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Objective To investigate the regulative effect of hemichannels protein Pannexin-1 on P2X7 receptor activation and caspase-1 mediated inflammatory response in the lungs of mice with lung injury. Methods Sixty male C57BL/6 mice were randomly divided into five groups with 12 mice in each group: sham operation group (Sham group), mechanical ventilation (MV) group, MV + low dose lipopolysaccharide (LPS) group (MLL group), MV + medium and high dose LPS group (MML group) and MV + high dose LPS group (MHL group). A "two-hit" lung injury model was reproduced by MV with high tidal volume combined with LPS injection in airway. All the mice underwent tracheotomy and intubation. After operation, the mice in Sham group were maintained spontaneous breathing, and those in other four groups were put on small animal ventilators to give MV with a large tidal volume of 28 mL/kg. After stable respiration in mice, those in the Sham group and MV group were injected 8 mL/kg of normal saline (NS) into the airway, and those in MLL, MML and MHL groups were given 2, 5 and 8 mg/kg of LPS respectively (diluted with NS into 8 mL/kg). After 4 hours on MV, the mice were sacrificed, and bronchoalveolar lavage fluid (BALF) was extracted to determine intracellular and extracellular ATP concentration. Lung tissue was harvested and water containing ratio of lungs was measured. The degree of lung pathological damage was observed after hematoxylin-eosin (HE) staining, and lung injury score was calculated. The expression of Pannexin-1 protein in lung tissue was calculated with immunohistochemistry. Western Blot and fluorescence quantitative reverse transcription-polymerase chain reaction (RT-qPCR) were used to detect the protein and mRNA expressions of Pannexin-1, P2X7 receptor, caspase-1 and interleukin-1β (IL-1β). Results There was no obvious pathological change in lung tissue in Sham group, intracellular ATP concentration was higher than extracellular ATP concentration, water content in lung tissue was lower, Pannexin-1 expression was low in lung tissue by immunohistochemical staining, and Pannexin-1, P2X7 receptor, caspase-1 and IL-1β were only expressed in micro-protein and mRNA in lung tissue. Compared with the Sham group, the alveolar lesions and hemorrhages in the MV group were not obvious, and lung injury score was slightly increased. There was no significant fluctuation between intracellular ATP concentration and extracellular ATP concentration. The water content in lung tissue was increased significantly, while the expressions of Pannexin-1, P2X7 receptor, caspase-1 and IL-1β in lung tissue were increased slightly. After LPS intervention, progressively increased lung exudation, ruptured alveoli, dilated capillaries, and inflammatory cells were found, and lung injury score was increased without significant difference among the three LPS doses groups. With the increase in LPS dosage, the concentration of extracellular ATP in BALF was increased, the concentration of intracellular ATP was decreased, the water containing ratio of lung tissue was increased gradually, and the protein and mRNA expressions of Pannexin-1, P2X7 receptor, caspase-1 and IL-1β in lung tissue were increased gradually in a dose-dependent manner. The parameters in MHL group showed significant differences as compared with those in MV group [lung injury score: 8.25±0.45 vs. 3.50±0.52; intracellular ATP concentration (μmol/L): 198.76±150.77 vs. 896.69±281.11, extracellular ATP concentration (μmol/L): 336.57±90.28 vs. 141.52±42.22; lung water containing rate: (6.37±0.11)% vs. (5.05±0.14)%; Pannexin-1 protein (gray value): 3.20±0.70 vs. 1.54±0.76, Pannexin-1 mRNA (2-ΔΔCT): 7.86±0.86 vs. 2.47±0.92; P2X7 receptor protein (gray value): 3.18±0.88 vs. 1.80±0.72, P2X7 receptor mRNA (2-ΔΔCT): 7.17±0.96 vs. 2.31±0.45; caspase-1 protein (gray value): 3.00±0.45 vs. 0.93±0.51, caspase-1 mRNA (2-ΔΔCT): 4.39±0.91 vs. 2.74±0.41; IL-1β protein (gray value): 2.54±1.08 vs. 1.16±0.53, IL-1β mRNA (2-ΔΔCT): 132.34±41.48 vs. 19.67±8.67; all P < 0.05]. Conclusion Pannexin-1 may be involved in LPS and MV induced lung injury, which may be regulated by intracellular release of ATP to the extracellular site and binding to P2X7 receptor on the cell surface, thereby regulating active caspase-1 production and release, involving in the production of IL-1β and other inflammatory factors eventually which leads to the occurrence and development of lung injury.
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Objective To analyze blood stream infections(BSI)in ICU patients,to explore the bacterial spectrum characteristics and time distribu?tion,so as to provide a reference for the clinical use of antibiotics. Methods A retrospective analysis was carried out. A total of 1 330 patients admit?ted in our hospital intensive care unit(ICU)from January 2012 to March 2013(15 months)were selected for the study,the occurrence rate of blood stream infections,the bacteria spectrum of it and the bacteria spectrum distribution in different period of time(admitted in ICU for the first week,sec?ond week and later)were analyzed. The subjects were divided into 2 groups(CVC cases and non?CVC cases)depended on CVC indwelling or not. Results There were 971 cases with central venous catheter(CVC),the occurrence of bloodstream infection were 96 cases,the infection rate was 9.89%,including 359 non?CVC cases and 12 blood stream infection cases. The infection rate was 3.34%,and the total blood infection rate was 8.12%. A total of 157 strains of pathogen were isolated,among which 16 strains were isolated from non?CVC cases. Infection of gram?negative bacilli, gram?positive cocci and fungi were 56.7%,32.5%and 10.8%,respectively. Staphylococcus(16.6%),Bauman acinetobacter(15.9%),Enterococ?cus(14.6%),Pseudomonasaeruginosa(10.2%)and Klebsiella(10.2%)were the most common bacteria. For the distribution of time,in non?CVC cases gram?negative bacilli were more than other bacilli in the first and second week(3 vs 1,4 vs 1)in ICU,more gram?positive cocci( 5 vs 2) were isolated after two weeks,no fungi were detected;in CVC cases,gram negative bacilli were in a dominant position all the time(the number of gram negative bacilli,gram positive bacteria and fungi were 31 cases,24 cases and 3 cases in the first week respectively,23 cases,12 cases,11 cas?es in the second week,26 cases,8 cases and 3 cases after the second week),the proportion of each species in the first week were 53.4%,41.4%and 5.2%,respectively,50%,26.1%and 23.9%in the second week,70.3%,21.6%and 8.1%after the second week . The highest fungemia was found in the second week. Conclusion For the 1st 2 weeks in ICU,the most common bacilli was gram negative bacilli with BSI. After 2 weeks admitted in the ICU,it was mainly gram negative bacilli in CVC cases,and mainly gram positive cocci in non?CVC cases. In the 2nd week,fungemia had the? highest probability in CVC cases,and it appeared low possibility in non?CVC cases. Non?CVC cases have a lower risk of blood stream infection.
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Objective To investigate the effect of cholecystokinin (CCK) on rat intestinal interstitial cells of Cajal (ICC) and the small intestinal motor function during experimentally induced acute pancreatitis (AP).Methods 20 male SD rats were divided with a random number table into model group (n =15) and control group (n =5):the 15 rats in the model group were further divided into 3 subgroups,i.e.0,20,40 μg/kg CCK sub-groups.L-omithine was intraperitoneally injected to induce pancreatitis,while normal saline was injected in the control group.24 hours after establishing AP model,CCK was administered intraperitoneally every day for 5 consecutive days.The rats were sacrificed by cervical dislocation 30 minutes after gavage with 2 ml ink.Length of the small intestine which have become black and that of the whole small intestine were measured.Intestinal sections were studied by confocal microscopy after immunofluorescence with specific antibodies.The number of positive cells was compared among the groups.Results In the control group,the number of ICC in the myenteric plexus and deep muscular plexus was (21.16 ± 3.19) /field and (17.20 ± 1.75) /field,respectively;in the AP group was (5.00 ± 1.05) /field and (4.52 ± 1.05) /field,respectively;in the AP + CCK20 group was (10.76 ± 2.09) /field and (9.84 ± 1.68) /field,respectively;in the AP + CCK40 group was (13.72 ±2.97) /field and (12.40 ± 1.81) /field,respectively;the number of ICC in the AP group were significantly lower than those in the control group (P =0.001).The ratio of transmission distance in small intestine in the control,AP,AP + CCK20,and AP + CCK40 groups was 0.71 ± 0.05,0.54 ± 0.07,0.68 ± 0.10,and 0.74 ± 0.07,respectively.The intestinal motor function was reduced in the AP group,demonstrated by shortened transmission distance,which was improved after the administration of CCK (P =0.003).Conclusions Pancreatitis can cause ICC damage,reduce ICC number,destroy ICC network and the small intestinal motor function.CCK can mitigate the damage to ICC and protect the integrity of ICC network,thereby improving intestinal motor function.
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Objective To analyze pathogen spectrum of intra-abdominal infection in patients in an intensive care unit (ICU).Methods Intra-abdominal infections and pathogens of 1 330 patients who admitted to ICU from January 2012 to March 2013 were analyzed retrospectively.Results 283 patients developed intra-abdominal infection,incidence of infection was 21.28%;133 (47.00%)patients were detected 186 isolates of pathogens,the proportion of gram-negative bacilli, gram-positive cocci,and fungi were 68.82%(n=128),28.49%(n= 53),and 2.69%(n=5)respectively.The major gram-negative bacilli were Escherichia coli ,Acinetobacter baumannii ,and Klebsiella pneumoniae ,the major gram-positive cocci were Enterococcus faecium,Staphylococcus aureus ,and Enterococcus faecalis .The detection rates of pathogens after patients stayed in ICU for ≤2,3-7,8-14,and>14 days were 70.43%(n=131),12.90%(n=24),10.22%(n=19), and 6.45%(n =12)respectively;Escherichia coli (n =51 )and Enterococcus faecium (n =21 )were the main pathogens when patients stayed in ICU for ≤48 hours,Acinetobacter baumannii was the main pathogen when patients stayed in ICU for >48 hours.Most intra-abdominal infection occurred after intestinal tract(53.23%)and hepatobiliary system operation (24.19%).39 (29.32%)patients isolated at least two kinds of pathogens,29 of whom isolated 2 kinds of pathogens. Conclusion Most pathogens of intra-abdominal infection in ICU patients are detected following intestinal tract and hepato-biliary operation,and mixed pathogens are common,predominantly gram-negative bacilli.Escherichia coli and Enterococcus faecium are the main pathogens when patients stayed in ICU for ≤48 hours,opportunistic pathogens are the main patho-gens when patients stay in ICU for >48 hours.
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Objective To retrospectively analyze bacterial time distribution of ICU?acquired infections in Shengjing Hospital of China Medical Uni?versity,so as to provide reference for the early antibiotic use for ICU?acquired infections. Methods A total of 1 330 cases in ICU from Jan. 2012 to Mar. 2013 were collected,the bacterial culture was positive in 254 cases. A total of 1 110 strains were collected from all the patients. Excluding 288 strains which were detected within 48 hours of patients′admission in ICU and 222 strains which were repeatedly detected in the same patients,600 strains were finally enrolled in the statistical analysis. Results The rate of ICU?acquired infections was 19.1%. Postoperative infections accounted for 74.3%,most of which occurred after neurosurgeries,and abdominal,orthopedic operations. Pulmonary infection ranked the first in ICU?acquired infections,accounting for 40.3%,followed by blood stream infection(25.3%),postoperative drainage infection(14.2%)and urinary tract infection (7.3%). The rate of pathogenic bacteria detection was the highest in the first week of patients′admission in ICU,and was getting lower as time went by. Strains detected in ICU mainly were Bauman Acinetobacter,Pseudomonas aeruginosa,Klebsiella pneumonia and Enterococcus faecium,most of strains resulting in infections were gram negative bacilli throughout the time. In addition,the infection rate of fungi was increased at 2 weeks of pa?tients′admission in ICU. Conclusion The treatment of ICU?acquired infections should be targeted at gram negative bacilli. The detection rate of op?portunistic pathogens gradually increased with prolonged stay in ICU,most of which are non?fermentative bacteria. Fungi infections are most likely to occur at 2 weeks of patients′admission in ICU.
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Objective To investigate the effect of dexmedetomidine (Dex) on postoperative sufentanil consumption in patient-controlled intravenous analgesia (PCIA).Methods Eighty patients (ASA Ⅰ or Ⅱ) undergoing abdominal hysterectomy and general anesthesia were divided into 2 groups with 40 cases each by random digits table.Patients in experiment group were received Dex 0.6 μg/kg (in 10 minutes).Patients in control group were recieved normal saline respectively by pumped infusion one hour before the operation finishing.All patients received a standadized sufentanil PCIA one hour before the operation finishing,sufentanil 2 μg/kg in 100 ml saline with tropisetron 5 mg,the loading dose was 4 ml,the backgroud dose was 1 ml/h,the controlled dose was 1 ml/h,the lock time was 10 minutes.The scores of VAS and RSS were recorded 1,2,6,12 and 24 hours after PCIA,and the incidence rate of the nausea,vomiting and shivering were recorded too for 24 hours.Results There was no statistical significance between the two groups in the scores of VAS and RSS after PCIA.The sufentanil consumption 1,2,6,12 and 24 hours after PCIA in experiment group [(4.5 ± 0.6),(7.4 ± 1.2),(14.2 ± 2.2),(25.4 ± 3.1),(40.1 ± 5.3) μg] was less than that in control group [(8.9 ± 0.9),(13.8 ± 2.9),(27.2 ± 4.1),(40.2 ± 5.2),(62.3 ± 7.1) μg] (P ＜0.05).The incidence of postoperative nausea,vomiting and shivering in experiment group [7.5％(3/40),2.5％(1/40),2.5％(1/40)] was less than that in control group [15.0％(6/40),7.5％(3/40),10.0％(4/40)](P ＜ 0.05).Conclusion The patients receive Dex 0.6 μg/kg one hour before the operation finishing,need less consumption of sufentanil and occur less postoperative nausea,vomiting and shivering.
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Objective To evaluate the efficacy of serum PCT level in deciding the development and progno-sis of sepsis and its conrrelation with APACHE Ⅱ scoring.Methods 56 patients of sepsis accepted intensive care treatment and were all given APACHE Ⅱ scoring within the first 24 h after admission to ICU.The PCT level at dif-ferent time(1 d,3 d,5 d-7 d,10 d after admission)was detected.All these patients were divided into survival group and death group based on the 28-day fatality.Results The PCT level declined gradually with the treatment and it decreased obviously from the third day in comparison with the original level before admission [survival group/death group:(2.98±0.48)μg/L/(4.98±0.66)μg/L vs(4.04±0.50)μg/L/(6.02±0.50)μg/L](P<O.05).The PCT level in survival group declined quickly with the patients'condition improved and almost decreased to the normal level in the 10 day[0.48 ±0.18)μg/L],while the PCT in the death group was still in a higher level than normal even though it showed a tendency to decrease[(4.04±0.45)μg/L].The APACHE Ⅱ scores in death group was obviously higher than the survival group(death group/survival group:25.86±8.73/12.07±6.20,P<0·05).The coefficient of correlation between PCT and APACHE Ⅱ scoring was 0.656(P<0.05).Conclusion PCT,a single serology index,is characterized with conveniently and quick-which is strongly correlated with APACHE Ⅱscoring.