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1.
Opt Lett ; 49(12): 3388-3391, 2024 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-38875627

RESUMO

We demonstrate an invertible all-optical gate on chip, with the roles of control and signal switchable by slightly adjusting their relative arrival time at the gate. It is based on the quantum Zeno blockade (QZB) driven by sum-frequency generation (SFG) in a periodically poled lithium niobate microring resonator. For two nearly identical nanosecond pulses, the later arriving pulse is modulated by the earlier arriving one, resulting in 2.4 and 3.9 power extinction between the two, respectively, when their peak powers are 1 mW and 2 mW, respectively. Our results, while to be improved and enriched, herald a new, to the best of our knowledge, paradigm of logical gates and circuits for exotic applications.

2.
Opt Lett ; 49(9): 2449-2452, 2024 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-38691741

RESUMO

Broadband frequency comb generation through cascaded quadratic nonlinearity remains experimentally untapped in free-space cavities with bulk χ(2) materials mainly due to the high threshold power and restricted ability of dispersion engineering. Thin-film lithium niobate (LN) is a good platform for nonlinear optics due to the tight mode confinement in a nano-dimensional waveguide, the ease of dispersion engineering, large quadratic nonlinearities, and flexible phase matching via periodic poling. Here we demonstrate broadband frequency comb generation through dispersion engineering in a thin-film LN microresonator. Bandwidths of 150 nm (80 nm) and 25 nm (12 nm) for center wavelengths at 1560 and 780 nm are achieved, respectively, in a cavity-enhanced second-harmonic generation (doubly resonant optical parametric oscillator). Our demonstration paves the way for pure quadratic soliton generation, which is a great complement to dissipative Kerr soliton frequency combs for extended interesting nonlinear applications.

3.
J Org Chem ; 2024 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-38959135

RESUMO

A photoredox-promoted decarboxylative C-H glycosylation for the synthesis of nonclassical heteroaryl C-glycosides is reported. This methodology is characterized by an exceedingly simple reaction system, high diastereoselectivity, and good functional group tolerance. Moreover, the operational procedure is simple, and the gram-scale reaction highlights the practical applicability of this protocol.

4.
Neurol Sci ; 45(6): 2719-2728, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38150131

RESUMO

OBJECTIVES: Patients with severe stroke are at high risk of developing acute respiratory distress syndrome (ARDS), but this severe complication was often under-diagnosed and rarely explored in stroke patients. We aimed to investigate the prevalence, early predictors, and outcomes of ARDS in severe stroke. METHODS: This prospective study included consecutive patients admitted to neurological intensive care unit (neuro-ICU) with severe stroke, including acute ischemic stroke, intracerebral hemorrhage, and subarachnoid hemorrhage. The incidence of ARDS was examined, and baseline characteristics and severity scores on admission were investigated as potential early predictors for ARDS. The in-hospital mortality, length of neuro-ICU stay, the total cost in neuro-ICU, and neurological functions at 90 days were explored. RESULTS: Of 140 patients included, 35 (25.0%) developed ARDS. Over 90% of ARDS cases occurred within 1 week of admission. Procalcitonin (OR 1.310 95% CI 1.005-1.707, P = 0.046) and PaO2/FiO2 on admission (OR 0.986, 95% CI 0.979-0.993, P < 0.001) were independently associated with ARDS, and high brain natriuretic peptide (OR 0.994, 95% CI 0.989-0.998, P = 0.003) was a red flag biomarker warning that the respiratory symptoms may be caused by cardiac failure rather than ARDS. ARDS patients had longer stays and higher expenses in neuro-ICU. Among patients with ARDS, 25 (62.5%) were moderate or severe ARDS. All the patients with moderate to severe ARDS had an unfavorable outcome at 90 days. CONCLUSIONS: ARDS is common in patients with severe stroke, with most cases occurring in the first week of admission. Procalcitonin and PaO2/FiO2 on admission are early predictors of ARDS. ARDS worsens both short-term and long-term outcomes. The conflict in respiratory support strategies between ARDS and severe stroke needs to be further studied.


