61 research outputs found

    Impact of two rounds of mass drug administration using diethylcarbamazine combined with albendazole on the prevalence of Brugia timori and of intestinal helminths on Alor Island, Indonesia

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    BACKGROUND: Annual mass drug administration (MDA) using diethylcarbamizine (DEC, 6 mg/kg) combined with albendazole (alb, 400 mg) is recommended by the Global Programme to Eliminate Lymphatic Filariasis (GPELF). This strategy has been shown to be efficient in the of control bancroftian filariasis, but data on brugian filariasis as well as on the positive side effects on intestinal helminths are lacking. METHODS: The effect of one selective treatment and two rounds of MDA using DEC and alb on the prevalence and intensity of Brugia timori infection were studied on Alor island using a cross-sectional and a cohort approach. Before the campaign and ten months after each treatment cycle microfilariae (mf) were assessed by filtration of night blood. Before and ten months after MDA, stool samples were collected and the prevalence of intestinal helminths were determined. RESULTS: In all, the mf-rate dropped from 26.8% before any treatment to 3.8% following the second MDA. Almost all mf-positive, treated individuals showed very low mf densities. The crude prevalence of hookworm dropped from 25.3% to 5.9%. The reduction of prevalence of Ascaris lumbricoides (32.3% to 27.6%) and Trichuris trichiura (9.4% to 8.9%) was less pronounced. Within a cohort of 226 individuals, which was examined annually, the prevalence of A. lumbricoides dropped from 43.8% to 26.5% and of T. trichiura from 12.8% to 6.6%. The results indicate that this MDA approach reduces not only the mf prevalence of B. timori but also the prevalence of hookworm and to a lesser extent also of A. lumbricoides and T. trichiura. CONCLUSION: The MDA using DEC and alb as recommended by GPELF is extremely effective for areas with brugian filariasis. The beneficial effect of MDA on intestinal helminths may strengthen the national programme to eliminate lymphatic filariasis in Indonesia and may set resources free which are otherwise used for deworming campaigns of schoolchildren

    Thoracic Surgery in the COVID-19 Pandemic: A Novel Approach to Reach Guideline Consensus

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    The COVID-19 pandemic challenges international and national healthcare systems. In the field of thoracic surgery, procedures may be deferred due to mandatory constraints of the access to diagnostics, staff and follow-up facilities. There is a lack of prospective data on the management of benign and malignant thoracic conditions in the pandemic. Therefore, we derived recommendations from 14 thoracic societies to address key questions on the topic of COVID-19 in the field of thoracic surgery. Respective recommendations were extracted and the degree of consensus among different organizations was calculated. A high degree of consensus was found to temporarily suspend non-critical elective procedures or procedures for benign conditions and to prioritize patients with symptomatic or advanced cancer. Prior to hospitalization, patients should be screened for respiratory symptoms indicating possible COVID-19 infection and most societies recommended to screen all patients for COVID-19 prior to admission. There was a weak consensus on the usage of serology tests and CT scans for COVID-19 diagnostics. Nearly all societies suggested to postpone elective procedures in patients with suspected or confirmed COVID-19 and recommended constant reevaluation of these patients. Additionally, we summarized recommendations focusing on precautions in the theater and the management of chest drains. This study provides a novel approach to informed guidance for thoracic surgeons during the COVID-19 pandemic in the absence of scientific evidence-based data

    The Novel Human Influenza A(H7N9) Virus Is Naturally Adapted to Efficient Growth in Human Lung Tissue

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    A novel influenza A virus (IAV) of the H7N9 subtype has been isolated from severely diseased patients with pneumonia and acute respiratory distress syndrome and, apparently, from healthy poultry in March 2013 in Eastern China. We evaluated replication, tropism, and cytokine induction of the A/Anhui/1/2013 (H7N9) virus isolated from a fatal human infection and two low-pathogenic avian H7 subtype viruses in a human lung organ culture system mimicking infection of the lower respiratory tract. The A(H7N9) patient isolate replicated similarly well as a seasonal IAV in explanted human lung tissue, whereas avian H7 subtype viruses propagated poorly. Interestingly, the avian H7 strains provoked a strong antiviral type I interferon (IFN-I) response, whereas the A(H7N9) virus induced only low IFN levels. Nevertheless, all viruses analyzed were detected predominantly in type II pneumocytes, indicating that the A(H7N9) virus does not differ in its cellular tropism from other avian or human influenza viruses. Tissue culture-based studies suggested that the low induction of the IFN-β promoter correlated with an efficient suppression by the viral NS1 protein. These findings demonstrate that the zoonotic A(H7N9) virus is unusually well adapted to efficient propagation in human alveolar tissue, which most likely contributes to the severity of lower respiratory tract disease seen in many patients

