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1.
Environ Monit Assess ; 196(3): 266, 2024 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-38353774

RESUMO

The increasing impact of human activities on ecosystems is provoking a profound and dangerous effect, particularly in wildlife. Examining the historical migration patterns of quail (Coturnix coturnix) offers a compelling case study to demonstrate the repercussions of human actions on biodiversity. Urbanization trends, where people gravitate toward mega-urban areas, amplify this effect. The proliferation of artificial urban ecosystems extends its influence across every biome, as human reliance on infrastructure and food sources alters ecological dynamics extensively. We examine European quail migrations pre- and post-World War II and in the present day. Our study concentrates on the Italian peninsula, investigating the historical and contemporary recovery of ringed quail populations. To comprehend changes in quail migration, we utilize trajectory analysis, open statistical data, and linear generalized models. We found that while human population and economic growth have shown a linear increase, quail recovery rates exhibit a U-shaped trajectory, and cereal and legume production displays an inverse U-shaped pattern. Generalized linear models have unveiled the significant influence of several key factors-time periods, cereal and legume production, and human demographics-on quail recovery rates. These factors closely correlate with the levels of urbanization observed across these timeframes. These insights underscore the profound impact of expanding human populations and the rise of mega-urbanization on ecosystem dynamics and services. As our planet becomes more urbanized, the pressure on ecosystems intensifies, highlighting the urgent need for concerted efforts directed toward conserving and revitalizing ecosystem integrity. Simultaneously, manage the needs and demands of burgeoning mega-urban areas. Achieving this balance is pivotal to ensuring sustainable coexistence between urban improvement and the preservation of our natural environment.


Assuntos
Coturnix , Fabaceae , Humanos , Animais , Codorniz , Cidades , Ecossistema , Monitoramento Ambiental , Biodiversidade , Grão Comestível , Verduras
2.
Eur J Orthop Surg Traumatol ; 34(1): 577-583, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37656276

RESUMO

PURPOSE: To compare clinical and radiological outcomes, implant survivorship at a minimum of 1-year follow-up using metaphyseal trabecular cones with or without impaction grafting in a complex revision TKA. METHODS: A retrospective comparative matched analysis was performed and 15 patients who underwent revision surgery using the combination of porous trabecular metaphyseal cone and diaphyseal impaction grafting (MC-IBG) were matched with a group of 13 patients who also underwent revision surgery using metaphyseal cone (MC) without impaction grafting. All included patients presented severe bone defect (AORI 2,3) and a rotating-hinge prosthesis were implanted. RESULTS: Both groups were comparable regarding the baseline demographic and clinical data. Patients had previously undergone a mean of 4 (range, 2-12) and 3 (range, 2-5) previous procedures in the MC-IBG and MC groups, respectively. The indications for revision were aseptic loosening in 11 (73.3%) and 11 (84.6%) patients; prosthetic joint infection in 4 (26.7%) and 2 (15.4%) in the MC-IBG and MC groups, respectively. There was no significant difference in the mean postoperative Knee Society Score between the study groups (p = 0.806). Overall, 4 patients had further revision. Two patients were revised in the MC-IBG group, one patient for aseptic loosening and the second one after 2 episodes of instability. Two patients in the MC group presented prosthetic joint infection and underwent a two-stage reimplantation. No significant difference was observed between the study groups at comparison (p = 0.92). CONCLUSION: Trabecular metal cones with diaphyseal impaction grafting provide an alternative technique in a complex revision TKA surgery with early clinical and radiographic success.


Assuntos
Artroplastia do Joelho , Prótese do Joelho , Humanos , Artroplastia do Joelho/efeitos adversos , Artroplastia do Joelho/métodos , Estudos Retrospectivos , Resultado do Tratamento , Desenho de Prótese , Prótese do Joelho/efeitos adversos , Reoperação , Articulação do Joelho/cirurgia
3.
Org Biomol Chem ; 20(44): 8662-8671, 2022 Nov 16.
Artigo em Inglês | MEDLINE | ID: mdl-36281944

RESUMO

Hydride transfer reactions involving 1,4-dihydropyridines play a central role in bioorganic chemistry as they represent an important share of redox metabolism. For this class of reactions, direct hydride transfer is the commonly accepted mechanism; however, an Alder-Ene-like pathway has been proposed as a plausible alternative. The reaction between 1,4-ditrimethylsilyl-1,4-dihydropyridine and α,ß-unsaturated nitriles is a solid candidate for this latter pathway. In this work, we perform high level ab initio and density functional theory computations to characterize the mechanism of this reaction, taking into account diverse reaction paths, and evaluating the effect of solvent polarity and variations in the chemical structure. Our analysis explains the stereochemical aspects of the reaction, characterizing the up to now unresolved spatial configurations of the predominant products, and may contribute to the understanding of enzymatic reactions involving NADP(H). The reactions are found to proceed in an asynchronous fashion, with transition states that display significant aromatic features. With this observation in mind, Alder-Ene and direct hydride transfer pathways can be understood as two extremes of a continuous mechanistic spectrum for this kind of reaction, with the analyzed systems located approximately equidistant from both ends.


