Endotoxin-induced alterations of adipose tissue function:a pathway to bovine metabolic stress

During the periparturient period, dairy cows exhibit negative energy balance due to limited appetite and increased energy requirements for lactogenesis. The delicate equilibrium between energy availability and expenditure puts cows in a state of metabolic stress characterized by excessive lipolysis in white adipose tissues(AT), increased production of reactive oxygen species, and immune cell dysfunction. Metabolic stress, especially in AT, increases the risk for metabolic and inflammatory diseases. Around parturition, cows are also susceptible to endotoxemia. Bacterial-derived toxins cause endotoxemia by promoting inflammatory processes and immune cell infiltration in different organs and systems while impacting metabolic function by altering lipolysis, mitochondrial activity, and insulin sensitivity. In dairy cows, endotoxins enter the bloodstream after overcoming the defense mechanisms of the epithelial barriers, particularly during common periparturient conditions such as mastitis, metritis, and pneumonia, or after abrupt changes in the gut microbiome. In the bovine AT, endotoxins induce a pro-inflammatory response and stimulate lipolysis in AT, leading to the release of free fatty acids into the bloodstream. When excessive and protracted, endotoxin-induced lipolysis can impair adipocyte's insulin signaling pathways and lipid synthesis. Endotoxin exposure can also induce oxidative stress in AT through the production of reactive oxygen species by inflammatory cells and other cellular components. This review provides insights into endotoxins' impact on AT function, highlighting the gaps in our knowledge of the mechanisms underlying AT dysfunction, its connection with periparturient cows' disease risk, and the need to develop effective interventions to prevent and treat endotoxemia-related inflammatory conditions in dairy cattle.

肝硬化患者血清ET、TNF-α和Endotoxin检测的临床意义

目的:探讨了肝硬化患者血清ET、TNF-α和endotoxin水平的变化及意义。方法:应用放射免疫分析和分光光度计测定法对61例肝硬化患者(其中30例伴肝硬化腹腔积液,31例无肝硬化腹腔积液)进行了血清ET、TNF-α和内毒素(endotoxin)检测,并与35例正常健康人作比较。结果:肝硬化患者血清ET水平非常显著地低于正常人组(P<0.01),而TNF-α和endotoxin水平非常显著地高于正常人组(P<0.01),肝硬化患者ET水平与TNF-α、endotoxin水平呈明显负相关(r=-0.4785、-0.5012,P<0.01)。结论:检测肝硬化患者血清ET、TNF-α和endotoxin水平的变化对了解病情、观察预后均具有重要的临床价值。

Effects of endotoxin on endothelin receptor in hepatic and intestinal tissues after endotoxemia in rats

INTRODUCTIONEndothelins(ETs) has a potent and sustainedvasoconstrictive effect on a variety of blood vessels.The vascular smooth muscle cell (VSMC)is thetarget for ETs.VSMC of the whole body containsendothelin receptor (ETR).A great number ofexperiments have shown that three distinctcomplementary DNAs of ETR have been identifiedi.e.,endothelin A receptor(ET_A receptor),endothelin B receptor(ET_B receptor)

Changes of plasma D(-) -lactate, diamine oxidase and endotoxin in patients with liver cirrhosis

BACKGROUND: Plasma D(-)-lactate and diamine oxidase (DAO) can reflect patients' intestinal mucosal condition. We evaluated the changes of plasma D (-)-lactate, DAO and endotoxin activities and their significance in patients with liver cirrhosis. METHODS: Fifty liver cirrhosis patients were enrolled into experimental group and 30 healthy people into control group. The plasma levels of D(-)-lactate, DAO and endo- toxin were detected spectrophotographically. RESULTS: The level of D(-)-lactate was significantly high- er in the experimental group than that in the control group (P<0.01). Significant differences of D (-)-lactate levels were observed in Child-Pugh subgroups of the experimen- tal group (P <0. 01). The level of DAO was significantly higher in the experimental group than that in the control group (P <0.01), but the level of DAO in Child-Pugh sub- group C was significantly lower than that in Child-Pugh subgroup B (P<0.01). The level of endotoxin was signifi- cantly increased in the experimental group except Child Pugh subgroup A (P<0.01). The plasma levels of D(-) lactate, DAO and endotoxin were positively correlated with each other (P<0.01). CONCLUSIONS: The data suggest that both plasma D(-) lactate and DAO activity are sensitive markers for early diagnosis of gut failure and endotoxemia in patients with liver cirrhosis. The impairment of intestinal barrier func- tion may be one of the critical reasons for deterioration of liver cirrhosis.

