Objective To explore the expression of neuronal nitric oxide synthase (nNOS) in the hippocampus in vascular dementia rats.Methods 60 rats were randomly divided into five groups: control group, model 12 h group,model 1 d group, model 3 d group and model 7 d group.An animal model of vascular dementia (VD) was established through repeated cerebral ischemia-reperfusion in rats with repeated bilateral common carotid arteries occlusion. The number of neurons in CA 1 area of hippocampus in every group was observed using HE staining. The expression of nNOS in the hippocampus in VD rats was detected by immunohistochemical staining and western blot method.Results The number of neurons in CA 1 area of hippocampus decreased significantly in 12 h, 1 d, 3 d and 7 d group. The expression of nNOS in CA 1 area of hippocampus was weak in control group and up-regulated in 12 h group and increased further in 1 d group. However, its expression decreased gradually in 3 d and 7 d group.Conclusion nNOS may be related to the injury of hippocampus at early phase in VD rats. It might be regarded as one of mechanisms to cause VD.

Objective To analyze the risk factors of pulmonary embolism in patients with negative Ddimer in serum in order to determine the need of pulmonary computed tomography angiograph (CTA) to confirm the final diagnosis in those patients for avoidance of misdiagnosis.Methods A retrospective analysis of 106 patients suspected to suffer from pulmonary embolism (PE) with serum negative D-dimer checked with pulmonary CTA was carried out.According to the results of CTA, the patients were divided into two groups, namely PE group (n =41) and non-PE group (n =65).The difference in clinic presentation, the time elapsed from onset to visit, N-terminal pro-brain natriuretic peptide (NT-proBNP), high risk factors (such as immobilization for 3 weeks, leg swelling and pain to palpation, history of deep vein thrombosis, malignancy) and Wells score (≥ 4 points indicates probability of PE).And logistic regression analysis was made to investigate the risk factors in PE with negative D-dimer.Results The analysis study showed that 38.6％ of total patients suspected to suffer from PE with serum negative D-dimer were checked by CTA to confirm the presence of PE.One important characteristics of the D-dimer negative PE patients was the longer time consumed from onset to visit [(9.51 ±2.01) d vs.(4.01 ±1.92) d, P＜ 0.05], and majority of the CTA positive patients suspected to suffer from PE with negative D-dimer had high risks of PE (P ＜0.01).Compared with the non-PE group, the Wells score ≥4 points and the level of serum NT-proBNP significantly increased in the PE group (P ＜ 0.01).Logistic regression analysis revealed that dyspnea, high NT-proBNP level and Wells sore ≥ 4 points were risk factors for D-dimer negative PE.Conclusion Delayed treatment was the main cause of misdiagnosis of D-dimer negative PE.Dyspnea, high NT-proBNP level and Wells sore ≥4 points were risk factors for suspected PE patients with negative D-dimer, and these patients should be confirmed by pulmonary CTA.On the contrary, PE could be excluded if patients with D-dimer negative had no these risk factors.

[ ABSTRACT] AIM:To explore whether IL-1βinhibits the oligodendrocyte precursor cell ( OPCs) differentiation and affects axonal myelination.METHODS:One-day-old SD rats were randomly divided into control group and LPS group ( 48 rats in each group) .The rats in LPS group were intraperitoneally injected with 1 mg/kg LPS.The rats in control group were injected with an equal volume of PBS.The rats in each group were further divided into 3 h, 24 h, 3 d, 7 d, 14 d and 28 d subgroups after injection.The expression of IL-1βand IL-1R1 in the rat corpus callosum at 3 h, 24 h, 3 d, 7 d was determined by double immunofluorescence and Western blotting.The myelin basic protein( MBP) expression in the rat cor-pus callosum at 14 d, 28 d after injection was also measured.In vitro, primary OPCs culture was performed and divided in-to control group, 30 μg/L IL-1βgroup, 30 μg/L IL-1β+IL-1Ra group and 30 μg/L IL-1Ra group.The expression of MBP in the OPCs induced differentiation for 3 d was observed by double immunofluorescence and Western blotting.RE-SULTS:The expression of IL-1βand IL-1R1 in the rat corpus callosum at 3 h, 24 h, 3 d, 7 d after LPS injection was ob-viously increased and the expression of MBP in the rat corpus callosum at 14 d, 28 d in LPS group was obviously decreased compared with control group in vivo.The level of MBP was significantly decreased after IL-1βtreatment for 3 d in vitro. However, IL-1Ra (IL-1R inhibitor) reversed the down-regulation of MBP expression.IL-1βinhibited the expression of p-ERK, ERK over-expression reversed the down-regulation of MBP expression compared with IL-1βgroup.CONCLUSION:IL-1βinhibits the differentiation of OPCs, which may be involved in ERK pathways, thus leading to axonal hypomyelination in the corpus callosum of septic neonatal rats.

ObjectiveTo investigate the clinical characteristics and pathogenic microorganisms in culture-positive sepsis, to identify its risk factors, and evaluate the prognosis on polymicrobial infection in intensive care unit (ICU).Methods A descriptive retrospective study was conducted. Clinical data of patients aged≥ 18 years, diagnosed as culture-positive sepsis, and admitted to six ICUs of Guangdong General Hospital from October 12th, 2012 to December 1st, 2014 were enrolled. Based on the number of isolated pathogens, patients were divided into polymicrobial infection group (≥two pathogens) and monomicrobial infection group (one pathogen) to investigate the clinical characteristics of patients with culture-positive sepsis and the causative pathogens. Multiple logistic regression was conducted to identify the risk factors for polymicrobial infection. Kaplan-Meier curve was plotted to analyze a 90-day survival rate from the onset of positive blood culture.Results 299 patients with positive blood culture were enrolled. A total of 450 strains of pathogens were isolated including 246 gram-positive cocci (54.67%), 167 gram-negative bacilli (37.11%) and 37 fungi (8.22%). Ninety-one patients had polymicrobial infection, and 208 with monomicrobial infection. Compared with monomicrobial infection group, patients suffering from polymicrobial infection had more advanced age (years: 73.19±18.02 vs. 60.83±18.06,t = -5.447,P = 0.000), also with higher incidence of cerebrovascular diseases [39.56% (36/91) vs. 17.79% (37/208),χ2 = 16.261,P = 0.000] or chronic renal insufficiency [15.38% (14/91) vs. 7.21% (15/208),χ2 = 4.828,P = 0.028], higher incidence of recent hospital stay (≥2 days) within 90 days [73.63% (67/91) vs. 61.54% (128/208),χ2 = 4.078,P = 0.043], longer mechanical ventilation duration [days: 4 (0, 17) vs. 1 (0, 6),U = 7 673.000,P = 0.006], longer length of hospital stay before blood was drawn for culture [days: 21 (7, 40) vs. 9 (3, 17),U = 6 441.500,P = 0.006], and higher incidence of pre-admission intravenous use of antibiotics [84.62% (77/91) vs. 66.83% (139/208),χ2 = 9.989,P = 0.002]. Multiple logistic regression analysis showed that advanced age [odd ratio (OR) = 1.032, 95% confidential interval (95%CI) = 1.015-1.050,P = 0.000], cerebrovascular diseases (OR = 2.247, 95%CI = 1.234-4.090,P = 0.008), prolonged mechanical ventilation (OR =1.041, 95%CI = 1.014-1.069,P = 0.003), and recent hospital stay (≥2 days) within 90 days (OR = 1.968, 95%CI =1.079-3.592,P = 0.027) were the independent risk factors for polymicrobial infection. In the polymicrobial infection group, the length of ICU stay [days: 46 (22, 77) vs. 13 (7, 22),U = 3 148.000,P = 0.000] and hospital stay [days:81 (47, 118) vs. 28 (17, 46),U = 3 620.000,P = 0.000] were significantly longer, and the ICU mortality [65.93%(60/91) vs. 43.75% (91/208),χ2 = 12.463,P = 0.000] and hospital mortality [68.13% (62/91) vs. 45.67% (95/208),χ2 = 12.804,P = 0.000] were significantly higher, and on the other hand the 90-day survival rate was significantly lower than that in the monomicrobial infection group (χ2 = 8.513,P = 0.004).Conclusions The most common pathogen of ICU sepsis is gram-positive cocci. Independent risk factors for polymicrobial infections were found to be advanced age, occurrence of cerebrovascular disease, prolonged mechanical ventilation, and recent hospitalization. Polymicrobial infection is associated with longer length of ICU and hospital stay, as well as higher mortality.

Objective To investigate the level of serum procalcitonin (PCT) for exploring the clinical value in identifying microorganism strains in the intensive care unit (ICU) patients with blood stream infections.Methods A retrospective analysis of patients with positive blood culture of a single strain and with serum PCT levels detected simultaneously was carried out from January 2010 through December 2012.The comparisons of PCT levels were done among Gram-negative (G-) bacteria,Gram-positive (G +) bacteria and fungi in patients with bloodstream infections.The diagnostic performance of PCT was determined by the receiver operating characteristic curve (ROC).Results A total of 524 patients with blood stream infection were enrolled and categorized into three different groups,namely G-bacteria infection group (n =206),G + bacteria infection group (n =276),and fungi infection group (n =42).The median value of PCT level of G-bacteria group was 14.9 ng/ml,which was significantly higher than that of the other two groups with 0.14 ng/ml and 1.76 ng/ml,respectively (P ＜ 0.01).Further,the PCT level of fungi group also obviously higher than that of G + bacteria group (P ＜ 0.001).According to ROC,PCT level at 2.11 ng/ml could distinguish G-bacteria infection from G + bacteria infection with sensitivity 82.8％ and specificity 80.1％,while PCT at 5.09 ng/ml was used to distinguish G-bacteria infection from fungi infection with sensitivity 68％ and specificity 73.8％.The area under the ROC of G + bacteria and fungi was 33.0％ (P ＜ O.01).Conclusions Serum PCT level is valid for distinguishing ICU patients with blood stream infection caused by G-bacteria from G+ bacteria or from fungi,but the validity of PCT for distinguishing G + bacteria from fungi infection needs to be set up by further studies.

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.

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 determine the likelihood of G-protein coupled receptor 56 (GPR56 ) induces axonal development and myelination in the corpus callosum of mouse brain.Methods A total of 64 Gpr56 +/-and Gpr56 -/-mice were selected and randomly divided into two groups:Gpr56 +/-group (n=32)and Gpr56 -/-group (n=32).According to number of days after birth,each group was further divided into 4 subgroups including P7d,P14d,P21d and P28d subgroups.Levels of neurofilament-200 (NF -200)and proteolipid protein (PLP ) of myelin basic protein in corpus callosum were measured with immunohistochemistry staining and Western blot in P7d、P14d、P21d、P28d Gpr56 +/- and Gpr56 -/-mice.Gpr56 +/-and Gpr56 -/-neurons were cultured using P1 d Gpr56 +/-and Gpr56 -/-mouse brain.The lengths of Gpr56 +/- and Gpr56 -/-neuronal axon were measured and compared with Image J software. Axonal myelination in the corpus callosum of mouse brain in each group was observed under electronic microscopy and the axonal diameters between subgroups were compared.Results The levels of NF-200 and PLP in the corpus callosum in P7d、P14d、P21d、P28d Gpr56 -/-mice decreased significantly compared with Gpr56 +/- mice.The length of Gpr56 -/-neuronal axon was shortened compared with Gpr56 +/-neuronal axon.The number of myelinated axons was obviously reduced in the corpus callosum in P28d Gpr56 -/-mice.The diameter of axon in the corpus callosum of P28d Gpr56 +/-mouse is longer than that of P28d Gpr56 -/-mouse. Conclusions GPR56 may be involved in axonal development and myelination in the corpus callosum of mouse brain.

Objective:To investigate the effect of melatonin (MEL) influence on lipopolysaccharide (LPS)-induced long-term anxiety-like behavior and activation of astrocytes in septic neonatal rats.Methods:Sprague-Dawley rats were randomly(random number) assigned to the control group, LPS group and LPS+MEL group. Sepsis model was intraperitoneally injected with LPS (1 mg/kg), and neonatal rats in the MEL group were administered with MEL (10 mg/kg) 30 min after LPS injection. At different time points after injection, rats in each group were divided into three subgroups: 3 d, 7 d and 28 d. The expression of GFAP and TNF-α in the corpus callosum was detected by immunofluorescence staining and Western blot. Open-field test was applied to observe anxiety-like behaviors. In vitro, cultured neonatal SD rat astrocytes were divided into the control group, LPS group, LPS+MEL group, and LPS+MEL+luzindole group. Immunofluorescence staining was used to observe the expression of GFAP and TNF-α. Expression of GFAP, TNF-α, p-NF-κBp65, NF-κBp65 protein in astrocytes were assessed by Western blot. RT-qPCR was used to investigate the mRNA expression of GDNF and BDNF. One-way ANOVA and two-way ANOVA were used for comparison of multiple groups of variables. A P<0.05 was considered statistically significant. Results:LPS reduced the duration of movement in the central area and distance in the central area/total distance in open-field test, while melatonin evidently reversed the LPS-induced anxiety-like behavior. Compared with the LPS group, the expressions of GFAP and TNF-α were significantly decreased in the corpus callosum at 3 d and 7 d in the MEL group ( P< 0.05). Compared with the LPS group, MEL could significantly decrease the expression of GFAP, TNF-α and p-NF-κBp65 in astrocytes ( P< 0.05), which could be blocked by Luzindole. In addition, compared with the LPS group, MEL pretreatment could reverse the down regulation of GDNF and BDNF induced by LPS ( P<0.05). Conclusions:MEL can relieve LPS-induced long-term anxiety-like behavior in septic neonatal rats. The mechanism may be related to the inhibition of astrocyte activation and inflammatory reaction through NF - κ B pathway.

Objective To explore whether hypertonic saline would partake in regulating Notch signaling in microglia in experimentally induced cerebral ischemic rats.Methods Male SD rats were randomly divided into sham group, cerebral ischemia group, normal saline group ( NS group ) , 10%hypertonic saline group (10%HS group) , the model of cerebral ischemia were established in all rats except the sham group by using middle cerebral artery occlusion ( MCAO) .After 2 hours of MCAO, the rats were through reperfusion for 24 h.In addition, rats in the normal saline group and 10% HS group were respectively treated with a continuous intravenous injection of normal saline (0.3 mL/h) and 10%HS (0.3 mL/h) by tail vein for 24 h.Immunofluorescence methods, RT-PCR and Western blot were used to detect the expression of Notch1 and intracellular Notch receptor domain ( NICD) .All data was analyzed by one-way analysis of variance ( ANOVA) , The intergroup comparisons were analyzed by the least-significant-difference (LSD) tests.Differences were considered statistically significant if P<0.05.Results Immunofluorescence showed that the expression of Notch1 and NICD were significantly increased in the microglia around peri-ischemia area in cerebral ischemia group and normal saline group compared to sham group;the expression of Notch1 and NICD in the microglia around peri-ischemia area were significantly reduced in 10% HS group compared to ischemia group and NS group.RT-PCR showed that the mRNA expression of Notch1 was significantly increased in ischemia group and NS group compared to sham group ( sham group: 1.000 ± 0.076; ischemia group: 2.203 ±0.283; NS group: 1.616 ±0.185; P <0.01 ); however, it was significantly reduced in 10% HS group compared to ischemia group and NS group ( ischemia group:2.203 ±0.283; NS group: 1.616 ±0.185; 10%HS group: 1.202 ±0.177; P <0.05 ) .Western blot showed that the protein expression of Notch1 was significantly increased in ischemia group and NS group compared to sham group ( sham group: 0.290 ±0.079; ischemia group: 0.750 ±0.029; NS group:0.765 ±0.182;P<0.01);but was significantly reduced in 10%HS group compared to ischemia group and NS group ( ischemia group:0.750 ±0.029; NS group:0.765 ±0.182;10%HS group:0.390 ±0.195;P<0.05 ) .The protein expression of NICD was significantly increased in ischemia group and NS group compared to sham group ( sham group: 0.401 ±0.196; ischemia group: 0.906 ±0.359; NS group:0.847 ±0.153;P<0.01);but was significantly reduced in 10%HS group compared to ischemia group and NS group ( ischemia group:0.906 ±0.359; NS group:0.847 ±0.153;10%HS group:0.561 ±0.165;P<0.05 ) .Conclusion Our results suggest that HS markedly suppresses Notch signaling in microglia around the ischemia tissue area in experimental induced cerebral ischemic rats.