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1.
Anal Chem ; 96(14): 5658-5663, 2024 Apr 09.
Artigo em Inglês | MEDLINE | ID: mdl-38529586

RESUMO

A novel methodology for investigating the behavior of nanoparticles in their mixtures in aqueous high-ionic strength conditions is presented in this work. Our approach utilizes Taylor dispersion analysis in capillaries connected to inductively coupled plasma mass spectrometry (ICP-MS) to probe metal-derived nanoparticles. This methodology simultaneously distinguishes between different kinds of nanoparticles and accurately determines their essential parameters, such as hydrodynamic size, diffusion coefficient, and elemental composition. Moreover, the isotope-specific ICP-MS detection allows for unique targeting of the fate of isotopically enriched nanoparticles. The complexity of our methodology opens the way for studying barely explored areas of interparticle interactions or unequivocal characterization of one type of nanoparticle in complex mixtures without any need for calibration as well as labor-consuming sample preparation.

2.
Int J Geriatr Psychiatry ; 39(1): e6041, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38217550

RESUMO

OBJECTIVES: The effects of the COVID-19 pandemic on cognitive decline are not fully understood. Higher social activity and relationships have been associated with decreased risk of dementia. We hypothesised that risk of transition to dementia would increase after the start of the first national lockdown. METHODS: We obtained data from the Brains for Dementia (BDR) cohort, which has collected roughly annual data on 3726 older adults with and without dementia since 2008. Data continued to be collected during the lockdowns, although by telephone and/or video call instead of in person. Individuals diagnosed with dementia at study entry were excluded from this study as were individuals with only one visit. Cognitive status was classified using the Clinical Dementia Rating (CDR) global score. Poisson regression with cubic splines to account for differences in age was used to compare the incidence of dementia before and after March 1st 2020. RESULTS: Out of 2242 individuals, 208 individuals developed dementia before and 50 developed dementia after 01/03/20. The incidence rate ratio of developing dementia after 01/03/20 was 0.847 (0.538-1.335) p = 0.570. In our secondary analysis we found that the positive association between mild cognitive impairment (MCI) and dementia incidence decreased after 1/3/20 (interaction effect p = 0.031). CONCLUSION: The incidence of dementia as defined using the CDR global score did not change significantly after the first lockdown began, but we found evidence that lockdown decreased the positive association between MCI and dementia incidence. This may reflect that individuals were progressing to dementia more rapidly and thus missing the MCI stage or that assessing patients over the phone made diagnosing MCI more challenging.


Assuntos
Doença de Alzheimer , COVID-19 , Disfunção Cognitiva , Demência , Humanos , Idoso , Estudos de Coortes , Pandemias , COVID-19/epidemiologia , Testes Neuropsicológicos , Progressão da Doença , Controle de Doenças Transmissíveis , Disfunção Cognitiva/psicologia , Demência/psicologia , Doença de Alzheimer/psicologia
3.
Rev Esp Enferm Dig ; 2024 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-38258758

RESUMO

Epstein-Barr virus-positive mucocutaneous ulcer (EBVMCU) is a new entity recently included in the classification of B-cell lymphoproliferative disorders associated with Epstein-Barr virus (EBV). It is related to immunosuppression and it usually appears in the oropharynx or the skin, being the colon an uncommon location. We present the case of a 31-year-old man with ulcerative proctitis being treated with azathioprine (AZA) and adalimumab (ADA), who was admitted to the hospital due to suspicion of a moderate-severe flare of ulcerative proctitis. Microbiological stool analyses were negative, with a positive fecal calprotectin test (2700 mg/kg). Rectoscopy showed severe endoscopic activity, taking multiple biopsies. Intravenous steroids were started at a dose of 60 mg/day. He presented a favorable clinical and analytical evolution, being discharged from the hospital. The histological results were received at gastroenterology consultation, being compatible with EBVMCU. AZA and ADA were withdrawn, whereas descending steroid regimen and oral and topical mesalazine were continued, being the clinical response adequate.

