929 resultados para Serum bone formation markers
Resumo:
To determine in Type 1 diabetes patients if levels of pigment epithelium-derived factor (PEDF), an anti-angiogenic, anti-inflammatory and antioxidant factor, are increased in individuals with complications and positively related to vascular and renal dysfunction, body mass index, glycated haemoglobin, lipids, inflammation and oxidative stress.
Resumo:
Coprolites from the Beechy Member of the Cretaceous Bearpaw Formation, southern Saskatchewan, presumably deposited by one or more species of mosasaur or large fish/shark, were recovered and analyzed using SEM/EDS. The data reveal the presence of pseudomorphous coccoid bacteria, potential filamentous bacteria, bacterial endospores and filamentous fungi. No recorded fossil plant or bone material could be identified, either within the highly compressed coprolitic mat-flattened full coprolite bolus - of recovered marine sediment encased in a mixed mat of hematite-apatite primary minerals heavily coated with Ca-smectite and nontronite, or the full coprolite bolus. The presence of fossil bacteria with morphological characteristics similar to those of endospores in other environments suggests that only robust microbial forms such as these survive diagenesis, partly with some carbon still intact, the remainder replaced with silica and iron. The data support the view that coprolites can serve as a useful source of information on the ancient microbial world. © 2012 Elsevier Ltd.
Resumo:
The diagnosis of patients with myelodysplastic syndromes (MDS) is largely dependent on morphologic examination of bone marrow aspirates. Several criteria that form the basis of the classifications and scoring systems most commonly used in clinical practice are affected by operator-dependent variation. To identify standardized molecular markers that would allow prediction of prognosis, we have used gene expression profiling (GEP) data on CD34+ cells from patients with MDS to determine the relationship between gene expression levels and prognosis.
Resumo:
Bone morphogenetic proteins (BMPs) are members of the TGFβ superfamily of secreted cysteine knot proteins that includes TGFβ1, nodal, activins and inhibins. BMPs were first discovered by Urist in the 1960s when he showed that implantation of demineralized bone into intramuscular tissue of rabbits induced bone and cartilage formation. Since this seminal discovery, BMPs have also been shown to play key roles in several other biological processes, including limb, kidney, skin, hair and neuronal development, as well as maintaining vascular homeostasis. The multifunctional effects of BMPs make them attractive targets for the treatment of several pathologies, including bone disorders, kidney and lung fibrosis, and cancer. This review will summarize current knowledge on the BMP signalling pathway and critically evaluate the potential of recombinant BMPs as pharmacological agents for the treatment of bone repair and tissue fibrosis in patients.
Resumo:
The present study assessed whether increased fruit and vegetable (F&V) intake reduced the concentrations of the inflammatory marker serum amyloid A (SAA) in serum, HDL2 and HDL3 and whether the latter reduction influenced any of the functional properties of these HDL subfractions. The present study utilised samples from two previous studies: (1) the FAVRIT (Fruit and Vegetable Randomised Intervention Trial) study - hypertensive subjects (systolic blood pressure (BP) range 140-190 mmHg; diastolic BP range 90-110 mmHg) were randomised to receive a 1-, 3- or 6-portion F&V/d intervention for 8 weeks, and (2) the ADIT (Ageing and Dietary Intervention Trial) study - older subjects (65-85 years) were randomised to receive a 2- or 5-portion F&V/d intervention for 16 weeks. HDL2 and HDL3 were isolated by rapid ultracentrifugation. Measurements included the following: serum high-sensitive C-reactive protein (hsCRP) by an immunoturbidimetric assay; serum IL-6 and E-selectin and serum-, HDL2- and HDL3-SAA by ELISA procedures; serum-, HDL2- and HDL3-cholesterol ester transfer protein (CETP) activity by a fluorometric assay. Although the concentrations of hsCRP, IL-6 and E-selectin were unaffected by increasing F&V intake in both studies (P>0·05 for all comparisons), those of SAA in HDL3 decreased in the FAVRIT cohort (P= 0·049) and those in HDL2 and HDL3 decreased in the ADIT cohort (P= 0·035 and 0·032), which was accompanied by a decrease in the activity of CETP in HDL3 in the FAVRIT cohort (P= 0·010) and in HDL2 in the ADIT cohort (P= 0·030). These results indicate that SAA responds to increased F&V intake, while other inflammatory markers remain unresponsive, and this leads to changes in HDL2 and HDL3, which may influence their antiatherogenic potential. Overall, the present study provides tangible evidence of the effectiveness of increased F&V intake, which may be of use to health policy makers and the general public.
