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1.
Cell Mol Life Sci ; 79(5): 260, 2022 Apr 27.
Artigo em Inglês | MEDLINE | ID: mdl-35474501

RESUMO

Osteoarthritis (OA) synovial membrane is mainly characterized by low-grade inflammation, hyperplasia with increased cell proliferation and fibrosis. We previously underscored a critical role for CEMIP in fibrosis of OA cartilage. However, its role in OA synovial membrane remains unknown. An in vitro model with fibroblast-like synoviocytes from OA patients and an in vivo model with collagenase-induced OA mice were used to evaluate CEMIP-silencing effects on inflammation, hyperplasia and fibrosis. Our results showed that i. CEMIP expression was increased in human and mouse inflamed synovial membrane; ii. CEMIP regulated the inflammatory response pathway and inflammatory cytokines production in vitro and in vivo; iii. CEMIP induced epithelial to mesenchymal transition pathway and fibrotic markers in vitro and in vivo; iv. CEMIP increased cell proliferation and synovial hyperplasia; v. CEMIP expression was increased by inflammatory cytokines and by TGF-ß signaling; vi. anti-fibrotic drugs decreased CEMIP expression. All these findings highlighted the central role of CEMIP in OA synovial membrane development and underscored that targeting CEMIP could be a new therapeutic approach.


Assuntos
Transição Epitelial-Mesenquimal , Hialuronoglucosaminidase , Osteoartrite , Animais , Citocinas/metabolismo , Fibrose , Humanos , Hialuronoglucosaminidase/metabolismo , Hiperplasia/metabolismo , Inflamação/patologia , Camundongos , Osteoartrite/metabolismo , Membrana Sinovial/metabolismo , Membrana Sinovial/patologia
2.
Biochem J ; 478(16): 3145-3155, 2021 08 27.
Artigo em Inglês | MEDLINE | ID: mdl-34405859

RESUMO

Autophagy receptor p62/SQSTM1 signals a complex network that links autophagy-lysosomal system to proteasome. Phosphorylation of p62 on Serine 349 (P-Ser349 p62) is involved in a cell protective, antioxidant pathway. We have shown previously that P-Ser349 p62 occurs and is rapidly degraded during human synovial fibroblasts autophagy. In this work we observed that fingolimod (FTY720), used as a medication for multiple sclerosis, induced coordinated expression of p62, P-Ser349 p62 and inhibitory TFEB form, phosphorylated on Serine 211 (P-Ser211 TFEB), in human synovial fibroblasts. These effects were mimicked and potentiated by proteasome inhibitor MG132. In addition, FTY720 induced autophagic flux, LC3B-II up-regulation, Akt phosphorylation inhibition on Serine 473 but down-regulated TFEB, suggesting stalled autophagy. FTY720 decreased cytoplasmic fraction contained TFEB but induced TFEB in nuclear fraction. FTY720-induced P-Ser211 TFEB was mainly found in membrane fraction. Autophagy and VPS34 kinase inhibitor, autophinib, further increased FTY720-induced P-Ser349 p62 but inhibited concomitant expression of P-Ser211 TFEB. These results suggested that P-Ser211 TFEB expression depends on autophagy. Overexpression of GFP tagged TFEB in HEK293 cells showed concomitant expression of its phosphorylated form on Serine 211, that was down-regulated by autophinib. These results suggested that autophagy might be autoregulated through P-Ser211 TFEB as a negative feedback loop. Of interest, overexpression of p62, p62 phosphorylation mimetic (S349E) mutant and phosphorylation deficient mutant (S349A) in HEK293 cells markedly induced P-Ser211 TFEB. These results showed that p62 is involved in regulation of TFEB phosphorylation on Serine 211 but that this involvement does not depend on p62 phosphorylation on Serine 349.


Assuntos
Autofagia , Fatores de Transcrição de Zíper de Leucina e Hélice-Alça-Hélix Básicos/metabolismo , Fibroblastos/metabolismo , Proteína Sequestossoma-1/metabolismo , Serina/metabolismo , Fatores de Transcrição de Zíper de Leucina e Hélice-Alça-Hélix Básicos/genética , Western Blotting , Células Cultivadas , Inibidores de Cisteína Proteinase/farmacologia , Fibroblastos/efeitos dos fármacos , Cloridrato de Fingolimode/farmacologia , Células HEK293 , Humanos , Imunossupressores/farmacologia , Leupeptinas/farmacologia , Microscopia de Fluorescência , Mutação , Fosforilação/efeitos dos fármacos , Pirazóis/farmacologia , Pirimidinas/farmacologia , Proteína Sequestossoma-1/genética , Serina/genética , Membrana Sinovial/citologia , Membrana Sinovial/metabolismo
3.
Proc Natl Acad Sci U S A ; 116(33): 16204-16209, 2019 Aug 13.
Artigo em Inglês | MEDLINE | ID: mdl-31332007

