Clinical relevance of 3D gait analysis in patients with haemophilia.

Haemophilia is characterized by a congenital deficiency of clotting factor VIII or IX. One of the consequences of haemophilia is joint bleedings. Repetitive haemathroses induce cartilage damage and chronic synovitis leading to joint deterioration, and to definitive haemophilic arthropathy which is source of walking disability. Three-dimension gait analysis (3DGA) appears particularly relevant in the case of haemophilia because it allows an evaluation of several joints in weight-bearing situations. The purpose of this study was to review the interest and the contribution of 3DGA in the management of patients with haemophilia. The greatest interest of gait analysis would be to detect early walking changes with a non-invasive and well-tolerated examination, especially in paediatric population. In adulthood, this technic may be also useful to help detect walking worsening in patients known to have already arthropathy. However, it takes time to realize and needs expensive equipment, which limits its possibility of routine use. Although generalizations of these results remain difficult, especially to compare patients with haemophilia to normal population. Indeed, in the studies, patient groups are small and usually heterogeneous in terms of age and target joints. It certainly results of the rarity of the disease. So, it could be interesting to perform a study with a larger cohort in order to allow subgroup analysis, helping to define clearly the place of 3DGA in the strategy of haemophilia evaluation.

Nanoemulsions and topical creams for the safe and effective delivery of lipophilic antioxidant coenzyme Q10.

Emulsion-based delivery systems have been developed to increase the topical bioavailability of lipophilic active compounds within skin membrane. The aim was to develop nanoemulsion from natural sources (rapeseed oil) with the same sources of pure phospholipids (lecithin) rich on mono and polyunsaturated fatty acids for encapsulation of hydrophobic antioxidant (Coenzyme Q10) giving nanoemulsion with double functionality. Nanoemulsions were used for cream preparation using xanthan gum and carboxylmethylcellulose as texturizing agents. The physico-chemical properties, toxicity and biocompatibility were evaluated. Physical stability was followed under different storage temperatures (25; 37 and 50 °C) for one month and revealed stable systems with 150 nm particle size. Anionic thickening addition influenced the electrophoretic mobility but not the size distribution. The addition of polyanionic thickening in nanoemulsions promoted negative surface charge that increased electrostatic repulsive forces between droplets avoiding destabilization phenomena such as coalescence and Ostwald ripening. Moreover, chemical stability evaluation of components confirmed the absence of interactions. FTIR analysis indicated the vibration band position of cis double stretching of unsaturated fatty acids between 3009 and 3006 cm-1, which characterized the non-oxidized oils with same intensities before and after sonication. Antioxidants measurement shown that CMC significantly reduced antioxidant activity due to masking action of CoQ10 functional groups by the carboxylmethylcellulose gum conversely to xanthan gum addition. Finally, in vitro biocompatibility results shown that CoQ10 protected the DNA, and xanthan gum improve glucose metabolism inducing a better cell growth, while carboxymethylcellulose which was not metabolized by fibroblast cell inducing lower growth rate.

Cutoffs of isokinetic strength ratio and hamstring strain prediction in professional soccer players.

Hamstring strain injuries frequently occur during professional soccer practice. Low hamstring strength represents an intrinsic modifiable risk factor but cutoffs of isokinetic knee strength ratios are controversial to predict hamstring strain in professional soccer players. We aimed to predict hamstring strain in accordance with cutoffs of isokinetic knee strength ratios. Bilateral, conventional, and functional isokinetic strength ratios were calculated in 194 professional soccer players at the beginning of 15 consecutive seasons. 36 soccer players presented a moderate hamstring strain and 158 were not injured. The different calculated isokinetic ratios were compared with the right and left limb of the uninjured population. Different usual cutoffs were tested: at 0.85 and 0.90 for the bilateral concentric and eccentric hamstring-to-hamstring ratio, at 0.60 and 0.47 for the conventional hamstring-to-quadriceps ratio and at 0.80 and 1 for the mixed hamstring-to-quadriceps ratio. The specific ratios for the studied population were also determined by the 10th percentile and then tested. Hamstring strain prediction was established in terms of odds ratios. No cutoff with bilateral, conventional, or functional isokinetic strength ratio was predictive of hamstring strain after univariate analysis. Specific cutoffs determined from the studied population were not more predictive. Very few injured soccer players presented values under the cutoffs at 0.47 for the conventional ratio and at 0.80 for the mixed ratio. Regardless of their values, cutoffs of isokinetic strength ratios were not predictive of hamstring injuries. The use of isokinetic cutoffs is not recommended to predict hamstring muscle strain in professional soccer players.

