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In recent years, the scientific community has tried to address the treatment of complex diseases such as cancer in a more appropriate and promising way. Regarding this and benefiting from the unique optical properties of gold nanoprisms (AuNPRs), the physicochemical properties of thermosensitive liposomes (TSLs), and the tunable drug encapsulation and release properties of silica nanoparticles (BioSi@NPs), this study has developed two nanoformulations. These nanoformulations have the potential to integrate chemotherapy and photothermal therapy within a single entity. Once their components were synthesized and characterized separately, two strategies were taken in order to develop these multifunctional nanoformulations: (1) covalent binding of AuNPRs to TSLs and (2) co-encapsulation of both components within BioSi@NPs, without modifying the optical and physicochemical properties of AuNPRs and TSLs. Finally, the suitability of both nanoformulations to carry and release hydrophilic drugs when triggered by a 1064 nm NIR laser has been explored by using the fluorescent probe 5(6)-carboxyfluorescein (CF) as a hydrophilic drug model. Different laser power and time of exposure were also tested evidencing that hydrophilic drugs were only released from TSLs in the presence of AuNPRs and that the drug release profile was dependent on the type of nanoformulation and irradiation conditions used. In conclusion, these multifunctional nanoformulations exhibit promising potential for controlled drug delivery in combined chemotherapy and phototherapy, with the capability to precisely control the release kinetics based on specific therapeutic needs.
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AIMS: To describe characteristics of applicant, tool, outcomes, regulatory responses and general learnings from European Medicines Agency (EMA) Qualification Procedures on patient-reported outcomes (PROs), observer-reported outcomes (ObsROs) and performance outcomes (PerfOs) finalized between January 2013 and December 2018. METHODS: Descriptive analysis, and qualitative review of the regulatory outcomes of the study procedures. RESULTS: Seventeen qualification programmes for PROs, 6 for ObsRO tools and 11 for PerfO tools were submitted by consortia, large and small/medium companies. Gastroenterology and neurology were the most frequent therapeutic areas. There was a high level of regulators' partial agreement (above 70%) with applicant's approaches with constructive input; EMA published Letters of Support for PRO (6), ObsRO (2) and PerfO (4) tools, and Qualification Opinions on PROs (2) and PerfOs (1). General issues related to Qualification Procedures on PROs raised by EU regulatorsincluded: population, appropriate studies to demonstrate ability to detect change, tool validation in interventional trials, anchoring, identification of the minimally important difference, item selection, weighting, and multiple domains. In addition, specific issues for ObsROs and PerfO tools validation are identified. CONCLUSIONS: Regulators discussed principles and challenges of validation tailored to specific setting in tool development, providing constructive feedback. Regulatory outputs supportive of further development were published in over one-third of programs. We encourage applicants intending to use or develop novel PRO, ObsRO and PerfO tools that will generate evidence for regulatory submissions on medicines to consider Qualification procedures for novel methods to seek feedback on the development and validation of these tools.
