Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 14 de 14
Filtrar
1.
J Therm Biol ; 99: 103016, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34420648

RESUMO

Temperature and salinity are abiotic factors that affect physiological responses in aquaculture species. The European sea bass (Dicentrarchus labrax) is a temperate species that is generally farmed at 18 °C in seawater (SW). In the wild, its incursions in shallow habitats such as lagoons may result in hyperthermal damage despite its high thermal tolerance. Meanwhile, the milkfish (Chanos chanos), a tropical species, is generally reared at 28 °C, and in winter, high mortality usually occurs under hypothermal stress such as cold snaps. This study compared changes in hepatic antioxidant enzymes (superoxide dismutase, SOD; and catalase, CAT) in these two important marine euryhaline aquaculture species in Europe and Southeast Asia, respectively, under temperature challenge combined with hypo-osmotic (fresh water, FW) stress. After a four-week hyper- or hypo-thermal treatment, hepatic SOD activity was upregulated in both species reared in SW and FW, indicating enhanced oxidative stress in European sea bass and milkfish. The expression profiles of sod isoforms suggested that in milkfish, the increase in reactive oxygen species (ROS) was mainly at the cytosol level, leading to increased sod1 expression. In European sea bass, however, no obvious difference was found between the expression of sod isoforms at different temperatures. A lower expression of sod2 was observed in FW compared to SW in the latter species. Moreover, no significant change was observed in the mRNA expression and activity of CAT in the livers of these two species under the different temperature treatments, with the exception of the lower CAT activity in milkfish challenged with SW at 18 °C. Taken together, our results indicated that the antioxidant responses were not changed under long-term hypoosmotic challenge but were enhanced during the four-week temperature treatments in livers of both the temperate and tropical euryhaline species.


Assuntos
Antioxidantes/metabolismo , Bass/metabolismo , Fígado/metabolismo , Salinidade , Temperatura , Animais , Aquicultura , Estresse Oxidativo , Espécies Reativas de Oxigênio , Água do Mar , Estresse Fisiológico , Superóxido Dismutase/metabolismo
2.
Chemistry ; 26(7): 1511-1517, 2020 Feb 03.
Artigo em Inglês | MEDLINE | ID: mdl-31867761

RESUMO

Solid-state 19 F NMR is a powerful method to study the interactions of biologically active peptides with membranes. So far, in labelled peptides, the 19 F-reporter group has always been installed on the side chain of an amino acid. Given the fact that monofluoroalkenes are non-hydrolyzable peptide bond mimics, we have synthesized a monofluoroalkene-based dipeptide isostere, Val-Ψ[(Z)-CF=CH]-Gly, and inserted it in the sequence of two well-studied antimicrobial peptides: PGLa and (KIGAKI)3 are representatives of an α-helix and a ß-sheet. The conformations and biological activities of these labeled peptides were studied to assess the suitability of monofluoroalkenes for 19 F NMR structure analysis.


Assuntos
Alcenos/química , Peptídeos Catiônicos Antimicrobianos/química , Membrana Celular/química , Espectroscopia de Ressonância Magnética , Sequência de Aminoácidos , Peptídeos Catiônicos Antimicrobianos/síntese química , Flúor/química , Conformação Proteica em alfa-Hélice , Coloração e Rotulagem/métodos
4.
J Immunol ; 191(7): 3594-604, 2013 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-24014878

RESUMO

Autoantibodies targeting conformationally intact myelin oligodendrocyte glycoprotein (MOG) are found in different inflammatory diseases of the CNS, but their antigenic epitopes have not been mapped. We expressed mutants of MOG on human HeLa cells and analyzed sera from 111 patients (104 children, 7 adults) who recognized cell-bound human MOG, but had different diseases, including acute disseminated encephalomyelitis (ADEM), one episode of transverse myelitis or optic neuritis, multiple sclerosis (MS), anti-aquaporin-4 (AQP4)-negative neuromyelitis optica (NMO), and chronic relapsing inflammatory optic neuritis (CRION). We obtained insight into the recognition of epitopes in 98 patients. All epitopes identified were located at loops connecting the ß strands of MOG. The most frequently recognized MOG epitope was revealed by the P42S mutation positioned in the CC'-loop. Overall, we distinguished seven epitope patterns, including the one mainly recognized by mouse mAbs. In half of the patients, the anti-MOG response was directed to a single epitope. The epitope specificity was not linked to certain disease entities. Longitudinal analysis of 11 patients for up to 5 y indicated constant epitope recognition without evidence for intramolecular epitope spreading. Patients who rapidly lost their anti-MOG IgG still generated a long-lasting IgG response to vaccines, indicating that their loss of anti-MOG reactivity did not reflect a general lack of capacity for long-standing IgG responses. The majority of human anti-MOG Abs did not recognize rodent MOG, which has implications for animal studies. Our findings might assist in future detection of potential mimotopes and pave the way to Ag-specific depletion.


