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1.
Eur Stroke J ; : 23969873241232327, 2024 Feb 19.
Artículo en Inglés | MEDLINE | ID: mdl-38372251

RESUMEN

INTRODUCTION: Aneurysmal subarachnoid hemorrhage (aSAH) and intracerebral hemorrhage (ICH) are main forms of hemorrhagic stroke. Data regarding cerebral small vessel disease (SVD) burden and incidental small lesions on diffusion-weighted imaging (DWI) following aSAH are sparse. PATIENTS AND METHODS: We retrospectively analyzed a prospective cohort of aSAH and ICH patients with brain MRI within 30 days after onset from March 2015 to January 2023. White matter hyperintensity (WMH), lacune, perivascular space, cerebral microbleed (CMB), total SVD score, and incidental DWI lesions were assessed and compared between aSAH and ICH. Clinical and radiological characteristics associated with small DWI lesions in aSAH were investigated. RESULTS: We included 180 patients with aSAH (median age [IQR] 53 [47-61] years) and 299 with ICH (63 [53-73] years). DWI lesions were more common in aSAH than ICH (47.8% vs 14.4%, p < 0.001). Higher total SVD score was associated with ICH versus aSAH irrespective of hematoma location, whereas DWI lesions and strictly lobar CMBs were correlated with aSAH. Multivariable analysis showed that shorter time from onset to MRI, anterior circulation aneurysm rupture, CMB ⩾ 5, and total SVD score were associated with DWI lesions in aSAH. DISCUSSION AND CONCLUSION: Incidental DWI lesions and strictly lobar CMBs were more frequent in aSAH versus ICH whereas ICH had higher SVD burden. Incidental DWI lesions in aSAH were associated with multiple clinical and imaging factors. Longitudinal studies to investigate the dynamic change and prognostic value of the covert hemorrhagic and ischemic lesions in aSAH seem justified.

2.
BMC Psychol ; 11(1): 77, 2023 Mar 22.
Artículo en Inglés | MEDLINE | ID: mdl-36949548

RESUMEN

BACKGROUND: The study burnout of medical students is more and more serious, which directly affects the study style of university and the learning quality of students. This has aroused the high attention of researchers and universities. This study aimed to explore the mechanism of the influence of school climate on academic burnout among medical students in Chinese cultural context. METHODS: 2411 medical students (50.52% female; mean age = 19.55, SD = 1.41, rang = 17-24 years) were investigated with psychological environment questionnaire, collective self-esteem scale, psychological capital scale and academic burnout scale. The data were analyzed by using a moderated mediation model with SPSS and the Process 4.0 macro. RESULTS: The results revealed that: (1) school climate had a significant negative predictive effect on academic burnout among medical students controlling for gender, grade and age (B = -0.40, p < 0.001). (2) Collective self-esteem played a partial mediating role in school climate and academic burnout (indirect effect = -0.28, 95% CI = [-0.32,-0.25], accounting for 52.83%). (3) The first and second half of the indirect effect of school climate on medical students' academic burnout were moderated by psychological capital (B = 0.03, p < 0.01; B = -0.09, p < 0.001).High level of psychological capital can enhance the link between school climate and collective self-esteem as well as the link between self-esteem and academic burnout. CONCLUSION: Creating a good school atmosphere and improving the level of collective self-esteem and psychological capital are beneficial to improve the academic burnout of medical students.


Asunto(s)
Agotamiento Profesional , Estudiantes de Medicina , Humanos , Femenino , Adulto Joven , Adulto , Masculino , Estudiantes de Medicina/psicología , Agotamiento Psicológico , Agotamiento Profesional/psicología , Instituciones Académicas , Aprendizaje
3.
World J Radiol ; 15(1): 10-19, 2023 Jan 28.
Artículo en Inglés | MEDLINE | ID: mdl-36721672

RESUMEN

Despite the recent progress of medical technology in the diagnosis and treatment of tumors, pancreatic carcinoma remains one of the most malignant tumors, with extremely poor prognosis partly due to the difficulty in early and accurate imaging evaluation. This paper focuses on the research progress of magnetic resonance imaging, nuclear medicine molecular imaging and radiomics in the diagnosis of pancreatic carcinoma. We also briefly described the achievements of our team in this field, to facilitate future research and explore new technologies to optimize diagnosis of pancreatic carcinoma.

