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1.
Artigo em Inglês | MEDLINE | ID: mdl-38607712

RESUMO

Generating realistic 3D human motion has been a fundamental goal of the game/animation industry. This work presents a novel transition generation technique that can bridge the actions of people in the foreground by generating 3D poses and shapes in-between photos, allowing 3D animators/novice users to easily create/edit 3D motions. To achieve this, we propose an adaptive motion network (ADAM-Net) that effectively learns human motion from masked action sequences to generate kinematically compliant 3D poses and shapes in-between given temporally-sparse photos. Three core learning designs underpin ADAM-Net. First, we introduce a random masking process that randomly masks images from an action sequence and fills masked regions in latent space by interpolation of unmasked images to simulate various transitions under given temporally-sparse photos. Second, we propose a long-range adaptive motion (L-ADAM) attention module that leverages visual cues observed from human motion to adaptively recalibrate the range that needs attention in a sequence, along with a multi-head cross-attention. Third, we develop a short-range adaptive motion (S-ADAM) attention module that weightedly selects and integrates adjacent feature representations at different levels to strengthen temporal correlation. By coupling these designs, the results demonstrate that ADAM-Net excels not only in generating 3D poses and shapes in-between photos, but also in classic 3D human pose and shape estimation.

2.
Artigo em Chinês | WPRIM (Pacífico Ocidental) | ID: wpr-687368

RESUMO

The purpose of this study was to combine morphological, microscopic, UHPLC multiple-component assay and fingerprinting studies in order to evaluate the quality of Moutan Cortex (MC) systematically. The root system of Paeonia suffruticosa was measured to compare the morphological variation and the chemical composition of different grades of MC was discussed according to previous studies. The difference between the main microscopic features of MC powder and the xylem powder is dramatic, the MC powder contains great amount of starch granules and clusters of calcium oxalate, while the xylem powder displays considerable vessels. Interestingly, the growth rings of P. suffruticosa was first reported in the xylem of the root transection, this can help to determine the growth years of the plant. Moreover, through the assay of 16 component, MC produced in Tongling and Bozhou in Anhui province were compared, content of PGG in MC produced in Bozhou was significantly higher than MC produced in Tongling (<0.01). MC with different growth years, MC with xylem and unprocessed MC and MC decoction pieces were compared respectively by combining the results of 16 compounds assay and fingerprinting. It is proposed that the quality evaluation standard include the assay of paeoniflorin. Above all, the holistic quality difference can be evaluated more comprehensively by combining multiple analytical methods.

3.
Proc Natl Acad Sci U S A ; 104(41): 16323-8, 2007 Oct 09.
Artigo em Inglês | MEDLINE | ID: mdl-17913893

RESUMO

Exposure to low Ca(2+) and/or Mg(2+) is tolerated by cardiac myocytes, astrocytes, and neurons, but restoration to normal divalent cation levels paradoxically causes Ca(2+) overload and cell death. This phenomenon has been called the "Ca(2+) paradox" of ischemia-reperfusion. The mechanism by which a decrease in extracellular Ca(2+) and Mg(2+) is "detected" and triggers subsequent cell death is unknown. Transient periods of brain ischemia are characterized by substantial decreases in extracellular Ca(2+) and Mg(2+) that mimic the initial condition of the Ca(2+) paradox. In CA1 hippocampal neurons, lowering extracellular divalents stimulates a nonselective cation current. We show that this current resembles TRPM7 currents in several ways. Both (i) respond to transient decreases in extracellular divalents with inward currents and cell excitation, (ii) demonstrate outward rectification that depends on the presence of extracellular divalents, (iii) are inhibited by physiological concentrations of intracellular Mg(2+), (iv) are enhanced by intracellular phosphatidylinositol 4,5-bisphosphate (PIP(2)), and (v) can be inhibited by Galphaq-linked G protein-coupled receptors linked to phospholipase C beta1-induced hydrolysis of PIP(2). Furthermore, suppression of TRPM7 expression in hippocampal neurons strongly depressed the inward currents evoked by lowering extracellular divalents. Finally, we show that activation of TRPM7 channels by lowering divalents significantly contributes to cell death. Together, the results demonstrate that TRPM7 contributes to the mechanism by which hippocampal neurons "detect" reductions in extracellular divalents and provide a means by which TRPM7 contributes to neuronal death during transient brain ischemia.


