RESUMO
OBJECTIVES: The aim of this work is to provide the first report of a transfusion-acquired HIV-1 infection and to verify transmission from the donor to the recipients using phylogenetic analysis of HIV-1 DNA sequences in a Brazilian blood bank. BACKGROUND: Although haemovigilance procedures based on phylogenetic analysis of HIV have been reported in several countries, this type of study has yet to be conducted in Latin America. MATERIALS AND METHODS: Upon identifying a HIV-1-positive repeat blood donor by enzyme immunoassay (EIA) blood screening, all recipients of the donor's previous donation were identified and tested for HIV-1 by EIA, nucleic acid amplification test and HIV-1 DNA sequencing and phylogenetic analysis. RESULTS: One of the recipients tested positive for HIV-1. The phylogenetic analysis showed a high genetic similarity among the viruses, thus supporting the hypothesis of transmission from the donor to the recipient. CONCLUSIONS: Phylogenetic analysis of HIV-1 DNA sequences has been a decisive tool in verifying suspected transmission of the virus from blood donor to recipient in Brazil.
Assuntos
Bancos de Sangue , Doadores de Sangue , Segurança do Sangue , Transfusão de Sangue , Patógenos Transmitidos pelo Sangue , DNA Viral/genética , Infecções por HIV , HIV-1/genética , Filogenia , Adulto , Brasil , Feminino , Infecções por HIV/genética , Infecções por HIV/transmissão , HumanosRESUMO
Mesenchymal stem cells (MSCs) have been recognized for their ability to differentiate into cells of different tissues such as bone, cartilage, or adipose tissue, and therefore are of great interest for potential therapeutic strategies. Adherent, colony-forming, fibroblastic cells were isolated from human bone marrow aspirates, from patients undergoing knee arthroplasties, and the MSCs phenotype characterized by flow cytometry. Afterward, cells were seeded onto electrospun polycaprolactone nanofiber meshes and cultured in a multichamber flow perfusion bioreactor to determine their ability to produce cartilagineous extracellular matrix. Results indicate that the flow perfusion bioreactor increased the chondrogenic differentiation of hBM-MSCs, as confirmed either by morphological and RT-PCR analysis. Cartilage-related genes such as aggrecan, collagen type II, and Sox9 were expressed. ECM deposition was also detected by histological procedures. Collagen type II was present in the samples, as well as collagen type I. Despite no statistically significant values being obtained for gene expression, the other results support the choice of the bioreactor for this type of culture.
Assuntos
Cartilagem/citologia , Células-Tronco Mesenquimais/citologia , Nanofibras/química , Engenharia Tecidual/métodos , Reatores Biológicos , Diferenciação Celular , Células Cultivadas , Colágeno Tipo I , Colágeno Tipo II , Fibroblastos/citologia , Humanos , PoliésteresRESUMO
Length and weight relationships and descriptive statistics are reported for six shrimp species caught off the Madeira archipelago between 1983 and 2014 using bottom and floating traps from depths ranging from 50 to 1,300 m. The parameter b ranged between 2.36 for Plesionika ensis and 2.97 for Plesionika williamsi. All species showed a pattern of negative allometric growth. To the authors' knowledge all weight-length relationships presented herein are recorded for the first time from the Madeira area, and in the cases of Ligur ensiferus and Plesionika ensis are the first references worldwide.
Assuntos
Decápodes/fisiologia , Animais , Oceano Atlântico , Tamanho Corporal , Peso Corporal , Feminino , Masculino , Pandalidae/fisiologia , PortugalRESUMO
Analysis of abundance and population structure of Plesionika narval was performed on data concerning 5,255 specimens obtained from 62 fishing sets carried out off the Madeira archipelago (Northeastern Atlantic) between 2004 and 2008 in a depth range from 101 to 350 m. Abundance ranged from 0.01 to 19.74 specimens-per-trap and significant differences were found between seasons, probably as a result of an increment of population in the spring during the recruitment season. The analysis of size distribution revealed that the carapace length (CL) ranged from 2.45 to 28.61 mm and that mean female size consistently exceeded that of males. Differences in mean CL were statistically significant between depth strata and seasons. Of the specimens sampled, 57.00% were males, 41.88% females and 1.42% undetermined. Sex ratio also differed significantly between seasons according to depth strata, consolidating the hypothesis of the existence of seasonal migrations related with the reproductive cycle of this species. Ovigerous females showed larger sizes and occurred all year around and remain in shallow waters in winter, summer and autumn and move to deeper waters in spring. The highest frequency of ovigerous females was recorded in summer, between 151 and 200 m deep supporting the hypothesis that spawning of this species occurs in shallow waters, especially in late summer.