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Medidas de Resultados Relatados pelo Paciente , Projetos de Pesquisa , HumanosRESUMO
Physiologically, renal medullary cells are surrounded by a hyperosmolar interstitium. However, different pathological situations can induce abrupt changes in environmental osmolality, causing cell stress. Therefore, renal cells must adapt to survive in this new condition. We previously demonstrated that, among the mechanisms involved in osmoprotection, renal cells upregulate triglyceride biosynthesis (which helps preserve glycerophospholipid synthesis and membrane homeostasis) and cyclooxygenase-2 (which generates prostaglandins from arachidonic acid) to maintain lipid metabolism in renal tissue. Herein, we evaluated whether hyperosmolality modulates phospholipase A2 (PLA2 ) activity, leading to arachidonic acid release from membrane glycerophospholipid, and investigated its possible role in hyperosmolality-induced triglyceride synthesis and accumulation. We found that hyperosmolality induced PLA2 expression and activity in Madin-Darby canine kidney cells. Cytosolic PLA2 (cPLA2) inhibition, but not secreted or calcium-independent PLA2 (sPLA2 or iPLA2 , respectively), prevented triglyceride synthesis and reduced cell survival. Inhibition of prostaglandin synthesis with indomethacin not only failed to prevent hyperosmolality-induced triglyceride synthesis but also exacerbated it. Similar results were observed with the peroxisomal proliferator activated receptor gamma (PPARγ) agonist rosiglitazone. Furthermore, hyperosmolality increased free intracellular arachidonic acid levels, which were even higher when prostaglandin synthesis was inhibited by indomethacin. Blocking PPARγ with GW-9662 prevented the effects of both indomethacin and rosiglitazone on triglyceride synthesis and even reduced hyperosmolality-induced triglyceride synthesis, suggesting that arachidonic acid may stimulate triglyceride synthesis through PPARγ activation. These results highlight the role of cPLA2 in osmoprotection, since it is essential to provide arachidonic acid, which is involved in PPARγ-regulated triglyceride synthesis, thus guaranteeing cell survival.
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PPAR gama , Prostaglandinas , Animais , Cães , PPAR gama/genética , Ácido Araquidônico/metabolismo , Rosiglitazona , Pressão Osmótica , Fosfolipases A2 , Indometacina , Homeostase , Glicerofosfolipídeos , TriglicerídeosRESUMO
Psychopharmacological treatment is an important component of the multimodal intervention approach to treating mental health conditions in children and adolescents. Currently, there are many unmet needs but also opportunities, alongside possible risks to consider, regarding the pharmacological treatment of mental health conditions in children and adolescents. In this Position Paper, we highlight and address these unmet needs and opportunities, including the perspectives of clinicians and researchers from the European College of Neuropsychopharmacology-Child and Adolescent Network, alongside those of experts by lived experience from national and international associations, via a survey involving 644 participants from 13 countries, and of regulators, through representation from the European Medicines Agency. We present and discuss the evidence base for medications currently used for mental disorders in children and adolescents, medications in the pipeline, opportunities in the development of novel medications, crucial priorities for the conduct of future clinical studies, challenges and opportunities in terms of the regulatory and legislative framework, and innovations in the way research is conducted, reported, and promoted.
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Transtornos Mentais , Psicofarmacologia , Adolescente , Humanos , Transtornos Mentais/tratamento farmacológico , Saúde MentalRESUMO
AIMS: Calcium oxalate (Oxa), constituent of most common kidney stones, damages renal tubular epithelial cells leading to kidney disease. Most in vitro studies designed to evaluate how Oxa exerts its harmful effects were performed in proliferative or confluent non-differentiated renal epithelial cultures; none of them considered physiological hyperosmolarity of renal medullary interstitium. Cyclooxygenase 2 (COX2) has been associated to Oxa deleterious actions; however, up to now, it is not clear how COX2 acts. In this work, we proposed an in vitro experimental system resembling renal differentiated-epithelial cells that compose medullary tubular structures which were grown and maintained in a physiological hyperosmolar environment and evaluated whether COX2 â PGE2 axis (COX2 considered a cytoprotective protein for renal cells) induces Oxa damage or epithelial restitution. MAIN METHODS: MDCK cells were differentiated with NaCl hyperosmolar medium for 72 h where cells acquired the typical apical and basolateral membrane domains and a primary cilium. Then, cultures were treated with 1.5 mM Oxa for 24, 48, and 72 h to evaluate epithelial monolayer restitution dynamics and COX2-PGE2 effect. KEY FINDINGS: Oxa completely turned the differentiated phenotype into mesenchymal one (epithelial-mesenchymal transition). Such effect was partially and totally reverted after 48 and 72 h, respectively. Oxa damage was even deeper when COX2 was blocked by NS398. PGE2 addition restituted the differentiated-epithelial phenotype in a time and concentration dependence. SIGNIFICANCE: This work presents an experimental system that approaches in vitro to in vivo renal epithelial studies and, more important, warns about NSAIDS use in patients suffering from kidney stones.
