Enhancing effect of ultrasound-mediated microbubble destruction on gene delivery into rat kidney via different administration routes

Objective:To investigate the efficiency ofβ-galactosidase gene transfer into rat kidney with ultrasound-mediated microbubble destruction via different injection routes.Methods:A total of 25 Wistar rats were randomly divided into 5 groups.Four groups received a mixture of optison microbubbles(0.2 mL) and lacz plasmids(25μg) injection via renal artery,tail vein,anterior tibial muscle and renal parenchyma,respectively.The control group received a mixture of PBS (xx mL) and lacz plasmids(25μg) via renal artery.Three days after the gene transfer,ultrasound with fixed frequency and power(1 MHz,xxW) was delivered to the kidneys for 3 min.The efficiency of the gene transfer and expression was evaluated on the basis ofβ-galactosidase expression.The side effects of this method were evaluated by immunohistological method. Results:β-galactosidase expression could be observed only in tubules but not in glomeruli and interstitial area.The efficiency of renal artery group was higher than that of tail vein,anterior tibial muscle and renal parenchyma group(P【0.05).Immunohistochemical analysis revealed co-expression ofβ-galactosidase with a roximal tubule marker,megalin,which suggested that ultrasound enhanced gene transfer into the proximal tubular epithelial cells.Noβ-galactosidase expression was observed in the extrarenal organs.There were no evident pathological and biochemical changes after gene transfer.Conclusions:Ultrasound-mediated microbubble destruction can transfer gene into kidney via renal artery,tail vein,anterior tibial muscle and renal parenchyma.Compared with renal artery,administrating microbubbles via tail vein and anterior tibial muscle are more convenient and less vulnerarious.

Analysis of Factors Associated with Death in Maintenance Hemodialysis Patients： A Multicenter Study in China

Background： Patients on hemodialysis have a high-mortality risk. Tiffs study analyzed factors associated with death in patients on maintenance hemodialysis （MHD）. While some studies used baseline data of MHD patients, this study used the most recent data obtained from patients just prior to either a primary endpoint or the end of the study period to iliad the characteristics of patients preceding death.Methods： Participants were selected from 16 blood purification centers in China from January 2012 to December 2014, Patients＇ data were collected retrospectively. Based on survival status, the participants were divided into two groups： survival group and the death group. Logistic regression analysis was performed to determine/＇actors associated with all-cause mortality.

Statistical Prediction in Pathological Types of Chronic Kidney Disease

To the Editor:In China,the pathological types such as mild lesion nephrosis（MLN）,focal segmental glomerulosclerosis（FSGS）,membranous nephropathy（MN）,and IgA nephropathy（IgAN）are presented as common types in patients with chronic kidney disease（CKD）.;For identifying the special CKD pathological types,ultrasound?guided percutaneous renal biopsy is an important diagnostic tool for nephrologists.Clinically,the postbiopsy complications,such as gross hematuria caused by renal hemorrhage,