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BACKGROUND AND AIM: There is limited data on natural course and interventions in stage-3 acute kidney injury (AKI-3) in patients with acute-on-chronic liver failure (ACLF). We studied the factors of AKI-3 reversal and outcomes of dialysis in ACLF patients. METHODS: Consecutive patients with ACLF were prospectively enrolled (n = 1022) and variables determining AKI and its outcomes were analysed. RESULTS: At 1 month, 337 (33%) patients had AKI-3, of which, 131 had AKI-3 at enrolment and 206 developed AKI-3 during hospital stay. Of patients with AKI-3 at enrolment, 18% showed terlipressin response, 21% had AKI resolution and 59% required dialysis. High MELD (≥35) (model 1), serum bilirubin (≥23 mg/dL) (model 2) and AARC score (≥11) (model 3) were independent risk factors for dialysis. Dialysis was associated with worse survival in all AKI patients but improved outcomes in patients with AKI-3 (p = .022, HR 0.69 [0.50-0.95]). Post-mortem kidney biopsies (n = 61) revealed cholemic nephropathy (CN) in 54%, acute tubular necrosis (ATN) in 31%, and a combination (CN and ATN) in 15%. Serum bilirubin was significantly higher in patients with CN, CN and ATN compared with ATN respectively ([30.8 ± 12.2] vs. [26.7 ± 12.0] vs. [18.5 ± 9.8]; p = .002). CONCLUSION: AKI-3 rapidly increases from 13% to 33% within 30 days in ACLF patients. Histopathological data suggested cholemic nephropathy as the predominant cause which correlated with high bilirubin levels. AKI-3 resolves in only one in five patients. Patients with AARC grade 3 and MELD >35 demand need for early dialysis in AKI-3 for improved outcomes.
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Injúria Renal Aguda , Insuficiência Hepática Crônica Agudizada , Humanos , Insuficiência Hepática Crônica Agudizada/complicações , Insuficiência Hepática Crônica Agudizada/terapia , Terlipressina , Injúria Renal Aguda/etiologia , Fatores de Risco , BilirrubinaRESUMO
Horizontal levees are a nature-based approach for removing nitrogen from municipal wastewater effluent while simultaneously providing additional benefits, such as flood control. To assess nitrogen removal mechanisms and the efficacy of a horizontal levee, we monitored an experimental system receiving nitrified municipal wastewater effluent for 2 years. Based on mass balances and microbial gene abundance data, we determined that much of the applied nitrogen was most likely removed by heterotrophic denitrifiers that consumed labile organic carbon from decaying plants and added wood chips. Fe(III) and sulfate reduction driven by decay of labile organic carbon also produced Fe(II) sulfide minerals. During winter months, when heterotrophic activity was lower, strong correlations between sulfate release and nitrogen removal suggested that autotrophic denitrifiers oxidized Fe(II) sulfides using nitrate as an electron acceptor. These trends were seasonal, with Fe(II) sulfide minerals formed during summer fueling denitrification during the subsequent winter. Overall, around 30% of gaseous nitrogen losses in the winter were attributable to autotrophic denitrifiers. To predict long-term nitrogen removal, we developed an electron-transfer model that accounted for the production and consumption of electron donors. The model indicated that the labile organic carbon released from wood chips may be capable of supporting nitrogen removal from wastewater effluent for several decades with sulfide minerals, decaying vegetation, and root exudates likely sustaining nitrogen removal over a longer timescale.
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Nitratos , Nitrogênio , Processos Autotróficos , Reatores Biológicos , Carbono , Desnitrificação , Compostos Férricos , Compostos Ferrosos , Minerais , Óxidos de Nitrogênio , Estações do Ano , Sulfatos , Sulfetos , Águas ResiduáriasRESUMO
The forage maturation hypothesis (FMH) states that energy intake for ungulates is maximised when forage biomass is at intermediate levels. Nevertheless, metabolic allometry and different digestive systems suggest that resource selection should vary across ungulate species. By combining GPS relocations with remotely sensed data on forage characteristics and surface water, we quantified the effect of body size and digestive system in determining movements of 30 populations of hindgut fermenters (equids) and ruminants across biomes. Selection for intermediate forage biomass was negatively related to body size, regardless of digestive system. Selection for proximity to surface water was stronger for equids relative to ruminants, regardless of body size. To be more generalisable, we suggest that the FMH explicitly incorporate contingencies in body size and digestive system, with small-bodied ruminants selecting more strongly for potential energy intake, and hindgut fermenters selecting more strongly for surface water.