RESUMO

Gas hydrates consist of hydrogen-bonded water frameworks enclosing guest gas molecules and have been the focus of intense research for almost 40 y, both for their fundamental role in the understanding of hydrophobic interactions and for gas storage and energy-related applications. The stable structure of methane hydrate above 2 GPa, where CH4 molecules are located within H2O or D2O channels, is referred to as methane hydrate III (MH-III). The stability limit of MH-III and the existence of a new high-pressure phase above 40 to 50 GPa, although recently conjectured, remain unsolved to date. We report evidence for a further high-pressure, room-temperature phase of the CH4-D2O hydrate, based on Raman spectroscopy in diamond anvil cell and ab initio molecular dynamics simulations including nuclear quantum effects. Our results reveal that a methane hydrate IV (MH-IV) structure, where the D2O network is isomorphic with ice Ih, forms at ∼40 GPa and remains stable up to 150 GPa at least. Our proposed MH-IV structure is fully consistent with previous unresolved X-ray diffraction patterns at 55 GPa [T. Tanaka et al., J. Chem. Phys. 139, 104701 (2013)]. The MH-III → MH-IV transition mechanism, as suggested by the simulations, is complex. The MH-IV structure, where methane molecules intercalate the tetrahedral network of hexagonal ice, represents the highest-pressure gas hydrate known up to now. Repulsive interactions between methane and water dominate at the very high pressure probed here and the tetrahedral topology outperforms other possible arrangements in terms of space filling.

4.
Geophys Res Lett ; 48(12): e2021GL092446, 2021 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-34219835

RESUMO

We carried out a series of silicate fractional crystallization experiments at lower mantle pressures using the laser-heated diamond anvil cell. Phase relations and the compositional evolution of the cotectic melt and equilibrium solids along the liquid line of descent were determined and used to assemble the melting phase diagram. In a pyrolitic magma ocean, the first mineral to crystallize in the deep mantle is iron-depleted calcium-bearing bridgmanite. From the phase diagram, we estimate that the initial 33%-36% of the magma ocean will crystallize to form such a buoyant bridgmanite. Substantial calcium solubility in bridgmanite is observed up to 129 GPa, and significantly delays the crystallization of the calcium silicate perovskite phase during magma ocean solidification. Residual melts are strongly iron-enriched as crystallization proceeds, making them denser than any of the coexisting solids at deep mantle conditions, thus supporting the terrestrial basal magma ocean hypothesis (Labrosse et al., 2007).

5.
Nature ; 511(7509): 303-6, 2014 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-25030166

RESUMO

The asteroid 4 Vesta was recently found to have two large impact craters near its south pole, exposing subsurface material. Modelling suggested that surface material in the northern hemisphere of Vesta came from a depth of about 20 kilometres, whereas the exposed southern material comes from a depth of 60 to 100 kilometres. Large amounts of olivine from the mantle were not seen, suggesting that the outer 100 kilometres or so is mainly igneous crust. Here we analyse the data on Vesta and conclude that the crust-mantle boundary (or Moho) is deeper than 80 kilometres.

6.
Acta Orthop Belg ; 86(4): 644-649, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33861912

RESUMO

Currently, patients who undergo total hip arthroplasty want a complete restoration of their hip function and not only pain relief. Templating in THA is essential for accurately predicting the optimal size of the implants required. It also reduces the risk of potential complications. To check the reproducibility of our preoperative planning, to compare the accuracy of templating between orthopedic surgeon (OS), orthopedic resident (OR) and data manager (DM), to determine the learning curve between the different planners and to evaluate the effect of body mass index impact on digital templating for THA. One hundred uncemented Corail ® Hip System using a ceramic on ceramic bearing surface were included into the study. The software used for templating was IMPAX-Orthopaedic-Tools. A calibration marker (28-mm ball) was used for calibration. All the anteroposterior pelvis radiographs were planned by three participants (OS, OR, DM). We systematically collected the precisely planned size measurements as well as the variation by 1 or 2 sizes of prostheses. At +/- 1 size, we did not find any significant difference between the participants with respectively 94%, 96% and 93% concordance for the cup, 88%, 90% and 90% for the stem and 85%, 84% and 83% for the neck. Our preoperative templating was accurate in predicting the required implant size and results were similar to those available in the literature. We did not find any difference between the planners and we were unable to objectivate a learning curve period. We conclude that this essential part of the planning procedure can be performed by the surgeon himself or an orthopedic resident or a data manager who has anatomical knowledge if the surgeon is unable to perform templating himself.