4.
Medicina (Kaunas) ; 59(8)2023 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-37629759

RESUMO

We present the case of a 62-year-old patient who developed melenas and in whom conventional endoscopic tests could not detect any bleeding lesion. In our case, capsule endoscopy and enteroscopy were the pivotal elements in establishing the diagnosis of a neuroendocrine tumour with an atypical location. As a result, it was possible to surgically remove the lesions at an early stage of the malignancy without metastatic disease and without the need for adjuvant therapy. Our case demonstrates the need for these new techniques in tumours of atypical location and aggressive course. Otherwise, this malignancy may be underdiagnosed until an advanced stage.


Assuntos
Endoscopia por Cápsula , Laparoscopia , Segunda Neoplasia Primária , Tumores Neuroendócrinos , Humanos , Pessoa de Meia-Idade , Tumores Neuroendócrinos/diagnóstico por imagem , Terapia Combinada
5.
Genome Res ; 24(8): 1371-83, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24989021

RESUMO

The generation of genetically modified animals is important for both research and commercial purposes. The rat is an important model organism that until recently lacked efficient genetic engineering tools. Sequence-specific nucleases, such as ZFNs, TALE nucleases, and CRISPR/Cas9 have allowed the creation of rat knockout models. Genetic engineering by homology-directed repair (HDR) is utilized to create animals expressing transgenes in a controlled way and to introduce precise genetic modifications. We applied TALE nucleases and donor DNA microinjection into zygotes to generate HDR-modified rats with large new sequences introduced into three different loci with high efficiency (0.62%-5.13% of microinjected zygotes). Two of these loci (Rosa26 and Hprt1) are known to allow robust and reproducible transgene expression and were targeted for integration of a GFP expression cassette driven by the CAG promoter. GFP-expressing embryos and four Rosa26 GFP rat lines analyzed showed strong and widespread GFP expression in most cells of all analyzed tissues. The third targeted locus was Ighm, where we performed successful exon exchange of rat exon 2 for the human one. At all three loci we observed HDR only when using linear and not circular donor DNA. Mild hypothermic (30°C) culture of zygotes after microinjection increased HDR efficiency for some loci. Our study demonstrates that TALE nuclease and donor DNA microinjection into rat zygotes results in efficient and reproducible targeted donor integration by HDR. This allowed creation of genetically modified rats in a work-, cost-, and time-effective manner.


Assuntos
Marcação de Genes , Engenharia Genética , Animais , Sequência de Bases , Células Cultivadas , Enzimas de Restrição do DNA/biossíntese , Enzimas de Restrição do DNA/genética , Feminino , Hipoxantina Fosforribosiltransferase/genética , Masculino , Microinjeções , Ratos Sprague-Dawley , Ratos Transgênicos , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/genética , Reparo de DNA por Recombinação , Zigoto
6.
J Sep Sci ; 40(11): 2482-2487, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28371129

RESUMO

The stacking effect on carboxylated magnetite core-shell nanoparticles using sodium borate buffer pH 9.5 as the background electrolyte is presented. The ionic strength of the background electrolyte ranged from 5 to 100 mM, and the ionic strength of a sample zone ranged from 5 to 100 mM. Moreover, water was used as the sample dispersant. Both stacking and de-stacking effects were observed when conductivities of the sample zone and the background electrolyte differed. An explanation of carboxylated magnetic core-shell nanoparticles behavior was suggested based on the Derjaguin-Landau-Verwey-Overbeek theory supposing that the aggregation point is defined by the energetic barrier as the sum of energies given by electrostatic interactions and Van der Waals interactions. Moreover, the stacking conditions were applied for the evaluation of the lowest detectable dilution of magnetic nanoparticles. The carboxylated magnetic nanoparticles were dispersed in 10 mM borate/NaOH pH 9.5 and injected for 60 s to the background electrolyte composed of 100 mM borate/NaOH pH 9.5 that allowed the detection of 100-fold diluted nanoparticles.

