844 research outputs found

    Development, Test and Validation of a Mechatronic Device for Spasticity Quantification

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    Abstract Spasticity is a common pathological phenomenon in clinical practices, frequently expressed as a stroke, multiple sclerosis or cerebral palsy. The accurate quantification of spasticity allows early action to prevent the potentially irreversible consequences. The aim of this work is to develop and implement a mechatronic device for the accurate quantification of spasticity, which is able to differentiate spasticity from other motor disorders. The proposed method is based on the quantification of the tonic stretch reflex threshold (TSRT) for the assessment of the range of motion of the limb affected by spasticity. In order to validate the developed device, experimental trials have been conducted, considering the flexor muscle of the elbow joint. The developed device was tested, first in a laboratory environment with healthy subjects and secondly, in a clinical environment with the collaboration of patients with spasticity. The evaluations in th clinical environment were performed on three different days in order to evaluate the reproducibility of the obtained results. The experimental trials confirm the sensibility, reproducibility and reliability of spasticity quantification based on the TSRT method. This project has been developed in cooperation with the Hospital of Braga and Fisimaia rehabilitation clinic, both in Portugal

    Translating chitosan to clinical delivery of nucleic acid-based drugs

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    A number of systems based on synthetic molecules, among them cationic liposomes and poly(ethylene imine)-based polymers, have been proposed as delivery vehicles for nucleic acids. Some of these systems have even reached the market, ensuring efficient and transient transfection levels in a variety of cell types. However, toxicity issues have limited their application in vivo. In this context, chitosan, a biocompatible and biodegradable polysaccharide, has been proposed as a promising alternative for the delivery of nucleic acid-based molecules. Here we present an overview of the state of the art of chitosan-based vectors for nucleic acid delivery and the most recent data on the in vivo testing of the proposed systems. We additionally express our view on the barriers that might be hampering the translation of this knowledge into clinical practice and the challenges that need to be fulfilled for these promising vehicles to reach patients.The Programa Operacional Factores de Competitividade — COMPETE and the Portuguese funds through FCT— Fundação para a Ciência e a Tecnologia (PTDC/CTM-NAN/115124/2009 and PEst C/SAU/LA0002/2011) that supported this work. C.P.G. and C.D.F.L. acknowledge FCT for their PhD scholarships (SFRH/BD/79930/2011 and SFRH/BD/77933/2011). P.M.D.M. is supported by a Marie Curie Actions grant within the framework of the European Union’s Seventh Framework Program (PIEF-GA-2011–300485). The authors would like to thank A. Nunes (IBMC-INEB) for her contribution to the graphic design of Figure 2

    Cognitive impairment induced by delta9-tetrahydrocannabinol occurs through heteromers between cannabinoid CB1 and serotonin 5-HT2A receptors

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    Delta-9-tetrahydrocannabinol (THC), the main psychoactive compound of marijuana, induces numerous undesirable effects, including memory impairments, anxiety, and dependence. Conversely, THC also has potentially therapeutic effects, including analgesia, muscle relaxation, and neuroprotection. However, the mechanisms that dissociate these responses are still not known. Using mice lacking the serotonin receptor 5-HT2A, we revealed that the analgesic and amnesic effects of THC are independent of each other: while amnesia induced by THC disappears in the mutant mice, THC can still promote analgesia in these animals. In subsequent molecular studies, we showed that in specific brain regions involved in memory formation, the receptors for THC and the 5-HT2A receptors work together by physically interacting with each other. Experimentally interfering with this interaction prevented the memory deficits induced by THC, but not its analgesic properties. Our results highlight a novel mechanism by which the beneficial analgesic properties of THC can be dissociated from its cognitive side effects

    Continuous increase of cardiovascular diseases, diabetes, and non-HIV related cancers as causes of death in HIV-infected individuals in Brazil: An analysis of nationwide data

