370 research outputs found
Evidence for Perchlorate-Coupled Molybdenum and Nickel Carbon Monoxide Dehydrogenase CO Oxidation and Characterization of Novel Perchlorate-Reducing Haloarchaea
Carbon monoxide (CO) has been exploited as a microbial energy source for much of life’s evolutionary history. A phylogenetically diverse array of microorganisms can oxidize CO using two distinct CO dehydrogenases, molybdenum-dependent (Mo-CODH) and nickel-dependent (Ni-CODH). Aerobes and facultative organisms contain Mo-CODHs which allow them to utilize oxygen as an electron acceptor in addition to alternatives such as nitrate and sulfate. Obligate anaerobic organisms contain Ni-CODHs, which oxidize CO at elevated concentrations, but cannot utilize oxygen. In systems where organic matter deposits are limited or absent, atmospheric trace gases such as CO are thought to assist in supporting the growth and survival of microbial communities. Extraterrestrially, the Martian atmosphere is dominated by CO2, however, CO also has also been documented at substantial levels. Martian regolith contains only trace levels of organic carbon, leaving CO as potentially the most abundant and available substrate capable of supporting near-surface microbial activity. However, Martian regolith also contains perchlorate, while potentially toxic it also serves an abundant potential oxidant. At locations such as the recurrent slope lineae, hypersaline perchlorate-based brines are thought to exist. Though previously unexplored for CO oxidation, chlorine oxyanions may act as suitable electron acceptors, expanding the current range of both Mo-CODH and Ni-CODH CO oxidizing microorganisms. This study used a variety of culture-dependent approaches, cultivating four novel haloarchaea from the Bonneville Salt Flats and surrounding saline soils capable of utilizing CO, ClO4-, or a metabolic coupling. Halovenus carboxidivorans was capable of CO oxidation, while Halobacterium bonnevillei and Halobaculum saliterrae, represent the first microbes capable of nitrate-dependent, perchlorate-coupled CO oxidation at concentrations up to 1 M ClO4-. All three isolates contained Mo-CODHs. The provisional species, Halanaeroarchaeum oxyrespirans, is capable of growth via perchlorate reduction, independently of nitrate, a first for haloarchaeal cryptic perchlorate reduction. Additionally, H. oxyrespirans, can respire oxygen, expanding the known capacities of the genus. Perchlorate-coupled CO oxidation was further expanded to include carboxidotrophic Ni-CODH containing microbes using the thermophilic Firmicute Moorella glycerini as a model organism. Collectively, the isolation of these haloarchaeal cultivars contributed to the expansion of haloarchaeal diversity through both physiological and genomic characterization
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Gaps in Treatment and Surveillance: Head and Neck Cancer Care in a Safety-Net Hospital.
Objective:Treatment delays and suboptimal adherence to posttreatment surveillance may adversely affect head and neck cancer (HNC) outcomes. Such challenges can be exacerbated in safety-net settings that struggle with limited resources and serve a disproportionate number of patients vulnerable to gaps in care. This study aims to characterize treatment delays and adherence with posttreatment surveillance in HNC care at an urban tertiary care public hospital in San Francisco. Study Design:Retrospective chart review. Setting:Urban tertiary care public hospital in San Francisco. Subjects and Methods:We identified all cases of HNC diagnosed from 2008 to 2010 through the electronic medical record. We abstracted data, including patient characteristics, disease characteristics, pathology and radiology findings, treatment details, posttreatment follow-up, and clinical outcomes. Results:We included 64 patients. Median time from diagnosis to treatment initiation (DTI) was 57 days for all patients, 54 days for patients undergoing surgery only, 49 days for patients undergoing surgery followed by adjuvant radiation ± chemotherapy, 65 days for patients undergoing definitive radiation ± chemotherapy, and 29 days for patients undergoing neoadjuvant chemotherapy followed by radiation or chemoradiation. Overall, 69% of patients completed recommended treatment. Forty-two of 61 (69%) patients demonstrated adherence to posttreatment visits in year 1; this fell to 14 out of 30 patients (47%) by year 5. Conclusion:DTI was persistently prolonged in this study compared with prior studies in other public hospital settings. Adherence to posttreatment surveillance was suboptimal and continued to decline as the surveillance period progressed
Prevalence and Correlates of Cost-Related Medication Nonadherence to Immunosuppressive Drugs After Heart Transplantation: The International Multicenter Cross-sectional Bright Study
