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1.
Comput Biol Med ; 175: 108546, 2024 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-38704902

RESUMO

Three-dimensional reconstruction of images acquired through endoscopes is playing a vital role in an increasing number of medical applications. Endoscopes used in the clinic are commonly classified as monocular endoscopes and binocular endoscopes. We have reviewed the classification of methods for depth estimation according to the type of endoscope. Basically, depth estimation relies on feature matching of images and multi-view geometry theory. However, these traditional techniques have many problems in the endoscopic environment. With the increasing development of deep learning techniques, there is a growing number of works based on learning methods to address challenges such as inconsistent illumination and texture sparsity. We have reviewed over 170 papers published in the 10 years from 2013 to 2023. The commonly used public datasets and performance metrics are summarized. We also give a taxonomy of methods and analyze the advantages and drawbacks of algorithms. Summary tables and result atlas are listed to facilitate the comparison of qualitative and quantitative performance of different methods in each category. In addition, we summarize commonly used scene representation methods in endoscopy and speculate on the prospects of deep estimation research in medical applications. We also compare the robustness performance, processing time, and scene representation of the methods to facilitate doctors and researchers in selecting appropriate methods based on surgical applications.

2.
Physiol Plant ; 176(2): e14296, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38650503

RESUMO

In Dunaliella tertiolecta, a microalga renowned for its extraordinary tolerance to high salinity levels up to 4.5 M NaCl, the mechanisms underlying its stress response have largely remained a mystery. In a groundbreaking discovery, this study identifies a choline dehydrogenase enzyme, termed DtCHDH, capable of converting choline to betaine aldehyde. Remarkably, this is the first identification of such an enzyme not just in D. tertiolecta but across the entire Chlorophyta. A 3D model of DtCHDH was constructed, and molecular docking with choline was performed, revealing a potential binding site for the substrate. The enzyme was heterologously expressed in E. coli Rosetta (DE3) and subsequently purified, achieving enzyme activity of 672.2 U/mg. To elucidate the role of DtCHDH in the salt tolerance of D. tertiolecta, RNAi was employed to knock down DtCHDH gene expression. The results indicated that the Ri-12 strain exhibited compromised growth under both high and low salt conditions, along with consistent levels of DtCHDH gene expression and betaine content. Additionally, fatty acid analysis indicated that DtCHDH might also be a FAPs enzyme, catalyzing reactions with decarboxylase activity. This study not only illuminates the role of choline metabolism in D. tertiolecta's adaptation to high salinity but also identifies a novel target for enhancing the NaCl tolerance of microalgae in biotechnological applications.


Assuntos
Betaína , Colina Desidrogenase , Tolerância ao Sal , Betaína/metabolismo , Tolerância ao Sal/genética , Colina Desidrogenase/metabolismo , Colina Desidrogenase/genética , Colina/metabolismo , Clorofíceas/genética , Clorofíceas/fisiologia , Clorofíceas/enzimologia , Clorofíceas/metabolismo , Microalgas/genética , Microalgas/enzimologia , Microalgas/metabolismo , Simulação de Acoplamento Molecular , Cloreto de Sódio/farmacologia
3.
J Agric Food Chem ; 72(17): 10005-10013, 2024 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-38626461

RESUMO

Dunaliella bardawil is a marine unicellular green algal that produces large amounts of ß-carotene and is a model organism for studying the carotenoid synthesis pathway. However, there are still many mysteries about the enzymes of the D. bardawil lycopene synthesis pathway that have not been revealed. Here, we have identified a CruP-like lycopene isomerase, named DbLyISO, and successfully cloned its gene from D. bardawil. DbLyISO showed a high homology with CruPs. We constructed a 3D model of DbLyISO and performed molecular docking with lycopene, as well as molecular dynamics testing, to identify the functional characteristics of DbLyISO. Functional activity of DbLyISO was also performed by overexpressing gene in both E. coli and D. bardawil. Results revealed that DbLyISO acted at the C-5 and C-13 positions of lycopene, catalyzing its cis-trans isomerization to produce a more stable trans structure. These results provide new ideas for the development of a carotenoid series from engineered bacteria, algae, and plants.


