Objective To investigate the chondrocyte proliferation and extracellular matrix biosynthesis of electrospun PCL scaffolds seeded with rabbit chondrocytes under flow perfusion culture in vitro.Methods Nonwoven PCL microfiber mats were fabricated,and contra-aperture cylindrical glass equipment as a perfusion bioreactor was designed and manufactured on our own.The experiment included peffusion culture group and static culture group.Primary chondrocytes were isolated from the knee joints of two-month-old New Zealand white rabbits and seeded into scaffolds.The scaffold-cell complexes were harvested at 3,7,and 14 days of culture for scanning electron micrograph (SEM) analysis,biochemical assay,real-time PCR and histology analysis.Results Electrospun PCL scaffolds were composed of microfibers with a diameter of 1.67±0.76 μm and pores with a diameter of 17.65±7.11 μm.SEM showed a better cell proliferation with typical morphology of chondrocytes under perfusion culture.At 7 days of culture,DNA content in perfusion culture group was higher than in static culture group.At 3,7 and 14 days of culture,compared with the static culture group,glycosaminoglycan (GAG) content and GAG/DNA ratio in perfusion culture group were higher,and the differences were statistically significant.At 14 days of culture,real-time PCR showed aggrecan and collagen type Ⅱ gene expression and collagen type Ⅱ to collagen type Ⅰ ratio were higher in perfusion culture group than in static culture group; HE and safranin O staining showed a significant cell proliferation,infiltration,as well as extracellular matrix biosynthesis in perfusion culture group.Conclusion Under flow perfusion culture,the electrospun PCL scaffolds seeded with rabbit chondrocytes can enhance chondrocyte proliferation and extracellular matrix biosynthesis,which is a promising method for cartilage tissue engineering.

Pancreatic leakage is most common among numerous complications after pancreaticoduodenectomy surgery.Predicting at early stage and taking preventive measures in time are of great importance to reducing the incidence of pancreatic leakage as well as its related complications.The article reviewed pancreatic leakage monitoring related reports worldwide in recent 10 years.It was found that some factors were useful for the prediction of pancreatic leakage including the drainage fluid amylase and leukocyte count on postoperative day 1 and 3,C-reactive protein on postoperative day 3,the combined detection of white blood cells and albumin on postoperative day 4,the serum urea nitrogen and the serum albumin on postoperative day 1 and 5-8 days,as well as the ratio of amylase level in abdominal drainage to abdominal drainage volume.

With the development of business of manned spaceflight, the body damage of astronauts on the space en-vironment has received growing concern. Weight loss is the most important cause of various diseases, and the weightlessness muscle atrophy is one of urgent problems to be solved in aerospace medicine. Although there is no concept of weightlessness or weightlessness muscle atrophy in the theory of traditional Chinese medicine (TCM), TCM can grasp the pathogenesis of complex diseases, and provide important theoretical references for the prevention and management of weightlessness diseases, especially weightlessness muscle atrophy. In this paper, TCM Cognition of weightlessness and the pathogenesis of weightlessness muscle atrophy was studied by the sight of TCM theory of qi hoisting. The discussion was made from aspects of circulation of qi and blood, zang-fu function. This work is wished to be beneficial to apply the TCM theory in aerospace medicine.

ObjectiveTo investigate the prevalence,antibiotic characteristics as well as molecular background of community-associated methicillin-sensitive Staphylococcus aureus (CA-MRSA) from patients with skin and sofi tissue infections from 4 different hospitals in Beijing.MethodsFive hundred and one patients were enrolled from 4 hospitals prospectively.Patients with skin and soft tissue infections and no risk factors for healthcare-associated acquisition were included.Sample from the infection sites were collected for culture.Case report form was filled out for each patient.Antibiotic susceptibility test and molecular analysis was performed for each Staphylococcus aureus isolate.ResultsTotally 164 Staphylococcus aureus isolates were cultured from the patients with skin and soft tissue infections.Of them 5 isolates were CA-MRSA.These 5 CA-MRSA isolates harbored SCCmec Ⅰ, SCCmec Ⅲ, SCCmec Ⅳ,SCCmec Ⅴ and untypable,respectively.CA-MRSA was highly resistant to β-lactamase,levofloxacin,erythromycin and clindamycin,but susceptible to vancomycin,teicoplanin,linezolid,daptomycin,and trimethoprim/sulfamethoxazole.Prevalence of PVL in community-associated methicillin sensitive Staphylococcus aureus(CA-MSSA) and CA-MRSA were 41.9％ and 2/5.Other toxins expressed similarly between them.Combined with multilocus sequence typing (MLST) and spa typing,the major clones of CA-MSSA were ST398-t034,ST7-t796,ST398-t571,ST1t127,and ST188-t189,while in CA-MRSA were ST239-t037-SCCmec Ⅰ,ST239-t632-SCCmecⅢ,ST59-t437-SCCmecV,ST8-t008-SCCmecⅣ,and ST6-t701-NT.ConclusionsThe low prevalence of CA-MRSA in Beijing and complexity of the genetic background in CA-MRSA were observed.Clone spread is not found among CA-MRSAisolates.CA-MRSAexhibithigher resistancecomparedwithmethicillinsensitive Staphylococcus aureus (MSSA).Rational drug use scheme is called in the clinical practice to prevent development of high level resistance.