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1.
Eur Radiol ; 33(11): 8046-8054, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37256350

RESUMO

OBJECTIVES: To evaluate the use of diffusion tensor imaging (DTI) and diffusion kurtosis imaging (DKI) for detection of microstructural changes in the trigeminal nerves of trigeminal neuralgia (TN) patients. METHODS: Forty TN patients and 40 healthy controls were examined using 3 T magnetic resonance imaging (MRI) to evaluate DTI and DKI parameters in trigeminal nerves. One-way ANOVA was used to test the differences in age, sex, and DTI and DKI parameters between the TN-affected sides, TN-unaffected sides, and controls. For parameters with inter-group differences, pairwise comparisons were performed. Then, the difference ratios (DRs) of the parameters with statistical differences were calculated and used for the receiver operating characteristic (ROC) analysis to assess their diagnostic performance. In addition, for the DTI and DKI parameter values with differences, we used pure DTI and DKI values to perform the ROC analysis. RESULTS: Compared to the unaffected sides and controls, the FA, MK, and Kr of the affected sides of TN patients were significantly reduced, while ADC was significantly increased (p < 0.05). The diagnostic efficiency of the FA DRs (AUC: 0.974; cutoff value: 0.038; sensitivity: 100%; specificity: 95.0%) was the highest among all DTI and DKI parameters. The DRs of FA and MK more efficiently diagnosed TN than pure FA and MK values. CONCLUSIONS: DTI and DKI allowed detection of microstructural changes in TN-affected trigeminal nerves. FA DR was the best independent predictor of microstructural changes in TN. CLINICAL RELEVANCE STATEMENT: Both DTI and DKI can be used for noninvasive quantitative evaluation of the changes in the microstructure of the cisternal segment of the cranial nerves in clinical practice. KEY POINTS: • Diffusion tensor imaging (DTI) can be used to evaluate the in vivo integrity of white matter and nerve fiber pathway. • Diffusion kurtosis imaging (DKI) has been shown to be considerable sensitive to microstructural changes. • DTI combined with DKI can comprehensively evaluate the status of the TN-affected trigeminal nerve.


Assuntos
Neuralgia do Trigêmeo , Substância Branca , Humanos , Neuralgia do Trigêmeo/diagnóstico por imagem , Imagem de Tensor de Difusão/métodos , Nervo Trigêmeo/diagnóstico por imagem , Imageamento por Ressonância Magnética
2.
Sensors (Basel) ; 23(12)2023 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-37420580

RESUMO

Graph convolutional networks are widely used in skeleton-based action recognition because of their good fitting ability to non-Euclidean data. While conventional multi-scale temporal convolution uses several fixed-size convolution kernels or dilation rates at each layer of the network, we argue that different layers and datasets require different receptive fields. We use multi-scale adaptive convolution kernels and dilation rates to optimize traditional multi-scale temporal convolution with a simple and effective self attention mechanism, allowing different network layers to adaptively select convolution kernels of different sizes and dilation rates instead of being fixed and unchanged. Besides, the effective receptive field of the simple residual connection is not large, and there is a great deal of redundancy in the deep residual network, which will lead to the loss of context when aggregating spatio-temporal information. This article introduces a feature fusion mechanism that replaces the residual connection between initial features and temporal module outputs, effectively solving the problems of context aggregation and initial feature fusion. We propose a multi-modality adaptive feature fusion framework (MMAFF) to simultaneously increase the receptive field in both spatial and temporal dimensions. Concretely, we input the features extracted by the spatial module into the adaptive temporal fusion module to simultaneously extract multi-scale skeleton features in both spatial and temporal parts. In addition, based on the current multi-stream approach, we use the limb stream to uniformly process correlated data from multiple modalities. Extensive experiments show that our model obtains competitive results with state-of-the-art methods on the NTU-RGB+D 60 and NTU-RGB+D 120 datasets.


Assuntos
Sistema Musculoesquelético , Esqueleto , Reconhecimento Psicológico , Algoritmos , Extremidades
3.
Nano Lett ; 19(2): 1234-1241, 2019 02 13.
Artigo em Inglês | MEDLINE | ID: mdl-30681870

RESUMO

Dual-band-gap systems are promising for solar water splitting due to their excellent light-harvesting capability and high charge-separation efficiency. However, a fundamental understanding of interfacial charge-transfer behavior in the dual-band-gap configuration is still incomplete. Taking CdS/reduced graphene oxide (CdS/RGO) nanoheterojunctions as a model solar water splitting system, we attempt here to highlight the interaction-dependent interfacial charge-transfer behavior based on both experimental observations and theoretical calculations. Experimental evidence points to charge transfer at the CdS-RGO interface playing a dominant role in the photocatalytic hydrogen production activity. By tuning the degree of reduction of RGO, the interfacial interaction, and, thereby, the charge transfer can be controlled at the CdS-RGO interface. This observation is supported by theoretical analysis, where we find that the interfacial charge transfer is a balance between the effective single-electron- and hole-transfer probability and the surface free electron and hole concentration, both of which are related to the surface potential and tailored by interfacial interaction. This mechanism is applicable to all systems for solar water splitting, providing a useful guidance for the design and study of heterointerfaces for high-efficiency energy conversion.