Assuntos
Distribuição Animal , Pandalidae/fisiologia , Animais , Oceano Atlântico , Tamanho Corporal , Feminino , Masculino , Dinâmica Populacional , Portugal , Reprodução , Estações do Ano , Razão de MasculinidadeRESUMO
Several experimental surveys were carried out in the Northeastern Atlantic, Madeira archipelago from 1991 to 2008 to explore new fisheries resources. This study examined the selectivity of bottom and floating traps and the analysis of yield-per-recruit (YPR) and biomass-per-recruit (BPR) providing helpful insight to the management of the shrimp Plesionika narval. A total of 28,262 specimens were sampled and the analysis of length at first capture returned higher values when using floating traps indicating that these traps are more selective, exerting less pressure on the resource. The YPR and BPR analysis showed that the stock is under exploited for the studied area and suggests that the use of floating traps in the commercial fisheries of P. narval is recommended, which will allow a higher maximum allowable limit of exploitation and greater yield. The results suggest that P. narval has the potential to support a viable and sustainable fishery using floating traps.
Assuntos
Conservação dos Recursos Naturais , Pesqueiros , Características de História de Vida , Pandalidae , Animais , Feminino , Masculino , PortugalRESUMO
Wharton's jelly stem cells (WJSCs) are a potential source of transplantable stem cells in cartilage-regenerative strategies, due to their highly proliferative and multilineage differentiation capacity. We hypothesized that a non-direct co-culture system with human articular chondrocytes (hACs) could enhance the potential chondrogenic phenotype of hWJSCs during the expansion phase compared to those expanded in monoculture conditions. Primary hWJSCs were cultured in the bottom of a multiwell plate separated by a porous transwell membrane insert seeded with hACs. No statistically significant differences in hWJSCs duplication number were observed under either of the culture conditions during the expansion phase. hWJSCs under co-culture conditions show upregulations of collagen type I and II, COMP, TGFß1 and aggrecan, as well as of the main cartilage transcription factor, SOX9, when compared to those cultured in the absence of chondrocytes. Chondrogenic differentiation of hWJSCs, previously expanded in co-culture and monoculture conditions, was evaluated for each cellular passage using the micromass culture model. Cells expanded in co-culture showed higher accumulation of glycosaminoglycans (GAGs) compared to cells in monoculture, and immunohistochemistry for localization of collagen type I revealed a strong detection signal when hWJSCs were expanded under monoculture conditions. In contrast, type II collagen was detected when cells were expanded under co-culture conditions, where numerous round-shaped cell clusters were observed. Using a micromass differentiation model, hWJSCs, previously exposed to soluble factors secreted by hACs, were able to express higher levels of chondrogenic genes with deposition of cartilage extracellular matrix components, suggesting their use as an alternative cell source for treating degenerated cartilage. Copyright © 2015 John Wiley & Sons, Ltd.