7.
Clin Immunol ; 166-167: 1-11, 2016 05.
Artigo em Inglês | MEDLINE | ID: mdl-27050759

RESUMO

BACKGROUND: The involvement of Mucosal Associated Invariant T (MAIT) cells, which are anti-microbial semi-invariant T cells, remains elusive in Multiple Sclerosis (MS). OBJECTIVE: Deciphering the potential involvement of MAIT cells in the MS inflammatory process. METHODS: By flow cytometry, blood MAIT cells from similar cohorts of MS patients and healthy volunteers (HV) were compared for frequency, phenotype, activation potential after in vitro TCR engagement by bacterial ligands and transmigration abilities through an in vitro model of blood-brain barrier. MS CNS samples were also studied by immunofluorescent staining and quantitative PCR. RESULTS AND CONCLUSION: Blood MAIT cells from relapsing-remitting MS patients and HV presented similar frequency, ex vivo effector phenotype and activation abilities. MAIT cells represented 0.5% of the total infiltrating T cells on 39 MS CNS lesions. This is low as compared to blood frequency (p<0.001), but consistent with their low transmigration rate. Finally, transcriptional over-expression of MR1 - which presents cognate antigens to MAIT cells - and of the activating cytokines IL-18 and IL-23 was evidenced in MS lesions, suggesting that the CNS microenvironment is suited to activate the few infiltrating MAIT cells. Taken together, these data place MAIT cells from MS patients as minor components of the inflammatory pathological process.


Assuntos
Encéfalo/imunologia , Células T Invariantes Associadas à Mucosa/imunologia , Esclerose Múltipla Crônica Progressiva/imunologia , Esclerose Múltipla Recidivante-Remitente/imunologia , Adulto , Barreira Hematoencefálica/imunologia , Barreira Hematoencefálica/metabolismo , Barreira Hematoencefálica/patologia , Encéfalo/irrigação sanguínea , Encéfalo/patologia , Estudos de Casos e Controles , Movimento Celular , Feminino , Regulação da Expressão Gênica , Antígenos de Histocompatibilidade Classe I/genética , Antígenos de Histocompatibilidade Classe I/imunologia , Humanos , Imunidade nas Mucosas , Imunofenotipagem , Interleucina-18/genética , Interleucina-18/imunologia , Interleucina-23/genética , Interleucina-23/imunologia , Masculino , Pessoa de Meia-Idade , Antígenos de Histocompatibilidade Menor/genética , Antígenos de Histocompatibilidade Menor/imunologia , Modelos Biológicos , Células T Invariantes Associadas à Mucosa/patologia , Esclerose Múltipla Crônica Progressiva/genética , Esclerose Múltipla Crônica Progressiva/patologia , Esclerose Múltipla Recidivante-Remitente/genética , Esclerose Múltipla Recidivante-Remitente/patologia , Receptores de Antígenos de Linfócitos T/genética , Receptores de Antígenos de Linfócitos T/imunologia
8.
J Am Soc Nephrol ; 26(8): 1795-805, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25556168

RESUMO

The role of Foxp3(+) regulatory T cells (Tregs) in operational tolerance remains elusive, as initial results revealed an increased frequency of this subset in tolerant patients but no functional differences compared with immunosuppressed recipients. In addition, recent studies of regulatory B cells strongly suggest that Tregs may not have a central role in kidney transplantation tolerance. However, recent investigations of the crucial role of Foxp3 demethylation in Treg function and the possibility of identifying distinct Foxp3 T cell subsets prompted us to more thoroughly characterize Tregs in operationally tolerant patients. Thus, we studied the level of demethylation of the Foxp3 Treg-specific demethylated region (TSDR) in circulating CD4(+) T cells and analyzed Treg subset frequency in tolerant patients, healthy volunteers, patients with stable graft function under immunosuppression, and chronically rejecting recipients. We observed a higher proportion of CD4(+) T cells with demethylated Foxp3 and a specific expansion of CD4(+) CD45RA(-) Foxp3(hi) memory Tregs exclusively in tolerant patients. The memory Tregs of tolerant recipients exhibited increased Foxp3 TSDR demethylation, expressed higher levels of CD39 and glucocorticoid-induced TNF-related receptor, and harbored greater suppressive properties than memory Tregs from patients with stable graft function. Taken together, our data demonstrate that operationally tolerant patients mobilize an array of potentially suppressive cells, including not only regulatory B cells but also Tregs. Our results also indicate that tolerant patients have potent CD4(+)CD45RA(-) Foxp3(hi) memory Tregs with a specific Foxp3 TSDR demethylation pattern, which may contribute to the maintenance of graft tolerance.