Assuntos
Síndrome do Desconforto Respiratório , Acidente Vascular Cerebral , Humanos , Síndrome do Desconforto Respiratório/epidemiologia , Síndrome do Desconforto Respiratório/complicações , Masculino , Feminino , Idoso , Estudos Prospectivos , Prevalência , Pessoa de Meia-Idade , Acidente Vascular Cerebral/epidemiologia , Acidente Vascular Cerebral/complicações , Unidades de Terapia Intensiva/estatística & dados numéricos , Índice de Gravidade de Doença , Mortalidade Hospitalar , Idoso de 80 Anos ou mais , Tempo de Internação/estatística & dados numéricos
5.
J Sci Food Agric ; 104(3): 1824-1832, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37884460

RESUMO

BACKGROUND: Rice taste is closely associated with endosperm composition, which varies among different rice layers. Although clarifying the relationship between this difference and nutritional taste can guide rice breeding and cultivation practices, research on this topic is limited. RESULTS: Here, typical rice varieties having excellent and poor taste characteristics were selected to analyze the distribution characteristics and differences of their components. The varieties with excellent taste exhibited lower apparent amylose content (AAC) and protein content (PC), lesser short-chain (Fa) and long-chain (Fb3 ) amylopectin (AP) and more medium-chain (Fb1+2 ) AP, higher long-to-short chain ratio (Fa:Fb3 ), and higher nitrogen (N), magnesium (Mg) and calcium (Ca) content in layer 1 (L1) than the varieties with poor taste. Layer 2 (L2) played a key role in AAC and PC regulation in the varieties with excellent taste by reducing AAC and appropriately increasing PC, consequently improving rice taste. AP structure in layer 3 (L3) substantially affected the taste of the two types of varieties. The mineral content was the highest in L1, and increased potassium (K), Ca, and Mg content improved taste in all varieties. CONCLUSION: AAC in each layer contributes to rice taste. PC and minerals primarily act on L1 and L2, whereas AP acts on L2 and L3. Therefore, the endosperm formation process should be exploited for improving rice taste. Furthermore, key resources and cultivation should be identified and regulated, respectively, to improve rice taste. © 2023 Society of Chemical Industry.


Assuntos
Oryza , Oryza/química , Paladar , Melhoramento Vegetal , Amilopectina/química , Endosperma/química , Amilose/análise , Minerais/análise , Magnésio/análise , Amido/química
6.
Epilepsia ; 64(6): 1594-1604, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-36892496

RESUMO

OBJECTIVE: This study was undertaken to characterize the blood-brain barrier (BBB) dysfunction in patients with new onset refractory status epilepticus (NORSE) using dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI). METHODS: This study included three groups of adult participants: patients with NORSE, encephalitis patients without status epilepticus (SE), and healthy subjects. These participants were retrospectively included from a prospective DCE-MRI database of neurocritically ill patients and healthy subjects. The BBB permeability (Ktrans) in the hippocampus, basal ganglia, thalamus, claustrum, periventricular white matter, and cerebellum were measured and compared between these three groups. RESULTS: A total of seven patients with NORSE, 14 encephalitis patients without SE, and nine healthy subjects were included in this study. Among seven patients with NORSE, only one had a definite etiology (autoimmune encephalitis), and the rest were cryptogenic. Etiology of encephalitis patients without SE included viral (n = 2), bacterial (n = 8), tuberculous (n = 1), cryptococcal (n = 1), and cryptic (n = 2) encephalitis. Of these 14 encephalitis patients without SE, three patients had seizures. Compared to healthy controls, NORSE patients had significantly increased Ktrans values in the hippocampus (.73 vs. .02 × 10-3 /min, p = .001) and basal ganglia (.61 vs. .003 × 10-3 /min, p = .007) and a trend in the thalamus (.24 vs. .08 × 10-3 /min, p = .017). Compared to encephalitis patients without SE, NORSE patients had significantly increased Ktrans values in the thalamus (.24 vs. .01 × 10-3 /min, p = .002) and basal ganglia (.61 vs. .004 × 10-3 /min, p = .013). SIGNIFICANCE: This exploratory study demonstrates that BBBs of NORSE patients were impaired diffusely, and BBB dysfunction in the basal ganglia and thalamus plays an important role in the pathophysiology of NORSE.