4.
Eur Radiol ; 28(4): 1748-1755, 2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29143940

RESUMO

OBJECTIVE: To investigate the value of histogram analysis of diffusion kurtosis imaging (DKI) maps in the evaluation of glioma grading. METHODS: A total of 39 glioma patients who underwent preoperative magnetic resonance imaging (MRI) were classified into low-grade (13 cases) and high-grade (26 cases) glioma groups. Parametric DKI maps were derived, and histogram metrics between low- and high-grade gliomas were analysed. The optimum diagnostic thresholds of the parameters, area under the receiver operating characteristic curve (AUC), sensitivity, and specificity were achieved using a receiver operating characteristic (ROC). RESULT: Significant differences were observed not only in 12 metrics of histogram DKI parameters (P<0.05), but also in mean diffusivity (MD) and mean kurtosis (MK) values, including age as a covariate (F=19.127, P<0.001 and F=20.894, P<0.001, respectively), between low- and high-grade gliomas. Mean MK was the best independent predictor of differentiating glioma grades (B=18.934, 22.237 adjusted for age, P<0.05). The partial correlation coefficient between fractional anisotropy (FA) and kurtosis fractional anisotropy (KFA) was 0.675 (P<0.001). The AUC of the mean MK, sensitivity, and specificity were 0.925, 88.5% and 84.6%, respectively. CONCLUSIONS: DKI parameters can effectively distinguish between low- and high-grade gliomas. Mean MK is the best independent predictor of differentiating glioma grades. KEY POINTS: • DKI is a new and important method. • DKI can provide additional information on microstructural architecture. • Histogram analysis of DKI may be more effective in glioma grading.


Assuntos
Neoplasias Encefálicas/diagnóstico por imagem , Neoplasias Encefálicas/patologia , Imagem de Difusão por Ressonância Magnética/métodos , Imagem de Tensor de Difusão/métodos , Glioma/diagnóstico por imagem , Glioma/patologia , Técnicas Histológicas , Adulto , Anisotropia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Gradação de Tumores , Período Pré-Operatório , Curva ROC , Sensibilidade e Especificidade
5.
BMC Infect Dis ; 18(1): 613, 2018 Dec 04.
Artigo em Inglês | MEDLINE | ID: mdl-30509199

RESUMO

BACKGROUND: Community-acquired pneumonia is a leading infectious cause of hospitalization. A few vaccines exist to prevent pneumococcal disease in adults, including a pneumococcal polysaccharide unconjugated vaccine and a protein conjugated polysaccharide vaccine. Previous studies on the human immune response to the unconjugated vaccine showed that the vaccine boosted the existing memory B cells. In the present study, we investigated the human B cell immune response following pneumococcal polysaccharide conjugate vaccination. METHODS: Plasmablast B cells from a pneumococcal polysaccharide conjugate vaccinee were isolated and cloned for analysis. In response to primary vaccination, identical sequences from the plasmablast-derived antibodies were identified from multiple B cells, demonstrating evidence of clonal expansion. We evaluated the binding specificity of these human monoclonal antibodies in immunoassays, and tested there in vitro function in a multiplexed opsonophagocytic assay (MOPA). To characterize the plasmablast B cell response to the pneumococcal conjugated vaccine, the germline usage and the variable region somatic hypermutations on these antibodies were analyzed. Furthermore, a serotype 4 polysaccharide-specific antibody was tested in an animal challenge study to explore the in vivo functional activity. RESULTS: The data suggests that the pneumococcal polysaccharide conjugate vaccine boosted memory B cell responses, likely derived from previous pneumococcal exposure. The majority of the plasmablast-derived antibodies contained higher numbers of variable region somatic hypermutations and evidence for selection, as demonstrated by replacement to silent ratio's (R/S) greater than 2.9 in the complementarity-determining regions (CDRs). In addition, we found that VH3/JH4 was the predominant germline sequence used in these polysaccharide-specific B cells. All of the tested antibodies demonstrated narrow polysaccharide specificity in ELISA binding, and demonstrated functional opsonophagocytic killing (OPK) activity in the MOPA assay. The in-vivo animal challenge study showed that the tested serotype 4 polysaccharide-specific antibody demonstrated a potent protective effect when administered prior to bacterial challenge. CONCLUSIONS: The findings on the pneumococcal polysaccharide conjugate vaccine responses from a vaccinated subject reported in this study are similar to previously published data on the pneumococcal polysaccharide unconjugated vaccine responses. In both vaccine regimens, the pre-existing human memory B cells were expanded after vaccination with preferential use of the germline VH3/JH4 genes.


