AIM: To observe the level of vascular endothelial growth factor (VEGF) secreted by monocytes cultured with electrical burn serum, and to explore the effect of VEGF on monocyte-endothelial cell adhesion.METH-ODS:The electrical burn serum of the rat was prepared.The normal serum from the rats without treating electric current was also collected for control.The contents of VEGF and its soluble receptor sFlt-1 in electrical burn group were determined by double-antibody sandwich ELISA.THP-1 cells were randomly divided into normal serum group and electrical burn serum group.The contents of VEGF and sFlt-1 in the culture supernatants were measured by double-antibody sandwich ELISA. THP-1 cells were also randomly divided into another 4 groups:normal serum group, electrical burn serum group, normal serum +inhibitor group and electrical burn serum +inhibitor group.THP-1 cells, which were incubated with the serum for 3 h and 6 h, were labeled with calcein-AM and then were added into the well with monolayer of endothelial cell line EA.hy926 to detect monocyte-endothelial cell adhesion.RESULTS:The levels of serum VEGF of the rats with electrical burns were significantly increased, the levels of serum sFlt-1 were significantly decreased as compared with the controls. The levels of VEGF secreted by THP-1 cells cultured with electrical burn serum were significantly increased, the levels of sFlt-1 were decreased correspondingly.Electrical burn serum enhanced monocyte-endothelial cell adhesion, sFlt-1 inhibi-ted the adhesion between monocytes and endothelial cells.CONCLUSION:The monocytes exposed to the electrical burn serum secrete VEGF, which enhance the adhesion between monocytes and endothelial cells.Blockage of VEGF activity may effectively inhibit monocyte-endothelial cell adhesion.

AIM: According to the functions of Lumbago Suppositiory (Radix Aconiti, Ramulus Cinnamoni, Moschus, etc) (LS), we observed the connection among anti-inflammatory, analgesia and promoting blood circulation and removing blood stasis. METHODS: Rat chemical radiculoneuritis model was set up to observe influence of LS on inflammation, pain threshold, gait and PLA_2 in serum, content of adrencorticoids and adrenalin. Cold accumulation type of blood stasis symptom model was built up to observe the influence of LS on blood rheological property, effect of LS on mouse's micro-circulation in ears was also observed. RESULTS: Lumbago Suppository inhibited inflammation of rat radiculoneuritis model obviously and had recovery of functions for gait and pain threshold. And it also could reduce the content of PLA_2 in serum and raise the level of adrenocorticoids and adrenalin. It also obviously changed "blood stasis symptom”, rat blood rheological property and auricle micro-circulation of mouse. CONCLUSION: Lumbago Suppository's functions of anti-inflammatory and analgesia have strong relation ships with promoting blood circulation and removing blood stasis.

