Separation of oxidant-initiated and redox-regulated steps in the NF-kappa B signal transduction pathway.

Studies presented here show that overall NF-kappa B signal transduction begins with a parallel series of stimuli-specific pathways through which cytokines (tumor necrosis factor alpha), oxidants (hydrogen peroxide and mitomycin C), and phorbol ester (phorbol 12-myristate 13-acetate) individually initiate signaling. These initial pathways culminate in a common pathway through which all of the stimulating agents ultimately signal NF-kappa B activation. We distinguish the stimuli-specific pathways by showing that the oxidative stimuli trigger NF-kappa B activation in only one of two human T-cell lines (Wurzburg but not Jurkat), whereas tumor necrosis factor alpha and phorbol 12-myristate 13-acetate readily stimulate in both lines. We propose the common pathway as the simplest way of accounting for the common requirements and properties of the signaling pathway. We include a redox-regulatory mechanism(s) in this common pathway to account for the previously demonstrated redox regulation of NF-kappa B activation in Jurkat cells (in which oxidants don't activate NF-kappa B); we put tyrosine phosphorylation in the common pathway by showing that kinase activity (inhibitable by herbimycin A and tyrphostin 47) is required for NF-kappa B activation by all stimuli tested in both cell lines. Since internal sites of oxidant production have been shown to play a key role in the cytokine-stimulated activation of NF-kappa B, and since tyrosine kinase and phosphatase activities are known to be altered by oxidants, these findings suggest that intracellular redox status controls NF-kappa B activation by regulating tyrosine phosphorylation event(s) within the common step of the NF-kappa B signal transduction pathway.     

Structural brain abnormalities in patients with schizophrenia and their healthy siblings

OBJECTIVE: The authors sought to investigate the contribution of genotype on structural brain abnormalities in schizophrenia. METHOD: Intracranial volumes and volumes of the cerebrum, white and gray matter, lateral and third ventricles, frontal lobes, caudate nucleus, amygdala, hippocampus, parahippocampal gyrus, and the cerebellum were measured in 32 same-sex siblings discordant for schizophrenia and 32 matched comparison subjects by means of magnetic resonance imaging. RESULTS: Third ventricle volumes did not differ between the schizophrenic patients and their healthy siblings. However, both had higher third ventricle volumes than did the comparison subjects. The schizophrenic patients had lower cerebrum volumes than did the comparison subjects, whereas the cerebrum volume of the healthy siblings did not significantly differ from the patients or comparison subjects. Additionally, patients with schizophrenia displayed a volume reduction of the frontal lobe gray matter and a volume increase of the caudate nuclei and lateral ventricles compared to both their healthy siblings and comparison subjects. Intracranial volume, CSF volume, or volumes of the cerebellum, amygdala, hippocampus, or the parahippocampal gyrus did not significantly differ among the patients, siblings, and comparison subjects. CONCLUSIONS: Healthy siblings share third ventricle enlargement with their affected relatives and may partially display a reduction in cerebral volume. These findings suggest that third ventricular enlargement, and to some extent cerebral volume decrease, may be related to genetic defects that produce a susceptibility to schizophrenia.     

KCa3.1—a microglial target ready for drug repurposing?

Over the past decade, glial cells have attracted attention for harboring unexploited targets for drug discovery. Several glial targets have attracted de novo drug discovery programs, as highlighted in this GLIA Special Issue. Drug repurposing, which has the objective of utilizing existing drugs as well as abandoned, failed, or not yet pursued clinical development candidates for new indications, might provide a faster opportunity to bring drugs for glial targets to patients with unmet needs. Here, we review the potential of the intermediate‐conductance calcium‐activated potassium channels K_Ca3.1 as the target for such a repurposing effort. We discuss the data on K_Ca3.1 expression on microglia in vitro and in vivo and review the relevant literature on the two K_Ca3.1 inhibitors TRAM‐34 and Senicapoc. Finally, we provide an outlook of what it might take to harness the potential of K_Ca3.1 as a bona fide microglial drug target. GLIA 2016;64:1733–1741     

T-, B- and NK-lymphoid, but not myeloid cells arise from human CD34(+)CD38(-)CD7(+) common lymphoid progenitors expressing lymphoid-specific genes.

Hematopoietic stem cells in the bone marrow (BM) give rise to all blood cells. According to the classic model of hematopoiesis, the differentiation paths leading to the myeloid and lymphoid lineages segregate early. A candidate 'common lymphoid progenitor' (CLP) has been isolated from CD34(+)CD38(-) human cord blood cells based on CD7 expression. Here, we confirm the B- and NK-differentiation potential of CD34(+)CD38(-)CD7(+) cells and show in addition that this population has strong capacity to differentiate into T cells. As CD34(+)CD38(-)CD7(+) cells are virtually devoid of myeloid differentiation potential, these cells represent true CLPs. To unravel the molecular mechanisms underlying lymphoid commitment, we performed genome-wide gene expression profiling on sorted CD34(+)CD38(-)CD7(+) and CD34(+)CD38(-)CD7(-) cells. Interestingly, lymphoid-affiliated genes were mainly upregulated in the CD7(+) population, while myeloid-specific genes were downregulated. This supports the hypothesis that lineage commitment is accompanied by the shutdown of inappropriate gene expression and the upregulation of lineage-specific genes. In addition, we identified several highly expressed genes that have not been described in hematopoiesis before.     

Consensus guidelines for microarray gene expression analyses in leukemia from three European leukemia networks.

