RESUMO
Osteoarthritis (OA) is one of the major causes of chronic pain. Although OA has long been considered a non-inflammatory "wear and tear" disease leading to loss of articular cartilage, recent findings provide convincing evidence that inflammatory mechanisms play a pivotal role in the pathophysiology of OA. In OA mononuclear cells (e.â¯g. Tcells and macrophages) infiltrate the synovial membrane and the levels of pro-inflammatory cytokines in peripheral blood and synovial fluid samples are elevated. Increased release of inflammatory mediators including interleukin (IL) IL-1ß, IL-6, IL-8, IL-15 und tumor necrosis factor alpha (TNFα) induces the expression of proteolytic enzymes such as matrix metalloproteinases resulting in cartilage breakdown. Molecular and cellular interactions between the immune and nervous system are also involved in the development of OA-related pain. Inflammatory mediators including IL-6 und TNFα lead to peripheral sensitization of joint nociceptors and growth factors (e.â¯g. NGF) trigger the expression of TRPV1 channels in primary afferents. Moreover, neuropeptides reduce the threshold of nociceptors of OA joints. The current review highlights the role of inflammatory mechanisms in OA-induced joint pain considering clinical signs of inflammation and major inflammatory pathways.
Assuntos
Cartilagem Articular , Osteoartrite , Citocinas , Humanos , Inflamação , Membrana SinovialRESUMO
OBJECTIVE: The purpose of this controlled laboratory study was to determine the efficacy of Interleukin-1 Receptor Antagonist Protein (IRAP) treatment as an early intervention strategy by examining the changes in microRNA and mRNA expression in cartilage in an ex-vivo porcine knee joint impact model. METHODS: Custom impact device was used to create replicable injury ex-vivo to intact porcine knee joint. Injury was caused by dropping a 10 kg weight one time from 1 m directly above the knee in extension. One hour after impact 20 µg/ml IRAP solution was intra-articularly injected. At 8 h post-injury, cartilage samples were harvested for cell viability and genetic expression analysis. Genetic expression of miR-27b, miR-140, miR-125b, ADAMTS-4, ADAMTS-5, MMP-3, IL-1ß, and TNF-α were analyzed by RT-PCR. Cell viability image analysis was performed using ImageJ software. Groups were compared by analysis of variance (ANOVA) followed by Tukey's post-hoc test. A P-value <0.05 was considered significant. RESULTS: At 8 h after IRAP treatment, expressions of ADAMTS-4, ADAMTS-5, MMP-3, IL-1ß, and TNF-α in cartilage were significantly down-regulated from injury group (all P < 0.001). MiR-140, miR-125b, and miR-27b expressions were significantly up-regulated after treatment as compared to control and injury groups (all P < 0.001). CONCLUSION: This study demonstrates that IRAP treatment administered during acute phase of cartilage impact injury increases expression levels of miR-140, miR-125b, and miR-27b in cartilage, indicating increased inhibition of their respective matrix-degrading enzymes. Clinically, these findings support the potential of IRAP treatment as an early intervention strategy for the prevention of cartilage degeneration after impact injury.