Evaluation of the pro-angiogenic effect of nanoscale extracellular vesicles derived from human umbilical cord mesenchymal stem cells.

Mesenchymal stem cells (MSCs) are a common tool in regenerative medicine. The nanoscale extracellular vesicles (nEVs) secreted by these cells were recently brought up to light thanks to their therapeutic potential. In this study, we assessed the in vitro behaviour of human umbilical vein endothelial cells (HUVECs) exposed to nEVs derived from human umbilical cord mesenchymal stem cells (hUC-MSCs). Nanoscale extracellular vesicles were isolated and characterized by NanoSight® and flow cytometry. HUVECs were stimulated with various concentrations of nEVs. To assess nEV interactions with HUVECs, confocal microscopy and angiogenesis assay were performed. The use of nEVs derived from hUC-MSCs was able to produce positive outcomes on HUVECs by acting on their angiogenic potential.

Transforming growth factor-beta 1 or ascorbic acid are able to differentiate Wharton's jelly mesenchymal stem cells towards a smooth muscle phenotype.

Wharton's jelly mesenchymal stem cells (WJ-MSCs) are widely used in tissue engineering. In vascular engineering, the ability to obtain a vessel replacement with contractile smooth muscle cells (SMC) is a key factor. In this work, we demonstrated that WJ-MSCs differentiate towards a SMC phenotype with various stimulations in vitro and that the modification of redox state could be involved. WJ-MSCs were isolated from umbilical cords. After their expansion, the cells were stimulated with ascorbic acid (AA, 300 µM) or transforming growth factor (TGF)-ß1 (1 to 5 ng/mL). SMC markers were analyzed by Western blot. Modification of redox state was evaluated by reactive oxygen species (ROS) production and glutathione (GSH) content measurements. TGF-ß1 or AA-stimulated WJ-MSCs express early and intermediate SMC markers. TGF-ß1 (5 ng/mL) modifies the redox state by a ROS production and a GSH content drop, while AA has no effect. This work showed that TGF-ß1 and AA are effective SMC phenotype inducers to differentiate WJ-MSCs.

Chronic low back pain among French healthcare workers and prognostic factors of return to work (RTW): a non-randomized controlled trial.

BACKGROUND: Many factors influence the return to work of workers with chronic low back pain (CLBP). They have been said to vary according to socio-professional group. This study first aimed to compare prognostic factors influencing the return to work of CLBP healthcare workers (HCWs) and other workers (non-HCWs) after rehabilitation coupled with an occupational intervention. The second objective was to improve the evolution of indicators such as clinical examination, psychosocial impact and pain impact. METHODS: Between 2007 and 2012, a cohort of 217 CLBP workers (54.8 %-women; mean age = 41.3 ± 9.5 years, 118 non-HCWs; 99 HCWs mainly from the public sector) was included in an ambulatory rehabilitation program (standard physiotherapy or intensive network physiotherapy) coupled with an occupational intervention. Workers completed a questionnaire and had a clinical examination at baseline and after 24 months' follow up. Physical, social and occupational data was collected at the same time. Statistical analyses were performed to evaluate prognostic factors for return to work and compare the two worker populations. RESULTS: There was no difference between groups for the rate of OP (occupational physician) intervention or type of physiotherapy. 77.3 % of workers returned to work after 2 years following inclusion. To be an HCW (OR 0.1; 95 % CI [0.03-0.34]), to have less than 112 sick- leave days (OR 1.00; 95 % CI [0.93-1.00]), a small fingertip-floor distance (OR 0.96; 95 % CI [0.93-0.99]), a low anxiety/depression score (OR 0.97; 95 % CI [0.95-1.00]), a low impact of CLBP on daily life (OR 0.96; 95 % CI [0.93-1.00]), and on quality of life (OR 0.98; 95 % CI [0.95-1.00]) at baseline were statistically associated with return to work after 2 years of follow up. Only the profession (workplace) was statistically associated with return to work after 2 years of follow up using multivariate analysis. CONCLUSION: To our knowledge, this is the first cohort study concerning predictive factors of RTW among CLBP workers after 2 years of follow up. Interventions in the work environment did not seem to predict job retention significantly. But only 50 % of the employees in both groups (HCW and non-HCW) had one intervention at their workplace after 2 years. This study underlined the fact that the type of physiotherapy with a well-trained physiotherapist used to take care of CLBP could not impact on the RTW forecast. To develop these initial results, it might be interesting to study the comparison between private and public sectors and to randomize the physiotherapeutic intervention.

