[Nuclear factor kappa B impairs insulin signaling pathway in skeletal muscle cells of rat with sepsis].

OBJECTIVE: To investigate the effects of nuclear factor kappa B (NF-kappaB) on insulin signaling in skeletal muscle cells of rat with sepsis. METHODS: SD rats were randomly divided into two groups: control group and sepsis group.Sepsis model was reproduced by cecal ligation and puncture in sepsis group. At 8, 16, 24, 48 and 72 h after operation, the gastrocnemius was harvested. Conventional HE staining was used to observe the morphology of skeletal muscle cells. IRS-1 protein and tyrosine phosphorylation of IRS-1 and Ser(307) phosphorylation of IRS-1 were detected by Western Blotting and immuno-precipitation. Activities of NF-kappaB in skeletal muscle cells were detected by electrophoretic mobility shift assay. RESULTS: Tyrosine phosphorylation of IRS-1 in sepsis group was significantly lower than in control group (P < 0.01), while Ser(307) phosphorylation of IRS-1 in sepsis group was significantly higher than in control group (P < 0.01). In sepsis group, NF-kappaB activity in skeletal muscle cells was significantly higher than in control group (P < 0.01). There was significant negative correlation between activity of NF-kappaB and tyrosine phosphorylation of IRS-1 (r = 0.972, P < 0.01). There was significant positive correlation between activities of NF-kappaB and Ser(307) phosphorylation of IRS-1 (r = 0.969, P < 0.01). CONCLUSIONS: There is no inflammatory cell infiltrate in skeletal muscle cells with sepsis. But the activity of NF-kappaB in skeletal muscle cells is obviously enhanced, and it is closely related with disorder of insulin signaling in skeletal muscle cells of rat with sepsis.

Omega-3 polyunsaturated fatty acids affect lipopolysaccharide-induced maturation of dendritic cells through mitogen-activated protein kinases p38.

OBJECTIVE: The omega-3 polyunsaturated fatty acids (PUFAs) play a key role as immune response modulators and suppressors of immunologic functions, such as lymphocyte proliferation, cytokine production, and cell surface molecular expression in T lymphocytes, monocytes, and natural killer cells. However, little is known about the effect of omega-3 PUFAs on dendritic cells (DCs). We studied the effect of omega-3 PUFAs on DCs and the related intracellular signal transduction pathway. METHODS: Dendritic cells were generated from human peripheral blood monocytes in the presence of granulocyte-macrophage colony-stimulating factors and interleukin (IL)-4 and treated with eicosapentaenoic acid (EPA), docosahexanoic acid (DHA), and stearic acid for 24 h. Lipopolysaccharide (LPS) was used for maturation of the DCs. The expressions of CD40, CD80, CD86, and human leukocyte antigen-DR (HLA-DR) were analyzed by flow cytometry; production of IL-12 and tumor necrosis factor-alpha were detected by reverse transcriptase-polymerase chain reaction and enzyme-linked immunosorbent assay. The proliferative ability of allogeneic T cells stimulated by DCs was evaluated by tritiated thymidine ((3)H-TdR). Western blot analysis of p38 mitogen-activated protein kinase was conducted. RESULTS: The omega-3 PUFAs reduced expression levels of costimulatory molecules CD80 and CD86 and major histocompatibility complex HLA-DR. IL-12 and tumor necrosis factor-alpha levels decreased significantly in the EPA and DHA groups. EPA and DHA also significantly reduced the proliferative ability of allogeneic T cells stimulated by DCs. The omega-3 PUFAs significantly inhibited LPS-induced p38 phosphorylation. CONCLUSION: The omega-3 PUFAs may inhibit LPS-induced DC maturation and upregulate cytokine production. Impaired p38 mitogen-activated protein kinase activity is a potential critical intracellular signaling transduction mechanism.

Modulation of mitogen­activated protein kinase attenuates sepsis­induced acute lung injury in acute respiratory distress syndrome rats.

Sepsis is the most important predisposing cause inducing acute respiratory distress syndrome (ARDS); however, the mechanism of sepsis leading to the development of ARDS remains to be elucidated. Suppression of the mitogen­activated protein kinase (MAPK) signal by blocking the phosphorylation of Jun N­terminal kinase (JNK) and p38 in lung tissues could alleviate acute lung injury induced by sepsis. MAPK signaling may have a crucial role in development of the sepsis­induced acute lung injury. The specific inhibitors of JNK and p38 MAPK, SP600125 and SB203580, were administrated by intragastric injection 4 h before induction of ARDS after cecal ligation and puncture (CLP). Rats were sacrificed at 1, 6 or 24 h after CLP challenge. The histological evaluation, lung water content, and biochemical analysis were performed. The results revealed that the JNK and p38 MAPK inhibitor improved lung permeability, attenuated system inflammation, further alleviated the lung injury induced by sepsis. In conclusion, JNK and p38 MAPK signaling are essential for the development of ARDS following sepsis. Further studies are needed to illuminate the detailed mechanisms of JNK and p38 MAPK signaling in sepsis­induced ARDS.

[Effects of insulin receptor substrate-1 and its serine phosphorylation and tyrosine phosphorylation on insulin resistance in skeletal muscle cells in the state of sepsis: experiment with rats].

OBJECTIVE: To investigate the effects of insulin receptor substrate (IRS)-1 and its serine (Ser)(307) phosphorylation and tyrosine (Tyr) phosphorylation on insulin resistance in skeletal muscle cells in the state of sepsis. METHODS: 120 SD rats were randomly divided into 3 groups: 10% group, with 10% of the total cecal length ligated and punctured without use of antibiotic so as to make sepsis model; 30% group, with 30% of the total cecal length ligated and punctured; and control group, undergoing sham operation. Fasting venous blood samples were collected before the operation to detect the fasting plasma glucose (FPG). 0, 8, 16, 24, and 48 hours after the operation 8 rats in each group underwent fasting of food and without fasting of water for 8 hours, i.e., until the 8 th, 16 th, 24 th, 48 th, and 72 nd hours after the operation. Then the rats underwent anesthesia, with blood sample from the vena cava and specimen of gastrocnemius of the hind leg collected, and then killed. The levels of FPG, fasting plasma insulin (FINS), tumor necrosis factor (TNF)-alpha, and interleukin (IL)-6 were measured. HOMA method was used to calculate the insulin resistance index (Ig-IRI). Immunohistochemistry was used to quantitatively examine the IRS-1 protein and its Ser(307) phosphorylation and Tyr phosphorylation in the gastrocnemius. Western blotting and immunoprecipitation were used to semi-quantitatively examine the changes in contents of IRS-1 and its Ser(307) phosphorylation and Tyr phosphorylation in the gastrocnemius respectively. RESULTS: The survival rates at different time points of the control group were all 100%, all significantly higher than those of the other 2 groups (all P < 0.01), and those of the 10% group were all significantly higher than those of the 30% group (all P < 0.01). The levels of TNF-alpha and IL-6 of the 10% and 30% groups at different time points were all significantly higher than those of the control group (all P < 0.01), and those of the 30% group were all significantly higher than those of the 10% group (all P < 0.01). The FPG, FINS, and IgIRI were not significantly different among the 3 groups before the operation, and those of the 10% and 30% groups at different time points after operation were all significantly higher than those of the control group (all P < 0.01) and peaked 8 h after the operation, with those of the 30% group all significantly higher than those of the 10% group (all P < 0.01). The degree of increase of FINS was remarkably higher than that of FPG. IRS-1 was positive and located in the cytoplasm of the gastrocnemius cells in both the control and 30% groups; IRS-1 Tyr phosphorylation was positive in the control group and sporadic positive in the 30% group. IRS-1 Ser(307) was negative in the control group and strong positive in the 30% group. Semi-quantitative examination showed that the IRS-1 level at different time points after operation of the 30% group were not significantly different from those of the control group (all P > 0.05), and IRS-1 Tyr phosphorylation degrees at different time points of the 30% group were all significantly lower than those of the control group (all P < 0.01), and the IRS-1 Ser(307) phosphorylation at different time points of the 30% group were all significantly higher than those of the control group (all P < 0.01). Spearman correlation analysis showed that IgIRI was significantly negatively correlated with IRS-1 Tyr phosphorylation (r = -0.957, P < 0.01), and significantly positively correlated with IRS-1 Ser(307) phosphorylation (r = -0.955, P < 0.01). CONCLUSION: Under the status of sepsis the IRS-1 content in the skeletal muscle cells is unchanged, the level of IRS-1 Tyr phosphorylation level is decreased, and the IRS-1 Ser phosphorylation is increased. The degrees of such changes are closely related with the degree of insulin resistance.

[Effects of high-volume continuous hemofiltration on inflammatory reaction in experimental porcine pancreatitis in pig].

OBJECTIVE: To investigate the effect of high-volume continuous hemofiltration on inflammatory reaction in experimental severe acute pancreatitis (SAP) in pigs. METHODS: SAP was reproduced in pigs by intraductal injection of sodium taurocholate and trypsin, and they were randomly divided into three groups. Control group consisted of animals with SAP running its spontaneous course. Low-volume continuous venovenous hemofiltration (CVVH) group animals received a low volume (20 ml.kg(-1).h(-1)) CVVH, and high-volume CVVH group animals received a high volume (100 ml.kg(-1).h(-1)) CVVH both started at the onset of SAP. Vital signs were monitored. The serum concentrations of tumor necrosis factor-alpha (TNF-alpha), interleukin-6 (IL-6), IL-10, and activated nuclear factor-kappaB (NF-kappaB) levels of peripheral blood mononuclear cell were determined at 0, 6, 12, 24, and 36 hours after the onset of SAP. RESULTS: The median survival time of control, low-volume and high-volume CVVH groups was respectively 41 hours, 50 hours and 65 hours. Survival time of the latter two groups was significantly higher than that in control group (P<0.05 and P<0.01), and the survival time of animals in high-volume CVVH group was significantly higher than low-volume CVVH (P<0.05). In the high-volume CVVH group, plasma contents of TNF-alpha, IL-6 and IL-10 were lower significantly than in the low-volume CVVH and control groups from the beginning to the end of the experiment. In high-volume CVVH group, the expressions of NF-kappaB activation at 6, 12 and 24 hours were lower than those in the control and low-volume CVVH groups respectively. CONCLUSION: Early CVVH can blunt the excessive inflammatory reaction in experiment porcine pancreatitis in pigs, obviously prolong survival time, and improve prognosis. High-volume CVVH is significantly efficacious compared with low-volume CVVH in these respects.

Amelioration of hemodynamics and oxygen metabolism by continuous venovenous hemofiltration in experimental porcine pancreatitis.

AIM: To investigate the potential role of continuous venovenous hemofiltration (CVVH) in hemodynamics and oxygen metabolism in pigs with severe acute pancreatitis (SAP). METHODS: SAP model was produced by intraductal injection of sodium taurocholate (4%, 1 mL/kg body weight (BW)) and trypsin (2 U/kg BW). Animals were allocated either to untreated controls as group 1 or to one of two treatment groups as group 2 receiving a low-volume CVVH (20 mL/(kg.h)), and group 3 receiving a high-volume CVVH (100 (mL/kg.h)). Swan-Ganz catheter was inserted during the operation. Heart rate, arterial blood pressure, cardiac output, mean pulmonary arterial pressure, pulmonary arterial wedge pressure, central venous pressure, systemic vascular resistance, oxygen delivery, oxygen consumption, oxygen extraction ratio, as well as survival of pigs were evaluated in the study. RESULTS: Survival time was significantly prolonged by low-volume and high-volume CVVHs, which was more pronounced in the latter. High-volume CVVH was significantly superior compared with less intensive treatment modalities (low-volume CVVH) in systemic inflammatory reaction protection. The major hemodynamic finding was that pancreatitis-induced hypotension was significantly attenuated by intensive CVVH (87.4+/-12.5 kPa vs 116.3+/-7.8 kPa, P<0.01). The development of hyperdynamic circulatory failure was simultaneously attenuated, as reflected by a limited increase in cardiac output, an attenuated decrease in systemic vascular resistance and an elevation in oxygen extraction ratio. CONCLUSION: CVVH blunts the pancreatitis-induced cardiovascular response and increases tissue oxygen extraction. The high-volume CVVH is distinctly superior in preventing sepsis-related hemodynamic impairment.

[Influence and mechanism of a tight control of blood glucose by intensive insulin therapy on human sepsis].

OBJECTIVE: To investigate the effect of a tight control of blood glucose by intensive insulin therapy on human sepsis, and to explore the potential mechanism of the intensive insulin therapy. METHODS: Eligible patients were randomized by a blinded pharmacist to receive tight control of blood glucose by intensive insulin therapy (maintenance of blood glucose at a level between 4.4 and 6.1 mmol/L) or to receive conventional treatment (maintenance of glucose at a level between 10.0 and 11.1 mmol/L). The expression of HLA-DR on peripheral monocytes was measured in 54 patients by flow cytometry on 24 h, 3 d, 5 d, 7 d, 10 d and 14 d of intensive care in parallel with serum c-reactive protein (CRP), severity of the disease (APACHE II score, SOFA score) and clinical data collection. RESULTS: Patients receiving intensive insulin therapy were less likely to require prolonged mechanical ventilation. Tight control of blood glucose significantly reduced the number of days during which leukopenia or leukocytosis and the days with hypo- or hyperthermia (P < 0.05). Hypoglycemia occurred in 3 patients (10.7%) in the tight control of blood glucose group. There were no instance of hemodynamic deterioration or convulsions. Compared with the conventional treatment, tight control of blood glucose also increased the HLA-DR expression of peripheral monocytes, and there were significantly difference on 3 d, 5 d and 7 d (P < 0.05). Whereas it suppressed the elevated serum CRP concentrations, there was significantly difference on 7 d (P < 0.05). CONCLUSIONS: Tight control of blood glucose by intensive insulin therapy expedited healing of human sepsis, and increased the HLA-DR expression of peripheral and suppressed the elevated serum CRP. So, it is necessary to use insulin to strict control the glucose levels in human sepsis.

[Experimental study of hemodynamics and oxygen metabolism in pigs with severe acute pancreatitis].

OBJECTIVE: To observe the changes in hemodynamics and oxygen metabolism in pigs with severe acute pancreatitis (SAP) so as to provide a theoretical basis for clinical treatment. METHODS: A porcine model of SAP was reproduced by infusing normal saline (1 ml/kg) of sodium taurocholate (4%) and trypsin (1%) into the pancreatic duct (n=8). Heart rate (HR), central venous pressure (CVP), mean arterial pressure (MAP), pulmonary arterial wedge pressure (PAWP), mean pulmonary arterial pressure(MPAP) and cardiac output were continuously measured with the aid of Swan-Ganz catheter and electrocardiography monitor, and cardiac index (CI) was calculated. Oxygen delivery (DO(2)), oxygen consumption (VODO(2)) and oxygen extraction (ODO(2)ext) were calculated according to the analysis of the blood-gases in arterial and mixed venous blood at 0, 6, 12, 24, 36 hours after taurocholic acid injection, and the result were analyzed. RESULTS: Compared with baseline (0 hour), MAP and CI decreased significantly 12 hours after the acid insult (all P<0.05). Both of partial pressure of artery (PaO(2)) and DO(2) showed a tendency to fall. Compared with 0 hour, PaO(2) decreased significantly at 6, 12, 24 and 36 hours (all P<0.05), and DO(2)at 24 hours (P<0.05). The trends of VO(2) and O(2)ext were consistent, both of them peaked at 6 hours (both P<0.05), then, began to lower, and the difference was statistically significance at 24 hours (both P<0.05). CONCLUSION: There is not only hemodynamic disturbances but also oxygen metabolism dysfunction in pigs with SAP. The pathogenesis of multiple organ dysfunction syndrome might be attributable to the lowering of VO(2) and O(2)ext.

[Clinicopathological study of primary meningeal hemangiopericytoma].

BACKGROUND AND OBJECTIVES: Meningeal hemangiopericytoma is an uncommon tumor. This study was designed to investigate the clinicopathological and biology behavior of primary meningeal hemangiopericytoma. METHODS: Clinical data, combined with histopathology and immunohistochemistry of 20 cases of meningeal hemangiopericytoma were reviewed, in which 4 specimens were examined with electron microscope. RESULTS: The average age of patients with primary meningeal hemangiopericytoma was 42.4 year-old (21-69 years). The ratio of male to female was 1.2: 1. Most of the patients went to hospital for the symptoms of central nervous system such as headache. The tumor could occur on any locus of the cranial or spinal dura. Grossly, many of the tumors had capsule, whose testure were tenacious, and part of them looks like fish meat. Histopathologically, the small vascular spaces in the tumor were rich, the typical antler-liked vessel could be found, the short-spindle tumor cells were around the vessel, and distributed by radiation-shape. The tumor cells were pleomorphic and atypical, and could be found mitotic activity. Staining of argyrophilic fiber: the argyrophilic fiber surrounded single tumor cell, and distributed by radiation-shape around vessel. Immunohistochemistry showed negative for S-100 protein, F VIII, EMA, GFAP and CD34, while Vim was positive. Electron microscopically, the rich bundles of 10nm long intermediate filaments could be found in tumor cells. The exobasallamina, of cells were evidenced, and distributed around single cell. Follow-up, 8 of 17 cases were relapsed (47.1%). CONCLUSION: Meningeal hemangiopericytoma is a low-malignant tumor original from meningeal mesenchymal tissue. The features of histopathology, immunphenotype and ultrastructure are similar to hemangiopericytoma of the soft tissue.