Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 38
Filtrar
Mais filtros

Base de dados
Tipo de documento
Intervalo de ano de publicação
1.
Genet Med ; 26(7): 101126, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38529886

RESUMO

PURPOSE: DISP1 encodes a transmembrane protein that regulates the secretion of the morphogen, Sonic hedgehog, a deficiency of which is a major cause of holoprosencephaly (HPE). This disorder covers a spectrum of brain and midline craniofacial malformations. The objective of the present study was to better delineate the clinical phenotypes associated with division transporter dispatched-1 (DISP1) variants. METHODS: This study was based on the identification of at least 1 pathogenic variant of the DISP1 gene in individuals for whom detailed clinical data were available. RESULTS: A total of 23 DISP1 variants were identified in heterozygous, compound heterozygous or homozygous states in 25 individuals with midline craniofacial defects. Most cases were minor forms of HPE, with craniofacial features such as orofacial cleft, solitary median maxillary central incisor, and congenital nasal pyriform aperture stenosis. These individuals had either monoallelic loss-of-function variants or biallelic missense variants in DISP1. In individuals with severe HPE, the DISP1 variants were commonly found associated with a variant in another HPE-linked gene (ie, oligogenic inheritance). CONCLUSION: The genetic findings we have acquired demonstrate a significant involvement of DISP1 variants in the phenotypic spectrum of midline defects. This underlines its importance as a crucial element in the efficient secretion of Sonic hedgehog. We also demonstrated that the very rare solitary median maxillary central incisor and congenital nasal pyriform aperture stenosis combination is part of the DISP1-related phenotype. The present study highlights the clinical risks to be flagged up during genetic counseling after the discovery of a pathogenic DISP1 variant.


Assuntos
Alelos , Holoprosencefalia , Fenótipo , Adolescente , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Masculino , Anodontia , Fenda Labial/genética , Fenda Labial/patologia , Fissura Palatina/genética , Fissura Palatina/patologia , Anormalidades Craniofaciais/genética , Anormalidades Craniofaciais/patologia , Heterozigoto , Holoprosencefalia/genética , Holoprosencefalia/patologia , Homozigoto , Incisivo/anormalidades , Proteínas de Membrana/genética , Mutação de Sentido Incorreto/genética
2.
BMC Cancer ; 23(1): 42, 2023 Jan 11.
Artigo em Inglês | MEDLINE | ID: mdl-36631762

RESUMO

BACKGROUND: This study aimed to develop an integrated model for predicting the occurrence of postoperative seizures in patients with diffuse high-grade gliomas (DHGGs) using clinical and RNA-seq data. METHODS: Patients with DHGGs, who received prophylactic anti-epileptic drugs (AEDs) for three months following surgery, were enrolled into the study. The patients were assigned randomly into training (n = 166) and validation (n = 42) cohorts. Differentially expressed genes (DEGs) were identified based on preoperative glioma-related epilepsy (GRE) history. Least absolute shrinkage and selection operator (LASSO) logistic regression analysis was used to construct a predictive gene-signature for the occurrence of postoperative seizures. The final integrated prediction model was generated using the gene-signature and clinical data. Receiver operating characteristic analysis and calibration curve method were used to evaluate the accuracy of the gene-signature and prediction model using the training and validation cohorts. RESULTS: A seven-gene signature for predicting the occurrence of postoperative seizures was developed using LASSO logistic regression analysis of 623 DEGs. The gene-signature showed satisfactory predictive capacity in the training cohort [area under the curve (AUC) = 0.842] and validation cohort (AUC = 0.751). The final integrated prediction model included age, temporal lobe involvement, preoperative GRE history, and gene-signature-derived risk score. The AUCs of the integrated prediction model were 0.878 and 0.845 for the training and validation cohorts, respectively. CONCLUSION: We developed an integrated prediction model for the occurrence of postoperative seizures in patients with DHGG using clinical and RNA-Seq data. The findings of this study may contribute to the development of personalized management strategies for patients with DHGGs and improve our understanding of the mechanisms underlying GRE in these patients.