Assuntos
Hipocampo/metabolismo , Neurônios/metabolismo , Canais de Cátion TRPM/metabolismo , Animais , Isquemia Encefálica/metabolismo , Isquemia Encefálica/patologia , Cátions Bivalentes/metabolismo , Morte Celular/fisiologia , Células Cultivadas , Hipocampo/citologia , Humanos , Camundongos , Interferência de RNA , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Traumatismo por Reperfusão/metabolismo , Traumatismo por Reperfusão/patologia , Canais de Cátion TRPM/antagonistas & inibidores , Canais de Cátion TRPM/genética , Transfecção
4.
J Neurochem ; 98(5): 1657-63, 2006 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-16879713

RESUMO

NMDA receptor function is modulated by both G-protein-coupled receptors and receptor tyrosine kinases. In acutely isolated rat hippocampal neurons, direct activation of the platelet-derived growth factor (PDGF) receptor or transactivation of the PDGF receptor by D4 dopamine receptors inhibits NMDA-evoked currents in a phospholipase C (PLC)-dependent manner. We have investigated further the ability of D2-class dopamine receptors to modulate NMDA-evoked currents in isolated rat prefrontal cortex (PFC). We have demonstrated that, similar to isolated hippocampal neurons, the application of PDGF-BB or quinpirole to isolated PFC neurons induces a slow-onset and long-lasting inhibition of NMDA-evoked currents. However, in contrast to hippocampal neurons, the inhibition of NMDA-evoked currents by quinpirole in PFC neurons is dependent upon D2/3, rather than D4, dopamine receptors. In PFC slices, application of both PDGF-BB and quinpirole induced a phosphorylation of the PDGF receptor at the PLCgamma binding and activation site, Tyr1021. The PDGF receptor kinase inhibitor, tyrphostin A9, and the D2/3 dopamine receptor antagonist, raclopride, inhibited quinpirole-induced Tyr1021 phosphorylation. These finding suggest that quinpirole treatment inhibits NMDAR signaling via PDGF receptor transactivation in both the hippocampus and the PFC, and that the effects of quinpirole in these regions are mediated by D4 and D2/3 dopamine receptors, respectively.


Assuntos
Agonistas de Aminoácidos Excitatórios/farmacologia , N-Metilaspartato/farmacologia , Inibição Neural/fisiologia , Neurônios/efeitos dos fármacos , Córtex Pré-Frontal/citologia , Receptores de Dopamina D2/fisiologia , Receptores do Fator de Crescimento Derivado de Plaquetas/fisiologia , Animais , Animais Recém-Nascidos , Benzamidas/farmacologia , Biotinilação/métodos , Western Blotting/métodos , Agonistas de Dopamina/farmacologia , Antagonistas de Dopamina/farmacologia , Interações Medicamentosas , Hipocampo/citologia , Técnicas In Vitro , Potenciais da Membrana/efeitos dos fármacos , Potenciais da Membrana/fisiologia , Inibição Neural/efeitos dos fármacos , Neurônios/fisiologia , Técnicas de Patch-Clamp/métodos , Piperazinas/farmacologia , Fator de Crescimento Derivado de Plaquetas/farmacologia , Quimpirol/farmacologia , Racloprida/farmacologia , Ratos , Ratos Wistar
5.
Chinese Journal of Traumatology ; (6): 293-297, 2006.
Artigo em Inglês | WPRIM (Pacífico Ocidental) | ID: wpr-280894

RESUMO

<p><b>OBJECTIVE</b>To investigate the detrimental effects of hemorrhagic shock on the structure and function of mitochondria DNA (mtDNA) encoding cytochrome oxidase genes in intestinal epithelial cells.</p><p><b>METHODS</b>Wistar rats were used and divided into two groups: hemorrhagic shock group and control group. Hemorrhagic shock model of rats was utilized in this experiment. The mtDNA was extracted from the intestinal epithelial cells and amplified by polymerase chain reaction (PCR) with different primers of cytochrome oxidase (COX I, COX II and COX III). The products of PCR were directly sequenced.</p><p><b>RESULTS</b>Hemorrhagic shock could result in the point mutagenesis in mitochondrial genome encoding cytochrome oxidase (COX I and COX II). There were 4, 4, 22, 16, 35 point mutations in COX I from 5545 to 6838 bp in 5 shocked rats. There were five point mutations in COX II from 7191 to 7542 bp at the site of t7191c, t7212c, a7386g, a7483g, c7542g in 1 shocked rat. There was no mutation found in COX III.</p><p><b>CONCLUSIONS</b>Hemorrhagic shock could significantly induce the damage of the gene of cytochrome oxidase encoded by mtDNA.</p>