Assuntos
Clorofíceas , Liases Intramoleculares , Licopeno , cis-trans-Isomerases , Proteínas de Algas/genética , Proteínas de Algas/metabolismo , Proteínas de Algas/química , Sequência de Aminoácidos , Carotenoides/metabolismo , Carotenoides/química , Clorofíceas/enzimologia , Clorofíceas/genética , Clorofíceas/química , Clorofíceas/metabolismo , Clorófitas/enzimologia , Clorófitas/genética , Clorófitas/química , Clorófitas/metabolismo , cis-trans-Isomerases/genética , cis-trans-Isomerases/metabolismo , cis-trans-Isomerases/química , Escherichia coli/genética , Escherichia coli/metabolismo , Licopeno/metabolismo , Licopeno/química , Simulação de Acoplamento Molecular , Alinhamento de Sequência
4.
Gastroenterology ; 2024 Mar 24.
Artigo em Inglês | MEDLINE | ID: mdl-38531513
5.
Sensors (Basel) ; 24(4)2024 Feb 12.
Artigo em Inglês | MEDLINE | ID: mdl-38400355

RESUMO

The frequent occurrence of extreme climate events has a significant impact on people's lives. Heavy rainfall can lead to an increase of regional Terrestrial Water Storage (TWS), which will cause land subsidence due to the influence of hydrological load. At present, regional TWS is mostly obtained from Gravity Recovery and Climate Experiment (GRACE) data, but the method has limitations for small areas. This paper used water level and flow data as hydrological signals to study the land subsidence caused by heavy rainfall in the Chaohu Lake area of East China (June 2016-August 2016). Pearson's correlation coefficient was used to study the interconnection between water resource changes and Global Navigation Satellites System (GNSS) vertical displacement. Meanwhile, to address the reliability of the research results, combined with the Coefficient of determination method, the research findings were validated by using different institutional models. The results showed that: (1) During heavy rainfall, the vertical displacement caused by atmospheric load was larger than non-tidal oceanic load, and the influence trends of the two were opposite. (2) The rapidly increasing hydrologic load in the Chaohu Lake area resulted in greater subsidence displacement at the closer CORS station (CHCH station) than the more distant CORS station (LALA station). The Pearson correlation coefficients between the vertical displacement and water level were as high as -0.80 and -0.64, respectively. The phenomenon confirmed the elastic deformation principle of disc load. (3) Although there was a systematic bias between the different environmental load deformation models, the deformation trends were generally consistent with the GNSS monitoring results. The average Coefficients of determination between the different models and the GNSS results were 0.63 and 0.77, respectively. The results demonstrated the effectiveness of GNSS in monitoring short-term hydrological load. This study reveals the spatial-temporal evolution of land deformation during heavy rainfall around Chaohu Lake, which is of reference significance for water resource management and infrastructure maintenance in this area.

6.
IEEE Trans Med Imaging ; 43(5): 1934-1944, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38198275

RESUMO

In recent years, an increasing number of medical engineering tasks, such as surgical navigation, pre-operative registration, and surgical robotics, rely on 3D reconstruction techniques. Self-supervised depth estimation has attracted interest in endoscopic scenarios because it does not require ground truth. Most existing methods depend on expanding the size of parameters to improve their performance. There, designing a lightweight self-supervised model that can obtain competitive results is a hot topic. We propose a lightweight network with a tight coupling of convolutional neural network (CNN) and Transformer for depth estimation. Unlike other methods that use CNN and Transformer to extract features separately and then fuse them on the deepest layer, we utilize the modules of CNN and Transformer to extract features at different scales in the encoder. This hierarchical structure leverages the advantages of CNN in texture perception and Transformer in shape extraction. In the same scale of feature extraction, the CNN is used to acquire local features while the Transformer encodes global information. Finally, we add multi-head attention modules to the pose network to improve the accuracy of predicted poses. Experiments demonstrate that our approach obtains comparable results while effectively compressing the model parameters on two datasets.