Assuntos
Di-Hidropiridinas , Nitrilas , Nitrilas/química , Di-Hidropiridinas/química , Oxirredução
4.
Proc Natl Acad Sci U S A ; 116(28): 13964-13969, 2019 07 09.
Artigo em Inglês | MEDLINE | ID: mdl-31243147

RESUMO

Carboxylases are biocatalysts that capture and convert carbon dioxide (CO2) under mild conditions and atmospheric concentrations at a scale of more than 400 Gt annually. However, how these enzymes bind and control the gaseous CO2 molecule during catalysis is only poorly understood. One of the most efficient classes of carboxylating enzymes are enoyl-CoA carboxylases/reductases (Ecrs), which outcompete the plant enzyme RuBisCO in catalytic efficiency and fidelity by more than an order of magnitude. Here we investigated the interactions of CO2 within the active site of Ecr from Kitasatospora setae Combining experimental biochemistry, protein crystallography, and advanced computer simulations we show that 4 amino acids, N81, F170, E171, and H365, are required to create a highly efficient CO2-fixing enzyme. Together, these 4 residues anchor and position the CO2 molecule for the attack by a reactive enolate created during the catalytic cycle. Notably, a highly ordered water molecule plays an important role in an active site that is otherwise carefully shielded from water, which is detrimental to CO2 fixation. Altogether, our study reveals unprecedented molecular details of selective CO2 binding and C-C-bond formation during the catalytic cycle of nature's most efficient CO2-fixing enzyme. This knowledge provides the basis for the future development of catalytic frameworks for the capture and conversion of CO2 in biology and chemistry.


Assuntos
Aminoácidos/química , Dióxido de Carbono/química , Ácidos Graxos Dessaturases/química , Modelos Moleculares , Aminoácidos/genética , Aminoácidos/metabolismo , Dióxido de Carbono/metabolismo , Proteínas de Transporte/química , Catálise , Domínio Catalítico/genética , Enzimas/química , Ácidos Graxos Dessaturases/metabolismo , Streptomycetaceae/química , Streptomycetaceae/enzimologia
5.
J Phys Chem A ; 124(5): 849-857, 2020 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-31951411

RESUMO

Local reactivity descriptors such as atom-condensed Fukui functions are promising computational tools to study chemical reactivity at specific sites within a molecule. Their applications have been mainly focused on isolated molecules in their most stable conformation without considering the effects of the surroundings. Here we propose to combine quantum mechanics/molecular mechanics Born-Oppenheimer molecular dynamics simulations to obtain the microstates (configurations) of a molecular system using different representations of the molecular environment and calculate Boltzmann-weighted atom-condensed local reactivity descriptors based on conceptual density functional theory. Our approach takes the conformational fluctuations of the molecular system and the polarization of its electron density by the environment into account, allowing us to analyze the effect of the molecular environment on reactivity. In this contribution, we apply the method mentioned above to the catalytic fixation of carbon dioxide by crotonyl-CoA carboxylase/reductase and study if the enzyme alters the reactivity of its substrate compared with an aqueous solution. Our main result is that the protein environment activates the substrate by the elimination of solute-solvent hydrogen bonds from aqueous solution in the two elementary steps of the reaction mechanism: the nucleophilic attack of a hydride anion from NADPH on the α,ß-unsaturated thioester and the electrophilic attack of carbon dioxide on the formed enolate species.


Assuntos
Dióxido de Carbono/química , Carbono-Carbono Ligases/química , Acil Coenzima A/química , Teoria da Densidade Funcional , Ligação de Hidrogênio , Modelos Químicos , Simulação de Dinâmica Molecular , NADP/química
6.
J Am Chem Soc ; 141(25): 9778-9782, 2019 06 26.
Artigo em Inglês | MEDLINE | ID: mdl-31188584

RESUMO

Developing new carbon dioxide (CO2) fixing enzymes is a prerequisite to create new biocatalysts for diverse applications in chemistry, biotechnology and synthetic biology. Here we used bioinformatics to identify a "sleeping carboxylase function" in the superfamily of medium-chain dehydrogenases/reductases (MDR), i.e. enzymes that possess a low carboxylation side activity next to their original enzyme reaction. We show that propionyl-CoA synthase from Erythrobacter sp. NAP1, as well as an acrylyl-CoA reductase from Nitrosopumilus maritimus possess carboxylation yields of 3 ± 1 and 4.5 ± 0.9%. We use rational design to engineer these enzymes further into carboxylases by increasing interactions of the proteins with CO2 and suppressing diffusion of water to the active site. The engineered carboxylases show improved CO2-binding and kinetic parameters comparable to naturally existing CO2-fixing enzymes. Our results provide a strategy to develop novel CO2-fixing enzymes and shed light on the emergence of natural carboxylases during evolution.


