Analysis on the diagnosis and treatment of necrotizing fasciitis complicated with sepsis / 中华危重病急救医学

Objective:To recognize the characteristics of necrotizing fasciitis patients complicated with sepsis and summarize the experience the treatment.Methods:A retrospective study was conducted. The clinical data of 57 patients with necrotizing fasciitis complicated with sepsis admitted to Guangdong Provincial People's Hospital from July 2009 to December 2019 was analyzed by collecting such factors as gender, age, complications, infection sites, pathogens, surgery information, treatment options and outcome. The patients were divided into debridement group ( n = 14) and control group ( n = 43) according to whether the debridement was completed within 48 hours of admission, and the mortality during hospitalization between the two groups was compared. A telephone follow-up had been done to record the long-term outcome of these patients. Results:Among 57 patients with necrotizing fasciitis complicated with sepsis, there were 43 males and 14 females with the average age of (57.9±12.1) years old. Most of the underlying diseases were diabetes mellitus (70.17%), other diseases included hypertension (8.77%), tumor chemotherapy (7.02%), liver disease (hepatitis, cirrhosis, 7.02%), coronary artery heart disease (3.51%), systemic lupus erythematosus (3.51%), etc. Most of the infection site was lower limbs (71.93%). There were 78 pathogens cultured in 57 patients, in which 52 were non-drug resistant bacteria (66.67%), and 26 were drug resistant bacteria (33.33%). There were 40 Gram positive (G +) bacteria (51.28%), 29 Gram negative (G -) bacteria (37.18%), 8 fungi (10.26%) and 1 mixed bacteria (1.28%). Finally, of 57 patients, 46 patients were cured, and 11 patients died with hospital mortality of 19.30%. Among 57 patients, the hospital mortality in the debridement group was significantly lower than that in the control group [0% (0/14) vs. 25.58% (11/43), P < 0.05]. Among the 46 cured patients, 11 had accepted amputations, accounting for 23.91%. In December 2020, 43 patients who were cured (3 patients were lost to follow-up) were followed up by telephone. Twenty-three patients were completely self-care, 9 patients were partly self-care, 8 patients were completely unable to take care of themselves, and 3 patients died. Conclusions:Necrotizing fasciitis with sepsis mostly occurs in people with weakened immunity, and has a high mortality and disability rate. Early identification and active surgical debridement may be the key to improve the treatment effect.

Application of venous super drainage technique in free flaps transfer / 中华显微外科杂志

To investigate the effect of venous super drainage applying in free flaps. Methods From June, 2017 to December, 2018, 7 cases who had severe soft tissue injuries were treated with free flap. Cause of injury: 1 electric injuries, 2 tumor-related wounds, 1 deep burns, 2 mechanical trauma, and 1 necrotizing fasciitis. All patients were underwent free flap transplantation. There were 5 cases of anterolateral thigh artery perforator flap, 1 case of superficial circumflex iliac artery perforator flap, and 1 case of first dorsal metatarsal artery perforator flap.The application of venous super-drainage technology was carried out according to needs and specific conditions. Two sets of venous passages were prepared in both recipient and donor site to form a double set of venous reflux super-drainage mode. Blood supply, swelling, exudation, secondary exploration and survival rate of the flap were observed after operation, and regularly followed-up. Results All 7 flaps survived. Venous super drainage technique was ap-plied in 7 cases. No arteriovenous crisis occurred after the operation. The flaps had good blood circulation, slight swelling, less exudation, rapid edema regression and no secondary surgical exploration. Followed-up for 2-18 (average 10.5) months, there was no infection recurred. Flaps survived well, and the donor sites healed well without sensory loss.The flexion and extension function of joint was normal. Conclusion The technique of venous super-drainage prepares 2 sets of venous systems for the free flap in the treatment of vascular pedicle in the free flap repair operation, which is conducive to reducing the venous crisis after flap surgery, reducing flap edema, reducing exudation, reducing secondary surgical exploration and improving the survival rate of the flap.

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.

Protective effects of valproic acid on gut barrier function after major burn injury and its mechanism / 中华危重病急救医学

Objective To investigate the potential protective effects of valproic acid (VPA) on gut barrier function after major burn injury in rats and its mechanism.Methods Forty male Sprague-Dawley (SD) rats were divided into sham + normal saline (NS),sham + VPA,scald + NS,and scald + VPA groups,with 10 rats in each group.Rat with 55％ total body surface area (TBSA) third-degree severe-bums model was reproduced by immersing into 80 ℃ water,and the rats in sham groups were given sham-bums by immersing into 37 ℃ water.The rats after severebums were immediately treated with 0.25 mL of 300 mg/kg VPA or NS by subcutaneous injection.Rats were sacrificed at 2 hours and 6 hours after injury,and abdominal aortic blood and ileal tissue were harvested.The levels of vascular endothelial growth factor (VEGF) were determined by enzyme-linked immunosorbent assay (ELISA).The intestinal permeability was evaluated by fluorescein isothiocyanate-dextran (FITC-dextran) determination.The histomorphological changes in gut barrier were evaluated by Chiu grading system.Levels of acetylated lysine at the ninth position of histone 3 protein (Ac-H3K9),hypoxia-inducible factor 1α (HIF-1α),zona occludens 1 (ZO-1) and myosin light chain kinase (MLCK) were determined by immunofluorescence staining and Western Blot.Results Compared with sham + NS group,rats in scald + NS group showed intestinal mucosal damage 2 hours after bum injury,as well as increased mucosal permeability,protein expression levels of HIF-1 α,VEGF,MLCK,and lowered levels of AC-H3K9 and ZO-1.These changes were much more prominent at 6 hours after injury.VPA treatment significantly attenuated the bum-induced intestinal damage.Compared with scald + NS group,the protective effects in scald + VPA group was not evident at 2 hours after injury;however,intestinal damage was much less severe at 6 hours after injury (Chiu score:2.03 ± 0.27 vs.3.12 ± 0.15),intestinal permeability was significantly decreased [FITC-dextran (μg/L):709 ± 76 vs.1138 ± 75],histone acetylation was enhanced [Ac-H3K9 (gray value):1.55 ± 0.12 vs.0.48±0.12],ZO-1 degradation was significantly inhibited (gray value:0.69 ± 0.12 vs.0.43 ± 0.16),the protein expression levels of VEGF and MLCK were significantly down-regulated [VEGF (ng/mg):51.7±3.7 vs.71.2±4.3,MLCK (gray value):1.98±0.20 vs.2.80±0.24],while the HIF-1 α protein expression levels were significantly reduced at both 2 hours and 6 hours after injury (gray value:2.50±0.39 vs.3.88±0.42 at 2 hours,1.83±0.42 vs.4.42±0.41 at 6 hours,all P ＜ 0.05).Conclusions Severe bum injury can induce histone deacetylation,ZO-1 degradation and intestinal barrier dysfunction.VPA can improve the levels of histone acetylation and ZO-1,and protect intestinal epithelial barrier function.These may probably be mediated through inhibiting HIF-1α and its downstream gene VEGF and MLCK.

Effects of electroacupuncture at Zusanli points on gut permeability in rats with intestinal ischemia/reperfusion injury / 中国中西医结合急救杂志

Objective To investigate the protective effects of elctroacupuncture(EA)at Zusanli(ST36) points on intestinal villas damage and mucosal permeability induced by small intestine pro-inflammatory factors in rats with intestinal ischemia/reperfusion(I/R). Methods 30 Sprague-Dawley(SD)rats were randomly divided into three groups(each,n=10):intestinal I/R group(model group),intestinal I/R+EA ST36 group(EA group)and intestinal I/R+sham EA group(SEA group). Rats were subjected to superior mesenteric artery(SMA)clamping at its root part to occlude the vessel for 30 minutes,followed by reperfusion for 60 minutes to form intestinal I/R models. Rats in EA group received EA at the bilateral ST36 points(2-3 mA,2-100 Hz)for 30 minutes immediately after ischemia,those in SEA group received EA at bilateral sham points(the point was located at 0.5 cm away from ST36 point in its lateral side)with the same frequency and intensity of stimulation as EA group for 30 minutes,and those in model group received no treatment. Animals were sacrificed 60 minutes after reperfusion and segments of distal part of ileum were harvested,then the levels of tumor necrosis factor-α(TNF-α)and interleukin-6(IL-6)in intestinal tissue were measured. Histopathologic changes were viewed and graded via light microscopy. A solution of fluorescein isothiocyanate(FITC)-dextran was injected into the lumen of the segment of intestine 30 minutes after reperfusion,systemic blood was drawn via abdominal aorta puncture at 60 minutes after reperfusion,and then the level of FITC-dextran in blood was measured to determine the changes in intestinal permeability. Results Compared to the model group and SEA group,EA ST36 significantly attenuated intestine TNF-α(pg/mg:3.01±0.50 vs. 8.65±1.02,8.42±1.41,both P0.05). Sections of distal ileum from animals in the model group and SEA group showed no obvious difference histologically,and the pathological manifestations were villous tip necrosis, blunt-shaped and collapse. Compared to the model group and SEA group,the intestinal villous injury in animals of EA group was much milder. Conclusion In rats with intestinal I/R injury,EA ST36 points has protective effect on the gut that is possibly due to the fact it may obviously lower the levels of the pro-inflammatory factors of small intestinal tissue,alleviate mucosal insult of gut and reduce the mucosal permeability.

Effects of endotoxin/lipopolysaccharide on proliferation and apoptosis of human umbilical cord mesenchymal stem cells / 中华烧伤杂志

<p><b>OBJECTIVE</b>To investigate the effects of different concentrations of lipopolysaccharide (LPS) on proliferation and apoptosis of human umbilical cord mesenchymal stem cells (hUCMSCs) in vitro, and to explore their possible mechanism.</p><p><b>METHODS</b>hUCMSCs from umbilical cord tissue of full-term healthy fetus delivered by caesarean section were isolated and cultured in vitro using tissue attachment method. The 3rd passage hUCMSCs were used in the study. Cells were divided into groups A, B, C, D, and E, which were treated with DMEM/F12 medium containing 0, 0.1, 1.0, 10.0, and 100.0 µg/mL of LPS respectively. In groups B, C, D, and E, methyl-thiazole-tetrazolium assay was used to detect proliferative activity of hUCMSCs at post treatment hour (PTH) 12, 24, and 48 (denoted as absorption value), with 5 samples in each group at each time point; apoptosis of hUCMSCs at PBH 24 was identified with acridine orange-ethidium bromide (AO-EB) staining, with 4 samples in each group; apoptotic rate of hUCMSCs was determined by flow cytometer, with 5 samples in each group. Above-mentioned indexes were determined in group A at the same time points. Data were processed with analysis of variance and LSD- t test.</p><p><b>RESULTS</b>(1) There was no statistically significant difference in proliferative activity of hUCMSCs at PTH 12 among groups A, B, C, D, and E (with t values from -1.67 to 1.33, P values above 0.05). Compared with that of group A, proliferative activity of hUCMSCs was increased in groups B, C, and D at PTH 24 and 48 (with t values from -13.42 to 17.34, P < 0.05 or P < 0.01), especially so in group C. Proliferative activity of hUCMSCs was lower in group E at PTH 24 and 48 than in group A (with t values respectively 8.64 and 17.34, P values below 0.01). (2) Obvious apoptosis of hUCMSCs was observed in group E but not in the other 4 groups with AO-EB staining. (3) Apoptosis rates of hUCMSCs in groups A, B, C, D, and E were respectively (3.1 ± 0.6)%, (2.6 ± 0.7)%, (2.9 ± 0.8)%, (3.1 ± 0.4)%, (25.1 ± 2.7)% (F = 272.19, P < 0.01). Apoptotic rate of hUCMSCs in group B, C, or D was respectively close to that in group A (with t values respectively 1.22, 0.57, -0.14, P values above 0.05), but it was higher in group E than in group A (t = -17.63, P < 0.01).</p><p><b>CONCLUSIONS</b>hUCMSCs proliferation may be promoted by low concentration of LPS. hUCMSCs proliferation is inhibited or induced to apoptosis along with the increase in concentration of LPS, and it may be related to activation of different major molecular signaling pathways by different concentrations of LPS.</p>

Effects of sivelestat on acute lung injury in dogs with severe burn-blast combined injury / 中华烧伤杂志

<p><b>OBJECTIVE</b>To observe and study the effects of sivelestat on acute lung injury in dogs with severe burn-blast combined injury.</p><p><b>METHODS</b>Thirty-two male beagle dogs of clean grade were divided into 4 groups: uninjured group (U), combined injury control group (CIC), combined injury+low dose of sivelestat group (CI+LS), combined injury+high dose of sivelestat group (CI+HS), with 8 dogs in each group. Except for the dogs in group U which were not injured, the dogs in the other 3 groups were inflicted with severe burn-blast combined injury. According to the Parkland formula, the dogs in groups U and CIC were infused with physiological saline, and the dogs in groups CI+LS and CI+HS received sivelestat with the dosage of 0.5 and 2.0 mg·kg(-1)·h(-1) respectively in addition. The 24 h continuous intravenous infusion was carried out for 2 days. At post injury hour (PIH) 6, CT scanning was conducted to observe the lung damage. At PIH 2, 6, 12, 24, and 48, mean arterial pressure (MAP), respiratory rate (RR), extra vascular lung water (EVLW), pulmonary vascular permeability index (PVPI), PaO2, and PaCO2 were measured; the contents of neutrophil elastase (NE), IL-8, and TNF-α were determined by ELISA. At PIH 48, all the dogs were sacrificed, and the lung tissues were harvested to measure the wet to dry lung weight ratio. The same examination was carried out in the dogs of the group U at the same time points. Data were processed with analysis of variance of repeated measurement and LSD test.</p><p><b>RESULTS</b>(1) CT images showed some exudative lesions in the dogs of groups CIC and CI+LS but not in the dogs of groups U and CI+HS. (2) No statistically significant differences were observed in MAP at each time point between every two groups (with P values above 0.05). The RR values in group U were significantly different from those of the other 3 groups at all time points (with P values below 0.05). The values of EVLW and PVPI in 3 combined injury groups were significantly different from those in group U at PIH 6, 12, 24, and 48 (with P values below 0.05). The values of RR and EVLW in group CI+LS were significantly different from those in group CI+HS at PIH 12, 24, and 48 (with P values below 0.05). The values of PVPI in group CI+LS were significantly different from those in group CI+HS at PIH 24 and 48 (with P values below 0.05). (3) The levels of PaO2 and PaCO2 showed significant differences between group U and the other 3 groups at each time point (with P values below 0.05). The levels of PaO2 in group CI+LS were significantly different from those in CI+HS group at PIH 12, 24, and 48 (with P values below 0.05). The level of PaCO2 showed significant differences between group CI+LS and group CI+HS at PIH 24 and 48 (with P values below 0.05). (4) The contents of NE (except for PIH 2), TNF-α, and IL-8 showed significant differences between group U and the other 3 groups at each time point (P < 0.05 or P < 0.01). At PIH 2, 6, 12, 24, and 48, the contents of NE in groups U, CIC, CI+LS, and CI+HS were respectively (69 ± 21), (83 ± 24), (80 ± 20), (75 ± 17), (72 ± 27) pg/mL; (66 ± 24), (196 ± 20), (231 ± 26), (252 ± 25), (266 ± 22) pg/mL ; (71 ± 22), (180 ± 27), (214 ± 21), (194 ± 24), (218 ± 20) pg/mL; (68 ± 22), (136 ± 24), (153 ± 22), (146 ± 26), (150 ± 28) pg/mL. NE values in group CI+HS were statistically different from those in groups CIC and CI+LS at PIH 6, 12, 24, and 48 (with P values below 0.05). The contents of TNF-α in group CI+LS were statistically different from those in groups CIC and CI+HS at PIH 24 and 48 (with P values below 0.05). The contents of IL-8 in group CI+LS were statistically different from those in group CI+HS at PIH 24 and 48 (with P values below 0.05). (5) At PIH 48, the wet to dry lung weight ratio of group CIC was statistically different from that in group CI+LS or group CI+HS (with P values below 0.05); there was also difference between group CI+LS and group CI+HS (P < 0.05).</p><p><b>CONCLUSIONS</b>Sivelestat, especially in a high dose, exerts a protective effect in acute lung injury after burn-blast combined injury through improving the index of blood gas analysis, ameliorating pulmonary edema, and lowering the production of pro-inflammatory mediators.</p>

Effects of oral pyruvate-glucose-electrolyte solution on organ function and survival in resuscitation of lethal hemorrhagic shock rats / 中华急诊医学杂志

Objective To study the effects of oral rehydration with the solution of pyruvate-glucoseelectrolyte (PGES) by comparison with the bicarbonate-glucose-electrolyte solution (BGES) on resuscitation in rats with lethal hemorrhagic shock.Methods Sixty adult male SD rats with intra-gastric tube,and cannulation of femoral artery and vein were subjected to 45％ total blood volume loss from the femoral artery,and then randomly divided into three groups (n =20 in each group):no fluid resuscitation group (NR),oral fluid resuscitation with the PGES group (PGES) and oral fluid resuscitation with the BGES group (BGES).In NR group,the animals received no fluid replacement or any other treatment.Rats in PGES and BGES groups were infused intra-gastrically with pre-warmed PGES or BGES in volume of 2 times shed blood given at 30 min after hemorrhage and completed within 6 hours.Blood samples in each group were collected from the abdominal aorta before or at 0,1,2,4 h post hemorrhage to detect serum alanine aminotransferase (ALT),creatinine (Cr),creatine phosphate kinase isoenzyme (CK-MB) and intestinal fatty acid binding protein (iFABP).Another 84 rats randomly divided into four groups:NR group (n =24),PGES group (n =24),BGES group (n =24),and no hemorrhage group (NH group,n =12).Rats in the three hemorrhage groups were treated the same as described above,and the rats in NH group underwent the same surgical procedure without hemorrhage were served as the sham group.All these rats were observed for their 24-hour survival rates.Results The 24-hour survival rates of PGES and BGES groups were both significantly higher than the rate of NR group (11/24 vs.1/24,x2 =18.087,P ＜0.01 ; 5/24 vs.1/24,x2 =6.445,P ＜ 0.05) ; the survival rate of PGES group was also significantly higher than that of BGES group (11/24 vs.5/24,x2 =4.02,P ＜ 0.05).All levels of ALT,CK-MB,Cr and iFABP in both the NR group and two oral resuscitation groups at 1 h,2 h and 4 h post hemorrhage were significantly higher than those before the blood loss,respectively (P ＜ 0.01).These biomarkers at 2 h,4 h post hemorrhage were significantly lower in the PGES and BGES groups than those in NR group (P ＜ 0.01) ; the serum levels of ALT,CK-MB,Cr and iFABP were significantly lower in the PGES group than those in the BGES group at 2 h and 4 h post hemorrhage,respectively (P ＜ 0.05).Conclusions Present results demonstrated that the pyruvate-enriched oral re-hydration solution (ORS =PGES) was more effective in preserving the organ function and prolonging the animal survival after resuscitation of lethal hemorrhagic shock in comparison with the bicarbonate-containing ORS (BGES).The oral re-hydration solution (PGES) recommended by the World Hygiene Organization (WHO ORS) may require further improvement in oral resuscitation of shock and the PGES may be recommended as a choice of oral re-hydration salts in the treatment of lethal hemorrhagic shock when intravenous administration is not available.

PPARγexpression in rat lung tissue after ventilator-induced lung injury / 局解手术学杂志

Objective To observe the changes of PPARγ expression in ventilator-induced lung injury rats and explore the role of PPARγ in the pathogenesis of ventilator-induced lung injury. Methods Sixty male Sprague-Dawley rats were randomly divided into 3 groups ( n=21 each ):group N received large tidal volume with mechanical ventilation ( Vt=12 mL/kg);group C received lower tidal volume with mechanical ventilation ( Vt=6 mL/kg);group R received room air without mechanical ventilation. Rats in every group were randomly divided into 3 subgroups respectively by 1,4 and 8 h. The samples of lung were collected at 1,4 and 8 h after ventilation. Lung pathological examina-tion, total protein and white blood cells in bronchoalveolar fluid and wet-to-dry weight were detected. The exoressions of PPARγmRNA were detected by RTPCR;PPARγ protein in lung tissues was detected by western bolt. Result After 4 and 8 h ventilation in group N,total pro-tein and WBC in bronchoalvelor fluid,W/D were markedly higher than those of group C and R (P 0. 05). Conclusion PPARγmRNA and protein expressions in the rats lung tissue of ventilator-induced lung injury were decreased and as-sociated with inflammation and damage of lung tissue.

Smac/DIABLO induces apoptosis in pancreatic cancer cells and increases the sensitivity of TRAIL and gemcitabine chemotherapy / 中华普通外科杂志

Objective To explore the effect of ectopic overexpression of Smac/DIABLO on the proliferation of pancreatic cancer cell line SW1990,and the sensitization to TRAIL and Gemcitabine induced apoptosis.Methods The Smac/DIABLO gene was transfected into the pancreatic cancer cell line SW1990 with the participation of Lipofectamine 2000 (SW1990/Smac).The cell line transfected with empty vector served as controls (SW1990/neo).The SW1990/neo and SW1990/Smac cells were assigned into the following treatment groups:TRAIL group,Gemcitabine group,TRAIL plus Gemcitabine group,and the control group.The SW1990 cells were treated with TRAIL and Gemcitabine in different concentrations and time.The cell growth inhibition rate (CGIR) was detected by MTT,the rate of apoptosis was measured by flow eytometry,the apoptosis morphous was observed by Heochst 33342 staining.The expressions of apoptosis-associated proteins such as Smas/DIABLO,XIAP,cytochrome C and caspase-3 were detected by Western blot.Results The cell growth of SW1990/Smac was significantly lower than growth of SW1990/ neo.The concentration of TRAIL were 200,500,1000 and 2500 ng/ml respectively.After 24 hours,the CGIR of SW1990/neo and SW1990/Smac were 11.11％,46.03％,67.08％,76.19％ and 22.11％,42.67％,56.63％,67.6％ respectively (P ＜ 0.05).The concentration of Gemcitabine were 10,20,40 and 60 μmol/L respectively.After 24 hours,the CGIR of SW1990/neo and SW1990/Smac were 15.2％,34.6％,55.16％,76.4％ and 22.65％,36.85％,55.11％,79.99％ respectively (P＜0.05).The cells of SW1990/neo and SW1990/Smac were treated by TRAIL(500 ng/ml),Gemcitabine (20 μmol/L) and combination group.The apoptosis rate were 5.64％,15.30％,27.27％ and 20.37％,23.27％,67.30％ (P ＜ 0.05) respectively.In combination group,the expressions of activators of caspase such as Smas/DIABLO,cytochrome C and caspase-3 increased significantly,while the expressions of inhibitor of apoptosis protein XIAP decreased.Conclusions Ectopic expression of Smac/DIABLO could induce the apoptosis of SW1990 cell,inhibit the cell proliferation,and enhence the sensitivity of SW1990 cell to TRAIL and Gemcitabine.The mechanism of apoptosis sensitization effect by Smac/DIABLO was associated with significant up-regulation of Smac/DIABLO,cytochrome C,down-regulation of XIAP,and the activation of caspase-3.