Neutralization assay using a modified vaccinia virus Ankara vector expressing the green fluorescent protein is a high-throughput method to monitor the humoral immune response against vaccinia virus

Vaccination against smallpox is again considered in order to face a possible bioterrorist threat, but the nature and the level of the immune response needed to protect a person from smallpox after vaccination are not totally understood. Therefore, simple, rapid, and accurate assays to evaluate the immune response to vaccinia virus need to be developed. Neutralization assays are usually considered good predictors of vaccine efficacy and more informative with regard to protection than binding assays. Currently, the presence of neutralizing antibodies to vaccinia virus is measured using a plaque reduction neutralization test, but this method is time-consuming and labor-intensive and has a subjective readout. Here, we describe an innovative neutralization assay based on a modified vaccinia virus Ankara (MVA) vector expressing the green fluorescent protein (MVA-gfp). This MVA-gfp neutralization assay is rapid and sensitive and has a high-throughput potential. Thus, it is suitable to monitor the immune response and eventually the efficacy of a large campaign of vaccination against smallpox and to study the vector-specific immune response in clinical trials that use genetically engineered vaccinia viruses. Most importantly, application of the highly attenuated MVA eliminates the safety concern in using the replication-competent vaccinia virus in the standard clinical laboratory.     

Emergence of translocation t(9;11)-positive leukemia during treatment of childhood acute lymphoblastic leukemia

Therapy-related acute myeloid leukemia (t-AML) characterized by the t(9;11)(p22;q23) translocation is one of the most frequent secondary malignancies. The timing of the initiation of translocation and of development of the malignant t(9;11) clone during chemotherapy is presently unknown. In the present study, we backtracked bone marrow samples from three children during treatment for acute lymphoblastic leukemia (ALL). Two patients developed a t(9;11)-positive t-AML 19 and 30 months after therapy start, whereas the third patient, diagnosed with a rare t(9;11)-positive ALL, suffered from an ALL relapse 23 months after initial diagnosis. The genomic MLL-MLLT3 (MLL-AF9) fusion site was amplified by a multiplex, nested long-range PCR and used as a clonal marker for quantification of the MLL-MLLT3-positive cells during chemotherapy. The t(9;11)-positive clone was detectable 13 and 18 months after therapy start in both t-AML cases, which was 6-12 months before clinical diagnosis of the secondary malignancy. In the t(9;11)-positive ALL patient, the identical leukemic clone reoccurred during maintenance therapy after a short molecular remission, 8 months before clinically overt ALL relapse. The time course and characteristics of the genomic breakpoints in the present t-AML cases support the hypothesis of translocation formation as a result of defective breakage repair after topoisomerase II cleavage.     

Helicase Hmi1 stimulates the synthesis of concatemeric mitochondrial DNA molecules in yeast Saccharomyces cerevisiae

Hmi1p is a helicase in the yeast Saccharomyces cerevisiae required for maintenance of the wild-type mitochondrial genome. Disruption of the HMI1 ORF generates ^– and ⁰ cells. Here we demonstrate that, in ^– yeast strains, Hmi1p stimulates the synthesis of long concatemeric mitochondrial DNA molecules associated with a reduction in the number of nucleoids used for mitochondrial DNA packaging. Surprisingly, the ATPase negative mutants of Hmi1p can also stimulate the synthesis of long concatemeric ^– mitochondrial DNA molecules and support the maintenance of the wild-type mitochondrial genome, albeit with reduced efficiency. We show that, in the mutant hmi1–5 background, the wild-type mitochondrial DNA is fragmented; and we propose that, in hmi1 yeast cells, the loss of the wild-type mitochondrial genome is caused by this fragmentation of the mitochondrial DNA.     

Evaluation of a New Automated Homogeneous PCR Assay,GenomEra C. difficile,for Rapid Detection of Toxigenic Clostridium difficile in Fecal Specimens

We evaluated a new automated homogeneous PCR assay to detect toxigenic Clostridium difficile, the GenomEra C. difficile assay (Abacus Diagnostica, Finland), with 310 diarrheal stool specimens and with a collection of 33 known clostridial and nonclostridial isolates. Results were compared with toxigenic culture results, with discrepancies being resolved by the GeneXpert C. difficile PCR assay (Cepheid). Among the 80 toxigenic culture-positive or GeneXpert C. difficile assay-positive fecal specimens, 79 were also positive with the GenomEra C. difficile assay. Additionally, one specimen was positive with the GenomEra assay but negative with the confirmatory methods. Thus, the sensitivity and specificity were 98.8% and 99.6%, respectively. With the culture collection, no false-positive or -negative results were observed. The analytical sensitivity of the GenomEra C. difficile assay was approximately 5 CFU per PCR test. The short hands-on (<5 min for 1 to 4 samples) and total turnaround (<1 h) times, together with the high positive and negative predictive values (98.8% and 99.6%, respectively), make the GenomEra C. difficile assay an excellent option for toxigenic C. difficile detection in fecal specimens.     

Emotional Exhaustion and Cognitive Performance in Apparently Healthy Teachers: A Longitudinal Multi‐source Study

We investigate how emotional exhaustion (EE), the core component of burnout, relates to cognitive performance, job performance and health. Cognitive performance was assessed by self‐rated cognitive stress symptoms, self‐rated and peer‐rated cognitive impairments in everyday tasks and a neuropsychological test of learning and memory (LGT‐3); job performance and physical health were gauged by self‐reports. Cross‐sectional linear regression analyses in a sample of 100 teachers confirm that EE is negatively related to cognitive performance as assessed by self‐rating and peer‐rating as well as neuropsychological testing (all p < .05). Longitudinal linear regression analyses confirm similar trends (p < .10) for self‐rated and peer‐rated cognitive performance. Executive control deficits might explain impaired cognitive performance in EE. In longitudinal analyses, EE also significantly predicts physical health. Contrary to our expectations, EE does not affect job performance. When reversed causation is tested, none of the outcome variables at Time 1 predict EE at Time 2. This speaks against cognitive dysfunctioning serving as a vulnerability factor for exhaustion. In sum, results underpin the negative consequences of EE for cognitive performance and health, which are relevant for individuals and organizations alike. In this way, findings might contribute to the understanding of the burnout syndrome. Copyright © 2012 John Wiley & Sons, Ltd.     

Does habitual body avoidance and checking behavior influence the decrease of negative emotions during body exposure in eating disorders?

Abstract

The aim of the present study was to assess whether habitual body avoidance and body-checking behavior influences the decrease of negative emotions during body exposure. Twenty-one eating-disordered female participants completed the Body Image Avoidance Questionnaire and the Body Checking Questionnaire. On another day, a 40-min body exposure session was conducted under standardized conditions. Every 10 min, negative emotions were assessed. It was shown that the extent of decrease in negative emotions during the body exposure session could be predicted by a lower degree of body checking. Results indicate that habitual checking behavior seems to negatively influence the effect of body exposure. Therefore, an adaptation of body exposure to patients with a higher degree of body-checking behavior might be promising.