Prevention of alterations in intestinal permeability is involved in zinc inhibition of acute ethanol-induced liver damage in mice

Acute ethanol exposure causes liver injury in experimental animals, and accumulating evidence suggests that a major responsible factor for the pathogenesis is endotoxemia, which results from bacterial endotoxin leakage from the small intestine due to increased intestinal permeability under alcohol challenge. The purpose of this study was to examine whether zinc pretreatment would inhibit acute ethanol-induced liver injury through prevention of intestinal permeability changes. Male 129 SvPCJ mice were treated with three intragastric doses of ZnSO4 at 5 mg of zinc ion per kg each dosing prior to acute ethanol challenge with a single oral dose of 6 g/kg ethanol. The zinc treatment did not alter the elevation of serum concentrations of alcohol. The acute ethanol exposure caused an elevation in serum alanine aminotransferase levels as well as fatty liver and hepatic degenerative necrotic foci as determined by biochemical assay and histochemical analysis, respectively. A significant increase in liver tumor necrosis factor-alpha (TNF-alpha) levels was detected by enzyme-linked immunosorbent assay. These pathological effects correlated well with increases in serum endotoxin levels. Importantly, acute ethanol treatment caused significant damage to the small intestine as determined by morphological analysis of intestinal sections and permeability assay. These alcohol-induced hepatic pathological changes and TNF-alpha elevation were significantly inhibited in the zinc-pretreated animals. The inhibitory action of zinc on alcohol-induced liver damage and activation of inflammation was associated with zinc suppression of alcohol-induced intestinal permeability changes. These results thus demonstrate that zinc prevention of increased intestinal permeability is importantly involved in the inhibition of acute ethanol-induced liver damage in mice.     

Alcohol-induced generation of lipid peroxidation products in humans

To address the hypothesis that elevated blood alcohol increases systemic oxidant stress, we measured urinary excretion of isoprostanes (iPs), free radical-catalyzed products of arachidonic acid. Ten healthy volunteers received acute doses of alcohol (Everclear-R) or placebo under randomized, controlled, double-blind conditions. Urinary iPF2a-III increased in a time- and dosage-dependent manner after dosing with alcohol, with the peak urinary iPF2a-III excretion correlating with the rise in blood alcohol. To determine whether oxidant stress was associated with alcohol-induced liver disease (ALD), we then studied the excretion of iP in individuals with a documented history of alcohol-induced hepatitis or alcohol-induced chronic liver disease (AC). Both urinary iPF2a-III and urinary iPF2a-VI were markedly increased in patients with acute alcoholic hepatitis. In general, urinary iPF2a-III was significantly elevated in cirrhotic patients, relative to controls, but excretion was more pronounced when cirrhosis was induced by alcohol than by hepatitis C. Excretion of iPF2a-VI, as well as 4-hydroxynonenal and the iPF2a-III metabolite, 2,3-dinor-5, 6-dihydro-iPF2a-III, was also increased in AC. Vitamin C, but not aspirin, reduced urinary iPs in AC. Thus, vasoactive iPs, which serve as indices of oxidant stress, are elevated in the urine in both acute and chronic ALD. Increased generation of iPs by alcohol in healthy volunteers is consistent with the hypothesis that oxidant stress precedes and contributes to the evolution of ALD.     

Immunohistochemical demonstration of acetaldehyde-modified epitopes in human liver after alcohol consumption.

Acetaldehyde, the toxic product of ethanol metabolism in the liver, covalently binds to a variety of proteins. Recent studies indicate that such binding can stimulate the production of antibodies against the acetaldehyde adducts. We raised rabbit antibodies which recognized various protein-acetaldehyde conjugates but not the corresponding control proteins. Such antibodies were used in immunohistochemical studies to find out whether acetaldehyde-generated epitopes can be detected from liver specimens of 13 human subjects with different degrees of alcohol consumption. While the specimens obtained from alcohol abusers (n = 4) and alcoholics (n = 3) exhibited marked positive staining for acetaldehyde adducts inside the hepatocytes in a granular uneven pattern, the control samples (n = 6) were almost devoid of immunoreactivity. In the alcohol abusers with an early stage of alcohol-induced liver damage, staining was detected exclusively around the central veins. The data indicate that intracellular acetaldehyde adducts occur in the centrilobular region of the liver of individuals consuming excessive amounts of alcohol. Immunohistochemical detection of such adducts may prove to be of value in the early identification of alcohol abuse and in elucidating the mechanisms of alcohol-induced organ damage.     

