ABSTRACT
Objective To investigate the role of epigenetic regulations of peroxisome proliferator-activated receptor γ coactivator 1α (PGC-1α) in the development of diabetic retinopathy and the metabolic memory phenomenon after hyperglycemia was terminated.Methods Diabetic rat model was established by intraperitoneal injection of streptozotocin (STZ).Sixty diabetic rats were randomly divided into 3 groups,poor glycemic control group rats were maintained in poor glycemic control for 4 months;semi glycemic control group rats were maintained in poor glycemic control for 2 months,followed by good glycemic control for 2 additional months;good glycemic control group rats were maintained in good glycemic control for 4 months.Twenty normal rats served as control group.The mRNA expression of PGC-1α and superoxide dismutase 2 (SOD2) of retina were measured by real-time PCR;the expression of PGC-1α and manganese superoxide dismutase (MnSOD) protein were measured by Western blot;the situation of DNA methylation in the promotor region of PPARGC1A was measured by bisulfite sequencing.Results The body-weight in the control group was significantly higher than that in the poor glycemic control group,semi glycemic control group and good glycemic control group (all at P =0.000).The blood glucose value in the poor glycemic control group was significantly higher than that in the control group (P =0.000).The expression levels of PGC-1 α mRNA were significantly lower and the expression levels of SOD2 mRNA were significantly higher in the good glycemic control group,semi glycemic control group and poor glycemic control group than those in the control group (all at P＜0.05).The expression levels of PGC-1α and SOD2 mRNA were significantly different between the good glycemic control group and poor glycemic control group (both at P＜0.05).Compared with the control group,the expression levels of PGC-1α and MnSOD protein were decreased in the diabetic model groups,with significant differences between them (all at P＜0.05).The expression level of PGC-1 α protein was significantly higher in the good glycemic control group than that in the poor glycemic control group (P＜0.05).Diabetes increased DNA methylation in the promotor region of PPARGC1A gene of retina.The DNA methylation level was significantly higher in the poor glycemic control group and semi glycemic control group than that in the control group (P =0.008,0.031).No statistical difference was found between the poor glycemic control group and semi glycemic control group (P ＞ 0.05).Conclusions The expressions of PGC-1o mRNA and protein and MnSOD protein in the retina of STZ induced diabetic rats are decreased,the expression of SOD2 mRNA is increased,the expression changes have metabolic memory characteristics.Increased DNA methylation in the promotor region of PPARGC1A when exposed to high glucose may have a role in the regulation of PGC-1 α expression and metabolic memory.
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Objective To explore the value of CT texture analysis (CTTA) in differential diagnosis of non clear-cell renal cell carcinoma (non-ccRCC) and clear-cell renal cell carcinoma (ccRCC).Methods A total of 100 ccRCC and 27 nonccRCC lesions were retrospectively analyzed.CTTA was performed on multiphasic CT images by using TexRAD software,and texture features were compared between ccRCC and non-ccRCC.Results Compared with ccRCC,the mean and standard deviation,entropy as well as the mean of positive pixels (MPP) were significantly lower,while kurtosis was higher in non-ccRCC lesions on enhanced CT images (P＜0.001).No significant difference was observed in skewness between nonccRCC and ccRCC (P＞0.05).MPP at coarse texture scale on corticomedullary images identified non-ccRCC from ccRCC with an AUC of 0.92±0.04,the sensitivity was 0.85,specificity was 0.93 and accuracy was 0.87.Conclusion There are significant differences in CTTA parameters between non-ccRCC and ccRCC.CTTA has clinical value in differential diagnosis of non-ccRCC and ccRCC.
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Objective To investigate the feasibility of using CT texture analysis to differentiate among lipid-poor adrenal adenoma,pheochromocytoma and adrenal metastases.Methods 66 lipid-poor adrenal adenoma,98 pheochromocytoma and 101 adrenal metastases lesions were analyzed retrospectively.All the patients had abdominal non-enhanced CT and adrenal enhanced CT scans.We used TexRAD software to analyze the textural features of CT images and compared the differences in each texture parameter among three adrenal lesions.Results On non-enhanced CT images,there were significant differences in Mean and Kurtosis at all the texture scales(SSF 0-6) among the three types of adrenal lesions (P<0.05),as well as SD at fine and coarse texture scale (SSF 2,6)(P<0.05).Entropy (SSF 0-3, 5-6) and MPP (SSF 0-2, 4-6) were significantly lower in lipid-poor adrenal adenoma and adrenal metastases than that in pheochromocytoma (P<0.05).There were significant differences in Skewness (SSF 0-3) among three types of lesions, which was lowest in pheochromocytoma and highest in adrenal metastases.On enhanced CT images, Mean, SD, Entrophy and MPP showed significantly differences among the three types of adrenal lesions at all the texture scales (SSF 0-6) (P<0.05), which were all highest in pheochromocytoma and lowest in adrenal metastases.Skewness (SSF 0) and Kurtosis (SSF 0, 2) were significantly lower in adrenal metastases than that in lipid-poor adrenal adenoma and pheochromocytoma (P<0.05).Conclusion There are significant differences in CT texture analysis parameters among lipid-poor adrenal adenoma,pheochromocytoma and adrenal metastases.CT texture analysis has potential clinical application values in differentiating these three adrenal lesions.
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Objective To investigate the feasibility of using low-dose prostate CT perfusion (pCTP)on a third-generation dual-source CT. Methods Nine patients with elevated prostate-specific antigen underwent pCTP before having prostate biopsy. We measured the blood flow (BF),blood volume (BV),mean transit time (MTT),permeability surface (PS),and time to peak(TTP)of both lesions and normal prostate tissue. The effective dose (ED)was calculated. Results Of the 9 cases,6 were prostate cancers and 3 were prostate hyperplasia with chronic inflammation. The average ED of the 9 pCTPs was (3.5±0.3)mSv. The BF (t=4.64,P<0.001),BV (t=3.27,P<0.001),and PS (t=3.58,P=0.004)of prostate cancer were significantly higher than those of normal prostate tissue and TTP (t=-1.26,P<0.001)of prostate cancer was significantly lower than that of normal prostate tissue. BF (t=3.96,P=0.001)and PS (t=2.91,P=0.021)of prostate hyperplasia with chronic inflammation were also significantly higher and TTP (t=-1.19,P<0.001)was significantly lower than those of normal prostate tissue. TTP of prostate cancer was significantly lower than that of prostate hyperplasia with chronic inflammation (t=-2.56,P=0.049). Conclusion sLow-dose pCTP is feasible on third-generation dual-source CT. The BF,PS,and TTP differ among prostate cancer,prostate hyperplasia with chronic inflammation,and normal prostate tissue.