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1.
Soft Matter ; 20(13): 2926-2936, 2024 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-38466036

RESUMO

Several hydrogels with boronate/diol ester cross-linking have been reported. However, multiple synthetic steps or expensive reagents are required to modify some diol moieties into polymers. Therefore, diol-modified polymers, which are easily and inexpensively prepared via a single-step process, are required for the formation of boronate esters. This study reports a novel hydrogel composed of phenylboronic acid-modified hyaluronic acid and salicylic acid-modified hyaluronic acid. This hydrogel is injectable, can self-heal at physiological pH, and can be easily and inexpensively prepared. The polymer system behaved as a sol at pH 12.0 and a weak gel at pH 9.4 and 11.2, whereas it behaved as a gel over a wide pH range of 4.0-8.2. The viscoelasticity of the system decreased in response to sugar at pH 7.3. Thus, salicylic acid can be considered a promising diol moiety for hydrogel formation via boronate ester cross-linking.


Assuntos
Ácidos Borônicos , Ácido Hialurônico , Hidrogéis , Ésteres , Polímeros , Ácido Salicílico , Concentração de Íons de Hidrogênio
2.
Environ Manage ; 73(4): 777-787, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38097676

RESUMO

Understanding the regeneration and succession of belowground communities, particularly in forests, is vital for maintaining ecosystem health. Despite its importance, there is limited knowledge regarding how fungal communities change over time during ecosystem development, especially under different forest restoration strategies. In this study, we focused on two restoration methods used in northern Japan: monoculture planting and natural regeneration. We examined the responses of the fungal community to monoculture plantations (active tree planting) and naturally regenerated (passive regeneration) forests over a 50-year chronosequence, using natural forests as a reference. Based on DNA metabarcoding, we assessed the richness of fungal Operational Taxonomic Units (OTUs) and their dissimilarity. Our findings revealed that soil fungal richness remained stable after natural regeneration but declined in monoculture plantations, from 354 to 247 OTUs. While the compositional dissimilarity of fungal assemblages between monoculture plantations and natural forests remained consistent regardless of the time since tree planting, it significantly decreased after natural regeneration, suggesting recovery to a state close to the reference level. Notably, the composition of key functional fungal groups-saprotrophic and ectomycorrhizal- has increasingly mirrored that of natural forests over time following passive natural regeneration. In summary, our study suggests that monoculture plantations may not be effective for long-term ecosystem function and service recovery because of their limited support for soil fungal diversity. These results underscore the importance of natural regeneration in forest restoration and management strategies.


Assuntos
Ecossistema , Micobioma , Solo , Florestas , Plantas/microbiologia , Árvores , Microbiologia do Solo
3.
Biomacromolecules ; 24(8): 3716-3728, 2023 08 14.
Artigo em Inglês | MEDLINE | ID: mdl-37467146

RESUMO

Hierarchical organization is one of the fundamental features observed in biological systems that allows for efficient and effective functioning. Virus-like particles (VLPs) are elegant examples of a hierarchically organized supramolecular structure, where many subunits are self-assembled to generate the functional cage-like architecture. Utilizing VLPs as building blocks to construct two- and three-dimensional (3D) higher-order structures is an emerging research area in developing functional biomimetic materials. VLPs derived from P22 bacteriophages can be repurposed as nanoreactors by encapsulating enzymes and modular units to build higher-order catalytic materials via several techniques. In this study, we have used coiled-coil peptide interactions to mediate the P22 interparticle assembly into a highly stable, amorphous protein macromolecular framework (PMF) material, where the assembly does not depend on the VLP morphology, a limitation observed in previously reported P22 PMF assemblies. Many encapsulated enzymes lose their optimum functionalities under the harsh conditions that are required for the P22 VLP morphology transitions. Therefore, the coiled-coil-based PMF provides a fitting and versatile platform for constructing functional higher-order catalytic materials compatible with sensitive enzymes. We have characterized the material properties of the PMF and utilized the disordered PMF to construct a biocatalytic 3D material performing single- and multistep catalysis.


