Objective To evaluate the protective effect of the angiotensin-converting enzyme inhibitor perindopril on diabetic glomerulopathy in rats with experimentally induced diabetes and study its possible mechanisms. Methods Changes of indexes, which include glomerular basement membrane thickness, mesangial matrix volume density, urinary protein excretion rate, plasma and renal tissue renin activity 、angiotensin Ⅱ concentration and renal angiotensinogen mRNA expression level in rats with experimentally induced diabetes, were observed. Results Angiotensin Ⅱ concentration increased in both the renal tissue and plasma in diabetic rats. Perindopril decreased proteinuria and delayed the progression of glomerular basement membrane thickening. However, it did not reduce the expansion of the mesangial matrix ( P

BACKGROUND:Half-ring sulcated external fixator is a bone external fixation device.Its structure is relatively simple,with multi-plane fixed,and small occupying space.So far,there are few experimental reports about construction of tibial defect model by it in large animals.OBJECTIVE:To validate the practicality and repeatability of half-ring sulcated external fixator in establishing tibial defect models in goats.DESIGN,TIME AND SETTING:The randomized controlled observation was performed at the Animal Laboratory of the Third Military Medical University from March 2005 to February 2007.MATERIALS:Nine healthy adult(Animal Center of Third Military Medical University);Half-ring sulcated external fixator,made by Professor Li of the Third Military Medical University;Osseous pin,ψ2.5 mm,Shanghai Medicai Instruments Co.,Ltd.METHODS:After animals were anesthetized,two needles were threaded in the same plane of cancellous bone about 1.5-2.0 cm above the superior articular surface of the tibia,named group 1.The angle between the two needles was 40°.One needle was threaded at the place of 3.0 to 5.0 cm under the group 1 and parallel with optional needle of the group 1,named group 2.Needles of group 4 were threaded at the cancellous bone that was 2.0 cm from the joint surface of inferior extremity of the tibia.One needle was threaded at the place of 3.0 to 5.0 cm from group 4 and parallel with optional needle of the group 4.The included angle between these two needles of group 2 and group 3 was 60°.There were totally 6 needles.Tibia was fixed by half-ring sulcated external fixator.According to the length of the tibia from X-ray,tibia and periosteum were amputated by wire saw between the two needles in the middle and inferior segment of the tibia to make segmental bone and periosteal defects of 20 percent of tibia.MAIN OUTCOME MEASURES:①Postoperative general state of the animals and effect of half-ring sulcated external fixator.②Self-repair of bone defects by X-ray and Lane-Sandhu scoring standards.RESULTS:Of the 9 selected goats,1 died of postoperative infection,and 1 developed pinhole infection and supplemented.All the others survived and were included in final analysis.The goats were awake within 2-6 hours after surgery and able to stand up to eat.The loosening nuts were screwed up.No external fixation failure or loosening was found.No skin was necrotic.Injured limb could touch the ground in 2 days,but could not bear load until 2 weeks.The goats could walk in three weeks with a slight limp,then moved freely without claudication in four weeks after the operation.At the 5th week after operation,the radiographs showed little periosteal reaction.At the 10th week after operation,sclerosis was found in the fracture ends,and medullary cavity started to close.Fifteen weeks after operation,the medullary cavity closed and periosteal reaction did not aggravate.Inaddition.Lane score was 0 at any time point.No bone formation was found in the histological examination at 5,10 and 15 weeks after operation,and Lane score was 0 at any time point.CONCLUSION:The goat model established in goat tibia with 20%defects by the half-ring sulcated external fixator shows no bone healing after 15 weeks by X-ray or histological exanimation,indicating this is a practical and repetitive method to establish animal models of large segmental defect for bone tissue engineering.

BACKGROUND:There are reports concerning differentiation of adipose-derived mesenchymal stem cells(ADSCs)into chondrocytes using gene transfection technique.However,the transfection of adenovirus and adeno-associated virus into ADSCs is various.It is controversial whether adeno-associated virus(AAV)can transfect ADSCs.OBJECTIVE:To observe the enhanced green fluorescent protein(EGFP)expression following Ad5-EGFP and rAAV2-EGFP transfection into ADSCs,and investigate the cell proliferation ability following transfection.METHODS:ADSCs were isolated from the adipose tissue,which was from 6-month-old New Zealand albino rabbit back and neck by mechanical digestion and enzyme digestion,then ADSCs were cultured and amplified in vitro.ADSCs were infected with Ad5-EGFP and rAAV2-EGFP,and the EGFP expression was observed.A total of 2 μL sodium butyrate(1 mol/L)was added into the medium after rAAV2-EGFP transfection.MTT assay was used to detect the gene transfection effects on reproductive activity of ADSCs.RESULTS AND CONCLUSION:ADSCs isolated and cultured in vitro were flat,long-spindle and amplified stabry.The cell morphology was uniform.Many green fluorescent cells were observed in Ad5-EGFP and rAAV2-EGFP groups.Transfection efficiencies were about 88% and 83%.Adenovirus and adeno-associated virus vector can be transfected with ADSCs,and transfection efficiency is high.Adeno-associated virus needs sodium butyrate to increase its level of gene expression.

In recent years, owing to the miniaturization of the fluidic environment, microfluidic technology offers unique opportunities for the implementation of nano drug delivery systems (NDDSs) production processes. Compared with traditional methods, microfluidics improves the controllability and uniformity of NDDSs. The fast mixing and laminar flow properties achieved in the microchannels can tune the physicochemical properties of NDDSs, including particle size, distribution and morphology, resulting in narrow particle size distribution and high drug-loading capacity. The success of lipid nanoparticles encapsulated mRNA vaccines against coronavirus disease 2019 by microfluidics also confirmed its feasibility for scaling up the preparation of NDDSs via parallelization or numbering-up. In this review, we provide a comprehensive summary of microfluidics-based NDDSs, including the fundamentals of microfluidics, microfluidic synthesis of NDDSs, and their industrialization. The challenges of microfluidics-based NDDSs in the current status and the prospects for future development are also discussed. We believe that this review will provide good guidance for microfluidics-based NDDSs.