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Sistema Digestório , Ruminantes , Animais , Tamanho CorporalRESUMO
BACKGROUND & AIMS: Little is known on the course of acute kidney injury (AKI) and its relation to non-kidney organ failures and mortality in critically ill patients with cirrhosis (CICs). METHODS: We conducted a large prospective, single-centre, observational study in which CICs were followed up daily, during the first 7 days of intensive care, collecting prespecified criteria for AKI, extrarenal extrahepatic organ failures (ERH-OFs) and systemic inflammatory response syndrome (SIRS). RESULTS: A total of 291 patients admitted to ICU were enrolled; 231 (79.4%) had at least one ERH-OFs, 168 (58%) had AKI at presentation, and 145 (49.8%) died by 28 days. At day seven relative to baseline, 151 (51.8%) patients had progressive or persistent AKI, while the rest remained free of AKI or had AKI improvement. The 28-day mortality rate was higher among patients with progressive/persistent AKI (74.2% vs 23.5%; P < .001) or maximum stage 3 of AKI in the first week. Two-level mixed logistic regression modelling identified independent baseline risk factors for progressive/persistent AKI, including 3 to 4 SIRS criteria, infections due to multidrug-resistant bacteria (MDR), elevated serum bilirubin, and number of ERH-OFs. Follow-up risk factors included increases in bilirubin and chloride levels, and new development of 2 or 3 ERH-OFs. CONCLUSIONS: Our results show that among CICs admitted to the ICU, the stage and course of AKI in the first week determines outcomes. Strategies combating MDR infections, multiorgan failure, liver failure and intense systemic inflammation could prevent AKI progression or persistence in CICs.
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Injúria Renal Aguda , Estado Terminal , Injúria Renal Aguda/epidemiologia , Injúria Renal Aguda/etiologia , Humanos , Unidades de Terapia Intensiva , Cirrose Hepática/complicações , Insuficiência de Múltiplos Órgãos/etiologia , Estudos Prospectivos , Fatores de RiscoRESUMO
There is a major demographic shift with increase in non-communicable diseases even in low- and middle-income countries. Many self-limiting illnesses are burdensome to people when they have limited access to health care system and poor family support. The aim of the study explores experiences of community health nurses in palliative care delivery in a primary health care setting. The study was conducted in Community Health Nursing Department, College of Nursing, CMC, Vellore. A qualitative research using a grounded theory approach was done which included in-depth interviews and focus group discussions from community health nursing faculty. This study used a deductive and inductive approach that stressed the process rather than the meaning of the studied phenomenon. The in-depth interviews lasted for 45 min-1 ½ h for each participant; focus group discussions were held in two sessions lasting for 2 ½ h. The group interviews were transcribed to verbatim. All transcripts were read multiple times to ensure correctness of the transcription by the authors to get an overall impression of the material before the initial coding. Authenticity, credibility, critical appraisal and integrity were demonstrated throughout the study. This study enlightens the experiences of the health care providers on palliative care delivery at the primary care setting and explores barriers, challenges and facilitators for delivery of good palliative home care. Totally, 15 subthemes were grouped under five major themes; community support, family support, acceptance of services, barriers and gaps in care. The in-depth interviews provided an insight into the experiences of the participants on successful collaborative services, caregivers fatigue and the barriers in providing services in the home care setting. Focus group discussion showed that a holistic approach to patient care in primary care setting is possible by community health nurses and a collaborative care from the secondary and tertiary care settings will bring down the non-compliance to the therapeutic regimen.
