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.

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.

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.

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.

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.

[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%.

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.

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.

Gut mucosal injury is attenuated by recombinant bactericidal/permeability-increasing protein in hind limb ischemia-reperfusion injury.

Lower limb ischemia-reperfusion injury (IRI) is associated with increased gut permeability to endotoxin, which not only directly damages enterocytes but also stimulates a systemic inflammatory response syndrome (SIRS), compounding gut injury. Recombinant bactericidal/permeability-increasing protein (rBPI21) is a novel anti-endotoxin therapy with proven benefit in sepsis. Its potential role in modulating remote gut injury in hind limb IRI was studied. Male Wistar rats were chosen for a prospective randomized control trial (n = 10 per group). The control group and two groups undergoing 3 hr bilateral hind limb ischemia with 2 hr reperfusion (I/R) were randomized to receive intravenously either control protein thaumatin at 2 mg/kg or rBPI21 at 2 mg/kg, respectively. Quantitative morphometric assessment of the small bowel was used as a measure of gut injury and, using an ex vivo everted gut sac model, translocation of 14C-labeled polyethylene glycol (PEG) was used as a measure of gut permeability. Our results indicate that hind limb IRI is associated with remote gut mucosal injury and increased permeability to macromolecules. rBPI21 anti-endotoxin therapy modulates remote gut injury associated with lower limb IRI in this model.

Recombinant bactericidal/permeability-increasing protein attenuates the systemic inflammatory response syndrome in lower limb ischemia-reperfusion injury.

OBJECTIVES: Hind limb ischemia-reperfusion (I/R) injury increases gut permeability, and resultant endotoxemia is associated with an amplified systemic inflammatory response syndrome leading to multiple organ dysfunction syndrome. We studied the potential role of recombinant bactericidal/permeability-increasing protein (rBPI(21) ), a novel antiendotoxin therapy, in modulating endotoxin-enhanced systemic inflammatory response syndrome in hind limb I/R injury. METHODS: In this prospective, randomized, controlled, experimental animal study, 48 male Wistar rats, weighing 300 to 350 g, were randomized to a control group (sham) and five groups undergoing 3 hours bilateral hind limb ischemia with 2 hours reperfusion (I/R) (n = 8 per group). The control and untreated I/R groups received thaumatin, a control-protein preparation, at 2 mg/kg. Treatment groups were administered rBPI(21) intravenously at 1, 2, or 4 mg/kg body weight at the beginning of reperfusion; an additional group was administered rBPI(21) intravenously at 2 mg/kg after 1 hour of reperfusion. Plasma interleukin-6 concentration was estimated by bioassay as a measure of systemic inflammation. Plasma endotoxin concentration was determined by use of an amebocyte lysate chromogenic assay. Crossreactive immunoglobulin G and M antibodies to the highly conserved inner core region of endotoxin were measured by use of an enzyme-linked immunosorbent assay. The lung tissue wet-to-dry weight ratio and myeloperoxidase concentration were used as markers of edema and neutrophil sequestration, respectively. RESULTS: I/R provoked highly significant elevation in plasma interleukin-6 concentrations (1351.20 pg/mL [860.16 - 1886.40 pg/mL]) compared with controls (125.32 pg/mL [87.76-157.52 pg/mL; P <.0001]), but treatment with rBPI(21) 2 mg/kg at onset of reperfusion (715.89 pg/mL [573.36-847.76 pg/mL]) significantly decreased interleukin-6 response compared with the nontreatment group ( P <.016). I/R increased plasma endotoxin concentrations significantly (21.52 pg/mL [6.20-48.23 pg/mL]), compared with control animals (0.90 pg/mL [0.00-2.30 pg/mL; P <.0001]), and treatment with rBPI(21) 4 mg/kg at reperfusion significantly decreased endotoxemia (1.30 pg/mL [1.20-2.20 pg/mL]), compared with the untreated group ( P <.001). The lung tissue myeloperoxidase level was significantly increased in the untreated I/R group (208.18% [128.79%-221.81%]), compared with in controls (62.00% [40.45%-80.92%; P <.0001]), and attenuated in those treated with rBPI(21) 2 mg/kg (129.54% [90.49%-145.78%; P <.05]). Data represent median and interquartile range, comparisons made with the nonparametric Mann-Whitney U test. CONCLUSIONS: These findings show that hind limb ischemia-reperfusion injury is associated with endotoxemia, elevations in plasma interleukin-6, and pulmonary leukosequestration. Treatment with rBPI(21) after ischemia reduces endotoxemia, the interleukin-6 response, and attenuates pulmonary leukosequestration in response to hind limb reperfusion injury.

Interleukin 10-deficient colitis: new similarities to human inflammatory bowel disease.

BACKGROUND: Interleukin (IL) 10 is a potent anti-inflammatory cytokine. Disruption of the IL-10 gene in C57/Black6 mice results in enterocolitis in the presence of intestinal bacteria. This study investigated gut mucosal barrier function sequentially during the development of colitis in this model. METHODS: Animals were bred in specific pathogen-free conditions and transferred to conventional housing at 4 weeks. Mice were evaluated at 6, 8, 10, 12, 14 and 15 weeks of age. Barrier function was assessed by measuring intestinal permeability and antibody response to systemic endotoxaemia (antibody to the core glycolipid region of lipopolysaccharide; EndoCAb). Colons were harvested and a histological injury score (HIS) was calculated. RESULTS: The HIS increased progressively until 12 weeks, with an associated increase in intestinal permeability, and immunoglobulin (Ig) M and IgG EndoCAb. The HIS correlated positively with both intestinal permeability and IgM and IgG EndoCAb. Intestinal permeability showed a positive correlation with EndoCAb. CONCLUSION: IL-10 knockout mice develop colitis with an associated disturbance in gut mucosal barrier function, as measured by increased permeability and endotoxaemia. The colitis found in the IL-10 knockout mouse shares these histological, physiological and biochemical features with human inflammatory bowel disease and is therefore suitable for therapeutic trials. A measure of endotoxaemia correlated directly with intestinal permeability in this model.

