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1.
Article in English | MEDLINE | ID: mdl-38789121

ABSTRACT

BACKGROUND AND PURPOSE: The Circle of Willis (COW) is a crucial mechanism for cerebral collateral circulation. This proof-ofconcept study aims to develop and assess an analysis method to characterize the hemodynamics of the arterial segments in COW using arterial spin labeling (ASL) based non-contrast enhanced dynamic magnetic resonance angiography (dMRA). MATERIALS AND METHODS: The developed analysis method uses a graph model, bootstrap strategy, and ensemble learning methodologies to determine the time-curve shift from ASL dMRA to estimate the flow direction within the COW. The performance of the method was assessed on 52 subjects, using the flow direction, either antegrade or retrograde, derived from 3D phase contrast (PC) MRI as the reference. RESULTS: A total of 340 arterial segments in COW were evaluated, among which 30 (8.8%) had retrograde flow according to 3D PC. The ASL dMRA-based flow direction estimation has an accuracy, sensitivity, and specificity of 95.47%, 80%, and 96.34%, respectively. CONCLUSIONS: Using ASL dMRA and the developed image analysis method to estimate the flow direction in COW is feasible. This study provides a new method to assess the hemodynamics of the COW, which could be useful for the diagnosis and study of cerebrovascular diseases. ABBREVIATIONS: COW = Circle of Willis; ASL = arterial spin labeling; dMRA =dynamic magnetic resonance angiography; PC = phase contrast.

2.
Magn Reson Imaging ; 110: 86-95, 2024 Jul.
Article in English | MEDLINE | ID: mdl-38631533

ABSTRACT

Segmentation of cerebral vasculature on MR vascular images is of great significance for clinical application and research. However, the existing cerebrovascular segmentation approaches are limited due to insufficient image contrast and complicated algorithms. This study aims to explore the potential of the emerging four-dimensional arterial spin labeling magnetic resonance angiography (4D ASL-MRA) technique for fast and accurate cerebrovascular segmentation with a simple machine-learning approach. Nine temporal features were extracted from the intensity-time signal of each voxel, and eight spatial features from the neighboring voxels. Then, the unsupervised outlier detection algorithm, i.e. Isolation Forest, is used for segmentation of the vascular voxels based on the extracted features. The total length of the centerlines of the intracranial arterial vasculature, the dice similarity coefficient (DSC), and the average Hausdorff Distance (AVGHD) on the cross-sections of small- to large-sized vessels were calculated to evaluate the performance of the segmentation approach on 4D ASL-MRA of 18 subjects. Experiments show that the temporal information on 4D ASL-MRA can largely improve the segmentation performance. In addition, the proposed segmentation approach outperforms the traditional methods that were performed on the 3D image (i.e. the temporal average intensity projection of 4D ASL-MRA) and the previously proposed frame-wise approach. In conclusion, this study demonstrates that accurate and robust segmentation of cerebral vasculature is achievable on 4D ASL-MRA by using a simple machine-learning approach with appropriate features.


Subject(s)
Algorithms , Imaging, Three-Dimensional , Machine Learning , Magnetic Resonance Angiography , Spin Labels , Humans , Magnetic Resonance Angiography/methods , Imaging, Three-Dimensional/methods , Male , Female , Adult , Cerebral Arteries/diagnostic imaging , Image Processing, Computer-Assisted/methods , Cerebrovascular Circulation , Brain/diagnostic imaging , Brain/blood supply
3.
IEEE Trans Med Imaging ; 42(12): 3639-3650, 2023 Dec.
Article in English | MEDLINE | ID: mdl-37471193

ABSTRACT

Magnetic particle imaging (MPI) is an emerging technique for determining magnetic nanoparticle distributions in biological tissues. Although system-matrix (SM)-based image reconstruction offers higher image quality than the X-space-based approach, the SM calibration measurement is time-consuming. Additionally, the SM should be recalibrated if the tracer's characteristics or the magnetic field environment change, and repeated SM measurement further increase the required labor and time. Therefore, fast SM calibration is essential for MPI. Existing calibration methods commonly treat each row of the SM as independent of the others, but the rows are inherently related through the coil channel and frequency index. As these two elements can be regarded as additional multimodal information, we leverage the transformer architecture with a self-attention mechanism to encode them. Although the transformer has shown superiority in multimodal fusion learning across several fields, its high complexity may lead to overfitting when labeled data are scarce. Compared with labeled SM (i.e., full size), low-resolution SM data can be easily obtained, and fully using such data may alleviate overfitting. Accordingly, we propose a pseudo-label-based progressive pretraining strategy to leverage unlabeled data. Our method outperforms existing calibration methods on a public real-world OpenMPI dataset and simulation dataset. Moreover, our method improves the resolution of two in-house MPI scanners without requiring full-size SM measurements. Ablation studies confirm the contributions of modeling SM inter-row relations and the proposed pretraining strategy.


