Inhibition of 5-lipoxygenase-activating protein (FLAP) reduces pulmonary vascular reactivity and pulmonary hypertension in hypoxic rats.

Chronically elevated shear stress and inflammation are important in hypertensive lung vessel remodeling. We postulate that 5-lipoxygenase (5-LO) is a molecular determinant of these processes. Immunohistology localized the 5-LO to macrophages of normal and chronically hypoxic rat lungs and also to vascular endothelial cells in chronically hypoxic lungs only. In situ hybridization of normal and chronically hypoxic lungs demonstrated that 5-LO mRNA is expressed in macrophages. Rats hypoxic for 4 wk-developed pulmonary hypertension increased translocation of the lung 5-LO from the cytosol to the membrane fraction and increased levels of lung tissue 5-lipoxygenase-activating protein (FLAP). A FLAP ligand, 3-[l-(4-chlorobenzyl)-3-t-butyl-thio-t-isopropylindol-2-yl]-2,2- dimethylpropanoic acid (MK-886), inhibited the acute angiotensin II and hypoxia-induced pulmonary vasoconstriction in vitro and the development of chronic hypoxic pulmonary hypertension in rats in vivo. Mice bred with the deletion of the 5-LO enzyme (5-LO knockout) developed less right heart hypertrophy than age-matched 5-LO competent mice. Our results support the hypothesis that the 5-LO is involved in lung vascular tone regulation and in the development of chronic pulmonary hypertension in hypoxic rodent models.

Can thymidine kinase levels in breast tumors predict disease recurrence?

BACKGROUND: Our previous study of thymidine kinase (TK) levels in the serum of breast cancer patients demonstrated a statistically significant positive correlation with cancer stage. In postsurgical follow-up studies of 20 patients with primary breast cancer, total serum TK levels rose with disease recurrence and continued to rise with disease progression but decreased with treatment response. PURPOSE: This study was designed to examine whether TK levels in primary breast tumors can be used to predict recurrence and to establish the relationship between TK levels and estrogen receptor (ER) status and recurrence. METHODS: Eighty-six patients with breast cancer were entered in this study. Tumors were assessed for ER status and TK levels, and the patients had follow-up for recurrence over a period of 41 months. By calculating the percent of TK activity in the presence of adenosine triphosphate (ATP) or cytidine triphosphate (CTP), we estimated the relative contributions of TK isozymes TK1 and TK2 to total TK activity. RESULTS: Total TK (TK1 plus TK2) levels in tumors were significantly (P < .001) elevated in patients who subsequently had recurrence compared with levels in those who did not. Calculations of the percent of TK activity in the presence of ATP or CTP showed that this elevation was due to increased TK1 isozyme levels. ER-negative (ER-) patients had significantly (P < .001) increased TK1 levels relative to those in ER-positive (ER+) patients. ER- patients with recurrence had significantly (P < .001) elevated total tumor TK levels compared with levels in those who did not have recurrence, and calculation of percent of TK activity with ATP or CTP indicated elevated TK1 levels. A similar pattern of increased levels of total tumor TK and TK1 was observed in ER+ patients with recurrence. CONCLUSIONS: The results indicate that total tumor TK levels were significantly higher in breast cancer patients who subsequently had recurrence than levels in those who did not. This finding appears to be largely caused by higher levels of TK1. IMPLICATIONS: Higher TK1 levels in tumors in patients who subsequently had disease recurrence almost certainly indicate a high rate of proliferation in such tumors at the time of excision. It appears that TK is a potentially useful marker in the management of breast cancer. With measurement of levels of TK, particularly TK1, in breast tumors and serum, it may be possible to predict recurrence of breast cancer.

Early diagnosis and effective treatment of pulmonary CMV infection after lung transplantation.