Assuntos
Encefalite , Estado Epiléptico , Adulto , Humanos , Barreira Hematoencefálica/diagnóstico por imagem , Estudos Retrospectivos , Estudos Prospectivos , Estado Epiléptico/diagnóstico por imagem , Estado Epiléptico/etiologia , Encefalite/complicações , Imageamento por Ressonância Magnética
7.
Bull Environ Contam Toxicol ; 109(5): 808-816, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36056950

RESUMO

Heavy metals pollution in pharmaceutical industries received increasing attention. A total of 94 soil samples were collected in this study. Results showed the mean contents of Hg, Cd, As, Pb, Ni and Cu were 0.21, 0.26, 9.59, 55.06, 51.52 and 50.81 mg·kg-1, respectively. The spatial distribution of metals in topsoil largely attributed to the pharmaceutical production process. The distribution of Hg and As were related to the production of medical absorbent cotton. While Ni was related to the fuel supply of Ni-rich coal. Cr, Cu and Pb mainly distributed in the process which they were used as catalysts. The vertical migration of metals was complex in soil. To a great extent, it was related to the texture of the soil and the properties of metals in this filed. The total non-cancer and cancer human health risk were within the limits of USEPA (10-6 a-1). This demonstrated the health risks of individual's exposure to heavy metals in this factory was acceptable.


Assuntos
Mercúrio , Metais Pesados , Poluentes do Solo , Humanos , Poluentes do Solo/análise , Chumbo , Monitoramento Ambiental/métodos , Medição de Risco , Metais Pesados/análise , Solo , Preparações Farmacêuticas , China
8.
Opt Lett ; 45(13): 3789-3792, 2020 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-32630955

RESUMO

Thin-film lithium-niobate-on-insulator (LNOI) has emerged as a superior integrated-photonics platform for linear, nonlinear, and electro-optics. Here we combine quasi-phase-matching, dispersion engineering, and tight mode confinement to realize nonlinear parametric processes with both high efficiency and wide wavelength tunability. On a millimeter-long, Z-cut LNOI waveguide, we demonstrate efficient (1900±500%W-1cm-2) and highly tunable (-1.71nm/K) second-harmonic generation from 1530 to 1583 nm by type-0 quasi-phase-matching. Our technique is applicable to optical harmonic generation, quantum light sources, frequency conversion, and many other photonic information processes across visible to mid-IR spectral bands.

9.
Phys Rev Lett ; 125(26): 263602, 2020 Dec 31.
Artigo em Inglês | MEDLINE | ID: mdl-33449782

RESUMO

Quantum photon sources of high rate, brightness, and purity are increasingly desirable as quantum information systems are quickly scaled up and applied to many fields. Using a periodically poled lithium niobate microresonator on chip, we demonstrate photon-pair generation at high rates of 8.5 and 36.3 MHz using only 3.4 and 13.4 µW pump power, respectively, marking orders of magnitude improvement over the state of the art, across all material platforms. These results constitute the first direct measurement of the device's giant single photon nonlinearity. The measured coincidence to accidental ratio is well above 100 at those high rates and reaches 14682±4427 at a lower pump power. The same chip enables heralded single-photon generation at tens of megahertz rates, each with low autocorrelation g_{H}^{(2)}(0)=0.008 and 0.097 for the microwatt pumps, which marks a new milestone. Such distinct performance, facilitated by the chip device's noiseless and giant optical nonlinearity, will contribute to the forthcoming pervasive adoption of quantum optical information technologies.

10.
Proc Natl Acad Sci U S A ; 114(24): 6197-6202, 2017 06 13.
Artigo em Inglês | MEDLINE | ID: mdl-28566497

RESUMO

Leveraging the most recent success in expanding the electrochemical stability window of aqueous electrolytes, in this work we create a unique Li-ion/sulfur chemistry of both high energy density and safety. We show that in the superconcentrated aqueous electrolyte, lithiation of sulfur experiences phase change from a high-order polysulfide to low-order polysulfides through solid-liquid two-phase reaction pathway, where the liquid polysulfide phase in the sulfide electrode is thermodynamically phase-separated from the superconcentrated aqueous electrolyte. The sulfur with solid-liquid two-phase exhibits a reversible capacity of 1,327 mAh/(g of S), along with fast reaction kinetics and negligible polysulfide dissolution. By coupling a sulfur anode with different Li-ion cathode materials, the aqueous Li-ion/sulfur full cell delivers record-high energy densities up to 200 Wh/(kg of total electrode mass) for >1,000 cycles at ∼100% coulombic efficiency. These performances already approach that of commercial lithium-ion batteries (LIBs) using a nonaqueous electrolyte, along with intrinsic safety not possessed by the latter. The excellent performance of this aqueous battery chemistry significantly promotes the practical possibility of aqueous LIBs in large-format applications.

11.
Zhongguo Dang Dai Er Ke Za Zhi ; 22(6): 643-650, 2020 Jun.
Artigo em Zh | MEDLINE | ID: mdl-32571466

RESUMO

OBJECTIVE: To study the association between maternal alcohol consumption and the risk of congenital heart disease (CHD) in offspring. METHODS: PubMed, Cochrane Library, Web of Science, Google Scholar, China Biology Medicine disc, Wanfang Database, CNKI Database, and Weipu Database were searched for the articles on the association between maternal alcohol consumption and congenital heart disease in offspring. These articles were published up to November 30, 2019. A random effects model or a fixed effects model was used for the pooled analysis of the results of each study, and then the pooled effective value and its 95%CI were calculated. A subgroup analysis was performed to explore heterogeneous regulators. Funnel plots and an Egger's test were used to assess publication bias. RESULTS: A total of 4 409 articles were searched, and 55 articles were finally included in this analysis, among which there were 6 cohort studies and 49 case-control studies. The Meta analysis showed heterogeneity across all studies (I2=74%, P<0.01). The random effects model showed that maternal alcohol consumption was associated with CHD in offspring, with an OR of 1.18 (95%CI: 1.09-1.28). The Egger's test showed a certain degree of publication bias (P<0.05), and after adjustment, the pooled OR of CHD in offspring was 1.10 (95%CI: 1.01-1.21). CONCLUSIONS: Maternal alcohol consumption may increase the risk of CHD in offspring.


Assuntos
Consumo de Bebidas Alcoólicas , Cardiopatias Congênitas , Estudos de Casos e Controles , China , Estudos de Coortes , Humanos , Fatores de Risco
12.
J Am Chem Soc ; 139(29): 9775-9778, 2017 07 26.
Artigo em Inglês | MEDLINE | ID: mdl-28704997

RESUMO

Rechargeable aqueous Zn/MnO2 battery chemistry in a neutral or mildly acidic electrolyte has attracted extensive attention recently because all the components (anode, cathode, and electrolyte) in a Zn/MnO2 battery are safe, abundant, and sustainable. However, the reaction mechanism of the MnO2 cathode remains a topic of discussion. Herein, we design a highly reversible aqueous Zn/MnO2 battery where the binder-free MnO2 cathode was fabricated by in situ electrodeposition of MnO2 on carbon fiber paper in mild acidic ZnSO4+MnSO4 electrolyte. Electrochemical and structural analysis identify that the MnO2 cathode experience a consequent H+ and Zn2+ insertion/extraction process with high reversibility and cycling stability. To our best knowledge, it is the first report on rechargeable aqueous batteries with a consequent ion-insertion reaction mechanism.

