Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 11 de 11
Filtrar
Mais filtros

Base de dados
Tipo de documento
Intervalo de ano de publicação
1.
Sci Rep ; 14(1): 496, 2024 01 04.
Artigo em Inglês | MEDLINE | ID: mdl-38177212

RESUMO

19ISP is a nucleoside-modified mRNA-lipid nanoparticle vaccine that targets 19 Ixodes scapularis proteins. We demonstrate that adult I. scapularis have impaired fecundity when allowed to engorge on 19ISP-immunized rabbits. 19ISP, therefore, has the potential to interrupt the tick reproductive cycle, without triggering some of the other effects associated with acquired tick resistance. This may lead to the development of new strategies to reduce I. scapularis populations in endemic areas.


Assuntos
Ixodes , Animais , Coelhos , Ixodes/genética , RNA Mensageiro/genética , Vacinação , Fertilidade
2.
HGG Adv ; 5(1): 100253, 2024 Jan 11.
Artigo em Inglês | MEDLINE | ID: mdl-37922902

RESUMO

The c.1222C>T (p.Arg408Trp) phenylalanine hydroxylase (PAH) variant is the most frequent cause of phenylketonuria (PKU), an autosomal recessive disorder characterized by accumulation of blood phenylalanine (Phe) to neurotoxic levels. Here we devised a therapeutic base editing strategy to correct the variant, using prime-edited hepatocyte cell lines engineered with the c.1222C>T variant to screen a variety of adenine base editors and guide RNAs in vitro, followed by assessment in c.1222C>T humanized mice in vivo. We found that upon delivery of a selected adenine base editor mRNA/guide RNA combination into mice via lipid nanoparticles (LNPs), there was sufficient PAH editing in the liver to fully normalize blood Phe levels within 48 h. This work establishes the viability of a base editing strategy to correct the most common pathogenic variant found in individuals with the most common inborn error of metabolism, albeit with potential limitations compared with other genome editing approaches.


Assuntos
Lipossomos , Nanopartículas , Fenilalanina Hidroxilase , Fenilcetonúrias , Camundongos , Animais , Edição de Genes , RNA Mensageiro/genética , RNA Guia de Sistemas CRISPR-Cas , Fenilcetonúrias/genética , Fenilalanina Hidroxilase/genética , Adenina
4.
J Biomech ; 149: 111480, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36791513

RESUMO

Post-traumatic osteoarthritis (PTOA), characterized by articular cartilage degradation initiated in an inflammatory environment after traumatic joint injury, can lead to alterations in cartilage biomechanical properties. Low dose dexamethasone (Dex) shows chondroprotection in cartilage challenged with inflammatory cytokines, but little is known about the structural biomechanical response of human cartilage to Dex in such a diseased state. This study examined changes in the biomechanical properties and biochemical composition of the cartilage within human osteochondral explants in response to treatment with exogenous cytokines, Dex, and a regimen of cyclic loading at the start and end of culture. Osteochondral explants were harvested from five pairs of human ankle talocrural joints (Collins grade 0-1) and cultured for 10 days with/without exogenous cytokines (100 ng/mL TNFα, 50 ng/mL IL-6, 250 ng/mL sIL-6R) ± Dex (100 nM). Biomechanical testing on day-0 and day-10 enabled estimation of the unconfined compression equilibrium modulus (Ey), dynamic stiffness (Ed) and hydraulic permeability (kp) of cartilage excised from bone, accompanied by biochemical assessment of media and cartilage tissue. Dex preserved chondrocyte cell viability and decreased sulfated glycosaminoglycan (sGAG) loss and nitric oxide release, but did not alter Ey, Ed and kp (before or after loading) on day-10. In the cytokine/cytokine+Dex treated groups, sGAG content exhibited a weaker correlation with Ey and Ed than at baseline, suggesting an important role for structural rather than biochemical changes in producing biomechanical alterations in response to cytokines and Dex. These findings aid in forming a more complete profile of potential clinical effects of Dex for use in OA/PTOA treatment regimens.


