168 research outputs found

    The state, its failure and external intervention in Africa

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    Accelerated processes of globalisation – in the form of structural adjustment plans and of democratisation processes – have seriously shaken the fragile foundations of African countries. These processes have contributed overall to widening the geographical scope of zones of limited statehood where the traditional monopoly of violence is challenged by multiple oligopolies of violence. During the 90s, this phenomenon was at best considered as a regionally limited problem with less significance for international stability. This however changed dramatically with the terrorist attacks in New York in 2001. The resulting US national security strategy, quickly followed by the EU, considered failed states as a major national security problem due to the fact that the attacks were partly planned in Afghanistan, a then collapsed state. The present paper is an attempt to shed a clarifying light on the phenomenon of fragile statehood as well as to explore ways of international intervention. Growing on a Weberian conception of the modern state, it identifies three core functions (monopoly of violence, provision of public goods and political order), which should all be fulfilled by well functioning states. The different stages of state fragility in Africa are then defined by the failing capacity of states to fulfil one or all of these functions. Amidst the whole range of arguments about the reasons of this situation, the paper identifies the deeply rooted neopatrimonial understanding of politics as the most salient explaining variable. The paper concludes by pointing to the fact that international attempts to prevent and to stop state failure as well as to rebuild collapsed states are still at an embryonic stage. Given the multidimensional and complex nature of the problem, an integrated approach among the donor countries will be necessary, which comprises coherent analysis and strategies. The concept of structural stability, formulated by the OECD and the EU still needs to be clarified and translated into concrete policy strategies

    CpG-ODN-induced sustained expression of BTLA mediating selective inhibition of human B cells

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    BTLA (B- and T-lymphocyte attenuator) is a prominent co-receptor that is structurally and functionally related to CTLA-4 and PD-1. In T cells, BTLA inhibits TCR-mediated activation. In B cells, roles and functions of BTLA are still poorly understood and have never been studied in the context of B cells activated by CpG via TLR9. In this study, we evaluated the expression of BTLA depending on activation and differentiation of human B cell subsets in peripheral blood and lymph nodes. Stimulation with CpG upregulated BTLA, but not its ligand: herpes virus entry mediator (HVEM), on B cells in vitro and sustained its expression in vivo in melanoma patients after vaccination. Upon ligation with HVEM, BTLA inhibited CpG-mediated B cell functions (proliferation, cytokine production, and upregulation of co-stimulatory molecules), which was reversed by blocking BTLA/HVEM interactions. Interestingly, chemokine secretion (IL-8 and MIP1β) was not affected by BTLA/HVEM ligation, suggesting that BTLA-mediated inhibition is selective for some but not all B cell functions. We conclude that BTLA is an important immune checkpoint for B cells, as similarly known for T cell

    MAGE-A3 and MAGE-A4 specific CD4+ T cells in head and neck cancer patients: detection of naturally acquired responses and identification of new epitopes

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    Frequent expression of cancer testis antigens (CTA) has been consistently observed in head and neck squamous cell carcinomas (HNSCC). For instance, in 52 HNSCC patients, MAGE-A3 and -A4 CTA were expressed in over 75% of tumors, regardless of the sites of primary tumors such as oral cavity or hypopharynx. Yet, T-cell responses against these CTA in tumor-bearing patients have not been investigated in detail. In this study, we assessed the naturally acquired T-cell response against MAGE-A3 and -A4 in nonvaccinated HNSCC patients. Autologous antigen-presenting cells pulsed with overlapping peptide pools were used to detect and isolate MAGE-A3 and MAGE-A4 specific CD4+ T cells from healthy donors and seven head and neck cancer patients. CD4+ T-cell clones were characterized by cytokine secretion. We could detect and isolate MAGE-A3 and MAGE-A4 specific CD4+ T cells from 7/7 cancer patients analyzed. Moreover, we identified six previously described and three new epitopes for MAGE-A3. Among them, the MAGE-A3111-125 and MAGE-A3161-175 epitopes were shown to be naturally processed and presented by DC in association with HLA-DP and DR, respectively. All of the detected MAGE-A4 responses were specific for new helper epitopes. These data suggest that naturally acquired CD4+ T-cell responses against CT antigens often occur in vivo in HNSCC cancer patients and provide a rationale for the development of active immunotherapeutic approaches in this type of tumo

    Uterine and Tubal Lavage for Earlier Cancer Detection Using an Innovative Catheter: A Feasibility and Safety Study

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    Objectives Poor survival of high-grade serous pelvic cancer is caused by a lack of effective screening measures. The detection of exfoliated cells from high-grade serous pelvic cancer, or precursor lesions, is a promising concept for earlier diagnosis. However, collecting those cells in the most efficient way while fulfilling all requirements for a screening approach is a challenge. We introduce a new catheter for uterine and tubal lavage (UtL) and the clinical evaluation of its performance. Methods/Materials In study I, the clinical feasibility of the UtL using the new catheter was examined in 93 patients admitted for gynecologic surgery under general anesthesia. In study II, the safety of the UtL procedure was assessed. The pain during and after the UtL performed under local anesthesia was rated on a visual analog scale by 22 healthy women. Results In study I, the UtL was carried out successfully in 92 (98.9%) of 93 cases by 16 different gynecologists. It was rated as easy to perform in 84.8% of patients but as rather difficult in cancer patients (odds ratio, 5.559;95% confidence interval, 1.434-21.546;P = 0.007). For benign conditions, dilatation before UtL was associated with menopause status (odds ratio, 4.929;95% confidence interval, 1.439-16.884;P = 0.016). In study II, the pain during UtL was rated with a median visual analog scale score of 1.6. During a period of 4 weeks after UtL, none of the participants had to use medication or developed symptoms requiring medical attention. The UtL took 6.5 minutes on average. The amount of extracted DNA was above the lower limit for a sensitive, deep-sequencing mutation analysis in all cases. Conclusions Our studies demonstrate that the UtL, using the new catheter, is a safe, reliable, and well-tolerated procedure, which does not require elaborate training. Therefore, UtL fulfils all prerequisites to be used in a potential screening setting