Resumo:
Background: Differentiation between septic and aseptic loosening of joint replacements is essential for successful revision surgery, but reliable markers for the diagnosis of low-grade infection are lacking. The present study was performed to assess intra-articular and systemic levels of antimicrobial peptides and proinflammatory cytokines as diagnostic markers for periprosthetic joint infection. Methods: Fifteen consecutive patients with staphylococcal periprosthetic joint infections and twenty control patients with aseptic loosening of total hip and knee replacements were included in this prospective, single-center, controlled clinical trial. Expression of the antimicrobial peptides human β-defensin-2 (HBD-2), human β-defensin-3 (HBD-3), and cathelicidin LL-37 (LL-37) was determined by ELISA (enzyme-linked immunosorbent assay) in serum and joint aspirates. Proinflammatory cytokines were assessed in serum and joint aspirates with use of cytometric bead arrays. C-reactive protein in serum, microbiology, and histopathology of periprosthetic tissue served as the “gold standard” for the diagnosis of infection. Results: The antimicrobial peptides HBD-3 and LL-37 were significantly elevated in joint aspirates from patients with periprosthetic joint infection compared with patients with aseptic loosening, and the area under the curve (AUC) in a receiver operating characteristic curve analysis was equal to 0.745 and 0.875, respectively. Additionally, significant local increases in the proinflammatory cytokines interleukin (IL)-1β, IL-4, IL-6, IL-17A, interferon (IFN)-γ, and tumor necrosis factor (TNF)-α were observed to be associated with infection. Logistic regression analysis indicated that the combination of an antimicrobial peptide with another synovial fluid biomarker improved diagnostic accuracy; the AUC value was 0.916 for LL-37 and IL-4, 0.895 for LL-37 and IL-6, 0.972 for HBD-3 and IL-4, and 0.849 for HBD-3 and IL-6. In contrast, the only antimicrobial peptides and cytokines in serum that showed a significant systemic increase in association with infection were HBD-2, IL-4, and IL-6 (all of which had an AUC value of <0.75). Conclusions: The present study showed promising results for the use of antimicrobial peptides and other biomarkers in synovial fluid for the diagnosis of periprosthetic joint infection, and analysis of the levels in synovial fluid was more accurate than analysis of serum.
Resumo:
For many decades Palaeolithic research viewed the development of early modern human behaviour as largely one of progress down a path towards the modernity of the present. The European Palaeolithic sequence the most extensively studied was for a long time the yard-stick against which records from other regions were judged. Recent work undertaken in Africa and increasingly Asia, however, now suggests that the European evidence may tell a story that is more parochial and less universal than previously thought. While tracking developments at the large scale (the grand narrative) remains important, there is growing appreciation that to achieve a comprehensive understanding of human behavioural evolution requires an archaeologically regional perspective to balance this. One of the apparent markers of human modernity that has been sought in the global Palaeolithic record, prompted by finds in the European sequence, is innovation in bonebased technologies. As one step in the process of re-evaluating and contextualizing such innovations, in this article we explore the role of prehistoric bone technologies within the Southeast Asian sequence, where they have at least comparable antiquity to Europe and other parts of Asia. We observe a shift in the technological usage of bone from a minor component to a medium of choice during the second half of the Last Termination and into the Holocene. We suggest that this is consistent with it becoming a focus of the kinds of inventive behaviour demanded of foraging communities as they adapted to the far-reaching environmental and demographic changes that were reshaping this region at that time. This record represents one small element of a much wider, much longerterm adaptive process, which we would argue is not confined to the earliest instances of a particular technology or behaviour, but which forms part of an on-going story of our behavioural evolution. © 2012 The McDonald Institute for Archaeological Research.
Resumo:
Critical functions of the immune system are maintained by the ability of myeloid progenitors to differentiate and mature into macrophages. We hypothesized that the cytoprotective gas molecule carbon monoxide (CO), generated endogenously by heme oxygenases (HO), promotes differentiation of progenitors into functional macrophages. Deletion of HO-1, specifically in the myeloid lineage (Lyz-Cre:Hmox1(flfl)), attenuated the ability of myeloid progenitors to differentiate toward macrophages and decreased the expression of macrophage markers, CD14 and macrophage colony-stimulating factor receptor (MCSFR). We showed that HO-1 and CO induced CD14 expression and efficiently increased expansion and differentiation of myeloid cells into macrophages. Further, CO sensitized myeloid cells to treatment with MCSF at low doses by increasing MCSFR expression, mediated partially through a PI3K-Akt-dependent mechanism. Exposure of mice to CO in a model of marginal bone marrow transplantation significantly improved donor myeloid cell engraftment efficiency, expansion and differentiation, which corresponded to increased serum levels of GM-CSF, IL-1α and MCP-1. Collectively, we conclude that HO-1 and CO in part are critical for myeloid cell differentiation. CO may prove to be a novel therapeutic agent to improve functional recovery of bone marrow cells in patients undergoing irradiation, chemotherapy and/or bone marrow transplantation.