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Oxalato de Cálcio , Cálculos Renais , Oxalato de Cálcio/química , Ciclo-Oxigenase 2/metabolismo , Dinoprostona/metabolismo , Células Epiteliais/metabolismo , Cálculos Renais/química , Células Madin Darby de Rim Canino , Animais , CãesRESUMO
This work describes the development and characterization of fluorescent nanocomposite hydrogels, with high swelling and absorption capacity, and prepared using a green protocol. These fluorescent materials are obtained by incorporating, for the first time, polyfluorenes-based nanoparticles with different emission bands-poly[9,9-dioctylfluorenyl-2,7-diyl] (PFO) and poly[(9,9-di-n-octylfluorenyl-2,7-diyl)-alt-(1,4-benzo-{2,1,3}-thiadiazole)] (F8BT)-into a three-dimensional polymeric network based on polyacrylamide. To this end, two strategies were explored: incorporation of the nanoparticles during the polymerization process (in situ) and embedment after the hydrogel formation (ex situ). The results show that the combination of PFO nanoparticles introduced by the ex situ method provided materials with good storage stability, homogeneity and reproducibility properties, allowing their preservation in the form of xerogel. The fluorescent nanocomposite hydrogels have been tested as a transportable and user-friendly sensing platform. In particular, the ability of these materials to specifically detect the enzyme alkaline phosphatase (ALP) has been evaluated as a proof-of-concept. The sensor was able to quantify the presence of the enzyme in an aqueous sample with a response time of 10 min and LOD of 21 nM. Given these results, we consider that this device shows great potential for quantifying physiological ALP levels as well as enzyme activity in environmental samples.
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Nanopartículas , Polímeros , Nanogéis , Fosfatase Alcalina , Reprodutibilidade dos Testes , HidrogéisRESUMO
Here, we present a study on the incorporation and characterization of the enzyme alkaline phosphatase (ALP) into a three-dimensional polymeric network through a green protocol to obtain transparent hydrogels (ALP@AETA) that can be stored at room temperature and potentially used as a disposable biosensor platform for the rapid detection of ALP inhibitors. For this purpose, different strategies for the immobilization of ALP in the hydrogel were examined and the properties of the new material, compared to the hydrogel in the absence of enzyme, were studied. The conformation and stability of the immobilized enzyme were characterized by monitoring the changes in its intrinsic fluorescence as a function of temperature, in order to study the unfolding/folding process inside the hydrogel, inherently related to the enzyme activity. The results show that the immobilized enzyme retains its activity, slightly increases its thermal stability and can be stored as a xerogel at room temperature without losing its properties. A small portion of a few millimeters of ALP@AETA xerogel was sufficient to perform enzymatic activity inhibition assays, so as a proof of concept, the device was tested as a portable optical biosensor for the detection of phosphate in water with satisfactory results. Given the good stability of the ALP@AETA xerogel and the interesting applications of ALP, not only in the environmental field but also as a therapeutic enzyme, we believe that this study could be of great use for the development of new devices for sensing and protein delivery.
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Fosfatase Alcalina , Enzimas Imobilizadas , Fosfatase Alcalina/metabolismo , Hidrogéis/farmacologia , Fosfatos , TemperaturaRESUMO
Abstract Spinal cord infarction is an uncommon phenomenon, which can be caused by different etiologies, constituting a real diagnostic challenge which can lead to devastating consequences. General anesthesia in beach chair positioning with intraoperative hypotension in order to avoid surgical bleeding are associated with hypoperfusion and potential neurological ischemia-related complications. We present a case of spinal cord ischemia in the context of shoulder surgery in a beach chair position.
