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The role of vitamin K in animal health has not received much attention. Vitamin K studies have, for the most part, addressed the use of animals in the investigation of vitamin K physiology and pathophysiology, often using the rodent as a model system. However, vitamin K performs the same role in animals as it does in man and there are areas, such as animal nutrition, where a better understanding of animal requirements in general, and with ageing, could benefit animal health and continued well‐being.

The potential benefit of vitamin K as a therapeutic in osteoporosis is controversial and the vitamin K regimen being used clinically (45 mg/day) employs doses that are many times higher than required to ensure maximal gamma-carboxylation of the vitamin K-dependent bone proteins. We therefore tested the hypothesis that vitamin K catabolites, 5-carbon (CAN5C) and 7-carbon carboxylic acid (CAN7C) aliphatic side-chain derivatives of the naphthoquinone moiety exert an osteotrophic role consistent with the treatment of osteoporosis.Osteoblast-like MG63 cell cultures were challenged with lipopolysaccharide and the levels of interleukin-6, an osteoclastogenic cytokine, measured with and without catabolites; low concentrations of CAN7C significantly inhibited interleukin-6 release, but CAN5C did not. In models of bone loss induced by ovariectomy or sciatic neurectomy in C57BL/6 mice, we found that the rarer CAN7C catabolite markedly restricted ovariectomy-induced bone loss and possibly limited sciatic neurectomy-induced bone loss. CAN7C activity depends on a free carboxylic acid and its particular side-chain structure.These in vivo data indicate for the first time that the clinical utility of vitamin K for osteoporosis may reside in an unusual catabolite.

Liver failure is associated with progressive cytotoxic brain oedema (astrocyte swelling), which underlies hepatic encephalopathy (HE). Ammonia and superimposed inflammation are key synergistic factors in HE, but the mechanism(s) involved remain unknown. We aimed to determine whether aquaporin-4 (AQP4), an astrocyte endfeet bi-directional water channel, is associated with the brain oedema of HE.Rats (n=60) received sham-operation (sham), 5 days hyperammonaemia-inducing diet (HD), galactosamine (GALN) induced acute liver failure (ALF), 4 weeks bile duct-ligation (BDL) induced cirrhosis, or caecal ligation and puncture (CLP), a 24h model of bacterial peritonitis. Rats from every group (except CLP) were randomised to receive intraperitoneal injections of lipopolysaccharide (LPS; 1mg/kg) or saline, prior to termination 3h later. Brain water, AQP4 protein expression (western blot) and AQP4 localisation by immunogold electron microscopy were investigated.Significant hyperammonaemia was observed in saline-injected BDL (p0.05), GALN (p0.01), and HD (p0.01), compared to sham rats. LPS injection did not affect arterial ammonia or plasma biochemistry in any of the treatment groups. Increased brain water was observed in saline-injected GALN (p0.05), HD (p0.01), and CLP (p0.001) compared to sham rats. Brain water was numerically increased in BDL rats, but this failed to reach significance (p=0.09). LPS treatment further increased oedema significantly in all treatment groups (p0.05, respectively). AQP4 expression was significantly increased in saline-injected BDL (p0.05), but not other treatment groups, compared to sham rats. Membrane polarisation was maintained in BDL rats.The results suggest that AQP4 is not directly associated with the development of brain oedema in liver failure, hyperammonaemia, or sepsis. In cirrhosis, there is increased AQP4 protein expression, but membrane polarisation, is maintained, possibly in a compensatory attempt to limit severe brain oedema.