Subject(s)
Magnetite Nanoparticles , Calibration , Diagnostic Imaging/methods , Image Processing, Computer-Assisted/methods , Magnetic Fields
4.
Article in English | MEDLINE | ID: mdl-37227906

ABSTRACT

Representation learning in heterogeneous graphs with massive unlabeled data has aroused great interest. The heterogeneity of graphs not only contains rich information, but also raises difficult barriers to designing unsupervised or self-supervised learning (SSL) strategies. Existing methods such as random walk-based approaches are mainly dependent on the proximity information of neighbors and lack the ability to integrate node features into a higher-level representation. Furthermore, previous self-supervised or unsupervised frameworks are usually designed for node-level tasks, which are commonly short of capturing global graph properties and may not perform well in graph-level tasks. Therefore, a label-free framework that can better capture the global properties of heterogeneous graphs is urgently required. In this article, we propose a self-supervised heterogeneous graph neural network (GNN) based on cross-view contrastive learning (HeGCL). The HeGCL presents two views for encoding heterogeneous graphs: the meta-path view and the outline view. Compared with the meta-path view that provides semantic information, the outline view encodes the complex edge relations and captures graph-level properties by using a nonlocal block. Thus, the HeGCL learns node embeddings through maximizing mutual information (MI) between global and semantic representations coming from the outline and meta-path view, respectively. Experiments on both node-level and graph-level tasks show the superiority of the proposed model over other methods, and further exploration studies also show that the introduction of nonlocal block brings a significant contribution to graph-level tasks.

6.
Neuroimage ; 240: 118382, 2021 10 15.
Article in English | MEDLINE | ID: mdl-34252524

ABSTRACT

Self-construal (orientations of independence and interdependence) is a fundamental concept that guides human behaviour, and it is linked to a large number of brain regions. However, understanding the connectivity of these regions and the critical principles underlying these self-functions are lacking. Because brain activity linked to self-related processes are intrinsic, the resting-state method has received substantial attention. Here, we focused on resting-state functional connectivity matrices based on brain asymmetry as indexed by the differential partition of the connectivity located in mirrored positions of the two hemispheres, hemispheric specialization measured using the intra-hemispheric (left or right) connectivity, brain communication via inter-hemispheric interactions, and global connectivity as the sum of the two intra-hemispheric connectivity. Combining machine learning techniques with hypothesis-driven network mapping approaches, we demonstrated that orientations of independence and interdependence were best predicted by the asymmetric matrix compared to brain communication, hemispheric specialization, and global connectivity matrices. The network results revealed that there were distinct asymmetric connections between the default mode network, the salience network and the executive control network which characterise independence and interdependence. These analyses shed light on the importance of brain asymmetry in understanding how complex self-functions are optimally represented in the brain networks.


Subject(s)
Brain/physiology , Default Mode Network/physiology , Executive Function/physiology , Functional Laterality/physiology , Machine Learning , Magnetic Resonance Imaging/methods , Adolescent , Adult , Brain/diagnostic imaging , Default Mode Network/diagnostic imaging , Female , Humans , Male , Young Adult
7.
Med Image Anal ; 73: 102163, 2021 10.
Article in English | MEDLINE | ID: mdl-34303170

ABSTRACT

As an extreme type of partial auditory deprivation, single-sided deafness (SSD) has been demonstrated to lead to extensive neural plasticity according to multimodal neuroimaging studies. Among them, resting-state functional magnetic resonance imaging (rs-fMRI) offers valuable information on functional connectivities (FCs). However, most previous SSD rs-fMRI studies assumed that the extracted FC remains stationary during the entire fMRI scan and neglected dynamic functional activities. Existing fixed window-based dynamic FC analysis also ignores dynamic functional activities under different temporal terms. Additionally, due to the cost constraints of using MRI machines, using data-driven methods for unbiased hypothesis investigations may require more effective sample data augmentation techniques. To tackle these challenges and problems together, in this study, we proposed a dynamic window with a random length and position to extract participants' dynamic characteristics under different temporal terms and to extract more information from the dataset. Then, we proposed a nodal efficiency-based correlation matrix to describe the relationships of synergism between regions as features and applied a linear support vector machine (SVM) model to learn the importance of the features, which helped to identify SSD patients and healthy controls. A total of 68 participants (including 23 with left SSD, 20 with right SSD and 25 healthy controls) were enrolled. Our proposed approach with a random window showed clear improvement compared with traditional static and fixed window-based dynamic FC by using the linear SVM model. FCs related to the frontoparietal, somatomotor, dorsal attention, limbic and default mode networks played significant roles in differentiating SSD patients from healthy controls. Additionally, FCs between the somatomotor and frontoparietal networks made the greatest contribution to the classification model. Regarding brain regions, FCs related to the superior frontal gyrus, superior parietal lobule, superior temporal gyrus, amygdala, and orbital gyrus played significant roles. These findings suggest that networks and regions related to higher-order cognitive functions showed the most significant FC alterations in SSD, which may represent a compensatory collaboration of cognitive resources in SSD.


