睑板腺处理对合并睑板腺功能障碍的翼状胬肉患者术后眼表的影响

目的探讨术前睑板腺处理对合并睑板腺功能障碍(Meibomian gland dysfunction,MGD)的翼状胬肉患者术后眼表的影响。方法选取患有MGD的翼状胬肉患者90眼,随机分为A组(48眼)、B组(42眼),A组术前1周予以清洁眼睑、热敷及药物治疗,并同时配合睑板腺按摩治疗,B组采取常规翼状胬肉手术术前准备。两组患者均行翼状胬肉切除联合角膜缘干细胞移植术。分别于术后3 d,术后1周、2周、4周比较两组的眼部舒适度评分及泪膜破裂时间(break-up time,BUT)。结果术后3 d、1周、2周与B组对比,A组眼部舒适度评分均低于B组(P0.01),术后1周、2周与B组对比,A组泪膜破裂时间明显长于B组,差异有统计学意义(P0.01)。结论术前睑板腺处理可以有效促进翼状胬肉合并MGD患者术后眼表的修复,稳定泪膜,提高患者的眼部舒适度。     

3D打印技术对胫骨平台骨折关节面复位的应用价值及术后CT结果研究

目的探讨3D打印技术对胫骨平台骨折关节面复位的应用价值及术后CT结果。方法选择2015年1月～2018年12月我院收治的60例胫骨平台骨折患者,随机分为两组各30例,对照组实施传统切开复位内固定术,观察组在3D打印技术指导下行切开复位内固定术,比较两组手术情况、关节面复位情况、临床疗效、膝关节活动度、膝关节功能评分。结果 (1)观察组复位固定时间、手术时间均较对照组缩短(P均0.05)。(2)观察组的关节面最大阶梯高度、关节面复位满意度评分均较对照组更高(P均0.05)。(3)观察组的优良率较对照组更高,其治疗后的伸膝最大角度、屈膝最大角度、膝关节功能评分均较对照组更高(P均0.05)。结论应用3D打印技术指导胫骨平台骨折手术,可更快、更好地复位关节面,有利于提高疗效,改善膝关节功能。     

Hepatitis B virus-like particles expressing Plasmodium falciparum epitopes induce complement-fixing antibodies against the circumsporozoite protein

The repetitive structure of compact virus-like particles (VLPs) provides high density displays of antigenic sequences, which trigger key parts of the immune system. The hepatitis B virus (HBV) and human papilloma virus (HPV) vaccines exploit the assembly competence of structural proteins, which are the effective immunogenic components of the prophylactic HBV and HPV vaccines, respectively. To optimize vaccine designs and to promote immune responses against protective epitopes, the “Asp-Ala-Asp-Pro” (NANP)-repeat from the Plasmodium falciparum circumsporozoite protein (CSP) was expressed within the exposed, main antigenic site of the small HBV envelope protein (HBsAgS); this differs from the RTS,S vaccine, in which CSP epitopes are fused to the N-terminus of HBsAgS. The chimeric HBsAgS proteins are assembly competent, produce VLPs, and provide a high antigenic density of the NANP repeat sequence. Chimeric VLPs with four or nine NANP-repeats (NANP4 and NANP9, respectively) were expressed in mammalian cells, the HBsAgS- and CSP-specific antigenicity of the VLPs was determined, and the immunogenicity of the VLPs assessed in relation to the induction of anti-HBsAgS and anti-CSP antibody responses. The chimeric VLPs induced high anti-CSP titres in BALB/c mice independent of the number of the NANP repeats. However, the number of NANP repeats influenced the activity of vaccine-induced antibodies measured by complement fixation to CSP, one of the proposed effector mechanisms for Plasmodium neutralization in vivo. Sera from mice immunized with VLPs containing nine NANP repeats performed better in the complement fixation assay than the group with four NANP repeats. The effect of the epitope-specific density on the antibody quality may instruct VLP platform designs to optimize immunological outcomes and vaccine efficacy.     

Identification of IgG1 Aggregation Initiation Region by Hydrogen Deuterium Mass Spectrometry

Antibody aggregates are a potential risk for immunogenicity; therefore, rational approaches to improve associated aggregation properties need to be developed. Here, we report the amino acid region responsible for aggregation initiation. Two types of therapeutic IgG1 antibody monomer samples were prepared: IgG1 mAb40-3M stored at 40°C for 3 months, which existed in monodisperse state, and the monomer mAb65-5m, which was dissociated from small soluble aggregates by heating at 65°C for 5 min. Hydrogen deuterium exchange mass spectrometry of mAb40-3M identified 2 sites in the Fc region (site 1, F239-M256; site 2, S428-G450) with increased exchange rates. Site 1 includes a region reported as being susceptible to structural change induced by stress. Exposure of site 1 was undetected after 2 months of storage at 40°C but was subsequently detectable after 3 months. As site 2 is spatially close to site 1, the structural change of site 1 could propagate site 2. Besides these 2 regions, hydrogen deuterium exchange mass spectrometry of mAb65-5m identified an exposure of I257-W281 in Fc (site 3), within which a peptide sequence with high aggregation tendency was discovered. We thus concluded that exposure of site 3 is a trigger for the association of a partially denatured antibody.     

Removal methods of rigid stylets to minimise adverse force and tracheal tube movement: a mathematical and in-vitro analysis in manikins

This study investigated displacement of the tracheal tube caused by different methods of intubating stylet removal, using in-vitro experiments and mathematical analysis. In the first in-vitro experiment, we measured the distance travelled by the tube tip during stylet extraction. Then, we investigated the ideal technique for stylet extraction using mathematical analysis, which would cause minimal tube displacement. Then, using a training manikin, we measured the force applied to the vocal cords and stylet extraction force during tracheal intubation. When the stylet was extracted along a straight path towards the stylet end, the distance travelled by the tube tip significantly increased as the bending angle increased. Mathematical analysis revealed that the stylet should be diagonally extracted (in the sagittal plane) at an appropriate angle, rather than along a straight path towards the direction of the stylet end. In simulated tracheal intubation, extraction force and force applied to the vocal cords both significantly increased as the bending angle increased. Compared with the ‘hockey stick’-shaped stylet, the arcuate-shaped stylet resulted in reduced force. Our results indicate the potential risk for vocal cord injury when using hockey stick-shaped stylets with large bending angles.     

Adsorptive removal of lead from aqueous solutions by amine–functionalized magMCM-41 as a low–cost nanocomposite prepared from rice husk: Modeling and optimization by response surface methodology

Amorphous silica that was extracted from rice husk was used to synthesize the magMCM-41 mesoporous silica. This was then functionalized by the APTMS group in order to produce NH₂-magMCM-41 as a novel and low–cost adsorbent. The XRD, VSM, N₂ adsorption–desorption, FT–IR, TGA, SEM and TEM analyses were utilized to characterize the produced materials. In order to optimize the adsorption of the Pb(II) ions, the RSM (response surface methodology) was applied by using the synthesized adsorbent in aqueous solutions. A rotatable CCD (central composite design) was adopted to carry out the experiments and RSM was used to analyze them. Three independent factors namely, initial solution pH (3–7), adsorbent dosage (0.1–2 g L^?1), and initial Pb(II) concentration (15–150 mg L^?1) were used to investigate the removal procedure. According to the obtained results, the initial solution pH of 5.22, adsorbent dosage of 0.1 g L^?1, and initial Pb(II) concentration of 150 mg L^?1 were considered as the optimum conditions with 64.32% removal of Pb(II) and an adsorption capacity of 540.64 mg g^?1. The maximum removal efficiency of Pb(II) ions was found to be 96.76%. The Sips isotherm model represents a better correlation with equilibrium data. It was reported by the kinetic study that data taken from the experiments fitted better to the pseudo–second–order model compared to the pseudo–first–order and intraparticle diffusion models. Finally, according to the thermodynamic study, the removal process strongly depends on temperature, which indicates an exothermic behavior and spontaneous nature of the adsorption.