Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 10 de 10
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Ying Yong Sheng Tai Xue Bao ; 31(10): 3340-3348, 2020 Oct.
Artigo em Chinês | MEDLINE | ID: mdl-33314823

RESUMO

To reveal mechanisms underlying the dieback of Malus sieversii in degraded wild fruit forest in Ili valley of China, we compared the differences in stem hydraulic architecture, water transport effectiveness and safety, as well as their influencing factors among three growth classes of dead branches ratios, including Class Ⅰ (<20%), Class Ⅱ (40%-60%) and Class Ⅲ (>80%), respectively. With the increases in degradation degree of Xinjiang wild fruit forest, sapwood-specific hydraulic conductivity and leaf-specific hydraulic conductivity decreased, without significant differences among the three growth classes. Branch embolism at dusk and hydraulic safety significantly increased. The xylem water potential at 50% loss of hydraulic conductivity was -1.87, -1.35 and -0.53 MPa for Class Ⅰ, Ⅱ and Ⅲ, respectively. Predawn and midday leaf water potential and the hydraulic safety margin exhibited an order of Ⅰ>Ⅱ>Ⅲ. Xylem anatomical cha-racteristics and branch and leaf traits related to hydraulics were significantly different among the three growth classes. Results from correlation analysis revealed a weak tradeoff between xylem-specific hydraulic efficiency and xylem safety of M. sieversii. Stem hydraulic architecture of M. sieversii altered with the decline of Xinjiang wild apple forest. With increasing degrees of degradation, the severity of xylem embolisms aggravated, resistance to cavitation embolisms reduced, and the risk of water imbalance increased.


Assuntos
Malus , China , Florestas , Frutas , Folhas de Planta , Caules de Planta , Árvores , Água , Xilema
2.
Neurol Res ; 42(1): 8-16, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31878844

RESUMO

Objectives: Long noncoding RNAs (lncRNAs) play substantial roles in cerebral ischemia. Growth arrest-specific 5 (GAS5) was reported to be involved in stroke. In the present study, we aimed to investigate the roles of GAS5 in cerebral condition and unveil the underlying mechanism.Method: Transient focal ischemia was induced by intraluminal occlusion of the right Middle cerebral artery occlusion (MCAO) and 2,3,5-triphenyltetrazolium chloride (TTC) staining was used to evaluate the volume of cerebral infarction. RT-qPCR was applied to evaluate the level of GAS5 and miR-221. Fluorescence activated Cell Sorting (FACS) and Terminal deoxynucleotidyl transferased (TUNEL)  were used for detection of apoptosis. Western blotting was applied for protein level. Luciferase assay was applied to reveal the underlying relationship between GAS5 and miR-221 or p53-upregulated modulator of apoptosis (PUMA) and miR-221.Results: The results indicated that GAS5 was up-regulated in MCAO rats and in vitro hypoxia cell model while miR-221 expression was decreased in vitro hypoxia cell model. GAS5 promoted cells apoptosis, while miR-221 inhibited cell apoptosis through regulation of PUMA and downstream JNK/H2AX signaling. Moreover, GAS5 and miR-221 have direct interaction and PUMA was the target of miR-221, indicating that GAS5 regulated PUMA through sponging miR-221.Conclusions: the present study revealed that GAS5 aggravated cell apoptosis in hypoxia condition via miR-221/PUMA axis, which may provide potential targets for the treatment of stroke.


Assuntos
Proteínas Reguladoras de Apoptose/biossíntese , Apoptose/fisiologia , Isquemia Encefálica/metabolismo , MicroRNAs/metabolismo , Neurônios/metabolismo , RNA Longo não Codificante/metabolismo , Animais , Isquemia Encefálica/patologia , Hipóxia Celular/fisiologia , Células Cultivadas , Células HEK293 , Humanos , Masculino , Neurônios/patologia , Ratos , Ratos Sprague-Dawley , Regulação para Cima/fisiologia
3.
Chin J Integr Med ; 25(6): 446-453, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-26016454