Cost-related medication nonadherence (CRMNA) refers to not taking medications as prescribed because of difficulties paying for them.; The aims of this study were (1) to assess the prevalence of CRMNA to immunosuppressants in heart transplant recipients internationally and (2) to determine multilevel correlates (patient, center, and healthcare system levels) of CRMNA.; Using data from the cross-sectional international BRIGHT study, applying multistaged sampling, CRMNA was assessed via 3 self-report items in 1365 patients from 36 heart transplant centers in 11 countries. Cost-related medication nonadherence was defined as any positive answer on any of the 3 items. Healthcare system-level (ie, insurance coverage, out-of-pocket expenditures) and patient-level (ie, intention, perceived financial burden, cost as a barrier, a health belief regarding medication benefits, cost-related self-efficacy, and demographic factors) CRMNA correlates were assessed. Correlates were examined using mixed logistic regression analysis.; Across all study countries, CRMNA had an average prevalence of 2.6% (range, 0% [Switzerland/Brazil] to 9.8% [Australia]) and was positively related to being single (odds ratio, 2.29; 95% confidence interval, 1.17-4.47), perceived financial burden (odds ratio, 2.15; 95% confidence interval, 1.55-2.99), and cost as a barrier (odds ratio, 2.60; 95% confidence interval, 1.66-4.07). Four protective factors were identified: white ethnicity (odds ratio, 0.37; 95% confidence interval, 0.19-0.74), intention to adhere (odds ratio, 0.44; 95% confidence interval, 0.31-0.63), self-efficacy (odds ratio, 0.54; 95% confidence interval, 0.43-0.67), and belief about medication benefit (odds ratio, 0.70; 95% confidence interval, 0.57-0.87). Regarding variability, 81.3% was explained at the patient level; 13.8%, at the center level; and 4.8%, at the country level.; In heart transplant recipients, the CRMNA prevalence varies across countries but is lower than in other chronically ill populations. Identified patient-level correlates are novel (ie, intention to adhere, cost-related barriers, and cost-related self-efficacy) and indicate patient-perceived medication cost burden
Clinical approach to the diagnosis of autoimmune encephalitis in the pediatric patient
Autoimmune encephalitis (AE) is an important and treatable cause of acute encephalitis. Diagnosis of AE in a developing child is challenging because of overlap in clinical presentations with other diseases and complexity of normal behavior changes. Existing diagnostic criteria for adult AE require modification to be applied to children, who differ from adults in their clinical presentations, paraclinical findings, autoantibody profiles, treatment response, and long-term outcomes.A subcommittee of the Autoimmune Encephalitis International Working Group collaborated through conference calls and email correspondence to consider the pediatric-specific approach to AE. The subcommittee reviewed the literature of relevant AE studies and sought additional input from other expert clinicians and researchers.Existing consensus criteria for adult AE were refined for use in children. Provisional pediatric AE classification criteria and an algorithm to facilitate early diagnosis are proposed. There is also discussion about how to distinguish pediatric AE from conditions within the differential diagnosis.Diagnosing AE is based on the combination of a clinical history consistent with pediatric AE and supportive diagnostic testing, which includes but is not dependent on antibody testing. The proposed criteria and algorithm require validation in prospective pediatric cohorts.Copyright © 2020 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of the American Academy of Neurology
Simian hemorrhagic fever virus infection of rhesus macaques as a model of viral hemorrhagic fever: Clinical characterization and risk factors for severe disease
AbstractSimian Hemorrhagic Fever Virus (SHFV) has caused sporadic outbreaks of hemorrhagic fevers in macaques at primate research facilities. SHFV is a BSL-2 pathogen that has not been linked to human disease; as such, investigation of SHFV pathogenesis in non-human primates (NHPs) could serve as a model for hemorrhagic fever viruses such as Ebola, Marburg, and Lassa viruses. Here we describe the pathogenesis of SHFV in rhesus macaques inoculated with doses ranging from 50PFU to 500,000PFU. Disease severity was independent of dose with an overall mortality rate of 64% with signs of hemorrhagic fever and multiple organ system involvement. Analyses comparing survivors and non-survivors were performed to identify factors associated with survival revealing differences in the kinetics of viremia, immunosuppression, and regulation of hemostasis. Notable similarities between the pathogenesis of SHFV in NHPs and hemorrhagic fever viruses in humans suggest that SHFV may serve as a suitable model of BSL-4 pathogens
O-GlcNAc regulates the mitochondrial integrated stress response by regulating ATF4
BackgroundAccumulation of mitochondrial dysfunctional is a hallmark of age-related neurodegeneration including Alzheimer’s disease (AD). Impairment of mitochondrial quality control mechanisms leading to the accumulation of damaged mitochondria and increasing neuronal stress. Therefore, investigating the basic mechanisms of how mitochondrial homeostasis is regulated is essential. Herein, we investigate the role of O-GlcNAcylation, a single sugar post-translational modification, in controlling mitochondrial stress-induced transcription factor Activating Transcription Factor 4 (ATF4). Mitochondrial dysfunction triggers the integrated stress response (ISRmt), in which the phosphorylation of eukaryotic translation initiation factor 2α results in the translation of ATF4.MethodsWe used patient-derived induced pluripotent stem cells, a transgenic mouse