RESUMO
PURPOSE: To evaluate two advanced diffusion models, diffusion kurtosis imaging and the newly proposed mean apparent propagation factor-magnetic resonance imaging, in the grading of gliomas and the assessing of their proliferative activity. METHODS: Fifty-nine patients with clinically diagnosed and pathologically proven gliomas were enrolled in this retrospective study. All patients underwent DKI and MAP-MRI scans. Manually outline the ROI of the tumour parenchyma. After delineation, the imaging parameters were extracted using only the data from within the ROI including mean diffusion kurtosis (MK), return-to-origin probability (RTOP), Q-space inverse variance (QIV) and non-Gaussian index (NG), and the differences in each parameter in the classification of glioma were compared. Receiver operating characteristic (ROC) curve analysis was used to evaluate the diagnostic performance of these parameters. RESULTS: MK, NG, RTOP and QIV were significantly different amongst the different grades of glioma. MK, NG and RTOP had excellent diagnostic value in differentiating high-grade from low-grade glioma, with largest areas under the curve (AUCs; 0.929, 0.933 and 0.819, respectively; P < 0.01). MK and NG had the largest AUCs (0.912 and 0.904) when differentiating grade II tumours from III tumours (P < 0.01) and large AUCs (0.791 and 0.786) when differentiating grade III from grade IV tumours. Correlation analysis of tumour proliferation activity showed that MK, NG and QIV were strongly correlated with the Ki-67 LI (P < 0.001). CONCLUSION: MK, RTOP and NG can effectively represent the microstructure of these altered tumours. Multimodal diffusion-weighted imaging is valuable for the preoperative evaluation of glioma grade and tumour proliferative activity.
Assuntos
Neoplasias Encefálicas , Glioma , Humanos , Estudos Retrospectivos , Neoplasias Encefálicas/diagnóstico por imagem , Neoplasias Encefálicas/patologia , Sensibilidade e Especificidade , Gradação de Tumores , Glioma/diagnóstico por imagem , Glioma/patologia , Imagem de Difusão por Ressonância Magnética/métodos , Imageamento por Ressonância Magnética , Proliferação de CélulasRESUMO
Arachidonic acid (AA) metabolism plays an important role in vascular homeostasis. We reported that DNA hypomethylation of EPHX2 induced a pro-inflammatory response in vascular endothelial cells (ECs). However, the change in the whole AA metabolism by DNA methylation is still unknown. Using a metabolomic approach, we investigated the effect of DNA methylation on the balance of AA metabolism and the underlying mechanism. ECs were treated with a DNA methyltransferase inhibitor 5-aza-2'-deoxycytidine (5-AZA), and AA metabolic profiles were analyzed. Levels of prostaglandin D2 (PGD2) and thromboxane B2 (TXB2), metabolites in the cyclooxygenase (COX) pathway, were significantly increased by 5-AZA treatment in ECs resulting from the induction of PGD2 synthase (PTGDS) and thromboxane A synthase 1 (TBXAS1) expression by DNA hypomethylation. This phenomenon was also observed in liver and kidney cell lines, indicating a universal mechanism. Pathophysiologically, homocysteine, known to cause DNA demethylation, induced a similar pattern of the change of AA metabolism. Furthermore, 5-AZA activated ECs, as evidenced by the upregulation of adhesion molecules. Indomethacin, a COX inhibitor, reversed the effects of 5-AZA on the levels of PGD2 and TXB2, EC activation and monocyte adhesion. In vivo, the plasma levels of PGD2 and TXB2 and the expression of In vivo PTGDS and TBXAS1 as well as adhesion molecules were increased in the aorta of the mice injected with 5-AZA. In conclusion, using a metabolomic approach, our study uncovered that DNA demethylation increased AA metabolites PGD2 and TXB2 by upregulating the expression of the corresponding enzymes, which might contribute to the DNA hypomethylation-induced endothelial activation.
Assuntos
Ácidos Araquidônicos/metabolismo , Metilação de DNA/fisiologia , Células Endoteliais da Veia Umbilical Humana/metabolismo , Animais , Azacitidina/análogos & derivados , Azacitidina/farmacologia , Metilação de DNA/efeitos dos fármacos , Decitabina , Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos , Regulação Enzimológica da Expressão Gênica/fisiologia , Células HEK293 , Células Endoteliais da Veia Umbilical Humana/citologia , Humanos , Oxirredutases Intramoleculares/biossíntese , Rim/citologia , Rim/enzimologia , Lipocalinas/biossíntese , Fígado/citologia , Fígado/enzimologia , Masculino , Metabolômica , Camundongos , Tromboxano-A Sintase/biossínteseRESUMO
Stem cell therapy holds great promise for future clinical practice for treatment of advanced liver diseases. However, the fate of stem cells after transplantation, including the distribution, viability, and the cell clearance, has not been fully elucidated. Herein, recent advances regarding the imaging tools for stem cells tracking mainly in chronic liver diseases with the advantages and disadvantages of each approach have been described. Magnetic resonance imaging is a promising clinical imaging modality due to non-radioactivity, excellent penetrability, and high spatial resolution. Fluorescence imaging and radionuclide imaging demonstrate relatively increased sensitivity, with the latter excelling in real-time monitoring. Reporter genes specialize in long-term tracing. Nevertheless, the disadvantages of low sensitivity, radiation, exogenous gene risk are inevitably present in each of these means, respectively. In this review, we aim to comprehensively evaluate the current state of methods for tracking of stem cell, highlighting their strengths and weaknesses, and providing insights into their future potential. Multimodality imaging strategies may overcome the inherent limitations of single-modality imaging by combining the strengths of different imaging techniques to provide more comprehensive information in the clinical setting.
Assuntos
Hepatopatias , Transplante de Células-Tronco , Humanos , Transplante de Células-Tronco/métodos , Genes Reporter , Imageamento por Ressonância Magnética/métodos , Hepatopatias/terapiaRESUMO
Introduction: The mechanism of internet game addiction is unclear. Whether anxiety mediates between resourcefulness and internet game addiction and whether gender affect its mediation role have not been studied previously. Methods: A total of 4,889 college students from a college in southwest China were included in this study to complete the investigation, in which three questionnaires were used for evaluation. Results: Pearson's correlation analysis indicated a remarkable negative correlation between resourcefulness with internet game addiction and anxiety, as well as a significant positive correlation between anxiety and this addiction. The structural equation model confirmed the mediation role of anxiety. The multi-group analysis confirmed the moderating role of gender in the mediation model. Discussion: These findings have advanced the results of existing studies, indicating the buffering effect of resourcefulness on internet game addiction and revealing the potential mechanism of this relationship.
Assuntos
Ansiedade , Comportamento Aditivo , Humanos , Ansiedade/epidemiologia , Transtornos de Ansiedade , Comportamento Aditivo/epidemiologia , Estudantes , InternetRESUMO
OBJECTIVE: To observe the genotypes and composition ratio of thalassemia in couples of reproductive age, and provide a reference for the prevention and control of thalassemia in Haikou. METHODS: Gene diagnosis was performed in 2 494 subjects who were screened for thalassemia before marriage or prenatal by cross-breakpoint PCR, PCR-reverse dot hybridization, and PCR-electrophoresis. RESULTS: A total of 1 037 thalassemia gene carriers were detected in 2 494 samples, with a detection rate of 41.57%, of which 75.02% was α-thalassemia, 18.61% was ß-thalassemia, and 6.36% was α-ß complex thalassemia. There were 778 cases of α-thalassemia, mainly of deletion type, accounting for 76.99% (599/778). Twenty genotypes were detected, the highest three was --SEA/αα (33.42%, 260/778), -α3.7/αα(23.91%, 186/778), and -α4.2/αα(19.02%, 148/778), respectively. A rare HKαα/-α3.7 was detected, who immigrated from other province. There were 193 cases of ß-thalassemia, all of them were light (ß0/ßA or ß+/ßA). Eight genotypes were detected, the highest two was 41-42M/N (74.61%, 144/193) and 654M/N (10.36%, 20/193), respectively. There were 66 cases of α-ß compound type of thalassemia, 15 genotypes were detected, the highest three was ααWS/αα complex 41-42M/N (28.79%, 19/66), -α3.7/αα complex 41-42M/N, and -α4.2/αα complex 41-42M/N (16.67%, 11/66 for both). CONCLUSION: In Haikou city, the gene carrying rate of thalassemia is very high, and the genotype distribution is different from other cities in Hainan Province, attention should be paid to the impact of population inflow on the frequency spectrum change of local thalassemia gene.
Assuntos
Talassemia alfa , Talassemia beta , Cidades , Feminino , Testes Genéticos , Genótipo , Humanos , Gravidez , Talassemia alfa/genética , Talassemia beta/genéticaRESUMO
Substantial evidence has shown that DNA methylation regulates the initiation of ovarian and sexual maturation. Here, we investigated the genome-wide profile of DNA methylation in porcine ovaries at single-base resolution using reduced representation bisulfite sequencing. The biological variation was minimal among the three ovarian replicates. We found hypermethylation frequently occurred in regions with low gene abundance, while hypomethylation in regions with high gene abundance. The DNA methylation around transcriptional start sites was negatively correlated with their own CpG content. Additionally, the methylation level in the bodies of genes was higher than that in their 5' and 3' flanking regions. The DNA methylation pattern of the low CpG content promoter genes differed obviously from that of the high CpG content promoter genes. The DNA methylation level of the porcine ovary was higher than that of the porcine intestine. Analyses of the genome-wide DNA methylation in porcine ovaries would advance the knowledge and understanding of the porcine ovarian methylome.
Assuntos
Metilação de DNA , DNA/química , Epigênese Genética , Ovário/fisiologia , Suínos , Animais , Ilhas de CpG , Feminino , Regiões Promotoras Genéticas , Análise de Sequência de DNARESUMO
OBJECTIVE: To classify the nasal tip hypertrophy according to the anatomic characters, so as to select the proper treatment methods. METHODS: From Jan. 2010 to Mar. 2012, 92 cases (aged 21-46 years,average 29 years old) with nasal tip hypertrophy were classified as soft tissue hypertrophy, the alar cartilage hypertrophy, separation of alar cartilage, secondary tip hypertrophy after operation, and compound hypertrophy. Treatment methods were selected according to the hypertrophy type, including soft tissue thinning hy medicine or operation, alar cartilage trimming and remodeling, autogenous ear and nasal septal cartilage grafts for elongation or remodeling of nasal tip or columella. RESULTS: The follow-up period was 3 months to one year. The nasal tip hypertrophy was corrected obviously with a natural and harmonious appearance. The results were evaluated hy patients as perfect in 59 cases, good in 26 cases and medium in 7 cases. CONCLUSION: Satisfactory results can he achieved for the nasal tip hypertrophy with appropriate methods according to the anatomic classification.