été Doctors Describe First Drone Delivery of Diabetes Meds to Patient By www.medicinenet.com Published On :: Tue, 31 Mar 2020 00:00:00 PDT Title: Doctors Describe First Drone Delivery of Diabetes Meds to PatientCategory: Health NewsCreated: 3/30/2020 12:00:00 AMLast Editorial Review: 3/31/2020 12:00:00 AM Full Article
été Blood Sugar Control May Aid Stroke Recovery in Diabetes Patients By www.medicinenet.com Published On :: Tue, 31 Mar 2020 00:00:00 PDT Title: Blood Sugar Control May Aid Stroke Recovery in Diabetes PatientsCategory: Health NewsCreated: 3/30/2020 12:00:00 AMLast Editorial Review: 3/31/2020 12:00:00 AM Full Article
été Family Ties Help Young Adults With Type 1 Diabetes Flourish By www.medicinenet.com Published On :: Wed, 8 Apr 2020 00:00:00 PDT Title: Family Ties Help Young Adults With Type 1 Diabetes FlourishCategory: Health NewsCreated: 4/8/2020 12:00:00 AMLast Editorial Review: 4/8/2020 12:00:00 AM Full Article
été Obesity Is Biggest Type 2 Diabetes Risk Factor By www.medicinenet.com Published On :: Fri, 17 Apr 2020 00:00:00 PDT Title: Obesity Is Biggest Type 2 Diabetes Risk FactorCategory: Health NewsCreated: 4/16/2020 12:00:00 AMLast Editorial Review: 4/17/2020 12:00:00 AM Full Article
été Could Your Contact Lenses Track, Treat Your Diabetes? By www.medicinenet.com Published On :: Mon, 27 Apr 2020 00:00:00 PDT Title: Could Your Contact Lenses Track, Treat Your Diabetes?Category: Health NewsCreated: 4/24/2020 12:00:00 AMLast Editorial Review: 4/27/2020 12:00:00 AM Full Article
été Heart Attacks, Strokes Are Declining Among People With Diabetes By www.medicinenet.com Published On :: Mon, 4 May 2020 00:00:00 PDT Title: Heart Attacks, Strokes Are Declining Among People With DiabetesCategory: Health NewsCreated: 5/1/2020 12:00:00 AMLast Editorial Review: 5/4/2020 12:00:00 AM Full Article
été Anti-KIT DNA Aptamer for Targeted Labeling of Gastrointestinal Stromal Tumor By mct.aacrjournals.org Published On :: 2020-05-04T05:39:42-07:00 Gastrointestinal stromal tumor (GIST), the most common sarcoma, is characterized by KIT protein overexpression, and tumors are frequently driven by oncogenic KIT mutations. Targeted inhibition of KIT revolutionized GIST therapy and ushered in the era of precision medicine for the treatment of solid malignancies. Here, we present the first use of a KIT-specific DNA aptamer for targeted labeling of GIST. We found that an anti-KIT DNA aptamer bound cells in a KIT-dependent manner and was highly specific for GIST cell labeling in vitro. Functionally, the KIT aptamer bound extracellular KIT in a manner similar to KIT mAb staining, and was trafficked intracellularly in vitro. The KIT aptamer bound dissociated primary human GIST cells in a mutation agnostic manner such that tumors with KIT and PDGFRA mutations were labeled. In addition, the KIT aptamer specifically labeled intact human GIST tissue ex vivo, as well as peritoneal xenografts in mice with high sensitivity. These results represent the first use of an aptamer-based method for targeted detection of GIST in vitro and in vivo. Full Article
été Redefining Medical Competencies for an Oral Medicine Specialty Training Curriculum Using a Modified Delphi Technique By www.jdentaled.org Published On :: 2019-12-01T06:00:19-08:00 This article describes the development of medical competencies for oral medicine specialty training in the UK and Ireland by a collaborative working group using a modified Delphi technique. The current specialty training curriculum for oral medicine (OM) in the UK was developed by a working group including members of the British Society for Oral Medicine (BSOM) and members of the Specialty Advisory Committee for Additional Dental Specialties (SACADS) and adopted by the UK General Dental Council (GDC) in 2010. When the curriculum was developed, the entry requirements for specialty training in OM included undergraduate degrees in both dentistry and medicine. At the time of adoption, the requirement for a medical degree was removed. Medical competencies were assumed to have been delivered in medical undergraduate and postgraduate training. Accordingly, there was a need to define the medical competencies for OM specialty training to benefit trainees, trainers, and assessors. In 2018, a group comprising specialty trainers, recent former specialty trainees, and current specialty trainees in OM held face-to-face meetings in addition to email discussions and developed an updated curriculum document to better reflect the medical competencies required in specialty training. A collaborative modified Delphi approach was used to evaluate medical foundation competencies and to include only those that were considered relevant to OM specialty training. A list of relevant and achievable medical competencies was determined that has been approved by SACADS and will be incorporated into a revised OM curriculum from the UK GDC. The newly agreed-upon document for medical competencies in OM specialty training will serve as a reference for trainees, trainers, and assessors and reflects a successful use of a modified Delphi approach. Full Article
été Residents Perspectives on and Application of Dental Public Health Competencies Using Case-Based Methods By www.jdentaled.org Published On :: 2019-12-01T06:00:19-08:00 The aims of this study were to qualitatively assess dental public health (DPH) residents’ perspectives on teaching methods for DPH competencies and to develop and implement a case-based simulation to address those competencies, constructed on the basis of the qualitative assessment. Focus group discussions were conducted with 18 DPH residents enrolled in two university-based DPH programs. Topic areas discussed in the two focus groups were perceived value of DPH competencies, ways to acquire new DPH skills/abilities, and additional skills/abilities needed by DPH residents. The focus groups’ responses showed that the residents felt competent in the analytical thinking competencies such as research methodology and critiquing literature. They emphasized the importance of learning leadership skills and reported feeling somewhat uncertain about their mastery of the policy and advocacy and system evaluation competencies. Of the two distinct categories of DPH skills and competencies— analytical/critical thinking and practical competencies—these residents reported that a greater proportion of time needed to be devoted to integrating the practical competencies into their education. Based on the residents’ feedback, the authors developed a structured seminar series taking a case-based approach to simulate real-world DPH problems, using real and semi-hypothetical planning projects to meet the residents’ perceived needs and covering gaps between didactic learning and practice. Full Article
été Knowledge, Attitudes and Practices of Dental Hygienists Regarding Diabetes Risk Assessments and Screenings By jdh.adha.org Published On :: 2020-04-30T12:39:03-07:00 Purpose: Untreated and poorly controlled diabetes causes increased levels of blood glucose associated with poor periodontal disease outcomes. Dental hygienists can play a significant role in screening patients for diabetes mellitus, leading to referral and early diagnosis. The purpose of this study was to determine the knowledge, attitudes, practices, and barriers faced by clinical dental hygienists regarding diabetes risk assessment and screenings.Methods: A mixed method design was used with a convenience sample of dental hygienists in clinical practice (n=316). A 32 item, electronic survey was validated at item-level, and participants were recruited through multiple dental hygiene Facebook groups. Descriptive statistics were used to analyze the data. The survey also included two open-ended attitude questions that were interpreted using thematic analysis to pinpoint common patterns within the data.Results: Dental hygienists had high knowledge scores regarding diabetes and oral health, although many were unaware of their states' specific statutes and regulations for screening practices. Nearly all (95.9%), were likely to educate and refer patients (82%), although fewer than half (40.9%), were likely to perform chairside screening for diabetes. Emergent themes for barriers to screening were time, money, patient acceptance/willingness, lack of education, not having the proper tools, and states' rules and regulations.Conclusion: Despite high knowledge scores regarding diabetes and oral health, there is a gap in regards to dental hygienists' willingness to perform diabetes screenings in a clinical setting. Dental hygienists should be capable of integrating chairside diabetes screening practices into the process of care with proper training. Full Article