Octreotide reduces alcohol-induced hypotension and orthostatic symptoms in primary autonomic failure

Symptomatic postural hypotension is a major problem in patientswith primary idiopathic autonomic failure, and ingestion ofsmall quantities of alcohol may worsen the degree of posturalhypotension. The proposed mechanisms include mesenteric vasodilatationand release of vasodilatory gut peptides. We measured systemic,mesenteric, other regional vascular and biochemical responsesto alcohol ingestion before and after pre-treatment with thesomatostatin analogue Octreotide (which inhibits the releaseof a wide range of gut peptides normally released inresponseto food ingestion) in six patients with primary autonomic failure.Octreotide effectively prevented alcohol-induced hypotensionand vasodilatation of the mesenteric vascular bed, with improvementof signs and symptoms of hypotension post-alcohol. This suggeststhat the mechanism of alcohol-induced symptomatic hypotensionin autonomic failure is at least partly mediated by releaseof vasodilatatory gut peptides with resultant mesenteric vasodilatation.     

Variations in HDL and VLDL levels chronic alcoholics. Influence of the degree of liver damage and of withdrawal of alcohol

Changes in plasma HDL and VLDL levels were investigated in 284 chronic alcoholics staying in a Detoxification Centre where they initiated or continued abstinence. The data show that the variations in plasma HDL are modulated by the degree of liver injury. In severe hepatic damage HDL levels are sharply decreased. An alcohol-induced rise in HDL can occur in the only subjects with no signs of hepatic insufficiency. This elevation is rapidly reversible after withdrawal of alcohol. Such a rise might reflect enhanced synthesis and release by liver but might also be due to an accelerated turnover of the VLDL.     

Protective effect of taurine against alendronate-induced gastric damage in rats

Alendronate (ALD) causes serious gastrointestinal adverse effects. The aim of this study was to investigate whether taurine (TAU), a semi-essential amino acid and an antioxidant, improves the alendronate-induced gastric injury. Rats were administered 20 mg/kg ALD by gavage for 4 days, either alone or following treatment with TAU (50 mg/kg, i.p.). On the last day of treatment, following drug administration, pylorus ligation was performed and 2 h later, rats were killed and stomachs were removed. Gastric acidity and tissue ulcer index values, lipid peroxidation and glutathione (GSH) levels, myeloperoxidase (MPO) activity as well as the histologic appearance of the stomach tissues were determined. Chronic oral administration of ALD induced significant gastric damage, increasing lipid peroxidation, MPO activity and collagen content, as well as decreasing tissue GSH levels. Treatment with TAU prevented the damage and also the changes in biochemical parameters. Findings of the present study suggest that ALD induces oxidative gastric damage by a local irritant effect, and that TAU ameliorates this damage by its antioxidant and/or membrane-stabilizing effects.     

Poly(adp-ribose) synthetase inhibition reduces bacterial translocation in rats after endotoxin challenge

We investigated whether 3-aminobenzamide (3-AB), a poly(ADP-ribose) synthetase (PARS) inhibitor, reduces bacterial translocation (BT) after intraperitoneal endotoxin administration. Wistar rats were randomized to receive intraperitoneal saline (control, n = 6); endotoxin (n = 8); 3-AB (n = 6); and 3-AB plus endotoxin (n = 8). Six hours later, to evaluate the endotoxin-related intestinal injury and BT, tissue and blood samples were collected. Administration of intraperitoneal endotoxin caused severe intestinal injury and BT to mesenteric lymph nodes. PARS inhibition with 3-AB completely prevented endotoxin-induced BT. No colony-forming bacteria was isolated from the samples obtained from 3-AB-pretreated animals under endotoxin challenge. Treatment with 3-AB significantly reduced the endotoxin-induced intestinal mucosal injury. The inhibition of PARS by its blocker 3-aminobenzamide during endotoxemia prevents bacterial translocation and intestinal injury in rats. PARS activation may provide a novel therapeutic approach in reducing gut barrier failure seen in endotoxemia.     