Assuntos
Algoritmos , Endoscopia , Imageamento Tridimensional , Redes Neurais de Computação , Humanos , Endoscopia/métodos , Imageamento Tridimensional/métodos , Processamento de Imagem Assistida por Computador/métodos
7.
Artigo em Inglês | MEDLINE | ID: mdl-37126612

RESUMO

High-accuracy, high-efficiency physics-based fluid-solid interaction is essential for reality modeling and computer animation in online games or real-time Virtual Reality (VR) systems. However, the large-scale simulation of incompressible fluid and its interaction with the surrounding solid environment is either time-consuming or suffering from the reduced time/space resolution due to the complicated iterative nature pertinent to numerical computations of involved Partial Differential Equations (PDEs). In recent years, we have witnessed significant growth in exploring a different, alternative data-driven approach to addressing some of the existing technical challenges in conventional model-centric graphics and animation methods. This paper showcases some of our exploratory efforts in this direction. One technical concern of our research is to address the central key challenge of how to best construct the numerical solver effectively and how to best integrate spatiotemporal/dimensional neural networks with the available MPM's pressure solvers. In particular, we devise the MPMNet, a hybrid data-driven framework supporting the popular and powerful Material Point Method (MPM), to combine the comprehensive properties of MPM in numerically handling physical behaviors ranging from fluid to deformable solids and the high efficiency of data-driven models. At the architectural level, our MPMNet comprises three primary components: A data processing module to describe the physical properties by way of the input fields; A deep neural network group to learn the spatiotemporal features; And an iterative refinement process to continue to reduce possible numerical errors. The goal of these special technical developments is to aim at involved numerical acceleration while preserving physical accuracy, realizing efficient and accurate fluid-solid interactions in a data-driven fashion. The extensive experimental results verify that our MPMNet can tremendously speed up the computation compared with the popular numerical methods as the complexity of interaction scenes increases while better retaining the numerical accuracy.

8.
IEEE Trans Vis Comput Graph ; 28(11): 3832-3842, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-36049001

RESUMO

The ecological validity of emotion-inducing scenarios is essential for emotion research. In contrast to the classical passive induction paradigm, immersive VR fully engages the psychological and physiological components of the subject, which is considered an ecologically valid paradigm for studying emotion. Several studies investigate the emotional responses to different VR tasks or games using subjective scales. However, little research regards VR as an eliciting material, especially when systematically analyzing emotional processes in VR from a neurophysiological perspective. To fill this gap and scientifically evaluate VR's ability to be used as an active method for emotion elicitation, we investigate the dynamic relationship between explicit information (subjective evaluations) and implicit information (objective neurophysiological data). A total of 28 participants are enlisted to watch eight VR videos while their SAM/IPQ scores and EEG data are recorded simultaneously. In ecologically valid scenarios, the subjective results demonstrate that VR has significant advantages for evoking emotion in arousal-valence. This conclusion is backed by our examination of objective neurophysiological evidence that VR videos effectively induce high-arousal emotions. In addition, we obtain features of critical channels and frequency oscillations associated with emotional valence, thereby validating previous research in more lifelike circumstances. In particular, we discover hemispheric asymmetry in the occipital region under high and low emotional arousal, which adds to our understanding of neural features and the dynamics of emotional arousal. As a result, we successfully integrate EEG and VR to demonstrate that VR is more pragmatic for evoking natural feelings and is beneficial for emotional research. Our research has set a precedent for new methodologies of using VR induction paradigms to acquire a more reliable explanation of affective computing.


Assuntos
Gráficos por Computador , Realidade Virtual , Humanos , Emoções/fisiologia , Nível de Alerta/fisiologia
9.
Front Med (Lausanne) ; 9: 916565, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35721059

RESUMO

Cellular senescence is associated with tumorigenesis, and the subtype and prognostic signatures of senescence-related genes (SRGs) in the tumor microenvironment (TME) and gut microbiota have not been fully determined. Analysis of 91 SRGs obtained from the GSEA and MSigDB, and mRNA sequencing of genes in the Gene Expression Omnibus (GEO) and The Cancer Genome Atlas (TCGA) databases enabled the identification of two distinct molecular types of colorectal cancer (CRC). Patient samples were clustered into two subtypes, with Kaplan-Meier survival analyses showing significant differences in patient survival between the two subtypes. Cluster C2 was associated with patient clinicopathological features, high immune score, high abundance of immune infiltrating cells and somewhat high abundance of bacteria. A risk model based on eight SRGs showed that a low risk score was characterized by inhibition of immune activity and was indicative of better prognosis in patients with CRC. In combination with clinical characteristics, risk score was found to be an independent prognostic predictor of survival in patients with CRC. In conclusion, the present study showed that senescence-related subtypes and a signature consisting of eight SRGs were associated with CRC patient prognosis, as well as with immune cell infiltration and gut microbiota. These findings may enable better prediction of CRC patient prognosis and facilitate individualized treatments.

10.
Front Neurorobot ; 16: 883816, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35645760

RESUMO

Rock drilling robots are able to greatly reduce labor intensity and improve efficiency and quality in tunnel construction. However, due to the characteristics of the heavy load, large span, and multi-joints of the robot manipulator, the errors are diverse and non-linear, which pose challenges to the intelligent and high-precision control of the robot manipulator. In order to enhance the control accuracy, a hybrid positional error compensation method based on Radial Basis Function Network (RBFN) and Light Gradient Boosting Decision Tree (LightGBM) is proposed for the rock drilling robot. Firstly, the kinematics model of the robotic manipulator is established by applying MDH. Then a parallel difference algorithm is designed to modify the kinematics parameters to compensate for the geometric error. Afterward, non-geometric errors are analyzed and compensated by applying RBFN and lightGBM including features and kinematics model. Finally, the experiments of the error compensation by combing combining the geometric and non-geometric errors verify the performance of the proposed method.

11.
Zhongguo Shi Yan Xue Ye Xue Za Zhi ; 30(2): 565-570, 2022 Apr.
Artigo em Chinês | MEDLINE | ID: mdl-35395998

RESUMO

AbstractObjective: To investigate the clinical phenotype and genotype of an ACTN1-associated thrombocytopenic family and explore its molecular pathogenesis. METHODS: All the family members' peripheral blood was collected for routine blood tests, blood smear, coagulation function, and platelet aggregation test. Flow cytometry was used to detect the expression of platelet CD41 and CD61. The proband and her father were tested bone marrow cytomorphology. Whole-exome sequencing techniques were performed to detect and uncover mutant loci of suspected pathogenic genes. Bioinformatics was used to assess the conserved nature of the mutated loci and to analyze the effect of the mutated genes leading to the function of the corresponding amino acid sequences. RESULTS: The platelet count of the proband was 88×109/L, and the blood smear showed dumbbell-shaped platelets, snake-shaped platelets and platelets of various sizes. Her bone marrow cytomorphology revealed normal megakaryocyte morphology with a count of 270. The platelet count of the proband's father was 74×109/L, with large platelets and platelets of various sizes observed in the blood smear, and the morphology of megakaryocytes was normal in bone marrow with a megakaryocyte count of 239. Her grandfather had a platelet count of 83×109/L, with snake-shaped platelets and platelets of various sizes on blood smears. Other family members were normal in all tests. The missense mutation c.2396G > A in exon 20 of the ACTN1 gene in the proband resulted in the mutation of 799 amino acids of the encoded protein, i.e., Arg, to His. The sequencing results of her father and grandfather at this locus were found to be consistent with her. Furthermore, bioinformatics analysis indicated that the locus was highly conserved across species and that variation in this locus might lead to functional impairment of the protein. The protein model analysis demonstrated that α-actin-1 at position 799 Arg and Glu at position 811 could form a critical salt bridge which stabilizes the conformation of the Ca2+ binding loop within the calmodulin-like motif. the mutation of R799H lost this critical salt bridge and destabilized this structural domain. CONCLUSION: In the present study, the newly uncovered missense mutation c.2396G>A in exon 20 of the ACTN1 gene is potentially the molecular mechanism for the thrombocytopenia.