été Heterosubtypic Protection Induced by a Live Attenuated Influenza Virus Vaccine Expressing Galactose-{alpha}-1,3-Galactose Epitopes in Infected Cells By mbio.asm.org Published On :: 2020-03-03T01:30:27-08:00 ABSTRACT Anti-galactose-α-1,3-galactose (anti-α-Gal) antibody is naturally expressed at a high level in humans. It constitutes about 1% of immunoglobulins found in human blood. Here, we designed a live attenuated influenza virus vaccine that can generate α-Gal epitopes in infected cells in order to facilitate opsonization of infected cells, thereby enhancing vaccine-induced immune responses. In the presence of normal human sera, cells infected with this mutant can enhance phagocytosis of human macrophages and cytotoxicity of NK cells in vitro. Using a knockout mouse strain that allows expression of anti-α-Gal antibody in vivo, we showed that this strategy can increase vaccine immunogenicity and the breadth of protection. This vaccine can induce 100% protection against a lethal heterosubtypic group 1 (H5) or group 2 (mouse-adapted H3) influenza virus challenge in the mouse model. In contrast, its heterosubtypic protective effect in wild-type or knockout mice that do not have anti-α-Gal antibody expression is only partial, demonstrating that the enhanced vaccine-induced protection requires anti-α-Gal antibody upon vaccination. Anti-α-Gal-expressing knockout mice immunized with this vaccine produce robust humoral and cell-mediated responses upon a lethal virus challenge. This vaccine can stimulate CD11blo/– pulmonary dendritic cells, which are known to be crucial for clearance of influenza virus. Our approach provides a novel strategy for developing next-generation influenza virus vaccines. IMPORTANCE Influenza A viruses have multiple HA subtypes that are antigenically diverse. Classical influenza virus vaccines are subtype specific, and they cannot induce satisfactory heterosubtypic immunity against multiple influenza virus subtypes. Here, we developed a live attenuated H1N1 influenza virus vaccine that allows the expression of α-Gal epitopes by infected cells. Anti-α-Gal antibody is naturally produced by humans. In the presence of this antibody, human cells infected with this experimental vaccine virus can enhance several antibody-mediated immune responses in vitro. Importantly, mice expressing anti-α-Gal antibody in vivo can be fully protected by this H1N1 vaccine against a lethal H5 or H3 virus challenge. Our work demonstrates a new strategy for using a single influenza virus strain to induce broadly cross-reactive immune responses against different influenza virus subtypes. Full Article
été Genetic and Chemical-Genetic Interactions Map Biogenesis and Permeability Determinants of the Outer Membrane of Escherichia coli By mbio.asm.org Published On :: 2020-03-10T01:30:41-07:00 ABSTRACT Gram-negative bacteria are intrinsically resistant to many antibiotics due to their outer membrane barrier. Although the outer membrane has been studied for decades, there is much to uncover about the biology and permeability of this complex structure. Investigating synthetic genetic interactions can reveal a great deal of information about genetic function and pathway interconnectivity. Here, we performed synthetic genetic arrays (SGAs) in Escherichia coli by crossing a subset of gene deletion strains implicated in outer membrane permeability with nonessential gene and small RNA (sRNA) deletion collections. Some 155,400 double-deletion strains were grown on rich microbiological medium with and without subinhibitory concentrations of two antibiotics excluded by the outer membrane, vancomycin and rifampin, to probe both genetic interactions and permeability. The genetic interactions of interest were synthetic sick or lethal (SSL) gene deletions that were detrimental to the cell in combination but had a negligible impact on viability individually. On average, there were ~30, ~36, and ~40 SSL interactions per gene under no-drug, rifampin, and vancomycin conditions, respectively; however, many of these involved frequent interactors. Our data sets have been compiled into an interactive database called the Outer Membrane Interaction (OMI) Explorer, where genetic interactions can be searched, visualized across the genome, compared between conditions, and enriched for gene ontology (GO) terms. A set of SSL interactions revealed connectivity and permeability links between enterobacterial common antigen (ECA) and lipopolysaccharide (LPS) of the outer membrane. This data set provides a novel platform to generate hypotheses about outer membrane biology and permeability. IMPORTANCE Gram-negative bacteria are a major concern for public health, particularly due to the rise of antibiotic resistance. It is important to understand the biology and permeability of the outer membrane of these bacteria in order to increase the efficacy of antibiotics that have difficulty penetrating this structure. Here, we studied the genetic interactions of a subset of outer membrane-related gene deletions in the model Gram-negative bacterium E. coli. We systematically combined these mutants with 3,985 nonessential gene and small RNA deletion mutations in the genome. We examined the viability of these double-deletion strains and probed their permeability characteristics using two antibiotics that have difficulty crossing the outer membrane barrier. An understanding of the genetic basis for outer membrane integrity can assist in the development of new antibiotics with favorable permeability properties and the discovery of compounds capable of increasing outer membrane permeability to enhance the activity of existing antibiotics. Full Article
été A Solution to Antifolate Resistance in Group B Streptococcus: Untargeted Metabolomics Identifies Human Milk Oligosaccharide-Induced Perturbations That Result in Potentiation of Trimethoprim By mbio.asm.org Published On :: 2020-03-17T01:30:14-07:00 ABSTRACT Adjuvants can be used to potentiate the function of antibiotics whose efficacy has been reduced by acquired or intrinsic resistance. In the present study, we discovered that human milk oligosaccharides (HMOs) sensitize strains of group B Streptococcus (GBS) to trimethoprim (TMP), an antibiotic to which GBS is intrinsically resistant. Reductions in the MIC of TMP reached as high as 512-fold across a diverse panel of isolates. To better understand HMOs’ mechanism of action, we characterized the metabolic response of GBS to HMO treatment using ultrahigh-performance liquid chromatography–high-resolution tandem mass spectrometry (UPLC-HRMS/MS) analysis. These data showed that when challenged by HMOs, GBS undergoes significant perturbations in metabolic pathways related to the biosynthesis and incorporation of macromolecules involved in membrane construction. This study represents reports the metabolic characterization of a cell that is perturbed by HMOs. IMPORTANCE Group B Streptococcus is an important human pathogen that causes serious infections during pregnancy which can lead to chorioamnionitis, funisitis, premature rupture of gestational membranes, preterm birth, neonatal sepsis, and death. GBS is evolving antimicrobial resistance mechanisms, and the work presented in this paper provides evidence that prebiotics such as human milk oligosaccharides can act as adjuvants to restore the utility of antibiotics. Full Article
été Activity and Metabolic Versatility of Complete Ammonia Oxidizers in Full-Scale Wastewater Treatment Systems By mbio.asm.org Published On :: 2020-03-17T01:30:15-07:00 ABSTRACT The recent discovery of complete ammonia oxidizers (comammox) contradicts the paradigm that chemolithoautotrophic nitrification is always catalyzed by two different microorganisms. However, our knowledge of the survival strategies of comammox in complex ecosystems, such as full-scale wastewater treatment plants (WWTPs), remains limited. Analyses of genomes and in situ transcriptomes of four comammox organisms from two full-scale WWTPs revealed that comammox were active and showed a surprisingly high metabolic versatility. A gene cluster for the utilization of urea and a gene encoding cyanase suggest that comammox may use diverse organic nitrogen compounds in addition to free ammonia as the substrates. The comammox organisms also encoded the genomic potential for multiple alternative energy metabolisms, including respiration with hydrogen, formate, and sulfite as electron donors. Pathways for the biosynthesis and degradation of polyphosphate, glycogen, and polyhydroxyalkanoates as intracellular storage compounds likely help comammox survive unfavorable conditions and facilitate switches between lifestyles in fluctuating environments. One of the comammox strains acquired from the anaerobic tank encoded and transcribed genes involved in homoacetate fermentation or in the utilization of exogenous acetate, both pathways being unexpected in a nitrifying bacterium. Surprisingly, this strain also encoded a respiratory nitrate reductase which has not yet been found in any other Nitrospira genome and might confer a selective advantage to this strain over other Nitrospira strains in anoxic conditions. IMPORTANCE The discovery of comammox in the genus Nitrospira changes our perception of nitrification. However, genomes of comammox organisms have not been acquired from full-scale WWTPs, and very little is known about their survival strategies and potential metabolisms in complex wastewater treatment systems. Here, four comammox metagenome-assembled genomes and metatranscriptomic data sets were retrieved from two full-scale WWTPs. Their impressive and—among nitrifiers—unsurpassed ecophysiological versatility could make comammox Nitrospira an interesting target for optimizing nitrification in current and future bioreactor configurations. Full Article
