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1.
Int J Mol Sci ; 24(21)2023 Oct 24.
Artigo em Inglês | MEDLINE | ID: mdl-37958515

RESUMO

Nanocarriers provide a number of undeniable advantages that could improve the bioavailability of active agents for human, animal, and plant cells. In this study, we compared hybrid nanoparticles (HNPs) consisting of a calcium phosphate core coated with chitosan with unmixed calcium phosphate (CaP) and chitosan nanoparticles (CSNPs) as carriers of a model substrate, enalaprilat. This tripeptide analog is an inhibitor of angiotensin-converting enzyme and was chosen by its ability to lower intraocular pressure (IOP). In particular, we evaluated the physicochemical characteristics of the particles using dynamic light scattering (DLS) and scanning electron microscopy (SEM) and analyzed their ability to incorporate and release enalaprilat. HNPs exhibited the highest drug loading capacity and both HNPs and CSNPs demonstrated slow drug release. The comparison of the physiological effects of enalaprilat-loaded CaP particles, HNPs, and CSNPs in terms of their impact on IOP in rabbits revealed a clear advantage of hybrid nanoparticles over both inorganic and chitosan nanoparticles. These results could have important mechanistic implications for developing nano-based delivery systems for other medical, veterinary, and agricultural applications.


Assuntos
Quitosana , Nanopartículas , Animais , Humanos , Coelhos , Portadores de Fármacos , Enalaprilato , Sistemas de Liberação de Medicamentos , Peptídeos , Fosfatos de Cálcio , Tamanho da Partícula , Liberação Controlada de Fármacos
2.
Nanomedicine ; 40: 102493, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-34775060

RESUMO

Formulations on the base of an inhibitor of angiotensin-converting enzyme, enalaprilat, were prepared by the inclusion of the drug into calcium phosphate (CaP)-particles in situ, followed by the covering of the particles with 5 kDa chitosan or 72 kDa glycol chitosan and cross-linking with sodium tripolyphosphate. Physicochemical characterization of the resulted hybrid particles was conducted using dynamic light scattering, as well as scanning and transmission electron microscopy. Enalaprilat-containing particles had a mean hydrodynamic diameter 180 nm and 260 nm and ζ-potential +7 mV and +16 mV for 5 kDa and 72 kDa chitosans, respectively. In vivo studies showed that enalaprilat within particles stayed longer in the tear fluid after single instillation and caused a significantly pronounced and prolonged decrease of intraocular pressure in rabbits, especially in the case of CaP-particles, covered by glycol chitosan. Thus, such formulations demonstrate potential as prospective therapeutic agents for the treatment of eye diseases.


Assuntos
Quitosana , Nanopartículas , Animais , Fosfatos de Cálcio , Quitosana/química , Composição de Medicamentos , Excipientes , Nanopartículas/química , Tamanho da Partícula , Coelhos
3.
Int J Mol Sci ; 22(22)2021 Nov 16.
Artigo em Inglês | MEDLINE | ID: mdl-34830247

RESUMO

Topical drug delivery is one of the most challenging aspects of eye therapy. Eye drops are the most prevalent drug form, especially for widely distributed anterior segment eye diseases (cataracts, glaucoma, dry eye syndrome, inflammatory diseases, etc.), because they are convenient and easy to apply by patients. However, conventional drug formulations are usually characterized by short retention time in the tear film, insufficient contact with epithelium, fast elimination, and difficulties in overcoming ocular tissue barriers. Not more than 5% of the total drug dose administered in eye drops reaches the interior ocular tissues. To overcome the ocular drug delivery barriers and improve drug bioavailability, various conventional and novel drug delivery systems have been developed. Among these, nanosize carriers are the most attractive. The review is focused on the different drug carriers, such as synthetic and natural polymers, as well as inorganic carriers, with special attention to nanoparticles and nanomicelles. Studies in vitro and in vivo have demonstrated that new formulations could help to improve the bioavailability of the drugs, provide sustained drug release, enhance and prolong their therapeutic action. Promising results were obtained with drug-loaded nanoparticles included in in situ gel.