model of AD, SH-SY5Y neuroblastoma and HeLa cell-lines to examine the effect of sustained O-GlcNAcase inhibition by Thiamet-G (TMG) on ISRmt using biochemical analyses.ResultsWe show that TMG elevates ATF4 protein levels upon mitochondrial stress in SH-SY5Y neuroblastoma and HeLa cell-lines. An indirect downstream target of ATF4 mitochondrial chaperone glucose-regulated protein 75 (GRP75) is significantly elevated. Interestingly, knock-down of O-GlcNAc transferase (OGT), the enzyme that adds O-GlcNAc, in SH-SY5Y increases ATF4 protein and mRNA expression. Additionally, ATF4 target gene Activating Transcription Factor 5 (ATF5) is significantly elevated at both the protein and mRNA level. Brains isolated from TMG treated mice show elevated levels of ATF4 and GRP75. Importantly, ATF4 occupancy increases at the ATF5 promoter site in brains isolated from TMG treated mice suggesting that O-GlcNAc is regulating ATF4 targeted gene expression. Interestingly, ATF4 and GRP75 are not induced in TMG treated familial Alzheimer’s Disease mice model. The same results are seen in a human in vitro model of AD.ConclusionTogether, these results indicate that in healthy conditions, O-GlcNAc regulates the ISRmt through regulating ATF4, while manipulating O-GlcNAc in AD has no effect on ISRmt
Household Food Insecurity and Children’s Physical Activity and Sedentary Behaviour in the United States: The Healthy Communities Study
OBJECTIVE: To examine associations between household food insecurity and children\u27s physical activity and sedentary behaviours. DESIGN: Secondary analysis was conducted on the Healthy Communities Study, an observational study from 2013 to 2015. Household food insecurity was assessed by two items from the US Department of Agriculture\u27s 18-item US Household Food Security Survey Module. Physical activity was measured using the 7-d Physical Activity Behavior Recall instrument. Data were analyzed using multilevel statistical modelling. SETTING: A total of 130 communities in the USA. PARTICIPANTS: In sum, 5138 US children aged 4-15 years. RESULTS: No associations were found for the relationship between household food insecurity and child physical activity. A significant interaction between household food insecurity and child sex for sedentary behaviors was observed (P = 0·03). CONCLUSIONS: Additional research capturing a more detailed assessment of children\u27s experiences of food insecurity in relation to physical activity is warranted. Future studies may consider adopting qualitative study designs or utilizing food insecurity measures that specifically target child-level food insecurity. Subsequent research may also seek to further explore sub-group analyses by sex
Economic evaluation of the NET intervention versus guideline dissemination for management of mild head injury in hospital emergency departments
Abstract Background Evidence-based guidelines for the management of mild traumatic brain injury (mTBI) in the emergency department (ED) are now widely available, and yet, clinical practice remains inconsistent with the guidelines. The Neurotrauma Evidence Translation (NET) intervention was developed to increase the uptake of guideline recommendations and improve the management of minor head injury in Australian emergency departments (EDs). However, the adoption of this type of intervention typically entails an upfront investment that may or may not be fully offset by improvements in clinical practice, health outcomes and/or reductions in health service utilisation. The present study estimates the cost and cost-effectiveness of the NET intervention, as compared to the passive dissemination of the guideline, to evaluate whether any improvements in clinical practice or health outcomes due to the NET intervention can be obtained at an acceptable cost. Methods and findings Study setting: The NET cluster randomised controlled trial [ACTRN12612001286831]. Study sample: Seventeen EDs were randomised to the control condition and 14 to the intervention. One thousand nine hundred forty-three patients were included in the analysis of clinical practice outcomes (NET sample). A total of 343 patients from 14 control and 10 intervention EDs participated in follow-up interviews and were included in the analysis of patient-reported health outcomes (NET-Plus sample). Outcome measures: Appropriate post-traumatic amnesia (PTA) screening in the ED (primary outcome). Secondary clinical practice outcomes: provision of written information on discharge (INFO) and safe discharge (defined as CT scan appropriately provided plus PTA plus INFO). Secondary patient-reported, post-discharge health outcomes: anxiety (Hospital Anxiety and Depression Scale), post-concussive symptoms (Rivermead), and preference-based health-related quality of life (SF6D). Methods: Trial-based economic evaluations from a health sector perspective, with time horizons set to coincide with the final follow-up for the NET sample (2 months post-intervention) and to 1-month post-discharge for the NET-Plus sample. Results: Intervention and control groups were not significantly different in health service utilisation received in the ED/inpatient ward following the initial mTBI presentation (adjusted mean difference 106, 341.78 per patient; 95%CI − 742; p = 0.094). Savings from lower health service utilisation are therefore unlikely to offset