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1.
Adv Sci (Weinh) ; : e2401392, 2024 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-38874431

RESUMO

Viral vectors and lipofection-based gene therapies have dispersion-dependent transduction/transfection profiles that thwart precise targeting. The study describes the development of focused close-field gene electrotransfer (GET) technology, refining spatial control of gene expression. Integration of fluidics for precise delivery of "naked" plasmid deoxyribonucleic acid (DNA) in sucrose carrier within the focused electric field enables negative biasing of near-field conductivity ("conductivity-clamping"-CC), increasing the efficiency of plasma membrane molecular translocation. This enables titratable gene delivery with unprecedently low charge transfer. The clinic-ready bionics-derived CC-GET device achieved neurotrophin-encoding miniplasmid DNA delivery to the cochlea to promote auditory nerve regeneration; validated in deafened guinea pig and cat models, leading to improved central auditory tuning with bionics-based hearing. The performance of CC-GET is evaluated in the brain, an organ problematic for pulsed electric field-based plasmid DNA delivery, due to high required currents causing Joule-heating and damaging electroporation. Here CC-GET enables safe precision targeting of gene expression. In the guinea pig, reporter expression is enabled in physiologically critical brainstem regions, and in the striatum (globus pallidus region) delivery of a red-shifted channelrhodopsin and a genetically-encoded Ca2+ sensor, achieved photoactivated neuromodulation relevant to the treatment of Parkinson's Disease and other focal brain disorders.

2.
Hear Res ; 426: 108637, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36306608

RESUMO

The emergence of therapeutics targeted at hearing loss holds great promise in the development of novel treatments for this heterogenous condition. Whilst such therapeutics are largely designed to be efficacious in and of themselves, the possibility of combination with devices, namely cochlear implants, could result in much more effective treatment options. Here, we review the otoprotective molecules currently in clinical development, as well as generic steroids, discussing mechanisms of action and mode of delivery to the perilymph of the cochlea. Presenting both preclinical and clinical data, we explore the challenges these molecules face in reaching the inner ear. Furthermore, we consider the role of the cochlear implant as a drug delivery platform along with the ability of these drugs to preserve residual hearing and improve outcomes in implant recipients.


Assuntos
Implante Coclear , Implantes Cocleares , Surdez , Humanos , Cóclea , Audição , Surdez/cirurgia
3.
PeerJ ; 3: e905, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25922793

RESUMO

Originally identified as an ornithischian dinosaur, Crosbysaurus harrisae has been found in New Mexico, Arizona, and its type locality in Texas, as well as in North Carolina. The genus has been reassessed by other workers in light of reinterpretations about the postcrania of another putative Triassic ornithischian, Revueltosaurus. The understanding of Triassic dental faunas has become more complicated by the extreme convergence between pseudosuchian archosaurs and ornithischian dinosaur dental morphologies. We report here on a new specimen of Crosbysaurus (MNA V10666) from the Chinle Formation at Comb Ridge in southeastern Utah. This new specimen is assigned to Crosbysaurus sp. on the basis of the unique compound posterior denticles, labiolingual width, and curvature. While MNA V10666 does not help resolve the affinities of Crosbysaurus, it does represent the extension of the geographic range of this taxon for approximately 250 kilometers. This is the first record of the genus Crosbysaurus in Utah and as such it represents the northernmost known record of this taxon. This indicates that Crosbysaurus was not limited to the southern area of the Chinle/Dockum deposition but instead was widespread across the Late Triassic paleoriver systems of western Pangea. The reported specimen was found in close association with a typical Late Triassic Chinle fauna, including phytosaurs, metoposaurs, and dinosauromorphs.

4.
MAbs ; 2(6): 625-38, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20930515

RESUMO

We report preclinical data for CEP-37247, the first human framework domain antibody construct to enter the clinic. At approximately 11 - 13kDa, domain antibodies or dAbs are the smallest antibody domain able to demonstrate the antigen-recognition function of an antibody, e.g. high selectivity and affinity for target antigen. CEP-37247 is a bivalent anti-tumor necrosis factor (TNF)α domain antibody protein construct combining the antigen-recognition function of a dAb with the pharmacological advantages of an antibody Fc region. As a homodimer, with each chain comprising VL dAb, truncated CH1, hinge, CH2 and CH3 domains, CEP-37247 has a molecular mass of approximately 78kDa, which is about half the size of a conventional IgG molecule. Surface plasmon resonance data demonstrate that CEP-37247 possesses high selectivity and affinity for TNFα. CEP-37247 is a potent neutralizer of TNFα activity in vitro in the L929 TNF-mediated cytotoxicity assay. In a human TNFα-over-expressing mouse model of polyarthritis, CEP-37247 prevents development of disease, and is at least as effective as the marketed product etanercept. Fc functionality is intact - CEP-37247 is capable of mediating antibody-dependent cell-mediated cytotoxicity and has a circulating half-life of approximately 4.5 days in cynomolgus macaques. Given the favorable properties outlined above, and its high expression levels (approaching 7 g/L) in a CHOK1 based-expression system, CEP-37247 is progressing into the clinic, where other potential advantages such as enhanced efficacy due to improved tissue distribution, and beneficial immunogenicity profile, will be evaluated.