Assuntos
Bacteriófago P22 , Peptídeos , Catálise , Biocatálise , Bacteriófago P22/química , Substâncias Macromoleculares
4.
Br J Clin Pharmacol ; 89(4): 1291-1303, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-36693240

RESUMO

AIMS: Standard doses of daptomycin at 4 and 6 mg/kg were used for the treatment of skin and soft tissue for infections and bacteraemia, respectively. However, increased doses of daptomycin are recommended for complicated infections by Gram-positive organisms. METHODS: A systematic review was conducted using 4 databases. We compared treatment success between standard-dose (SD, 4-6 mg/kg) and high-dose (HD, >6 mg/kg) daptomycin in patients with all-cause bacteraemia, complicated bacteraemia, infective endocarditis, osteomyelitis and foreign body/prosthetic infection as the primary outcome. We also compared the success between SD and HD2 (≥8 mg/kg) daptomycin treatments in patients with these diseases as the secondary outcome. The incidence of creatine phosphokinase (CPK) elevation was evaluated as safety. RESULTS: In patients with complicated bacteraemia and infective endocarditis, the treatment success was significantly lower in the SD group than in the HD group (odds ratio [OR] 0.48, 95% confidence interval [CI] 0.30-0.76 and OR 0.50, 95% CI 0.30-0.82) and HD2 group (OR 0.38, 95% CI 0.21-0.69 and OR 0.30, 95% CI 0.15-0.60), respectively. A significant difference was demonstrated only in the HD2 group in patients with bacteraemia, including simple infection. SD did not decrease the success rate for the treatment of osteomyelitis and foreign body/prosthetic infection. The incidence of elevated CPK was significantly lower in SD group than in HD group. CONCLUSION: SD daptomycin was associated with significantly lower treatment success than HD in patients with complicated bacteraemia/infective endocarditis. The CPK elevation should be considered in patients treated with high daptomycin doses.


Assuntos
Bacteriemia , Daptomicina , Endocardite , Osteomielite , Humanos , Daptomicina/efeitos adversos , Antibacterianos/efeitos adversos , Bacteriemia/tratamento farmacológico , Osteomielite/induzido quimicamente , Osteomielite/tratamento farmacológico , Endocardite/complicações , Endocardite/tratamento farmacológico , Endocardite/induzido quimicamente , Resultado do Tratamento , Estudos Retrospectivos
5.
Br J Clin Pharmacol ; 88(5): 1985-1998, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-34902879

RESUMO

AIMS: The present systematic review and meta-analysis evaluated the incidence of elevated creatine phosphokinase (CPK) levels between daptomycin alone and concomitant daptomycin and statin use. METHODS: We searched the PubMed, Web of Sciences, Cochrane Library and ClinicalTrials.gov databases. We analysed the incidence of elevated CPK between daptomycin alone and concomitant daptomycin and statins among studies defining CPK elevation as levels ≥ the upper limit of normal (ULN) or ≥5× ULN. We also analysed the incidence of rhabdomyolysis between the groups. We then calculated the odds ratios (ORs) and 95% confidence intervals (CIs) based on the included studies. RESULTS: Comparing CPK elevation defined as CPK levels ≥ULN, a significantly higher incidence of CPK elevation was observed with concomitant daptomycin and statin use than with daptomycin alone (OR = 2.55, 95% CI 1.78-3.64, P < .00001, I2  = 0%). Likewise, when CPK elevation was defined as CPK levels ≥5× ULN, a significantly higher incidence of CPK elevation was detected with concomitant daptomycin and statin use than with daptomycin alone (OR = 1.89, 95% CI 1.06-3.35, P = .03, I2  = 48%). The incidence of rhabdomyolysis was significantly higher following concomitant daptomycin and statin use than with daptomycin alone (OR = 11.60, 95% CI 1.81-74.37, P = .01, I2  = 0%). CONCLUSION: The combined use of daptomycin and statins were significant risk factors for the incidence of CPK elevation defined as levels ≥ULN or ≥5× ULN and rhabdomyolysis.


