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1.
BMC Public Health ; 19(1): 1337, 2019 Oct 22.
Article in English | MEDLINE | ID: mdl-31640650

ABSTRACT

BACKGROUND: Burnout is a syndrome characterized by emotional exhaustion, increased depersonalization, and a diminished sense of personal accomplishment due to chronic emotional stress at work. Burnout impacts job satisfaction, job performance, vulnerability to illnesses, and interpersonal relationships. There is a gap in the systematic data on the burden of burnout among healthcare professionals from different sectors of healthcare in Middle Eastern countries. Our objective was to examine the burden of burnout among healthcare providers in the Middle East, how it was assessed, which sectors were included, and what interventions have been used. METHODS: Articles were found through a systematic review of search results including PubMed, Web of Science (Thomson Reuters), and PsycINFO (EBSCO) using search terms reflecting burnout in Middle Eastern countries among populations of healthcare providers. Studies were included if they examined a quantitative measure of burnout among healthcare providers in the Middle East. RESULTS: There were 138 articles that met our inclusion criteria for this systematic review. Studies focused on burnout in the Middle East among physicians (N = 54 articles), nurses (N = 55), combined populations of healthcare workers (N = 22), and medical students (N = 7). The Maslach Burnout Inventory was the most common tool to measure burnout. Burnout is common among physicians, nurses, and other healthcare professionals, with prevalence estimates predominantly ranging between 40 and 60%. Burnout among healthcare providers in the Middle East is associated with characteristics of their work environments, exposure to violence and terror, and emotional distress and low social support. CONCLUSIONS: Burnout is highly prevalent among healthcare providers across countries in the Middle East. Previous studies examining burnout in this region have limitations in their methodology. More thoroughly developed epidemiologic studies of burnout are necessary. Health system strengthening is needed in a region that has endured years of ongoing conflict, and there is an urgency to design and implement programs that tackle burnout among health professionals.


Subject(s)
Burnout, Professional/epidemiology , Health Personnel/psychology , Humans , Middle East/epidemiology , Prevalence
2.
J Econ Entomol ; 105(4): 1465-70, 2012 Aug.
Article in English | MEDLINE | ID: mdl-22928330

ABSTRACT

The aphid Amphorophora agathonica Hottes (Hemiptera: Aphididae) is an important virus vector in red (Rubus idaeus L.) and black (Rubus occidentalis L.) raspberries in North America. Raspberry resistance to A. agathonica in the form of a single dominant gene named Ag1 has been relied upon to help control aphid-transmitted plant viruses; however, the mechanism of resistance to the insect is poorly understood. Aphid feeding was monitored using an electrical penetration graph on the resistant red raspberry 'Tulameen' and compared with a susceptible control, 'Vintage'. There were no differences in pathway feeding behaviors of aphids as they moved toward the phloem. Once in the phloem, however, aphids feeding on resistant plants spent significantly more time salivating than on susceptible plants, and ingested significantly less phloem sap. This suggests that a mechanism for resistance to A. agathonica is located in the phloem. Reduced ingestion of phloem may result in inefficient acquisition of viruses and is a likely explanation for the lack of aphid-transmitted viruses in plantings of resistant cultivars.


Subject(s)
Aphids/physiology , Feeding Behavior , Host-Parasite Interactions/immunology , Rosaceae/parasitology , Animals , Electricity , Electronics/methods , Rosaceae/immunology
3.
Protein Eng Des Sel ; 19(6): 255-64, 2006 Jun.
Article in English | MEDLINE | ID: mdl-16549400

ABSTRACT

Yeast display provides a system for engineering high-affinity proteins using a fluorescent-labeled ligand and fluorescence-activated cell sorting (FACS). In cases where it is difficult to obtain purified ligands, or to access FACS instrumentation, an alternative selection strategy would be useful. Here we show that yeast expressing high-affinity proteins against a mammalian cell surface ligand could be rapidly selected by density centrifugation. Yeast cell-mammalian cell conjugates were retained at the density interface, separated from unbound yeast. High-affinity T cell receptors (TCRs) displayed on yeast were isolated using antigen presenting cells that expressed TCR ligands, peptides bound to products of the major histocompatibility complex (MHC). The procedure yielded 1000-fold enrichments, in a single centrifugation, of yeast displaying high-affinity TCRs. We defined the affinity limits of the method and isolated high-affinity TCR mutants against peptide variants that differed by only a single residue. The approach was applied to TCRs specific for class I or class II MHC, an important finding since peptide-class II MHC ligands have been particularly difficult to purify. As yeast display has also been used previously to identify antigen-specific antibodies, the method should be applicable to the selection of antibodies, as well as TCRs, with high-affinity for tumor cell-surface antigens.


