[Intein-Mediated Protein trans-Splicing of the Recombinant Streptavidin on Magnetosomes].

When expressing streptavidin recombinant polypeptide on magnetosomes (called bacterial magnetic nanoparticles, or BMPs), the presence of endogenous bacterial biotin might be detrimental. In the study, the streptavidin monomer fragment (S1-116) was fused with the intein N-terminal (termed precursor S1-116-IN), and S1-116-IN was expressed in E. coli (BL21). Meanwhile, the SA117-160 fragment was fused with the C-terminal intein, and then this chimeric polypeptide was expressed on magnetosomes by fusion with magnetosome membrance protein MamF. In the in vitro protein splicing system, the purified engineered magnetosomes (BMP-SA117-160-IC) and the S1-116-IN precursor were mixed. Intein-mediated trans-splicing reaction was induced to produce the functional magnetic beads BMP-SA. Our results indicate that intein-mediated protein trans-splicing may lead to efficient synthesis of the recombinant streptavidin on the magnetosomes, showing its promising potential to produce other functional magnetic nanoparticles.

A survey of the blood supply in China during 2012-2014.

OBJECTIVES: The aim of this study was to identify the status of the blood supply in China during 2012-2014. BACKGROUND: China is a middle-income country, which contains more than 20% of the world population. Increasing the blood supply in China, along with increased healthcare coverage, involves many challenges. METHODS: A survey questionnaire regarding blood centre activities was sent to all of the blood centres in 32 provinces via the Internet. The data were collected from the responses and analysed using Microsoft Excel 2013. RESULTS: The total supply of whole blood and red blood cells (RBCs) in 2012 was 18 644 700 units; in 2013, 18 985 800 units; and in 2014, 19 658 800 units. A similar trend of the total platelet supply was also observed during the same period of 2012-2014, as follows: 1 019 100 units in 2012, 1 168 400 units in 2013 and 1 276 200 units in 2014. Similarly, the plasma supply was 27 529 300 units in 2012 and 27 657 600 units in 2013, which rose to 28 307 500 units in 2014. The total cryoprecipitate supply was 1 653 900, 1 891 300 and 2 366 500 units in 2012, 2013 and 2014, respectively. When the blood supply was analysed according to the geographic regional population, large differences in the rates of blood supply between regions were evident. CONCLUSIONS: The blood product supply in China is steadily increasing. Blood centres in China continue to face challenges regarding their ability to provide a sufficient blood supply in the future.

Mur (MNS 10) screening with a novel loop-mediated isothermal amplification assay in Zhongshan, China.

BACKGROUND: The distribution of the Mur blood group antigen is 5-7% in the south of China, and a much higher prevalence is observed in some areas of the region. Anti-Mur can cause hemolytic disease of the newborn and severe transfusion reactions. OBJECTIVES: Genetic testing is more ideal than conventional serological tests because antibodies for detection are usually not available. METHODS: In this study, a novel loop-mediated isothermal amplification (LAMP) assay for the detection of Mur blood group antigen was established. RESULTS: Fifteen of 275 (5·5%) samples were confirmed by LAMP as Mur antigen positive. All the Mur antigen-positive samples were GP.Mur subtype which was confirmed with sequencing. CONCLUSION: The LAMP method has identical results with conventional serology method but more suitable for large-scale screening.

Effect of ORF119 gene deletion on the replication and virulence of orf virus.

Orf is a severe infectious disease of sheep and goats caused by orf virus (ORFV). To investigate the role of ORF119 gene of ORFV, we constructed ORFV with deleted ORF119 gene and LacZ as reporter gene (ORFV-Δ119-LacZ) via homologous recombination. The results showed that wild-type ORF-SHZ1 and ORFV-Δ119-LacZ deletion viruses replicated in Vero cells to similar titers. Relative transcriptional levels of virulence genes OVIFNR, GIF, VEGF and VIL-10 of ORFV-Δ119-LacZ deletion virus were slightly but not significantly lower after 24 hr compared with the wtORF-SHZ1 virus. In vivo experiments showed that 2-month-old lambs inoculated with ORFV-Δ119-LacZ deletion virus exhibited a similar total clinical score compared with those inoculated with wtORF-SHZ1 virus. Based on these results, we conclude that deletion of the ORF119 gene has no significant effect on ORFV replication and virulence.

Expression of bovine Mx1 protein inhibits the replication of foot-and-mouth disease virus in BHK-21 cells.

Mx proteins belonging to the dynamin superfamily of large GTPases inhibit replication of a wide range of RNA viruses. In this study, we examined whether bovine Mx1 protein could interfere with the replication of foot-and-mouth disease virus (FMDV). For this purpose we established cloned BHK-21 cells expressing bovine Mx1 protein (BM1 cells) and infected them with FMDV serotype O. Cloned BHK-21 cells expressing neomycin resistance instead of Mx1 protein (BH1 cells) and original BHK-21 cells served as negative controls. The results showed that the expression of bovine Mx1 protein reduced viral yields by 90% and levels of viral VP1 mRNA by 60%. These findings correlated with a significant reduction of viral antigen detectable in infected cells by immunofluorescent assay. These results demonstrate that bovine Mx1 protein interferes with the replication of FMDV.

[Clinicopathological and therapeutic analysis of Castleman's disease in children].

Objective: To investigate the clinical features, pathological phenotype, treatment and prognosis of Castleman's disease in children. Methods: Clinical data of 15 children diagnosed with Castleman's disease in Henan Provincial People's Hospital and the First Affiliated Hospital of Zhengzhou University from May 2010 to October 2019 were analyzed retrospectively. The clinical characteristics, laboratory examination and histopathological data were analyzed. Results: Among the 15 Castleman's disease patients, 12 were males and 3 females. The age of first visit was 12 (10, 15) years. The time from mass discovery to pathologic diagnosis was 9.0 (2.0, 13.0) months. The majority of patients were unicentric (13 cases), and the histopathological type was hyaline vascular (11 cases). Unicentric lesions were most common in the neck (11 cases), all 13 patients received complete surgical resection of the lesions, the follow-up time was 20.0 (13.5, 50.5) months, and the prognosis was good. Two cases were multicentric type, the pathological types were mixed variant, meeting the criteria of idiopathic Castleman's disease, the two children underwent partial surgical resection, one was treated with rituximab and prednisone and the other was treated with thalidomide and prednisone. The follow-up time was 32 months and 10 month, both of them had good prognosis. Conclusions: Most cases of Castleman's disease in children are diagnosed late, and the unicentric type is dominant. The most common pathological type is hyaline vascular, which is characterized by painless lymphadenopathy, while multicentric type has systemic symptoms and both of them have a good overall prognosis.

Expression of activin A and follistatin in glioblastoma and their effects on U87 in vitro.

In some cancer cell lines, the gene encoding activin A (inhibin ßA [INHBA]) is over-expressed and enhances cancer proliferation. Protein levels of activin A and follistatin were assessed in glioblastoma and normal brain tissues in this study, and the effect of activin A and follistatin treatment on the proliferation of U87 human glioblastoma cells in vitro was also studied. High levels of activin A were observed in glioblastomas compared with normal brain tissue. In contrast, follistatin levels were similar between the two tissues. [(3)H]Thymidine assay showed that activin A (3 - 30 ng/ml) produced a dose-dependent increase in DNA synthesis of U87 cells compared with controls. Flow cytometric analyses showed that activin A increased the proliferative index of U87 cells compared with controls. Activin A also induced up-regulation of p-SMAD2/3 in a dose-dependent manner. Treatment of U87 cells with follistatin blocked these activin A-induced effects. The disequilibrium between activin A and follistatin may play a role in the development of glioblastoma.

A comparative study of digital and anatomical techniques in skull base measurement.

This study compared the accuracy of measurements of the skull base made using computed tomography (CT) images and an image-guided surgery system with those made using scientific callipers in order to evaluate the practicability of replacing conventional direct anatomical measurements with digitized techniques in skull base surgery. Important bony landmarks and parameters were measured using the three different methods in 25 cadaver skull bases. No statistically significant differences were observed between the methods. Coefficient of variation calculations indicated that data obtained from CT images was the most stable. Digital methods of navigation have the potential to reflect individual skull base anatomical features more accurately than traditional group-based data, but it is important to assess their accuracy. This study demonstrated that CT imageology and image-guided surgery systems can provide accurate anatomical measurements. Digital methods are also more flexible and less variable, and may have wide applications in this field. Though not perfect, digital imaging is a promising tool for skull base surgery.

[To evaluate the disk position of the temporomandibular joint using calcium suppressed spectral-based CT images in the patients with temporomandibular disorder].

Objective: To evaluate the application of calcium suppressed (CaSupp) spectral CT technique in evaluating disk position and measuring the thickness of the posterior band of temporomandibular joint (TMJ). Methods: The twenty-three temporomandibular disorder patients [mean age 23(12~62) years, male/female=14/9] were performed with oblique sagittal and coronal proton density weighted imaging (PDWI) and spectral CT scans from February to July, 2019 in Department of Radiology, Hainan Hospital of General Hospital of Chinese PLA, and 45 TMJ joints were evaluated. The subjects were classified into two groups according to the scanning modalities: MRI measurement group and CaSupp spectral-based CT group. The CaSupp technique were applied with the spectral-based CT images and CaSupp images were generated. The oblique sagittal and coronal CaSupp imaged were reformatted by perpendicular to the long axis of the condyle. The TMJ disk positions were evaluated on oblique sagittal and coronal images, and the maximal disk thickness were measured on the oblique sagittal images. Results: The joint position was basically consistent on MRI and CaSupp images for the 45 TMJ joints. The intra-class coefficient value was 0.843 (0.712, 0.914) for the measurement of the posterior band of the TMJ disk between MRI and CaSupp images. Bland-Altman presented that the [95.6% (43/45)] points with the difference located in the 95% agreement interval. Wilcoxon paired text demonstrated that there was no significant different for the thickness of the posterior band between MRI [2.57 (1.76, 3.65) mm] and CaSupp images [2.67 (1.74, 4.56) mm] (P=0.07). Conclusions: The CaSupp spectral-based CT could be used to evaluated the TMJ disk position and the thickness of the posterior band.

[Effects of butylphthalide on plasma nitric oxide and endothelin-1 in severe elderly OSAHS patients].

Objective:To investigate the effect of butylphthalide on plasma nitric oxide(NO) and endothelin-1(ET-1) in severe elderly OSAHS patients. Method:A total of 120 severe elderly OSAHS patients were chosen by PSG measurement. According to random number table method, OSAHS patients were randomly divided into non-invasive ventilation control group(n=40), butylphthalide treatment group(n=40) and butylphthalide combined with non-invasive ventilation group (n=40). Non-invasive ventilation control group was given double level airway positive pressure ventilation treatment for six months, butylphthalide treatment group accepted oral butylphthalide therapy for six months, butylphthalide combined with non-invasive ventilation group was given double level airway positive pressure ventilation treatment and accepted oral butylphthalide therapy for six months. The changes of plasma NO and ET-1 were detected by immunoenzyme adsorption before treatment and three and six months after treatment. Result:The difference of plasma NO and ET-1 before treatment in the three groups was not statistically significant (P>0.05). Compared with before treatment, the level of plasma NO decreased and the level of plasma ET-1 increased in the three groups after three and six months treatment (P<0.01). Compared with butylphthalide treatment group, the level of plasma NO increased and the level of plasma ET-1 decreased after 3 and 6 months of treatment in both non-invasive ventilation control group and butylphthalide combined with non-invasive ventilation group (P<0.05). Compared with non-invasive ventilation control group, the level of plasma NO increased and the level of plasma ET-1 decreased after 3 and 6 months of treatment in butylphthalide combined with non-invasive ventilation group (P<0.05). Conclusion:Butylphthalide may improve the vascular endothelial function of severe elderly OSAHS patients by increasing the level of NO and decreasing the level of ET-1 in plasma.