153 research outputs found
Enhancement of HIV-1 infection and intestinal CD4+ T cell depletion ex vivo by gut microbes altered during chronic HIV-1 infection
Additional file 3: Table S2. Clinical Study Participant Characteristics
Diverse Intestinal Bacteria Contain Putative Zwitterionic Capsular Polysaccharides with Anti-inflammatory Properties
Zwitterionic capsular polysaccharides (ZPSs) are bacterial products that modulate T cells, including inducing anti-inflammatory IL-10-secreting T regulatory cells (Tregs). However, only a few diverse bacteria are known to modulate the host immune system via ZPS. We present a genomic screen for bacteria encoding ZPS molecules. We identify diverse host-associated bacteria, including commensals and pathogens with known anti-inflammatory properties, with the capacity to produce ZPSs. Human mononuclear cells stimulated with lysates from putative ZPS-producing bacteria induce significantly greater IL-10 production and higher proportions of Tregs than lysates from non-ZPS-encoding relatives or a commensal strain of Bacteroides cellulosilyticus in which a putative ZPS biosynthetic operon was genetically disrupted. Similarly, wild-type B. cellulosilyticus DSM 14838, but not a close relative lacking a putative ZPS, attenuated experimental colitis in mice. Collectively, this screen identifies bacterial strains that may use ZPSs to interact with the host as well as those with potential probiotic properties
Re-emphasizing the concept of adequacy of intraoperative assessment of the axillary sentinel lymph nodes for identifying nodal positivity during breast cancer surgery
BACKGROUND: Although sentinel lymph node (SLN) biopsy is a standard of care for the evaluation of the axillary lymph nodes during breast cancer surgery, a substantial degree of variation exists among individual surgeons as to what represents an adequate assessment. The aim of the current study was to assess when metastatic disease was first identified within consecutively harvested SLN candidates for invasive breast cancers demonstrating a positive SLN. METHODS: We retrospectively analyzed a series of 400 breast cancers from a recently published prospective randomized clinical trial. A combined radiocolloid and blue dye technique was used. All potential SLN candidates, containing counts of at least 10% of the hottest SLN and/or containing blue dye, were harvested and were consecutively numbered in the order of the decreasing level of counts (with the hottest SLN representing SLN #1). RESULTS: Among 371 invasive breast cancers, a SLN was identified within 353 cases (95%). Mean number of SLNs identified was 2.5 (range, 1 to 9), with a single SLN identified in 104 (29%) cases, two identified in 110 (31%), three identified in 73 (21%), four identified in 35 (10%), five identified in 16 (5%), and six or more identified in 15 (4%). A positive SLN was found in 104 (29%) cases. SLN #1 was the first positive SLN in 86 (83%). SLN #2 was the first positive SLN in 15 (14%). SLN #3, SLN #4, and SLN #5 were the first positive SLN in one case (1%) each. A positive SLN was found in 18% (19/104) of cases when a single SLN was identified, as compared to in 34% (85/249) when two or more SLNs were identified (P = 0.003). CONCLUSION: The accurate and optimal assessment of the axilla during breast cancer surgery requires persistence and diligence for attempting to identify all potential SLN candidates in order to avoid failing to recognize a positive SLN. The scenario in which only a single negative SLN candidate is intraoperatively identified is one that should raise some concern to the operating surgeon
Phase coexistence and electric-field control of toroidal order in oxide superlattices
Systems that exhibit phase competition, order parameter coexistence, and emergent order parameter topologies constitute a major part of modern condensed-matter physics. Here, by applying a range of characterization techniques, and simulations, we observe that in PbTiO>3/SrTiO>3 superlattices all of these effects can be found. By exploring superlattice period-, temperature- and field-dependent evolution of these structures, we observe several new features. First, it is possible to engineer phase coexistence mediated by a first-order phase transition between an emergent, low-temperature vortex phase with electric toroidal order and a high-temperature ferroelectric a>1/a>2 phase. At room temperature, the coexisting vortex and ferroelectric phases form a mesoscale, fibre-textured hierarchical superstructure. The vortex phase possesses an axial polarization, set by the net polarization of the surrounding ferroelectric domains, such that it possesses a multi-order-parameter state and belongs to a class of gyrotropic electrotoroidal compounds. Finally, application of electric fields to this mixed-phase system permits interconversion between the vortex and the ferroelectric phases concomitant with order-of-magnitude changes in piezoelectric and nonlinear optical responses. Our findings suggest new cross-coupled functionalities.A.R.D. acknowledges support from the Army Research Office under grant
W911NF-14-1-0104 and the Department of Energy, Office of Science, Office of Basic Energy Sciences under grant no. DE-SC0012375 for synthesis and structural study of the materials. Z.H. acknowledges support from NSF-MRSEC grant number DMR-1420620 and NSF-MWN grant number DMR-1210588. A.K.Y. acknowledges support from the Office of Basic Energy Sciences, US Department of Energy DE-AC02-05CH11231. C.T.N. acknowledge support from the Office of Basic Energy Sciences, US Department of Energy DE-AC02-05CH11231. S.L.H. acknowledges support from the National Science Foundation under the MRSEC programme (DMR-1420620). M.R.M. acknowledges support from the National Science Foundation Graduate Research Fellowship under grant number DGE-1106400. K.-D.P., V.K. and M.B.R. acknowledge support from the US Department of Energy, Office of Basic Sciences, Division of Material Sciences and