IL-1 receptor antagonist ameliorates inflammasome-dependent alcoholic steatohepatitis in mice

Alcoholic liver disease (ALD) is characterized by steatosis and upregulation of proinflammatory cytokines, including IL-1β. IL-1β, type I IL-1 receptor (IL-1R1), and IL-1 receptor antagonist (IL-1Ra) are all important regulators of the IL-1 signaling complex, which plays a role in inflammation. Furthermore, IL-1β maturation is dependent on caspase-1 (Casp-1). Using IL-1Ra–treated mice as well as 3 mouse models deficient in regulators of IL-1β activation (Casp-1 and ASC) or signaling (IL-1R1), we found that IL-1β signaling is required for the development of alcohol-induced liver steatosis, inflammation, and injury. Increased IL-1β was due to upregulation of Casp-1 activity and inflammasome activation. The pathogenic role of IL-1 signaling in ALD was attributable to the activation of the inflammasome in BM-derived Kupffer cells. Importantly, in vivo intervention with a recombinant IL-1Ra blocked IL-1 signaling and markedly attenuated alcohol-induced liver inflammation, steatosis, and damage. Furthermore, physiological doses of IL-1β induced steatosis, increased the inflammatory and prosteatotic chemokine MCP-1 in hepatocytes, and augmented TLR4-dependent upregulation of inflammatory signaling in macrophages. In conclusion, we demonstrated that Casp-1–dependent upregulation of IL-1β and signaling mediated by IL-1R1 are crucial in ALD pathogenesis. Our findings suggest a potential role of IL-1R1 inhibition in the treatment of ALD.     

Effect of daily ethanol ingestion on intestinal permeability to macromolecules

The effects of regular ethyl alcohol ingestion on morphological and permeability characteristics of the small intestine were assessed in mature rats using the tracer protein, horseradish peroxidase. Thirty adult rats were divided into two groups and provided a standard commercial diet in pellet form. Each morning, after an overnight fast, every animal in the experimental group was administered by gavage an aliquot of 20% ethanol; animals in the control group were provided aliquots of 20% sucrose in water by the same method. After 4 and 8 weeks on the gavage routine (and 10 days and 4 weeks after gavage cessation), jejunal permeability to horseradish peroxidase was examined in animals from each group. Using a routine ligated-loop procedure and light and electron microscopy, ethanol-exposed rats demonstrated increased intestinal permeability to horseradish peroxidase by 4 weeks; sucrose-exposed animals revealed little alteration in mucosal integrity. It is proposed that regular ingestion of sizable amounts of alcohol alters morphological characteristics of the gut and increase the permeability of the mucosa to "undigested" macromolecules.     

Prevention of ethanol-induced liver injury in rats by an agonist of peroxisome proliferator-activated receptor-gamma,pioglitazone

Agonists of peroxisome proliferator-activated receptor (PPAR)-gamma have been shown to reduce tumor necrosis factor-alpha (TNF-alpha)-induced insulin resistance. On the other hand, sensitization of Kupffer cells to lipopolysaccharide (LPS) and their production of TNF-alpha are critical for progression of alcoholic liver injury. This study was intended to determine whether pioglitazone, a PPAR-gamma agonist, could prevent alcohol-induced liver injury. Rats were given ethanol (5 g/kg b.wt.) and pioglitazone (500 microg/kg) once every 24 h intragastrically. Ethanol for 8 weeks caused pronounced steatosis, necrosis, and inflammation in the liver. These pathological parameters were diminished greatly by pioglitazone. Kupffer cells were sensitized to LPS after ethanol for 4 weeks as evidenced by aggravation of liver pathology induced by LPS (5 mg/kg) and enhancement of LPS (100 ng/ml)-induced intracellular Ca2+ concentration elevation in Kupffer cells. The parameters were diminished by treatment with pioglitazone. LPS-induced TNF-alpha production by Kupffer cells from the 4-week ethanol group was 3 to 4 times higher than control. This increase was blunted by 70% with pioglitazone. Gut permeability was 10-fold higher in the 4-week ethanol group, and pioglitazone treatment did not change the value. Inclusion of TNF-alpha in culture media of Kupffer cells enhanced CD14 expression, LPS-induced intracellular Ca2+ concentration response, and production of TNF-alpha. These results indicate that pioglitazone prevents alcoholic liver injury through abrogation of Kupffer cell sensitization to LPS.     

Second hit post burn increased proximal gut mucosa epithelial cells damage

Secondary infections after burn are common and are a major contributor to morbidity and mortality. We previously showed that burn disrupted proximal gut mucosal homeostasis through increased epithelial cell apoptosis. In the present study, we sought to determine whether proximal gut mucosal disruption is additively affected by secondary endotoxemia after a severe burn. C57BL/6 mice received 30% total body surface area full-thickness scald burns and were randomized to receive saline or LPS 1 mg/kg body weight given intraperitoneally 72 h after burn. Proximal small bowel was harvested 12 h after LPS injection. Mucosal height and epithelial cell number were assessed on hematoxylin-eosin sections, intestinal epithelial cell apoptosis was identified by terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling, and cell proliferation by immunohistochemical staining for proliferating cell nuclear antigen. Results showed that proximal gut mucosa impairment occurred 12 h after injury, including significantly decreased proximal gut wet weight, gut mucosal height, and epithelial cell number associated with increased proximal gut epithelial apoptosis (P < 0.05). This impairment diminished 72 h after burn. Second-hit endotoxemia caused additional proximal gut mucosa damage with decreased proximal gut weight, cell number, and mucosal height (P < 0.05) and significantly increased small intestinal epithelial apoptosis and mucosal atrophy, even after the first event, indicating a second detrimental effect of endotoxemia after the initial injury.     

In vivo delivery of antisense oligonucleotides in pH-sensitive liposomes inhibits lipopolysaccharide-induced production of tumor necrosis factor-alpha in rats

Kupffer cells play an important role in the pathogenesis of liver diseases. During endotoxemia and alcohol-induced liver disease, tissue injury is preceded by an excessive release of cytokines by these macrophages. Tumor necrosis factor-alpha (TNF-alpha) is one of the key cytokines associated with liver injury. Pre-exposure of animals to TNF-alpha antibodies has been shown to prevent macrophage-mediated liver injury in experimental animals. In this article, we describe a method to encapsulate in pH-sensitive liposomes and to deliver an antisense phosphorothioate oligonucleotide (TJU-2755) against TNF-alpha. We describe the efficacy of this formulation in inhibiting endotoxin-mediated production of TNF-alpha. The liposomes prepared were stable for over 4 weeks at pH 7.4, but readily released their contents when exposed to an acidic environment below pH 6, similar to the pH that exists in early endosomes. Male Sprague-Dawley rats were administered (i.v.) liposome-encapsulated TJU-2755 (1-2 mg/kg body wt.). Empty liposomes served as controls. Forty-eight hours postinjection, the animals were administered a single dose of lipopolysaccharide (50 microg/kg body wt.) and were sacrificed 90 min later. The TNF-alpha produced by excised liver incubated ex vivo and the levels of plasma TNF-alpha were determined. After a single administration of liposome-encapsulated antisense TJU-2755, a 30% reduction in TNF-alpha produced by liver slices was observed. Two daily doses of the antisense oligonucleotide inhibited TNF-alpha production by 50%. This was associated with a 65 to 70% reduction in plasma levels of TNF-alpha, compared with controls. These results indicate that oligonucleotide TJU-2755 encapsulated in pH-sensitive liposomes can be used to effectively reduce endotoxin-mediated production of TNF-alpha in macrophages in vivo and thus may be of value in attenuating or preventing macrophage-mediated liver injury.     

