Potential lack of “standardized” processing techniques for production of allogeneic and xenogeneic bone blocks for application in humans

In the present study, the structure of two allogeneic and three xenogeneic bone blocks, which are used in dental and orthopedic surgery, were histologically analyzed. The ultimate goal was to assess whether the components postulated by the manufacturer can be identified after applying conventional histological and histochemical staining techniques. Three samples of each material, i.e. allogeneic material-1 and -2 as well as xenogeneic material-1, -2 and -3, were obtained commercially. After decalcification and standardized embedding processes, conventional histological staining was performed in order to detect inorganic matrix, cellular or organic matrix components. Allogeneic material-1 showed trabecular bone-like structures, which were free of cellular components as well as of organic matrix. The allogeneic material-2 showed trabecular bone structures, in which connective tissue and cellular remnants were embedded. Additionally, some connective tissue, which resembled fat-like tissue, was found within this material. The xenogeneic material-1 showed trabecular bone-like structures and contained organic components comparable to that demonstrated for the allogeneic material-2. The xenogeneic material-2 showed trabecular bone structures with single cells located in lacunae. The xenogeneic material-3 also showed trabecular structures. Neither cellular nor organic matrix components were found within this material. According to the data of the present study, the allogeneic material-1 and the xenogeneic material-3 were the only investigated materials for which the obtained histological data were in accordance with the manufactureŕs advertised information. The remaining three materials showed discrepancies—although the manufacturers of all five bone substitute materials stated that their blocks were free of organic/cellular remnants. These data are of great clinical and material science interest. It seems that even patented processing techniques are not always able to deliver reproducible materials. Although the manufacturers of all five bone blocks stated that their blocks were free of organic/cellular remnants, our histological analysis revealed that three out of five bone blocks did contain such remnants. Such specimens might be able to induce an immune response within the recipient.     

CBL结合循证医学思维在临床免疫学检验实验课教学中的应用

目的 探讨案例教学法 (case-based learning，CBL) 结合循证医学思维在临床免疫学检验实验课教学中的应用价值。方法 选取首都医科大学 2016 级本科临床检验专业 A 班学生为对照组，B 班学生为实验组，实验组采用常规教学方法结合 CBL 结合循证医学思维的教学方法进行教学，对照组只采用常规教学方法教学，最后以笔试、问卷调查方式进行分析。结果 90% 以上的学生认为 CBL 结合循证医学思维的教学方法新颖、生动，有助于对理论知识的理解和记忆，理论联系实际。对照组考试平均分数为 (84.5±5.1) 分，实验组为 (88.1±4.3) 分；对照组病例分析题 ( 总分 40 分 ) 平均分为 (27.2±3.7) 分，实验组为 (36.3±4.1) 分。结论 CBL 结合循证医学思维的教学方法培养学生提出、分析和解决问题的能力，能帮助学生更好地掌握临床免疫学检查技术。     

Bioabsorbable steroid-eluting sinus stents for patients with refractory frontal diseases undergoing a revision Draf 3 procedure: a case series

Background: Bioabsorbable steroid-eluting sinus stents are safe and effective in maintaining the patency of the frontal sinus ostium.

Aims/objectives: To assess the efficacy of steroid-eluting sinus stents in improving postoperative outcomes following revision and re-revision Draf 3 procedures in patients with frontal diseases.

Material and methods: Patients with recalcitrant chronic frontal rhinosinusitis (FRS) and mucocele who underwent revision and re-revision Draf 3 procedures from 2015 to 2017 were included. Preoperative disease parameters, demographics, and endoscopic and radiographic images were recorded.

Results: Seven patients undergoing the Draf 3 procedure for recalcitrant chronic FRS (43%) and mucocele after complete resection of benign tumours in the frontal sinus (57%) were followed up for a mean of 16.5 months. At the end of follow-up, seven (100%) patients were asymptomatic and all patients (100%) had patent neo-ostia.

Conclusions and significance: The use of bioabsorbable steroid-eluting sinus stents had no unanticipated consequences, and the drainage pathways of the frontal neo-ostium remained patent. Steroid-eluting sinus stents may decrease recurrence rates in revision cases where patients have extensive scarring or neo-osteogenesis of the operative field from prior Draf 2 or 3 procedures. Further follow-up of the current cases and studies with larger cohorts are needed.     

原发性闭角型青光眼合并视网膜色素变性的临床特征分析

目的 分析原发性闭角型青光眼合并视网膜色素变性患者的临床特征。 方法 本研究纳入2013年4月至2017年4月于首都医科大学附属北京同仁医院眼科中心住院治疗的原发性闭角型青光眼(primary angle closure glaucoma ,PACG)合并视网膜色素变性(retinitis pigmentosa,RP)患者32例,和同期入院的不合并RP的PACG患者229例。根据青光眼类型将其分为4组,急性闭角型青光眼合并RP组(acute angle closure glaucoma with retinitis pigmentosa, AACG-RP)12例、慢性闭角型青光眼合并RP组(chronic angle closure glaucoma with retinitis pigmentosa, CACG-RP)20例、急性闭角型青光眼不合并RP组(AACG-non RP)94例、慢性闭角型青光眼不合并RP组(CACG-non RP)135例,比较4组患者的发病年龄和眼轴长度等参数。 结果 患者平均发病年龄AACG-RP组(39.00±12.07)岁、CACG-RP组(43.85±12.79)岁、AACG-non RP组(66.44±9.40)岁、CACG-non RP组(63.95±10.42)岁,4组之间差异有统计学意义(F=47.70,P<0.05)。患者平均眼轴长度AACG-RP组(21.31±1.37)mm、CACG-RP组(22.33±1.09)mm、AACG-non RP组(22.31±1.03)mm、CACG-non RP组(22.47±1.01)mm,4组之间差异有统计学意义(F=19.09,P<0.05)。 结论 原发性闭角型青光眼患者合并视网膜色素变性患者中,急性闭角型青光眼患者较慢性闭角型青光眼患者发病更早,眼轴更短。原发性闭角型青光眼合并视网膜色素变性患者,尤其是急性闭角型青光眼合并视网膜色素变性患者较无视网膜色素变性者发病年龄更早,且眼轴更短。