Assuntos
Cartilagem Articular/metabolismo , Condrócitos/metabolismo , Condrogênese , Regulação da Expressão Gênica , Células-Tronco Mesenquimais/metabolismo , Cartilagem Articular/citologia , Condrócitos/citologia , Técnicas de Cocultura , Humanos , Células-Tronco Mesenquimais/citologiaRESUMO
Vaccine approaches to infectious diseases are widely applied and appreciated. Amongst them, vectors based on recombinant viruses have shown great promise and play an important role in the development of new vaccines. Many viruses have been investigated for their ability to express proteins from foreign pathogens and induce specific immunological responses against these antigens in vivo. Generally, gene-based vaccines can stimulate potent humoral and cellular immune responses and viral vectors might be an effective strategy for both the delivery of antigen-encoding genes and the facilitation and enhancement of antigen presentation. In order to be utilized as a vaccine carrier, the ideal viral vector should be safe and enable efficient presentation of required pathogen-specific antigens to the immune system. It should also exhibit low intrinsic immunogenicity to allow for its re-administration in order to boost relevant specific immune responses. Furthermore, the vector system must meet criteria that enable its production on a large-scale basis. Several viral vaccine vectors have thus emerged to date, all of them having relative advantages and limits depending on the proposed application, and thus far none of them have proven to be ideal vaccine carriers. In this review we describe the potential, as well as some of the foreseeable obstacles associated with viral vaccine vectors and their use in preventive medicine.
Assuntos
Vetores Genéticos/imunologia , Vacinas de DNA/imunologia , Vacinas Virais/imunologia , Viroses/prevenção & controle , Adenoviridae/imunologia , Alphavirus/imunologia , Herpesviridae/imunologia , Humanos , Poliovirus/imunologia , Poxviridae/imunologia , Recombinação Genética , Vacinas Virais/genética , Viroses/genética , Viroses/imunologiaRESUMO
Previously, we have demonstrated a role for fibroblast growth factor (Fgf) in spinal cord regeneration in both zebrafish and mouse. We have shown that exogenous Fgf2 treatment attenuates astrocytic gliosis and induces glia cells to become progenitors that undergo neurogenesis as well as differentiating into bipolar astrocytes that support axonal regeneration (Goldshmit et al., 2012, 2014). One of the downstream signaling target genes of Fgf is spry4, which acts as a feedback inhibitor for Fgf signaling. In this study we examined the effects of increased endogenous Fgf signaling, in spry4-/- mice, on the early events that occur after spinal cord injury (SCI). We demonstrate that in spry4-/- mice inflammatory responses, such as tumor necrosis factor α (TNFα) secretion and macrophage/neutrophil invasion into the lesion site are reduced. In addition, astrocytic gliosis is attenuated and neuronal survival is increased. These results further support a pro-regenerative role of Fgf after SCI, and suggest that increased endogenous Fgf signaling after SCI may contribute to functional recovery and therefore presents this pathway as a target for new therapy development.
Assuntos
Fator 2 de Crescimento de Fibroblastos/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Traumatismos da Medula Espinal/metabolismo , Traumatismos da Medula Espinal/fisiopatologia , Regeneração da Medula Espinal , Animais , Sobrevivência Celular , Fator 2 de Crescimento de Fibroblastos/farmacologia , Gliose/metabolismo , Inflamação/metabolismo , Camundongos Endogâmicos C57BL , Camundongos Knockout , Proteínas do Tecido Nervoso/genética , Neurogênese , Neuroglia/metabolismo , Fosforilação , Transdução de Sinais/efeitos dos fármacos , Traumatismos da Medula Espinal/genética , Regeneração da Medula Espinal/genética , Fator de Necrose Tumoral alfa/metabolismoRESUMO
Paracrine signalling from chondrocytes has been reported to increase the synthesis and expression of cartilage extracellular matrix (ECM) by stem cells. The use of conditioned medium obtained from chondrocytes for stimulating stem cells chondrogenic differentiation may be a very interesting alternative for moving into the clinical application of these cells, as chondrocytes could be partially replaced by stem cells for this type of application. In the present study we aimed to achieve chondrogenic differentiation of two different sources of stem cells using conditioned medium, without adding growth factors. We tested both human bone marrow-derived mesenchymal stem cells (hBSMCs) and human Wharton's jelly-derived stem cells (hWJSCs). Conditioned medium obtained from a culture of human articular chondrocytes was used to feed the cells during the experiment. Cultures were performed in previously produced three-dimensional (3D) scaffolds, composed of a blend of 50:50 chitosan:poly(butylene succinate). Both types of stem cells were able to undergo chondrogenic differentiation without the addition of growth factors. Cultures using hWJSCs showed significantly higher GAGs accumulation and expression of cartilage-related genes (aggrecan, Sox9 and collagen type II) when compared to hBMSCs cultures. Conditioned medium obtained from articular chondrocytes induced the chondrogenic differentiation of MSCs and ECM formation. Obtained results showed that this new strategy is very interesting and should be further explored for clinical applications.