Assuntos
Daptomicina , Inibidores de Hidroximetilglutaril-CoA Redutases , Rabdomiólise , Antibacterianos/efeitos adversos , Creatina Quinase , Daptomicina/efeitos adversos , Humanos , Inibidores de Hidroximetilglutaril-CoA Redutases/efeitos adversos , Incidência , Estudos Retrospectivos , Rabdomiólise/induzido quimicamente , Rabdomiólise/epidemiologia
6.
Pharm Res ; 38(6): 1041-1055, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-34013390

RESUMO

PURPOSE: This study evaluated the population pharmacokinetics of daptomycin in nonobese elderly patients with hypoalbuminemia and chronic kidney disease (CKD) using the glomerular filtration rate estimated from cystatin C (eGFRcys) and estimated its optimal dose. METHODS: We performed population pharmacokinetic analysis of the unbound concentrations of daptomycin. The probability of target attainment of 90% for achieving an area under the concentration-time curve of unbound daptomycin at steady state/ minimum inhibitory concentration ratio of ≥66.6 was stochastically simulated. RESULTS: In the population pharmacokinetic analysis of 25 patients aged ≥65 years, the two-compartment model using eGFRcys and age as covariates of clearance in central compartment of unbound daptomycin were optimal. The unbound fraction rate (fu) was 0.05-0.14. According to the Monte Carlo simulation, the optimal doses for patients with eGFRcys of 20-60 mL/min and aged 65-95 years were calculated as 200-500 mg q24h. CONCLUSION: These results suggest that establishing the dose using total concentrations may result in under- or overestimation caused by alterations in fu. The optimal dose for nonobese elderly patients with hypoalbuminemia and CKD depends on eGFRcys and age, and a standard dose may be insufficient for some patients.


Assuntos
Antibacterianos/sangue , Cistatina C/sangue , Daptomicina/sangue , Hipoalbuminemia/sangue , Método de Monte Carlo , Insuficiência Renal Crônica/sangue , Idoso , Idoso de 80 Anos ou mais , Antibacterianos/administração & dosagem , Antibacterianos/farmacocinética , Cistatina C/administração & dosagem , Cistatina C/farmacocinética , Daptomicina/administração & dosagem , Daptomicina/farmacocinética , Relação Dose-Resposta a Droga , Feminino , Taxa de Filtração Glomerular/efeitos dos fármacos , Taxa de Filtração Glomerular/fisiologia , Humanos , Hipoalbuminemia/tratamento farmacológico , Masculino , Estudos Prospectivos , Ligação Proteica/efeitos dos fármacos , Ligação Proteica/fisiologia , Insuficiência Renal Crônica/tratamento farmacológico
7.
J Phys Ther Sci ; 33(6): 495-498, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-34177114

RESUMO

[Purpose] To develop a quantitative motion analysis software specific to boxing (Fist Tactics Support) and to verify its effectiveness based on the percentage of hits that land on the participants. [Participants and Methods] A total of 24 male professional boxers were divided into two groups: those who used Fist Tactics Support to analyze fight videos and instituted training changes based on the results (Fist Tactics Support group, 12 participants) and those who did not (control group, 12 participants). The overall percentage of hits that landed on the participants in the fights was compared between the two groups and between pre- and post-intervention. [Results] There were no significant differences between the two groups; however, the percentage of hits that landed on the boxers of the Fist Tactics Support group was significantly lower at post-intervention than at pre-intervention. [Conclusion] The use of scientific analysis results in boxing may facilitate the primary prevention of sports injuries.

8.
Phys Rev Lett ; 125(14): 147001, 2020 Oct 02.
Artigo em Inglês | MEDLINE | ID: mdl-33064501

RESUMO

We report on strain engineering of superconductivity in RuO_{2} single-crystal films, which are epitaxially grown on rutile TiO_{2} and MgF_{2} substrates with various crystal orientations. Systematic mappings between the superconducting transition temperature and the lattice parameters reveal that shortening of specific ruthenium-oxygen bonds is a common feature among the superconducting RuO_{2} films. Ab initio calculations of electronic and phononic structures for the strained RuO_{2} films suggest the importance of soft phonon modes for emergence of the superconductivity. The findings indicate that simple transition metal oxides such as those with a rutile structure may be suitable for further exploring superconductivity by controlling phonon modes through the epitaxial strain.

9.
Biomacromolecules ; 21(6): 2060-2072, 2020 06 08.
Artigo em Inglês | MEDLINE | ID: mdl-32319761

RESUMO

Hierarchically self-assembled structures are common in biology, but it is often challenging to design and fabricate synthetic analogs. The archetypal cell is defined by hierarchically organized multicompartmentalized structures with boundaries that delineate the interior from exterior environments and is an inspiration for complex functional materials. Here, we have demonstrated an approach to the design and construction of a nested protein cage system that can additionally incorporate the packing of other functional macromolecules and exhibit some of the features of a minimal synthetic cell-like material. We have demonstrated a strategy for controlled co-packaging of subcompartments, ferritin (Fn) cages, together with active cellobiose-hydrolyzing ß-glycosidase enzyme macromolecules, CelB, inside the sequestered volume of the bacteriophage P22 capsid. Using controlled in vitro assembly, we were able to modulate the stoichiometry of Fn cages and CelB encapsulated inside the P22 to control the degree of compartmentalization. The co-encapsulated enzyme CelB showed catalytic activity even when packaged at high total macromolecular concentrations comparable to an intracellular environment. This approach could be used as a model to create synthetic protein-based protocells that can confine smaller functionalized proto-organelles and additional macromolecules to support a range of biochemical reactions.


Assuntos
Bacteriófago P22 , Capsídeo , Proteínas do Capsídeo , Celobiose , Ferritinas , Glucosidases
10.
J Infect Chemother ; 26(3): 272-279, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31732440

RESUMO

OBJECTIVE: At the Yokohama General Hospital, pharmacist-led antimicrobial stewardship programs (ASP) including antifungal stewardship programs (AFP) were started in 2012. To investigate the efficacy of the programs, we compared several parameters that are recommended for the measurement of ASP in Japan based on pre- and post-AFP activities. PATIENTS AND METHODS: The subjects were inpatients who developed candidemia between April 2008 and March 2016. They were divided into two groups: pre-AFP (April 2008 until March 2012) and post-AFP (April 2012 until March 2016). The results were compared between the two groups. RESULTS: The cumulative optimal antifungal drug usage rate, as a process parameter, significantly increased in the post-AFP group (p = 0.025). Furthermore, the days of therapy of antifungal drugs in the pre- and post-AFP groups was median 6.0 (interquartile range [IQR] 0.3-15.7) and median 3.4 (IQR 1.9-3.4) per 1,000 patient-days, respectively; there was a significant decrease in the post-AFP group (p < 0.001). Expenditure on antifungal drugs, as an outcome parameter, in the pre- and post-AFP groups was 9390.5 ± 5687.1 and 5930.8 ± 4687.0 US dollars, respectively; there was a significant decrease in the post-AFP group (p = 0.002). CONCLUSIONS: These results suggest that pharmacist-led antifungal stewardship activities improve both outcome and process parameters.


Assuntos
Antifúngicos , Gestão de Antimicrobianos , Candidemia/tratamento farmacológico , Idoso , Idoso de 80 Anos ou mais , Antifúngicos/administração & dosagem , Antifúngicos/efeitos adversos , Antifúngicos/uso terapêutico , Candidemia/mortalidade , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Farmacêuticos , Estudos Retrospectivos , Resultado do Tratamento
11.
J Exp Bot ; 70(19): 5131-5144, 2019 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-31257428

RESUMO

The improvement of leaf net photosynthetic rate (An) is a major challenge in enhancing crop productivity. However, the genetic control of An among natural genetic accessions is still poorly understood. The high-yielding indica cultivar Takanari has the highest An of all rice cultivars, 20-30% higher than that of the high-quality japonica cultivar Koshihikari. By using reciprocal backcross inbred lines and chromosome segment substitution lines derived from a cross between Takanari and Koshihikari, we identified three quantitative trait loci (QTLs) where the Takanari alleles enhanced An in plants with a Koshihikari genetic background and five QTLs where the Koshihikari alleles enhanced An in plants with a Takanari genetic background. Two QTLs were expressed in plants with both backgrounds (type I QTL). The expression of other QTLs depended strongly on genetic background (type II QTL). These beneficial alleles increased stomatal conductance, the initial slope of An versus intercellular CO2 concentration, or An at CO2 saturation. Pyramiding of these alleles consistently increased An. Some alleles positively affected biomass production and grain yield. These alleles associated with photosynthesis and yield can be a valuable tool in rice breeding programs via DNA marker-assisted selection.


Assuntos
Oryza/genética , Fotossíntese/genética , Folhas de Planta/metabolismo , Locos de Características Quantitativas , Alelos , Mapeamento Cromossômico , Oryza/metabolismo
12.
Int J Syst Evol Microbiol ; 69(3): 696-700, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30605075

RESUMO

Two strains of a psychrophilic basidiomycetous yeast species belonging to the genus Vishniacozyma were isolated from sediments and soil at the front of a retreating glacier on northern Ellesmere Island in the Canadian Arctic. Analysis of the large subunit D1/D2 region and the internal transcribed spacer (ITS) regions of the rDNA indicated that these strains represented a novel species. The closest relatives of the novel species were Vishniacozyma globispora and V. dimennae, which exhibited sequence similarities of 82.2 and 81.6 %, respectively, to the ITS region of the novel species, and contained 61 and 57 nt substitutions, respectively, in the D1/D2 domain, in comparison with the novel species. Strains of the novel species were able to grow at sub-zero temperatures and in vitamin-free medium. These characteristics allow the strains to survive and grow in perennially cold, oligotrophic habitats in the Canadian High Arctic. The name Vishniacozyma ellesmerensis sp. nov. is proposed. The type strain is JCM 32573T (=UAMH 11973T=G3-4-8T) and the MycoBank number is MB825501.


Assuntos
Basidiomycota/classificação , Sedimentos Geológicos/microbiologia , Camada de Gelo/microbiologia , Filogenia , Microbiologia do Solo , Regiões Árticas , Basidiomycota/isolamento & purificação , Canadá , DNA Fúngico/genética , DNA Espaçador Ribossômico/genética , Técnicas de Tipagem Micológica , Análise de Sequência de DNA
13.
Int J Syst Evol Microbiol ; 69(4): 944-948, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30605078

RESUMO

Four strains isolated from sediment sampled at the front of a retreating glacier on northern Ellesmere Island in the Canadian high Arctic, namely JCM 32575T, JCM 32576, JCM 32577 and JCM 32578, belong to a novel psychrophilic basidiomycetous yeast species in the genus Mrakia. Molecular phylogenetic analysis indicated that these strains are most closely related to the type strains of Mrakia aquatica and Mrakianic combsii, but with 8-9 and 7-12 nt substitutions in ITS and in the D1/D2 domain of the LSU rRNA gene, respectively. The strains grew at sub-zero temperatures and in vitamin-free media, with lipase and cellulase highly active even at -3 °C. These characteristics likely allow this yeast species to grow and survive in extremely cold, oligotrophic environments, such as the fronts of retreating glaciers in the high Arctic. The name Mrakia hoshinonis sp. nov. is proposed, with type strain JCM 32575T (UAMH 11969) and MycoBank number MB 825484.


Assuntos
Basidiomycota/classificação , Camada de Gelo/microbiologia , Filogenia , Regiões Árticas , Basidiomycota/isolamento & purificação , Canadá , DNA Fúngico/genética , Genes de RNAr , Técnicas de Tipagem Micológica , Análise de Sequência de DNA
14.
Biol Pharm Bull ; 42(1): 144-148, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30606986

RESUMO

The transnasal route for the delivery of water-soluble macromolecules, such as bioactive peptides and proteins, has attracted interest, although the use of permeation enhancers is required due to the poor permeabilities of these macromolecules across the nasal mucosa. With polycationic compounds, such as poly-L-arginine and chitosan, the nasal absorption of hydrophilic macromolecules is molecular weight- and concentration-dependently enhanced without causing cytotoxicity. In the present study, we evaluated the effect of various molecular weights and concentrations of poly-L-ornithine (PLO), a polycationic compound, on the nasal absorption and the damage to the nasal mucosa in vivo. PLO enhanced the nasal absorption of fluorescein isothiocyanate-dextran (FD-4), used as a model drug, and the bioavailability of FD-4 increased with the concentration of PLO. The enhancement effect was also dependent on the molecular weight. The administration of PLO at a concentration that sufficed for enhancing the nasal absorption had no effect on the activity of lactic dehydrogenase and the protein leakage in the nasal fluid, as indices of nasal mucosa damage. These findings suggest that a transnasal delivery system using PLO is a useful strategy for improving the nasal absorption of water-soluble macromolecules without toxicity to the nasal mucosa.