Assuntos
Fatores de Transcrição Forkhead/metabolismo , Transplante de Rim , Linfócitos T Reguladores/metabolismo , Tolerância ao Transplante/imunologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Antígenos CD/metabolismo , Apirase/metabolismo , Estudos de Casos e Controles , Metilação de DNA , Feminino , Proteína Relacionada a TNFR Induzida por Glucocorticoide/metabolismo , Humanos , Antígenos Comuns de Leucócito , Masculino , Pessoa de Meia-Idade , Adulto Jovem
9.
J Am Soc Nephrol ; 26(10): 2588-98, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25644114

RESUMO

Whereas a B cell-transcriptional profile has been recorded for operationally tolerant kidney graft patients, the role that B cells have in this tolerance has not been reported. In this study, we analyzed the role of B cells from operationally tolerant patients, healthy volunteers, and kidney transplant recipients with stable graft function on T cell suppression. Proliferation, apoptosis, and type I proinflammatory cytokine production by effector CD4(+)CD25(-) T cells were measured after anti-CD3/anti-CD28 stimulation with or without autologous B cells. We report that B cells inhibit CD4(+)CD25(-) effector T cell response in a dose-dependent manner. This effect required B cells to interact with T-cell targets and was achieved through a granzyme B (GzmB)-dependent pathway. Tolerant recipients harbored a higher number of B cells expressing GzmB and displaying a plasma cell phenotype. Finally, GzmB(+) B-cell number was dependent on IL-21 production, and B cells from tolerant recipients but not from other patients positively regulated both the number of IL-21(+) T cells and IL-21 production, suggesting a feedback loop in tolerant recipients that increases excessive B cell activation and allows regulation to take place. These data provide insights into the characterization of B cell-mediated immunoregulation in clinical tolerance and show a potential regulatory effect of B cells on effector T cells in blood from patients with operationally tolerant kidney grafts.


Assuntos
Linfócitos B/imunologia , Transplante de Rim , Tolerância ao Transplante , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
10.
Kidney Int ; 87(5): 984-95, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25629549

RESUMO

Patients tolerant to a kidney graft display a specific blood cell transcriptional pattern but results from five different studies were inconsistent, raising the question of relevance for future clinical application. To resolve this, we sought to identify a common gene signature, specific functional and cellular components, and discriminating biomarkers for tolerance following kidney transplantation. A meta-analysis of studies identified a robust gene signature involving proliferation of B and CD4 T cells, and inhibition of CD14 monocyte related functions among 96 tolerant samples. This signature was further supported through a cross-validation approach, yielding 92.5% accuracy independent of the study of origin. Experimental validation, performed on new tolerant samples and using a selection of the top-20 biomarkers, returned 91.7% of good classification. Beyond the confirmation of B-cell involvement, our data also indicated participation of other cell subsets in tolerance. Thus, the use of the top 20 biomarkers, mostly centered on B cells, may provide a common and standardized tool towards personalized medicine for the monitoring of tolerant or low-risk patients among kidney allotransplant recipients. These data point to a global preservation of genes favoring the maintenance of a homeostatic and 'healthy' environment in tolerant patients and may contribute to a better understanding of tolerance maintenance mechanisms.


Assuntos
Aloenxertos/imunologia , Tolerância Imunológica/genética , Transplante de Rim , Biomarcadores/sangue , Humanos , Leucócitos Mononucleares/fisiologia , Transcriptoma
11.
Transpl Int ; 28(8): 938-59, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25851900

