In vitro exposure of isolated cells to native gaseous compounds Development and validation of an optimized system for human lung cells

An exposure system for adherent growing cells to native gaseous compounds was developed using air/liquid culture techniques on the basis of the Cultex system'. In contrast to other exposure systems the reproducible testing of native environmentally relevant gases without changing their physical or chemical properties including heating, CO2- content and humidity is possible. Specially designed systems for medium flow and gas support guarantee the nutrification and humidification as well as the direct gas contact of the exposed cells which are cultivated on microporous membranes (0.4 microm pore size). The system works independently of a cell culture incubator offering the possibility to analyze any relevant gas mixture directly under indoor or outdoor conditions. Several experimental approaches were carried out to characterize the properties of the system. In exploratory experiments without cells, the reproducibility and quality of the gas/membrane contact could be demonstrated. Exposures of human lung fibroblasts (Lk004 cells) and human lung epithelial cells (HFBE-21 cells) to synthetic air, ozone (202 ppb, 510 ppb) and nitrogen dioxide (75 ppb to 1,200 ppb) established that cells could be treated for 120 minutes without significant loss of cellular viability. At the same time, the experiments confirmed that such exposure times are long enough to detect biological effects of environmentally relevant gas mixtures. The analysis of viability (viable cell number, tetrazoliumsalt cleavage) and intracellular end-points (oxidized/reduced glutathione, ATP/ADP) showed that both gases induced relevant cellular changes. In summary, the efficiency and practicability of this newly developed exposure system for adherent human lung cells could be clearly demonstrated.     

Serum markers detect the presence of liver fibrosis: a cohort study

BACKGROUND & AIMS: Histologic examination of a liver biopsy specimen is regarded as the reference standard for detecting liver fibrosis. Biopsy can be painful and hazardous, and assessment is subjective and prone to sampling error. We developed a panel of sensitive automated immunoassays to detect matrix constituents and mediators of matrix remodeling in serum to evaluate their performance in the detection of liver fibrosis. METHODS: In an international multicenter cohort study, serum levels of 9 surrogate markers of liver fibrosis were compared with fibrosis stage in liver biopsy specimens obtained from 1021 subjects with chronic liver disease. Discriminant analysis of a test set of samples was used to identify an algorithm combining age, hyaluronic acid, amino-terminal propeptide of type III collagen, and tissue inhibitor of matrix metalloproteinase 1 that was subsequently evaluated using a validation set of biopsy specimens and serum samples. RESULTS: The algorithm detected fibrosis (sensitivity, 90%) and accurately detected the absence of fibrosis (negative predictive value for significant fibrosis, 92%; area under the curve of a receiver operating characteristic plot, .804; standard error, .02; P < .0001; 95% confidence interval, .758-.851). Performance was excellent for alcoholic liver disease and nonalcoholic fatty liver disease. The algorithm performed equally well in comparison with each of the pathologists. In contrast, pathologists' agreement over histologic scores ranged from very good to moderate (kappa = .97-.46). CONCLUSIONS: Assessment of liver fibrosis with multiple serum markers used in combination is sensitive, specific, and reproducible, suggesting they may be used in conjunction with liver biopsy to assess a range of chronic liver diseases.     

Prevalence of allergic sensitization to indoor fungi in West Virginia

Exposure to indoor fungi is of growing concern in residential and occupational environments in the United States. The purpose of this study was to determine the prevalence of sensitization to common indoor fungal species in an atopic population. We evaluated 102 patients (73 female and 29 male patients) for immunoglobulin E (IgE) reactivity to a panel of skin-prick test (SPT) reagents used for routine allergy testing. Patients also were tested for six additional fungi that are common indoor contaminants. All patients had symptoms consistent with allergic rhinitis or asthma. The presence of specific IgE against the fungal species was determined using immunoblotting. Of the 102 eligible patients, 68% had at least one positive skin test. The most prevalent positive SPTs were to dust mites, cats, vernal grass, and short ragweed. Overall, 21/102 (21%) patients with asthma or allergic rhinitis were skin test positive to at least one fungal extract. Of the patients with a positive SPT to fungi, 12/21 (58%) showed sensitivity to one or more of the newly tested species; most notably Trichoderma viride (8%), Chaetomium globosum (7%), Paecilomyces variotii (7%), and Acremonium strictum (6%). Immunoblotting revealed specific IgE against a number of protein bands belonging to these fungal species. The prevalence of fungal sensitization was common, particularly for indoor fungal contaminants that are not routinely included in SPT panels. Cross-reactivity with other fungi may partially explain our results; however, skin testing for these indoor fungi may provide useful diagnostic information.     

Impaired emotional learning and reduced amygdala size in schizophrenia: a 3-month follow-up

Individuals with schizophrenia have difficulties in emotional information processing. A relationship between behavioral variables of emotional processing and structural amygdala alterations in schizophrenia has been proposed but not shown, yet. Morphological studies of amygdala size in schizophrenia have yielded inconsistent results. The current study assessed paired associates learning of emotional and neutral faces in 16 subjects with schizophrenia during acute episode and in relative remission after 3 months. Sixteen matched controls were studied for comparison. Subjects also underwent structural magnetic resonance imaging (3D-MRI) at the first time of assessment. Subjects with schizophrenia showed a significant decrease (by 13%) in total size of the amygdala compared to controls, which was more pronounced on the right side. Subjects with schizophrenia improved associative learning of facial identities but not of emotional facial expressions after relative remission of psychotic symptoms. Volume of the right amygdala in subjects with schizophrenia and in controls was significantly related to emotional learning, indicating better learning in subjects with larger amygdala size. Our results indicate that subjects with schizophrenia have a deficit to form associations when emotionally loaded material is used. This deficit seems to be trait-like and independent of disease state. It seems to be linked to size reduction of the right amygdala in schizophrenia.