Assuntos
Actinina , Anemia , Trombocitopenia , Actinina/genética , Plaquetas/metabolismo , Plaquetas/patologia , Feminino , Humanos , Masculino , Megacariócitos , Mutação de Sentido Incorreto , Linhagem , Trombocitopenia/genética
12.
Clin Epigenetics ; 13(1): 223, 2021 12 16.
Artigo em Inglês | MEDLINE | ID: mdl-34915915

RESUMO

BACKGROUND: Patients with severe acute pancreatitis (SAP) have a high mortality, thus early diagnosis and interventions are critical for improving survival. However, conventional tests are limited in acute pancreatitis (AP) stratification. We aimed to assess AP severity by integrating the informative clinical measurements with cell free DNA (cfDNA) methylation markers. METHODS: One hundred and seventy-five blood samples were collected from 61 AP patients at multiple time points, plus 24 samples from healthy individuals. Genome-wide cfDNA methylation profiles of all samples were characterized with reduced representative bisulfite sequencing. Clinical blood tests covering 93 biomarkers were performed on AP patients within 24 h. SAP predication models were built based on cfDNA methylation and conventional blood biomarkers separately and in combination. RESULTS: We identified 565 and 59 cfDNA methylation markers informative for acute pancreatitis and its severity. These markers were used to develop prediction models for AP and SAP with area under the receiver operating characteristic of 0.92 and 0.81, respectively. Twelve blood biomarkers were systematically screened for a predictor of SAP with a sensitivity of 87.5% for SAP, and a specificity of 100% in mild acute pancreatitis, significantly higher than existing blood tests. An expanded model integrating 12 conventional blood biomarkers with 59 cfDNA methylation markers further improved the SAP prediction sensitivity to 92.2%. CONCLUSIONS: These findings have demonstrated that accurate prediction of SAP by the integration of conventional and novel blood molecular markers, paving the way for early and effective SAP intervention through a non-invasive rapid diagnostic test.


Assuntos
Ácidos Nucleicos Livres/genética , Metilação de DNA/genética , Pancreatite/diagnóstico , Adulto , Idoso , Biomarcadores/análise , Biomarcadores/sangue , Feminino , Estudo de Associação Genômica Ampla/métodos , Estudo de Associação Genômica Ampla/estatística & dados numéricos , Humanos , Masculino , Pessoa de Meia-Idade , Pancreatite/genética , Valor Preditivo dos Testes , Índice de Gravidade de Doença
13.
Clin Lab ; 67(3)2021 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-33739027

RESUMO

BACKGROUND: N-myc downstream regulated gene 1 (NDRG1) was involved in cell differentiation and was recently reported to exert various effects in tumorigenesis. The aim of this study was to assess its diagnostic value in urine as a useful marker for bladder cancer (BC). METHODS: In this study, we recruited 119 BC patients, 65 patients with non-cancerous bladder diseases, and 60 healthy volunteers as control. Their urine concentrations of NDRG1, nuclear matrix protein 22 (NMP22), and creatinine (Cr) were measured and relevant clinical information was retrieved from their medical history records. RESULTS: The expression of NDRG1/Cr and NMP22/Cr in urine were significantly higher in BC patients than those in non-cancerous bladder diseases (p = 0.009 and p = 0.023) and healthy controls (p = 0.005 and p = 0.002). The level of NDRG1/Cr was significantly associated with pathologic T stage (p < 0.001) and pathological grade (p < 0.001). The ROC of NDRG1/Cr to diagnose BC was 0.713 (95% CI, 0.630 - 0.797), with a sensitivity of 63.8% and a specificity of 73.4% at a cutoff of 76.3 ng/mg. NMP22/Cr was 0.705 (95% CI, 0.626 - 0.784), with a sensitivity of 64.2% and a specificity of 66.2% at a cutoff of 12.1 ng/mg. NDRG1/Cr in combination with NMP22/Cr shows a ROC of 0.719 (95% CI, 0.632 0.806) with a sensitivity of 64.9% and specificity of 75.9% Conclusions: Urine NDRG1 may be useful in a minimally invasive modality for determining bladder cancer. Predictive value of the two biomarkers was slightly higher than that of routine NMP22 parameter alone.


Assuntos
Líquidos Corporais , Neoplasias da Bexiga Urinária , Biomarcadores Tumorais , Humanos , Sensibilidade e Especificidade , Neoplasias da Bexiga Urinária/diagnóstico , Urina
14.
Biol Reprod ; 104(3): 717-730, 2021 03 11.
Artigo em Inglês | MEDLINE | ID: mdl-33330922

RESUMO

Humanin (HN) is a mitochondrial-derived peptide that protects many cells/tissues from damage. We previously demonstrated that HN reduces stress-induced male germ cell apoptosis in rodents. HN action in neuronal cells is mediated through its binding to a trimeric cell membrane receptor composed of glycoprotein 130 (gp130), IL-27 receptor subunit (IL-27R, also known as WSX-1/TCCR), and ciliary neurotrophic factor receptor subunit (CNTFR). The mechanisms of HN action in testis remain unclear. We demonstrated in ex-vivo seminiferous tubules culture that HN prevented heat-induced germ cell apoptosis was blocked by specific anti-IL-27R, anti-gp130, and anti-EBI-3, but not by anti-CNTFR antibodies significantly. The cytoprotective action of HN was studied by using groups of il-27r-/- or ebi-3-/- mice administered the following treatment: (1) vehicle; (2) a single intraperitoneal (IP) injection of HN peptide; (3) testicular hyperthermia; and (4) testicular hyperthermia plus HN. We demonstrated that HN inhibited heat-induced germ cell apoptosis in wildtype but not in il-27r-/- or ebi-3-/- mice. HN restored heat-suppressed STAT3 phosphorylation in wildtype but not il-27r-/- or ebi-3-/- mice. Dot blot analyses showed the direct interaction of HN with IL-27R or EBI-3 peptide. Immunofluorescence staining showed the co-localization of IL-27R with HN and gp130 in Leydig cells and germ cells. We conclude that the anti-apoptotic effects of HN in mouse testes are mediated through interaction with EBI-3, IL-27R, and activation of gp130, whereas the role of CNTFR needs further studies. This suggests a multicomponent tissue-specific receptor for HN in the testis and links HN action with the IL-12/IL-27 family of cytokines.


Assuntos
Células-Tronco Germinativas Adultas/efeitos dos fármacos , Interleucinas/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/farmacologia , Antígenos de Histocompatibilidade Menor/metabolismo , Receptores de Citocinas/metabolismo , Células-Tronco Germinativas Adultas/metabolismo , Animais , Anticorpos Neutralizantes , Apoptose , Regulação da Expressão Gênica , Temperatura Alta , Fragmentos Fc das Imunoglobulinas , Imunoglobulina G , Interleucinas/genética , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Antígenos de Histocompatibilidade Menor/genética , Receptores de Citocinas/genética , Receptores de Interleucina , Fator de Transcrição STAT3/genética , Fator de Transcrição STAT3/metabolismo
15.
Int J Clin Exp Pathol ; 13(2): 272-276, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32211109

RESUMO

Anorectal melanoma (ARM) is rare and lethal. We report a case of a 48-year-old woman with 9 months of rectal swelling and bleeding. Physical examination revealed a mass about 5 × 6 cm on the anterior wall of the rectum, 3 cm from the anal verge, and the patient underwent abdominoperineal resection (APR). After hematoxylin-eosin staining and immunohistochemical staining, it was considered an ARM, which is an aggressive disease with a poor survival. Immunohistochemical staining showed the tumor to be positive for S-100, Melan A, Ki67 proliferative index of 70%, and negative for HMB45. The melanoma had infiltrated the adventitia and metastasized to the (intestinal) 16/16 lymph nodes with cancerous nodule formation. There were multiple organs with metastasis (liver, spleen, pancreas, lung and subcutaneous soft tissue) three months after operation. Overall, pre-operative biopsy may be insufficient to make a definite diagnosis, and immunohistochemistry is necessary. Therefore, the gold standard treatment for ARM is oncological radical surgical resection.