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Millions of people are exposed to toxic levels of dissolved arsenic in groundwater used for drinking. Iron electrocoagulation (FeEC) has been demonstrated as an effective technology to remove arsenic at an affordable price. However, FeEC requires long operating times (â¼hours) to remove dissolved arsenic due to inherent kinetics limitations. Air cathode Assisted Iron Electrocoagulation (ACAIE) overcomes this limitation by cathodically generating H2O2 in situ. In ACAIE operation, rapid oxidation of Fe(II) and complete oxidation and removal of As(III) are achieved. We compare FeEC and ACAIE for removing As(III) from an initial concentration of 1464 µg/L, aiming for a final concentration of less than 4 µg/L. We demonstrate that at short electrolysis times (0.5 min), i.e., high charge dosage rates (1200 C/L/min), ACAIE consistently outperformed FeEC in bringing arsenic levels to less than WHO-MCL of 10 µg/L. Using XRD and XAS data, we conclusively show that poor arsenic removal in FeEC arises from incomplete As(III) oxidation, ineffective Fe(II) oxidation and the formation of Fe(II-III) (hydr)oxides at short electrolysis times (<20 min). Finally, we report successful ACAIE performance (retention time 19 s) in removing dissolved arsenic from contaminated groundwater in rural California.
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Arsênio , Água Subterrânea , Poluentes Químicos da Água , Purificação da Água , Eletrocoagulação , Peróxido de Hidrogênio , Ferro , OxirreduçãoRESUMO
The G2019S substitution in the Leucine-rich repeat kinase 2 (LRRK2) is significantly associated with Parkinson's disease (PD). This substitution was identified in both familial and sporadic forms of PD with a higher frequency. Few computational studies have reported the impact of G2019S substitution on inhibitors of the kinase domain of LRRK2. However, no computational study deeply investigated the possible impact of the G2019S substitution on the kinase domain in its Apo conformation. Therefore, in this study, we used 200â¯ns molecular dynamic simulation using the GROMACS 5.1.4 package software to investigate the impact of the G2019S substitution on the structure of the kinase domain of LRRK2. Our results indicate that the G2019S substitution affects the dynamics and stability of LRRK2 by decreasing the flexibility and increasing the compactness of the kinase domain and showing its tendency to be in an active conformation for long time interval because of the high energy barrier between active and inactive conformation. This study predicts the molecular pathogenicity mechanism of the G2019S on patients with PD and provides a potential platform for developing therapeutics for patients with PD that harbor this amino acid substitution.
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Substituição de Aminoácidos/genética , Serina-Treonina Proteína Quinase-2 com Repetições Ricas em Leucina/química , Serina-Treonina Proteína Quinase-2 com Repetições Ricas em Leucina/genética , Simulação de Dinâmica Molecular , Doença de Parkinson/genética , Humanos , Ligação de Hidrogênio , Análise de Componente Principal , Domínios Proteicos , Estrutura Secundária de Proteína , Solventes , TermodinâmicaRESUMO
Synthesis and anion binding properties of hybrid macrocycles containing ammonium and hydrogen bond donor groups are reported. Receptor properties were studied in a 10 mM MES buffer solution at pH 6.2, at which the receptors carry two positive charges at the secondary amine groups. Receptor 1 was found to bind fluoride with the highest affinity (105 M-1) and selectivity among the synthesized receptors. It was the only receptor that demonstrated fluorescence increase upon addition of fluoride. Other titration experiments with halides and oxyanions led to an anion-induced aggregation and fluorescence quenching. The mechanism of the particular turn-on fluorescence for fluoride was explained by the ability of receptor 1 to encapsulate several fluoride anions. Multiple anion coordination resulted in the protonation of the tertiary amine group and subsequent hindering of the PET process. 1H and 19F NMR titrations, single-crystal X-ray structure of chloride complex, and DFT calculation suggest that 1 can perfectly accommodate two fluoride anions in the inner cavity but only one chloride, keeping the second chloride in the outer coordination sphere. Thus, the importance of size selectivity, which is reflected in a collective behavior of molecules in an aqueous solution, represents a new strategy for the design of highly selective probes for fluoride functioning in an aqueous solution.
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Camptothecin (CPT), a monoterpene indole alkaloid, is a potent inhibitor of eukaryotic topoisomerase I (Top 1). Because of this property, several derivatives of CPT are widely used as chemotherapeutic agents. The compound is produced by several plant species, including Nothapodytes nimmoniana (Family: Icacinaceae) presumably as a deterrent to insect pests. Here, we report, a lepidopteran larva, Lymantria sp. of Lymantriidae family which feeds voraciously on the leaves of N. nimmoniana, without any adverse consequences. Larval body weight and molting period were unaffected despite captive feeding of the larva with CPT enriched leaves. Mass spectrometric analysis indicated that nearly 46% of the ingested CPT was excreted while the rest was sequestered predominantly in the exuviae and setae (~35%). Although most of the CPT was in the parental form as found in the plant, traces of inactive, sulfated forms of CPT were recovered from the larva. Compared to that in plant, there were no critical mutations at the CPT binding domain of the insect's Top 1. The gut pH of the larva was alkaline (pH 10.0). The alkaline gut environment converts CPT from its active, lactone form to inactive, carboxylate form. It is likely that such conversion might help the larva to reduce the overall burden of CPT in its gut. We discuss the results in the context of the mechanisms of resistance adapted by insects to plant toxins.