Treatment of hyperammonemia and hepatic encephalopathy in cirrhosis is an unmet clinical need. The aims of this study were to determine whether L-ornithine and phenylacetate/phenylbutyrate (administered as the pro-drug phenylbutyrate) (OP) combined are synergistic and produce sustained reduction in ammonia by L-ornithine acting as a substrate for glutamine synthesis, thereby detoxifying ammonia, and the phenylacetate excreting the ornithine-derived glutamine as phenylacetylglutamine in the urine. Sprague-Dawley rats were studied 4 weeks after bile duct ligation (BDL) or sham operation. Study 1: Three hours before termination, an internal carotid sampling catheter was inserted, and intraperitoneal saline (placebo), OP, phenylbutyrate, or L-ornithine were administered after randomization. BDL was associated with significantly higher arterial ammonia and brain water and lower brain myoinositol (P < 0.01, respectively), compared with sham-operated controls, which was significantly improved in the OP-treated animals; arterial ammonia (P < 0.001), brain water (P < 0.05), brain myoinositol (P < 0.001), and urinary phenylacetylglutamine (P < 0.01). Individually, L-ornithine or phenylbutyrate were similar to the BDL group. In study 2, BDL rats were randomized to saline or OP administered intraperitoneally for 6 hours or 3, 5, or 10 days and were sacrificed between 4.5 and 5 weeks. The results showed that the administration of OP was associated with sustained reduction in arterial ammonia (P < 0.01) and brain water (P < 0.01) and markedly increased arterial glutamine (P < 0.01) and urinary excretion of phenylacetylglutamine (P < 0.01) in each of the OP treated groups. Conclusion: The results of this study provide proof of the concept that L-ornithine and phenylbutyrate/phenylacetate act synergistically to produce sustained improvement in arterial ammonia, its brain metabolism, and brain water in cirrhotic rats. (HEPATOLOGY 2009.)

Hyperammonemia is a feature of liver failure, which is associated with increased risk of infection. The aims of the present study were to determine in vitro, in rats fed an ammoniagenic diet and in patients with cirrhosis, whether induction of hyperammonemia results in neutrophil dysfunction. As hyperammonemia produces cell swelling, we explored the role of the osmoregulating, p38 mitogen-activated protein kinase (p38 MAPK ) pathway in mediating this neutrophil dysfunction. Neutrophils were isolated from blood of healthy volunteers and incubated with either 75 M ammonia or phosphate-buffered saline. Both groups were studied under hyponatremic conditions and/or with the addition of p38 MAPK modulators. Neutrophil phagocytosis was measured in naive rats and rats fed an ammoniagenic diet and in patients with stable cirrhosis given placebo (n 8) or an amino acid solution inducing hyperammonemia (n 8). Cell volume and phagocytosis was analyzed by fluorescentactivated cell sorting using fluorescein isothiocyanate–labeled E. coli. p38 MAPK phosphorylation was measured by western blotting. In healthy neutrophils incubated with ammonia and in rats fed an ammoniagenic diet, neutrophils showed evidence of swelling, impaired phagocytosis, and increased spontaneous oxidative burst compared to controls. Phagocytosis was significantly impaired in patients with induced hyperammonemia compared to placebo. The effects of hyperammonemia and hyponatremia were synergistic. The p38 MAPK intracellular signaling pathways were activated in healthy neutrophils exposed to ammonia in association with increased burst activity. Neutrophil phagocytic dysfunction was abrogated by the addition of a p38 MAPK agonist. Conclusion: Ammonia produces neutrophil swelling and impairs neutrophil phagocytosis. The p38 MAPK intracellular signaling pathway has been shown to be important in mediating the ammonia-induced neutrophil dysfunction. (HEPATOLOGY 2008;48:1202-1212.)

Hepatic encephalopathy (HE) is a common neuropsychiatric complication of liver disease affecting about 20-30% patients with cirrhosis. HE may only affect quality of life (e.g. impairments in attention; coordination; driving ability), but in some patients this progresses to coma and death; defining mortality in those with acute liver failure. HE is thought to occur through accumulation of ammonia as a by-product of protein metabolism. In liver failure ammonia accumulates to toxic levels, resulting in ammonia-associated brain swelling. Presently, there is no proven therapy for HE though recent studies suggest that during liver failure, ammonia removal by skeletal muscle (by conversion to glutamine) can be manipulated; also that ammonia and amino acid metabolism should be viewed in terms of their interorgan relationship. This led us to develop a novel concept for ammonia removal. Preliminary studies provide the proof of concept that the combination of L-ornithine (amino acid) with phenylactetate, as L-ornithine phenylacetate (OP), reduces toxic levels of ammonia by (1) L-ornithine acting as a substrate for glutamine synthesis from ammonia in skeletal muscle and (2) phenylacetate excreting the ornithine-related glutamine as phenylacetylglutamine in the kidneys. As both L-ornithine and phenylacetate are already available for human use, data showing its usefulness in ammonia lowering could translate quickly into providing the much needed therapy for HE patients.

This study explores the hypothesis that the inflammatory response induced by administration of lipopolysaccharide (LPS) exacerbates brain edema in cirrhotic rats; and if so whether this is associated with altered brain metabolism of ammonia or anatomical disturbance of the blood-brain barrier. Adult Sprague-Dawley rats 4 weeks after bile duct ligation (BDL)/Sham-operation, or naive rats fed a hyperammonemic diet (HD), were injected with LPS (0.5 mg/kg, intraperitoneally) or saline, and killed 3 hours later. LPS administration increased brain water in HD, BDL, and sham-operated groups significantly (P < 0.05), but this was associated with progression to pre-coma stages only in BDL rats. LPS induced cytotoxic brain swelling and maintained anatomical integrity of the blood-brain barrier. Plasma/brain ammonia levels were higher in HD and BDL rats than in sham-operated controls and did not change with LPS administration. Brain glutamine/myoinositol ratio was increased in the HD group but reduced in the BDL animals. There was a background pro-inflammatory cytokine response in the brains of cirrhotic rats, and plasma/brain tumor necrosis factor alpha (TNF-α) and IL-6 significantly increased in LPS-treated animals. Plasma nitrite/nitrate levels increased significantly in LPS groups compared with non-LPS controls; however, frontal cortex nitrotyrosine levels only increased in the BDL + LPS rats (P < 0.005 versus BDL controls). Conclusion: Injection of LPS into cirrhotic rats induces pre-coma and exacerbates cytotoxic edema because of the synergistic effect of hyperammonemia and the induced inflammatory response. Although the exact mechanism of how hyperammonemia and LPS facilitate cytotoxic edema and pre-coma in cirrhosis is not clear, our data support an important role for the nitrosation of brain proteins. (HEPATOLOGY 2007.)

Background: Increased intracranial pressure (ICP) worsens the outcome of acute liver failure (ALF). This study investigates the underlying pathophysiological mechanisms and evaluates the therapeutic effect of albumin dialysis in ALF with use of the Molecular Adsorbents Recirculating System without hemofiltration/dialysis (modified, M-MARS). Methods: Pigs were randomized into three groups: sham, ALF, and ALF + M-MARS. ALF was induced by hepatic devascularization (time = 0). M-MARS began at time = 2 and ended with the experiment at time = 6. ICP, arterial ammonia, brain water, cerebral blood flow (CBF), and plasma inflammatory markers were measured. Results: ICP and arterial ammonia increased significantly over 6 hrs in the ALF group, in comparison with the sham group. M-MARS attenuated (did not normalize) the increased ICP in the ALF group, whereas arterial ammonia was unaltered by M-MARS. Brain water in the frontal cortex (grey matter) and in the subcortical white matter at 6 hrs was significantly higher in the ALF group than in the sham group. M-MARS prevented a rise in water content, but only in white matter. CBF and inflammatory mediators remained unchanged in all groups. Conclusion: The initial development of cerebral edema and increased ICP occurs independently of CBF changes in this non-inflammatory model of ALF. Factor(s) other than or in addition to hyperammonemia are important, however, and may be more amenable to alteration by albumin dialysis.

Background/Aims: Ammonia reduction is the target for therapy of hepatic encephalopathy (HE) but lack of quantitative data about how the individual organs handle ammonia limit our ability to develop novel therapeutic strategies. The study aims were to evaluate interorgan ammonia metabolism quantitatively in a devascularised pig model of acute liver failure (ALF). Methods: Ammonia and amino acid fluxes were measured across the portal drained viscera (PDV), kidneys, hind-leg, and lungs in ALF pigs. Results: ALF pigs developed hyperammonemia and increased glutamine levels, while glutamate levels were decreased. PDV contributed to the hyperammonemic state mainly through increased shunting and not as a result of increased glutamine breakdown. The kidneys were quantitatively as important as PDV in systemic ammonia release, while muscle took up ammonia. Data suggest that the lungs are able to remove ammonia from the circulation during the initial stage of ALF. Conclusions: Our study provides the novel observation of glutamate deficiency in a pig model of ALF. Furthermore, the kidneys are quantitatively as important as PDV in ammonia production and the muscles play an important role in ammonia removal. AD - Digestive Surgery, University Hospital Northern Norway, Norway. AU - Ytrebo LM AU - Sen S AU - Rose C AU - Ten Have GA AU - Davies NA AU - Hodges S AU - Nedredal GI AU - Romero-Gomez M AU - Williams R AU - Revhaug A AU - Jalan R AU - Deutz NE LA - ENG PT - JOURNAL ARTICLE DEP - 20060615 TA - Am J Physiol Gastrointest Liver Physiol JID - 100901227

