Left-Right and Upper-Lower Visual Field Asymmetries for Face Matching, Letter Naming, and Lexical Decision

The relation between left-right and upper-lower visual field (VF) asymmetries was examined for face matching, letter naming and lexical decision. Stimuli were flashed in the VF quadrants. Face matching resulted in a lower-left and upper-right VF advantage. Letter-naming resulted in a robust upper-right VF advantage. For lexical decision, no upper/lower asymmetries were found. Words were processed faster in the right than in the left VF, while nonwords were processed equally fast in both VFs. The results are discussed in terms of hypothesized structural connections of the lower versus upper visual field to dorsal versus ventral visual pathways and in terms of attentional mechanisms related to the processing of visual information in the VF quadrants

Hospital process orientation from an operations management perspective: Development of a measurement tool and practical testing in three ophthalmic practices

Background: Although research interest in hospital process orientation (HPO) is growing, the development of a measurement tool to assess process orientation (PO) has not been very successful yet. To view a hospital as a series of processes organized around patients with a similar demand seems to be an attractive proposition, but it is hard to operationalize this idea in a measurement tool that can actually measure the level of PO. This research contributes to HPO from an operations management (OM) perspective by addressing the alignment, integration and coordination of activities within patient care processes. The objective of this study was to develop and practically test a new measurement tool for assessing the degree of PO within hospitals using exist

Phosphoinositide-dependent kinase 1 controls migration and malignant transformation but not cell growth and proliferation in PTEN-null lymphocytes

In normal T cell progenitors, phosphoinositide-dependent kinase l (PDK1)–mediated phosphorylation and activation of protein kinase B (PKB) is essential for the phosphorylation and inactivation of Foxo family transcription factors, and also controls T cell growth and proliferation. The current study has characterized the role of PDK1 in the pathology caused by deletion of the tumor suppressor phosphatase and tensin homologue deleted on chromosome 10 (PTEN). PDK1 is shown to be essential for lymphomagenesis caused by deletion of PTEN in T cell progenitors. However, PTEN deletion bypasses the normal PDK1-controlled signaling pathways that determine thymocyte growth and proliferation. PDK1 does have important functions in PTEN-null thymocytes, notably to control the PKB–Foxo signaling axis and to direct the repertoire of adhesion and chemokine receptors expressed by PTEN-null T cells. The results thus provide two novel insights concerning pathological signaling caused by PTEN loss in lymphocytes. First, PTEN deletion bypasses the normal PDK1-controlled metabolic checkpoints that determine cell growth and proliferation. Second, PDK1 determines the cohort of chemokine and adhesion receptors expressed by PTEN-null cells, thereby controlling their migratory capacity

Chromosome specific DNA hybridization in suspension for flow cytometric detection of chimerism in bone marrow transplantation and leukemia

Flow cytometry was used to measure the fluorescence intensity of nuclei that were subjected to fluorescent in situ hybridization in suspension with chromosome specific DNA probes. Paraformaldehyde-fixed nuclei were protein digested with trypsin and hybridized simultaneously with a biotin-and DIG labeled chromosome specific centromere probe. A number of probes were tested in the suspension hybridizations. The method yielded fluorescent hybridization signals that allow discrimination between Y chromosome positive and negative nuclei when analyzed by flow cytometry. The method is especially suited for analysis of bone marrow cells derived from patients who have received a sex-mismatched allogeneic bone marrow transplantation. Male leukemia cells with a trisomy for chromosome 8 were mixed with normal female cells and simultaneously hybridized in suspension with a DIG labeled probe specific for chromosome 8 and the biotin labeled Y chromosome probe. Y chromosome positive or negative nuclei were s

The use of FISH with chromosome-specific repetitive DNA probes for the follow-up of leukemia patients

The use of fluorescence in situ hybridization (FISH) for the purpose of repeated follow-up examination of bone marrow samples from 38 leukemia patients was investigated. On the basis of conventional cytogenetic analysis, patients with acute leukemia whose leukemic cells carried numerical chromosomal aberrations were selected and followed with repetitive DNA probes that specifically hybridize to one chromosome type. Repeated cytogenetic metaphase analyses would have been laborious and not sensitive or quantitative enough to follow declining numbers of aberrant cells. FISH, as an interphase cytogenetic technique, provides a rapid and simple alternative with high sensitivity. Although FISH data before and after chemotherapy were in agreement with bone marrow cytology in 30 of 38 patients, discrepancies were noticed in specific cases. These could be explained by the presence of cytogenetically distinct subclones that behave differently during treatment, the presence of differentiated leukemic cells, changes in the chromosomal constitution caused by clonal relapse, or the fact that a numerical aberration is found by conventional chromosome banding analysis while the target region to which the probe is directed is still present in the nucleus as a diploid set

Genetics and Not Shared Environment Explains Familial Resemblance in Adult Metabolomics Data

Metabolites are small molecules involved in cellular metabolism where they act as reaction substrates or products. The term ‘metabolomics’ refers to the comprehensive study of these molecules. The concentrations of metabolites in biological tissues are under genetic control, but this is limited by environmental factors such as diet. In adult mono- and dizygotic twin pairs, we estimated the contribution of genetic and shared environmental influences on metabolite levels by structural equation modeling and tested whether the familial resemblance for metabolite levels is mainly explained by genetic or by environmental factors that are shared by family members. Metabolites were measured across three platforms: two based on proton nuclear magnetic resonance techniques and one employing mass spectrometry. These three platforms comprised 237 single metabolic traits of several chemical classes. For the three platforms, metabolites were assessed in 1407, 1037 and 1116 twin pairs, respectively. We carried out power calculations to establish what percentage of shared environmental variance could be detected given these sample sizes. Our study did not find evidence for a systematic contribution of shared environment, defined as the influence of growing up together in the same household, on metabolites assessed in adulthood. Significant heritability was observed for nearly all 237 metabolites; significant contribution of the shared environment was limited to 6 metabolites. The top quartile of the heritability distribution was populated by 5 of the 11 investigated chemical classes