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Humanos , Articulação do Ombro/cirurgia , Isquemia do Cordão Espinal/complicações , Artroscopia/efeitos adversos , Ombro/cirurgia , Posicionamento do Paciente/efeitos adversos , Complicações Intraoperatórias/etiologia , Isquemia/complicaçõesRESUMO
The loss of mobility is a common trait in multiple health conditions (e.g., Parkinson's disease) and is associated with reduced quality of life. In this context, being able to monitor mobility in the real world, is important. Until recently, the technology was not mature enough for this; but today, miniaturized sensors and novel algorithms promise to monitor mobility accurately and continuously in the real world, also in pathological populations. However, before any such methodology can be employed to support the development and testing of new drugs in clinical trials, they need to be qualified by the competent regulatory agencies (e.g., European Medicines Agency). Nonetheless, to date, only very narrow scoped requests for regulatory qualification were successful. In this work, the Mobilise-D Consortium shares its positive experience with the European regulator, summarizing the two requests for Qualification Advice for the Mobilise-D methodologies submitted in October 2019 and June 2020, as well as the feedback received, which resulted in two Letters of Support publicly available for consultation on the website of the European Medicines Agency. Leveraging on this experience, we hereby propose a refined qualification strategy for the use of digital mobility outcome (DMO) measures as monitoring biomarkers for mobility in drug trials.
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The present work describes the development of an easy-to-use portable electrochemical biosensor based on alkaline phosphatase (ALP) as a recognition element, which has been immobilized in acrylamide-based hydrogels prepared through a green protocol over disposable screen-printed electrodes. To carry out the electrochemical transduction, an electroinactive substrate (hydroquinone diphosphate) was used in the presence of the enzyme and then it was hydrolyzed to an electroactive species (hydroquinone). The activity of the protein within the matrix was determined voltammetrically. Due to the adhesive properties of the hydrogel, this was easily deposited on the surface of the electrodes, greatly increasing the sensitivity of the biosensor. The device was optimized to allow the determination of phosphate ion, a competitive inhibitor of ALP, in aqueous media. Our study provides a proof-of-concept demonstrating the potential use of the developed biosensor for in situ, real-time measurement of water pollutants that act as ALP inhibitors.
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Técnicas Biossensoriais , Poluentes da Água , Acrilamida , Fosfatase Alcalina , Técnicas Biossensoriais/métodos , Técnicas Eletroquímicas/métodos , Eletrodos , Hidrogéis , Hidroquinonas , FosfatosRESUMO
INTRODUCTION: The aim of the study was twofold: a) to determine the prevalence of symptoms of depression and anxiety and sleep disturbances in young patients with vertically-transmitted HIV infection compared to uninfected peers, and b) to identify sociodemographic, psychosocial and medication-related variables and other clinical risk and protective factors related to psychological symptoms. METHODS: We conducted a cross-sectional study in two groups with independent measures (36 youth with vertically transmitted HIV infection and 39 HIV-negative peers). We used 3 standardised assessment tools and a sociodemographic/psychosocial questionnaire (STAI, BDI, PSQI and adapted sociodemographic test). We performed univariate and multivariable analyses. RESULTS: The univariate analysis did not find significant differences between groups either in psychosocial factors or in the clinical scores. The multivariable analysis found that the presence of psychological symptoms was strongly associated with sociodemographic factors and past events. CONCLUSIONS: Psychosocial factors and the social environment seemed to correlate more strongly to psychological symptoms than HIV status and to explain better the current psychological state of individuals.
