RESUMO
We have investigated the shape of the OH/OD stretching Raman band of water as a function of the excitation wavelength in the deep UV region (200-266 nm). By analyzing the spectral profiles, we highlighted selective pre-resonance effects in the high wavenumber component of the OH/OD stretching band, associated to distorted H-bonded water configurations. A van't Hoff treatment of the temperature-dependent Raman spectra provides an estimate of the thermal energy associated to the change from ordered (ice-like) to disordered configurations that agrees with values obtained by related methods based on a two-state model of water. These results open the possibility of exploiting the observed pre-resonance deep-UV signal enhancement to investigate H-bonding properties in aqueous media.
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The human telomeric G-quadruplex structural motif of DNA has come to be known as a new and stimulating target for anticancer drug discovery. Small molecules that interact with G-quadruplex structures in a selective way have gained impressive interest in recent years as they may serve as potential therapeutic agents. Here, we show how circular dichroism, UV resonance Raman and small angle X-ray scattering spectroscopies can be effectively combined to provide insights into structural and molecular aspects of the interaction between human telomeric quadruplexes and ligands. This study focuses on the ability of berberine and palmatine to bind with human telomeric quadruplexes and provides analysis of the conformational landscape visited by the relevant complexes upon thermal unfolding. With increasing temperature, both free and bound G-quadruplexes undergo melting through a multi-state process, populating different intermediate states. Despite the structural similarity of the two ligands, valuable distinctive features characterising their interaction with the G-quadruplex emerged from our multi-technique approach.
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Alcaloides de Berberina/metabolismo , Berberina/metabolismo , DNA/metabolismo , Quadruplex G , Berberina/química , Alcaloides de Berberina/química , Dicroísmo Circular , DNA/química , DNA/genética , Humanos , Ligantes , Espalhamento a Baixo Ângulo , Análise Espectral Raman , Difração de Raios XRESUMO
In the current post-antibiotic era, botanicals represent one of the most employed nutritional strategies to sustain antibiotic-free and no-antibiotic-ever production. Botanicals can be classified either as plant extracts, meaning the direct products derived by extraction from the raw plant materials (essential oils (EO) and oleoresins (OR)), or as nature-identical compounds (NIC), such as the chemically synthesised counterparts of the pure bioactive compounds of EO/OR. In the literature, differences between the use of EO/OR or NIC are often unclear, so it is difficult to attribute certain effects to specific bioactive compounds. The aim of the present review was to provide an overview of the effects exerted by botanicals on the health status and growth performance of poultry and pigs, focusing attention on those studies where only NIC were employed or those where the composition of the EO/OR was defined. In particular, phenolic compounds (apigenin, quercetin, curcumin and resveratrol), organosulfur compounds (allicin), terpenes (eugenol, thymol, carvacrol, capsaicin and artemisinin) and aldehydes (cinnamaldehyde and vanillin) were considered. These molecules have different properties such as antimicrobial (including antibacterial, antifungal, antiviral and antiprotozoal), anti-inflammatory, antioxidant, immunomodulatory, as well as the improvement of intestinal morphology and integrity of the intestinal mucosa. The use of NIC allows us to properly combine pure compounds, according to the target to achieve. Thus, they represent a promising non-antibiotic tool to allow better intestinal health and a general health status, thereby leading to improved growth performance.