Assuntos
Carboxiliases/química , Oxirredutases/química , Archaea/enzimologia , Proteínas Arqueais/química , Proteínas Arqueais/genética , Proteínas Arqueais/metabolismo , Proteínas de Bactérias/química , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Ciclo do Carbono , Dióxido de Carbono/química , Dióxido de Carbono/metabolismo , Carboxiliases/genética , Carboxiliases/metabolismo , Domínio Catalítico/genética , Cinética , Simulação de Dinâmica Molecular , Mutagênese Sítio-Dirigida , Oxirredutases/genética , Oxirredutases/metabolismo , Sphingomonadaceae/enzimologia , Água/química , Água/metabolismo
7.
J Comput Chem ; 40(13): 1401-1413, 2019 05 15.
Artigo em Inglês | MEDLINE | ID: mdl-30770583

RESUMO

Carboxylation reactions represent a very special class of chemical reactions that is characterized by the presence of a carbon dioxide (CO2 ) molecule as reactive species within its global chemical equation. These reactions work as fundamental gear to accomplish the CO2 fixation and thus to build up more complex molecules through different technological and biochemical processes. In this context, a correct description of the CO2 electronic structure turns out to be crucial to study the chemical and electronic properties associated with this kind of reactions. Here, a systematic study of CO2 electronic structure and its contribution to different carboxylation reaction electronic energies has been carried out by means of several high-level ab initio post-Hartree Fock (post-HF) and density functional theory (DFT) calculations for a set of biochemistry and inorganic systems. We have found that for a correct description of the CO2 electronic correlation energy it is necessary to include post-CCSD(T) contributions (beyond the gold standard). These high-order excitations are required to properly describe the interactions of the four π-electrons associated with the two degenerated π-molecular orbitals of the CO2 molecule. Likewise, our results show that in some reactions it is possible to obtain accurate reaction electronic energy values with computationally less demanding methods when the error in the electronic correlation energy compensates between reactants and products. Furthermore, the provided post-HF reference values allowed to validating different DFT exchange-correlation functionals combined with different basis sets for chemical reactions that are relevant in biochemical CO2 fixing enzymes. © 2019 Wiley Periodicals, Inc.


Assuntos
Dióxido de Carbono/química , Ácidos Carboxílicos/química , Teoria da Densidade Funcional , Elétrons
8.
J Antimicrob Chemother ; 74(12): 3489-3496, 2019 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-31504589

RESUMO

OBJECTIVES: NDM carbapenemases have spread worldwide. However, little information exists about the impact of NDM-producing Enterobacteriaceae in Spain. By WGS, we sought to elucidate the population structure of NDM-like-producing Klebsiella pneumoniae and Escherichia coli in Spain and to determine the plasmids harbouring blaNDM-like genes. METHODS: High-resolution SNP typing, core-genome MLST and plasmid reconstruction (PlasmidID) were performed on 59 NDM-like-producing K. pneumoniae and 8 NDM-like-producing E. coli isolated over an 8 year period in Spain. RESULTS: Five major epidemic clones of NDM-producing K. pneumoniae caused five important nationwide outbreaks: ST437/NDM-7, ST437/NDM-1, ST147/NDM-1, ST11/NDM-1 and ST101/NDM-1; in contrast, the spread of NDM-producing E. coli was polyclonal. Three blaNDM types were identified: blaNDM-1, 61.2%; blaNDM-7, 32.8%; and blaNDM-5, 6%. Five K. pneumoniae isolates co-produced other carbapenemases (three blaOXA-48 and two blaVIM-1). The average number of acquired resistance genes was higher in K. pneumoniae than in E. coli. The plasmids encoding blaNDM-like genes belonged to IncFII, IncFIB, IncX3, IncR, IncN and IncC types, of which IncF, IncR and IncC were associated with MDR. The genetic surroundings of blaNDM-like genes showed a highly variable region upstream of ISAba125. CONCLUSIONS: In recent years NDM-producing K. pneumoniae and E. coli have emerged in Spain; the spread of a few high-risk K. pneumoniae clones such as ST437/NDM-7, ST437/NDM-1, ST147/NDM-1, ST11/NDM-1 and ST101/NDM-1 have caused several interregional outbreaks. In contrast, the spread of NDM-producing E. coli has been polyclonal. Plasmid types IncFII, IncFIB, IncX3, IncR, IncN and IncC carried blaNDM, and the same IncX3 plasmid was detected in K. pneumoniae and E. coli.


