RESUMO
AIM: To analyze and identify the proteomic differences between liquefied after-cataracts and normal lenses by means of liquefied chromatography-tandem mass spectrometry (LC-MS/MS). METHODS: Three normal lenses and three liquefied after-cataracts were exposed to depolymerizing reagents to extract the total proteins. Protein concentrations were separated using two-dimensional gel electrophoresis (2-DE). The digitized images obtained with a GS-800 scanner were then analyzed with PDQuest7.0 software to detect the differentially-expressed protein spots. These protein spots were cut from the gel using a proteome work spot cutter and subjected to in-gel digestion with trypsin. The digested peptide separation was conducted by LC-MS/MS. RESULTS: The 2-DE maps showed that lens proteins were in a pH range of 3-10 with a relative molecular weight of 21-70 kD. The relative molecular weight of the more abundant proteins was localized at 25-50 kD, and the isoelectric points were found to lie between PI 4-9. The maps also showed that the protein level within the liquefied after-cataracts was at 29 points and significantly lower than in normal lenses. The 29 points were identified by LC-MS/MS, and ten of these proteins were identified by mass spectrometry and database queries: beta-crystallin B1, glyceraldehyde-3-phosphate dehydrogenase, carbonyl reductase (NADPH) 1, cDNA FLJ55253, gamma-crystallin D, GAS2-like protein 3, sorbitol dehydrogenase, DNA FLJ60282, phosphoglycerate kinase, and filensin. CONCLUSION: The level of the ten proteins may play an important role in the development of liquefied after-cataracts.
RESUMO
PURPOSE: To report the feasibility of parametric color-coded digital subtraction angiography (DSA) in complementing the traditional, subjective way of leptomeningeal collateral assessment in acute middle cerebral artery (MCA) occlusions. METHODS: Thirty-three consecutive patients with acute MCA occlusion who received endovascular treatment were recruited for investigation. Eighteen of 33 consecutive patients were included. The target downstream territory (TDT) of MCA and reference point at terminal internal carotid artery of each patient was contoured by 5 raters independently on the basis of anteroposterior 2-dimensional DSA. Two parameters of relative maximum density of TDT (rDensitymax) and peak time interval (ΔPT) between reference and TDT were extracted by the use of parametric DSA analysis software. Interrater reliability was tested with intraclass correlation coefficients. Parameters with sufficient interrater reliability entered validity evaluation. Then, the correlation test with the American Society of Interventional and Therapeutic Neuroradiology collateral grading system and efficacy in predicting favorable clinical outcome was evaluated. RESULTS: The intraclass correlation coefficient of rDensitymax and ΔPT were 0.983, 95% confidence interval 0.968-0.993 and 0.831, 95% confidence interval 0.705-0.923, respectively. The parameter rDensitymax showed a strong correlation with the American Society of Interventional and Therapeutic Neuroradiology collateral grading system score (r of Spearman correlation test = 0.869, P < 0.001) and mRS at 3 months (partial correlation coefficient = 0.616, P = 0.009), whereas ΔPT_average did not. A cut-off point of 0.224 in rDensitymax predicted a favorable clinical outcome with high sensitivity and specificity. CONCLUSIONS: The relative maximum contrast density of MCA territory on 2-dimensional DSA measured by parametric imaging technique appears to be a simple and reliable metric for the assessment of leptomeningeal collaterals in cases of acute MCA occlusion.