Validation of a new fluidic device for mechanical stimulation and characterization of microspheres: A first step towards cartilage characterization.

Articular cartilage is made of chondrocytes surrounded by their extracellular matrix that can both sense and respond to various mechanical stimuli. One of the most widely used in vitro model to study cartilage growth is the model of mesenchymal stromal cells-derived cartilage micropellet. However, mechanical stimulation of micropellets has never been reported probably because of their small size and imperfect round shape. The objective of the study was to develop an original custom-made device allowing both the mechanical stimulation and characterization of cartilage micropellets. The fluidic-based device was designed for the concomitant stimulation or characterization of six microspheres placed into the conical wells of a tank. In the present study, the device was validated using alginate-, collagen- and crosslinked collagen-based microspheres. Different types and ranges of pressure signals (square, sinusoidal and constant) were applied. The mechanical properties of microspheres were equivalent to those determined by a conventional compression test. Accuracy, repeatability and reproducibility of all types of pressure signals were demonstrated even though square signals were less accurate and sinusoidal signals were less reproducible than the others. The interest of this new device lies in the reliability to mechanically stimulate and characterize microspheres with diameters in the range of 900 to 1500 µm. Mechanical stimulation can be performed on six microspheres in parallel allowing the mechanical and molecular characterization of the same group of cartilage micropellets. The device will be useful to evaluate the growth of cartilage micropellets under mechanical stimuli.

RAPID3? Aptly named!

The RAPID3 score is the sum of three 0-10 patient self-report scores: pain, functional impairment on MDHAQ, and patient global estimate. It requires 5 seconds for scoring and can be used in all rheumatologic conditions, although it has mostly been used in rheumatoid arthritis where cutoffs for low disease activity (<6/30) or high disease activity (>12/30) have been set. A RAPID3 score of ≤ 3/30 with 1 or 0 swollen joints (RAPID3 ≤ 3 + ≤ SJ1) provides remission criteria comparable to Boolean, SDAI, CDAI, and DAS28 remission criteria, in far less time than a formal joint count. RAPID3 performs as well as the DAS28 in separating active drugs from placebos in clinical trials. RAPID3 also predicts subsequent structural disease progression. RAPID3 can be determined at short intervals at home, allowing the determination of the area under the curve of disease activity between two visits and flare detection. However, RAPID3 should not be seen as a substitute for DAS28 and face to face visits in routine care. Monitoring patient status with only self-report information without a rheumatologist's advice (including joints and physical examination, and consideration of imaging and laboratory tests) may indeed be as undesirable for most patients than joint examination without a patient questionnaire. Conversely, combining the RAPID3 and the DAS28 may consist in faster or more sensitive confirmation that a medication is effective. Similarly, better enquiring of most important concerns of patients (pain, functional status and overall opinion on their disorder) should reinforces patients' confidence in their rheumatologist and treatments.

Three-dimensional manipulation with scanning near-field optical nanotweezers.

Recent advances in nanotechnologies have prompted the need for tools to accurately and non-invasively manipulate individual nano-objects. Among the possible strategies, optical forces have been predicted to provide researchers with nano-optical tweezers capable of trapping a specimen and moving it in three dimensions. In practice, however, the combination of weak optical forces and photothermal issues has thus far prevented their experimental realization. Here, we demonstrate the first three-dimensional optical manipulation of single 50 nm dielectric objects with near-field nanotweezers. The nano-optical trap is built by engineering a bowtie plasmonic aperture at the extremity of a tapered metal-coated optical fibre. Both the trapping operation and monitoring are performed through the optical fibre, making these nanotweezers totally autonomous and free of bulky optical elements. The achieved trapping performances allow for the trapped specimen to be moved over tens of micrometres over a period of several minutes with very low in-trap intensities. This non-invasive approach is foreseen to open new horizons in nanosciences by offering an unprecedented level of control of nanosized objects, including heat-sensitive biospecimens.

