Objective To observe the effect of lung protective ventilation strategy on oxygenation and pulmonary inflammatory response in dogs with severe smoke inhalation injury.Methods Twelve local healthy male dogs were selected and anesthetized underwent endotracheal intubation, the time controlled smoke was applied to replicate the model of severe smoke inhalation injury, and they were divided into two groups according to the random number table: conventional ventilation group (CV group) and protective ventilation group (PV group), each receiving corresponding ventilation mode for 8 hours respectively. The blood gas analyses were detected before injury, immediately after injury and at ventilation for 2, 4, 6, 8 hours. The contents of tumor necrosis factor-α (TNF-α), interleukin-10 (IL-10) in serum were detected by the enzyme-linked immunosorbent assay (ELISA) at each time point. Animals were killed after 8-hour ventilation, and different parts of the lung tissues were obtained for pathological examinations of lung tissues and evaluation of injury scores. The levels of inflammatory factors as TNF-α and IL-10 in lung homogenates were measured by ELISA.Results The arterial partial pressure (PaO2) levels in CV and PV groups were significantly decreased after injury compared with those before injury [mmHg (1 mmHg = 0.133 kPa): 57±19 vs. 128±31, 58±15 vs. 126±22, bothP < 0.01]. Compared with those before injury, the pH values and arterial carbon dioxide partial pressure (PaCO2) levels after injury in two groups had no statistically significant differences at each time point (bothP > 0.05). At 6 hours ventilation, PaO2 level in PV group was significantly higher than that in CV group (mmHg: 121±11 vs. 105±11,P < 0.05). The comparisons of PaO2 levels, pH values and PaCO2 levels at 2, 4, 8 hours of ventilation between the two groups showed no statistically significant differences (allP > 0.05). The histopathological changes revealed that there were alveolar tissue edema and inflammatory cells infiltration in both groups, the degree of severity in CV group was more prominent and its pulmonary tissue injury score was higher than that in PV group (3.68±0.22 vs. 3.27±0.35, P < 0.05). The serum levels of TNF-α and IL-10 after smoke injury were significantly increased in CV and PV groups [TNF-α (μg/L): 4.32±1.13 vs. 0.35±0.11, 4.51±2.02 vs. 0.41±0.08; IL-10 (ng/L): 16.73±2.31 vs. 4.27±0.56, 18.39±3.15 vs. 4.03±1.07, allP < 0.01]. Compared with CV group, the levels of TNF-α were significantly lower at 6 hours and 8 hours of ventilation [6 hours (μg/L): 2.62±0.34 vs. 3.65±1.08, 8 hours (μg/L): 3.02±0.31 vs. 4.21±1.27, bothP < 0.05), while the contents of IL-10 were obviously increased in PV group [6 hours (ng/L): 21.07±2.95 vs. 16.11±3.02, 8 hours (ng/L): 23.57±2.69 vs. 18.28±3.21, bothP < 0.05]. The content of TNF-α in lung homogenate in CV group was significantly higher than that in PV group (μg/L: 5.85±2.57 vs. 3.08±1.17,P < 0.05), but the content of IL-10 in lung homogenate of CV group was markedly lower than that in CP group (ng/L: 19.64±3.16 vs. 24.05±2.09, P < 0.05).Conclusion Lung protective ventilation strategy can effectively improve oxygenation and pulmonary inflammatory response in dogs with severe smoke inhalation injury, thus the lung injury is alleviated and the strategy has protective effect on damaged lung tissues.

Objective To discuss the effects of bone marrow-derived mesenchymal stem cells (MSCs) on vascular endothelial growth factor (VEGF) in lung tissue and in plasma, and extra-vascular lung water at the early stage of smog inhalation injury. Method The rabbit model of smog inhalation injury was established by using home-made smog generator, and the rabbit models were randomly(random number) divided into control group (group S, n = 32) and MSCs treatment group (group M, n = 32). Ten mL phosphate-buffered saline (PBS) was injected into ear marginal vein immediately after injury in rabbits of group S. The third generation of MSCs 1/10/10 mL PBS was injected into ear marginal vein immediately after injury in rabbits of group M. The levels of VEGF in peripheral blood and lung tissue were neasured 0 h,2 h,4 h and 6 hours after injection respectively, and analyzed. The right lung of rabbits was taken out to measure and calculate lung water mass fraction after experiment.Results In lung tissue, the levels of VEGF decreased gradually in group S (P ＜ 0.05), and though the levels of VEGF in lung tissue appeared with significant decreasing trend in group M (P ＜ 0.05), they were still higher than those of group S at corresponding intervals ( P ＜ 0.05). In peripheral blood, the levels of VEGF increased gradually in group S ( P ＜ 0. 05), and the levels of VEGF in group M appeared with markedly increasing trend ( P ＜ 0.05),but they were lower significantly than those in group S at corresponding intervals ( P ＜ 0.05). Conclusions MSCs engraftment to the rabbits with smog inhalation injury could increase VEGF in lung tissue, decrease VEGF in plasma and reduce extra-vascular lung water, showing protective effect on smog inhalation injury to a certain extent.

OBJECTIVETo observe and compare the effects of two kinds of lung recruitment maneuvers, namely sustained inflation (SI) and incremental positive end-expiratory pressure (PEEP) (IP) on oxygenation, respiratory mechanics, and hemodynamics of dogs with severe smoke inhalation injury.

METHODSAfter being treated with conventional mechanical ventilation, 12 dogs were inflicted with severe smoke inhalation injury. They were divided into group SI and group IP according to the random number table, with 6 dogs in each group. Dogs in group SI were subjected to continuous positive airway pressure ventilation, with inspiratory pressure of 25 cmH2O (1 cmH2o = 0. 098 kPa), and it was sustained for 20 s. PEEP level in group IP was gradually increased by 5 cmH2O every 5 min up to 25 cmH2O, and then it was decreased by 5 cmH2O every 5 min until reaching 2-3 cmH2O. Then the previous ventilation mode was resumed in both groups for 8 hours. Blood gas analysis (pH value, PaO2, and PaCO2), oxygenation index (OI), respiratory mechanics parameters [peak inspiratory pressure (PIP), mean airway pressure, and dynamic lung compliance], and hemodynamic parameters [heart rate, mean arterial pressure (MAP), pulmonary arterial pressure (PAP), and cardiac output (CO)] were recorded or calculated before injury, immediately after injury, and at post ventilation hour (PVH) 2, 4, 6, 8. Data were processed with analysis of variance of repeated measurement and LSD-t test.

RESULTS(1) At PVH 6 and 8, pH values of dogs in group SI were significantly lower than those in group IP (with t values respectively 2. 431 and 2. 261, P values below 0.05); PaO2 levels in group SI [(87 ± 24), (78 ± 14) mmHg, 1 mmHg =0. 133 kPa] were lower than those in group IP [ (114 ± 18) , (111 ± 17) mmHg, with t values respectively 2. 249 and 3.671, P <0.05 or P <0.01]; OI values in group SI were significantly higher than those in group IP (with t values respectively 2.363 and 5.010, P <0.05 or P <0.01). No significant differences were observed in PaCO2 level within each group or between the two groups (with t values from 0. 119 to 1. 042, P values above 0.05). Compared with those observed immediately after injury, the pH values were significantly lowered (except for dogs in group IP at PVH 6 and 8, with t values from 2.292 to 3.222, P <0.05 or P <0.01), PaO2 levels were significantly elevated (with t values from 4. 443 to 6.315, P <0.05 or P <0.01), and OI values were significantly lowered (with t values from 2.773 to 9.789, P <0.05 orP <0.01) in both groups at all the treatment time points. (2) The PIP level at each time point showed no significant differences between two groups (with t values from 0. 399 to 1. 167, P values above 0. 05). At PVH 4 and 8, the mean airway .pressure values of dogs in group SI were significantly higher than those in group IP (with t values respectively 1.926 and 1. 190, P values below 0.05). At PVH 4, 6, and 8, the dynamic lung compliance levels of dogs in group SI [(9.5 ± 1.9), (12.8 ± 2. 1), (13. 1 ± 1.8) mL/cmH2O] were significantly lower than those in group IP [(11.6 ± 1.2), (15.4 ± 1.8), (14.9 ± 0.8) mL/cmH2O], with t values respectively 2. 289, 2. 303, 2. 238, P values below 0.05. Compared with those observed immediately after injury, PIP and the mean airway pressure values of dogs in two groups were significantly lowered at each treatment time point (with t values from 2. 271 to 7. 436, P <0. 05 or P < 0.01); the dynamic lung compliance levels were significantly elevated in both groups at PVH 6 and 8 (with t values from 2. 207 to 4. 195, P < 0.05 or P <0.01). (3) Heart rate, MAP, and PAP levels at each time point between two groups showed no significant differences (with t values from 0. 001 to 1. 170, P values above 0. 05). At PVH 4, 6, and 8, CO levels in group IP [(0. 6 + 0. 3), (0. 6 + 0. 4), (0. 5 + 0. 7) L/min] were significantly lower than those in group SI [(1.5 0.7), (1.8 + 1.1), (1.6 +0.9) L/min], with t values respectively 3. 028, 2.511, 2.363, P values below 0.05. Compared with that observed immediately after injury, CO level in group IP was significantly lowered at PVH 4, 6, or 8 (with t values respectively 2. 363, 2. 302, 2. 254, P values below 0. 05).