Assuntos
Cartilagem Articular/metabolismo , Cistinil Aminopeptidase/farmacologia , Regulação da Expressão Gênica , MicroRNAs/genética , Osteoartrite/genética , RNA Mensageiro/genética , Animais , Cartilagem Articular/patologia , Condrócitos/metabolismo , Condrócitos/patologia , Modelos Animais de Doenças , MicroRNAs/biossíntese , Osteoartrite/metabolismo , Osteoartrite/patologia , RNA Mensageiro/biossíntese , SuínosRESUMO
This study aimed to evaluate the impact of contrast media application on CT attenuation of the bone using a novel calcium-only imaging technique (VCa) from dual-layer spectral detector CT (DLCT), which enables CT-based bone mineral density measurement unimpeded by soft tissue components. For this, true non-contrast (TNC) and venous phase images (VP) of n = 97 patients were acquired. CT attenuation of the first lumbar vertebra (L1) was measured in TNC-VCa, VP-VCa, and in virtual non-contrast images (VNC). CT attenuation was significantly higher in VP-VCa than in TNC-VCa (p < 0.001), although regression analyses revealed a strong linear association between these measures (R2 = 0.84). A statistical model for the prediction of TNC-VCa CT attenuation was established (TNC-VCa[HU] = - 6.81 + 0.87 × VP-VCa[HU]-0.55 × body weight[kg]) and yielded good agreement between observed and predicted values. Furthermore, a L1 CT attenuation threshold of 293 HU in VP-VCa showed a sensitivity of 90% and a specificity of 96% for detecting osteoporosis. The application of contrast media leads to an overestimation of L1 CT attenuation in VCa. However, CT attenuation values from VP-VCa can be used within CT-based opportunistic osteoporosis screening eighter by applying a separate threshold of 293 HU or by converting measured data to TNC-VCa CT attenuation with the given regression equation.
Assuntos
Densidade Óssea , Cálcio , Meios de Contraste , Tomografia Computadorizada por Raios X , Humanos , Meios de Contraste/química , Feminino , Masculino , Tomografia Computadorizada por Raios X/métodos , Idoso , Pessoa de Meia-Idade , Cálcio/metabolismo , Densidade Óssea/efeitos dos fármacos , Vértebras Lombares/diagnóstico por imagem , Idoso de 80 Anos ou mais , Coluna Vertebral/diagnóstico por imagem , Adulto , Osteoporose/diagnóstico por imagemRESUMO
Osteoarthritis of the knee is one of the most important degenerative joint diseases in the clinical routine. The treatment of knee osteoarthritis is not only based on the stage, symptoms and duration of the joint disease, but also depends on the existing arthrosis pattern. In the case of unicompartmental arthrosis, damage typical for osteoarthritis is limited to just one joint compartment. Both the conservative and the surgical treatment of unicompartmental osteoarthritis of the knee have to respect the individual characteristics of the respective forms of osteoarthritis. In the context of this manuscript, the genesis, the diagnostics and the guideline-based stage-adapted conservative and operative treatment of unicompartmental osteoarthritis of the knee are addressed.
Assuntos
Artroplastia do Joelho , Osteoartrite do Joelho , Humanos , Osteoartrite do Joelho/diagnóstico , Artroplastia do Joelho/métodos , Osteotomia/métodos , Articulação do Joelho/cirurgia , Adaptação FisiológicaRESUMO
An evaluation of energy thresholding and acquisition mode for metal artifact reduction in Photon-counting detector CT (PCD-CT) compared to conventional energy-integrating detector CT (EID-CT) was performed. Images of a hip prosthesis phantom placed in a water bath were acquired on a scanner with PCD-CT and EID-CT (tube potentials: 100, 120 and 140 kVp) and energy thresholds (above 55-75 keV) in Macro and Chess mode. Only high-energy threshold images (HTI) were used. Metal artifacts were quantified by a semi-automated segmentation algorithm, calculating artifact volumes, means and standard deviations of CT numbers. Images of a human cadaver with hip prosthesis were acquired on the PCD-CT in Macro mode as proof-of-concept. Images at 140 kVp showed less metal artifacts than 120 kVp or 100 kVp. HTI (70, 75 keV) had fewer artifacts than low energy thresholds (55, 60, 65 keV). Fewer artifacts were observed in the Macro-HTI (8.9-13.3%) for cortical bone compared to Chess-HTI (9.4-19.1%) and EID-CT (10.7-19.0%) whereas in bone marrow Chess-HTI (19.9-45.1%) showed less artifacts compared to Macro-HTI (21.9-38.3%) and EID-CT (36.4-54.9%). Noise for PCD-CT (56-81 HU) was higher than EID-CT (33-36 HU) irrespective of tube potential. High-energy thresholding could be used for metal artifact reduction in PCD-CT, but further investigation of acquisition modes depending on target structure is required.