Subject(s)
Brain , Deafness , Brain/diagnostic imaging , Brain Mapping , Cognition , Humans , Magnetic Resonance Imaging , Neural Pathways
8.
Article in English | MEDLINE | ID: mdl-33886448

ABSTRACT

A bacterial strain designated RZ02T was isolated from surface seawater collected from the Yellow Sea in PR China and characterized by polyphasic taxonomy. Cells of strain RZ02T were Gram-stain-negative, aerobic, non-motile, catalase- and oxidase-positive rods forming ochre-pigmented colonies. Growth occurred at 7-36 °C (optimum, 30 °C), at pH 6.0-9.0 (optimum, pH 7.0) and with 1-5 % (optimum, 2 %) NaCl. The major cellular fatty acids (>10 %) of strain RZ02T were summed feature 8 (C18 : 1 ω6c and/or C18 : 1 ω7c), summed feature 3 (C16 : 1 ω7c and/or C16 : 1 ω6c) and C16 : 0. The major polar lipids were phosphatidylethanolamine, phosphatidylglycerol, phosphatidylcholine, diphosphatidylglycerol and sphingoglycolipid. The genome size of strain RZ02T was 2.79 Mbp with a G+C content of 55.5 mol%. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain RZ02T was mostly related to Pontixanthobacter luteolus SW-109T and Pontixanthobacter aestiaquae HDW-31T (97.3 and 97.1% sequence similarity, respectively), and formed a phyletic lineage with members of the genus Pontixanthobacter. The phylogenetic analysis based on the up-to-date bacterial core gene sequences confirmed that strain RZ02T clustered within the genus Pontixanthobacter. The average nucleotide identity and in silico DNA-DNA hybridization values between strain RZ02T and P. luteolus SW-109T and P. aestiaquae HDW-31T were 72.8 and 72.9 % and 18.7 and 18.5%, respectively. Based on these evidences, strain RZ02T is proposed to represent a novel species of the genus Pontixanthobacter under the name Pontixanthobacter rizhaonensis sp. nov. The type strain is RZ02T (=KCTC 62828T=MCCC 1K04521T). In addition, based on the results of whole genome analyses, proposals of Pseudopontixanthobacter gen. nov., Pseudopontixanthobacter confluentis comb. nov. and Pseudopontixanthobacter sediminis comb. nov. are also included.


Subject(s)
Alphaproteobacteria/classification , Phylogeny , Seawater/microbiology , Alphaproteobacteria/isolation & purification , Bacterial Typing Techniques , Base Composition , China , DNA, Bacterial/genetics , Fatty Acids/chemistry , Nucleic Acid Hybridization , Phospholipids/chemistry , Pigmentation , RNA, Ribosomal, 16S/genetics , Sequence Analysis, DNA
9.
Cardiovasc Diabetol ; 19(1): 71, 2020 05 30.
Article in English | MEDLINE | ID: mdl-32473648

ABSTRACT

BACKGROUND: Postprandial hyperglycemia was reported to play a key role in established risk factors of coronary artery diseases (CAD) and cardiovascular events. Serum 1,5-anhydroglucitol (1,5-AG) levels are known to be a clinical marker of short-term postprandial glucose (PPG) excursions. Low serum 1,5-AG levels have been associated with occurrence of CAD. However, the relationship between 1,5-AG levels and coronary plaque rupture has not been fully elucidated. The aim of this study was to evaluate 1,5-AG as a predictor of coronary plaque rupture in diabetic patients with acute coronary syndrome (ACS). METHODS: A total of 144 diabetic patients with ACS were included in this study. All patients underwent intravascular ultrasound examination, which revealed 49 patients with plaque rupture and 95 patients without plaque rupture in the culprit lesion. Fasting blood glucose (FBG), hemoglobin A1c (HbA1c) and 1,5-AG levels were measured before coronary angiography. Fasting urinary 8-iso-prostaglandin F2α (8-iso-PGF2α) level was measured and corrected by creatinine clearance. RESULTS: Patients with ruptured plaque had significantly lower serum 1,5-AG levels, longer duration of diabetes, higher HbA1c and FBG levels than patients without ruptured plaque in our study population. In multivariate analysis, low 1,5-AG levels were an independent predictor of plaque rupture (odds ratio 3.421; P = 0.005) in diabetic patients with ACS. The area under the receiver-operating characteristic curve for 1,5-AG (0.658, P = 0.002) to predict plaque rupture was superior to that for HbA1c (0.587, P = 0.087). Levels of 1,5-AG were significantly correlated with urinary 8-iso-prostaglandin F2α levels (r = - 0.234, P = 0.005). CONCLUSIONS: Serum 1,5-AG may identify high risk for coronary plaque rupture in diabetic patients with ACS, which suggests PPG excursions are related to the pathogenesis of plaque rupture in diabetes.