Assuntos
Escherichia coli/genética , Klebsiella pneumoniae/genética , Filogenia , Plasmídeos/genética , beta-Lactamases/genética , Antibacterianos/farmacologia , Técnicas de Tipagem Bacteriana , Farmacorresistência Bacteriana Múltipla , Infecções por Enterobacteriaceae/microbiologia , Escherichia coli/classificação , Escherichia coli/enzimologia , Genoma Bacteriano , Humanos , Klebsiella pneumoniae/classificação , Klebsiella pneumoniae/enzimologia , Testes de Sensibilidade Microbiana , Tipagem de Sequências Multilocus , Polimorfismo de Nucleotídeo Único , Espanha , Virulência/genética , Sequenciamento Completo do Genoma
9.
Artigo em Inglês | MEDLINE | ID: mdl-28137818

RESUMO

We studied in parallel the population structure of 90 carbapenemase-producing and 88 carbapenemase-susceptible Klebsiella pneumoniae isolates collected in 20 Spanish hospitals, in the context of the EuSCAPE project. Fourteen and 50 multilocus sequence types (MLSTs) were detected among the carbapenemase-producing and carbapenem-susceptible isolates, respectively. ST11 and ST15 clones were more frequent in the carbapenemase-producing group than in the carbapenemase-susceptible group (P < 0.0001). Among the members of the carbapenem-suceptible group, the cefotaxime-resistant population showed population parameters that differed between the populations of the wild-type strains and the carbapenemase producers.


Assuntos
Antibacterianos/farmacologia , Proteínas de Bactérias/metabolismo , Carbapenêmicos/farmacologia , Klebsiella pneumoniae/efeitos dos fármacos , beta-Lactamases/metabolismo , Proteínas de Bactérias/genética , Cefotaxima/farmacologia , Farmacorresistência Bacteriana/genética , Klebsiella pneumoniae/enzimologia , Testes de Sensibilidade Microbiana , Tipagem de Sequências Multilocus , beta-Lactamases/genética
10.
J Antimicrob Chemother ; 72(12): 3283-3287, 2017 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-29029114

RESUMO

OBJECTIVES: There is little information about carbapenemase-producing (CP) Citrobacter spp. We studied the molecular epidemiology and microbiological features of CP Citrobacter spp. isolates collected in Spain (2013-15). METHODS: In total, 119 isolates suspected of being CP by the EUCAST screening cut-off values were analysed. Carbapenemases and ESBLs were characterized using PCR and sequencing. The genetic relationship among Citrobacter freundii isolates was studied by PFGE. RESULTS: Of the 119 isolates, 63 (52.9%) produced carbapenemases, of which 37 (58.7%) produced VIM-1, 20 (31.7%) produced OXA-48, 12 (19%) produced KPC-2, 2 (3.2%) produced NDM-1 and 1 (1.6%) produced VIM-2; 9 C. freundii isolates co-produced VIM-1 plus OXA-48. Fourteen isolates (22.2%) also carried ESBLs: 8 CTX-M-9 plus SHV-12, 2 CTX-M-9, 2 SHV-12 and 2 CTX-M-15. Fifty-seven isolates (90.5%) were C. freundii, 4 (6.3%) were Citrobacter koseri, 1 (1.6%) was Citrobacter amalonaticus and 1 (1.6%) was Citrobacter braakii. By EUCAST breakpoints, eight (12.7%) of the CP isolates were susceptible to the four carbapenems tested. In the 53 CP C. freundii analysed by PFGE, a total of 44 different band patterns were observed. Four PFGE clusters were identified: cluster 1 included eight isolates co-producing VIM-1 and OXA-48; blaVIM-1 was carried in a class 1 integron (intI-blaVIM-1-aacA4-dfrB1-aadA1-catB2-qacEΔ1/sul1) and blaOXA-48 was carried in a Tn1999.2 transposon. CONCLUSIONS: We observed the clonal and polyclonal spread of CP Citrobacter spp. across several Spanish geographical areas. Four species of Citrobacter spp. produced up to five carbapenemase types, including co-production of VIM-1 plus OXA-48. Some CP Citrobacter spp. isolates were susceptible to the four carbapenems tested, a finding with potential clinical implications.


Assuntos
Proteínas de Bactérias/genética , Enterobacteriáceas Resistentes a Carbapenêmicos/enzimologia , Enterobacteriáceas Resistentes a Carbapenêmicos/genética , Citrobacter/enzimologia , Citrobacter/genética , Infecções por Enterobacteriaceae/microbiologia , Variação Genética , beta-Lactamases/genética , Enterobacteriáceas Resistentes a Carbapenêmicos/classificação , Enterobacteriáceas Resistentes a Carbapenêmicos/isolamento & purificação , Citrobacter/classificação , Citrobacter/isolamento & purificação , Eletroforese em Gel de Campo Pulsado , Infecções por Enterobacteriaceae/epidemiologia , Genótipo , Humanos , Epidemiologia Molecular , Tipagem Molecular , Reação em Cadeia da Polimerase , Análise de Sequência de DNA , Espanha/epidemiologia
11.
J Antimicrob Chemother ; 71(8): 2131-8, 2016 08.
Artigo em Inglês | MEDLINE | ID: mdl-27147304