Assuntos
Imidazóis/metabolismo , Absorção Nasal/efeitos dos fármacos , Peptídeos/metabolismo , Éteres Fenílicos/metabolismo , Tensoativos/metabolismo , Água , Animais , Sinergismo Farmacológico , Imidazóis/administração & dosagem , Masculino , Absorção Nasal/fisiologia , Peptídeos/administração & dosagem , Éteres Fenílicos/administração & dosagem , Ratos , Ratos Wistar , Solubilidade/efeitos dos fármacos , Tensoativos/administração & dosagem , Água/metabolismo
15.
Chem Soc Rev ; 47(10): 3433-3469, 2018 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-29497713

RESUMO

Within the materials science community, proteins with cage-like architectures are being developed as versatile nanoscale platforms for use in protein nanotechnology. Much effort has been focused on the functionalization of protein cages with biological and non-biological moieties to bring about new properties of not only individual protein cages, but collective bulk-scale assemblies of protein cages. In this review, we report on the current understanding of protein cage assembly, both of the cages themselves from individual subunits, and the assembly of the individual protein cages into higher order structures. We start by discussing the key properties of natural protein cages (for example: size, shape and structure) followed by a review of some of the mechanisms of protein cage assembly and the factors that influence it. We then explore the current approaches for functionalizing protein cages, on the interior or exterior surfaces of the capsids. Lastly, we explore the emerging area of higher order assemblies created from individual protein cages and their potential for new and exciting collective properties.


Assuntos
Proteínas/síntese química , Humanos , Nanotecnologia , Conformação Proteica , Proteínas/química , Proteínas/metabolismo
16.
J Phys Ther Sci ; 31(4): 318-325, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31037002

RESUMO

[Purpose] Considering that respiratory muscle fatigue is a cause of respiratory failure, we aimed to clarify the characteristics of respiratory muscle fatigue under inhalation load and investigate its impact on individual respiratory muscles. [Participants and Methods] The study included 14 healthy adult male volunteers. Maximal inspiratory and expiratory mouth pressures were measured under inhalation load and while at rest. The statuses of the trapezius, sternocleidomastoid, pectoralis major, diaphragm, rectus abdominis, and external and internal abdominal oblique muscles were also assessed using electromyographic frequency analysis. [Results] The maximal inspiratory and expiratory mouth pressures decreased over time and recovered after rest. The median power frequency decreased significantly in the sternocleidomastoid and rectus abdominis muscles at maximal inspiratory and expiratory mouth pressures, respectively, under inhalation load. [Conclusion] As a characteristic of respiratory muscle fatigue, there is a possibility that decreases in maximal inspiratory and expiratory mouth pressures as a result of the inhalation load affect muscle fatigue in the sternocleidomastoid and rectus abdominis muscles.

17.
Oecologia ; 186(3): 843-853, 2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-29273834

RESUMO

In Arctic tundra, plant pathogens have substantial effects on the growth and survival of hosts, and impacts on the carbon balance at the scale of ecological systems. To understand these effects on carbon dynamics across different scales including plant organ, individual, population and ecosystem, we focused on two primary factors: host productivity reduction and carbon consumption by the pathogen. We measured the effect of the pathogen on photosynthetic and respiratory activity in the host. We also measured respiration and the amount of carbon in the pathogen. We constructed a model based on these two factors, and calculated pathogenic effects on the carbon balance at different organismal and ecological scales. We found that carbon was reduced in infected leaves by 118% compared with healthy leaves; the major factor causing this loss was pathogenic carbon consumption. The carbon balance at the population and ecosystem levels decreased by 35% and 20%, respectively, at an infection rate of 30%. This case study provides the first evidence that a host plant can lose more carbon through pathogenic carbon consumption than through a reduction in productivity. Such a pathogenic effect could greatly change ecosystem carbon cycling without decreasing annual productivity.