Subject(s)
Acute Coronary Syndrome/blood , Coronary Artery Disease/blood , Coronary Vessels/diagnostic imaging , Deoxyglucose/blood , Diabetes Mellitus, Type 2/blood , Plaque, Atherosclerotic , Ultrasonography, Interventional , Acute Coronary Syndrome/diagnostic imaging , Acute Coronary Syndrome/urine , Aged , Biomarkers/blood , Biomarkers/urine , Blood Glucose/metabolism , Coronary Artery Disease/diagnostic imaging , Coronary Artery Disease/urine , Diabetes Mellitus, Type 2/diagnosis , Diabetes Mellitus, Type 2/urine , Dinoprost/analogs & derivatives , Dinoprost/urine , Female , Glycated Hemoglobin/metabolism , Humans , Male , Middle Aged , Predictive Value of Tests , Prospective Studies , Rupture, Spontaneous
10.
Ecotoxicol Environ Saf ; 172: 423-431, 2019 May 15.
Article in English | MEDLINE | ID: mdl-30735974

ABSTRACT

The photocatalytic performance of layered double hydroxides (LDH) is usually confined to the slow interface mobility and high recombination rate of photogenerated electron-hole pairs in material. To overcome the low photocatalytic efficiency, novel Ag2O/Ag decorated LDH (LDH-Ag2O/Ag) was successfully synthesized by depositing Ag2O on the surface of LDH and then converted to Ag° nanoparticles in the right position after heat treatment. The as-synthesized LDH-Ag2O/Ag composites were characterized by Powder X-ray diffraction (XRD), Scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), UV-visible diffuse reflectance spectra (UV-vis DRS), photoluminescence spectra (PL) and transient photocurrent (TPC) analysis. Compared with virgin LDH, the photocatalytic activities of LDH-Ag2O/Ag composites were enhanced significantly. The optimum photocatalytic efficiency of LDH-Ag10 (0.0184 min-1) was nearly 46 times higher than that of virgin LDH (0.0004 min-1). The result of active species trapping experiments indicated that •OH, h+, and •O2- have an effect on the TC degradation, where •OH played the predominant role during the photocatalytic process. The possible photocatalytic mechanisms involving the charge transfer pathway and reactive species generation during the process of TC degradation were also discussed. The improved photocatalytic activity of LDH-Ag2O/Ag could be attributed to the synergetic effect between LDH and Ag2O/Ag that extended visible light range and reduced photogenerated charge carriers recombination.


Subject(s)
Light , Oxides/chemistry , Silver Compounds/chemistry , Tetracycline/chemistry , Anti-Bacterial Agents/chemistry , Catalysis , Hydroxides/chemistry , Microscopy, Electron, Transmission , Photoelectron Spectroscopy , X-Ray Diffraction
11.
J Ultrasound Med ; 38(5): 1191-1200, 2019 May.
Article in English | MEDLINE | ID: mdl-30208234

ABSTRACT

OBJECTIVES: The changes in the viscoelasticity of the Achilles tendon are related to tendinopathy. Therefore, constructing a data model in the healthy population is essential to understanding the key factors affecting the viscoelasticity of the Achilles tendon. The purpose of our research was to obtain large sample data, construct a data model, and determine parameters that affect the elastic modulus of the Achilles tendon in healthy Chinese adults. METHODS: We designed a prospective multicenter clinical trial to evaluate the viscoelasticity of the Achilles tendon by using shear wave elastography. A total of 1165 healthy adult participants from 17 Chinese hospitals were recruited for the assessment. The necessary parameters (age, height, weight, and body mass index) were recorded. The elastic modulus (Young modulus) was obtained from the middle of the Achilles tendon and calculated with feet in naturally relaxed, dorsal, and plantar positions. The thickness and perimeter of the Achilles tendon were measured via cross section on the same site. A multiple linear regression was performed to find the key factors affecting the Young modulus of the Achilles tendon. RESULTS: The Young modulus of the left Achilles tendon in the natural relaxed position followed a normal distribution (P > .05) with a mean ± SD of 374.24 ± 106.12 kPa. The regression equations showed a positive correlation between the Young modulus and weight and a negative correlation between the Young modulus and the circumference or thickness of the left Achilles tendon (P < .05). CONCLUSIONS: The Young modulus of the Achilles tendon as measured by shear wave elastography is related to body weight as well as the perimeter or thickness of the tendon.


Subject(s)
Achilles Tendon/physiology , Elastic Modulus/physiology , Elasticity Imaging Techniques/methods , Achilles Tendon/diagnostic imaging , Adult , China , Female , Humans , Male , Prospective Studies , Reference Values
12.
Luminescence ; 32(8): 1547-1553, 2017 Dec.
Article in English | MEDLINE | ID: mdl-28636187

ABSTRACT

The specificity for early diagnostic of prostate-specific antigen (PSA) is low because the current technology mostly allows the detection of only one biomarker at one time. In this work, a dual-labeled chemiluminescence enzyme immunoassay (CLEIA) for simultaneous measurement of total PSA (TPSA) and free PSA (FPSA) was proposed. Anti-PSA McAb (Mab1) was immobilized on a microplate as the solid phase, horseradish peroxidase (HRP)-labeled anti-TPSA monoclonal antibody (McAb2) and alkaline phosphatase (ALP)-labeled anti-FPSA McAb3 were used as detection antibodies. Two chemiluminescence reactions of HRP with luminol and ALP with 4-methoxy-4-(3-phosphate-phenyl)-spiro-(1,2-dioxetane-3,2'-adamantane) (AMPPD) were used as the signal detecting system. Based on a sandwich model, the amount of FPSA and TPSA could be determined simultaneously. The effects of several physico-chemical parameters were studied and optimized. Cross-reactivities of six common tumor markers in serum were studied. The proposed method presented the sensitivity of 0.03 ng ml-1 and 0.05 ng ml-1 for FPSA and TPSA respectively, with low cross-reactivities. Compared with the results from commercial chemiluminescent kits there was good correlation, indicating that this established method could be used to simultaneously to measure the concentrations of FPSA and TPSA in one serum sample and also could greatly facilitate the early diagnosis for PCa in clinical practice.


Subject(s)
Immunoenzyme Techniques , Luminescence , Luminescent Measurements , Prostate-Specific Antigen/analysis , Prostatic Neoplasms/diagnosis , Humans , Kinetics , Luminescent Agents/chemistry , Luminol/chemistry , Male
13.
Fish Shellfish Immunol ; 41(2): 260-3, 2014 Dec.
Article in English | MEDLINE | ID: mdl-25218682

ABSTRACT

Monoclonal antibodies (MAbs) specifically against coelomocytes of Apostichopus japonicus were employed to study the ontogenesis of coelomocytes by indirect immunofluorescence assay technique (IIFAT). Different developmental stages were identified by histochemical staining method. Stages including blastula, gastrula, auricularia (small-auricular larvae, mid-auricular larvae and big-auricular larvae), doliolaria, pentactula and juvenile were examined. The positive reactions with both MAb1C2 against all the types of coelomocytes and MAb3F6 specific to spherulocytes, were observed firstly at the blastula stage of the embryos. The positive reaction with MAb1E2 against lymphoid cells was observed from the big-auricular larvae, which indicated that lymphoid cells may not be progenitor cells or stem cells for A. japonicus. An increase of fluorescence intensity for each cell may imply a possible enhancement of the innate defensive mechanism as the embryogenesis progress.


Subject(s)
Sea Cucumbers/cytology , Sea Cucumbers/growth & development , Animals , Antibodies, Monoclonal/metabolism , Fluorescent Antibody Technique, Indirect , Life Cycle Stages/physiology , Molecular Probe Techniques
14.
Article in Chinese | MEDLINE | ID: mdl-24822363

ABSTRACT

OBJECTIVE: To clone and express transferrin (Tsf) from Culex pipiens pallens in Pichia pastoris, and detect its antibacterial activity. METHODS: The coding region of transferrin from Culex pipiens pallens was amplified by RT-PCR. The product of RT-PCR was inserted into the downstream of gene encoding a-factor signal sequence in a Pichia pastoris secreting expression vector pGAPZalpha-A. The recombinant pGAPZalpha-A-Tsf vector was transformed into P. pastoris GS115 by electroporation. Recombinant strains pGAPZa-A-Tsf/GS115 were screened by Zeocin resistance and PCR. Recombinant protein was detected by SDS-PAGE and Western blotting. The recombinant transferrin protein was purified by using Ni-NTA resin. The antibacterial activity of the purified transferrin against Escherichia coli was detected. RESULTS: The transferrin gene with 2,100 bp was obtained by RT-PCR. The product of recombinant plasmid pGAPZalpha-A-Tsf was approximately 2 127 bp by double digestion with restriction enzymes, consistent with the anticipated fragment length. Sequencing results showed that the inserted sequence was correct. PCR result showed that the recombinant plasmid pGAPZalpha-A-Tsf/GS115 was constructed. The results of SDS-PAGE and Western blotting showed that the relative molecular weight (Mr) of the protein was about 80,200. The recombinant transferrin protein showed antibacterial activity against Escherichia coli, and the minimum concentration was 0.25 mg/ml. CONCLUSION: The recombinant transferrin protein from Culex pipiens pallens has been expressed in P. pastoris, and shows antibacterial activity against E. coli.


Subject(s)
Anti-Infective Agents/pharmacology , Culex/metabolism , Escherichia coli/drug effects , Transferrin/pharmacology , Animals , Blotting, Western , Cloning, Molecular , Culex/genetics , Electrophoresis, Polyacrylamide Gel , Gene Expression , Genetic Vectors , Molecular Weight , Pichia/genetics , Pichia/metabolism , Polymerase Chain Reaction , Recombinant Proteins , Transferrin/genetics , Transferrin/metabolism
15.
Article in Chinese | MEDLINE | ID: mdl-25782251

ABSTRACT

OBJECTIVE: To understand the cross-resistance of Culex pipiens pallens to common pesticides, so as to provide the evidence for improving the application of chemical pesticides. METHODS: The IV instar larvae of DDVP-resistant, propoxur-resistant and cypermethrin-resistant strains as well as the sensitive strain of Culex pipiens pallens were collected to detect the resistance to DDVP, propoxur and cypermethrin based on the WHO bioassay method. RESULTS: The resistance coefficients of DDVP-resistant strain to DDVP, propoxur and cypermethrin were 14.47, 8.96 and 207.27 respectively. The resistance coefficients of propoxur-resistant strain to DDVP, propoxur and cypermethrin were 3.27, 6.93 and 8.65 respectively. The resistance coefficients of cypermethrin-resistant strain to DDVP, propoxur and cypermethrin were 2.93, 1.61 and 501.11 respectively. CONCLUSION: The resistance and cross-resistance could be generated during the long-term application of a single kind of chemical pesticide, and we should pay more attention to the varieties and dosages of them.


Subject(s)
Culex/drug effects , Insecticide Resistance , Insecticides/pharmacology , Animals , Culex/growth & development , Larva/drug effects , Parasitic Sensitivity Tests
16.
PLoS One ; 8(11): e79201, 2013.
Article in English | MEDLINE | ID: mdl-24265759

ABSTRACT

Wogonin is a plant monoflavonoid which has been reported to inhibit cell growth and/or induce apoptosis in various tumors. The present study examined the apoptosis-inducing activity and underlying mechanism of action of wogonin in A549 cells. The results showed that wogonin was a potent inhibitor of the viability of A549 cells. Apoptotic protein changes detected after exposure to wogonin included decreased XIAP and Mcl-1 expression, increased cleaved-PARP expression and increased release of AIF and cytochrome C. Western blot analysis showed that the activity of c-Myc/Skp2 and HDAC1/HDAC2 pathways, which play important roles in tumor progress, was decreased. Quantitative PCR identified increased levels of c-Myc mRNA and decreased levels of its protein. Protein levels of Fbw7α, GSK3ß and Thr58-Myc, which are involved in c-Myc ubiquitin-dependent degradation, were also analyzed. After exposure to wogonin, Fbw7α and GSK3ß expression decreased and Thr58-Myc expression increased. However, MG132 was unable to prevent c-Myc degradation. The present results suggest that wogonin has multiple anti-cancer effects associated with degradation of c-Myc, SKP2, HDAC1 and HDAC2. Its ability to induce apoptosis independently of Fbw7α suggests a possible use in drug-resistance cancer related to Fbw7 deficiency. Further studies are needed to determine which pathways are related to c-Myc and Fbw7α reversal and whether Thr58 phosphorylation of c-Myc is dependent on GSK3ß.


Subject(s)
Adenocarcinoma/metabolism , Apoptosis/drug effects , Cell Cycle Proteins/metabolism , F-Box Proteins/metabolism , Flavanones/pharmacology , Histone Deacetylase 1/metabolism , Histone Deacetylase 2/metabolism , Lung Neoplasms/metabolism , Proto-Oncogene Proteins c-myc/metabolism , S-Phase Kinase-Associated Proteins/metabolism , Signal Transduction/drug effects , Ubiquitin-Protein Ligases/metabolism , Adenocarcinoma/genetics , Adenocarcinoma of Lung , Cell Cycle/drug effects , Cell Line, Tumor , Cell Proliferation/drug effects , Cell Survival/drug effects , F-Box-WD Repeat-Containing Protein 7 , Gene Expression Regulation, Neoplastic/drug effects , Glycogen Synthase Kinase 3/metabolism , Glycogen Synthase Kinase 3 beta , Histone Deacetylase 1/genetics , Histone Deacetylase 2/genetics , Humans , Lung Neoplasms/genetics , Membrane Potential, Mitochondrial , Proto-Oncogene Proteins c-myc/genetics , RNA, Messenger/genetics , RNA, Messenger/metabolism
17.
Ultrasound Med Biol ; 39(11): 2001-10, 2013 Nov.
Article in English | MEDLINE | ID: mdl-23969167

ABSTRACT

The myocardial microenvironment plays a decisive role in the survival, migration and differentiation of stem cells. We studied myocardial micro-environmental changes induced by ultrasound-targeted microbubble destruction (UTMD) and their influence on the transplantation of mesenchymal stem cells (MSCs). Various intensities of ultrasound were applied to the anterior chest in canines with myocardial infarction after intravenous injection of microbubbles. The expression of cytokines and adhesion molecules in the infarcted area of the myocardium was detected after three sessions of UTMD in 1 wk. Real-time quantitative reverse transcription polymerase chain reaction (RTQ-PCR) showed that the expression of vascular cell adhesion molecule-1 (VCAM-1), stromal cell-derived factor-1 (SDF-1) and vascular endothelial growth factor (VEGF) in the 1.5 W/cm(2) and 1 W/cm(2) groups was markedly increased compared with the 0.5 W/cm(2) or the control groups (3.8- to 4.7-fold, p < 0.01), and the expression of interleukin-1ß (IL-1ß) in the 1.5 W/cm(2) group was increased twofold over the 1.0 W/cm(2) group, whereas the 0.5 W/cm(2) group experienced no significant changes. UTMD at 1.0 W/cm(2) was performed as previously described before mesenchymal stem cell (MSC) transplantation. Myocardial perfusion, angiogenesis and heart function were investigated before and 1 month after MSC transplantation. Coronary angiography and 99mTc-tetrofosmin scintigraphy revealed that myocardial perfusion was markedly improved after UTMD + MSCs treatment (p < 0.05). At echocardiographic analysis, heart function and the wall motion score index were significantly improved by UTMD + MSCs treatment compared with MSCs or UTMD alone and the control. In a canine model of myocardial infarction, therapeutic effects were markedly enhanced by MSC transplantation after the myocardial micro-environmental changes induced by UTMD; therefore, this novel method may be useful as an efficient approach for cellular therapy.


Subject(s)
Fluorocarbons/therapeutic use , Myocardial Infarction/physiopathology , Myocardial Infarction/therapy , Neovascularization, Physiologic/radiation effects , Sonication/methods , Stem Cell Niche/radiation effects , Stem Cell Transplantation , Animals , Combined Modality Therapy , Dogs , Fluorocarbons/radiation effects , Microbubbles/therapeutic use , Radiation Dosage , Treatment Outcome
18.
Fish Shellfish Immunol ; 35(5): 1654-7, 2013 Nov.
Article in English | MEDLINE | ID: mdl-23911653

ABSTRACT

The sea cucumber, Apostichopus japonicus possesses a variety of cells populating in both the coelomic (cells in the coelomic are called coelomocytes) and water-vascular system. In this study, we compared cells in these two systems of A. japonicus on total cell number, cell types and surface antigens through monoclonal antibodies against coelomocytes. The results demonstrated that the cell types observed in coelomic also could be found in water-vascular system, but the total cell number and percentages of each type were different. The total number of coelomocytes was 2-3 times of that in water-vascular system. Lymphoid cells were numerically dominant in coelomic system, while spherulocytes with pseudopods in water-vascular system. Results of indirect immunofluorescence assay technique showed that both coelomocytes and cells in water-vascular system could be recognized by the corresponding MAbs, and the distribution of its positive signals was not different. In conclusion, cell types and surface antigens in coelomic and water-vascular system were same, but the total cell number and percentages of each type were different. And further researches are needed on whether there are differences in functions of the different composition.