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Ração Animal , Criação de Animais Domésticos/métodos , Anti-Infecciosos/farmacologia , Nível de Saúde , Extratos Vegetais/farmacologia , Aves Domésticas , Suínos , Acroleína/análogos & derivados , Acroleína/farmacologia , Animais , Antibacterianos , Benzaldeídos/farmacologia , Suplementos Nutricionais , Dissulfetos/farmacologia , Intestinos/efeitos dos fármacos , Magnoliopsida/química , Carne , Óleos Voláteis/química , Óleos Voláteis/farmacologia , Fenóis/farmacologia , Extratos Vegetais/biossíntese , Extratos Vegetais/química , Aves Domésticas/crescimento & desenvolvimento , Aves Domésticas/microbiologia , Ácidos Sulfínicos/farmacologia , Suínos/crescimento & desenvolvimento , Suínos/microbiologia , Terpenos/farmacologiaRESUMO
BACKGROUND: The aim of this study was to assess the efficacy of an endoluminal vacuum device (Endo-SPONGE®) in the treatment of rectal anastomotic leaks. METHODS: All studies looking at endoluminal vacuum therapy with Endo-SPONGE® in the treatment of rectal anastomotic leaks were included. A comprehensive search was conducted as per Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Primary outcome was defined as the rate of total anastomotic salvage, with secondary outcomes including rate of ileostomy closure, additional transrectal closures and functional outcomes RESULTS: Sixteen studies met the inclusion criteria. There was a significant publication bias (z = 3.53, p = 0.0004). Two hundred sixty-six patients were identified. The median treatment failure rate was 11.8% (range 0-44%), with random effects model of 0.17 (95% CI 0.11-0.22). There was improvement with early therapy start (OR 3.48) and negative correlation with neoadjuvant radiotherapy (OR 0.56). Fifty-one percent of all diverting stomas were closed at the end of treatment period and 12.8% of patients required an additional trans-rectal closure of the abscess cavity. CONCLUSIONS: Endo-SPONGE® seems to be a useful method of rectal anastomotic leak treatment in selected group of patients; however, the quality of available data is poor and it is impossible to draw a final conclusion. There is unexpected high rate of permanent ileostomy. There is a need for further assessment of this therapy with well-designed randomised or cohort studies.
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Neoplasias Retais , Estomas Cirúrgicos , Anastomose Cirúrgica/efeitos adversos , Fístula Anastomótica/etiologia , Feminino , Humanos , Ileostomia/efeitos adversos , Neoplasias Retais/cirurgia , Reto/cirurgia , Resultado do TratamentoRESUMO
Bovine mastitis affects dairy cattle worldwide and Staphylococcus aureus is one of the most common microorganisms involved in subclinical and chronic disease. Superantigens, such as enterotoxins contribute to S. aureus persistence and pathogenicity in this disease. Subclinical and chronic mastitis cases were diagnosed and S. aureus isolates from sub-clinical cases were investigated for carriage of virulence and antibiotic resistance genes that may contribute to long-term carriage and infection. Over a 12-month period, 116 S. aureus strains were recovered from 68 cows with subclinical mastitis. Classical enterotoxin genes (sea-see) were detected in 24.1% of isolates, and pvl and tsst-1 were identified in 3.4% and 46.6% the isolates, respectively. 18.1% that were persistent isolates were identified and characterized by pulsed field gel electrophoresis (PFGE), MLST, spa typing. Four isolates were methicillin-resistant S. aureus (MRSA) and belonged to SCCmec type I. Molecular typing showed that the agrI group was the most frequent, and a rare isolate was positive for both agrI and agrIII groups. Molecular characterization revealed the persistence of the spa type t10856 (ST133, clonal complex CC133, agr I), in a single animal for nine months and the persistence t605 (ST126, CC126) colonizing four animals for four months. These strains have been described recently in other herds in the same region, indicating their transmissibility and clonal expansion. We conclude that animals with subclinical mastitis are an important and somewhat overlooked reservoir for transmission within and between herds, and may carry virulence and antibiotic resistance genes contributing to persistent colonization, hinder the control of mastitis and may cause risks to the public health.