Assuntos
Artroplastia de Quadril , Prótese de Quadril , Cirurgiões Ortopédicos , Articulação do Quadril/diagnóstico por imagem , Articulação do Quadril/cirurgia , Humanos , Cuidados Pré-Operatórios , Estudos Prospectivos , Reprodutibilidade dos Testes
7.
Proc Natl Acad Sci U S A ; 113(40): 11127-11130, 2016 10 04.
Artigo em Inglês | MEDLINE | ID: mdl-27647917

RESUMO

We performed laser-heated diamond anvil cell experiments combined with state-of-the-art electron microanalysis (focused ion beam and aberration-corrected transmission electron microscopy) to study the distribution and valence of iron in Earth's lower mantle as a function of depth and composition. Our data reconcile the apparently discrepant existing dataset, by clarifying the effects of spin (high/low) and valence (ferrous/ferric) states on iron partitioning in the deep mantle. In aluminum-bearing compositions relevant to Earth's mantle, iron concentration in silicates drops above 70 GPa before increasing up to 110 GPa with a minimum at 85 GPa; it then dramatically drops in the postperovskite stability field above 116 GPa. This compositional variation should strengthen the lowermost mantle between 1,800 km depth and 2,000 km depth, and weaken it between 2,000 km depth and the D" layer. The succession of layers could dynamically decouple the mantle above 2,000 km from the lowermost mantle, and provide a rheological basis for the stabilization and nonentrainment of large low-shear-velocity provinces below that depth.

8.
Aging Clin Exp Res ; 30(4): 315-321, 2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-28560544

RESUMO

AIMS: The objective of this study is to characterize, based on clinical, radiographic, health-related, quality-of-life-related, and demographic variables, the profile of a large, homogeneous, cohort of patients undergoing knee or hip arthroplasty, in a public hospital. Current regulatory guidelines for structure-modifying agent are not clear regarding hard clinical endpoint. The "need for surgery" has been suggested as a potential relevant outcome, but, until now, it is poorly defined. By characterizing a large number of patients who undergo total hip or total knee replacement, this paper aims at providing a contribution to the better definition of the "need for surgery" in advanced OA of the lower limbs. METHODS: Consecutive patients who underwent primary knee arthroplasty (KA) or hip arthroplasty (HA) between December 2008 and February 2013, in an academic hospital, and who were diagnosed with hip or knee osteoarthritis (OA) (ACR criteria). Data collected at baseline included demographic and clinical data; Kellgren-Lawrence radiological grading; Western Ontario and Mc Master Universities Arthritis Index (WOMAC); EuroQol five dimensions questionnaire and EuroQol visual analog scale; and 36-item Short Form Health Survey. RESULTS: 626 subjects were included, 346 with hip OA and 280 with knee OA. Significant differences between subjects in need of an HA or of a KA were seen in terms of age (66.5 years versus 65 for hip), duration of complaints (2188 days versus 1146.5 for hip), BMI (28.68 kg/m² versus 27.07), radiological status (severe OA were found in 79.85% in knee group and 68.73% in hip group), comorbidities (FCI higher in knee group), traumatic of surgical history (37 versus 6%), and health-related quality of life and function (patients with HA had a poorer clinical status regarding WOMAC and WOMAC subscale). CONCLUSION: Significant differences were observed between patients undergoing KA or HA. These differences might be useful to better understand the "need for surgery" status in these indications. This concept may help to define responders and failures to pharmacological treatment of OA.


Assuntos
Artroplastia de Quadril , Artroplastia do Joelho , Osteoartrite do Quadril/cirurgia , Osteoartrite do Joelho/cirurgia , Idoso , Estudos de Coortes , Comorbidade , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
9.
Proc Natl Acad Sci U S A ; 112(27): 8216-20, 2015 Jul 07.
Artigo em Inglês | MEDLINE | ID: mdl-26100876

RESUMO

The richness of the phase diagram of water reduces drastically at very high pressures where only two molecular phases, proton-disordered ice VII and proton-ordered ice VIII, are known. Both phases transform to the centered hydrogen bond atomic phase ice X above about 60 GPa, i.e., at pressures experienced in the interior of large ice bodies in the universe, such as Saturn and Neptune, where nonmolecular ice is thought to be the most abundant phase of water. In this work, we investigate, by Raman spectroscopy up to megabar pressures and ab initio simulations, how the transformation of ice VII in ice X is affected by the presence of salt inclusions in the ice lattice. Considerable amounts of salt can be included in ice VII structure under pressure via rock-ice interaction at depth and processes occurring during planetary accretion. Our study reveals that the presence of salt hinders proton order and hydrogen bond symmetrization, and pushes ice VII to ice X transformation to higher and higher pressures as the concentration of salt is increased.