4.
Front Psychol ; 13: 851912, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35719582

RESUMEN

Learning burnout is an important indicator that reflects an individual's learning state. Understanding the influencing factors and mechanism of learning burnout of medical students has practical significance for improving their mental health. This study aimed to explore the mediating roles of school identity and collective self-esteem between school psychological environment and learning burnout in medical students. A total of 2,031 medical students (942 men and 1,089 women, age range: 17-23 years) were surveyed using the School Psychological Environment Questionnaire (SPEQ), School Identity Questionnaire (SIQ), Collective Self-esteem Scale (CSES), and Learning Burnout Scale (LBS). The results showed the following: (1) school psychological environment had a negative effect on learning burnout among medical students (ß = -0.19, p < 0.001), and (2) school identity and collective self-esteem played significant mediating roles between school psychological environment and learning burnout [95% CI = (-0.43, -0.31)]. Specifically, there were three paths that school psychological environment and learning burnout: first, through the independent mediating role of school identity; second, through the independent mediating role of collective self-esteem; and third, through the chain mediating roles of school identity and collective self-esteem. The findings reveal that school psychological environment not only directly influences the learning burnout of medical students but also indirectly influences it through school identity and collective self-esteem. Thus, this study has some important implications for prevention and intervention of learning burnout among medical students.

5.
Front Aging Neurosci ; 14: 880897, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35493922

RESUMEN

Conventional transcranial electrical stimulation (tES) is a non-invasive method to modulate brain activity and has been extensively used in the treatment of Parkinson's disease (PD). Despite promising prospects, the efficacy of conventional tES in PD treatment is highly variable across different studies. Therefore, many have tried to optimize tES for an improved therapeutic efficacy by developing novel tES intervention strategies. Until now, these novel clinical interventions have not been discussed or reviewed in the context of PD therapy. In this review, we focused on the efficacy of these novel strategies in PD mitigation, classified them into three categories based on their distinct technical approach to circumvent conventional tES problems. The first category has novel stimulation modes to target different modulating mechanisms, expanding the rang of stimulation choices hence enabling the ability to modulate complex brain circuit or functional networks. The second category applies tES as a supplementary intervention for PD hence amplifies neurological or behavioral improvements. Lastly, the closed loop tES stimulation can provide self-adaptive individualized stimulation, which enables a more specialized intervention. In summary, these novel tES have validated potential in both alleviating PD symptoms and improving understanding of the pathophysiological mechanisms of PD. However, to assure wide clinical used of tES therapy for PD patients, further large-scale trials are required.

6.
Front Med (Lausanne) ; 9: 819670, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35402463

RESUMEN

Background: Due to the high recurrence rate in hepatocellular carcinoma (HCC) after resection, preoperative prognostic prediction of HCC is important for appropriate patient management. Exploring and developing preoperative diagnostic methods has great clinical value in treating patients with HCC. This study sought to develop and evaluate a novel combined clinical predictive model based on standard triphasic computed tomography (CT) to discriminate microvascular invasion (MVI) in hepatocellular carcinoma (HCC). Methods: The preoperative findings of 82 patients with HCC, including conventional clinical factors, CT imaging findings, and CT texture analysis (TA), were analyzed retrospectively. All included cases were divided into MVI-negative (n = 33; no MVI) and MVI-positive (n = 49; low or high risk of MVI) groups. TA parameters were extracted from non-enhanced, arterial, portal venous, and equilibrium phase images and subsequently calculated using the Artificial Intelligence Kit. After statistical analyses, a clinical model comprising conventional clinical and CT image risk factors, radiomics signature models, and a novel combined model (fused radiomic signature) was constructed. The area under the curve (AUC) of the receiver operating characteristics (ROC) curve was used to assess the performance of the various models in discriminating MVI. Results: We found that tumor diameter and pathological grade were effective clinical predictors in clinical model and 12 radiomics features were effective for MVI prediction of each CT phase. The AUCs of the clinical, plain, artery, venous, and delay models were 0.77 (95% CI: 0.67-0.88), 0.75 (95% CI: 0.64-0.87), 0.79 (95% CI: 0.69-0.89), 0.73 (95% CI: 0.61-0.85), and 0.80 (95% CI: 0.70-0.91), respectively. The novel combined model exhibited the best performance, with an AUC of 0.83 (95% CI: 0.74-0.93). Conclusions: Models derived from triphasic CT can preoperatively predict MVI in patients with HCC. Of the models tested here, the novel combined model was most predictive and could become a useful tool to guide subsequent personalized treatment of HCC.