Previous studies suggest reduced hepatic endothelial nitric oxide synthase activity contributes to increased intrahepatic resistance. Asymmetric dimethylarginine (ADMA), an endogenous nitric oxide synthase inhibitor, undergoes hepatic metabolism via dimethylarginine-dimethylamino-hydrolase, and is derived by the action of protein-arginine-methyltransferases. Our study assessed whether ADMA, and its stereo-isomer symmetric dimethylarginine (SDMA), are increased in alcoholic hepatitis patients, and determined any relationship with severity of portal hypertension (hepatic venous pressure gradient measurement) and outcome. Fifty-two patients with decompensated alcoholic cirrhosis were studied, 27 with acute alcoholic hepatitis and cirrhosis, in whom hepatic venous pressure gradient was higher (P = 0.001) than cirrhosis alone, and correlated with ADMA measurement. Plasma ADMA and SDMA were significantly higher in alcoholic hepatitis patients and in nonsurvivors. Dimethylarginine-dimethylamino-hydrolase protein expression was reduced and protein-arginine-methyltransferase-1 increased in alcoholic hepatitis livers. ADMA, SDMA and their combined sum, which we termed a dimethylarginine score, were better predictors of outcome compared with Pugh score, MELD and Maddrey's discriminant-function. Conclusion: Alcoholic hepatitis patients have higher portal pressures associated with increased ADMA, which may result from both decreased breakdown (decreased hepatic dimethylarginine-dimethylamino-hydrolase) and/or increased production. Elevated dimethylarginines may serve as important biological markers of deleterious outcome in alcoholic hepatitis.

We describe a method for the determination of the two major urinary metabolites of vitamin K as the methyl esters of their agyclone structures, 2-methyl-3-(3-3-carboxymethylpropyl)-1,4-naphthoquinone (5C-side-chain metabolite) and 2-methyl-3-(5-carboxy-3-methyl-2-pentenyl)-1,4-naphthoquinone (7C-side-chain metabolite), by HPLC with electrochemical detection (ECD) in the redox mode. Urinary salts were removed by reversed-phase (C18) solid phase extraction (SPE) and the predominately conjugated vitamin K metabolites hydrolysed with methanolic HCl. The resultant carboxylic acid aglycones were quantitatively methylated with diazomethane and fractionated by normal-phase (silica) SPE. Final analysis was by reversed-phase (C18) HPLC with a methanol-aqueous mobile phase. Metabolites were detected by amperometric, oxidative ECD of their quinol forms, which were generated by post-column coulometric reduction at an upstream electrode. The assay gave excellent linearity (r2 typically = 0.999) and high sensitivity with an on-column detection limit of

The link between alcohol consumption and liver disease is not direct and several factors including autoimmunity to hepatocyte components have been implicated. We have previously identified alcohol dehydrogenase (ADH) as an autoantigen in autoimmune liver disease and in a proportion of patients with alcoholic liver disease. The aim of the present study is to investigate the association between the presence of anti-ADH antibodies, alcohol consumption and severity of liver damage in alcoholic patients. The presence of antibodies to human ADH β2 and horse ADH was investigated in 108 patients with documented history of alcohol consumption and alcohol related liver disease, 86 being active alcohol abusers and 22 on sustained alcohol withdrawal, 39 with non-alcohol related disease and 22 normal subjects. Antibodies to either ADH form were more frequently detected in active alcohol abusers (55/86, 64%) than in patients on sustained alcohol withdrawal longer than 6 months (1/8, 13%, p