Engineering, under Award No. DE-SC0008807. A.F. acknowledges support from the Swiss National Science Foundation. P.G.-F. and J.J. acknowledge financial support from the Spanish Ministry of Economy and Competitiveness through grant number FIS2015-64886-C5-2-P. J.I. is supported by the Luxembourg National Research Fund (Grant FNR/C15/MS/10458889 NEWALLS). L.-Q.C. is supported by the US Department of Energy, Office of Basic Energy Sciences under Award FG02-07ER46417. R.R. and L.W.M. acknowledge support from the Gordon and Betty Moore Foundation’s EPiQS Initiative, under grant GBMF5307. The Advanced Light Source is supported by the Director, Office of Science, Office of Basic Energy Sciences, of the US Department of Energy under Contract No. DE-C02-05CH11231. Nanodiffraction measurements were supported by the US Department of Energy, Office of Science, Office of Basic Energy Sciences, Materials Sciences and Engineering Division. This research used resources of
the Advanced Photon Source, a US Department of Energy (DOE) Office of Science User Facility operated for the DOE Office of Science by Argonne National Laboratory under Contract No. DE-AC02-06CH11357. Electron microscopy of superlattice structures was performed at the Molecular Foundry at Lawrence Berkeley National Laboratory, supported by the Office of Science, Office of Basic Energy Sciences, US Department of Energy (DE-AC02-05CH11231).Peer Reviewe
Commensal and Pathogenic Bacteria Indirectly Induce IL-22 but Not IFNγ Production From Human Colonic ILC3s via Multiple Mechanisms
Innate lymphoid cells (ILCs) are a diverse family of cells that play critical roles in mucosal immunity. One subset of the ILC family, Group 3 ILCs (ILC3s), has been shown to aid in gut homeostasis through the production of IL-22. IL-22 promotes gut homeostasis through its functional effect on the epithelial barrier. When gut epithelial barrier integrity is compromised, such as in Human Immunodeficiency Virus (HIV) infection and inflammatory bowel disease (IBD), microbes from the gut lumen translocate into the lamina propria, inducing a multitude of potentially pathogenic immune responses. In murine models of bacterial infection, there is evidence that bacteria can induce pro-inflammatory IFNγ production in ILC3s. However, the impact of diverse translocating bacteria, particularly commensal bacteria, in dictating IFNγ versus IL-22 production by human gut ILC3s remains unclear. Here, we utilized an in vitro human lamina propria mononuclear cell (LPMC) model to evaluate ILC3 cytokine production in response to a panel of enteric Gram-positive and Gram-negative commensal and pathogenic bacteria and determined potential mechanisms by which these cytokine responses were induced. The percentages of IL-22-producing ILC3s, but not IFNγ-producing ILC3s, were significantly increased after LPMC exposure to both Gram-positive and Gram-negative commensal or pathogenic bacterial stimuli. Stimulation of IL-22 production from ILC3s was not through direct recognition of bacterial antigen by ILC3s, but rather required the help of accessory cells within the LPMC population. CD11c+ myeloid dendritic cells generated IL-23 and IL-1β in response to enteric bacteria and contributed to ILC3 production of IL-22. Furthermore, ligation of the natural cytotoxicity receptor NKp44 on ILC3s in response to bacteria stimulation also significantly increased the percentage of IL-22-producing ILC3s. Overall, these data demonstrate that human gut microbiota, including commensal bacteria, indirectly modulate colonic ILC3 function to induce IL-22, but additional signals are likely required to induce IFNγ production by colonic ILC3s in the setting of inflammation and microbial translocation
A black‐box automated approach to calibrate numerical simulations and optimize cover design: Application to a flow control layer constructed on an experimental waste rock pile
Mining operations often produce large volumes of waste rock to access economically valuable mineralized zones. Waste rock is usually stored in surface piles, the construction and reclamation of which represent a challenge for the industry. A flow control layer (FCL) made of crushed waste rock or sand and constructed on top of each waste rock bench could contribute to control water infiltration, thus improving waste rock pile stability and limiting contamination. An experimental waste rock pile was built and instrumented at the Tio mine (Rio Tinto Fer et Titane, Canada) to evaluate the performance of an FCL in field conditions. Large infiltration tests and rainfall monitoring were carried out, and measured outflow and water contents were used to calibrate numerical simulations. However, data were noisy and sometimes incomplete, and the models were difficult to calibrate. A new automated calibration approach was therefore proposed. An algorithm was developed to automate the numerical simulation calibration, using a black-box method that involves solving an optimization problem on a function without an analytic form. The approach was applied on measurements obtained from large-scale infiltration tests and validated using 2 yr of field monitoring data. Finally, the automated approach was adapted to optimize the design of the FCL, and an optimal design (material properties and layer thickness) was recommended based on local climate conditions. The proposed automated method could contribute to reduce the bias induced by manual calibration and allows for rapid multivariable calibration and optimization for a broad spectrum of mine waste cover system applications
