that frequently had irregular outlines and prominent nucleoli. The predominant feature of the cytoplasm was abundant rough endoplasmic reticulum. Zymogen granules were rare. Adjacent cells sometimes were jointed by an apical junctional complex to form a lumen into which projected irregular microvilli. A basal lamina sometimes occurred at the bases of the tumor cells. The fine structural similarity of these tumor cells to acinar cells was noted.

Hormonal control of pancreatic growth.

Investigations have outlined pancreatic secretory and synthetic responses to gastrointestinal hormones. However, there is little information concerning hormonal influences on pancreatic growth. These studies were designed to examine effects of chronic administration of bethanechol and cholecystokinin-pancreozymin (CCK-PZ) on the pancreas. Male albino rats were given saline, bethanechol, 6 mg/kg, or CCK-PZ, 20 U/kg, intraperitoneally twice daily and killed after 5 days. The following changes were studied; pancreatic weight; RNA, DNA, and protein content; and [(14)C]thymidine incorporation into DNA. Bethanechol administration was associated with a 20% increase in pancreatic weight and a 33% increase in mg protein/100 mug DNA. In bethanechol-treated groups, amounts of DNA/gram body weight and incorporation of [(14)C]thymidine into DNA were similar to controls. CCK-PZ administration was associated with a 71% increase in pancreatic weight and a 38% increase in mg protein/100 mug DNA. In CCK-PZ-treated groups, amounts of DNA/gram body weight were increased by 42% and [(14)C]thymidine incorporation into DNA was increased by 185%. These studies indicate that bethanechol administration was associated with increases in pancreatic cell mass (hypertrophy). CCK-PZ administration was associated with increases in cell mass and cell numbers (hypertrophy and hyperplasia). This information suggests the importance of CCK-PZ in maintaining pancreatic functional integrity. Although bethanechol and CCK-PZ elicit similar secretory responses, their mode of action on the cell, at least as far as growth influences are concerned, appears to be different.