Assuntos
Doenças do Sistema Nervoso Central/imunologia , Epitopos/química , Epitopos/imunologia , Inflamação/imunologia , Glicoproteína Mielina-Oligodendrócito/imunologia , Adolescente , Adulto , Sequência de Aminoácidos , Substituição de Aminoácidos , Animais , Autoanticorpos/imunologia , Autoanticorpos/metabolismo , Doenças do Sistema Nervoso Central/genética , Criança , Pré-Escolar , Epitopos/metabolismo , Feminino , Glicosilação , Humanos , Imunoglobulina G/imunologia , Lactente , Inflamação/genética , Masculino , Camundongos , Pessoa de Meia-Idade , Modelos Moleculares , Mutação , Glicoproteína Mielina-Oligodendrócito/genética , Glicoproteína Mielina-Oligodendrócito/metabolismo , Ligação Proteica/imunologia , Conformação Proteica , Estabilidade Proteica , Alinhamento de Sequência , Transfecção , Adulto Jovem
5.
J Immunother Cancer ; 11(12)2023 12 14.
Artigo em Inglês | MEDLINE | ID: mdl-38097343

RESUMO

BACKGROUND: C reactive protein (CRP) kinetics have recently been suggested as predictive biomarkers for the efficacy of immune checkpoint inhibitor (ICI) therapy in selected cancer types. The aim of this study was to characterize early CRP kinetics as a tumor-agnostic biomarker for ICI treatment outcomes. METHODS: In this multicenter retrospective cohort study, two independent cohorts of patients with various cancer types undergoing palliative ICI treatment at Austrian academic centers served as the discovery (n=562) and validation cohort (n=474). Four different patterns of CRP kinetics in the first 3 months of ICI therapy were defined (CRP-flare responders, CRP-responders, CRP non-responders, patients with all-normal CRP). Objective response rate (ORR), progression-free survival (PFS) and overall survival (OS) were defined as coprimary endpoints. Univariable and multivariable logistic regression, landmark analysis and Cox regression including CRP kinetics as time-dependent variable were performed. RESULTS: The ORR in patients with all-normal CRP, CRP responders, CRP flare-responders and CRP non-responders was 41%, 38%, 31% and 12%, respectively. The median OS and PFS estimates were 24.5 months (95% CI 18.5 to not reached) and 8.2 months (95% CI 5.9 to 12.0) in patients with all-normal CRP, 16.1 months (95% CI 12.6 to 19-8) and 6.1 months (95% CI 4.9 to 7.2) in CRP-responders, 14.0 months (95% CI 8.5 to 19.4) and 5.7 months (95% CI 4.1 to 8.5) in CRP flare-responders and 8.1 months (95% CI 5.8 to 9.9) and 2.3 months (95% CI 2.2 to 2.8) in CRP non-responders (log-rank p for PFS and OS<0.001). These findings prevailed in multivariable analysis and could be fully confirmed in our validation cohort. Pooled subgroup analysis suggested a consistent predictive significance of early CRP kinetics for treatment efficacy and outcome independent of cancer type. CONCLUSION: Early CRP kinetics represent a tumor-agnostic predictor for treatment response, progression risk and mortality in patients with cancer undergoing ICI therapy.


Assuntos
Proteína C-Reativa , Neoplasias , Humanos , Inibidores de Checkpoint Imunológico/farmacologia , Inibidores de Checkpoint Imunológico/uso terapêutico , Estudos Retrospectivos , Biomarcadores Tumorais , Neoplasias/tratamento farmacológico
6.
Opt Express ; 19(8): 7530-6, 2011 Apr 11.
Artigo em Inglês | MEDLINE | ID: mdl-21503060

RESUMO

We demonstrate a gallium arsenide photonic crystal cavity injection-based electro-optic modulator coupled to a fiber taper waveguide. The fiber taper serves as a convenient and tunable waveguide for cavity coupling with minimal loss. Localized electrical injection of carriers into the cavity region via a laterally doped p-i-n diode combined with the small mode volume of the cavity enable ultra-low energy modulation at sub-fJ/bit levels. Speeds of up to 1 GHz are demonstrated with photoluminescence lifetime measurements revealing that the ultimate limit goes well into the tens of GHz.