Assuntos
Animais , Masculino , Ratos , Sequência de Bases , DNA Mitocondrial , Genética , Complexo IV da Cadeia de Transporte de Elétrons , Genética , Mucosa Intestinal , Mutação , Reação em Cadeia da Polimerase , Ratos Wistar , Choque Hemorrágico , Genética
6.
Cell ; 118(6): 687-98, 2004 Sep 17.
Artigo em Inglês | MEDLINE | ID: mdl-15369669

RESUMO

Ca2+ toxicity remains the central focus of ischemic brain injury. The mechanism by which toxic Ca2+ loading of cells occurs in the ischemic brain has become less clear as multiple human trials of glutamate antagonists have failed to show effective neuroprotection in stroke. Acidosis is a common feature of ischemia and is assumed to play a critical role in brain injury; however, the mechanism(s) remain ill defined. Here, we show that acidosis activates Ca2+ -permeable acid-sensing ion channels (ASICs), inducing glutamate receptor-independent, Ca2+ -dependent, neuronal injury inhibited by ASIC blockers. Cells lacking endogenous ASICs are resistant to acid injury, while transfection of Ca2+ -permeable ASIC1a establishes sensitivity. In focal ischemia, intracerebroventricular injection of ASIC1a blockers or knockout of the ASIC1a gene protects the brain from ischemic injury and does so more potently than glutamate antagonism. Thus, acidosis injures the brain via membrane receptor-based mechanisms with resultant toxicity of [Ca2+]i, disclosing new potential therapeutic targets for stroke.


Assuntos
Acidose/metabolismo , Isquemia Encefálica/metabolismo , Cálcio/metabolismo , Ácido Glutâmico/metabolismo , Proteínas de Membrana/metabolismo , Degeneração Neural/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Canais de Sódio/metabolismo , Canais Iônicos Sensíveis a Ácido , Acidose/complicações , Acidose/tratamento farmacológico , Animais , Isquemia Encefálica/tratamento farmacológico , Células COS , Cálcio/toxicidade , Bloqueadores dos Canais de Cálcio/farmacologia , Sinalização do Cálcio/efeitos dos fármacos , Sinalização do Cálcio/genética , Células Cultivadas , Modelos Animais de Doenças , Desenho de Fármacos , Antagonistas de Aminoácidos Excitatórios/farmacologia , Ácido Glutâmico/toxicidade , Masculino , Proteínas de Membrana/antagonistas & inibidores , Proteínas de Membrana/genética , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Degeneração Neural/tratamento farmacológico , Degeneração Neural/etiologia , Proteínas do Tecido Nervoso/antagonistas & inibidores , Proteínas do Tecido Nervoso/genética , Fármacos Neuroprotetores/farmacologia , Ratos , Receptores de Glutamato/efeitos dos fármacos , Receptores de Glutamato/metabolismo , Bloqueadores dos Canais de Sódio/farmacologia , Canais de Sódio/genética
7.
Cell ; 115(7): 863-77, 2003 Dec 26.
Artigo em Inglês | MEDLINE | ID: mdl-14697204

RESUMO

Excitotoxicity in brain ischemia triggers neuronal death and neurological disability, and yet these are not prevented by antiexcitotoxic therapy (AET) in humans. Here, we show that in neurons subjected to prolonged oxygen glucose deprivation (OGD), AET unmasks a dominant death mechanism perpetuated by a Ca2+-permeable nonselective cation conductance (IOGD). IOGD was activated by reactive oxygen/nitrogen species (ROS), and permitted neuronal Ca2+ overload and further ROS production despite AET. IOGD currents corresponded to those evoked in HEK-293 cells expressing the nonselective cation conductance TRPM7. In cortical neurons, blocking IOGD or suppressing TRPM7 expression blocked TRPM7 currents, anoxic 45Ca2+ uptake, ROS production, and anoxic death. TRPM7 suppression eliminated the need for AET to rescue anoxic neurons and permitted the survival of neurons previously destined to die from prolonged anoxia. Thus, excitotoxicity is a subset of a greater overall anoxic cell death mechanism, in which TRPM7 channels play a key role.


