Malnutrition and cachexia are associated with poor CAR T-cell therapy outcomes including survival.

BACKGROUND & AIMS: Chimeric Antigen Receptor (CAR) T-cell therapy has emerged as a revolutionary treatment for patients with refractory or relapsed B-cell malignancies. However, a significant proportion of patients experience negative outcomes, including severe inflammatory toxicities and relapse. Cachexia and malnutrition are known secondary syndromes in many cancer patients, attributed to the effects of active malignancy, systemic inflammation, and cumulative treatment burden; however, further research is required to accurately characterise these issues in CAR T-cell patients. The aims of this service evaluation were to explore the changes in nutritional status (malnutrition and cachexia) in CAR T-cell therapy patients and the potential impact on patient outcomes including survival. Additionally, we describe the utilisation of dietetic resources in this specific patient population in a London tertiary referral centre. METHODS: Adult haematology patients receiving licensed CD19-targeting CAR T-cell therapy at University College London Hospital between 01/04/19 and 01/09/21 were included. Data were collected from the time of treatment consent, and throughout admission to day of discharge: body weight (BW), C-reactive protein, albumin, lactate dehydrogenase, nutrition-risk screening scores (hospital-specific) and dietetic input. Clinical outcomes such as 12-month all-cause mortality, intensive care unit (ICU) admission, high-grade toxicities, and length of hospital stay (LoS) were also recorded. Cachexia and malnutrition were defined using the modified Glasgow Prognostic Score (mGPS) and Global Leadership Initiative on Malnutrition (GLIM) consensus, respectively. RESULTS: 114 patients (55.6 ± 15.1 years; 57% males) with B-cell non-Hodgkin's lymphoma (n = 109) and B-cell acute lymphoblastic leukaemia (n = 5), receiving axicabtagene ciloleucel (n = 89) and tisagenlecleucel (n = 25) were included. Median LoS for treatment was 34 (27-38) days. Prior to treatment, 31.5% of patients developed malnutrition, with pre-cachexia/refractory cachexia (mGPS) identified in 43.6% of patients. This altered nutritional status pre-treatment was significantly associated with adverse patient outcomes post-infusion; mGPS was independently associated with inferior overall survival (HR = 3.158, CI = 1.36-7.323, p = 0.007), with malnutrition and mGPS associated with increased LoS (p = 0.037), sepsis (p = 0.022) and ICU admission (p = 0.039). During admission, patients experienced significant BW loss (-5.6% (-8.8 to -2.4); p=<0.001), with 68.4% developing malnutrition. Malnutrition screening during admission identified 57% patients at-risk, with 66.6% of patients referred to dietetics; however, there was a lack of malnutrition screening and dietetic referrals prior to treatment. CONCLUSION: Pre-treatment malnutrition and cachexia was significantly associated with adverse CAR T patient outcomes, including mGPS cachexia status independently associated with inferior overall survival. Further research in this novel space is essential to confirm the extent and impact of nutritional issues, to assist with implementing dietetic pathways, and to identify potential interventions with a view to optimising outcomes.

Post-Transcriptional Regulation of Hepatic DDAH1 with TNF Blockade Leads to Improved eNOS Function and Reduced Portal Pressure In Cirrhotic Rats.

Portal hypertension (PH) is a major cause of morbidity and mortality in chronic liver disease. Infection and inflammation play a role in potentiating PH and pro-inflammatory cytokines, including TNF, are associated with severity of PH. In this study, cirrhotic bile duct ligated (BDL) rats with PH were treated with Infliximab (IFX, a monoclonal antibody against TNF) and its impact on modulation of vascular tone was assessed. BDL rats had increased TNF and NFkB compared to sham operated rats, and their reduction by IFX was associated with a reduction in portal pressure. IFX treatment also reduced hepatic oxidative stress, and biochemical markers of hepatic inflammation and injury. IFX treatment was associated with an improvement in eNOS activity and increased L-arginine/ADMA ratio and DDAH1 expression. In vitro analysis of HepG2 hepatocytes showed that DDAH1 protein expression is reduced by oxidative stress, and this is in part mediated by post-transcriptional regulation by the 3'UTR. This study supports a role for the DDAH1/ADMA axis on the effect of inflammation and oxidative stress in PH and provides insight for new therapies.