酒精性肝病患者血中睾酮和雌二醇水平的变化研究

目的观察酒精性肝病（alcoholic liver disease ALD）患者血清中睾酮（testosterone,T）和雌二醇（es-tradiol,E2）水平的变化。方法对长期嗜酒者、健康人进行血清T、E2的检测。结果在269例嗜酒者中符合ALD（A组）诊断者75例,占27.9%;其余为嗜酒组（B组）。A组的血清T[（12.8±6.57）nmol/L]较B组[（23.8±9.62）nmol/L]和对照组[（29.7±10.52）nmol/L]都降低（P〈0.01）;B组的血清T[（23.8±9.62）nmol/L]较对照组[（29.7±10.52）nmol/L]水平低（P〈0.01）。A组的血清E2[（237.4±109.46）pmol/L]较B组[（133.5±66.15）pmol/L]和对照组[（128.3±54.77）pmol/L]明显增高（P〈0.01）,B组的E2水平高于对照组（P〉0.05）。结论嗜酒者和酒精性肝病患者血清睾酮水平均降低,而在酒精性肝病患者中血清E2水平增加高,嗜酒者和对照组血清E2水平差异无统计学意义,说明慢性酒精中毒对男性睾丸功能有一定的影响。     

复方片仔癀肝宝对酒精诱导的慢性肝损伤氧化应激的保护作用研究

目的:探讨复方片仔癀肝宝对酒精性肝病(Aleoholie Liver Disease,ALD)模型大鼠氧化应激的保护作用。方法:60只SPF级SD大鼠,随机分为正常对照组、模型组、阳性药对照组及肝宝低、中、高剂量组,每组10只。除正常对照组外其余各组用酒精联合高脂饲料喂养2周,造ALD模型,连续给药4周后取材。全自动生化仪检测血清中谷丙转氨酶(ALT)、谷草转氨酶(AST)、碱性磷酸酶(ALP)、乳酸脱氢酶(LDH)的含量变化;检测肝组织中超氧化物歧化酶(SOD)、丙二醛(MDA)和谷胱甘肽过氧化物酶(GSH-Px)的表达;HE染色,观察肝组织病理变化。结果 :模型组血清中ALT、AST、ALP、LDH的活性较正常对照组均有明显的上升,且肝组织中MDA水平明显上升,SOD、GSH-Px水平明显下降(P0.01)。与模型组相比,肝宝各组ALT、AST、ALP、LDH的活性及MDA水平明显降低,而SOD、GSH-Px水平明显上升(P0.05)。HE染色结果显示复方片仔癀肝宝不同剂量组对肝组织脂肪变性、肝内脂类聚集有明显的改善作用,并且存在剂量效应关系。结论:复方片仔癀肝宝能显著减轻酒精和高脂诱导的肝损伤,其机制可能与提高肝组织的抗氧化能力有关。     

Use of the triolein breath test in alcoholics with liver damage

The triolein breath test (TBT) is a simple, noninvasive technique for the evaluation of steatorrhea. However, because it depends on intermediary hepatic processes, and because both liver damage and pancreatic dysfunction often co-exist in the alcoholic, the overall usefulness of the test in patients with liver injury was reassessed. We found that even in the absence of steatorrhea, a majority of patients with advanced liver injury (alcoholic hepatitis, cirrhosis, or both) had abnormal TBT results that failed to correct with pancreatic extract. In contrast, patients with less severe lesions (steatosis) had results that were not significantly different from those in normal controls. Inasmuch as the abnormal TBT results in patients with advanced alcohol-induced lesions did not correct with pancreatic extract, the test may not accurately differentiate pancreatic from nonpancreatic steatorrhea in some alcoholics.     