    A Theory of Cheap Control in Embodied Systems

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    We present a framework for designing cheap control architectures for embodied agents. Our derivation is guided by the classical problem of universal approximation, whereby we explore the possibility of exploiting the agent's embodiment for a new and more efficient universal approximation of behaviors generated by sensorimotor control. This embodied universal approximation is compared with the classical non-embodied universal approximation. To exemplify our approach, we present a detailed quantitative case study for policy models defined in terms of conditional restricted Boltzmann machines. In contrast to non-embodied universal approximation, which requires an exponential number of parameters, in the embodied setting we are able to generate all possible behaviors with a drastically smaller model, thus obtaining cheap universal approximation. We test and corroborate the theory experimentally with a six-legged walking machine. The experiments show that the sufficient controller complexity predicted by our theory is tight, which means that the theory has direct practical implications. Keywords: cheap design, embodiment, sensorimotor loop, universal approximation, conditional restricted Boltzmann machineComment: 27 pages, 10 figure

    Human alveolar progenitors generate dual lineage bronchioalveolar organoids

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    Mechanisms of epithelial renewal in the alveolar compartment remain incompletely understood. To this end, we aimed to characterize alveolar progenitors. Single-cell RNA-sequencing (scRNA-seq) analysis of the HTII-280+/EpCAM+ population from adult human lung revealed subclusters enriched for adult stem cell signature (ASCS) genes. We found that alveolar progenitors in organoid culture in vitro show phenotypic lineage plasticity as they can yield alveolar or bronchial cell-type progeny. The direction of the differentiation is dependent on the presence of the GSK-3β inhibitor, CHIR99021. By RNA-seq profiling of GSK-3β knockdown organoids we identified additional candidate target genes of the inhibitor, among others FOXM1 and EGF. This gives evidence of Wnt pathway independent regulatory mechanisms of alveolar specification. Following influenza A virus (IAV) infection organoids showed a similar response as lung tissue explants which confirms their suitability for studies of sequelae of pathogen-host interaction

    Maintenance of Hair Follicle Immune Privilege Is Linked to Prevention of NK Cell Attack

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    Hair follicles (HFs) enjoy a relative immune privilege (IP) that is characterized by downregulation of major histocompatibility complex (MHC) class I and local expression of potent immunosuppressants. Normally, natural killer (NK) cells attack cells with absent/low MHC class I expression. However, because few perifollicular NK cells are found around healthy human anagen HFs, we asked how HFs escape from NK cell attack. This study suggests that this happens via an active NK cell suppression. Alopecia areata (AA), an organ-specific autoimmune disease thought to result from a collapse of HF-IP, in contrast, shows striking defects in NK cell inhibition/containment. We show that the NK cell inhibitor macrophage migration inhibitory factor is strongly expressed by the HF epithelium, and very few CD56+/NKG2D+ NK cells are observed in and around normal anagen HFs compared to AA with prominent aggregations of CD56+/NKG2D+ NK around AA-HFs. By flow cytometry, many fewer NK function-activating receptors (NKG2D, NKG2C) and significantly more killer cell Ig-like receptors-2D2/2D3 were found to be expressed on peripheral blood CD56+ NK cells of healthy controls than on those of AA patients. In addition, only weak immunoreactivity for MHC class I chain-related A gene was observed in normal anagen HFs compared to AA. To our knowledge, this defect is previously unreported and must be taken into account in AA pathogenesis and its management

    Genetic risk and a primary role for cell-mediated immune mechanisms in multiple sclerosis.

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    Multiple sclerosis is a common disease of the central nervous system in which the interplay between inflammatory and neurodegenerative processes typically results in intermittent neurological disturbance followed by progressive accumulation of disability. Epidemiological studies have shown that genetic factors are primarily responsible for the substantially increased frequency of the disease seen in the relatives of affected individuals, and systematic attempts to identify linkage in multiplex families have confirmed that variation within the major histocompatibility complex (MHC) exerts the greatest individual effect on risk. Modestly powered genome-wide association studies (GWAS) have enabled more than 20 additional risk loci to be identified and have shown that multiple variants exerting modest individual effects have a key role in disease susceptibility. Most of the genetic architecture underlying susceptibility to the disease remains to be defined and is anticipated to require the analysis of sample sizes that are beyond the numbers currently available to individual research groups. In a collaborative GWAS involving 9,772 cases of European descent collected by 23 research groups working in 15 different countries, we have replicated almost all of the previously suggested associations and identified at least a further 29 novel susceptibility loci. Within the MHC we have refined the identity of the HLA-DRB1 risk alleles and confirmed that variation in the HLA-A gene underlies the independent protective effect attributable to the class I region. Immunologically relevant genes are significantly overrepresented among those mapping close to the identified loci and particularly implicate T-helper-cell differentiation in the pathogenesis of multiple sclerosis

    Novel Genetic Tools for Diaminopimelic Acid Selection in Virulence Studies of Yersinia pestis