Objective: To explore the differential expression of microRNAs in the serum among patients with electrical burn or thermal burn and healthy persons and to explore the significance. Methods: In this study we included three patients with electrical burn and three patients with thermal burn, conforming to the inclusion criteria and hospitalized in our burn ward from June to August 2015, and three healthy adult volunteers. Their serum samples were separated from whole blood and divided into electrical burn group, thermal burn group, and normal control group. Total RNA was extracted from their serum samples using Trizol method. The differentially expressed microRNAs (with differential ratio larger than or equal to 2.000, less than or equal to 0.500) among the three groups were screened by microRNA chip technique. Then cluster and Venn diagram analysis of the differentially expressed microRNAs were performed. Enrichment analysis of Kyoto encyclopedia of genes and genomes (KEGG) signaling pathway was performed on the distinctly changed microRNAs (with differential ratio larger than or equal to 5.000, less than or equal to 0.500). Results: There were 220 differentially expressed microRNAs among serum of the three groups. MicroRNA expression profiles in serum of electrical burn and thermal burn groups were different from that in serum of normal control group. Compared with those in serum of normal control group, the expressions of 59 microRNAs changed more than 2.000 times in serum of electrical burn group, with 50 up-regulated microRNAs and 9 down-regulated microRNAs; the expressions of 40 microRNAs changed more than 2.000 times in serum of thermal burn group, with 21 up-regulated microRNAs and 19 down-regulated microRNAs. Compared with those in serum of thermal burn group, the expressions of 167 microRNAs changed more than 2.000 times in serum of electrical burn group. There were 17 exclusively expressed microRNAs in serum of thermal burn group and 26 exclusively expressed microRNAs in serum of electrical burn group, compared with those in serum of normal control group. Enrichment analysis of KEGG signaling pathway showed that compared with those in serum of normal control group, microRNAs which changed distinctly in serum of electrical burn group took part in the insulin secretion signaling pathway, arrhythmogenic right ventricular cardiomyopathy signaling pathway, hypertrophic cardiomyopathy signaling pathway, glutamatergic synapse signaling pathway, calcium signaling pathway, cyclic adenosine monophosphate signaling pathway, glycerophospholipid metabolism, pyrimidine metabolism, serotonergic synapse signaling pathway, etc, while microRNAs which changed distinctly in serum of thermal burn group took part in the tumor transcription misregulation signaling pathway, proteoglycans in tumor signaling pathway, microRNAs in tumor signaling pathway, long-term potentiation signaling pathway, citrate cycle signaling pathway, tumor necrosis factor signaling pathway, focal adhesion signaling pathway, endocytosis signaling pathway, insulin secretion signaling pathway, p53 signaling pathway, and estrogen signaling pathway, etc. Conclusions MicroRNA expression profiles in serum of electrical and thermal burn are different from that in serum of healthy adult. The signaling pathways enriched with target genes which are regulated by the differentially expressed microRNAs are related to the pathological changes and clinical manifestations after electrical or thermal burn.

Objective: To explore differential expression of microRNAs in serum of patients with severe burn and analysis of the signaling pathway at early stage. Methods: In this study, we included three healthy adult volunteers and three patients with severe burn, conforming to the inclusion criteria and hospitalized in Tongren Hospital of Wuhan University & Wuhan Third Hospital in July 2015. Venous whole blood of 6 mL of each burn patient and healthy volunteer was collected at 24 to 48 h post injury of burn patients. The whole blood was divided into burn group and healthy control group. Whole blood of 2 mL of each one was used to determine white blood cell count and neutrophile granulocyte content. Serum was separated from the other whole blood of 4 mL of each one. Half of serum was used to determine content of blood glucose, total protein, and albumin; another half of serum was used to extract total RNA with Trizol method. The differentially expressed microRNA, with differential expression ratio larger than or equal to 1.500 between 2 groups, were screened by microRNA chip technique. Then cluster analysis and functional enrichment analysis of Kyoto encyclopedia of genes and genomes (KEGG) signaling pathway were performed on the differentially expressed microRNAs. Data were processed with t test. Results: (1) Content of white blood cell count, neutrophile granulocyte of whole blood, and blood glucose of serum of patients in burn group was obviously higher than that in healthy control group (with t values from 4.27 to 7.83, P<0.05 or P<0.01). Content of total protein and albumin of serum of patients in burn group was significantly lower than that in healthy control group (with t values respectively -12.80 and -12.36, P values below 0.01). (2)Compared with those in serum of healthy control group, differential expression ratios of 48 microRNAs in serum of burn group were larger than 1.500, with 22 up-regulated microRNAs and 26 down-regulated microRNAs. MicroRNA expression profile in serum of burn group was different from that of healthy control group. (3)Functional enrichment analysis of KEGG signaling pathway showed that compared with those in serum of healthy control group, microRNAs of differential expression in serum of burn group took part in tumor transcription misregulation signaling pathway, tumor proteoglycan signaling pathway, long-term potentiation signaling pathway, tumor associated microRNAs signaling pathway, citrate cycle signaling pathway, tumor necrosis factor signaling pathway, focal adhesion signaling pathway, endocytosis signaling pathway, insulin secretion signaling pathway, and estrogen signaling pathway. Conclusions MicroRNA expression profile in serum of patients with severe burn is different from that in serum of healthy adults. MicroRNAs of differential expression may take part in important pathophysiological process of energy metabolism, inflammatory response, and regulation of blood glucose at early stage of severe burn.

ObjectiveTo investigate the occurrence rule and mechanism of ischemia-reperfusion injury (IRI)-induced gastric oxidative damage during perioperative period of liver transplantation.Methods Twenty-eight SD rats were randomized into 4 groups according to the random number table. The modelof orthotopic autologous liver transplantation was established in 3 groups, which were 4 h, 8 h, 16 h group according to the reperfusion time of the liver grafts. The other group was set as Sham group. Gastric tissues were stained with HE to observe pathological changes of gastric mucosal injury. Superoxide anion (O2-), malondialdehyde (MDA), glutathione (GSH) and glutathione peroxidase (GSH-PX) in gastric tissues were detected. The expression of thioredoxin (Trx)-2 in gastric tissues was detected by Western blot. The comparison on experimental data was conducted using one-way analysis of variance and LSD-t test.Results In 4 h group, congestion, edema and hemorrhage were observed in deep stratum and submucous stratum of stomach, as well as disorganized glands, regional hemorrhage and necrosis, and erosion was observed deep to the muscularis mucosa. In 8 h group and 16 h group, gastric mucosal injury was alleviated, and only congestion and edema in superifcial and deep layer were observed. In Sham group, the epithelium structure of most gastric mucosa was intact. The O2- and MDA of 4 h group were respectively (185±26) U/mg and (0.4±0.1) nmol/mg and those of 8 h group were respectively (192±59) U/mg and (0.5±0.1) nmol/mg, which were signiifcantly higher than (102±34) U/mg and (0.2±0.1) nmol/mg of Sham group (LSD-t=4.99, 4.23 and 6.37, 4.52;P<0.05). GSH and GSH-PX of 4 h group were respectively (17±6) mg/g and (781±174) U/mg and those of 8 h group were respectively (15±4) mg/g and (750±160) U/mg, which were signiifcantly lower than (30±6) mg/g and (1 162±215) U/mg of Sham group (LSD-t=-3.26,-4.01 and-3.78,-4.36;P<0.05). The O2-, MDA, GSH and GSH-PX of 16 h group were respectively (169±27) U/mg, (0.3±0.1) nmol/mg, (25±8) mg/g and (1 108±183) U/mg, and signiifcant difference was observed comparing with 8 h group (LSD-t=-2.85,-3.46, 2.66, 3.69;P<0.05). The relative expression of Trx-2 in 4 h group and 8 h group were respectively 52±10 and 43±8, which were signiifcantly lower than 125±16 of Sham group (LSD-t=-5.34,-6.23;P<0.05). The expression of Trx-2 in 16 h group was 160±18, which was signiifcantly higher than that of 8 h group (LSD-t=4.75,P<0.05). ConclusionIRI causes gastric oxidative damage in the early phase after liver transplantation in rats, which may be associated with the decrease of Trx-2 expression, increase of active oxygen and decrease in organic antioxidative ability.

Objective:To investigate the early changes in serum osteoprotegerin/receptor activator of nuclear factor-κB ligand (RANKL) and related indexes of calcium and phosphorus in severe burn patients.Methods:Thirty severe burn patients who met the inclusion criteria and were admitted to Tongren Hospital of Wuhan University & Wuhan Third Hospital within 8 hours post injury from June 2017 to December 2018 were recruited into severe burn group (24 males and 6 females, aged (38±13) years). Ten healthy volunteers with normal physical examination results in the Physical Examination Center of the same hospital in the same period of time were recruited into healthy control group (7 males and 3 females, aged (37±8) years). A prospective controlled study was conducted. The fasting venous blood of 5 mL was taken from each patient in severe burn group on post injury day (PID) 1, 7, 14, 21, and 28, respectively, and the fasting venous blood of 5 mL was taken from each volunteer in healthy control group. The serum osteoprotegerin, RANKL, 25 hydroxyvitamin D, and parathyroid hormone (PTH) levels were determined by enzyme-linked immunosorbent assay, and the RANKL/osteoprotegerin ratio was calculated. Serum albumin, serum calcium, and serum phosphorus levels were determined by bromocresol green method, methylthymol blue method, and phosphomolybdic acid method, respectively. Data were statistically analyzed with Fisher′s exact probability test, analysis of variance for repeated measurement, Mann-Whitney U test, independent sample t test, and Bonferroni correction. Results:(1) The serum osteoprotegerin levels of patients in severe burn group on PID 1, 7, 14, 21, and 28 were 155.11 (102.91, 187.02), 170.07 (84.60, 196.86), 174.95 (59.09, 208.35), 190.01 (47.08, 214.52), and 188.85 (58.73, 223.13) pg/mL, respectively, which were significantly higher than 33.34 (28.59, 45.68) pg/mL of volunteers in healthy control group, Z=-3.436, -4.311, -3.248, -2.811, -4.217, P<0.01. The serum levels of RANKL of patients in severe burn group on PID 1, 7, 14, 21, and 28 were (1 869±791), (1 746±857), (1 781±713), (2 015±825), and (2 272±583) pg/mL, respectively, significantly higher than (49±16) pg/mL of volunteers in healthy control group, t=12.600, 10.844, 13.294, 13.041, 20.880, P<0.01. The ratios of RANKL/osteoprotegerin of patients in severe burn group on PID 1, 7, 14, 21, and 28 were 12.23 (8.10, 24.73), 11.40 (8.25, 16.96), 11.15 (6.91, 38.32), 12.98 (9.22, 49.68), and 13.91 (10.29, 40.68), respectively, which were significantly higher than 1.17 (0.91, 1.74) of volunteers in healthy control group, Z=-4.560, -4.529, -4.529, -4.560, -4.623, P<0.01. (2) The serum level of 25 hydroxyvitamin D of patients in severe burn group on PID 1 was significantly lower than that of volunteers in healthy control group ( Z=-2.749, P<0.01). Compared with those of volunteers in healthy control group, the serum levels of albumin of patients in severe burn group on PID 1, 7, 14, 21, and 28 were significantly lower ( t=-4.374, -7.689, -8.257, -7.651, -6.259, P<0.01), the serum levels of PTH were significantly elevated ( Z=-4.685, -4.685, -4.685, -4.654, -4.685, P<0.01), and the serum levels of phosphorus were not changed significantly. The serum levels of calcium of patients in severe burn group on PID 1, 7, 14, and 21 were significantly lower than the level of volunteers in healthy control group ( Z=-2.375, -3.455, -2.442, -2.016, P<0.05 or P<0.01). Conclusions:The serum osteoprotegerin, RANKL, RANKL/osteoprotegerin ratio, and PTH are increased, and the serum 25 hydroxyvitamin D, albumin, and calcium are decreased in the early stage of severe burn patients, which may be the mechanism leading to bone loss in patients.