7.
Clin Epigenetics ; 13(1): 1, 2021 01 06.
Artigo em Inglês | MEDLINE | ID: mdl-33407852

RESUMO

BACKGROUND: Chronic myelomonocytic leukemia (CMML) is an aggressive hematopoietic malignancy that arises from hematopoietic stem and progenitor cells (HSPCs). Patients with CMML are frequently treated with epigenetic therapeutic approaches, in particular the hypomethylating agents (HMAs), azacitidine (Aza) and decitabine (Dec). Although HMAs are believed to mediate their efficacy via re-expression of hypermethylated tumor suppressors, knowledge about relevant HMA targets is scarce. As silencing of tumor-suppressive micro-RNAs (miRs) by promoter hypermethylation is a crucial step in malignant transformation, we asked for a role of miRs in HMA efficacy in CMML. RESULTS: Initially, we performed genome-wide miR-expression profiling in a KrasG12D-induced CMML mouse model. Selected candidates with prominently decreased expression were validated by qPCR in CMML mice and human CMML patients. These experiments revealed the consistent decrease in miR-125a, a miR with previously described tumor-suppressive function in myeloid neoplasias. Furthermore, we show that miR-125a downregulation is caused by hypermethylation of its upstream region and can be reversed by HMA treatment. By employing both lentiviral and CRISPR/Cas9-based miR-125a modification, we demonstrate that HMA-induced miR-125a upregulation indeed contributes to mediating the anti-leukemic effects of these drugs. These data were validated in a clinical context, as miR-125a expression increased after HMA treatment in CMML patients, a phenomenon that was particularly pronounced in cases showing clinical response to these drugs. CONCLUSIONS: Taken together, we report decreased expression of miR-125a in CMML and delineate its relevance as mediator of HMA efficacy within this neoplasia.


Assuntos
Antimetabólitos Antineoplásicos/uso terapêutico , Azacitidina/uso terapêutico , Metilação de DNA/efeitos dos fármacos , Decitabina/uso terapêutico , Regulação da Expressão Gênica/efeitos dos fármacos , Leucemia Mielomonocítica Crônica/tratamento farmacológico , Leucemia Mielomonocítica Crônica/genética , RNA Mensageiro , Animais , Modelos Animais de Doenças , Estudo de Associação Genômica Ampla , Humanos , Camundongos
8.
J Clin Microbiol ; 46(11): 3804-7, 2008 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-18832133

RESUMO

The performance of the 3M rapid detection influenza A+B (3M flu) assay was compared to the performance of other immunochromatographic assays. The clinical and analytical performance of the 3M flu assay was superior to that of BinaxNOW and Directigen EZ assays and equivalent to that of the QuickVue assay. The 3M flu assay offers an objective output and direct linkage to laboratory information systems.


Assuntos
Antígenos Virais/análise , Vírus da Influenza A/isolamento & purificação , Vírus da Influenza B/isolamento & purificação , Influenza Humana/diagnóstico , Antígenos Virais/imunologia , Humanos , Vírus da Influenza A/imunologia , Vírus da Influenza B/imunologia , Sensibilidade e Especificidade
9.
Ann Clin Transl Neurol ; 2(3): 295-301, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25815356

RESUMO

We present histological, MRI, and clinical features of an adult patient with relapsing encephalomyelitis and antibodies against myelin oligodendrocyte glycoprotein (MOG). Furthermore, we report molecular details of the recognized epitope that is specific for human MOG. A brain biopsy revealed multiple sclerosis (MS)-type II pathology. Some features overlapped with both MS and neuromyelitis optica spectrum disorders (NMOSD), whereas others were distinct from both MS and NMOSD. Immunoadsorption and rituximab induced clinical stabilization. This case contributes a new, so far missing link in the emerging spectrum of MOG-antibody-associated encephalomyelitis.

11.
Ther Adv Neurol Disord ; 5(3): 147-59, 2012 May.
Artigo em Inglês | MEDLINE | ID: mdl-22590479

RESUMO

B cells and antibodies constitute an important element in different inflammatory diseases of the central nervous system (CNS). Autoantibodies can serve as a biomarker to identify disease subgroups and may in addition contribute to the pathogenic process. One candidate autoantigen for multiple sclerosis (MS) is myelin oligodendrocyte glycoprotein (MOG). MOG is localized at the outermost surface of myelin in the CNS and has been the focus of extensive research for more than 30 years. Its role as an important autoantigen for T cells and as a target of demyelinating autoantibodies has been established in several variants of experimental autoimmune encephalomyelitis (EAE), an animal model of MS. The literature regarding antibodies to MOG in MS patients is confusing and contradictory. Recent studies, however, have described high levels of antibodies to conformationally correct MOG in pediatric acquired demyelination, both acute disseminated encephalomyelitis (ADEM) and MS. In adult MS, such antibodies are rarely found and then only at low levels. In this review, we summarize key findings from animal models and patient studies, discuss challenges in detecting anti-MOG antibodies in patients and present recent approaches to identifying new autoantigens in MS.