Assuntos
Cartilagem Articular , Osteoartrite , Humanos , Citocinas/metabolismo , Citocinas/farmacologia , Cartilagem Articular/fisiologia , Condrócitos/metabolismo , Osteoartrite/metabolismo , Dexametasona/farmacologia , Dexametasona/metabolismo
5.
NPJ Vaccines ; 7(1): 155, 2022 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-36456563

RESUMO

Malaria is a deadly disease responsible for between 550,000 and 627,000 deaths annually. There is a pressing need to develop vaccines focused on malaria elimination. The complex lifecycle of Plasmodium falciparum provides opportunities not only to target the infectious sporozoite stage, introduced by anopheline mosquitoes, but also the sexual stages, which are ingested by mosquitoes during blood feeding, leading to parasite transmission. It is widely recognized that a vaccine targeting multiple stages would induce efficacious transmission reducing immunity. Technological advancements offer new vaccine platforms, such as mRNA-LNPs, which can be used to develop highly effective malarial vaccines. We evaluated the immunogenicity of two leading P. falciparum vaccine candidates, Pfs25 and PfCSP, delivered as mRNA-LNP vaccines. Both vaccines induced extremely potent immune responses when administered alone or in combination, which were superior to Pfs25 and PfCSP DNA vaccine formulations. Purified IgGs from Pfs25 mRNA-LNPs immunized mice were highly potent in reducing malaria transmission to mosquitoes. Additionally, mice after three and four immunizations with PfCSP mRNA-LNP provided evidence for varying degrees of protection against sporozoite challenge. The comparison of immune responses and stage-specific functional activity induced by each mRNA-LNP vaccine, administered alone or in combination, also supports the development of an effective combination vaccine without any risk of immune interference for targeting malaria parasites at various life cycle stages. A combination of vaccines targeting both the infective stage and sexual/midgut stages is expected to interrupt malaria transmission, which is critical for achieving elimination goals.

6.
Arthritis Res Ther ; 24(1): 198, 2022 08 18.
Artigo em Inglês | MEDLINE | ID: mdl-35982461

RESUMO

BACKGROUND: Traumatic knee injuries in humans trigger an immediate increase in synovial fluid levels of inflammatory cytokines that accompany impact damage to joint tissues. We developed a human in vitro cartilage-bone-synovium (CBS) coculture model to study the role of mechanical injury and inflammation in the initiation of post-traumatic osteoarthritis (PTOA)-like disease. METHODS: Osteochondral plugs (cartilage-bone, CB) along with joint capsule synovium explants (S) were harvested from 25 cadaveric distal femurs from 16 human donors (Collin's grade 0-2, 23-83years). Two-week monocultures (cartilage (C), bone (B), synovium (S)) and cocultures (CB, CBS) were established. A PTOA-like disease group was initiated via coculture of synovium explants with mechanically impacted osteochondral plugs (CBS+INJ, peak stress 5MPa) with non-impacted CB as controls. Disease-like progression was assessed through analyses of changes in cell viability, inflammatory cytokines released to media (10-plex ELISA), tissue matrix degradation, and metabolomics profile. RESULTS: Immediate increases in concentrations of a panel of inflammatory cytokines occurred in CBS+INJ and CBS cocultures and cultures with S alone (IL-1, IL-6, IL-8, and TNF-α among others). CBS+INJ and CBS also showed increased chondrocyte death compared to uninjured CB. The release of sulfated glycosaminoglycans (sGAG) and associated ARGS-aggrecan neoepitope fragments to the medium was significantly increased in CBS and CBS+INJ groups. Distinct metabolomics profiles were observed for C, B, and S monocultures, and metabolites related to inflammatory response in CBS versus CB (e.g., kynurenine, 1-methylnicotinamide, and hypoxanthine) were identified. CONCLUSION: CBS and CBS+INJ models showed distinct cellular, inflammatory, and matrix-related alterations relevant to PTOA-like initiation/progression. The use of human knee tissues from donors that had no prior history of OA disease suggests the relevance of this model in highlighting the role of injury and inflammation in earliest stages of PTOA progression.