Severe paraneoplastic hypoglycemia in a patient with a gastrointestinal stromal tumor with an exon 9 mutation: a case report
BACKGROUND: Non-islet cell tumor induced hypoglycemia (NICTH) is a very rare phenomenon, but even more so in gastrointestinal stromal tumors. It tends to present in large or metastatic tumors, and can appear at any time in the progression of the disease. We present herein a case of NICTH in a GIST tumor and report an exon 9 mutation associated to it. CASE PRESENTATION: A thirty nine year-old man with a recurrent, metastatic gastrointestinal stromal tumor presented to the hospital with nausea, dizziness, loss of consciousness, and profound hypoglycemia (20 mg/dL). There was no evidence of factitious hypoglycemia. He was stabilized with a continuous glucose infusion and following selective vascular embolization, the patient underwent debulking of a multicentric 40 cm × 25 cm × 10 cm gastrointestinal stromal tumor. After resection, the patient became euglycemic and returned to his normal activities. Tumor analysis confirmed excessive production of insulin-like growth factor II m-RNA and the precursor protein, "big" insulin-like growth factor II. Mutational analysis also identified a rare, 6 bp tandem repeat insert (gcctat) at position 1530 in exon 9 of KIT. CONCLUSION: Optimal management of gastrointestinal stromal tumor-induced hypoglycemia requires a multidisciplinary approach, and surgical debulking is the treatment of choice to obtain immediate symptom relief. Imatinib or combinations of glucocorticoids and growth hormone are alternative palliative strategies for symptomatic hypoglycemia. In addition, mutations in exon 9 of the tyrosine kinase receptor KIT occur in 11–20% of GIST and are often associated with poor patient outcomes. The association of this KIT mutation with non-islet cell tumor induced hypoglycemia has yet to be established
Diverse Intestinal Bacteria Contain Putative Zwitterionic Capsular Polysaccharides with Anti-inflammatory Properties
Zwitterionic capsular polysaccharides (ZPSs) are bacterial products that modulate T cells, including inducing anti-inflammatory IL-10-secreting T regulatory cells (Tregs). However, only a few diverse bacteria are known to modulate the host immune system via ZPS. We present a genomic screen for bacteria encoding ZPS molecules. We identify diverse host-associated bacteria, including commensals and pathogens with known anti-inflammatory properties, with the capacity to produce ZPSs. Human mononuclear cells stimulated with lysates from putative ZPS-producing bacteria induce significantly greater IL-10 production and higher proportions of Tregs than lysates from non-ZPS-encoding relatives or a commensal strain of Bacteroides cellulosilyticus in which a putative ZPS biosynthetic operon was genetically disrupted. Similarly, wild-type B. cellulosilyticus DSM 14838, but not a close relative lacking a putative ZPS, attenuated experimental colitis in mice. Collectively, this screen identifies bacterial strains that may use ZPSs to interact with the host as well as those with potential probiotic properties
Targeting Protein-Protein Interactions for Parasite Control
Finding new drug targets for pathogenic infections would be of great utility for humanity, as there is a large need to develop new drugs to fight infections due to the developing resistance and side effects of current treatments. Current drug targets for pathogen infections involve only a single protein. However, proteins rarely act in isolation, and the majority of biological processes occur via interactions with other proteins, so protein-protein interactions (PPIs) offer a realm of unexplored potential drug targets and are thought to be the next-generation of drug targets. Parasitic worms were chosen for this study because they have deleterious effects on human health, livestock, and plants, costing society billions of dollars annually and many sequenced genomes are available. In this study, we present a computational approach that utilizes whole genomes of 6 parasitic and 1 free-living worm species and 2 hosts. The species were placed in orthologous groups, then binned in species-specific ortholgous groups. Proteins that are essential and conserved among species that span a phyla are of greatest value, as they provide foundations for developing broad-control strategies. Two PPI databases were used to find PPIs within the species specific bins. PPIs with unique helminth proteins and helminth proteins with unique features relative to the host, such as indels, were prioritized as drug targets. The PPIs were scored based on RNAi phenotype and homology to the PDB (Protein DataBank). EST data for the various life stages, GO annotation, and druggability were also taken into consideration. Several PPIs emerged from this study as potential drug targets. A few interactions were supported by co-localization of expression in M. incognita (plant parasite) and B. malayi (H. sapiens parasite), which have extremely different modes of parasitism. As more genomes of pathogens are sequenced and PPI databases expanded, this methodology will become increasingly applicable
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