The early diagnosis and effective treatment of cytomegalovirus (CMV) pneumonia remains a keystone for patient survival after lung transplantation. At present, the use of DHPG (ganciclovir sodium) opens the possibility of a potent antiviral therapy. The use of monoclonal antibodies directed to immediate early CMV antigens offers a fast method to detect the early phase of systemic or local viral replication. Five single lung and heart-lung transplant patients at high risk for CMV infection (donor, CMV-positive; recipient, CMV-negative) were monitored by cellular immunohistology for immediate early antigens. Specimens from bronchoalveolar lavage (n = 39) and bronchial biopsies (n = 17), and peripheral blood leukocytes (n = 57) were examined. In peripheral blood leukocytes and bronchial biopsy specimens no CMV-positive cells were detected. The bronchoalveolar lavage analysis of two patients showed immediate early antigen-positive cells after 1 to 3 months. At the same time the patients had clinical symptoms that could also be related to lung rejection. Serologic conversion (CMV-IgM) occurred only 6 days later in one patient with informative follow-up analysis; CMV culture (available 4 to 6 weeks later) confirmed the diagnosis retrospectively. DHPG treatment was started immediately and resulted in CMV antigen negativity in bronchoalveolar lavage fluid after one or two courses (10 mg/kg/day; 14 days). Direct antigen detection offers a fast and specific monitoring of early CMV infection. The implications to the clinical management of lung transplant patients are discussed.

The prognostic significance of marrow micrometastases in women with early breast cancer.

Twenty-five patients with early breast cancer (T0-T2, N0-N1, M0) have been studied prospectively to determine the relationship between marrow micrometastases, disease-free interval and survival. Marrow specimens were aspirated from three sites immediately prior to breast surgery. An immunocytochemical technique using monoclonal antibody LICR.LON.M8.4 was employed to detect micrometastases. The minimum follow-up was 38 months. Twelve of the 25 patients (48%) had micrometastatic lesions in their marrow at presentation. Four of these patients developed distal recurrence during follow-up, causing death in two of them. Five of the 13 patients with no evidence of micrometastases developed distant recurrence and four of them have died. There was no correlation between the state of the marrow and the development of metastatic disease, although axillary lymph node status, disease stage and tumour volume correlated significantly with outcome (all P less than 0.025). Micrometastatic lesions appear to be common in the marrow of patients with early breast cancer. We have been unable to demonstrate that they have prognostic significance.

Differential systemic and pulmonary hemodynamic effects of L-arginine in patients with coronary artery disease or primary pulmonary hypertension.

The endothelial EDRF/NO-mediated relaxing mechanism is impaired in atherosclerotic and in hypertensive arteries. Recently, it was suggested that primary pulmonary hypertension might be another disease in which the endothelial EDRF/NO pathway is disturbed. We tested the hypothesis that intravenous administration of L-arginine (L-ARG), the physiological precursor of EDRF/NO, stimulates the production of NO, subsequently increasing plasma cGMP levels and reducing systemic and/or pulmonary blood pressure, in patients with coronary artery disease (CAD, n = 16) or with primary pulmonary hypertension (PPH, n = 5). L-ARG (30 g, 150 ml, 15 min) or placebo (150 ml NaCl) was infused in CAD patients, and L-ARG was infused in PPH patients during cardiac catheterization. Mean aortic (Pao) and pulmonary (PAPmean) arterial pressures were continuously monitored. Cardiac output (CO, by thermodilution), total peripheral resistance (TPR), and pulmonary vascular resistance (PVR) were measured before and during the infusions. In CAD patients Pao decreased from 87.2 +/- 4.9 to 81.8 +/- 5.1 mmHg during L-ARG (p < 0.05), whereas PAPmean and PVR were unchanged. TPR decreased from 1008.9 +/- 87.9 to 845.0 +/- 81.7 dyne x sec x cm-5 during L-ARG administration (p < 0.01). CO significantly increased during L-ARG (from 7.3 +/- 2.8 to 8.1 +/- 0.9 l/min, p < 0.05). Placebo did not significantly influence any of the hemodynamic parameters. Plasma cGMP (determined by RIA) slightly increased by 12.2 +/- 9.6% during L-ARG, but slightly decreased during placebo (-12.3 +/- 9.2%) (p < 0.05 for L-ARG vs. placebo). In PPH patients, L-ARG induced no significant change in Pao, TPR, and CO, PAPmean was 59.4 +/- 8.5 mmHg at the beginning of the study and was not significantly reduced by L-ARG nor was PVR (basal: 1042.4 +/- 211.4 dyne x sec x cm-5) changed by L-ARG. Plasma cGMP was not significantly affected by L-ARG in these patients. We conclude that L-ARG stimulates NO production and induces vasorelaxation in CAD patients but not in patients with primary pulmonary hypertension.

Circulating neutrophil priming and systemic inflammation in limb ischaemia-reperfusion injury.

