Evaluation of three commercially available hepatitis C virus antibody detection assays under the conditions of a clinical virology laboratory.

BACKGROUND: Most studies evaluating antibody detection assays are conducted on samples from healthy blood donors but not on samples of hospitalized patients which can show non-specific reactions. OBJECTIVES: To compare the performance of three commercial automated assays for the detection of hepatitis C virus (HCV) antibodies, Monolisa anti-HCV Plus version 2, Axsym anti-HCV 3.0 and Vitros anti-HCV, on a population of hospitalized patients. STUDY DESIGN: The specificity of the assays was prospectively evaluated in 2020 routine serum samples. In order to assign the serostatus of each sample, those giving positive or discordant results were further tested by three immunoblots and by RT-PCR (Roche). Moreover, the sensitivity was evaluated on eight commercial HCV seroconversion panels. RESULTS: The Monolisa, Axsym and Vitros assays showed specificities of 99.64%, 99.12% and 99.33%, respectively. Concerning the sensitivity, among 49 samples, the number of positive results was 21, 24 and 24 for the Monolisa, Axsym and Vitros kits, respectively. The differences were not statistically significant at an alpha risk of 5%. CONCLUSIONS: All assays appeared to be reliable for routine screening, but there were a surprising number of indeterminate samples that could not be resolved by confirmatory tests.     

A new strategy for label-free detection of lymphoma cancer cells

In this paper, a new strategy for highly selective and sensitive direct detection of lymphoma cells by exploiting the interaction between a peptide and its B-cell receptor, has been evaluated. In particular, an idiotype peptide, able to specifically bind the B-cell receptor of A20 cells in mice engrafted with A20 lymphoma, has been used as molecular probe. The new detection technique has been demonstrated on a planar crystalline silicon chip. Coverage of 85% of silicon surface and detection efficiency of 8.5 × 10⁻³ cells/μm² were obtained. The recognition strategy promises to extend its application in studying the interaction between ligands and their cell-surface receptors.OCIS codes: (000.1430) Biology and medicine, (280.1415) Biological sensing and sensors     

Effect of Helicobacter pylori eradication on bulbitis and duodenal gastric metaplasia

BACKGROUND/AIMS: Duodenal gastric metaplasia seems to be linked to infection by Helicobacter pylori, to the extent of acid secretion and to bulbitis. An investigation was made of the relationship between bulbitis and duodenal gastric metaplasia, or whether bulbitis can arise along with duodenal gastric metaplasia after Helicobacter pylori eradication in an average of six years. METHODOLOGY: We compared 22 patients with duodenal ulcers [male/female 16/6; (mean age+/-SD) 55+/-12 years] Helicobacter pylori-negative after eradication, with 23 Helicobacter pylori-positive patients free from active duodenal ulcers [male/female 17/6; (mean age+/-SD) 59+/-12 years]. RESULTS: The bulbitis score was found to be lower in the Helicobacter pylori-negative than in the Helicobacter pylori-positive group (p=0.02). The duodenal gastric metaplasia score in the Helicobacter pylori-negative was higher than in the Helicobacter pylori-positive group (p=0.001). We failed to find any relationship between the presence of bulbitis and duodenal gastric metaplasia. We found a non-significant inverse correlation between the presence of duodenal gastric metaplasia and chronic body gastritis (p=0.07). CONCLUSIONS: Bulbitis and duodenal gastric metaplasia may depend on different causal factors not related to Helicobacter pylori infection. The extension of duodenal gastric metaplasia with time following recovery from peptic ulcer disease may represent a mucosal protection factor against acid.     