7.
Molecules ; 26(13)2021 Jun 26.
Artículo en Inglés | MEDLINE | ID: mdl-34206871

RESUMEN

Hepatocellular carcinoma (HCC) is the fifth most common cancer worldwide. Studies have shown that bradykinin (BK) is highly expressed in liver cancer. We designed the novel BK receptor inhibitors J051-71 and J051-105, which reduced the viability of liver cancer cells and inhibited the formation of cancer cell colonies. J051-71 and J051-105 reduced cell proliferation and induced apoptosis in HepG2 and BEL-7402 cells, which may be due to the inhibition of the extracellular regulated protein kinase (ERK) signaling pathway. In addition, these BK receptor inhibitors reversed the cell proliferation induced by BK in HepG2 and BEL-7402 cells by downregulating B1 receptor expression. Inhibiting B1 receptor expression decreased the protein levels of p-ERK and reduced the malignant progression of HCC, providing a potential target for HCC therapy.


Asunto(s)
Antineoplásicos/farmacología , Apoptosis/efectos de los fármacos , Antagonistas de los Receptores de Bradiquinina/farmacología , Carcinoma Hepatocelular/metabolismo , Proliferación Celular/efectos de los fármacos , Neoplasias Hepáticas/metabolismo , Antagonistas de los Receptores de Bradiquinina/síntesis química , Antagonistas de los Receptores de Bradiquinina/química , Carcinoma Hepatocelular/tratamiento farmacológico , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Quinasas MAP Reguladas por Señal Extracelular/metabolismo , Humanos , Concentración 50 Inhibidora , Neoplasias Hepáticas/tratamiento farmacológico , Sistema de Señalización de MAP Quinasas/efectos de los fármacos
8.
Eur Neurol ; 84(5): 361-367, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34315157

RESUMEN

INTRODUCTION: This study aims to analyze the permeability of intra- and peri-meningiomas regions and compare the microvascular permeability between peritumoral brain edema (PTBE) and non-PTBE using DCE-MRI. METHODS: This was a retrospective of patients with meningioma who underwent surgery. The patients were grouped as PTBE and non-PTBE. The DCE-MRI quantitative parameters, including volume transfer constant (Ktrans), rate constant (Kep), extracellular volume (Ve), and mean plasma volume (Vp), obtained using the extended Tofts-Kety 2-compartment model. Logistic regression analysis was conducted to explore the risk factor of PTBE. RESULTS: Sixty-three patients, diagnosed as fibrous meningioma, were included in this study. They were 17 males and 46 females, aged from 32 to 88 years old. Kep and Vp were significantly lower in patients with PTBE compared with those without (Kep: 0.1852 ± 0.0369 vs. 0.5087 ± 0.1590, p = 0.010; Vp: 0.0090 ± 0.0020 vs. 0.0521 ± 0.0262, p = 0.007), while there were no differences regarding Ktrans and Ve (both p > 0.05). The multivariable analysis showed that tumor size ≥10 cm3 (OR = 4.457, 95% CI: 1.322-15.031, p = 0.016) and Vp (OR = 0.572, 95%CI: 0.333-0.981, p = 0.044) were independently associated with PTBE in patients with meningiomas. CONCLUSION: DCE-magnetic resonance imaging·Meningioma·Blood vessel MRI can be used to quantify the microvascular permeability of PTBE in patients with meningioma.


Asunto(s)
Edema Encefálico , Neoplasias Meníngeas , Meningioma , Adulto , Anciano , Anciano de 80 o más Años , Edema Encefálico/diagnóstico por imagen , Edema Encefálico/etiología , Permeabilidad Capilar , Medios de Contraste , Femenino , Humanos , Imagen por Resonancia Magnética , Masculino , Neoplasias Meníngeas/diagnóstico por imagen , Meningioma/diagnóstico por imagen , Persona de Mediana Edad , Estudios Retrospectivos
9.
Transl Lung Cancer Res ; 10(3): 1501-1511, 2021 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-33889525