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Genótipo , Mastite Bovina/microbiologia , Infecções Estafilocócicas/microbiologia , Infecções Estafilocócicas/veterinária , Staphylococcus aureus/genética , Staphylococcus aureus/patogenicidade , Animais , Antibacterianos/farmacologia , Proteínas de Bactérias/genética , Toxinas Bacterianas/genética , Bovinos , DNA Bacteriano , Eletroforese em Gel de Campo Pulsado , Enterotoxinas/genética , Exotoxinas/genética , Feminino , Leucocidinas/genética , Staphylococcus aureus Resistente à Meticilina/genética , Testes de Sensibilidade Microbiana , Leite/microbiologia , Tipagem Molecular/métodos , Tipagem de Sequências Multilocus , Staphylococcus aureus/isolamento & purificação , Superantígenos/genética , Transativadores/genética , Virulência/genética , Fatores de Virulência/genéticaRESUMO
Bovine mastitis has been a concern for dairy herd for decades. The adaptation capacity of one of the main species responsible for this disease, Staphylococcus aureus (S. aureus), plays a pivotal role in this issue. The aim of this study was to establish a molecular and phenotypic profile of 285 S. aureus strains isolated from milk of subclinical mastitis cows from 18 different farms in São Paulo State using spa typing, multilocus sequence typing (MLST), pulsed field gel electrophoresis (PFGE), agr cluster (I, II, III and IV) typing, PCR for genes including enterotoxins (sea, seb, sec, sed, see, seg, seh, sei), toxic shock syndrome toxin (tsst-1), and Panton-Valentine leucocidin (pvl), as well as in vitro resistance assays for 12 antibiotics. The results showed a wide variety of strains with a high toxigenic potential; concomitantly, sec, seg and seh were prevalent. In addition, we observed a predominance of the spa types t605 (ST 126, CC126) and t127 (ST1, CC1) and the unusual presence of t321 causing bovine mastitis, which has been previously reported only in swine. The most frequent ST were ST126 (70.5%) and ST1 (10.5%). Regarding PFGE, we observed four major groups and six profile patterns. The highest resistance was observed for streptomycin (9.5%), followed by tetracycline (3.5%), clindamycin (9.3%), and erythromycin (2.8%). The tsst-1 gene was detected in 36.8% of isolates and pvl was not observed. One hundred and thirty-six (47.7%) isolates possessed agr type II, followed by types III (20%) and I (8.1%), with type IV not being detected. We observed that the same spa type could result in different PFGE profiles, so the exclusive use of spa type sequences can lead to incorrect interpretations regarding the spread of clones in an epidemiological context.
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Infecções Assintomáticas , Mastite Bovina/epidemiologia , Mastite Bovina/microbiologia , Leite/microbiologia , Infecções Estafilocócicas/veterinária , Staphylococcus aureus/classificação , Staphylococcus aureus/genética , Animais , Antibacterianos/farmacologia , Brasil/epidemiologia , Bovinos , Farmacorresistência Bacteriana , Eletroforese em Gel de Campo Pulsado , Técnicas de Genotipagem , Epidemiologia Molecular , Tipagem de Sequências Multilocus , Reação em Cadeia da Polimerase , Infecções Estafilocócicas/epidemiologia , Infecções Estafilocócicas/microbiologia , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/isolamento & purificação , Fatores de Virulência/genéticaRESUMO
The objectives of this study were to estimate the accuracy of Somaticell (Idexx Laboratories Inc., Westbrook, ME), California Mastitis Test (CMT), and microbiological examination of composite milk (MEC) to diagnose Streptococcus agalactiae intramammary infections (IMI), and to assess the agreement between Somaticell and CMT to detect these infections. A secondary objective was to estimate quarter- and cow-level prevalence of S. agalactiae IMI in the herds included in the study. Seven farms were included in the study. The CMT was performed and aseptic milk samples were collected from all quarters of all lactating cows. Composite milk samples were produced in the laboratory by mixing milk from all quarters of each sampled cow. The Somaticell test was performed on a subset of S. agalactiae-positive (n = 167) and S. agalactiae-negative (n = 152) quarter milk samples. Microbiological examination of quarter milk samples (MEQ) was considered the reference test for diagnosing S. agalactiae IMI. The accuracy of all tests at various thresholds was estimated using Bayesian latent class models. Apparent prevalence of S. agalactiae IMI was 15.8% (n = 184/1,164) at the quarter level (based on MEQ) and 28.5% (n = 83/291) at the cow level (based on MEC). True prevalence, as determined by Bayesian models, was 13.0% [95% credible interval (CR): 6.4-24.4%] at the quarter level, and 25.6% (95% CR: 15.3-39.5%) at the cow level. At the cow level (n = 285), sensitivity and specificity of MEC were 95.6 and 99.5%, respectively. The accuracy of Somaticell (n = 319 quarters) to identify S. agalactiae-infected quarters was 75.4, 86.4, 88.9, 89.4, and 91.0% at thresholds of 98,000, 147,000, 205,000, 244,000, and 282,000 cells/mL, respectively. The accuracy of CMT was 87.6, 90.7, 90.8, and 87.4% at thresholds of trace, 1, 2, and 3, respectively. The areas under the receiver operating characteristic curve for Somaticell and CMT were 94.5% (95% confidence interval: 91.8-97.2%) and 92.0% (88.6-95.4%), respectively. At the tested thresholds, the sensitivity of Somaticell ranged from 94.9 to 99.5% to detect S. agalactiae IMI, and specificity ranged from 48.1 to 87.1%. The sensitivity of Somaticell at the lowest threshold (69,000 cells/mL; sensitivity = 99.9%; 95% CR: 98.2-100%) was higher than that of CMT at any tested threshold. Results of this study could be used at the farm level to reduce the use of antimicrobials and reach specific goals in S. agalactiae eradication programs.