The Nebivolol action on vascular tone is dependent on actin cytoskeleton polymerization and Rho-A activity into ECs and SMCs.

Nitric oxide is implicated in the target action of Nebivolol, a selective ß1 adrenoceptor blocker used in hypertension treatment. As the Nitric Oxide (NO) production and the actin cytoskeleton are linked, the aim of this work was to study the involvement of actin cytoskeleton on mechanism of action of Nebivolol in cultured endothelial cells. We studied the effect of Nebivolol (200 µM) on actin filaments remodeling and its impact on NO production and eNOS activation. Results showed that Nebivolol perturbs actin filaments polymerization, increases NO production and eNOS activity between 30 minutes and 1 h. Stabilization of actin filaments with phalloïdine (50 µM) abolishes Nebivolol effects on eNOS activation and NO production. Furthermore, Rho-kinase activity decreased during the first hour of Nebivolol treatment, then increased after 3 h, while actin filaments repolymerized, eNOS activation and NO production decreased. In SMCs, Nebivolol induced a decrease in the Rho-kinase activity from 1 h until 24 h of incubation. In conclusion, we suggest that Nebivolol induced NO production in Endothelial Cells (ECs) via complementary actions between actin cytoskeleton remodeling inducing eNOS activation and Rho-kinase implication. The effect of Nebivolol on ECs occurs during the first hour, this effect on SMCs seems to be maintained until 24 h, explaining persisted action of Nebivolol observed in vivo.

Muscular isokinetic strength recovery after knee anterior cruciate ligament reconstruction revision: preliminary study.

METHOD: Thirty-nine revision of ACL reconstructions were evaluated: 23 primary ACL reconstructions with bone-patellar tendon-bone graft (BPTB) revised with hamstring tendon (HT) grafts, 10 primary ACL reconstructions with HT grafts revised with ipsilateral BPTB graft (iBPTB) and finally 6 primary ACL reconstructions with BPTB grafts revised with contralateral BPTB (cBPTB) grafts were compared with 78 primary ACL reconstructions (46 HT grafts and 32 BPTB grafts). Recovery of isokinetic muscle strength was evaluated at 4, 6 and 12 months post-revision surgery. RESULTS: Deficits in muscle strength at 12 months post-revision ACL surgery were comparable to the one observed for primary ACL reconstruction with the same technique. At 4 and 6 months post-surgery, strength deficits for the knee extensors were less pronounced after revision ACL reconstruction with HT grafts (25%±16 vs. 37%±16; P<0.001) and iBPTB grafts (41%±11 vs. 17%±17; P<0.001). DISCUSSION: Lower strength deficits for the knee extensors after revision ACL reconstruction with HT grafts can be explained by a less intensive rehabilitation program due to lower stakes in resuming sport activities. With cBPTB, donor-site morbidity could explain the decreased strength deficits for knee extensors. CONCLUSION: Deficits in isokinetic muscle strength after ACL revision seem similar to the ones observed after primary ACL reconstruction with the same surgical technique.

Brillouin spectroscopy: a new tool to decipher viscoelastic properties of biological scaffold functionalized with nanoscale films.

BACKGROUND: In tissue engineering, the endothelialization of vascular scaffold can be a crucial step to improve graft patency. A functional cellularization requires coating surfaces. Since 2003, our group used polyelectrolyte multilayer films (PEMFs) made of poly(allylamine hydrochloride) and polystyren sulfonate to coat luminal surface of blood vessel. Previous results showed that PEMFs have remarkable effect on cellular behavior: adhesion, proliferation, differentiation. However, no method seems adapted for in vitro measurement of the viscoelastic shift after PEMFs buildup. OBJECTIVE: In this present work, we proposed to use a new analytical method based on Brillouin spectroscopy (BS) to investigate the influence PEMFs coating on vessel intrinsic viscoelasticy. METHODS: On human umbilical arteries and rabbit vessels, PEMFs were buildup and the luminal surfaces viscoelasticy were measuring by BS. RESULTS: It seems that these films do not alter dynamic functionality and BS could be an interesting method for understanding the role of the tissue architecture, the interrelation between the different structures constituting the wall and the influence of this architecture on the tissue behavior, especially with the characterized components of the different vascular wall. CONCLUSION: The ability of BS to characterize biological samples opens potential applications in tissue engineering field, especially as a tool for a better understanding of vascular diseases.