Assuntos
Anti-Inflamatórios/administração & dosagem , Portadores de Fármacos/farmacocinética , Nanotecnologia/métodos , Soluções Oftálmicas/administração & dosagem , Polímeros/farmacocinética , Administração Oftálmica , Animais , Segmento Anterior do Olho/efeitos dos fármacos , Segmento Anterior do Olho/metabolismo , Segmento Anterior do Olho/patologia , Anti-Inflamatórios/farmacocinética , Disponibilidade Biológica , Catarata/tratamento farmacológico , Catarata/metabolismo , Catarata/patologia , Portadores de Fármacos/síntese química , Portadores de Fármacos/classificação , Liberação Controlada de Fármacos , Síndromes do Olho Seco/tratamento farmacológico , Síndromes do Olho Seco/metabolismo , Síndromes do Olho Seco/patologia , Glaucoma/tratamento farmacológico , Glaucoma/metabolismo , Glaucoma/patologia , Humanos , Micelas , Nanogéis/química , Nanopartículas/administração & dosagem , Nanopartículas/metabolismo , Nanotecnologia/instrumentação , Soluções Oftálmicas/farmacocinética , Polímeros/síntese química , Polímeros/classificação
4.
Heart Lung Circ ; 30(11): 1752-1761, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34426074

RESUMO

PURPOSE: To identify the features of early vascular ageing (EVA) in patients with metabolic syndrome (MetS), to assess the accuracy of existing methods for determining vascular age in MetS, and to derive a new score (VAmets) for the calculation of vascular age and predicting EVA in patients with MetS. METHODS: Prospective open cohort study using routinely collected data from general practice. A total of 750 patients (age, 35-80 yrs old) with MetS were examined. EVA syndrome was detected in 484 patients with MetS and carotid-femoral pulse wave velocity (cfPWV) values exceeding average expected for age values by 2 or more standard deviations (SD). RESULTS: The presence of type 2 diabetes and insulin resistance (IR) were associated with greater risk of EVA in MetS patients; the odds ratios were 2.75 (95% confidence interval [CI]: 2.34, 3.35) and 1.57 (95% CI: 1.16, 2.00), respectively. In addition, the risk of EVA increased by 76% with an increase in homeostatic model assessment ofinsulin resistance (HOMA-IR) by 1 unit, by 17% with an increase in high-sensitivity C-reactive protein (hs-CRP) by 1 mg/L, by 4% with an increase in diastolic blood pressure (DBP) by 1 mmHg, and by 1% with each (1) µmol/L increase in the level of uric acid (UA). The area under the curve (AUC) for predicting EVA in patients with MetS was 0.949 (95% CI: 0.936-0.963), 0.630 (95% CI: 0.589-0.671), 0.697 (95% CI: 0.659-0.736) and 0.686 (95% CI: 0.647-0.726), for vascular age calculated from carotid-femoral pulse wave velocity (cfPWV), Systematic COronary Risk Evaluation (SCORE) scale, QRESEARCH cardiovascular risk algorithm (QRISK-3) scale, and Framingham scale, respectively. Diabetes mellitus and clinical markers of IR (yes/no), HOMA-IR and UA level were used to develop a new VAmets score for EVA prediction providing a total accuracy of 0.830 (95% CI: 0.799-0.860). Based on the results of the study, a VAmets calculator was developed for diagnosing EVA in patients with MetS. (The calculator is available online at https://apps.medhub.pro/evams/) CONCLUSION: Carotid-femoral pulse wave velocity is at present the most widely studied index of arterial stiffness and fulfils most of the stringent criteria for a clinically useful biomarker of EVA in patients with MetS. There are parallel efforts for the effective identification and integration of a simple clinical score into clinical practice. Our score (VAmets) may accurately identify patients with MetS and EVA on the basis of widely available clinical variables and classic cardiovascular risk factors, and may assist in prioritising the calculation and use of vascular age in routine care.


Assuntos
Diabetes Mellitus Tipo 2 , Síndrome Metabólica , Rigidez Vascular , Adulto , Idoso , Idoso de 80 Anos ou mais , Envelhecimento , Estudos de Coortes , Diabetes Mellitus Tipo 2/complicações , Diabetes Mellitus Tipo 2/diagnóstico , Diabetes Mellitus Tipo 2/epidemiologia , Humanos , Síndrome Metabólica/diagnóstico , Síndrome Metabólica/epidemiologia , Pessoa de Meia-Idade , Estudos Prospectivos , Análise de Onda de Pulso , Fatores de Risco
5.
Anesthesiology ; 132(4): 692-701, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32022771

