Role of interferon regulatory factor-1 in lipopolysaccharide-induced mitochondrial damage and oxidative stress responses in macrophages.

Sepsis causes many early deaths; both macrophage mitochondrial damage and oxidative stress responses are key factors in its pathogenesis. Although the exact mechanisms responsible for sepsis-induced mitochondrial damage are unknown, the nuclear transcription factor, interferon regulatory factor-1 (IRF-1) has been reported to cause mitochondrial damage in several diseases. Previously, we reported that in addition to promoting systemic inflammation, IRF-1 promoted the apoptosis of and inhibited autophagy in macrophages. In the present study, we hypothesized that lipopolysaccharide (LPS)-induced IRF-1 activation in macrophages may promote mitochondrial damage and oxidative stress. In vitro, LPS was found to promote IRF-1 activation, reactive oxygen species (ROS) production, adenosine triphosphate (ATP) depletion, superoxide dismutase (SOD) consumption, malondialdehyde (MDA) accumulation and mitochondrial depolarization in macrophages in a time- and dose-dependent manner. These effects were abrogated in cells in which IRF-1 was knocked down. Furthermore, IRF-1 overexpression increased LPS-induced oxidative stress responses and mitochondrial damage. In vivo, peritoneal macrophages obtained from IRF-1 knockout (KO) mice produced less ROS and had less mitochondrial depolarization and damage following the administration of LPS, when compared to their wild-type (WT) counterparts. In addition, IRF-1 KO mice exhibited a decreased release of mitochondrial DNA (mtDNA) following the administration of LPS. Thus, IRF-1 may be a critical factor in augmenting LPS-induced oxidative stress and mitochondrial damage in macrophages.

[The experiment study of treatment of infectious acute lung injury by intravenous administration of adenovirus borne inhibitor of nuclear factor-ΚB gene in rat].

OBJECTIVE: To observe the effects of adenovirus borne IΚB gene, an inhibitor of nuclear factor-ΚB (NF-ΚB), infused via central vein, to treat infectious acute lung injury (ALI) in rats. METHODS: According to random number table method, 30 pathogen-free Sprague-Dawley (SD) rats were randomly divided into three groups: sham group, ALI model group, IΚB gene treatment group, with 10 rats in each group. The rats of IΚB gene treatment group were infused 1 ml adenovirus borne IΚB gene (titre: 1×10(9)pfu ), the rats of sham group and ALI model group were infused 1 ml normal saline through central vein. Subsequently, the rats of ALI model group and the IΚB gene treatment group were given 1 ml lipopolysaccharide (LPS, 5 ml/kg) through tail vein to reproduce model of ALI. On the other hand, the rats of sham group were given 1 ml normal saline through tail vein. Blood gas analysis, the ratio of wet to dry weight (W/D) of lung, plasma contents of tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6), and protein expression of NF-ΚBp65 in lung tissue were determined, the pathobiological changes in lung tissue were microscopically observed and the scores of lung injury were calculated after 7 days. RESULTS: The rats in three groups survived, except 1 rat died in ALI model group.Blood pH and partial pressure of arterial carbon dioxide (PaCO(2)) showed no obviously differences among three groups. Partial pressure of arterial oxygen (PaO(2) ) was highest in sham group and the lowest in ALI model group. The plasma content of TNF-α (µg/L) and IL-6 (ng/L ) in ALI model group were obviously higher than those in sham group (TNF-α: 5.20±1.09 vs. 3.01±0.46; IL-6: 540.28±100.78 vs. 214.45±61.37, both P<0.05). The plasma content of TNF-α and IL-6 in IΚB gene treatment group were obviously lower than those in ALI model group (TNF-α: 3.70±0.96 vs. 5.20±1.09, IL-6: 356.49±60.58 vs. 540.28±100.78, both P<0.05), and TNF-α content had restored to the level observed in sham group. The ratio of W/D of lung was lowest in sham group (4.49±0.36) and highest in ALI model group (5.78±0.43), and that of IΚB gene treatment group (5.33±0.38) was lower than that of ALI group. The score of lung injury was lowest in sham group (0.17±0.41) and highest in ALI model group (2.29±0.76), and that of IΚB gene treatment group (1.57±0.53) was lower than that of ALI group. The scale of NF-ΚBp65 immunohistochemistry was lowest in sham group (1.00±0.89) and highest in ALI model group (9.43±1.13), and that of IΚB gene treatment group (4.00±1.15) was lower than the latter. The differences of all the above parameters in three groups were statistically significant (all P<0.05 ). CONCLUSION: Increased expression of IΚB gene by an infusion of adenovirus borne IΚB gene through central vein can lower the levels of pro-inflammatory factors, such as TNF-α and IL-6, restrain the NF-ΚB activation, reduce lung water, alleviate alveolar collapse and lung consolidation in ALI in rats, thus lung injury is ameliorated.