RESUMO

OBJECTIVE: To investigate the hepatoprotective effect of Xijiao Dihuang Decoction (, XJDHD) on lipopolysaccharide (LPS)- and tumor necrosis factor alpha (TNF-α)-induced acute liver failure (ALF) as well as the underlying mechanism of action, and to clarify the key herbs and components of XJDHD. METHODS: LPS/D-galactosamine (D-GalN) or TNF-α/D-GalN were intraperitoneally injected into C57BL/6J mice to induce ALF. Simultaneously, XJDHD or its individual herbs and components were orally administered. Survival rates, transaminase levels in serum, and hepatic histology were examined to evaluate the effects of XJDHD. The terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) assay and real-time polymerase chain reaction were additionally performed to expound the mechanism underlying the anti-apoptotic activity of XJDHD. RESULTS: Oral administration of XJDHD protected mice from lethal liver failure induced by LPS and TNF-α, with notable amelioration of liver injury in histology and a significant decrease in transaminase levels in serum. XJDHD significantly inhibited apoptosis of hepatocytes and enhanced expression of the antiapoptosis genes, c-Flip, Iap1, Gadd45b and A20. In addition, Rehmannia glutinosa Libosch. was identified as the key herb of XJDHD and galactose as the effective component of Rehmannia glutinosa Libosch. that protects against ALF. CONCLUSIONS: XJDHD inhibits TNF-α-induced apoptosis of hepatocytes by promoting the expression of nuclear factor κ B-regulated anti-apoptotic genes. Rehmannia glutinosa Libosch. is the effective herb of XJDHD and galactose is an active component in this protection.


Assuntos
Medicamentos de Ervas Chinesas/uso terapêutico , Falência Hepática Aguda/induzido quimicamente , Falência Hepática Aguda/tratamento farmacológico , Substâncias Protetoras/uso terapêutico , Rehmannia/química , Animais , Apoptose/efeitos dos fármacos , Citocinas/biossíntese , Galactosamina , Hepatócitos/efeitos dos fármacos , Hepatócitos/patologia , Lipopolissacarídeos , Falência Hepática Aguda/patologia , Masculino , Camundongos Endogâmicos C57BL , Fator de Necrose Tumoral alfa
4.
Int J Med Robot ; 13(3)2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-27538708

RESUMO

BACKGROUND: Percutaneous cervical pedicle screw fixation has been proven to be an effective method of cervical screw instrumentation, which has the advantages of less invasiveness and low blood loss. Emerging evidence has indicated that the cervical spinous process plays an important role in percutaneous spine surgery. However, there is a limited amount of information on the fundamental research of pedicle and its associated imaging parameter measurement. The purpose of this study was to measure the anatomic data of the pedicle screw channel (PSC) using reverse engineering and three-dimensional reconstruction, and also to discuss the three-dimensional relationship between the cervical spinous process and the pedicle screw channel. METHODS: Twenty adult subjects (10 males, 10 females, age range 19-46 years) were studied using the method of three-dimensional CT reconstruction and reverse engineering. The centrum was divided into 10 equal parts from front to back. The bisectors were defined as borderline depths of the centrum, from front to back, 100%, 90%, 80%, 70%, 60%, 50%, 40%, 30%, 20%, 10%, 0% of borderline depths were presented. Then, a 3D coordinate system was constructed to measure all the data, including the radius of the inscribed circle, the length of the PSC, the insertion angle, the distances from entry point to cervical spinous process and skin depth. All the indexes were measured from 70% to 90% borderline depth. RESULTS: The radius of the inscribed circles from C3 to C7 at 90% borderline depth were 2.94 ± 0.55 mm, 3.04 ± 0.40 mm, 3.15 ± 0.36 mm, 3.28 ± 0.47 mm, 3.89 ± 0.54 mm, respectively. The lengths of the PSC were between 25 and 32 mm. The insertion angles for 70% to 90% borderline depth were 28.33°, 34.28°, 37.92°, respectively. The relationship between the PSC and spinous process was measured as the distance from the entry point to the end of the spinous process, which were, respectively, 26.91 mm, 28.18 mm, 30.03 mm, 35.67 mm, 41.99 mm from C3 to C7 .The distance from the skin to the entry point of C3-7 increased gradually. CONCLUSIONS: The measurements of this study could provide detailed information for percutaneous cervical screw fixation. The data of the relationship between the cervical spinous process and the pedicle screw channel present valuable technical information for the design, optimization and clinical application of the aiming device for percutaneous cervical pedicle screw fixation. Copyright © 2016 John Wiley & Sons, Ltd.