RESUMO
The Indian Ocean Experiment (INDOEX) was an international, multiplatform field campaign to measure long-range transport of air pollution from South and Southeast Asia toward the Indian Ocean during the dry monsoon season in January to March 1999. Surprisingly high pollution levels were observed over the entire northern Indian Ocean toward the Intertropical Convergence Zone at about 6 degrees S. We show that agricultural burning and especially biofuel use enhance carbon monoxide concentrations. Fossil fuel combustion and biomass burning cause a high aerosol loading. The growing pollution in this region gives rise to extensive air quality degradation with local, regional, and global implications, including a reduction of the oxidizing power of the atmosphere.
Assuntos
Poluição do Ar , Aerossóis , Agricultura , Ásia , Sudeste Asiático , Atmosfera , Biomassa , Carbono , Monóxido de Carbono , Cinza de Carvão , Combustíveis Fósseis , Resíduos Industriais , Óxidos de Nitrogênio , Oceanos e Mares , Ozônio , Material Particulado , Estações do AnoRESUMO
The mechanism(s) and site(s) of action of volatile inhaled anesthetics are unknown in spite of the clinical use of these agents for more than 150 years. In the present study, the model eukaryote Saccharomyces cerevisiae was used to investigate the action of anesthetic agents because of its powerful molecular genetics. It was found that growth of yeast cells is inhibited by the five common volatile anesthetics tested (isoflurane, halothane, enflurane, sevoflurane, and methoxyflurane). Growth inhibition by the agents is relatively rapid and reversible. The potency of these compounds as yeast growth inhibitors directly correlates with their lipophilicity as is predicted by the Meyer-Overton relationship, which directly correlates anesthetic potency of agents and their lipophilicity. The effects of isoflurane on yeast cells were characterized in the most detail. Yeast cells survive at least 48 h in a concentration of isoflurane that inhibits colony formation. Mutants resistant to the growth-inhibitory effects of isoflurane are readily selected. The gene identified by one of these mutations, zzz4-1, has been cloned and characterized. The predicted ZZZ4 gene product has extensive homology to phospholipase A2-activating protein, a GO effector protein of mice. Both zzz4-1 and a deletion of ZZZ4 confer resistance to all five of the agents tested, suggesting that signal transduction may be involved in the response of these cells to volatile anesthetics.
Assuntos
Anestésicos Inalatórios/farmacologia , Proteínas de Transporte , Genes Fúngicos , Éteres Metílicos , Proteínas de Saccharomyces cerevisiae , Saccharomyces cerevisiae/efeitos dos fármacos , Proteínas Adaptadoras de Transdução de Sinal , Sequência de Aminoácidos , Animais , Sequência de Bases , DNA Fúngico/química , DNA Fúngico/efeitos dos fármacos , DNA Fúngico/genética , Enflurano/farmacologia , Éteres/farmacologia , Proteínas Fúngicas/química , Proteínas Fúngicas/genética , Halotano/farmacologia , Isoflurano/farmacologia , Metoxiflurano/farmacologia , Camundongos , Dados de Sequência Molecular , Mutagênese , Oligodesoxirribonucleotídeos , Proteínas/química , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/crescimento & desenvolvimento , Homologia de Sequência de Aminoácidos , Sevoflurano , Relação Estrutura-AtividadeRESUMO
To investigate the mechanism of action of volatile anesthetics, we are studying mutants of the yeast Saccharomyces cerevisiae that have altered sensitivity to isoflurane, a widely used clinical anesthetic. Several lines of evidence from these studies implicate a role for ubiquitin metabolism in cellular response to volatile anesthetics: (i) mutations in the ZZZ1 gene render cells resistant to isoflurane, and the ZZZ1 gene is identical to BUL1 (binds ubiquitin ligase), which appears to be involved in the ubiquitination pathway; (ii) ZZZ4, which we previously found is involved in anesthetic response, is identical to the DOA1/UFD3 gene, which was identified based on altered degradation of ubiquitinated proteins; (iii) analysis of zzz1Delta zzz4Delta double mutants suggests that these genes encode products involved in the same pathway for anesthetic response since the double mutant is no more resistant to anesthetic than either of the single mutant parents; (iv) ubiquitin ligase (MDP1/RSP5) mutants are altered in their response to isoflurane; and (v) mutants with decreased proteasome activity are resistant to isoflurane. The ZZZ1 and MDP1/RSP5 gene products appear to play important roles in determining effective anesthetic dose in yeast since increased levels of either gene increases isoflurane sensitivity whereas decreased activity decreases sensitivity. Like zzz4 strains, zzz1 mutants are resistant to all five volatile anesthetics tested, suggesting there are similarities in the mechanisms of action of a variety of volatile anesthetics in yeast and that ubiquitin metabolism affects response to all the agents examined.
