2,381 research outputs found

    Bone mechanical stimulation with piezoelectric materials

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    This chapter summarized explores in vivo use of a piezoelectric polymer for bone mechanical stimulatio

    Decoy activity through microRNAs : the therapeutic implications

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    Introduction: microRNAs (miRNAs), small noncoding RNAs, are deregulated in several diseases including cancer. miRNAs regulate gene expression at a posttranscriptional level by binding to 5´UTR, coding regions or 3´UTR of messenger RNAs (mRNA), inhibiting mRNA translation or causing mRNA degradation. The same miRNA can have multiple mRNA targets, and the same mRNA can be regulated by various miRNAs. Areas covered: Recently, seminal contributions by several groups have implicated miRNAs as components of an RNA--RNA language that involves crosstalk between competing endogenous RNAs through a decoy mechanism. We review the studies that described miRNAs as players in a biological decoy activity. miRNAs can either be trapped by competing endogenous RNAs or interact with proteins that have binding sites for mRNAs. Expert opinion: The miRNA decoy functions have implications for the design of therapeutic approaches in human diseases, including specific ways to overcome resistance to drug therapy and future miRNA-based clinical trials design.M.I.A. is supported by a PhD fellowship (SFRH/BD/47031/2008) from Fundacão para a Ciência e Tecnologia, Portugal. Dr. Calin is The Alan M. Gewirtz Leukemia & Lymphoma Society Scholar. He is also supported as a Fellow at The University of Texas MD Anderson Research Trust, as a University of Texas System Regents Research Scholar, and by the CLL Global Research Foundation. Work in Dr. Calin’s laboratory is supported in part by an NIH/NCI grant (CA135444), a Department of Defense Breast Cancer Idea Award, Developmental Research Awards in Breast Cancer, Ovarian Cancer, Brain Cancer, Prostate Cancer, Multiple Myeloma, and Leukemia SPOREs, the Laura and John Arnold Foundation, the RGK Foundation and the Estate of C. G. Johnson, Jr. The authors disclose no conflicts of interests and no funding was received in preparation of this manuscript

    Descrição de uma forma autossômica dominante de síndrome de Kabuki por mutação no gene MLL2

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    Aims: Although there are more than 400 cases of Kabuki syndrome described in the literature, it is believed that this syndrome is under-diagnosed. Most cases occur sporadically, despite cases with autosomal dominant familial transmission being described. Here we describe three cases identified in the same family. Cases description: A family (mother and two children) was diagnosed with Kabuki syndrome. The three patients show the typical characteristics (facial appearance, musculoskeletal abnormalities, cognitive impairment, growth retardation and peculiar dermatoglyphic pattern) associated with other anomalies described in the syndrome (congenital heart disease and increased susceptibility to infections). Genetic studies revealed a nonsense mutation c.14710 C > T (p.Arg4904X) in the MLL2 gene in the three members of the family. Conclusions: With the description of another case of familial Kabuki syndrome, the authors wish to illustrate the autosomal dominant inheritance with variable expressivity, which are present in this situation, and to alert to the need for a rigorous clinical and molecular evaluation of the affected patient’s relatives, allowing appropriate genetic counseling

    Entrapment ability and release profile of corticosteroids from starch-based microparticles

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    We previously described the synthesis of starchbased microparticles that were shown to be bioactive (when combined with Bioactive Glass 45S5) and noncytotoxic. To further assess their potential for biomedical applications such as controlled release, three corticosteroids with a similar basic structure—dexamethasone (DEX), 16-methylprednisonole (MP), and 16-methylprednisolone acetate (MPA) - were used as models for the entrapment and release of bioactive agents. DEX, MP, and MPA were entrapped into starch-based microparticles at 10% wt/wt of the starch-based polymer and the loading efficiencies, as well as the release profiles, were evaluated. Differences were found for the loading efficiencies of the three corticosteroids, with DEX and MPA being the most successfully loaded (82 and 84%, respectively), followed by MP (51%). These differences might be explained based on the differential distribution of the molecules within the matrix of the microparticles. Furthermore, a differential burst release was observed in the first 24 h for all corticosteroids with DEX and MP being more pronounced (around 25%), whereas only 12% of MPA was released during the same time period. Whereas the water uptake profile can account for this first stage burst release, the subsequent slower release stage was mainly attributed to degradation of the microparticle network. Differences in the release profiles can be explained based on the structure of the molecule, because MPA, a more bulky and hydrophobic molecule, is released at a slower rate compared with DEX and MP. In this work, it is shown that these carriers were able to sustain a controlled release of the entrapped corticosteroids over 30 days, which confirms the potential of these systems to be used as carriers for the delivery of bioactive agents