the significantly higher upfront cost of the intervention (mean difference 135, 169.89 per patient; 95%CI 297, p = 0.009). This effect is larger in absolute magnitude over the longer follow-up in the NET-plus sample (adjusted mean difference 96, 1246 per additional patient appropriately screened for PTA (525, $2055). For NET to be considered cost-effective with 95% confidence, decision-makers would need to be willing to trade one quality-adjusted life year (QALY) for 25 additional patients appropriately screened for PTA. While these results reflect our best estimate of cost-effectiveness given the data, it is possible that a NET intervention that has been scaled and streamlined ready for wider roll-out may be more or less cost-effective than the NET intervention as delivered in the trial. Conclusions While the NET intervention does improve the management of mTBI in the ED, it also entails a significant increase in cost and—as delivered in the trial—is unlikely to be cost-effective at currently accepted funding thresholds. There may be a scope for a scaled-up and streamlined NET intervention to achieve a better balance between costs and outcomes. Trial registration Australian New Zealand Clinical Trials Registry ACTRN12612001286831, date registered 12 December 2012
Generation of Diversity in Streptococcus mutans Genes Demonstrated by MLST
Streptococcus mutans, consisting of serotypes c, e, f and k, is an oral aciduric organism associated with the initiation and progression of dental caries. A total of 135 independent Streptococcus mutans strains from caries-free and caries-active subjects isolated from various geographical locations were examined in two versions of an MLST scheme consisting of either 6 housekeeping genes [accC (acetyl-CoA carboxylase biotin carboxylase subunit), gki (glucokinase), lepA (GTP-binding protein), recP (transketolase), sodA (superoxide dismutase), and tyrS (tyrosyl-tRNA synthetase)] or the housekeeping genes supplemented with 2 extracellular putative virulence genes [gtfB (glucosyltransferase B) and spaP (surface protein antigen I/II)] to increase sequence type diversity. The number of alleles found varied between 20 (lepA) and 37 (spaP). Overall, 121 sequence types (STs) were defined using the housekeeping genes alone and 122 with all genes. However π, nucleotide diversity per site, was low for all loci being in the range 0.019–0.007. The virulence genes exhibited the greatest nucleotide diversity and the recombination/mutation ratio was 0.67 [95% confidence interval 0.3–1.15] compared to 8.3 [95% confidence interval 5.0–14.5] for the 6 concatenated housekeeping genes alone. The ML trees generated for individual MLST loci were significantly incongruent and not significantly different from random trees. Analysis using ClonalFrame indicated that the majority of isolates were singletons and no evidence for a clonal structure or evidence to support serotype c strains as the ancestral S. mutans strain was apparent. There was also no evidence of a geographical distribution of individual isolates or that particular isolate clusters were associated with caries. The overall low sequence diversity suggests that S. mutans is a newly emerged species which has not accumulated large numbers of mutations but those that have occurred have been shuffled as a consequence of intra-species recombination generating genotypes which can be readily distinguished by sequence analysis
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Population stratification may bias analysis of PGC-1α as a modifier of age at Huntington disease motor onset
Huntington’s disease (HD) is an inherited neurodegenerative disorder characterized by motor, cognitive and behavioral disturbances, caused by the expansion of a CAG trinucleotide repeat in the HD gene. The CAG allele size is the major determinant of age at onset (AO) of motor symptoms, although the remaining variance in AO is highly heritable. The rs7665116 SNP in PPARGC1A, encoding the mitochondrial regulator PGC-1α, has been reported to be a significant modifier of AO in three European HD cohorts, perhaps due to affected cases from Italy. We attempted to replicate these findings in a large collection of (1,727) HD patient DNA samples of European origin. In the entire cohort, rs7665116 showed a significant effect in the dominant model (p value = 0.008) and the additive model (p value = 0.009). However, when examined by origin, cases of Southern European origin had an increased rs7665116 minor allele frequency (MAF), consistent with this being an ancestry-tagging SNP. The Southern European cases, despite similar mean CAG allele size, had a significantly older mean AO (p < 0.001), suggesting population-dependent phenotype stratification. When the generalized estimating equations models were adjusted for ancestry, the effect of the rs7665116 genotype on AO decreased dramatically. Our results do not support rs7665116 as a modifier of AO of motor symptoms, as we found evidence for a dramatic effect of phenotypic (AO) and genotypic (MAF) stratification among European cohorts that was not considered in previously reported association studies. A significantly older AO in Southern Europe may reflect population differences in genetic or environmental factors that warrant further investigation
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