Assuntos
Proteínas Adaptadoras de Transdução de Sinal , Anestésicos Inalatórios/farmacologia , Proteínas de Transporte/metabolismo , Isoflurano/farmacologia , Ligases/metabolismo , Proteínas de Saccharomyces cerevisiae , Saccharomyces cerevisiae/efeitos dos fármacos , Saccharomyces cerevisiae/metabolismo , Complexos Ubiquitina-Proteína Ligase , Ubiquitinas/metabolismo , Proteínas de Transporte/genética , Cisteína Endopeptidases , Resistência Microbiana a Medicamentos , Complexos Endossomais de Distribuição Requeridos para Transporte , Enflurano/farmacologia , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Expressão Gênica , Halotano/farmacologia , Ligases/genética , Metoxiflurano/farmacologia , Éteres Metílicos/farmacologia , Complexos Multienzimáticos , Mutagênese , Fenótipo , Complexo de Endopeptidases do Proteassoma , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/crescimento & desenvolvimento , Sevoflurano , Temperatura , Ubiquitina-Proteína LigasesRESUMO
Deregulation of microRNAs (miRs) contributes to progression and metastasis of prostate and other cancers. miR-23b and -27b, encoded in the same miR cluster (miR-23b/-27b), are downregulated in human metastatic prostate cancer compared with primary tumors and benign tissue. Expression of miR-23b/-27b decreases prostate cancer cell migration, invasion and results in anoikis resistance. Conversely, antagomiR-mediated miR-23b and -27b silencing produces the opposite result in a more indolent prostate cancer cell line. However, neither miR-23b/-27b expression or inhibition impacts prostate cancer cell proliferation suggesting that miR-23b/-27b selectively suppresses metastasis. To examine the effects of miR-23b/-27b on prostate cancer metastasis in vivo, orthotopic prostate xenografts were established using aggressive prostate cancer cells transduced with miR-23b/-27b or non-targeting control miRNA. Although primary tumor formation was similar between miR-23b/-27b-transduced cells and controls, miR-23b/-27b expression in prostate cancer cells decreased seminal vesicle invasion and distant metastases. Gene-expression profiling identified the endocytic adaptor, Huntingtin-interacting protein 1-related (HIP1R) as being downregulated by miR-23b/-27b. Increased HIP1R expression in prostate cancer cells inversely phenocopied the effects of miR-23b/-27b overexpression on migration, invasion and anchorage-independent growth. HIP1R rescued miR-23b/-27b-mediated repression of migration in prostate cancer cells. HIP1R mRNA levels were decreased in seminal vesicle tissue from mice bearing miR-23b/-27b-transduced prostate cancer cell xenografts compared with scrambled controls, suggesting HIP1R is a key functional target of miR-23b/-27b. In addition, depletion of HIP1R led to a more rounded, less mesenchymal-like cell morphology, consistent with decreased metastatic properties. Together, these data demonstrate that the miR-23b/-27b cluster functions as a metastasis-suppressor by decreasing HIP1R levels in pre-clinical models of prostate cancer.