    Physical properties and biocompatibility of Chitosan/soy blended membranes

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    Blends of polysaccharides and proteins are a source for the development of novel materials with interesting and tailorable properties, with potential to be used in a range of biomedical applications. in this work a series of blended membranes composed by chitosan and soy protein isolate was prepared by solvent casting methodology. in addition, cross-linking was performed in situ with glutaraldehyde solutions in the range 5 × 10–3 – 0.1 M. Furthermore, the influence of the composition and cross-linking on the degradation behaviour, water uptake and cell adhesion was investigated. The obtained results showed that the incorporation of chitosan, associated to network formation by cross linking, promoted a slight decrease of water absorption and a slower degradability of the membranes. Moreover, direct contact biocompatibility studies, with L929 cells, indicate that the cross-linking enhances the capability of the material to support cell growth.Fundação para a Ciência e a Tecnologia (FCT

    Chitosan/TPP microparticles obtained by microemulsion method applied in controlled release of heparin

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    AbstractThis work deals with the preparation of chitosan/tripolyphosphate microparticles (CHT/TPP) using microemulsion system based on water/benzyl alcohol. The morphology of the microparticles was evaluated by scanning electron microscopy (SEM). The microparticles were also characterized through infrared spectroscopy (FTIR) and wide-angle X-ray scattering (WAXS). The morphology and crystallinity of microparticles depended mainly on CHT/TPP ratio. Studies of controlled release of HP were evaluated in distilled water and in simulated gastric fluid. Besides, the profile of HP releasing could be tailored by tuning the CHT/TPP molar ratio. Finally, these prospective results allow the particles to be employed as site-specific HP controlled release system

    Single-cell resolution imaging of retinal ganglion cell apoptosis in vivo using a cell-penetrating caspase-activatable peptide probe

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    Peptide probes for imaging retinal ganglion cell (RGC) apoptosis consist of a cell-penetrating peptide targeting moiety and a fluorophore-quencher pair flanking an effector caspase consensus sequence. Using ex vivo fluorescence imaging, we previously validated the capacity of these probes to identify apoptotic RGCs in cell culture and in an in vivo rat model of N-methyl- D-aspartate (NMDA)-induced neurotoxicity. Herein, using TcapQ488, a new probe designed and synthesized for compatibility with clinically-relevant imaging instruments, and real time imaging of a live rat RGC degeneration model, we fully characterized time- and dose-dependent probe activation, signal-to-noise ratios, and probe safety profiles in vivo. Adult rats received intravitreal injections of four NMDA concentrations followed by varying TcapQ488 doses. Fluorescence fundus imaging was performed sequentially in vivo using a confocal scanning laser ophthalmoscope and individual RGCs displaying activated probe were counted and analyzed. Rats also underwent electroretinography following intravitreal injection of probe. In vivo fluorescence fundus imaging revealed distinct single-cell probe activation as an indicator of RGC apoptosis induced by intravitreal NMDA injection that corresponded to the identical cells observed in retinal flat mounts of the same eye. Peak activation of probe in vivo was detected 12 hours post probe injection. Detectable fluorescent RGCs increased with increasing NMDA concentration; sensitivity of detection generally increased with increasing TcapQ488 dose until saturating at 0.387 nmol. Electroretinography following intravitreal injections of TcapQ488 showed no significant difference compared with control injections. We optimized the signal-to-noise ratio of a caspase-activatable cell penetrating peptide probe for quantitative non-invasive detection of RGC apoptosis in vivo. Full characterization of probe performance in this setting creates an important in vivo imaging standard for functional evaluation of future probe analogues and provides a basis for extending this strategy into glaucoma-specific animal models

    Innate immune responses and antioxidant/oxidant imbalance are major determinants of human Chagas disease.