Assuntos
Diferenciação Celular/efeitos dos fármacos , Condrócitos/citologia , Condrogênese/efeitos dos fármacos , Meios de Cultivo Condicionados/farmacologia , Células-Tronco Mesenquimais/citologia , Células da Medula Óssea/citologia , Células da Medula Óssea/efeitos dos fármacos , Células da Medula Óssea/metabolismo , Cartilagem Articular/citologia , Diferenciação Celular/genética , Células Cultivadas , Condrócitos/efeitos dos fármacos , Condrócitos/metabolismo , Condrogênese/genética , DNA/metabolismo , Matriz Extracelular/metabolismo , Glicosaminoglicanos/metabolismo , Humanos , Células-Tronco Mesenquimais/efeitos dos fármacos , Células-Tronco Mesenquimais/metabolismo , Reação em Cadeia da Polimerase em Tempo Real , Coloração e RotulagemRESUMO
An antigen of apparent molecular mass of 30 kDa, termed p30, was purified from Leishmania (L.) chagasi amastigotes after separation of parasite extracts by sodium dodecyl sulfate-polyacrylamide gel eletroctrophoresis followed by electroelution. The use of the purified antigen in lymphocyte cultures from BALB/c mice previously immunised with L. (L.) chagasi amastigotes led to high levels of proliferation. Animal immunisation with p30 plus complete Freund's adjuvant either by subcutaneous or intraperitoneal route led to comparable antigenic stimulation. Similar stimulation indices induced by p30 were also obtained when animals were immunised with Corynebacterium parvum as adjuvant by the intraperitoneal route. Detection of IL-2 and IFN-gamma in the supernatants from lymphocytes stimulated by p30 and inhibition of the production of these lymphokines in the presence of anti-CD4 strongly indicated the involvement of the Th1 subset in the responses elicited by p30 antigen. Immunisation of BALB/c mice with p30 provided partial protection against challenge with L. (L.) chagasi amastigotes, indicating a protective role for p30 and that Th1 can be related to accquired resistance to visceral leishmaniasis in a murine model. Further characterisation studies were performed by the use of a monoclonal antibody directed to a cysteine proteinase of 30 kDa from L. (L.) amazonensis amastigotes. Despite the cross-reactivity presented by p30 from both Leishmania species, the p30 from L. (L.) chagasi amastigotes lacks proteolytic activity.
Assuntos
Antígenos de Protozoários/isolamento & purificação , Interações Hospedeiro-Parasita , Leishmania/química , Animais , Antígenos de Protozoários/química , Western Blotting , Eletroforese em Gel de Poliacrilamida , Feminino , Leishmania/fisiologia , Camundongos , Camundongos Endogâmicos BALB C , Peso Molecular , Células Th1/parasitologiaRESUMO
A 20-year-old man died from Aspergillus pneumonia three weeks after heavy exposure to grain dust. Lung biopsy and autopsy demonstrated a distinctive form of suppurating granulomatous bronchopneumonia caused by Aspergillus fumigatus, which was the sole agent cultured from the tissue. The liver and lymph nodes contained pigmented lipid histiocytes characteristic of chronic granulomatous disease, and subsequently both of the patient's brothers were found to have X-linked chronic granulomatous disease. The authors suggest that this morphologic expression of Aspergillus pneumonia should raise a suspicion of neutrophil dysfunction or chronic granulomatous disease.
