463 research outputs found

    Thiahelicene-grafted halloysite nanotubes: Characterization, biological studies and pH triggered release

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    A novel drug delivery nanosystem was here designed, linking thiahelicenes to halloysite nanotubes. Tetrathia[7]helicenes are very promising DNA intercalators, whose usage in biomedical field has been so far limited by their poor bioavailability. The study of appropriate drug delivery systems is needed to exploit helicenes as therapeutics. In this work, imine chemistry was adopted to covalently attach the bioactive compound and release it in acidic environments such as those surrounding tumour cells. To this aim, halloysite nanotubes were functionalized with (3-aminopropyl)triethoxysilane. The latter acted as linker providing NH2 groups to react with the formyl moiety of the thiahelicene derivative. The nanoconstruct preparation was studied in depth by surface-sensitive spectroscopies and angle-resolved X-ray absorption, to investigate the attachment mode, surface coverage and molecular orientation of the thiahelicene units. Release tests were carried out also in vitro on two tumour cell lines with different extracellular pH values. Mildly acidic pH conditions catalyzed the hydrolysis of the imine bond and promoted the cytotoxic compound release, which proved selective to slight pH differences, confirming the potential of this novel nanoconstruct

    Direct comparison of B-Type Natriuretic Peptide (BNP) and amino-terminal proBNP in a large population of patients with chronic and symptomatic heart failure: the Valsartan Heart Failure (Val-HeFT) data

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    Background: The B-type or brain natriuretic peptides (BNP) and the amino-terminal probrain natriuretic peptide (NT-proBNP) are good markers of prognosis and diagnosis in chronic heart failure (HF). It is unclear, however, whether differences in their biological characteristics modify their clinical correlates and prognostic performance in HF. This work aimed to provide a direct comparison of the prognostic value of BNP and NTproBNP in patients with chronic and stable HF. Methods: We measured BNP and NT-proBNP at baseline in 3916 patients enrolled in the Valsartan Heart Failure Trial. To identify the variables associated with both peptides, we conducted simple and multivariable linear regression analyses. We used Cox multivariable regression models to evaluate the independent prognostic value for all-cause mortality, mortality and morbidity, and hospitalization for HF. Prognostic performance was assessed by pairwise comparisons of the area under the curve of receiver-operator characteristic curves. Results: NT-proBNP and BNP had similar relationships with age, left ventrical ejection fraction, and internal diameter and creatinine clearance. Either peptide ranked as the first independent predictor of outcome after adjustment for major confounding clinical characteristics. ROC curves were almost superimposable for all-cause mortality (area under the curve (SE): BNP 0.665 (0.011) vs NT-proBNP 0.679 (0.011); P 0.0734), but NT-proBNP was superior to BNP for predicting mortality and morbidity (P 0.032) or hospitalization for HF (P 0.0143). Overall sensitivity and specificity ranged from 0.590 to 0.696. Conclusions: The natriuretic peptides BNP and NTproBNP showed subtle differences in their relation to clinical characteristics and prognostic performance in a large population of patients with chronic and stable HF. They were the most powerful independent markers of outcome in HF

    2018 MAX-C/ExoMars Mission: The Orleans Mars-Analogue Rock Collection for Instrument Testing

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    International audienceIn order to reply to the exobiological goals of the 2018 MAX-C/ExoMars mission, the Orléans-OSUC analogue rock collection and database contains well characterised Mars analogue rocks and minerals for use in instrument testing and in situ missions

    The role of klotho in systemic sclerosis

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    The aim was to evaluate the role of klotho in the pathogenesis of systemic sclerosis (SSc), through the measurement of its serum concentration in SSc patients compared to healthy controls, and to assess the association with cutaneous and visceral involvement. Blood samples obtained from both SSc patients and healthy controls were analysed by an ELISA assay for the detection of human klotho. SSc patients were globally evaluated for disease activity and assessed through the modified Rodnan\u2019s Skin Score, Medsger\u2019s scale, pulmonary function tests, 2D-echocardiography, nailfold capillaroscopy and laboratory tests. Our cohort consisted of 69 SSc patients (61 females, mean age 64.5\ub112.5 years, median disease duration 9.0 (IQR 8) years) and 77 healthy controls (28 females, mean age 49.7\ub110.2 years). In the group of SSc patients, 19 (27.5%) suffered from a diffuse form of SSc. All patients were receiving IV prostanoids, and some of them were concomitantly treated with immunosuppressive drugs (prednisone, hydroxychloroquine, mofetil mycophenolate, methotrexate, cyclosporin A and azathioprine). The median serum concentration of klotho was significantly lower in patients compared to controls (0.23 ng/mL vs 0.60 ng/mL; p<0.001). However, Spearman\u2019s test showed no significant association between klotho serum levels and disease activity, concerning either clinical, laboratory or instrumental findings. Our data show a significant deficit of klotho in SSc patients although any significant association was detected between klotho serum concentration and the clinical, laboratory or instrumental features of the disease. However, due to the limits of the study, further investigations are required

    Precision-based exercise as a new therapeutic option for children and adolescents with haematological malignancies

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    Children and adolescents with haematological malignancies (pedHM) are characterized by a severe loss of exercise ability during cancer treatment, lasting throughout their lives once healed and impacting their social inclusion prospects. The investigation of the effect of a precision-based exercise program on the connections between systems of the body in pedHM patients is the new frontier in clinical exercise physiology. This study is aimed at evaluating the effects of 11 weeks (3 times weekly) of combined training (cardiorespiratory, resistance, balance and flexibility) on the exercise intolerance in PedHM patients. Two-hundred twenty-six PedHM patients were recruited (47% F). High or medium frequency participation (HAd and MAd) was considered when a participant joined; &gt; 65% or between 30% and &lt; 64% of training sessions, respectively. The \u201cup and down stairs\u2019\u2019 test (TUDS), \u201c6 min walking\u201d test (6MWT), the \u201c5 Repetition Maximum strength\u201d leg extension and arm lateral raise test (5RM-LE and 5RM-ALR), flexibility (stand and reach), and balance (stabilometry), were performed and evaluated before and after training. The TUDS, the 5RM-LE and 5RM-ALR, and the flexibility exercises showed an increase in HAd and MAd groups (P &lt; 0.05), while the 6MWT and balance tests showed improvement only in HAd group (P &lt; 0.0001). these results support the ever\u2010growing theory that, in the case of the treatment of PedHM, \u2018exercise is medicine\u2019 and it has the potential to increase the patient\u2019s chances of social inclusion

    Placental ERR&#947;-CYP19 expressions and circulating 17-Beta Estradiol in IUGR pregnancies

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    Introduction: Sex steroids are regulating factors for intrauterine growth. 17- f Estradiol (E2) is particularly critical to a physiological pregnancy, as increased maternal E2 was correlated to lower birth weight. The placenta itself is a primary source of estrogens, synthetized from cholesterol precursors. Cytochrome P450 aromatase (encoded by CYP19 gene) is a rate-limiting enzyme for E2 biosynthesis. CYP19 transcription is supported by Estrogen Related-Receptor Gamma (ERR\u3b3), thus having an indirect role in placental steroidogenesis. Here we investigated maternal E2 levels and placental CYP19 and ERR expressions in pregnancies with intrauterine growth restriction (IUGR). Methods: Singleton pregnancies were studied. E2 was measured in maternal plasma by electrochemiluminescence in 16 term controls and 11 IUGR (classified by umbilical artery doppler Pulsatility Index) at elective cesarean section, and also in 13 controls during pregnancy at a gestational age comparable to IUGR. CYP19 and ERR\u3b3 expressions were analyzed in placental tissue. Maternal/fetal characteristics, placental and molecular data were compared among study groups and tested for correlations. Results: Maternal E2 plasma concentrations were significantly decreased in IUGR compared to controls at delivery. When analyzing normal pregnancies at the same IUGR gestational age, E2 levels were not different to IUGR. However, E2 levels at delivery positively correlated with placental efficiency. Placental CYP19 was significantly higher in IUGR placental tissue versus controls, with levels specifically increased in female IUGR placentas. ERR\u3b3 expression was not different among groups. Discussion: We report a positive correlation between 17- f Estradiol levels and placental efficiency, that might indicate a disrupted steroidogenesis in IUGR pregnancies. Moreover, we showed alterations of CYP19 in IUGR placentas, possibly indicating a compensatory effect to the adverse IUGR intrauterine environment, also depending on fetal sex. Further studies are needed to deeper investigate IUGR alterations in the complex interaction among molecules involved in placental steroidogenesis

    Testing the theory of immune selection in cancers that break the rules of transplantation

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    Modification of cancer cells likely to reduce their immunogenicity, including loss or down-regulation of MHC molecules, is now well documented and has become the main support for the concept of immune surveillance. The evidence that these modifications, in fact, result from selection by the immune system is less clear, since the possibility that they may result from reorganized metabolism associated with proliferation or from cell de-differentiation remains. Here, we (a) survey old and new transplantation experiments that test the possibility of selection and (b) survey how transmissible tumours of dogs and Tasmanian devils provide naturally evolved tests of immune surveillance
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