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Camptotecina/farmacologia , Magnoliopsida/química , Mariposas/efeitos dos fármacos , Sequência de Aminoácidos , Animais , Sítios de Ligação , Camptotecina/química , Camptotecina/classificação , Camptotecina/metabolismo , Cromatografia Líquida de Alta Pressão , DNA Topoisomerases Tipo I/química , DNA Topoisomerases Tipo I/genética , DNA Topoisomerases Tipo I/metabolismo , Resistência a Medicamentos , Concentração de Íons de Hidrogênio , Proteínas de Insetos/antagonistas & inibidores , Proteínas de Insetos/genética , Proteínas de Insetos/metabolismo , Mucosa Intestinal/metabolismo , Intestinos/química , Larva/metabolismo , Espectroscopia de Ressonância Magnética , Magnoliopsida/metabolismo , Mariposas/crescimento & desenvolvimento , Mariposas/metabolismo , Mutação , Folhas de Planta/química , Folhas de Planta/metabolismo , Espectrometria de Massas por Ionização por ElectrosprayRESUMO
Charcot-Marie-Tooth disease (CMT) is one of the most commonly inherited congenital neurological disorders, affecting approximately 1 in 2500 in the US. About 80 genes were found to be in association with CMT. The phosphoribosyl pyrophosphate synthetase 1 (PRPS1) is an essential enzyme in the primary stage of de novo and salvage nucleotide synthesis. The mutations in the PRPS1 gene leads to X-linked Charcot-Marie-Tooth neuropathy type 5 (CMTX5), PRS super activity, Arts syndrome, X-linked deafness-1, breast cancer, and colorectal cancer. In the present study, we obtained 20 missense mutations from UniProt and dbSNP databases and applied series of comprehensive in silico prediction methods to assess the degree of pathogenicity and stability. In silico tools predicted four missense mutations (D52H, M115 T, L152P, and D203H) to be potential disease causing mutations. We further subjected the four mutations along with native protein to 50 ns molecular dynamics simulation (MDS) using Gromacs package. The resulting trajectory files were analyzed to understand the stability differences caused by the mutations. We used the Root Mean Square Deviation (RMSD), Radius of Gyration (Rg), solvent accessibility surface area (SASA), Covariance matrix, Principal Component Analysis (PCA), Free Energy Landscape (FEL), and secondary structure analysis to assess the structural changes in the protein upon mutation. Our study suggests that the four mutations might affect the PRPS1 protein function and stability of the structure. The proposed study may serve as a platform for drug repositioning and personalized medicine for diseases that are caused by the PRPS1 deficiency.
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Ataxia/genética , Doença de Charcot-Marie-Tooth/genética , Surdocegueira/genética , Doenças Genéticas Ligadas ao Cromossomo X/genética , Mutação/genética , Ribose-Fosfato Pirofosfoquinase/deficiência , Sequência de Aminoácidos , Doença de Charcot-Marie-Tooth/diagnóstico , Humanos , Fenótipo , Ribose-Fosfato Pirofosfoquinase/genéticaRESUMO
The NF1 gene encodes for neurofibromin protein, which is ubiquitously expressed, but most highly in the central nervous system. Non-synonymous SNPs (nsSNPs) in the NF1 gene were found to be associated with Neurofibromatosis Type 1 disease, which is characterized by the growth of tumors along nerves in the skin, brain, and other parts of the body. In this study, we used several in silico predictions tools to analyze 16 nsSNPs in the RAS-GAP domain of neurofibromin, the K1444N (K1423N) mutation was predicted as the most pathogenic. The comparative molecular dynamic simulation (MDS; 50 ns) between the wild type and the K1444N (K1423N) mutant suggested a significant change in the electrostatic potential. In addition, the RMSD, RMSF, Rg, hydrogen bonds, and PCA analysis confirmed the loss of flexibility and increase in compactness of the mutant protein. Further, SASA analysis revealed exchange between hydrophobic and hydrophilic residues from the core of the RAS-GAP domain to the surface of the mutant domain, consistent with the secondary structure analysis that showed significant alteration in the mutant protein conformation. Our data concludes that the K1444N (K1423N) mutant lead to increasing the rigidity and compactness of the protein. This study provides evidence of the benefits of the computational tools in predicting the pathogenicity of genetic mutations and suggests the application of MDS and different in silico prediction tools for variant assessment and classification in genetic clinics.