    Antigen-specific immune responses to influenza vaccine in utero

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    Initial immune responses to allergens may occur before birth, thereby modulating the subsequent development of atopy. This paradigm remains controversial, however, due to the inability to identify antigen-specific T cells in cord blood. The advent of MHC tetramers has revolutionized the detection of antigen-specific T cells. Tetramer staining of cord blood after CMV infection has demonstrated that effective CD8+ antigen-specific immune responses can follow intrauterine viral infections. We hypothesized that sensitization to antigens occurs in utero in humans. We studied cord blood B and T cell immune responses following vaccination against influenza during pregnancy. Anti-Fluzone and anti-matrix protein IgM antibodies were detected in 38.5% (27 of 70) and 40.0% (28 of 70), respectively, of cord blood specimens. Using MHC tetramers, HA-specific CD4+ T cells were detected among 25.0% (3 of 12) and 42.9% (6 of 14) of cord blood specimens possessing DRB1*0101 and DRB1*0401 HLA types, respectively, and were detected even when the DRB1 HLA type was inherited from the father. Matrix protein–specific CD8+ T cells were detected among 10.0% (2 of 20) of HLA-A*0201+ newborns. These results suggest that B and T cell immune responses occur in the fetus following vaccination against influenza and have important implications for determining when immune responses to environmental exposures begin

    Genotype-Phenotype Correlation in 153 Adult Patients With Congenital Adrenal Hyperplasia due to 21-Hydroxylase Deficiency: Analysis of the United Kingdom Congenital Adrenal Hyperplasia Adult Study Executive (CaHASE) Cohort

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    CONTEXT: In congenital adrenal hyperplasia (CAH) due to 21-hydroxylase deficiency, a strong genotype-phenotype correlation exists in childhood. However, similar data in adults are lacking. OBJECTIVE: The objective of the study was to test whether the severity of disease-causing CYP21A2 mutations influences the treatment and health status in adults with CAH. RESEARCH DESIGN AND METHODS: We analyzed the genotype in correlation with treatment and health status in 153 adults with CAH from the United Kingdom Congenital adrenal Hyperplasia Adult Study Executive cohort. RESULTS: CYP21A2 mutations were distributed similarly to previously reported case series. In 7 patients a mutation was identified on only 1 allele. Novel mutations were detected on 1.7% of alleles (5 of 306). Rare mutations were found on 2.3% of alleles (7 of 306). For further analysis, patients were categorized into CYP21A2 mutation groups according to predicted residual enzyme function: null (n = 34), A (n = 42), B (n = 36), C (n = 34), and D (n = 7). Daily glucocorticoid dose was highest in group null and lowest in group C. Fludrocortisone was used more frequently in patients with more severe genotypes. Except for lower female height in group B, no statistically significant associations between genotype and clinical parameters were found. Androgens, blood pressure, lipids, blood glucose, and homeostasis model assessment of insulin resistance were not different between groups. Subjective health status was similarly impaired across groups. CONCLUSIONS: In adults with classic CAH and women with nonclassic CAH, there was a weak association between genotype and treatment, but health outcomes were not associated with genotype. The underrepresentation of males with nonclassic CAH may reflect that milder genotypes result in a milder condition that is neither diagnosed nor followed up in adulthood. Overall, our results suggest that the impaired health status of adults with CAH coming to medical attention is acquired rather than genetically determined and therefore could potentially be improved through modification of treatment

    Two specific populations of GABAergic neurons originating from the medial and the caudal ganglionic eminences aid in proper navigation of callosal axons.

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    The corpus callosum (CC) plays a crucial role in interhemispheric communication. It has been shown that CC formation relies on the guidepost cells located in the midline region that include glutamatergic and GABAergic neurons as well as glial cells. However, the origin of these guidepost GABAergic neurons and their precise function in callosal axon pathfinding remain to be investigated. Here, we show that two distinct GABAergic neuronal subpopulations converge toward the midline prior to the arrival of callosal axons. Using in vivo and ex vivo fate mapping we show that CC GABAergic neurons originate in the caudal and medial ganglionic eminences (CGE and MGE) but not in the lateral ganglionic eminence (LGE). Time lapse imaging on organotypic slices and in vivo analyses further revealed that CC GABAergic neurons contribute to the normal navigation of callosal axons. The use of Nkx2.1 knockout (KO) mice confirmed a role of these neurons in the maintenance of proper behavior of callosal axons while growing through the CC. Indeed, using in vitro transplantation assays, we demonstrated that both MGE- and CGE-derived GABAergic neurons exert an attractive activity on callosal axons. Furthermore, by combining a sensitive RT-PCR technique with in situ hybridization, we demonstrate that CC neurons express multiple short and long range guidance cues. This study strongly suggests that MGE- and CGE-derived interneurons may guide CC axons by multiple guidance mechanisms and signaling pathways. © 2013 Wiley Periodicals, Inc. Develop Neurobiol 73: 647-672, 2013
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