A plethora of studies have documented that gene expression profiling using DNA microarrays for various types of hematological malignancies provides novel information, which may have diagnostic and prognostic implications. However, to successfully use microarrays for this purpose, the quality and reproducibility of the whole procedure need to be guaranteed. Critical steps of the method are handling, processing and storage of the leukemic sample, purification of tumor cells (or lack thereof), RNA extraction methods, quality control of RNA, labeling techniques, hybridization, washing, scanning, spot filtering, normalization and initial interpretation, and finally the biostatistical analysis. These items have been extensively discussed and evaluated in different multi-center quality rounds within the three networks, that is, I-BFM-SG, the German Competence Network 'Acute and Chronic Leukemias' and the European LeukemiaNet. Based on the exchange of knowledge and experience between the three networks over the last few years, we have formulated guidelines for performing microarray experiments in leukemia. We confine ourselves to leukemias, but many of these requirements also apply to lymphomas or other clinical samples, including solid tumors.     

Automated separation of gray and white matter from MR images of the human brain

A simple automatic procedure for segmentation of gray and white matter in high resolution 1.5T T1-weighted MR human brain images was developed and validated. The algorithm is based on histogram shape analysis of MR images that were corrected for scanner nonuniformity. Calibration and validation was done on a set of 80 MR images of human brains. The automatic method's values for the gray and white matter volumes were compared with the values from thresholds set twice by the best three of six raters. The automatic procedure was shown to perform as good as the best rater, where the average result of the best three raters was taken as reference. The method was also compared with two other histogram-based threshold methods, which yielded comparable results. The conclusion of the study thus is that automated threshold based methods can separate gray and white matter from MR brain images as reliably as human raters using a thresholding procedure.     

The economics of optimal health and productivity in smallholder livestock systems in developing countries.

Livestock kept or produced in smallholder farming systems are an important component of the agricultural economy in the developing world. The role of livestock on smallholder farms varies widely, providing draught power for crop production or as a production activity for subsistence needs or market sale under systems ranging from extensive pastoralist to intensive, peri-urban feeder and dairy systems. A set of unique conditions and features characterise smallholder systems, and these need to be appreciated when assessing the strategies that have evolved for managing animal health in smallholder systems, and evaluating opportunities for improving disease control strategies. To provide a framework for discussing animal health issues and analytical methodogies, a typology of smallholder livestock and crop/livestock systems is developed. The typology considers livestock systems both in terms of the degree of intensification, as measured by market orientation and intensity of factor use, and in terms of importance within the household economy, as measured by contribution to household income. A number of characteristics are identified that distinguish smallholder systems from the commercialised systems of developed countries, including the multiple functions livestock serve, the integrated nature of livestock activities, multiple objectives of producers and lower capacity to bear risk at the household level, as well as poor infrastructure, markets, and access to information at the community level. Three representative smallholder livestock systems from Africa are described in detail, highlighting the relevant characteristics and the implications for analysing disease control strategies. Smallholder dairy systems in Kenya demonstrate the role of individual producer decision-making for animal health management in intensive, market-oriented systems, placing emphasis on farm-level risk and production management aspects of disease control. In extensive pastoralist systems where epidemic disease are still important and infrastructure is poor, disease control primarily involves managing communal natural resources, requiring a different analytical approach. Finally, in crop farming systems using draught cattle, the livestock activity is an integrated component of crop production and this must be reflected in the approach used to evaluate draught animal health management. Continued development of analytical approaches and decision-support tools for disease control strategies adapted to the special characteristics of these systems will be needed as smallholder systems continue to intensify in areas with good market access, and those in marginal areas face increasing pressures to optimally manage the natural resource base.     

SMART—An Integrated Wireless System for Monitoring Unattended Patients

Monitoring vital signs and locations of certain classes of ambulatory patients can be useful in overcrowded emergency departments and at disaster scenes, both on-site and during transportation. To be useful, such monitoring needs to be portable and low cost, and have minimal adverse impact on emergency personnel, e.g., by not raising an excessive number of alarms. The SMART (Scalable Medical Alert Response Technology) system integrates wireless patient monitoring (ECG, SpO₂), geo-positioning, signal processing, targeted alerting, and a wireless interface for caregivers. A prototype implementation of SMART was piloted in the waiting area of an emergency department and evaluated with 145 post-triage patients. System deployment aspects were also evaluated during a small-scale disaster-drill exercise.     

Cellular expression of K-type pyruvate kinase in normal and neoplastic human tissues

The cellular expression of K-type pyruvate kinase was studied immunohistochemically in several normal and neoplastic tissues of human origin. The authors used the monoclonal antibody, designated as ES1, which was raised against human K-type pyruvate kinase. In contrast to the normal counterparts, a strong immunoreactivity was found in a rhabdomyosarcoma (n = 1), in a carcinoma of the pancreas (n = 1), and in neurofibromas (n = 2). Furthermore, the staining in leiomyosarcomas (n = 2) was shown to be more intense when compared with both normal smooth muscle cells and leiomyomas (n = 2). These findings show that knowledge about the cellular expression of the K-type pyruvate kinase identifies cell types for which its expression serves as oncodevelopmental marker. In addition, these immunohistochemical studies give information whether shifts toward K-type containing isozymes of pyruvate kinase, which are determined by electrophoresis in whole cytosolic extracts of various tumors, are due to an altered gene expression or due to proliferation of cells which normally express already the K-type pyruvate kinase. The first possibility probably occurs in rhabdomyosarcomas. The latter possibility seems to be valid for astrocytomas because astrocytes express the K-type pyruvate kinase in normal brain.