Assuntos
Anticorpos Monoclonais/isolamento & purificação , Linfócitos B/imunologia , Memória Imunológica , Infecções Pneumocócicas/prevenção & controle , Vacinas Pneumocócicas/uso terapêutico , Hipermutação Somática de Imunoglobulina , Adulto , Animais , Anticorpos Antibacterianos/imunologia , Linfócitos B/metabolismo , Células Cultivadas , Feminino , Rearranjo Gênico do Linfócito B/genética , Rearranjo Gênico do Linfócito B/imunologia , Humanos , Memória Imunológica/genética , Memória Imunológica/imunologia , Camundongos , Camundongos Endogâmicos C57BL , Infecções Pneumocócicas/genética , Infecções Pneumocócicas/imunologia , Infecções Pneumocócicas/microbiologia , Vacinas Pneumocócicas/imunologia , Sorogrupo , Hipermutação Somática de Imunoglobulina/genética , Hipermutação Somática de Imunoglobulina/imunologia , Streptococcus pneumoniae/imunologia , Vacinação , Vacinas Conjugadas/imunologia , Vacinas Conjugadas/uso terapêutico
6.
World J Surg Oncol ; 14(1): 153, 2016 May 26.
Artigo em Inglês | MEDLINE | ID: mdl-27230124

RESUMO

BACKGROUND: High-intensity focused ultrasound (HIFU) is a noninvasive therapy that makes entire coagulative necrosis of a tumor in deep tissue through the intact skin. There are many reports about the HIFU's efficacy in the treatment of patients with breast cancer, but randomized clinical trials are rare which emphasize on the systematic assessment of histological changes in the ablated tumor vascularities, while clinical trials utilizing bevacizumab and other anti-angiogenic drugs in breast cancer have not demonstrated overall survival benefit. The purpose of this study is to evaluate the damage effect of HIFU on breast cancer tissues and their vascularities. METHODS: Randomized clinical trials and the modality of treat-and-resect protocols were adopted. The treated outcome of all patients was followed up in this study. The target lesions of 25 breast cancer patients treated by HIFU were observed after autopsy. One slide was used for hematoxylin-eosin (HE) staining, one slide was used for elastic fiber staining by Victoria blue and Ponceau's histochemical staining, and one slide was used for vascular endothelial cell immunohistochemical staining with biotinylated-ulex europaeus agglutinin I (UEAI); all three slides were observed under an optical microscopic. One additional slide was systematically observed by electron microscopy. RESULTS: The average follow-up time was 12 months; no local recurrence or a distant metastatic lesion was detected among treated patients. Histological examination of the HE slides indicated that HIFU caused coagulative necrosis in the tumor tissues and their vascularities: all feeder vessels less than 2 mm in diameter in the insonated tumor were occluded, the vascular elasticity provided by fibrin was lost, the cells were disordered and delaminated, and UEAI staining of the target lesions was negative. Immediately after HIFU irradiation, the tumor capillary ultrastructure was destroyed, the capillary endothelium was disintegrated, the peritubular cells were cavitated, and the plasma membrane was incomplete. CONCLUSIONS: HIFU ablation can destroy all proliferating tumor cells and their growing vascularities simultaneously; this may break interdependent vicious cycle of tumor angiogenesis and neoplastic cell growth that results in infinite proliferation. While it cannot cause tumor resistance to HIFU ablation, it may be a new anti-angiogenic strategy that needs further clinical observation and exploration. Furthermore, the treatment indications of HIFU ablation were reviewed and discussed in this manuscript.


Assuntos
Neoplasias da Mama/patologia , Carcinoma Ductal de Mama/secundário , Carcinoma Lobular/secundário , Ablação por Ultrassom Focalizado de Alta Intensidade/efeitos adversos , Recidiva Local de Neoplasia/patologia , Neovascularização Patológica/patologia , Adulto , Idoso , Inibidores da Angiogênese/uso terapêutico , Neoplasias da Mama/irrigação sanguínea , Neoplasias da Mama/terapia , Carcinoma Ductal de Mama/irrigação sanguínea , Carcinoma Ductal de Mama/terapia , Carcinoma Lobular/irrigação sanguínea , Carcinoma Lobular/terapia , Estudos de Casos e Controles , Feminino , Seguimentos , Humanos , Metástase Linfática , Mastectomia , Pessoa de Meia-Idade , Gradação de Tumores , Invasividade Neoplásica , Recidiva Local de Neoplasia/irrigação sanguínea , Recidiva Local de Neoplasia/terapia , Estadiamento de Neoplasias , Prognóstico , Adulto Jovem
7.
Inquiry ; 61: 469580241254539, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38798062

RESUMO

The aim of this study is to investigate the relationship between the perceived value of outdoor activities and exercise persistence among elderly Chinese individuals. Specifically, the study aims to explore whether motivation for active social adaptation mediates this relationship. Three hundred twenty-five subjects were randomly chosen and invited to complete 3 questionnaires about the perceived value of outdoor activity, the motivation for active social adaptation, and the adherence to physical exercise. The results showed that older people's perception of the value of outdoor activity (function, landscape, and cost) has a statistically significant effect on their adherence to exercise. The mediating role of motivation for active social adaptation was also statistically significant, and the mediating role of active environmental adaptation motivation affected the perceived functional value, perceived landscape value of outdoor activities on adherence to exercise. Hence, it is concluded that older Chinese adults' perception of the value of outdoor activities promotes their adherence to exercise and reinforces it based on active social adaptation motivation.