10.
Rheumatology (Oxford) ; 54(6): 1087-92, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25389358

RESUMO

OBJECTIVE: Glucocorticoids are powerful anti-inflammatory compounds that also induce the expression of leptin and leptin receptor (Ob-R) in synovial fibroblasts through TGF-ßsignalling and Smad1/5 phosphorylation. Compound A (CpdA), a selective glucocorticoid receptor agonist, reduces inflammation in murine arthritis models and does not induce diabetes or osteoporosis, thus offering an improved risk:benefit ratio in comparison with glucocorticoids. Due to the detrimental role of leptin in OA pathogenesis, we sought to determine whether CpdA also induced leptin and Ob-R protein expression as observed with prednisolone. METHODS: Human synovial fibroblasts and chondrocytes were isolated from the synovium and cartilage of OA patients after joint surgery. The cells were treated with prednisolone, TGF-ß1, TNF-α and/or CpdA. Levels of leptin, IL-6, IL-8, MMP-1 and MMP-3 were measured by ELISA and expression levels of Ob-R phospho-Smad1/5, phospho-Smad2, α-tubulin and glyceraldehyde 3-phosphate dehydrogenase were analysed by western blotting. RESULTS: CpdA, unlike prednisolone, did not induce leptin secretion or Ob-R protein expression in OA synovial fibroblasts. Moreover, CpdA decreased endogenous Ob-R expression and down-regulated prednisolone-induced leptin secretion and Ob-R expression. Mechanistically, CpdA, unlike prednisolone, did not induce Smad1/5 phosphorylation. CpdA, similarly to prednisolone, down-regulated endogenous and TNF-α-induced IL-6, IL-8, MMP-1 and MMP-3 protein secretion. The dissociative effect of CpdA was confirmed using chondrocytes with no induction of leptin secretion, but with a significant decrease in IL-6, IL-8, MMP-1 and MMP-3 protein secretion. CONCLUSION: CpdA, unlike prednisolone, did not induce leptin or Ob-R in human OA synovial fibroblasts, thereby demonstrating an improved risk:benefit ratio.


Assuntos
Condrócitos/metabolismo , Fibroblastos/metabolismo , Osteoartrite/metabolismo , Prednisolona/farmacologia , Receptores de Glucocorticoides/agonistas , Membrana Sinovial/metabolismo , Idoso , Idoso de 80 Anos ou mais , Western Blotting , Condrócitos/efeitos dos fármacos , Ensaio de Imunoadsorção Enzimática , Feminino , Fibroblastos/efeitos dos fármacos , Gliceraldeído-3-Fosfato Desidrogenases/efeitos dos fármacos , Gliceraldeído-3-Fosfato Desidrogenases/metabolismo , Humanos , Interleucina-6/metabolismo , Interleucina-8/efeitos dos fármacos , Interleucina-8/metabolismo , Leptina/metabolismo , Masculino , Metaloproteinase 1 da Matriz/efeitos dos fármacos , Metaloproteinase 1 da Matriz/metabolismo , Metaloproteinase 3 da Matriz/efeitos dos fármacos , Metaloproteinase 3 da Matriz/metabolismo , Pessoa de Meia-Idade , Receptores para Leptina/efeitos dos fármacos , Receptores para Leptina/metabolismo , Proteínas Smad Reguladas por Receptor/efeitos dos fármacos , Proteínas Smad Reguladas por Receptor/metabolismo , Membrana Sinovial/efeitos dos fármacos , Fator de Crescimento Transformador beta1/efeitos dos fármacos , Fator de Crescimento Transformador beta1/metabolismo , Tubulina (Proteína)/efeitos dos fármacos , Tubulina (Proteína)/metabolismo , Fator de Necrose Tumoral alfa/efeitos dos fármacos , Fator de Necrose Tumoral alfa/metabolismo
11.
Malar J ; 14: 26, 2015 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-25626915

RESUMO

BACKGROUND: The present External Quality Assessment (EQA) assessed reading and interpretation of malaria rapid diagnostic tests (RDTs) in the Democratic Republic of the Congo (DRC). METHODS: The EQA consisted of (i) 10 high-resolution printed photographs displaying cassettes with real-life results and multiple choice questions (MCQ) addressing individual health workers (HW), and (ii) a questionnaire on RDT use addressing the laboratory of health facilities (HF). Answers were transmitted through short message services (SMS). RESULTS: The EQA comprised 2344 HW and 1028 HF covering 10/11 provinces in DRC. Overall, median HW score (sum of correct answers on 10 MCQ photographs for each HW) was 9.0 (interquartile range 7.5 - 10); MCQ scores (the % of correct answers for a particular photograph) ranged from 54.8% to 91.6%. Most common errors were (i) reading or interpreting faint or weak line intensities as negative (3.3%, 7.2%, 24.3% and 29.1% for 4 MCQ photographs), (ii) failure to distinguish the correct Plasmodium species (3.4% to 7.0%), (iii) missing invalid test results (8.4% and 23.6%) and (iv) missing negative test results (10.0% and 12.4%). HW who were trained less than 12 months ago had best MCQ scores for 7/10 photographs as well as a significantly higher proportion of 10/10 scores, but absolute differences in MCQ scores were small. HW who had participated in a previous EQA performed significantly better for 4/10 photographs compared to those who had not. Except for two photographs, MCQ scores were comparable for all levels of the HF hierarchy and non-laboratory staff (HW from health posts) had similar performance as to laboratory staff. Main findings of the questionnaire were (i) use of other RDT products than recommended by the national malaria control programme (nearly 20% of participating HF), (ii) lack of training for a third (33.6%) of HF, (iii) high proportions (two-thirds, 66.5%) of HF reporting stock-outs. CONCLUSIONS: The present EQA revealed common errors in RDT reading and interpretation by HW in DRC. Performances of non-laboratory and laboratory staff were similar and dedicated training was shown to improve HW competence although to a moderate extent. Problems in supply, distribution and training of RDTs were detected.