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Mastite Bovina/diagnóstico , Leite/microbiologia , Infecções Estreptocócicas/veterinária , Streptococcus agalactiae/isolamento & purificação , Animais , Teorema de Bayes , California/epidemiologia , Bovinos , Fazendas , Feminino , Lactação , Mastite Bovina/epidemiologia , Mastite Bovina/microbiologia , Leite/normas , Prevalência , Sensibilidade e Especificidade , Infecções Estreptocócicas/diagnóstico , Infecções Estreptocócicas/epidemiologia , Infecções Estreptocócicas/microbiologiaRESUMO
The focus of this work is on addressing how the adsorption properties of cyclodextrin (CD) based polymeric hydrogels (cyclodextrin nanosponges, CDNS) can be regulated by a precise control of a crucial parameter such as the characteristic pore size of the polymer network. With this aim, Small Angle Neutron Scattering (SANS) experiments are performed on different CDNS polymer formulations, differing by (i) the chemical structure of the cross-linking agent used for the polymerization of CD, which affects the flexibility of the strands between two crosslinking junctions, (ii) the relative molar ratio of cross-linker to monomer, affecting the cross-linking density, and (iii) the dimension of the CD macrocycle, regulating the steric hindrance and number of available reactive sites on the monomer. The analysis of the experimental data in terms of a two-correlation-length model allows one to extract a correlation length ζ that is interpreted as an experimental assessment of the average mesh-size of the cross-linked polymer, confirming the effective nano-size of the cavities formed in the network of CDNS. The hydration-dependence of ζ is modelled by an empirical functional form, that provides as key parameters the swelling rate of the polymeric network and the upper limit for the mesh size of the material. These parameters are useful for the characterization of the dynamic response of the hydrogel to swelling and the maximum mesh size compatible with the chemical structure of the polymer.
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UV Raman and Brillouin light scattering (BLS) experiments have been used in this study to explore the complex phase change behavior occurring in pH-responsive polysaccharide hydrogels as a function of temperature. Due to the different physical quantities measured by the two techniques, the joint analysis of Raman and BLS spectra has provided an unprecedented large-scale characterization of the molecular rearrangements and of the different kinds of hydrophilic and hydrophobic interactions that cooperate to determine the phase transformation observed in these hydrogels during the heating of the gel. As the main result, the analysis of the Raman and BLS spectra showed the existence of a correlation between the local (molecular) and collective properties of the gels during the phase transformation undergone by the system, which is markedly triggered by pH. The joint set of experimental results suggests a model according to which the mechanism of pH dependence in the hydrogels under investigation is dominated by the interactions involving the hydrophobic parts of the polymer skeleton, whereas the solvation process observed under heating of the gels is driven by the progressive distancing of the polymer domains among them, as monitored by the Brillouin sound velocity.