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    Introduction: After antiretroviral therapy (ART) became available, there was a decline in the number of deaths in persons infected with HIV. Thereafter, there was a decrease in the proportion of deaths attributed to opportunistic infections and an increase in the proportion of deaths attributed to chronic comorbidities. Herein we extend previous observations from a nationwide survey on temporal trends in causes of death in HIV-infected patients in Brazil. Methods: We describe temporal trends in causes of death among adults who had HIV/AIDS listed in the death certificate to those who did not. All death certificates issued in Brazil from 1999 to 2011 and listed in the national mortality database were included. Generalized linear mixed-effects logistic models were used to study temporal trends in proportions. Results: In the HIV-infected population, there was an annual adjusted average increase of 6.0%, 12.0%, 4.0% and 4.1% for cancer, external causes, cardiovascular diseases (CVD) and diabetes mellitus (DM), respectively, compared to 3.0%, 4.0%, 1.0% and 3.9%, in the non-HIV group. For tuberculosis (TB), there was an adjusted average increase of 0.3%/year and a decrease of 3.0%/year in the HIV and the non-HIV groups, respectively. Compared to 1999, the odds ratio (OR) for cancer, external causes, CVD, DM, or TB in the HIV group were, respectively, 2.31, 4.17, 1.76, 2.27 and 1.02, while for the non-HIV group, the corresponding OR were 1.31, 1.63, 1.14, 1.62 and 0.67. Interactions between year as a continuous or categorical variable and HIV were significant (p <0.001) for all conditions, except for DM when year was considered as a continuous variable (p = 0.76). Conclusions: Non HIV-related co-morbidities continue to increase more rapidly as causes of death among HIV-infected individuals than in those without HIV infection, highlighting the need for targeting prevention measures and surveillance for chronic diseases among those patients. © 2014 Paula et al

    Candida bracarensis: Evaluation of virulence factors and its tolerance to Amphotericin B and Fluconazole

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    Candida bracarensis is an uncommon Candida species found during an epidemiological study of candidiasis performed in Braga, Portugal. Initially, it was identified as C. glabrata, but recently detailed analyses pointed out their differences. So, little information is still available about C. bracarensis virulence factors and antifungal susceptibilities. Therefore, the main goal of this work is to evaluate the ability of C. bracarensis to form biofilms, to produce hydrolytic enzymes (proteases, phospholipases and hemolysins), as well as its susceptibility to amphotericin B and fluconazole. It was shown, for the first time, that all C. bracarensis strains were able to form biofilms and display proteinase and hemolytic activities. Moreover, although planktonic cells presented antifungal susceptibility, amphotericin B and fluconazole were unable to inhibit biofilm formation and eradicate pre-formed biofilms. Due to the propensity of C. bracarensis to display antifungal resistance and virulence attributes, the control of these emerging pathogens is recommended.This work was supported by the projects PTDC/SAU-MIC/119069/2010, PEst-OE/EQB/LA0023/2013, from Fundação para a Ciência e Tecnologia (FCT), Portugal and ‘‘BioHealth—Biotechnology and Bioengineering approaches to improve health quality’’, Ref. NORTE-07-0124FEDER-000027, co-funded by the Programa Operacional Regional do Norte (ON.2 – O Novo Norte), QREN, FEDER. The authors also acknowledge the project ‘‘Consolidating Research Expertise and Resources on Cellular and Molecular Biotechnology at CEB/IBB’’, Ref. FCOMP-01-0124-FEDER027462

    Two-pion Bose-Einstein correlations in central Pb-Pb collisions at sNN\sqrt{s_{\rm NN}} = 2.76 TeV

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    The first measurement of two-pion Bose-Einstein correlations in central Pb-Pb collisions at sNN=2.76\sqrt{s_{\rm NN}} = 2.76 TeV at the Large Hadron Collider is presented. We observe a growing trend with energy now not only for the longitudinal and the outward but also for the sideward pion source radius. The pion homogeneity volume and the decoupling time are significantly larger than those measured at RHIC.Comment: 17 pages, 5 captioned figures, 1 table, authors from page 12, published version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/388

    Suppression of charged particle production at large transverse momentum in central Pb-Pb collisions at sNN=2.76\sqrt{s_{\rm NN}} = 2.76 TeV