RESUMO

In kidney transplantation, minimizing the side effects of the immunosuppressive regimen and inducing tolerance to allograft are the two main objectives to improve outcome. At present, these objectives are far from being achieved and remain elusive for the majority of transplant recipients. Rejection rate and mortality on the long term are still unacceptable. There is thus a pressing need to improve this situation. Therefore, some spontaneously tolerant kidney recipients are described in clinics, and recent advances in immunological and molecular techniques have led to a resurgence of interest in studying those rare transplanted recipients through coordinated efforts from international consortia. Indeed, they offer, on the one hand, the possibility to develop specific biomarkers indicative of this state that would constitute a major advantage in the care of the patients allowing personalized minimization of drugs, so reducing related costs and side effects. On the other hand, they represent a unique model of study to understand the mechanisms of regulation implicated in this state that may help the development of inducing therapies. Recent efforts, concentrated on noninvasive analyses of peripheral blood, identified a predominance of several B-cell subsets, some of which harbouring regulatory functions, and related marker genes. These findings, validated in independent multicentric cohorts, led credence to an unsuspected role for the B-cell compartment in tolerance to kidney allograft. The identification of patients, harbouring these markers, among immunosuppressed recipients with stable graft function and the existence of drugs with selective effect on B cell pave the way for the possibility to improve long-term graft outcomes. Therefore, before routine application, these findings need to be confirmed in large prospective studies in the context of planned reduced immunosuppression.


Assuntos
Subpopulações de Linfócitos B/metabolismo , Rejeição de Enxerto/prevenção & controle , Terapia de Imunossupressão/métodos , Imunossupressores/administração & dosagem , Transplante de Rim , Medicina de Precisão/métodos , Tolerância ao Transplante/imunologia , Biomarcadores/sangue , Esquema de Medicação , Rejeição de Enxerto/sangue , Rejeição de Enxerto/diagnóstico , Rejeição de Enxerto/imunologia , Humanos , Terapia de Imunossupressão/efeitos adversos , Imunossupressores/uso terapêutico
12.
BMJ Case Rep ; 16(5)2023 May 02.
Artigo em Inglês | MEDLINE | ID: mdl-37130632

RESUMO

This case report describes a clinical presentation of spondylodiscitis, following an emergency ureteric stent placement for an infected and obstructed kidney in a woman in her late 70s who presented with right flank pain, raised inflammatory markers and an acute kidney injury. Non-contrast CT kidney, ureters and bladder (KUB) revealed a 9 mm obstructing stone and prompt decompression with a JJ stent was performed. Although the urine culture showed no growth at first, an extended spectrum beta-lactamase Escherichia coli was found in a subsequent urine culture after discharge. Postoperatively, the patient described a novel, worsening lower back pain and had persistently elevated inflammatory markers. An MRI revealed spondylodiscitis of L5/S1, for which she was treated with a 6-week course of antibiotics, and she has made a good but slow recovery. This case shows the unusual finding of spondylodiscitis postureteric stent placement and clinicians should be aware of this rare complication.


Assuntos
Discite , Ureter , Feminino , Humanos , Ureter/cirurgia , Discite/etiologia , Antibacterianos/uso terapêutico , Escherichia coli , Stents/efeitos adversos
13.
J Biomed Mater Res B Appl Biomater ; 111(2): 271-283, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36507699

RESUMO

This unique study provides information on Cr species and their distribution in periprosthetic tissues of patients with metal-on-polyethylene joint implants. Co-Cr-Mo alloy has been widely used in joint replacement and represents a source of metal derived species. In the case of chromium, previous studies on periprosthetic tissues revealed mainly Cr(III) distribution, whereas the potential release of carcinogenic Cr(VI) species has been still a subject of debate. Here, an analytical approach utilizing speciation and fractionation was developed to analyze periprosthetic tissue samples collected from wide range of patients with failed total hip or knee replacements. The results reveal that Cr(III) is mainly released in the form of insoluble CrPO4 and Cr2 O3 particles. The highest Cr contents were found in periprosthetic tissues of patients suffering from aseptic loosening and having more Cr-based implants in the body. Cr species penetrated tissue layers, but their levels decreased with the distance from an implant. The detailed speciation/fractionation study carried out using the set of consecutive periprosthetic tissues of a patient with extensive metallosis showed the presence of trace amounts of free Cr(III), nanoparticles, and metal-protein complexes, but the majority of Cr still occurred in CrPO4 form. Carcinogenic Cr(VI) species were not detected. Up to date, there is no published human tissue study focused on the detailed speciation of both soluble and insoluble Cr-based species in the context of failing total hip and knee replacements.


Assuntos
Artroplastia de Quadril , Artroplastia do Joelho , Prótese de Quadril , Humanos , Falha de Prótese , Cromo , Metais
14.
Foods ; 12(11)2023 May 23.
Artigo em Inglês | MEDLINE | ID: mdl-37297337

RESUMO

Pereskia aculeata Miller is an edible plant species belonging to the Cactaceae family. It has the potential to be used in the food and pharmaceutical industries due to its nutritional characteristics, bioactive compounds, and mucilage content. Pereskia aculeata Miller is native to the Neotropical region, where it is traditionally employed as food in rural communities, being popularly known as 'ora-pro-nobis' (OPN) or the Barbados gooseberry. The leaves of OPN are distinguished by their nontoxicity and nutritional richness, including, on a dry basis, 23% proteins, 31% carbohydrates, 14% minerals, 8% lipids, and 4% soluble dietary fibers, besides vitamins A, C, and E, and phenolic, carotenoid, and flavonoid compounds. The OPN leaves and fruits also contain mucilage composed of arabinogalactan biopolymer that presents technofunctional properties such as thickener, gelling, and emulsifier agent. Moreover, OPN is generally used for pharmacological purposes in Brazilian folk medicine, which has been attributed to its bioactive molecules with metabolic, anti-inflammatory, antioxidant, and antimicrobial properties. Therefore, in the face of the growing research and industrial interests in OPN as a novel food source, the present work reviews its botanical, nutritional, bioactive, and technofunctional properties, which are relevant for the development of healthy and innovative food products and ingredients.

15.
Bioinformatics ; 27(5): 725-6, 2011 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-21216776

RESUMO

UNLABELLED: MADGene is a software environment comprising a web-based database and a java application. This platform aims at unifying gene identifiers (ids) and performing gene set analysis. MADGene allows the user to perform inter-conversion of clone and gene ids over a large range of nomenclatures relative to 17 species. We propose a set of 23 functions to facilitate the analysis of gene sets and we give two microarray applications to show how MADGene can be used to conduct meta-analyses. AVAILABILITY: The MADGene resources are freely available online from http://www.madtools.org, a website dedicated to the analysis and annotation of DNA microarray data.


Assuntos
Biologia Computacional/métodos , Análise de Sequência com Séries de Oligonucleotídeos/métodos , Software , Análise por Conglomerados , Bases de Dados Genéticas , Internet , Metanálise como Assunto , Interface Usuário-Computador
16.
J Neurotrauma ; 39(7-8): 473-486, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-35029131

RESUMO

Traumatic brain injury (TBI) is a major health concern and leading cause of death and disability in young adults in the United Kingdom and worldwide; however, there is a paucity of disease modifying therapies for the treatment of TBI. This review investigates the potential of the renin-angiotensin system (RAS) as a treatment pathway for TBI in adults. Relevant electronic databases were searched on December 18, 2019, and updated May 16, 2021. All English language articles with adult human or animal populations investigating RAS drugs as an intervention for TBI or reporting genetic evidence relevant to the RAS and TBI were screened. Eighteen pre-clinical randomized controlled trials (RCTs) (n = 2269) and two clinical cohort studies (n = 771) were included. Meta-analyses of six pre-clinical RCTs (n = 99) indicated that candesartan improved neurological function over the short term (< 7 days: standardized mean difference [SMD] 0.61, 95% confidence interval [CI] 0.19-1.03, I2 = 0%) and over the long term (≥ 7 days: SMD 1.06, 95% CI 0.38; 1.73, I2 = 0%) post-TBI. Findings were similar for most secondary outcomes. There was a suggestion of benefit from other RAS-targeting drugs, although evidence was limited because there were few small studies. There was insufficient evidence to enable strong assessment of these drugs on mortality post-TBI. We conclude that angiotensin-receptor blockers, especially candesartan, show positive outcomes post-TBI in pre-clinical studies with moderate quality of evidence (Grading of Recommendations Assessment, Development and Evaluation [GRADE]). More research into the effect of regulatory-RAS targeting drugs is needed. Clinical trials of candesartan following TBI are recommended, because there is strong and consistent evidence of neuroprotection shown by these pre-clinical studies.


