Comparison of two rapid whole-blood tests for Helicobacter pylori infection in Chinese patients

Consecutive Chinese patients undergoing endoscopy for dyspepsia were tested for Helicobacter pylori infection by two rapid whole-blood tests: FlexPack HP (Abbott Laboratories) and Helisal One-Step (Cortecs Diagnostics). Biopsy-based tests (rapid urease test and histology) and the [13C]urea breath test were used as the "gold standard." One hundred sixty-one consecutive patients were studied, and 88 (54.7%) were confirmed to have H. pylori infection. The sensitivities, specificities, and positive and negative predictive values were 81.8%, 83.6% (P = 0.008), 85.7% (P = 0.04), and 79.2% for FlexPack HP and 84.1%, 63.0% (P = 0.008), 73.3% (P = 0.047), and 76.7% for Helisal One-Step, respectively.     

The pathogenesis of gonococcal urethritis in men: confocal and immunoelectron microscopic analysis of urethral exudates from men infected with Neisseria gonorrhoeae

Confocal and immunoelectron microscopic analysis of urethral exudates from 12 men with gonococcal urethritis showed that Neisseria gonorrhoeae can invade urethral epithelial cells. Studies with acridine orange stain demonstrated that the majority of organisms within urethral epithelial cells were viable at the time of fixation. Three-dimensional modeling of an infected epithelial cell using image analysis of 21 digitized confocal sections stained with YOYO-1 and DiIC 18(3) revealed that gonococcal invasion of these cells occurred in a polar fashion, most likely at the epithelial luminal surface. Serial immunoelectron micrographs showed evidence of membrane fusion with pedestal formation between the gonococcus and the epithelial cell, gonococci within vacuoles, and occasional gonococci free in the cytoplasm. Immunoelectron microscopy studies showed ruptured vacuoles at the cell surface releasing organisms. These studies demonstrate that urethral epithelial cells are invaded by gonococci during the course of infection in males.     

Immunogenetic analysis of the heavy chain variable regions of IgE from patients allergic to peanuts

Although the histologic examination of routine tissues, such as hernia sacs and intervertebral disks, has shown a low incidence of detecting clinically significant unsuspected disease, the cost-effectiveness of histologic examination has not been determined. By using a theoretical model that assumed variable costs and gains in life expectancy secondary to detecting clinically significant disease, a threshold incidence of disease detection at which histologic examination is cost-effective was determined. By using the University of lowa (Iowa City) cost of examination (approximately $25), at least 1 of every 2,000 examinations would have to show clinically significant disease for histologic examination to be cost-effective. This threshold incidence decreases as production costs decrease or life-year values increase. Before definitive policy conclusions can be made, additional studies are needed to better define the trade-off between cost and the value of information and the incidence of detecting clinically significant disease.     

The effect of the sulfonylurea glyburide on nitric oxide in streptozotocin-induced diabetic rat

1. The interaction between nitric oxide (NO) and superoxide anions has received a great deal of attention. Because NO is rapidly inactivated by superoxide anions, it has been suggested that an enhanced formation of this radical may be involved in the accelerated breakdown of NO. 2. In the present study, we administrated glyburide (glibenclamide) to Streptozotocin-induced diabetic rats and determined the effect of such treatment on serum nitrite+nitrate levels. Serum nitrite+nitrate levels were reduced in diabetic animals (P<0.001). Administration of glyburide to diabetic rats reversed the diabetes-induced changes, suggesting that glyburide may directly increase serum nitrite+nitrate levels.     

Comparison of effects of uroguanylin, guanylin, and Escherichia coli heat-stable enterotoxin STa in mouse intestine and kidney: evidence that uroguanylin is an intestinal natriuretic hormone

BACKGROUND: Uroguanylin and guanylin are intestinal peptides that activate a receptor-guanylate cyclase, which is also a receptor for Escherichia coli heat-stable enterotoxin (STa). These peptides may have a role in the body's regulation of fluid and electrolytes. METHODS: STa, bioactive guanylin, and bioactive uroguanylin were evaluated for effects in: 1) the suckling mouse intestinal fluid secretion assay; 2) an in vitro suckling mouse intestinal loop assay; 3) an intestinal receptor autoradiography assay; 4) a control or agonist-stimulated assay for cGMP response in T84 cells; and 5) an in vivo renal function assay in mice. RESULTS: In vivo, orally administered uroguanylin and STa but not guanylin, stimulated intestinal fluid secretion. All three peptides activated intestinal guanylate cyclase and had common intestinal receptors. In vitro, after pretreatment with chymotrypsin, only uroguanylin and STa retained agoinst activity. Chymostatin preserved guanylin activity. STa and uroguanylin induced diuresis, natriuresis, and kaliuresis. Guanylin was less potent than uroguanylin and STa. CONCLUSIONS: The results suggest that the endogenous intestinal peptides, uroguanylin and guanylin, regulate water and electrolyte homeostasis both through local effects on intestinal epithelia and endocrine effects on the kidney.