CONCLUSIONSBoth lung recruitment maneuvers can effectively improve oxygenation and lung compliance of dogs with severe smoke inhalation injury. IP is more effective in improving lung compliance, while SI shows less impact on the hemodynamic parameters.

Animals ; Blood Gas Analysis ; veterinary ; Dogs ; Hemodynamics ; Lung Compliance ; physiology ; Oxygen ; blood ; Oxygen Consumption ; physiology ; Positive-Pressure Respiration ; methods ; Respiration, Artificial ; Respiratory Mechanics ; Severity of Illness Index ; Smoke ; adverse effects ; Smoke Inhalation Injury ; physiopathology ; therapy

OBJECTIVETo study the drug resistance of Acinetobacter baumannii (AB) producing VIM-2-type metallo-β-lactamase (MBL) isolated from burn patients of our ward against carbapenem antibiotics and its homology.

METHODSA total of 400 strains of AB (identified) were isolated from sputum, urine, blood, pus, and wound drainage. of burn patients hospitalized in our ward from September 2011 to March 2014. Drug resistance of the 400 strains of AB to 15 antibiotics, including compound sulfamothoxazole, aztreonam, etc. , was tested using the automatic microorganism identifying and drug sensitivity analyzer. Among the carbapenems-resistant AB isolates, modified Hodge test was applied to screen carbapenemase-producing strains. The carbapenemase genes of the carbapenemase-producing strains, and the mobile genetic elements class I-integron (Intl1) gene and conserved sequence (CS) of carbapenemase-producing strains carrying blaVIM-2 gene were determined with PCR and DNA sequencing. For carbapenemase-producing strains carrying blaVIM-2 gene, synergism test with imipenem-ethylene diamine tetraacetic acid (EDTA) and enhancement test with imipenem-EDTA and ceftazidime-EDTA were used to verify the MBL-producing status. Drug resistance of the VIM-2-type MBL-producing AB strains was analyzed. For VIM-2-type MBL-producing AB strains, plasmid conjugation experiment was used to explore the transfer of plasmid; outer membrane protein (OMP) CarO gene was detected by PCR. For VIM-2-type MBL-producing AB strains carrying CarO gene, the protein content of CarO was analyzed with sodium dodecyl sulfate polyacrylamide gel electro- phoresis. The repetitive consensus sequence of Enterobacteriaceae genome PCR (ERIC-PCR) was carried out for gene typing of VIM-2-type MBL-producing AB strains to analyze their homology.

RESULTS(1) The resistant rates of the 400 strains of AB against levofloxacin and compound sulfamethoxazole were low. A total of 381 carbapenems-resistant AB strains were screened, including 240 carbepenemase-producing strains. (2) Out of the 240 carbepenemase-producing strains, 18 strains were found to harbor the blaVIM-2 gene, accounting for 7.5%; 133 strains carried the blaTEM-1 gene, accounting for 55.42%; 195 strains carried the blaOXA23 gene, accounting for 81.25%; 188 strains carried the bla(armA) gene, accounting for 78.33%. (3) Eighteen carbepenemase-producing strains which carried the bla(VIM-2) gene were found to carry the Intl1 gene, showing the Intl1-VIM linkage. Simultaneously, Intl1 variable area CS showed diversity. (4) Eighteen carbepenemase-producing strains which carried the blaVIM-2 gene were verified to produce MBL. The resistant rates of the 18 strains of AB against compound sulfamethoxazole were the lowest, followed by levofloxacin and cefoperazone/sulbactam, and those against the other antibiotics were above 60.00%. (5) Through multiple joint tests, plasmid conjugation experiment positive transfer strain was not found in 18 VIM-2-type MBL-producing AB strains. (6) Nine out of the 18 VIM-2-type MBL-producing AB strains were found to carry CarO gene. The OMP CarO of VIM-2-type MBL-producing AB strains carrying CarO gene was lost or lowered in the protein content. (7) The 18 VIM-2-type MBL-producing AB strains were classified into 6 genotypes by the ERIC-PCR. There were respectively 6, 4, 3, and 1 stain (s) in genotypes A, B, C, and F, and there were 2 strains in genotypes D and E respectively.

CONCLUSIONSThe resistance mechanism of AB against carbapenems is mainly mediated by blaTEM-1, blaOXA-23, and bla(arma); meanwhile, VIM-2-type MBL-producing and lack or change in OMP CarO are attributable to carbapenems resistance of clinically isolated AB from burn wards, and the Intl1 gene may take a part in blaVIM-2 gene transmission.

Acinetobacter baumannii ; drug effects ; enzymology ; genetics ; isolation & purification ; Anti-Bacterial Agents ; pharmacology ; therapeutic use ; Bacterial Proteins ; Burns ; drug therapy ; microbiology ; Carbapenems ; pharmacology ; Drug Resistance, Bacterial ; Genes, Bacterial ; Humans ; Imipenem ; pharmacology ; Microbial Sensitivity Tests ; Sulbactam ; pharmacology ; beta-Lactamases ; genetics

OBJECTIVETo explore the preventive effect of lanthanum chloride on enteral bacterial translocation in scalded rats.

METHODSNinety Sprague-Dawley (SD) rats were employed in the study and randomly divided into three groups, i.e. normal control (A), burn control (B) and treatment (C) groups. Plasmid PUC19 labelled by JM109 was transfected to Escherichia coli (E. coli), so that restriction endonuclease finger - print image spectrum analysis could be applied to the tracing and quantification of the translocation of E. coli from intestine to mesenteric lymph nodes (MLNs) and blood. The intestinal tissue contents of endotoxin (ET), nitric oxide (NO), nitric oxide synthase (NOS), malondialdehyde (MDA) and superoxide dismutase (SOD) were determined.

RESULTSIt was identified that the bacteria in MLNs and blood exhibited the same gene map with those from gastric gavage in B and C groups. But the bacterial quantity in MLNs in C group on 3 postburn day (PBD) was much lower than that in B group (P < 0.05). The intestinal MDA content in C group on 1 and 3 PBDs was obviously higher than that in B group (P < 0.05).

CONCLUSIONBacteria (E. coli) could be translocated from gut to MLNs and blood, which could be evidently alleviated by lanthanum chloride by means of its bactericidal property, inhibition of NOS activity, so that NO production decreased, and its ability to increase SOD activity leading to less production of MDA.

Animals ; Burns ; drug therapy ; microbiology ; Endotoxins ; blood ; metabolism ; Escherichia coli ; drug effects ; growth & development ; metabolism ; Escherichia coli Infections ; blood ; microbiology ; prevention & control ; Female ; Intestines ; drug effects ; metabolism ; microbiology ; Lanthanum ; pharmacology ; Lymph Nodes ; drug effects ; microbiology ; Male ; Malondialdehyde ; blood ; metabolism ; Mesentery ; drug effects ; microbiology ; Nitric Oxide ; blood ; metabolism ; Nitric Oxide Synthase ; blood ; metabolism ; Rats ; Rats, Sprague-Dawley ; Superoxide Dismutase ; blood ; metabolism

Objective To observe image quality and impact factors for single heart beat coronary CTA (CCTA) with prospectively ECG-triggered CT in patients with low,high heart rate (HR) and arrhythmia.Methods Single heart-beat CCTA was performed for 208 patients with prospectively ECG-triggered 256-slice wide-detector CT without drug control of HR.The patients were divided into 3 groups,including low HR group (n=87,HR≤70 bpm),high HR group (n=38,HR＞70 bpm) and arrhythmia group (n=83,HR variation ＞ 10 bpm in 5 cardiac cycles).The normal reconstruction phase was set as 75％ or 45％ in R-R interval,while the optimal phase was that with the least motion artifacts.Univariate linear regression was used to analyze the impact factors for image quality.Results Compared with images of normal phase,the optimal phase of 105 patients (105/208,50.48％) was altered.In the optimal images,imaging quality,SNR and CNR were not significantly different among 3 groups (all P＞0.05).Image quality was significantly influenced by reconstruction phase and artifact type (both P＜0.001).Conclusion During prospectively ECG-triggered 256-slice wide-detector CCTA without drug control of HR,high HR and arrhythmia are not significant impact factors of image quality.