The pathophysiological basis of acute-on-chronic liver failure (ACLF) is unclear but systemic inflammatory response is thought to be important. In patients with ACLF, the molecular adsorbents recirculating system (MARS) improves individual organ function, but the effect of MARS on the proposed mediators of systemic inflammatory response is unclear. The present study was designed to determine the effect of MARS on the cytokine profile, oxidative stress, nitric oxide, and ammonia. A total of 18 patients with alcohol-related ACLF due to inflammation-related precipitants were randomized to receive standard medical therapy (SMT) alone, or with MARS therapy over 7 days. Plasma cytokines, malondialdehyde (MDA), free radical production, nitrate / nitrite (NOx), and ammonia were measured. Encephalopathy improved significantly with MARS (P < .01), but not with SMT. Mean arterial pressure and renal function remained unchanged. No significant change of plasma cytokines and ammonia levels were observed in either group. Plasma MDA levels did not change either. There was a fall in NOx (P < .05) with MARS, but not with SMT. In conclusion, in inflammation-related ACLF patients, albumin dialysis using MARS results in improvement of encephalopathy, independent of changes of ammonia or cytokines, without improving blood pressure or renal function. These results should temper the liberal use of MARS until further data is available. (Liver Transpl 2004;10:1109–1119.)

The role of proinflammatory cytokines in the pathogenesis of portal hypertension is unclear.This study tests the hypothesis that tumour necrosis factor alpha (TNF-alpha) is an important mediator of the circulatory disturbances in alcoholic hepatitis (AH) and evaluates the acute and short term effect of a single infusion of the monoclonal chimeric anti-TNF-alpha antibody (Infliximab) on portal and systemic haemodynamics in 10 patients with severe biopsy proven AH. Cardiovascular haemodynamics, hepatic venous pressure gradient (HVPG), and hepatic and renal blood flow were measured before, 24 hours after Infliximab, and prior to hospital discharge.Serum bilirubin (p0.05), C reactive protein (p0.001), and white cell count (p0.01) were reduced significantly, as were plasma levels of interleukin (IL)-6 and IL-8 after treatment. Of the 10 patients, nine were alive at 28 days. Mean HVPG decreased significantly at 24 hours (23.4 (2.8) to 14.3 (1.9) mm Hg; p0.001) with a sustained reduction prior to discharge (12.8 (1.9) mm Hg; p0.001). Mean arterial pressure and systemic vascular resistance increased significantly (p0.001and p0.01, respectively), mirrored by a reduction in cardiac index (5.9 (0.5) to 4.7 (0.5) l/min/m(2); p0.05) prior to discharge. Hepatic and renal blood flow also increased significantly (506.2 (42.9) to 646.3 (49.2) ml/min (p=0.001) and 424.3 (65.12) to 506.3 (85.7) ml/min (p=0.001), respectively) prior to discharge.The results of this study illustrate that anti-TNF-alpha treatment in AH patients produces a highly significant, early, and sustained reduction in HVPG, possibly through a combination of a reduction in cardiac output and intrahepatic resistance. In addition, there was a reduction in hepatic inflammation and improved organ blood flow, suggesting an important role for TNF-alpha in mediating the circulatory disturbances in AH.

Albumin concentration is diminished in patients with liver failure. Albumin infusion improves survival of cirrhotic patients with spontaneous bacterial peritonitis, and it is hypothesized that this may be due in part to its detoxifying capabilities. The aim of this study was to perform detailed quantitative and qualitative assessment of albumin function in patients with cirrhosis. Healthy controls and patients with acute deterioration of cirrhosis requiring hospital admission (n = 34) were included. Albumin function was assessed using affinity of the fatty acid binding sites using a spin label (16 doxyl-stearate) titration and electron paramagnetic resonance spectroscopy and ischemia-modified albumin (IMA) was measured. Twenty-two patients developed acute-on-chronic liver failure. Twelve were treated with the Molecular Adsorbents Recirculating System (MARS) and 10 with standard medical therapy. For each parameter measured, the patients' albumin had reduced functional ability, which worsened with disease severity. Fifteen patients died, and IMA, expressed as an albumin ratio (IMAR), was significantly higher in nonsurvivors compared with survivors (P < 0.001; area under the receiver operating curve = 0.8). No change in the patients' albumin function was observed following MARS therapy. A significant negative correlation between IMAR and the fatty acid binding coefficients for sites 1 and 2 (P < 0.001 for both) was observed, indicating possible sites of association on the protein. Conclusion: The results of this study suggests marked dysfunction of albumin function in advanced cirrhosis and provide further evidence for damage to the circulating albumin, which is not reversed by MARS therapy. IMAR correlates with disease severity and may have prognostic use in acute-on-chronic liver failure. (HEPATOLOGY 2009;50:555–564.)