Assuntos
Anticorpos Monoclonais , Especificidade de Anticorpos/imunologia , Sítios de Ligação de Anticorpos/imunologia , Animais , Anticorpos Monoclonais/química , Anticorpos Monoclonais/imunologia , Anticorpos Monoclonais/farmacocinética , Citotoxicidade Celular Dependente de Anticorpos , Área Sob a Curva , Ensaio de Imunoadsorção Enzimática , Feminino , Humanos , Macaca fascicularis , Masculino , Camundongos , Ressonância de Plasmônio de Superfície , Fator de Necrose Tumoral alfa/antagonistas & inibidores
5.
IEEE Trans Neural Netw ; 20(8): 1352-7, 2009 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-19596632

RESUMO

One of the open problems in neural network research is how to automatically determine network architectures for given applications. In this brief, we propose a simple and efficient approach to automatically determine the number of hidden nodes in generalized single-hidden-layer feedforward networks (SLFNs) which need not be neural alike. This approach referred to as error minimized extreme learning machine (EM-ELM) can add random hidden nodes to SLFNs one by one or group by group (with varying group size). During the growth of the networks, the output weights are updated incrementally. The convergence of this approach is proved in this brief as well. Simulation results demonstrate and verify that our new approach is much faster than other sequential/incremental/growing algorithms with good generalization performance.


Assuntos
Inteligência Artificial , Redes Neurais de Computação , Algoritmos , Classificação/métodos , Simulação por Computador , Bases de Dados Factuais , Aprendizagem/fisiologia , Neurônios/fisiologia , Reconhecimento Automatizado de Padrão/métodos , Análise de Regressão , Transmissão Sináptica/fisiologia , Fatores de Tempo
6.
Mol Plant ; 1(2): 347-58, 2008 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-19825544

RESUMO

There is now growing evidence that membrane vesicle trafficking proteins, especially of the superfamily of SNAREs, are critical for cellular signalling in plants. Work from this laboratory first demonstrated that a soluble, inhibitory (dominant-negative) fragment of the SNARE NtSyp121 blocked K+ and Cl- channel responses to the stress-related hormone abscisic acid (ABA), but left open a question about functional impacts on signal intermediates, especially on Ca2+-mediated signalling events. Here, we report one mode of action for the SNARE mediated directly through alterations in Ca2+ channel gating and its consequent effects on cytosolic-free [Ca2+] ([Ca2+]i) elevation. We find that expressing the same inhibitory fragment of NtSyp121 blocks ABA-evoked stomatal closure, but only partially suppresses stomatal closure in the presence of the NO donor, SNAP, which promotes [Ca2+]i elevation independently of the plasma membrane Ca2+ channels. Consistent with these observations, Ca2+ channel gating at the plasma membrane is altered by the SNARE fragment in a manner effective in reducing the potential for triggering a rise in [Ca2+]i, and we show directly that its expression in vivo leads to a pronounced suppression of evoked [Ca2+]i transients. These observations offer primary evidence for the functional coupling of the SNARE with Ca2+ channels at the plant cell plasma membrane and, because [Ca2+]i plays a key role in the control of K+ and Cl- channel currents in guard cells, they underscore an important mechanism for SNARE integration with ion channel regulation during stomatal closure.


Assuntos
Ácido Abscísico/farmacologia , Cálcio/metabolismo , Ativação do Canal Iônico/fisiologia , Proteínas SNARE/fisiologia , Vicia/fisiologia , Membrana Celular/efeitos dos fármacos , Membrana Celular/fisiologia , Dexametasona/farmacologia , Ativação do Canal Iônico/efeitos dos fármacos , Fragmentos de Peptídeos/farmacologia , Plantas Geneticamente Modificadas/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/fisiologia , Nicotiana/efeitos dos fármacos , Nicotiana/fisiologia , Vicia/efeitos dos fármacos
7.
Proc Natl Acad Sci U S A ; 100(19): 11116-21, 2003 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-12949257

RESUMO

Abscisic acid (ABA) triggers a complex sequence of signaling events that lead to concerted modulation of ion channels at the plasma membrane of guard cells and solute efflux to drive stomatal closure in plant leaves. Recent work has indicated that nitric oxide (NO) and its synthesis are a prerequisite for ABA signal transduction in Arabidopsis and Vicia guard cells. Its mechanism(s) of action is not well defined in guard cells and, generally, in higher plants. Here we show directly that NO selectively regulates Ca2+-sensitive ion channels of Vicia guard cells by promoting Ca2+ release from intracellular stores to raise cytosolic-free [Ca2+]. NO-sensitive Ca2+ release was blocked by antagonists of guanylate cyclase and cyclic ADP ribose-dependent endomembrane Ca2+ channels, implying an action mediated via a cGMP-dependent cascade. NO did not recapitulate ABA-evoked control of plasma membrane Ca2+ channels and Ca2+-insensitive K+ channels, and NO scavengers failed to block the activation of these K+ channels evoked by ABA. These results place NO action firmly within one branch of the Ca2+-signaling pathways engaged by ABA and define the boundaries of parallel signaling events in the control of guard cell movements.


Assuntos
Ácido Abscísico/metabolismo , Canais de Cloreto/fisiologia , Óxido Nítrico/fisiologia , Canais de Potássio/fisiologia , Transdução de Sinais , Vicia faba/metabolismo , Cálcio/metabolismo , ADP-Ribose Cíclica/antagonistas & inibidores , Guanilato Ciclase/antagonistas & inibidores , Vicia faba/citologia
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