New imaging tools for mouse models of osteoarthritis.

Osteoarthritis (OA) is a chronic degenerative disease characterized by a disruption of articular joint cartilage homeostasis. Mice are the most commonly used models to study OA. Despite recent reviews, there is still a lack of knowledge about the new development in imaging techniques. Two types of modalities are complementary: those that assess structural changes in joint tissues and those that assess metabolism and disease activity. Micro MRI is the most important imaging tool for OA research. Automated methodologies for assessing periarticular bone morphology with micro-CT have been developed allowing quantitative assessment of tibial surface that may be representative of the whole OA joint changes. Phase-contrast X-ray imaging provides in a single examination a high image precision with good differentiation between all anatomical elements of the knee joint (soft tissue and bone). Positron emission tomography, photoacoustic imaging, and fluorescence reflectance imaging provide molecular and functional data. To conclude, innovative imaging technologies could be an alternative to conventional histology with greater resolution and more efficiency in both morphological analysis and metabolism follow-up. There is a logic of permanent adjustment between innovations, 3R rule, and scientific perspectives. New imaging associated with artificial intelligence may add to human clinical practice allowing not only diagnosis but also prediction of disease progression to personalized medicine.

[A man with a painful swelling of the thigh]. / Een man met een pijnlijke zwelling van het bovenbeen.

A 49-year old male patient presented with a painful swelling of the left thigh after a football trauma. An isolated musculotendinous rectus femoris rupture was diagnosed with ultrasound and MRI. 3 months after surgical repair he was fully recovered in function and strength.

C1 inhibitor function using contact-phase proteases as target: evaluation of an innovative assay.

BACKGROUND: Controlling prekallikrein activation by C1 inhibitor (C1Inh) represents the most essential mechanism for angioedema patient protection. C1Inh function in the plasma is usually measured based on the residual activity of the C1s protease not involved in the pathological process. We have hereby proposed an alternative enzymatic measurement of C1Inh function based on contact-phase activation and correlation with angioedema diagnostic requirements. METHODS: The contact phase was reconstituted using the purified components, with C1Inh standard or plasma sample. The kinetics of the amidase activity were monitored using Pro-Phe-Arg-pNA, independently of alpha2-macroglobulin. We prevented any interference from a possible high plasma kininogenase activity by preincubating the samples with protease inhibitor. Receiver operating characteristics (ROC) were used to calculate the assay's diagnostic performance. RESULTS: The calibration curve was built using C1Inh standard (threshold limit 0.10 × 10(-3) U, i.e., 0.2 pmol), and C1Inh function was quantified in the sample, with a reference interval established based on healthy individuals (n = 281; men: 0.61-1.10 U/ml, median: 0.85 U/ml; women: 0.42-1.08 U/ml, median: 0.74 U/ml). The median values of female donors were lower than those of the others due to estrogen, yet C1Inh function remained within the reference interval. The ROC curve calculation provided the following optimum diagnostic cutoff values: women 0.36 U/ml (area under curve [AUC]: 0.99; sensitivity: 93.48%; specificity: 99.37%); and men 0.61 U/ml (AUC: 1; sensitivity: 100.0%; specificity: 100.0%). CONCLUSION: The performance outcome provided features suitable for angioedema diagnostic or follow-up. Established by means of the kinin formation process, this assay should be preferred over the method based on a C1s protease target.

Kinematic dynamo action in square and hexagonal patterns.

We consider kinematic dynamo action in rapidly rotating Boussinesq convection just above onset. The velocity is constrained to have either a square or a hexagonal pattern. For the square pattern, large-scale dynamo action is observed at onset, with most of the magnetic energy being contained in the horizontally averaged component. As the magnetic Reynolds number increases, small-scale dynamo action becomes possible, reducing the overall growth rate of the dynamo. For the hexagonal pattern, the breaking of symmetry between up and down flows results in an effective pumping velocity. For intermediate rotation rates, this additional effect can prevent the growth of any mean-field dynamo, so that only a small-scale dynamo is eventually possible at large enough magnetic Reynolds number. For very large rotation rates, this pumping term becomes negligible, and the dynamo properties of square and hexagonal patterns are qualitatively similar. These results hold for both perfectly conducting and infinite magnetic permeability boundary conditions.