Assuntos
Aspergilose Broncopulmonar Alérgica/etiologia , Doença Granulomatosa Crônica/complicações , Adulto , Aspergilose Broncopulmonar Alérgica/patologia , Aspergillus fumigatus , Pulmão de Fazendeiro/etiologia , Pulmão de Fazendeiro/patologia , Doença Granulomatosa Crônica/genética , Doença Granulomatosa Crônica/patologia , Humanos , Pulmão/patologia , MasculinoRESUMO
Abstract Length and weight relationships and descriptive statistics are reported for six shrimp species caught off the Madeira archipelago between 1983 and 2014 using bottom and floating traps from depths ranging from 50 to 1,300 m. The parameter b ranged between 2.36 for Plesionika ensis and 2.97 for Plesionika williamsi. All species showed a pattern of negative allometric growth. To the authors' knowledge all weight-length relationships presented herein are recorded for the first time from the Madeira area, and in the cases of Ligur ensiferus and Plesionika ensis are the first references worldwide.
Resumo As relações peso-comprimento e a estatística descritiva foram estimadas para seis espécies de camarões, capturados ao largo do arquipélago da Madeira, entre 1983 e 2014, usando armadilhas de fundo e alvoradas entre os 50 e 1.300 metros de profundidade. O parâmetro b variou entre 2,36 para Plesionika ensis e 2,97 para Plesionika williamsi. Todas as espécies evidenciaram um padrão de crescimento alométrico negativo. De acordo com o conhecimento dos autores, todas as relações peso-comprimento são aqui apresentadas pela primeira vez para a área da Madeira e no caso de Ligur ensiferus e Plesionika ensis são a primeira referência mundial.
Assuntos
Animais , Masculino , Feminino , Decápodes/fisiologia , Portugal , Peso Corporal , Oceano Atlântico , Pandalidae/fisiologia , Tamanho CorporalRESUMO
Abstract Analysis of abundance and population structure of Plesionika narval was performed on data concerning 5,255 specimens obtained from 62 fishing sets carried out off the Madeira archipelago (Northeastern Atlantic) between 2004 and 2008 in a depth range from 101 to 350 m. Abundance ranged from 0.01 to 19.74 specimens-per-trap and significant differences were found between seasons, probably as a result of an increment of population in the spring during the recruitment season. The analysis of size distribution revealed that the carapace length (CL) ranged from 2.45 to 28.61 mm and that mean female size consistently exceeded that of males. Differences in mean CL were statistically significant between depth strata and seasons. Of the specimens sampled, 57.00% were males, 41.88% females and 1.42% undetermined. Sex ratio also differed significantly between seasons according to depth strata, consolidating the hypothesis of the existence of seasonal migrations related with the reproductive cycle of this species. Ovigerous females showed larger sizes and occurred all year around and remain in shallow waters in winter, summer and autumn and move to deeper waters in spring. The highest frequency of ovigerous females was recorded in summer, between 151 and 200 m deep supporting the hypothesis that spawning of this species occurs in shallow waters, especially in late summer.
Resumo O estudo de abundância e dinâmica populacional de Plesionika narval foi efetuado com 5.255 espécimes provenientes de 62 lances de pesca realizados ao largo do arquipélago da Madeira (Atlântico Nordeste) de 2004 a 2008 entre 101 e 350 m de profundidade. A abundância oscilou entre 0,01 e 19,74 espécimes-por-armadilha com diferenças significativas entre estações provavelmente devido ao aumento da população na primavera durante o período de recrutamento. A análise da distribuição de tamanhos revelou que o comprimento da carapaça (CL) variou entre 2,45 e 28,61 mm e que o tamanho médio das fêmeas excedeu o dos machos. Verificaram-se diferenças significativas no CL médio entre estrato de profundidade e estação. Do total amostrado, 57,00% foram machos, 41,88% fêmeas e 1,42% indeterminados. A razão de sexos também diferiu significativamente entre estações de acordo com a profundidade, consolidando a hipótese da existência de migrações sazonais relacionadas com o ciclo reprodutivo desta espécie. As fêmeas ovadas apresentaram maiores tamanhos e ocorreram durante todo o ano permanecendo em águas pouco profundas no inverno, verão e outono e migrando para águas profundas na primavera. A maior frequência de fêmeas ovadas foi registada no verão, entre 151 e 200 m de profundidade reforçando a hipótese de que a desova desta espécie ocorre em águas menos profundas, especialmente no final do verão.
