Evaluation of Renal Pathophysiological Processes Induced by an Iodinated Contrast Agent in a Diabetic Rabbit Model Using Intravoxel Incoherent Motion and Blood Oxygenation Level-Dependent Magnetic Resonance Imaging

OBJECTIVE: To examine the potential of intravoxel incoherent motion (IVIM) and blood oxygen level-dependent (BOLD) magnetic resonance imaging for detecting renal changes after iodinated contrast-induced acute kidney injury (CI-AKI) development in a diabetic rabbit model. MATERIALS AND METHODS: Sixty-two rabbits were randomized into 2 groups: diabetic rabbits with the contrast agent (DCA) and healthy rabbits with the contrast agent (NCA). In each group, 6 rabbits underwent IVIM and BOLD imaging at 1 hour, 1 day, 2 days, 3 days, and 4 days after an iohexol injection while 5 rabbits were selected to undergo blood and histological examinations at these specific time points. Iohexol was administrated at a dose of 2.5 g I/kg of body weight. Further, the apparent transverse relaxation rate (R2*), average pure molecular diffusion coefficient (D), pseudo-diffusion coefficient (D*), and perfusion fraction (f) were calculated. RESULTS: The D and f values of the renal cortex (CO) and outer medulla (OM) were significantly decreased compared to baseline values in the 2 groups 1 day after the iohexol injection (p < 0.05). A marked reduction in the D* values for both the CO and OM was also observed after 1 hour in each group (p < 0.05). In the OM, a persistent elevation of the R2* was detected for 4 days in the DCA group (p < 0.05). Histopathological changes were prominent, and the pathological features of CI-AKI aggravated in the DCA group until day 4. The D, f, and R2* values significantly correlated with the histological damage scores, hypoxia-inducible transcription factor-1α expression scores, and serum creatinine levels. CONCLUSION: A combination of IVIM and BOLD imaging may serve as a noninvasive method for detecting and monitoring CI-AKI in the early stages in the diabetic kidney.

Treatment of renal anemia: Erythropoiesis stimulating agents and beyond

Anemia, complicating the course of chronic kidney disease, is a significant parameter, whether interpreted as subjective impairment or an objective prognostic marker. Renal anemia is predominantly due to relative erythropoietin (EPO) deficiency. EPO inhibits apoptosis of erythrocyte precursors. Studies using EPO substitution have shown that increasing hemoglobin (Hb) levels up to 10–11 g/dL is associated with clinical improvement. However, it has not been unequivocally proven that further intensification of erythropoiesis stimulating agent (ESA) therapy actually leads to a comprehensive benefit for the patient, especially as ESAs are potentially associated with increased cerebro-cardiovascular events. Recently, new developments offer interesting options not only via stimulating erythropoeisis but also by employing additional mechanisms. The inhibition of activin, a member of the transforming growth factor superfamily, has the potential to correct anemia by stimulating liberation of mature erythrocyte forms and also to mitigate disturbed mineral and bone metabolism as well. Hypoxia-inducible factor prolyl hydroxylase inhibitors also show pleiotropic effects, which are at the focus of present research and have the potential of reducing mortality. However, conventional ESAs offer an extensive body of safety evidence, against which the newer substances should be measured. Carbamylated EPO is devoid of Hb augmenting effects whilst exerting promising tissue protective properties. Additionally, the role of hepcidin antagonists is discussed. An innovative new hemodialysis blood tube system, reducing blood contact with air, conveys a totally different and innocuous option to improve renal anemia by reducing mechanical hemolysis.

Construction of the recombinant adenovirus RNA interference vector of human hypoxia-inducible transcription factor-1? gene and its effect on expression of HIF-1? gene in human lung adenocarcinoma cells SPCA-1 / 基础医学与临床

Objective To construct the RNA interference(RNAi)recombinant adenovirus vector targeting at human hypoxia-inducible transcription factor 1?(HIF-1?)and to evaluate its effect on human lung adenocarcinoma cell line SPCA-1.Methods The recombinant adenovirus Ad was constructed.HIF-1? inserted with HIF-1? RNAi fragment via AdEasy system.The virus was purifed by CsCl gradient centrifuge.The functional titer of recombinant adenovirus was measured by transfection test in HEK 293 cells.SPCA-1 cells were transducted with 2 multiplicity of infection(MOI)Ad.HIF1? in vitro,the expression rate of green fluorescence protein(GFP)was recorded by flow cytometry,HIF-1? mRNA and protein level was measured by Real-Time RT-PCR and flow cytometry.ResultsThe recombinant shuttle plasmid PAdTrack.HIF-1? and adenovirus plasmid Ad.HIF-1? were all correct shown by enzyme digestion confirmation.The plasmid pAd.HIF-1? was transducted into HEK293 cells,15%GFP expressionwere seen after 3 days.The final titers of recombinant adenovirus were 5.0?1010 TU/mL.SPCA-1 cells was transducted by Ad.HIF-1? in vitro for 48 h,GFP expression rate was 92%,HIF-1? mRNA and protein level decreased 89% and 87%,respectively.Conclusion RNAi adenovirus vector of human HIF-1? gene has been successfully constructed,which could facilitate the research onHIF-1? gene related gene therapy for lung cancer.