BACKGROUND: Recruitment and activation of neutrophils is a key step in the development of local and systemic injury in lower limb ischaemia-reperfusion. We hypothesis that increased circulating neutrophil priming is responsible for systemic inflammation. METHODS: Anaesthetised ventilated swine (n = 6 per group) underwent mid-line laparotomy and were randomised to control group or bilateral external iliac artery occlusion for two hours followed by two and a half hours reperfusion (I/R group). Using luminol, respiratory burst activity was assayed with a BioOrbit Luminometer to detect whole blood chemiluminescence (CL) by stimulation with phorbol 1,2-myristate 1,3-acetate (PMA) in the absence or presence of tumour necrosis factor (TNF) respectively. PMN priming is expressed as the ratio of whole blood CL in the presence of TNF to that without. We measured plasma interleukin(IL)-6 and tumour necrosis factor alpha by bioassay as a measure of systemic inflammation. The alveolar-arterial (A-a) gradient was measured using the formula [(A-a)gradient = fraction inspired O2 x 710-(arterial pCO2/0.8)-arterial pO2], it is a measure of lung function, a large gradient being indicative of impaired oxygen transport and hence lung injury. RESULTS: Lower limb I/R caused significantly greater PMN priming, 0.83 +/- 0.14, compared to control group, 0.22 +/- 0.04, (p < 0.001). Plasma IL-6, a reliable indicator of systemic inflammation, was significantly increased in I/R group after two and a half hours of reperfusion, 1295.0 (833.9-2073.0) pg/L, compared to control, 382.9 (367.4-568.3) pg/L, (p < 0.005). Plasma tumour necrosis factor alpha was significantly elevated after one hour of reperfusion in the I/R group, 86.8 (48.7-106.6) pg/ml, compared to the control group, 32.7 (0.9-42.8) pg/ml, (p < 0.01). (A-a) gradient was significantly increased after IRI, 407.97 +/- 53.13, compared to the control, 183.19 +/- 45.75, (p < 0.005). Mean pulmonary artery pressure was significantly greater after IRI, 38.80 +/- 4.87 mmHg, compared to control, 27.86 +/- 1.92 mmHg, (p < 0.005). Data represents mean +/- standard error mean or median (interquartile range), statistical comparisons using one-way Anova with Student's "t"-test and Kruskall-Wallis Anova with the Mann-Whitney U test. CONCLUSIONS: Priming of neutrophils increases their circulating respiratory burst activity and ability to induce tissue injury. Systemic PMN priming during hind limb ischaemia-reperfusion injury is associated with the systemic inflammatory response syndrome.

Hepatic cytokine response can be modulated using the Kupffer cell blocker gadolinium chloride in obstructive jaundice.

INTRODUCTION: Depletion of Kupffer cells by gadolinium chloride (GdCl(3)) reduces the systemic response during sepsis. The study aim was to investigate the effect of this depletion on hepatic proinflammatory cytokine response to portal endotoxaemia. METHODS: Sixteen Wistar rats were randomised to receive either saline IV (n = 8) or GdCl(3) (10 mg/kg IV, n = 8) six days after bile duct ligation (BDL). 24 h later the animals were perfused for 2 h, using isolated hepatic perfusion. Aliquots of effluent perfusate were collected at 20-min intervals for cytokine analysis. Sections of liver were sampled and the hepatic Kupffer cell number of each group was measured using ED1 immunohistochemistry. RESULTS: Pre-treatment with GdCl(3) resulted in significantly reduced serum bilirubin concentrations but significantly elevated serum ALP and AST levels compared to the control group. It was also associated with a significant reduction in Kupffer cell numbers and a corresponding significant reduction in hepatic TNFα and IL-6 production in response to portal endotoxaemia. CONCLUSIONS: Pre-treatment with GdCl(3) in jaundiced animals reduced Kupffer cell numbers, attenuated liver enzyme abnormalities and reduced TNFα and IL-6 in response to portal endotoxaemia. Hepatic Kupffer cells, therefore, play a significant role in the development of an exaggerated inflammatory response in obstructive jaundice.

Anti-endotoxin hyperimmune globulin attenuates portal cytokinaemia, phagocytic cell priming, and acute lung injury after lower limb ischaemia-reperfusion injury.

OBJECTIVES: Acute limb ischaemia is a common and often lethal clinical event. Reperfusion of an ischaemic limb has been shown to induce a remote gut injury associated with transmigration of endotoxin into the portal and systemic circulation, which in turn has been implicated in the conversion of the sterile inflammatory response to a sepsis syndrome, after lower torso ischaemia-reperfusion injury. This study tests the hypothesis that an anti-endotoxin hyperimmune globulin attenuates ischaemia-reperfusion (I/R) associated sepsis syndrome. DESIGN: Prospective, randomised placebo controlled trial, animal experiment. MATERIALS AND METHODS: Experimental porcine model, bilateral hind limb I/R injury, randomised to receive anti-endotoxin hyperimmune globulin or placebo. RESULTS: Bilateral hind limb I/R injury significantly increased intestinal mucosal acidosis, portal endotoxaemia, plasma cytokine (TNF-alpha, IL-6, IL-8) concentrations, circulating phagocytic cell priming and pulmonary leukosequestration, oedema, and capillary-alveolar protein leak. Conversely, pigs treated with anti-endotoxin hyperimmune globulin (IgG) 20mg/kg at onset of reperfusion had significantly reduced portal endotoxaemia, early circulating phagocytic cell priming, plasma cytokinaemia and attenuation of acute lung injury. CONCLUSIONS: Endotoxin translocation across a hyperpermeable gut barrier, phagocytic cell priming and cytokinaemia are key events of limb I/R injury induced systemic inflammation and acute lung injury. This study shows that an anti-endotoxin hyperimmune globulin attenuates portal endotoxaemia, which may reduce early phagocytic cell activation, cytokinaemia and ultimately acute lung injury.

Patterns of bacterial translocation in experimental biliary obstruction.

INTRODUCTION: Biliary obstruction is associated with impaired intestinal barrier function and translocation of enteric bacteria to the systemic circulation. Traditional live culture techniques may overlook translocation of dead bacterial fragments that stimulate the inflammatory response. The aim of this study was to estimate the extent and pattern of bacterial translocation in experimental biliary obstruction. MATERIALS AND METHODS: Thirty 9-week-old male Wistar rats were randomized to undergo bile duct ligation (BDL, n = 20) or sham operation (n = 10). Seven days after operation, each animal received 1 ml of (111)indium-oxyquinolone-labeled Escherichia coli p.o. Samples of liver, spleen, mesenteric lymph nodes, and lung were harvested 4 h later and analyzed for live bacteria and (111)indium activity. RESULTS: There was significantly more live bacterial translocation detected in BDL animals than in sham-operated animals (P = 0.00008, chi(2)). Labeled bacterial fragments were detected in all locations sampled in all animals. Sham-operated animals had significantly more labeled bacterial fragments detected in the liver (P = 0.0001) and the spleen (P = 0.03) than the BDL animals. The mean total bacterial survival in the BDL group was 30 +/- 13% and 0% in the sham operated group. CONCLUSION: These results demonstrate that non-viable bacterial fragments are present in sterile extra-intestinal sites in normal animals and that translocation of live bacteria is markedly increased in experimental biliary obstruction. These results also suggest that failure of bacterial killing is an important factor facilitating bacterial translocation in the presence of established biliary obstruction.

The probiotic bacterium Lactobacillus plantarum species 299 reduces intestinal permeability in experimental biliary obstruction.

AIMS: Extrahepatic biliary obstruction is associated with the failure of intestinal barrier function, allowing bacteria and other substances from the intestine to enter the circulation and initiate a systemic inflammatory response, causing impairment of organ function. Probiotic bacteria have been shown to have beneficial effects on intestinal barrier function in other conditions, but their effects have never been studied in biliary obstruction. METHODS AND RESULTS: This study examined the effects of enteral administration of Lactobacillus plantarum species 299 (LP299) in oatmeal fibre compared with sterile oatmeal fibre in water or water alone in an animal model of biliary obstruction. Administration of LP299 was associated with reduced intestinal permeability compared with sterile oatmeal alone (0.262 +/- 0.105%vs 0.537 +/- 0.037%, P=0.019, percentage excretion of (14)Carbon), but there was no evidence of reduced endotoxin exposure or blunting of the systemic inflammatory response. Animals receiving sterile oatmeal fibre alone also failed to develop the hyperpermeability after biliary obstruction seen in animals receiving water only (0.512+/- 0.05%vs 0.788 +/- 0.18%), suggesting that oatmeal itself may have some beneficial effects on intestinal barrier function. CONCLUSION: Enteral administration of the probiotic bacterium LP299 reduces intestinal hyperpermeability associated with experimental biliary obstruction. SIGNIFICANCE AND IMPACT OF THE STUDY: This study provides insight to direct further work into the modulation of intestinal barrier function by probiotic bacteria.

Glutamine improves intestinal barrier function in experimental biliary obstruction.

OBJECTIVE: To determine the effects of enteral administration of glutamine on intestinal barrier function in experimental biliary obstruction. BACKGROUND: Extrahepatic biliary obstruction is associated with the failure of intestinal barrier function, allowing bacteria and other substances from the intestine to enter the circulation and initiate a systemic inflammatory response, causing impairment of multiple organs. The amino acid glutamine has been shown to improve intestinal barrier function in other conditions, but its effects in biliary obstruction have not been fully examined. METHODS: This study examined the effects of enteral administration of glutamine on intestinal permeability and on bacterial translocation from the intestine in a rodent model of biliary obstruction. RESULTS: Glutamine was shown to reduce intestinal permeability measured as percentage excretion of 14C 7 days after biliary obstruction (0.35+/-0.03 vs. 0.56+/-0.085% in controls, p=0.028), and glutamine administration was also associated with a decreased incidence of bacterial translocation to extra-intestinal sites (p=0.03). Radiolabelled bacterial studies also demonstrated reduced translocation of bacterial fragments to extra-intestinal sites in glutamine-treated animals (p=0.01). There was also some evidence of decreased exposure to endotoxin, reduced systemic inflammation and increased bacterial killing by the immune system in glutamine-treated animals. CONCLUSIONS: Glutamine modulates intestinal permeability and reduces bacterial translocation in an animal model of experimental biliary obstruction and may increase bacterial killing by the immune system.

Metallothionein crypt-restricted immunopositivity indices (MTCRII) correlate with aberrant crypt foci (ACF) in mouse colon.

Metallothionein (MT) crypt-restricted immunopositivity indices (MTCRII) are colonic crypt stem cell mutation markers that may be induced early and in abundance after mutagen treatment. Metallothionein is the endogenous reporter gene for MTCRII, but is not typically implicated in the classical pathway of colorectal tumorigenesis. Hence, the oncological relevance of MTCRII is unclear. This study tests the hypothesis that MTCRII induced by N-methyl-N-nitrosourea (MNU) and lambda carrageenan (lambdaCgN) associate with aberrant crypt foci (ACF) in mouse colon. Undegraded lambdaCgN and MNU were tested alone and in combination against MTCRII and ACF in Balb/c mice, at 20 weeks after the start of treatment. MTCRII were unaffected by lambdaCgN alone. Combined lambdaCgN/MNU treatments induced greater MTCRII (P < 0.01) as well as greater number (P < 0.001) and crypt multiplicity (P < 0.01) of ACF than MNU alone. MTCRII were approximately 10-fold more numerous than ACF, although linear correlations were observed between these parameters (r = 0.732; P < 0.01). MTCRII are induced by lambdaCgN/MNU interactions in sufficient numbers to provide statistical power from relatively small sample sizes and correlate with ACF formation. MTCRII could thus provide the basis for a novel medium-term murine bioassay relevant to early-stage colorectal tumorigenesis.

Effect of supplemental L-arginine in a chemical-induced model of colorectal cancer.

L-Arginine inhibits the development of spontaneous, transplantable solid tumors and chemically induced mammary tumors. The aim of the present study was to investigate the effect of l-arginine on chemically induced colorectal cancer in male Wistar rats. Colorectal cancer was induced in all animals by weekly subcutaneous injections of the colonic procarcinogen 1,2-dimethylhydrazine (DMH) at a dosage of 20 mg/kg body weight. Arginine was given in a 1% solution of drinking water. Group I was the DMH control; group II, arginine for 22 weeks; group III, arginine for the first 10 weeks only. Lymphocyte function was evaluated by measuring the thymic lymphocyte proliferative response to the T cell mitogen phytohemagglutinin. The results show that tumor incidence and tumor burden (tumors/rat and tumors/tumor-bearing rat) were significantly reduced in both groups of animals receiving arginine compared to DMH controls (p < 0.05). The tumor areas and volumes were also reduced in both arginine groups (p < 0.05). Thymic lymphocyte stimulation indices were significantly increased by arginine supplementation (p < 0.05). These results would be in keeping with the reduction in colorectal tumor production due to a "nonspecific" stimulation of the host immune system by L-arginine.