été Sulfamoyl Heteroarylcarboxylic Acids as Promising Metallo-{beta}-Lactamase Inhibitors for Controlling Bacterial Carbapenem Resistance By mbio.asm.org Published On :: 2020-03-17T01:30:15-07:00 ABSTRACT Production of metallo-β-lactamases (MBLs), which hydrolyze carbapenems, is a cause of carbapenem resistance in Enterobacteriaceae. Development of effective inhibitors for MBLs is one approach to restore carbapenem efficacy in carbapenem-resistant Enterobacteriaceae (CRE). We report here that sulfamoyl heteroarylcarboxylic acids (SHCs) can competitively inhibit the globally spreading and clinically relevant MBLs (i.e., IMP-, NDM-, and VIM-type MBLs) at nanomolar to micromolar orders of magnitude. Addition of SHCs restored meropenem efficacy against 17/19 IMP-type and 7/14 NDM-type MBL-producing Enterobacteriaceae to satisfactory clinical levels. SHCs were also effective against IMP-type MBL-producing Acinetobacter spp. and engineered Escherichia coli strains overproducing individual minor MBLs (i.e., TMB-2, SPM-1, DIM-1, SIM-1, and KHM-1). However, SHCs were less effective against MBL-producing Pseudomonas aeruginosa. Combination therapy with meropenem and SHCs successfully cured mice infected with IMP-1-producing E. coli and dually NDM-1/VIM-1-producing Klebsiella pneumoniae clinical isolates. X-ray crystallographic analyses revealed the inhibition mode of SHCs against MBLs; the sulfamoyl group of SHCs coordinated to two zinc ions, and the carboxylate group coordinated to one zinc ion and bound to positively charged amino acids Lys224/Arg228 conserved in MBLs. Preclinical testing revealed that the SHCs showed low toxicity in cell lines and mice and high stability in human liver microsomes. Our results indicate that SHCs are promising lead compounds for inhibitors of MBLs to combat MBL-producing CRE. IMPORTANCE Carbapenem antibiotics are the last resort for control of severe infectious diseases, bloodstream infections, and pneumonia caused by Gram-negative bacteria, including Enterobacteriaceae. However, carbapenem-resistant Enterobacteriaceae (CRE) strains have spread globally and are a critical concern in clinical settings because CRE infections are recognized as a leading cause of increased mortality among hospitalized patients. Most CRE produce certain kinds of serine carbapenemases (e.g., KPC- and GES-type β-lactamases) or metallo-β-lactamases (MBLs), which can hydrolyze carbapenems. Although effective MBL inhibitors are expected to restore carbapenem efficacy against MBL-producing CRE, no MBL inhibitor is currently clinically available. Here, we synthesized 2,5-diethyl-1-methyl-4-sulfamoylpyrrole-3-carboxylic acid (SPC), which is a potent inhibitor of MBLs. SPC is a remarkable lead compound for clinically useful MBL inhibitors and can potentially provide a considerable benefit to patients receiving treatment for lethal infectious diseases caused by MBL-producing CRE. Full Article
été Cooperation and Cheating through a Secreted Aminopeptidase in the Pseudomonas aeruginosa RpoS Response By mbio.asm.org Published On :: 2020-03-17T01:30:15-07:00 ABSTRACT The global stress response controlled by the alternative sigma factor RpoS protects enteric bacteria from a variety of environmental stressors. The role of RpoS in other, nonenteric bacteria, such as the opportunistic pathogen Pseudomonas aeruginosa, is less well understood. Here, we employed experimental social evolution to reveal that cooperative behavior via secreted public goods is an important function in the RpoS response of P. aeruginosa. Using whole-genome sequencing, we identified rpoS loss-of-function mutants among isolates evolved in a protein growth medium that requires extracellular proteolysis. We found that rpoS mutants comprise up to 25% of the evolved population and that they behave as social cheaters, with low fitness in isolation but high fitness in mixed culture with the cooperating wild type. We conclude that rpoS mutants cheat because they exploit an RpoS-controlled public good produced by the wild type, the secreted aminopeptidase PaAP, and because they do not carry the metabolic costs of expressing PaAP and many other gene products in the large RpoS regulon. Our results suggest that PaAP is an integral part of a proteolytic sequence in P. aeruginosa that permits the utilization of protein as a nutrient source. Our work broadens the scope of stress response functions in bacteria. IMPORTANCE Bacterial stress responses are generally considered protective measures taken by individual cells. Enabled by an experimental evolution approach, we describe a contrasting property, collective nutrient acquisition, in the RpoS-dependent stress response of the opportunistic human pathogen P. aeruginosa. Specifically, we identify the secreted P. aeruginosa aminopeptidase (PaAP) as an essential RpoS-controlled function in extracellular proteolysis. As a secreted "public good," PaAP permits cheating by rpoS mutants that save the metabolic costs of expressing RpoS-controlled genes dispensable under the given growth conditions. Proteolytic enzymes are important virulence factors in P. aeruginosa pathogenesis and constitute a potential target for antimicrobial therapy. More broadly, our work contributes to recent findings in higher organisms that stress affects not only individual fitness and competitiveness but also cooperative behavior. Full Article
été Bordetella Dermonecrotic Toxin Is a Neurotropic Virulence Factor That Uses CaV3.1 as the Cell Surface Receptor By mbio.asm.org Published On :: 2020-03-24T01:31:01-07:00 ABSTRACT Dermonecrotic toxin (DNT) is one of the representative toxins produced by Bordetella pertussis, but its role in pertussis, B. pertussis infection, remains unknown. In this study, we identified the T-type voltage-gated Ca2+ channel CaV3.1 as the DNT receptor by CRISPR-Cas9-based genome-wide screening. As CaV3.1 is highly expressed in the nervous system, the neurotoxicity of DNT was examined. DNT affected cultured neural cells and caused flaccid paralysis in mice after intracerebral injection. No neurological symptoms were observed by intracerebral injection with the other major virulence factors of the organisms, pertussis toxin and adenylate cyclase toxin. These results indicate that DNT has aspects of the neurotropic virulence factor of B. pertussis. The possibility of the involvement of DNT in encephalopathy, which is a complication of pertussis, is also discussed. IMPORTANCE Bordetella pertussis, which causes pertussis, a contagious respiratory disease, produces three major protein toxins, pertussis toxin, adenylate cyclase toxin, and dermonecrotic toxin (DNT), for which molecular actions have been elucidated. The former two toxins are known to be involved in the emergence of some clinical symptoms and/or contribute to the establishment of bacterial infection. In contrast, the role of DNT in pertussis remains unclear. Our study shows that DNT affects neural cells through specific binding to the T-type voltage-gated Ca2+ channel that is highly expressed in the central nervous system and leads to neurological disorders in mice after intracerebral injection. These data raise the possibility of DNT as an etiological agent for pertussis encephalopathy, a severe complication of B. pertussis infection. Full Article
été Glycemic Variability in Diabetes Increases the Severity of Influenza By mbio.asm.org Published On :: 2020-03-24T01:31:01-07:00 ABSTRACT People with diabetes are two times more likely to die from influenza than people with no underlying medical condition. The mechanisms underlying this susceptibility are poorly understood. In healthy individuals, small and short-lived postprandial peaks in blood glucose levels occur. In diabetes mellitus, these fluctuations become greater and more frequent. This glycemic variability is associated with oxidative stress and hyperinflammation. However, the contribution of glycemic variability to the pathogenesis of influenza A virus (IAV) has not been explored. Here, we used an in vitro model of the pulmonary epithelial-endothelial barrier and novel murine models to investigate the role of glycemic variability in influenza severity. In vitro, a history of glycemic variability significantly increased influenza-driven cell death and destruction of the epithelial-endothelial barrier. In vivo, influenza virus-infected mice with a history of glycemic variability lost significantly more body weight than mice with constant blood glucose levels. This increased disease severity was associated with markers of oxidative stress and hyperinflammation both in vitro and in vivo. Together, these results provide the first indication that glycemic variability may help drive the increased risk of severe influenza in people with diabetes mellitus. IMPORTANCE Every winter, people with diabetes are at increased risk of severe influenza. At present, the mechanisms that cause this increased susceptibility are unclear. Here, we show that the fluctuations in blood glucose levels common in people with diabetes are associated with severe influenza. These data suggest that glycemic stability could become a greater clinical priority for patients with diabetes during outbreaks of influenza. Full Article