Growth rate degeneracies in kinematic dynamos.

We consider the classical problem of kinematic dynamo action in simple steady flows. Due to the adjointness of the induction operator, we show that the growth rate of the dynamo will be exactly the same for two types of magnetic boundary conditions: the magnetic field can be normal (infinite magnetic permeability, also called pseudovacuum) or tangent (perfect electrical conductor) to the boundaries of the domain. These boundary conditions correspond to well-defined physical limits often used in numerical models and relevant to laboratory experiments. The only constraint is for the velocity field u to be reversible, meaning there exists a transformation changing u into -u. We illustrate this surprising property using S_{2}T_{2} type of flows in spherical geometry inspired by [Dudley and James, Proc. R. Soc. London A 425, 407 (1989)]. Using both types of boundary conditions, it is shown that the growth rates of the dynamos are identical, although the corresponding magnetic eigenmodes are drastically different.

Association of HLA-G 3' untranslated region polymorphisms with antibody response against Plasmodium falciparum antigens: preliminary results.

Host and Plasmodium interactions result in highly variable clinical phenotypes, partly explained by the nature and level of anti-malarial antibody response. Human leukocyte antigen (HLA)-G can create a tolerogenic environment, allowing parasites to escape from anti-malarial immunity. We performed a family-based association study encompassing 483 Sereer individuals (261 children and their parents), and reported two independent signals at the HLA-G 3' untranslated region associated with antibody response to specific Plasmodium falciparum blood stage antigens, previously associated with malaria protection: (i) +3010G together with +3142C with total IgG and IgG1 against GLURP and (ii) +3196G with IgG3 against MSP2. While these results require further investigation, they suggest for the first time a role of HLA-G in the regulation of humoral immune response in malaria.

The PhaSeal® system: impact of its use on workplace contamination and duration of chemotherapy preparation.

PURPOSE: The primary objective of this study was to compare the levels of environmental contamination before and after the introduction of PhaSeal® (closed-system drug transfer device) in two hospital pharmacies. Our secondary objective was to assess the impact of the device on the duration of drug preparation compared to procedures involving the use of needles and syringes. METHODS: The study involved two French hospitals, which prepared antineoplastic chemotherapy using a biological safety cabinet and an isolator. Five skilled pharmacy technicians at each hospital prepared a total of 100 chemotherapy preparations using the standard procedure and 100 using the PhaSeal® system. To control for possible contamination occurring in the course of the procedure, we used fluorescein which becomes fluorescent when exposed to UV light. To reply the second objective, we timed the duration of the different steps of the manipulation. RESULTS: Our findings showed a major reduction in the contamination of the work environment when using the PhaSeal® system for drug preparation. Reduction rates higher than 93% were obtained, whatever the type of protection used. On the duration of preparation, our results indicate that this duration would be approximately 1 h longer for the preparation of 100 samples. CONCLUSION: In conclusion, this study clearly establishes the benefit of using PhaSeal® for protecting the staff members who work with hazardous agents. It also indicates that the duration of drug preparation is not impacted by the use of the system.

[Practice guidelines of the use of bisphosphonates in solid tumours with bone metastases and in multiple myeloma]. / Guide de recommandations d'utilisation des bisphosphonates dans les lésions osseuses malignes des tumeurs solides et du myélome multiple.

