支气管扩张剂雾化吸入在支气管镜检查患者肺功能保护中的临床应用

目的探索操作前应用短效支气管扩张剂雾化吸入对接受支气管镜检查的患者肺功能的保护作用。 方法分析我院2019年2月至2019年4月收治的拟行气管镜检查的患者36例,随机分为对照组和观察组：对照组患者接受操作前常规的丁卡因压缩空气雾化机雾化吸入,观察组患者接受操作前丁卡因联合短效支气管扩张剂压缩空气雾化机雾化吸入;比较两组患者支气管镜检查前、后生命征、氧饱和度、肺功能指标变化。 结果操作前两组患者生命征、氧饱和度、通气功能指标等均无统计学差异,支气管镜检查后患者的收缩压、氧饱和度、通气功能指标等较操作前明显变化,而接受操作前短效支气管扩张剂雾化吸入的患者通气功能、氧饱和度等指标明显优于对照组患者,而且心率更加稳定。 结论支气管镜操作可导致操作后患者通气功能指标下降,支气管镜操作前应用短效支气管扩张剂雾化吸入治疗可有效保护患者肺功能,提高了围操作期的安全性。     

异种去抗原松质骨成骨效能的实验研究

 目的：研究异种去抗原松质骨与基因重组人骨形成蛋白2 (recombinant human bone morphogenetic protein 2, rhBMP-2)复合后的生物相容性和成骨效能。方法：28只新西兰大白兔28处颌骨缺损完全随机分为3组：异种去抗原松质骨/rhBMP-2组（A组）、异种去抗原松质骨组（B组）和空白对照组（C组）。A组和B组每组12处骨缺损,于4、8和12周分别进行大体观察、X线检查、HE染色和新生骨量测定;C组共4处骨缺损于12周时进行大体观察、X线检查和HE染色。结果：X线显示,随着时间的增长,2组的植入骨逐渐降解吸收,由自体骨替代,A组较B组显著;C组12周时无法完成愈合。骨密度测量显示,随着时间的增长,A和B组的骨密度值增加,2组之间存在显著差异（P<0.05）。HE染色可见A组的新生血管、纤维组织和新生骨均较B组多;植入骨降解速度快于B组;A组新生骨面积大于B组（P<0.05）。结论：异种去抗原松质骨是rhBMP-2的良好载体;异种去抗原松质骨/rhBMP-2复合材料能持续成骨,可加速骨缺损修复的速度,是一种较好的骨修复材料。     

Strabismus genetics across a spectrum of eye misalignment disorders

Eye misalignment, called strabismus, is amongst the most common phenotypes observed, occurring in up to 5% of individuals in a studied population. While misalignment is frequently observed in rare complex syndromes, the majority of strabismus cases are non‐syndromic. Over the past decade, genes and pathways associated with syndromic forms of strabismus have emerged, but the genes contributing to non‐syndromic strabismus remain elusive. Genetic testing for strabismus risk may allow for earlier diagnosis and treatment, as well as decreased frequency of surgery. We review human and model organism literature describing non‐syndromic strabismus, including family, twin, linkage, and gene expression studies. Recent advances in the genetics of Duane retraction syndrome are considered, as relatives of those impacted show elevated familial rates of non‐syndromic strabismus. As whole genome sequencing efforts are advancing for the discovery of the elusive strabismus genes, this overview is intended to support the interpretation of the new findings.     

Optimization of the thermoelectric performance of layer-by-layer structured copper-phthalocyanine (CuPc) thin films doped with hexacyano-trimethylene-cyclopropane (CN6-CP)

Copper-phthalocyanine (CuPc), as a classical small molecular organic semiconductor, has been applied in many fields. However, the low intrinsic conductivity limits its application in thermoelectricity. Here, hexacyano-trimethylene-cyclopropane (CN6-CP), a strong electron acceptor, is synthesized as dopant for CuPc thin films to improve their conductivities. Multilayer thin films constructed from alternate thermally evaporated CuPc and CN6-CP thin layers are investigated. Under the optimized condition, the doped CuPc film with a conductivity of 0.76 S cm⁻¹ and a Seebeck coefficient of 130 μV K⁻¹, shows a high power factor of 1.3 μW m⁻¹ K⁻² and the carrier concentration is estimated to be 2.8 × 10²⁰ cm⁻³. Considering the relatively superior performance, the CN6-CP doped CuPc film is a promising small molecular organic thermoelectric (OTE) material. In addition, for those highly crystalline materials with poor solubility, the layer-by-layer structure offers a general strategy for investigation and optimization of their TE performance.

The alternately deposited multilayer structure of a small molecular semiconductor and dopant molecules offers a general strategy for investigating their TE performance.     

DhhP,a Cyclic di-AMP Phosphodiesterase of Borrelia burgdorferi,Is Essential for Cell Growth and Virulence

Cyclic di-AMP (c-di-AMP) is a recently discovered second messenger in bacteria. Most of work on c-di-AMP signaling has been done in Gram-positive bacteria, firmicutes, and actinobacteria, where c-di-AMP signaling pathways affect potassium transport, cell wall structure, and antibiotic resistance. Little is known about c-di-AMP signaling in other bacteria. Borrelia burgdorferi, the causative agent of Lyme disease, is a spirochete that has a Gram-negative dual membrane. In this study, we demonstrated that B. burgdorferi BB0619, a DHH-DHHA1 domain protein (herein designated DhhP), functions as c-di-AMP phosphodiesterase. Recombinant DhhP hydrolyzed c-di-AMP to pApA in a Mn²⁺- or Mg²⁺-dependent manner. In contrast to c-di-AMP phosphodiesterases reported thus far, DhhP appears to be essential for B. burgdorferi growth both in vitro and in the mammalian host. Inactivation of the chromosomal dhhP gene could be achieved only in the presence of a plasmid-encoded inducible dhhP gene. The conditional dhhP mutant had a dramatic increase in intracellular c-di-AMP level in comparison to the isogenic wild-type strain. Unlike what has been observed in Gram-positive bacteria, elevated cellular c-di-AMP in B. burgdorferi did not result in an increased resistance to β-lactamase antibiotics, suggesting that c-di-AMP''s functions in spirochetes differ from those in Gram-positive bacteria. In addition, the dhhP mutant was defective in induction of the σ^S factor, RpoS, and the RpoS-dependent outer membrane virulence factor OspC, which uncovers an important role of c-di-AMP in B. burgdorferi virulence.     

Immunogenicity of recombinant human bocavirus‐1,2 VP2 gene virus‐like particles in mice

Human bocavirus (HBoV), a recently identified pathogen with a worldwide distribution is closely related to paediatric acute respiratory infection and gastroenteritis. The present study was performed to evaluate the immunogenicity of HBoV1 and HBoV2 virus‐like particles (VLPs) as vaccine candidates in mice. Both HBoV1 and HBoV2 VLPs were expressed in the bacmid virus–SF9 cell system. Mice were inoculated three times at 3‐week intervals with HBoV VLPs at one dose intramuscular (i.m.) or intradermal (i.d.) with or without the addition of the alum adjuvant. ELISA was used to detected antibody, and ELISPOT was used to test cellular immune responses. HBoV‐specific IgG antibodies were induced and alum adjuvant improved the antibody titres and avidity, while the inoculation pathway had no influence. T helper type 1/ type 2 immune responses were balanced induced by HBoV1 VLPs but not HBoV2 VLPs. Serum IgG antibody cross‐reactivity rates of the two subtypes were similar, but cross‐reactions of HBoV1 immunization groups were higher. The single i.m. group had more interferon‐γ‐secreting splenocytes. These data indicate that HBoV VP2 VLPs have good immunogenicity with induction of strong humoral and cellular immune responses, and they may be potential candidate vaccines for HBoV infection.     

‘Default’ generated neonatal regulatory T cells are hypomethylated at conserved non‐coding sequence 2 and promote long‐term cardiac allograft survival

Regulatory T (Treg) cells play an important role in the maintenance of immune self-tolerance and homeostasis. We previously reported that neonatal CD4⁺ T cells have an intrinsic ‘default’ mechanism to become Treg (neoTreg) cells in response to T-cell receptor (TCR) stimulation. However, the underlying mechanisms are unclear and the effects of neoTreg cells on regulating immune responses remain unknown. Due to their involvement in Foxp3 regulation, we examined the role of DNA methyltransferase 1 (DNMT1) and DNMT3b during the induction of neoTreg cells in the Foxp3^gfp mice. The function of neoTreg cells was assessed in an acute allograft rejection model established in RAG2^−/− mice with allograft cardiac transplantation and transferred with syngeneic CD4⁺ effector T cells. Following ex vivo TCR stimulation, the DNMT activity was increased threefold in adult CD4⁺ T cells, but not significantly increased in neonatal cells. However, adoptively transferred neoTreg cells significantly prolonged cardiac allograft survival (mean survival time 47 days, P < 0·001) and maintained Foxp3 expression similar to natural Treg cells. The neoTreg cells were hypomethylated at the conserved non-coding DNA sequence 2 locus of Foxp3 compared with adult Treg cells. The DNMT antagonist 5-aza-2′-deoxycytidine (5-Aza) induced increased Foxp3 expression in mature CD4⁺ T cells. 5-Aza-inducible Treg cells combined with continuous 5-Aza treatment prolonged graft survival. These results indicate that the ‘default’ pathway of neoTreg cell differentiation is associated with reduced DNMT1 and DNMT3b response to TCR stimulus. The neoTreg cells may be a strategy to alleviate acute allograft rejection.