Assessment of ornithine decarboxylase activity in rectal mucosa as a marker for colorectal adenomas and carcinomas.

We have investigated the role of ornithine decarboxylase activity in rectal mucosa as a marker for colorectal neoplasia. Biopsies of normal rectal mucosa were taken from 18 patients with adenomas greater than 1 cm diameter, 11 with carcinomas and 16 controls. The mean ornithine decarboxylase activity in normal rectal mucosa of adenoma patients, 6.52 nmol CO2 released h-1 (mg cell protein)-1, was significantly lower than that in controls, 16.8, P = 0.006. The difference in rectal ornithine decarboxylase activities between cancer patients, 3.58, and controls was also significant, P = 0.001. These preliminary results suggest that ornithine decarboxylase may be a useful marker in screening for colorectal neoplasia.

[Lung transplantation. Possibilities and limitations]. / Lungentransplantation. Möglichkeiten und Grenzen.

Lung transplantation is an option for patients with endstage pulmonary diseases without contraindications. Recent European studies showed a survival benefit for patients with cystic fibrosis, fibrosis and emphysema after lung transplantation. Early mortality has been reduced recently by surgical improvements. Life expectancy after lung transplantation has improved in recent years but is still lower than in patients with other solid organ transplantations. Quality of life is consistently improved but exercise tolerance keeps reduced in comparison to the normal population. Specific problems described in detail are frequent organ rejections and infections, airway problems and a high incidence of malignant diseases. 5-year survival after lung transplantation is in average 60%.

[Lung transplantation in Hanover: an interim balance-sheet after ten years]. / Lungentransplantation in Hannover: eine Zwischenbilanz nach zehn Jahren. 10 Jahre Lungentransplantation.

BACKGROUND: We reviewed our experience with various forms of lung transplantation (heart-lung [HLTx], bilateral lung [BLTx] and single lung [SLTx]) from December 1987 to September 1998 at Hannover University. PATIENTS: In 258 patients 282 procedures (46 HLTx, 142 BLTx and 94 SLTx) were performed. Major indications were pulmonary fibrosis (n = 73), obstructive lung disease (n = 55), cystic fibrosis (n = 48), primary pulmonary hypertension (PPHT, n = 36), secondary pulmonary hypertension (n = 30) and retransplantation (n = 24). RESULTS: The 1-, 3- and 5-year survival rates in all 258 recipients were 77%, 70% and 63% respectively. Significantly better 1-year survival was noted in patients with cystic fibrosis (90%), pulmonary fibrosis (81%), obstructive lung disease (71%) and secondary pulmonary hypertension (83%) when compared to patients with primary pulmonary hypertension (58%). There was no significant difference in actuarial 1-year survival rates between the different procedures (HLTx 78%, BLTx 77%, SLTx 77%). Bronchiolitis obliterans syndrome (BOS) proved to be the major obstacle for long term survival. Actuarial freedom from BOS was 80% at 1 year and only 45% at 5 years. Various treatment strategies including augmentation of immunosuppression could only temporarily halt the deterioration of lung function in the majority of patients with BOS. CONCLUSIONS: Lung transplantation provides a true therapeutic option for patients with endstage lung disease. However, improved long term outlook will depend on a better understanding and treatment of bronchiolitis obliterans.

Probiotic therapy fails to improve gut permeability in a hapten model of colitis.

BACKGROUND: Studies in clinical and experimental inflammatory bowel disease (IBD) have shown disturbances in intestinal bacterial flora with an increase in potentially pathogenic and a decrease in protective organisms. It was hypothesized that Lactobacillus plantarum species 299 (LP299), a probiotic, would ameliorate colitis and improve intestinal permeability in experimental colitis. This study investigated the effect of LP299 in the trinitrobenzenesulfonic acid/ethanol (TNBS/E) rat model of colitis. METHODS: Twelve week old male Wistar rats were randomized to receive rectal instillates of either TNBS/E (n = 48) or saline (n = 16). For the next 7 days the animals were gavaged with 2.5 ml of oat fibre suspension containing 10(9) colony forming units (CFU) of LP299 (LP299/OF), oat fibre suspension alone (OF) or no treatment. At the end of the experiment rats received radiolabelled polyethylene glycol and urine was collected for 24 h to assess permeability. Animals were then anaesthetized and colons were harvested for colon macroscopic scoring (CMS). RESULTS: TNBS/E per rectum resulted in a greater CMS (P < 0.001) and gut permeability (P = 0.006) than saline. Administration of LP299/OF or oat fibre alone did not result in a reduction in CMS or gut permeability when compared to colitic controls. CONCLUSIONS: LP299/OF, when administered after TNBS instillation, does not reduce the severity of colitis or improve gut permeability in this hapten model of colitis.