Assuntos
Cartilagem Articular , Osteoartrite , Cartilagem Articular/metabolismo , Citocinas/metabolismo , Humanos , Inflamação/metabolismo , Osteoartrite/etiologia , Osteoartrite/metabolismo , Membrana Sinovial/metabolismo
7.
Vaccines (Basel) ; 9(12)2021 Dec 16.
Artigo em Inglês | MEDLINE | ID: mdl-34960236

RESUMO

Vaccination is a key component of public health policy with demonstrated cost-effective benefits in protecting both human and animal populations. Vaccines can be manufactured under multiple forms including, inactivated (killed), toxoid, live attenuated, Virus-like Particles, synthetic peptide, polysaccharide, polysaccharide conjugate (glycoconjugate), viral vectored (vector-based), nucleic acids (DNA and mRNA) and bacterial vector/synthetic antigen presenting cells. Several processes are used in the manufacturing of vaccines and recent developments in medical/biomedical engineering, biology, immunology, and vaccinology have led to the emergence of innovative nucleic acid vaccines, a novel category added to conventional and subunit vaccines. In this review, we have summarized recent advances in vaccine technologies and platforms focusing on their mechanisms of action, advantages, and possible drawbacks.

8.
Cartilage ; 12(2): 237-250, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-30569762

RESUMO

OBJECTIVE: Previous studies have shown that intrinsic behavior of subchondral bone marrow stem cells (BMSCs) is influenced by donors and locations. To understand the variability in cartilage repair outcomes following bone marrow stimulation, we tested the hypothesis that in vivo cartilage repair correlates with in vitro biological properties of BMSCs using a rabbit model. METHODS: Full-thickness cartilage defects were created in the trochlea and condyle in one knee of skeletally mature New Zealand White rabbits (n = 8) followed by microdrilling. Three-week repair tissues were analyzed by macroscopic International Cartilage Repair Society (ICRS) scores, O'Driscoll histological scores, and Safranin-O (Saf-O) and type-II collagen (Coll-II) % stain. BMSCs isolated from contralateral knees were assessed for cell yield, surface marker expression, CFU-f, %Saf-O, and %Coll-II in pellet culture followed by correlation analyses with the above cartilage repair responses. RESULTS: In vivo cartilage repair scores showed strong, positive correlation with cell number, clonogenic, chondrogenic, and matrix production (Coll-II, GAG) potential of in vitro TGF-ßIII stimulated BMSC cultures. Trochlear repair showed clear evidence of donor dependency and strong correlation was observed for interdonor variation in repair and the above in vitro properties of trochlear BMSCs. Correlation analyses indicated that donor- and location-dependent variability observed in cartilage repair can be attributed to variation in the properties of BMSCs in underlying subchondral bone. CONCLUSION: Variation in cell number, clonogenic, chondrogenic, and matrix production potential of BMSCs correlated with repair response observed in vivo and appear to be responsible for interanimal variability as well as location-dependent repair.


Assuntos
Medula Óssea , Matriz Óssea/citologia , Cartilagem Articular/citologia , Condrogênese/fisiologia , Células-Tronco Mesenquimais/fisiologia , Animais , Artroplastia Subcondral , Matriz Óssea/cirurgia , Osso e Ossos , Cartilagem Articular/cirurgia , Contagem de Células , Células Cultivadas , Colágeno Tipo II/metabolismo , Modelos Animais de Doenças , Proteínas da Matriz Extracelular/metabolismo , Membro Posterior , Transplante de Células-Tronco Mesenquimais , Coelhos
9.
J Tissue Eng Regen Med ; 13(4): 599-611, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30706995

RESUMO

Bone-marrow stimulation (BMS) improves knee-joint function but elicits incomplete repair. Liquid chitosan (CS)-glycerol phosphate/blood clots have been shown to improve BMS-based cartilage repair. Platelet-rich-plasma (PRP)-a rich source of growth factors and cytokines-improves recruitment and chondrogenic potential of subchondral mesenchymal stem cells. We hypothesised that repair response in a rabbit chronic-defect model will improve when freeze-dried CS/PRP is used to augment BMS. Bilateral trochlear defects created in New Zealand white rabbits were allowed to progress to a chronic stage over 4 weeks. Chronic defects were debrided and treated by BMS in second surgery, then augmented with PRP (BMS + PRP) or freeze-dried CS/PRP implants (BMS + CS/PRP). The quality of 8-week repair tissue was assessed by macroscopic, histological, and micro computed tomography (Micro-CT) analysis. ICRS macroscopic scores indicated fibrocartilaginous or fibrous repair in control defects that were improved in the BMS + CS/PRP group. An overall improvement in repair in BMS + CS/PRP group was further confirmed by higher O'Driscoll scores, %Saf-O and %Coll-II values. Micro-CT analysis of subchondral bone indicated ongoing remodelling with repair still underway. Quality and quantity of cartilage repair was improved when freeze-dried CS/PRP implants were used to augment BMS in a chronic defect model.