RESUMO

BACKGROUND: The authors previously reported that perioperative aspirin and/or clonidine does not prevent a composite of death or myocardial infarction 30 days after noncardiac surgery. Moreover, aspirin increased the risk of major bleeding and clonidine caused hypotension and bradycardia. Whether these complications produce harm at 1 yr remains unknown. METHODS: The authors randomized 10,010 patients with or at risk of atherosclerosis and scheduled for noncardiac surgery in a 1:1:1:1 ratio to clonidine/aspirin, clonidine/aspirin placebo, clonidine placebo/aspirin, or clonidine placebo/aspirin placebo. Patients started taking aspirin or placebo just before surgery; those not previously taking aspirin continued daily for 30 days, and those taking aspirin previously continued for 7 days. Patients were also randomly assigned to receive clonidine or placebo just before surgery, with the study drug continued for 72 h. RESULTS: Neither aspirin nor clonidine had a significant effect on the primary 1-yr outcome, a composite of death or nonfatal myocardial infarction, with a 1-yr hazard ratio for aspirin of 1.00 (95% CI, 0.89 to 1.12; P = 0.948; 586 patients [11.8%] vs. 589 patients [11.8%]) and a hazard ratio for clonidine of 1.07 (95% CI, 0.96 to 1.20; P = 0.218; 608 patients [12.1%] vs. 567 patients [11.3%]), with effect on death or nonfatal infarction. Reduction in death and nonfatal myocardial infarction from aspirin in patients who previously had percutaneous coronary intervention at 30 days persisted at 1 yr. Specifically, the hazard ratio was 0.58 (95% CI, 0.35 to 0.95) in those with previous percutaneous coronary intervention and 1.03 (95% CI, 0.91to 1.16) in those without (interaction P = 0.033). There was no significant effect of either drug on death, cardiovascular complications, cancer, or chronic incisional pain at 1 yr (all P > 0.1). CONCLUSIONS: Neither perioperative aspirin nor clonidine have significant long-term effects after noncardiac surgery. Perioperative aspirin in patients with previous percutaneous coronary intervention showed persistent benefit at 1 yr, a plausible sub-group effect.


Assuntos
Analgésicos/administração & dosagem , Anti-Inflamatórios não Esteroides/administração & dosagem , Aspirina/administração & dosagem , Clonidina/administração & dosagem , Assistência Perioperatória/métodos , Complicações Pós-Operatórias/diagnóstico , Idoso , Analgésicos/efeitos adversos , Anti-Inflamatórios não Esteroides/efeitos adversos , Aspirina/efeitos adversos , Clonidina/efeitos adversos , Feminino , Seguimentos , Humanos , Internacionalidade , Masculino , Pessoa de Meia-Idade , Infarto do Miocárdio/diagnóstico , Infarto do Miocárdio/epidemiologia , Infarto do Miocárdio/prevenção & controle , Assistência Perioperatória/efeitos adversos , Complicações Pós-Operatórias/epidemiologia , Complicações Pós-Operatórias/prevenção & controle , Fatores de Tempo
6.
J Cell Physiol ; 232(5): 904-912, 2017 05.
Artigo em Inglês | MEDLINE | ID: mdl-27684052

RESUMO

Systemic inflammatory response syndrome (SIRS) development is accompanied by mitochondrial dysfunction and excessive ROS production. Mitochondrial dysfunctions also occur in many SIRS-related diseases and may be critical for their pathogenesis; therefore, a use of mitochondria-targeted drugs is a promising trend in SIRS research and therapy. Here, we review recent studies concerning the application of the mitochondria-targeted antioxidants and uncouplers of oxidative phosphorylation in animal models of SIRS and related diseases. We propose that a new class of uncouplers of oxidative phosphorylation, lipophilic cations could be a base for a new generation of drugs for SIRS treatment. J. Cell. Physiol. 232: 904-912, 2017. © 2016 Wiley Periodicals, Inc.


Assuntos
Antioxidantes/farmacologia , Mitocôndrias/metabolismo , Fosforilação Oxidativa/efeitos dos fármacos , Síndrome de Resposta Inflamatória Sistêmica/metabolismo , Animais , Antioxidantes/química , Antioxidantes/uso terapêutico , Ensaios Clínicos como Assunto , Humanos , Mitocôndrias/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo , Síndrome de Resposta Inflamatória Sistêmica/tratamento farmacológico , Síndrome de Resposta Inflamatória Sistêmica/patologia
7.
Biochim Biophys Acta Mol Basis Dis ; 1863(4): 968-977, 2017 04.
Artigo em Inglês | MEDLINE | ID: mdl-28131916

RESUMO

Mitochondrial dysfunctions occur in many diseases linked to the systemic inflammatory response syndrome (SIRS). Mild uncoupling of oxidative phosphorylation is known to rescue model animals from pathologies related to mitochondrial dysfunctions and overproduction of reactive oxygen species (ROS). To study the potential of SIRS therapy by uncoupling, we tested protonophore dinitrophenol (DNP) and a free fatty acid (FFA) anion carrier, lipophilic cation dodecyltriphenylphosphonium (C12TPP) in mice and in vitro models of SIRS. DNP and C12TPP prevented the body temperature drop and lethality in mice injected with high doses of a SIRS inducer, tumor necrosis factor (TNF). The mitochondria-targeted antioxidant plastoquinonyl decyltriphenylphosphonium (SkQ1) which also catalyzes FFA-dependent uncoupling revealed similar protective effects and downregulated expression of the NFκB-regulated genes (VCAM1, ICAM1, MCP1, and IL-6) involved in the inflammatory response of endothelium in aortas of the TNF-treated mice. In vitro mild uncoupling rescued from TNF-induced endothelial permeability, disassembly of cell contacts and VE-cadherin cleavage by the matrix metalloprotease 9 (ММР9). The uncouplers prevented TNF-induced expression of MMP9 via inhibition of NFκB signaling. Water-soluble antioxidant Trolox also prevented TNF-induced activation and permeability of endothelium in vitro via inhibition of NFκB signaling, suggesting that the protective action of the uncouplers is linked to their antioxidant potential.


Assuntos
Permeabilidade Capilar/efeitos dos fármacos , Endotélio Vascular/metabolismo , Compostos Heterocíclicos/farmacologia , Compostos Organofosforados/farmacologia , Fosforilação Oxidativa/efeitos dos fármacos , Síndrome de Resposta Inflamatória Sistêmica/metabolismo , Fator de Necrose Tumoral alfa/metabolismo , Desacopladores/farmacologia , Animais , Antioxidantes/farmacologia , Cromanos/farmacologia , Endotélio Vascular/patologia , Regulação da Expressão Gênica/efeitos dos fármacos , Camundongos , NF-kappa B/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Transdução de Sinais/efeitos dos fármacos , Síndrome de Resposta Inflamatória Sistêmica/tratamento farmacológico , Síndrome de Resposta Inflamatória Sistêmica/patologia
8.
Glob Chang Biol ; 23(7): 2602-2617, 2017 07.
Artigo em Inglês | MEDLINE | ID: mdl-27935174

RESUMO

Ocean warming, acidification, deoxygenation and reduced productivity are widely considered to be the major stressors to ocean ecosystems induced by emissions of CO2 . However, an overlooked stressor is the change in ocean circulation in response to climate change. Strong changes in the intensity and position of the western boundary currents have already been observed, and the consequences of such changes for ecosystems are beginning to emerge. In this study, we address climatically induced changes in ocean circulation on a global scale but relevant to propagule dispersal for species inhabiting global shelf ecosystems, using a high-resolution global ocean model run under the IPCC RCP 8.5 scenario. The » degree model resolution allows improved regional realism of the ocean circulation beyond that of available CMIP5-class models. We use a Lagrangian approach forced by modelled ocean circulation to simulate the circulation pathways that disperse planktonic life stages. Based on trajectory backtracking, we identify present-day coastal retention, dominant flow and dispersal range for coastal regions at the global scale. Projecting into the future, we identify areas of the strongest projected circulation change and present regional examples with the most significant modifications in their dominant pathways. Climatically induced changes in ocean circulation should be considered as an additional stressor of marine ecosystems in a similar way to ocean warming or acidification.


Assuntos
Mudança Climática , Ecossistema , Aquecimento Global , Movimentos da Água , Dióxido de Carbono , Clima , Oceanos e Mares , Água do Mar
9.
Mult Scler ; 23(2_suppl): 155-165, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28643590

RESUMO

BACKGROUND: In order to assess the value of management strategies in multiple sclerosis (MS), outcome data have to be combined with cost data. This, in turn, requires that cost data be regularly updated. OBJECTIVE AND METHODS: This study is part of a cross-sectional retrospective study in 16 countries collecting current data on resource consumption, work capacity and health-related quality of life (HQoL). Descriptive analyses are presented by level of severity; costs are estimated in the societal perspective, in RUB 2015. RESULTS: A total of 208 patients (mean age: 38.5 years) participated in the Russian study; 97% were below retirement age, and of these, 49% were employed. MS was reported to affect productivity at work in 63% of patients. Overall, 87% and 41% of patients felt that fatigue and cognition were a problem. The mean utility and costs were 0.769 and 578,000 RUB at Expanded Disability Status Scale (EDSS) 0-3, 0.509 and 826,000 RUB at EDSS 4-6.5, and 0.071 and 1,013,000 RUB at EDSS 7-9. The average cost of a relapse was 33,000 RUB. CONCLUSION: This study illustrates the burden of MS on Russian patients and provides current data that are important for developing health policies.