Objective:To observe the changes in the related indicators of bone formation and bone resorption in severely burned rats.Methods:The experimental research method was adopted. Thirty female Sprague-Dawley rats aged 6 to 8 weeks were divided into sham injury group, 12% total body surface area (TBSA) full-thickness burn group, and 24%TBSA full-thickness burn group according to the random number table, with 10 rats in each group. The rats were treated on the back correspondingly, after which, the burned rats were rehydrated by intraperitoneal injection according to the Parkland formula, and the wound was coated with 20 g/L iodophor until wound healing. On post injury day (PID) 28, the tibia tissue of rats in each group was collected. The new bone tissue and the number of osteoclasts were observed after staining with Masson and tartrate-resistant acid phosphatase, respectively. The abdominal aortic blood of rats in each group was harvested for serum preparation. The bone metabolism indexes of serum calcium ion and phosphorus ion concentration were determined by the methyl thymol blue colorimetric method and phosphomolybdic acid method, respectively. The serum levels of bone formation marker of aminoterminal propeptide of type 1 procollagen (P1NP) and bone resorption marker of beta-carboxy-terminated peptide of type Ⅰ collagen (β-CTX) were determined by enzyme-linked immunosorbent assay. The first lumbar spine tissue of rats in each group was collected, and the mRNA expression levels of osteoprotegerin, receptor activator of nuclear factor-κB ligand (RANKL), tumor necrosis factor receptor-associated factor 6 (TRAF-6), nuclear factor of activated T cell 1 (NFATC1), c-Fos, and c-Src were detected by real-time fluorescent quantitative reverse transcription polymerase chain reaction. Data were statistically analyzed with one-way analysis of variance, Bonferroni method, Welch test, Games-Howell test, Kruskal-Wallis test, Mann-Whitney U test, and Bonferroni correction. Results:On PID 28, compared with that in sham injury group, the formation of new bone tissue in the tibia tissue of rats in the two burn groups was decreased, and the larger the burn area, the more obvious the decrease. The numbers of osteoclasts in the tibia tissue of rats in the two burn groups were similar, both significantly more than the number in sham injury group. On PID 28, the serum calcium ion concentration and serum level of β-CTX of rats in the three groups were similar ( P>0.05). The serum phosphorus ion concentration of rats in 24%TBSA full-thickness burn group was significantly higher than that in 12%TBSA full-thickness burn group ( P<0.05), and the serum phosphorus ion concentrations in the two burn groups were significantly higher than the concentration in sham injury group ( P<0.01). The serum level of P1NP of rats in 24%TBSA full-thickness burn group was significantly lower than that in sham injury group ( P<0.01). On PID 28, the mRNA expression levels of osteoprotegerin in the first lumbar spine tissue of rats in sham injury group, 12%TBSA full-thickness burn group, and 24%TBSA full-thickness burn group were 1.01±0.20, 1.71±0.83, and 2.24±0.51, respectively, and that in 24%TBSA full-thickness burn group was significantly higher than that in sham injury group ( P<0.01). The mRNA expression level of RANKL in the first lumbar spine tissue of rats in 24%TBSA full-thickness burn group was 1.31±0.17, which was significantly higher than 1.00±0.14 in sham injury group and 0.97±0.10 in 12%TBSA full-thickness burn group ( P<0.01). The mRNA expression levels of TRAF-6, NFATC1 ( Z=3.141, 3.782), and c-Src in the first lumbar tissue of rats in 12%TBSA full-thickness burn group and 24%TBSA full-thickness burn group and the mRNA expression level of c-Fos in the first lumbar tissue of rats in 12%TBSA full-thickness burn group were significantly higher than those in sham injury group ( P<0.05 or P<0.01). The mRNA expression levels of c-Fos and c-Src in the first lumbar spine tissue of rats in 12%TBSA full-thickness burn group were significantly higher than those in 24%TBSA full-thickness burn group ( P<0.01). Conclusions:Severe burns can cause a decrease in the generation of new bone tissue, an increase in the number of osteoclasts and the serum phosphorus ion concentration, and a decrease in the serum level of P1NP in rats. The level of osteoprotegerin, RANKL, TRAF-6, NFATC1, c-Fos, and c-Src in bone tissue showed an increasing trend while the level of NFATC1, c-Fos, and c-Src showed a decreasing trend with the increase of burn area.

Objective:To investigate the causes of death and etiological characteristics of skin tissue donors, and to provide reference for allogeneic skin transplantation.Methods:From October 2008 to October 2018, 49 skin tissue donors accepted by the Burn Department of Wuhan Third Hospital met the inclusion criteria of this study, and a cross-sectional study was conducted. According to the cause of death, the donors were divided into accidental death group (19 cases) and non-accidental death group (30 cases). The sex and death age of 49 donors were recorded, and the death age between different sex donors and that of donors between accidental death group and non-accidental death group were compared. Diseases or circumstances that caused the death of donors, hepatitis B, hepatitis C, acquired immunodeficiency syndrome, syphilis virus carrying status, and peripheral blood microbial culture results of 49 donors were recorded, and the detection of blood-borne infectious risk factors of donors between accidental death group and non-accidental death group was compared. Abnormal skin tissue was also selected during allogenic skin graft preparing for pathological examination. Data were statistically analyzed with Mann-Whitney U test and continuity correction chi-square test. Results:(1) Out of the 49 donors in this group, 38 were male (77.55%) and 11 were female (22.45%). The death age was 42.00 (24.00, 55.00) years, and the death age of male donors was similar to that of female donors ( Z=0.120, P>0.05). The death age of donors in accidental death group was lower than that in non-accidental death group, but the difference was not statistically significant ( Z=-1.581, P>0.05). (2) Among the causes and circumstances of the 49 donors in this group, there were 19 cases (38.78%) of injury, poisoning, and some other consequences of external causes, 11 cases (22.45%) of circulatory system diseases, 9 cases (18.37%) of tumors, 3 cases (6.12%) of nervous system diseases, 2 cases (4.08%) of respiratory system diseases, and 2 cases (4.08%) of congenital malformation, deformation, and chromosome abnormality, 1 case (2.04%) of blood and hematopoietic organ diseases and some diseases related to immune mechanism, 1 case (2.04%) of digestive system disease, and 1 case (2.04%) of genitourinary system disease. (3) There were 9 donors (18.37%) with blood-borne infectious risk factors among the 49 donors in this group, including 8 cases (16.33%) of blood-borne infectious diseases, which were 5 cases (10.20%) of hepatitis B, 2 cases (4.08%) of syphilis, and 1 case (2.04%) of hepatitis C, respectively. Blood microorganism culture was positive in 1 case (2.04%), in which multi-drug resistant Pseudomonas aeruginosa was detected. Risk factors of blood-borne infection were detected in 2 donors in accidental death group, with detection ratio lower than that in non-accidental death group (7 cases), but the difference was not statistically significant ( χ2=0.562, P>0.05). (4) A total of 8 donors′ abnormal skin tissue were selected, including 4 cases of intradermal pigmented nevus, 1 case of scar, 1 case of pseudoepithelioma hyperplasia, 1 case of epidermal verrucous hyperplasia, and 1 case of large amount of pigment granules in dermis. Conclusions:Non-accidental death caused by diseases is the main cause of death of skin tissue donors, and the risk of donor-derived infection of non-accidentally dead donors is slightly higher than that of accidentally dead donors. Before the allogeneic skin is obtained and transplanted, the cause of death of the donor should be carefully investigated, and the health status should be evaluated, so as to avoid the occurrence of donor-derived infection.

OBJECTIVETo investigate the mechanism of drug resistance of carbapenems-resistant Acinetobacter baumannii (CRAB) in burn patients and the antimicrobial activity of a combination of drugs against this bacteria in vitro.

METHODSA total of 135 strains of Acinetobacter baumannii (AB) from wound excretion, sputum, and venous catheter wall of patients hospitalized in our department from January 2011 to July 2013 were collected individually. Drug resistance of 135 strains of AB to 12 antibiotics commonly-used in clinic was detected using K-B paper diffusion method. Among the CRAB strains, double-disk synergy test was used to screen metallo-β-lactamase (MBL)-producing strains, and the drug resistance rates between MBL-producing strains and non-MBL-producing strains were compared. Minimal inhibitory concentration (MIC), 50% MIC (MIC50), and 90% MIC (MIC90) of cefoperazone/sulbactam, imipenem, cefepime, ampicillin/sulbactam, and amikacin used alone against MBL-producing CRAB were determined by broth microdilution method. MIC, MIC50, and MIC90 of amikacin respectively combined with imipenem, cefoperazone/sulbactam, cefepime, or ampicillin/sulbactam against MBL-producing CRAB were determined by checkerboard method with diluted agar. Fractional inhibitory concentration (FIC) index was calculated to determine the antibacterial effect of each combination of two antibiotics. Synergy with FIC lower than or equal to 0.5, or additivity with FIC higher than 0.5 and lower than or equal to 1.0 was regarded as effective, and indifference with FIC higher than 1.0 and lower than or equal to 2.0 or antagonism with FIC higher than 2.0 was regarded as ineffective. The effective rate was calculated. Data were processed with Chi-square test.

RESULTSThe resistant rates of the 135 strains of AB to imipenem, meropenem, and ceftazidime were high, and those of piperacillin/tazobactam and ampicillin/sulbactam were low. A total of 120 strains of CRAB was screened, accounting for 88.89%, among which the MBL-producing strains accounted for 78.33% (94/120). The resistant rates of MBL-producing strains to piperacillin/tazobactam, imipenem, meropenem, piperacillin, and cefepime were respectively 59.5%, 87.2%, 93.5%, 87.0%, 86.0%, and they were significantly higher than those of non-MBL-producing strains (respectively 43.0%, 81.3%, 87.5%, 78.4%, 64.0%, with χ(2) values from 4.571 to 8.260, P < 0.05 or P < 0.01). Among the inhibition concentrations of each of the 5 antibiotics used alone against MBL-producing strains, MIC, MIC50, and MIC90 of ampicillin/sulbactam were the lowest, respectively 4.00, 16, 64 µg/mL, while those of cefepime were high, respectively 32.00, 128, 512 µg/mL. MIC, MIC50, and MIC90 of amikacin combined with each of the other 4 antibiotics were decreased from 50.00% to 98.44% as compared with that of single administration of each antibiotic. Among the 94 strains of MBL-producing CRAB, the synergic, additive, indifferent, and antagonistic effects were respectively observed in 40, 33, 6, and 15 strains applied with combination of amikacin and ampicillin/sulbactam; 42, 30, 5, 17 strains applied with combination of amikacin and cefoperazone/sulbactam; 38, 15, 19, 22 strains applied with combination of amikacin and cefepime; 34, 2, 37, 21 strains applied with combination of amikacin and imipenem, among which the antibacterial effective rates decreased successively, respectively 77.7%, 76.6%, 56.4%, and 38.3%. The former two rates were respectively significantly higher than the latter two rates (with χ(2) values from 8.618 to 29.889, P values below 0.01).

CONCLUSIONSProduction of MBL is the main mechanism of resistance of the CRAB isolated from burn patients hospitalized in our department against carbapenems in about 3 years. The antibacterial effects of amikacin combined with each of the former-mentioned 4 agents are better than those of each of the five antibiotics used singly, and the effects are particularly obvious when combining amikacin with compound agent containing enzyme inhibitors.

Acinetobacter Infections ; drug therapy ; microbiology ; Acinetobacter baumannii ; drug effects ; isolation & purification ; Ampicillin ; pharmacology ; Anti-Bacterial Agents ; pharmacology ; Carbapenems ; pharmacology ; Cephalosporins ; pharmacology ; Drug Resistance ; Humans ; In Vitro Techniques ; Microbial Sensitivity Tests ; Penicillanic Acid ; analogs & derivatives ; pharmacology ; Pharmaceutical Preparations ; Piperacillin ; pharmacology ; Sulbactam ; pharmacology ; Thienamycins ; pharmacology ; beta-Lactamase Inhibitors ; pharmacology

OBJECTIVETo observe the change in phosphoinositide 3-kinase/protein kinase B (PI3K/Akt) signal pathway in monocytes as induced by serum of rats with electrical burn, and to explore the effects of PI3K/Akt pathway on monocyte-endothelial cell adhesion.

METHODSSixty-four SD rats of clean grade were inflicted with electrical burn for the collection of serum of rats with electrical burn; another group of twenty-four SD rats were used to obtain normal serum without treatment. (1) Human monocyte line THP-1 was routinely cultured. The THP-1 cells in logarithmic phase were divided into normal serum group (resuspended in RPMI 1640 medium with 20% normal rat serum) and burn serum group (resuspended with RPMI 1640 medium with 20% serum of rats with electrical burn) according to the random number table, with 6 wells in each group. Morphology of THP-1 cells in normal serum group was observed at post culture hour (PCH) 24, and that in burn serum group at PCH 3, 6, 24. The contents of TNF-α in culture supernatant were determined by double-antibody sandwich ELISA at the corresponding time point in each group. The state of Akt activation was determined by Western blotting at PCH 3, 6, 24. (2) Another portion of THP-1 cells were divided into 4 groups according to the random number table, with 6 wells in each group. Cells in normal serum group and burn serum group were given with the same culture condition as above; cells in normal serum+inhibitor group and burn serum+inhibitor group were cultured with the same culture conditions as in the former two groups correspondingly with addition of 100 nmol/L wortmannin in the nutrient solution. At PCH 3 and 6, THP-1 cells were added into the well with a monolayer of endothelial cell line EA.hy926 to observe the monocyte-endothelial cell adhesion. Data were processed with one-way analysis of variance and LSD- t test.

RESULTS(1) In normal serum group, THP-1 cells showed growth in suspension, with uniform shape at PCH 24. In burn serum group, the cell shape became irregular though the membrane was complete at PCH 3; cellular size became irregular and cell membrane and cytoplasm were swollen at PCH 6; cell membrane was disrupted with death of cells at PCH 24. The contents of TNF-α in culture supernatant in normal serum group at PCH 24 and in burn serum group at PCH 3, 6, 24 were respectively (38.5 ± 1.4), (75.1 ± 1.5), (91.5 ± 1.8), (117.0 ± 1.4) pg/mL (F = 1 415.306, P < 0.01). The contents of TNF-α in culture supernatant in burn serum group at PCH 3, 6, 24 were all significantly higher than the content of TNF-α in normal serum group at PCH 24 (with t values respectively 29.614, 42.852, 63.485, P values below 0.01). The ratio values of phosphorylated Akt to Akt in burn serum group at PCH 3, 6, 24 were respectively 2.66, 3.69, 1.17 times of those in normal serum group at the corresponding time point. (2) In normal serum group, normal serum+inhibitor group, burn serum group, and burn serum+inhibitor group at PCH 3 and 6, the numbers of THP-1 cells adherent to endothelial cells were respectively (231 ± 45), (280 ± 47), (703 ± 169), (335 ± 85) per 100-time field; (219 ± 49), (235 ± 21), (562 ± 123), (226 ± 29) per 100-time field (with F values respectively 25.630 and 18.975, P values below 0.01). The number of THP-1 cells adhered to EA.hy926 cells was significantly more in burn serum group than in normal serum group at PCH 3 and 6 (with t values respectively 6.189 and 6.601, P values below 0.01). The number of THP-1 cells adherent to EA.hy926 cells was significantly fewer in burn serum+inhibitor group than in burn serum group at PCH 3 and 6 (with t values respectively 6.821 and 6.465, P values below 0.01).

CONCLUSIONSThe serum of rats suffering from electrical burn can induce the monocytes to secrete TNF-α, thus enhancing monocyte-endothelial cell adhesion, but it can be inhibited by blocking PI3K/Akt signal pathway.

Animals ; Burns, Electric ; blood ; Cell Line ; Humans ; Monocytes ; Phosphatidylinositol 3-Kinases ; metabolism ; Proto-Oncogene Proteins c-akt ; metabolism ; Rats ; Serum ; Signal Transduction ; Tissue Adhesions ; metabolism ; pathology ; Tumor Necrosis Factor-alpha ; metabolism