431 research outputs found

    Decitabine impact on the endocytosis regulator RhoA, the folate carriers RFC1 and FOLR1, and the glucose transporter GLUT4 in human tumors.

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    BackgroundIn 31 solid tumor patients treated with the demethylating agent decitabine, we performed tumor biopsies before and after the first cycle of decitabine and used immunohistochemistry (IHC) to assess whether decitabine increased expression of various membrane transporters. Resistance to chemotherapy may arise due to promoter methylation/downregulation of expression of transporters required for drug uptake, and decitabine can reverse resistance in vitro. The endocytosis regulator RhoA, the folate carriers FOLR1 and RFC1, and the glucose transporter GLUT4 were assessed.ResultsPre-decitabine RhoA was higher in patients who had received their last therapy >3 months previously than in patients with more recent prior therapy (P = 0.02), and varied inversely with global DNA methylation as assessed by LINE1 methylation (r = -0.58, P = 0.006). Tumor RhoA scores increased with decitabine (P = 0.03), and RFC1 also increased in patients with pre-decitabine scores ≤150 (P = 0.004). Change in LINE1 methylation with decitabine did not correlate significantly with change in IHC scores for any transporter assessed. We also assessed methylation of the RFC1 gene (alias SLC19A1). SLC19A1 methylation correlated with tumor LINE1 methylation (r = 0.45, P = 0.02). There was a small (statistically insignificant) decrease in SLC19A1 methylation with decitabine, and there was a trend towards change in SLC19A1 methylation with decitabine correlating with change in LINE1 methylation (r = 0.47, P <0.15). While SLC19A1 methylation did not correlate with RFC1 scores, there was a trend towards an inverse correlation between change in SLC19A1 methylation and change in RFC1 expression (r = -0.45, P = 0.19).ConclusionsIn conclusion, after decitabine administration, there was increased expression of some (but not other) transporters that may play a role in chemotherapy uptake. Larger patient numbers will be needed to define the extent to which this increased expression is associated with changes in DNA methylation

    Epigenetics as a mechanism driving polygenic clinical drug resistance

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    Aberrant methylation of CpG islands located at or near gene promoters is associated with inactivation of gene expression during tumour development. It is increasingly recognised that such epimutations may occur at a much higher frequency than gene mutation and therefore have a greater impact on selection of subpopulations of cells during tumour progression or acquisition of resistance to anticancer drugs. Although laboratory-based models of acquired resistance to anticancer agents tend to focus on specific genes or biochemical pathways, such 'one gene : one outcome' models may be an oversimplification of acquired resistance to treatment of cancer patients. Instead, clinical drug resistance may be due to changes in expression of a large number of genes that have a cumulative impact on chemosensitivity. Aberrant CpG island methylation of multiple genes occurring in a nonrandom manner during tumour development and during the acquisition of drug resistance provides a mechanism whereby expression of multiple genes could be affected simultaneously resulting in polygenic clinical drug resistance. If simultaneous epigenetic regulation of multiple genes is indeed a major driving force behind acquired resistance of patients' tumour to anticancer agents, this has important implications for biomarker studies of clinical outcome following chemotherapy and for clinical approaches designed to circumvent or modulate drug resistance

    Increased Serum and Musculotendinous Fibrogenic Proteins following Persistent Low-Grade Inflammation in a Rat Model of Long-Term Upper Extremity Overuse.

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    We examined the relationship between grip strength declines and muscle-tendon responses induced by long-term performance of a high-repetition, low-force (HRLF) reaching task in rats. We hypothesized that grip strength declines would correlate with inflammation, fibrosis and degradation in flexor digitorum muscles and tendons. Grip strength declined after training, and further in weeks 18 and 24, in reach limbs of HRLF rats. Flexor digitorum tissues of reach limbs showed low-grade increases in inflammatory cytokines: IL-1β after training and in week 18, IL-1α in week 18, TNF-α and IL-6 after training and in week 24, and IL-10 in week 24, with greater increases in tendons than muscles. Similar cytokine increases were detected in serum with HRLF: IL-1α and IL-10 in week 18, and TNF-α and IL-6 in week 24. Grip strength correlated inversely with IL-6 in muscles, tendons and serum, and TNF-α in muscles and serum. Four fibrogenic proteins, TGFB1, CTGF, PDGFab and PDGFbb, and hydroxyproline, a marker of collagen synthesis, increased in serum in HRLF weeks 18 or 24, concomitant with epitendon thickening, increased muscle and tendon TGFB1 and CTGF. A collagenolytic gelatinase, MMP2, increased by week 18 in serum, tendons and muscles of HRLF rats. Grip strength correlated inversely with TGFB1 in muscles, tendons and serum; with CTGF-immunoreactive fibroblasts in tendons; and with MMP2 in tendons and serum. Thus, motor declines correlated with low-grade systemic and musculotendinous inflammation throughout task performance, and increased fibrogenic and degradative proteins with prolonged task performance. Serum TNF-α, IL-6, TGFB1, CTGF and MMP2 may serve as serum biomarkers of work-related musculoskeletal disorders, although further studies in humans are needed