RESUMO

OBJECTIVES: The objective of this study was to analyse the microbiological traits and the population structure of carbapenemase-producing (CP) Escherichia coli isolates collected in Spain between 2012 and 2014. METHODS: Two-hundred-and-thirty-nine E. coli isolates non-susceptible to carbapenems were studied. The carbapenemase genes and the phylogenetic groups were characterized using PCR. MLST was carried out using the typing schemes of the University of Warwick and the Institut Pasteur. The diversity of the population structure was estimated by calculating a simple diversity index (SDI). RESULTS: One-hundred-and-twenty-one isolates (50.6%) produced carbapenemases, of which 87 (71.9%) were OXA-48, 27 (22.3%) were VIM-1, 4 (3.3%) were KPC-2, 2 (1.7%) were NDM and 1 (0.8%) was IMP-22; 4 isolates were collected in 2012, 40 in 2013 and 77 in 2014. Ertapenem was more sensitive than imipenem or meropenem for screening for OXA-48-producing E. coli. Using the Warwick typing scheme, 59 different STs were identified, the most prevalent being ST131 (16.5%). The population diversity was higher among VIM-1-producing isolates (SDI = 81.5%) than among OXA-48-producing isolates (SDI = 44.8%). The Pasteur scheme had a higher discrimination capability (SDI = 55.4%) than the Warwick scheme (SDI = 48.8%). CONCLUSIONS: A progressive increase in the prevalence of CP E. coli was observed, mainly due to the dissemination of OXA-48 producers. The most sensitive method for detecting decreased susceptibility of CP E. coli to carbapenems was disc diffusion with ertapenem using the EUCAST screening cut-offs. The spread of CP E. coli was due to a polyclonal population. The Pasteur scheme showed the highest discrimination power. Surveillance is crucial for the early detection of CP E. coli.


Assuntos
Proteínas de Bactérias/metabolismo , Infecções por Escherichia coli/epidemiologia , Infecções por Escherichia coli/microbiologia , Proteínas de Escherichia coli/metabolismo , Escherichia coli/enzimologia , Variação Genética , Filogenia , beta-Lactamases/metabolismo , Idoso , Idoso de 80 Anos ou mais , Antibacterianos/farmacologia , Proteínas de Bactérias/genética , Testes de Sensibilidade a Antimicrobianos por Disco-Difusão , Ertapenem , Escherichia coli/classificação , Escherichia coli/genética , Escherichia coli/isolamento & purificação , Proteínas de Escherichia coli/genética , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Epidemiologia Molecular , Tipagem de Sequências Multilocus , Reação em Cadeia da Polimerase , Prevalência , Espanha/epidemiologia , beta-Lactamases/genética , beta-Lactamas/farmacologia
12.
J Antimicrob Chemother ; 71(12): 3392-3399, 2016 12.
Artigo em Inglês | MEDLINE | ID: mdl-27530752

RESUMO

OBJECTIVES: We analysed the microbiological traits and population structure of KPC-producing Enterobacteriaceae isolates collected in Spain between 2012 and 2014. We also performed a comparative WGS analysis of the three major KPC-producing Klebsiella pneumoniae clones detected. METHODS: Carbapenemase and ESBL genes were sequenced. The Institut Pasteur MLST scheme was used. WGS data were used to construct phylogenetic trees, to identify the determinants of resistance and to de novo assemble the genome of one representative isolate of each of the three major K. pneumoniae clones. RESULTS: Of the 2443 carbapenemase-producing Enterobacteriaceae isolates identified during the study period, 111 (4.5%) produced KPC. Of these, 81 (73.0%) were K. pneumoniae and 13 (11.7%) were Enterobacter cloacae. Three major epidemic clones of K. pneumoniae were identified: ST11/KPC-2, ST101/KPC-2 and ST512/KPC-3. ST11/KPC-2 differed from ST101/KPC-2 and ST512/KPC-3 by 27 819 and 6924 SNPs, respectively. ST101/KPC-2 differed from ST512/KPC-3 by 28 345 SNPs. Nine acquired resistance genes were found in ST11/KPC-2, 11 in ST512/KPC-3 and 13 in ST101/KPC-2. ST101/KPC-2 had the highest number of virulence genes (20). An 11 bp deletion at the end of the mgrB sequence was the cause of colistin resistance in ST512/KPC-3. CONCLUSIONS: KPC-producing Enterobacteriaceae are increasing in Spain. Most KPC-producing K. pneumoniae isolates belonged to only five clones: ST11 and ST512 caused interregional spread, ST101 caused regional spread and ST1961 and ST678 produced independent hospital outbreaks. ST101/KPC-2 had the highest number of resistance and virulence genes. ST101/KPC-2 and ST512/KPC-3 were recently implicated in the spread of KPC in Italy.


