Stem cell possesses the capability of self-regeneration and multidirectional differentiation.Although renal transplantation being the best way for the treatment of end-stage nephropathy,the shortage of donor kidney arouses the treatment with transplantation of stem cells taking emphasis in recent years.The process and mechanism of this therapy are complicated and the authors review in detail the experimental research advancement on stem cells engraftment for the treatment.The correlative interventional technology is also evaluated.(J Intervent Radiol,2006,15: 632-635)

Objective To explore the influence of home synthesize magnetic iron oxide (called Fe2O3-PLL) labeling on peripheral blood endothelial progenitor cells (EPCs) bionomics to provide experimental foundation for MR imaging ex and in vivo. Methods Fe2O3 was incubated with PLL for 2 hours to obtain a complex of Fe2O3-PLL. Rabbit peripheral blood mononuclear cells were isolated and EPCs were selected by adherence method. Fe2O3-PLL was used to label EPCs. Prussian blue stain and electron microscope was used for showing intracellular iron. MTT assay was assessed to evaluate the difference of growth curve between unlabeled and labeled with 25 mg/L Fe2O3-PLL. Flow cytometry was performed to analyze cell cycle, cell apoptosis and the expression of surface markers of labeled and unlabeled cells. Expressions of Enos, KDR and Vwf at Mrna levels among unlabeled and labeled EPCs were detected by real-time polymerase chain reaction. Calcium ion channel and membrane fluidity were observed and analyzed by laser confocal microscopy. Statistical analyses were used with ANOVA and t test. Results Almost 100% cells were labeled by Fe2O3-PLL, iron-containing vesicles were intracytoplasma. There was no statistical difference in cells growth curve, cell life cycle [(93.74±3.52)% ,(94.57±3.66)% ] and cell apoptosis rate(12. 89±1.81) %, (11.67±1.18) %) between labeling with Fe2O3-PLL at a concentration of 25 mg/L and unlabeled cells (t = 0. 283, P > O. 05 ; t = 0. 977, P > 0. 05). There was also no statistical difference in relative amount of Enos, KDR and Vwf at Mrna levels and the expression of sudace phenotypic markers (CD34, CD106, CD146 and KDR) between two groups (P > 0. 05). In addition,Labeling had little influence on calcium ion channel and didn't significantly alter cell membrane fluidity.Conclusions The rabbit peripberal blood EPCs can be effective labeled with Fe2O3-PLL and without significant influence on cells bionomics at a low concentration of 25 mg/L. Almost every cell can be labeled and the labeled cells can be used further.

Objective To evaluate the 1.5 T magnetic resonance imaging system to depict and track in vivo of magnetically labeled endothelial progenitor cells(EPCs),and to study the possibility for preventing the atherosclerotic plaque formation in New Zealand rabbit model of carotid arterial injury after transplantation.Methods New Zealand rabbit EPCs were isolated,confirmed,expanded and then incubated with home synthesized Fe_2O_3-PLL,Prussian blue stain was performed for showing intracellular irons.The model of carotid arterial injury was performed by 2.5F balloons,the group A of 8 rabbits received magnetically labeled EPCs,group B of 3 rabbits received fluorescent-labeled EPCs and the group C of 5 rabbits were given same volume saline injection after endothelial injury of the carotid artery.MR imaging and histology were performed and compared 4 days later for randomly chosen three rabbit,each from one of the three group;all the other rabbits were fed with high lipid diet and examed using MR imaging and histology after 15 weeks.Results Epcs labeling efficiency was more than 95% by Prussian blue stain, 4 days after transplantation of EPCs,only in group A,the injured endothelium of carotid artery had signal intensity loss in T_2 * WI,which were correlated well with the area where the most Prussian blue staining positive cells were found in histopathology analyses.The rabbits of group A and B which received EPCs transplantation exhibited fewer plaques formation than those of the group C(P

OBJECTIVE: It provides reference for accurate and efficient supervision of medical artificial intelligence industry. METHODS: By summarizing the main responsibility dilemma of medical artificial intelligence diagnosis products, sorting out relevant researches at home and abroad, the primary responsibility system of medical artificial intelligence diagnosis products is constructed. RESULTS: A medical artificial intelligence diagnosis products primary responsibility system with the marketing authorization holder as the "first responsible person" is established, and three safeguard measures are proposed, namely, algorithm transparency and interpretability, classification supervision mode and social co-governance supervision mode. CONCLUSIONS The medical artificial intelligence diagnosis products primary responsibility system is helpful to implement the primary responsibility, to build "responsible and beneficial" artificial intelligence, and to realize "self-discipline", "good governance" and "in good order".
Artificial Intelligence ; China ; Humans

Objective: To explore the prognosis and risk factors of pyelectasis in high-risk infants. Methods: This was a retrospective study. Totally 960 high-risk infants, who accepted type B ultrasonic examination for fetus at 28th week of gestation and for newborns in 48 hours after birth, were included in the study in departments of obstetrics and eonatology, Shunyi Maternal and Children's Hospital of Beijing Children's Hospital during May 2012 to April 2013. The degree of pyelectasis was classified using Grignon grade and the paients were followed up for 3 years. The factors of epidemiology, high risk pregnant women, fetus and high-risk newborns that relate to pyelectasis were summarized. High-risk factors were analyzed by using logistic multivariate regression analysis. Results: Of 960 high-risk infants, 103 had abnormal urinary ultrasound results, 87 (9.1% of high-risk infants) were diagnosed with pyelectasis, 16 (1.7% of high-risk infants) were diagnosed with congenital anomalies of the kidney and urinary tract. According to the degree of pyelectasis, 68 infants were Grignon grade Ⅰ, male:female ratio=5.8∶1, left side:right side ratio=1.91∶1; 19 infants were Grignon grade Ⅱ, male:female ratio=5.33∶1, left side:right side ratio=2.12∶1. Postnatal follow-up results showed that pyelectasis disappeared in 48 cases (55% of pyelectasis cae), 40 infants were Grignon grade Ⅰ (59% of all Grignon grade Ⅰ patients), 8 infants were Grignon grade Ⅱ (42% of all Grignon grade Ⅱ patients); The result of risk factors analysis showed that the risk of pyelectasis in males was 4.368 times that of females (95%CI: 2.33-8.189, P<0.05); the risk of pyelectasis in low birth weight infants was 22.434 times that of non low birth weight infants (95% CI: 5.883-85.547, P<0.05). Conclusion The incidence of pyelectasis in high-risk infants was 9.1%. The mitigation rate of pyelectasis in Grignon grade Ⅰ to Ⅱ in fetal or newborn period is high. Patients in Grignon grade Ⅲ and above in fetal or new born period had high risk of congenital anomalies of the kidney and urinary tract. The risk of pyelectasis of male was higher than that of female; the risk of pyelectasis of low birth weight infant was higher than appropriate for gestational age infants.