été Complete Structure of the Enterococcal Polysaccharide Antigen (EPA) of Vancomycin-Resistant Enterococcus faecalis V583 Reveals that EPA Decorations Are Teichoic Acids Covalently Linked to a Rhamnopolysaccharide Backbone By mbio.asm.org Published On :: 2020-04-28T01:30:42-07:00 ABSTRACT All enterococci produce a complex polysaccharide called the enterococcal polysaccharide antigen (EPA). This polymer is required for normal cell growth and division and for resistance to cephalosporins and plays a critical role in host-pathogen interaction. The EPA contributes to host colonization and is essential for virulence, conferring resistance to phagocytosis during the infection. Recent studies revealed that the "decorations" of the EPA polymer, encoded by genetic loci that are variable between isolates, underpin the biological activity of this surface polysaccharide. In this work, we investigated the structure of the EPA polymer produced by the high-risk enterococcal clonal complex Enterococcus faecalis V583. We analyzed purified EPA from the wild-type strain and a mutant lacking decorations and elucidated the structure of the EPA backbone and decorations. We showed that the rhamnan backbone of EPA is composed of a hexasaccharide repeat unit of C2- and C3-linked rhamnan chains, partially substituted in the C3 position by α-glucose (α-Glc) and in the C2 position by β-N-acetylglucosamine (β-GlcNAc). The so-called "EPA decorations" consist of phosphopolysaccharide chains corresponding to teichoic acids covalently bound to the rhamnan backbone. The elucidation of the complete EPA structure allowed us to propose a biosynthetic pathway, a first essential step toward the design of antimicrobials targeting the synthesis of this virulence factor. IMPORTANCE Enterococci are opportunistic pathogens responsible for hospital- and community-acquired infections. All enterococci produce a surface polysaccharide called EPA (enterococcal polysaccharide antigen) required for biofilm formation, antibiotic resistance, and pathogenesis. Despite the critical role of EPA in cell growth and division and as a major virulence factor, no information is available on its structure. Here, we report the complete structure of the EPA polymer produced by the model strain E. faecalis V583. We describe the structure of the EPA backbone, made of a rhamnan hexasaccharide substituted by Glc and GlcNAc residues, and show that teichoic acids are covalently bound to this rhamnan chain, forming the so-called "EPA decorations" essential for host colonization and pathogenesis. This report represents a key step in efforts to identify the structural properties of EPA that are essential for its biological activity and to identify novel targets to develop preventive and therapeutic approaches against enterococci. Full Article
été Moving Upstream to Impact Health: Building a Physician Workforce that Understands Social Determinants By www.ncmedicaljournal.com Published On :: 2020-05-04T06:50:30-07:00 Decades of rallying cries from professional societies, medical education and training programs, and government stakeholders have distilled the conversation of social determinants of health (SDOH) from theoretical proposals into practical solutions [1-3]. No longer standing on the precipice of change, we are now in the trenches. The nation's health care system recognizes SDOH as important drivers of health and is taking steps to address them in the practice environment. More widespread action and attention by the health care system drives the need to train the next generation of physicians in the concepts and actions related to SDOH. This includes SDOH as a core part of the medical curriculum, offering clinical and research experiences and service in the community [4-5]. Unfortunately, to date only a handful of programs have brought this vision to fruition. Across the country, most programs offer educational content that is largely didactic and provided in short or one-time sessions [6]. Though a start, such approaches are insufficient to prepare the next generation of physicians for their important work ahead. In New Orleans, the NOLA Hotspotters are an interdisciplinary group of medical, public health, nursing, and pharmacy students inspired by the work out of Camden, New Jersey, to "hot spot" patients with high utilization, which is often related to social needs [7]. While the results of the Camden program have been widely discussed following publication of their work, we argue the benefit of such a program exists beyond reduced emergency department visits or health care spending [8]. The... Full Article
été Clinical and pathologic phenotype of a large family with heterozygous STUB1 mutation By ng.neurology.org Published On :: 2020-03-23T12:45:09-07:00 Objective To describe the clinical and pathologic features of a novel pedigree with heterozygous STUB1 mutation causing SCA48. Methods We report a large pedigree of Dutch decent. Clinical and pathologic data were reviewed, and genetic analyses (whole-exome sequencing, whole-genome sequencing, and linkage analysis) were performed on multiple family members. Results Patients presented with adult-onset gait disturbance (ataxia or parkinsonism), combined with prominent cognitive decline and behavioral changes. Whole-exome sequencing identified a novel heterozygous frameshift variant c.731_732delGC (p.C244Yfs*24) in STUB1 segregating with the disease. This variant was present in a linkage peak on chromosome 16p13.3. Neuropathologic examination of 3 cases revealed a consistent pattern of ubiquitin/p62-positive neuronal inclusions in the cerebellum, neocortex, and brainstem. In addition, tau pathology was present in 1 case. Conclusions This study confirms previous findings of heterozygous STUB1 mutations as the cause of SCA48 and highlights its prominent cognitive involvement, besides cerebellar ataxia and movement disorders as cardinal features. The presence of intranuclear inclusions is a pathologic hallmark of the disease. Future studies will provide more insight into its pathologic heterogeneity. Full Article
été MtSSPdb: The Medicago truncatula Small Secreted Peptide Database By www.plantphysiol.org Published On :: 2020-05-08T08:30:48-07:00 A growing number of small secreted peptides (SSPs) in plants are recognized as important regulatory molecules with roles in processes such as growth, development, reproduction, stress tolerance, and pathogen defense. Recent discoveries further implicate SSPs in regulating root nodule development, which is of particular significance for legumes. SSP-coding genes are frequently overlooked, because genome annotation pipelines generally ignore small open reading frames, which are those most likely to encode SSPs. Also, SSP-coding small open reading frames are often expressed at low levels or only under specific conditions, and thus are underrepresented in non-tissue-targeted or non-condition-optimized RNA-sequencing projects. We previously identified 4,439 SSP-encoding genes in the model legume Medicago truncatula. To support systematic characterization and annotation of these putative SSP-encoding genes, we developed the M. truncatula Small Secreted Peptide Database (MtSSPdb; https://mtsspdb.noble.org/). MtSSPdb currently hosts (1) a compendium of M. truncatula SSP candidates with putative function and family annotations; (2) a large-scale M. truncatula RNA-sequencing-based gene expression atlas integrated with various analytical tools, including differential expression, coexpression, and pathway enrichment analyses; (3) an online plant SSP prediction tool capable of analyzing protein sequences at the genome scale using the same protocol as for the identification of SSP genes; and (4) information about a library of synthetic peptides and root and nodule phenotyping data from synthetic peptide screens in planta. These datasets and analytical tools make MtSSPdb a unique and valuable resource for the plant research community. MtSSPdb also has the potential to become the most complete database of SSPs in plants. Full Article
été ONE-HELIX PROTEIN1 and 2 Form Heterodimers to Bind Chlorophyll in Photosystem II Biogenesis By www.plantphysiol.org Published On :: 2020-05-08T08:30:48-07:00 Members of the light-harvesting complex protein family participate in multiple processes connected with light sensing, light absorption, and pigment binding within the thylakoid membrane. Amino acid residues of the light-harvesting chlorophyll a/b-binding proteins involved in pigment binding have been precisely identified through x-ray crystallography experiments. In vitro pigment-binding studies have been performed with LIGHT-HARVESTING-LIKE3 proteins, and the pigment-binding ability of cyanobacterial high-light-inducible proteins has been studied in detail. However, analysis of pigment binding by plant high-light-inducible protein homologs, called ONE-HELIX PROTEINS (OHPs), is lacking. Here, we report on successful in vitro reconstitution of Arabidopsis (Arabidopsis thaliana) OHPs with chlorophylls and carotenoids and show that pigment binding depends on the formation of OHP1/OHP2 heterodimers. Pigment-binding capacity was completely lost in each of the OHPs when residues of the light-harvesting complex chlorophyll-binding motif required for chlorophyll binding were mutated. Moreover, the mutated OHP variants failed to rescue the respective knockout (T-DNA insertion) mutants, indicating that pigment-binding ability is essential for OHP function in vivo. The scaffold protein HIGH CHLOROPHYLL FLUORESCENCE244 (HCF244) is tethered to the thylakoid membrane by the OHP heterodimer. We show that HCF244 stability depends on OHP heterodimer formation and introduce the concept of a functional unit consisting of OHP1, OHP2, and HCF244, in which each protein requires the others. Because of their pigment-binding capacity, we suggest that OHPs function in the delivery of pigments to the D1 subunit of PSII. Full Article
été MtSSPdb: A New Database for the Small Secreted Peptide Research Community By www.plantphysiol.org Published On :: 2020-05-08T08:30:48-07:00 Full Article
été "Detection of SV40 like viral DNA and viral antigens in malignant pleural mesothelioma." M. Ramael, J. Nagels, H. Heylen, S. De Schepper, J. Paulussen, M. De Maeyer and C. Van Haesendonck. Eur Respir J 1999; 14: 1381-1386. By erj.ersjournals.com Published On :: 2020-05-07T01:15:55-07:00 Full Article
été Dissimilarity of the gut-lung axis and dysbiosis of the lower airways in ventilated preterm infants By erj.ersjournals.com Published On :: 2020-05-07T01:15:54-07:00 Background Chronic lung disease of prematurity (CLD), also called bronchopulmonary dysplasia, is a major consequence of preterm birth, but the role of the microbiome in its development remains unclear. Therefore, we assessed the progression of the bacterial community in ventilated preterm infants over time in the upper and lower airways, and assessed the gut–lung axis by comparing bacterial communities in the upper and lower airways with stool findings. Finally, we assessed whether the bacterial communities were associated with lung inflammation to suggest dysbiosis. Methods We serially sampled multiple anatomical sites including the upper airway (nasopharyngeal aspirates), lower airways (tracheal aspirate fluid and bronchoalveolar lavage fluid) and the gut (stool) of ventilated preterm-born infants. Bacterial DNA load was measured in all samples and sequenced using the V3–V4 region of the 16S rRNA gene. Results From 1102 (539 nasopharyngeal aspirates, 276 tracheal aspirate fluid, 89 bronchoalveolar lavage, 198 stool) samples from 55 preterm infants, 352 (32%) amplified suitably for 16S RNA gene sequencing. Bacterial load was low at birth and quickly increased with time, but was associated with predominant operational taxonomic units (OTUs) in all sample types. There was dissimilarity in bacterial communities between the upper and lower airways and the gut, with a separate dysbiotic inflammatory process occurring in the lower airways of infants. Individual OTUs were associated with increased inflammatory markers. Conclusions Taken together, these findings suggest that targeted treatment of the predominant organisms, including those not routinely treated, such as Ureaplasma spp., may decrease the development of CLD in preterm-born infants. Full Article
été Forced oscillation technique for optimising PEEP in ventilated extremely preterm infants By erj.ersjournals.com Published On :: 2020-05-07T01:15:54-07:00 Ventilatory settings are critical in mechanically ventilated extremely preterm newborn infants due to the risk of ventilation-induced lung injury (VILI) and the subsequent development of bronchopulmonary dysplasia (BPD) [1]. Positive end-expiratory pressure (PEEP) settings usually rely on blood gases, oxygen requirement, lung auscultation, evaluation of chest radiograph and assessment of the pressure/volume curves provided by ventilators. Studies of optimal PEEP settings in the surfactant-treated preterm infant in need of mechanical ventilation are limited and evidence-based clinical guidelines are sparse [2, 3]. A bedside method identifying the PEEP value that comprises maximal lung volume recruitment and minimising tissue overdistension could improve real-time optimisation of PEEP and potentially minimise the risk of VILI and BPD [4, 5]. Full Article
été Climate Change as a Social Determinant of Health By pediatrics.aappublications.org Published On :: 2020-05-01T01:00:46-07:00 Full Article
été Rates and Stability of Mental Health Disorders in Children Born Very Preterm at 7 and 13 Years By pediatrics.aappublications.org Published On :: 2020-05-01T01:00:46-07:00 OBJECTIVES: Children born very preterm (VPT) are at an increased risk of developing mental health (MH) disorders. Our aim for this study was to assess rates of MH disorders in children born VPT and term at 13 years of age and stability of MH disorders between ages 7 and 13 years by using a diagnostic measure. METHODS: Participants were from the Victorian Infant Brain Study longitudinal cohort and included 125 children born VPT (<30 weeks’ gestational age and/or <1250 g) and 49 children born term (≥37 weeks’ gestational age) and their families. Participants were followed-up at both 7 and 13 years, and the Development and Well-Being Assessment was administered to assess for MH disorders. RESULTS: Compared with term peers, 13-year-olds born VPT were more likely to meet criteria for any MH disorder (odds ratio 5.9; 95% confidence interval 1.71–20.03). Anxiety was the most common disorder in both groups (VPT = 14%; term = 4%), whereas attention-deficit/hyperactivity disorder carried the greatest differential elevated risk (odds ratio 5.6; 95% confidence interval 0.71–43.80). Overall rates of MH disorders remained stable between 7 and 13 years, although at an individual level, many participants shifted in or out of diagnostic categories over time. CONCLUSIONS: Children born VPT show higher rates of MH disorders than their term peers, with changing trajectories over time. Findings highlight the importance of early identification and ongoing assessment to support those with MH disorders in this population. Full Article
été Network Implementation of Guideline for Early Detection Decreases Age at Cerebral Palsy Diagnosis By pediatrics.aappublications.org Published On :: 2020-05-01T01:00:46-07:00 BACKGROUND AND OBJECTIVES: Early diagnosis of cerebral palsy (CP) is critical in obtaining evidence-based interventions when plasticity is greatest. In 2017, international guidelines for early detection of CP were published on the basis of a systematic review of evidence. Our study aim was to reduce the age at CP diagnosis throughout a network of 5 diverse US high-risk infant follow-up programs through consistent implementation of these guidelines. METHODS: The study leveraged plan-do-study-act and Lean methodologies. The primary outcome was age at CP diagnosis. Data were acquired during the corresponding 9-month baseline and quarterly throughout study. Balancing measures were clinic no-show rates and parent perception of the diagnosis visit. Clinic teams conducted strengths, weaknesses, opportunities, and threats analyses, process flow evaluations, standardized assessments training, and parent questionnaires. Performance of a 3- to 4-month clinic visit was a critical process step because it included a Hammersmith Infant Neurologic Examination, a General Movements Assessment, and standardized assessments of motor function. RESULTS: The age at CP diagnosis decreased from a weighted average of 19.5 (95% confidence interval 16.2 to 22.8) to 9.5 months (95% confidence interval 4.5 to 14.6), with P = .008; 3- to 4-month visits per site increased from the median (interquartile range) 14 (5.2–73.7) to 54 (34.5–152.0), with P < .001; and no-show rates were not different. Parent questionnaires revealed positive provider perception with improvement opportunities for information content and understandability. CONCLUSIONS: Large-scale implementation of international guidelines for early detection of CP is feasible in diverse high-risk infant follow-up clinics. The initiative was received positively by families and without adversely affecting clinic operational flow. Additional parent support and education are necessary. Full Article
été IRAK1 Is a Critical Mediator of Inflammation-Induced Preterm Birth [CLINICAL AND HUMAN IMMUNOLOGY] By www.jimmunol.org Published On :: 2020-05-04T13:00:27-07:00 Key Points IRAK1 is hyperactivated in human preterm birth and in mouse and rhesus IUI models. IRAK1 deletion and inhibition reduces preterm birth. IRAK1 induces preterm birth by upregulating COX-2. Full Article
été Heterogeneous Nuclear Ribonucleoprotein L Negatively Regulates Foot-and-Mouth Disease Virus Replication through Inhibition of Viral RNA Synthesis by Interacting with the Internal Ribosome Entry Site in the 5' Untranslated Region [Virus-Cell Interactio By jvi.asm.org Published On :: 2020-05-04T08:00:46-07:00 Upon infection, the highly structured 5' untranslated region (5' UTR) of picornavirus is involved in viral protein translation and RNA synthesis. As a critical element in the 5' UTR, the internal ribosome entry site (IRES) binds to various cellular proteins to function in the processes of picornavirus replication. Foot-and-mouth disease virus (FMDV) is an important member in the family Picornaviridae, and its 5' UTR contains a functional IRES element. In this study, the cellular heterogeneous nuclear ribonucleoprotein L (hnRNP L) was identified as an IRES-binding protein for FMDV by biotinylated RNA pulldown assays, mass spectrometry (MS) analysis, and determination of hnRNP L-IRES interaction regions. Further, we found that hnRNP L inhibited the growth of FMDV through binding to the viral IRES and that the inhibitory effect of hnRNP L on FMDV growth was not due to FMDV IRES-mediated translation, but to influence on viral RNA synthesis. Finally, hnRNP L was demonstrated to coimmunoprecipitate with RNA-dependent RNA polymerase (3Dpol) in an FMDV RNA-dependent manner in the infected cells. Thus, our results suggest that hnRNP L, as a critical IRES-binding protein, negatively regulates FMDV replication by inhibiting viral RNA synthesis, possibly by remaining in the replication complex. IMPORTANCE Picornaviruses, as a large family of human and animal pathogens, cause a bewildering array of disease syndromes. Many host factors are implicated in the pathogenesis of these viruses, and some proteins interact with the viral IRES elements to affect function. Here, we report for the first time that cellular hnRNP L specifically interacts with the IRES of the picornavirus FMDV and negatively regulates FMDV replication through inhibiting viral RNA synthesis. Further, our results showed that hnRNP L coimmunoprecipitates with FMDV 3Dpol in a viral RNA-dependent manner, suggesting that it may remain in the replication complex to function. The data presented here would facilitate further understanding of virus-host interactions and the pathogenesis of picornavirus infections. Full Article