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The study addresses the life cycle cost assessment (LCCA) of steel bridges, focusing on the maintenance activities and the maintenance scenario. Firstly, the unit costs of maintenance activities and their durability (i.e. the time between two activities) are evaluated. Pragmatic data are provided for the environment category C4 and for three activities: Patch Up, Overcoating and Remove & Replace. A comparative LCCA for a typical hypothetic steel girder bridge is carried out, either painted or hot-dip galvanized (HDG), in the environmental class C4. The LCC versus the cumulated life is provided for both options. The initial cost of the steel unpainted option is only 50.3% of the HDG option. It is shown that after 'Overcoating' occurring at 18.5 years, the total Net Present Value (NPV) of the painted option surpasses that of the HDG option. A sensitivity analysis of the NPV to the cost and service life parameters, the escalation and discount rates is then performed. The discount and escalation rates, considerably influences the total LCC, following a non-linear trend. The total LCC decreases with the discount rate increasing and, conversely, increases with the escalation rate increasing. Secondly, the influence of the maintenance scenario on the total LCC is assessed based on a probabilistic approach. A permutation of the three independent maintenance activities assumed to occur six times over the life of the bridge is considered and a probability of occurrence is associated to each unique scenario. The most probable scenarios are then classified according to their NPV or achieved service life. This approach leads to the definition of a cost-effective maintenance scenario i.e. the scenario, within all the considered permutations, that has the minimum LCC in a range of lifespan. Besides, the probabilistic analysis also shows that, whatever the scenario, the return on investment period ranges between 18.5 years and 24.2 years. After that period, the HDG option becomes economic.
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Pintura , Aço , Análise Custo-BenefícioRESUMO
We investigated the efficacies of cefotaxime (CTX) and amoxicillin (AMX)-clavulanate (CLA) (AMC) against extended-spectrum-ß-lactamase (ESBL)-producing Escherichia coli in vitro and in a murine model of urinary tract infection (UTI). MICs, the checkerboard dilution method, and time-kill curves were used to explore the in vitro synergism between cefotaxime and amoxicillin-clavulanate against two isogenic E. coli strains-CFT073-RR and its transconjugant, CFT073-RR Tc bla(CTX-M-15)-harboring a bla(CTX-M-15) plasmid and a bla(OXA-1) plasmid. For in vivo experiments, mice were separately infected with each strain and treated with cefotaxime, amoxicillin, and clavulanate, alone or in combination, or imipenem, using therapeutic regimens reproducing time of free-drug concentrations above the MIC (fT≥MIC) values close to that obtained in humans. MICs of amoxicillin, cefotaxime, and imipenem were 4/>1,024, 0.125/1,024, and 0.5/0.5 mg/liter, for CFT073-RR and CFT073-RR Tc bla(CTX-M-15), respectively. The addition of 2 mg/liter of clavulanate (CLA) restored the susceptibility of CFT073-RR Tc bla(CTX-M-15) to CTX (MICs of the CTX-CLA combination, 0.125 mg/liter). The checkerboard dilution method and time-kill curves confirmed an in vitro synergy between amoxicillin-clavulanate and cefotaxime against CFT073-RR Tc bla(CTX-M-15). In vivo, this antibiotic combination was similarly active against both strains and as effective as imipenem. In conclusion, the cefotaxime and amoxicillin-clavulanate combination appear to be an effective, easy, and already available alternative to carbapenems for the treatment of UTI due to CTX-M-producing E. coli strains.