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Genes da Neurofibromatose 1 , Mutação , Neurofibromatose 1/genética , Neurofibromina 1/genética , Sequência de Aminoácidos , Humanos , Modelos Moleculares , Simulação de Dinâmica Molecular , Conformação ProteicaRESUMO
The 2-hydroxyglutaric aciduria (2-HGA) is a rare neurometabolic disorder that leads to the development of brain damage. It is classified into three categories: D-2-HGA, L-2-HGA, and combined D,L-2-HGA. The D-2-HGA includes two subtypes: type I and type II caused by the mutations in D2HGDH and IDH2 proteins, respectively. In this study, we studied six mutations, four in the D2HGDH (I147S, D375Y, N439D, and V444A) and two in the IDH2 proteins (R140G, R140Q). We performed in silico analysis to investigate the pathogenicity and stability changes of the mutant proteins using pathogenicity (PANTHER, PhD-SNP, SIFT, SNAP, and META-SNP) and stability (i-Mutant, MUpro, and iStable) predictors. All the mutations of both D2HGDH and IDH2 proteins were predicted as disease causing except V444A, which was predicted as neutral by SIFT. All the mutants were also predicted to be destabilizing the protein except the mutants D375Y and N439D. DSSP plugin of the PyMOL and Molecular Dynamics Simulations (MDS) were used to study the structural changes in the mutant proteins. In the case of D2HGDH protein, the mutations I147S and V444A that are positioned in the beta sheet region exhibited higher Root Mean Square Deviation (RMSD), decrease in compactness and number of intramolecular hydrogen bonds compared to the mutations N439D and D375Y that are positioned in the turn and loop region, respectively. While the mutants R140Q and R140QG that are positioned in the alpha helix region of the protein. MDS results revealed the mutation R140Q to be more destabilizing (higher RMSD values, decrease in compactness and number of intramolecular hydrogen bonds) compared to the mutation R140G of the IDH2 protein. This study is expected to serve as a platform for drug development against 2-HGA and pave the way for more accurate variant assessment and classification for patients with genetic diseases.
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Oxirredutases do Álcool/genética , Encefalopatias Metabólicas Congênitas/genética , Isocitrato Desidrogenase/genética , Mutação de Sentido Incorreto , Doenças Raras/genética , Oxirredutases do Álcool/química , Sequência de Aminoácidos , Encefalopatias Metabólicas Congênitas/classificação , Biologia Computacional/métodos , Bases de Dados Genéticas , Descoberta de Drogas , Humanos , Ligação de Hidrogênio , Isocitrato Desidrogenase/química , Simulação de Dinâmica Molecular , Polimorfismo de Nucleotídeo Único , Conformação Proteica em alfa-Hélice/genética , Conformação Proteica em Folha beta/genética , Doenças Raras/classificaçãoRESUMO
Spinal muscular atrophy (SMA) is a neuromuscular disorder caused by the mutations in survival motor neuron 1 gene (SMN1). The molecular pathology of missense mutations in SMN1 is not thoroughly investigated so far. Therefore, we collected all missense mutations in the SMN1 protein, using all possible search terms, from three databases (PubMed, PMC and Google Scholar). All missense mutations were subjected to in silico pathogenicity, conservation, and stability analysis tools. We used statistical analysis as a QC measure for validating the specificity and accuracy of these tools. PolyPhen-2 demonstrated the highest specificity and accuracy. While PolyPhen-1 showed the highest sensitivity; overall, PolyPhen2 showed better measures in comparison to other in silico tools. Three mutations (D44V, Y272C, and Y277C) were identified as the most pathogenic and destabilizing. Further, we compared the physiochemical properties of the native and the mutant amino acids and observed loss of H-bonds and aromatic stacking upon the cysteine to tyrosine substitution, which led to the loss of aromatic rings and may reduce protein stability. The three mutations were further subjected to Molecular Dynamics Simulation (MDS) analysis using GROMACS to understand the structural changes. The Y272C and Y277C mutants exhibited maximum deviation pattern from the native protein as compared to D44V mutant. Further MDS analysis predicted changes in the stability that may have been contributed due to the loss of hydrogen bonds as observed in intramolecular hydrogen bond analysis and physiochemical analysis. A loss of function/structural impact was found to be severe in the case of Y272C and Y277C mutants in comparison to D44V mutation. Correlating the results from in silico predictions, physiochemical analysis, and MDS, we were able to observe a loss of stability in all the three mutants. This combinatorial approach could serve as a platform for variant interpretation and drug design for spinal muscular dystrophy resulting from missense mutations.