Influence of splanchnic vascular infusion on the content of endotoxins in plasma and the translocation of intestinal bacteria in rats with acute hemorrhage necrosis pancreatitis

The main reason for the death of the patient with acute hemorrhage necrosis pancreatitis (AHNP) is pancreatic infection and multi-organ failure caused by endotoxemia and intestinal bacterial translocation[1-7]. However, the pathogenesis of endotoxemia and intestinal bacterial translocation remains a question[8-10]; moreover, no effective method of prevention and cure for it has been found till now[11 -15] In the present study, we infused low dose dopamine and low molecular weight dextran through the catheters to abdominal aorta and portal vein, and observed its influence on the endotoxin concentration in plasma and the rate of translocation of intestinal bacteria in AHNP rats.

Experimental study on the role of endotoxin in the development of hepatopulmonary syndrome

AIM: To evaluate the role of intestinal endotoxemia in the genesis of hepatopulmonary syndrome. METHODS: A rat model of cirrhosis was prepared with the method of compound factors. At the end of the eighth week, rats with cirrhosis were treated with 300 μg LPS/100 g body weight, and 1 g/rat of glycine about four h prior to LPS. After three h of LPS treatment, blood and tissues were collected for various measurements. Kupffer cells were isolated from male Wistar rats and cultured, and divided into five groups. Supernatant was harvested at 3 h after treatment with LPS for measurement of tumor necrosis factor-alpha (TNF-α). RESULTS: Our results showed that in rats with cirrhosis, slowed and deepened breath with occasional pause was. PaO2, PaCO2 and standard bicarbonate (SB) in arterial blood were decreased. Arterial O2 and actual bicarbonate (AB) were markedly decreased. There was a close correlation between decreased O2 and endotoxin. Metabolic acidosis accompanying respiratory alkalosis was the primary type of acid-base imbalance. The alveolar-arterial oxygen gradient was sharply widened. Massive accumulation of giant macrophages in the alveolar spaces and its wall and widened alveolar wall architecture were observed. The number of bacterial translocations in mesenteric lymph nodes increased. The ratio of TC99M-MAA brain-over-lung radioactivity rose. Endotoxin, and TNF-α, endothelin-1 (ET-1), nitric oxide (NO) in plasma and ET-1, carbon monoxide (CO) in lung homogenates increased. After administration of a given dosage of LPS in rats with cirrhosis, various pathological parameters worsened. Plasma level of endotoxin was related to TNF-α, ET-1, NO in plasma and ET-1, NO, CO in lung homogenates. TNF-α level was related to ET-1 and NO in plasma and lung homogenates and CO in lung homogenate as well. The level of TNF-α increased after infusion of LPS into culture supernatant of Kupffer cells in vitro. However, TNF-α significantly decreased after pretreatment with glycine, PD98059 and SB212850. Glycine could antagonize the effect of LPS in vivo and in vitro. CONCLUSION: Intestinal endotoxemia accompanying by cirrhosis may be an important mechanism in the development of hepatopulmonary syndrome in rats. Overproduction of TNF-α due to endotoxin stimulation of Kupffer cells via mitogen-activated protein kinase (MAPK) signal transduction pathway may be a major mechanism mediating the pathologic alterations of hepatopulmonary syndrome.