Assuntos
MicroRNAs/genética , Neoplasias da Próstata/genética , Proteínas de Transporte Vesicular/genética , Proteínas Adaptadoras de Transdução de Sinal , Animais , Linhagem Celular Tumoral , Movimento Celular/genética , Regulação Neoplásica da Expressão Gênica , Humanos , Masculino , Camundongos , Proteínas dos Microfilamentos , Invasividade Neoplásica/genética , Metástase Neoplásica , Próstata/patologia , Neoplasias da Próstata/patologia , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Oncogenic RAS promotes production of reactive oxygen species (ROS), which mediate pro-malignant signaling but can also trigger DNA damage-induced tumor suppression. Thus RAS-driven tumor cells require redox-protective mechanisms to mitigate the damaging aspects of ROS. Here, we show that MutT Homolog 1 (MTH1), the mammalian 8-oxodGTPase that sanitizes oxidative damage in the nucleotide pool, is important for maintaining several KRAS-driven pro-malignant traits in a nonsmall cell lung carcinoma (NSCLC) model. MTH1 suppression in KRAS-mutant NSCLC cells impairs proliferation and xenograft tumor formation. Furthermore, MTH1 levels modulate KRAS-induced transformation of immortalized lung epithelial cells. MTH1 expression is upregulated by oncogenic KRAS and correlates positively with high KRAS levels in NSCLC human tumors. At a molecular level, in p53-competent KRAS-mutant cells, MTH1 loss provokes DNA damage and induction of oncogene-induced senescence. In p53-nonfunctional KRAS-mutant cells, MTH1 suppression does not produce DNA damage but reduces proliferation and leads to an adaptive decrease in KRAS expression levels. Thus, MTH1 not only enables evasion of oxidative DNA damage and its consequences, but can also function as a molecular rheostat for maintaining oncogene expression at optimal levels. Accordingly, our results indicate MTH1 is a novel and critical component of oncogenic KRAS-associated malignancy and its inhibition is likely to yield significant tumor-suppressive outcomes in KRAS-driven tumors.
Assuntos
Carcinoma Pulmonar de Células não Pequenas/metabolismo , Dano ao DNA , Enzimas Reparadoras do DNA/biossíntese , Regulação Neoplásica da Expressão Gênica , Neoplasias Pulmonares/metabolismo , Monoéster Fosfórico Hidrolases/biossíntese , Proteínas Proto-Oncogênicas/metabolismo , Proteínas ras/metabolismo , Animais , Carcinoma Pulmonar de Células não Pequenas/genética , Carcinoma Pulmonar de Células não Pequenas/patologia , Proliferação de Células/genética , Enzimas Reparadoras do DNA/genética , Feminino , Humanos , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/patologia , Masculino , Camundongos , Camundongos Nus , Monoéster Fosfórico Hidrolases/genética , Proteínas Proto-Oncogênicas/genética , Proteínas Proto-Oncogênicas p21(ras) , Proteína Supressora de Tumor p53/genética , Proteína Supressora de Tumor p53/metabolismo , Regulação para Cima , Proteínas ras/genéticaRESUMO
Aseptic loosening of the femoral component is an important indication for revision surgery in unicompartmental knee replacement (UKR). A new design of femoral component with an additional peg was introduced for the cemented Oxford UKR to increase its stability. The purpose of this study was to compare the primary stability of the two designs of component. Medial Oxford UKR was performed in 12 pairs of human cadaver knees. In each pair, one knee received the single peg and one received the twin peg design. Three dimensional micromotion and subsidence of the component in relation to the bone was measured under cyclical loading at flexion of 40° and 70° using an optical measuring system. Wilcoxon matched pairs signed-rank test was performed to detect differences between the two groups. There was no significant difference in the relative micromotion (p = 0.791 and 0.380, respectively) and subsidence (p = 0.301 and 0.176, respectively) of the component between the two groups at both angles of flexion. Both designs of component offered good strength of fixation in this cadaver study.