Assuntos
Exercício Físico , Motivação , Humanos , Masculino , Feminino , Idoso , Exercício Físico/psicologia , Pessoa de Meia-Idade , China , Inquéritos e Questionários , Ajustamento Social , Idoso de 80 Anos ou mais
8.
Vaccines (Basel) ; 12(5)2024 Apr 28.
Artigo em Inglês | MEDLINE | ID: mdl-38793720

RESUMO

Multivalent pneumococcal vaccines have been developed successfully to combat invasive pneumococcal diseases (IPD) and reduce the associated healthcare burden. These vaccines employ pneumococcal capsular polysaccharides (PnPs), either conjugated or unconjugated, as antigens to provide serotype-specific protection. Pneumococcal capsular polysaccharides used for vaccine often contain residual levels of cell wall polysaccharides (C-Ps), which can generate a non-serotype specific immune response and complicate the desired serotype-specific immunity. Therefore, the C-P level in a pneumococcal vaccine needs to be controlled in the vaccine process and the anti C-P responses need to be dialed out in clinical assays. Currently, two types of cell-wall polysaccharide structures have been identified: a mono-phosphocholine substituted cell-wall polysaccharide C-Ps1 and a di-phosphocholine substituted C-Ps2 structure. In our effort to develop a next-generation novel pneumococcal conjugate vaccine (PCV), we have generated a monoclonal antibody (mAb) specific to cell-wall polysaccharide C-Ps2 structure. An antibody-enhanced HPLC assay (AE-HPLC) has been established for serotype-specific quantification of pneumococcal polysaccharides in our lab. With the new anti C-Ps2 mAb, we herein extend the AE-HPLC assay to the quantification and identification of C-Ps2 species in pneumococcal polysaccharides used for vaccines.

9.
Sheng Wu Yi Xue Gong Cheng Xue Za Zhi ; 29(4): 673-6, 681, 2012 Aug.
Artigo em Chinês | MEDLINE | ID: mdl-23016414

RESUMO

This study evaluated the clinical value of three-dimensional computed tomography (3D-CT) images in the knees following arthroscopic anterior cruciate ligament (ACL) reconstruction. Sixty-five consecutive patients underwent arthroscopic ACL reconstruction with single-incision and single-tunnel techniques. Preoperative and postoperative (12 months in between) clinical evaluation were performed using the Lysholm knee score and a KT-1000 arthrometer (side to side). Computed tomography (CT) of the knees was performed in a week after operation in all cases and at mean follow-up of 12 months. All of the clinical evaluation scales performed showed an overall improvement. 3D-CT images can display not only the bone tunnels of the knees including femoral and tibia very distinctly, but also the contour of the reconstructed ACL including adjacent structures. The average femoral tunnel diameter increased significantly (3%) from (9.15 +/- 0.03) mm postoperatively to (9.48 +/- 0.5) mm after 12 months; tibial tunnel increased significantly (12%) from (9.11 +/- 0.09) mm to (10.2 +/- 0.3) mm. There was no statistical difference between tunnel enlargements. So multi-slices spiral CT can evaluate the contour and changes of contour and changes of the knee after ACL reconstruction, which will be helpful in the intraoperative location and postoperative assessment of the knees.


Assuntos
Reconstrução do Ligamento Cruzado Anterior/métodos , Ligamento Cruzado Anterior/diagnóstico por imagem , Imageamento Tridimensional , Traumatismos do Joelho/diagnóstico por imagem , Tomografia Computadorizada por Raios X/métodos , Adulto , Ligamento Cruzado Anterior/cirurgia , Lesões do Ligamento Cruzado Anterior , Artroscopia , Feminino , Humanos , Traumatismos do Joelho/cirurgia , Masculino , Pessoa de Meia-Idade , Período Pós-Operatório , Adulto Jovem
10.
Materials (Basel) ; 15(19)2022 Oct 06.
Artigo em Inglês | MEDLINE | ID: mdl-36234268