Resumo:
We report a case study of a female who received an allogeneic bone marrow transplantation (BMT) from a sex-mismatched related donor and who, after a twenty-year interval, developed an acute fulminant biopsy-proven demyelinating disorder of cerebral white matter which followed a remitting-relapsing chronic course. In situ hybridization studies using Y-chromosome-specific markers revealed Y-chromosome-positive mononuclear cells in biopsy samples of white matter. Magnetic resonance imaging (MRI) studies of the asymptomatic healthy male donor showed multiple white matter lesions. These observations suggest that donor lymphocytes were sensitized to central nervous system (CNS) antigens prior to or at the time of transplantation but remained dormant for 20 years before becoming activated to cause widespread demyelination.
Resumo:
This review describes an approach to the prevention of graft-versus-host disease (GVHD) and graft rejection following allogeneic BMT that differs from conventional methods. Ultraviolet (UV) irradiation inhibits the proliferative responses of lymphoid cells to mitogens and alloantigens by inactivation of T lymphocytes and dendritic cells, and in animal models this can prevent both GVHD and graft rejection. It is important that the marrow repopulating capacity of haemopoietic stem cells is not damaged by the irradiation process. We have found that polymorphic microsatellite markers are a sensitive way of assessing the impact of UV irradiation on chimerism after BMT in rodents.
Resumo:
O cimento ósseo acrílico é o único material utilizado para a fixação de próteses em cirurgias ortopédicas, surgindo como uma alternativa às técnicas não cimentadas. Cerca de um milhão de pacientes são anualmente tratados para a substituição total da articulação do quadril e do joelho. Com a maior expectativa de vida da população e o aumento do número de cirurgias realizadas por ano espera-se que o uso do cimento ósseo aumente substancialmente. A fraca ligação do cimento ao osso é um problema comum que pode causar perda asséptica da prótese. Assim, torna-se necessário investir no desenvolvimento de cimentos ósseos alternativos que permitam promover maior estabilidade e melhor desempenho do implante. O principal objetivo desta tese foi desenvolver um cimento ósseo bioativo, capaz de ligar-se ao osso, com propriedades melhoradas relativamente aos sistemas convencionais. A preparação dos materiais foi realizada por dois processos diferentes, a polimerização por via térmica e a polimerização por via química. Inicialmente, utilizando o processo térmico, foram desenvolvidos compósitos de PMMA-co-EHA reforçados com vidro de sílica (CSi) e vidro de boro (CB) e comparados em termos do seu comportamento in vitro em meio acelular e celular. A formação de precipitados de fosfato de cálcio foi observada sobre a superfície de todos os compósitos indicando que estes materiais são potencialmente bioativos. Em relação à avaliação biológica o CSi demonstrou um efeito indutor da proliferação das células. As células apresentaram uma morfologia normal e alta taxa de crescimento quando comparadas com o padrão de cultura. Por outro lado ocorreu inibição da proliferação celular para o CB provavelmente devido à sua elevada taxa de degradação, levando a uma elevada concentraçao de iões de B e de Mg no meio de cultura. O efeito do vidro nos cimentos curados por via química, incorporando um activador de baixa toxicidade, também foi avaliado. Os resultados sugerem que as novas formulações podem diminuir o efeito exotérmico na cura do cimento e melhorar as propriedades mecânicas (flexão e compressão). Outro estudo conduzido neste trabalho explorou a possibilidade de incorporar ibuprofeno (fármaco anti-inflamatório) no cimento, dando origem a um material capaz de ser simultaneamente, bioativo e promotor da libertação controlada de fármacos. Neste contexto foi evidenciado que o desempenho do cimento desenvolvido pode contribuir para minimizar o processo inflamatório associado a uma cirurgia ortopédica. Finalmente, a fase sólida do cimento ósseo bioativo foi modificada por diferentes polímeros biodegradáveis. A adição deste enchimento deu origem a um cimento parcialmente biodegradável que pode permitir a formação de poros e o crescimento ósseo para o interior do cimento, resultando numa melhor fixação da prótese.