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    Molecular studies of bacterial virulence are enhanced by expression of recombinant DNA during infection to allow complementation of mutants and expression of reporter proteins in vivo. For highly pathogenic bacteria, such as Yersinia pestis, these studies are currently limited because deliberate introduction of antibiotic resistance is restricted to those few which are not human treatment options. In this work, we report the development of alternatives to antibiotics as tools for host-pathogen research during Yersinia pestis infections focusing on the diaminopimelic acid (DAP) pathway, a requirement for cell wall synthesis in eubacteria. We generated a mutation in the dapA-nlpB(dapX) operon of Yersinia pestis KIM D27 and CO92 which eliminated the expression of both genes. The resulting strains were auxotrophic for diaminopimelic acid and this phenotype was complemented in trans by expressing dapA in single and multi-copy. In vivo, we found that plasmids derived from the p15a replicon were cured without selection, while selection for DAP enhanced stability without detectable loss of any of the three resident virulence plasmids. The dapAX mutation rendered Y. pestis avirulent in mouse models of bubonic and septicemic plague which could be complemented when dapAX was inserted in single or multi-copy, restoring development of disease that was indistinguishable from the wild type parent strain. We further identified a high level, constitutive promoter in Y. pestis that could be used to drive expression of fluorescent reporters in dapAX strains that had minimal impact to virulence in mouse models while enabling sensitive detection of bacteria during infection. Thus, diaminopimelic acid selection for single or multi-copy genetic systems in Yersinia pestis offers an improved alternative to antibiotics for in vivo studies that causes minimal disruption to virulence

    LEADER 5: prevalence and cardiometabolic impact of obesity in cardiovascular high-risk patients with type 2 diabetes mellitus: baseline global data from the LEADER trial

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    Background: Epidemiological data on obesity are needed, particularly in patients with type 2 diabetes mellitus (T2DM) and high cardiovascular (CV) risk. We used the baseline data of liraglutide effect and action in diabetes: evaluation of CV outcome results—A long term Evaluation (LEADER) (a clinical trial to assess the CV safety of liraglutide) to investigate: (i) prevalence of overweight and obesity; (ii) relationship of the major cardiometabolic risk factors with anthropometric measures of adiposity [body mass index (BMI) and waist circumference (WC)]; and (iii) cardiometabolic treatment intensity in relation to BMI and WC. Methods: LEADER enrolled two distinct populations of high-risk patients with T2DM in 32 countries: (1) aged ≥50 years with prior CV disease; (2) aged ≥60 years with one or more CV risk factors. Associations of metabolic variables, demographic variables and treatment intensity with anthropometric measurements (BMI and WC) were explored using regression models (ClinicalTrials.gov identifier: NCT01179048). Results: Mean BMI was 32.5 ± 6.3 kg/m2 and only 9.1 % had BMI <25 kg/m2. The prevalence of healthy WC was also extremely low (6.4 % according to International Joint Interim Statement for the Harmonization of the Metabolic Syndrome criteria). Obesity was associated with being younger, female, previous smoker, Caucasian, American, with shorter diabetes duration, uncontrolled blood pressure (BP), antihypertensive agents, insulin plus oral antihyperglycaemic treatment, higher levels of triglycerides and lower levels of high-density lipoprotein cholesterol. Conclusions: Overweight and obesity are prevalent in high CV risk patients with T2DM. BMI and WC are related to the major cardiometabolic risk factors. Furthermore, treatment intensity, such as insulin, statins or oral antihypertensive drugs, is higher in those who are overweight or obese; while BP and lipid control in these patients are remarkably suboptimal. LEADER confers a unique opportunity to explore the longitudinal effect of weight on CV risk factors and hard endpoints

    Pneumolysin induced mitochondrial dysfunction leads to release of mitochondrial DNA

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    Abstract Streptococcus pneumoniae (S.pn.) is the most common bacterial pathogen causing community acquired pneumonia. The pore-forming toxin pneumolysin (PLY) is the major virulence factor of S.pn. and supposed to affect alveolar epithelial cells thereby activating the immune system by liberation of danger-associated molecular patterns (DAMP). To test this hypothesis, we established a novel live-cell imaging based assay to analyse mitochondrial function and associated release of mitochondrial DNA (mtDNA) as DAMP in real-time. We first revealed that bacterially released PLY caused significant changes of the cellular ATP homeostasis and led to morphologic alterations of mitochondria in human alveolar epithelial cells in vitro and, by use of spectral live-tissue imaging, in human alveoli. This was accompanied by strong mitochondrial calcium influx and loss of mitochondrial membrane potential resulting in opening of the mitochondrial permeability transition pore and mtDNA release without activation of intrinsic apoptosis. Moreover, our data indicate cellular mtDNA liberation via microvesicles, which may contribute to S.pn. related pro-inflammatory immune activation in the human alveolar compartment
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