Assuntos
Testes Diagnósticos de Rotina/métodos , Testes Diagnósticos de Rotina/normas , Malária/diagnóstico , Plasmodium/isolamento & purificação , Sistemas Automatizados de Assistência Junto ao Leito , Competência Profissional/normas , Telefone Celular , República Democrática do Congo , Pesquisa sobre Serviços de Saúde/métodos , Humanos , Fotografação , Controle de Qualidade , Inquéritos e Questionários , Telemedicina/métodos
12.
Malar J ; 13: 20, 2014 Jan 13.
Artigo em Inglês | MEDLINE | ID: mdl-24418119

RESUMO

BACKGROUND: In most sub-Saharan African countries malaria rapid diagnostic tests (RDTs) are now used for the diagnosis of malaria. Most RDTs used detect Plasmodium falciparum histidine-rich protein-2 (PfHRP2), though P. falciparum-specific parasite lactate dehydrogenase (Pf-pLDH)-detecting RDTs may have advantages over PfHRP2-detecting RDTs. Only few data are available on the use of RDTs in severe illness and the present study compared Pf-pLDH to PfHRP2-detection. METHODS: Hospitalized children aged one month to 14 years presenting with fever or severe illness were included over one year. Venous blood samples were drawn for malaria diagnosis (microscopy and RDT), culture and complete blood count. Leftovers were stored at -80 °C and used for additional RDT analysis and PCR. An RDT targeting both PfHRP2 and Pf-pLDH was performed on all samples for direct comparison of diagnostic accuracy with microscopy as reference method. PCR was performed to explore false-positive RDT results. RESULTS: In 376 of 694 (54.2%) included children, malaria was microscopically confirmed. Sensitivity, specificity, positive predictive value (PPV) and negative predictive value were 100.0, 70.9, 69.4 and 100.0%, respectively for PfHRP2-detection and 98.7, 94.0, 91.6 and 99.1%, respectively for Pf-pLDH-detection. Specificity and PPV were significantly lower for PfHRP2-detection (p <0.001). For both detection antigens, specificity was lowest for children one to five years and in the rainy season. PPV for both antigens was highest in the rainy season, because of higher malaria prevalence. False positive PfHRP2 results were associated with prior anti-malarial treatment and positive PCR results (98/114 (86.0%) samples tested). CONCLUSION: Among children presenting with severe febrile illness in a seasonal hyperendemic malaria transmission area, the present study observed similar sensitivity but lower specificity and PPV of PfHRP2 compared to Pf-pLDH-detection. Further studies should assess the diagnostic accuracy and safety of an appropriate Pf-pLDH-detecting RDT in field settings and if satisfying, replacement of PfHRP2 by Pf-pLDH-detecting RDTs should be considered.


Assuntos
Antígenos de Protozoários , Testes Diagnósticos de Rotina/métodos , L-Lactato Desidrogenase , Malária Falciparum/diagnóstico , Proteínas de Protozoários , Adolescente , Burkina Faso/epidemiologia , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Recém-Nascido , Malária Falciparum/epidemiologia , Malária Falciparum/parasitologia , Masculino , Reação em Cadeia da Polimerase , Prevalência , Estações do Ano , Sensibilidade e Especificidade
13.
Malar J ; 13: 505, 2014 Dec 17.
Artigo em Inglês | MEDLINE | ID: mdl-25519980

RESUMO

BACKGROUND: Rapid diagnostic tests (RDTs) largely account for the scale-up of malaria diagnosis in endemic settings. However, diversity in labelling including the instructions for use (IFU) limits their interchangeability and user-friendliness. Uniform, easy to follow and consistent labelling, aligned with international standards and appropriate for the level of the end user's education and training, is crucial but a consolidated resource of information regarding best practices for IFU and labelling of RDT devices, packaging and accessories is not available. METHODS: The Roll Back Malaria Partnership (RBM) commissioned the compilation of international standards and regulatory documents and published literature containing specifications and/or recommendations for RDT design, packaging and labelling of in vitro diagnostics (IVD) (which includes RDTs), complemented with a questionnaire based survey of RDT manufacturers and implementers. A summary of desirable RDT labelling characteristics was compiled, which was reviewed and discussed during a RBM Stakeholder consultation meeting and subsequently amended and refined by a dedicated task force consisting of country programme implementers, experts in RDT implementation, IVD regulatory experts and manufacturers. RESULTS: This process led to the development of consensus documents with a list of suggested terms and abbreviations as well as specifications for labelling of box, device packaging, cassettes, buffer bottle and accessories (lancets, alcohol swabs, transfer devices, desiccants). Emphasis was placed on durability (permanent printing or water-resistant labels), legibility (font size, letter type), comprehension (use of symbols) and ease of reference (e.g. place of labelling on the box or cassette packaging allowing quick oversight). A generic IFU template was developed, comprising background information, a template for procedure and reading/interpretation, a selection of appropriate references and a symbol key of internationally recognized symbols together with suggestions about appropriate lay-out, style and readability. CONCLUSIONS: The present document together with its additional files compiled proposes best practices in labelling and IFU for malaria RDTs. It is expected that compliance with these best practices will increase harmonization among the different malaria RDT products available on the market and improve their user-friendliness.


