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1.
Opt Express ; 32(3): 2942-2958, 2024 Jan 29.
Article in English | MEDLINE | ID: mdl-38297530

ABSTRACT

A method for spectral reflectance factor reconstruction based on wideband multi-illuminant imaging was proposed, using a programmable LED lighting system and modified Bare Bones Particle Swarm Optimization algorithms. From a set of 16 LEDs with different spectral power distributions, nine light sources with correlated color temperatures in the range of 1924 K - 15746 K, most of them daylight simulators, were generated. Samples from three color charts (X-Rite ColorChecker Digital SG, SCOCIE ScoColor paint chart, and SCOCIE ScoColor textile chart), were captured by a color industrial camera under the nine light sources, and used in sequence as training and/or testing colors. The spectral reconstruction models achieved under multi-illuminant imaging were trained and tested using the canonical Bare Bones Particle Swarm Optimization and its proposed modifications, along with six additional and commonly used algorithms. The impacts of different illuminants, illuminant combinations, algorithms, and training colors on reconstruction accuracy were studied comprehensively. The results indicated that training colors covering larger regions of color space give more accurate reconstructions of spectral reflectance factors, and combinations of two illuminants with a large difference of correlated color temperature achieve more than twice the accuracy of that under a single illuminant. Specifically, the average reconstruction error by the method proposed in this paper for patches from two color charts under A + D90 light sources was 0.94 and 1.08 CIEDE2000 color difference units. The results of the experiment also confirmed that some reconstruction algorithms are unsuitable for predicting spectral reflectance factors from multi-illuminant images due to the complexity of optimization problems and insufficient accuracy. The proposed reconstruction method has many advantages, such as being simple in operation, with no requirement of prior knowledge, and easy to implement in non-contact color measurement and color reproduction devices.

2.
Neurochem Res ; 48(2): 519-536, 2023 Feb.
Article in English | MEDLINE | ID: mdl-36309937

ABSTRACT

Recent reports have suggested that abnormal miR-29c expression in hippocampus have been implicated in the pathophysiology of some neurodegenerative and neuropsychiatric diseases. However, the underlying effect of miR-29c in regulating hippocampal neuronal function is not clear. In this study, HT22 cells were infected with lentivirus containing miR-29c or miR-29c sponge. Cell counting kit-8 (CCK8) and lactate dehydrogenase (LDH) assay kit were applied to evaluate cell viability and toxicity before and after TNF-α administration. Reactive oxygen species (ROS) generation and mitochondrial membrane potential (MMP) were measured with fluorescent probes. Hoechst 33258 staining and TUNEL assay were used to evaluate cell apoptosis. The expression of key mRNA/proteins (TNFR1, Bcl-2, Bax, TRADD, FADD, caspase-3, -8 and -9) in the apoptosis pathway was detected by PCR or WB. In addition, the protein expression of microtubule-associated protein-2 (MAP-2), nerve growth-associated protein 43 (GAP-43) and synapsin-1 (SYN-1) was detected by WB. As a result, we found that miR-29c overexpression could improve cell viability, attenuate LDH release, reduce ROS production and inhibit MMP depolarization in TNF-α-treated HT22 cells. Furthermore, miR-29c overexpression was found to decrease apoptotic rate, along with decreased expression of Bax, cleaved caspase-3, cleaved caspase-9, and increased expression of Bcl-2 in TNF-α-treated HT22 cells. However, miR-29c sponge exhibited an opposite effects. In addition, in TNF-α-treated HT22 cells, miR-29c overexpression could decrease the expressions of TNFR1, TRADD, FADD and cleaved caspase-8. However, in HT22 cells transfected with miR-29c sponge, TNF-α-induced the expressions of TNFR1, TRADD, FADD and cleaved caspase-8 was significantly exacerbated. At last, TNF-α-induced the decreased expression of MAP-2, GAP-43 and SYN-1 was reversed by miR-29c but exacerbated by miR-29c sponge. Overall, our study demonstrated that miR-29c protects against TNF-α-induced HT22 cells injury through alleviating ROS production and reduce neuronal apoptosis. Therefore, miR-29c might be a potential therapeutic agent for TNF-α accumulation and toxicity-related brain diseases.