Assuntos
Animais , Masculino , Feminino , Pandalidae/fisiologia , Distribuição Animal , Portugal , Reprodução , Estações do Ano , Razão de Masculinidade , Oceano Atlântico , Dinâmica Populacional , Tamanho CorporalRESUMO
Zero-valent iron nanoparticles (nZVIs) are often used in environmental remediation. Their high surface area that is associated with their high reactivity makes them an excellent agent capable of transforming/degrading contaminants in soils and waters. Due to the recent development of green methods for the production of nZVIs, the use of this material became even more attractive. However, the knowledge of its capacity to degrade distinct types of contaminants is still scarce. The present work describes the study of the application of green nZVIs to the remediation of soils contaminated with a common anti-inflammatory drug, ibuprofen. The main objectives of this work were to produce nZVIs using extracts of grape marc, black tea and vine leaves, to verify the degradation of ibuprofen in aqueous solutions by the nZVIs, to study the remediation process of a sandy soil contaminated with ibuprofen using the nZVIs, and to compare the experiments with other common chemical oxidants. The produced nZVIs had nanometric sizes and were able to degrade ibuprofen (54 to 66% of the initial amount) in aqueous solutions. Similar remediation efficiencies were obtained in sandy soils. In this case the remediation could be enhanced (achieving degradation efficiencies above 95%) through the complementation of the process with a catalyzed nZVI Fenton-like reaction. These results indicate that this remediation technology represents a good alternative to traditional and more aggressive technologies.
Assuntos
Recuperação e Remediação Ambiental/métodos , Ibuprofeno/química , Ferro/química , Nanopartículas Metálicas/química , Poluentes do Solo/química , Cromatografia Líquida , Microscopia Eletrônica de TransmissãoRESUMO
The Finite Element Method is a well-known technique, being extensively applied in different areas. Studies using the Finite Element Method (FEM) are targeted to improve cardiac ablation procedures. For such simulations, the finite element meshes should consider the size and histological features of the target structures. However, it is possible to verify that some methods or tools used to generate meshes of human body structures are still limited, due to nondetailed models, nontrivial preprocessing, or mainly limitation in the use condition. In this paper, alternatives are demonstrated to solid modeling and automatic generation of highly refined tetrahedral meshes, with quality compatible with other studies focused on mesh generation. The innovations presented here are strategies to integrate Open Source Software (OSS). The chosen techniques and strategies are presented and discussed, considering cardiac structures as a first application context.
RESUMO
Abstract Several experimental surveys were carried out in the Northeastern Atlantic, Madeira archipelago from 1991 to 2008 to explore new fisheries resources. This study examined the selectivity of bottom and floating traps and the analysis of yield-per-recruit (YPR) and biomass-per-recruit (BPR) providing helpful insight to the management of the shrimp Plesionika narval. A total of 28,262 specimens were sampled and the analysis of length at first capture returned higher values when using floating traps indicating that these traps are more selective, exerting less pressure on the resource. The YPR and BPR analysis showed that the stock is under exploited for the studied area and suggests that the use of floating traps in the commercial fisheries of P. narval is recommended, which will allow a higher maximum allowable limit of exploitation and greater yield. The results suggest that P. narval has the potential to support a viable and sustainable fishery using floating traps.
