AIM: To obtain a high and stable expression analog of human basic fibroblast growth factor by genetic engineering. METHODS: The cysteins 78 and 96 of natural hbFGF polypeptide was substituted with serines by means of site-directed mutagenesis. Using pET- 3c as vector, the mutated polynucleotide was cloned and then transferred into BL21 (DE3)plysS. After induction by IPTG, the analog was obtained and analyzed by SDS - PAGE. RESULTS: After purification the form of soluble mutant increased remarkably but the forms of dimmer and higher multimer were reduced greatly to no more than 8% of the total recombinant protein. By MTT assay, the analog showed the same biological activity. This new analog represented a desirable complementation for native hbFGF to develop pharmaceutical drug in clinical use. CONCLUSION: Substitution of certain amino acids of polypeptide without altering native protein' s bioactivity to get the analog is an effective means to increase stability of foreign protein and its solubility in E. coli.

Objective To investigate microbial characteristics and predisposing factors in gram-negtive bacteria blood stream infection. Methods A descriptive retrospective study was conducted. Patients diagnosed as sepsis with blood culture of G- bacilli and without sepsis were enrolled. The patients were all admitted to ICUs of Guangdong General Hospital from October, 2012 to December, 2014. The clinical characteristics and outcomes were compared. Multiple logistic regression was used to analyse the predisposing factors for sepsis of G- bacilli. Results A total of 148 patients suffered from sepsis of G-bacilli including Acinetobacter baumannii, Escherichia coli and Klebsiella pneumoniae were enrolled. Single-factor analysis showed that patients with sepsis of G- bacilli infection had older ages, higher incidence of coronary heart diseases or congestive heart failure, cerebrovascular diseases or chronic renal insufficiency, hypertension, also higher incidence of longer length of hospital stay before blood was drawn for culture, and higher incidence using of vasoactive agents and pre-admission intravenous antibiotics and lower plasma albumin level (P < 0.05). Conclusions Coronary heart disease or congestive heart failure, chronic renal insufficiency and pre-admission intravenous antibiotics were independent predisposing factors for sepsis of G-bacilli.

Objective To investigate the risk factors and prognosis of blood stream infection in patients of intensive care unit (ICU).Methods Clinical data of all patients with culture-positive sepsis were collected from all ICUs of Guangdong General Hospital from October 12th, 2012 to December 1st, 2014 for retrospective study.Physiological characteristics and laboratory data were compared between patients with blood culture-positive sepsis group and patients without sepsis of control group.Logistic regression analysis was made to identify the risk factors for blood stream infection.Patients with blood culture-positive sepsis group were further divided into survivor and non-survivor groups according to the clinical outcomes.Physiological and laboratory data were compared between two groups.Logistic regression analysis was also performed to identify the risk factors for mortality.Results There were 299 patients with positive blood culture sepsis admitted in the ICUs in two years.Of them, 250 patients infected with Gram positive cocci including staphylococcus haemolyticus, staphylococcus epidermidis, staphylococcus capitis and staphylococcus aureus accounting for the majority.There were 174 patients infected with Gram negative bacilli including acinetobacter baumannii, Escherichia coli and Klebsiella pneumoniaesubsp.pneumoniae accounting for the majority.A univariate analysis demonstrated that there were significant differences in hypertension (P =0.001), diabetes (P =0.01), coronary heart diseases and heart failure (P =0.000), chronic renal insufficiency (P =0.000), prolonged mechanical ventilation (P =0.000), pre-admission intravenous administration of antibiotics (P =0.000), and hypoalbuminemia (P =0.008) between culture positive group and control group.A logistic regression analysis demonstrated that diabetes [OR =2.158, 95％ CI (1.230, 3.787), P =0.007], chronic renal insufficiency [OR =13.410, 95％ CI (1.715, 104.879), P =0.013], pre-admission intravenous administration of antibiotics [OR =8.375, 95％ CI (5.267, 13.317), P=0.000] were independent risk factors for bloodstream infections in ICU.In patients with positive blood culture, the non-survivor group had patients with higher advance of old age, higher rate of hypertension, coronary heart diseases or congestive heart failure, tumor and chronic renal insufficiency, prolonged mechanical ventilation and higher incidence of surgery and pre-admission intravenous administration of antibiotics compared with the survivor group.The advance of old age [OR =1.023, 95％ CI (1.008-1.037), P =0.002], prolonged mechanical ventilation [OR =1.055, 95％ CI (1.024, 1.088), P =0.000] and hypoalbuminemia [OR =0.933, 95％ CI (0.898, 0.971), P =0.001] were independently associated with mortality of bloodstream infection in ICU.Conclusions Diabetes, chronic renal insufficiency and pre-admission intravenous administration of antibiotics were associated with the development of blood stream infection in ICU.The advance of old age, prolonged mechanical ventilation and hypoalbuminemia were independent risk factors for mortality in patients with culture-positive sepsis in ICU.

AIM: To screen the cytotoxicity of degradable calcium metaphosphate (dCMP) compared with hydroxyapatite (HA). The proliferation and differentiation abilities of human marrow mesenchymal stem cells (MSC) were used to exhibit the cytotoxicity. METHODS: The cell morphology of MSC was analysed after direct contact with dCMP at different time points by scanning electron microscopy analysis. The degradation products of dCMP and HA were analysed with inductively coupled plasma torch and ion chromatography. The cytotoxic effect of degradation products of dCMP was evaluated by FACS, quantitative assay of ALP and ARS, respectively. RESULTS: dCMP enhanced the proliferation of MSC, but didn't interfere the osteogenic differentiation process of MSC and its mineralization. HA inhibited the proliferation of MSC and the mineralization of osteogenic differentiated MSC, while it did not interfere the osteogenic differentiation process of MSC. CONCLUSION: dCMP had a better cytocompatibility with MSC than HA, which might allow for its use as skeleton scaffolds.

Objective To investigate the effect of interleukin-1β (IL-1β) on the expression of synaptic protein SNAP-25 in the hippocampus in septic neonatal rat induced by systemic lipopolysaceharide (LPS) injection.Methods Sprague-Dawley (SD) rats were randomly divided into two groups:control group and sepsis group.The rat model of sepsis was produced by intraperitoneal injection of 1 mg/kg LPS,and rats in the control group were injected with an equal volume of 0.01 mol/L phosphate buffered saline (PBS).The expression levels of IL-1β and IL-1R1 in the hippocampus at 1,2 and 3 d,and synaptosomal-associated protein 25 (SNAP-25) at 7,14 and 24 d after LPS intraperitoneal injection were detected by Western blot.After cultured for 24 h,primary hippocampal neurons were divided into four groups including the control group,IL-1β (40 ng/mL) treatment group,IL-1β (40 ng/mL) + IL-1Ra (40 ng/mL) treatment group,and IL-1Ra (40 ng/mL) treatment group.The effect of IL-1β on SNAP-25 expression in primary hippocampal neuron was determined by Western blot and real-time PCR.The purity of hippocampal neurons were identified by NeuN immunofluorescence staining and the activity of neurons were detected by CCK-8 assay.All data were analyzed by SPSS version 22.0.The data were analyzed by student-t test and Dunnett-t test.The interaction effects were analyzed by factorial ANOVA.Differences were considered to be statistically significant if P＜ 0.05.Results Compared with the control group,the expressions of IL-1β and IL-1R1 were significantly increased in the hippocampus at 1,2 and 3 d after intraperitoneal injection of LPS (P＜0.05).The expression of SNAP-25 protein was decreased at 7,14,and 28 d after intraperitoneal injection of LPS (P＜0.05).The purity of primary neurons was about up to 92％.The activity of primary neurons was not relatively changed after treated with IL-1β at a dose less than 40 ng/mL.The level of SNAP-25 protein was obviously decreased in primary neurons at 24 h after IL-1β treatment (P＜0.05).IL-1Ra treatment might reverse the effect of IL-1β on primary neurons (P＜0.05).While,the expression of SNAP-25 mRNA was not statistically different in each group (P＞0.05).Conclusions IL-1β may possibly inhibit the expression level of SNAP-25 protein in the hippocampus in the septic rats through its receptor IL-1R1,which would contribute to cognitive dysfunction of septic neonatal rats in later life.

Platelet-derived growth factor receptor beta (PDGFRB) rearrangements play an important role in the pathogenesis of eosinophilia-associated myeloid/lymphoid neoplasms. Up to now, more than 70 PDGFRB fusions have been identified. Here, a novel PDGFRB fusion gene CSNK2A1-PDGFRB has been identified in myeloproliferative neoplasm (MPN) with eosinophilia by RNA-sequencing, which has been verified by reverse transcription polymerase chain reaction and Sanger sequencing. The new PDGFRB fusion partner gene CSNK2A1 encoded one of the two catalytic subunit of casein kinase II (CK2). To our knowledge, this is the first report on the involvement of CSNK2A1 in fusion genes, especially fusion with another kinase PDGFRB in MPN. In addition, the CSNK2A1-PDGFRB fusion retained the entire kinase domain of PDGFRB and response to imatinib at low concentration. The patient with CSNK2A1-PDGFRB was sensitive to imatinib treatment and acquired sustained complete remission.

Platelet-derived growth factor receptor beta (PDGFRB) rearrangements play an important role in the pathogenesis of eosinophilia-associated myeloid/lymphoid neoplasms. Up to now, more than 70 PDGFRB fusions have been identified. Here, a novel PDGFRB fusion gene CSNK2A1-PDGFRB has been identified in myeloproliferative neoplasm (MPN) with eosinophilia by RNA-sequencing, which has been verified by reverse transcription polymerase chain reaction and Sanger sequencing. The new PDGFRB fusion partner gene CSNK2A1 encoded one of the two catalytic subunit of casein kinase II (CK2). To our knowledge, this is the first report on the involvement of CSNK2A1 in fusion genes, especially fusion with another kinase PDGFRB in MPN. In addition, the CSNK2A1-PDGFRB fusion retained the entire kinase domain of PDGFRB and response to imatinib at low concentration. The patient with CSNK2A1-PDGFRB was sensitive to imatinib treatment and acquired sustained complete remission.