Objective To construct tissue-engineered skin containing melanin with mixed culture of human keratinocytes (KCs) and melanocytes (MCs) on de-epidermized dermis (DED) in vitro. Methods Single-cell suspension was obtained by digestion of isolated preputial epidermis with pancreatin. Keratinocyte serum-free medium (K-SFM) and modified M254 culture medium were used to culture KCs and MCs respectively. Third-passage KCs were seeded into cell culture flasks and cultured for 48 hours; then, third-passage MCs were seeded into the same cell culture flasks with the MC/KC ratio being 1: 10 followed by a 5-day coculture. The suspension of third-passage KCs and MCs with the MC/KC ratio of 10:1 were seeded onto the surface of a prepared DED and maintained at the air-liquid interface for 11 days following a 4-day submerged culture.Subsequently, the constructed tissue-engineered skin was examined with HE staining, immunohistochemical staining for keratin and Masson-Fontana staining. Results After coculture in flasks for 5 days, KCs exhibited a typical paving-stone appearance, MCs with projected dendrites were scattered in the extracellular space between KCs. HE staining revealed 3 to 6 layers of cells with the formation of stratum corneum after mixed culture on DED for 15 days. Keratin protein was positive throughout the artificial epidermis, and melanin pigments were located in the basal layer of the epidermis as Masson-Fontana staining showed. Conclusions The co-culture of MCs and KCs can form single-cell layers with the contact between MCs and KCs in flasks, and construct tissue-engineered skin with melanin component on DED in vitro.

BACKGROUND: Vessel extracellular matrix (VECM) is a natural scaffold material obtained from vascular tissues, which can stimulate angiogenesis and accelerate vascularization of tissue-engineered graft, however, the mechanism is poorly understood.OBJECTIVE: To explore the vascularization effects of release of vascular endothelial growth factor (VEGF) from VECM in ureteral reconstitution.DESIGN, TIME AND SETTING: An in vitro cytology observation. The experiment was performed at the Biomedical Engineering Laboratory of First Clinical Medical Science College, Wuhan University, between April and August in 2009.MATERIALS: Abdominal aorta was obtained from 5 rabbits to prepare VECM.METHODS: The VEGF released from VECM in vitro was evaluated by ELISA, the effects of cell proliferation by the released VEGF was detected by MTT colorimetric assay. The defected ureters of rabbits were repaired by homologous VECM in vivo.Then the recovery of the defected ureters and the situation of vasculogenesis were detected at different time point.MAIN OUTCOME MEASURES: The detection of VEGF contents in VECM; and the effects of VECM on vascular endothelial cell proliferation and ureteral reconstitution.RESULTS: In vitro experiment presented that the peak amplitude concentration of VEGF released from VECM in PBS solution was (124.10±1.42) ng/L, which showed proliferative effect on vascular endothelial cells. In vivo, there were some blood vessels on the VECM at 2 weeks after implantation. Epithelial coverage was evident in the lumen of the marginal part of the VECM grafts and the smooth muscle extended from the transition zone. After 8 weeks, the quantity of the blood vessel was increased and the caliber of the blood vessels became wide. There was thickness epithelial lamina in the graft, and the muscle fibers had an organized spatial alignment, forming variably sized bundles. After 16 weeks, there were no significant differences between the regenerative tissue and the normal tissue in morphology.CONCLUSION: The homologous VECM can release VEGF when implanted as tissue engineer biomaterial and might be an ideal replacement biomaterial for ureteral reconstitution.

Objective To investigate the variations of glomerular function in rabbits with partial unilateral ureteral obstruction (PUUO). Methods Thirty healty adult Japanese White Rabbits were randomly divided into the control group (6 rabbits) and the obstruction group (24 rabbits). The right PUUO model was established according to Cheng′s method. According to the PUUO duration, they were eaqually divided into four subgroups:the 7 day PUUO group, the 14 d PUUO group, the 28 d PUUO group and the 56 d PUUO group. The dynamic renal imaging was performed on all rabbits, and the glomerular filtration rate (GFR) was also calculated. The correlation between the renal function and PUUO duration was analyzed , and functional variations in the healthy kidneys were observed. Results (1)To the control group, no significant difference in the renal function was found between the left and the right kidneys (t = -0.145, P = 0.894). However, to the PUUO group, the right renal GFRs were significantly lower than the left renal GFRs (P < 0.05). (2) To the right renal GFR, significant difference was observed between the 7 day PUUO group and the control group (t = 5.066, P = 0.001),but not among the 7 day PUUO group, the 14 day PUUO group, the 28 day and the 56 day PUUO group (P > 0.05), (3)No significant differences were found in the left renal GFRs among the five groups. Conclusions The function of PUUO kidneys is characterized by an obvious decrease in the early stage, followed with a steady state. The basic function of the opposite healthy kidney does not present the compensation phenomenon.

Background: High-dose dual therapy (HDDT) is a novel regimen for the eradication of Helicobacter pylori (Hp) infection, however, its efficacy and safety remain unclear. Aims: To evaluate the efficacy, safety and compliance of HDDT for Hp eradication. Methods: Randomized controlled trials (RCTs) on HDDT for eradication of Hp infection were retrieved from PubMed, Embase, The Cochrane Library, Web of Science from the date of database establishment to October 2020. Literatures were enrolled according to the inclusion and exclusion criteria, and the data were extracted. RevMan 5.2 software was used for performing meta-analysis. Results: Nine RCTs including 2 627 patients were included. Meta-analysis results showed that no significant differences in ITT eradication (85.4% vs. 79.8%, RR=1.03, 95% CI: 0.96-1.10, P=0.40), PP eradication (88.7% vs. 83.4%, RR=1.01, 95% CI: 0.95-1.08, P=0.68), and compliance (96.5% vs. 95.9%, RR=1.01, 95% CI: 0.99-1.02, P=0.37) were found between HDDT and the guideline-recommended regimens, however, the incidence of adverse events was significantly decreased in HDDT (15.3% vs. 27.0%, RR=0.57, 95% CI: 0.42-0.76, P=0.000 2). Conclusions: There are no significant differences in eradication rates and compliance between HDDT and the guideline-recommended regimens, however, HDDT is much safer.