Resumo Vários cruzeiros de investigação foram realizados no Atlântico Nordeste, arquipélago da Madeira entre 1991 e 2008 visando a exploração de novos recursos pesqueiros. O presente estudo contemplou a comparação da seletividade de pesca entre armadilhas de fundo e flutuantes e a análise de rendimento por recruta (YPR) e biomassa por recruta (BPR) facultando informação essencial para a gestão do camarão Plesionika narval. Um total de 28,262 especimens foram amostrados e a análise de comprimento de primeira captura retornou valores mais elevados aquando da utilização de armadilhas flutuantes, indicando que essas armadilhas são mais seletivas e exercem menos pressão sobre o recurso. A análise YPR e BPR mostrou que o estoque se encontra sob explorado para a área de estudo e recomenda a utilização de armadilhas flutuantes na pesca comercial de P. narval, que permitirão um limite máximo de exploração com rendimento superior. Os resultados sugerem que P. narval tem o potencial para suportar uma pescaria viável e sustentável mediante a utilização de armadilhas flutuantes.
Assuntos
Animais , Masculino , Feminino , Conservação dos Recursos Naturais , Pandalidae , Pesqueiros , Portugal , Características de História de VidaRESUMO
Tissue engineering sustains the need of a three-dimensional (3D) scaffold to promote the regeneration of tissues in volume. Usually, scaffolds are seeded with an adequate cell population, allowing their growth and maturation upon implantation in vivo. Previous studies obtained by our group evidenced significant growth patterns and osteogenic differentiation of human bone marrow mesenchymal stem cells (hBMSCs) when seeded and cultured on melt-based porous chitosan fibre mesh scaffolds (cell constructs). Therefore, it is crucial to test the in vivo performance of these in vitro 3D cell constructs. In this study, chitosan-based scaffolds were seeded and cultured in vitro with hBMSCs for 3 weeks under osteogenic stimulation conditions and analysed for cell adhesion, proliferation and differentiation. Implantation of 2 weeks precultured cell constructs in osteogenic culture conditions was performed into critical cranial size defects in nude mice. The objective of this study was to verify the scaffold integration and new bone formation. At 8 weeks of implantation, scaffolds were harvested and prepared for micro-computed tomography (µCT) analysis. Retrieved implants showed good integration with the surrounding tissue and significant bone formation, more evident for the scaffolds cultured and implanted with human cells. The results of this work demonstrated that chitosan-based scaffolds, besides supporting in vitro proliferation and osteogenic differentiation of hBMSCs, induced bone formation in vivo. Thus, their osteogenic potential in orthotopic location in immunodeficient mice was validated, evidencing good prospects for their use in bone tissue-engineering therapies.
Assuntos
Células da Medula Óssea/citologia , Butileno Glicóis/química , Quitosana/química , Polímeros/química , Células Estromais/citologia , Engenharia Tecidual/métodos , Alicerces Teciduais/química , Fosfatase Alcalina/metabolismo , Animais , Osso e Ossos/citologia , Osso e Ossos/metabolismo , Sobrevivência Celular , Células Cultivadas , Humanos , Camundongos , Camundongos Nus , Fenótipo , Porosidade , Microtomografia por Raio-X/métodosRESUMO
Native articular cartilage is subjected to synovial fluid flow during normal joint function. Thus, it is believed that the morphogenesis of articular cartilage may be positively regulated by the application of similar stimulation in vitro. In the present study, the effect of fluid flow over the chondrogenic differentiation of human bone marrow-derived mesenchymal stem cells (hBM-MSCs) was investigated. We intended to find out whether the shear stress caused by perfusion of the medium through the constructs was capable of augmenting the differentiation process. Human BMSCs were isolated from bone marrow aspirates and were characterized by flow cytometry. After expansion, hBM-MSCs were seeded statically onto fibre mesh scaffolds, consisting of a blend of 50:50 chitosan:poly(butylene terephthalate adipate) (CPBTA). Constructs were cultured in a flow-perfusion bioreactor for 28 days, using complete medium for chondrogenesis supplemented by TGFß3. An enhanced ECM deposition and collagen type II production was observed in the bioreactor samples when compared to the static controls. Moreover, it was observed that hBM-MSCs, in static cultures, take longer to differentiate. ECM accumulation in these samples is lower than in the bioreactor sections, and there is a significant difference in the expression of collagen type I. We found that the flow-induced shear stress has a beneficial effect on the chondrogenic differentiation of hMSCs.