Influence of serum percentage on the behavior of Wharton's jelly mesenchymal stem cells in culture.

BACKGROUND: Mesenchymal stem cells (MSCs) are multipotent cells able to differentiate into several lineages with valuable applications in regenerative medicine. MSCs differentiation is highly dependent on physicochemical properties of the culture substrate, cell density and on culture medium composition. OBJECTIVE: In this study, we assessed the influence of fetal bovine serum (FBS) level on Wharton's jelly (WJ)-MSCs behavior seeded on polyelectrolyte multilayer films (PEMF) made of four bilayers of poly-allylamine hydrochloride (PAH) as polycation and poly-styrene sulfonate (PSS) as polyanion. METHODS: MSCs isolated from WJ by explants method were amplified until the third passage. Their phenotypic characterization was performed by flow cytometry analyses. MSCs were seeded on PEMF, in Endothelial growth medium-2 (EGM-2) supplemented by either 5% or 2% FBS. Cell's behavior was monitored for 20 days by optical microscopy and immunofluorescence. RESULTS: Until 2 weeks on glass slides, no difference was observed whatever the FBS percentage. Then with 5% FBS, MSCs formed three-dimensional spheroids on PSS/PAH after 20 days of culture with a nuclear aggregate. Whereas, with 2% FBS, these spheroids did not appear and cells grown in 2D conserved the fibroblast-like morphology. CONCLUSIONS: The decrease of FBS percentage from 5% to 2% avoids 3D cell spheroids formation on PAH/PSS. Such results could guide bioengineering towards building 2D structures like cell layers or 3D structures by increasing the osteogenic or chondrogenic differentiation potential of MSCs.

Reversing charges or how to improve Wharton's jelly mesenchymal stem cells culture on polyelectrolyte multilayer films.

BACKGROUND: Polyelectrolyte multilayer (PEMs) films made of poly(allylamine hydrochloride) (PAH) as polycation and poly(styrene sulfonate) (PSS) as polyanion, with a PAH ending layer, can be used as a coating in order to improve the anti-thrombogenicity and patency of vascular grafts in vascular engineering field. They induce strong adhesion of mature endothelial cells on glass, expanded polytetrafluoroethylene and cryopreserved arteries. Despite their outstanding effect on mature and progenitor endothelial cells, PEMs ending with PAH showed a poor outcome on Wharton's jelly mesenchymal stem cells (WJ-MSCs) culture. OBJECTIVE: The aim of this work was to examine the influence of the ending charge of PEMs on WJ-MSCs behavior. METHODS: WJ-MSCs amplified until the 3rd passage were seeded and cultured on (PAH-PSS)3-PAH and on (PAH-PSS)4 coated glass for 10 days. Stem cell phenotype was checked by flow cytometry and cell morphology was followed by bright field microscopy. RESULTS: Flow cytometry analysis showed that WJ-MSCs were positive for MSC's markers CD73, CD90 and CD105 and negative for hematopoietic markers CD34 and CD45. Light microscopy showed development of nodule-like structures after 10 days of culture on (PAH-PSS)3-PAH, which resulted in a disturbance of cell monolayer. Whereas WJ-MSCs cultured on (PAH-PSS)4 ending with PSS showed a normal cell growth like on collagen and reached confluence after 10 days. CONCLUSION: The culture surface seems to have a determining role in WJ-MSC's "spatial" behavior, which could be considered in the field of tissue engineering.

Introduction to regenerative medicine and tissue engineering.

Human tissues don't regenerate spontaneously, explaining why regenerative medicine and cell therapy represent a promising alternative treatment (autologous cells or stem cells of different origins). The principle is simple: cells are collected, expanded and introduced with or without modification into injured tissues or organs. Among middle-term therapeutic applications, cartilage defects, bone repair, cardiac insufficiency, burns, liver or bladder, neurodegenerative disorders could be considered.

SHG as a new modality for large field of view imaging to monitor tissue collagen network.

For this study, we have considered a new large field of view imaging dedicated to matrix collagen (no stained samples). To integrate a multidimensional scale (non-sliced samples), a femtosecond oscillator (two photon excitation laser) has been coupled with a large field optical setup to collect SHG signal. We introduced an index (F-SHG) based on decay time response measured by TCSPC for, respectively, Fluorescence (F) and Second Harmonic Generation (SHG) values. For samples where protein collagen is the major component of extracellular matrix (skin) or not (nacre), we compared the index distribution (from 2 to 12) obtained with large field optical setup. In this work, we showed for the first time that multiscale large field imaging combined to multimodality approaches (SHG-TCSPC) could be an innovative and non invasive technique to detect and identify some biological interest molecules (collagen) in biomedical topics.