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    Inclusive transverse momentum spectra of primary charged particles in Pb-Pb collisions at sNN\sqrt{s_{_{\rm NN}}} = 2.76 TeV have been measured by the ALICE Collaboration at the LHC. The data are presented for central and peripheral collisions, corresponding to 0-5% and 70-80% of the hadronic Pb-Pb cross section. The measured charged particle spectra in η<0.8|\eta|<0.8 and 0.3<pT<200.3 < p_T < 20 GeV/cc are compared to the expectation in pp collisions at the same sNN\sqrt{s_{\rm NN}}, scaled by the number of underlying nucleon-nucleon collisions. The comparison is expressed in terms of the nuclear modification factor RAAR_{\rm AA}. The result indicates only weak medium effects (RAAR_{\rm AA} \approx 0.7) in peripheral collisions. In central collisions, RAAR_{\rm AA} reaches a minimum of about 0.14 at pT=6p_{\rm T}=6-7GeV/cc and increases significantly at larger pTp_{\rm T}. The measured suppression of high-pTp_{\rm T} particles is stronger than that observed at lower collision energies, indicating that a very dense medium is formed in central Pb-Pb collisions at the LHC.Comment: 15 pages, 5 captioned figures, 3 tables, authors from page 10, published version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/98

    Distribution of Cortical Endoplasmic Reticulum Determines Positioning of Endocytic Events in Yeast Plasma Membrane

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    In many eukaryotes, a significant part of the plasma membrane is closely associated with the dynamic meshwork of cortical endoplasmic reticulum (cortical ER). We mapped temporal variations in the local coverage of the yeast plasma membrane with cortical ER pattern and identified micron-sized plasma membrane domains clearly different in cortical ER persistence. We show that clathrin-mediated endocytosis is initiated outside the cortical ER-covered plasma membrane zones. These cortical ER-covered zones are highly dynamic but do not overlap with the immobile and also endocytosis-inactive membrane compartment of Can1 (MCC) and the subjacent eisosomes. The eisosomal component Pil1 is shown to regulate the distribution of cortical ER and thus the accessibility of the plasma membrane for endocytosis

    Antimicrobial activity of sesquiterpene lactones isolated from traditional medicinal plant, Costus speciosus (Koen ex.Retz.) Sm

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    <p>Abstract</p> <p>Background</p> <p><it>Costus speciosus </it>(Koen ex.Retz.) Sm (Costaceae) is an Indian ornamental plant which has long been used medicinally in traditional systems of medicine. The plant has been found to possess diverse pharmacological activities. Rhizomes are used to treat pneumonia, rheumatism, dropsy, urinary diseases, jaundice, skin diseases and leaves are used<b/>to treat mental disorders.</p> <p>Method</p> <p>Antibacterial and antifungal activities were tested using Disc diffusion method and Minimum Inhibitory <b>Concentration </b>(MIC). Column chromatography was used to isolate compounds from hexane extract. X-ray crystallography technique and GC-MS analysis were used to identify the compounds</p> <p>Results</p> <p>Antibacterial and antifungal activities were observed in hexane, chloroform, ethyl acetate and methanol extracts. Hexane extract of <it>C.speciosus </it>showed good activity against tested fungi also. Two sesquiterpenoid compounds were isolated (costunolide and eremanthin) from the hexane extract. Both the compounds did not inhibit the growth of tested bacteria. But, both the compounds inhibited the tested fungi. The compound costunolide showed significant antifungal activity. The MIC values of costunolide were; 62.5 μg/ml against <it>Trichophyton mentagrophytes</it>, 62. μg/ml against <it>T. simii</it>, 31.25 μg/ml against <it>T. rubrum </it>296, 62.5 μg/ml against <it>T. rubrum </it>57, 125 μg/ml against <it>Epidermophyton floccosum</it>, 250 μg/ml against <it>Scopulariopsis </it>sp, 250 μg/ml against <it>Aspergillus niger</it>, 125 μg/ml against <it>Curvulari lunata</it>, 250 μg/ml against <it>Magnaporthe grisea</it>.</p> <p>Conclusion</p> <p>Hexane extract showed promising antibacterial and antifungal activity. The isolated compound costunolide showed good antifungal activity.</p
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