Assuntos
Lesões Encefálicas Traumáticas , Sistema Renina-Angiotensina , Animais , Lesões Encefálicas Traumáticas/tratamento farmacológico , Humanos , Reino Unido
17.
BMC Genomics ; 12: 113, 2011 Feb 16.
Artigo em Inglês | MEDLINE | ID: mdl-21324190

RESUMO

BACKGROUND: DNA microarray technology has had a great impact on muscle research and microarray gene expression data has been widely used to identify gene signatures characteristic of the studied conditions. With the rapid accumulation of muscle microarray data, it is of great interest to understand how to compare and combine data across multiple studies. Meta-analysis of transcriptome data is a valuable method to achieve it. It enables to highlight conserved gene signatures between multiple independent studies. However, using it is made difficult by the diversity of the available data: different microarray platforms, different gene nomenclature, different species studied, etc. DESCRIPTION: We have developed a system tool dedicated to muscle transcriptome data. This system comprises a collection of microarray data as well as a query tool. This latter allows the user to extract similar clusters of co-expressed genes from the database, using an input gene list. Common and relevant gene signatures can thus be searched more easily. The dedicated database consists in a large compendium of public data (more than 500 data sets) related to muscle (skeletal and heart). These studies included seven different animal species from invertebrates (Drosophila melanogaster, Caenorhabditis elegans) and vertebrates (Homo sapiens, Mus musculus, Rattus norvegicus, Canis familiaris, Gallus gallus). After a renormalization step, clusters of co-expressed genes were identified in each dataset. The lists of co-expressed genes were annotated using a unified re-annotation procedure. These gene lists were compared to find significant overlaps between studies. CONCLUSIONS: Applied to this large compendium of data sets, meta-analyses demonstrated that conserved patterns between species could be identified. Focusing on a specific pathology (Duchenne Muscular Dystrophy) we validated results across independent studies and revealed robust biomarkers and new pathways of interest. The meta-analyses performed with MADMuscle show the usefulness of this approach. Our method can be applied to all public transcriptome data.


Assuntos
Biologia Computacional/métodos , Bases de Dados Genéticas , Perfilação da Expressão Gênica , Músculos/metabolismo , Animais , Análise por Conglomerados , Genômica , Humanos , Anotação de Sequência Molecular , Distrofia Muscular de Duchenne/genética , Análise de Sequência com Séries de Oligonucleotídeos , Software
18.
Proc Natl Acad Sci U S A ; 105(10): 3968-73, 2008 Mar 11.
Artigo em Inglês | MEDLINE | ID: mdl-18316736

RESUMO

Bacteria able to transfer electrons to metals are key agents in biogeochemical metal cycling, subsurface bioremediation, and corrosion processes. More recently, these bacteria have gained attention as the transfer of electrons from the cell surface to conductive materials can be used in multiple applications. In this work, we adapted electrochemical techniques to probe intact biofilms of Shewanella oneidensis MR-1 and Shewanella sp. MR-4 grown by using a poised electrode as an electron acceptor. This approach detected redox-active molecules within biofilms, which were involved in electron transfer to the electrode. A combination of methods identified a mixture of riboflavin and riboflavin-5'-phosphate in supernatants from biofilm reactors, with riboflavin representing the dominant component during sustained incubations (>72 h). Removal of riboflavin from biofilms reduced the rate of electron transfer to electrodes by >70%, consistent with a role as a soluble redox shuttle carrying electrons from the cell surface to external acceptors. Differential pulse voltammetry and cyclic voltammetry revealed a layer of flavins adsorbed to electrodes, even after soluble components were removed, especially in older biofilms. Riboflavin adsorbed quickly to other surfaces of geochemical interest, such as Fe(III) and Mn(IV) oxy(hydr)oxides. This in situ demonstration of flavin production, and sequestration at surfaces, requires the paradigm of soluble redox shuttles in geochemistry to be adjusted to include binding and modification of surfaces. Moreover, the known ability of isoalloxazine rings to act as metal chelators, along with their electron shuttling capacity, suggests that extracellular respiration of minerals by Shewanella is more complex than originally conceived.