été Sample multiplexing for targeted pathway proteomics in aging mice [Systems Biology] By www.pnas.org Published On :: 2020-05-05T10:31:24-07:00 Pathway proteomics strategies measure protein expression changes in specific cellular processes that carry out related functions. Using targeted tandem mass tags-based sample multiplexing, hundreds of proteins can be quantified across 10 or more samples simultaneously. To facilitate these highly complex experiments, we introduce a strategy that provides complete control over... Full Article
été Detecting electronic coherences by time-domain high-harmonic spectroscopy [Physics] By www.pnas.org Published On :: 2020-05-05T10:31:24-07:00 Ultrafast spectroscopy is capable of monitoring electronic and vibrational states. For electronic states a few eV apart, an X-ray laser source is required. We propose an alternative method based on the time-domain high-order harmonic spectroscopy where a coherent superposition of the electronic states is first prepared by the strong optical... Full Article
été New HST data and modeling reveal a massive planetesimal collision around Fomalhaut [Astronomy] By www.pnas.org Published On :: 2020-05-05T10:31:24-07:00 The apparent detection of an exoplanet orbiting Fomalhaut was announced in 2008. However, subsequent observations of Fomalhaut b raised questions about its status: Unlike other exoplanets, it is bright in the optical and nondetected in the infrared, and its orbit appears to cross the debris ring around the star without... Full Article
été Determining the Bioenergetic Capacity for Fatty Acid Oxidation in the Mammalian Nervous System [Research Article] By mcb.asm.org Published On :: 2020-04-28T08:00:17-07:00 The metabolic state of the brain can greatly impact neurologic function. Evidence of this includes the therapeutic benefit of a ketogenic diet in neurologic diseases, including epilepsy. However, brain lipid bioenergetics remain largely uncharacterized. The existence, capacity, and relevance of mitochondrial fatty acid β-oxidation (FAO) in the brain are highly controversial, with few genetic tools available to evaluate the question. We have provided evidence for the capacity of brain FAO using a pan-brain-specific conditional knockout (KO) mouse incapable of FAO due to the loss of carnitine palmitoyltransferase 2, the product of an obligate gene for FAO (CPT2B–/–). Loss of central nervous system (CNS) FAO did not result in gross neuroanatomical changes or systemic differences in metabolism. Loss of CPT2 in the brain did not result in robustly impaired behavior. We demonstrate by unbiased and targeted metabolomics that the mammalian brain oxidizes a substantial quantity of long-chain fatty acids in vitro and in vivo. Loss of CNS FAO results in robust accumulation of long-chain acylcarnitines in the brain, suggesting that the mammalian brain mobilizes fatty acids for their oxidation, irrespective of diet or metabolic state. Together, these data demonstrate that the mammalian brain oxidizes fatty acids under normal circumstances with little influence from or on peripheral tissues. Full Article
été Designing and Evaluating a Prediabetes Shared Decision Aid By www.jabfm.org Published On :: 2020-03-16T09:31:37-07:00 Background: Prediabetes is increasing in prevalence and is associated with risk of developing diabetes, heart disease, stroke, and retinopathy. Clinicians have limited tools to facilitate prediabetes discussions within primary care visits. Purpose: 1) Develop a Patient and Stakeholder Advisory Committee (PASAC) to design, evaluate, and revise a prediabetes shared decision aid, and 2) evaluate the feasibility and experience of implementing the tool within primary care practice. Methods: A prediabetes decision aid (double-sided infographic with decision questions) was created by a PASAC that included patients, primary care clinicians, diabetes educators, endocrinologists, and pharmacists. Five clinicians within 3 primary care practices tested the prediabetes tool with 50 adult patients with prediabetes. Patients completed 2 surveys immediately after the office visit and 6 weeks later. Clinicians and PASAC members completed a postintervention survey. Results: The prediabetes shared decision aid was created through a deliberative process over 3 PASAC meetings. Ninety-six percent of patients felt the tool prepared them to decide on a diabetes prevention plan, and 100% of clinicians would use the tool again and felt the tool did not extend visit length. Discussion: It was feasible to cocreate a prediabetes shared decision aid within a PASAC and implement the tool within a primary care setting. Patients and clinicians reported a prediabetes discussion, which may mitigate rates of progression to diabetes and associated complications. Future research should evaluate which of the intervention components most effectively promotes discussion of prediabetes within a primary care setting. Full Article
été Turning Points as Opportunities to Partner with Patients Living with type 2 Diabetes or Prediabetes By www.jabfm.org Published On :: 2020-03-16T09:31:37-07:00 Introduction: Understanding patients’ perspectives about their diabetes and what causes those perspectives to shift is critical to building a treatment strategy with the patient and facilitating patient self-management behavior. Key "turning points" can provide crucial opportunities to enact a change in perspective. The goal of this study is to identify "turning points" that have significance to diabetes-related health. Methods: Research coordinators interviewed 33 patients aged 25 to 65 diagnosed with type 2 diabetes mellitus or prediabetes at medical centers in Augusta, Georgia, and Las Vegas, Nevada. Retrospective interview technique and turning point analysis was employed to plot health or diabetes management changes from diagnosis up to the present day. The constant comparative method was used to conduct a thematic analysis. Axial coding identified properties characterizing each turning point. Results: Patients reported 5 interrelated turning points occurring at various times after diagnosis: 1) gaining knowledge, either through patients own research and/or a health care class; 2) making lifestyle changes, including exercising and healthier eating; 3) encountering a life-changing event/transition, including events that derailed healthy behavior, motivated health behavior, and removed barriers to enacting healthy behavior; 4) receiving social support, either through holding patients accountable or encouraging them to enact healthy behavior; and 5) interacting with clinicians, such as medication changes or behavior changes critical to disease management. Discussion: These turning points provide specific moments throughout diabetes care in which family physicians can effectively partner with patients. By prompting, facilitating, or attending to these turning points, family physicians can partner with patients throughout diabetes care. Full Article
été Lowering Gestational Diabetes Risk by Prenatal Weight Gain Counseling By www.jabfm.org Published On :: 2020-03-16T09:31:37-07:00 Purpose: Excess weight gain during pregnancy is at epidemic proportions, and pregnancy complications are also on the rise. We sought to determine whether better weight gain counseling of expectant mothers will improve obstetric outcomes. Methods: Our historic control study design included 2 years of preintervention data, then 6 months of physician and staff training in prenatal weight gain counseling in accordance with 2009 Institute of Medicine guidelines, and finally, 2 more years of data collection for postintervention outcomes. Seven family medicine residency clinics monitored 1571 continuity prenatal cases. Counseling recommendations were noted and the following outcomes were analyzed: gestational age, birth weight, route of delivery, and the incidences of hypertension and gestational diabetes. Multiple logistic regression was used to control for demographic variables and body mass index at enrollment. Results: Institute of Medicine congruent counseling increased from 10% to 63% (P < .01). Excess weight gain decreased from 46.4% to 41.5% (adjusted odds ratio [AOR] = 0.85; 95% CI, 0.63–1.16; P = .10). Gestational diabetes decreased significantly from 11.5% to 7.3% (P = .008). The difference remained statistically significant even after adjusting for prepregnancy obesity and other clinical and demographic characteristics (AOR = 0.54; 95% CI, 0.32–0.91; P = .02). Differences in gestational age, birth weight, hypertension, primary cesarean, and shoulder dystocia were not statistically significant. Conclusions: Improved weight gain counseling of prenatal patients by physicians did reduce the pregnancy complication of gestational diabetes. This occurred even though the trend toward less excess weight gain was not statistically significant. Full Article