ER stress activates the NLRP3 inflammasome via an UPR-independent pathway.

Uncontrolled endoplasmic reticulum (ER) stress responses are proposed to contribute to the pathology of chronic inflammatory diseases such as type 2 diabetes or atherosclerosis. However, the connection between ER stress and inflammation remains largely unexplored. Here, we show that ER stress causes activation of the NLRP3 inflammasome, with subsequent release of the pro-inflammatory cytokine interleukin-1ß. This ER-triggered proinflammatory signal shares the same requirement for reactive oxygen species production and potassium efflux compared with other known NLRP3 inflammasome activators, but is independent of the classical unfolded protein response (UPR). We thus propose that the NLRP3 inflammasome senses and responds to ER stress downstream of a previously uncharacterized ER stress response signaling pathway distinct from the UPR, thus providing mechanistic insight to the link between ER stress and chronic inflammatory diseases.

Using the Risk Assessment and Predictor Tool (RAPT) for patients after total knee replacement surgery.

OBJECTIVES: The aim of this study was to use the Risk Assessment and Predictor Tool (RAPT) to evaluate the risk of complications in patients hospitalized after total knee replacement (TKR) surgery. METHOD: The medical charts of 272 patients who had TKR surgery for knee osteoarthritis (OA) were included in the study. The presurgical RAPT score and Lequesne functional pain index score were determined based on a thorough analysis of the medical charts. Complications that had an impact on the vital prognosis or knee prosthesis outcomes were reported. Patients were compared according to the RAPT and a relative risk of complications was established. RESULTS: Only 12.2% of patients hospitalized in a Physical Medicine and Rehabilitation (PM&R) center after their surgery could have been discharged home directly after their initial hospital stay for TKR surgery (score RAPT more than 9). These patients were mostly men and significantly younger. Their Lequesne score was significantly lower by an average of at least two points. Their relative risk of complications was 0.45 vs. 2.16 for patients who had a RAPT score less than 6. CONCLUSION: Patients with a RAPT score more than 9 have a low risk of complications. They should not systematically be admitted to a PM&R unit after surgery. On the other hand, for patients with a RAPT score less than 6 a hospital stay in a PM&R care center is justified after TKR surgery.

The NLRP3 inflammasome in health and disease: the good, the bad and the ugly.

While interleukin (IL)-1ß plays an important role in combating the invading pathogen as part of the innate immune response, its dysregulation is responsible for a number of autoinflammatory disorders. Large IL-1ß activating platforms, known as inflammasomes, can assemble in response to the detection of endogenous host and pathogen-associated danger molecules. Formation of these protein complexes results in the autocatalysis and activation of caspase-1, which processes precursor IL-1ß into its secreted biologically active form. Inflammasome and IL-1ß activity is required to efficiently control viral, bacterial and fungal pathogen infections. Conversely, excess IL-1ß activity contributes to human disease, and its inhibition has proved therapeutically beneficial in the treatment of a spectrum of serious, yet relatively rare, heritable inflammasomopathies. Recently, inflammasome function has been implicated in more common human conditions, such as gout, type II diabetes and cancer. This raises the possibility that anti-IL-1 therapeutics may have broader applications than anticipated previously, and may be utilized across diverse disease states that are linked insidiously through unwanted or heightened inflammasome activity.

Atherosclerosis in ApoE-deficient mice progresses independently of the NLRP3 inflammasome.

The interleukin-1 (IL-1) family of cytokines has been implicated in the pathogenesis of atherosclerosis in previous studies. The NLRP3 inflammasome has recently emerged as a pivotal regulator of IL-1ß maturation and secretion by macrophages. Little is currently known about a possible role for the NLRP3 inflammasome in atherosclerosis progression in vivo. We generated ApoE-/- Nlrp3-/-, ApoE-/- Asc-/- and ApoE-/- caspase-1-/- double-deficient mice, fed them a high-fat diet for 11 weeks and subsequently assessed atherosclerosis progression and plaque phenotype. No differences in atherosclerosis progression, infiltration of plaques by macrophages, nor plaque stability and phenotype across the genotypes studied were found. Our results demonstrate that the NLRP3 inflammasome is not critically implicated in atherosclerosis progression in the ApoE mouse model.