RESUMO

Polytetrafluoroethylene (PTFE) plays an important role in semiconductor manufacturing. It is an important processing material for the key sealing components in the field of immersion lithography. The lack of research related to the mechanical processing of PTFE leads to many challenges in producing complex parts. This paper conducted a drilling experiment on PTFE. The effect of cutting parameters on the drilling performance was investigated. Thrust, torque, surface roughness, and drilling temperature were used to evaluate the influence of cutting parameters on drilling performance. In addition, the empirical mathematical models of thrust and torque were developed using analysis of variance (ANOVA). The results indicated that the spindle speed had the most important effect on the thrust and the feed rate had the most significant effect on the torque. The lowest values of thrust and torque were, respectively, 22.64 N and 0.12 Nm, achieved in the case of spindle speed of 5000 rev/min, and feed rate of 50 mm/min. The surface quality is also best at this cutting parameter. Studies have shown that higher spindle speeds with lower feed rates are ideal parameters for improving the drilling performance and machining quality of PTFE. In addition, it was found that the temperature differences due to different drilling depths were related to chip accumulation. Surface roughness inconsistencies at various locations in the inner wall of the hole were influenced by chip adhesion during machining. This paper provides a suggestion for optimizing cutting parameters and hole quality.

11.
Phys Rev Lett ; 105(17): 175301, 2010 Oct 22.
Artigo em Inglês | MEDLINE | ID: mdl-21231058

RESUMO

Fermi gases confined in tight one-dimensional waveguides form two-particle bound states of atoms in the presence of a strongly attractive interaction. Based on the exact solution of the one-dimensional spin-1/2 interacting Fermi gas, we demonstrate that a stable excited state with no pairing between attractive fermionic atoms can be realized by a sudden switch of interaction from the strongly repulsive regime to strongly attractive regime. Such a state is an exact fermionic analog of the experimentally observed super-Tonks-Girardeau state of bosonic Cesium atoms [Science 325, 1224 (2009)] and should be possible to be observed by the experiment. The frequency of the lowest breathing mode of the fermionic super-Tonks-Girardeau gas is calculated as a function of the interaction strength, which could be used as a detectable signature for the experimental observation.

12.
Onco Targets Ther ; 13: 12811-12827, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33363386

RESUMO

BACKGROUND: The incidence rate of cervical cancer is the highest in the reproductive tract and is not sensitive to chemotherapy. An appropriate amount of anti-angiogenic agents can reconstruct tumor blood vessels in a short period of time and form vascular homeostasis, increase the function of blood vessel perfusion and reverse the multidrug resistance of chemotherapy, which is also called "vascular normalization." Endostar (a recombinant human endostatin) was developed by China and as a multi-target anti-angiogenesis agent. Many reports about endostar involved the treatment of non-small cell lung cancer, fewer reports are on cervical cancer. PURPOSE: To determine whether endostar can rebuild tumor vascular homeostasis and enhance chemotherapy effects for patients with cervical cancer. METHODS: In this study, the patients with cervical cancer within stage IIB2 were selected, endostar combined with cisplatin+paclitaxel neoadjuvant chemotherapy (NACT) before radical surgical operation was adopted, patients outcome and adverse reaction were followed up. The changes of tumor vascular structure and perfusion function before and after endostar given were evaluated by histopathology and dynamic contrast-enhanced magnetic resonance imaging (DEC-MRI). VEGF-Notch signal pathway was detected for the regulating mechanism of vascular proliferation in different groups. GraphPad Prism 6 software was used for statistical analysis of the study results. RESULTS: Endostar enhanced the short-term (2 year) overall survival (OS), progression-free survival (PFS) rates for cervical cancer patients. All the same, endostar increased long-term (5 year) OS for cervical cancer patients. Endostar therapy exhibited with mild adverse reaction. MRI showed endostar+NACT further reduce tumor volume than NACT alone. The parameters of Ktrans, Ve for DEC-MRI in endostar group exhibited obviously increase than NACT group. Tumor vascular maturation index α-SMA/CD31 in endostar group increased obviously than NACT group, correspondingly Ki67 staining for tumor proliferative rates, lymphovascular space invasion in endostar group further declined than NACT group. The genes and proteins expression of VEGFR2, Notch1, Notch 4, Dll4, Jag1 were obviously downregulated in endostar group comparing to NACT group. CONCLUSION: Endostar restored vascular homeostasis in cervical cancer temporarily, enhanced chemotherapeutic agents effects in cervical cancer, increased patient OS ratio. Endostar+NACT treatment may provide a new target therapy for cervical cancer.