Value of determining carbohydrate-deficient transferrin isoforms in the diagnosis of alcoholic liver disease

OBJECTIVE: To determine whether isoform separation of carbohydrate-deficient transferrin (CDT) is of value in the diagnosis of alcoholic liver disease (ALD) and is specific to ALD when compared with other liver diseases. PATIENTS AND METHODS: During 1995 and 1996, 47 patients with ALD were evaluated with CDT at the Mayo Clinic in Rochester, Minn. The diagnosis of ALD was based on biochemical and histological analyses and on a history of drinking that exceeded 5 years with an average alcohol intake of more than 60 g/d. Disease controls included nonalcoholic steatohepatitis (NASH) (n = 26) and other liver disease (n = 22). Normal controls (n = 21) were healthy individuals without liver disease. Transferrin isoforms were quantified by densitometry of Coomassie-stained transferrins after affinity purification and isoelectric focusing. The pentasialo, tetrasialo, trisialo, disialo, monosialo, and asialo isoforms were quantified as percentages of total band densities. RESULTS: Receiver operating characteristic (ROC) curves were constructed for each isoform. The curves for total desialated isoforms (sum of disialo, monosialo, and asialo) displayed the best relationship between sensitivity and specificity with an ROC-area under the curve (AUC) of 0.922. The ROC-AUC values for individual transferrin isoforms in ALD vs NASH for pentasialo, tetrasialo, trisialo, disialo, monosialo, and asialo were 0.806, 0.917, 0.885, 0.933, 0.804, and 0.785, respectively. Only 58% of patients with ALD were detected at a specificity that excluded ALD in 84% of those who did not have it. CONCLUSION: Within alcohol ingestion times reported to us, no associations with recent drinking were observed. Alcohol as a cause of liver disease is not perfectly established by CDT analysis, although a high total CDT value favors ALD over NASH.     

Abnormal permeability of inner and outer mitochondrial membranes contributes independently to mitochondrial dysfunction in the liver during acute endotoxemia

OBJECTIVE: This study was designed to determine the role played by the mitochondrial permeability transition in the pathogenesis of mitochondrial damage and dysfunction in a representative systemic organ during the acute phase of endotoxemia. DESIGN: A well-established, normotensive feline model was employed to determine whether pretreatment with cyclosporine A, a potent inhibitor of the mitochondrial permeability transition, normalizes mitochondrial ultrastructural injury and dysfunction in the liver during acute endotoxemia. SETTING: The Ohio State University Medical Center research laboratory. SUBJECTS: Random source, adult, male conditioned cats. INTERVENTIONS: Hemodynamic resuscitation and maintenance of acid-base balance and tissue oxygen availability were provided, as needed, to minimize the potentially confounding effects of tissue hypoxia and/or acidosis on the experimental results. Treatment groups received isotonic saline vehicle (control; n = 6), lipopolysaccharide (3.0 mg/kg, intravenously; n = 8), or cyclosporine A (6.0 mg/kg, intravenously; n = 6) or tacrolimus (FK506, 0.1 mg/kg, intravenously; n = 4) followed in 30 mins by lipopolysaccharide (3.0 mg/kg, intravenously). Liver samples were obtained 4 hrs posttreatment, and mitochondrial ultrastructure, function, and cytochrome c, Bax, and ceramide contents were assessed. MEASUREMENTS AND MAIN RESULTS: As expected, significant mitochondrial injury was apparent in the liver 4 hrs after lipopolysaccharide treatment, despite maintenance of regional tissue oxygen availability. Namely, mitochondria demonstrated high-amplitude swelling and exhibited altered respiratory function. Cyclosporine A pretreatment attenuated lipopolysaccharide-induced mitochondrial ultrastructural abnormalities and normalized mitochondrial respiratory control, reflecting protection against inner mitochondrial membrane damage. However, an abnormal permeability of outer mitochondrial membranes to cytochrome c was observed in all lipopolysaccharide-treated groups and was associated with increased mitochondrial concentrations of Bax and ceramide. CONCLUSIONS: These studies confirm that liver mitochondria are early targets of injury during endotoxemia and that inner and outer mitochondrial membrane damage occurs through different mechanisms. Inner mitochondrial membrane damage appears to relate to the mitochondrial permeability transition, whereas outer mitochondrial membrane damage can occur independent of the mitochondrial permeability transition. Preliminary evidence suggests that Bax may participate in lipopolysaccharide-induced outer mitochondrial membrane damage, but further investigations are needed to confirm this.     

