Reducing the incidence of healthcare-associated infection in department of critical care medicine by risk assessment method / 中国感染控制杂志

Objective To explore the effect of risk assessment method on the incidence of healthcare-associated infection (HAI) in high-risk departments.Methods A hospital was selected as the research object, risk assessment of HAI management at the hospital and department level was carried out, high-risk departments and high-risk links were screened out, targeted intervention was performed. Patients hospitalized in April-June 2017 were as control group and those hospitalized in July-September 2017 were as intervention group, incidence of HAI between two groups was compared.Results Through risk assessment at the hospital level, department of critical care medicine was the department with the highest risk, risk assessment at the department level showed that without wearing isolation clothes when contacting isolated patients during diagnosis and treatment, without using sterile sheeting when catheterization, and low correct rate of hand hygiene were high-risk links in department of critical care medicine. Targeted intervention was performed, isolation clothing allocation rate for contacting isolated patients increased from 0 to 100％, compliance rate to wearing isolation clothing among medical staff increased from 0 to 97.62％, implementation rate of using sterile sheet for deep vein catheterization increased from 72.50％ to 100％; hand hygiene correct rate increased from 85.00％ to 96.59％. Incidence of HAI decreased from 5.90％ to 2.64％, difference was statistically significant (P＜0.05).Conclusion Implementing risk assessment management of HAI in medical institutions can effectively guide the prevention and control of HAI in high-risk departments, and improve the level of HAI management.

Expression of a human myofibrillogenesis regulator 1 gene in E. coli and its immunogenicity / 中国医学科学院学报

<p><b>OBJECTIVE</b>To study the expression of human myofibrillogenesis regulator 1 (MR-1) gene in E. coli and obtain the MR-1 protein and its antibody for further investigation of its biological function.</p><p><b>METHODS</b>Expression vectors pGEX-5X-1, pET30a (+), and pET24a (+), as well as host strain E. coli BL21 (DE3) and BL21-CodonPlus (DE3) -RIL were used for expression of MR-1. MR-1 N-terminal with GST or T7-tag or C-terminal with His-tag, separately, or N terminal with T7-tag and C terminal with His-tag, simultaneously, were fused in plasmids pGEX-5X-1, pET30a (+) , and pET24a (+). The expressed MR-1-T protein, separated and purified by preparative SDS-PAGE, was applied to immunize the rabbits. The titer of the antibody was assayed by ELISA and its immunogenicity was tested by Western blot with pcDNA3/MR-1 transfected human breast cancer cell MCF7.</p><p><b>RESULTS</b>The MR-1 protein was successfully expressed as inclusion body by fusing its N-terminal with T7-tag in E. coli BL21-CodonPlus (DE3) -RIL. MR-1 protein was purified by electro-elution from SDS-PAGE gel. Using this purified protein, polyclonal antibody in rabbit against MR-1 was essentially generated. ELISA and Western blot showed the titer of this antibody was about 1:10(5) with high immunogenicity.</p><p><b>CONCLUSIONS</b>The N-terminal fusion tag is the most important mechanism for MR-1 expression. The polyclonal antibody of the generated MR-1 protein in E. coli may be applied for its further biological function studies.</p>

Cloning of mMR-1 gene and expression in Pichia pastoris systems / 生物工程学报

hMR-1 (Homo Myofibrillogenesis Regulator 1, AF417001) is a novel homo gene, which was firstly cloned in our laboratory. The former studies revealed that hMR-1 is a transmembrane protein which shows protein interaction with sarcomeric proteins like myomesin I, myosin regulatory light chain, alpha-enolase and some cell regulator proteins such as eukaryotic translation initiation factor3 subunit 5 (eIF3S5) and etc. In this work, we focused on cloning the homologous gene of hMR-1 from mouse C57BL/6J and exploring its expression using Pichia pastoris yeast system. Two pairs of primers were synthesized according to the hMR-1 gene homologous sequence on mouse genome chromosome 1. The mouse MR-1 gene (mMR-1) was cloned by PCR following the first round RT-PCR from mouse C57BL/6J spleen total RNA. Sequence analysis verified that mMR-1 gene and amino acids sequence showed 90.4% and 90.1% identity with hMR-1, respectively. The prediction of hydrophobic transmembrane structure of mMR-1 suggested it is also a transmembrane protein. The mMR-1 Pichia pastoris expression vector pPIC9-mMR-1 was constructed by fusion of the flanking mMR-1 ORF in the pPIC9 plasmid. After linearization of pPIC9-mMR-1 with Sal I, the 8.5kb DNA fragment was transformed into Pichia pastoris GS115 strain by electroporation. GS115/Mut+ pPIC9-mMR-1 transformants were selected on minimal methanol medium. Integration of mMR-1 gene into the yeast genome in the recombinants was verified by PCR from the transformants total DNA. The mMR-1 protein was expressed by induction under the concentration of 0.5 % methanol. The specific induced protein of 25 kD molecular mass in SDS-PAGE was confirmed to be the mMR-1 protein by Western blot rsing hMR-1 polyclonal antibody. The expression level of this recombinant mMR-1 protein was about 50 mg/L. The successful expression of mMR-1 in the Pichia pastoris GS115 will facilitate the further functional analysis of the novel gene MR-1 in animal model.