Assuntos
Combinação Amoxicilina e Clavulanato de Potássio/farmacologia , Antibacterianos/farmacologia , Cefotaxima/farmacologia , Pielonefrite/tratamento farmacológico , Infecções Urinárias/tratamento farmacológico , Escherichia coli Uropatogênica/efeitos dos fármacos , beta-Lactamases/genética , Combinação Amoxicilina e Clavulanato de Potássio/sangue , Combinação Amoxicilina e Clavulanato de Potássio/farmacocinética , Animais , Antibacterianos/sangue , Antibacterianos/farmacocinética , Cefotaxima/sangue , Cefotaxima/farmacocinética , Modelos Animais de Doenças , Sinergismo Farmacológico , Quimioterapia Combinada , Feminino , Expressão Gênica , Humanos , Imipenem/farmacologia , Camundongos , Camundongos Endogâmicos CBA , Testes de Sensibilidade Microbiana , Plasmídeos/química , Plasmídeos/metabolismo , Pielonefrite/sangue , Pielonefrite/microbiologia , Pielonefrite/patologia , Infecções Urinárias/sangue , Infecções Urinárias/microbiologia , Infecções Urinárias/patologia , Escherichia coli Uropatogênica/enzimologia , Escherichia coli Uropatogênica/genética , Resistência beta-Lactâmica/genética , beta-Lactamases/metabolismoRESUMO
The focus of the present work is to shed light on possible modifications of the molecular properties of polysaccharide hydrogels induced by the establishment of specific non-covalent interactions during the loading of a guest compound inside the gel phase. With this aim, a case study of the encapsulation of caffeine (Caf) inside cyclodextrin-based hydrogels, namely, cyclodextrin nanosponges (NS), is systematically investigated here by using UV Raman scattering experiments. The UV Raman spectra of the hydrogels, analysed as a function of temperature, concentration of the guest molecule loaded in the gel phase and pH, prove particularly informative both on the structural rearrangements of the hydrophobic/hydrophilic groups of the polymeric network and on the breaking/formation of specific guest-matrix interactions. Analysis of the temperature dependence of dynamical parameters, i.e., the dephasing time associated with specific vibrational modes of the polymer backbone, enables the proposal of a molecular picture in which the loading of Caf in NS hydrogels tends to favour access of the water solvent to the more hydrophobic portions of the polymer matrix, which is in turn reflected in a marked increase in the solvation of the whole system. The achievements of this work appear of interest with respect to the design of new possible strategies for controlling the diffusion/release of bioactive molecules inside hydrogel networks, besides corroborating the potential of UV Raman scattering experiments to give new molecular insights into complex phenomena affecting hydrogel phases.
RESUMO
The fundamental question of how the reorganization of the hydrogen-bond (HB) network of water is influenced by the combination of nano-confinement and hydrophobic/hydrophilic solvation effects is addressed here using a spectroscopic study of water absorbed in a model, pH-sensitive polysaccharide hydrogel. The effects of temperature, hydration level and pH on the vibrational dynamics associated with the water molecules and the polymer skeleton are disentangled and analysed by a complementary and combined use of UV-Raman scattering and IR spectroscopy. The experimental data give evidence that the solvation effects in the hydrogel matrix are essentially dominated by the hydration of more hydrophobic parts of the polymer network, while the effect of pH on the HB reorganization of confined water molecules is found to be similar to that induced by cooling of the system. A tentative explanation of these results has been provided in terms of interplay between different kinds of interactions, i.e. hydrophobic vs. hydrophilic.
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BACKGROUND: The effect of freezing-thawing equine adipose tissue-derived mesenchymal stem cells (eATMSCs) have been poorly investigated. OBJECTIVE: This study is to test the influence of cryopreservation solution and temperature when adding the cryoprotectant for freezing eATMSCs, and to investigate the effects of cryopreservation on their stemness features. MATERIALS AND METHODS: Four freezing protocols were evaluated. Viability and proliferation ability of cryopreserved cells were investigated by MTT assay. Fresh and frozen thawed eATMSCs were compared for morphology, phenotypic characteristics (flow cytometry), and differentiation potential. RESULTS: A higher value of viable cells for samples frozen in FBS and a positive effect of CPA equilibration at low temperature in samples frozen in medium were observed. Morphology was similar for fresh and cryopreserved cells, such as CD expression and differentiation potential. CONCLUSION: eATMSCs can be safely stored for clinical use. FBS is superior to medium for freezing, but CPA equilibration at low temperature is beneficial when freezing in serum- free medium.