Assuntos
Reatores Biológicos , Células da Medula Óssea/citologia , Diferenciação Celular/efeitos dos fármacos , Quitosana/farmacologia , Condrogênese/efeitos dos fármacos , Células-Tronco Mesenquimais/citologia , Engenharia Tecidual/instrumentação , Biomarcadores/metabolismo , Células da Medula Óssea/efeitos dos fármacos , Células da Medula Óssea/metabolismo , Células da Medula Óssea/ultraestrutura , Separação Celular , Forma Celular/efeitos dos fármacos , Células Cultivadas , Condrogênese/genética , Colágeno Tipo I/metabolismo , Colágeno Tipo II/metabolismo , DNA/metabolismo , Citometria de Fluxo , Humanos , Imuno-Histoquímica , Células-Tronco Mesenquimais/efeitos dos fármacos , Células-Tronco Mesenquimais/metabolismo , Células-Tronco Mesenquimais/ultraestrutura , Perfusão , Poliésteres/farmacologia , Reação em Cadeia da Polimerase em Tempo Real , Reologia/efeitos dos fármacos , Coloração e Rotulagem , Alicerces Teciduais/químicaRESUMO
The Jarisch-Herxheimer reaction (JHR) is a syndrome observed after antimicrobial treatment of some infectious diseases. The syndrome has clinical characteristics of an inflammatory reaction to antibiotic treatment. A prospective study of patients with a clinical and laboratory diagnosis of syphilis was conducted at a sexually transmitted diseases clinic in Rio de Janeiro, Brazil. Patients were treated with benzathine penicillin and observed for the JHR. A total of 115 patients were included in this study. Fifty-one patients (44%) had secondary syphilis; 37 (32%), primary; 26 (23%), latent; and one (1%), tertiary syphilis. Ten patients (9%) developed the JHR. All JHRs occurred in patients with secondary and latent syphilis. No patients experienced an allergic reaction to penicillin. The JHR occurred less frequently than in previous studies. It is important that health-care professionals recognize the clinical characteristics of the JHR so that it is not misinterpreted as an allergic reaction to penicillin.
Assuntos
Antibacterianos/administração & dosagem , Antibacterianos/efeitos adversos , Inflamação/induzido quimicamente , Penicilina G Benzatina/administração & dosagem , Penicilina G Benzatina/efeitos adversos , Sífilis/tratamento farmacológico , Adolescente , Adulto , Brasil , Feminino , Humanos , Masculino , Estudos Prospectivos , Adulto JovemRESUMO
Blends of chitosan and synthetic aliphatic polyesters (polybutylene succinate, polybutylene succinate adipate, polycaprolactone, and polybutylene terepthalate adipate) were compounded with and without hydroxyapatite, a bioactive mineral filler known to enhance osteoconduction. The blends and composites were compression molded with two different granulometric salt sizes (63-125 microm and 250-500 microm) having different levels of salt content (60, 70, and 80%) by weight. By leaching the salt particles, it was possible to produce porous scaffolds with distinct morphologies. The relationship between scaffold morphology and mechanical properties was evaluated using scanning electron microscopy, microcomputed tomography, compression testing, differential scanning calorimetry, small-angle X-ray scattering (SAXS), and wide-angle X-ray scattering. The produced scaffolds are characterized by having different morphologies depending on the average particle size and the amount of NaCl used. Specimens with higher porosity level have a less organized pore structure but increased interconnectivity of the pores. The stress-strain curve under compression displayed a linear elasticity followed by a plateau whose characteristics depend on the scaffold polymer composition. A decrease in the salt particle size used to create the porosity caused in general a decrease in the mechanical properties of the foams. Composites with hydroxyapatite had a sharp reduction in yield stress, modulus, and strain at break. The melting temperature decreased with increased chitosan content. SAXS results indicate no preferential crystalline orientation in the scaffolds. Cytotoxicity evaluation were carried out using standard tests (accordingly to ISO/EN 10993 part 5 guidelines), namely MTS test with a 24-h extraction period, revealing that L929 cells had comparable metabolic activities to that obtained for the negative control.