Assuntos
Testes Diagnósticos de Rotina/métodos , Malária/diagnóstico , Guias de Prática Clínica como Assunto , Rotulagem de Produtos/normas , Humanos
14.
Skeletal Radiol ; 43(2): 169-78, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24281772

RESUMO

OBJECTIVE: We sought to optimize the kilovoltage, tube current, and the radiation dose of computed tomographic arthrography of the hip joint using in vitro methods. MATERIALS AND METHODS: A phantom was prepared using a left femoral head harvested from a patient undergoing total hip arthroplasty and packed in a condom filled with iodinated contrast. The right hip joint of a cadaver was also injected with iodinated contrast. The phantom and the cadaver were scanned using different values of peak kilovoltage (kVp) and tube current (milliamp seconds, mAs). Three different regions of interest (ROI) were drawn in the cartilage, subchondral bone plate, and intraarticular contrast. The attenuation values, contrast/noise ratio (CNR), and effective dose were calculated. Two independent observers classified the quality of the contrast-cartilage interface and the cartilage-subchondral bone plate interface as (1) diagnostic quality or (2) nondiagnostic quality. RESULTS: Contrast, cartilage, and subchondral bone plate attenuation values decreased at higher kVp. CNR increased with both kVp and mAs. The qualitative analysis showed that in both phantom and cadaver, at 120 kVp and 50 mAs, the contrast-cartilage and cartilage-subchondral bone plate interfaces were of diagnostic quality, with an effective dose decreased to 0.5 MSv. CONCLUSIONS: The absolute effective dose is not directly related to the quality of images but to the specific combination of kVp and mAs used for image acquisition. The combination of 120 kVp and 50 mAs can be suggested to decrease the dose without adversely affect the visibility of cartilage and subchondral bone plate.


Assuntos
Artrografia/métodos , Cartilagem Articular/diagnóstico por imagem , Articulação do Quadril/diagnóstico por imagem , Proteção Radiológica/métodos , Interpretação de Imagem Radiográfica Assistida por Computador/métodos , Tomografia Computadorizada por Raios X/métodos , Algoritmos , Cadáver , Humanos , Pessoa de Meia-Idade , Doses de Radiação , Intensificação de Imagem Radiográfica/métodos , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
15.
Phys Rev Lett ; 111(16): 164302, 2013 Oct 18.
Artigo em Inglês | MEDLINE | ID: mdl-24182269

RESUMO

We study the dynamics of successive slip events at a frictional interface with finite-element simulations. Because of the viscous properties of the material, the stress concentrations created by the arrest of precursory slip are not erased by the propagation of the following rupture but reappear with the relaxation of the material. We show that the amplitude of the stress concentrations follows an exponential decay, which is controlled by the bulk material properties. These results highlight the importance of viscosity in the heterogeneous stress state of a frictional interface and reveal the "memory effect" that affects successive ruptures.

16.
Bull World Health Organ ; 91(6): 441-8, 2013 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-24052681

RESUMO

OBJECTIVE: To report the findings of a second external quality assessment of Giemsa-stained blood film microscopy in the Democratic Republic of the Congo, performed one year after the first. METHODS: A panel of four slides was delivered to diagnostic laboratories in all provinces of the country. The slides contained: (i) Plasmodium falciparum gametocytes; (ii) P. falciparum trophozoites (reference density: 113,530 per µl); (iii) Trypanosoma brucei subspecies; and (iv) no parasites. FINDINGS: Of 356 laboratories contacted, 277 (77.8%) responded. Overall, 35.0% of the laboratories reported all four slides correctly but 14.1% reported correct results for 1 or 0 slides. Major errors included not diagnosing trypanosomiasis (50.4%), not recognizing P. falciparum gametocytes (17.5%) and diagnosing malaria from the slide with no parasites (19.0%). The frequency of serious errors in assessing parasite density and in reporting false-positive results was lower than in the previous external quality assessment: 17.2% and 52.3%, respectively, (P < 0.001) for parasite density and 19.0% and 33.3%, respectively, (P < 0.001) for false-positive results. Laboratories that participated in the previous quality assessment performed better than first-time participants and laboratories in provinces with a high number of sleeping sickness cases recognized trypanosomes more frequently (57.0% versus 31.2%, P < 0.001). Malaria rapid diagnostic tests were used by 44.3% of laboratories, almost double the proportion observed in the previous quality assessment. CONCLUSION: The overall quality of blood film microscopy was poor but was improved by participation in external quality assessments. The failure to recognize trypanosomes in a country where sleeping sickness is endemic is a concern.


