Biomechanical comparison of three internal fixation configurations for low transcondylar fractures of the distal humerus

BackgroundWe aimed to evaluate the biomechanical stiffness and strength of different internal fixation configurations and find suitable treatment strategies for low transcondylar fractures of the distal humerus.Methods and materialsThirty 4^th generation composite humeri were used to create low transcondylar fracture models that were fixed by orthogonal and parallel double plates as well as posterolateral plate and medial screw (PPMS) configurations (n=10 in each group) using an anatomical locking compression plate-screw system and fully threaded medial cortical screws. Posterior bending (maximum 50 N), axial loading (maximum 200 N) and internal rotation (maximum 10 N·m) were tested, in that order, for each specimen. Stiffness under different biomechanical settings among different configurations were compared. Another 18 sets of fracture models were created using these three configurations (n=6 in each group) and the load to failure under axial loading among different configurations was compared.ResultsUnder posterior bending, the stiffness of parallel group was higher than orthogonal group (P<0.001), and orthogonal group was higher than PPMS group (P<0.001). Under axial loading, the stiffness of parallel group was higher than orthogonal group (P=0.001) and PPMS group (P<0.001); however, the difference between orthogonal and PPMS group was not statistically significant (P>0.05). Under internal rotation, the stiffness of parallel group was higher than orthogonal group (P=0.044), and orthogonal group was higher than PPMS group (P=0.029). In failure test under axial loading, the load to failure in the orthogonal group was lower than parallel group (P=0.009) and PPMS group (P=0.021), but the difference between parallel group and PPMS group was not statistically significant (P>0.05). All specimens in orthogonal group demonstrated “distal medial failure”; most specimens had “distal medial and trochlear failure” in the parallel group; most specimens exhibited “contact failure” in the PPMS group.ConclusionFor treating low transcondylar fractures, the overall stiffness and strength of the parallel configuration were superior to those of the orthogonal and PPMS configurations. Nevertheless, the PPMS configuration can provide adequate stability and stiffness comparable to double-plate configurations under axial loading. Therefore, the PPMS construct may have certain clinical value.     

女性致密性骨炎血清骨转换生化标志物水平变化研究

背景 致密性骨炎（OCI）和其他疾病有时难以鉴别，探讨血清骨转换生化标志物可为OCI的鉴别诊断提供依据。 目的 探索女性OCI患者的血清骨转换生化标志物的水平变化及临床意义。 方法 回顾性选取2013年6月至2022年2月在北京积水潭医院门诊及住院诊断为OCI的61例女性患者作为观察组，年龄15~50岁，平均（33.8±6.6）岁，病程2周~15年。选择同期61例女性体检健康者作为对照组，年龄15~48岁，平均（35.6±7.6）岁。比较两组一般临床资料和血清骨转换生化标志物水平，并对血清骨转换生化标志物与病情相关指标进行相关性分析。 结果 观察组血清白蛋白（45.4±2.9）g/L低于对照组（46.5±2.8）g/L（t=2.190，P<0.05）。血清骨转换生化标志物比较结果显示，观察组血清1型胶原羧基末端肽β特殊序列（β-CTX）〔0.28（0.23，0.37）μg/L〕、N-端骨钙素（OC）〔13.1（11.2，16.2）μg/L〕、25-羟维生素D3〔25-（OH）VD3〕〔（14.1±5.1）μg/L〕低于对照组〔0.36（0.29，0.48）μg/L，15.6（13.7，17.3）μg/L，（17.5±6.6）μg/L〕（Z=-2.983、-3.255，t=3.081，P<0.05）。长病程亚组OC水平〔14.6（12.4，18.5）μg/L〕高于短病程亚组〔11.7（10.2，14.0）μg/L〕（Z=-2.407，P<0.05）。多孕亚组β-CTX〔0.25（0.22，0.32）μg/L〕、OC水平〔12.2（10.3，15.0）μg/L〕低于非多孕亚组〔0.33（0.26，0.44）μg/L、13.4（12.0，18.8）μg/L〕（Z=-2.486、-1.897，P<0.05）。相关性分析显示，观察组血清1型前胶原氨基端延长肽（tP1NP）与妊娠次数、生产次数均呈负相关（rs=-0.276、-0.298，P<0.05），OC与体质指数（BMI）、视觉模拟评分法（VAS）评分、妊娠次数均呈负相关（rs=-0.284、-0.374、-0.360，P<0.05），25-（OH）VD3水平与BMI呈正相关（rs=0.275，P<0.05）。 结论 女性OCI患者血清OC、β-CTX水平明显降低，可为鉴别其他疾病提供依据；血清OC水平可以反映OCI患者的严重程度，同时OC水平与患者妊娠次数相关；tP1NP与妊娠次数、生产次数相关。     

Stem cell therapy: A promising treatment for COVID-19

Novel coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has become a global pandemic. SARS-CoV-2 is an RNA virus and has a glycosylated spike (S) protein used for genome encoding. COVID-19 can lead to a cytokine storm and patients usually have early respiratory signs and further secondary infections, which can be fatal. COVID-19 has entered an emergency phase, but there are still no specific effective drugs for this disease. Mesenchymal stem cells (MSCs) are multipotent stromal cells, which cause antiapoptosis and can repair damaged epithelial cells. Many clinical trials have proved that MSC therapy could be a potential feasible therapy for COVID-19 patients, especially those with acute respiratory distress syndrome, without serious adverse events or toxicities. However, more studies are needed in the future, in order to confirm the effect of this therapy.     

土茯苓的临床应用及其用量探究

通过总结分析经典名方和现代医家运用土茯苓的临床配伍及用量,探讨得出其临床用量范围为9~240 g。依据疾病和证型的特点,选择土茯苓的不同配伍和用量,如配伍威灵仙等解毒除湿,治疗风湿免疫系统疾病,常用30~60 g;配伍败酱草利湿通淋,治疗泌尿系统疾病,常用15~60 g;配伍椿根白皮等解毒杀虫,治疗妇科疾病,常用10~60 g。若病情急重,或病程缠绵,可重用至120~240 g,但应用大剂量时需注意配伍防护,随病情变化及时加减,中病即止。     

根深叶茂花自开——中国小儿骨科的起源和发展

我国小儿骨科源起于20世纪50年代,中华人民共和国成立后,曾经在欧美国家接受过现代骨科学教育的中国骨科奠基人孟继懋、叶衍庆、方先之等学者们先后在北京、上海、天津等大城市组建了骨科为主的医院或研究所:北京积水潭医院、上海瑞金医院伤骨科研究所、天津骨科医院等,专门诊治骨科患者并进行教学和科研培训,早期主要治疗骨髓炎、骨结核、骨折等疾病[1]。1954 年天津骨科医院成立了专门的小儿骨科,是国内最早成立的独立建制的科室。     

Characteristic chemical profile of Juhe Fang extract with lipid-lowering properties

ObjectiveThe objective of this study was to verify the lipid-lowering effect of Juhe Fang extract (JHFE) and to determine its characteristic chemical profile in vitro and in vivo.MethodsA hyperlipidemia model was established by feeding mice a high-fat diet (HFD). After treatment for 30 days, serum total cholesterol (TC), triglyceride (TG), high-density lipoprotein cholesterol (HDL-C) and low-density lipoprotein cholesterol (LDL-C) levels were measured with an automatic biochemistry analyzer. The components from JHFE obtained from in vivo and in vitro experiments were investigated using an UPLC-Q Exactive-Orbitrap MS/MS.ResultsThe TC, TG, and LDL-C in the serum significantly decreased and the HDL-C significantly increased after JHFE treatment. A total of 95 compounds from JHEF including 15 phenolic acids (PA), 4 phenylethanoid glycosides (PG), 24 flavonoids (F), 14 triterpenoids (T), 10 diterpenoid glycosides (D), 18 alkaloids (A) and 10 others (O) were identified. Trigonelline was discovered for the first time in a herbal medicine of Juhe Fang. Furthermore, 68 compounds were identified in vivo including 28 prototype compounds and 40 metabolites. The metabolic characteristics of these components were revealed including identification of new metabolites of 4-hydroxyphenyl ethyl-8-O-[α-L- arabinopyranosyl-(1 → 6)]-β-D-glucopyranoside (PEG) and lirinidine. A total of 43 components from JHFE were absorbed and/or metabolized. The contribution rate of each type of chemical component from JHFE to its lipid-lowering effect from high to low were A, F, PG, PA, D and T.ConclusionThe results of this study showed that JHFE demonstrated a significant lipid-lowering effect in a high-fat diet (HFD)-induced hyperlipidemia mouse model. Specific types of PA, PG, F, D, T and A formed the pharmaceutical architecture of the lipid-lowering effect of JHFE. This study should prove useful for clarifying the components responsible for the lipid-lowering effect of JHFE and provide a basis for precision quality control research.