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Enzimas Reparadoras do DNA/genética , Atrofia Muscular Espinal/genética , Mutação de Sentido Incorreto , Proteínas Nucleares/genética , Bases de Dados Factuais , Exodesoxirribonucleases , Humanos , Simulação de Dinâmica MolecularAssuntos
Necrose da Cabeça do Fêmur , Cabeça do Fêmur , Humanos , Acetábulo , Pacientes , Estudos RetrospectivosRESUMO
Klebsiella pneumoniae, BA6753 was cultured from a patient in the Clinical Microbiology Laboratory of Christian Medical College. K. pneumoniae, BA6753 has a multidrug resistance plasmid encoding novel FosA variant-7, fosfomycin resistance enzyme. Minimal side effects and a wide range of bactericidal activity of fosfomycin have resulted in its expanded clinical use that prompts the rise of fosfomycin-resistant strains. At present, there are no effective inhibitors available to conflict the FosA-medicated fosfomycin resistance. To develop effective FosA inhibitors, it is crucial to understand the structural and dynamic properties of resistance enzymes. Hence, the present study focuses on the identification of potent inhibitors that can effectively bind to the fosfomycin resistance enzyme, thus predispose the target to inactivate by the second antibiotic. Initially, a series of active compounds were screened against the resistant enzyme, and the binding affinities were confirmed using docking simulation analysis. For efficient activity, the binding affinity of the resistance enzyme ought to be high with the inhibitor than the fosfomycin drug. Consequently, the enzyme-ligand complex which showed higher binding affinity than the fosfomycin was employed for subsequent analysis. The stability of the top scoring enzyme-ligand complex was further validated using molecular dynamics simulation studies. On the whole, we presume that the compound 19583672 demonstrates a higher binding affinity for the resistance enzyme comparing to other compounds and fosfomycin. We believe that further enhancement of the lead compound can serve as a potential inhibitor against resistance enzyme in drug discovery process. J. Cell. Biochem. 118: 4088-4094, 2017. © 2017 Wiley Periodicals, Inc.
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Proteínas de Bactérias/química , Farmacorresistência Bacteriana , Fosfomicina , Klebsiella pneumoniae/enzimologia , Simulação de Acoplamento Molecular , Simulação de Dinâmica Molecular , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Humanos , Klebsiella pneumoniae/genética , Klebsiella pneumoniae/isolamento & purificaçãoRESUMO
This is the first report of a simultaneous ultraviolet/visible/NIR and longwave infrared laser-induced breakdown spectroscopy (UVN + LWIR LIBS) measurement. In our attempt to study the feasibility of combining the newly developed rapid LWIR LIBS linear array detection system to existing rapid analytical techniques for a wide range of chemical analysis applications, two different solid pharmaceutical tablets, Tylenol arthritis pain and Bufferin, were studied using both a recently designed simultaneous UVN + LWIR LIBS detection system and a fast AOTF NIR (1200 to 2200 nm) spectrometer. Every simultaneous UVN + LWIR LIBS emission spectrum in this work was initiated by one single laser pulse-induced micro-plasma in the ambient air atmosphere. Distinct atomic and molecular LIBS emission signatures of the target compounds measured simultaneously in UVN (200 to 1100 nm) and LWIR (5.6 to 10 µm) spectral regions are readily detected and identified without the need to employ complex data processing. In depth profiling studies of these two pharmaceutical tablets without any sample preparation, one can easily monitor the transition of the dominant LWIR emission signatures from coating ingredients gradually to the pharmaceutical ingredients underneath the coating. The observed LWIR LIBS emission signatures provide complementary molecular information to the UVN LIBS signatures, thus adding robustness to identification procedures. LIBS techniques are more surface specific while NIR spectroscopy has the capability to probe more bulk materials with its greater penetration depth. Both UVN + LWIR LIBS and NIR absorption spectroscopy have shown the capabilities of acquiring useful target analyte spectral signatures in comparable short time scales. The addition of a rapid LWIR spectroscopic probe to these widely used optical analytical methods, such as NIR spectroscopy and UVN LIBS, may greatly enhance the capability and accuracy of the combined system for a comprehensive analysis.