Assuntos
Medula Óssea/patologia , Cartilagem Articular/patologia , Quitosana/farmacologia , Liofilização , Injeções , Plasma Rico em Plaquetas/química , Próteses e Implantes , Cicatrização , Animais , Medula Óssea/efeitos dos fármacos , Remodelação Óssea , Cartilagem Articular/diagnóstico por imagem , Cartilagem Articular/efeitos dos fármacos , Cartilagem Articular/cirurgia , Modelos Animais de Doenças , Feminino , Inflamação/patologia , Projetos Piloto , Implantação de Prótese , Coelhos , Cicatrização/efeitos dos fármacos
10.
Cartilage ; 9(4): 378-390, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-29156978

RESUMO

OBJECTIVE: Bone marrow stimulation procedures initiate repair by fracturing or drilling subchondral bone at base of cartilaginous defect. Earlier studies have shown that defect location and animal age affect cartilage repair outcome, suggesting a strong influence of structural and biological characteristics of subchondral bone. Here, we analyzed comprehensive biological characteristics of bone marrow progenitor cells (BMPCs) in subchondral bone of young and old rabbit condyle and trochlea. We tested the hypothesis that in vitro biological properties of BMPCs are influenced by location, age of donor and method of their isolation. DESIGN: In vitro biological properties, including cell yield, colony-forming unit fibroblasts (CFU-f), surface marker expression, and differentiation potential were determined. Comparisons were carried out between trochlea versus condyle and epiphyseal versus metaphyseal bone using old ( N = 5) and young animal knees ( N = 8) to generate collagenase and explant-derived BMPC cultures. RESULTS: CFU-f, cell yield, expression of stem cell markers, and osteogenic differentiation were significantly superior for younger animals. Trochlear subchondral bone yielded the most progenitors with the highest clonogenic potential and cartilaginous matrix expression. Trochlear collagenase-derived BMPCs had higher clonogenic capacity than explant-derived ones. Epiphyseal cells generated a larger chondrogenic pellet mass than metaphyseal-derived BMPCs. All older pellet cultures and one non-responder young rabbit failed to accumulate glycosaminoglycans (GAGs). CONCLUSION: Taken together, these results suggest that properties intrinsic to subchondral progenitors could significantly influence cartilage repair potential, and could partly explain variability in cartilage repair outcomes using same cartilage repair approach.


Assuntos
Células da Medula Óssea/fisiologia , Osso e Ossos/citologia , Células-Tronco/fisiologia , Ulna/citologia , Animais , Condrogênese , Ensaio de Unidades Formadoras de Colônias , Osteogênese , Coelhos
11.
Can J Diet Pract Res ; 60(3): 159, 1999.
Artigo em Inglês | MEDLINE | ID: mdl-11551326

RESUMO

The Ottawa-Carleton Heart Beat Restaurant Program is intended to encourage restaurateurs to provide lower-fat and higher-fibre choices. Restaurants participating in this program are promoted through a dining guide and a newspaper supplement. In addition, all participating restaurants receive promotional materials - decal, certificate, menu inserts, table tents, and staff poster - for display. To determine restaurateurs' awareness of the program, provision of healthy food choices, and use of promotional materials, a survey was administered to 142 of the 222 participating restaurants. Results show that 92% of the restaurateurs were aware they were participating in this program, most restaurants could provide the healthy food choices, and 75% of restaurateurs recalled receiving the promotional materials. However, fewer than 33% used the table tents and menu inserts. Slightly more used the staff poster, and 45% or more used the decal and the certificate. These results indicate future directions for such programs.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA