11 research outputs found

    Retrospective French nationwide survey of childhood aggressive vascular anomalies of bone, 1988-2009

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    <p>Abstract</p> <p>Objective</p> <p>To document the epidemiological, clinical, histological and radiological characteristics of aggressive vascular abnormalities of bone in children.</p> <p>Study design</p> <p>Correspondents of the French Society of Childhood Malignancies were asked to notify all cases of aggressive vascular abnormalities of bone diagnosed between January 1988 and September 2009.</p> <p>Results</p> <p>21 cases were identified; 62% of the patients were boys. No familial cases were observed, and the disease appeared to be sporadic. Mean age at diagnosis was 8.0 years [0.8-16.9 years]. Median follow-up was 3 years [0.3-17 years]. The main presenting signs were bone fracture (n = 4) and respiratory distress (n = 7), but more indolent onset was observed in 8 cases. Lung involvement, with lymphangiectasies and pleural effusion, was the most frequent form of extraosseous involvement (10/21). Bisphosphonates, alpha interferon and radiotherapy were used as potentially curative treatments. High-dose radiotherapy appeared to be effective on pleural effusion but caused major late sequelae, whereas antiangiogenic drugs like alpha interferon and zoledrenate have had a limited impact on the course of pulmonary complications. The impact of bisphosphonates and alpha interferon on bone lesions was also difficult to assess, owing to insufficient follow-up in most cases, but it was occasionally positive. Six deaths were observed and the overall 10-year mortality rate was about 30%. The prognosis depended mainly on pulmonary and spinal complications.</p> <p>Conclusion</p> <p>Aggressive vascular abnormalities of bone are extremely rare in childhood but are lifethreatening. The impact of anti-angiogenic drugs on pulmonary complications seems to be limited, but they may improve bone lesions.</p

    Could conservative iron chelation lead to neuroprotection in amyotrophic lateral sclerosis?

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    Iron accumulation has been observed in mouse models and both sporadic and familial forms of Amyotrophic lateral sclerosis. Iron chelation could reduce iron accumulation and the related excess of oxidative stress in the motor pathways. However, classical iron chelation would induce systemic iron depletion. We assess the safety and efficacy of conservative iron chelation (i.e. chelation with low risk of iron depletion) in a murine preclinical model and pilot clinical trial. In Sod1G86R mice, deferiprone increased the mean life span as compared with placebo. The safety was good, without anemia after 12 months of deferiprone in the 23 ALS patients enrolled in the clinical trial. The decreases in the ALS Functional Rating Scale and the body mass index (BMI) were significantly smaller for the first 3 months of deferiprone treatment (30 mg/kg/day) than for the first treatment-free period. Iron levels in the cervical spinal cord, medulla oblongata and motor cortex (according to MRI), as well as cerebrospinal fluid levels of oxidative stress and neurofilament light chains were lower after deferiprone treatment. Our observation leads to the hypothesis that moderate iron chelation regimen that avoids changes in systemic iron levels may constitute a novel therapeutic modality of neuroprotection for ALS

    Gene expression profiling of cytochromes P450, ABC transporters and their principal transcription factors in the amygdala and prefrontal cortex of alcoholics, smokers and drug-free controls by qRT-PCR

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    1. Ethanol consumption and smoking alter the expression of certain drug-metabolizing enzymes and transporters, potentially influencing the tissue-specific effects of xenobiotics

    Whole and fractionated human platelet lysate biomaterials-based biotherapy induces strong neuroprotection in experimental models of amyotrophic lateral sclerosis

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    International audienceAmyotrophic lateral sclerosis (ALS) is a devastating neurodegenerative disease of motor neurons leading to death within 3 years and without a curative treatment. Neurotrophic growth factors (NTFs) are pivotal for cell survival. A reason for the lack of patient efficacy with single recombinant NTF brain infusion is likely to be due to the synergistic neuroprotective action of multiple NTFs on a diverse set of signaling pathways. Fractionated (protein size <50, <30, <10, <3 kDa) heat-treated human platelet lysate (HHPL) preparations were adapted for use in brain tissue with the aim of demonstrating therapeutic value in ALS models and further elucidation of the mechanisms of action. In neuronal culture all fractions induced Akt-dependent neuroprotection as well as a strong anti-apoptotic and anti-ferroptotic action. In the <3 kDa fraction anti-ferroptotic properties were shown to be GPX4 dependent highlighting a role for other platelet elements associated with NTFs. In the SOD1G86

    Orai1 Inhibitors as Potential Treatments for Pulmonary Arterial Hypertension

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    International audienceRationale: Pulmonary arterial hypertension (PAH) is characterized by progressive distal pulmonary artery (PA) obstruction, leading to right ventricular hypertrophy and failure. Exacerbated intracellular calcium (Ca2+) signaling contributes to abnormalities in PA smooth muscle cells (PASMCs), including aberrant proliferation, apoptosis resistance, exacerbated migration, and arterial contractility. Store-operated Ca2+ entry (SOCE) is involved in Ca2+ homeostasis in PASMCs, but its properties in PAH are unclear.Methods: Using a combination of Ca2+ imaging, molecular biology, in-vitro, ex-vivo, and in-vivo approaches, we investigated the roles of the Orai1 SOC channel in PA remodeling in PAH and determined the consequences of pharmacological Orai1 inhibition in vivo using experimental models of pulmonary hypertension (PH). Results: SOCE and Orai1 mRNA and protein were increased in human PASMCs (hPASMCs) from patients with PAH (PAH-hPASMCs). We found that MEK1/2, nuclear factor of activated T cells (NFAT), and nuclear factor-kappa B (NFƘB) contribute to the upregulation of Orai1 expression in PAH-hPASMCs. Using siRNA and Orai1 inhibitors, we found that Orai1 inhibition reduced SOCE, mitochondrial Ca2+ uptake, aberrant proliferation, apoptosis resistance, migration, and excessive calcineurin activity in PAH-hPASMCs. Orai1 inhibitors reduced agonist-evoked constriction in human PAs. In experimental rat models of PH evoked by chronic-hypoxia, monocrotaline, or Sugen/hypoxia, administration of Orai1 inhibitors (BTP2, JPIII, or 5J4) protected against PH. Conclusions: In human PAH and experimental PH, Orai1 expression and activity are increased. Orai1 inhibition normalizes the PAH-hPASMCs phenotype and attenuates PH in rat models. These results suggest that Orai1 should be considered as a relevant therapeutic target for PAH

    Extreme selective sweeps independently targeted the X chromosomes of the great apes

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    The unique inheritance pattern of the X chromosome exposes it to natural selection in a way that is different from that of the autosomes, potentially resulting in accelerated evolution. We perform a comparative analysis of X chromosome polymorphism in 10 great ape species, including humans. In most species, we identify striking megabase-wide regions, where nucleotide diversity is less than 20% of the chromosomal average. Such regions are found exclusively on the X chromosome. The regions overlap partially among species, suggesting that the underlying targets are partly shared among species. The regions have higher proportions of singleton SNPs, higher levels of population differentiation, and a higher nonsynonymous-to-synonymous substitution ratio than the rest of the X chromosome. We show that the extent to which diversity is reduced is incompatible with direct selection or the action of background selection and soft selective sweeps alone, and therefore, we suggest that very strong selective sweeps have independently targeted these specific regions in several species. The only genomic feature that we can identify as strongly associated with loss of diversity is the location of testis-expressed ampliconic genes, which also have reduced diversity around them. We hypothesize that these genes may be responsible for selective sweeps in the form of meiotic drive caused by an intragenomic conflict in male meiosis
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