Electrical excitation of surface plasmons by an individual carbon nanotube transistor.

We demonstrate here the realization of an integrated, electrically driven, source of surface plasmon polaritons. Light-emitting individual single-walled carbon nanotube field effect transistors were fabricated in a plasmonic-ready platform. The devices were operated at ambient conditions to act as an electroluminescence source localized near the contacting gold electrodes. We show that photon emission from the semiconducting channel can couple to propagating surface plasmons developing in the electrical terminals. Our results show that a common functional element can be operated for two different platforms emphasizing thus the high degree of compatibility between state-of-the-art nano-optoelectronics devices and a plasmonic architecture.

Electron-induced limitation of surface plasmon propagation in silver nanowires.

Plasmonic circuitry is considered as a promising solution-effective technology for miniaturizing and integrating the next generation of optical nano-devices. A key element is the shared metal network between electrical and optical information enabling an efficient hetero-integration of an electronic control layer and a plasmonic data link. Here, we investigate to what extent surface plasmons and current-carrying electrons interfere in such a shared circuitry. By synchronously recording surface plasmon propagation and electrical output characteristics of individual chemically-synthesized silver nanowires we determine the limiting factors hindering the co-propagation of an electrical current and a surface plasmon in these nanoscale circuits.

Interleukin 34 expression is associated with synovitis severity in rheumatoid arthritis patients.

OBJECTIVES: Interleukin (IL) 34 is a new cytokine implicated in macrophage differentiation and osteoclastogenesis. This study assessed IL-34 expression in the tissue of patients with rheumatoid arthritis (RA). METHODS: Immunohistochemistry was performed in synovial biopsies from patients with RA (n=20), osteoarthritis (n=3) or other inflammatory arthritis (n=4). IL-34 was detected in the synovial fluid by ELISA and its messenger RNA expression was studied by quantitative PCR in rheumatoid synovial fibroblasts after stimulation by tumour necrosis factor α (TNFα) and IL-1ß. Wild-type, jnk1(-/-)-jnk2(-/-) and nemo(-/-) murine fibroblasts and pharmacological inhibition were used to determine the involvement of nuclear factor kappa B (NF-κB) and JNK in that effect. RESULTS: IL-34 was expressed in 24/27 biopsies, with three samples from RA patients being negative. A significant association was found between IL-34 expression and synovitis severity. Levels of IL-34 and the total leucocyte count in synovial fluid were correlated. TNFα and IL-1ß stimulated IL-34 expression by synovial fibroblasts in a dose/time-dependent manner through the NF-κB and JNK pathway. CONCLUSION: This work for the first time identifies IL-34 expression in the synovial tissue of patients with arthritis. This cytokine, as a downstream effector of TNFα and IL-1ß, may contribute to inflammation and bone erosions in RA.

Rituximab therapy for systemic vasculitis associated with rheumatoid arthritis: Results from the AutoImmunity and Rituximab Registry.

OBJECTIVE: Rituximab improves articular symptoms in rheumatoid arthritis (RA) and it recently has been shown to be an effective induction therapy for antineutrophil cytoplasmic antibody-associated vasculitis. We assessed the efficacy and safety of rituximab in a real-life clinical setting among patients with systemic rheumatoid vasculitis (SRV). METHODS: We analyzed data from the AutoImmunity and Rituximab registry, which includes patients with autoimmune diseases treated with rituximab. RESULTS: Of the 1,994 patients with RA enrolled in the registry, 17 were treated with rituximab for active SRV. At baseline, the mean Birmingham Vasculitis Activity Score for RA (BVAS/RA) was 9.6, with a mean prednisone dosage of 19.2 mg/day. After 6 months of rituximab therapy, 12 patients (71%) achieved complete remission of their vasculitis, 4 had a partial response, and 1 died with uncontrolled vasculitis. Mean BVAS/RA was reduced to 0.6 and mean prednisone dosage to 9.7 mg/day. At 12 months, 14 patients (82%) were in sustained complete remission. Severe infection occurred in 3 patients, corresponding to a 6.4 per 100 patient-years rate. In the 6 patients who received further rituximab as maintenance therapy between months 6 and 12, no relapse of vasculitis was observed. However, among the 9 patients who did not, a relapse was observed in 3 patients who were treated with methotrexate alone. Remission was reestablished by reintroducing rituximab in 2 cases. CONCLUSION: Complete remission of SRV was achieved in nearly three-fourths of patients receiving rituximab in daily practice, with a significant decrease in daily prednisone dosage and an acceptable toxicity profile. Rituximab represents a suitable therapeutic option to induce remission in SRV, but maintenance therapy seems to be necessary.