Assuntos
Artroplastia do Joelho , Prótese do Joelho , Desenho de Prótese , Falha de Prótese , Idoso , Idoso de 80 Anos ou mais , Artroplastia do Joelho/métodos , Cimentação/métodos , Feminino , Fêmur , Humanos , Masculino , Pessoa de Meia-IdadeRESUMO
Efficient methods to immobilize small molecules under continuous-flow microfluidic conditions would greatly improve label-free molecular interaction studies using biosensor technology. At present, small-molecule immobilization chemistries require special conditions and in many cases must be performed outside the detector and microfluidic system where real-time monitoring is not possible. Here, we have developed and optimized a method for on-chip bioorthogonal chemistry that enables rapid, reversible immobilization of small molecules with control over orientation and immobilization density, and apply this technique to surface plasmon resonance (SPR) studies. Immobilized small molecules reverse the orientation of canonical SPR interaction studies, and also enable a variety of new SPR applications including on-chip assembly and interaction studies of multicomponent structures, such as functionalized nanoparticles, and measurement of bioorthogonal reaction rates. We use this approach to demonstrate that on-chip assembled functionalized nanoparticles show a preserved ability to interact with their target protein, and to measure rapid bioorthogonal reaction rates with k(2) > 10(3) M(-1) s(-1). This method offers multiple benefits for microfluidic biological applications, including rapid screening of targeted nanoparticles with vastly decreased nanoparticle synthetic requirements, robust immobilization chemistry in the presence of serum, and a continuous flow technique that mimics biologic contexts better than current methods used to measure bioorthogonal reaction kinetics such as NMR or UV-vis spectroscopy (e.g., stopped flow kinetics). Taken together, this approach constitutes a flexible and powerful technique for evaluating a wide variety of reactions and intermolecular interactions for in vitro or in vivo applications.
Assuntos
Nanopartículas/química , Proteínas/metabolismo , Ressonância de Plasmônio de Superfície , Técnicas Biossensoriais , Ciclização , Cicloparafinas/química , Cicloparafinas/metabolismo , Cinética , Ligantes , Técnicas Analíticas Microfluídicas/instrumentação , Ligação Proteica , Proteínas/químicaRESUMO
Three beta-substituted ethylsulfonyl chlorides 1-3 were synthesized and their usefulness as 5'-OH protecting groups for oligonucleotide synthesis studied. The formation of the corresponding 5'-beta-R-ethyl-sulfonic acid esters was investigated in respect to fast and complete capping. The 5'-sulfonates 4-9 were prepared and the deprotection was studied using reversed phase HPLC as the analytical tool.
Assuntos
Hidrocarbonetos Clorados/síntese química , Nucleosídeos , Nucleotídeos , Oligonucleotídeos/síntese química , Cromatografia Líquida de Alta Pressão , Indicadores e ReagentesRESUMO
Fecal chymotrypsin determination and secretin-pancreozymin test with volume-loss corrected were carried out intra-individually on 57 clinically normal test subjects and 51 patients with chronic pancreatic disease. A good correlation could be established in every case between the chymotrypsin activity in stool and the chymotrypsin output in the duodenal aspirate. False-positive chymotrypsin activity was not to be found in healthy subjects. On the other hand, however, the chymotrypsin activity in stool compared with the result of the secretin-pancreozymin test was found to be false negative in 21% of all patients with chronic pancreatic disease (some or all parameters pathological). In patients with a clear deficiency in the exocrine function of pancreas (all parameters pathological) the chymotrypsin activity was nevertheless seen to be false-negative in only 9.9% of the cases. Thus the fecal chymotrypsin determination can be used as screening test for the clearly reduced pancreatic exocrine insufficiency.