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Compared with ferromagnetic (FM) materials, antiferromagnetic (AFM) materials have the advantages of not generating stray fields, resisting magnetic field disturbances, and displaying ultrafast dynamics and are thus considered as ideal candidate materials for next-generation high-speed and high-density magnetic storage. In this study, a new AFM device was constructed based on density functional theory calculations through the formation of a CrBr3/Ca2N van der Waals heterostructure. The FM ground state in CrBr3 undergoes an AFM transition when combining with the electride Ca2N. In such a system, since the metal Ca atoms form the exposed layer in the electride, the heterostructure interface has a high binding energy and a large amount of charge transfer. However, for individual electron doping, the FM ground state in the CrBr3 monolayer is robust. Therefore, the main factor in magnetic phase transition is the interface orbital coupling caused by the strong binding energy. Furthermore, the interface coupling effect was revealed to be a competition between direct exchange and superexchange interactions. Additionally, different pathways of orbital hybridization cause a transition of the magnetic anisotropy from out-of-plane to in-plane. This work not only provides a feasible strategy for changing the ground state of magnetic materials on electride substrates but also brings about more possibilities for the construction and advancement of new AFM devices.
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Advancing technology and growing interdisciplinary fields create the need for new materials that simultaneously possess several significant physics qualities to meet human demands. Dirac half-metals with massless fermions hold great promise in spintronic devices and optoelectronic devices associated with nontrivial band topologies. In this work, we predict that a MnBr3 monolayer will be an intrinsic Dirac half-metal based on first-principles calculations. The lattice dynamics and thermodynamic stabilities were demonstrated by calculating the phonon spectra and performing molecular dynamics simulations. One property of a MnBr3 monolayer is that facile magnetization of its in-plane can be accomplished. A change in the magnetization direction significantly modifies the electronic band structure. When considering the spin-orbit coupling effect, the Dirac cone around the Fermi level in the spin-up channel opens a gap of 35 meV, which becomes a topological nontrivial insulator with a Chern number of -1. The Chern number sign and the chiral edge current can be tuned by changing the magnetization direction. The electronic band structure and magnetic anisotropy energy can be further modulated by applying biaxial and uniaxial strain, as well as introducing interlayer coupling in the bilayer. The unique performance of MnBr3 will broaden the utilization of two-dimensional magnetism in widespread application.
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BACKGROUND: The inhibition of osteogenic differentiation is a major factor in glucocorticoid-induced bone loss, but there is currently no effective treatment. Dopamine, a major neurotransmitter, transmits signals via five different seven-transmembrane G protein-coupled receptors termed D1 to D5. Although the relevance of the neuroendocrine system in bone metabolism has emerged, the precise effects of dopamine receptor signaling on osteoblastogenesis remain unknown. METHODS: In vitro, western blotting and immunofluorescence staining were used to observe the expression of dopamine receptors in MC3T3-E1 and BMSCs cells treated with dexamethasone (Dex). In addition, Alizarin red S (ARS) and alkaline phosphatase (ALP) staining and western blotting were used to evaluate the effect of D1R activation on osteogenic differentiation in Dex-induced MC3T3-E1 cells via the ERK1/2 signaling pathway. In vivo, micro-CT and hematoxylin and eosin (H&E), toluidine blue and immunohistochemical staining were used to determine the effect of D1R activation on Dex-induced bone loss. RESULTS: We demonstrated that the trend in D1R but not D2-5R was consistent with that of osteogenic markers in the presence of Dex. We also demonstrated that the activation of D1R promoted Dex-induced osteogenic differentiation by activating the ERK1/2 pathway in vitro. We further demonstrated that a D1R agonist could reduce Dex-induced bone loss, while pretreatment with a D1R inhibitor blocked the effect of a D1R agonist in vivo. CONCLUSIONS: Activation of D1R promotes osteogenic differentiation and reduces Dex-induced bone loss by activating the ERK1/2 pathway. Hence, D1R could serve as a potential therapeutic target for glucocorticoid-induced osteoporosis.
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Glucocorticoides , Osteogénesis , Diferenciación Celular , Glucocorticoides/efectos adversos , Sistema de Señalización de MAP Quinasas , Osteoblastos , Transducción de SeñalRESUMEN
Read-across, has generated much attention and has been used in many regulatory schemes as an alternative approach to testing globally. The regulatory application of read-across in the chemical management in China is progressing but still limited. A workshop on the "Read-across: Principle, case study and its potential regulatory application in China", organized by the Chemical Risk Assessment Specialty Group under the Committee of Industrial Toxicology of Chinese Society of Toxicology, was held on May 28, 2019 to discuss the potential broader application and acceptance of read-across to support chemical risk assessment in China. The Workshop included global experts from regulatory agencies, academia and industry. Scientific presentations and constructive discussions raised awareness on the use of read-across in different regions, identified barriers to regulatory acceptance, and participants also brainstormed on practical strategies to help facilitate the further regulatory application of read-across approaches in China.
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Seguridad Química , Medición de Riesgo/métodos , China , Agencias Gubernamentales , Sustancias Peligrosas , IndustriasRESUMEN
BACKGROUND The development and progression of hepatocellular carcinoma (HCC) are associated with obesity and hepatosteatosis. AMP-activated protein kinase (AMPK) regulates metabolic homeostasis. This study aimed to investigate the effects of treatment with the adenosine monophosphate (AMP) analog, 5-aminoimidazole-4-carboxamide ribonucleotide (AICAR) on hepatosteatosis in a mouse model fed a high-fat diet (HFD), and on hepatocellular carcinoma (HCC) induced by diethylnitrosamine (DEN) in the HFD mouse model. MATERIAL AND METHODS Male C57BL/6 male mice from two weeks of age were fed a high-fat diet, resulting in hepatosteatosis. HFD mice (15-20 per group) were treated with AICAR and without AICAR. HFD mice were treated with DEN, with and without AICAR. Mouse liver tissues were examined histologically using lipid histochemical stains, immunohistochemistry, and immunofluorescence. Levels of cytokines, alanine transaminase (ALT), triacylglyceride (TAG), and apoptosis were determined. Western blot was used to detect AMPK, pAMPK, STAT3, and pSTAT3. Real-time polymerase chain reaction (RT-PCR) detected expression of the ACL, FAS, CD36, ATGL, CPT1, and IL6 genes. RESULTS In the HFD mouse model, AICAR treatment inhibited hepatic lipid synthesis and IL-6 expression. In the DEN-treated mice, AICAR treatment reduced tumorigenesis, IL-6 signaling, and STAT3 activation. Short-term AICAR treatment had no significant effect in advanced HCC. CONCLUSIONS In an HFD mouse model, treatment with AICAR reduced the development of hepatosteatosis, and following treatment with the liver carcinogen, DEN, AICAR reduced the development of HCC. These preliminary findings support further studies on the role of AICAR in fatty liver disease and HCC.
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Aminoimidazol Carboxamida/análogos & derivados , Hígado Graso/tratamiento farmacológico , Hígado Graso/fisiopatología , Ribonucleótidos/farmacología , Proteínas Quinasas Activadas por AMP/metabolismo , Adenosina Monofosfato/análogos & derivados , Aminoimidazol Carboxamida/metabolismo , Aminoimidazol Carboxamida/farmacología , Animales , Carcinogénesis/efectos de los fármacos , Carcinogénesis/metabolismo , Carcinoma Hepatocelular/tratamiento farmacológico , Carcinoma Hepatocelular/metabolismo , Dieta Alta en Grasa , Dietilnitrosamina , Modelos Animales de Enfermedad , Interleucina-6 , Metabolismo de los Lípidos , Neoplasias Hepáticas/metabolismo , Masculino , Ratones , Ratones Endogámicos C57BL , Ribonucleótidos/metabolismo , Factor de Transcripción STAT3/metabolismo , Triglicéridos/metabolismoRESUMEN
BACKGROUND: Gastrointestinal fistula (GIF) in severe acute pancreatitis (SAP) is considered as a sparse episode and studied sporadically in the literature. There is paucity of data on the prediction of the effect on risk of GIF in patient with SAP. This study was aimed to investigate risk factors related to GIF in the development of SAP. METHODS: The clinical data of 344 patients with SAP from 2011 to 2016 were reviewed retrospectively. All patients were divided into the GIF group and the non-GIF group, and their data analyzed with respect to 15 parameters were applied to explore potential risk factors for GIF in patients with SAP. RESULTS: Of the 344 eligible patients, 52 (15.12%) progressed to GIF. Only occurrence of infected pancreatic and extra-pancreatic necrosis (IPN) (P = 0.004, OR = 3.012) and modified CT severity index (MCTSI) (P = 0.033, OR = 1.183) were proved to be independent risk factors for GIF in patients with SAP, and blood type B (P = 0.048, OR = 2.096, 95% CI: 0.748-3.562) indicated weaker association of risk factor for GIF. The early (48-72 h after admission) enteral nutrition (EEN) (P = 0.016, OR = 0.267) acted as a protective factor. CONCLUSIONS: Occurrence of IPN and high MCTSI are independent risk factors for the development of GIF in patients with SAP, blood type B reveals a potential correlation with GIF in patients with SAP. EEN is helpful to prevent the progression of GIF secondary to SAP.
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Sistema del Grupo Sanguíneo ABO , Fístula del Sistema Digestivo/sangre , Fístula del Sistema Digestivo/etiología , Páncreas/patología , Pancreatitis/complicaciones , Enfermedad Aguda , Adulto , Anciano , China , Nutrición Enteral , Femenino , Humanos , Masculino , Persona de Mediana Edad , Necrosis , Factores Protectores , Estudios Retrospectivos , Factores de Riesgo , Índice de Severidad de la EnfermedadRESUMEN
Splicing factor proline- and glutamine-rich (SFPQ) regulates transcripts in skeletal muscle metabolism and tumorigenesis. As osteosarcoma (OS) is the most common malignant bone tumor characterized by genome instability, such as MYC amplification, this study aimed to investigate the role and mechanism of SFPQ in OS. Expression of SFPQ in OS cell lines and human OS tissues was detected using quantitative real-time PCR, western blot, and fluorescence in situ hybridization (FISH) analyses. The oncogenic role of SFPQ in OS cells and murine xenograft models and the underlying mechanism of SFPQ on the c-Myc signaling pathway were assessed in vitro and in vivo. Results showed that SFPQ expression was upregulated and correlated with poor prognosis in OS patients. SFPQ overexpression promoted the malignant biological behavior of OS cells, while its knockdown markedly reduced the oncogenic function of OS. Additionally, depletion of SFPQ inhibited OS growth and bone destruction in nude mice. SFPQ overexpression induced malignant biological behaviors, which could be rescued by the depletion of c-Myc. These results suggest an oncogenic role of SFPQ in OS, possibly through the c-Myc signaling pathway.
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Currently, the failure rate for internal fixation in patients with osteoporosis can be reduced by antiosteoporosis therapy alone. However, the administration of anti-osteoporotic drugs is not a complete solution. Therefore, it is necessary to investigate other causes of surgical failure, such as inflammation. In recent years, the inflammation caused by macrophage M1 polarization has garnered wide attention. The purpose of this research is to explore the inhibitory effect of avicularin (AL) on macrophage M1 polarization, by which it ameliorates inflammation, thus alleviating implant instability. We established an osteoporosis mouse model of implant loosening. The mouse tissues were taken out for morphological analysis, staining analysis and bone metabolic index analysis. In in vitro experiments, bone marrow derived macrophages (BMDM) and RAW264.7 cells were polarized to M1 macrophages using lipopolysaccharide (LPS), and analyzed by immunofluorescence (IF) staining, Western blot (WB) and flow cytometry. WB was also used to analyze the nuclear factor kappa-B (NF-κB) pathway. In addition, the expression levels of inflammatory cytokines were detected in cell supernatant using ELISA kits. Through observation of this experiments, we found that AL can inhibit M1 polarization of macrophages. Moreover, it can significantly inhibit the release of inflammatory factors to improve multiple mouse femur parameters. Furthermore, AL inhibited the phosphorylation of IKBα and P65 in the NF-κB pathway. The above data indicate that AL ameliorates inflammatory responses by inhibiting macrophage M1 polarization via its inhibitory effect on the NF-κB pathway, thus alleviating the instability of implants in mice with osteoporosis.
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FN-kappa B , Transducción de Señal , Ratones , Animales , FN-kappa B/metabolismo , Macrófagos/metabolismo , Inflamación/tratamiento farmacológico , Inflamación/metabolismo , Lipopolisacáridos/farmacología , Lipopolisacáridos/metabolismo , Activación de MacrófagosRESUMEN
Research on the implications of ferroptosis in tumors has increased rapidly in the last decades. There are evidences that ferroptosis is involved in several aspects of cancer biology, including tumor progression, metastasis, immunomodulation, and therapeutic response. Nonetheless, the interaction between ferroptosis-related lncRNAs (FRLs) and the osteosarcoma immune microenvironment is poorly understood. In this study, a risk model composed of FRLs was developed using univariate and LASSO Cox regression analyses. On the basis of this model, FRL scores were calculated to systematically explore the role of the model in predicting the prognosis and immune characteristics of osteosarcoma patients. Survival analysis showed that osteosarcoma samples with lower FRL-score had better overall survival. After predicting the abundance of immune cells in osteosarcoma microenvironment by single-sample gene-set enrichment analysis (ssGSEA) and ESTIMATE analysis, we found that the FRL-score could distinguish immune function, immune score, stromal score, tumor purity, and tumor infiltration of immune cells in different osteosarcoma patients. In addition, FRL-score was also associated with immune checkpoint gene expression and half-maximal inhibitory concentration of chemotherapeutic agents. Finally, we confirmed that knockdown of RPARP-AS1 suppressed the malignant activity of osteosarcoma cells in vitro experiments. In general, the FRL-based prognostic signature could promote our understanding of the immune microenvironment characteristics of osteosarcoma and guide more effective treatment regimens.
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OBJECTIVE: Osteosarcoma is the most frequent primary bone malignancy, associated with frequent recurrence and lung metastasis. RNA-binding proteins (RBPs) are pivotal in regulating several aspects of cancer biology. Nonetheless, interaction between RBPs and the osteosarcoma immune microenvironment is poorly understood. We investigated whether RBPs can predict prognosis and immunotherapy response in osteosarcoma patients. METHODS: We constructed an RBP-related prognostic signature (RRPS) by univariate coupled with multivariate analyses and verified the independent prognostic efficacy of the signature. Single-sample Gene Set Enrichment Analysis (ssGSEA) along with ESTIMATE analysis were carried out to investigate the variations in immune characteristics between subgroups with various RRPS-scores. Furthermore, we investigatedpossible small molecule drugs using the connectivity map database and validated the expression of hub RBPs by qRT-PCR. RESULTS: The RRPS, consisting of seven hub RBPs, was an independent prognostic factor compared to traditional clinical features. The RRPS could distinguish immune functions, immune score, stromal score, tumor purity and tumor infiltration by immune cells in different osteosarcoma subjects. Additionally, patients with high RRPS-scores had lower expression of immune checkpoint genes than patients with low RRPS-scores. We finally identified six small molecule drugs that may improve prognosis in osteosarcoma patients and substantiated notable differences in the contents of these RBPs. CONCLUSION: We evaluated the prognostic value and clinical application of an RBPs-based prognostic signature and identified promising biomarkers to predict immune cell infiltration and immunotherapy response in osteosarcoma.
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Osteosarcoma is a primary malignant bone tumor that occurs frequently in children and adolescents and has a propensity for drug resistance, recurrence, and metastasis. The purpose of this study was to identify potential target genes to predict metastasis and survival in patients with osteosarcoma. We analyzed gene expression profiles and corresponding clinical data of patients with osteosarcoma in the Gene Expression Omnibus database and identified 202 genes that were differentially expressed between osteosarcoma cells and normal osteoblasts. Univariate and multivariable Cox regression analyses identified four risk genes that affected osteosarcoma prognosis: MCAM, ENPEP, LRRC1, and CPE. Independent prognostic analyses and clinical correlation studies showed that the four risk genes constituted an independent prognostic signature that correlated with survival and clinical parameters including age and distant metastasis. In a single-sample Gene Set Enrichment Analysis, risk scores based on the prognostic signature correlated with tumor infiltration by immune cells and immune functions in osteosarcoma. A subsequent analysis showed that the expression levels of the four genes in the prognostic signature were predictive of overall survival and metastasis-free survival of patients with osteosarcoma. Furthermore, Human Cancer Metastasis Database and qRT-PCR analyses demonstrated that the four risk genes are overexpressed in osteosarcoma tissues and cell lines. In summary, we developed and validated a four-gene prognostic signature that may be useful in osteosarcoma diagnosis and metastasis prediction.
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Osteosarcoma is a common malignant bone tumor with a propensity for drug resistance, recurrence, and metastasis. A growing number of studies have elucidated the dual role of pyroptosis in the development of cancer, which is a gasdermin-regulated novel inflammatory programmed cell death. However, the interaction between pyroptosis and the overall survival (OS) of osteosarcoma patients is poorly understood. This study aimed to construct a prognostic model based on pyroptosis-related genes to provide new insights into the prognosis of osteosarcoma patients. We identified 46 differentially expressed pyroptosis-associated genes between osteosarcoma tissues and normal control tissues. A total of six risk genes affecting the prognosis of osteosarcoma patients were screened to form a pyroptosis-related signature by univariate and LASSO regression analysis and verified using GSE21257 as a validation cohort. Combined with other clinical characteristics, including age, gender, and metastatic status, we found that the pyroptosis-related signature score, which we named "PRS-score," was an independent prognostic factor for patients with osteosarcoma and that a low PRS-score indicated better OS and a lower risk of metastasis. The result of ssGSEA and ESTIMATE algorithms showed that a lower PRS-score indicated higher immune scores, higher levels of tumor infiltration by immune cells, more active immune function, and lower tumor purity. In summary, we developed and validated a pyroptosis-related signature for predicting the prognosis of osteosarcoma, which may contribute to early diagnosis and immunotherapy of osteosarcoma.
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There exists an emergency clinical demand to overcome TRAIL/Apo2L (tumor necrosis factor-related apoptosis-inducing ligand) resistance, which is a major obstacle attributed to insufficient level or mutation of TRAIL receptors. Here, we developed an iron oxide cluster-based nanoplatform for both sensitization and MR image-guided evaluation to improve TRAIL/Apo2L efficacy in colorectal cancer, which has an inadequate response to TRAIL/Apo2L or chemotherapy. Specifically, NanoTRAIL (TRAIL/Apo2L-iron oxide nanoparticles) generated ROS (reactive oxygen species)-triggered JNK (c-Jun N-terminal kinase) activation and induced subsequent autophagy-assisted DR5 upregulation, resulting in a significant enhanced antitumor efficacy of TRAIL/Apo2L, which confirmed in both TRAIL-resistant HT-29, intermediately resistant SW-480 and sensitive HCT-116 cells. Furthermore, in a subcutaneous colorectal cancer mouse model, the in vivo tumor retention of NanoTRAIL can be demonstrated by MR T2 weighted contrast imaging, and NanoTRAIL significantly suppressed tumor growth and prolonged the survival time without observable adverse effects compared with control and TRAIL/Apo2L monotherapy. Importantly, in the study of colorectal cancer patient-derived xenograft models, we found that the NanoTRAIL treatment could significantly improve the survival outcome with consistent ROS-dependent autophagy-assisted DR5 upregulation and tumor apoptosis. Our results describe a transformative design that can be applied clinically to sensitize Apo2L/TRAIL-resistant patients using FDA-approved iron oxide nanoparticles.
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Nanopartículas Magnéticas de Óxido de Hierro , Neoplasias , Animales , Apoptosis , Línea Celular Tumoral , Humanos , Ratones , Estrés Oxidativo , Receptores del Ligando Inductor de Apoptosis Relacionado con TNF/genética , Receptores del Ligando Inductor de Apoptosis Relacionado con TNF/metabolismo , Ligando Inductor de Apoptosis Relacionado con TNF/metabolismo , Factor de Necrosis Tumoral alfa/metabolismo , Regulación hacia ArribaRESUMEN
(-)-Epigallocatechin-3-gallate (EGCG), a major component of green tea, protects against certain types of cancers, although the mechanism has not yet been determined. It was previously demonstrated that EGCG blocks aryl hydrocarbon receptor (AhR)-mediated transcription induced by the potent carcinogen 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). Unlike other AhR antagonists that directly bind to the AhR, EGCG inhibits AhR-mediated transcription by binding to hsp90. We hypothesize that EGCG exerts anti-AhR and anticancer effects by acting as an hsp90 inhibitor. Using proteolytic footprinting, immunoprecipitation, and an ATP-agarose pull-down assay, EGCG was found to directly modulate the conformation of hsp90 and bind at or near to a C-terminal ATP binding site. Hsp90 chaperone function, as assessed by its ability to mediate refolding of denatured luciferase, was inhibited by EGCG treatment. Hsp90 dimerization, which occurs at the C-terminal end, was also inhibited by EGCG treatment. Coimmunoprecipitation studies showed that EGCG stabilizes an AhR complex that includes hsp90 and XAP2 (hepatitis B virus X-associated protein 2), and decreases the association of aryl hydrocarbon nuclear translocator (Arnt) with ligand-activated AhR. Thus, EGCG, through its ability to bind to hsp90, blocks AhR response element (AhRE) recognition. These studies indicate a novel mechanism whereby EGCG inhibits ligand-induced AhRE binding and AhR-mediated transcriptional activity. In EGCG-treated human ovarian carcinoma SKOV3 cells, decreased levels of several cancer-related hsp90 client proteins, such as ErbB2, Raf-1 and phospho-AKT, were observed. EGCG also modified the association of hsp90 with several cochaperones. Overall, these data indicate that EGCG is a novel hsp90 inhibitor. Further studies are needed to determine if this has a role in the antitumor actions of EGCG.
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Catequina/análogos & derivados , Proteínas HSP90 de Choque Térmico/antagonistas & inhibidores , Animales , Sitios de Unión/genética , Catequina/metabolismo , Catequina/farmacología , Línea Celular Tumoral , Pollos , Dimerización , Relación Dosis-Respuesta a Droga , Glutatión Transferasa/metabolismo , Proteínas HSP90 de Choque Térmico/genética , Proteínas HSP90 de Choque Térmico/aislamiento & purificación , Humanos , Ligandos , Ratones , Modelos Biológicos , Chaperonas Moleculares/antagonistas & inhibidores , Chaperonas Moleculares/genética , Mapeo Peptídico , Plásmidos , Unión Proteica/genética , Conformación Proteica/efectos de los fármacos , Receptores de Hidrocarburo de Aril/metabolismo , Proteínas Recombinantes de Fusión/metabolismo , Elementos de Respuesta/efectos de los fármacos , Té/genética , Factores de Tiempo , Transcripción Genética/efectos de los fármacosRESUMEN
BACKGROUND: Hepatocellular carcinoma (HCC) (about 85-90% of primary liver cancer) is particularly prevalent in China because of the high prevalence of chronic hepatitis B infection. HCC is the fourth most common malignancy and the third leading cause of tumor-related deaths in China. It poses a significant threat to the life and health of Chinese people. SUMMARY: This guideline presents official recommendations of the National Health and Family Planning Commission of the People's Republic of China on the surveillance, diagnosis, staging, and treatment of HCC occurring in China. The guideline was written by more than 50 experts in the field of HCC in China (including liver surgeons, medical oncologists, hepatologists, interventional radiologists, and diagnostic radiologists) on the basis of recent evidence and expert opinions, balance of benefits and harms, cost-benefit strategies, and other clinical considerations. KEY MESSAGES: The guideline presents the Chinese staging system, and recommendations regarding patients with HCC in China to ensure optimum patient outcomes.
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OBJECTIVE: To examine the nephrotoxicity induced caused by combined effect of arsenic and cadmium in exposed workers. METHODS: Urinary cadmium and arsenic were used as the exposure biomarkers of cadmium and arsenic. Urinary beta2-microglobulin (Ubeta2-MG), albumin (UALB) and N-acetyl-beta-D-glucosaminidase (UNAG) were measured as the effective biomarkers of tubular and glomerular dysfunction induced by cadmium and arsenic. RESULTS: The combination of cadmium and arsenic induced more severe renal injury than that caused by either of the chemicals given alone. There were positive correlations and significant dose-effect among the concentrations of urinary cadmium, arsenic and levels of Ubeta2-MG, UALB, UNAG (P<0.05, P<0.01). CONCLUSION: Cadmium combined with arsenic may have additive effect on renal dysfunction in workers exposed to arsenic and cadmium.
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Arsénico/toxicidad , Cadmio/toxicidad , Riñón/efectos de los fármacos , Exposición Profesional , Adulto , Albuminuria/inducido químicamente , Arsénico/orina , Cadmio/orina , Relación Dosis-Respuesta a Droga , Femenino , Humanos , Masculino , Persona de Mediana Edad , Microglobulina beta-2/orinaRESUMEN
The ubiquitin interaction motif-containing protein RAP80 was recently found to play a key role in DNA damage response (DDR) signaling by facilitating the translocation of several DDR mediators, including BRCA1, to ionizing irradiation (IR)-induced foci. In this study, we examine the effect of the loss of RAP80 on genomic stability and the susceptibility to cancer development in RAP80 null (RAP80(-/-)) mice. RAP80(-/-) mice are viable and did not exhibit any apparent developmental defects. Mouse embryonic fibroblasts (MEF) derived from RAP80(-/-) mice underwent premature senescence compared with wild-type (WT) MEFs, were more sensitive to IR, and exhibited a higher level of spontaneous and IR-induced genomic instability. RAP80(-/-) thymocytes were more sensitive to IR-induced cell death than WT thymocytes. RAP80(-/-) mice were more susceptible to spontaneous lymphoma development and the development of 7,12-dimethylbenz(a)anthracene-induced mammary gland tumors. Moreover, the loss of RAP80 accelerated tumor formation in both p53(-/-) and p53(+/-) mice. Our data indicate that RAP80-deficiency promotes genomic instability and causes an increase in cancer risk consistent with the concept that RAP80 exhibits a tumor suppressor function.
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Proteínas de Ciclo Celular/genética , Inestabilidad Genómica/genética , Factores de Transcripción/genética , Proteínas Supresoras de Tumor/genética , Animales , Benzo(a)Antracenos , Células Cultivadas , Senescencia Celular/genética , Senescencia Celular/efectos de la radiación , Proteínas de Unión al ADN , Embrión de Mamíferos/citología , Femenino , Fibroblastos/metabolismo , Fibroblastos/efectos de la radiación , Regulación Neoplásica de la Expresión Génica , Inestabilidad Genómica/efectos de la radiación , Chaperonas de Histonas , Estimación de Kaplan-Meier , Linfoma/genética , Linfoma/patología , Masculino , Neoplasias Mamarias Experimentales/inducido químicamente , Neoplasias Mamarias Experimentales/genética , Neoplasias Mamarias Experimentales/patología , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Timocitos/metabolismo , Timocitos/efectos de la radiación , Proteína p53 Supresora de Tumor/genéticaRESUMEN
GLI-similar (Glis) 1-3 proteins constitute a subfamily of the Krüppel-like zinc finger transcription factors that are closely related to the Gli family. Glis1-3 play critical roles in the regulation of a number of physiological processes and have been implicated in several pathologies. Mutations in GLIS2 have been linked to nephronophthisis, an autosomal recessive cystic kidney disease. Loss of Glis2 function leads to renal atrophy and fibrosis that involves epithelial-mesenchymal transition (EMT) of renal tubule epithelial cells. Mutations in human GLIS3 have been implicated in a syndrome characterized by neonatal diabetes and congenital hypothyroidism (NDH) and in some patients accompanied by polycystic kidney disease, glaucoma, and liver fibrosis. In addition, the GLIS3 gene has been identified as a susceptibility locus for the risk of type 1 and 2 diabetes. Glis3 plays a key role in pancreatic development, particularly in the generation of ß-cells and in the regulation of insulin gene expression. Glis2 and Glis3 proteins have been demonstrated to localize to the primary cilium, a signaling organelle that has been implicated in several pathologies, including cystic renal diseases. This association suggests that Glis2/3 are part of primary cilium-associated signaling pathways that control the activity of Glis proteins. Upon activation in the primary cilium, Glis proteins may translocate to the nucleus where they subsequently regulate gene transcription by interacting with Glis-binding sites in the promoter regulatory region of target genes. In this review, we discuss the current knowledge of the Glis signaling pathways, their physiological functions, and their involvement in several human pathologies.