Resumo:
Bioactive glasses and glass-ceramics are a class of third generation biomaterials which elicit a special response on their surface when in contact with biological fluids, leading to strong bonding to living tissues. The purpose of the present study was to develop diopside based alkali-free bioactive glasses in order to achieve good sintering behaviour, high bioactivity, and a dissolution/ degradation rates compatible with the target applications in bone regeneration and tissue engineering. Another aim was to understand the structure-property relationships in the investigated bioactive glasses. In this quest, various glass compositions within the Diopside (CaMgSi2O6) – Fluorapatite (Ca5(PO4)3F) – Tricalcium phosphate (3CaO•P2O5) system have been investigated. All the glasses were prepared by melt-quenching technique and characterized by a wide array of complementary characterization techniques. The glass-ceramics were produced by sintering of glass powders compacts followed by a suitable heat treatment to promote the nucleation and crystallization phenomena. Furthermore, selected parent glass compositions were doped with several functional ions and an attempt to understand their effects on the glass structure, sintering ability and on the in vitro bio-degradation and biomineralization behaviours of the glasses was made. The effects of the same variables on the devitrification (nucleation and crystallization) behaviour of glasses to form bioactive glass-ceramics were also investigated. Some of the glasses exhibited high bio-mineralization rates, expressed by the formation of a surface hydroxyapatite layer within 1–12 h of immersion in a simulated body fluid (SBF) solution. All the glasses showed relatively lower degradation rates in comparison to that of 45S5 Bioglass®. Some of the glasses showed very good in vitro behaviour and the glasses co-doped with zinc and strontium showed an in vitro dose dependent behaviour. The as-designed bioactive glasses and glass–ceramic materials are excellent candidates for applications in bone regeneration and for the fabrication of scaffolds for tissue engineering.
Resumo:
Mesenchymal stromal cells are adult stem cells found mostly in the bone marrow. They have immunosuppressive properties and they have been successfully applied as biological therapy in several clinical trials regarding autoimmune diseases. Despite the great number of clinical trials, MSCs’ action is not fully understand and there are no identified markers that correlate themselves with the immunomodulatory power. A lipidomic approach can solve some of these problems once lipids are one of the major cells’ components. Therefore, in this study cells’ lipidome was analysed and its deviations were evaluated according to the medium of culture and to the presence of pro-inflammatory stimuli, mimicking physiological conditions in which these cells are used. This was the first study ever made that aimed to analyse the differences in the phospholipid profile between mesenchymal stromal cells non-stimulated and stimulated with proinflammatory stimulus. This analysis was conducted in both cells cultured in medium supplemented with animal serum and in cells cultured in a synthetic medium. In cells cultured in the standard medium the levels of phosphatidylcholine (PC) species with shorter fatty acids (FAs) acyl chains decreased under pro-inflammatory stimuli. The level of PC(40:6) also decreased, which may be correlated with enhanced levels of lysoPC (LPC)(18:0) - an anti-inflammatory LPC - observed in cells subjected to TNF-α and IFN-γ. Simultaneously, the relative amounts of PC(36:1) and PC(38:4) increased. TNF-α and IFN- γ also enhanced the levels of phosphatidylethanolamine PE(40:6) and decreased the levels of PE(38:6). Higher expression of phosphatidylserine PS(36:1) and sphingomyelin SM(34:0) along with a decrease in PS(38:6) levels were observed. However, in cells cultured in a synthetic medium, TNF-α and IFN-γ only enhanced the levels of PS(36:1). These results indicate that lipid metabolism and signaling is modulated during mesenchymal stromal cells action.
Resumo:
Gla-rich protein (GRP) is a vitamin K-dependent protein related to bone and cartilage recently described. This protein is characterized by a large number of Gla (γ-carboxyglutamic acid) residues being the protein with the highest Gla content of any known protein. It was found in a widely variety of tissues but highest levels was found in skeletal and cartilaginous tissues. This small secreted protein was also expressed and accumulated in soft tissues and it was clearly associated with calcification pathologies in the same tissues. Although the biological importance of GRP remains to be elucidated, it was suggested a physiological role in cartilage development and calcification process during vertebrate skeleton formation. Using zebrafish, an accepted model to study skeletal development, we have described two grp paralog genes, grp1 and grp2, which exhibited distinct patterns of expression, suggesting different regulatory pathways for each gene. Gene synteny analysis showed that grp2 gene is more closely related to tetrapod grp, although grp1 gene was proposed to be the vertebrate ortholog by sequence comparison. In addition, we identified a functional promoter of grp2 gene and using a functional approach we confirmed the involvement of transcription factors from Sox family (Sox9b and Sox10) in the regulation of grp2 expression. In an effort to provide more information about the function of grp isoforms, we generated two zebrafish transgenic lines capable to overexpress conditionally grp genes and possible roles in the skeleton development were studied. To better understand GRP function a mammalian system was used and the analysis of knockout mice showed that GRP is involved in chondrocyte maturation and the absence of GRP is associated to proteoglycans loss in calcified articular cartilage. In addition, we detected differences in chondrogenesis markers in articular chondrocyte primary culture. Overall, our data suggest a main role for GRP on chondrocyte differentiation.