Bisphosphonates are indicated for the treatment of bone lesions in patients with solid tumours or multiple myeloma. Bisphosphonates have proven their effectiveness in reducing the number of bone complications (hypercalcemia, pain, disease-related fractures, spinal cord compression) and delaying their occurrence in patients with bone tumours; they have also been shown to reduce the need for bone surgery and palliative or pain-relieving radiotherapy in these patients. International recommendations for the treatment of bone lesions related to malignant solid tumours and multiple myeloma have been established. We have elaborated clinical practice guidelines on the use of bisphosphonates to assist treatment decision-making in bone oncology. The guide contains decision trees and tables with information to guide pre-treatment evaluation and patient follow-up, as well as indications and conditions of use of bisphosphonates. In 2007, the regional cancer network of Rhône-Alpes, ONCORA, formed a working group (GIP ONCORA) to elaborate the guideline. The final version was then discussed and adopted at a plenary session in July 2009, during a collaborative workshop on supportive care recommendations organized by ONCORA and the regional cancer network of Lorraine.

Recent advances on the non-classical major histocompatibility complex class I HLA-G molecule.

The human leukocyte antigen (HLA)-G non-classical major histocompatibility complex (MHC) class I molecule was originally described in first-trimester trophoblasts at the fetal-maternal interface in 1990. Eight years later, the First International Conference on this molecule was inaugurated by Prof Jean Dausset, recipient of the Nobel Prize in Medicine. The Fifth International Conference on HLA-G, held in Paris on July 2009, began with a tribute to Prof Jean Dausset who left us recently. This conference was co-chaired by Dr Edgardo D. Carosella and Prof Hans Grosse-Wilde, included 57 oral presentations and was attended by approximately 140 delegates from 16 countries. We summarize here the major advances on the HLA-G molecule that were reported, including findings on its biological activity and characterization of new mechanisms of action, notably through mesenchymal stem cells and regulatory cells, and the previously unexplored role of HLA-G on immune cells such as gammadelta T-cells and B lymphocytes. Furthermore, the role of HLA-G during pregnancy was revisited and its impact in pathologies such as cancer, autoimmune disorders and transplantation was further extended.

[Improvement of quality of practices for the preparation of cytotoxic drugs: results of a "before-after" study]. / Optimisation des procédures de manipulation des chimiothérapies anticancéreuses : impact des contrôles de contamination environnementaux.

Despite the publication of guidelines for handling antineoplastic agents, measurable amounts of these drugs are still found at various hospital sites. In this context, the French cancer network ONCORA supported the present study to assess the impact of environmental contamination controls on the quality of practices during the preparation of cytotoxic drugs. The first part of the study was conducted at five voluntary hospitals. A total of 65 wipe samples of objects and surfaces were taken in the drug preparation rooms and analyzed for the presence of 5-fluorouracil (5-FU). Measurable amounts of 5-FU were detected in 21 samples (32%). Many surfaces within Biological Safety Cabinets and isolators were found contaminated (36%). The worse results were obtained on gloves and on the outside of infusion bags. The same method was applied during the second part of the study, conducted six months after the end of the first audit. Global contamination was reduced to 17%. This study shows that appropriate handling helps decrease the number of samples contaminated, making it possible to recommend these controls for evaluating and improving the quality of practices. Since 2007, the network's laboratory has extended its activities to all French hospitals interested in this quality assurance programme.

[Aprepitant for the prevention of cisplatine induced nausea and vomiting: an observational study]. / Aprépitant pour la prévention des nausées et vomissements induits par une chimiothérapie à base de cisplatine: étude observationnelle.

Aprepitant is actually recommended in the prevention of nausea and vomiting induced by high emetic risk chemotherapy using cisplatin. We performed an observational prospective study on 101 patients evaluating the efficacy of aprepitant in the clinical conditions of use of cisplatin, out of context of clinical trial. We did not perform any intervention on the choice of anti-emetic treatment by the clinicians. Data on anti-emetic treatments were collected from prescriptions by a pharmacist after prior consultation with a medical doctor. Inclusions were closed when we lay 50 patients who received aprepitant associated to standard anti-emetic treatment (ondansetron and prednisolone) and 51 patients who received standard anti-emetic treatment. We observed a significant positive effect of aprepitant in the prevention of acute (84 vs 74.4 %, P = 0.24) and delayed vomiting (84 vs 60.8%, P = 0.009). But there was not a significant difference between the two groups regarding the prevention of nausea and the rate of complete response (absence of nausea and vomiting during five days).