Subject(s)
MicroRNAs , Tumor Necrosis Factor-alpha , Mice , Animals , Reactive Oxygen Species/metabolism , Caspase 3/metabolism , Tumor Necrosis Factor-alpha/pharmacology , Tumor Necrosis Factor-alpha/metabolism , Caspase 8/metabolism , Caspase 8/pharmacology , Receptors, Tumor Necrosis Factor, Type I , bcl-2-Associated X Protein/metabolism , GAP-43 Protein/metabolism , Cell Line , Apoptosis , Proto-Oncogene Proteins c-bcl-2/metabolism , MicroRNAs/metabolism , Hippocampus/metabolism
3.
Langmuir ; 39(1): 142-154, 2023 01 10.
Article in English | MEDLINE | ID: mdl-36579802

ABSTRACT

In this work, a protonated graphitic carbon nitride (P-g-C3N4)-coated graphene oxide (GO) composite (GO/P-g-C3N4) was prepared via wet-chemistry exfoliation, followed by a freeze-drying process. The GO/P-g-C3N4 composite was found to have an outstanding photodegradation performance effect on the reactive red 195 (RR195) dye and very strong antibacterial properties. Both the GO structure and the dispersed state of P-g-C3N4 were found to play a significant role in enhancing the photocatalytic activity of GO/P-g-C3N4. The GO/P-g-C3N4 obtained via freeze-drying retained a large number of oxygen-containing groups and showed higher catalytic activity and reusability than the reduced GO (rGO)/g-C3N4 obtained via thermal reduction. Characterization of the samples indicates that GO/P-g-C3N4 has a higher specific surface area and photocurrent density than rGO/g-C3N4; it is likely that these properties lead to the superior photocatalytic activity observed in GO/P-g-C3N4. Adsorption energy calculations indicate that O2 can be readily adsorbed onto the GO surface, which results in stronger oxidizing superoxide anion radicals (•O2-) and holes (h+); these active radicals can rapidly degrade RR195 dyes. Moreover, broad-spectrum antibacterial activity (demonstrated against Staphylococcus aureus and Escherichia coli) was observed in the case of the GO/P-g-C3N4 composite irradiated with visible light. This work offers new insights into the design of cost-effective g-C3N4-based photocatalysts for environmental remediation.


Subject(s)
Anti-Bacterial Agents , Anti-Bacterial Agents/pharmacology , Anti-Bacterial Agents/chemistry , Catalysis , Escherichia coli , Photolysis , Oxidants, Photochemical
4.
Sensors (Basel) ; 23(13)2023 Jul 04.
Article in English | MEDLINE | ID: mdl-37447985

ABSTRACT

Land cover data are important basic data for earth system science and other fields. Multi-source remote sensing images have become the main data source for land cover classification. There are still many uncertainties in the scale effect of image spatial resolution on land cover classification. Since it is difficult to obtain multiple spatial resolution remote sensing images of the same area at the same time, the main current method to study the scale effect of land cover classification is to use the same image resampled to different resolutions, however errors in the resampling process lead to uncertainty in the accuracy of land cover classification. To study the land cover classification scale effect of different spatial resolutions of multi-source remote sensing data, we selected 1 m and 4 m of GF-2, 6 m of SPOT-6, 10 m of Sentinel-2, and 30 m of Landsat-8 multi-sensor data, and explored the scale effect of image spatial resolution on land cover classification from two aspects of mixed image element decomposition and spatial heterogeneity. For the study area, we compared the classification obtained from GF-2, SPOT-6, Sentinel-2, and Landsat-8 images at different spatial resolutions based on GBDT and RF. The results show that (1) GF-2 and SPOT-6 had the best classification results, and the optimal scale based on this classification accuracy was 4-6 m; (2) the optimal scale based on linear decomposition depended on the study area; (3) the optimal scale of land cover was related to spatial heterogeneity, i.e., the more fragmented and complex was the space, the smaller the scale needed; and (4) the resampled images were not sensitive to scale and increased the uncertainty of the classification. These findings have implications for land cover classification and optimal scale selection, scale effects, and landscape ecology uncertainty studies.


Subject(s)
Environmental Monitoring , Remote Sensing Technology , Satellite Imagery , Environmental Monitoring/methods , Image Processing, Computer-Assisted
5.
Appl Opt ; 61(2): 546-553, 2022 Jan 10.
Article in English | MEDLINE | ID: mdl-35200896

ABSTRACT

The ability to identify virus particles is important for research and clinical applications. Because of the optical diffraction limit, conventional optical microscopes are generally not suitable for virus particle detection, and higher resolution instruments such as transmission electron microscopy (TEM) and scanning electron microscopy (SEM) are required. In this paper, we propose a new method for identifying virus particles based on polarization parametric indirect microscopic imaging (PIMI) and deep learning techniques. By introducing an abrupt change of refractivity at the virus particle using antibody-conjugated gold nanoparticles (AuNPs), the strength of the photon scattering signal can be magnified. After acquiring the PIMI images, a deep learning method was applied to identify discriminating features and classify the virus particles, using electron microscopy (EM) images as the ground truth. Experimental results confirm that gold-virus particles can be identified in PIMI images with a high level of confidence.