Assuntos
Vértebras Cervicais/diagnóstico por imagem , Vértebras Cervicais/cirurgia , Imageamento Tridimensional/métodos , Parafusos Pediculares , Adulto , Engenharia Biomédica , Feminino , Fixação Interna de Fraturas/métodos , Humanos , Interpretação de Imagem Assistida por Computador/métodos , Masculino , Pessoa de Meia-Idade , Procedimentos Cirúrgicos Minimamente Invasivos/métodos , Doenças da Coluna Vertebral/diagnóstico por imagem , Doenças da Coluna Vertebral/cirurgia , Tomografia Computadorizada por Raios X , Adulto Jovem
5.
Ann Anat ; 210: 76-83, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-27986617

RESUMO

OBJECTIVE: We investigated and compared the functionality of two 3D visualization software provided by a CT vendor and a third-party vendor, respectively. Using surgical anatomical measurement as baseline, we evaluated the accuracy of 3D visualization and verified their utility in computer-aided anatomical analysis. METHODS: The study cohort consisted of 50 adult cadavers fixed with the classical formaldehyde method. The computer-aided anatomical analysis was based on CT images (in DICOM format) acquired by helical scan with contrast enhancement, using a CT vendor provided 3D visualization workstation (Syngo) and a third-party 3D visualization software (Mimics) that was installed on a PC. Automated and semi-automated segmentations were utilized in the 3D visualization workstation and software, respectively. The functionality and efficiency of automated and semi-automated segmentation methods were compared. Using surgical anatomical measurement as a baseline, the accuracy of 3D visualization based on automated and semi-automated segmentations was quantitatively compared. RESULTS: In semi-automated segmentation, the Mimics 3D visualization software outperformed the Syngo 3D visualization workstation. No significant difference was observed in anatomical data measurement by the Syngo 3D visualization workstation and the Mimics 3D visualization software (P>0.05). CONCLUSIONS: Both the Syngo 3D visualization workstation provided by a CT vendor and the Mimics 3D visualization software by a third-party vendor possessed the needed functionality, efficiency and accuracy for computer-aided anatomical analysis.


Assuntos
Processamento de Imagem Assistida por Computador/métodos , Imageamento Tridimensional/métodos , Software , Adulto , Artérias/anatomia & histologia , Automação , Osso e Ossos/anatomia & histologia , Cadáver , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Reprodutibilidade dos Testes , Pele/anatomia & histologia , Tomografia Computadorizada por Raios X
6.
Ying Yong Sheng Tai Xue Bao ; 27(7): 2239-2248, 2016 Jul.
Artigo em Chinês | MEDLINE | ID: mdl-29737132

RESUMO

Soil samples and environmental factors in 60 plots of 20 communities in the wild fruit forest in Yili valley were investigated, and then the stoichiometric characteristics of soil organic carbon (C), total nitrogen (N), total phosphorus (P) and total potassium (K) in 0-10 cm and 10-20 cm layers and their influencing factors were studied. The results showed that soil C, N, P and K contents in 0-10 cm layer were 73.15, 7.00, 1.14 and 14.74 g·kg-1, respectively. Soil C:N, C:P, C:K, N:P, N:K and P:K were 10.37, 62.73, 5.05, 6.05, 0.48 and 0.08, respectively. Except for K and C:N, the stoichiometric values in 0-10 cm layer were significantly higher than that in 10-20 cm layer. Soil P, K, C:N and P:K presented high stability (CV=8%-24%), while others showed moderate variability (CV=28%-46%). Soil nutrient contents and their stoichiometric ratios differed markedly in different sampling sites, communities and slope aspects. Except the power relationship between C and N, all the soil nutrient contents and their stoichiometric ratios represented quadratic relationships, indicating nonlinear coupling among soil stoichiometric traits. Slope aspect, precipitation and temperature were the main factors influencing soil stoichiometry in the wild fruit forest in Yili region.


