Cartilage surface of early osteoarthritis in rats induced by papain under scanning electron microscope / 中国组织工程研究

BACKGROUND:Osteoarthritis animal models induced by papain are commonly used for studying osteoarthritis. OBJECTIVE:To observe the morphology of articular cartilage surface during early osteoarthritis process in rats induced by papain and L-cysteine under scanning electron microscope. METHODS:The right knees of Sprague-Dawley rats were given 0.15 mL mixed solution of 2%papain and 0.03 mol/L L-cysteine in the ratio of 2:1. The left knees were given injections of 0.15 mL 0.9%NaCl, as the control group. Another two rats (four knees) maintained untreated, as the normal control group. Al the rats were observed with scanning electron microscope at 2, 4, 6 weeks after injection, to explore the surface morphology of medial condyle of femur. RESULTS AND CONCLUSION:The condyles of normal and control groups revealed numerous shal ow pits on the surface of articular cartilage. At 2 weeks after injection, the surfaces of condyles were unsmooth, presenting the shrinkage and distortion. The thinner articular cartilage and local tiny cracks were seen at 4 weeks. The deep and great cracks and cartilage defect were observed on the surface of cartilage at 6 weeks. The time of 4-6 weeks is a reference point for establishing early osteoarthritis model in rats through injections of 2%papain and 0.03 mol/L L-cysteine.

Empiric initial therapy in peritoneal dialysis-related peritonitis / 中华肾脏病杂志

Objective To investigate the pathogens,drug resistance and outcomes of continuous ambulatory peritoneal dialysis(CAPD) patients with peritoneal dialysis-related peritonitis in our peritoneal dialysis(PD) centers. Method Data including clinical manifestations,pathogens,treatment,outcome of 93 CAPD cases with peritoneal dialysis-related peritonitis in our peritoneal dialysis(PD) centers were retrospectively analyzed.Results Dialysate culture of 75cases was positive with a positive rate of 80.2％,including 45 cases of gram-positive cocci,21cases of gram-negative bacilli,2 cases of fungi and 5 cases of mixed infection.Coagulase-negative staphylococci were the most common gram-positive cocci.All the gram-positive cocci were sensitive to vancomycin,but the resistance rate to cefazolin was 60.0％ with an increasing tendence year by year.Resistance rate of gram-negative bacilli to ceftazidime was 46.1％.All the gram-negative bacilli were sensitive to imipenem.The withdraw rate of CAPD was 17.2％(16/93) because of peritonitis. Noobviousside-effectofperitonealadministrationofvancomycinwasfound.Conclusions Gram-positive cocci are major pathogens in CAPD-related peritonitis.Now cefasolin is not suitable for the empiric initial treatment.Peritoneal administration of vancomycin should be recommended for peritonitis caused by gram-positive cocci.

Investigation of Underpotential Deposition of Lead on Rotating Silver Disk Electrode by Chronocoulometry / 分析化学

The monolayer charge of lead underpotential deposition (UPD) was studied by chronocoulometry. On the rotating silver disk electrode (Ag-RDE), the monolayer charge of UPD lead could reaches steady state at different Pb2+ concentration levels by changing reduction time of UPD Pb2+ . A supporting electrolyte solution of 0.01 mol/L HNO3 + 0.01 mol/L NaCl was used. The steady state charge measured was 393.3 μC/cm2, which corresponded to a surface cover of 2 × 10-9 mol/cm2 Pb2+ on the electrode surface.