Osteogenesis promoted by calcium phosphate N,N-dicarboxymethyl chitosan

The effects of N,N-dicarboxymethyl chitosan (DCMC) on the precipitation of insoluble calcium salts, namely phosphate, sulfate, oxalate, carbonate, bicarbonate and fluoride, and magnesium salts, namely phosphate and carbonate, were studied. Results indicated that the chelating ability of DCMC interfered effectively with the well-known physico-chemical behaviour of magnesium and calcium salts. Dicarboxymethyl chitosan formed self-sustaining gels upon mixing with calcium acetate, as a consequence of calcium chelation. DCMC mixed with calcium acetate and with disodium hydrogen phosphate in appropriate ratios (molar ratio Ca/DCMC close to 2.4) yielded a clear solution, from which, after dialysis and freeze-drying, an amorphous material was isolated containing an inorganic component about one half its weight. This compound was used for the treatment of bone lesions in experimental surgery and in dentistry. Bone tissue regeneration was promoted in sheep, leading to complete healing of otherwise non-healing surgical defects. Radiographic evidence of bone regeneration was observed in human patients undergoing apicectomies and avulsions. The DCMC–CaP chelate favoured osteogenesis while promoting bone mineralization.     

Activation Status of Receptor Tyrosine Kinases as an Early Predictive Marker of Response to Chemotherapy in Osteosarcoma

Receptor tyrosine kinases (RTKs) are membrane receptors that play a vital role in various biological processes, in particular, cell survival, cell proliferation, and cell differentiation. These cellular processes are composed of multitiered signaling cascades of kinases starting from ligand binding to extracellular domains of RTKs that activate the entire pathways through tyrosine phosphorylation of the receptors and downstream effectors. A previous study reported that, based on proteomics data, RTKs were a major candidate target for osteosarcoma. In this study, activation profiles of six candidate RTKs, including c-Met, c-Kit, VEGFR2, HER2, FGFR1, and PDGFRα, were directly examined from chemonaive fresh frozen tissues of 32 osteosarcoma patients using a multiplex immunoassay. That examination revealed distinct patterns of tyrosine phosphorylation of RTKs in osteosarcoma cases. Unsupervised hierarchical clustering was calculated using Pearson uncentered correlation coefficient to classify RTKs into two groups—Group A (c-Met, c-Kit, VEGFR2, and HER2) and Group B (FGFR1 and PDGFRα)—based on tyrosine phosphorylation patterns. Nonactivation of all Group A RTKs was associated with shorter overall survival in stage IIB osteosarcoma patients. Percentages of tumor necrosis in patients with inactive Group A RTKs were significantly lower than those in patients with at least one active Group A RTK. Paired primary osteosarcoma cells with fresh osteosarcoma tissue were extracted and cultured for cytotoxicity testing. Primary cells with active Group A RTKs tended to be sensitive to doxorubicin and cisplatin. We also found that osteosarcoma cells with active Group A RTKs were more proliferative than cells with inactive Group A RTKs. These findings indicate that the activation pattern of Group A RTKs is a potential risk stratification and chemoresponse predictor and might be used to guide the optimum chemotherapy regimen for osteosarcoma patients.     

托烷司琼与帕洛诺司琼用于小儿骨科术后镇痛预防恶心呕吐的效果研究

摘要 目的：比较托烷司琼与帕洛诺司琼用于小儿骨科术后镇痛时预防恶心呕吐的效果。方法：纳入2019年3月到2021年3月在我院进行骨科手术的儿童60例,根据术后镇痛泵中使用止吐药物的不同分为托烷司琼组和帕洛诺司琼组,每组30例,比较两组患儿术前、术后的心率（HR）、平均动脉压（MAP）,在术后48小时内,观察两组患儿恶心呕吐、头晕头痛、皮肤瘙痒以及呼吸抑制等术后并发症。视觉模拟评分法（VAS）评估患儿术后疼痛,Ramsay量表评估患儿术后镇静效果。结果：托烷司琼和帕洛诺司琼组患儿在术前和术后HR和MAP比较均无显著差异（P>0.05）;托烷司琼组和帕洛诺司琼组患儿术后VAS评分、Ramsay评分均随时间延长而降低,且同一时间点两组患儿VAS评分无显著差异（P>0.05）;帕洛诺司琼组术后PONV发生率（20.00 %）高于托烷司琼组（3.33 %）（P<0.05）。帕洛诺司琼组和托烷司琼组患儿出现头晕头痛、皮肤瘙痒以及呼吸抑制例数分别为3/2例、1/0例和1/0例。两组间术后并发症发生率比较无差异（P>0.05）。结论：托烷司琼与帕洛诺司琼对骨科手术后儿童血流动力学、疼痛和镇静效果并无差异,但在预防术后恶心呕吐方面托烷司琼效果优于帕洛诺司琼。     

A simple and inexpensive method for evaluation of in vitro cell adhesion on screws

Only a limited number of techniques are available for assessing the effect of different coating materials on cell adherence to screws. In this study, we describe a simple and inexpensive method for evaluation of cell adhesion on irregular surfaces such as the surgical or implant screws. For this purpose, we prepared semi-submerged screws in the petri dishes using agar. Using BSA- or HA-coated screws, we tested whether BSA or HA could improve cell adherence when used as coating materials. Agar-coated screws were used as internal control. Then the “ratio of cell adherence” was calculated by subtracting the reference RCA value obtained from the agar coated screws (internal control). When compared to that of the non-coated screws both the HA- and BSA-coating improved cell adherence on the screws by 2.34 and 2.72 fold respectively. Similarly, MTT assay data revealed that the metabolic capacities of cells on HA- or BSA-coated screws were improved by 2.36 and 2.86 fold respectively. These findings suggest that this protocol can be used for comparing the ability of cells to attach on irregular surfaces such as dental or orthopedic screws and assessing their viability.     

老年骨科全麻患者术后麻醉恢复室谵妄的影响因素分析及防范措施

目的:分析老年骨科全麻患者术后麻醉恢复室谵妄的影响因素,并探讨相关防范措施。方法:选取2018年7月-2020年6月期间我院收治的200例老年骨科全麻患者,收集患者的临床资料。根据其术后麻醉恢复室是否出现谵妄分为观察组(术后发生谵妄)和对照组(术后未发生谵妄),分析术后麻醉恢复室谵妄的影响因素。结果:200例老年骨科全麻患者中,发生术后谵妄的患者83例,发生率为41.50%(83/200)。单因素分析结果显示,老年骨科全麻患者术后麻醉恢复室谵妄与年龄、合并其它基础疾病、吸烟史、术前血糖、术前血红蛋白、术前红细胞压积、手术类型、术中失血量、电解质紊乱有关(P<0.05),而与性别、体质量指数(BMI)、Zung焦虑自评量表(SAS)评分、术前总蛋白、抑郁自评量表(SDS)评分、血钾、手术时间无关(P>0.05)。多因素Logistic回归分析结果显示:年龄>75岁、合并其它基础疾病、术前血红蛋白<12g/dl、术中失血量≥200 mL、电解质紊乱均为老年骨科全麻患者术后发生谵妄的危险因素(P<0.05)。结论:引起老年骨科全麻患者术后麻醉恢复室谵妄的危险因素较多,包括年龄、合并其它基础疾病、术前血红蛋白、术中失血量、电解质紊乱等,临床应采取必要的防范措施,合理制定手术方案,以降低患者术后谵妄的发生率。     

Phagocytic release of human leukocyte neutral proteases: Analysis of cartilage degradation products

Human polymorphonuclear leukocyte neutral proteases (HLNP) released during the process of phagocytosis of aggregated human gamma globulin were tested for their ability to degrade intact rabbit ear cartilage. Using ³⁵S-labeled cartilage as substrate, HLNP derived from 45 × 10⁷ cells released about 45% of the total incorporated ³⁵S. DE-52 chromatography of incubation supernatants revealed a single ³⁵S peak associated with minimal quantities of peptide or protein material as estimated by absorbance at OD_{230 + 280 nm}. Analytical ultracentrifugation gave a molecular weight of 51,800. Incubation of cartilage with excess α-chymotrypsin released ³⁵S-containing protein and peptide elements (M_r 79,400). Therefore, degradation, of the proteoglycans of intact cartilage by HLNP is more extensive than that noted with bovine pancreas α-chymotrypsin. The products of HLNP and α-chymotrypsin digestion of cartilage contained chondroitin sulfates A and/or C since both materials (after column chromatography) were sensitive to chrondroitinase ABC and AC digestion. Collagenolytic activity of HLNP is minimal compared to proteolytic activity as evidenced by the lack of hydroxyproline containing peptides released from cartilage during enzyme incubation. It is suggested that HNLP incubated with intact cartilage may serve as a relevant model in the search for new agents which could combat enzyme-mediated cartilage destruction.     

Lymphocyte-Related Inflammation and Immune-Based Scores Predict Prognosis of Chordoma Patients After Radical Resection

The inflammatory microenvironment plays a critical role in the development and progression of malignancies. In the present study, we aimed to evaluate the prognostic value of lymphocyte-related inflammation and immune-based prognostic scores in patients with chordoma after radical resection, including the neutrophil-lymphocyte ratio (NLR), platelet-lymphocyte ratio (PLR), monocyte-lymphocyte ratio (MLR), and systemic immune-inflammation index (SII). A total of 172 consecutive patients with chordoma who underwent radical resection were reviewed. R software was used to randomly select 86 chordoma patients as a training set and 86 chordoma patients as a validation set. Potential prognostic factors were also identified, including age, sex, tumor localization, KPS, Enneking stage, tumor size, and tumor metastasis. Overall survival (OS) was calculated using the Kaplan–Meier method and multivariate Cox regression analyses. NLR, PLR, SII, Enneking stage, tumor differentiation and tumor metastasis were identified as significant factors from the univariate analysis in both the training and validation sets and were subjected to multivariate Cox proportional hazards analysis. The univariate analysis showed that NLR ≥1.65, PLR ≥121, and SII ≥370×10⁹/L were significantly associated with poor OS. In the multivariate Cox proportional hazard analysis, SII, Enneking stage and tumor metastasis were significantly associated with OS. As noninvasive, low-cost, reproducible prognostic biomarkers, NLR, PLR and SII could help predict poor prognosis in patients with chordoma after radical resection. This finding may contribute to the development of more effective tailored therapy according to the characteristics of individual tumors.     

Mercury leads to abnormal red blood cell adhesion to laminin mediated by membrane sulfatides

Exposure to mercury is associated with numerous health problems, affecting different parts of the human body, including the nervous and cardiovascular systems in adults and children; however, the underlying mechanisms are yet to be fully elucidated. We investigated the role of membrane sulfatide on mercuric ion (Hg²⁺) mediated red blood cell (RBC) adhesion to a sub-endothelial matrix protein, laminin, using a microfluidic system that mimics microphysiological flow conditions. We exposed whole blood to mercury (HgCl₂), at a range of concentrations to mimic acute (high dose) and chronic (low dose) exposure, and examined RBC adhesion to immobilized laminin in microchannels at physiological flow conditions. Exposure of RBCs to both acute and chronic levels of Hg²⁺ resulted in elevated adhesive interactions between RBCs and laminin depending on the concentration of HgCl₂ and exposure duration. BCAM-Lu chimer significantly inhibited the adhesion of RBCs that had been treated with 50 μM of HgCl₂ solution for 1 h at 37 °C, while it did not prevent the adhesion of 3 h and 24 h Hg²⁺-treated RBCs. Sulfatide significantly inhibited the adhesion of RBC that had been treated with 50 μM of HgCl₂ solution for 1 h at 37 °C and 0.5 μM of HgCl₂ solution for 24 h at room temperature (RT). We demonstrated that RBC BCAM-Lu and RBC sulfatides bind to immobilized laminin, following exposure of RBCs to mercuric ions. The results of this study are significant considering the potential associations between sulfatides, red blood cells, mercury exposure, and cardiovascular diseases.     

两种压疮评估量表在骨科患者中的应用研究

目的:比较分析Waterlow和Norton两种压疮评估量表在预测骨折患者压疮中的临床效果。方法:选取某院骨科患者186例,由2名临床护士分别用2种量表对患者进行皮肤评估和量表评分,两者分别独立进行,比较分析两种量表对患者压疮的预测效果。结果:患者共发生压疮5例,发生率为2.69%(5/186);Waterlow量表和Norton量表的临界预测值分别为17分和14分;而二者的受试者工作特征曲线(Receiver Operator Curve,ROC)下面积分别为0.647和0.439。结论:Waterlow量表包含了与骨科疾病相关的压疮危险因素,更加适用于预测骨科患者压疮,但仍需要做进一步改进。     

Analysis of a femoral hip prosthesis designed to reduce stress shielding

The natural stress distribution in the femur is significantly altered after total hip arthroplasty (THA). When an implant is introduced, it will carry a portion of the load, causing a reduction of stress in some regions of the remaining bone. This phenomenon is commonly known as stress shielding. In response to the changed mechanical environment the shielded bone will remodel according to Wolff's law, resulting in a loss of bone mass through the biological process called resorption. Resorption can, in turn, cause or contribute to loosening of the prosthesis. The problem is particularly common among younger THA recipients. This study explores the hypothesis that through redesign, a total hip prosthesis can be developed to substantially reduce stress shielding. First, we describe the development of a new femoral hip prosthesis designed to alleviate this problem through a new geometry and system of proximal fixation. A numerical comparison with a conventional intramedullary prosthesis as well as another proximally fixed prosthesis, recently developed by Munting and Verhelpen (1995. Journal of Biomechanics 28(8), 949–961) is presented. The results show that the new design produces a more physiological stress state in the proximal femur.