Assuntos
Epilepsia , Glioma , Humanos , Estudos Retrospectivos , Glioma/genética , Glioma/cirurgia , Curva ROC , Epilepsia/genética , Epilepsia/cirurgia , Convulsões/genética
3.
J Headache Pain ; 24(1): 4, 2023 Jan 14.
Artigo em Inglês | MEDLINE | ID: mdl-36641423

RESUMO

BACKGROUND: While new genetic analysis methods are widely used in the clinic, few researchers have focused on trigeminal neuralgia (TN) with familial clustering (≥ 2 TN patients in one kindred family). Previous literature suggests that familial trigeminal neuralgia (FTN) may be associated with inherited genetic factors. To date, few next-generation sequencing studies have been reported for FTN. This study investigated the pathogenic mechanism of FTN by using whole-exome sequencing (WES) technology, which may enhance our understanding of human TN pathophysiology.  METHOD: We performed WES for 7 probands from families of FTN. Sanger sequencing was performed for two control groups (FTN family members group and nonfamilial TN subject group) to potentially identify new FTN-related gene mutations. In families where FTN probands carried potentially pathogenic gene mutations, the ribonucleic acid (RNA) of FTN probands and related family members, as well as nonfamilial TN patients were analysed by RNA sequencing (RNA-seq) to confirm differential gene expression. RESULTS: Seven probands were derived from 3 Chinese families. WES and Sanger sequencing identified MARS1 mutation c.2398C > A p.(Pro800Thr) in Family 1. MARS1 mutation was confirmed in 14/26 [53.8%] members of Family 1 in FTN family member group, while none of nonfamilial TN subjects had this MARS1 mutation. RNA-seq showed that 3 probands in Family 1 had higher expression of Fosl1 (Fos-like antigen 1) and NFE2 (Nuclear factor, erythroid 2) than 3 subjects in the nonfamilial TN subject group. Fosl1 and NFE2 are genes related to integrated stress response (ISR). CONCLUSION: MARS1 mutations may cause chronic activation of ISR, contribute to ISR pathophysiological changes in FTN, and cause/accelerate peripheral nerve degeneration. The findings of this study can enrich our knowledge of the role of molecular genetics in TN in humans.


Assuntos
Metionina tRNA Ligase , Neuralgia do Trigêmeo , Humanos , Mutação , Linhagem , Neuralgia do Trigêmeo/genética , Metionina tRNA Ligase/genética
4.
Neuroradiology ; 64(9): 1819-1828, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35348814

RESUMO

PURPOSE: The study aimed to assess how isocitrate dehydrogenase 1 (IDH1) mutation status in patients with glioma may alter functional connectivity (FC) in the default mode network (DMN) and fronto-parietal network (FPN). METHODS: Using resting-state functional magnetic resonance imaging, a seed-based FC analysis was employed to investigate connectivity within and between networks in seventeen patients with IDH1-mutant glioma (IDH1-M), eleven patients with IDH1-wildtype glioma (IDH1-WT), and nineteen healthy controls (HC). RESULTS: For FC within the DMN, compared to HC, both IDH1-M and IDH1-WT exhibited significantly increased FC between the posterior cingulate cortex (PCC) and the right retrosplenial cortex, right precuneus/cuneus, and right middle cingulate cortex and between the right lateral parietal cortex (LP_R) and the right middle temporal gyrus. For FC within the FPN, compared with HC, IDH1-M showed significantly greater FC between the right posterior parietal cortex (PPC_R) and the right inferior, right medial, and right middle frontal gyrus, and IDH1-WT showed significantly increased FC between the PPC_R and the right middle frontal gyrus. For FC between the DMN and FPN, relative to IDH1-WT and HC, IDH1-M exhibited significantly increased FC between the LP_R and the right superior frontal gyrus and between the PPC_R and the right precuneus/cuneus. In contrast, compared to IDH1-M and HC, IDH1-WT showed significantly reduced FC between the PPC_R and the right angular gyrus. CONCLUSION: The preliminary findings revealed that there should be differences in the patterns of network reorganization between IDH1-M and IDH1-WT with different growth kinetics.


Assuntos
Mapeamento Encefálico , Glioma , Encéfalo , Lobo Frontal/diagnóstico por imagem , Glioma/diagnóstico por imagem , Glioma/genética , Humanos , Isocitrato Desidrogenase/genética , Imageamento por Ressonância Magnética , Mutação
5.
J Prosthodont ; 31(5): 374-384, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-34499376

RESUMO

PURPOSE: The fracture resistance of dental post systems is influenced by the material of the post. The purpose of this systematic review and meta-analysis was to assess if there is a difference in fracture resistance between prefabricated dental titanium posts and fiber posts. METHODS: An online electronic search was performed using the PubMed, Scopus, and Web of Science databases for in vitro studies published from 2010 to 2020 in English. The retrieved eligible studies that compared the fracture resistance of titanium and fiber posts on human teeth were selected. The pooled standardized mean difference (SMD) with a 95% confidence interval was calculated. In addition, the trial sequential analysis (TSA) was performed to test if the available studies are sufficient to make conclusive evidence. RESULTS: Of the 1165 retrieved studies, 17 studies were included in the qualitative analysis, while 16 studies were included in the quantitative analysis. Because of the high heterogeneity among studies, data from 10 studies were pooled and submitted to TSA. A total of 852 teeth were evaluated for fracture of the posts in 27 independent comparison groups. The pooled effect of the residual studies revealed no significant difference between titanium and fiber posts (SMD = -0.12; 95% CI = -0.30, 0.06; p = 0.20). Results of the TSA revealed no conclusive evidence. CONCLUSIONS: The results of the current evidence revealed no significant difference between fiber and titanium posts. The evidence is insufficient, and more standardized in vitro studies are required.


Assuntos
Técnica para Retentor Intrarradicular , Fraturas dos Dentes , Dente não Vital , Resinas Compostas , Falha de Restauração Dentária , Análise do Estresse Dentário , Vidro , Humanos , Técnica para Retentor Intrarradicular/efeitos adversos , Titânio , Fraturas dos Dentes/etiologia
6.
Mol Cell Proteomics ; 15(2): 614-23, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26598640

RESUMO

We aimed to globally discover serum biomarkers for diagnosis of gastric cancer (GC). GC serum autoantibodies were discovered and validated using serum samples from independent patient cohorts encompassing 1,401 participants divided into three groups, i.e. healthy, GC patients, and GC-related disease group. To discover biomarkers for GC, the human proteome microarray was first applied to screen specific autoantibodies in a total of 87 serum samples from GC patients and healthy controls. Potential biomarkers were identified via a statistical analysis protocol. Targeted protein microarrays with only the potential biomarkers were constructed and used to validate the candidate biomarkers using 914 samples. To provide further validation, the abundance of autoantibodies specific to the biomarker candidates was analyzed using enzyme-linked immunosorbent assays. Receiver operating characteristic curves were generated to evaluate the diagnostic accuracy of the serum biomarkers. Finally, the efficacy of prognosis efficacy of the final four biomarkers was evaluated by analyzing the clinical records. The final panel of biomarkers consisting of COPS2, CTSF, NT5E, and TERF1 provides high diagnostic power, with 95% sensitivity and 92% specificity to differentiate GC patients from healthy individuals. Prognosis analysis showed that the panel could also serve as independent predictors of the overall GC patient survival. The panel of four serum biomarkers (COPS2, CTSF, NT5E, and TERF1) could serve as a noninvasive diagnostic index for GC, and the combination of them could potentially be used as a predictor of the overall GC survival rate.


Assuntos
Biomarcadores Tumorais/biossíntese , Proteínas de Neoplasias/biossíntese , Neoplasias Gástricas/sangue , Neoplasias Gástricas/genética , Biomarcadores Tumorais/sangue , Detecção Precoce de Câncer , Feminino , Humanos , Masculino , Proteínas de Neoplasias/sangue , Prognóstico , Análise Serial de Proteínas , Proteoma/genética , Neoplasias Gástricas/patologia
7.
Addict Biol ; 22(2): 435-445, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26692025

RESUMO

The glutamatergic projection from the ventral subiculum of the hippocampus (vSUB) to the nucleus accumbens (NAc) shell has been reported to play a key role in drug-related behavior. The GluN2B subunit of N-methyl-D-aspartate receptors (NMDARs) in the NAc can be selectively elevated after the retrieval of drug-conditioned memory. However, whether the increased GluN2B-containing NMDARs (GluN2B-NMDARs) are able to alter the synaptic plasticity of the vSUB-NAc glutamatergic pathway remains unclear. Here, we found that the long-term potentiation (LTP) in the vSUB-NAc pathway was facilitated and the GluN2B subunit protein level was elevated in synaptoneurosomes of the NAc shell, but not in the core, following morphine-induced conditioned place preference (CPP) expression in rats. The facilitated LTP was prevented by the GluN2B-NMDAR antagonist RO25-6981. Also, a neurochemical disconnection following microinjection of RO25-6981 into the NAc shell, plus microinfusion of GABA agonist baclofen and muscimol into the contralateral vSUB prevented the expression of morphine-induced CPP. These findings suggest that the retrieval of drug-associated memory potentiated synaptic plasticity in the vSUB-NAc pathway, which was dependent on GluN2B-NMDAR activation in the NAc shell. These findings provide a new explanation for the mechanisms that underlie the morphine-associated-context memory. The GluN2B-NMDARs may be regarded as a potential target for erasing morphine-related memory.