été The aerodynamic force platform as an ergometer [METHODS [amp ] TECHNIQUES] By jeb.biologists.org Published On :: 2020-04-06T07:24:08-07:00 Marc E. Deetjen, Diana D. Chin, and David LentinkAnimal flight requires aerodynamic power, which is challenging to determine accurately in vivo. Existing methods rely on approximate calculations based on wake flow field measurements, inverse dynamics approaches, or invasive muscle physiological recordings. In contrast, the external mechanical work required for terrestrial locomotion can be determined more directly by using a force platform as an ergometer. Based on an extension of the recent invention of the aerodynamic force platform, we now present a more direct method to determine the in vivo aerodynamic power by taking the dot product of the aerodynamic force vector on the wing with the representative wing velocity vector based on kinematics and morphology. We demonstrate this new method by studying a slowly flying dove, but it can be applied more generally across flying and swimming animals as well as animals that locomote over water surfaces. Finally, our mathematical framework also works for power analyses based on flow field measurements. Full Article
été Secondary osteon structural heterogeneity between the cranial and caudal cortices of the proximal humerus in white-tailed deer [RESEARCH ARTICLE] By jeb.biologists.org Published On :: 2020-05-04T02:24:22-07:00 Jack Nguyen and Meir M. BarakCortical bone remodeling is an ongoing process triggered by microdamage, where osteoclasts resorb existing bone and osteoblasts deposit new bone in the form of secondary osteons (Haversian systems). Previous studies revealed regional variance in Haversian systems structure and possibly material, between opposite cortices of the same bone. As bone mechanical properties depend on tissue structure and material, it is predicted that bone mechanical properties will vary in accordance with structural and material regional heterogeneity. To test this hypothesis, we analyzed the structure, mineral content and compressive stiffness of secondary bone from the cranial and caudal cortices of the white-tailed deer proximal humerus. We found significantly larger Haversian systems and canals in the cranial cortex but no significant difference in mineral content between the two cortices. Accordingly, we found no difference in compressive stiffness between the two cortices and thus our working hypothesis was rejected. Seeing that the deer humerus is curved and thus likely subjected to bending during habitual locomotion, we expect that similar to other curved long bones, the cranial cortex of the deer humerus is likely subjected primarily to tensile strains and the caudal cortex is likely subject primarily to compressive strains. Consequently, our results suggest that strain magnitude (larger in compression) and sign (compression vs. tension) affect differently the osteoclasts and osteoblasts in the BMU. Our results further suggest that osteoclasts are inhibited in regions of high compressive strains (creating smaller Haversian systems) while osteoblasts’ osteoid deposition and mineralization is not affected by strain magnitude and sign. Full Article
été An Interrater Reliability Study of Pulmonary Function Assessment With a Portable Spirometer By rc.rcjournal.com Published On :: 2020-04-28T00:42:49-07:00 BACKGROUND:In this study, we aimed to validate the agreement between pulmonary function measurements obtained with a portable spirometer and measurements obtained with conventional spirometry in Chinese pediatric and adult populations.METHODS:Pulmonary function testing was performed to evaluate subjects enrolled at Shanghai Zhongshan Hospital (n = 104) and Shanghai Children's Medical Center (n = 103). The portable spirometers and conventional devices were applied to each subject with a 20-min quiescent period between each measurement. Pulmonary function parameters of FVC, FEV1, peak expiratory flow, maximum expiratory flow at 25%, 50%, and 75% of FVC (MEF25, MEF50, and MEF75, respectively), and FEV1/FVC% were compared with intraclass correlation and Bland-Altman methods.RESULTS:A satisfactory concordance of pulmonary function was observed between spirometry measurements obtained with portable versus conventional spirometers. Intraclass correlation indicated excellent reliability (>0.75) for all pulmonary function indicators in pediatric and adult subjects. Significant positive correlations of all variables measured with different spirometers were observed (all P < .001). No significant bias was observed in either group, although limits of agreement varied. Funnel effects were observed for peak expiratory flow in pediatric subjects and for FVC, FEV1, MEF50, and MEF25 in adult subjects.CONCLUSIONS:The portable spirometer is an alternative to the conventional device for the measurement of pulmonary function. Compared with the conventional device, the portable spirometer is expected to provide convenient, operational, and financial advantages. Full Article
été Determinants of Exercise Capacity Assessed With the Modified Shuttle Test in Individuals With Cystic Fibrosis By rc.rcjournal.com Published On :: 2020-04-28T00:42:49-07:00 BACKGROUND:Patients with cystic fibrosis develop decreased exercise capacity. However, the main factors responsible for this decline are still unclear. Thus, the objective of this study was to evaluate the factors influencing exercise capacity assessed with the modified shuttle test (MST) in individuals with cystic fibrosis.METHODS:A cross-sectional study was carried out in subjects with a diagnosis of cystic fibrosis who were 6–26 y old and were regularly monitored at 2 cystic fibrosis reference centers in Brazil. Individuals who were unable to perform the tests or who exhibited hemodynamic instability and exacerbation of respiratory symptoms were excluded. Anthropometric, clinical, and genotype data were collected. In addition, lung function and exercise capacity were evaluated with the MST.RESULTS:73 subjects (mean age 12.2 ± 4.9 y and FEV1 76.8 ± 23.3%) were included. The mean distance achieved in the MST was 765 ± 258 m (71.6% of predicted). The distance achieved on the MST correlated significantly with age (r = 0.49, P < .001), body mass index (r = 0.41, P < .001), resting heart rate (r = −0.51, P < .001), and FEV1 (r = 0.24, P = .042). Subjects with FEV1 > 67% of predicted (P = .02) and those with resting heart rate < 100 beats/min (P = .01) had a greater exercise capacity. Resting heart rate, age, and FEV1 (%) were found as significant variables to explain the distance achieved on the MST (R2 = 0.48, standard error = 191.0 m).CONCLUSIONS:The main determinants of exercise capacity assessed with the MST in individuals with cystic fibrosis were resting heart rate, age, and lung function. Full Article
été {alpha}-Synuclein filaments from transgenic mouse and human synucleinopathy-containing brains are maȷor seed-competent species [Molecular Bases of Disease] By www.jbc.org Published On :: 2020-05-08T03:41:14-07:00 Assembled α-synuclein in nerve cells and glial cells is the defining pathological feature of neurodegenerative diseases called synucleinopathies. Seeds of α-synuclein can induce the assembly of monomeric protein. Here, we used sucrose gradient centrifugation and transiently transfected HEK 293T cells to identify the species of α-synuclein from the brains of homozygous, symptomatic mice transgenic for human mutant A53T α-synuclein (line M83) that seed aggregation. The most potent fractions contained Sarkosyl-insoluble assemblies enriched in filaments. We also analyzed six cases of idiopathic Parkinson's disease (PD), one case of familial PD, and six cases of multiple system atrophy (MSA) for their ability to induce α-synuclein aggregation. The MSA samples were more potent than those of idiopathic PD in seeding aggregation. We found that following sucrose gradient centrifugation, the most seed-competent fractions from PD and MSA brains are those that contain Sarkosyl-insoluble α-synuclein. The fractions differed between PD and MSA, consistent with the presence of distinct conformers of assembled α-synuclein in these different samples. We conclude that α-synuclein filaments are the main driving force for amplification and propagation of pathology in synucleinopathies. Full Article