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Infecções por HIV , Adolescente , Ansiedade/epidemiologia , Estudos Transversais , Infecções por HIV/complicações , Infecções por HIV/epidemiologia , Infecções por HIV/psicologia , Humanos , Prevalência , Fatores de RiscoRESUMO
BACKGROUND: Chagas disease (CD) has become an emerging global health problem in association with the immigration of individuals from endemic areas (in LatinAmerica) to other countries.Spain is the country in Europe with the highest number of CD cases. Concerning pediatric CD, treatment is not only better tolerated by younger children but also has greater cure possibilities. The aim of this study was to describe clinical and epidemiological aspects of CD in a pediatric population diagnosed of 10 hospitals in the Community of Madrid during the 2004-2018 period, as well as the safety and efficacy of CD treatment on this population. METHODOLOGY/PRINCIPAL FINDINGS: A multicenter, retrospective, descriptive study was conducted. The studied population included all identified children under the age of 18 with a diagnosis of CD. Diagnosis was performed with a positive parasitological test (with subsequent confirmation) or confirmed persistence of positive serology beyond 9 months, for children younger than one year-old, and with two different positive serological tests, for children older than one. Fifty-one children were included (59% male; 50.9% born in Spain). All mothers were from Latin America. The median age at diagnosis was 0.7 months for those under one year of age, and 11.08 years for those older than one year-old. Only one case presented a symptomatic course (hydrops faetalis, haemodynamic instability at birth, ascites, anaemia). For 94% treatment was completed. Considering patients who received benznidazole (47), AE were recorded in 48,9%. Among the 32 patients older than one year-old treated with benznidazole, 18 (56.25%) had adverse events whereas in the 15 under one year, 5(33,3%) did. Eigtheen (78.2%) of the patients with benznidazole AE were older than one year-old(median age 11.4 years). Of the patients treated with nifurtimox (9), AE were reported in 3 cases (33,3%). Cure was confirmed in 80% of the children under one year-old vs 4.3% in those older (p<0.001). Loss to follow- up occurred in 35.3% of patients. CONCLUSIONS/SIGNIFICANCES: Screening programs of CD since birth allow early diagnosis and treatment, with a significantly higher cure rate in children treated before one year of age, with lower incidence of adverse events. The high proportion of patients lost to follow-up in this vulnerable population is of concern.
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Doença de Chagas , Trypanosoma cruzi , Doença de Chagas/diagnóstico , Doença de Chagas/tratamento farmacológico , Doença de Chagas/epidemiologia , Criança , Emigração e Imigração , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Nifurtimox/uso terapêutico , Estudos RetrospectivosRESUMO
The unfolded protein response (UPR) is a complex network of intracellular pathways that transmits signals from ER lumen and/or ER bilayer to the nuclear compartment in order to activate gene transcription. UPR is activated by the loss of ER capacities, known as ER stress, and occurs to restore ER properties. In this regard, glycerolipid (GL) synthesis activation contributes to ER membrane homeostasis and IRE1α-XBP1, one UPR pathway, has a main role in lipogenic genes transcription. Herein, we describe the strategy and methodology used to evaluate whether IRE1α-XBP1 pathway regulates lipid metabolism in renal epithelial cells subjected to hyperosmolar environment. XBP1s activity was hindered by blocking IRE1α RNAse activity and by impeding its expression; under these conditions, we determined GL synthesis and lipogenic enzymes expression.
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Endorribonucleases , Proteínas Serina-Treonina Quinases , Estresse do Retículo Endoplasmático/genética , Endorribonucleases/genética , Endorribonucleases/metabolismo , Lipídeos , Proteínas Serina-Treonina Quinases/genética , Resposta a Proteínas não Dobradas , Proteína 1 de Ligação a X-Box/genética , Proteína 1 de Ligação a X-Box/metabolismoRESUMO
In this study, we employed the copolymer poly(methyl vinyl ether-alt-maleic monoethyl ester) (PMVEMA-Es) and three fluorene-based cationic conjugated polyelectrolytes to develop fluorescent nanoparticles with emission in the blue, green and red spectral regions. The size, Zeta Potential, polydispersity, morphology, time-stability and fluorescent properties of these nanoparticles were characterized, as well as the nature of the interaction between both PMVEMA-Es and fluorescent polyelectrolytes. Because PMVEMA-Es contains a carboxylic acid group in its structure, the effects of pH and ionic strength on the nanoparticles were also evaluated, finding that the size is responsive to pH and ionic strength, largely swelling at physiological pH and returning to their initial size at acidic pHs. Thus, the developed fluorescent nanoparticles can be categorized as pH-sensitive fluorescent nanogels, since they possess the properties of both pH-responsive hydrogels and nanoparticulate systems. Doxorubicin (DOX) was used as a model drug to show the capacity of the blue-emitting nanogels to hold drugs in acidic media and release them at physiological pH, from changes in the fluorescence properties of both nanoparticles and DOX. In addition, preliminary studies by super-resolution confocal microscopy were performed, regarding their potential use as image probes.