A comparison between bisphosphonates and other treatments for osteoporosis.

Since their development 30 years ago, bisphosphonates are now one of the standard therapy in the management of osteoporosis. Improvements in terms of anti-resorptive potency have leaded to new molecules available either orally or intravenously, from weekly to yearly administration. Overall tolerance of bisphosphonates is good with regards to the risk of mandibular necrosis, not comparable with those observed in cancer treatment, and with no causal link yet established in osteoporotic patients. Compliance remains poor and should be improved by a better education of the patients about their treatment. Other treatments like teriparatide, raloxifene or strontium ranelate are now also available and give more therapeutic options but also more questions on the best molecule to choose for each patient. There is currently no valid basis for distinguishing in a formal and objective manner the different new-generation bisphosphonates, in terms of efficacy against either vertebral, peripheral or hip fractures. In a same way, comparison between bisphosphonates and the other treatments available for osteoporosis is hard in absence of proper randomised controlled study. This review gives an overview of the recent data on the efficacity and tolerance of bisphosphonates in the different forms of osteoporosis and compares them to the other treatments currently available.

Alternative use of bisphosphonate therapy for rheumatic disease.

Bisphosphonates are widely use for pathologies such as osteoporosis, Paget's disease or bone metastasis. However, their potent antiresorptive properties open new therapeutic opportunities for other conditions associated with an increased focal or systemic bone remodelling. Moreover, apart from their antiresorptive activity, bisphosphonates could also have others properties through a specific analgesic or anti-inflammatory effect. Thus, rheumatic diseases like rheumatoid arthritis, spondylarthritis or SAPHO syndrome (acronym for synovitis, acne, pustulosis, hyperostosis and osteitis) that are associated with systemic and sometimes focal bone loss could be good candidates for bisphosphonate therapy. Other non-inflammatory rheumatic diseases like bone osteonecrosis, algodystrophy, fibrous dysplasia or neuropathic osteoarthropathy are also associated with pain and an increase of focal bone remodelling. Several studies have shown that bisphosphonate could have promising therapeutic potential in these inflammatory or non-inflammatory diseases where therapeutic options are usually few. This review will focus on the new potential alternative indications for bisphosphonate in rheumatic diseases.

Lymphoma in patients treated with anti-TNF: results of the 3-year prospective French RATIO registry.

OBJECTIVE: To describe cases of lymphoma associated with anti-TNF therapy, identify risk factors, estimate the incidence and compare the risks for different anti-TNF agents. METHODS: A national prospective registry was designed (Research Axed on Tolerance of bIOtherapies; RATIO) to collect all cases of lymphoma in French patients receiving anti-TNF therapy from 2004 to 2006, whatever the indication. A case-control analysis was conducted including two controls treated with anti-TNF per case and an incidence study of lymphoma with the French population was used as the reference. RESULTS: 38 cases of lymphoma, 31 non-Hodgkin's lymphoma (NHL) (26 B cell and five T cell), five Hodgkin's lymphoma (HL) and two Hodgkin's-like lymphoma were collected. Epstein-Barr virus was detected in both of two Hodgkin's-like lymphoma, three of five HL and one NHL. Patients receiving adalimumab or infliximab had a higher risk than those treated with etanercept: standardised incidence ratio (SIR) 4.1 (2.3-7.1) and 3.6 (2.3-5.6) versus 0.9 (0.4-1.8). The exposure to adalimumab or infliximab versus etanercept was an independent risk factor for lymphoma in the case-control study: odds ratio 4.7 (1.3-17.7) and 4.1 (1.4-12.5), respectively. The sex and age-adjusted incidence rate of lymphoma was 42.1 per 100 000 patient-years. The SIR was 2.4 (95% CI 1.7 to 3.2). CONCLUSION: The two to threefold increased risk of lymphoma in patients receiving anti-TNF therapy is similar to that expected for such patients with severe inflammatory diseases. Some lymphomas associated with immunosuppression may occur, and the risk of lymphoma is higher with monoclonal-antibody therapy than with soluble-receptor therapy.