été The major subunit of widespread competence pili exhibits a novel and conserved type IV pilin fold [Protein Structure and Folding] By www.jbc.org Published On :: 2020-05-08T03:41:14-07:00 Type IV filaments (T4F), which are helical assemblies of type IV pilins, constitute a superfamily of filamentous nanomachines virtually ubiquitous in prokaryotes that mediate a wide variety of functions. The competence (Com) pilus is a widespread T4F, mediating DNA uptake (the first step in natural transformation) in bacteria with one membrane (monoderms), an important mechanism of horizontal gene transfer. Here, we report the results of genomic, phylogenetic, and structural analyses of ComGC, the major pilin subunit of Com pili. By performing a global comparative analysis, we show that Com pili genes are virtually ubiquitous in Bacilli, a major monoderm class of Firmicutes. This also revealed that ComGC displays extensive sequence conservation, defining a monophyletic group among type IV pilins. We further report ComGC solution structures from two naturally competent human pathogens, Streptococcus sanguinis (ComGCSS) and Streptococcus pneumoniae (ComGCSP), revealing that this pilin displays extensive structural conservation. Strikingly, ComGCSS and ComGCSP exhibit a novel type IV pilin fold that is purely helical. Results from homology modeling analyses suggest that the unusual structure of ComGC is compatible with helical filament assembly. Because ComGC displays such a widespread distribution, these results have implications for hundreds of monoderm species. Full Article
été Pathogenesis and Management of Indirect Hyperbilirubinemia in Preterm Neonates Less Than 35 Weeks: Moving Toward a Standardized Approach By neoreviews.aappublications.org Published On :: 2020-05-01T01:00:20-07:00 Premature infants have a higher incidence of indirect hyperbilirubinemia than term infants. Management of neonatal indirect hyperbilirubinemia in late preterm and term neonates has been well addressed by recognized, consensus-based guidelines. However, the extension of these guidelines to the preterm population has been an area of uncertainty because of limited evidence. This leads to variation in clinical practice and lack of recognition of the spectrum of bilirubin-induced neurologic dysfunction (BIND) in this population. Preterm infants are metabolically immature and at higher risk for BIND at lower bilirubin levels than their term counterparts. Early use of phototherapy to eliminate BIND and minimize the need for exchange transfusion is the goal of treatment in premature neonates. Although considered relatively safe, phototherapy does have side effects, and some NICUs tend to overuse phototherapy. In this review, we describe the epidemiology and pathophysiology of BIND in preterm neonates, and discuss our approach to standardized management of indirect hyperbilirubinemia in the vulnerable preterm population. The proposed treatment charts suggest early use of phototherapy in preterm neonates with the aim of reducing exposure to high irradiance levels, minimizing the need for exchange transfusions, and preventing BIND. The charts are pragmatic and have additional curves for stopping phototherapy and escalating its intensity. Having a standardized approach would support future research and quality improvement initiatives that examine dose and duration of phototherapy exposure with relation to outcomes. Full Article
été Recycling of heterogeneous material in the subduction factory: evidence from the sedimentary melange of the Internal Ligurian Units, Italy By jgs.lyellcollection.org Published On :: 2020-05-04T02:10:48-07:00 In the Northern Apennine (Italy), the Internal Ligurian Units consist of Middle–Late Jurassic ophiolites covered by thick sedimentary deposits whose top is represented by the Early Paleocene Bocco Shale. This formation is characterized by mass-transport deposits interlayered with thin-bedded siliciclastic turbidites. The sedimentological and structural features of these mass-transport deposits reveal a long-lived history of recycling of heterogeneous material in a subduction setting. This history started with the frontal accretion of a fragment of oceanic crust into an accretionary prism whose lower slope was subsequently affected by tectonic erosion and consequent instability, leading to the production of mass-transport deposits and the transfer of material to the lower plate. These mass-transport deposits were subsequently underthrust and then again transferred to the base of the accretionary prism by coherent underplating, before their exhumation to the surface. The Bocco Shale is thus representative of a subduction setting where both accretionary and erosive events occurred, depending on changing boundary conditions. The reconstructed history for the Bocco Shale indicates that the sedimentary and gravitational processes both at the prism front and on the prism slope, possibly induced by alternating accretion and erosion events, are the most efficient mechanisms of lithological mixing and recycling in subduction margins. Full Article
été Development of an Extended-Specificity Multiplex Immunoassay for Detection of Streptococcus pneumoniae Serotype-Specific Antigen in Urine by Use of Human Monoclonal Antibodies [Diagnostic Laboratory Immunology] By cvi.asm.org Published On :: 2017-12-05T08:00:30-08:00 Current pneumococcal vaccines cover the 10 to 23 most common serotypes of the 92 presently described. However, with the increased usage of pneumococcal-serotype-based vaccines, the risk of serotype replacement and an increase in disease caused by nonvaccine serotypes remains. Serotype surveillance of pneumococcal infections relies heavily on culture techniques, which are known to be insensitive, particularly in cases of noninvasive disease. Pneumococcal-serotype-specific urine assays offer an alternative method of serotyping for both invasive and noninvasive disease. However, the assays described previously cover mainly conjugate vaccine serotypes, give little information about circulating nonvaccine serotypes, and are currently available only in one or two specialist laboratories. Our laboratory has developed a Luminex-based extended-range antigen capture assay to detect pneumococcal-serotype-specific antigens in urine samples. The assay targets 24 distinct serotypes/serogroups plus the cell wall polysaccharide (CWP) and some cross-reactive serotypes. We report that the assay is capable of detecting all the targeted serotypes and the CWP at 0.1 ng/ml, while some serotypes are detected at concentrations as low as 0.3 pg/ml. The analytical serotype specificity was determined to be 98.4% using a panel of polysaccharide-negative urine specimens spiked with nonpneumococcal bacterial antigens. We also report clinical sensitivities of 96.2% and specificities of 89.9% established using a panel of urine specimens from patients diagnosed with community-acquired pneumonia or pneumococcal disease. This assay can be extended for testing other clinical samples and has the potential to greatly improve serotype-specific surveillance in the many cases of pneumococcal disease in which a culture is never obtained. Full Article
été Fluorescent Hybridization of Mycobacterium leprae in Skin Samples Collected in Burkina Faso [Mycobacteriology and Aerobic Actinomycetes] By jcm.asm.org Published On :: 2020-04-23T08:00:29-07:00 Leprosy is caused by Mycobacterium leprae, and it remains underdiagnosed in Burkina Faso. We investigated the use of fluorescent in situ hybridization (FISH) for detecting M. leprae in 27 skin samples (skin biopsy samples, slit skin samples, and skin lesion swabs) collected from 21 patients from Burkina Faso and three from Côte d’Ivoire who were suspected of having cutaneous leprosy. In all seven Ziehl-Neelsen-positive skin samples (four skin biopsy samples and three skin swabs collected from the same patient), FISH specifically identified M. leprae, including one FISH-positive skin biopsy sample that remained negative after testing with PCR targeting the rpoB gene and with the GenoType LepraeDR assay. Twenty other skin samples and three negative controls all remained negative for Ziehl-Neelsen staining, FISH, and rpoB PCR. These data indicate the usefulness of a microscopic examination of skin samples after FISH for first-line diagnosis of cutaneous leprosy. Accordingly, FISH represents a potentially useful point-of-care test for the diagnosis of cutaneous leprosy. Full Article
été Nanopore Sequencing Reveals Novel Targets for Detection and Surveillance of Human and Avian Influenza A Viruses [Virology] By jcm.asm.org Published On :: 2020-04-23T08:00:29-07:00 Accurate detection of influenza A virus (IAV) is crucial for patient management, infection control, and epidemiological surveillance. The World Health Organization and the Centers for Disease Control and Prevention have recommended using the M gene as the diagnostic gene target for reverse-transcription-PCR (RT-PCR). However, M gene RT-PCR has reduced sensitivity for recent IAV due to novel gene mutations. Here, we sought to identify novel diagnostic targets for the molecular detection of IAV using long-read third-generation sequencing. Direct nanopore sequencing from 18 nasopharyngeal specimens and one saliva specimen showed that the 5' and 3' ends of the PB2 gene and the entire NS gene were highly abundant. Primers selected for PB2 and NS genes were well matched with seasonal or avian IAV gene sequences. Our novel PB2 and NS gene real-time RT-PCR assays showed limits of detection similar to or lower than that of M gene RT-PCR and achieved 100% sensitivity and specificity in the detection of A(H1N1), A(H3N2), and A(H7N9) in nasopharyngeal and saliva specimens. For 10 patients with IAV detected by M gene RT-PCR conversion in sequentially collected specimens, NS and/or PB2 gene RT-PCR was positive in 2 (20%) of the initial specimens that were missed by M gene RT-PCR. In conclusion, we have shown that PB2 or NS gene RT-PCRs are suitable alternatives to the recommended M gene RT-PCR for diagnosis of IAV. Long-read nanopore sequencing facilitates the identification of novel diagnostic targets. Full Article