Assuntos
Infecções por Enterobacteriaceae/epidemiologia , Infecções por Enterobacteriaceae/microbiologia , Enterobacteriaceae/enzimologia , Genoma Bacteriano , Genótipo , Análise de Sequência de DNA , beta-Lactamases/genética , Infecção Hospitalar/epidemiologia , Infecção Hospitalar/microbiologia , Enterobacteriaceae/classificação , Enterobacteriaceae/genética , Enterobacteriaceae/isolamento & purificação , Humanos , Epidemiologia Molecular , Tipagem de Sequências Multilocus , Prevalência , Espanha/epidemiologia
13.
Phys Chem Chem Phys ; 18(34): 24033-42, 2016 Sep 14.
Artigo em Inglês | MEDLINE | ID: mdl-27524496

RESUMO

Methyl transfer reactions play an important role in biology and are catalyzed by various enzymes. Here, the influence of the molecular environment on the reaction mechanism was studied using advanced ab initio methods, implicit solvation models and QM/MM molecular dynamics simulations. Various conceptual DFT and electronic structure descriptors identified different processes along the reaction coordinate e.g. electron transfer. The results show that the polarity of the solvent increases the energy required for the electron transfer and that this spontaneous process is located in the transition state region identified by the (mean) reaction force analysis and takes place through the bonds which are broken and formed. The inclusion of entropic contributions and hydrogen bond interactions in QM/MM molecular dynamics simulations with a validated DFTB3 Hamiltonian yields activation barriers in good agreement with the experimental values in contrast to the values obtained using two implicit solvation models.

14.
J Comput Aided Mol Des ; 29(10): 951-61, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26276557

RESUMO

S-Adenosylmethionine (AdoMet) is involved in many biological processes as cofactor in enzymes transferring its sulfonium methyl group to various substrates. Additionally, it is used as drug and nutritional supplement to reduce the pain in osteoarthritis and against depression. Due to the biological relevance of AdoMet it has been part of various computational simulation studies and will also be in the future. However, to our knowledge no rigorous force field parameter development for its simulation in biological systems has been reported. Here, we use electronic structure calculations combined with molecular dynamics simulations in explicit solvent to develop force field parameters compatible with the AMBER99 force field. Additionally, we propose new dynamic Hirshfeld-I atomic charges which are derived from the polarized electron density of AdoMet in aqueous solution to describe its electrostatic interactions in biological systems. The validation of the force field parameters and the atomic charges is performed against experimental interproton NOE distances of AdoMet in aqueous solution and crystal structures of AdoMet in the cavity of three representative proteins.


Assuntos
Simulação de Dinâmica Molecular , S-Adenosilmetionina/química , Dicroísmo Circular , Espectroscopia de Ressonância Magnética , Conformação Molecular , Reprodutibilidade dos Testes , Solventes , Espectrofotometria Ultravioleta , Eletricidade Estática
15.
Artigo em Inglês | MEDLINE | ID: mdl-38506473

RESUMO

OBJECTIVE: This study aimed to estimate amyotrophic lateral sclerosis (ALS) incidence and survival rates in the Metropolitan region of Chile. METHODS: We conducted a cohort study of ALS cases in the Metropolitan Region from 2016 to 2019. A total of 219 ALS patients were recruited from Corporación ELA-Chile registry, in collaboration with neurologists from Sociedad de Neurología, Psiquiatría y Neurocirugía de Chile. We calculated incidence rates by sex and age and determined median survival from onset and diagnosis. Survival analysis used the Kaplan-Meier statistic, estimating hazard ratios for age, sex, time from symptom onset and from diagnosis using a Weibull regression model. All analyses were done using R 4.1.0. RESULTS: Overall, ALS diagnosis incidence was 0.97 cases per 100,000 inhabitants, peaking in the 70-79 age group and declining thereafter. The male-to-female ratio was 1.23. The median time to death from diagnosis was 2.3 years (95% confidence interval [CI]: 1.9-2.5), and from the first symptom, it was 3.1 years (95% CI: 2.8-3.5). CONCLUSIONS: This is the first population-based study reporting ALS incidence and survival rates in Chile's Metropolitan region. Incidence resembled other Latin American studies. Median survival from diagnosis and from the first symptom were in line with previous findings. Our results corroborated lower ALS rates in Latin America, consistent with prior research.