RESUMEN

BACKGROUND: Circulating cell-free DNA (cfDNA) detection for non-invasive diagnosis requires higher sensitivity and accuracy due to the low circulating tumor DNA (ctDNA) content. Many methods have been developed to improve detection of ctDNA, including ultra-deep sequencing or enrichment of shorter cfDNA fragments, such as those in the range of 90-150 bp. METHODS: Here, we developed a method for single-stranded DNA (ssDNA) library preparation with a large proportion of magnetic beads to enrich the shorter cfDNA fragments. We aimed to determine if this could increase the ctDNA content and thus improve the sensitivity of ctDNA detection by testing the method in blood samples from patients with advanced cancers (non-small cell lung cancers, esophageal squamous cell carcinoma, cholangiocarcinoma, colorectal cancer and liver cancer). RESULTS: This method was able to obtain shorter cfDNA both in commercial cfDNA references and real world clinical cfDNA samples. Plasmid simulation experiments showed that using a large proportion of magnetic beads to construct the library could obtain more ctDNA derived from shorter-fragment plasmids, which could significantly improve the detection of ctDNA especially in the low-variant allele frequency sample. In real-world clinical samples, this method may be able to increase the opportunity to obtain alteration reads from short fragments, which was important to low frequency detection. CONCLUSIONS: The ssDNA library preparation with large proportion of magnetic beads could increase the opportunity to obtain alteration reads from short fragments, which is crucial for low variant allele frequency detection.

10.
World J Clin Cases ; 8(18): 4272-4279, 2020 Sep 26.
Artículo en Inglés | MEDLINE | ID: mdl-33024789

RESUMEN

BACKGROUND: Lymphoplasmacyte-rich meningioma (LPRM) is one of the rarest variants of meningioma and is classified as grade I (benign) tumor. It is characterized by abundant infiltrates of lymphocytes and plasma cells. Here, we report an extremely rare case of LPRM with an atypical imaging finding of multiple cysts around a solid mass. CASE SUMMARY: The patient was a 36-year-old man with intermittent headache, dizziness, and vomiting for 2 years. Computed tomography and magnetic resonance imaging presented a cystic solid mass in the right frontal lobe with heavy peritumoral edema and obvious contrast enhancement. The patient was treated with right frontotemporal craniotomy, and gross total resection of the tumor was achieved without adjuvant therapy. There was no clinical or neuroradiological evidence of recurrent or residual tumor for 3 years after initial surgery. CONCLUSION: LPRM is one of the rarest variants of meningioma. Although, the mass of this case had common features, multiple cysts with nonuniform size and thin wall around the solid part are uncommon imaging finding, increasing the rate of misdiagnosis. The definitive diagnosis of LPRM relies on histopathological findings.

11.
Environ Pollut ; 265(Pt B): 114970, 2020 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-32806447

RESUMEN

A better understanding of the sources of organophosphate esters (OPEs) is a prerequisite for OPE control and the establishment of related environmental policies. Sources of OPEs in 35 major inflow rivers to the Bohai Sea of China were quantitatively analyzed using three effective receptor models (principal component analysis-multiple linear regression (PCA-MLR), positive matrix factorization (PMF), and Unmix) in this paper. The similarities and differences in results from PCA-MLR, PMF, and Unmix were discussed in depth. All three models well predicted the spatial variability of the total concentrations of nine OPEs (triethyl phosphate, tri-n-butyl phosphate, triisobutyl phosphate, tri (2-ethylhexyl) phosphate, tri (2-chloroethyl) phosphate, tris(1-chloro-2-propyl) phosphate, tris(1,3-dichloro-2-propyl) phosphate, triphenyl phosphate, and triphenylphosphine oxide) (∑9OPEs) (r2 = 0.90-0.96, p = 0.000) and explained 98.4%-101.2% of the observed ∑9OPEs. The predicted ∑9OPEs values from each pairwise model were significantly correlated (r2 = 0.88-0.91, p = 0.000). Three OPE sources were extracted by all three models: rigid and flexible polyurethane foam/coating, cellulosic/acrylic/vinyl polymer/unsaturated polyester, and polyvinyl chloride, contributing 49.9%, 29.7%, and 20.5% by PCA-MLR, 57.9%, 28.6%, and 13.5% by PMF, and 47.9%, 30.8%, and 22.4% by Unmix to the ∑9OPEs, respectively. PMF was recommended as the preferred receptor model for analyzing OPE sources in water during the monitoring period because of its optimal performance.