12.
J Neurol Sci ; 319(1-2): 2-7, 2012 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-22647585

RESUMO

The growing complexity number of multiple sclerosis (MS) therapy emphasizes the need for an individualized approach, tailoring therapy to the needs of the individual patient. There is evidence supporting the immunopathological heterogeneity of MS, based on the analysis of biopsy and autopsy tissues. In clinical practice it is impossible to differentiate between the pathological subtypes of MS, because blood or CSF markers of pathological heterogeneity are lacking. Identification of such markers would be important, because "tailored therapy" and "biomarkers for patient stratification" may be considered as two sides of the same coin. In this article, we discuss the emerging role of autoantibodies as potential biomarkers, focusing on myelin oligodendrocyte glycoprotein (MOG) as one of the best characterized autoantigens in MS. In addition, we discuss several strategies for the identification of novel candidate autoantigens.


Assuntos
Autoanticorpos/imunologia , Esclerose Múltipla/tratamento farmacológico , Autoanticorpos/sangue , Humanos , Esclerose Múltipla/sangue , Esclerose Múltipla/imunologia , Glicoproteína Mielina-Oligodendrócito/imunologia
13.
Structure ; 20(4): 688-97, 2012 Apr 04.
Artigo em Inglês | MEDLINE | ID: mdl-22483115

RESUMO

The discoidin domain receptors, DDR1 and DDR2, are constitutively dimeric receptor tyrosine kinases that are activated by triple-helical collagen. Aberrant DDR signaling contributes to several human pathologies, including many cancers. We have generated monoclonal antibodies (mAbs) that inhibit DDR1 signaling without interfering with collagen binding. The crystal structure of the monomeric DDR1 extracellular region bound to the Fab fragment of mAb 3E3 reveals that the collagen-binding discoidin (DS) domain is tightly associated with the following DS-like domain, which contains the epitopes of all mAbs. A conserved surface patch in the DS domain outside the collagen-binding site is shown to be required for signaling. Thus, the active conformation of the DDR1 dimer involves collagen-induced contacts between the DS domains, in addition to the previously identified association of transmembrane helices. The mAbs likely inhibit signaling by sterically blocking the extracellular association of DDR1 subunits.


Assuntos
Anticorpos Neutralizantes/química , Colágeno/química , Receptores Proteína Tirosina Quinases/química , Receptores Mitogênicos/química , Sítios de Ligação , Colágeno/genética , Cristalografia por Raios X , Receptor com Domínio Discoidina 1 , Receptores com Domínio Discoidina , Citometria de Fluxo , Células HEK293 , Humanos , Fragmentos Fab das Imunoglobulinas/química , Modelos Moleculares , Ligação Proteica , Multimerização Proteica , Estrutura Secundária de Proteína , Estrutura Terciária de Proteína , Subunidades Proteicas/antagonistas & inibidores , Subunidades Proteicas/química , Subunidades Proteicas/genética , Receptores Proteína Tirosina Quinases/antagonistas & inibidores , Receptores Proteína Tirosina Quinases/genética , Receptores Mitogênicos/genética , Proteínas Recombinantes de Fusão/química , Proteínas Recombinantes de Fusão/genética , Transdução de Sinais/genética , Transfecção
14.
Nat Commun ; 2: 539, 2011 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-22086339

RESUMO

Low-power and electrically controlled optical sources are vital for next generation optical interconnect systems to meet strict energy demands. Current optical transmitters consisting of high-threshold lasers plus external modulators consume far too much power to be competitive with future electrical interconnects. Here we demonstrate a directly modulated photonic crystal nanocavity light-emitting diode (LED) with 10 GHz modulation speed and less than 1 fJ per bit energy of operation, which is orders of magnitude lower than previous solutions. The device is electrically controlled and operates at room temperature, while the high modulation speed results from the fast relaxation of the quantum dots used as the active material. By virtue of possessing a small mode volume, our LED is intrinsically single mode and, therefore, useful for communicating information over a single narrowband channel. The demonstrated device is a major step forward in providing practical low-power and integrable sources for on-chip photonics.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA