Effect of 5 methods of critical illness score in the prognosis evaluation of sepsis-associated encephalopathy / 中华急诊医学杂志

Objective:To explore the effect of pediatric critical illness score (PCIS), pediatric risk of mortality Ⅲ score (PRISM Ⅲ), pediatric logistic organ dysfunction 2 (PELOD-2), pediatric sequential organ failure assessment (p-SOFA) score and Glasglow coma scale (GCS) in the prognosis evaluation of septic-associated encephalopathy (SAE).Methods:The data of children with SAE admitted to the Pediatric Intensive Care Unit (PICU), Guangdong Provincial People’s Hospital, Guangdong Academy of Medical Sciences from January 2010 to December 2020 were retrospectively analyzed. They were divided into the survival and death groups according to the clinical outcome on the 28th day after admission. The efficiency of PCIS, PRISM Ⅲ, PELOD-2, p-SOFA and GCS scores for predicting death were evaluated by the area under the ROC curve (AUC). The Hosmer-Lemeshow goodness-of-fit test assessed the calibration of each scoring system.Results:Up to 28 d after admission, 72 of 82 children with SAE survived and 10 died, with a mortality rate of 12.20%. Compared with the survival group, the death group had significantly lower GCS [7 (3, 12) vs. 12 (8, 14)] and PCIS scores [76 (64, 82) vs. 82 (78, 88)], and significantly higher PRISM Ⅲ [14 (12, 17) vs. 7 (3, 12)], PELOD-2 [8 (5, 13) vs. 4 (2, 7)] and p-SOFA scores [11 (5, 12) vs. 6 (3, 9)] ( P<0.05). The AUCs of PCIS, PRISM Ⅲ, PELOD-2, p-SOFA and GCS scores for predicting SAE prognosis were 0.773 ( P=0.012, AUC>0.7), 0.832 ( P=0.02, AUC>0.7), 0.767 ( P=0.014, AUC>0.7), 0.688 ( P=0.084, AUC<0.7), and 0.692 ( P=0.077,AUC<0.7), respectively. Hosmer-Lemeshow goodness-of-fit test showed that PCIS ( χ2=5.329, P=0.722) predicted the mortality and the actual mortality in the best fitting effect, while PRISM Ⅲ ( χ2=12.877, P=0.177), PELOD-2 ( χ2=8.487, P=0.205), p-SOFA ( χ2=9.048, P=0.338) and GCS ( χ2=3.780, P=0.848) had poor fitting effect. Conclusions:The PCIS, PRISM Ⅲ and PELOD-2 scores have good predictive ability assessing the prognosis of children with SAE, while the PCIS score can more accurately evaluate the fitting effect of SAE prognosis prediction.

Melatonin inhibits astrocyte activation in periventricular white matter via NF-κB pathway / 中华急诊医学杂志

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.

Effect of melatonin on oligodendrocyte maturation and differentiation in corpus callosum of septic neonatal rats / 中华急诊医学杂志

Objective:To investigate the effect of melatonin on oligodendrocyte maturation and differentiation in corpus callosum of septic neonatal rats induced by systemic lipopolysaccharide (LPS) injection.Methods:Sprague-Dawley rats were randomly allocated into the control group, septic experimental group, and melatonin group. In the septic experimental group, rats were intraperitoneally administrated with lipopolysaccharide (LPS) (1 mg/kg). In the melatonin group, melatonin was intraperitoneally administered (10 mg/kg) at 0.5 h after LPS injection. The expression level of IL-6, olig1, olig2, and the MAG protein were detected by Western blot at different time points in the three groups. BV-2 cells were used in vitro. For drug administration, the effect of LPS, melatonin and melatonin receptor antagonist, luzindole, on IL-6 expression in BV-2 microglia cell was determined by Western blot. The medium of BV2 cell were collected to treat primary OPCs. The expression level of olig1, olig2 and MAG protein in primary OPCs were detected by Western blot. SPSS 20.0 statistical software was used for analysis, and the data were analyzed by one-way ANOVA and two-way ANOVA. Differences were considered to be statistically significantly if P<0.05. Result:Compared with the LPS group, the expression of IL-6 was significantly decreased in the corpus callosum at 6 h, l d, and 3 d in the melatonin group ( P<0.05). The expression of olig1, olig2 and MAG protein were increased at day 7, 14, and 28 in the melatonin group compared with the LPS group ( P<0.05). In vitro the expressions of IL-6 was significantly increased after LPS treatment ( P<0.05), but was decreased in the LPS+melatonin treatment group ( P<0.05). After treatment with melatonin receptor inhibitor, luzindole, the expressions level of IL-6 was increased ( P<0.05). The expression of olig1, olig2 and MAG protein were decreased with conditioned medium in the LPS BV2 cell group than the control group in the primary OPCs ( P<0.05). However, those were increased with conditioned medium in the LPS+melatonin BV2 cell group than the LPS group ( P<0.05). Conclusions:Melatonin may inhibit the inflammation response in the corpus callosum through its receptor, and may promote the maturation and differentiation of oligodendrocyte, suggesting that melatonin may have therapeutic effect on neuroinflammation and axonal hypomyelination on PWM in septic neonatal rats.

Effect of IL-1β on expression of SNAP-25 in the hippocampus in septic neonatal rats / 中华急诊医学杂志

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.

Effects of allogeneic bone marrow mesenchymal stem cells on polarization of peritoneal macrophages in rats with sepsis / 中华烧伤杂志

Objective@#To explore the effects of allogeneic bone marrow mesenchymal stem cells (BMSCs) on polarization of peritoneal macrophages isolated from rats with sepsis induced by endotoxin/lipopolysaccharide (LPS).@*Methods@#(1) BMSCs were isolated, cultured and purified from 5 SD rats with whole bone marrow adherent method. The third passage of cells were collected for morphologic observation, detection of expressions of stem cell surface markers CD29, CD44, CD45, and CD90 with flow cytometer, and identification of osteogenic and adipogenic differentiation. (2) Another 45 SD rats were divided into sham injury group (SI, n=5), LPS control group (LC, n=20), and BMSCs-treated group (BT, n=20) according to the random number table. Rats in groups LC and BT were injected with LPS (5 mg/kg) via tail vein to induce sepsis; rats in group SI were injected with the same amount of normal saline to simulate the damage. At post injury hour (PIH) 1, rats in group BT were given 1 mL BMSCs (2×106/mL) via tail vein injection; rats in another two groups were injected with equal volume of phosphate buffer saline. Five rats in group SI at PIH 24 and in groups LC and BT at PIH 6, 12, 24, and 48 were sacrificed to harvest lung tissue for pathological observation with HE staining. In addition, rats in group SI at PIH 24 and in groups LC and BT at PIH 24 and 48 were simultaneously performed with intraperitoneal injection of low-glucose DMEM. Then peritoneal fluid was harvested to culture peritoneal macrophages. Flow cytometer was used to assess the positive expression of cell makers of macrophages including CD68 (making gate), CD11c, and CD206 in group SI at PIH 24 and in groups LC and BT at PIH 24 and 48. Data were processed with one-way analysis of variance and LSD test.@*Results@#(1) The third passage of cells showed uniform fiber-like shape similar to fibroblasts. These cells showed positive expressions of CD29, CD44, CD90 and weak positive expression of CD45. They were able to differentiate into osteoblasts and adipocytes. These cells were identified as BMSCs. (2) At PIH 24, the structure of pulmonary alveoli of rats in group SI was clear and complete with no congestion or inflammatory cell infiltration. At PIH 6, the structure of pulmonary alveoli of rats in groups LC and BT was clear with a small amount of inflammatory cell infiltration, slight congestion and pulmonary interstitial thickening. At PIH 12, the inflammatory responses in lung tissue of rats in group LC were more severe than those in group BT with a large amount of inflammatory cell infiltration, serious congestion, and obvious pulmonary interstitial thickening. The pathological results of rats in group BT at PIH 12 was consistent with the results at PIH 6. At PIH 24, the pathological results of rats in groups LC and BT were similar to the results at PIH 12. At PIH 48, the structure of pulmonary alveoli tissue of rats in group LC was still severely disrupted, with a large number of inflammatory cell infiltration and congestion in lung tissue, but pulmonary interstitial thickening was slightly alleviated than before. The condition of rats in group BT nearly recovered to that in group SI. (3) At PIH 24, the positive expression rate of CD11c in peritoneal macrophages of rats in group LC [(83±10)%] was close to that in group BT [(87±7)%, P>0.05], and they were both significantly higher than the rate in group SI [(55±12)%, with P values below 0.01]. The positive expression rate of CD11c in peritoneal macrophages of rats in group LC [(59±11)%] at PIH 48 was close to that in group SI at PIH 24 (P>0.05), and they were both significantly higher than the rate in group BT [(20±11)%] at PIH 48 (with P values below 0.01). At PIH 24, the positive expression percentages of CD206 in peritoneal macrophages of rats were similar among the three groups (with P values above 0.05). The positive expression percentage of CD206 in peritoneal macrophages of rats in group SI at PIH 24 was close to that in group BT at PIH 48 (P>0.05), and they were both significantly lower than the percentage in group LC at PIH 48 (with P values below 0.01).@*Conclusions@#BMSCs can reduce the pathological inflammatory responses in the lung of rats with sepsis and inhibit peritoneal macrophages from polarizing into M1 phenotype, whereas they can not promote macrophages to polarize into M2 phenotype.

The effectiveness evaluation of helicopter emergency medical services on transporting critical patients / 中华急诊医学杂志

Objective To explore the advantages and disadvantages of helicopter emergency medical services of South China in the long-distance transport for critical patients.Methods A total of 30 patients who received helicopter emergency medical services by Guangdong Generral Hospital from August 2004 to December 2014 were selected as the observation group,and the other 30 patients with similar conditions who received ground emergency medical services were selected as the control group.To analyses the difference between the two groups in the disease,transport distance,transportation time,costs and compliction by χ2-test,t-test and nonparametric test according types of data.Results There were significantly difference between two groups in transport distances (km) [578.0 (313.0,707.5)vs.214.5 (101.5,313.5),P 0.05).Conclusions Helicopter emergency medical services could shorten the transportation time of critical patients on long distance transportation,and improve the efficiency of first-aid.However,there were many disadvantages that need to be improved in the helicopter emergency medical service of China.

The effect of hypertonic saline on notch signaling pathway in experimentally induced cerebral ischemic rats / 中华急诊医学杂志

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.

Analysis of microbial characteristics and predisposing factor in gram-negative bacteria blood stream infection / 实用医学杂志

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.

Microbial characteristics in culture-positive sepsis and risk factors of polymicrobial infection in ICU / 中华危重病急救医学

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.

Effects of microglia-derived IL-1βon differentiation of OPCs in corpus callosum of septic neonatal rats / 中国病理生理杂志

[ 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.

The analysis of risk factors of pulmonary embolism in patients with negative D-dimer / 中华急诊医学杂志

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.

Risk factors and prognosis of bloodstream infection in the ICU patients / 中华急诊医学杂志

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.

Effect of GPR56 on axonal development and myelination / 中华急诊医学杂志

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.

The clinical significance of procalcitonin to identifying microorganism strains in ICU patients with bloodstream infection / 中华急诊医学杂志

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.

Expression of nNOS in the hippocampus in vascular dementia rats / 临床神经病学杂志

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.