Assuntos
Analgésicos Opioides/farmacologia , Comportamento Animal/efeitos dos fármacos , Condicionamento Operante , Hipocampo/efeitos dos fármacos , Potenciação de Longa Duração/efeitos dos fármacos , Morfina/farmacologia , Núcleo Accumbens/efeitos dos fármacos , Receptores de N-Metil-D-Aspartato/efeitos dos fármacos , Animais , Baclofeno/farmacologia , Agonistas de Receptores de GABA-A/farmacologia , Agonistas dos Receptores de GABA-B/farmacologia , Hipocampo/metabolismo , Masculino , Memória/efeitos dos fármacos , Muscimol/farmacologia , Núcleo Accumbens/metabolismo , Fenóis/farmacologia , Piperidinas/farmacologia , Ratos , Ratos Sprague-Dawley , Receptores de N-Metil-D-Aspartato/antagonistas & inibidores , Receptores de N-Metil-D-Aspartato/metabolismo
8.
Addict Biol ; 20(5): 927-40, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25736529

RESUMO

Emerging evidence indicates that metabotropic glutamate receptor 5 (mGluR5) critically modulates drug and drug-related behaviors. However, the role of mGluR5 in the opiate-induced contextual memory remains unclear. Here, we found that microinfusion of the mGluR5 antagonist 3-((2-Methyl-1,3-thiazol-4-yl)ethynyl)pyridine (MTEP) into the nucleus accumbens (NAc) shell, but not into the core, significantly attenuated the expression of morphine conditioned place preference (CPP) in rats. Following the expression of morphine CPP, the protein level of membrane mGluR5 was selectively increased in the NAc shell. In primary striatal neurons, we observed that treatment with the mGluR5 agonist CHPG increased the phosphorylation level of extracellular signal-regulated kinase (ERK), which was dependent on the mGluR5-inositol-1,4,5-trisphosphate-reactive oxygen species (ROS) pathway. Moreover, the microinjection of the ROS scavenger Tempol into the NAc shell of rats blocked the expression of morphine CPP. Further, the administration of t-BOOH, a ROS donor, into the NAc shell rescued the retrieval impairment of morphine CPP produced by MTEP. Our previous study demonstrated that the expression of morphine CPP increased the phosphorylation of ERK selectively in the NAc shell. Thus, results of the present study suggest that mGluR5 in the NAc shell, but not in the core, is essential for the retrieval of morphine contextual memory, which is mediated at least in part, through the ROS/ERK signaling pathway. Uncovering the molecular basis of opiate contextual memory will benefit the development of new therapeutic approaches for the treatment of opiate addiction.


Assuntos
Memória/efeitos dos fármacos , Morfina/farmacologia , Núcleo Accumbens/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Receptor de Glutamato Metabotrópico 5/metabolismo , Transdução de Sinais/efeitos dos fármacos , Analgésicos Opioides/farmacologia , Animais , Condicionamento Operante/efeitos dos fármacos , Masculino , Modelos Animais , Dados de Sequência Molecular , Núcleo Accumbens/efeitos dos fármacos , Ratos , Ratos Sprague-Dawley
9.
Pharmazie ; 69(3): 203-7, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24716410

RESUMO

Intermittent high glucose (IHG), one of the general and important symptoms of patients with diabetes, has greater effect than sustained high glucose on the development of diabetic cardiovascular complications, in which endothelial dysfunction caused by oxidative stress is regarded as the initiation. However, no study investigated either the degree of endothelial DNA oxidation caused by IHG or the potential protective effects of antioxidants. In this study, DNA oxidation, including 8-hydroxy-2'-deoxyguanosine (8-OHdG) concentration and comet assay, was studied in human umbilical vein endothelial cells (HUVECs) under IHG with or without treatment of Ginkgo biloba extract (EGb 761). We found that high glucose, especially IHG, increased reactive oxygen species generation, 8-OHdG content and oxidative DNA damage in HUVECs. These high glucose-induced oxidative stress could be suppressed by EGb 761 (25-100 microg/ml) in a dose-dependent manner through the improvement of total antioxidant capacity. Our results indicated that the presence of significant DNA oxidation in HUVECs exposed to high glucose, and especially higher in the cells in IHG conditions. EGb 761, an antioxidant herbal medicine, can remarkably alleviate endothelial DNA oxidation caused by IHG, which may provide a novel approach for endothelial protection in the presence of IHG.


Assuntos
Dano ao DNA , Ginkgo biloba/química , Glucose/farmacologia , Células Endoteliais da Veia Umbilical Humana/metabolismo , Extratos Vegetais/farmacologia , 8-Hidroxi-2'-Desoxiguanosina , Antioxidantes/farmacologia , Linhagem Celular , Desoxiguanosina/análogos & derivados , Desoxiguanosina/metabolismo , Eletroforese em Gel de Poliacrilamida , Células Endoteliais da Veia Umbilical Humana/efeitos dos fármacos , Humanos , Oxirredução
10.
ACS Catal ; 14(10): 7707-7716, 2024 May 17.
Artigo em Inglês | MEDLINE | ID: mdl-38779184

RESUMO

Nonthermal plasma (NTP) offers the potential for converting CH4 with CO2 into liquid products under mild conditions, but controlling liquid selectivity and manipulating intermediate species remain significant challenges. Here, we demonstrate the effectiveness of the Cu/UiO-66-NH2 catalyst in promising the conversion of CH4 and CO2 into oxygenates within a dielectric barrier discharge NTP reactor under ambient conditions. The 10% Cu/UiO-66-NH2 catalyst achieved an impressive 53.4% overall liquid selectivity, with C2+ oxygenates accounting for ∼60.8% of the total liquid products. In situ plasma-coupled Fourier-transform infrared spectroscopy (FTIR) suggests that Cu facilitates the cleavage of surface adsorbed COOH species (*COOH), generating *CO and enabling its migration to the surface of Cu particles. This surface-bound *CO then undergoes C-C coupling and hydrogenation, leading to ethanol production. Further analysis using CO diffuse reflection FTIR and 1H nuclear magnetic resonance spectroscopy indicates that in situ generated surface *CO is more effective than gas-phase CO (g) in promoting C-C coupling and C2+ liquid formation. This work provides valuable mechanistic insights into C-C coupling and C2+ liquid production during plasma-catalytic CO2 oxidation of CH4 under ambient conditions. These findings hold broader implications for the rational design of more efficient catalysts for this reaction, paving the way for advancements in sustainable fuel and chemical production.

11.
Cell Rep Med ; 4(11): 101236, 2023 11 21.
Artigo em Inglês | MEDLINE | ID: mdl-37827154

RESUMO

Despite potential impact on the graft vs. leukemia (GVL) effect, immunotherapy targeting CTLA-4 and/or PD-1 has not been successfully combined with bone marrow transplant (BMT) because it exacerbates graft vs. host disease (GVHD). Here, using models of GVHD and leukemia, we demonstrate that targeting hypoxia-inducible factor 1α (HIF1α) via pharmacological or genetic approaches reduces GVHD by inducing PDL1 expression on host tissue while selectively inhibiting PDL1 in leukemia cells to enhance the GVL effect. More importantly, combination of HIF1α inhibition with anti-CTLA-4 antibodies allows simultaneous inhibition of both PDL1 and CTLA-4 checkpoints to achieve better outcomes in models of mouse and human BMT-leukemia settings. These findings provide an approach to enhance the curative effect of BMT for leukemia and broaden the impact of cancer immunotherapy.


Assuntos
Doença Enxerto-Hospedeiro , Leucemia , Humanos , Antígeno CTLA-4 , Doença Enxerto-Hospedeiro/prevenção & controle , Subunidade alfa do Fator 1 Induzível por Hipóxia , Imunoterapia , Leucemia/genética , Leucemia/terapia , Animais , Camundongos
12.
Biosensors (Basel) ; 12(4)2022 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-35448306

RESUMO

The increasing levels of environmental estrogens are causing negative effects on water, soil, wildlife, and human beings; label-free immunosensors with high specificities and sensitivities are being developed to test estrogeneous chemicals in complex environmental conditions. For the first time, highly fluorescent graphene quantum dots (GQDs) were prepared using a visible-Fenton catalysis reaction with graphene oxide (GO) as a precursor. Different microscopy and spectroscopy techniques were employed to characterize the physical and chemical properties of the GQDs. Based on the fluorescence resonance energy transfer (FRET) between amino-functionalized GQDs conjugated with anti-lipovitellin monoclonal antibodies (Anti-Lv-mAb) and reduced graphene oxide (rGO), an ultrasensitive fluorescent "ON-OFF" label-free immunosensor for the detection of lipovitellin (Lv), a sensitive biomarker derived from Paralichthys olivaceus for environmental estrogen, has been established. The immunosensor has a wide linear test range (0.001-1500 ng/mL), a lower limit of detection (LOD, 0.9 pg/mL), excellent sensitivity (26,407.8 CPS/(ng/mL)), and high selectivity and reproducibility for Lv quantification. The results demonstrated that the visible-Fenton is a simple, mild, green, efficient, and general approach to fabricating GQDs, and the fluorescent "ON-OFF" immunosensor is an easy-to-use, time-saving, ultrasensitive, and accurate detection method for weak estrogenic activity.


Assuntos
Técnicas Biossensoriais , Grafite , Pontos Quânticos , Técnicas Biossensoriais/métodos , Proteínas do Ovo , Grafite/química , Humanos , Imunoensaio/métodos , Pontos Quânticos/química , Reprodutibilidade dos Testes
13.
Trends Ecol Evol ; 37(3): 193-196, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-35000798

RESUMO

Greenspaces represent an ark for urban biodiversity, but understanding their carrying capacity to sustain species remains challenging. Old greenspaces that were fragmented from natural habitats are now overcrowded, while revegetated new greenspaces remain vacant. This is because they have different processes leading towards biodiversity equilibrium, and conservation management needs to differentiate between fragmented and revegetated greenspaces.


Assuntos
Biodiversidade , Ecossistema , Cidades , Conservação dos Recursos Naturais
14.
ACS Omega ; 6(48): 32904-32916, 2021 Dec 07.
Artigo em Inglês | MEDLINE | ID: mdl-34901641

RESUMO

Fluorescent N-doped carbon nanodots (CNDs) are a type of environmentally friendly nanomaterial that is promising for application in cell imaging and optoelectronics. In this paper, a natural amino acid (l-glutamic acid) was used as a precursor, and two different morphological and structured N-doped carbon quantum dots (CQDs) were synthesized via a one-step ultrasonic-assisted hydrothermal method at 230 and 250 °C. Various microscopy and spectroscopy techniques were employed to characterize the morphology, structure, optical properties, and stability of the CQDs. The results showed that N-CQDs-1 are new CNDs composed of amorphous carbon with a large amount of pyroglutamic acid, and N-CQDs-2 are composed of pure amorphous carbon. The CQDs exhibit excellent optical properties, such as 40.5% quantum yield, strong photobleaching resistance, and superior photostability. Combining the fluorescence lifetimes and radiative and non-radiative decay constants, the photoluminescence mechanism of the CQDs was qualitatively explained. The two CQDs were used for BV2 cell imaging and showed good results, implying the ultrasonic-assisted hydrothermal approach as a facile method to obtain structure- and morphology-controllable N-doped CQDs with prospect for application in cell imaging.

15.
Nanomaterials (Basel) ; 11(11)2021 Oct 22.
Artigo em Inglês | MEDLINE | ID: mdl-34835564

RESUMO

High fluorescent graphene quantum dots (GQDs) are promising in bioimaging and optoelectronics. In this paper, bright blue fluorescent N-doped GQDs were synthesized using a ultrasonic-assisted hydrothermal method. The morphology, structure, surface chemistry, optical properties, and stability subject to photo-bleaching, temperature, pH and preservation period for the N-GQDs were investigated in detail using various microscopy and spectroscopy techniques. The results showed that the N-GQDs possessed an average size of 2.65 nm, 3.57% N doping, and up to 54% quantum yield (QY). The photoluminescence (PL) spectra of the N-GQDs are excitation dependent when excited in the range of 300-370 nm and excitation independent in the range of 380-500 nm for the core and surface states emission. The N-GQDs showed excellent photo-bleaching resistance and superior photo-stability. At room temperature and in the pH range of 3-8, the fluorescence of the N-GQDs was almost invariable. The N-GQDs can be stably preserved for at least 40 days. The average decay lifetime of the N-GQDs was 2.653 ns, and the radiative and nonradiative decay rate constants were calculated to be 2.04 × 108 s-1 and 1.73 × 108 s-1, respectively. The PL mechanism was qualitatively explained. The N-GQDs was used for cell imaging, and it showed good results, implying great potential applications for bioimaging or biomarking.

16.
Oxid Med Cell Longev ; 2021: 8847844, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33763175

RESUMO

Oxidative stress of the retinal pigment epithelium (RPE) is an essential element contributing to the progression of age-related macular degeneration (AMD). Notably, the activation of Nrf2 is regarded as an effective strategy for controlling oxidation. The novel 2,3-dihydroflavonoid compound farrerol, which is extracted from Rhododendron, possesses antioxidant properties. In this study, we investigated the mechanism by which farrerol protects against oxidative damage mediated by hydrogen peroxide (H2O2) in adult retinal pigment epithelial cell line 19 (ARPE-19) cells. Farrerol supplementation conspicuously reversed H2O2-related cell damage through declining the generation of intracellular reactive oxygen species (ROS) and MDA and increasing the concentrations of GSH and SOD. According to the results of the apoptosis assay, a farrerol pretreatment decreased the protein expression of the Bax/Bcl-2, cleaved caspase-3, PARP, caspase-8, and caspase-9 proteins. Furthermore, farrerol markedly activated Nrf2, thereby increasing the levels of antioxidant enzymes downstream of Nrf2, such as HO-1, NQO1, and GCLM. Knockdown of Nrf2 with a specific siRNA successfully suppressed farrerol-mediated HO-1 transcription and partially abolished the cytoprotective effect on ARPE-19 cells. Meanwhile, farrerol induced Akt and MAPK phosphorylation in a dose-related way. However, inhibiting Akt and MAPK substantially blocked the cytoprotective functions of farrerol. Therefore, farrerol enhanced Nrf2-mediated cytoprotection of oxidative damage caused by H2O2, which may be inseparable from the activation of Akt and MAPK.


Assuntos
Cromonas/farmacologia , Peróxido de Hidrogênio/toxicidade , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Proteínas Proto-Oncogênicas c-akt/metabolismo , Epitélio Pigmentado da Retina/enzimologia , Epitélio Pigmentado da Retina/patologia , Apoptose/efeitos dos fármacos , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Cromonas/química , Citoproteção/efeitos dos fármacos , Ativação Enzimática/efeitos dos fármacos , Humanos , Oxirredução , Epitélio Pigmentado da Retina/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos
17.
Int J Surg Case Rep ; 79: 67-69, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33434771

RESUMO

Penile gangrene is a rare but fatal complication of calciphylaxis in end-stage renal disease (ESRD). To date, there are no guidelines on its management, and outcomes are generally poor with high mortality rate. We present a case of a diabetic patient with ESRD presenting with dry gangrene of the glans penis due to calciphylaxis and successfully treated with intravenous sodium thiosulfate (STS) and early total parathyroidectomy. We further analysed existing literatures on cases that utilized STS in the treatment of penile calciphylaxis.

18.
J Exp Clin Cancer Res ; 40(1): 278, 2021 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-34470658

RESUMO

BACKGROUND: Glioblastoma multiforme (GBM), a lethal brain tumor, remains the most daunting challenge in cancer therapy. Overexpression and constitutive activation of PDGFs and PDGFRα are observed in most GBM; however, available inhibitors targeting isolated signaling pathways are minimally effective. Therefore, better understanding of crucial mechanisms underlying GBM is needed for developing more effective targeted therapies. METHODS: Target genes controlled by HIF1α in GBM were identified by analysis of TCGA database and by RNA-sequencing of GBM cells with HIF1α knockout by sgRNA-Cas9 method. Functional roles of HIF1α, PDGFs and PDGFRs were elucidated by loss- or gain-of-function assays or chemical inhibitors, and compared in response to oxygen tension. Pharmacological efficacy and gene expression in mice with intracranial xenografts of primary GBM were analyzed by bioluminescence imaging and immunofluorescence. RESULTS: HIF1α binds the PDGFD proximal promoter and PDGFRA intron enhancers in GBM cells under normoxia or mild-hypoxia to induce their expression and maintain constitutive activation of AKT signaling, which in turn increases HIF1α protein level and activity. Paradoxically, severe hypoxia abrogates PDGFRα expression despite enhancing HIF1α accumulation and corresponding PDGF-D expression. Knockout of HIF1A, PDGFD or PDGFRA in U251 cells inhibits cell growth and invasion in vitro and eradicates tumor growth in vivo. HIF1A knockdown in primary GBM extends survival of xenograft mice, whereas PDGFD overexpression in GL261 shortens survival. HIF1α inhibitor Echinomycin induces GBM cell apoptosis and effectively inhibits growth of GBM in vivo by simultaneously targeting HIF1α-PDGFD/PDGFRα-AKT feedforward pathway. CONCLUSIONS: HIF1α orchestrates expression of PDGF-D and PDGFRα for constitutive activation of AKT pathway and is crucial for GBM malignancy. Therefore, therapies targeting HIF1α should provide an effective treatment for GBM.


Assuntos
Antibióticos Antineoplásicos/uso terapêutico , Neoplasias Encefálicas/patologia , Equinomicina/uso terapêutico , Glioblastoma/patologia , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Hipóxia/metabolismo , Linfocinas/metabolismo , Oxigênio/metabolismo , Fator de Crescimento Derivado de Plaquetas/metabolismo , Receptor alfa de Fator de Crescimento Derivado de Plaquetas/metabolismo , Animais , Neoplasias Encefálicas/tratamento farmacológico , Neoplasias Encefálicas/metabolismo , Linhagem Celular Tumoral , Proliferação de Células , Ativação Enzimática , Glioblastoma/tratamento farmacológico , Glioblastoma/metabolismo , Humanos , Linfocinas/genética , Camundongos , Camundongos Endogâmicos NOD , Invasividade Neoplásica , Fator de Crescimento Derivado de Plaquetas/genética , Proteínas Proto-Oncogênicas c-akt/metabolismo , Receptor alfa de Fator de Crescimento Derivado de Plaquetas/genética
19.
Mol Med ; 16(11-12): 465-70, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20644901

RESUMO

Inflammation plays an important role in the pathophysiology of the metabolic syndrome (MS). We determined whether the overexpression of interleukin (IL)-18 could aggravate left ventricular (LV) remodeling and diastolic dysfunction in fructose-fed rats (FFRs). To create an animal model for MS, male Wistar rats received 10% fructose in water for 8 months. We used an adenovirus encoding rat IL-18 to overexpress IL-18 in FFRs by intravenous administration. IL-18 overexpression led to increases in collagen volume fraction and collagen deposition. LV systolic function was unaltered. But the LV end-diastolic pressure and the time constant of isovolumic relaxation (tau) were increased. Peak negative value of time derivative of LV pressure (-dp/dt) was decreased. Isovolumic relaxation time and myocardial index, as assessed by echocardiography, were increased. Overexpression of IL-18 leads to aggravated LV remodeling and dysfunction in FFRs. Attenuation of the inflammatory process may provide a novel therapeutic strategy in treating metabolic cardiomyopathy.


Assuntos
Cardiomiopatias/fisiopatologia , Insuficiência Cardíaca Diastólica/fisiopatologia , Interleucina-18/metabolismo , Disfunção Ventricular Esquerda/fisiopatologia , Animais , Cardiomiopatias/diagnóstico por imagem , Ecocardiografia , Fibrose/diagnóstico por imagem , Fibrose/metabolismo , Fibrose/fisiopatologia , Frutose/administração & dosagem , Frutose/metabolismo , Insuficiência Cardíaca Diastólica/diagnóstico por imagem , Masculino , Ratos , Ratos Wistar , Disfunção Ventricular Esquerda/diagnóstico por imagem , Remodelação Ventricular
20.
Microb Pathog ; 49(5): 305-10, 2010 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-20624451

RESUMO

Streptococcus suis serotype 2 is an important porcine and human zoonotic pathogen. Few virulence factors have been identified and the pathogenesis of infection is not fully understood. We have identified a novel virulence-related gene, virA, of S. suis 2. To investigate its role in pathogenesis, a virA deletion mutant of S. suis 2 wild-type strain ZY458, 458Deltavir, was constructed using suicide vector pSET4s, and a functionally complemented strain 458Deltavir(pvir) was constructed using shuttle plasmid pAT18 containing the virA gene. All rabbits infected with ZY458 and 458Deltavir(pvir) exhibited body weight loss and developed severe clinical symptoms. All 5 rabbits infected with ZY458, and 4 of 5 infected with 458Deltavir(pvir), died within 6 days of infection. In contrast, all 5 rabbits inoculated with 458Deltavir gained weight normally and none developed any clinical symptoms during the entire course monitored. These results indicate that virA plays an important role in the pathogenicity of S. suis serotype 2. To investigate the virA gene further, we compared and analyzed the sequences of virA from wild-type virulent and avirulent strains. Results showed that functional virA appears to exist only in virulent strains and has been structurally mutated in avirulent strains. In conclusion, virA gene is a novel identified virulence-relate gene. It may play a key role in the evolution and pathogenicity of S. suis serotype 2.


Assuntos
Proteínas de Bactérias/genética , Streptococcus suis/genética , Streptococcus suis/patogenicidade , Fatores de Virulência/genética , Animais , Proteínas de Bactérias/fisiologia , Peso Corporal , DNA Bacteriano/química , DNA Bacteriano/genética , Modelos Animais de Doenças , Deleção de Genes , Teste de Complementação Genética , Dados de Sequência Molecular , Mutação , Plasmídeos , Coelhos , Análise de Sequência de DNA , Homologia de Sequência de Aminoácidos , Infecções Estreptocócicas/microbiologia , Infecções Estreptocócicas/patologia , Análise de Sobrevida , Virulência , Fatores de Virulência/fisiologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA