SDF-1α/CXCR4 信号通路在轴向应力刺激促进骨再生中的作用研究

目的通过轴向应力刺激促进骨再生，观察基质细胞衍生因子 1α/趋化因子 CXC 亚族受体 4（stromal cell-derived factor 1α/cysteine X cysteine receptor 4，SDF-1α/CXCR4）信号通路变化，探讨轴向应力刺激促进骨再生的机制。方法取 72 只雄性新西兰大白兔，于右后肢胫骨近端内侧制备直径 8 mm 圆形皮质骨缺损并脱蛋白松质骨支架修复模型，随机分为 3 组（n=24）。A 组腹腔注射 PBS，B 组术肢给予应力刺激治疗+腹腔注射 PBS，C 组术肢给予应力刺激治疗+腹腔注射 CXCR4 拮抗剂（AMD3100）。术后 2、4、8、12 周，摄 X 线片并采用 Lane-Sandhu X 线评分标准评价骨愈合情况，取标本行 HE 染色观察新生骨组织及支架降解，免疫组织化学染色观察 VEGF、CXCR4 表达水平；4、8 周取标本 Western blot 检测 SDF-1α 及 CXCR4 蛋白表达水平；12 周行 Micro-CT 检查，计算新生骨体积及新生骨密度。 结果X 线片检查示，除术后 2 周各组骨缺损区及支架无明显变化外，4、8 及 12 周时 B 组骨愈合评分均高于 A、C 组（P<0.05）。12 周时 Micro-CT 扫描可见 B 组骨缺损修复、髓腔再通，新生骨体积及骨密度均高于 A、C 组（P<0.05）。HE 染色显示，术后 4 周开始 B 组骨再生及支架降解均明显快于 A、C 组。免疫组织化学染色示，各组 VEGF 及 CXCR4 阳性表达均在 4 周达峰值；各时间点 B 组 VEGF 及 CXCR4 表达量均显著高于 A、C 组（P<0.05）。Western blot 检测显示，4、8 周时 B 组 SDF-1α 与 CXCR4 表达量均显著高于 A、C 组（P<0.05）。 结论轴向应力刺激促进骨再生可能与其促进骨缺损区组织高表达 SDF-1α，激活与其下游调控 BMSCs 募集的 CXCR4 信号有关。     

A Positive Feedback Loop Between Th17 Cells and Dendritic Cells in Patients with Endplate Inflammation

Background: Endplate inflammation remains a difficult disease to treat, in part due to its unclear pathology. Previous experiments showed that patients with idiopathic inflammation presented a systemic upregulation of Th17 cells. Here, we investigated how this change might affect the inflammatory environment in endplate inflammation.

Methods: Peripheral blood was obtained from patients and healthy controls, and Th17 cells were examined.Results: Th17 cells significantly increased the differentiation of CD11c+ and DC-SIGN+ dendritic cells (DCs) from circulating monocytes in the absence of exogenous stimulation as well as in the presence of LPS stimulation. Th17 cells also increased CD80 and CD86 expression by DCs. Importantly, although Th17 cells from both healthy controls and patients with endplate inflammation could induce CD11c, DC-SIGN, CD80, and CD86 expression, Th17 cells from patients with endplate inflammation showed significantly more potent capacity. Both contact-dependent and IL-17-dependent mechanisms were employed by Th17 cells, since blocking cell-to-cell contact significantly inhibited Th17-mediated differentiation of CD11c+ DCs, and neutralization of IL-17 reduced the expression of CD80 and CD86. Strikingly, DCs following incubation with Th17 cells, but not the DCs derived directly from monocytes without Th17 cells, could significantly promote the expression of IL-17 from naive CD4+ T cells.

Conclusions: These results demonstrated that Th17 cells from patients with endplate inflammation could potently induce the differentiation and activation of DCs that preferentially promoted IL-17 response in a positive feedback loop.     

Serum TLR2 and TLR4 levels in colorectal cancer and their association with systemic inflammatory markers,tumor characteristics,and disease outcome

Toll‐like receptors (TLRs) are involved in colorectal cancer (CRC) pathogenesis. However, the significance of serum TLR concentrations in CRC is unknown. We analyzed serum TLR2 and TLR4 concentrations with ELISA in preoperative samples from 118 patients with CRC and 88 matched controls. We also assessed tissue TLR expression with immunohistochemistry and by detecting serum determinants of systemic inflammation. Most participants (>70%) had undetectable serum TLR2. The mean serum TLR4 levels were lower in patients than in controls (1.1 vs 1.8 ng/mL; p = 0.015). Undetectable TLR4 was more common in stage I (39%) than in stages II–IV (11%, p < 0.001). TLR2 or TLR4 expression in tumor cells did not correlate with serum levels, but abundant TLR2 expression in normal colon epithelium was associated with detectable serum TLR2 (p = 0.034). Undetectable serum TLR2 was linked to high modified Glasgow prognostic scores (p = 0.010), high CRP levels (p = 0.013), blood vessel invasion (p = 0.013), and tended to be associated with worse 5‐year survival (p = 0.052). In conclusion, serum TLR2 levels were inversely associated with systemic inflammation in patients with CRC. Moreover, serum TLR2 levels might depend more on normal colorectal mucosa contributions than on tumor tissue contributions. Further studies are required to assess the prognostic value of serum TLR2.     

Pannexin 1 channels facilitate communication between T cells to restrict the severity of airway inflammation

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An update on epidemiology,diagnosis & management of NMO-SD in the tertiary neurology department of Marrakech (Morocco)

IntroductionNeuromyelitis optica (NMO) and NMO spectrum disorders (NMO-SD) are inflammatory demyelinating diseases of the central nervous system. There are few epidemiological studies devoted to NMO, especially in Africa and the Middle East, but individual cases and series have been reported from many countries across the African continent.ObjectivesTo describe the epidemiology, diagnosis, and management of NMO patients followed at the Mohammed VI University Hospital of Marrakech.Patients and methodsThis was a hospital-based retrospective study of 52 patients with NMO diagnosed and followed at the Neurology department of the University Hospital of Marrakech from 2004 to July 2019. The 2006 diagnostic criteria of NMOSD were used for patients admitted before 2015 for inflammatory disease of the central nervous system and the 2015 diagnostic criteria of NMO-SD for all patients thereafter. Collected data were analysed using SPSS software.ResultsThe study concerned 52 patients, 18 males and 34 females. Median age at disease onset was 32.5 years (range 7–55). Mean time between symptom onset and diagnosis of NMO was nine months 18 days (range 7 days to 4 years). In most patients, manifestations included visual acuity, tetraparesis, and sensorial disorders. Refractory vomiting and hiccup were noted in the first attack in 19% of patients. Two patients had hypersomnia and polyphagia, and one had been treated for depression ten months before the development of severe tetraplegia. Magnetic resonance imaging did not show any brain lesions in 29% of patients. Cervical myelitis extending to more than three vertebrae was found in 60% of patients. AQP4-antibody assay was performed only in 57.7% of patients, and was positive in 38.4%; anti-MOG was positive in four anti-AQP4 seronegative patients. Management strategies for NMO-SD included methylprednisolone pulses (70% of patients), plasmapheresis (25%), and rituximab (since 2017) for 46%. Outcome was favourable in 40% of patients and has remained stable in 50% of them.ConclusionAnti-NMO assays, made available during the last five years with the help of The Guthy-Jackson Charitable Foundation, have led to a clear jump in the number of cases diagnosed. Major advances in the field of epidemiology, imaging, and pathophysiology of NMO-SD have led to improved patient care and outcome.     

Open tibial fractures in major trauma centres: A national prospective cohort study of current practice

Aims

To assess current national practice in the management of severe open tibial fractures against national standards, using data collected by the Trauma and Audit Research Network.

股骨转子间骨折的稳定性重建概念演化与研究进展

目的总结近年来股骨转子间骨折在稳定性重建方面的概念演化与研究进展。方法查阅国内外相关文献并结合自身经验，从股骨转子间骨折的解剖特点、稳定型骨折与不稳定型骨折分类、稳定性复位与不稳定性复位、术中加压初始稳定与术后滑动二次稳定、内固定术后稳定性评估、早期下地站立负重等方面进行总结分析。结果股骨转子间骨折发生于股骨颈干骺端转换区，具有天然的内翻不稳定倾向。骨折复位质量是影响后续内固定物安放的最重要前提因素。判断骨折复位质量有对线和对位两方面，对线采用 Garden 指数；在对位方面，随着皮质对位理念（正性、中性、负性）的提出，特别强调前内侧皮质的相互砥住支撑（解剖、正性），是获得骨折稳定性复位的关键，而不再强调后内侧小转子骨块的作用。术后影像学的稳定性评分为早期下地站立负重提供了量化指标。但术中的前内侧皮质支撑复位，在术后头颈骨块滑动获得二次稳定的过程中，仍有皮质对位丢失现象，需研究其危险因素和防范措施。结论股骨转子间骨折在取得良好对线的基础上，只要获得了前内侧皮质的相互砥住和支撑，并用内固定器械维持住，就获得了术后稳定性。术后稳定性评分优良者，可以安全地早期下地负重、站立行走活动。     

Neonatal Cardiac Arrest From Left Ventricular Cardiac Hemangioma: A Surprising Presentation

Cardiac hemangioma is rare, even more when leading to a cardiovascular collapse in a seemingly healthy newborn. A 6-day-old neonate had a tamponade caused by a basolateral hemangioma of the left ventricle. Partial surgical resection was performed. A congenital lobular capillary hemangioma was diagnosed upon histologic examination. The patient recovered completely and shows normal development at the 12-month follow-up.