13.
Int J Clin Exp Pathol ; 12(7): 2405-2424, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31934068

RESUMO

BACKGROUND: The methods used to rebuild tumour vascular structure and function are called vascular normalization. Vascular normalization methods often block a single angiogenic molecular pathway, but tumor molecular pathways are interconnected and unstable. Since the vascular structure is not repaired, vascularity can be normalized only within a limited time. Amniotic epithelial cells (AECs) are used in tissue engineering to increase blood perfusion and promote wound healing. There have been no reports on the use of AECs in treatment to promote tumor vascular restoration. METHODS: The multipotential stem cell features of AECs were detected by immunofluorescence (IF), RT-PCR, and western blot. A nude rat in situ endometrial carcinoma model was developed. AECs were transfected with lentivirus-green fluorescent protein (GFP)-luciferase (Luc). The vascular formation abilities of AECs were monitored in vitro and in vivo under different conditions. AECs were injected by the rat tail vein, tumour vascular structural and perfusion changes were monitored, and the synergistic effects of AECs with cisplatin (DDP) chemotherapy were evaluated. RESULTS: AECs expressed the stem cell markers OCT4, Nanog, and CK19 at high levels. AECs could differentiate into adipocytes, chondrocytes, and osteocytes. Lentiviral GFP-Luc was successfully transfected into AECs, and GFP-labelled AECs formed vascular tube-like structures and invaded tumor tissue to form vascular structures in vitro. Kinetic luciferase imaging confirmed that AECs homed to rat uterine tumor tissues after injection by the tail vein. After AEC injection, tumour vascular α-SMA/CD31 labelling increased in vascular pericytes, while detection of VEGF-A expression by ELISA decreased. Cadherin labelling showed that basement membrane integrity improved distinctly in the AEC group compared with that in the corresponding control group. Hoechst 33342 and ultrasound Doppler detection showed that tumor vascular perfusion was ameliorated; pimonidazole perfusion showed reduced tumour tissue anoxia, and FITC-dextran perfusion confirmed that vascular leakage was obviously reduced in the AEC group compared with that in the control group. Tumor apoptosis and the rat survival rate in the AEC + DDP group were further enhanced, as demonstrated by CD31 (or α-SMA) IF and GFP colocalization, as well as GFP western blot. AECs differentiated into tumor vascular endotheliocytes or pericytes and enhanced tumor vascular integrity. CONCLUSION: AECs had the characteristics of pluripotent stem cells, and they could vascularize tissues under different conditions. AECs integrated into endometrial cancer vascular structures in nude rats, reduced dysregulated tumour angiogenesis, improved the efficiency of tumour vascular perfusion, and enhanced the cytotoxic effects of DDP. These findings provide a new method for the reconstruction of tumor vessels.

14.
AIDS Res Hum Retroviruses ; 23(1): 86-92, 2007 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-17263637

RESUMO

Quantitative analysis of cell-mediated immune responses induced by candidate HIV vaccines requires robust procedures for collecting and processing human peripheral mononuclear blood cells (PBMCs). We evaluated several parameters in order to optimize a sample handling process that would be suitable for a multicenter clinical trial. Among the findings, systematic increases in the magnitude of IFN-gamma ELISpot responses were observed when the time from blood collection to PBMC freezing was reduced to <12 h. By implementing these improvements within an ongoing clinical trial, the estimated immunologic response rates to an adenovirus- based HIV vaccine increased by more than 20 percentage points to approximately 80% of the vaccine recipients against any of the vaccine antigens and the average levels of T cell response improved more than 3-fold. These studies establish the importance of optimal conditions for PBMC collection and handling to the success of a clinical development program.


Assuntos
Vacinas contra a AIDS/imunologia , Leucócitos Mononucleares/imunologia , Manejo de Espécimes , Vacinas contra a AIDS/uso terapêutico , Adenoviridae/genética , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD8-Positivos/imunologia , Células Cultivadas , Ensaios Clínicos como Assunto , Criopreservação , Ensaio de Imunoadsorção Enzimática , Infecções por HIV/prevenção & controle , Soronegatividade para HIV , Humanos , Imunidade Celular , Interferon gama/imunologia , Linfócitos T/imunologia , Fatores de Tempo
15.
AIDS Res Hum Retroviruses ; 23(1): 67-76, 2007 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-17263635

RESUMO

The importance of host cellular immune responses, particularly CD8(+) cytotoxic T-lymphocyte (CTL) responses, in control of human immunodeficiency virus type 1 (HIV-1) infection has been demonstrated in many clinical studies. These studies, along with vaccination challenge studies in rhesus macaques, indicate the importance of cellular immune responses against HIV-1. Toward this end, we evaluated anti-HIV-1 cellular immune responses in a cohort of 54 subjects who were chronically infected with HIV-1. By validation of IFN-gamma ELISpot assay, we established a dual cut-off criterion for scoring a positive response. The magnitude and frequency of cellular immune responses were measured against HIV-1 antigens (Gag, Pol, Nef, Rev, and Tat), using synthetic peptides as antigens in ELISpot assay. Here we showed that HIV-1 Gag, Pol, and Nef were frequent targets of T cell responses in these subjects, whereas Tat and Rev were less frequently recognized. We further evaluated the possible association between host cellular immune responses and corresponding plasma viral loads in this cohort. By performing ranking correlation analysis, we demonstrated a positive correlation between host viral loads and ELISpot responses of HIV Gag and Pol in untreated subjects. For the subjects under antiviral regimens, however, we did not find any significant association. Our findings suggest that the high levels of ELISpot responses in chronically infected subjects were reflective of their persistent viral infection.