Subject(s)
Directed Molecular Evolution , Fungal Proteins/genetics , Major Histocompatibility Complex , Protein Engineering/methods , Receptors, Antigen, T-Cell/metabolism , Yeasts/genetics , Cell Differentiation/genetics , Cell Differentiation/physiology , Flow Cytometry/methods , Fluorescent Dyes/chemistry , Fungal Proteins/chemistry , Fungal Proteins/metabolism , Gene Library , Histocompatibility Antigens Class II/chemistry , Histocompatibility Antigens Class II/genetics , Histocompatibility Antigens Class II/metabolism , Ligands , Mutation , Receptors, Antigen, T-Cell/genetics , Receptors, Antigen, T-Cell/isolation & purification
4.
J Virol ; 73(8): 6506-16, 1999 Aug.
Article in English | MEDLINE | ID: mdl-10400746

ABSTRACT

Hepatitis C virus (HCV) is prevalent worldwide and has become a major cause of liver dysfunction and hepatocellular carcinoma. The high prevalence of HCV reflects the persistent nature of infection and the large frequency of cases that resist the current interferon (IFN)-based anti-HCV therapeutic regimens. HCV resistance to IFN has been attributed, in part, to the function of the viral nonstructural 5A (NS5A) protein. NS5A from IFN-resistant strains of HCV can repress the PKR protein kinase, a mediator of the IFN-induced antiviral and apoptotic responses of the host cell and a tumor suppressor. Here we examined the relationship between HCV persistence and resistance to IFN therapy. When expressed in mammalian cells, NS5A from IFN-resistant HCV conferred IFN resistance to vesicular stomatitis virus (VSV), which normally is sensitive to the antiviral actions of IFN. NS5A blocked viral double-stranded RNA (dsRNA)-induced PKR activation and phosphorylation of eIF-2alpha in IFN-treated cells, resulting in high levels of VSV mRNA translation. Mutations within the PKR-binding domain of NS5A restored PKR function and the IFN-induced block to viral mRNA translation. The effects due to NS5A inhibition of PKR were not limited to the rescue of viral mRNA translation but also included a block in PKR-dependent host signaling pathways. Cells expressing NS5A exhibited defective PKR signaling and were refractory to apoptosis induced by exogenous dsRNA. Resistance to apoptosis was attributed to an NS5A-mediated block in eIF-2alpha phosphorylation. Moreover, cells expressing NS5A exhibited a transformed phenotype and formed solid tumors in vivo. Disruption of apoptosis and tumorogenesis required the PKR-binding function of NS5A, demonstrating that these properties may be linked to the IFN-resistant phenotype of HCV.


Subject(s)
Antiviral Agents/pharmacology , Apoptosis , Hepacivirus/physiology , Interferon-alpha/pharmacology , Viral Nonstructural Proteins/metabolism , eIF-2 Kinase/metabolism , Binding Sites , Drug Resistance, Microbial , Eukaryotic Initiation Factor-2/metabolism , HeLa Cells , Hepacivirus/drug effects , Humans , Mutagenesis , Phosphorylation , Poly I-C , Protein Biosynthesis , RNA, Double-Stranded , RNA, Messenger , RNA, Viral , Viral Nonstructural Proteins/genetics , eIF-2 Kinase/antagonists & inhibitors
6.
Mol Cell Biol ; 18(9): 5208-18, 1998 Sep.
Article in English | MEDLINE | ID: mdl-9710605

ABSTRACT

The PKR protein kinase is a critical component of the cellular antiviral and antiproliferative responses induced by interferons. Recent evidence indicates that the nonstructural 5A (NS5A) protein of hepatitis C virus (HCV) can repress PKR function in vivo, possibly allowing HCV to escape the antiviral effects of interferon. NS5A presents a unique tool by which to study the molecular mechanisms of PKR regulation in that mutations within a region of NS5A, termed the interferon sensitivity-determining region (ISDR), are associated with sensitivity of HCV to the antiviral effects of interferon. In this study, we investigated the mechanisms of NS5A-mediated PKR regulation and the effect of ISDR mutations on this regulatory process. We observed that the NS5A ISDR, though necessary, was not sufficient for PKR interactions; we found that an additional 26 amino acids (aa) carboxyl to the ISDR were required for NS5A-PKR complex formation. Conversely, we localized NS5A binding to within PKR aa 244 to 296, recently recognized as a PKR dimerization domain. Consistent with this observation, we found that NS5A from interferon-resistant HCV genotype 1b disrupted kinase dimerization in vivo. NS5A-mediated disruption of PKR dimerization resulted in repression of PKR function and inhibition of PKR-mediated eIF-2alpha phosphorylation. Introduction of multiple ISDR mutations abrogated the ability of NS5A to bind to PKR in mammalian cells and to inhibit PKR in a yeast functional assay. These results indicate that mutations within the PKR-binding region of NS5A, including those within the ISDR, can disrupt the NS5A-PKR interaction, possibly rendering HCV sensitive to the antiviral effects of interferon. We propose a model of PKR regulation by NS5A which may have implications for therapeutic strategies against HCV.


Subject(s)
Hepacivirus/physiology , Interferons/pharmacology , Viral Nonstructural Proteins/metabolism , eIF-2 Kinase/metabolism , Animals , Base Sequence , Binding Sites , COS Cells , Cloning, Molecular , DNA Primers , Dimerization , Escherichia coli , Gene Expression Regulation, Enzymologic , Hepacivirus/drug effects , Hepacivirus/pathogenicity , Models, Biological , Molecular Sequence Data , Mutagenesis, Site-Directed , Point Mutation , Polymerase Chain Reaction , RNA-Dependent RNA Polymerase/metabolism , Recombinant Proteins/biosynthesis , Recombinant Proteins/chemistry , Recombinant Proteins/metabolism , Sequence Deletion , Transfection , Viral Nonstructural Proteins/biosynthesis , Viral Nonstructural Proteins/chemistry , Virus Replication , eIF-2 Kinase/chemistry
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