Research on HLA-G: an update.

Human leukocyte antigen (HLA)-G is a nonclassical HLA class I molecule from the major histocompatibility complex, which was initially shown to confer protection to the fetus from her mother's immune system. The Third International Conference on HLA-G, held in 2003, showed that beyond its role in fetal-maternal tolerance, HLA-G exerts tolerogenic functions involved in transplant acceptance as well as in tumoral and viral immune escape. The Fourth International Conference, which took place in Paris on July 2006, counted 72 oral presentations and about 200 attendees from 25 countries. The reports presented brought new insight into HLA-G research, and we summarize here the major advances on the HLA-G biology that were reported. Abstracts for all presentations can be found in volume 68 issue number 4 of Tissue Antigens.

Functions of HLA-G in the immune system.

Human leukocyte antigen (HLA)-G is a nonclassical HLA class I molecule that has tolerogenic functions and acts on cells of both innate and adaptive immunity. The molecular mechanism leading to tolerance involves the interaction between HLA-G and inhibitory receptors that are expressed at the surface of immune cells. In this review, we will briefly summarize the key advances on the relationships between HLA-G and the immune system and their consequences in pathology.

[Immediate hypersensitivity is rarely implicated in drug induced urticaria]. / L'hypersensibilité immédiate est rarement en cause dans les urticaires médicamenteuses.

INTRODUCTION: The unexpected appearance of acute urticaria during the course of drug treatment gives rise to the following question: is it an allergic urticaria (due to an immediate hypersensitivity: IgE mediated specific immunity) or is it pseudo-allergic? We report our findings in an immuno-allergological study of patients who were sent for drug intolerance which presented as immediate hypersensivity (urticaria, angiooedema, anaphylactic shock). METHODS: A prospective study was conducted including all the patients who were sent to the unit for urticaria or angiooedema type drug intolerance. Patients were questioned about previous chronic urticaria and also about urticaria after taking different medicines. The clinical examination looked for a dermographism. All the patients then took skin tests for immediate hypersensitivity, the molecule was contra-indicated and tests for cross-reactivity were conducted. PATIENTS: Three hundred fifty patients were sent to this unit between February 2000 and April 2001 for drug intolerance, mostly with urticaria/angiooedema but in 7 cases with anaphylactic shock. The incriminated drugs were varied: 50 p. 100 were due mainly to penicillins and cephalosporins. Other drug groups were also involved: non steroid anti-inflammatories, aspirin and paracetamol for the most part, along with local anesthetics, morphine-based products, contrast iodine products, corticosteroids. RESULTS: Of the 350 patients tested, only 22 were allergic and had positive tests for the incriminated drug. In these 22 patients, with the exception of 2 of them, the effects were severe (anaphylactic shock in 7 patients) and the urticaria was only a minor manifestation of the reaction. The drugs responsible were cephalosporin (10 patients), the penicillin (6 patients), insulin (2 patients), gonadorelin (1 patient), carboxymethylcellulose (1 patient), lidocain (1 patient), and sulfamethoxazole (1 patient). The 328 other patients had negative tests and were able to retake the tested molecule without incident. Most of them had antecedents of chronic urticaria or dermographism. DISCUSSION: Only 22 patients of the 350, i.e. 6 p. 100 were genuinely allergic. These patients were those who presented the most severe symptoms. The other patients, i.e. the majority, suffered from pseudo-allergic drug-induced urticaria, which made retaking the medicines possible.

Comparison of ceftazidime degradation in glass bottles and plastic bags under various conditions.