Validity of the polymyalgia rheumatica activity score in primary care practice.

OBJECTIVE: To evaluate the validity and reliability of the polymyalgia rheumatica (PMR) activity score (PMR-AS) for relapse diagnosis by general practitioners (GPs) who manage a large proportion of patients with PMR. METHODS: Seven clinical vignettes of PMR were used, for which 35 rheumatologists previously made a diagnosis of relapse or no relapse with greater than 80% agreement. These vignettes were submitted to 163 GPs, who were asked to assess disease activity using a visual analogue scale (VASph), this being the only physician-dependent component of the PMR-AS. The 1116 available vignette-GP combinations were used to assess differences in VASph assessed by GPs versus rheumatologists. Statistical associations linking a relapse diagnosis by the rheumatologists (the reference standard) to the value of the GP-assessed PMR-AS or its components (GP-assessed VASph, visual analogue scale pain score, C-reactive protein, morning stiffness and elevation of upper limbs) were evaluated. RESULTS: No significant differences were found between VASph scores by GPs versus rheumatologists for any of the vignettes. A relapse diagnosis was strongly associated with PMR-AS values of 7 or more (sensitivity 99.4%; specificity 93.3%; agreement 95.9% (95% CI 94.5% to 97.0%) with kappa = 0.92). Of the 590 GP-vignette combinations with PMR-AS values lower than 7, all but three (0.5%) had no relapse diagnosis. Of 510 combinations with PMR-AS values of 7 or more, only 42 (8%) had no flare diagnosis. CONCLUSIONS: This study supports the validity of the PMR-AS in primary care practice and provides evidence that a good scoring system can be useful to guide clinical and therapeutic decisions.

Characteristics and survival of 26 patients with paraneoplastic arthritis.

OBJECTIVE: To date, only a few series of patients with paraneoplastic arthritis have been published. The charts of patients with cancer-associated arthritis were collected in order to describe characteristics of this rheumatism. METHODS: A questionnaire was created for this study and validated by experts based on specific criteria of inclusion and exclusion. Histology of neoplasia was included. RESULTS: In all, 16 males and 10 females with a mean (range) age of 57.5 years (28-85) were recruited from 17 nationwide centres in France. Patients presented with symmetric polyarthritis involving wrists and hands (85%) and extra-articular symptoms were frequent (84%). There was no specific biologic or radiographic feature. The mean (range) delay between the diagnosis of rheumatism and neoplasia was 3.6 months (0-21.2). Tumours were usually diagnosed after articular symptoms occurred (88.5%). Twenty patients had a solid cancer, and six a haematological malignancy. Adenocarcinoma of the lungs was the most frequent type of solid cancer (60%). Tumours were diagnosed at an early stage, which may explain the good median survival of 1.21 years (range 0.64-present) with a mean follow-up of 1.9 years (range 0.16-10). The percentage of articular symptoms resolution was significantly higher in patients with solid tumours, as compared to patients with haemopathy (p = 0.007). In cases of tumour relapse, rheumatic symptoms did not recur for 75% of patients. CONCLUSIONS: Underlying neoplasia should be considered in male patients with new onset polyarthritis, smokers, and particularly in patients chronically ill. Additional investigations should then be performed to diagnose cancer at an early stage.

