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The effects of known or suspected factors that promote chondrogenic differentiation in growth plate and arteries. Some aspects of chondrogenic differentiation of vascular smooth muscle cells (VSMCs), which suggest that a cartilage-like tissue forms in some types of vascular calcifications are highlighted.

Objective: To describe malaria during pregnancy outside endemic areas.Materials and methods: We retrospectively reviewed all cases of imported malaria during pregnancy, diagnosed over a 11-year period in a French hospital.Results and conclusion: We recovered 18 cases, all from sub-Saharan countries. The infection could appear distantly from arrival in France (up to 36 months), was asymptomatic in 3 cases, with anemia being the most common marker of infection (n = 14). The adverse consequences for the fetus (n = 3) or the newborn (n = 4) were frequent. Physicians should be aware of these atypical presentations in order to anticipate the diagnosis and improve the maternal and fetal prognosis. [ABSTRACT FROM AUTHOR]

The synthesis of Ti3C2Tx (and Ti2CTx alike) MXenes is performed with a new etching environment (FeF3/HCl). Significant differences in terms of surface functionalization (including the insertion of iron cations between the MXene sheets), morphology, nature of impurities, water intercalation and reactivity are obtained in comparison with samples prepared by conventional HF or LiF/HCl etching methods. In particular, the new synthesis method allows modifying the reactivity of Ti3C2vs. water with improved selectivity towards the formation of TiO2 anatase nanoparticles on the MXene sheets whereas rutile TiO2 nanoparticles are favoured by the LiF/HCl method. The role of the Fen+ and Al3+ cations inherent to this synthesis process in the inhibition of the anatase to rutile transformation is shown to be a key parameter. In addition, the MXene oxidation rate in water is also increased when the material is prepared with FeF3/HCl compared to the LiF/HCl method owing to the surface modification of the MXene during the etching step. This oxidation rate can easily be tuned by adjusting the duration of immersion. This work expands the number of etching methods to form MXenes while offering new opportunities in the rationalized design of MXene@TiO2 nanocomposite structures for future applications. [ABSTRACT FROM AUTHOR]

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The aim of the present work was to characterize the odontoblastic proliferation, differentiation, and matrix mineralization in culture of the recently established M2H4 rat cell line. Proliferation was assessed by cell counts, differentiation by RT-PCR analysis, and mineralization by alizarin red staining, atomic absorption spectrometry, and FTIR microspectroscopy. The results showed that M2H4 cell behavior closely mimics in vivo odontoblast differentiation, with, in particular, temporally regulated expression of DMP-1 and DSPP . Moreover, the mineral phase formed by M2H4 cells was similar to that in dentin from rat incisors. Finally, because in mice, transforming growth factor (TGF)-β1 over-expression in vivo leads to an hypomineralization similar to that observed in dentinogenesis imperfecta type II, effects of TGF-β1 on mineralization in M2H4 cell culture were studied. Treatment with TGF-β1 dramatically reduced mineralization, whereas positive control treatment with bone morphogenetic protein-4 enhanced it, suggesting that M2H4 cell line is a promising tool to explore the mineralization mechanisms in physiopathologic conditions. [ABSTRACT FROM AUTHOR]

An in vitro model of Giardia duodenalis and the Caco2 cell line enable the study of parameters that could play a part in trophozoite attachment. We explored the role of membranous lectins of G. duodenalis in attachment-inhibition studies using carbohydrates in solution. Attachment rates were reduced by 14% and 23% in the presence of 100 mmol/l mannose-6-phosphate and glucose, respectively, as compared with control values. No significant modification was observed after trophozoite trypsinization at room temperature or at 37° C. The inhibitory effects of colchicine (35%) and nocodazole (70%) suggest a primordial role of the cytoskeleton; microtubules appear to be the principal effectors of trophozoite fixation. Scanning electron microscopy revealed circular imprints on the Caco2 brush border after trophozoite detachment. The mechanisms of attachment of G. duodenalis to intestinal enterocyte-like cells in culture are thus essentially of the mechanical or hydrodynamic type; surface lectins would appear to intervene in the specificity for duodenal cells. [ABSTRACT FROM AUTHOR]

This report describes a technique for studying the adherence and growth of Giardia intestinalis trophozoites (strains PARIS/86/LCF/1, PARIS/86/LCF/2 and PARIS/88/LCF/8) using the human colon carcinoma cell line Caco2. Giardia trophozoites were cultured with Caco2 cells in a modified HSP culture medium. The biochemical differentiation of Caco2 cells was established by an increase in sucrase isomaltase activities to values of 4.51±0.90 and 10.39±3.00 milliunits/mg protein for 8- and 12-day-old cultures, respectively. Giardia, adherence to 8- and 12-day-old Caco2 cells reached a value of >75% after 60 and 30 min, respectively. Adherence diminished significantly at 24° C and was almost undetectable at 4° C. Depletion of divalent cations reduced the proportion of adherent trophozoites by up to 46%. Adherence was pH-independent between pH 6.0 and 7.6. Parasite growth increased when Caco2 cell monolayers were used instead of exenic cultures. This in vitro human cell model may contribute to the study of the mechanisms and factors involved in the host-parasite interaction. [ABSTRACT FROM AUTHOR]

