ABSTRACT
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.
ABSTRACT
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.
ABSTRACT
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.