16.
Artigo em Inglês | MEDLINE | ID: mdl-37865869

RESUMO

OBJECTIVE: The Latin American Epidemiologic study of ALS (LAENALS) aims to gather data on ALS epidemiology, phenotype, and risk factors in Cuba, Chile, and Uruguay, to understand the impact of genetic and environmental factors on ALS. METHODS: A harmonized data collection protocol was generated, and a Latin-American Spanish language Register was constructed. Patient data were collected in Uruguay in 2018, in Chile from 2017 to 2019, and in Cuba between 2017 and 2018. Statistical analysis was performed using SPSS 25.0.0 software. Crude cumulative incidence, standardized incidence, and prevalence were calculated in the population aged 15 years and older. RESULTS: During 2017-2019, 90 people with ALS from Uruguay (55.6% men), 219 from Chile (54.6% men), and 49 from Cuba (55.1% men) were included. The cumulative crude incidence in 2018 was 1.73/100,000 persons in Uruguay, 1.08 in Chile and 0.195 in Cuba. Crude prevalence in 2018 was 2.19 per 100,000 persons in Uruguay, 1.39 in Chile and 0.55 in Cuba. Mean age at onset was 61.8 ± 11.96 SD years in Uruguay, 61.9 ± 10.4 SD years in Chile, and 60.21 ± 12.45 SD years in Cuba (p = 0.75). Median survival from onset was 32.43 months (21.93 - 42.36) in Uruguay, 24 months (13.5 - 33.5) in Chile, and 29 months (15 - 42.5) in Cuba (p = 0.006). CONCLUSIONS: These preliminary data from LAENALS confirm the lower incidence and prevalence of ALS in counties with admixed populations. The LAENALS database is now open to other Latin American countries for harmonized prospective data collection.


Assuntos
Esclerose Lateral Amiotrófica , Masculino , Humanos , Feminino , América Latina/epidemiologia , Esclerose Lateral Amiotrófica/diagnóstico , Esclerose Lateral Amiotrófica/epidemiologia , Cuba/epidemiologia , Uruguai/epidemiologia , Prevalência
17.
Antimicrob Agents Chemother ; 57(12): 6344-7, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24041898

RESUMO

We report the epidemiological impact of carbapenemase-producing Enterobacteriaceae (CPE) in Spain in 2012. Of the 237 carbapenemases detected, 163 were from the OXA-48 group, 60 were from VIM-1, 8 were from KPC-2, 5 were from IMP, and 1 was from NDM-1. Interhospital spread of carbapenemase-producing Klebsiella pneumoniae was due to a limited number of multilocus sequence types (MLST) and carbapenemase types, including ST15-VIM-1, ST11-OXA-48, ST405-OXA-48, ST101-KPC-2, and ST11-VIM-1. The number of CPE cases in Spain has increased sharply in recent years, due mainly to the emergence of OXA-48.


Assuntos
Proteínas de Bactérias/metabolismo , Enterobacteriaceae/enzimologia , beta-Lactamases/metabolismo , Antibacterianos/farmacologia , Proteínas de Bactérias/genética , Enterobacteriaceae/efeitos dos fármacos , Enterobacteriaceae/genética , Humanos , Testes de Sensibilidade Microbiana , Tipagem de Sequências Multilocus , Espanha , beta-Lactamases/genética
18.
J Antimicrob Chemother ; 68(2): 317-21, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23034714

RESUMO

OBJECTIVES: To describe the molecular and population-level characterization of a selected group of OXA-48-like-producing Klebsiella pneumoniae isolates collected in Spain between January 2011 and May 2012. METHODS: During the study period, 151 OXA-48-like-producing K. pneumoniae isolates were collected from 10 hospitals in six different Spanish regions. From these, a representative sample of 21 isolates that caused hospital outbreaks and single infections was selected for further in-depth analysis. Molecular epidemiology was investigated using PFGE and multilocus sequence typing (MLST). Resistance genes were characterized by PCR and sequencing. Plasmids carrying bla(OXA-48-like) were studied by PFGE with S1 nuclease digestion. RESULTS: All 21 isolates had ertapenem MICs ≥ 1 mg/L, but 47.6% remained susceptible to imipenem and meropenem; bla(OXA-48) was identified in 19 isolates (90.5%) and the novel bla(OXA-244) and bla(OXA-245) genes were detected in 1 isolate each. With one exception, all isolates that contained bla(OXA-48-like) also contained bla(CTX-M-15). PFGE typing revealed six clusters comprising isolates that belonged to MLST types ST11, ST16, ST392, ST405, ST437 and ST663, respectively. Two main clusters were identified: PFGE cluster 1 (12 isolates, belonging either to ST405 or ST663, from seven hospitals), and PFGE cluster 2 (4 ST16 isolates from two hospitals). Six of seven donor isolates conjugated successfully; bla(OXA-48-like) (but not bla(CTX-M-15)) was carried on ≈ 60 kb Inc L/M plasmids. CONCLUSIONS: Multidrug-resistant K. pneumoniae producing OXA-48-like carbapenemase are emerging as important pathogens in Spain due to intra- and inter-hospital, clonal and non-clonal dissemination.