Assuntos
Linfócitos T CD8-Positivos/imunologia , Infecções por HIV/imunologia , HIV-1/imunologia , Linfócitos T Citotóxicos/imunologia , Adulto , Negro ou Afro-Americano/estatística & dados numéricos , Contagem de Linfócito CD4 , Doença Crônica , Estudos de Coortes , Estudos Transversais , Ensaio de Imunoadsorção Enzimática , Feminino , Citometria de Fluxo , Produtos do Gene gag/imunologia , Produtos do Gene nef/imunologia , Produtos do Gene pol/imunologia , Produtos do Gene tat/imunologia , Infecções por HIV/virologia , Hispânico ou Latino/estatística & dados numéricos , Humanos , Imunidade Celular , Interferon gama/imunologia , Masculino , RNA Viral/sangue , Carga Viral , População Branca/estatística & dados numéricos , Produtos do Gene nef do Vírus da Imunodeficiência Humana , Produtos do Gene tat do Vírus da Imunodeficiência Humana
16.
Oncotarget ; 8(12): 19577-19591, 2017 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-28121624

RESUMO

OBJECTIVES: To evaluate damage effect of High-intensity focused ultrasound on early stage endometrial cancer tissues and their vascularities. MATERIALS AND METHODS: Rabbit endometrial cancer models were established via tumor blocks implantation for a prospective control study. Ultrasonic ablation efficacy was evaluated by pathologic and imaging changes. The target lesions of experimental rabbits before and after ultrasonic ablation were observed after autopsy. The slides were used for hematoxylin-eosin staining, elastic fiber staining and endothelial cell staining; the slides were observed by optical microscopy. One slide was observed by electron microscopy. Then the target lesions of experimental animals with ultrasonic ablation were observed by vascular imaging, one group was visualized by digital subtract angiography, one group was quantified by color Doppler flow imaging, and one group was detected by dye perfusion.SPSS 19.0 software was used for statistical analyses. RESULTS: Histological examination indicated that High-intensity focused ultrasound caused the tumor tissues and their vascularities coagulative necrosis. Tumor vascular structure components including elastic fiber, endothelial cells all were destroyed by ultrasonic ablation. Digital subtract angiography showed tumor vascular shadow were dismissed after ultrasonic ablation. After ultrasonic ablation, gray-scale of tumor nodules enhanced in ultrasonography, tumor peripheral and internal blood flow signals disappeared or significantly reduced in color Doppler flow imaging. Vascular perfusion performed after ultrasonic ablation, tumor vessels could not filled by dye liquid. CONCLUSION: High-intensity focused ultrasound as a noninvasive method can destroy whole endometrial cancer cells and their supplying vascularities, which maybe an alternative approach of targeted therapy and new antiangiogenic strategy for endometrial cancer.


Assuntos
Neoplasias do Endométrio/patologia , Ablação por Ultrassom Focalizado de Alta Intensidade/efeitos adversos , Neovascularização Patológica/patologia , Neoplasias Uterinas/patologia , Animais , Modelos Animais de Doenças , Neoplasias do Endométrio/irrigação sanguínea , Neoplasias do Endométrio/radioterapia , Feminino , Coelhos , Neoplasias Uterinas/irrigação sanguínea
17.
J Immunol Methods ; 442: 20-28, 2017 03.
Artigo em Inglês | MEDLINE | ID: mdl-28034712

RESUMO

Dilutions are a common source of analytical error, both in terms of accuracy and precision, and a common source of analyst mistakes. When serial dilutions are used, errors compound, even when employing laboratory automation. Direct point dilutions instead of serial dilutions can reduce error but is often impractical as they require either large diluent volumes or very small sample volumes when performed with traditional liquid handling equipment. We evaluated preparation of dilution curves using a picoliter digital dispenser, the HP, Inc. / TECAN D300 which is capable of accurately delivering picoliter volumes directly into sample wells filled with assay diluent. Dilution linearity and variability of the direct dilutions were similar to or less than those generated with a traditional liquid handler as measured using a fluorophore assay and an ELISA used to measure vaccine potency. Minimum concentrations for detergent in the dispensed sample were identified but no correlation with detergent characteristics was observed. The tolerance to protein in the sample was evaluated as well with up to 5% BSA having no impact on dispense linearity and precision. We found the digital dispenser to reduce automation complexity while maintaining or improving assay performance in addition to facilitating complex plate lay-outs.