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Insecticidal protein genes from the bacterium Bacillus thuringiensis (Bt) are expressed by transgenic Bt crops (Bt crops) for effective and environmentally safe pest control. The development of resistance to these insecticidal proteins is considered the most serious threat to the sustainability of Bt crops. Resistance in fall armyworm (Spodoptera frugiperda) populations from Puerto Rico to transgenic corn producing the Cry1Fa insecticidal protein resulted, for the first time in the United States, in practical resistance, and Bt corn was withdrawn from the local market. In this study, we used a field-collected Cry1Fa corn-resistant strain (456) of S. frugiperda to identify the mechanism responsible for field-evolved resistance. Binding assays detected reduced Cry1Fa, Cry1Ab, and Cry1Ac but not Cry1Ca toxin binding to midgut brush border membrane vesicles (BBMV) from the larvae of strain 456 compared to that from the larvae of a susceptible (Ben) strain. This binding phenotype is descriptive of the mode 1 type of resistance to Bt toxins. A comparison of the transcript levels for putative Cry1 toxin receptor genes identified a significant downregulation (>90%) of a membrane-bound alkaline phosphatase (ALP), which translated to reduced ALP protein levels and a 75% reduction in ALP activity in BBMV from 456 compared to that of Ben larvae. We cloned and heterologously expressed this ALP from susceptible S. frugiperda larvae and demonstrated that it specifically binds with Cry1Fa toxin. This study provides a thorough mechanistic description of field-evolved resistance to a transgenic Bt crop and supports an association between resistance and reduced Cry1Fa toxin binding and levels of a putative Cry1Fa toxin receptor, ALP, in the midguts of S. frugiperda larvae.
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Fosfatase Alcalina/metabolismo , Proteínas de Bactérias/toxicidade , Endotoxinas/toxicidade , Proteínas Hemolisinas/toxicidade , Resistência a Inseticidas , Plantas Geneticamente Modificadas/parasitologia , Spodoptera/efeitos dos fármacos , Zea mays/parasitologia , Animais , Toxinas de Bacillus thuringiensis , Proteínas de Bactérias/genética , Endotoxinas/genética , Trato Gastrointestinal/efeitos dos fármacos , Trato Gastrointestinal/enzimologia , Proteínas Hemolisinas/genética , Ligação Proteica , Porto Rico , Spodoptera/fisiologia , Estados UnidosRESUMO
OBJECTIVES: To estimate the potential economic benefits of closing the Indigenous health gap by quantifying the economic burden associated with Indigenous health inequality in the Northern Territory. DESIGN, SETTING AND PARTICIPANTS: A cost-of-illness study was conducted from a societal perspective for NT residents for the period 2009-2013. The total cost of the Indigenous health gap was estimated by calculating the cost differences between Indigenous and non-Indigenous populations in health services, lost productivity and lost life-years on the basis of data from the 2011 census, as well as on burden of disease, health expenditure, welfare, taxation and other published financial data. MAIN OUTCOME MEASURES: The total and per capita costs in three categories were analysed: direct health costs, the indirect costs of lost productivity, and intangible costs associated with premature deaths. RESULTS: The excess cost of the Indigenous health gap was estimated to be $16.7 billion for the 5-year study period, equivalent to 19% of the NT gross state product. The excess costs associated with the Indigenous health gap included 22% caused by higher health expenditure for servicing the gap, 35% attributable to lost productivity caused by illness, and 43% associated with lost life-years. CONCLUSIONS: Our findings highlight the long term potential benefits of the Australian governments' Closing the Gap initiative for the NT. Successful implementation of this initiative will require improving government services by combating discrimination, developing local economies, overcoming poverty, and reducing the disadvantages associated with remoteness.