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Portadores de Fármacos/síntese química , Fluorenos/química , Anidridos Maleicos/química , Polivinil/química , Antibióticos Antineoplásicos/farmacologia , Cor , Doxorrubicina/farmacologia , Portadores de Fármacos/química , Ésteres/química , Transferência Ressonante de Energia de Fluorescência/métodos , Humanos , Concentração de Íons de Hidrogênio , Éteres Metílicos/química , Nanogéis/química , Nanopartículas/química , Tamanho da Partícula , Polímeros/química , Compostos de Vinila/químicaRESUMO
A highly stable and reusable fluorescent multisample nanobiosensor for the detection of α-glucosidase inhibitors has been developed by coupling fluorescent liposomal nanoparticles based on conjugated polymers (L-CPNs) to the enzyme α-glucosidase, one of the main target enzymes in the treatment of type 2 diabetes. The mechanism of sensing is based on the fluorescence "turn-on" of L-CPNs by p-nitrophenol (PNP), the end product of the enzymatic hydrolysis of p-nitrophenyl-α-d-glucopyranoside. L-CPNs, composed of lipid vesicles coated with a blue-emitting cationic polyfluorene, were designed and characterized to obtain a good response to PNP. Two nanobiosensor configurations were developed in this study. In the first step, a single-sample nanobiosensor composed of L-CPNs and α-glucosidase entrapped in a sol-gel glass was developed in order to characterize and optimize the device. In the second part, the nanobiosensor was integrated and adapted to a multiwell microplate and the possibility of reusing it and performing multiple measurements simultaneously with samples containing different α-glucosidase inhibitors was investigated. Using super-resolution confocal microscopy, L-CPNs could be visualized within the sol-gel matrix, and the quenching of their fluorescence, induced by the substrate, was directly observed in situ. The device was also shown to be useful not only as a platform for screening of antidiabetic drugs but also for quantifying their presence. The latter application was successfully tested with the currently available drug, acarbose.
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Técnicas Biossensoriais/métodos , Fluorescência , Inibidores de Glicosídeo Hidrolases/farmacologia , Hipoglicemiantes/farmacologia , Nanopartículas/administração & dosagem , Polímeros/química , alfa-Glucosidases/química , Acarbose/farmacologia , Fluorenos/química , Corantes Fluorescentes , Inibidores de Glicosídeo Hidrolases/isolamento & purificação , Humanos , Hipoglicemiantes/isolamento & purificação , Lipossomos/química , Nanopartículas/química , alfa-Glucosidases/análiseRESUMO
ABSTRACT: Brain atrophy has been observed in perinatally HIV-infected patients (PHIV) despite initiation on combined antiretroviral treatment (cART), but neuroimaging studies are limited. We aimed to evaluate cortical thickness (CT) and subcortical gray matter (GM) volumes of PHIV youths with stable immunovirological situation and with a normal daily performance.A prospective cross-sectional study was conducted. A total of 25 PHIV patients on cART and 25 HIV-negative (HIV-) controls matched by age, sex, level of education, and socioeconomic status underwent a magnetic resonance imaging scan. CAT12 toolbox was used to extract CT values from T1w images using parcellations from Desikan-Killiany atlas (DK40). To measure regional brain volumes, native segmented images were parceled in regions of interest according to the Neuromorphometrics Atlas. Neuropsychological assessment and psychopathological symptoms were documented.Fifty participants were included (60% females, median