Renal ectopic lipid deposition in rats with early-stage diabetic nephropathy evaluated by the MR mDixon-Quant technique: association with the expression of SREBP-1 and PPARα in renal tissue.

Background: Renal ectopic lipid deposition (ELD) plays a significant role in the development of diabetic nephropathy (DN). This study aimed to use the magnetic resonance (MR) mDixon-Quant technique to evaluate renal ELD and its association with the expression of sterol regulatory element binding protein 1 (SREBP-1) and peroxisome proliferator-activated receptor alpha (PPARα) in renal tissue. Methods: Seventy male Sprague-Dawley (SD) rats were randomly divided into experimental (n=50) and control groups (n=20). A high-fat diet combined with low-dose streptozotocin (STZ) was administered to the experimental group to establish a type 2 diabetes mellitus (T2DM) model. The rats received renal mDixon-Quant scans and blood lipid and histopathological examinations in batches after the T2DM model was established. According to the histopathological findings, the included rats were stratified into control and early DN groups. Renal fat fraction (FF), blood lipid level, the ratio of the integrated optical density of intracellular lipid droplets and the total area of all the cells (IOD/TAC), and the expression of SREBP-1 and PPARɑ in renal tissue were analyzed. Results: Compared to the controls, renal FF, IOD/TAC, the expression of SREBP-1 in renal tissue, and serum total cholesterol (TC), triglyceride (TG) and low-density lipoprotein (LDL) levels were higher in the early DN group, while the expression of PPARɑ in renal tissue and the high-density lipoprotein (HDL) level were lower (all P values <0.001). Renal FF gradually increased with the progression of disease [r=0.810 (95% CI: 0.675-0.928), P<0.001]. Positive correlations between renal FF and each of the following: TC, TG, LDL, IOD/TAC, and the expression of SREBP-1 [r=0.479 (95% CI: 0.353-0.640, P=0.012), 0.576 (95% CI: 0.283-0.842, P=0.002), 0.441 (95% CI: 0.305-0.606, P=0.021), 0.911 (95% CI: 0.809-0.964, P<0.001) and 0.800 (95% CI: 0.640-0.910, P<0.001), respectively] and negative correlations between renal FF and each of the following: HDL and the expression of PPARɑ [r=-0.611 (95% CI: -0.809 to -0.469, P=0.001) and -0.748 (95% CI: -0.886 to -0.585, P<0.001), respectively] were found. Conclusions: Renal lipid deposition evaluated by the MR mDixon-Quant technique is associated with the blood lipid level, histological fat quantification, and the expression of SREBP-1 and PPARɑ in renal tissue. The renal FF value might serve as a biomarker for better understanding of renal lipid metabolism in early-stage DN.

Whole-tumor histogram analysis of apparent diffusion coefficients for predicting lymphovascular space invasion in stage IB-IIA cervical cancer.

Objectives: To investigate the value of apparent diffusion coefficient (ADC) histogram analysis based on whole tumor volume for the preoperative prediction of lymphovascular space invasion (LVSI) in patients with stage IB-IIA cervical cancer. Methods: Fifty consecutive patients with stage IB-IIA cervical cancer were stratified into LVSI-positive (n = 24) and LVSI-negative (n = 26) groups according to the postoperative pathology. All patients underwent pelvic 3.0T diffusion-weighted imaging with b-values of 50 and 800 s/mm2 preoperatively. Whole-tumor ADC histogram analysis was performed. Differences in the clinical characteristics, conventional magnetic resonance imaging (MRI) features, and ADC histogram parameters between the two groups were analyzed. Receiver operating characteristic (ROC) analysis was used to evaluate the diagnostic performance of ADC histogram parameters in predicting LVSI. Results: ADCmax, ADCrange, ADC90, ADC95, and ADC99 were significantly lower in the LVSI-positive group than in the LVSI-negative group (all P-values < 0.05), whereas no significant differences were reported for the remaining ADC parameters, clinical characteristics, and conventional MRI features between the groups (all P-values > 0.05). For predicting LVSI in stage IB-IIA cervical cancer, a cutoff ADCmax of 1.75×10-3 mm2/s achieved the largest area under ROC curve (Az) of 0.750, followed by a cutoff ADCrange of 1.36×10-3 mm2/s and ADC99 of 1.75×10-3 mm2/s (Az = 0.748 and 0.729, respectively), and the cutoff ADC90 and ADC95 achieved an Az of <0.70. Conclusion: Whole-tumor ADC histogram analysis has potential value for preoperative prediction of LVSI in patients with stage IB-IIA cervical cancer. ADCmax, ADCrange, and ADC99 are promising prediction parameters.

A novel mutation in AlphaA-crystallin (CRYAA) caused autosomal dominant congenital cataract in a large Chinese family.

Hereditary cataract is a phenotypically and genetically heterogeneous lens disease that is responsible for a significant proportion of the visual impairment and blindness that occurs in children. In a five-generation Chinese family with autosomal dominant inherited congenital cataract, clinical examination showed three cataract phenotypes: punctuate, nuclear, and total cataracts. Linkage analysis was performed and positive two-point LOD scores (with maximum of 4.43 and 4.27 at theta=0) were obtained for markers D21S1411 and D21S1890 on chromosome 21q22.3, flanking the CRYAA (alphaA-crystallin-encoding gene) locus. Sequencing of CRYAA revealed a novel heterozygous G>A transition (c.346G>A) in exon 3 that cosegregated with the disease phenotype and results in a conservative substitution of Arg to His at codon 116 (p.R116H). To understand the molecular basis of cataract formation, mutant and wild-type alphaA-crystallins were expressed in E. coli. RP-HPLC (reverse phase-high-performance liquid chromatography) suggested an increased hydrophobicity of the mutant recombinant protein, compared to that of wild-type alphaA-crystallins. Furthermore, loss of chaperone activity of the mutant was seen in DTT (DL-dithiothreitol)-induced insulin aggregation assay. FPLC (fast protein liquid chromatography) purification showed that the His-116 mutant protein had increased binding affinity to lysozyme. Gain of activated lysozyme binding, elevation of hydrophobicity and loss of chaperone activity of the mutant protein may be some of the molecular mechanisms underlying cataract in this large family.

[Posterior continuous curvilinear capsulorhexis with optic capture of the posterior chamber intraocular lens in pediatric cataract].

OBJECTIVE: To assess the clinical effects of posterior continuous curvilinear capsulorhexis with optic capture of the posterior chamber intraocular lens in pediatric cataract. METHODS: Fifty-one cases (83 eyes) received posterior continuous curvilinear capsulorhexis with optic capture of the posterior chamber intraocular lens. Preoperative and postoperative visual acuity and refractive error were recorded. Intraoperative and postoperative complications were observed. The follow-up period was from 6 to 36 months. RESULTS: Implantation of optic capture of the posterior chamber intraocular lens was successfully performed in 75 eyes (90.4%). The mean postoperative best corrected distant visual acuity achieved 0.5 or better in 75 eyes (48.0%). No eyes with optic capture were found optic axis opaque. The major complications of optic capture were anterior chamber fibrous exudation, iris posterior synechia and lenticular precipitates. CONCLUSION: Optic capture of the posterior chamber intraocular lens is safe and effective in the treatment of pediatric cataract to posterior continuous curvilinear capsulorhexis especially in the prevention of secondary opacification from the visual axis.