Assuntos
Efeitos Psicossociais da Doença , Emprego/estatística & dados numéricos , Custos de Cuidados de Saúde/estatística & dados numéricos , Esclerose Múltipla , Qualidade de Vida , Adulto , Idoso , Estudos Transversais , Eficiência , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Esclerose Múltipla/economia , Esclerose Múltipla/epidemiologia , Esclerose Múltipla/fisiopatologia , Esclerose Múltipla/terapia , Estudos Retrospectivos , Federação Russa/epidemiologia , Índice de Gravidade de Doença
10.
Nanomedicine ; 13(8): 2575-2585, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28756094

RESUMO

A creation of nanotraps that could selectively recognize the chemotactic mediators of leukocyte adhesion and eliminate them from the bloodstream and tissue intercellular matrix is a promising approach for the treatment of various inflammatory and autoimmune diseases. We designed nanotraps as artificial decoy receptors based on poly(lactic acid) (PLA) nanoparticles covered by heparin and bearing on the surface two fragments of CCR5 receptor (N-terminal domain, Nt, and second extracellular loop, ECL2), responsible for chemokine binding. In order to attach Nt and ECL2 to the heparin shell, the corresponding peptides were modified with N- and/or C-terminal oligolysines. The presence of the nanotraps in the cell medium completely eliminated the activating effect of a CCR5 ligand, chemokine Rantes, while strongly decreasing the adhesion of monocytes to the human endothelial cells. We found that the modified ECL2 alone was also able to prevent monocyte adhesion, thus acting as a decoy receptor itself.


Assuntos
Materiais Biomiméticos/química , Quimiocinas/isolamento & purificação , Proteínas Imobilizadas/química , Receptores CCR5/química , Biomimética , Adesão Celular , Células Hep G2 , Heparina/química , Células Endoteliais da Veia Umbilical Humana , Humanos , Inflamação/terapia , Modelos Moleculares , Nanomedicina , Poliésteres/química , Propriedades de Superfície
11.
Glob Chang Biol ; 22(6): 2038-53, 2016 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-26855008

RESUMO

Ocean warming 'hotspots' are regions characterized by above-average temperature increases over recent years, for which there are significant consequences for both living marine resources and the societies that depend on them. As such, they represent early warning systems for understanding the impacts of marine climate change, and test-beds for developing adaptation options for coping with those impacts. Here, we examine five hotspots off the coasts of eastern Australia, South Africa, Madagascar, India and Brazil. These particular hotspots have underpinned a large international partnership that is working towards improving community adaptation by characterizing, assessing and projecting the likely future of coastal-marine food resources through the provision and sharing of knowledge. To inform this effort, we employ a high-resolution global ocean model forced by Representative Concentration Pathway 8.5 and simulated to year 2099. In addition to the sea surface temperature, we analyse projected stratification, nutrient supply, primary production, anthropogenic CO2 -driven ocean acidification, deoxygenation and ocean circulation. Our simulation finds that the temperature-defined hotspots studied here will continue to experience warming but, with the exception of eastern Australia, may not remain the fastest warming ocean areas over the next century as the strongest warming is projected to occur in the subpolar and polar areas of the Northern Hemisphere. Additionally, we find that recent rapid change in SST is not necessarily an indicator that these areas are also hotspots of the other climatic stressors examined. However, a consistent facet of the hotspots studied here is that they are all strongly influenced by ocean circulation, which has already shown changes in the recent past and is projected to undergo further strong change into the future. In addition to the fast warming, change in local ocean circulation represents a distinct feature of present and future climate change impacting marine ecosystems in these areas.


Assuntos
Mudança Climática , Ecossistema , Água do Mar/química , Temperatura , Movimentos da Água , Adaptação Fisiológica , Austrália , Brasil , Dióxido de Carbono/análise , Índia , Madagáscar , Modelos Teóricos , Oceanos e Mares , África do Sul
12.
Soft Matter ; 12(31): 6601-9, 2016 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-27439890

RESUMO

We report the development of a highly stable nanomaterial based on ferromagnetic nanoparticles dispersed in a thermotropic liquid crystal. The long-term colloidal stability and homogeneity were achieved through surface modification of the nanoparticles with a mixture of a dendritic oligomesogenic surfactant and hexylphosphonic acid and confirmed by optical and electron microscopy. The nanomaterial has an increased sensitivity to the magnetic field possessing collective and non-collective magneto-optical responses in contrast to the undoped LC. The effective coupling of the spherical particles with the LC director is due to the arrangement of the nanoparticles in chains.

13.
J Med Genet ; 52(12): 848-55, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26475045

RESUMO

OBJECTIVE: A recent large-scale study in multiple sclerosis (MS) using the ImmunoChip platform reported on 11 loci that showed suggestive genetic association with MS. Additional data in sufficiently sized and independent data sets are needed to assess whether these loci represent genuine MS risk factors. METHODS: The lead SNPs of all 11 loci were genotyped in 10 796 MS cases and 10 793 controls from Germany, Spain, France, the Netherlands, Austria and Russia, that were independent from the previously reported cohorts. Association analyses were performed using logistic regression based on an additive model. Summary effect size estimates were calculated using fixed-effect meta-analysis. RESULTS: Seven of the 11 tested SNPs showed significant association with MS susceptibility in the 21 589 individuals analysed here. Meta-analysis across our and previously published MS case-control data (total sample size n=101 683) revealed novel genome-wide significant association with MS susceptibility (p<5×10(-8)) for all seven variants. This included SNPs in or near LOC100506457 (rs1534422, p=4.03×10(-12)), CD28 (rs6435203, p=1.35×10(-9)), LPP (rs4686953, p=3.35×10(-8)), ETS1 (rs3809006, p=7.74×10(-9)), DLEU1 (rs806349, p=8.14×10(-12)), LPIN3 (rs6072343, p=7.16×10(-12)) and IFNGR2 (rs9808753, p=4.40×10(-10)). Cis expression quantitative locus effects were observed in silico for rs6435203 on CD28 and for rs9808753 on several immunologically relevant genes in the IFNGR2 locus. CONCLUSIONS: This study adds seven loci to the list of genuine MS genetic risk factors and further extends the list of established loci shared across autoimmune diseases.


Assuntos
Esclerose Múltipla/genética , Estudos de Casos e Controles , Frequência do Gene , Loci Gênicos , Predisposição Genética para Doença , Estudo de Associação Genômica Ampla , Humanos , Polimorfismo de Nucleotídeo Único , Fatores de Risco
14.
Nature ; 457(7229): 577-80, 2009 Jan 29.
Artigo em Inglês | MEDLINE | ID: mdl-19177128

RESUMO

The addition of iron to high-nutrient, low-chlorophyll regions induces phytoplankton blooms that take up carbon. Carbon export from the surface layer and, in particular, the ability of the ocean and sediments to sequester carbon for many years remains, however, poorly quantified. Here we report data from the CROZEX experiment in the Southern Ocean, which was conducted to test the hypothesis that the observed north-south gradient in phytoplankton concentrations in the vicinity of the Crozet Islands is induced by natural iron fertilization that results in enhanced organic carbon flux to the deep ocean. We report annual particulate carbon fluxes out of the surface layer, at three kilometres below the ocean surface and to the ocean floor. We find that carbon fluxes from a highly productive, naturally iron-fertilized region of the sub-Antarctic Southern Ocean are two to three times larger than the carbon fluxes from an adjacent high-nutrient, low-chlorophyll area not fertilized by iron. Our findings support the hypothesis that increased iron supply to the glacial sub-Antarctic may have directly enhanced carbon export to the deep ocean. The CROZEX sequestration efficiency (the amount of carbon sequestered below the depth of winter mixing for a given iron supply) of 8,600 mol mol(-1) was 18 times greater than that of a phytoplankton bloom induced artificially by adding iron, but 77 times smaller than that of another bloom initiated, like CROZEX, by a natural supply of iron. Large losses of purposefully added iron can explain the lower efficiency of the induced bloom(6). The discrepancy between the blooms naturally supplied with iron may result in part from an underestimate of horizontal iron supply.


Assuntos
Carbono/metabolismo , Ferro/metabolismo , Água do Mar/química , Regiões Antárticas , Clorofila/análise , Clorofila/metabolismo , Clorofila A , Eutrofização , Geografia , Sedimentos Geológicos/química , Oceanos e Mares , Fitoplâncton/metabolismo , Estações do Ano , Fatores de Tempo
15.
Int J Mol Sci ; 16(8): 20067-81, 2015 Aug 24.
Artigo em Inglês | MEDLINE | ID: mdl-26305248

RESUMO

Multiple sclerosis (MS) is an autoimmune neuro-inflammatory disease arising from complex interactions of genetic, epigenetic, and environmental factors. Variations in genes of some microRNAs--key post-transcriptional regulators of many genes--can influence microRNAs expression/function and contribute to MS via expression changes of protein-coding target mRNA genes. We performed an association study of polymorphous variants of MIR146A rs2910164, MIR196A2 rs11614913, MIR499A rs3746444 MIR223 rs1044165 and their combinations with MS risk and severity. 561 unrelated patients with bout-onset MS and 441 healthy volunteers were enrolled in the study. We observed associations of MS risk with allele MIR223*T and combination (MIR223*T + MIR146A*G/G) carriage in the entire groups and in women at Bonferroni-corrected significance level (pcorr < 0.05). Besides, MIR146A*G/G association with MS was observed in women with nominal significance (pf = 0.025). No MS associations were found in men. A more severe MS course (MSSS value > 3.5) was associated with the carriage of MIR499A*C/T and, less reliably, of MIR499A*C (pcorr = 0.006 and pcorr = 0.024, respectively) and with the carriage of combinations (MIR499A*C/T + MIR196A2*C) and (MIR499A*C + MIR196A2*C) (pcorr = 0.00078 and pcorr = 0.0059, respectively). These associations also showed gender specificity, as they were not significant in men and substantially reinforced in women. The strongest association with MS severity was observed in women for combination (MIR499A*C/T + MIR196A2*C): pcorr = 4.43 × 10(-6) and OR = 3.23 (CI: 1.99-5.26).


Assuntos
Estudos de Associação Genética/métodos , MicroRNAs/genética , Esclerose Múltipla/genética , Polimorfismo de Nucleotídeo Único , Adolescente , Adulto , Feminino , Predisposição Genética para Doença , Humanos , Masculino , Esclerose Múltipla/patologia , Fatores Sexuais , Adulto Jovem
16.
Sci Total Environ ; 947: 174623, 2024 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-38997015

RESUMO

Balancing blue growth with the conservation of wild species and habitats is a key challenge for global ocean management. This is exacerbated in Global South nations, such as Tanzania, where climate-driven ocean change requires delicate marine spatial planning (MSP) trade-offs to ensure climate resilience of marine resources relied upon by coastal communities. Here, we identified challenges and opportunities that climate change presents to the near-term spatial management of Tanzania's artisanal fishing sector, marine protected areas and seaweed farming. Specifically, spatial meta-analysis of climate modelling for the region was carried out to estimate the natural distribution of climate resilience in the marine resources that support these socially important sectors. We estimated changes within the next 20 and 40 years, using modelling projections forced under global emissions trajectories, as well as a wealth of GIS and habitat suitability data derived from globally distributed programmes. Multi-decadal analyses indicated that long-term climate change trends and extreme weather present important challenges to the activity of these sectors, locally and regionally. Only in few instances did we identify areas exhibiting climate resilience and opportunities for sectoral expansion. Including these climate change refugia and bright spots in effective ocean management strategies may serve as nature-based solutions: promoting adaptive capacity in some of Tanzania's most vulnerable economic sectors; creating wage-gaining opportunities that promote gender parity; and delivering some economic benefits of a thriving ocean where possible. Without curbs in global emissions, however, a bleak future may emerge for globally valuable biodiversity hosted in Tanzania, and for its coastal communities, despite the expansion of protected areas or curbs in other pressures. Growing a sustainable ocean economy in this part of the Global South remains a substantial challenge without global decarbonization.

17.
Zootaxa ; 3736: 159-74, 2013 Nov 12.
Artigo em Inglês | MEDLINE | ID: mdl-25112620

RESUMO

Daphnia O.F. Müller (Crustacea: Cladocera: Daphniidae) is an important model in biology. It was concluded earlier that subgenus Daphnia s.str. occurs mainly in the northern hemisphere, subgenus Daphnia (Ctenodaphnia) in the southern hemisphere, which could suggest that: (1) the subgeneric differentiation is correlated with the Laurasia-Gondwanaland subdivision and (2) D. (Ctenodaphnia) is a taxon of Gondwanian origin. Some authors even discussed mechanisms of maintaince of the "ancient subgeneric north-south split", regarding such a pattern as paradoxical. But both molecular clock calculations and fossils of both subgenera from the Jurassic/Cretaceous boundary of Mongolia compromise such ideas and suggest an earlier, Pangaean, differentiation of the subgenera.        We discuss the distribution of Daphnia worldwide based on recent literature. Our analysis covers literature data on all described and on undescribed taxa revealed by genetical methods. Distributional data were associated with five main zones: southern cold (I), southern temperate (II), tropical (III), northern temperate (IV), and northern cold (V) zone. We found no "subgeneric north-south split": the distribution of Daphnia s.str. is dissymmetric between the hemispheres (antipolar), while that of Ctenodaphnia is sub-symmetric (bipolar). We suggest that both patterns are not of Mesozoic, but of Cenozoic origin. Mesozoic differentiation of the subgenera does not contradict a recent origin of the extant species, as found in e.g. Notostraca. A superficially attractive hypothesis about a Gondwanian origin of a taxon (Daphnia (Ctenodaphnia)) therefore did not pass the test of the fossil records. In addition, we agree with the opinion that an antipolar is only a variant of a bipolar pattern, as a result of an extinction in the southern hemisphere, and that these patterns are mid-late Cenozoic instead of Mesozoic.