Subject(s)
Body Water/cytology , Cells/cytology , Extracellular Space , Sea Cucumbers/cytology , Animals , Antibodies, Monoclonal , Cell Count , Fluorescent Antibody Technique, Indirect , Lymphocytes/cytology
19.
J Zhejiang Univ Sci B ; 13(11): 875-83, 2012 Nov.
Article in English | MEDLINE | ID: mdl-23125080

ABSTRACT

OBJECTIVE: XRCC1 polymorphism is a research hotpot in individual treatment for non-small cell lung cancer (NSCLC). To obtain the association between XRCC1 polymorphism and clinical outcome of platinum-based treatment for NSCLC, a meta-analysis was conducted. METHODS: Databases including PubMed, Embase, Cochrane, and Chinese National Knowledge Infrastructure (CNKI) were searched for publications that met the inclusion criteria. A fixed effect model was used to estimate pooled odds ratio (OR) and hazard ratio (HR) with 95% confidence interval (CI) for the association between XRCC1 Arg399Gln and response or survival of platinum-based treatment for advanced NSCLC. A chi-squared-based Q-test was used to test the heterogeneity hypothesis. Egger's test was used to check publication bias. RESULTS: Seventeen published case-control studies that focus on the association between XRCC1 Arg399Gln and response or survival of platinum-based treatment for advanced NSCLC in 2256 subjects were included in this meta-analysis, of whom 522 were AA genotypes (23.2% frequency), 916 AG genotypes (40.6% frequency), and 818 GG genotypes (36.2% frequency). The overall response rate (ORR) was 45.2% (110/243) for AA genotype patients, 29.9% for AG genotype (73/244), and 30.7% for GG genotype (124/403). The heterogeneity test did not show any heterogeneity and the Egger's test did not reveal an obvious publication bias among the included studies. The meta-analysis indicated that AA genotype patients presented higher response rates toward platinum drug treatment compared with G model (GG+GA) patients (GG vs. AA model: OR=0.489, 95% CI 0.266-0.900, P=0.021; AG vs. AA model: OR=0.608, 95% CI 0.392-0.941, P=0.026; GA+AA vs. GG model: OR=1.259, 95% CI 0.931-1.701, P=0.135; GG+GA vs. AA model: OR=0.455, 95% CI 0.313-0.663, P=0.0001). However, no evidence validates XRCC1 associates with the survival following platinum drug therapy. CONCLUSIONS: Our meta-analysis suggested that XRCC1 Arg399Gln is related with the sensitivity of NSCLC patients to platinum-based treatment. AA genotype patients present more desirable curative effectiveness compared with other patients.


Subject(s)
Carcinoma, Non-Small-Cell Lung/drug therapy , DNA-Binding Proteins/genetics , Lung Neoplasms/drug therapy , Platinum Compounds/pharmacology , Platinum Compounds/therapeutic use , Carcinoma, Non-Small-Cell Lung/genetics , Carcinoma, Non-Small-Cell Lung/metabolism , DNA-Binding Proteins/metabolism , Genotype , Humans , Lung Neoplasms/genetics , Lung Neoplasms/metabolism , Polymorphism, Single Nucleotide , X-ray Repair Cross Complementing Protein 1
20.
Chin J Cancer Res ; 24(4): 291-8, 2012 Dec.
Article in English | MEDLINE | ID: mdl-23359329

ABSTRACT

OBJECTIVE: To evaluate the efficacy and toxicity of the combination regimen of paclitaxel, cisplatin and 5-FU (PCF) as first-line or second-line therapy in patients with advanced gastric and esophagogastric junction (EGJ) adenocarcinoma in China. METHODS: The patients were treated with paclitaxel 150 mg/m(2) on d1; fractionated cisplatin 15 mg/m(2) and continuous infusion 5-FU 600 mg/(m(2)·d) intravenously on d1-d5 of a 21-d cycle until disease progression or unacceptable toxicities. RESULTS: Seventy-five patients have been enrolled, among which, 41 received PCF regimen as the first-line therapy (group A) and 34 received the regimen as the second-line therapy (group B) with the median age of 59 years old and Karnofsky performance status (KPS) score ≥80. Toxicities were analyzed in all 75 patients. Seventy-one patients were evaluable for efficacy. The median overall survival (mOS) was 12.0 months (95% CI: 7.9-16.2 months) in group A and 7.3 months (95% CI: 4.3-10.3 months) in group B, respectively. The median progression-free survival (mPFS) was 5.7 months (95% CI: 4.1-7.2 months) and 5.0 months (95% CI: 3.1-6.9 months), respectively. The response rate (CR+PR) was 40% (16/40; 95% CI: 24.9-56.7%) in group A and 22.6% (7/31; 95% CI: 9.6-41.1%) in group B. Major grade 3 or 4 adverse events include neutropenia (41.3%), febrile neutropenia (9.3%), nausea/anorexia (10.7%), and vomiting (5.3%). There was no treatment-related death. CONCLUSIONS: The combination chemotherapy with PCF is active and tolerable as first-line and second-line therapy in Chinese patients with advanced gastric and EGJ adenocarcinoma. The response and survival of PCF are same as those of DCF, but the tolerance is much better.

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