Assuntos
Florestas , Solo/química , Carbono/análise , China , Ecologia , Frutas , Nitrogênio/análise , Fósforo/análise , Potássio/análise
7.
World J Gastroenterol ; 21(27): 8373-81, 2015 Jul 21.
Artigo em Inglês | MEDLINE | ID: mdl-26217089

RESUMO

AIM: To establish a clinical scoring model to predict risk of acute-on-chronic liver failure (ACLF) in chronic hepatitis B (CHB) patients. METHODS: This was a retrospective study of 1457 patients hospitalized for CHB between October 2008 and October 2013 at the Beijing Ditan Hospital, Capital Medical University, China. The patients were divided into two groups: severe acute exacerbation (SAE) group (n = 382) and non-SAE group (n = 1075). The SAE group was classified as the high-risk group based on the higher incidence of ACLF in this group than in the non-SAE group (13.6% vs 0.4%). Two-thirds of SAE patients were randomly assigned to risk-model derivation and the other one-third to model validation. Univariate risk factors associated with the outcome were entered into a multivariate logistic regression model for screening independent risk factors. Each variable was assigned an integer value based on the regression coefficients, and the final score was the sum of these values in the derivation set. Model discrimination and calibration were assessed using area under the receiver operating characteristic curve and the Hosmer-Lemeshow test. RESULTS: The risk prediction scoring model included the following four factors: age ≥ 40 years, total bilirubin ≥ 171 µmol/L, prothrombin activity 40%-60%, and hepatitis B virus DNA > 10(7) copies/mL. The sum risk score ranged from 0 to 7; 0-3 identified patients with lower risk of ACLF, whereas 4-7 identified patients with higher risk. The Kaplan-Meier analysis showed the cumulative risk for ACLF and ACLF-related death in the two risk groups (0-3 and 4-7 scores) of the primary cohort over 56 d, and log-rank test revealed a significant difference (2.0% vs 33.8% and 0.8% vs 9.4%, respectively; both P < 0.0001). In the derivation and validation data sets, the model had good discrimination (C index = 0.857, 95% confidence interval: 0.800-0.913 and C index = 0.889, 95% confidence interval: 0.820-0.957, respectively) and calibration demonstrated by the Hosmer-Lemeshow test (χ (2) = 4.516, P = 0.808 and χ (2) = 1.959, P = 0.923, respectively). CONCLUSION: Using the scoring model, clinicians can easily identify patients (total score ≥ 4) at high risk of ACLF and ACLF-related death early during SAE.


Assuntos
Insuficiência Hepática Crônica Agudizada/virologia , Técnicas de Apoio para a Decisão , Hepatite B Crônica/complicações , Insuficiência Hepática Crônica Agudizada/sangue , Insuficiência Hepática Crônica Agudizada/diagnóstico , Insuficiência Hepática Crônica Agudizada/mortalidade , Adulto , Fatores Etários , Área Sob a Curva , Bilirrubina/sangue , Biomarcadores/sangue , Distribuição de Qui-Quadrado , China , DNA Viral/genética , Progressão da Doença , Feminino , Vírus da Hepatite B/genética , Hepatite B Crônica/sangue , Hepatite B Crônica/diagnóstico , Hepatite B Crônica/mortalidade , Hospitais Universitários , Humanos , Estimativa de Kaplan-Meier , Modelos Logísticos , Masculino , Análise Multivariada , Valor Preditivo dos Testes , Prognóstico , Protrombina/análise , Curva ROC , Reprodutibilidade dos Testes , Estudos Retrospectivos , Medição de Risco , Fatores de Risco , Carga Viral
8.
J Huazhong Univ Sci Technolog Med Sci ; 34(4): 575-581, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25135730

RESUMO

Obstructive nephropathy ultimately leads to end-stage renal failure. Renovascular lesions are involved in various nephropathies, and most renal diseases have an ischemic component that underlies the resulting renal fibrosis. The aim of this study was to investigate whether morphological changes occur in the renal vasculature in hydronephrosis and the possible mechanisms involved. A model of complete unilateral ureteral obstruction (CUUO) was used. Experimental animals were divided into five groups: a normal control group (N) and groups of animals at 1st week (O1), 2nd week (O2), 4th week (O4) and 8th week (O8) after CUUO. Blood pressure was measured, renal arterial trees and glomeruli were assessed quantitatively, and renovascular three-dimensional reconstruction was performed on all groups. Glomerular ultrastructural changes were examined by transmission electron microscopy. The results showed that the systolic blood pressure was significantly increased in the obstructed groups (O1, O2, O4 and O8). Three-dimensional reconstruction showed sparse arterial trees in the O8 group, and a tortuous and sometimes ruptured glomerular basement membrane was found in the O4 and O8 groups. Furthermore, epithelial media thickness and media/lumen ratio were increased, lumen diameters were decreased, and the cross-sectional area of the media was unaltered in the segmental renal artery, interlobar artery and afferent arterioles, respectively. In conclusion, renal arterial trees and glomeruli were dramatically altered following CUUO and the changes may be partially ascribed to vascular remodeling. Elucidation of the molecular mechanisms of renovascular morphological alterations will enable the development of potential therapeutic approaches for hydronephrosis.