Endotoxaemia contributes to neutrophil dysfunction, infection risk and mortality in patients with alcoholic cirrhosis. As probiotics may decrease Gram-negative gut organisms, we hypothesised that probiotic treatment would restore neutrophil function.In an open-label study, patients with alcoholic cirrhosis (n=12) received Lactobacillus casei Shirota (6.5 x 10(9)) 3 times daily for 4 weeks. Data were compared to healthy controls (n=13) and cirrhotic patients (n=8) who did not receive probiotics. Neutrophil oxidative burst, phagocytosis, toll-like-receptor (TLR) expression, plasma cytokines and ex vivo endotoxin-stimulated cytokine production were measured.Baseline neutrophil phagocytic capacity in patients was significantly lower compared to healthy controls (73% versus 98%, p0.05), but normalised at the end of the study (n=10, 100%, p0.05). No improvement was seen in disease controls. Soluble TNF-receptor (sTNFR)-1 and-2 and interleukin (IL)10 were significantly elevated in patients' plasma but did not change during the study. Ex vivo endotoxin-stimulated levels of sTNFR1, sTNFR2 and IL10 were significantly lower at the end of the study (p0.05). TLR2, 4 and 9 were overexpressed in patients. TLR4 expression normalised by the end of the study.Our data provide a proof-of-concept that probiotics restore neutrophil phagocytic capacity in cirrhosis, possibly by changing IL10 secretion and TLR4 expression, warranting larger randomised controlled and mechanistic studies.

Mortality in patients with alcoholic hepatitis (AH) remains high, and although corticosteroids are widely used for treatment, the results vary considerably. In AH, neutrophils are primed and infiltrate the liver to produce injury, but paradoxically, the main cause of death in such patients is infection. Our prospective study addressed this paradox of primed neutrophils on the one hand and increased risk of infection on the other. We hypothesized that the full activation of neutrophils by a humoral factor such as endotoxin renders them unable to respond to further bacterial challenge. We analyzed neutrophil oxidative burst and phagocytosis in whole blood by fluorescence-activated cell sorting analysis in 63 alcoholic patients with cirrhosis and patients with cirrhosis with superimposed AH (cirrhosis + AH). In 16 patients, ex vivo studies determined whether the removal of endotoxin restored neutrophil function. A resting burst greater than or equal to 5%, indicating neutrophil activation and a reduced phagocytic capacity lower than 42%, was associated with significantly greater risk of infection, organ failure, and mortality. This defective neutrophil function was transmissible through patients' plasma to normal neutrophils, and patients' neutrophil function could be restored by normal plasma. The ex vivo removal of endotoxin from patients' plasma decreased the resting burst and increased the phagocytic function. Conclusions. Our study provides the rationale for a goal-directed approach to the management of patients with cirrhosis and AH, in which the assessment of neutrophil function may be an important biomarker to select patients for immunosuppressive therapy. The neutrophil dysfunction in cirrhosis and AH is reversible, with endotoxin-removal strategies providing new targets for intervention.

Background & Aims: Increased intrahepatic resistance in cirrhosis is associated with reduced endothelial NO synthase (eNOS) activity and exacerbated by superimposed inflammation. NOSTRIN induces intracellular translocation of eNOS and reduces NO generation. Our aims were to quantify and compare hepatic expression of eNOS, NOSTRIN, NOSIP, and caveolin-1 in alcoholic cirrhosis with or without superimposed alcoholic hepatitis and in normal livers. Methods: Biopsy specimens from 20 decompensated alcoholic cirrhotic patients with portal hypertension (10 with alcoholic hepatitis) and 6 normal livers were analyzed: real-time polymerase chain reaction for quantification of messenger RNA; Western blotting; and enzyme assays of eNOS in normal and diseased liver were performed. Localization and interaction of eNOS and NOSTRIN in liver was assessed by immunohistochemistry and co-immunoprecipitation. Results: eNOS mRNA was significantly increased and eNOS activity decreased in alcoholic hepatitis patients, despite no differences in eNOS protein expression among the patients. Patients with alcoholic hepatitis had significantly higher hepatic levels of NOSTRIN and caveolin-1 mRNA compared with cirrhosis alone or normal biopsy specimens. A NOSTRIN splice variant, not present in normal tissue, was detected on mRNA and protein levels in all alcoholic patients. Coimmunoprecipitation demonstrated association among NOSTRIN, eNOS, and caveolin-1. Conclusions: An increase in mRNA and protein of NOSTRIN and its shortened variant in alcoholic hepatitis may partly account for the paradox of increased mRNA levels and normal protein expression but decreased enzymatic activity of eNOS in diseased liver. Such intracellular regulators of NO production may be important in the development of increased intrahepatic resistance in alcoholic hepatitis patients.

The production of nitric oxide (NO) in liver disease and its role in vascular control has been a subject of much interest in recent years. However, the activity of guanylate cyclase (GC), the enzyme activated by NO has received little attention with regard to liver disease. In this study we have utilised a quantitative cytochemical technique to examine the activity of GC on a per cell basis in a rat model of cirrhosis. Our results show a significant reduction in GC activity, indicating that vascular regulation is likely to be substantially affected irrespective of NO generation in this disease model.

Vitamin K is well known for its role in the synthesis of a number of blood coagulation factors. During recent years vitamin K-dependent proteins were discovered to be of vital importance for bone and vascular health. Recommendations for dietary vitamin K intake have been made on the basis of the hepatic requirements for the synthesis of blood coagulation factors. Accumulating evidence suggests that the requirements for other functions than blood coagulation may be higher. This paper is the result of a closed workshop (Paris, November 2002) in which a number of European vitamin K experts reviewed the available data and formulated their standpoint with respect to recommended dietary vitamin K intake and the use of vitamin K-containing supplements.

Background/Aims: Severe alcoholic hepatitis (AH) is associated with high mortality. Tumor necrosis factor-alpha (TNF) has been demonstrated to play an important role in its pathophysiology. Methods: Twelve patients with biopsy-confirmed AH and a Maddrey discriminant factor >32 were treated with a single infusion of the anti-TNF monoclonal antibody Infliximab at a dose of 5 mg/kg body weight. Serial measurements were made for various cytokines using specific enzyme-linked immunoassays (ELISA). In four patients, liver biopsy samples were available pretreatment and on day+28 of therapy. Results: Ten of the 12 patients are alive at a median of 15 (12–20) months. Two patients died within 30 days from septicemia. Serum bilirubin levels, Maddrey score, neutrophil count and C-reactive protein fell significantly within the first month. There was an early, though not significant, decrease in plasma levels of proinflammatory cytokines (interleukins (IL)-1, IL-6, IL-8, interferon-gamma), whereas plasma levels of TNF remained near the sensitivity limit of the assay throughout the treatment course. While TNF mRNA expression in the liver did not change, expression of IL-8, a cytokine regulated mainly by TNF, was almost absent on day+28. Conclusions: Our data suggest that randomized controlled trials of anti-TNF antibody in severe AH are warranted.

This study aimed to detect the levels of osteocalcin in gingival crevicular fluid (GCF) from healthy (or =3 mm sulcus depth and non-bleeding) and diseased sites (or =6 mm probing depth and bleeding) in subjects with adult periodontitis, in order to further investigate its potential as a possible marker of the disease process. Periodontal probing depths, attachment levels and gingival indices were recorded from one healthy and one diseased site in each of 20 subjects with adult periodontitis. Both GCF accumulated in the periodontal pocket or sulci and GCF flowing into the periodontal pocket or sulci over a three-minute interval were sampled. The amounts of osteocalcin in each GCF sample was determined using immunoassays. A mean of 2.34 ng/site (2.7 microg/ml) osteocalcin was found at diseased sites and a mean of 2.47 ng/site (5.47 microg/ml) was found at healthy sites for the accumulated GCF collection method. A mean of 0.17 ng/ site (2.17 microg/ml) osteocalcin was found at diseased sites and a mean of 0.14 ng/ site (1.85 microg/ml) at healthy sites for the flow method of GCF collection. There were no statistically significant differences between osteocalcin levels in diseased and healthy sites in subjects with adult periodontitis.

Phylloquinone is a lipid soluble vitamin which is an absolute growth requirement for black-pigmented anaerobes, many of which are implicated in the aetiology of periodontal diseases. This cross-sectional study aimed to detect the levels of phylloquinone in GCF from healthy and diseased sites in subjects with adult periodontitis, in order to investigate further its potential role in the disease process. The sample consisted of eighteen patients with adult periodontitis. Periodontal probing depths, attachment levels and gingival indices were recorded from one healthy and one diseased site in each subject. GCF was sampled and the amount of phylloquinone in each sample was determined using reverse-phase high performance liquid chromatography coupled to electrochemical detection. The mean amount of phylloquinone in accumulated GCF from diseased sites was 406 pg/site and 80 pg/site from healthy sites (p=0.013). When the amounts of phylloquinone in GCF were expressed as concentrations the values were 228 ng/ml and 3350 ng/ml for diseased and healthy sites respectively (p=0.084). These findings suggest the levels of phylloquinone in GCF differs in periodontal health and disease in subjects with adult periodontitis. The total phylloquinone at diseased sites may provide the nutritional requirements favouring the growth of black-pigmented anaerobes.

A new preparative method for isolating homogeneous cardiotoxins from cobra venoms is described. The technique, based on reverse-phase high-pressure liquid chromatography, was used to isolate eight cardiotoxins of known sequence from four different venoms. In each case the method was found to be particularly efficient at removing trace quantities of contaminating phospholipase. Cardiotoxins isolated in this manner were found to retain their full biological activity. Without exception the purified cardiotoxins lacked powerful haemolytic activity at concentrations up to 0.01 mM (about 100 micrograms ml-1), although some lysis of human erythrocytes was induced at higher concentrations. The cardiotoxins displayed a wide range of depolarizing activity on cultured skeletal muscle, the lowest activity being associated with the highest LD50 value. Correlating variations in amino acid sequence and variations in depolarization potency revealed the importance of residues in the second and third loops, especially lysine-46, serine-48 and lysine-52, together with a number of hydrophobic residues. Further modifications of pharmacological activity were associated with the presence of additional basic residues in the first and second loops and to minor differences in secondary structure.

The oral commensal Gram-negative bacterium Actinobacillus actinomycetemcomitans is believed to be the causative organism of localized juvenile periodontitis, a disease in which there is rapid loss of alveolar bone supporting the teeth. Previously, we have reported that gentle saline extraction of this bacterium removed a loosely adherent proteinaceous fraction from the cell surface of the bacterium, which we have termed surface-associated material. This material contained potent bone-resorbing activity. We now report that surface-associated material is also a potent stimulator of cytokines, and in particular, interleukin-6 (IL-6) synthesis, while the lipopolysaccharide from this bacterium is only a weak stimulator of IL-6 synthesis by fibroblasts and monocytes. In contrast to enteric lipopolysaccharide (LPS), which induces fibroblast IL-1, IL-6 and tumour necrosis factor (TNF) alpha synthesis, surface-associated material stimulated gingival fibroblasts to synthesize only IL-6, with no induction of IL-1 or TNF (the normal inducers of IL-6 synthesis). Reverse transcriptase PCR also failed to detect mRNA for IL-1 or TNF in surface-associated-material-stimulated fibroblasts, although both mRNAs were present in Escherichia coli LPS-stimulated cells. Neutralizing antibodies to IL-1 and/or TNF or the natural IL-1 receptor antagonist (IL-1ra) inhibited enteric LPS-induced IL-6 synthesis, but did not inhibit surface-associated-material-induced synthesis. In addition, dexamethasone, which completely suppressed LPS-induced IL-6 synthesis, only inhibited surface-associated-material-induced IL-6 synthesis by 50%. This suggests that the active constituent in the surface-associated material stimulates IL-6 gene transcription by a transcriptional control mechanism distinct to that of E. coli LPS. The IL-6 stimulating activity of the surface-associated material is inhibited by both heat and trypsin, suggesting that it is proteinaceous. The activity has been isolated using anion-exchange, reverse-phase and size-exclusion HPLC. The active moiety is a peptide of molecular mass 2kDa which may be the product of a bacterial short open reading frame.