    Macular telangiectasia type 2 - Visual acuity, disease endstage and the MacTel Area. MacTel Project Report No. 8

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    Purpose: To report the visual acuity measures from the MacTel registry study and to investigate and describe phenotypic findings in eyes with substantial vision loss due to MacTel type 2 Design: Cross-sectional multi-center study. Subjects: Participants of the Natural History Observation (and Registry) of MacTel Study. Methods: Best–corrected visual acuity (BCVA) data, retinal imaging data and clinical data were accessed from the MacTel study databases in May 2019. Main Outcome Measures: Frequency distribution of BCVA and its relation to age. Morphological changes in eyes with very late disease stages, defined by a BCVA ≤ 20/200. Average retinal thickness of ETDRS fields on OCT. Dimensions of the area affected by MacTel (MacTel area). Results: BCVA was ≤20/50 in 37.3% and ≤20/200 in 3.8% of 4449 eyes of 2248 patients. 18.4% and 0.7% of all patients had bilateral BCVA ≤20/50 and ≤20/200, respectively. There was an asymmetry between right and left eyes (median BCVA 71 versus 74 letters), a finding supported by more advanced morphological changes in right eyes. BCVA correlated with participant’s age, but the effect size was small. If a neovascularization or macular hole was present, bilateral occurrence was frequent (33% or 17%, respectively), and BCVA was >20/200 (79% or 78% respectively) or ≥20/50 (26% or 13%, respectively). Eyes with advanced disease (BCVA ≤20/200) showed the following characteristics: 1) Atrophy of the foveal photoreceptor layer with or without associated subretinal fibrosis; 2) an affected area, termed here the “MacTel area”, limited to a horizontal diameter not exceeding the distance between the temporal optic disc margin and foveal center, and the vertical diameter not exceeding approximately 0.85 times this distance. Exceptions were eyes with large active or inactive neovascular membranes; 3) reduced retinal thickness measures within the MacTel area; and 4) less frequent retinal greying and more frequent hyperpigmentations compared to eyes with better BCVA. Conclusions: Severe vision loss is rare in MacTel and is related to photoreceptor atrophy in most people. Results indicate disease asymmetry with slightly worse vision and more advanced disease manifestation in right eyes. MacTel-related neurodegeneration does not spread beyond the limits of the “MacTel area”

    Expression and Function of Ccbe1 in the Chick Early Cardiogenic Regions Are Required for Correct Heart Development

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    During the course of a differential screen to identify transcripts specific for chick heart/hemangioblast precursor cells, we have identified Ccbe1 (Collagen and calcium-binding EGF-like domain 1). While the importance of Ccbe1 for the development of the lymphatic system is now well demonstrated, its role in cardiac formation remained unknown. Here we show by whole-mount in situ hybridization analysis that cCcbe1 mRNA is initially detected in early cardiac progenitors of the two bilateral cardiogenic fields (HH4), and at later stages on the second heart field (HH9-18). Furthermore, cCcbe1 is expressed in multipotent and highly proliferative cardiac progenitors. We characterized the role of cCcbe1 during early cardiogenesis by performing functional studies. Upon morpholino-induced cCcbe1 knockdown, the chick embryos displayed heart malformations, which include aberrant fusion of the heart fields, leading to incomplete terminal differentiation of the cardiomyocytes. cCcbe1 overexpression also resulted in severe heart defects, including cardia bifida. Altogether, our data demonstrate that although cardiac progenitors cells are specified in cCcbe1 morphants, the migration and proliferation of cardiac precursors cells are impaired, suggesting that cCcbe1 is a key gene during early heart development.FCT [SFRH/BD/65628/2009, SFRH/BPD/86497/2012, SFRH/BPD/41081/2007]; F.C.T.B.I. fellowship [PTDC/SAU-BID/114902/ 2009]; FCT; Institute for Biotechnology Bioengineering (Centro Biomedicina Molecular e Celular (IBB/CBME), Laboratorio Associado (LA) in the frame of Project [PestOE/EQB/LA0023/2013]info:eu-repo/semantics/publishedVersio