Subject(s)
Deep Learning , Metal Nanoparticles , Gold , Microscopy, Electron, Transmission , Virion
6.
Hum Mol Genet ; 28(20): 3475-3485, 2019 10 15.
Article in English | MEDLINE | ID: mdl-31518400

ABSTRACT

Hypoxia associated with the high metabolic demand of rods has been implicated in the pathology of age-related macular degeneration (AMD), the most common cause of adult blindness in the developed world. The majority of AMD-associated severe vision loss cases are due to exudative AMD, characterized by neovascularization. To further investigate the causes and histopathology of exudative AMD, we conditionally induced hypoxia in a novel preclinical AMD model (Pde6gcreERT2/+;Vhl-/-) by targeting Vhl and used multimodal imaging and immunohistochemistry to track the development of hypoxia-induced neovascularization. In addition to developing a preclinical model that phenocopies exudative AMD, our studies revealed that the photoreceptor hypoxic response initiates and drives type 3 neovascularization, mainly in the outer retina. Activation of the VHL-HIF1a-VEGF-EPO pathway in the adult retina led to long-term neovascularization, retinal hemorrhages and compromised retinal layers. Our novel preclinical model would accelerate the testing of therapies that use metabolomic approaches to ameliorate AMD.


Subject(s)
Hypoxia/metabolism , Hypoxia/pathology , Macular Degeneration/metabolism , Macular Degeneration/pathology , Neovascularization, Pathologic/metabolism , Neovascularization, Pathologic/pathology , Animals , Erythropoietin/metabolism , Hypoxia-Inducible Factor 1, alpha Subunit/metabolism , Mice , Vascular Endothelial Growth Factor A/metabolism
7.
Opt Express ; 29(2): 1221-1231, 2021 Jan 18.
Article in English | MEDLINE | ID: mdl-33726341

ABSTRACT

Optical-matter interactions and photon scattering in a sub-wavelength space are of great interest in many applications, such as nanopore-based gene sequencing and molecule characterization. Previous studies show that spatial distribution features of the scattering photon states are highly sensitive to the dielectric and structural properties of the nanopore array and matter contained on or within them, as a result of the complex optical-matter interaction in a confined system. In this paper, we report a method for shape characterization of subwavelength nanowells using photon state spatial distribution spectra in the scattering near field. Far-field parametric images of the near-field optical scattering from sub-wavelength nanowell arrays on a SiN substrate were obtained experimentally. Finite-difference time-domain simulations were used to interpret the experimental results. The rich features of the parametric images originating from the interaction of the photons and the nanowells were analyzed to recover the size of the nanowells. Experiments on nanoholes modified with Shp2 proteins were also performed. Results show that the scattering distribution of modified nanoholes exhibits significant differences compared to empty nanoholes. This work highlights the potential of utilizing the photon status scattering of nanowells for molecular characterization or other virus detection applications.


Subject(s)
Microscopy, Polarization/instrumentation , Nanostructures/chemistry , Scattering, Radiation , Silicon Compounds/chemistry , Equipment Design , Light , Photons
8.
Cell Microbiol ; 22(9): e13232, 2020 09.
Article in English | MEDLINE | ID: mdl-32452132

ABSTRACT

Plasmodium falciparum responsible for the most virulent form of malaria invades human erythrocytes through multiple ligand-receptor interactions. The P. falciparum reticulocyte binding protein homologues (PfRHs) are expressed at the apical end of merozoites and form interactions with distinct erythrocyte surface receptors that are important for invasion. Here using a range of monoclonal antibodies (mAbs) against different regions of PfRH1 we have investigated the role of PfRH processing during merozoite invasion. We show that PfRH1 gets differentially processed during merozoite maturation and invasion and provide evidence that the different PfRH1 processing products have distinct functions during invasion. Using in-situ Proximity Ligation and FRET assays that allow probing of interactions at the nanometre level we show that a subset of PfRH1 products form close association with micronemal proteins Apical Membrane Antigen 1 (AMA1) in the moving junction suggesting a critical role in facilitating junction formation and active invasion. Our data provides evidence that time dependent processing of PfRH proteins is a mechanism by which the parasite is able to regulate distinct functional activities of these large processes. The identification of a specific close association with AMA1 in the junction now may also provide new avenues to target these interactions to prevent merozoite invasion.


Subject(s)
Antigens, Protozoan/metabolism , Erythrocytes/parasitology , Host-Parasite Interactions , Membrane Proteins/metabolism , Plasmodium falciparum/physiology , Protozoan Proteins/metabolism , Reticulocytes/metabolism , Tight Junctions/metabolism , Antibodies, Monoclonal , Antigens, Protozoan/genetics , Erythrocytes/metabolism , Membrane Proteins/genetics , Merozoites/metabolism , Plasmodium falciparum/chemistry , Protozoan Proteins/genetics , Tight Junctions/parasitology
9.
BMC Ophthalmol ; 20(1): 134, 2020 Apr 06.
Article in English | MEDLINE | ID: mdl-32252692