Assuntos
Carbono , Ecossistema , Regiões Árticas , Ciclo do Carbono , Plantas , Tundra
18.
Bioconjug Chem ; 28(8): 2114-2124, 2017 08 16.
Artigo em Inglês | MEDLINE | ID: mdl-28612603

RESUMO

Virus-like particles are unique platforms well suited for the construction of nanomaterials with broad-range applications. The research presented here describes the development of a modular approach for the covalent attachment of protein domains to the exterior of the versatile bacteriophage P22 virus-like particle (VLP) via a sortase-mediated ligation strategy. The bacteriophage P22 coat protein was genetically engineered to incorporate an LPETG amino acid sequence on the C-terminus, providing the peptide recognition sequence utilized by the sortase enzyme to catalyze peptide bond formation between the LPETG-tagged protein and a protein containing a polyglycine sequence on the N-terminus. Here we evaluate attachment of green fluorescent protein (GFP) and the head domain of the influenza hemagglutinin (HA) protein by genetically producing polyglycine tagged proteins. Attachment of both proteins to the exterior of the P22 VLP was found to be highly efficient as judged by SDS-PAGE densitometry. These results enlarge the tool kit for modifying the P22 VLP system and provide new insights for other VLPs that have an externally displayed C-terminus that can use the described strategy for the modular modification of their external surface for various applications.


Assuntos
Bacteriófago P22 , Proteínas do Capsídeo/química , Proteínas do Capsídeo/metabolismo , Cisteína Endopeptidases/metabolismo , Proteínas de Fluorescência Verde/metabolismo , Hemaglutininas Virais/metabolismo , Proteínas de Fluorescência Verde/química , Hemaglutininas Virais/química , Modelos Moleculares , Domínios Proteicos
19.
J Magn Reson Imaging ; 45(4): 1144-1153, 2017 04.
Artigo em Inglês | MEDLINE | ID: mdl-27689830

RESUMO

PURPOSE: To evaluate Arg-Gly-Asp (RGD)-conjugated human ferritin (HFn) iron oxide nanoparticles for in vivo magnetic resonance imaging (MRI) of vascular inflammation and angiogenesis in experimental carotid disease and abdominal aortic aneurysm (AAA). MATERIALS AND METHODS: HFn was genetically engineered to express the RGD peptide and Fe3 O4 nanoparticles were chemically synthesized inside the engineered HFn (RGD-HFn). Macrophage-rich left carotid lesions were induced by ligation in FVB mice made hyperlipidemic and diabetic (n = 14), with the contralateral right carotid serving as control. Murine AAAs were created by continuous angiotensin II infusion in ApoE-deficient mice (n = 12), while control mice underwent saline infusion (n = 8). All mice were imaged before and after intravenous injection with either RGD-HFn-Fe3 O4 or HFn-Fe3 O4 using a gradient-echo sequence on a whole-body 3T clinical scanner, followed by histological analysis. The nanoparticle accumulation was assessed by the extent of T2*-induced carotid lumen reduction (% lumen loss) or aortic T2*-weighted signal intensity reduction (% SI [signal intensity] loss). RESULTS: RGD-HFn-Fe3 O4 was taken up more than HFn-Fe3 O4 in both the ligated left carotid arteries (% lumen loss; 69 ± 9% vs. 36 ± 7%, P = 0.01) and AAAs (% SI loss; 47 ± 6% vs. 20 ± 5%, P = 0.01). The AAA % SI loss correlated positively with AAA size (r = 0.89, P < 0.001). Histology confirmed the greater accumulation and colocalization of RGD-HFn-Fe3 O4 to both vascular macrophages and endothelial cells. CONCLUSION: RGD-HFn-Fe3 O4 enhances in vivo MRI by targeting both vascular inflammation and angiogenesis, and provides a promising translatable MRI approach to detect high-risk atherosclerotic and aneurysmal vascular diseases. LEVEL OF EVIDENCE: 1 J. Magn. Reson. Imaging 2017;45:1144-1153.