OBJECTIVE: To study the effect of type of container on ceftazidime stability in intravenous solutions. METHODS: One hundred millilitre polypropylene (PP) and polyvinyl chloride (PVC) bags and 100-mL glass bottles were filled with 5% dextrose or 0.9% sodium chloride solutions containing ceftazidime (Fortumset) at 40 mg/mL. Three containers of each solution were stored at 20 and 35 degrees C. One millilitre samples were drawn from each container at 0 and 20 h and assayed. Pyridine concentrations, the main degradation product of ceftazidime, were determined by high-pressure liquid chromatography. RESULTS: Pyridine levels increased during storage and were higher in PVC and PP bags than in glass bottles in both diluents. Solutions stored in PP bags showed better stability than in PVC bags. CONCLUSION: This study shows that ceftazidime undergoes slower degradation in PP than PVC containers although the difference is small. Glass bottles seems to be the better container for storing ceftazidime solutions, whatever storage temperature and diluent used.

TCR dynamics on the surface of living T cells.

T lymphocyte activation by specific antigen requires prolonged TCR occupancy and sustained signaling. This is accomplished by the formation of a specialized signaling domain, the immunological synapse, at the T cell-antigen-presenting cell contact site. Surface receptors and signaling components are progressively recruited into this domain where they are organized in defined three-dimensional structures. To better understand how TCR are supplied to the signaling domain during the activation process, we measured (using confocal microscopy and photo-bleaching recovery techniques) lateral mobility of GFP-tagged TCR on living Jurkat cell surface. We show that: (i) surface-expressed TCR exhibit an intrinsic, actin cytoskeleton-independent, lateral mobility which allows them to passively diffuse over the entire T cell surface within approximately 60 min and (ii) non-stimulated TCR rapidly enter the signaling domain. Our results indicate that TCR lateral mobility per se is sufficient to ensure TCR supply to the immunological synapse in the course of sustained T cell activation.

Drug-induced urticaria.

The occurrence of acute urticaria during treatment with drugs is a frequent event which poses two problems: 1) is the urticaria connected with the drug administration or with the underlying pathology which led to the prescription of the drug; 2) is the urticaria allergic in origin, i.e. due to specific immunity triggers, in particular IgE directed against the drug, or is the urticaria pseudo-allergic in origin, i.e. due to non-specific activation of mastocytes [1]? This question is of major importance because allergic events caused by IgE are potentially fatal while pseudo-allergic events are only rarely life-threatening. In this article we will not deal with contact urticaria where the cause is easily identifiable [2].

Adult corneal epithelium basal cells possess the capacity to activate epidermal, pilosebaceous and sweat gland genetic programs in response to embryonic dermal stimuli.

Recent work has shown remarkable plasticity between neural and hematopoeitic, as well as between hematopoeitic and muscle stem cells, depending on environmental stimuli (Fuchs, E. and Segre, J. A. (2000) Cell 100, 143-155). Stem cells give rise to a proliferative transient amplifying population (TA), which is generally considered to be irreversibly committed. Corneal epithelium provides a particularly useful system for studying the ability of TA cells to activate different genetic programs in response to a change in their fibroblast environment. Indeed, corneal stem and TA cells occupy different localities - stem cells at the periphery, and TA cells more central (Lehrer, M. S., Sun, T. T. and Lavker, R. M. (1998) J. Cell Sci. 111, 2867-2875) - and thus can be discretely dissected from each other. It is well known that pluristratified epithelia of cornea and skin display distinct programs of differentiation: corneal keratinocytes express keratin pair K3/K12 and epidermal keratinocytes keratin pair K1-2/K10; moreover, the epidermis forms cutaneous appendages, which express their own set of keratins. In our experiments, central adult rabbit corneal epithelium was thus associated either with a mouse embryonic dorsal, upper-lip or plantar dermis before grafting onto nude mice. Complementary experiments were performed using adult mouse corneal epithelium from the Rosa 26 strain. The origin of the differentiated structures were identified in the first case by Hoechst staining and in the second by the detection of beta-galactosidase activity. The results show that adult central corneal cells are able to respond to specific information originating from embryonic dermis. They give rise first to a new basal stratum, which does not express anymore corneal-type keratins, then to pilosebaceous units, or sweat glands, depending of the dermis, and finally to upper layers expressing epidermal-type keratins. Our results provide the first evidence that a distinct TA cell population can be reprogrammed.