ABSTRACT

BACKGROUND: Inflammation of RPE cells led to different kinds of eye diseases and affected the normal function of the retina. Furthermore, higher levels of ROCK1 and ROCK2 induced injury of endothelial cells and many inflammatory diseases of the eyes. Ripasudil, which was used for the treatment of glaucoma, was one kind of the inhibitor of ROCK1 and ROCK2, but whether ripasudil could relieve the LPS-induced inflammation and damage of RPE cells was not clear. METHODS: We used LPS to stimulate ARPE-19 cells, the RPE cell line. After that, we detected the levels of ROCK1 and ROCK2 by western-blotting after the stimulation of LPS and treatment of ripasudil. Then luciferase reporter assays were used to confirm the targeting effect of miR-136-5p on ROCK1 and ROCK2. At last, the levels of NLRP3, ASC, caspase1, IL-1ß and IL-18 were detected with the western-blotting after the knockdown of miR-136-5p. RESULTS: The levels of ROCK1, ROCK2 and miR-136-5p in ARPE-19 cells were promoted after the stimulation of LPS. After the treatment of ripasudil, the expression levels of ROCK1, ROCK2 and miR-136-5p were suppressed. The expression of ROCK1 and ROCK2 was targeted and inhibited by the miR-136-5p. The levels of inflammation related proteins NLRP3, ASC, caspase1, IL-1ß and IL-18 was also inhibited after the treatment of ripasudil. However, the expression of these proteins was rescued after the knockdown of miR-136-5p. CONCLUSION: Ripasudil relieved the inflammatory injury of RPE cells by upregulating miR-136-5p, therefore inhibiting the expression of ROCK1, ROCK2, NLRP3, ASC, caspase1, IL-1ß and IL-18.


Subject(s)
Gene Expression Regulation/drug effects , Inflammation/drug therapy , Isoquinolines/pharmacology , MicroRNAs/genetics , NLR Family, Pyrin Domain-Containing 3 Protein/antagonists & inhibitors , Retinal Pigment Epithelium/drug effects , Sulfonamides/pharmacology , rho-Associated Kinases/antagonists & inhibitors , Apoptosis , Blotting, Western , Cell Line , Drug Delivery Systems , Enzyme-Linked Immunosorbent Assay , Humans , Inflammation/metabolism , NLR Family, Pyrin Domain-Containing 3 Protein/metabolism , Real-Time Polymerase Chain Reaction , Retinal Pigment Epithelium/metabolism , Sincalide/metabolism , Up-Regulation , rho-Associated Kinases/metabolism
10.
BMC Ophthalmol ; 20(1): 256, 2020 Jun 29.
Article in English | MEDLINE | ID: mdl-32600279

ABSTRACT

BACKGROUND: To describe the clinical characteristics and analyze the predictive factors associated with improved visual acuity of 359 patients with infectious endophthalmitis. METHODS: This study retrospectively analyzed 359 eyes of 359 patients with infectious endophthalmitis from January 2014 to December 2018. The findings summarized some epidemiological characteristics of these patients, including age, sex, occupation, patient visit time, etiology, causative organisms, therapy, and best-corrected visual acuity. Multivariate logistic regression was performed to predict the relative factors of improved visual acuity (VA). RESULTS: Overall, 283 (78.83%) patients were male. The mean age was 48.0 ± 18.27 years. Ocular trauma, especially open globe injuries (246, 68.5%) was the most common etiology of infectious endophthalmitis in this study. The etiologies of infectious endophthalmitis were open globe injuries (68.5%), intraocular surgery (22.6%), and corneal ulcer-associated (6.7%) and endogenous causes (2.2%). In the etiology classification and visual acuity improvement group, had statistically significant differences in factors such as age, sex, patient visit time, pre-therapy visual acuity, etc. The average Logarithm of the Minimum Angle of Resolution (logMAR) best-corrected visual acuity on pre-therapy was 2.28 ± 0.60, and it had significantly improved to 1.67 ± 0.83 post-therapy (P < 0.05). Logistic regression analysis showed that visit time > 7 day (P = 0.034, OR = 0.522, 95% CI: 0.286-0.953), pre-therapy VA ≦logMAR 2.3 (P = 0.032, OR = 1.809, 95% CI: 1.052-3.110), post-surgical (vs. posttraumatic; P = 0.023, OR = 2.100, 95% CI: 1.109-3.974), and corneal ulcer-associated etiologies (vs. posttraumatic; P = 0.005, OR = 0.202, 95%CI: 0.066-0.621) were significantly associated with improved visual acuity after adjusting for possible confounding factors. CONCLUSIONS: Among the patients with infectious endophthalmitis, middle-aged male, especially farmers and workers, accounted for a large proportion. Open globe injuries were the main cause and the gram-positive bacteria were the major causative organisms. The final visual outcomes seemed to vary according to the type of endophthalmitis, but early treatment and good initial visual acuity were important factors for visual acuity improvement.


Subject(s)
Corneal Ulcer , Endophthalmitis , Eye Infections, Bacterial , Eye Injuries, Penetrating , Adult , Aged , Endophthalmitis/epidemiology , Endophthalmitis/therapy , Eye Infections, Bacterial/epidemiology , Eye Infections, Bacterial/therapy , Eye Injuries, Penetrating/surgery , Female , Humans , Male , Middle Aged , Retrospective Studies , Visual Acuity , Vitrectomy
11.
Chin J Cancer Res ; 31(6): 974-983, 2019 Dec.
Article in English | MEDLINE | ID: mdl-31949399

ABSTRACT

OBJECTIVE: This study evaluated the feasibility of different cervical cancer screening strategies in urban China. METHODS: A Markov model was constructed to simulate a hypothetical cohort of 100,000 females aged 30-59 years in a 20-year period. Screening strategies included liquid-based cytology (LBC) every three years, human papillomavirus (HPV) DNA testing every three and five years, respectively, and a combination of HPV DNA testing and LBC (HPV+LBC) every three and five years, respectively. Model outcomes included cumulative incidence over 20 years, cumulative risk of cervical cancer, costs, life year saved (LYS), quality-adjusted life years (QALYs) and benefits. The cost-effectiveness ratios (CERs), incremental cost-effectiveness ratios (ICERs), cost-utility ratios (CURs), and benefit-cost ratios (BCRs) were used as outcomes in the health economic evaluation analysis. Univariate sensitivity analyses were performed to examine the stability of the results. RESULTS: The cumulative incidence of the five screening strategies ranged from 833.02 to 1,158.07 cases per 100,000 females. HPV DNA testing was most effective in reducing the cumulative risk of cervical cancer, saving life years and QALYs and gaining benefits. The CERs of HPV DNA testing every three and five years, and LBC every three years were considered to be very cost-effective if they were below China's GDP per capita. The CERs of HPV+LBC were considered to be cost-effective if they were below three times GDP per capita. The incremental cost-effectiveness analysis showed that HPV DNA testing every three and five years, LBC every three years and HPV+LBC every five years were dominant strategies. CONCLUSIONS: The findings of this study indicated that HPV DNA testing every five years or LBC every three years should be recommended in urban China.

12.
Cell Microbiol ; 19(9)2017 09.
Article in English | MEDLINE | ID: mdl-28409866

ABSTRACT

The successful invasion of Plasmodium is an essential step in their life cycle. The parasite reticulocyte-binding protein homologues (RHs) and erythrocyte-binding like proteins are two families involved in the invasion leading to merozoite-red blood cell (RBC) junction formation. Ca2+ signaling has been shown to play a critical role in the invasion. RHs have been linked to Ca2+ signaling, which triggers the erythrocyte-binding like proteins release ahead of junction formation, consistent with RHs performing an initial sensing function in identifying suitable RBCs. RH5, the only essential RHs, is a highly promising vaccine candidate. RH5-basigin interaction is essential for merozoite invasion and also important in determining host tropism. Here, we show that RH5 has a distinct function from the other RHs. We show that RH5-Basigin interaction on its own triggers a Ca2+ signal in the RBC resulting in changes in RBC cytoskeletal proteins phosphorylation and overall alterations in RBC cytoskeleton architecture. Antibodies targeting RH5 that block the signal prevent invasion before junction formation consistent with the Ca2+ signal in the RBC leading to rearrangement of the cytoskeleton required for invasion. This work provides the first time a functional context for the essential role of RH5 and will now open up new avenues to target merozoite invasion.


Subject(s)
Basigin/metabolism , Calcium Signaling/physiology , Carrier Proteins/metabolism , Erythrocytes/physiology , Merozoites/pathogenicity , Plasmodium falciparum/pathogenicity , Antibodies, Monoclonal/immunology , Antigens, Protozoan/biosynthesis , Carrier Proteins/antagonists & inhibitors , Carrier Proteins/immunology , Cell Line , Cytoskeleton/parasitology , Cytoskeleton/pathology , Erythrocytes/parasitology , Host-Parasite Interactions/physiology , Humans , Malaria, Falciparum/parasitology , Plasmodium falciparum/metabolism , Protozoan Proteins/biosynthesis
13.
Mol Pharm ; 15(10): 4326-4335, 2018 10 01.
Article in English | MEDLINE | ID: mdl-29257894

ABSTRACT

While tuberculosis (TB) disease was discovered more than a century ago, it has not been eradicated yet. Quite contrary, at present, TB constitutes one of the top 10 causes of death and has shown signs of increasing. To complement the conventional diagnostic procedure of applying microbiological culture that takes several weeks and remains expensive, high resolution computer tomography (CT) of pulmonary images has been resorted to not only for aiding clinicians to expedite the process of diagnosis but also for monitoring prognosis when administering antibiotic drugs. This research undertakes the investigation of predicting multidrug-resistant (MDR) patients from drug-sensitive (DS) ones based on CT lung images to monitor the effectiveness of treatment. To contend with smaller data sets (i.e., hundreds) and the characteristics of CT TB images with limited regions capturing abnormities, patch-based deep convolutional neural network (CNN) allied to support vector machine (SVM) classifier is implemented on a collection of data sets from 230 patients obtained from the ImageCLEF 2017 competition. As a result, the proposed architecture of CNN + SVM + patch performs the best with classification accuracy rate at 91.11% (79.80% in terms of patches). In addition, a hand-crafted SIFT based approach accomplishes 88.88% in terms of subject and 83.56% with reference to patches, the highest in this study, which can be explained away by the fact that the data sets are in small numbers. Significantly, during the Tuberculosis Competition at ImageCLEF 2017, the authors took part in the task of classification of 5 types of TB disease and achieved the top one with regard to averaged classification accuracy (i.e., ACC = 0.4067), which is also premised on the approach of CNN + SVM + patch. On the other hand, when the whole slices of 3D TB data sets are applied to train a CNN network, the best result is achieved through the application of CNN coupled with orderless pooling and SVM at 64.71% accuracy rate.


Subject(s)
Deep Learning , Tomography, X-Ray Computed/methods , Tuberculosis, Multidrug-Resistant/diagnostic imaging , Humans , Neural Networks, Computer , Support Vector Machine
14.
Mol Microbiol ; 102(3): 386-404, 2016 11.
Article in English | MEDLINE | ID: mdl-27438226

ABSTRACT

Erythrocyte invasion by merozoite is a multistep process involving multiple ligand-receptor interactions. The Plasmodium falciparum reticulocyte binding protein homologues (PfRHs) consists of five functional members. The differential expression of PfRHs has been linked to the utilization of different invasion pathways by the merozoites as well as a mechanism of immune evasion. PfRHs are expressed at the apical end of merozoite and form interactions with distinct red blood cell (RBC) surface receptors that are important for successful invasion. Here we show that PfRH2b undergoes processing before and during merozoite invasion. The different processed fragments bind to chymotrypsin sensitive RBC surface receptors. We also show that PfRH2b follows the merozoite tight junction during invasion. Monoclonal antibodies (mAbs) inhibit merozoites invasion by blocking tight junction formation. mAbs binding to PfRH2b block merozoites intracellular Ca2+ signal necessary for EBA175 surface expression. The data suggests that a conserved function of PfRHs, where their interaction with RBC surface receptors facilitated recruitment of EBA175 and other tight junction proteins necessary for merozoite invasion by modulating merozoite intracellular Ca2+ signals.


Subject(s)
Antibodies, Monoclonal/pharmacology , Erythrocytes/parasitology , Plasmodium falciparum/drug effects , Plasmodium falciparum/metabolism , Protozoan Proteins/antagonists & inhibitors , Animals , Antibodies, Monoclonal/immunology , Antibody Specificity , Chymotrypsin/metabolism , Erythrocytes/drug effects , Erythrocytes/metabolism , Host-Parasite Interactions , Humans , Merozoites/drug effects , Merozoites/metabolism , Protozoan Proteins/immunology , Protozoan Proteins/metabolism , Receptors, Cell Surface/metabolism
15.
Biomed Chromatogr ; 30(6): 802-9, 2016 Jun.
Article in English | MEDLINE | ID: mdl-26347996

ABSTRACT

The aim of this study was to investigate the effects of verapamil on the pharmacokinetics of pristimerin in rats. A sensitive and reliable LC-MS/MS method was developed and applied for the determination of pristimerin in rat plasma. The pharmacokinetics of orally administered pristimerin with and without verapamil pretreatment was investigated. The results indicated that, when the rats were pretreated with verapamil, the peak concentration of pristimerin increased from 189.13 to 277.53 ng/mL (46.7%), and the AUC0-t increased by approximately 82.0%. Additionally, the effects of verapamil on the absorption and metabolic stability of pristimerin were investigated using the Caco-2 cell transwell model and rat liver microsomes. A markedly higher transport of pristimerin across the Caco-2 cells was observed in the basolateral-to-apical direction and was abrogated in the presence of the P-gp inhibitor, verapamil. These results indicated that P-gp might be involved in the absorption of pristimerin. Of note, the metabolic half-life of pristimerin was prolonged by the pretreatment with verapamil. In conclusion, verapamil could affect the pharmacokinetics of pristimerin, and it might work through increasing the absorption of pristimerin by inhibiting P-gp, or through slowing down the metabolism of pristimerin in the rat liver. Copyright © 2015 John Wiley & Sons, Ltd.


Subject(s)
Calcium Channel Blockers/pharmacology , Triterpenes/pharmacokinetics , Verapamil/pharmacology , Animals , Area Under Curve , Caco-2 Cells , Chromatography, Liquid , Drug Interactions , Humans , Limit of Detection , Male , Mass Spectrometry , Pentacyclic Triterpenes , Rats , Rats, Sprague-Dawley , Reproducibility of Results
16.
Surg Today ; 45(5): 585-94, 2015 May.
Article in English | MEDLINE | ID: mdl-25256939

ABSTRACT

PURPOSE: We conducted this meta-analysis to establish whether pancreaticogastrostomy (PG) or pancreaticojejunostomy (PJ) is the better method of reconstruction for reducing the risk of postoperative pancreatic fistula (POPF). METHODS: This study involved a systematic article search and review of published randomized controlled trials (RCTs) comparing PG vs. PJ after pancreaticoduodenectomy (PD). Cochrane's risk of bias-assessing tool was used to assess the quality of included studies. The fixed-effect model, random-effect model, and subgroup analysis were performed for the sensitivity analysis. RESULTS: Six RCTs reporting data on 998 patients were included. The incidence of POPF was lower in the PG group (risk ratio, RR = 0.65, 95 % CI 0.43-0.97, P = 0.03), but there was no significant difference in delayed gastric emptying, intra-abdominal fluid collection, biliary fistula, wound infection, postpancreatectomy hemorrhage, overall postoperative complication, or postoperative mortality between the procedures. CONCLUSIONS: This meta-analysis shows that PG is superior to PJ for reducing the incidence of POPF, but there were no differences in other complications or mortality. Therefore, it may be considered as an alternative to PJ and further RCTs are needed to prove our findings.


Subject(s)
Gastrostomy , Pancreatic Fistula/prevention & control , Pancreaticoduodenectomy , Pancreaticojejunostomy , Postoperative Complications/prevention & control , Randomized Controlled Trials as Topic , Adult , Aged , Aged, 80 and over , Databases, Bibliographic , Female , Gastrostomy/methods , Humans , Incidence , Male , Middle Aged , Pancreatic Fistula/epidemiology , Pancreaticojejunostomy/methods , Postoperative Complications/epidemiology , Risk , Young Adult
17.
Reprod Biol Endocrinol ; 12: 96, 2014 Oct 09.
Article in English | MEDLINE | ID: mdl-25296555

ABSTRACT

BACKGROUND: The goal of this study was to assess the association between endometrial thickness on the chorionic gonadotropin (hCG) day and in vitro fertilization and embryo transfer (IVF-ET) outcome in normal responders after GnRH antagonist administration. METHODS: A retrospective cohort study was performed in normal responders with GnRH antagonist administration from January 2011-December 2013. Patients were divided into four groups according to endometrial thickness, as follows: <7 mm (group 1), > = 7- < 8 mm (group 2), > = 8- < 14 mm (group 3), and > =14 mm (group 4). RESULTS: A total of 2106 embryo transfer cycles were analyzed. The pregnancy rate (PR) was 44.87%.The clinical pregnancy rate, ongoing pregnancy rate and the implantation rate (17.28%, 13.79%, 10.17%, respectively) were significantly lower in group 1 compared to the other three groups (p < 0.05). The miscarriage rate was higher in patients with endometrial thickness less than 7 mm. The clinical pregnancy rate, ongoing pregnancy rate and implantation rate were highest in patients with endometrial thickness higher than 14 mm, but showed no difference in patients with those of endometrial thickness between 8-14 mm. CONCLUSIONS: There is a correlation between endometrial thickness measured on hCG day and clinical outcome in normal responders with GnRH antagonist administration. The pregnancy rate was lower in patients with endometrial thickness less than 7 mm compared with patients with endometrial thickness more than 7 mm.


Subject(s)
Embryo Transfer , Endometrium/drug effects , Fertility Agents, Female/pharmacology , Fertilization in Vitro , Gonadotropin-Releasing Hormone/analogs & derivatives , Gonadotropin-Releasing Hormone/antagonists & inhibitors , Infertility, Female/therapy , Abortion, Spontaneous/chemically induced , Abortion, Spontaneous/prevention & control , Adult , China/epidemiology , Chorionic Gonadotropin/pharmacology , Cohort Studies , Endometrium/diagnostic imaging , Endometrium/pathology , Female , Fertility Agents, Female/adverse effects , Gonadotropin-Releasing Hormone/adverse effects , Gonadotropin-Releasing Hormone/pharmacology , Humans , Infertility, Female/pathology , Organ Size/drug effects , Pregnancy , Pregnancy Maintenance/drug effects , Pregnancy Rate , Retrospective Studies , Sperm Injections, Intracytoplasmic , Ultrasonography
18.
Cell Microbiol ; 15(1): 35-44, 2013 Jan.
Article in English | MEDLINE | ID: mdl-23046317

ABSTRACT

Malaria remains a serious public health problem with significant morbidity and mortality accounting for nearly 20% of all childhood deaths in Africa. The cyclical invasion, cytoadherence and destruction of the host's erythrocyte by the parasite are responsible for the observed disease pathology. The invasive form of the parasite, the merozoite, uses a complex set of interactions between parasite ligands and erythrocyte receptors that leads to the formation of a tight junction and ultimately successful erythrocyte invasion. Understanding the molecular mechanism underlying host cell recognition and invasion is crucial for the development of a targeted intervention strategy. Two parasite protein families termed reticulocyte-binding-like protein homologues (RBL) and the erythrocyte-binding-like (EBL) protein family are conserved in all Plasmodium species and have been shown to play an important role in host cell recognition and invasion. Over the last few years significant new insights have been gained in understanding the function of the RBL family and this review attempts to provide an update with a specific focus on the role of RBL in signal transduction pathways during invasion.


Subject(s)
Endocytosis , Erythrocytes/parasitology , Plasmodium/pathogenicity , Protozoan Proteins/metabolism , Virulence Factors/metabolism , Models, Biological , Signal Transduction
19.
J Assist Reprod Genet ; 31(12): 1655-63, 2014 Dec.
Article in English | MEDLINE | ID: mdl-25227693

ABSTRACT

PURPOSE: To investigate how effectively density gradient centrifugation (DGC) improves sperm nuclear integrity and to determine whether the sperm chromatin dispersion (SCD) test of sperm nuclear integrity in native or DGC-treated semen can predict the outcome of assisted reproductive technology (ART) in couples undergoing intracytoplasmic sperm injection (ICSI). METHODS: The DNA integrity of spermatozoa from 63 male factor infertility patients undergoing ICSI was analyzed by the SCD test before and after DGC. The predictive value of the sperm DNA fragmentation index (DFI) for ART outcomes was assessed in a cohort of 45 patients who were undergoing fresh embryo transfer. For the analysis, they were divided into pregnant and non-pregnant groups and, independently, into high sperm DFI (DFI > 30%) and low sperm DFI (DFI ≤ 30%) groups. Both raw and DGC semen parameters were examined. RESULTS: In the asthenospermia and oligozoospermia groups, DGC decreased the sperm DFI from 31.5 ± 19.7 and 28.5 ± 10.3 to 19.2 ± 18.3 and 16.0 ± 12.8, respectively (P < 0.01). DGC decreased the sperm DFI in the severe oligozoospermia group from 41.4 ± 19.0 to 36.3 ± 20.6 (P > 0.01). The pregnant and non-pregnant groups did not differ in their fertilization rate and sperm DFI in native or DGC semen (P > 0.05). There was also no significant difference between the high sperm DFI (DFI > 30%) and low sperm DFI (DFI ≤ 30 %) groups with regard to fertilization rate, implantation rate, and clinical pregnancy rate for both native and DGC semen (P > 0.05). The patients undergoing ICSI with a high sperm DFI had a higher pregnancy loss rate (defined as spontaneous miscarriage or biochemical pregnancy) compared with patients with a low sperm DFI in both the native and DGC semen groups. CONCLUSIONS: DGC highly significantly reduces sperm DNA fragmentation in the semen of ICSI patients, with the exception of those with severe oligozoospermia. The results of the SCD test of sperm DNA fragmentation in native or DGC semen do not correlate with the fertilization rate, implantation rate, or clinical pregnancy rate in patients undergoing ICSI.


Subject(s)
Centrifugation, Density Gradient/methods , Fertilization in Vitro , Infertility, Male/genetics , Sperm Injections, Intracytoplasmic/methods , Abortion, Spontaneous/genetics , Abortion, Spontaneous/physiopathology , Adult , Chromatin/genetics , DNA Fragmentation , Embryo Transfer , Female , Humans , Infertility, Male/pathology , Male , Pregnancy , Pregnancy Rate , Semen Analysis
20.
Heliyon ; 10(3): e24846, 2024 Feb 15.
Article in English | MEDLINE | ID: mdl-38322889

ABSTRACT

Quantitative analysis of the process of urban expansion and evolution is of great practical significance for the future planning and development potential of valley cities. Based on GEE cloud platform and Landsat satellite data, this paper analyzed the spatio-temporal change characteristics and transfer rules of land cover in Xining City and its surrounding areas in the past 33 years by using random forest algorithm, spatio-temporal consistency test, land use dynamic attitude, transfer matrix and transfer hot spot analysis methods. The results show that the accuracy range of the preliminary classification of construction land is improved by 1.57%-3.53 % by using the spatio-temporal consistency test algorithm. The characteristics of land cover change in the study area are mainly the increase of construction land and forest area, the decrease of cultivated land and grassland area, the small change of water body and unused land, and the change of land cover type from cultivated land to urban construction land is prominent. The hot areas of construction land have gradually shifted from the central and eastern districts of the city in 1987 to the hot areas dominated by the Haihu New District of the West of the city, the Biological Park and the higher education base of the North District of the city, the South New District of the city, Duoba Town and the Ganhe Industrial Park in 2019.

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