Assuntos
Aneurisma da Aorta Abdominal/fisiopatologia , Doenças das Artérias Carótidas/fisiopatologia , Ferritinas/metabolismo , Inflamação/fisiopatologia , Imageamento por Ressonância Magnética/métodos , Oligopeptídeos/metabolismo , Animais , Aneurisma da Aorta Abdominal/diagnóstico por imagem , Aneurisma da Aorta Abdominal/metabolismo , Artérias Carótidas/diagnóstico por imagem , Artérias Carótidas/metabolismo , Artérias Carótidas/fisiopatologia , Doenças das Artérias Carótidas/diagnóstico por imagem , Doenças das Artérias Carótidas/metabolismo , Modelos Animais de Doenças , Compostos Férricos/metabolismo , Inflamação/diagnóstico por imagem , Inflamação/metabolismo , Masculino , Camundongos , Nanopartículas , Neovascularização Patológica/diagnóstico por imagem , Neovascularização Patológica/metabolismo , Neovascularização Patológica/fisiopatologia , Doenças Vasculares/diagnóstico por imagem , Doenças Vasculares/metabolismo , Doenças Vasculares/fisiopatologia
20.
Nitric Oxide ; 67: 1-9, 2017 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-28438687

RESUMO

Loss of nitric oxide (NO) bioavailability underlies the development of hypertensive heart disease. We investigated the effects of dietary nitrite on NG-nitro-l-arginine methyl ester (l-NAME)-induced hypertension. Sprague-Dawley rats were divided into five groups: an untreated control group, an l-NAME-treated group, and three other l-NAME-treated groups supplemented with 10 mg/L or 100 mg/L of nitrite or 100 mg/L of captopril in drinking water. After the 8-week experimental period, mean arterial blood pressure was measured, followed by sampling of blood and heart tissue for assessment of nitrite/nitrate levels in the plasma and heart, the plasma level of angiotensin II (AT II), and the heart transcriptional levels of AT II type 1 receptor (AT1R), transforming growth factor-ß1 (TGF-ß1), and connective tissue proteins such as type 1 collagen and fibronectin. Heart tissue was analyzed by histopathological morphometry, including assessments of ventricular and coronary vascular hypertrophy and fibrosis, as well as immunohistochemistry analyses of myocardial expression of AT1R. l-NAME treatment reduced the plasma nitrate level and led to the development of hypertension, with increased plasma levels of AT II and increased heart transcriptional levels of AT1R and TGF-ß1-mediated connective tissue proteins, showing myocardial and coronary arteriolar hypertrophy and fibrosis. However, dietary nitrite supplementation inhibited TGF-ß1-mediated cardiac remodeling by suppressing AT II and AT1R. These results suggest that dietary nitrite levels achievable via a daily high-vegetable diet could improve hypertensive heart disease by inhibiting AT II-AT1R-mediated cardiac remodeling.


Assuntos
Suplementos Nutricionais , Hipertensão/induzido quimicamente , NG-Nitroarginina Metil Éster/efeitos adversos , Nitritos/uso terapêutico , Remodelação Ventricular/efeitos dos fármacos , Angiotensina II/sangue , Angiotensina II/metabolismo , Animais , Anti-Hipertensivos/administração & dosagem , Anti-Hipertensivos/sangue , Anti-Hipertensivos/uso terapêutico , Captopril/uso terapêutico , Cardiomegalia/induzido quimicamente , Cardiomegalia/tratamento farmacológico , Colágeno Tipo I/genética , Colágeno Tipo I/metabolismo , Vasos Coronários/patologia , Fibronectinas/genética , Fibronectinas/metabolismo , Fibrose/tratamento farmacológico , Ventrículos do Coração/patologia , Masculino , Miocárdio/patologia , Nitratos/sangue , Nitritos/administração & dosagem , Nitritos/sangue , RNA/genética , RNA/metabolismo , Ratos Sprague-Dawley , Receptor Tipo 1 de Angiotensina/metabolismo , Fator de Crescimento Transformador beta/genética , Fator de Crescimento Transformador beta/metabolismo
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