D-2-hydroxyglutaric aciduria in three patients with proven SSADH deficiency: genetic coincidence or a related biochemical epiphenomenon?

Succinic semialdehyde dehydrogenase (SSADH) deficiency and D-2-hydroxyglutaric aciduria (D-2-HGA) are rare inborn errors of metabolism primarily revealed by urinary organic acid screening. Three patients with proven SSADH deficiency excreted, in addition to GHB considerable amounts of D-2-HG. We examined whether these patients suffered from two inborn errors of metabolism by measuring D-2-HG concentrations in the culture medium of cells from these patients. In addition, mutation analysis of the D-2-hydroxyglutarate dehydrogenase gene was performed. Normal concentrations of D-2-HG were measured in the culture media of fibroblasts or lymphoblasts derived from the three patients. In one patient, we found a heterozygous likely pathogenic mutation in the D-2-hydroxyglutarate dehydrogenase gene. These combined results argue against the hypothesis that the patients are affected with "primary" D-2-HGA in combination with their SSADH deficiency. Moderately increased levels of D-2-HG were also found in urine, plasma, and cerebrospinal fluid samples derived from 12 other patients with SSADH deficiency, revealing that D-2-HG is a common metabolite in this disease. The increase of D-2-HG in SSADH deficiency can be explained by the action of hydroxyacid-oxoacid transhydrogenase, a reversible enzyme that oxidases GHB in the presence of 2-ketoglutarate yielding SSA and D-2-HG.

Clinical practice decision tree for the choice of the first disease modifying antirheumatic drug for very early rheumatoid arthritis: a 2004 proposal of the French Society of Rheumatology.

OBJECTIVE: To elaborate a clinical practice decision tree for the choice of the first disease modifying antirheumatic drug (DMARD) for untreated rheumatoid arthritis of less than six months' duration. METHODS: Four steps were employed: (1) review of published reports on DMARD efficacy against rheumatoid arthritis; (2) inventory of the information available to guide DMARD choice; (3) selection of the most pertinent information by 12 experts using a Delphi method; and (4) choice of DMARDs in 12 clinical situations defined by items selected in step 3 (28 joint disease activity score (DAS 28): < or =3.2; >3.2 and < or =5.1; >5.1; rheumatoid factor status (positive/negative); structural damage (with/without)-that is, 3 x 2 x 2). Thus, multiplied by all the possible treatment pairs, 180 scenarios were obtained and presented to 36 experts, who ranked treatment choices according to the Thurstone pairwise method. RESULTS: Among the 77 items identified, 41 were selected as pertinent to guide the DMARD choice. They were reorganised into five domains: rheumatoid arthritis activity, factors predictive of structural damage; patient characteristics; DMARD characteristics; physician characteristics. In the majority of situations, the two top ranking DMARD choices were methotrexate and leflunomide. Etanercept was an alternative for these agents when high disease activity was associated with poor structural prognosis and rheumatoid factor positivity. CONCLUSIONS: Starting with simple scenarios and using the pairwise method, a clinical decision tree could be devised for the choice of the first DMARD to treat very early rheumatoid arthritis.

[Management of phenylketonuria and hyperphenylalaninemia: the French guidelines]. / Consensus national sur la prise en charge des enfants dépistés avec une hyperphénylalaninémie.

Phenylketonuria (PKU) is an inherited metabolic disease affecting about one birth out of 15 000. From 1978, a national systematic neonatal screening was set up in France with a regional organisation. French rational and guidelines have been established by the national PKU group with the collaboration of all the physicians responsible for the regional centres. These guidelines specify the minimal diagnosis procedures leading to an optimal treatment of all patients. A low-phenylalanine diet must be started as soon as possible in the neonatal period for all newborns whose phenylalanine levels are above 10 mg/dl. The dietary control must keep the phenylalanine plasma levels between 2 and 5 mg/dl until 10 years of age. After this age, several data argue for a progressive and controlled relaxation of the diet, keeping the phenylalanine level below 15 mg/dl until the end of the adolescence and below 20 to 25 mg/dl in adulthood. All PKU patients must be followed up for life, in order to screen those who may not bear the diet relaxation and in order to strictly prevent maternal PKU deleterious consequences.