Assuntos
Distribuição Animal , Daphnia/fisiologia , Altitude , Animais , Biodiversidade , Daphnia/classificação , Ecossistema , Feminino , Fósseis , Masculino
18.
Pharmaceutics ; 15(2)2023 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-36839871

RESUMO

Improvement of the efficiency of drug penetration into the eye tissues is still an actual problem in ophthalmology. One of the most promising solutions is drug encapsulation in carriers capable of overcoming the cornea/sclera tissue barrier. Formulations on the base of antioxidant enzyme, superoxide dismutase 1 (SOD1), and an inhibitor of angiotensin-converting enzyme, enalaprilat, were prepared by simultaneous inclusion of both drugs into calcium phosphate (CaP) particles in situ with subsequent covering of the particles with 5 kDa chitosan. The formulations obtained were characterized by dynamic light scattering and scanning electron microscopy. Hybrid CaP-chitosan particles co-loaded with SOD1 and enalaprilat had a mean hydrodynamic diameter of 120-160 nm and ζ-potential +20 ± 1 mV. The percentage of the inclusion of SOD1 and enalaprilat in hybrid particles was 30% and 56%, respectively. The ability of SOD1 and enalaprilat to reduce intraocular pressure (IOP) was examined in vivo in normotensive Chinchilla rabbits. It was shown that topical instillations of SOD1/enalaprilat co-loaded hybrid particles were much more effective in decreasing IOP compared to free enzyme or free enalaprilat and even to the same particles that contained a single drug. Thus, the proposed formulations demonstrate potential as prospective therapeutic agents for the treatment of glaucoma.

19.
Antioxidants (Basel) ; 12(3)2023 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-36978858

RESUMO

Many muscular pathologies are associated with oxidative stress and elevated levels of the tumor necrosis factor (TNF) that cause muscle protein catabolism and impair myogenesis. Myogenesis defects caused by TNF are mediated in part by reactive oxygen species (ROS), including those produced by mitochondria (mitoROS), but the mechanism of their pathological action is not fully understood. We hypothesized that mitoROS act by triggering and enhancing mitophagy, an important tool for remodelling the mitochondrial reticulum during myogenesis. We used three recently developed probes-MitoTracker Orange CM-H2TMRos, mito-QC, and MitoCLox-to study myogenesis in human myoblasts. Induction of myogenesis resulted in a significant increase in mitoROS generation and phospholipid peroxidation in the inner mitochondrial membrane, as well as mitophagy enhancement. Treatment of myoblasts with TNF 24 h before induction of myogenesis resulted in a significant decrease in the myoblast fusion index and myosin heavy chain (MYH2) synthesis. TNF increased the levels of mitoROS, phospholipid peroxidation in the inner mitochondrial membrane and mitophagy at an early stage of differentiation. Trolox and SkQ1 antioxidants partially restored TNF-impaired myogenesis. The general autophagy inducers rapamycin and AICAR, which also stimulate mitophagy, completely blocked myogenesis. The autophagy suppression by the ULK1 inhibitor SBI-0206965 partially restored myogenesis impaired by TNF. Thus, suppression of myogenesis by TNF is associated with a mitoROS-dependent increase in general autophagy and mitophagy.

20.
Mult Scler Relat Disord ; 79: 104996, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37703639

RESUMO

BACKGROUND: Cerebrospinal fluid (CSF) indices reflecting intrathecal antibody production and blood-brain barrier impairment are not routinely assessed in patients with autoimmune encephalitis (AE). We aimed to study CSF indices and their association with the prognosis of AE. METHODS: This retrospective cohort study conducted at Amrita Institute of Medical Sciences (AIMS), Kochi, India, included 60 patients aged more than 18 years with definite/probable/possible AE admitted to the Department of Neurology from August 2016 to November 2021. We introduced a classification of treatment response based on modified Rankin Scale change over time and treatment modalities. RESULTS: In our cohort of 60 patients (six [10%] seropositive cases), a good rapid treatment response was associated with CSF white blood cell count of more than 4 cells/mm3 (OR, 4.57; 95% CI 1.31-15.96; P = .02) and positive immunoglobulin G (IgG) Local Synthesis (OR, 7.27; 95% CI 1.56-33.86; P = .01). Albumin Index had association with a poor Glasgow Coma Scale score at the nadir of the disease (OR, 1.17; 95% CI 1.01-1.34; P = .04). Similar results were yielded in the seronegative cohort. IgG Local Synthesis appeared to be a strong predictor for good rapid treatment response in both univariate and multivariate (adjusted OR, 28.71; 95% CI 2.12-389.22; P= .01) analysis. Time to immunotherapy was reversely correlated with good response overall (in the cohort with outliers removed [N = 49]: unadjusted OR 0.97, 95% CI 0.95-0.99; P= .01; adjusted OR 0.97; 95% CI 0.95-0.99; P= .008). CONCLUSION: CSF indices reflecting intrathecal antibody production and blood-brain barrier impairment appear to be promising predictors of disease severity and therapeutic response in patients with autoimmune encephalitis.


Assuntos
Doenças Autoimunes do Sistema Nervoso , Encefalite , Humanos , Estudos Retrospectivos , Encefalite/terapia , Imunoglobulina G/líquido cefalorraquidiano
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