Objective To evaluate the role of mitochondrial fission in anoxia-reoxygenation injury to rat hippocampal neurons.Methods Neurons were enzymatically isolated from hippocampi of newborn Sprague-Dawley rats (less than 24 h old).The primary hippocampal neurons were cultured and seeded in 25 mm × 25 mm culture flasks at a density of 7 × 105/ml.The cultured neurons were randomly assigned into 3 groups (n =18 each) using a random number table:control group (C group),anoxia-reoxygenation group (I/R group),and mitochondrial fission inhibitor mdivi-1 group (M group).In group I/R,the vehicle dimethyl sulfoxide (DMSO,final concentration ＜ 0.1％) was added prior to anoxia and the cells were then incubated for 40 min.In group M,mdivi-1 (dissolved in DMSO,final concentration of DMSO ＜ 0.1％) was added prior to anoxia and the cells were then incubated for 40 min.The hippocampal neurons were subjected to oxygen-glucose deprivation (OGD) for 6 h followed by restoration of O2 supply for 20 h.After 20 h of reoxygenation,the level of reactive oxygen species (ROS) (by ELISA),cell apoptosis (using flow cytometry),and expression of mitochondrial fission protein Drp1,Bcl-2 and Bax (by Western blot) were measured.The apoptosis rate and the ratio of Bcl-2 to Bax were calculated.Results Compared with C group,ROS content and apoptosis rate were significantly increased,the expression of Drp1 and Bax was up-regulated,the expression of Bcl-2 was down-regulated,and the ratio of Bcl-2 to Bax was decreased in I/R group (P ＜ 0.05).Compared with I/R group,ROS content and apoptosis rate were significantly decreased,the expression of Drp1 and Bax was down-regulated,the expression of Bcl-2 was up-regulated,and the ratio of Bcl-2 to Bax was increased in M group (P ＜ 0.05).Conclusion Mitochondrial fission is involved in anoxia-reoxygenation injury to rat hippocampal neurons via mitochondria-mediated apoptotic pathway.

Objective To evaluate the reliability of lactate clearance rate in evaluating the efficacy of early fluid resuscitation in the patients with severe sepsis.Methods One hundred and forty-two patients with severe sepsis,aged 28-87 yr,were enrolled in the study.Isotonic crystalloid fluid was infused after admission to ICU to maintain central venous pressure ≥ 8 mmHg,mean arterial pressure ≥ 65 mmHg,central venous oxygen saturation (ScvO2) ≥ 70％,and urine output ≥ 0.5 ml·kg 1 ·h-1 within 6 h.The patients were divided into 2 groups according to the treatment outcome:survival group and death group.Immediately before fluid resuscitation and at 6,12 and 24 h after fluid resuscitation,blood samples were collected from the central vein for blood gas analysis and ScvO2 was recorded.Blood samples were collected from the peripheral vein for determination of the concentration of lactate and lactate clearance rate was calculated.Results Compared with survival group,the lactate clearance rate was significantly decreased at 6,12 and 24 h after fluid resuscitation,and no significant change in ScvO2 was found in death group.Conclusion Lactate clearance rate can evaluate the efficacy of early fluid resuscitation in the patients with severe sepsis.

Objective To investigate the risk factors of ICU delirium in critically ill patients. Methods A total of 1 74 critically ill patients in ICU who were older than 18 yrs and stayed in ICU exceeding 24 hs from January 201 5 to June 201 5 were enrolled.Patients were divided into delirium group and non delirium group.Delirium was assessed twice daily with the Confusion Assessment Method for the ICU (CAM-ICU)during the first 7 days.The factors such as history of alcoholism and other 12 factors were analyzed by univariate and multivariate logistic regression analysis to identify those risk factors associated with delirium.Results With 22 cases of delirium in 1 74 patients,the in-cidence of delirium was 12.64% (delirium group).Variables associated with delirium were coronary heart history,operation,tracheal intubation,clinical use of mechanical ventilation,hypoxemia and Benzodiazepine.Multivariate logistic regression analysis showed that coronary heart disease (OR 3.932,95%CI 1.225-12.61 7),surgery(OR 9.691,95%CI 2.103-44.657),hypoxemia(OR 6.595, 95%CI 1.377-31.585),Benzodiazepine use (OR 7.620,95%CI 1.713-33.899)was independent risk factors of delirium in critically ill patients (P < 0.05 or P < 0.01 ).Conclusion Coronary heart disease,surgery,hypoxemia and Benzodiazepine are independent risk factors of ICU delirium in criti-cally ill patients.Early screening and prevention of delirium should be given to reduce the occurrence of delirium for patients in ICU.

Background:Colorectal polyps,especially adenomatous polyps are the precusor of colorectal cancer. Screening and polypectomy by using colonoscopy is an important approach for prevention of colorectal cancer. Aims:To conduct a retrospective analysis among 1 613 cases of patients with colorectal polyps in Jiading District,Shanghai,China for guiding the management of colonoscopy surveillance of colorectal polyps. Methods:A total of 2 652 colorectal polyps detected by colonoscopy from Jan. 2013 to Aug. 2014 in the Endoscopy Center of Shanghai Ruijin Hospital Northern Branch were recruited in the study. Clinicopathological features of the polyps,coincidence rate of biopsy pathology and polypectomy pathology,and the re-detected polyps in colonoscopic follow-up were analyzed. Results:In 2 652 colorectal polyps,1 996 (75. 3% )were located in distal colon;adenomatous polyps accounted for 77. 5%(2 056 / 2 652)of the polyps detected by colonoscopy,of which 804(39. 1% )were found to have intraepithelial neoplasia. Both biopsy pathology and polypectomy pathology were obtained in 447 polyps,with an overall coincidence rate of 60. 4% ;as for adenomas,the coincidence rate was 68. 1% . Two hundred and eighteen pathologically proved polyps were found in a 1. 5-year colonoscopic follow-up, among which 74. 3% were adenomatous polyps;the re-detection rate of polyps located in proximal colon or less than 1. 0 cm in diameter was significantly higher than polyps located in distal colon and more than 1. 0 cm in diameter, respectively(12. 3% vs. 6. 9% and 9. 0% vs. 4. 5% ,P all < 0. 01). Conclusions:Adenomatous polyps account for high proportion of colorectal polyps detected by colonoscopy. Pathological examination of resection specimens and periodical follow-up are important for patients with colorectal polyps after endoscopic polypectomy.

Objective To evaluate effect of dexmedetomidine on mitochondrion-dependent apoptosis during hypoxia-reoxygenation (H/R) injury to hippocampal neurons of rats.Methods The primarily cultured hippocampal neurons of Sprague-Dawley rats were divided into 4 groups (n =40 each) using a random number table method:control group (C group),vehicle group (V group),H/R group and dexmedetomidine group (D group).Hippocampal neurons were subjected to oxygen-glucose deprivation followed by restoration of oxygen supply to establish the model of H/R injury.Dexmedetomidine 1 μmol/L was added at 6 h of reoxygenation in D group.The viability of neurons was measured by methyl thiazolyl tetrazolium assay at 20 h of reoxygenation.The ultrastructure of mitochondria was observed by transmission electron microscopy.The expression of cytochrome c (Cyt c),caspase-3,Fis1 and Drp1 was detected by Western blot.The neuronal apoptosis was detected by flow cytometry,and apoptosis rate was calculated.Results Compared with C group,no significant change was found in the viability of neurons in group V (P＞0.05),and the viability of neurons was significantly decreased,the apoptosis rate was increased,the expression of Cyt c,caspase-3,Fis1 and Drp1 was up-regulated (P＜0.05),and the damage to mitochondrial ultrastructure was accentuated in H/R and D groups.Compared with H/R group,the viability of neurons was significantly increased,the apoptosis rate was decreased,the expression of Cyt c,caspase-3,Fis1 and Drp1 was down-regulated (P＜0.05),and the damage to mitochondrial ultrastructure was significantly attenuated in D group.Conclusion The nechanism by which dexmedetomidine reduces the H/R injury to hippocampal neurons is related to inhibiting mitochondrion-dependent apoptosis in rats.

Clinical data of 12 cases of Trousseau syndrome with cerebral infarction as initial presentation admitted in the neurology department of the Fourth Affiliated Hospital of Hebei Medical University from December 2011 to December 2017 were retrospectively analyzed.Of the 12 patients,4 cases had risk factors for cerebral infarction and 8 ones had no risk factors.There were 2 patients with 1 lesion and 10 patients with two or more lesions in brain imaging.The infarction lesions of 9 patients were located in 2 or more arterial blood supply areas.Ten patients showed an elevated plasma D-dimer level,5 had elevated fibrinogen level,7 showed increased blood platelet count and 8 had increased homocysteine level.Ten cases were confirmed by pathology,2 cases by clinic and imaging diagnosis.The study suggests that multiple lesions with several cerebral arteries involved,high plasma D-dimer and fibrinogen levels may be the clinical characteristics of Trousseau syndrome with initial presentation as acute ischemic stroke and lacking of risk factors.The hypercoagulation state may be the important pathogenesis of this disorder.

Objective To investigate the dose level of pediatric CT scan in one hospital, and to provide recommendations for optimized scanning. Methods The CT scan data of children were collected from this hospital to analyze the differences in typical dose values and typical scanning parameters between different age groups and different scanning parts. Results The sample size was >10 for routine cranial scan, routine maxillary sinus scan, and routine chest scan in each age group, and the 1-year-old group and the 5-year-old group had the same kV, mA, and CTDIvol values of routine cranial scan and maxillary sinus scan, but with relatively great differences in the parameters of chest scan. Conclusion Scanning parameters in this hospital can be further optimized, and optimization measures should be adopted continuously.

Objective To compare H_p(3) calibration with a homemade (A) thermoluminescent dosimeter (TLD) and an imported (B) TLD in a standard X-ray RQR radiation field, to explore the different responses of A and B, and to provide foundation for the calibration of H_p(3). Methods A column mode was selected. H_p(3) calibration was performed using A and B in a standard X-ray RQR radiation field in the Secondary Standard Dosimetry Laboratory, National Institute for Radiological Protection, China Center for Disease Control and Prevention. Angle response, energy response, and linear response were calibrated with RQR4 (60 kV), RQR7 (90 kV), and RQR9 (120 kV), respectively. Results In terms of angle response, the calibration results of A were relatively high, while the calibration results of B were relatively low. In terms of energy response, the calibration results showed a similar pattern to angle response. In terms of linear response, the calibration results of both A and B were satisfactory. Conclusion Both A and B can be used for normal calibration of H_p(3) in a standard X-ray RQR radiation field. However, in actual monitoring, attention should be paid to the energy and angle response values of TLDs.