16.
Exp Mol Pathol ; 109: 42-50, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31085184

RESUMO

Subfertility is a major concern of long-term cancer survivors at the reproductive age. We have previously demonstrated that a potent humanin analogue, HNG, protected chemotherapy-induced apoptosis in germ cells but not cancer cells in a metastatic melanoma allograft model. In this study, we utilized severe combined immuno-deficiency (SCID) mice bearing human medulloblastoma to study the effect of HNG in Temozolomide (TMZ) induced male germ cell apoptosis and white blood cell (WBC) suppression. Human medulloblastoma DAOY cells were injected subcutaneously into the right flank of male SCID mice. Three weeks later, groups of tumor-bearing mice received one of the following treatments: vehicle, HNG, TMZ, or TMZ + HNG. 24 h after last injection, the tumors weights, complete blood counts, liver and spleen weights, male germ cell apoptosis was assessed. HNG did not affect TMZ's significant anti-tumor action. HNG significantly prevented TMZ-induced germ cell apoptosis and attenuated the suppressed total WBC and granulocyte counts in SCID mice with or without TMZ treatment. HNG also attenuated TMZ-induced body weight loss and decrease of spleen and liver weights. In conclusion, HNG ameliorated TMZ-induced germ cell apoptosis; WBC and granulocytes loss; and decreased body/organ weights without compromising the TMZ's anti-cancer action on medulloblastoma xenografts in SCID mice.


Assuntos
Apoptose/efeitos dos fármacos , Neoplasias Cerebelares/tratamento farmacológico , Peptídeos e Proteínas de Sinalização Intracelular/farmacologia , Meduloblastoma/tratamento farmacológico , Espermatozoides/efeitos dos fármacos , Temozolomida/farmacologia , Ensaios Antitumorais Modelo de Xenoenxerto/métodos , Animais , Antineoplásicos Alquilantes/farmacologia , Linhagem Celular Tumoral , Neoplasias Cerebelares/patologia , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/química , Fígado/efeitos dos fármacos , Fígado/patologia , Masculino , Meduloblastoma/patologia , Camundongos SCID , Tamanho do Órgão/efeitos dos fármacos , Espermatozoides/citologia , Baço/efeitos dos fármacos , Baço/patologia , Carga Tumoral/efeitos dos fármacos
17.
Artigo em Inglês | MEDLINE | ID: mdl-30371373

RESUMO

In this paper, we propose a novel feature learning framework for video person re-identification (re-ID). The proposed framework largely aims to exploit the adequate temporal information of video sequences and tackle the poor spatial alignment of moving pedestrians. More specifically, for exploiting the temporal information, we design a temporal residual learning (TRL) module to simultaneously extract the generic and specific features of consecutive frames. The TRL module is equipped with two bi-directional LSTM (BiLSTM), which are respectively responsible to describe a moving person in different aspects, providing complementary information for better feature representations. To deal with the poor spatial alignment in video re- ID datasets, we propose a spatial-temporal transformer network (ST2N) module. Transformation parameters in the ST2N module are learned by leveraging the high-level semantic information of the current frame as well as the temporal context knowledge from other frames. The proposed ST2N module with less learnable parameters allows effective person alignments under significant appearance changes. Extensive experimental results on the largescale MARS, PRID2011, ILIDS-VID and SDU-VID datasets demonstrate that the proposed method achieves consistently superior performance and outperforms most of the very recent state-of-the-art methods.

18.
Mol Cell Biochem ; 425(1-2): 125-138, 2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-27848074

RESUMO

Vascular endothelial cells are highly sensitive to oxidative stress, and this is one of the mechanisms by which widespread endothelial dysfunction is induced in most cardiovascular diseases and disorders. However, how these cells can survive in oxidative stress environments remains unclear. Salidroside, a traditional Chinese medicine, has been shown to confer vascular protective effects. We aimed to understand the role of autophagy and its regulatory mechanisms by treating human umbilical vein endothelial cells (HUVECs) with salidroside under oxidative stress. HUVECs were treated with salidroside and exposed to hydrogen peroxide (H2O2). The results indicated that salidroside exerted cytoprotective effects in an H2O2-induced HUVEC injury model and suppressed H2O2-induced apoptosis of HUVECs. Pretreatment with 3-methyladenine (3-MA), an autophagy inhibitor, increased oxidative stress-induced HUVEC apoptosis, while the autophagy activator rapamycin induced anti-apoptosis effects in HUVECs. Salidroside increased autophagy and decreased apoptosis of HUVECs in a dose-dependent manner under oxidative stress. Moreover, 3-MA attenuated salidroside-induced HUVEC autophagy and promoted apoptosis, whereas rapamycin had no additional effects compared with salidroside alone. Salidroside upregulated AMPK phosphorylation but downregulated mTOR phosphorylation under oxidative stress; however, administration of compound C, an AMPK inhibitor, abrogated AMPK phosphorylation and increased mTOR phosphorylation and apoptosis compared with salidroside alone. These results suggest that autophagy is a protective mechanism in HUVECs under oxidative stress and that salidroside might promote autophagy through activation of the AMPK pathway and downregulation of mTOR pathway.


Assuntos
Proteínas Quinases Ativadas por AMP/metabolismo , Apoptose/efeitos dos fármacos , Autofagia/efeitos dos fármacos , Glucosídeos/farmacologia , Células Endoteliais da Veia Umbilical Humana/enzimologia , Estresse Oxidativo/efeitos dos fármacos , Fenóis/farmacologia , Transdução de Sinais/efeitos dos fármacos , Serina-Treonina Quinases TOR/metabolismo , Humanos
20.
Int J Biochem Cell Biol ; 69: 241-8, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26555753

RESUMO

Butyrate regulates multiple host cellular events including the cell cycle; however, little is known about the molecular mechanism by which butyrate induces a global down-regulation of the expression of genes associated with the cell cycle. Here, we demonstrate that treating HEK293T cells and the non-small-cell lung cancer cell line A549 with a high concentration of sodium butyrate reduces cyclin B1 expression. The underlying mechanism is related to the destabilization of its mRNA by tristetraprolin, which is up-regulated in response to sodium butyrate. Specifically, the sodium butyrate stimulation reduces the mRNA and protein expression of cyclin B1 and, conversely, upregulates tristetraprolin expression. Importantly, the overexpression of tristetraprolin in HEK293T decreases the mRNA and protein expression of cyclin B1; in contrast, knockdown of tristetraprolin mediated by small interfering RNA increases its expression in response to sodium butyrate treatment for both HEK293T and A549 cells. Furthermore, results from luciferase reporter assays and RNA immunoprecipitation indicate that sodium butyrate accelerates 3' UTR-dependent cyclin B1 decay by enhancing the binding of tristetraprolin to the 3' untranslated region of cyclin B1. Surprisingly, the overexpression of tristetraprolin prevents the formation of processing bodies, and the siRNA-mediated silencing of EDC4 does not restore the sodium butyrate-induced reduction of cyclin B1 expression. Thus, we confirm that NaBu regulates ZFP36-mediated cyclin B1 expression in a manner that is independent of the formation of P-bodies. The above findings disclose a novel mechanism of sodium butyrate-mediated gene expression regulation and might benefit its application in tumor treatment.


Assuntos
Ácido Butírico/farmacologia , Ciclina B1/metabolismo , Regiões 3' não Traduzidas , Sequência de Bases , Linhagem Celular Tumoral , Ciclina B1/genética , Regulação para Baixo , Expressão Gênica , Células HEK293 , Humanos , Dados de Sequência Molecular , Processamento Pós-Transcricional do RNA , Estabilidade de RNA , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Tristetraprolina/metabolismo , Tristetraprolina/farmacologia , Tristetraprolina/fisiologia
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