[Efficacy observation of electroacupuncture intervention on severe acute pancreatitis at early stage complicated with intestinal paralysis].

OBJECTIVE: To explore the clinical efficacy of electroacupuncture intervention on severe acute pancreatitis (SAP) at early stage complicated with intestinal paralysis. METHODS: Sixty-eight cases of SAP were randomly divided into observation group (48 cases) and control group (20 cases). In observation group, according to the course of sickness, the early-stage subgroup (30 cases, hospitalized in 3 d) and late-stage subgroup (18 cases, hospitalized in 3-7 d) were subdivided. In control group, the conventional treatment was applied. In observation group, based on the same treatment as control group, electroacupuncture was supplemented at Zhongwan (CV 12), Zusanli (ST 36), Neiguan (PC 6), Hegu (LI 4), etc. Acute physiology and chronic health evaluation (APACHE) II scores, the recovery time of intestinal paralysis and laboratory indices, complications, operation transfer rate, death rate and the admission time were compared among groups after treatment. RESULTS: The total effective rate was 83.3% (25/30) in early-stage subgroup, which was superior to 72.2% (13/18) in late-stage subgroup and 65.0% (13/20) in control group (P < 0.05, P < 0.01). In early-stage subgroup, the remission time of abdominal pain, the remission time of abdominal distention, the recovery time of borborygums, the recovery time of gas discharge, and the recovery time of defecation were all shorter significantly than those in late-stage subgroup and control group (P < 0.05, P < 0.01). In early-stage subgroup, APACHE II scores, the recovery time of WBC and blood/uric amylase, complications, operation transfer rate, death rate and admission time were all lower remarkably than those in late-stage subgroup and control group (P < 0.05, P < 0.01); but, there were no statistical significant differences in comparison between late-stage subgroup and control group (all P > 0.05). CONCLUSION: The clinical efficacy of electroacupuncture intervention on SAP complicated with intestinal paralysis is superior remarkably to that of conventional treatment, and the efficacy of electroacupuncture intervention at early stage is better than that at late stage.

[Clinical experience of successful management of a human case with A/H5N1 infection in Hunan Province].

OBJECTIVE: To study the clinical features and successful management of a survived human case with A/H5N1 infection. METHODS: The data of a confirmed case of human case with A/H5N1 infection in Hunan province were collected and analyzed. RESULTS: This patient with A/H5N1 infection in Hunan province was confirmed by reverse-transcription polymerase chain reaction (RT-PCR) for A/H5N1 in airway secretions. The main clinical presentations included fever, cough and dyspnea. An extensive pulmonary infiltration developed quickly, followed by multi-organ dysfunction. Early administration of oseltamivir, early protection of organ function and extensive support were effective for the cure of the disease in this case. CONCLUSION: Early administration of oseltamivir, early protection of organ function and adequate support therapy may be useful for the treatment of human A/H5N1 infection.

[Prophylactic effect of ambroxol on acute hydrochloric acid aspiration - induced lung injury].

OBJECTIVE: To evaluate the protective effect of ambroxol, a muco-active drug, on acute hydrochloric acid-induced lung injury in rats. METHODS: Thirty pathogen-free SD rats were randomly divided into three groups: group A (n=10) and group B (n=10) were injected normal saline (NS) intraperitoneally (6.7 ml/kg), and group C with ambroxol (50 mg/kg), once a day for 3 consecutive days. Then animals received in tracheal instillation of NS (group A, pH 5.3, 1.2 ml/kg) or hydrochloric acid/NS (group B and C, pH 1.25, 1.2 ml/kg). Five hours after instillation of the injury vehicle, the arterial gas was determined, and the extent of lung injury was assessed by measuring the ratio of wet to dry weight (W/D) and evaluation of pathological change in lung tissue. RESULTS: (1)Partial pressure of oxygen in arterial blood (PaO(2)) was significantly lower in group B than in groups A and C, although pH and partial pressure of carbon dioxide in arterial blood (PaCO(2)) in three groups showed little difference (all P<0.01). (2)The W/D was the highest in group B and the lowest in group A. (3)Severe acute lung injuries were detected in group B by pathological examination, the extent of injury was less in group C than in group B, but more severe than in group A (group A vs. B and B vs. C in mean pathologic score, P<0.01 and P<0.05, respectively). CONCLUSION: Hydrochloric-acid aspiration may induce an acute and diffuse lung injury, with manifestations of hyperpnea, lower PaO(2) and severe pathological changes in lung tissues. Ambroxol may have a protective effect against lung injury induced by hydrochloric acid.