    Improved functionalization of oleic acid-coated iron oxide nanoparticles for biomedical applications

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    Superparamagnetic iron oxide nanoparticles can providemultiple benefits for biomedical applications in aqueous environments such asmagnetic separation or magnetic resonance imaging. To increase the colloidal stability and allow subsequent reactions, the introduction of hydrophilic functional groups onto the particles’ surface is essential. During this process, the original coating is exchanged by preferably covalently bonded ligands such as trialkoxysilanes. The duration of the silane exchange reaction, which commonly takes more than 24 h, is an important drawback for this approach. In this paper, we present a novel method, which introduces ultrasonication as an energy source to dramatically accelerate this process, resulting in high-quality waterdispersible nanoparticles around 10 nmin size. To prove the generic character, different functional groups were introduced on the surface including polyethylene glycol chains, carboxylic acid, amine, and thiol groups. Their colloidal stability in various aqueous buffer solutions as well as human plasma and serum was investigated to allow implementation in biomedical and sensing applications.status: publishe

    Prévalence de l’hépatite B chez les personnes infectées par le VIH à Parakou au Bénin

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    Introduction: la co-infection avec l'hépatite B est l'un des défis majeurs de la prise en charge du VIH depuis l'amélioration de l'accès aux  antirétroviraux en Afrique. La présente étude visait à estimer la prévalence de l'hépatite B chez les personnes séropositives au VIH à Parakou et décrire les facteurs associés. Méthodes: il s'agit d'une étude transversale menée de Mai 2011 à Juin 2012 dans le service de Médecine du CHU de Parakou. Ont été inclus tous les adultes séropositifs au VIH vus en  consultation ou hospitalisés. Les données ont été collectées par interviews et dépouillement de dossiers médicaux. L'antigène HBs a été recherché par un test rapide et l'ALAT a été dosé. L'analyse des données a été faite avec le logiciel EpiInfo 3.5.1. Les proportions ont été comparées grâce au test de Chi-deux ou au test de Fisher au seuil de significativité de 5%. Un modèle de régression logistique multivariable a permis d'expliquer la prévalence de l'hépatite B.Résultats: sur les 744 sujets inclus on a dénombré 555 femmes. L'âge moyen était de 35,5 + 10,1 ans. La  prévalence de l'hépatite B a été estimée à 16,9% (IC95 : 14,3%-19,9%). Cette prévalence était plus élevée chez les sujets originaires du  Borgou/Alibori et ceux au stade 4 de l'OMS. Conclusion: la prévalence de la co-infection VIH/VHB au CHU Parakou est élevée. Le dispositif national de prise en charge et de prévention de l'hépatite B chez les personnes  séropositives au VIH doit être renforcé

    Cardiovascular safety during treatment with baricitinib in rheumatoid arthritis

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    Objective To assess the frequency of cardiovascular and venous thromboembolic events in clinical studies of baricitinib, an oral, selective JAK1 and JAK2 inhibitor approved in more than 50 countries for the treatment of moderately‐to‐severely active rheumatoid arthritis (RA). Methods Data were pooled from 9 RA studies. Placebo comparison up to 24 weeks included data from 6 studies. Randomized dose comparison between baricitinib doses of 2 mg and 4 mg used data from 4 studies and from the associated long‐term extension study. The data analysis set designated “All‐bari‐RA” included all baricitinib exposures at any dose. Results Overall, 3,492 RA patients received baricitinib (7,860 patient‐years of exposure). No imbalance compared to the placebo group was seen in the incidence of major adverse cardiovascular events (MACE) (incidence rates [IRs] of 0.5 per 100 patient‐years for placebo and 0.8 per 100 patient‐years for 4 mg baricitinib), arterial thrombotic events (ATE) (IRs of 0.5 per 100 patient‐years for placebo and 0.5 per 100 patient‐years for 4 mg baricitinib), or congestive heart failure (CHF) broad term (IRs of 4.3 per 100 patient‐years for placebo and 2.4 per 100 patient‐years for 4 mg baricitinib). Deep vein thrombosis (DVT)/pulmonary embolism (PE) were reported in 0 of 1,070 patients treated with placebo and 6 of 997 patients treated with 4 mg baricitinib during the placebo‐controlled period; these events were serious in 2 of 6 patients, while all 6 had risk factors and 1 patient developed DVT/PE after discontinuation of the study drug. In the 2 mg–4 mg‐extended data analysis set, IRs of DVT/PE were comparable between the doses across event types (IRs of 0.5 per 100 patient‐years in those receiving 2 mg baricitinib and 0.6 per 100 patient‐years in those receiving 4 mg baricitinib). In the All‐bari‐RA data analysis set, the rates were stable over time, with an IR of DVT/PE of 0.5 per 100 patient‐years. Conclusions In RA clinical trials, no association was found between baricitinib treatment and the incidence of MACE, ATE, or CHF. With regard to incidence of DVT/PE, 6 events occurred in patients treated with 4 mg baricitinib, but no cases of DVT/PE were reported in the placebo group. During longer‐term evaluation, the incidence of DVT/PE was similar between the baricitinib dose groups, with consistent IR values over time, and this was similar to the rates previously reported in patients with RA