Assuntos
Biofilmes , Flavinas/metabolismo , Shewanella/fisiologia , Eletrodos , Transporte de Elétrons , Mononucleotídeo de Flavina/metabolismo , Modelos Biológicos , Oxirredução
19.
J Bacteriol ; 192(2): 467-74, 2010 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-19897659

RESUMO

The Mtr respiratory pathway of Shewanella oneidensis strain MR-1 is required to effectively respire both soluble and insoluble forms of oxidized iron. Flavins (riboflavin and flavin mononucleotide) recently have been shown to be excreted by MR-1 and facilitate the reduction of insoluble substrates. Other Shewanella species tested accumulated flavins in supernatants to an extent similar to that of MR-1, suggesting that flavin secretion is a general trait of the species. External flavins have been proposed to act as both a soluble electron shuttle and a metal chelator; however, at biologically relevant concentrations, our results suggest that external flavins primarily act as electron shuttles for MR-1. Using deletion mutants lacking various Mtr-associated proteins, we demonstrate that the Mtr extracellular respiratory pathway is essential for the reduction of flavins and that decaheme cytochromes found on the outer surface of the cell (MtrC and OmcA) are required for the majority of this activity. Given the involvement of external flavins in the reduction of electrodes, we monitored current production by Mtr respiratory pathway mutants in three-electrode bioreactors under controlled flavin concentrations. While mutants lacking MtrC were able to reduce flavins at 50% of the rate of the wild type in cell suspension assays, these strains were unable to grow into productive electrode-reducing biofilms. The analysis of mutants lacking OmcA suggests a role for this protein in both electron transfer to electrodes and attachment to surfaces. The parallel phenotypes of Mtr mutants in flavin and electrode reduction blur the distinction between direct contact and the redox shuttling strategies of insoluble substrate reduction by MR-1.


Assuntos
Eletrodos , Flavinas/metabolismo , Shewanella/metabolismo , Transdução de Sinais/fisiologia , Proteínas de Bactérias/genética , Proteínas de Bactérias/fisiologia , Reatores Biológicos , Citocromos/metabolismo , Transporte de Elétrons/genética , Transporte de Elétrons/fisiologia , Compostos Férricos/metabolismo , Microscopia Confocal , Oxirredução , Shewanella/genética , Transdução de Sinais/genética
20.
J Cell Mol Med ; 14(6B): 1443-52, 2010 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-19793385

RESUMO

Risk stratification in advanced heart failure (HF) is crucial for the individualization of therapeutic strategy, in particular for heart transplantation and ventricular assist device implantation. We tested the hypothesis that cardiac gene expression profiling can distinguish between HF patients with different disease severity. We obtained tissue samples from both left (LV) and right (RV) ventricle of explanted hearts of 44 patients undergoing cardiac transplantation or ventricular assist device placement. Gene expression profiles were obtained using an in-house microarray containing 4217 muscular organ-relevant genes. Based on their clinical status, patients were classified into three HF-severity groups: deteriorating (n= 12), intermediate (n= 19) and stable (n= 13). Two-class statistical analysis of gene expression profiles of deteriorating and stable patients identified a 170-gene and a 129-gene predictor for LV and RV samples, respectively. The LV molecular predictor identified patients with stable and deteriorating status with a sensitivity of 88% and 92%, and a specificity of 100% and 96%, respectively. The RV molecular predictor identified patients with stable and deteriorating status with a sensitivity of 100% and 96%, and a specificity of 100% and 100%, respectively. The molecular prediction was reproducible across biological replicates in LV and RV samples. Gene expression profiling has the potential to reproducibly detect HF patients with highest HF severity with high sensitivity and specificity. In addition, not only LV but also RV samples could be used for molecular risk stratification with similar predictive power.


Assuntos
Insuficiência Cardíaca/genética , Insuficiência Cardíaca/patologia , Viés , Análise por Conglomerados , Feminino , Perfilação da Expressão Gênica , Regulação da Expressão Gênica , Humanos , Masculino , Pessoa de Meia-Idade , Reprodutibilidade dos Testes , Medição de Risco
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