age 20âyears [interquartile range, IQR 19-23], 64% Whites). No differences regarding neuropsychological tests or psychopathological symptoms were found between groups (all Pâ>â.05). All participants presented an average performance in the Fluid Intelligence (FI) test (PHIV mean: -0.12, HIV- mean: 0.24), When comparing CT, PHIV-infected patients showed thinner cortices compared with their peers in fusiform gyrus (Pâ=â.000, Pâ=â.009), lateral-orbitofrontal gyrus (Pâ=â.006, Pâ=â.0024), and right parsobitalis gyrus (Pâ=â.047). Regarding subcortical GM volumes, PHIV patients showed lower right amygdala (Pâ=â.014) and left putamen (Pâ=â.016) volumes when compared with HIV- controls. Within the PHIV group, higher CD4 count was associated with higher volumes in right putamen (Bâ=â0.00000038, Pâ=â.045). Moreover, increased age at cART initiation and lower nadir CD4 count was associated with larger volumes in left accumbens (Bâ=â0.0000046, Pâ=â.033; Bâ=â-0.00000008, Pâ=â.045, respectively).PHIV patients showed thinner cortices of areas in temporal, orbito-frontal and occipital lobes and lower volumes of subcortical GM volumes when compared with the HIV- control group, suggesting cortical and subcortical brain alterations in otherwise neuroasymptomatic patients. Nevertheless, larger and longitudinal studies are required to determine the impact of HIV on brain structure in PHIV patients and to further identify risk and protective factors that could be implicated.
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Substância Cinzenta/patologia , Infecções por HIV/fisiopatologia , Infecções por HIV/transmissão , Transmissão Vertical de Doenças Infecciosas/estatística & dados numéricos , Fatores Etários , Antirretrovirais/uso terapêutico , Atrofia , Gânglios da Base/diagnóstico por imagem , Gânglios da Base/patologia , Contagem de Linfócito CD4 , Estudos Transversais , Feminino , Substância Cinzenta/diagnóstico por imagem , Infecções por HIV/tratamento farmacológico , Infecções por HIV/epidemiologia , Humanos , Imageamento por Ressonância Magnética , Masculino , Estudos Prospectivos , Fatores Socioeconômicos , Adulto JovemRESUMO
Micro-/nano-structured scaffolds with a weight composition of 46.6% α-tricalcium phosphate (α-TCP)-53.4% silicocarnotite (SC) were synthesized by the polymer replica method. The scanning electron microscopy (SEM) analysis of the scaffolds and natural cancellous bone was performed for comparison purposes. Scaffolds were obtained at three cooling rates via the eutectoid temperature (50 °C/h, 16.5 °C/h, 5.5 °C/h), which allowed the surface nanostructure and mechanical strength to be controlled. Surface nanostructures were characterized by transmission electron microscopy (TEM) and Raman analysis. Both phases α-TCP and SC present in the scaffolds were well-identified, looked compact and dense, and had neither porosities nor cracks. The non-cytotoxic effect was evaluated in vitro by the proliferation ability of adult human mesenchymal stem cells (ah-MSCs) seeded on scaffold surfaces. There was no evidence for cytotoxicity and the number of cells increased with culture time. A dense cell-hydroxyapatite layer formed until 28 days. The SEM analysis suggested cell-mediated extracellular matrix formation. Finally, scaffolds were functionalized with the alkaline phosphatase enzyme (ALP) to achieve biological functionalization. The ALP was successfully grafted onto scaffolds, whose enzymatic activity was maintained. Scaffolds mimicked the micro-/nano-structure and chemical composition of natural cancellous bone by considering cell biology and biomolecule functionalization.