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    We investigated the pathological and diagnostic role of selected markers of inflammation, oxidant/antioxidant status, and cellular injury in human Chagas disease. METHODS: Seropositive/chagasic subjects characterized as clinically-symptomatic or clinically-asymptomatic (n = 116), seronegative/cardiac subjects (n = 102), and seronegative/healthy subjects (n = 45) were analyzed for peripheral blood biomarkers. RESULTS: Seropositive/chagasic subjects exhibited an increase in sera or plasma levels of myeloperoxidase (MPO, 2.8-fold), advanced oxidation protein products (AOPP, 56%), nitrite (5.7-fold), lipid peroxides (LPO, 12-17-fold) and malondialdehyde (MDA, 4-6-fold); and a decline in superoxide dismutase (SOD, 52%) and glutathione (GSH, 75%) contents. Correlation analysis identified a significant (p0.95). The MPO (r = 0.664) and LPO (r = 0.841) levels were also correlated with clinical disease state in chagasic subjects (p<0.001). Seronegative/cardiac subjects exhibited up to 77% decline in SOD, 3-5-fold increase in LPO and glutamate pyruvate transaminase (GPT) levels, and statistically insignificant change in MPO, AOPP, MDA, GPX, GSH, and creatine kinase (CK) levels. CONCLUSIONS: The interlinked effects of innate immune responses and antioxidant/oxidant imbalance are major determinants of human Chagas disease. The MPO, LPO and nitrite are excellent biomarkers for diagnosing seropositive/chagasic subjects, and MPO and LPO levels have potential utility in identifying clinical severity of Chagas diseaseFil: Dhiman, Monisha. University Of Texas Medical Branch. Department Of Microbiology & Immunology And Pathology; United State of America;Fil: Coronado, Yun A.. University Of Texas Medical Branch. Department Of Microbiology & Immunology And Pathology; United State of America;Fil: Vallejo, Cecilia K.. University Of Texas Medical Branch. Department Of Microbiology & Immunology And Pathology; United State of America;Fil: Petersen, John R.. University of Texas Medical Branch. Department of Pathology; United States of America;Fil: Ejilemele, Adetoum. University of Texas Medical Branch. Department of Pathology; United States of America;Fil: Nuñez, Sonia. Hospital Público de Gestión Descentralizada San Bernardo (HPGDSA); Argentina;Fil: Zago, María Paola. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - CONICET - Salta. Instituto de Patologia Experimental; Argentina;Fil: Spratt, Heidi. Departments of Biochemistry and Molecular Biology and Preventive Medicine and Community Health. University of Texas Medical Branch; United States of America;Fil: Garg, Nisha Jain. University of Texas Medical Branch. Department of Pathology; United States of America

    Monocarboxylate transporter 4 (MCT4) and CD147 overexpression is associated with poor prognosis in prostate cancer

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    BACKGROUND. Monocarboxylate transporters (MCTs) are transmembrane proteins involved in the transport of monocarboxylates across the plasma membrane, which appear to play an important role in solid tumours, however the role of MCTs in prostate cancer is largely unknown.The aim of the present work was to evaluate the clinico-pathological value of monocarboxylate transporters (MCTs) expression, namely MCT1, MCT2 and MCT4, together with CD147 and gp70 as MCT1/4 and MCT2 chaperones, respectively, in prostate carcinoma. METHODS. Prostate tissues were obtained from 171 patients, who performed radical prostatectomy and 14 patients who performed cystoprostatectomy. Samples and clinico-pathological data were retrieved and organized into tissue microarray (TMAs) blocks. Protein expression was evaluated by immunohistochemistry in neoplastic (n= 171), adjacent non-neoplastic tissues (n= 135), PIN lesions (n=40) and normal prostatic tissue (n=14). Protein expression was correlated with patients' clinicopathologic characteristics. RESULTS. In the present study, a significant increase of MCT2 and MCT4 expression in the cytoplasm of tumour cells and a significant decrease in both MCT1 and CD147 expression in prostate tumour cells was observed when compared to normal tissue. All MCT isoforms and CD147 were expressed in PIN lesions. Importantly, for MCT2 and MCT4 the expression levels in PIN lesions were between normal and tumour tissue, which might indicate a role for these MCTs in the malignant transformation. Associations were found between MCT1, MCT4 and CD147 expressions and poor prognosis markers; importantly MCT4 and CD147 overexpression correlated with higher PSA levels, Gleason score and pT stage, as well as with perineural invasion and biochemical recurrence. CONCLUSIONS. Our data provides novel evidence for the involvement of MCTs in prostate cancer. According to our results, we consider that MCT2 should be further explored as tumour marker and both MCT4 and CD147 as markers of poor prognosis in prostate cancer.NPG, CP and VMG received fellowships from the Portuguese Foundation for Science and Technology (FCT), refs. SFRH/BD/61027/2009, SFRH/BPD/69479/ 2010 and SFRH/BI/33503/2008, respectively. This work was supported by the FCT grant ref. PTDC/SAU-FCF/104347/2008, under the scope of Programa Operacional Temático Factores de Competitividade” (COMPETE) of Quadro Comunitário de Apoio III and co-financed by Fundo Comunitário Europeu FEDER
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