Assuntos
Ensaio de Imunoadsorção Enzimática/instrumentação , Ensaios de Triagem em Larga Escala/instrumentação , Potência de Vacina , Automação Laboratorial , Calibragem , Detergentes/química , Ensaio de Imunoadsorção Enzimática/normas , Desenho de Equipamento , Corantes Fluorescentes/química , Ensaios de Triagem em Larga Escala/normas , Miniaturização , Padrões de Referência , Reprodutibilidade dos Testes , Espectrometria de Fluorescência
18.
ACS Appl Mater Interfaces ; 9(49): 42723-42733, 2017 Dec 13.
Artigo em Inglês | MEDLINE | ID: mdl-29193959

RESUMO

The semiconductor/electrolyte interface plays a crucial role in photoelectrochemical (PEC) water-splitting devices as it determines both thermodynamic and kinetic properties of the photoelectrode. Interfacial engineering is central for the device performance improvement. Taking the cheap and stable hematite (α-Fe2O3) wormlike nanostructure photoanode as a model system, we design a facile sacrificial interlayer approach to suppress the crystal overgrowth and realize Ti doping into the crystal lattice of α-Fe2O3 in one annealing step as well as to avoid the consequent anodic shift of the photocurrent onset potential, ultimately achieving five times increase in its water oxidation photocurrent compared to the bare hematite by promoting the transport of charge carriers, including both separation of photogenerated charge carriers within the bulk semiconductor and transfer of holes across the semiconductor-electrolyte interface. Our research indicates that understanding the semiconductor/electrolyte interfacial engineering mechanism is pivotal for reconciling various strategies in a beneficial way, and this simple and cost-effective method can be generalized into other systems aiming for efficient and scalable solar energy conversion.

19.
PLoS One ; 11(3): e0152209, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27008550

RESUMO

Dengue is one of the most important mosquito-borne infections accounting for severe morbidity and mortality worldwide. Recently, the tetravalent chimeric live attenuated Dengue vaccine Dengvaxia® was approved for use in several dengue endemic countries. In general, live attenuated vaccines (LAV) are very efficacious and offer long-lasting immunity against virus-induced disease. Rationally designed LAVs can be generated through reverse genetics technology, a method of generating infectious recombinant viruses from full length cDNA contained in bacterial plasmids. In vitro transcribed (IVT) viral RNA from these infectious clones is transfected into susceptible cells to generate recombinant virus. However, the generation of full-length dengue virus cDNA clones can be difficult due to the genetic instability of viral sequences in bacterial plasmids. To circumvent the need for a single plasmid containing a full length cDNA, in vitro ligation of two or three cDNA fragments contained in separate plasmids can be used to generate a full-length dengue viral cDNA template. However, in vitro ligation of multiple fragments often yields low quality template for IVT reactions, resulting in inconsistent low yield RNA. These technical difficulties make recombinant virus recovery less efficient. In this study, we describe a simple, rapid and efficient method of using LONG-PCR to recover recombinant chimeric Yellow fever dengue (CYD) viruses as potential dengue vaccine candidates. Using this method, we were able to efficiently generate several viable recombinant viruses without introducing any artificial mutations into the viral genomes. We believe that the techniques reported here will enable rapid and efficient recovery of recombinant flaviviruses for evaluation as vaccine candidates and, be applicable to the recovery of other RNA viruses.


Assuntos
Vacinas contra Dengue/síntese química , Vírus da Dengue/imunologia , Vacinas de DNA/síntese química , Animais , Chlorocebus aethiops , Dengue/prevenção & controle , Vacinas contra Dengue/imunologia , Vírus da Dengue/genética , Feminino , Macaca mulatta , Masculino , Testes de Neutralização , Reação em Cadeia da Polimerase/métodos , Proteínas Recombinantes de Fusão/genética , Vacinas de DNA/imunologia , Células Vero/virologia , Vírus da Febre Amarela/genética
20.
J Plant Physiol ; 162(10): 1141-8, 2005 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-16255172

RESUMO

We have used Western blue-visualized in situ-hybridization (ISH) to monitor the expression of apomixis-specific gene-1 (ASG-1, GenBank accession number AB000809) during gametogenesis in obligate-sexual and facultative-apomictic (aposporic) genotypes of guinea grass (Panicum maximum). The in situ-analysis revealed that ASG-1 is not expressed in the ovule during early floral development in both, the facultative apomicts (A1 stage) and the obligate sexuals (S1 stage). With the appearance of the aposporous initial cell(s) in the ovule of the apomictic type (A2-1 stage), ASG-1 expression is strong and specific to this apomixis-specific cell. ASG-1 expression continued through different stages of aposporous embryo sac development (A2-2 stage), indicating that the gene may play a role in this developmental process. Regular embryo sacs in sexual types did not show hybridization signals (S2 stage). However, strong ASG-1 expression was detected in immature pollen grains and young embryos in both reproductive types, suggesting that ASG-1 may be an allele derived from the obligate-sexual wild type. Expression in pollen grains faded with maturation. In a heterologous system, using Paspalum notatum, a facultative-aposporic tropical grass (bahia grass), identical results were obtained. The results are discussed in view of the fact, that ASG-1 shows some homology to genes known to be seed- or embryo-specific or involved in processes related to cell growth.


Assuntos
Gametogênese , Regulação da Expressão Gênica no Desenvolvimento , Regulação da Expressão Gênica de Plantas , Genes de Plantas , Panicum/genética , Hibridização In Situ , Panicum/crescimento & desenvolvimento , RNA Mensageiro/genética
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