Endotoxins in the prostatic secretions of chronic prostatitis patients

Aim: To evaluate the clinical significance of the quantitative determinations of endotoxins in the expressed prostatic secretions (EPS) of chronic prostatitis (CP) patients. Methods: The EPS of 45 patients with CP and 15 normal volunteers were obtained for microscopic examination, bacterial culture and endotoxin determination. The level of endotoxins was determined by the Limulus-amebocyte-lysate test with chromogenic substrate. Results: Patients with CP had higher mean levels of endotoxins in EPS than normal volunteers [52.06 ± 32.83 EU.L^(-1) vs. 4.77 ± 4.14 EU'L^(-1) (P < 0.05)]. The levels of endotoxins in CP type Ⅱ, type Ⅲa and type Ⅲb were 68.62 ± 34.78 EU.L^(-1), 45.30± 23.33 EU.L^(-1) and 15.83 ± 5.31 EU·L^(-1), respectively [type Ⅱ vs. type Ⅲa (P > 0.05), type Ⅲb vs. normal controls (P > 0.05), type Ⅱ/type Ⅲa vs. normal controls P < 0.05)]. Conclusion: CP patients have elevated levels of endotoxins in the EPS, which suggests that inflammation is a feature of this disease. EPS endotoxin determination is not only helpful in diagnostic confirmation, but also in evaluating the response to treatment in CP patients.

Effect of endotoxin on fibronectin synthesis of rat primary cultured hepatocytes

AIM To investigate the effect of endotoxin on liver fibrosis and further define the role of hepatocytes in production of fibronectin in primary liver cell culture by endotoxin.METHODS After isolation and seeding of hepatocytes, the obtained cells were added to various doses (0, 5, 10, 15 and 20mg/L) of LPS treated culture media. The cells were collected and counted at various periods (0, 12, 24, 48, 72, 96, 120h). The concentrations of fibronectin were tested by electrophoresis.RESULTS The fibronectin levels tended to increase with prolongation of culture time. There was a sharp increase after 72h in 10 or 15 LPS treated group. The peak level of fibronectin was above 20mg/L. However, cell proliferation was inhibited during the course. Cell number of untreated control group (4.6±0.1×106) was about three-fold that of 20 LPS treated group (1.6±0.2×106) at 120h.CONCLUSION Hepatocytes have a potent ability to produce fibronectin stimulated by endotoxin, suggesting that hepatocytes might participate in the process of liver fibrosis.

Evaluation on Sensitivity of the Human Sperm Motility Assay for Detecting Endotoxin in Culture Medium

Objective To investigate the sensitivity of the human sperm motility assay for detecting endotoxin in culture mediumMaterials &. Methods Motile sperm were separated and exposed to different concentrations of endotoxin (0.5 ng/mL, 1ng/mL, 10ng/mL, 1000ng/mL, 10 000ng/ mL, and 50 000ng/mL), and sperm motility was determined after incubation. Effects of endotoxin on sperm motility in media without albumin were also examined. In addition, at the same concentrations of endotoxin (0. 5ng/mL, 1 ng/mL, and 10 ng/ mL ) , the sensitivity of the human sperm motility assay was compared to those of 1-cell and 2-cell mouse embryo bioassays.Results At levels of 0. 5ng/mL-1000ng/mL endotoxin in media with 2mg/mL albumin, sperm did not show significant change in motility during 24 h of incubation when compared with the control (P>0. 05). However, the sperm motility was significantly inhibited at endotoxin dosages of 10 000 and 50 000 ng/mL. In the absence of albumin supplementation, at endotoxin levels of 50 000ng/mL, and 1 000ng/mL, there was a marked decrease in sperm motility compared with the control after 2 h or 8 h of incubation, respectively (P<0. 01). In media containing 0. 5 ng/mL and 1 ng/ mL endotoxin, 1-cell and 2-cell mouse embryos had significantly reduced developmental rates in all developmental stages, and at the level of 10ng/mL, the development of the embryos was arrested. Conclusion The human sperm motility assay could detect high levels of endotoxin in culture medium but its sensitivity to endotoxin would be inferior to that of the 1-cell or 2-cell mouse embryo bioassay. In the absence of albumin supplementation, the sensitivity of the sperm motility assay could be improved.