Ethyl pyruvate ameliorates acute alcohol-induced liver injury and inflammation in mice

Ethyl pyruvate dissolved in a calcium-containing balanced salt solution--Ringer's ethyl pyruvate solution (REPS)--ameliorates ileal mucosal hyperpermeability and decreases the expression of several proinflammatory genes when it is used instead of Ringer's lactate solution (RLS) to resuscitate mice from hemorrhagic shock. Herein, we sought to determine whether delayed treatment with REPS would be beneficial in a murine model of acute alcoholic liver injury associated with binge drinking. Mice were gavaged with 3 doses of ethanol (5 g/kg each dose) over a 12-hour period and then randomized to treatment with 3 intraperitoneal doses of REPS or RLS over 12 hours. Compared with sham-treated controls not subjected to alcohol intoxication, RLS-treated mice demonstrated histologic evidence of fatty change and piecemeal necrosis of hepatocytes in the liver, as well as a significant increase in the plasma concentration of alanine aminotransferase. Biochemical changes induced by alcohol administration included increased hepatic lipid peroxidation, nuclear factor-kappaB activation, and tumor necrosis factor-alpha messenger RNA expression. All of these alcohol-induced effects were ameliorated by treatment with REPS instead of RLS. These data support the view that treatment with REPS ameliorates the hepatic inflammatory response and decreases hepatocellular injury in mice subjected to acute alcohol intoxication.     

创伤后内毒素血症与脏器损害关系及其防治新方法的系列研究

目的：从不同的作用环节采用多种干预手段以阻断肠源性内毒素血症的发生，观察其对机体炎症反应、免疫反应、脏器损害和预后的影响。方法：采用多种动物分别建立了不同致伤方式诱发脓毒症及多脏器功能失常综合征（MODS）的模型；并结合临床病例进行前瞻性研究。结果：分别应用杀菌-通透性增加蛋白、抗核心脂多糖（LPS）单抗及Re型LPS抗血清、低剂量多粘菌素B、选择性消化道脱污染及抗肿瘤坏死因子（TNF）单抗等措施，可显著中和循环内毒素，能有效地减轻肝、肺、肾及肠道等器官损害和明显提高动物存活率；并且抗内毒素可不同程度地抑制循环和组织中细胞因子mRNA及蛋白质的表达和改善机体细胞免疫功能；临床观察显示，大面积烧伤和创伤患者24小时内血浆内毒素含量显著升高，其升高程度与血浆TNF呈正相关，这一趋势以并发脓毒症、MODS者尤为明显。结论：肠源性内毒素血症与脓毒症、脏器功能损害密切相关；创伤早期采取有效措施及时防止肠源性内毒素血症对创伤所致脓毒症及MODS具有一定的防护效应，动物预后明显改善；其作用机制与抑制细胞因子的基因表达、分泌及提高机体全身免疫状况有关。     

Increased high-density lipoprotein cholesterol concentration in alcoholics is related to low cholesteryl ester transfer protein activity

Cholesteryl ester transfer protein (CETP) facilitates the transfer of cholesteryl esters from HDL to apoB-containing lipoproteins. Since alcoholics have high HDL cholesterol and low LDL cholesterol levels, a defect in cholesteryl ester transfer could be responsible for the alcohol-induced alteration in cholesterol distribution between lipoproteins. To test this hypothesis, we compared CETP activity in plasma from 30 alcoholics without severe liver damage and 16 control subjects. Plasma CETP activity was 28% lower in the alcoholics compared with the controls (P less than 0.001), while the teetotallers among the latter had slightly higher CETP activity than those who consumed alcohol in moderation. CETP activity increased slowly after ethanol withdrawal, but did not reach the control level within the 7-day observation period. A positive correlation was observed between plasma CETP activity and the LDL cholesterol HDL cholesterol ratio (r = 0.480, P less than 0.002), whereas CETP activity showed a negative correlation with HDL cholesterol level (r = -0.467, P less than 0.001). The results indicate that defective transfer of cholesteryl esters from HDL to LDL contributes to the high HDL cholesterol levels in alcoholics.