    Contrast sensitivity and visual acuity under low light conditions in macular telangiectasia type 2

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    BACKGROUND/AIM: Macular pigment optical density (MPOD) is centrally depleted early on in macular telangiectasia type 2 (MacTel). Contrast sensitivity (CS) might be related to MPOD, and thus impaired in early MacTel. The effect of low luminance was assessed on both CS and best corrected visual acuity (BCVA). METHODS: This is a cross-sectional study. Pelli-Robson charts were used for CS testing at 1 m in photopic (110 lux) and mesopic (1 lux) conditions. BCVA was tested with ETDRS charts and low luminance visual acuity (LLVA) with a 2.0 log unit neutral density filter. MPOD was obtained with dual-wavelength autofluorescence. RESULTS: One hundred and three eyes of 52 patients with MacTel (mean±SD age 62.9±10.2, range 35-77) were compared with 34 healthy eyes of 17 controls (mean±SD age 65.2±7.4, range 53-78). CS was significantly lower in the eyes with MacTel. This impairment was higher in low light conditions (low light contrast sensitivity (LL-CS)). Eyes at the early stages of MacTel had significantly lower LL-CS than controls, but normal (photopic) CS. The results were similar but less pronounced for BCVA/LLVA. Decrease in CS was correlated with loss of MPOD. CONCLUSIONS: Low light conditions have a detrimental effect on visual performance in MacTel. Impaired CS might correlate with MPOD depletion as a pathognomonic finding in MacTel. Functional impairment might precede structural disintegration, indicating dysfunction at the cellular level. The applied tests might be useful as additional functional assessments in clinical routine and as outcome measures in future interventional clinical trials

    Macular Telangiectasia Type 2: A Classification System Using MultiModal Imaging MacTel Project Report Number 10

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    Purpose: To develop a severity classification for macular telangiectasia type 2 (MacTel) disease using multimodal imaging. Design: An algorithm was used on data from a prospective natural history study of MacTel for classification development. Subjects: A total of 1733 participants enrolled in an international natural history study of MacTel. Methods: The Classification and Regression Trees (CART), a predictive nonparametric algorithm used in machine learning, analyzed the features of the multimodal imaging important for the development of a classification, including reading center gradings of the following digital images: stereoscopic color and red-free fundus photographs, fluorescein angiographic images, fundus autofluorescence images, and spectral-domain (SD)-OCT images. Regression models that used least square method created a decision tree using features of the ocular images into different categories of disease severity. Main Outcome Measures: The primary target of interest for the algorithm development by CART was the change in best-corrected visual acuity (BCVA) at baseline for the right and left eyes. These analyses using the algorithm were repeated for the BCVA obtained at the last study visit of the natural history study for the right and left eyes. Results: The CART analyses demonstrated 3 important features from the multimodal imaging for the classification: OCT hyper-reflectivity, pigment, and ellipsoid zone loss. By combining these 3 features (as absent, present, noncentral involvement, and central involvement of the macula), a 7-step scale was created, ranging from excellent to poor visual acuity. At grade 0, 3 features are not present. At the most severe grade, pigment and exudative neovascularization are present. To further validate the classification, using the Generalized Estimating Equation regression models, analyses for the annual relative risk of progression over a period of 5 years for vision loss and for progression along the scale were performed. Conclusions: This analysis using the data from current imaging modalities in participants followed in the MacTel natural history study informed a classification for MacTel disease severity featuring variables from SD-OCT. This classification is designed to provide better communications to other clinicians, researchers, and patients. Financial Disclosure(s): Proprietary or commercial disclosure may be found after the references
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