Assuntos
Hipóxia-Isquemia Encefálica/metabolismo , Ativação do Canal Iônico/fisiologia , Canais Iônicos/deficiência , Proteínas de Membrana , Degeneração Neural/metabolismo , Neurotoxinas/antagonistas & inibidores , Proteínas Quinases/deficiência , Animais , Ácido Araquidônico/metabolismo , Cálcio/metabolismo , Sinalização do Cálcio/fisiologia , Cátions/metabolismo , Morte Celular/fisiologia , Linhagem Celular , Sobrevivência Celular/fisiologia , Glucose/deficiência , Humanos , Hipóxia-Isquemia Encefálica/fisiopatologia , Ativação do Canal Iônico/efeitos dos fármacos , Canais Iônicos/antagonistas & inibidores , Canais Iônicos/genética , Ferro/metabolismo , Camundongos , Degeneração Neural/fisiopatologia , Neurotoxinas/metabolismo , Inibidores de Proteínas Quinases , Proteínas Quinases/genética , Proteínas Serina-Treonina Quinases , Interferência de RNA , RNA Interferente Pequeno , Espécies Reativas de Oxigênio/metabolismo , Canais de Cátion TRPM
8.
J Physiol ; 550(Pt 2): 385-99, 2003 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-12777448

RESUMO

The effects of extracellular pH (pHo) on calcium-sensing non-selective cation (csNSC) channels in cultured mouse hippocampal neurons were investigated using whole-cell voltage-clamp and current-clamp recordings. Decreasing extracellular Ca2+ concentrations ([Ca2+]o) activated slow and sustained inward currents through the csNSC channels. Decreasing pHo activated amiloride-sensitive transient proton-gated currents which decayed to baseline in several seconds. With proton-gated channels inactivated by pre-perfusion with low pH solution or blocked by amiloride, decreasing pHo to 6.5 inhibited the csNSC currents with a leftward shift of the Ca2+ dose-inhibition curve. Increasing pH to 8.5, on the other hand, caused a rightward shift of the Ca2+ dose-inhibition curve and potentiated the csNSC currents. Intracellular alkalinization following bath perfusion of quinine mimicked the potentiation of the csNSC currents by increasing pHo, while intracellular acidification by addition and subsequent withdrawal of NH4Cl mimicked the inhibition of the csNSC currents by decreasing pHo. Intracellular pH (pHi) imaging demonstrated that decreasing pHo induced a corresponding decrease in pHi. Including 30 mM Hepes in the pipette solution eliminated the effects of quinine and NH4Cl on the csNSC currents, but only partially reduced the effect of lowering pHo. In current-clamp recordings, decreasing [Ca2+]o induced sustained membrane depolarization and excitation of hippocampal neurons. Decreasing pHo to 6.5 inhibited the low [Ca2+]o-induced csNSC channel-mediated membrane depolarization and the excitation of neurons. Our results indicate that acidosis may inhibit low [Ca2+]o-induced neuronal excitation by inhibiting the activity of the csNSC channels. Both the extracellular and the intracellular sites are involved in the proton modulation of the csNSC channels.


Assuntos
Acidose/fisiopatologia , Cálcio/farmacologia , Hipocampo/metabolismo , Neurônios/metabolismo , Receptores de Detecção de Cálcio/antagonistas & inibidores , Amilorida/farmacologia , Animais , Células Cultivadas , Diuréticos/farmacologia , Estimulação Elétrica , Eletrofisiologia , Hipocampo/citologia , Hipocampo/efeitos dos fármacos , Concentração de Íons de Hidrogênio , Potenciais da Membrana/fisiologia , Camundongos , Neurônios/efeitos dos fármacos , Técnicas de Patch-Clamp
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