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Tecido Adiposo/citologia , Criopreservação/métodos , Crioprotetores/farmacologia , Meios de Cultura Livres de Soro/farmacologia , Células-Tronco Mesenquimais/fisiologia , Animais , Diferenciação Celular/efeitos dos fármacos , Citometria de Fluxo , Congelamento , Cavalos , Células-Tronco Mesenquimais/citologiaRESUMO
OBJECTIVES: Temocillin is a 6α-methoxy derivative of ticarcillin that is resilient to ESBLs. Prospective data about its in vivo activity remain scarce. Our aims were: (i) to evaluate the activity of temocillin in a urinary tract infection (UTI) model due to ESBL-producing Escherichia coli and compare it with that of imipenem; and (ii) to define in vivo susceptibility breakpoints. METHODS: Mice were infected with a susceptible E. coli CFT073-RR or its transconjugant (CFT073-RR Tc) harbouring a blaCTX-M-15-carrying plasmid, using an ascending UTI model. Therapeutic regimens were chosen in order to reproduce percentage of time of free drug concentrations above MIC (fT>MIC) obtained in humans with standard regimens of temocillin (200 mg/kg every 2 h for 2 g every 12 h) or imipenem (100 mg/kg every 2 h for 1 g every 8 h). Additional regimens of temocillin (200 mg/kg every 4 and 6 h) with reduced fT>MIC were studied. RESULTS: MICs of temocillin and imipenem were 4/8 and 0.5/0.5 mg/L, for CFT073-RR and CFT073-RR Tc, respectively. In vivo, when given every 2 h (fT>MICâ=â82% and 70%), temocillin was bactericidal and as effective as imipenem in kidneys against both strains without selecting resistant mutants. Temocillin remained active even when given every 4 h, generating an fT>MIC of 41% and 35%, which corresponded to a breakpoint of 16 mg/L in humans with the standard regimen. CONCLUSIONS: Our observations support the consideration of a standard regimen of temocillin as an alternative to carbapenems for the treatment of UTI due to CTX-M-producing E. coli strains with an MIC of 16 mg/L or less.
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Antibacterianos/administração & dosagem , Infecções por Escherichia coli/tratamento farmacológico , Escherichia coli/enzimologia , Penicilinas/administração & dosagem , Infecções Urinárias/tratamento farmacológico , beta-Lactamases/metabolismo , Animais , Modelos Animais de Doenças , Infecções por Escherichia coli/microbiologia , Feminino , Imipenem/administração & dosagem , Camundongos Endogâmicos CBA , Testes de Sensibilidade Microbiana , Resultado do TratamentoRESUMO
Bone metastases from carcinomas are epidemiologically rising because of the increased survival rate of oncologic patients, related to several factors such as improvement of primary and secondary screening, advancement of medical research and technology and the better understanding of mechanisms underlying bone metastases origination from primary tumor. Skeletal Related Events (SREs) can seriously affect quality of life in patients with metastatic disease. These events include the necessity of radiotherapy or bone surgery, malignant hypercalcemia, pathologic fractures and spinal cord compression. Among the SREs, pathologic fractures are the most disabling events and represent an emergency in these delicate patients. A pathologic fracture is defined as a fracture that occurs at the level of a pre-existing bone lesion (that is often a tumor), spontaneously or as the result of low-energy trauma (1). The pre-existence of the metastatic lesion in the bone, its evaluation and the assessment of progression can make these complications predictable and preventable. Pathologic fractures imply several severe consequences, including patient immobilization (in the case of fractures involving the lower limbs), loss of autonomy, anaemia, need of blood transfusion, discontinuation of medical therapies or radiotherapy and protracted hospitalization. Secondary effects of prolonged immobilization and loss of autonomy further lengthen this list of complications in patients who are already significantly limited in their activities. In the present paper, the authors present a review on the main aspects involved in bone metastastic disease: biology, quality of life, economic impact and survival.
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The molecular dynamics of water and a polymer matrix is here explored in a paradigmatic model of a polysaccharide hydrogel, by the combined use of UV Raman scattering and infrared measurements. The case example of cyclodextrin nanosponges (CDNS)/hydrogel is chosen since the simultaneous presence in the structure of the polymer matrix of both hydrophilic and hydrophobic sites mimics the complexity of polysaccharide hydrogels. In this way, the contributions provided by the balance between the hydrophilicity/hydrophobicity and the grade of entanglement of the polymer hydrogel to lead to the formation of the gel phase are separately accounted and evaluated. As main results, we found that the hydrophobic CH groups inserted on the aromatic ring of CDNS experience a more pronounced dynamic perturbation with respect to the carbonyl groups due to the collision between the solvent and vibrating atoms of the polymer. The overall results provide a detailed molecular picture of the swelling phenomena occurring when a chemically cross-linked polymer contacts with water or biological fluids and exploits the potentiality of UV Raman spectroscopy to retrieve dynamic information besides their structural counterpart obtained by the classical analysis of the basic features of vibrational spectra.