Over-starvation aggravates intestinal injury and promotes bacterial and endotoxin translocation under high-altitude hypoxic environment

AIM:To study whether over-starvation aggravates intestinal mucosal injury and promotes bacterial and endotoxin translocation in a high-altitude hypoxic environment.METHODS:Sprague-Dawley rats were exposed to hy-pobaric hypoxia at a simulated altitude of 7000 m for 72 h.Lanthanum nitrate was used as a tracer to detect intestinal injury.Epithelial apoptosis was observed with terminal deoxynucleotidyl transferase dUTP nick end labeling staining.Serum levels of diamino oxidase(DAO),malondialdehyde(MDA),glutamine(Gln),superoxide dismutase(SOD) and endotoxin were measured in intestinal mucosa.Bacterial translocation was detected in blood culture and intestinal homogenates.In addition,rats were given Gln intragastrically to observe its protective effect on intestinal injury.RESULTS:Apoptotic epithelial cells,exfoliated villi and inflammatory cells in intestine were increased with edema in the lamina propria accompanying effusion of red blood cells.Lanthanum particles were found in the intercellular space and intracellular compartment.Bacterial translocation to mesenteric lymph nodes(MLN) and spleen was evident.The serum endotoxin,DAO and MDA levels were significantly higher while the serum SOD,DAO and Gln levels were lower in intestine(P< 0.05).The bacterial translocation number was lower in the high altitude hypoxic group than in the high altitude starvation group(0.47±0.83 vs 2.38±1.45,P<0.05).The bacterial translocation was found in each organ,especially in MLN and spleen but not in peripheral blood.The bacterial and endotoxin translocations were both markedly improved in rats after treatment with Gln.CONCLUSION:High-altitude hypoxia and starvation cause severe intestinal mucosal injury and increase bacterial and endotoxin translocation,which can be treated with Gln.

Effects of recombinant human growth hormone on intestinal translocation of bacteria and endotoxin in rats with obstructive jaundice

Extrahepatic biliary obstruction promotes intestinal translocation of bacteria and endotoxin and this process is an important cause of morbidity and mortality in patients with jaundice. This study was undertaken to investigate the effect and mechanism of recombinant human growth hormone (rhGH) and to alleviate intestinal translocation of bacteria and endotoxin in murine obstructive jaundice. METHODS:A group of 42 Wistar rats were divided into 3 groups:sham operation (SO), bile duct ligation (BDL), and BDL and rhGH treatment (rhGH). By the end of the experiment,on day 7, the animals were killed, and their liver function and serum endotoxin were measured, bacterial cultures of the liver, kidney and mesenchymal lymph were made. Terminal ileum mucosa was observed under an electron microscope. RESULTS:Liver function was improved more significantly in the rhGH group than in the BDL group. The value of endotoxin in the rhGH group was 0.38±0.03 EU/ml, significantly lower than that in the BDL group (0.65±0.04 EU/ml, P【0.01), and similar to that in the SO group (0.30±0.02 EU/ml, P】0.05). The rate of bacteria translocation in the liver, kidney and mesenteric lymph was much higher in the BDL group than in other two groups. The rate of bacteria translocation in mesenteric lymph was 64.29%,significantly higher than that in the SO group and the rhGH group (P【0.05). There was no significant difference in bacteria translocation rate between the SO group and the rhGH group (P】0.05). Under an electron microscope , ileum mucosa epithelial cells in the BDL group were necrotic, and organelle were markedly metamorphic. In the rhGH group, ultrastructural changes were less evident or similar to those in the SO group. CONCLUSION:rhGH has significant protective effects on intestinal mucosa barrier in obstructive jaundice, and reduces intestinal translocation of bacteria and endotoxin.

Removing Endotoxin from Protein Solution by Chitosan Modified Affinity Membrane

Affinity membrane was prepared with chitosan immobilized on the hydrophile- modified poly(vinylidene fluoride) (PVDF) membrane. Fourier transform infrared spectroscopy (FTIR.) analysis indicated that the contents of —NH2 and —OH groups increased and fluoride decreased on the membrane surface after modification. Using this kind of affinity membrane, the effects of operation parameters such as pH, ionic strength and flow rate, on the amount of endotoxin removed were investigated. The results showed that the equilibrium adsorption capacity and the dissociation constant of the affinity membrane to endotoxin were 21.4 EU·mg-1 membrane and 0.50EU·ml-1, respectively, at pH 7.0 and ionic strength 0.2 mol·L-1. Adsorption appeared to follow a typical Langmuir adsorption isotherm. At pH 5.0, ionic strength of 0.2 mol·L-1, the removal rate of endotoxin from BSA solution with the chitosan affinity membrane was up to 88.6% (11.50 EU·mg-1 membrane), and the recovery of BSA was 93.4% (0.187mg·mg-1 membrane), while at pH 11.0, ionic strength of 0.2mol·L-1, the removal rate of endotoxin from lysozyme solution was 72.4% (9.92EU·mg-1 membrane), and the recovery of lysozyme was 92.3% (0.104 mg·mg-1 membrane).

Effects of Dahuang( Rhubarb) Retention Enema on Leukocyte Interleukin-6,High Sentive C Reactive Protein and Endotoxin in Patients with Acute Pancreatitis

[Objectives] To observe the clinical effect of Dahuang( Rhubarb) retention enema on patients with severe acute pancreatitis and its influences on leukocyte interleukin 6( IL-6),high sentive C reactive protein( hs-CRP) and endotoxin. [Methods]86 cases of acute pancreatitis were randomly divided into the control group( 43 cases) and the treatment group( 43 cases). The control group was given saline enema and routine treatment of western medicine,while the treatment group was treated with Dahuang( Rhubarb) decoction retention enema and routine treatment,2 times/d. After 7 days of treatment,two groups of clinical curative effects were compared. And changes of IL-6,hs-CRP,endotoxin and amylase levels before and after treatment in two groups were compared. [Results] Abdominal pain,abdominal distension,exhaust defecation,bowel sounds in treatment group patients were obviously improved. After treatment,the decline levels of serum IL-6,hsCRP,endotoxin and amylase in the treatment group were significantly better than those in the control group. [Conclusions] Dahuang( Rhubarb) retention enema can significantly improve the clinical curative effect of severe acute pancreatitis,and its mechanism may be related to the inhibition of inflammatory reaction.

Experimental Study on Inactivation of Bacterial Endotoxin by Using Dielectric Barrier Discharge

The low-temperature plasma （LTP） generated by dielectric barrier discharge （DBD） was used to sterilize the E.coli endotoxin, which is usually difficult to kill by traditional methods. Three different concentrations of bacterial endotoxin （1 EU/mL, 0.5 EU/mL and 0.25 EU/mL） were treated by LTP for different time （20 s, 40 s and 60 s）. Tachypleus amebocyte lysate （TAL） method was employed to detect the concentration variation of bacterial endotoxin before and af- ter the plasma treatment, and endotoxic shock mice model was used to evaluate the inactivation effects of LTP on endotoxin for further study. Experimental results demonstrated that, DBD plasma can inactivate the bacterial endotoxin quickly and effectively, and when the LTP treatment time was increased, the concentrations of bacterial endotoxin decreased gradually （after 60 s plasma treatment, its inactivation effect was beyond the Chinese pharmacopoeia standard）, and the average survival time of mice gradually extended. The possible inactivation mechanisms are proposed to be related to reactive oxygen species （ROSs）.

Evaluation of Endotoxin in Culture Medium for Human in vitro Fertilization

To determine whether the presence of bacterial endotoxin in the commercial culture media utilized for human in vitro fertilization （IVF）, and evaluate the difference in detecting endotoxin in culture medium between the human sperm motility assay and the 2-cell mouse embryo assay. Methods Thirty-six batches of culture media commonly used in IVF laboratories from 3 manufacturers were determined for thepresence ofendotoxin before using the medium for the assisted reproductive programs （group A）. After being used, 25 specimens among above media were also tested （group B）. The chromogenic limulus amoebocyte lysate （LAL） test was used for quantification the content of endotoxin. In addition, the human sperm motility assay was compared with the 2-cell mouse embryo assay to evaluate the difference in detecting endotoxin in culture medium. Results Endotoxin was not detected in group A. However, 2 samples were positive in group B, Sperm did not show significant change in motility in group A during 24 h of incubation when compared with the control （P〉0. 05）. However, in group A the 2-cell embryo development to blastocyst was suppressed in 3 batches of media. Conclusions Regular screening of each batch of culture medium should be performed if possible although there was no evidence of endotoxin contamination in commercially prepared pre-tested media. Culture environment should be stringently controlled in case the medium is polluted. The sensitivity of the sperm motility assay was lower than that of the mouse embryo assay for detecting low levels of endotoxin or toxic compounds in the medium.

The U937 cell line induced to express CD14 protein by 1,25-dihydroxyvitamin D3 and be sensitive to endotoxin stimulation

BACKGROUND: CD14 was first described as a differentia- tion antigen on the surface of myeloid lineage cells. It acts as a glycosylphosphatidylinositol ( GPI)-anchored receptor for the complex of lipopolysaccharide (LPS) and plays a key role in the activation of LPS-induced monocytes. The purpose of this study was to observe the expression of CD14 protein and its gene in the human U937 promonocytic cell line when these cells were exposed to 1,25-dihydroxyvita- min D3 ( VitD3 ) and investigate their sensitivity to endo- toxin stimulation. METHODS: U937 cells were exposed to (0.1 μmol) VitD3 for 24 hours and were induced to express the CD14 mRNA gene and CD14 protein, then their responses were observed when they were stimulated with different concentrations of LPS for different time. RESULTS: The U937 cells induced by VitD3 were found to stably express CD14 mRNA and CD14 protein. And CD14 protein enhanced the sensitivity of U937/CD14 cells to li- popolysaccharide ( LPS ) stimulation. NF-ΚB in U937/ CD14 cells can be activated with low concentration of LPS (1 ng/ml-10 ng/ml), the TNF-α mRNA gene was in- duced , and then TNF-α was produced and released into the supernatant of culture. CONCLUSION: VitD3 can induce U937 cell to express the CD14 gene and CD14 protein and enhance the response of this type of cells to LPS stimulation.

Experimental Study on the Mechanism of Protective Effect of Free Fu on Gut-derived Endotoxin-Mediated Lung Damage

The effect of tumor necrosis factor-α (TNF-α) on endotoxin (ET)-mediated lung damage caused by incomplete ligation of large intestine and the influence of free Fu on the expression of TNF-α mRNA were explored. Forty SD rats were randomly divided into 4 groups: normal control group, model group, ligation group and treatment group (n=10 in each group). The models were made by the method of partly ligating the rectum outside the body. The plasma level of lipopolysaccaride was measured by dynamic nephelo metric method and the serum level of TNF-α was detected by the method of radioactive immunity. The expression of TNF-α mRNA in lung tissue was detected by RT-PCR method. The results were compared among the 4 groups. The results showed the plasma levels of ET and serum TNF-α in the model group and the expression of TNF-α mRNA in the lung tissues were remarkably higher than those in the normal control group (P<0.01). After the treatment of free Fu, all of the above indexes in the treatment group were all decreased as compared with model group (all P<0.01), and the damage to lung was alleviated. It was concluded that TNF-α might play a very important role in the ET-mediated lung damage caused by incomplete ligation of large intestine, free Fu could protect the lung from damage.

Enteral glutamine pretreatment does not decrease plasma endotoxin level induced by ischemia-reperfusion injury in rats

AIM:To investigate whether oral glutamine pretreatment prevents impairment of intestinal mucosal integrity during ischemia-reperfusion (I/R) in rats. METHODS: The study was performed as two series with 40 rats in each. Each series of animals was divided into four groups. The first group was used as a control. Animals in the second group were only pretreated with oral glutamine, 1 g/kg for 4 d. The third group received a normal diet, and underwent intestinal I/R, while the fourth group was pretreated with oral glutamine in the same way, and underwent intestinal I/R. Intestinal mucosal permeability to 51Cr-labeled EDTA was measured in urine in the first series of animals. In the second series, histopathological changes in intestinal tissue and plasma endotoxin levels were evaluated. RESULTS: Intestinal I/R produced a significant increase in intestinal permeability, plasma endotoxin level and worsened histopathological alterations. After intestinal I/R, permeability was significantly lower in glutamine- treated rats compared to those which received a normal diet. However, no significant change was observed in plasma endotoxin levels or histopathological findings. CONCLUSION: Although glutamine pretreatment seems to be protective of intestinal integrity, upon I/R injury, such an effect was not observable in the histopathological changes or plasma endotoxin level.

Arachidonic acid Metabolism in Galactosamine／Endotoxin Indudced Acute Liver injury in Rats

The changes of the levels of LTC4, PGI2 and TXA2 in the liver tissue in SD rats with GaIN/LPS-induced acute liver injury was studied with radioimmunoassay (RIA). As a result,12h after the administration of GaIN/LPS, serum AST (398±37u), ALT (565 ±43u) increased (P<0.001 ) and the concentration of TXA2 (12188±588pg/g· w· wt) in liver tissue increased sigiuficantly(p<0.001), while the content of LTC4 (9713± 3557ng/g·w·wt ) and PGI2 (1748±560 pg/g· w·wt) in liver tissue were not obviously changed(p>0.05) and the inflammatory changes of the pathological findings were observed. The improvement of serum ALT (300±168u)(p< 0.05) and AST(273±424 u) (P<0. 05) and histopathological damage was observed after the administration of diethylcarbamazine (DEC), a LTA4 synthesis inhibitor, the liver TXA2(12740±699) concentration significantly increased (P<0. 001), while the levels of LTC4 (8179±1653) and PGI2 (2320±630) were not obviously changed. Serum ALT (536±74u) and AST (416± 41u)(P> 0. 05) levels and histopathology did not change with administration of indomethacin, a cyclooxygenase inhibitor, but the liver LTC4 (12166±13027) contents increased (P<0.05 ) and TXA2 (1868±791) reduced significantly (P<0. 001). The present study suggests that arachidonic acid metabolism in rats with acute liver injury are significantly abnormal. Leukotrienes and thromboxane are important inflammatory mediators in the liver injury.

Assessment of Endotoxin Removal from Reclaimed Wastewater Using Coagulation-Flocculation

Following biological treatment, wastewater continues to have endotoxic active materials. However, because there is a trend of potable reuse and because endotoxic active materials potentially have harmful effects on human health, their removal from water is crucial. Lipopolysaccharide endotoxin has hydrophobic groups, and their removal using a coagulation-flocculation alternative is believed to be efficient. Thus, their removal from reclaimed wastewater using the coagulation-flocculation process was assessed. Secondary effluent samples from a wastewater treatment plant located in Sapporo, Japan, were investigated. It was found that this process gave satisfactory results in removing endotoxins, with an optimum removal rate of up to 40.5%. The endotoxin removal was maximized by adjusting the pH at the low range 4 - 5.5, with an aluminum sulfate dose of 80 mg/L. Further increases of the coagulant dose did not improve the removal efficiency. DOC and turbidity removal were at their optimum at higher pH range 5.5 - 6.5. Thus coagulation and flocculation could be considered as the first barrier and should be followed by other treatments to safely reuse reclaimed wastewater.