Assuntos
Corantes Azur , Corantes , Laboratórios , Malária/diagnóstico , Microscopia , Garantia da Qualidade dos Cuidados de Saúde/métodos , Tripanossomíase Africana/diagnóstico , Adolescente , Adulto , República Democrática do Congo , Erros de Diagnóstico/prevenção & controle , Erros de Diagnóstico/estatística & dados numéricos , Humanos , Laboratórios/normas , Laboratórios/estatística & dados numéricos , Plasmodium falciparum/isolamento & purificação , Trypanosoma brucei brucei/isolamento & purificação , Adulto Jovem
17.
Skeletal Radiol ; 42(11): 1573-82, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-23974466

RESUMO

OBJECTIVE: To assess the intraobserver, interobserver, and test-retest reproducibility of minimum joint space width (mJSW) measurement of medial and lateral patellofemoral joints on standing "skyline" radiographs and to compare the mJSW of the patellofemoral joint to the mean cartilage thickness calculated by quantitative magnetic resonance imaging (qMRI). MATERIALS AND METHODS: A couple of standing "skyline" radiographs of the patellofemoral joints and MRI of 55 knees of 28 volunteers (18 females, ten males, mean age, 48.5 ± 16.2 years) were obtained on the same day. The mJSW of the patellofemoral joint was manually measured and Kellgren and Lawrence grade (KLG) was independently assessed by two observers. The mJSW was compared to the mean cartilage thickness of patellofemoral joint calculated by qMRI. RESULTS: mJSW of the medial and lateral patellofemoral joint showed an excellent intraobserver agreement (interclass correlation (ICC) = 0.94 and 0.96), interobserver agreement (ICC = 0.90 and 0.95) and test-retest agreement (ICC = 0.92 and 0.96). The mJSW measured on radiographs was correlated to mean cartilage thickness calculated by qMRI (r = 0.71, p < 0.0001 for the medial PFJ and r = 0.81, p < 0.0001 for the lateral PFJ). However, there was a lack of concordance between radiographs and qMRI for extreme values of joint width and KLG. Radiographs yielded higher joint space measures than qMRI in knees with a normal joint space, while qMRI yielded higher joint space measures than radiographs in knees with joint space narrowing and higher KLG. CONCLUSIONS: Standing "skyline" radiographs are a reproducible tool for measuring the mJSW of the patellofemoral joint. The mJSW of the patellofemoral joint on radiographs are correlated with, but not concordant with, qMRI measurements.


Assuntos
Cartilagem Articular/anatomia & histologia , Cartilagem Articular/diagnóstico por imagem , Imageamento por Ressonância Magnética/métodos , Articulação Patelofemoral/anatomia & histologia , Articulação Patelofemoral/diagnóstico por imagem , Posicionamento do Paciente/métodos , Tomografia Computadorizada por Raios X/métodos , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Variações Dependentes do Observador , Intensificação de Imagem Radiográfica/métodos , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
18.
Int Orthop ; 37(1): 131-6, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23180104

RESUMO

PURPOSE: The aim of the study was to control the in vivo localisation of implanted cells in cell-based therapies. Labelling cells with (111)indium-oxine is one of the most interesting methods proposed. We evaluated this method in the setting of autologous osteoblast implantation in nonunion fractures. METHODS: An in vitro study of osteoblasts was conducted after (111)indium-oxine labelling. Radioactivity retention and viability, proliferation and the ability to produce alkaline phosphatase were evaluated in a seven-day culture. In vivo labelling of implanted osteoblastic cells was conducted during a therapeutic trial of atrophic nonunion fractures, with the leakage outside the nonunion site and local uptake evolution at four, 24 and 48 hour being studied. RESULTS: The mean labelling efficiency for osteoprogenitors was 78.8 ± 4.6 %. The intracellular retention was 89.4 ± 2.1 % at three hours and 67.3 ± 4.7 % at 18 hours. The viability assessed at three hours was 93.7 ± 0.6 %. After seven days of culture, morphology and alkaline phosphatase staining were similar for both labelled and unlabelled control cells, although the proliferation rate was decreased in the labelled cells. Some local intraosseous leakage was observed in four of 17 cases. All patients showed uptake at the injection site, with four having no other uptake. Four patients showed additional uptake in the bladder, liver and spleen, while 11 patients had additional uptake in the lungs in addition to the bladder, liver and spleen. The activity ratios (injection site/body) were 48 ± 28 % at four hours, 40 ± 25 % at 24 hours and 35 ± 25 % at 48 hours. After correcting for decay, the activity within the injection site was 82 ± 15 % at 24 hours and 69 ± 11 % at 48 hours compared with the activity measured at four hours. No relationship was found between uptake and radiological bone repair. CONCLUSIONS: The (111)indium-oxine labelling appears to be a good method for monitoring the behaviour of the osteoblastic cells after their implantation in atrophic nonunion fractures.