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A detailed experimental and theoretical vibrational analysis of hydrogels of ß-cyclodextrin nanosponges (ß-CDNS), obtained by polymerization of ß-cyclodextrin (ß-CD) with the cross-linking agent ethylenediaminetetraacetic acid (EDTA), is reported here. Thorough structural characterization is achieved by exploiting the complementary selection rules of FTIR-ATR and Raman spectroscopies and by supporting the spectral assignments by DFT calculations of the spectral profiles. The combined analysis of the FTIR-ATR spectra of the polymers hydrated with H2O and D2O allowed us to isolate the HOH bending of water molecules not involved in symmetrical, tetrahedral environments. The analysis of the HOH bending mode was carried out as a function of temperature, showing the existence of a supercooled state of the water molecules. The highest level of cooperativity of the hydrogen bond scheme was reached at a value of the ß-CD/EDTA molar ratio n = 6. Finally, the connectivity pattern of "uncoupled" water molecules bound to the nanosponge backbone was found to be weakened by increasing T. The temperature above which the population of non-tetracoordinated water molecules becomes predominant turned out to be independent of the parameter n.
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The molecular connectivity and the extent of hydrogen-bond patterns of water molecules confined in the polymer hydrogels, namely, cyclodextrin nanosponge hydrogels, are here investigated by using vibrational spectroscopy experiments. The proposed spectroscopic method exploits the combined analysis of the vibrational spectra of polymers hydrated with water and deuterated water, which allows us to separate and selectively investigate the temperature-evolution of the HOH bending mode of engaged water molecules and of the vibrational modes assigned to specific chemical groups of the polymer matrix involved in the physical interactions with water. As main results, we find a strong experimental evidence of a liquid-like behaviour of water molecules confined in the nano-cavities of hydrogel and we observe a characteristic destructuring effect on the hydrogen-bonds network of confined water induced by thermal motion. More interestingly, the extent of this temperature-disruptive effect is found to be selectively triggered by the cross-linking degree of the hydrogel matrix. These results give a more clear picture of the molecular mechanism of water confinement in the pores of nanosponge hydrogel and open the possibility to exploit the spectroscopic method here proposed as investigating tools for water-retaining soft materials.
Assuntos
Hidrogéis/química , Polímeros/química , Água/química , Ciclodextrinas/química , Ligação de Hidrogênio , Nanoestruturas/química , Espectroscopia de Infravermelho com Transformada de Fourier , Análise Espectral Raman , TemperaturaRESUMO
Over the past decade, stem cell research has emerged as an area of major interest for its potential in regenerative medicine applications. This is in constant need of new cell sources to conceive regenerative medicine approaches for diseases that are still without therapy. Scientists drew the attention towards alternative sources such as foetal adnexa and fluid, as these sources possess many advantages: first of all, cells can be extracted from discarded foetal material and it is non-invasive and inexpensive for the patient; secondly, abundant stem cells can be obtained; and finally, these stem cell sources are free from ethical considerations. Cells derived from foetal adnexa and fluid preserve some of the characteristics of the primitive embryonic layers from which they originate. Many studies have demonstrated the differentiation potential in vitro and in vivo towards mesenchymal and non-mesenchymal cell types; in addition, the immune-modulatory properties make these cells a good candidate for allo- and xenotransplantation. Naturally occurring diseases in domestic animals can be more ideal as disease model of human genetic and acquired diseases and could help to define the potential therapeutic use efficiency and safety of stem cells therapies. This review offers an update on the state of the art of characterization of domestic animals' MSCs derived from foetal adnexa and fluid and on the latest findings in pre-clinical or clinical setting of the stem cell populations isolated from these sources.