13.
Nano Lett ; 16(7): 4521-7, 2016 07 13.
Artigo em Inglês | MEDLINE | ID: mdl-27322663

RESUMO

All-solid-state lithium-sulfur batteries (ASSLSBs) using highly conductive sulfide-based solid electrolytes suffer from low sulfur utilization, poor cycle life, and low rate performance due to the huge volume change of the electrode and the poor electronic and ionic conductivities of S and Li2S. The most promising approach to mitigate these challenges lies in the fabrication of a sulfur nanocomposite electrode consisting of a homogeneous distribution of nanosized active material, solid electrolyte, and carbon. Here, we reported a novel bottom-up method to synthesize such a nanocomposite by dissolving Li2S as the active material, polyvinylpyrrolidone (PVP) as the carbon precursor, and Li6PS5Cl as the solid electrolyte in ethanol, followed by a coprecipitation and high-temperature carbonization process. Li2S active material and Li6PS5Cl solid electrolyte with a particle size of ∼4 nm were uniformly confined in a nanoscale carbon matrix. The homogeneous nanocomposite electrode consisting of different nanoparticles with distinct properties of lithium storage capability, mechanical reinforcement, and ionic and electronic conductivities enabled a mechanical robust and mixed conductive (ionic and electronic conductive) sulfur electrode for ASSLSB. A large reversible capacity of 830 mAh/g (71% utilization of Li2S) at 50 mA/g for 60 cycles with a high rate performance was achieved at room temperature even at a high loading of Li2S (∼3.6 mg/cm(2)). This work provides a new strategy to design a mechanically robust, mixed conductive nanocomposite electrode for high-performance all-solid-state lithium sulfur batteries.

14.
J Stroke Cerebrovasc Dis ; 26(1): e1-e4, 2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-28341077

RESUMO

OBJECTIVE: To explore Notch3 mutation sites of Chinese patients with cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL). METHODS: Direct sequencing of all exons in Notch3 gene was performed on 12 unrelated suspected CADASIL cases from mainland China. RESULT: A missense p.Arg587Cys (1759C>T) mutation in exon 11 was identified in 2 patients through genetic analysis. CONCLUSION: Chinese patients with CADASIL of R587C mutation in exon 11 was firstly reported.


Assuntos
CADASIL/genética , Mutação de Sentido Incorreto , Receptor Notch3/genética , Povo Asiático/genética , Encéfalo/diagnóstico por imagem , CADASIL/diagnóstico por imagem , China , Éxons , Família , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
15.
Angew Chem Int Ed Engl ; 56(43): 13526-13530, 2017 10 16.
Artigo em Inglês | MEDLINE | ID: mdl-28849616

RESUMO

The redox chemistry of magnesium and its application in rechargeable Mg batteries has received increasing attention owing to the unique benefits of Mg metal electrodes, namely high reversibility without dendrite formation, low reduction potentials, and high specific capacities. The Mg/S couple is of particular interest owing to its high energy density and low cost. Previous reports have confirmed the feasibility of a rechargeable Mg/S battery; however, only limited cycling stability was achieved, and the complicated procedure for the preparation of the electrolytes has significantly compromised the benefits of Mg/S chemistry and hindered the development of Mg/S batteries. Herein, we report the development of the first rechargeable Mg/S battery with a MgTFSI2 /MgCl2 /DME electrolyte (DME=1,2-dimethoxyethane, TFSI=bis(trifluoromethanesulfonyl)imide) and realize the best cycling stability among all reported Mg/S batteries by suppressing polysulfide dissolution. Mechanistic studies show that the battery works via S0 /MgSx redox processes and that the large voltage hysteresis is mainly due to the Mg anode overpotential.

16.
Angew Chem Int Ed Engl ; 55(25): 7136-41, 2016 06 13.
Artigo em Inglês | MEDLINE | ID: mdl-27120336

RESUMO

A new super-concentrated aqueous electrolyte is proposed by introducing a second lithium salt. The resultant ultra-high concentration of 28 m led to more effective formation of a protective interphase on the anode along with further suppression of water activities at both anode and cathode surfaces. The improved electrochemical stability allows the use of TiO2 as the anode material, and a 2.5 V aqueous Li-ion cell based on LiMn2 O4 and carbon-coated TiO2 delivered the unprecedented energy density of 100 Wh kg(-1) for rechargeable aqueous Li-ion cells, along with excellent cycling stability and high coulombic efficiency. It has been demonstrated that the introduction of a second salts into the "water-in-salt" electrolyte further pushed the energy densities of aqueous Li-ion cells closer to those of the state-of-the-art Li-ion batteries.

17.
J Environ Sci (China) ; 26(3): 593-600, 2014 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-25079272

RESUMO

Organochlorine pesticide (OCP) concentrations in tree bark from the upper Yellow River region were determined. Total OCP concentrations ranged from 2.7 to 82 ng/g dw, with a mean of 20 ng/g dw. Concentrations of total (Σ) DDTs (0.49-37 ng/g dw), HCHs (0.55-4.5 ng/g dw), and HCB (0.1-1.0 ng/g dw) were much higher than the other OCPs and accounted for 89% of the ΣOCP concentrations. p,p'-DDT was the dominant member of the DDT pesticide group and ß-HCH was the dominant HCH isomer. The p,p'-DDT/p,p'-DDE and α-HCH/γ-HCH ratios suggested that there were recent DDT and γ-HCH releases. OCP concentrations in the air were estimated from the tree bark, and the estimated median ΣDDTs, ΣHCHs, and HCB concentrations in the air were 0.09, 0.14, and 0.024 pg/m(3), respectively. The relationship between total OCP concentrations and socioeconomic and natural environment indices were assessed using multiple linear regression analysis, and a regression equation including all these factors was obtained. Population density and tertiary industry were the two dominant factors that appeared to affect OCP concentrations in the upper Yellow River region.


Assuntos
Poluentes Atmosféricos/análise , Hidrocarbonetos Clorados/análise , Praguicidas/análise , Casca de Planta/química , China , Meio Ambiente , Análise de Regressão , Fatores Socioeconômicos
18.
Am J Infect Control ; 52(7): 827-833, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38281685

RESUMO

BACKGROUND: Patients with neurocritically illness are an under-recognized population at high risk of sepsis. We aimed to investigate the prevalence, early predictors, and outcomes of sepsis in neuro-ICU. METHODS: Daily and accumulative incidences of sepsis in neuro-ICU were explored. Demographics, medical history, baseline disease severity scores, and baseline biomarkers regarding inflammation, immunology, organ function, and nutritional status were collected and analyzed as potential predictors of sepsis. Logistic regression analyses were used to determine the independent predictors, and a nomogram was used to estimate the individual probability of sepsis in neuro-ICU. RESULTS: 153 patients were included in this study. Fifty-nine (38.6%) patients developed sepsis, and 21 (14%) patients developed septic shock. More than 86% of the septic cases occurred within the first week. Sequential organ failure assessment score ((relative risk) RR 1.334, P = .026), history of diabetes (RR 2.346, P = .049), and transferrin (RR 0.128, P = .042) on admission are independent predictors of sepsis. Septic patients had significantly higher mortality (P = .011), higher medical cost (P = .028), and a lower rate of functional independence (P = .010), compared to patients without sepsis. CONCLUSIONS: Sepsis afflicted more than one-third of neurocritically-ill patients and occurred mostly in the first week of admission. History of diabetes, serum transferrin, and sequential organ failure assessment score on admission were early predictors. Sepsis led to significantly worse outcomes and higher medical costs.