Development and reversibility of T lymphocyte dysfunction in experimental obstructive jaundice.

This study evaluates the effect of experimental biliary obstruction by bile duct ligation (BDL) and biliary drainage on cell-mediated immunity in Wistar rats. Immune status has been assessed by a mitogen stimulation test of T lymphocytes with phytohaemagglutinin. Animals were followed for up to 35 days after BDL. Regression analysis showed a significant negative correlation between lymphocyte function and the period of jaundice (correlation coefficient -0.57, P less than 0.001). Following BDL for 21 days, groups of animals had internal biliary drainage for 7, 14 and 28 days, and external drainage for 14 days. Compared with obstructed animals, 14 days internal drainage was required to improve lymphocyte function (P less than 0.05). Animals which had 14 days of external drainage had significantly lower lymphocyte stimulation than internal drainage animals (P less than 0.05). The results demonstrate that obstructive jaundice produces a progressive reduction of T lymphocyte function. This can be reversed by biliary drainage, internal drainage being more effective than external drainage.

Bactericidal/permeability-increasing protein attenuates systemic inflammation and acute lung injury in porcine lower limb ischemia-reperfusion injury.

OBJECTIVE: To investigate the role of recombinant bactericidal/permeability-increasing protein (rBPI21) in the attenuation of the sepsis syndrome and acute lung injury associated with lower limb ischemia-reperfusion (I/R) injury. SUMMARY BACKGROUND DATA: Gut-derived endotoxin has been implicated in the conversion of the sterile inflammatory response to a lethal sepsis syndrome after lower torso I/R injury. rBPI21 is a novel antiendotoxin therapy with proven benefit in sepsis. METHODS: Anesthetized ventilated swine underwent midline laparotomy and bilateral external iliac artery occlusion for 2 hours followed by 2.5 hours of reperfusion. Two groups (n = 6 per group) were randomized to receive, by intravenous infusion over 30 minutes, at the start of reperfusion, either thaumatin, a control-protein preparation, at 2 mg/kg body weight, or rBPI21 at 2 mg/kg body weight. A control group (n = 6) underwent laparotomy without further treatment and was administered thaumatin at 2 mg/kg body weight after 2 hours of anesthesia. Blood from a carotid artery cannula was taken every half-hour for arterial blood gas analysis. Plasma was separated and stored at -70 degrees C for later determination of plasma tumor necrosis factor (TNF)-alpha, interleukin (IL)-6 by bioassay, and IL-8 by enzyme-linked immunosorbent assay (ELISA), as a markers of systemic inflammation. Plasma endotoxin concentration was measured using ELISA. Lung tissue wet-to-dry weight ratio and myeloperoxidase concentration were used as markers of edema and neutrophil sequestration, respectively. Bronchoalveolar lavage protein concentration was measured by the bicinclinoic acid method as a measure of capillary-alveolar protein leak. The alveolar-arterial gradient was measured; a large gradient indicated impaired oxygen transport and hence lung injury. RESULTS: Bilateral hind limb I/R injury increased significantly intestinal mucosal acidosis, intestinal permeability, portal endotoxemia, plasma IL-6 concentrations, circulating phagocytic cell priming and pulmonary leukosequestration, edema, capillary-alveolar protein leak, and impaired gas exchange. Conversely, pigs treated with rBPI21 2 mg/kg at the onset of reperfusion had significantly reduced intestinal mucosal acidosis, portal endotoxin concentrations, and circulating phagocytic cell priming and had significantly less pulmonary edema, leukosequestration, and respiratory failure. CONCLUSIONS: Endotoxin transmigration across a hyperpermeable gut barrier, phagocytic cell priming, and cytokinemia are key events of I/R injury, sepsis, and pulmonary dysfunction. This study shows that rBPI21 ameliorates these adverse effects and may provide a novel therapeutic approach for prevention of I/R-associated sepsis syndrome.