Clinical characteristics of human cytomegalovirus pneumonia in children and the diagnosis value of detecting human cytomegalovirus DNA in bronchoalveolar lavage fluid / 中国小儿急救医学

Objective:To investigate the clinical features, therapy and prognosis of human cytomegalovirus(HCMV)pneumonia in pediatric patients, and to analyze the diagnosis value of detecting HCMV DNA in bronchoalveolar lavage fluid(BALF)by real-time PCR.Methods:The clinical characteristics of 58 pediatric inpatients who were HCMV DNA positive in BALF were retrospectively reviewed.All the patients were from Shengjing Hospital of China Medical University from January 2015 to December 2019.Clinical, radiologic, laboratory and microbiologic data was collected for each patient.The study cohort was divided into HCMV productive infection and latent infection consisting of 22 and 36 patients respectively, based on the HCMV active infection in lung or not.Receiver operating characteristic(ROC)curve was used to assess utility of detecting HCMV DNA in BALF and establish a threshold for diagnosis.Results:(1)Compared with patients in latent infection group, the children in productive infection group had a lower age of onset( P<0.05), a higher proportion of male( P<0.05), and more prolonged hospitalization stay( P<0.05). Pulmonary rales, hypoxemia and higher AST, CK, LDH in serum were easier to detect in productive infection group( P<0.05). Higher HCMV DNA copies in BALF was also detected( P<0.01). Patients in productive infection group had significantly more exposure to additional oxygen treatment or mechanical ventilation and systemic hormone therapy( P<0.05), while with poorer outcomes( P<0.05). (2) ROC curve analysis showed that the AUC for HCMV DNA in BALF in diagnosis of HCMV pneumonia was 0.708 with a threshold of 8.83×10 3 copies/mL, a sensitivity of 77.27%, and a specificity of 58.33%. Conclusion:Those who are diagnosed HCMV pneumonia have a lower age of onset with higher male proportion.These children suffered severer clinical signs.The patients with HCMV DNA copies higher than 8.83×10 3 copies/mL in BALF would be more likely to be diagnosed as HCMV pneumonia.

Production of high-purity recombinant human vascular endothelial growth factor (rhVEGF165) by Pichia pastoris / 生物工程学报

Vascular endothelial growth factor (VEGF165) is a highly specific vascular endothelial growth factor that can be used to treat many cardiovascular diseases. The development of anti-tumor drugs and disease detection reagents requires highly pure VEGF165 (at least 95% purity). To date, the methods for heterologous expression and purification of VEGF165 require multiple purification steps, but the product purity remains to be low. In this study, we optimized the codons of the human VEGF165 gene (vegf165) according to the yeast codon preference. Based on the Pichia pastoris BBPB vector, we used the Biobrick method to construct a five-copy rhVEGF165 recombinant expression vector using Pgap as the promoter. In addition, a histidine tag was added to the vector. Facilitated by the His tag and the heparin-binding domain of VEGF165, we were able to obtain highly pure rhVEGF165 (purity > 98%) protein using two-step affinity chromatography. The purified rhVEGF165 was biologically active, and reached a concentration of 0.45 mg/mL. The new design of the expression vector enables production of active and highly pure rhVEGF165 ) in a simplified purification process, the purity of the biologically active natural VEGF165 reached the highest reported to date.

Biossimilares: uma discussão de controvérsias / Biossimilars: a discussion on the controverses

Com o vencimento da patente dos três primeiros anti-TNFs o interesse comercial para o desenvolvimento de cópias conhecidas como biossimilares despertou grande interesse e se encontra em desenvolvimento. No Brasil, a regulação prevê que um verdadeiro biossimilar seja aquele que tenha estudos adequadamente bem feitos de comparação com o produto original (inovador). Entretanto, em alguns países da América Latina, a intenção de cópias (biocópias) foi registrada e está disponível no mercado. No artigo, fazemos uma exposição ampla sobre o momento atual e como o reumatologista deve atualizar-se com a nova perspectiva dos biossimilares.

Screening of recombinant bacterium for expression of human peptide antibiotic hPAB-? multimers and evaluation of its fermentation / 医学研究生学报

Objective: To screen the best genetic engineering bacterium for the production of peptide antibiotic hPAB-? and evaluate its fermentation level in bottle. Methods:After analysis of the interest fusion protein expression levels of 8 recombinant bacteria containing 1-8 copies of human peptide antibiotic hPAB-? expressing plasmid respectively,2-5 copies expressing bacteria were chosen for the further study of their bacteria yield,expression forms of the target protein, dissolution of the inclusion bodies and the efficiency of fusion protein purification by affinity chromatography, then the best engineering bacterium with the certain copies of interest peptide expressing plasmid was screened out and its optimal fermentation parameters in bottle were also studied. Results:The recombinant bacterium transformed by 3 copies of interest peptide expressing plasmid was the best candidate for its bacteria yield (3.153 g/L) and fusion protein expression level (27.7%) were the highest among 1-8 copies candidates. The inclusion bodies of 3 copies target fusion protein could be easily dissolved by 8 mol/L urea and captured by Ni-NTA column. The elution of the fusion protein could be directly cleaved to monomer by adding 2 mol/L hydroxylamine, adjusting pH to 9.0 and incubating at 45℃ for 2 h. The optimal fermentation conditions of the selected recombinant bacteria were: culture the organisms with modified M9-CAA media at 37℃ and 160 r/min to (A 600 )≈2.5, then add IPTG to the final concentration 100 ?mol/L to induce the expression of target fusion protein for 5 h. Conclusion:The engineering bacterium containing 3 copies interest peptide recombinant expressing plasmid is the best candidate for the production of peptide antibiotic hPAB-?,and its fermentation parameters are confirmed.

Protective Effect of Ganciciovir on Acute Cerebral Injury of Mice Caused by Herpes Simplex Virus / 实用儿科临床杂志

Objective To study the protective effect and mechanism of ganciclovir(GCV) on acute cerebral injury of mice caused by herpes simplex virus(HCV). Methods Mice model of acute cerebral injury caused by HCV were established, morphological changes in the brain tissue of mouse treated with GCV were observed under the electronic microscope, and the mortality were compared. The HSV - I DNA copies of brain tissue were detected by fluorescent quantitative polymerase chain reaction. Results In the infected model group, there were obvious swelling, karyopyknosis and destruction of the structure in the brain cells, as well as myelin sheath solution and vacuolar degeneration in the mitochondrion and crest were destroyed. There were the virions in the nucleolus. With the GCV treatment, the symptoms were improved, the mortality much lowered, the yields of HSV - I DNA much lower. Conclusions GCV may restrain replication of HSV-Ⅰ effectively and lower the mortality of mice with acute cerebral injury caused by herpes simplex virus significantly.

Effect of ERG6 Gene Extra Copies on Aspergillus fumigatus / 微生物学通报

To investigate the role of ERC,6 gene in the growth rate and antifungal susceptibility,Aspergillus fumigatus strain with extra copies of ERG6 gene was constructed.Open reading frame (ORF) of putative ERG6 gene was searched in A.fumigatus genome.A PCR fragment, ERG6 ORF sandwiched by its flanking sequences (about 1 kb respectively),was amplified and was then subcloned into vector pRG-AMA1- NotI to produce a recombinant plasmid pERG6,which was further transformed into uracil auxotroph A.fumigatus strain AF293.1 to produce the transformant AF-pERG6.In the same time,empty plasmid pRG-AMA1-NotI was also transformed into A.fumigatus strain AF293.1 to produce the transformant AF-empty as a control.Radial growth of the transformants was tested on minimal medium (MM) and YAG medi- um.Antifungal susceptibilities of these resahing transformants,AF-pERG6 and AF-empty,to the common antifungal agents were performed by using both disk diffusion and broth microdillution methods.A.fumigatus genome contains a ERG6 gene,of which the ORF size is 1 256 bp.Comparing to Candida albicans and Sacchromyces cerivisiae sterol methyltransferase,A.fumigatus Erg6p had 57% and 50% identity, and had 70% and 63% similarity in amino acid sequences,respectively.Radial growth of transformant AF-pERG6 was slower than that of transformant AF-empty.The antifungal susceptibilties of transformant AF-pERG6 to the antifungal drugs itraconazole,voriconazole,terbin- aline,amphotericin B,caspofungin and grisefolvin were same to that of transformant AF-empty.In A.fumigatus,extra copies of ERG6 gene have no effect on antifungal susceptibilities to itraconazole,voriconazole,terbinafine,amphotericin B,caspofungin and grisefolvin.Radial growth of A.fumigatus harboring extra copies of ERG6 gene becomes slower compared to the control.