Assuntos
Proteínas de Bactérias/genética , Infecções por Klebsiella/epidemiologia , Infecções por Klebsiella/microbiologia , Klebsiella pneumoniae/enzimologia , beta-Lactamases/genética , Idoso , Idoso de 80 Anos ou mais , Antibacterianos/farmacologia , Proteínas de Bactérias/metabolismo , Análise por Conglomerados , DNA Bacteriano/química , DNA Bacteriano/genética , Farmacorresistência Bacteriana Múltipla , Feminino , Hospitais , Humanos , Klebsiella pneumoniae/classificação , Klebsiella pneumoniae/genética , Klebsiella pneumoniae/isolamento & purificação , Masculino , Testes de Sensibilidade Microbiana , Pessoa de Meia-Idade , Epidemiologia Molecular , Dados de Sequência Molecular , Tipagem de Sequências Multilocus , Plasmídeos , Reação em Cadeia da Polimerase , Espanha/epidemiologia , beta-Lactamases/metabolismo
19.
Sci Total Environ ; 893: 164913, 2023 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-37327910

RESUMO

Public health risks are related to environmental management practices, and are essential to the understanding of ecosystem dynamics. The expansion of urbanized areas affects migratory bird networks and can impact the population sizes of migratory species and, in parallel, increase the risk of diseases carried by migratory species spreading into urban areas. Taking the European population of the common quail as a case study, we reconstructed its migratory network between Europe and the Maghreb using quail recoveries from the Italian Bird Ringing Scheme. We showed that soils at the central European migratory node have been degraded through urbanization and reforestation, decreasing the number of successful migrations over this area. Conceptual models incorporating the One Health approach, natural and social capital, landscape infrastructure, and ecosystem services could explain the relationships between climate warming and extensively developed, intensively developed, and urbanized ecosystems. Failed migratory flights of quail over central Europe highlight not only the problems of infrastructure design and their impact on ecosystems services, but also on One Health parameters. The damage to migratory network nodes presents a global threat to biodiversity and can increase the spread of diseases. To address this challenge we propose: i) improvements in land quality; ii) transboundary migration monitoring programmes; and iii) management plans for migratory birds - the overall aim being to optimize infrastructures to improve the quality of human life. Lessons drawn from a better understanding of the migratory networks of quail in relation to different ecosystems provide useful tools to improve infrastructure management and political decision making processes.


Assuntos
Técnicas Biossensoriais , Coturnix , Animais , Humanos , Ecossistema , Conservação dos Recursos Naturais , Codorniz
20.
Antimicrob Agents Chemother ; 56(1): 54-8, 2012 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-21986825

RESUMO

Little information is available about pediatric infections caused by extended-spectrum-ß-lactamase (ESBL)-producing Escherichia coli. We characterized an outbreak caused by a CTX-M-14-producing E. coli isolate in a neonatal intensive care unit (NICU) and studied other infections caused by ESBL-producing E. coli in non-NICU pediatric units. All children ≤4 years old who were infected or colonized by ESBL-producing E. coli isolates between January 2009 and September 2010 were included. Molecular epidemiology was studied by phylogroup analysis, pulsed-field gel electrophoresis (PFGE), and multilocus sequence typing. Antibiotic resistance genes were analyzed by PCR and sequencing. Plasmids were studied by PFGE with S1 nuclease digestion and by incompatibility group analysis using a PCR-based replicon-typing scheme. Of the ESBL-producing E. coli isolates colonizing or infecting the 30 newborns, identical PFGE results were observed for 21 (70%) isolates, which were classified as CTX-M-14-producing E. coli of ST23 phylogroup A. bla(CTX-M-14a) was linked to ISEcp1 and was carried on an ∼80-bp IncK plasmid. A smaller ongoing outbreak due to SHV-12-producing ST131 E. coli was also identified in the same NICU. Fifteen additional infections with ESBL-producing E. coli were identified in non-NICU pediatric units, but none was caused by the CTX-M-14-producing E. coli epidemic clone. Overall, CTX-M-14 (71.1%), CTX-M-15 (13.3%), and SHV-12 (13.3%) were the most important ESBLs causing pediatric infections in this study. Infections of newborns with CTX-M-14-producing E. coli were caused by both clonal and nonclonal isolates.


Assuntos
Antibacterianos/administração & dosagem , Surtos de Doenças , Infecções por Escherichia coli/tratamento farmacológico , Escherichia coli/efeitos dos fármacos , Criança , Pré-Escolar , Impressões Digitais de DNA , Eletroforese em Gel de Campo Pulsado , Escherichia coli/enzimologia , Escherichia coli/genética , Infecções por Escherichia coli/epidemiologia , Infecções por Escherichia coli/microbiologia , Feminino , Humanos , Lactente , Recém-Nascido , Unidades de Terapia Intensiva Neonatal , Masculino , Tipagem de Sequências Multilocus , Filogenia , Plasmídeos , Reação em Cadeia da Polimerase , Análise de Sequência de DNA , Espanha/epidemiologia , Inibidores de beta-Lactamases , beta-Lactamases/metabolismo
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