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Custos de Cuidados de Saúde/tendências , Necessidades e Demandas de Serviços de Saúde/estatística & dados numéricos , Serviços de Saúde do Indígena/economia , Disparidades nos Níveis de Saúde , Expectativa de Vida/tendências , Efeitos Psicossociais da Doença , Feminino , Custos de Cuidados de Saúde/estatística & dados numéricos , Humanos , Masculino , Northern TerritoryRESUMO
Transcription initiation involves the conversion from closed promoter complexes, comprising RNA polymerase (RNAP) and double-stranded promoter DNA, to open complexes, in which the enzyme is able to access the DNA template in a single-stranded form. The complex between bacterial RNAP and its major variant sigma factor sigma(54) remains as a closed complex until ATP hydrolysis-dependent remodeling by activator proteins occurs. This remodeling facilitates DNA melting and allows the transition to the open complex. Here we present cryoelectron microscopy reconstructions of bacterial RNAP in complex with sigma(54) alone, and of RNAP-sigma(54) with an AAA+ activator. Together with photo-crosslinking data that establish the location of promoter DNA within the complexes, we explain why the RNAP-sigma(54) closed complex is unable to access the DNA template and propose how the structural changes induced by activator binding can initiate conformational changes that ultimately result in formation of the open complex.
Assuntos
RNA Polimerases Dirigidas por DNA/genética , RNA Polimerases Dirigidas por DNA/metabolismo , Ativação Enzimática , Archaea/genética , Archaea/metabolismo , Proteínas Arqueais/genética , Proteínas Arqueais/metabolismo , Bactérias/genética , Bactérias/metabolismo , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Holoenzimas/genética , Holoenzimas/metabolismo , Processamento de Imagem Assistida por Computador , Modelos Moleculares , Regiões Promotoras Genéticas , Conformação Proteica , Subunidades Proteicas/genética , Subunidades Proteicas/metabolismo , RNA Polimerase Sigma 54/química , RNA Polimerase Sigma 54/genética , RNA Polimerase Sigma 54/metabolismo , Moldes GenéticosRESUMO
Intestinal P-glycoprotein (P-gp) and drug-metabolizing enzymes (DMEs) play an important role in the first-pass-metabolism (FPM) and pharmacokinetics (PK) of majority of drugs. Paracetamol is primarily metabolized by conjugation reactions and a little amount (â¼15%) undergoes cytochrome P450 (CYP2E1)-mediated oxidative metabolism produces a hepatotoxic metabolite, N-acetyl-p-benzoquinonimine (NAPQI). Quercetin and chrysin are naturally occurring flavonoids, reported as modulators of P-gp and DMEs. Therefore, the objective of this study was to evaluate the effects of quercetin and chrysin on the pharmacokinetics of paracetamol using rats and non-everted gut sacs in vitro. Paracetamol was given orally (100 mg/kg) to rats alone and in combination with quercetin (5, 10 and 20 mg/kg) and chrysin (50, 100 and 200 mg/kg) once daily for 21 consecutive days. Blood samples were collected on the 1st day in single dose pharmacokinetic study (SDS) and on the 21st day in multiple pharmacokinetic studies (MDS). The plasma concentrations of paracetamol were determined by HPLC and PK parameters were calculated by using Kinetica (Version 5.1). The maximum plasma concentration (Cmax) and area under the curve (AUC0-12) of paracetamol was significantly increased by quercetin and chrysin co-administration in SDS and MDS. In non-everted rat gut sac method, the absorption of paracetamol was increased by presence of P-gp inhibitors (verapamil, quinidine and ketoconazole), quercetin and chrysin (50 µg/mL). Our findings suggested that the quercetin and chrysin might be inhibited the P-gp and metabolism of paracetamol; thereby increased the systemic exposure of paracetamol. Further studies are needed to evaluate whether the quercetin or chrysin are involved in the formation of NAPQI by CYP2E1 or not on isolated rat hepatocytes or using cell lines.