[Clinical study of low molecular weight heparin therapy for sepsis].

OBJECTIVE: To investigate the therapeutic effect of low molecular weight heparin (LMWH) therapy on sepsis. METHODS: Forty sepsis patients were randomly divided into two groups: routine treatment group and LMWH treatment group. Score of acute physiology and chronic health evaluation II (APACHE II), the days in intensive care unit (ICU) and mortality rate in 28 days were observed, and the levels of interleukin-6 (IL-6), malondialdehyde (MDA), superoxide dismutase (SOD), coagulation function and platelet count (PLT) were determined before and after treatment in the two groups. RESULTS: Both APACHE II and IL-6 levels in LMWH group decreased with passage of time, the differences were significant between the results on day 7 and that of pretreatment (both P<0.05). In the routine treatment group, APACHE II and IL-6 levels decreased first and then increased, and they were higher than those in LMWH group 7 days after treatment (both P<0.05). In LMWH group, the time of stay in ICU was (9.92+/-6.81)days, the mortality rate in 28 days was 40.9%, and they all were lower than those in routine treatment group [(12.85+/-9.14)days and 50.0%], but the difference was not statistically significant (both P>0.05). After treatment SOD level elevated [(159.13+/-99.31) kU/L vs.(318.38+/-284.29) kU/L] and MDA level lowered [(17.72+/-14.89) micromol/L vs.(6.62+/-5.53) micromol/L] in LMWH group. The changes in MDA and SOD in routine treatment were reverse to those of the LMWH group [SOD: (180.99+/-169.40) kU/L vs. (135.16+/-107.73) kU/L; MDA: (17.25+/-15.74) micromol/L vs. (20.77+/-16.87) micromol/L]. The difference was significant between the two groups after treatment (both P<0.05). The difference in coagulation function and PLT was not significant between the two groups. CONCLUSION: LMWH can ameliorate sepsis by down-regulating the levels of pro-inflammatory cytokines, and suppressing the release of oxygen-derived free radicals. It is a promising treatment measure in sepsis patient with safety and no severe side effects.

[Extracorporeal membrane oxygenation treatment with high-volume hemofiltration in patients with multiple organ dysfunction syndrome].

OBJECTIVE: To evaluate whether extracorporeal membrane oxygenation (ECMO) with high-volume hemofiltration (HVHF) improves hypoxemia and renal function in patients with multiple organ dysfunction syndrome (MODS). METHODS: The study was executed in 8 MODS patients with acute respiratory distress syndrome (ARDS) and acute renal failure (ARF). They were randomly assigned to either 8 hours of HVHF combined with ECMO or HVHF alone in random order. The changes in arterial oxygen pressure(PO(2)), pulse oxygen saturation (SpO(2)), arterial carbon dioxide pressure (PCO(2)), serum creatinine (SCr) and blood urea nitrogen (BUN) levels were measured. RESULTS: Compared with that of before the treatment, PO(2) was increased significantly at 1, 4, 8 hours, and SpO(2) was increased significantly at 4, 8 hours after ECMO with HVHF in MODS patients, the changes of PO(2), SpO(2)and PCO(2)were not significantly during HVHF (all P>0.05). The average concentrations of BUN and SCr were decreased significantly after HVHF or HVHF with ECMO therapy in MODS patients. CONCLUSION: HVHF with ECMO, which can improve hypoxemia significantly, may be a better option for the treatment of MODS patients.

[Effects of high-volume hemofiltration on serum levels of tumor necrosis factor and its receptors in patients with multiple organ dysfunction syndromes].

OBJECTIVE: To investigate whether serum tumor necrosis factor-alpha (TNF-alpha) and its receptors can be removed by high-volume hemofiltration (HVHF) or continuous veno-venous hemofiltration (CVVH). METHODS: The study was performed in 12 multiple organ dysfunstion syndrome (MODS) patients with acute renal failure (ARF). They were randomized to receive either CVVH (n=10) or HVHF (n=8). TNF-alpha and soluble tumor necrosis factor-receptor (sTNF-R1 and sTNF-R2) concentrations were measured in serum by enzyme-linked immunoadsorbent assay (ELISA). RESULTS: Compared with that before the therapy, the average concentrations of plasma creatinine and urea were decreased significantly 8 hours after HVHF or CVVH in MODS patients with ARF (P<0.001). In patients on HVHF, the serum TNF-alpha concentrations were significantly lower 8 hours after treatment (P<0.01) compared with that before treatment, 1 hour and 4 hours after treatment. There were not significant changes in the serum TNF-alpha concentrations in patients on CVVH and the serum sTNF-R1 and sTNF-R2 concentrations in patients on CVVH or HVHF. CONCLUSION: In MODS patients with ARF undergoing HVHF, the serum TNF-alpha concentrations dropped significantly, but the serum sTNF-R1 and sTNF-R2 concentrations do not change significantly. Our study suggests that HVHF may be the better option for the treatment of MODS patients.

[Effect of ulinastatin on lung injury after dilute hydrochloric acid aspiration].

OBJECTIVE: To determine the effect of ulinastatin (UTI) on blocking the development of acute lung injury (ALI) induced by acid aspiration in the early period. METHODS: The SD rats were randomly divided into 3 groups: control group (n = 10), injury group (n = 10), and UTI-treated group (n = 10). The rats in the control group were injected intrabronchialy saline while the other 2 groups were injected HCl. The UTI-treated group was injected UTI at 4 x 10(4) U/kg after acid instillation. Blood gas as well as wet/dry weight ratio (W/D) of the left lung was measured. The changes of IL-8 and TNF-alpha levels in the pulmonary tissues were determined by enzyme-linked immunosorbent assay. RESULTS: The result of blood gas analysis in the UTI-treated group was much better than that in the injury group (P < 0.01). W/ D and IL-8, TNF-alpha levels were lower in the UTI-treated group than those in the injury group significantly (P < 0. 01), and there was no difference between the UTI-treated group and the control group in IL-8 and TNF-alpha levels (P > 0. 05). CONCLUSION: UTI administration can lessen the development of ALI induced by acid aspiration in the early period.

[Oxidative and anti-oxidative effects of ambroxol on acute hydrochloric acid-induced lung injury in rats].

OBJECTIVE: To evaluate the protective effect of ambroxol on acute hydrochloric acid-induced lung injury in rats. METHODS: Thirty pathogen-free SD rats were randomly divided into 3 groups: Group A (n=10) served as control group, and received intracheal instillation of normal saline (NS, pH5.3, 1.2 ml/kg) with pre-treatment of intraperitoneal NS; Group B (n=10) received intracheal instillation of hydrochloric acid /NS (pH1.25, 1.2 ml/kg) with pre-treatment of intraperitoneal NS; and Group C received intracheal instillation of hydrochloric acid /NS (pH1.25, 1.2 ml/kg) with pre-treatment of intraperitoneal ambroxol (50 mg/kg/d, 3 days). Five hours after the instillation of the injury vehicle, the arterial gas was examined, the levels of superoxide dismutase (SOD), malondialdehyde (MDA) in the blood and homogenate of harvested lung were assayed respectively. RESULTS: PaO2 in Group B was significantly lower than that in Group A and C (P < 0.01), and pH and PaCO2 in the 3 groups had little difference (P > 0.05). MDA in the lungs of Group B increased obviously, and levels of SOD in the lung and blood decreased significantly in Group B (Group B vs Group A, P < 0.01). Levels of SOD of Group C in the lung and blood were markedly higher than those of Group B (P < 0.01), MDA of Group C was obviously lower than that of Group B (P < 0.01), and MDA of blood in the 3 groups had no significant difference (P > 0.05). CONCLUSION: Ambroxol can inhibit lipid peroxidation and increase antioxidant activity, which may be one of the mechanisms in protecting lung tissue from hydrochloric acid-induced injury.