[Chronic lower back pain: a new therapeutic approach]. / Lombalgies chroniques: une autre approche thérapeutique.

Lower back pain is a common complaint of patients seen in our consultations. Despite progress, surgical procedures are still often unsuccessful in relieving pain. Blocks performed in the epidural spaces or more often in the articular facets have provided poor relief of chronic lower back pain. The pain has vegetative components. Considering anatomic findings, we describe the innervation of the peridiscal tIssues which suffer during degenarative conditions. We analyze the course of the autogenic nerves mediating lumbar pain, and select the site of the blocks necessary to obtain optimal selective pain relief. A well-defined block at the level of the communicating rami is described.

Could rheumatoid arthritis result from an abnormal T cell response towards lubricin/superficial zone protein?

The lack of some suppressor T cells (including TCD4+CD25+(high) positively selected first in thymic medulla) specific to a restricted set of autoantigens may be the common link between all patterns of rheumatoid arthritis. In other words, instead of a 'peak' of TCD4+ effector T cells common to all patients with rheumatoid arthritis (which has so far never been demonstrated), a 'hole' in TCD4+CD25+(high) responses towards a limited set of autoantigens responsible for the normal maintenance of tolerance within the joints may be shared by many patients with rheumatoid arthritis. The hallmark of this disorder is the involvement of tissues subjected to friction stress bathed in a lubricating fluid (rheumatoid nodules and bursae, tendinous sheaths, pleura, pericardium, sclera, and joints covered by hyaline cartilage). Consequently, autoantigens shared by all forementioned places may be better candidates than autoantigens restricted to the hyaline cartilage (like collagen II). Tenosynovitis, bursitis and rheumatoid nodules can herald rheumatoid arthritis, and rheumatoid pericarditis is very frequent at the histological level. Lubricin and superficial zone protein (SZP), which are closely related products of the megacaryocyte stimulating factor (MSF) gene, are among the best candidate autoantigens for such a positive selection of suppressor T cells. Lubricin is responsible for most of the lubricating properties of synovial fluid, and SZP (expressed by the superficial articular chondrocytes from diarthrodial cartilages and lining cells of synovial villi) also shares lubricating and cytoprotective properties. Moreover, the expression of lubricin is very probable in pericardium and pleura, and can be induced by friction stress. Although this mucinous glycoprotein may already share close similarities at the antigenic levels with mucins previously demonstrated in Hassall's corpuscles of the thymus, evidence for the ectopic expression of lubricin/SZP within normal human thymus may further support this hypothesis. The prenatal positive selection within the thymus of a functional pool of TCD4+CD25+(high) clones specific for most peripheral tissues is critical (at least in mice) for the quality of tolerance for the rest of the organism's lifespan. Therefore, a poor expression of lubricin/SZP early in life within the human thymus may also favour a lack of suppressor T cells specific to tissues bathed with synovial fluid, i.e. the onset of rheumatoid arthritis later on in life. As studies of human thymus long before the onset of rheumatoid arthritis are hampered for obvious reasons, studies of murine thymus could be a first step. In as much as the human counterpart of lubricin is expressed in the thymic medulla of mice, the generation of knocked-out mice for its expression within the thymus could be one of the best models to test the above hypothesis. The stimulation of TCD4+CD25+(high) clones specific for immunodominant epitopes from the joints/synovial fluid (belonging perhaps to lubricin or SZP) could help restore a normal balance between effector T cells and suppressor T cells in rheumatoid arthritis patients.