Assuntos
Pressão Sanguínea , Membrana Basal Glomerular , Hidronefrose , Animais , Modelos Animais de Doenças , Membrana Basal Glomerular/irrigação sanguínea , Membrana Basal Glomerular/patologia , Membrana Basal Glomerular/fisiopatologia , Hidronefrose/patologia , Hidronefrose/fisiopatologia , Masculino , Coelhos , Artéria Renal/patologia , Artéria Renal/fisiopatologia
9.
Hum Vaccin Immunother ; 9(7): 1430-7, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23571172

RESUMO

Enterovirus 71 (EV71) is one of the major causative agents for hand, foot and mouth disease (HFMD) in childhood. Nowadays, HFMD or EV71 infections have already become an important public health issue throughout the world. Vaccination may be the most effective measure to control the transmission of the virus. Therefore, to pave EV71 vaccine into human clinical trial, in the present study a comprehensive preclinical safety assessment of inactivated EV71 vaccine including single- and repeat-dose toxicity studies were conducted in rats and cynomolgus monkeys. No abnormal findings were observed in rats following single intramuscular administration with EV71 vaccine (640 U). The results also showed no obvious systemic toxicities from four repetitive intramuscular injections, with a 14-d interval, of two dosages of EV71 vaccine in the two animal species. Antinuclear antibody response was not detected after the repeated administrations. Histopathological examination demonstrated the minimal to severe inflammatory changes in muscle tissues of the injection sites in EV71 vaccine-injected animals and most of findings have been improved over time. Furthermore, test article could induce highly EV71-specfic neutralizing antibody response in both animal species. Taken together, these data suggested a favorable safety profile for inactivated EV71 vaccine and supported this product to enter human phase I clinical trial.


Assuntos
Enterovirus Humano A/imunologia , Doença de Mão, Pé e Boca/imunologia , Doença de Mão, Pé e Boca/prevenção & controle , Vacinas Virais/efeitos adversos , Vacinas Virais/uso terapêutico , Animais , Anticorpos Antinucleares/sangue , Anticorpos Neutralizantes/sangue , Anticorpos Antivirais/sangue , Feminino , Macaca fascicularis , Masculino , Ratos , Ratos Wistar , Vacinas de Produtos Inativados/efeitos adversos , Vacinas de Produtos Inativados/imunologia , Vacinas de Produtos Inativados/uso terapêutico , Vacinas Virais/imunologia
10.
Surg Radiol Anat ; 30(5): 437-42, 2008 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-18414767

RESUMO

The aim of this study was to establish a 3D digitized model of pelvic vasculature for anatomic study, preoperative planning, and virtual reality. Three adult fresh cadavers were perfused with carboxymethyl cellulose/lead oxide mixture to mark blood vessels, and subjected to multilayer spiral computed tomography scanning to obtain a series of thin sections. Then, the 2D images of the pelvis and pelvic blood vessels were transformed into 3D digitized models using Mimics 11.0. The 2D images of carboxymethyl cellulose/lead oxide filled arteries had the features of entire outline and few constructed defects. The 3D digitized models of the pelvis and pelvic artery system displayed spatial location and the adjacent relationship of arteries with the pelvis. Not only the well-known arteries but also the tiny blood vessels in the reconstructed structures were well demonstrated and observed interactively. The reconstructed tissue flaps, including a lobulated skin flap with the pedicle of superficial epigastric artery, and an iliac flap with the pedicle of deep iliac circumflex artery, demonstrated their blood supply area. This indicated that the modified technique of vascular perfusion with carboxymethyl cellulose/lead oxide and reconstitution with Mimics 11.0 software contributed to 3D digitized model of pelvic vasculature.


Assuntos
Imageamento Tridimensional/métodos , Pelve/irrigação sanguínea , Carboximetilcelulose Sódica , Feminino , Humanos , Chumbo , Masculino , Pessoa de Meia-Idade , Modelos Anatômicos , Óxidos , Pelve/anatomia & histologia , Pelve/diagnóstico por imagem , Retalhos Cirúrgicos/irrigação sanguínea , Tomografia Computadorizada Espiral , Adulto Jovem
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...