Inhaled iloprost to treat severe pulmonary hypertension. An uncontrolled trial. German PPH Study Group.

BACKGROUND: Inhaled aerosolized iloprost, a stable prostacyclin analogue, has been considered a selective pulmonary vasodilator in the management of pulmonary hypertension. OBJECTIVE: To assess the efficacy of inhaled iloprost in the treatment of life-threatening pulmonary hypertension. DESIGN: Open, uncontrolled, multicenter study. SETTING: Intensive care units and pulmonary hypertension clinics at six university hospitals in Germany. PATIENTS: 19 patients who had progressive right-heart failure despite receiving maximum conventional therapy (12 with primary pulmonary hypertension, 3 with pulmonary hypertension related to collagen vascular disease without lung fibrosis, and 4 with secondary pulmonary hypertension). INTERVENTION: Inhaled iloprost, 6 to 12 times daily (50 to 200 microg/d). MEASUREMENTS: Right-heart catheterization and distance walked in 6 minutes at baseline and after 3 months of therapy. RESULTS: During the first 3 months of therapy, New York Heart Association functional class improved in 8 patients and was unchanged in 7 patients. Four patients died, 3 of right-heart failure and 1 of sepsis. The acute hemodynamic response to inhaled iloprost was predominant pulmonary vasodilatation with little systemic effect at baseline and at 3 months (data available for 12 patients). Hemodynamic variables were improved at 3 months, and the distance walked in 6 minutes improved by 148 m (95% CI, 4.5 to 282 m; P = 0.048). Of the 15 patients who continued to use inhaled iloprost, 8 stopped: Four had lung transplantation, 1 switched to intravenous prostacyclin therapy, and 3 died. Seven patients are still receiving inhaled iloprost (mean +/-SD) duration of therapy, 536 +/- 309 days; mean dosage, 164 +/- 38 microg/d). CONCLUSIONS: Inhaled iloprost may offer a new therapeutic option for improvement of hemodynamics and physical function in patients with life-threatening pulmonary hypertension and progressive right-heart failure that is refractory to conventional therapy.

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.

[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.

Prostaglandins induce vascular endothelial growth factor in a human monocytic cell line and rat lungs via cAMP.

Prostaglandins have emerged as a therapeutic option for patients with peripheral vascular disease as well as pulmonary hypertension as a means to increase blood flow. We tested the hypothesis that prostaglandins regulate vascular endothelial growth factor (VEGF) expression in the human monocytic THP-1 cell line and in isolated perfused rat lungs. Our data show that the stable PGI2-analogue iloprost induces VEGF gene expression (predominantly VEGF121, but also VEGF165 isoforms) and VEGF protein synthesis in THP-1 cells. This effect is abolished by dexamethasone and by Rp-cAMP, a specific inhibitor of cAMP-dependent protein kinase (PKA) activation. The calcium channel blocker diltiazem has no effect on the iloprost-induced VEGF gene expression, and depletion of intracellular Ca2+ stores by long-term exposure (16 h) of THP-1 cells to thapsigargin does not inhibit iloprost-induced VEGF gene expression, suggesting that an increase in intracellular Ca2+ is not essential for VEGF gene induction by iloprost. However, an increase of intracellular Ca2+ by a short-term (2 h) exposure of THP-1 cells to thapsigargin or to the calcium-ionophore A23187 increases VEGF mRNA levels, indicating that a change in intracellular Ca2+ by itself can alter VEGF gene expression. The effects of thapsigargin or A23187 on VEGF gene expression are also mediated via cAMP-PKA since they are inhibited by Rp-cAMP. In isolated perfused rat lungs, PGI2 and PGE2 increases VEGF mRNA abundance whereas Rp-cAMP inhibits the prostaglandin-induced VEGF gene activation. Thus, our data suggest that prostaglandins stimulate VEGF gene expression in monocytic cells and in rat lungs via a cAMP-dependent mechanism.

Cytokine profile in chronic cardiac failure.

Elevated tumour necrosis factor alpha (TNF-alpha) has been demonstrated in chronic cardiac failure (CCF) and may relate to severity of CCF and development of cachexia. We measured TNF receptor p55 in addition to TNF-alpha in an attempt to improve the detection rate of TNF-alpha activation, and simultaneously measured interleukin 6 (IL-6), interleukin 8 (IL-8) and C-reactive protein. Thirty-four patients with CCF and 24 control subjects were studied. Only TNF receptor p55 [6.95 (0.77-42.3) vs. 5.52 (1.50-13.36) ng mL-1 (median (range)] and IL-6 [0.335 (0-9.79) vs. 0(0-14.71) pg mL-1) were significantly elevated in patients compared with control subjects (both P < 0.05). All inflammatory markers were more frequently elevated in patients, but none correlated with any of the clinical parameters studied. Reasons for inflammatory marker elevation in CCF are uncertain, but future studies should measure the p55 TNF receptor and IL-6 in addition to TNF-alpha, to improve detection of cytokine activity.

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.

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.