Pathogenetic characteristics of 104 children with acute septic osteomyelitis / 中华急诊医学杂志

Objective:To identify the pathogens isolated in the subperiosteal abscesses from the pediatric patients with acute osteomyelitis and to investigate the characteristics of bacterial drug resistance.Methods:A retrospective study was conducted on children with acute septic osteomyelitis who were hospitalized in the Children's Hospital, Zhejiang University School of Medicine from January 1, 2011 to March 1, 2018. The results of bacterial cultures isolated from the subperiosteal abscesses or bone marrow fluid were collected. The Merier automatic bacterial identification system (i.e., Vitek) was used to identify the bacteria and to assess the drug sensitivity.Results:(1) A total of 104 pediatric patients were included and 60 (57.7%) were male. Sixty-six strains of pathogens were isolated from 65 patients (62.5%). Among them, 53 strains (51.0%) were Staphylococcus aureus; 3 strains were Escherichia coli; 2 strains (1.9%) were Pseudomonas aeruginosa; 2 strains (1.9%) were Streptococcus pneumoniae, 2 strains (1.9%) were Ochrobactrum anthropi, and 4 strains (3.8%) were other bacteria. Pathogens were not found in 39 patients (37.5%). (2) Staphylococcus aureus accounted for 81.5% (53/65) of the pathogen-positive cases. Among them, 23 strains (43.4%) were methicillin-resistant Staphylococcus aureus (MRSA). Aureus-positive children were statistically significantly older ( P=0.028), heavier ( P=0.040) and had higher C-reactive protein (CRP) level ( P=0.038) than the aureus-negative children. (3) All the 53 Staphylococcus aureus strains were resistant to penicillin and 56.6% of them were only sensitive to benzocillin. The resistance rates to compound sulfamethoxazole, tetracycline, clindamycin and erythromycin were 11.3%, 30.2%, 67.9% and 69.8%, respectively. The sensitivity rate of the strains to furantoin was 90.2%. All strains were sensitive to quinupristin/dalfopristin, linezolid, rifampicin, tigecycline, levofloxacin, moxifloxacin, ciprofloxacin and vancomycin. There was 69.8% of the strains resistant to three or more different types of antibiotics. Conclusions:Staphylococcus aureus is the most common pathogen that causes the acute septic osteomyelitis in children, and the resistance rate to Benzocillin is relatively high. Therefore, Benzocillin and Clindamycin, as the traditionally-used drugs, should not be considered as the first choice when empirically using intravenous antibiotics. In the present study, pathogens in 39 patients (37.5%) were not detected in their subperiosteal abscesses or bone marrow fluid, so further effort should be made to investigate the etiology of these patients.

Three-dimensional parallel collagen scaffold promotes tendon extracellular matrix formation / 浙江大学学报·医学版

<p><b>OBJECTIVE</b>To investigate the effects of three-dimensional parallel collagen scaffold on the cell shape, arrangement and extracellular matrix formation of tendon stem cells.</p><p><b>METHODS</b>Parallel collagen scaffold was fabricated by unidirectional freezing technique, while random collagen scaffold was fabricated by freeze-drying technique. The effects of two scaffolds on cell shape and extracellular matrix formation were investigated in vitro by seeding tendon stem/progenitor cells and in vivo by ectopic implantation.</p><p><b>RESULTS</b>Parallel and random collagen scaffolds were produced successfully. Parallel collagen scaffold was more akin to tendon than random collagen scaffold. Tendon stem/progenitor cells were spindle-shaped and unified orientated in parallel collagen scaffold, while cells on random collagen scaffold had disorder orientation. Two weeks after ectopic implantation, cells had nearly the same orientation with the collagen substance. In parallel collagen scaffold, cells had parallel arrangement, and more spindly cells were observed. By contrast, cells in random collagen scaffold were disorder.</p><p><b>CONCLUSION</b>Parallel collagen scaffold can induce cells to be in spindly and parallel arrangement, and promote parallel extracellular matrix formation; while random collagen scaffold can induce cells in random arrangement. The results indicate that parallel collagen scaffold is an ideal structure to promote tendon repairing.</p>

Progress on treatment of tendinopathy with platelet-enriched plasma / 浙江大学学报·医学版

Platelet-enriched plasma (PRP) contains high concentration of platelets and abundant growth factors, which is made by centrifuging of blood and separating of blood elements. PRP promotes tendon repair by releasing various cytokines to enhance cell proliferation, tenogenic differentiation, formation and secretion of matrix; meantime, it can reduce pain by inhibiting the expression of pain-associated molecules. A number of clinical studies demonstrated that PRP was effective in treatment of tendinopathy, including patellar tendinopathy, lateral epicondylitis and plantar fasciopathy. However, some studies did not support this conclusion, because of disparity of PRP types, therapeutic courses and injections protocols in clinical application. Based on its safety, PRP can be a choice of treatment for tendinopathy, in case other non-surgical therapies are of no effect.