The generation of tetrahedral mesh models for neuroanatomical MRI

In this article, we describe a detailed method for automatically generating tetrahedral meshes from 3D images having multiple region labels. An adaptively sized tetrahedral mesh modeling approach is described that is capable of producing meshes conforming precisely to the voxelized regions in the image. Efficient tetrahedral mesh improvement is then performed minimizing an energy function containing three terms: a smoothing term to remove the voxelization, a fidelity term to maintain continuity with the image data, and a novel elasticity term to prevent the tetrahedra from becoming flattened or inverted as the mesh deforms while allowing the voxelization to be removed entirely. The meshing algorithm is applied to structural MR image data that has been automatically segmented into 56 neuroanatomical sub-divisions as well as on two other examples. The resulting tetrahedral representation has several desirable properties such as tetrahedra with dihedral angles away from 0 and 180 degrees, smoothness, and a high resolution. Tetrahedral modeling via the approach described here has applications in modeling brain structure in normal as well as diseased brain in human and non-human data and facilitates examination of 3D object deformations resulting from neurological illness (e.g. Alzheimer's disease), development, and/or aging.     

Resting-state fMRI can reliably map neural networks in children

Resting-state MRI (rs-fMRI) is a powerful procedure for studying whole-brain neural connectivity. In this study we provide the first empirical evidence of the longitudinal reliability of rs-fMRI in children. We compared rest-retest measurements across spatial, temporal and frequency domains for each of six cognitive and sensorimotor intrinsic connectivity networks (ICNs) both within and between scan sessions. Using Kendall'sW, concordance of spatial maps ranged from .60 to .86 across networks, for various derived measures. The Pearson correlation coefficient for temporal coherence between networks across all Time 1-Time 2 (T1/T2) z-converted measures was .66 (p<.001). There were no differences between T1/T2 measurements in low-frequency power of the ICNs. For the visual network, within-session T1 correlated with the T2 low-frequency power, across participants. These measures from resting-state data in children were consistent across multiple domains (spatial, temporal, and frequency). Resting-state connectivity is therefore a reliable method for assessing large-scale brain networks in children.     

Chemokines and Antimicrobial Peptides Have a cag-Dependent Early Response to Helicobacter pylori Infection in Primary Human Gastric Epithelial Cells

Helicobacter pylori infection systematically causes chronic gastric inflammation that can persist asymptomatically or evolve toward more severe gastroduodenal pathologies, such as ulcer, mucosa-associated lymphoid tissue (MALT) lymphoma, and gastric cancer. The cag pathogenicity island (cag PAI) of H. pylori allows translocation of the virulence protein CagA and fragments of peptidoglycan into host cells, thereby inducing production of chemokines, cytokines, and antimicrobial peptides. In order to characterize the inflammatory response to H. pylori, a new experimental protocol for isolating and culturing primary human gastric epithelial cells was established using pieces of stomach from patients who had undergone sleeve gastrectomy. Isolated cells expressed markers indicating that they were mucin-secreting epithelial cells. Challenge of primary epithelial cells with H. pylori B128 underscored early dose-dependent induction of expression of mRNAs of the inflammatory mediators CXCL1 to -3, CXCL5, CXCL8, CCL20, BD2, and tumor necrosis factor alpha (TNF-α). In AGS cells, significant expression of only CXCL5 and CXCL8 was observed following infection, suggesting that these cells were less reactive than primary epithelial cells. Infection of both cellular models with H. pylori B128ΔcagM, a cag PAI mutant, resulted in weak inflammatory-mediator mRNA induction. At 24 h after infection of primary epithelial cells with H. pylori, inflammatory-mediator production was largely due to cag PAI substrate-independent virulence factors. Thus, H. pylori cag PAI substrate appears to be involved in eliciting an epithelial response during the early phases of infection. Afterwards, other virulence factors of the bacterium take over in development of the inflammatory response. Using a relevant cellular model, this study provides new information on the modulation of inflammation during H. pylori infection.     

Investigation of the infertile couple: when is the appropriate time to explore female infertility?

While the appropriate method for the investigation of female infertility continues to be debated, the timing of the investigation has received less attention. The current approach is time-consuming, and paradoxically may lead to overtreatment as well as undertreatment. Recent findings on fecundity and the conception window in humans have important implications for the timing of the investigation of female infertility. The findings support the view that fertility-oriented intercourse may have a major impact in reducing the time to pregnancy. Procedures for the investigation of female infertility are becoming less invasive and more accurate, while the therapies for infertility are more effective. It is proposed that under appropriate circumstances female infertility should be investigated after 6 months of fertility-oriented intercourse.