儿童难治性食管狭窄应用全覆膜支架治疗的并发症及处理对策

目的探讨应用镍钛合金全覆膜食管支架治疗儿童难治性食管狭窄的并发症及处理对策。方法回顾性分析2009年5月-2016年12月于该院应用镍钛合金网格编织型的覆膜支架治疗9例难治性食管狭窄患儿的临床资料,支架置入术后定期随访,观察患儿支架置入后的效果及并发症等。结果 9例患儿均成功行支架置入术,所有患儿置入后狭窄梗阻症状均得到明显缓解;术后1~7 d所有患儿均有呕吐及不同程度的胸痛症状;1例患儿置入后因哭闹不安不能忍受于术后36 h取出支架;2例于支架取出3个月后出现再狭窄,其中1例并发肉芽组织增生;1例食管穿孔患儿支架置入术1周出现支架移位贴壁不良,原支架取出后重置新支架,2个月后再行支架取出,瘘口愈合。结论镍钛合金全覆膜金属支架治疗儿童难治性良性食管狭窄安全有效,但与支架置入相关的并发症不容忽视,支架个体化设计与并发症的及时处理对提高临床疗效至关重要。

Serial Expression of the Truncated Fragments of the Nucleocapsid Protein of CCHFV and Identification of the Epitope Region

The Crimean-congo hemorrhagic fever virus(CCHFV)is a geographically widespread fatal pathogen. Identification of the epitope regions of the virus is important for the diagnosis and epidemiological studies of CCHFV infections.In this study,expression vectors carrying series truncated fragments of the NP(nucleocapsid protein)gene from the S fragment of CCHFV strain YL04057 were constructed.The recombinant proteins were expressed in E.coli and purified for detection.The antigenic of the truncated fragments of NP was detected with a polyclonal serum(rabbit)and 2 monoclonal(mAbs)(14B7 and 43E5)against CCHFV by Western-blot analyses. The results showed that the three expressed constructs,which all contained the region 235AA to 305AA could be detected by mAbs polyclonal serum.The results suggest that region 235-305 aa of NP is a highly antigenic region and is highly conserved in the NP protein.

Genetic Modification of Baculovirus Expression Vectors

As a protein expression vector, the baculovirus demonstrates many advantages over other vectors. With the development of biotechnology, baculoviral vectors have been genetically modified to facilitate high level expression of heterologous proteins in both insect and mammalian cells. These modifications include utilization of different promoters and signal peptides, deletion or replacement of viral genes for increasing protein secretion, integration of polycistronic expression cassette for producing protein complexes, and baculovirus pseudotyping, promoter accommodation or surface display for enhancing mammalian cell targeting gene delivery. This review summarizes the development and the current state of art of the baculovirus expression system. Further development of baculovirus expression systems will make them even more feasible and accessible for advanced applications.

Lesions of mediodorsal thalamic nucleus reverse abnormal firing of the medial prefrontal cortex neurons in parkinsonian rats

The dysfunction of the medial prefrontal cortex is associated with affective disorders and non-motor features in Parkinson’s disease.However,the exact role of the mediodorsal thalamic nucleus in the function of the prefrontal cortex remains unclear.To study the possible effects of the mediodorsal thalamic nucleus on the neurological function of the medial prefrontal cortex,a model of Parkinson’s disease was established by injecting 8μg 6-hydroxydopamine into the substantia nigra compacta of rats.After 1 or 3 weeks,0.3μg ibotenic acid was injected into the mediodorsal thalamic nucleus of the midbrain.At 3 or 5 weeks after the initial injury,neuronal discharge in medial prefrontal cortex of rat brain was determined electrophysiologically.The numbers of dopamine-positive neurons and tyrosine hydroxylase immunoreactivity in substantia nigra compacta and ventral tegmental area were detected by immunohistochemical staining.Results demonstrated that after injury,the immunoreactivity of dopamine neurons and tyrosine hydroxylase decreased in the substantia nigra compacta and ventral tegmental areas of rats.Compared with normal medial prefrontal cortical neurons,at 3 and 5 weeks after substantia nigra compacta injury,the discharge frequency of pyramidal neurons increased and the discharge pattern of these neurons tended to be a burst-discharge,with an increased discharge interval.The discharge frequency of interneurons decreased and the discharge pattern also tended to be a burst-discharge,but the discharge interval was only higher at 3 weeks.At 3 weeks after the combined lesions,the discharge frequency,discharge pattern and discharge interval were restored to a normal level in pyramidal neurons and interneurons in medial prefrontal cortex.These findings have confirmed that mediodorsal thalamic nucleus is involved in regulating neuronal activities of the medial prefrontal cortex.The changes in the function of the mediodorsal thalamic nucleus may be associated with the abnormal discharge activity of the medial prefrontal cortex neurons after substantia nigra compacta injury.All experimental procedures were approved by the Institutional Animal Care and Use Committee of Xi’an Jiaotong University,China(approval No.XJTULAC2017-067)on August 26,2017.

Construction of the Bac-to-Bac System of Bombyx mori Nucleopolyhedroviru

To construct the Bac-to-Bac expression system of Bombyx mori nucleopolyhedrovirus(BmNPV),a transfer vector was constructed which contained an Escherichia coli(E.coli)mini-F replicon and a lacZ:attTN7:lacZ cassette within the upstream and downstream regions of the BmNPV polyhedrin gene.B.mori larvae were cotransfected with wild-type BmNPV genomic DNA and the transfer vector through subcutaneous injection to generate recombinant viruses by homologous recombination in vivo.The genomic DNA of budded viruses extracted from the hemolymph of the transfected larvae was used to transform E.coli DH10B.Recombinant bacmids were screened by kanamycin resistance,PCR and restriction enzyme(REN)digestion.One of the bacmid colonies,BmBacJS13,which had similar REN profiles to that of wild-type BmNPV,was selected for further research.To investigate the infectivity of BmBacJS13,the polyhedrin gene was introduced into the bacmid and the resultant recombinant(BmBacJS13-ph)was transfected to BmN cells.The budded viruses were collected from the supernatant of the transfected cells and used for infecting BmN cells.Growth curve analysis indicated that BmBacJS13-ph had a similar growth curve to that of wild-type BmNPV.Bio-assays indicated that BmBacJS13-ph was also infectious to B.mori larvae.