Evaluation of cardiovascular risk-lowering health benefits accruing from laboratory-based, community-based and exercise-referral exercise programmes.

BACKGROUND: To evaluate the ability of community-based exercise programmes to facilitate public participation in exercise and hence improved cardiovascular health, we assessed the respective impacts of: a continuously monitored exercise programme based within our university (study 1); a Valleys Regional Park-facilitated community-based outdoor exercise programme (study 2); a Wales National Exercise Referral Scheme-delivered exercise-referral programme (study 3). METHODS: Biomolecular (monocytic PPARγ target gene expression), vascular haemodynamic (central/peripheral blood pressure, arterial stiffness), clinical (insulin sensitivity, blood lipids) and anthropometric (body mass index, waist circumference, heart rate) parameters were investigated using RT-PCR, applanation tonometry, chemical analysis and standard anthropometric techniques. RESULTS: In studies 1-3, 22/28, 32/65 and 11/14 participants adhered to their respective exercise programmes, and underwent significant increases in physical activity levels. Importantly, beneficial effects similar to those seen in our previous studies (eg, modulations in expression of monocytic PPARγ target genes, decreases in blood pressure/arterial stiffness, improvements in blood lipids/insulin sensitivity) were observed (albeit to slightly differing extents) only in participants who adhered to their respective exercise programmes. While study 1 achieved more intense exercise and more pronounced beneficial effects, significant cardiovascular risk-lowering health benefits related to biomolecular markers, blood pressure, arterial stiffness and blood lipids were achieved via community/referral-based delivery modes in studies 2 and 3. CONCLUSIONS: Because cardiovascular health benefits were observed in all 3 studies, we conclude that the majority of benefits previously reported in laboratory-based studies can also be achieved in community-based/exercise-referral settings. These findings may be of use in guiding policymakers with regard to introduction and/or continued implementation of community/referral-based exercise programmes.

Moderate-intensity exercise alters markers of alternative activation in circulating monocytes in females: a putative role for PPARγ.

PURPOSE: Monocytes may be primed towards differentiation into classically activated M1 macrophages or alternatively activated M2 macrophages. M1 macrophages greatly contribute to the inflammation which promotes insulin resistance, whereas M2 macrophages resolve inflammation. We have previously shown that exercise increases M2 marker expression in mixed mononuclear cells, possibly via activation of the nuclear transcription factor PPARγ. However, these effects have not been demonstrated specifically within monocytes. Thus, we aimed to investigate whether moderate-intensity exercise elicited similar effects on monocytic M1/M2 marker expression and PPARγ activity to those reported previously in mononuclear cells, so as to further elucidate the mechanisms by which exercise may alter inflammatory status and, accordingly, prevent insulin resistance. METHODS/RESULTS: 19 sedentary females completed an 8 week moderate-intensity exercise programme (walking 45 min, thrice weekly). Monocytes were isolated from blood via immunomagnetic separation; monocyte expression of M2 markers (Dectin-1: 2.6 ± 1.9-fold; IL-10: 3.0 ± 2.8-fold) significantly increased, whilst the expression of the M1 marker MCP-1 significantly decreased (0.83 ± 0.2 cf. basal), over the duration of the programme. Serum PPARγ activity levels and PPARγ target-genes (CD36: 1.9 ± 1.5-fold; LXRα: 5.0 ± 4.7-fold) were significantly increased after the 8 week exercise programme. Associated with these effects were significant improvements in systemic insulin sensitivity (McAuley's ISI: Δ0.98 M/mU/L cf. basal). CONCLUSION: Exercise participation suppressed M1 markers and induced M2 markers in monocytes, potentially via PPARγ-triggered signalling, and these effects may contribute (perhaps via priming of monocytes for differentiation into M2 tissue-macrophages) to improved systemic insulin sensitivity in exercising participants. These findings provide an alternative mechanism by which exercise may exert its anti-inflammatory effects in order to prevent insulin resistance and type 2 diabetes.