Assuntos
Sepse , Humanos , Masculino , Sepse/epidemiologia , Sepse/mortalidade , Sepse/complicações , Feminino , Pessoa de Meia-Idade , Estudos Prospectivos , Prevalência , Idoso , Adulto , Estado Terminal , Fatores de Risco , Unidades de Terapia Intensiva , Doenças do Sistema Nervoso/epidemiologia , Doenças do Sistema Nervoso/etiologia , Prognóstico
19.
Chem Commun (Camb) ; 60(45): 5860-5863, 2024 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-38753015

RESUMO

A photoredox promoted decarboxylative C-H glycosylation has been developed for the synthesis of heteroaryl C-glycosides. This methodology is characterized by its exceedingly simple reaction system, high diastereoselectivity and good functional group tolerance. Moreover, this innovative approach circumvents the need for high temperatures, transition metals, and photocatalysts, providing an environmentally friendly, straightforward, and efficient protocol.

20.
J Surg Res ; 183(2): 894-9, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23478084

RESUMO

BACKGROUND: Dendritic cells (DCs) are the principal antigen-presenting cells involved in primary immune response and immunoregulation. The function of DCs is believed to depend on their degree of maturation. Mature DCs activate immune responses, whereas immature DCs (imDCs) tend to induce immune tolerance. CD1 is involved in regulating the development of imDCs, which have important roles in initiating or suppressing the immune response after transplantation. MATERIALS AND METHODS: We used male BALB/c mice and C57BL/6 mice (aged 8-10 wk, 18-22 g). We isolated and purified T lymphocytes from mouse spleen. Immature DCs modified by viral delivery of interleukin-10 (IL-10) were stimulated with granulocyte macrophage colony-stimulating factor and lipopolysaccharide (LPS) and treated with anti-CD1d in vitro. We used mixed lymphocyte cultures to evaluate the heterogeneity of T lymphocyte response. We also examined the proliferation of T lymphocytes and the expression of cytokines. RESULTS: CD1d blockade did not impair granulocyte macrophage colony-stimulating factor and LPS-stimulated DC maturation. We observed a dramatic increase in allogeneic T lymphocyte proliferation (stimulation index) at all tested responder-stimulator ratios in response to imDCs cultured in the presence of LPS (P < 0.05). CD1d has an important role in imDC-primed T cell response (P < 0.05). CD1d blockade reduced the capacity of imDCs to prime allogeneic T cells. T cells pre-sensitized by LPS-stimulated imDCs showed remarkably elevated proliferation in response to T cells from either BALB/c or C57BL/6 mice (P < 0.01). We observed a significant decrease in the proliferation of T cells pre-sensitized by stimulated imDCs after CD1d blockade. Lipopolysaccharide stimulation caused elevated the production of IL-12 and tumor necrosis factor-α (TNF-α) (P < 0.01) and decreased the secretion of IL-10 (P < 0.05). The addition of CD1d neutralization antibody did not significantly change the concentrations of IL-12, TNF-α, or IL-10 produced by imDCs cultured in the presence of LPS (P > 0.05). CONCLUSIONS: Blockade of CD1d impaired the ability of imDCs to stimulate allogeneic T cell response. By reduced T cell proliferation, the secretion of IL-12 and TNF-α decreased and production of a T-helper type 2 cytokine IL-10 increased, which indicates the potential of CD1d blockade as a method to induce immune tolerance to allograft antigens in transplantation.


Assuntos
Anticorpos Monoclonais/farmacologia , Antígenos CD1d/efeitos dos fármacos , Antígenos CD1d/fisiologia , Proliferação de Células/efeitos dos fármacos , Células Dendríticas/fisiologia , Linfócitos T/citologia , Animais , Anticorpos Monoclonais/imunologia , Antígenos CD1d/imunologia , Diferenciação Celular/efeitos dos fármacos , Diferenciação Celular/fisiologia , Células Cultivadas , Citocinas/metabolismo , Células Dendríticas/citologia , Células Dendríticas/efeitos dos fármacos , Fator Estimulador de Colônias de Granulócitos e Macrófagos/farmacologia , Tolerância Imunológica/efeitos dos fármacos , Tolerância Imunológica/fisiologia , Técnicas In Vitro , Lipopolissacarídeos/farmacologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Modelos Animais , Linfócitos T/efeitos dos fármacos , Transplante Homólogo
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