Nous avons souhaité valider in vivo nos hypothèses suggérant une implication du métabolisme de la sphingosine 1-phosphate (S1P) dans l'inflammation et l'ossification ectopique de l'enthèse. La S1P est un lipide bioactif impliqué dans l'homéostasie osseuse et dans des physiopathologies ostéoarticulaires ; son taux est notamment plus élevé dans le sérum des patients atteints de spondyloarthrite (SpA). Nous avons utilisé un modèle d'enthésopathies de type SpA : les souris TgA86±. Le premier objectif était d'évaluer l'impact du blocage de l'axe S1P sur les manifestations arthritiques et, en particulier, sur la néoformation osseuse pathologique. Le deuxième objectif est de caractériser les modulations du métabolisme de la S1P au niveau systémique et dans une enthèse atteinte et de les corréler avec les phénomènes osseux articulaires. Trois groupes de 15 souris ont été comparés : wild-type , TgA86± et TgA86± traitées par un inhibiteur pharmacologique général de la voie S1P : le Fingolimod (0,1 mg/kg/jour dans l'eau de boisson). Des scores cliniques ont été réalisés pour juger de l'évolution des manifestations de type SpA, axiales et périphériques, pendant 30 semaines (souris âgées de 5 à 35 semaines). Des mesures de longueur de la queue et d'épaisseur de la patte postérieure ont été réalisées après 10, 20 et 30 semaines de traitement. Des analyses d'immunohistologie et d'histomorphométrie osseuse sont en cours. Les atteintes axiales des souris TgA86± se manifestent dès l'âge de 4 semaines par des courbures de la queue. Le nombre et l'angle des courbures augmentent rapidement jusqu'à 8 semaines, puis une ankylose s'installe progressivement. Les atteintes périphériques touchent les quatre membres, plus tardivement et plus graduellement (progression des semaines 6 à 24). À partir de la semaine 13 et jusqu'au sacrifice (semaine 35), les souris traitées par le Fingolimod ont des scores cliniques légèrement inférieurs (d'environ 5 % ; p = 0,27 ± 0,15). Les pattes postérieures des souris TgA86± sont significativement enflées (+0,135 mm à 30 semaines ; p = 0,01), et leur queue est bien plus courte à cause de ses nombreuses courbures (p = 0,01). Le Fingolimod ne paraît pas avoir d'effet sur le gonflement des articulations, mais semble légèrement atténuer le raccourcissement de la queue (−1,8 cm avec Fingolimod versus −2,3 cm sans traitement, à 30 semaines ; p = 0,07). Dans nos conditions expérimentales, l'effet du blocage de l'axe S1P par le Fingolimod sur les manifestations spondyloarthritiques des souris TgA86± semble faible, mais bénéfique, avec une légère réduction des signes cliniques, particulièrement axiaux. Nous supposons que la néoformation osseuse conduisant à l'ankylose pourrait être impactée, ce qui est en cours d'analyse. Nos résultats préliminaires nous encouragent à poursuivre ce travail de caractérisation du métabolisme de la S1P dans l'inflammation et l'ossification ectopique de l'enthèse, pour une meilleure compréhension des enthésopathies. [ABSTRACT FROM AUTHOR]

We carried out a quantitative and qualitative analysis of intestinal digestion of neutral lipids in suckling rats infected with Giardia duodenalis. Total lipids were measured after extraction from the contents of the stomach, proximal and distal small bowel, caecum and colon. Amounts gradually fell from the stomach to the colon and were identical in infected animals and controls, although high values were occasionally found in the caecum of infected rats. Relative glyceride quantities were determined by means of high-performance thin-layer chromatography. Triglycerides were absent from the distal small bowel, and only free fatty acids and cholesterol were present in the caecum, reflecting normal digestion of neutral lipids in infected suckling rats. Our results suggest that G. duodenalis does not impair intestinal fat digestion in suckling rats. [ABSTRACT FROM AUTHOR]

Abstract: Although anti-tumor necrosis factor (TNF)-α treatments efficiently block inflammation in ankylosing spondylitis (AS), they are inefficient to prevent excessive bone formation. In AS, ossification seems more prone to develop in sites where inflammation has resolved following anti-TNF therapy, suggesting that TNF-α indirectly stimulates ossification. In this context, our objectives were to determine and compare the involvement of Wnt proteins, which are potent growth factors of bone formation, in the effects of TNF-α on osteoblast function. In human mesenchymal stem cells (MSCs), TNF-α significantly increased the levels of Wnt10b and Wnt5a. Associated with this effect, TNF-α stimulated tissue-non specific alkaline phosphatase (TNAP) and mineralization. This effect was mimicked by activation of the canonical β-catenin pathway with either anti-Dkk1 antibodies, lithium chloride (LiCl) or SB216763. TNF-α reduced, and activation of β-catenin had little effect on expression of osteocalcin, a late marker of osteoblast differentiation. Surprisingly, TNF-α failed to stabilize β-catenin and Dkk1 did not inhibit TNF-α effects. In fact, Dkk1 expression was also enhanced in response to TNF-α, perhaps explaining why canonical signaling by Wnt10b was not activated by TNF-α. However, we found that Wnt5a also stimulated TNAP in MSCs cultured in osteogenic conditions, and increased the levels of inflammatory markers such as COX-2. Interestingly, treatment with anti-Wnt5a antibodies reduced endogenous TNAP expression and activity. Collectively, these data suggest that increased levels of Dkk1 may blunt the autocrine effects of Wnt10b, but not that of Wnt5a, acting through non-canonical signaling. Thus, Wnt5a may be potentially involved in the effects of inflammation on bone formation. [Copyright &y& Elsevier]