Asunto(s)
Retardadores de Llama/análisis , Ríos , China , Monitoreo del Ambiente , Ésteres , Organofosfatos
12.
Sci Total Environ ; 656: 1199-1206, 2019 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-30625651

RESUMEN

The concentrations and congener-specific profiles of polybrominated diphenyl ethers (PBDEs) were investigated in the atmosphere, soil and moss samples were collected from Ny-Ålesund, Svalbard in the Arctic and King Georgia Island (KGI), Fildes Peninsula in Antarctica, respectively. The congener profiles of PBDEs were symmetrical between gas and moss, as well as between particles and soil at Ny-Ålesund and KGI, respectively, similar to a "mirror image". The proportions of highly brominated congeners (for example, BDE-99, -153 and -183) in the particle phase and soil were higher than those in the gas phase and moss, while tri- and tetra-BDEs possessed higher proportions in the gas phase and moss at both sites. The slopes of log-log linear correlations between the gas-particle partition coefficient (Kp) and sub-cooled liquid vapor pressures (p°L) of PBDEs were observed at both sites compared with the values in the urban areas. Moreover, the slopes of logKp vs. logp°L (-0.51 at Ny-Ålesund and - 0.29 at KGI) were notably close to the slopes of log-log linear correlations between the dimensionless soil-moss quotient (QSM) and p°L (-0.42 at Ny-Ålesund and -0.22 at KGI). Significant correlations between particle fraction (φparticle) and soil fraction (φsoil) at both sites indicated that the gas-particle partitioning of PBDEs is directly related to their distribution in moss and soil.

13.
Plant Cell ; 29(9): 2269-2284, 2017 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-28842534

RESUMEN

Plants have evolved an array of adaptive responses to low Pi availability, a process modulated by various external stimuli and endogenous growth regulatory signals. Little is known about how these signaling processes interact to produce an integrated response. Arabidopsis thaliana PHOSPHATE STARVATION RESPONSE1 (PHR1) encodes a conserved MYB-type transcription factor that is essential for programming Pi starvation-induced gene expression and downstream Pi starvation responses (PSRs). Here, we show that loss-of-function mutations in FHY3 and FAR1, encoding two positive regulators of phytochrome signaling, and in EIN3, encoding a master regulator of ethylene responses, cause attenuated PHR1 expression, whereas mutation in HY5, encoding another positive regulator of light signaling, causes increased PHR1 expression. FHY3, FAR1, HY5, and EIN3 directly bind to the PHR1 promoter through distinct cis-elements. FHY3, FAR1, and EIN3 activate, while HY5 represses, PHR1 expression. FHY3 directly interacts with EIN3, and HY5 suppresses the transcriptional activation activity of FHY3 and EIN3 on PHR1 Finally, both light and ethylene promote FHY3 protein accumulation, and ethylene blocks the light-promoted stabilization of HY5. Our results suggest that light and ethylene coordinately regulate PHR1 expression and PSRs through signaling convergence at the PHR1 promoter.


Asunto(s)
Proteínas de Arabidopsis/genética , Arabidopsis/genética , Arabidopsis/efectos de la radiación , Etilenos/farmacología , Regulación de la Expresión Génica de las Plantas , Luz , Fosfatos/deficiencia , Factores de Transcripción/genética , Arabidopsis/efectos de los fármacos , Proteínas de Arabidopsis/metabolismo , Secuencia de Bases , Regulación de la Expresión Génica de las Plantas/efectos de los fármacos , Regulación de la Expresión Génica de las Plantas/efectos de la radiación , Modelos Biológicos , Regiones Promotoras Genéticas , Unión Proteica/efectos de los fármacos , Unión Proteica/efectos de la radiación , Estabilidad Proteica/efectos de los fármacos , Estabilidad Proteica/efectos de la radiación , Factores de Transcripción/metabolismo
14.
Tumour Biol ; 37(11): 15097-15105, 2016 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-27662838

RESUMEN

Tumor-derived autophagome (DRibble) is an effective therapeutic cancer vaccine inducing T cell recognition and death of tumor cells in mice. However, the potential for improved anti-tumor response still remains. Our previous study demonstrated that two repeats of a mycobacterial HSP70407-426 (M2) peptide acted as adjuvant in improving anti-tumor efficacy of human umbilical vein endothelial cell (HUVEC) vaccine. Here, a DRibble vaccine conjugated with M2 (DRibble-M2) was designed as a novel vaccine to enhance anti-tumor activity. Compared with DRibble alone, DRibble-M2 vaccination more significantly inhibited the growth of mouse Lewis lung cancer both in a subcutaneous tumor model and in a lung metastasis model. Higher expression of antigen-specific CTL was induced by DRibble-M2. DRibble-M2 induced higher CD83 and CD86 expression in DC2.4 and also improved the internalization of DRibble antigen into DC2.4. Our data indicated that DRibble-M2 is a potential vaccine for clinical cancer therapy.


Asunto(s)
Autofagosomas/inmunología , Vacunas contra el Cáncer/inmunología , Carcinoma Pulmonar de Lewis/terapia , Epítopos/inmunología , Proteínas HSP70 de Choque Térmico/inmunología , Inmunoterapia Activa , Fragmentos de Péptidos/inmunología , Adyuvantes Inmunológicos , Animales , Apoptosis , Vacunas contra el Cáncer/administración & dosificación , Carcinoma Pulmonar de Lewis/inmunología , Carcinoma Pulmonar de Lewis/patología , Proliferación Celular , Células Cultivadas , Células Dendríticas/inmunología , Citometría de Flujo , Células Endoteliales de la Vena Umbilical Humana/inmunología , Humanos , Inmunoterapia Adoptiva , Masculino , Ratones , Ratones Endogámicos C57BL , Linfocitos T Citotóxicos/inmunología
15.
J Environ Sci (China) ; 43: 250-256, 2016 May.
Artículo en Inglés | MEDLINE | ID: mdl-27155431

RESUMEN

Concentrations of 16 polybrominated diphenyl ether (PBDE) congeners were measured in river sediments, paddy soils and three species of paddy-field organisms (crab, loach and carp) collected from the Liaohe River Basin, northeastern China. The total contents of PBDEs (∑16PBDEs) in sediments and paddy soils were in the ranges of 273.4-3246.3pg/g dry weight (dw), and 192.1-1783.8pg/gdw, respectively. BDE 209 was the dominant congener both in sediments and paddy soils. The concentrations of ∑16PBDEs in sediments were significantly higher than those in the adjacent paddy soils, indicating a potential transport of PBDEs from river to paddy ecosystems via river water irrigation. The biota-soil accumulation factor (BSAF) was calculated as the ratio between the lipid-normalized concentration in paddy-field organisms and the total organic carbon-normalized concentration in paddy soil. The average BSAF values of ∑15PBDEs followed the sequence of crab (3.6)>loach (3.3)>carp (2.1). BDE 154 had the highest BSAF value, and a parabolic trend between BSAF values of individual PBDE congeners and their logKOW values was observed. In view of the fact that crab had the larger BSAF value and higher lipid content, the ecological risk and health risk for crab cultivation in paddy fields should be of particular concern.


Asunto(s)
Ecosistema , Monitoreo del Ambiente , Éteres Difenilos Halogenados/análisis , Contaminantes Químicos del Agua/análisis , China , Sedimentos Geológicos , Oryza , Ríos
16.
J Nanosci Nanotechnol ; 15(4): 2619-27, 2015 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-26353473

RESUMEN

Gene transfer mediated by mannosylated chitosan (MCS) is a safe and promising approach for gene and vaccine delivery. MCS nanoparticles based gene delivery system showed high in vivo delivery efficiency and elicited strong immune responses in mice. However, little knowledge about the cell binding, transfection efficiency and intracellular trafficking of MCS nanoparticles had been acquired. In this study, using gastrin-releasing peptide as a model plasmid (pGRP), the binding of MCS/pGRP nanoparticles to macrophages and the intracellular trafficking of MCS/pGRP nanoparticles in macrophages were investigated. MCS-mediated transfection efficiency in macrophages was also evaluated using pGL-3 as a reporter gene. The results showed that the binding and transfection efficiency of MCS nanoparticles in macrophages was higher than that of CS, which was attributed to the interaction between mannose ligands in MCS and mannose receptors on the surface of macrophages. Observation with a confocal laser scanning microscope indicated the cellular uptake of MCS/pGRP nanoparticles were more than that of CS/pGRP nanoparticles in macrophages. MCS/pGRP nanoparticles were taken up by macrophages and most of them were entrapped in endosomal/lysosomal compartments. After the nanoparticles escaping from endosomal/lysosomal compartments, naked pGRP entered the nucleus, and a few MCS might enter the nucleus in terms of nanoparticles. Overall, MCS has the potential to be an excellent macrophage-targeting gene delivery carrier.


Asunto(s)
Quitosano/química , Técnicas de Transferencia de Gen , Manosa/química , Nanopartículas/química , Transfección/métodos , Animales , Línea Celular , Péptido Liberador de Gastrina/genética , Péptido Liberador de Gastrina/metabolismo , Humanos , Espacio Intracelular/metabolismo , Luciferasas/genética , Luciferasas/metabolismo , Macrófagos , Ratones , Plásmidos/genética
17.
Nanoscale Res Lett ; 9(1): 408, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-25232292

RESUMEN

Thermal transport properties of graphene with nanosized constrictions are investigated using nonequilibrium molecular dynamics simulations. The results show that the nanosized constrictions have a significant influence on the thermal transport properties of graphene. The thermal resistance of the nanosized constrictions is on the order of 10(7) to 10(9) K/W at 150 K, which reduces the thermal conductivity by 7.7% to 90.4%. It is also found that the constriction resistance is inversely proportional to the width of the constriction and independent of the heat current. Moreover, we developed an analytical model for the ballistic thermal resistance of the nanosized constrictions in two-dimensional nanosystems. The theoretical prediction agrees well with the simulation results in this paper, which suggests that the thermal transport across the nanosized constrictions in two-dimensional nanosystems is ballistic in nature. PACS: 65.80.CK; 61.48.Gh; 63.20.kp; 31.15.xv.

18.
Tumour Biol ; 34(5): 3173-82, 2013 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-23771850

RESUMEN

Angiogenesis inhibitors combined with other anticancer drugs have been shown to inhibit tumor growth in animal models and some of them were recently used in clinical trials. In the present study, a whole hepatocellular carcinoma cell lysate based vaccine with diphtheria toxin (DT) and two tandem repeats of microbial HSP70 peptide epitope 407-426 (2 mHSP70407-426, M2) as adjuvant, which was called HDM, was combined with a whole human umbilical vein endothelial cell (HUVEC) vaccine to develop a combination treatment regimen. This combination treatment regimen was named HUVEC-HDM, which was supposed to enhance its antitumor efficiency. HUVEC-HDM was administrated subcutaneously in both prophylactic and therapeutic procedures. Compared to either single vaccine, HUVEC-HDM induced a more significant inhibition on the growth and metastasis of H22 hepatocellular carcinoma in mice and prolonged the survival of tumor-bearing mice. Besides, HUVEC-HDM immunization elicited strong humoral and cellular immune responses targeting tumor cell as well as tumor angiogenesis, which could be responsible for the enhanced antitumor effect. Moreover, histochemistry analysis showed that HUVEC-HDM induced large areas of continuous necrosis within tumors, correlating well with the extent of tumor inhibition. These results not only highlight the superiority of the combined HUVEC-HDM treatment regimen, but also support the translation of such approaches into the clinic for the treatment of patients with hepatocellular carcinoma.


Asunto(s)
Vacunas contra el Cáncer , Carcinoma Hepatocelular/terapia , Células Endoteliales de la Vena Umbilical Humana/trasplante , Neoplasias Hepáticas Experimentales/terapia , Neoplasias Pulmonares/terapia , Animales , Anticuerpos Antineoplásicos/sangre , Carcinoma Hepatocelular/irrigación sanguínea , Carcinoma Hepatocelular/patología , Extractos Celulares/inmunología , Línea Celular Tumoral , Proliferación Celular , Citotoxicidad Inmunológica , Células Endoteliales de la Vena Umbilical Humana/inmunología , Células Endoteliales de la Vena Umbilical Humana/metabolismo , Humanos , Inmunidad Celular , Inmunidad Humoral , Neoplasias Hepáticas Experimentales/irrigación sanguínea , Neoplasias Hepáticas Experimentales/patología , Neoplasias Pulmonares/irrigación sanguínea , Neoplasias Pulmonares/secundario , Masculino , Ratones , Ratones Endogámicos BALB C , Ratones Desnudos , Trasplante de Neoplasias , Neovascularización Patológica/prevención & control , Linfocitos T Citotóxicos/fisiología
19.
Mol Pharm ; 10(8): 2904-14, 2013 Aug 05.
Artículo en Inglés | MEDLINE | ID: mdl-23768205

RESUMEN

Chitosan (CS) has been extensively used as a protein drug and gene delivery carrier, but its delivery efficiency is unsatisfactory. In this study, a mannose ligand was used to modify CS, which could enhance the delivery efficiency of CS via mannose receptor-mediated endocytosis. A preventative anti-GRP DNA vaccine (pCR3.1-VS-HSP65-TP-GRP6-M2, pGRP) was condensed with mannosylated chitosan (MCS) to form MCS/pGRP nanoparticles. Nanoparticles were intranasally administered in a subcutaneous mice prostate carcinoma model to evaluate the efficacy on inhibition of the growth of tumor cells. The titers of anti-GRP IgG that lasted for 11 weeks were significantly higher than that for administration of CS/pGRP nanoparticles (p < 0.01) and intramuscular administration of a pGRP solution (p < 0.05) to mice. In addition, immunization with MCS/pGRP nanoparticles could suppress the growth of tumor cells. The average tumor weight (0.79 ± 0.30 g) was significantly lower than that in the CS/pGRP nanoparticle group (1.69 ± 0.15 g) (p < 0.01) or that in the pGRP group (1.12 ± 0.37 g) (p < 0.05). Cell binding and cellular uptake results indicated that MCS/pGRP nanoparticles bound with C-type lectin receptors on macrophages. MCS was an efficient targeting gene delivery carrier and could be used in antitumor immunotherapy.


Asunto(s)
Quitosano/química , Manosa/química , Nanopartículas/química , Vacunas/administración & dosificación , Administración Intranasal , Animales , Western Blotting , Línea Celular , Ensayo de Inmunoadsorción Enzimática , Inmunoterapia , Masculino , Ratones , Ratones Endogámicos C57BL , Nanopartículas/administración & dosificación , Mucosa Nasal/metabolismo , Neoplasias de la Próstata/inmunología , Neoplasias de la Próstata/terapia , Vacunas/química , Vacunas/uso terapéutico
20.
Tumour Biol ; 34(3): 1399-408, 2013 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-23456765

RESUMEN

Vaccination with xenogeneic or syngeneic endothelial cells targeting tumor angiogenesis is effective for inhibiting tumor growth. OK432, an effective adjuvant, was mixed with viable human umbilical vein endothelial cells (HUVECs) to prepare a novel HUVECs-OK432 vaccine, which could have an improved therapeutic efficacy. In this study, HUVECs-OK432 was administrated in mice by subcutaneous injection in a therapeutic procedure. The results showed that a stronger HUVEC-specific Abs and cytotoxic T lymphocyte immune response were elicited, which resulted in significant inhibition on the growth of B16F10 melanoma and remarkably prolonged survival of B16F10 melanoma-bearing mice compared with HUVECs. Besides, parallel results were obtained in vitro showing a stronger inhibition of HUVEC proliferation by immune sera of HUVECs-OK432 than that of HUVECs. Moreover, histochemistry and immunohistochemistry analysis showed that HUVECs-OK432 induced large areas of continuous necrosis within tumors and significantly reduced the vessel density, correlating well with the extent of tumor inhibition. Our present results suggest that OK432 could be employed as an effective adjuvant for HUVEC vaccines and therefore should be useful for adjuvant immunotherapy of cancer.


Asunto(s)
Adyuvantes Inmunológicos/uso terapéutico , Vacunas contra el Cáncer/uso terapéutico , Células Endoteliales de la Vena Umbilical Humana/inmunología , Melanoma Experimental/terapia , Picibanil/uso terapéutico , Linfocitos T Citotóxicos/inmunología , Animales , Ensayo de Inmunoadsorción Enzimática , Humanos , Linfocitos/citología , Linfocitos/inmunología , Masculino , Melanoma Experimental/inmunología , Melanoma Experimental/mortalidad , Ratones , Ratones Endogámicos C57BL , Tasa de Supervivencia , Células Tumorales Cultivadas , Vacunación
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