Assuntos
Consolidação da Fratura/fisiologia , Fraturas não Consolidadas/terapia , Radioisótopos de Índio , Osteoblastos/transplante , Compostos Radiofarmacêuticos , Adolescente , Adulto , Proliferação de Células , Sobrevivência Celular , Células Cultivadas , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Compostos Organometálicos , Oxiquinolina/análogos & derivados , Estudos Prospectivos , Transplante Autólogo
19.
Malar J ; 11: 326, 2012 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-22974115

RESUMO

BACKGROUND: Malaria rapid diagnostic tests (RDTs) are protected from humidity-caused degradation by a desiccant added to the device packaging. The present study assessed malaria RDT products for the availability, type and design of desiccants and their information supplied in the instructions for use (IFU). METHODS: Criteria were based on recommendations of the World Health Organization (WHO), the European Community (CE) and own observations. Silica gel sachets were defined as self-indicating (all beads coated with a humidity indicator that changes colour upon saturation), partial-indicating (part of beads coated) and non-indicating (none of the beads coated). Indicating silica gel sachets were individually assessed for humidity saturation and (in case of partial-indicating silica gels) for the presence of indicating beads. RESULTS: Fifty malaria RDT products from 25 manufacturers were assessed, 14 (28%) products were listed by the "Global Fund Quality Assurance Policy" and 31 (62%) were CE-marked. All but one product contained a desiccant, mostly (47/50, 94%) silica gel. Twenty (40%) RDT products (one with no desiccant and 19 with non-indicating desiccant) did not meet the WHO guidelines recommending indicating desiccant. All RDT products with self- or partial-indicating silica gel (n = 22 and 8 respectively) contained the toxic cobalt dichloride as humidity indicator. Colour change indicating humidity saturation was observed for 8/16 RDT products, at a median incidence of 0.8% (range 0.05%-4.6%) of sachets inspected. In all RDTs with partial-indicating silica gel, sachets with no colour indicating beads were found (median proportion 13.5% (0.6%-17.8%) per product) and additional light was needed to assess the humidity colour. Less than half (14/30, 47%) IFUs of RDT products with indicating desiccants mentioned to check the humidity saturation before using the test. Information on properties, safety hazards and disposal of the desiccant was not included in any of the IFUs. There were no differences between Global Fund-listed and CE marked RDT products compared to those which were not. Similar findings were noted for a panel of 11 HIV RDTs that was assessed with the same checklist as the malaria RDTs. CONCLUSION: RDTs showed shortcomings in desiccant type and information supplied in the IFU.


Assuntos
Testes Diagnósticos de Rotina/normas , Higroscópicos/farmacologia , Malária/diagnóstico , Rotulagem de Produtos , Testes Diagnósticos de Rotina/métodos , Fidelidade a Diretrizes , Pesquisa sobre Serviços de Saúde , Humanos
20.
Malar J ; 11: 359, 2012 Oct 29.
Artigo em Inglês | MEDLINE | ID: mdl-23107162

RESUMO

BACKGROUND: Rapid diagnosis of Plasmodium falciparum infections is important because of the potentially fatal complications. SDFK90 is a recently marketed malaria rapid diagnostic test (RDT) targeting both histidine-rich protein 2 (PfHRP2) and P. falciparum-specific Plasmodium lactate dehydrogenase (Pf-pLDH). The present study evaluated its diagnostic accuracy. METHODS: SDFK90 was tested against a panel of stored whole blood samples (n= 591) obtained from international travellers suspected of malaria, including the four human Plasmodium species and Plasmodium negative samples. Microscopy was used as a reference method, corrected by PCR for species diagnosis. In addition, SDFK90 was challenged against 59 P. falciparum samples with parasite density ≥4% to assess the prozone effect (no or weak visible line on initial testing and a higher intensity upon 10-fold dilution). RESULTS: Overall sensitivity for the detection of P. falciparum was 98.5% and reached 99.3% at parasite densities >100/µl. There were significantly more PfHRP2 lines visible compared to Pf-pLDH (97.3% vs 86.9%), which was mainly absent at parasite densities <100/µl. Specificity of SDFK90 was 98.8%. No lot-to-lot variability was observed (p = 1.00) and test results were reproducible. A prozone effect was seen for the PfHRP2 line in 14/59 (23.7%) P. falciparum samples tested, but not for the Pf-pLDH line. Few minor shortcomings were observed in the kit's packaging and information insert. CONCLUSIONS: SDFK90 performed excellent for P. falciparum diagnosis. The combination of PfHRP2 and Pf-pLDH ensures a low detection threshold and counters potential problems of PfHRP2 detection such as gene deletions and the prozone effect.


Assuntos
Antígenos de Protozoários/sangue , Testes Diagnósticos de Rotina/métodos , L-Lactato Desidrogenase/sangue , Malária Falciparum/diagnóstico , Plasmodium falciparum/imunologia , Proteínas de Protozoários/sangue , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Plasmodium falciparum/isolamento & purificação , Sensibilidade e Especificidade , Adulto Jovem
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