PO-25 - FATCAT: an observational cohort study investigating fractal dimension (df) as a biomarker of thrombogenicity in cancer associated thrombosis during chemotherapy for lung cancer.

INTRODUCTION: Venous thromboembolism (VTE), comprising deep vein thrombosis (DVT) and pulmonary embolism (PE) are common complications in patients with cancer, affecting up to 18% of patients. VTE risk is increased by surgery and disease progression, whilst chemotherapy further increases risk up to 7-fold compared to patients without cancer. VTE contributes significantly to morbidity and mortality in patients with cancer, and is the second most common cause of death. Lung cancer is well established to be high risk for VTE, with up to a 22-fold increase in VTE risk associated with this malignancy, and 12% incidence in a recent study of patients with lung cancer undergoing chemotherapy. Furthermore, platinum based chemotherapy agents used in treatment of lung cancer are further associated with increased VTE risk. AIM: Current risk assessment tools have little value in predicting VTE risk, but prophylactic anticoagulation of patients with cancer increases bleeding incidence and no overall survival benefit. There is therefore a need for a pragmatic test with which assesses coagulation in patients with cancer, and potentially predict VTE risk, leading to personalised management and targeted treatment. We have previously demonstrated that fractal dimension (df) is sensitive to changes in clot microstructure in patients with lung cancer, assessing global coagulation in these patients. Furthermore, df is significantly different in patients with extensive disease (stages 3&4), which conventional laboratory markers failed to identify. Given the increased risk of VTE associated with chemotherapy, FATCAT will aim to assess changes in df in a larger cohort of patients with lung cancer undergoing chemotherapy, quantifying changes in df and relating these to clinical outcome. MATERIALS AND METHODS: This is a prospective observational cohort study investigating changes in df in patients with lung cancer undergoing chemotherapy. Patients will have a new diagnosis of cytologically or histologically confirmed lung cancer planned for chemotherapy and no history of previous cancer treatment, any thromboembolic / haemostatic disorders or be on anticoagulation. RESULTS: Following a power calculation, 300 patients will be recruited and followed up for 1 year. df, Doppler ultrasonography and standard coagulation markers will be performed on recruitment, at the mid point, and on completion of chemotherapy in line with standard diagnostic procedures i.e. CT scanning. CONCLUSIONS: The primary endpoint of the study will be VTE diagnosis, whilst secondary outcomes will determine the change in df during and after treatment with chemotherapy.

Effects of exercise intensity on clot microstructure and mechanical properties in healthy individuals.

BACKGROUND: Exercise is well established to lead to exercise-induced hypercoagulability, as demonstrated by kinetic coagulation markers. It remains unclear as to whether exercise-induces changes lead in clot development and increased polymerisation. Fractal dimension (df) has been shown to act as a marker of clot microstructure and mechanical properties, and may provide a more meaningful method of determining the relationship between exercise-induced hypercoagulability and potential clot development. METHODS: df was measured in 24 healthy individuals prior to, after 5min of submaximal exercise, following maximal exercise, 45min of passive recovery and following 60min of recovery. Results were compared with conventional markers of coagulation, fibrinolysis and SEM images. RESULTS: Significantly increased df was observed following exercise, returning to resting values following 60min of recovery. The relationship between df and mature clot microstructure was confirmed by SEM: higher df was associated with dense clots formed of smaller fibrin fibres immediately following exercise compared to at rest. Conventional markers of coagulation confirmed findings of previous studies. CONCLUSION: This study demonstrates that df is a sensitive technique which quantifies the structure and properties of blood clots following exercise. In healthy individuals, the haemostatic balance between coagulation and fibrinolysis is maintained in equilibrium following exercise. In individuals with underlying vascular damage who participate in exercise, this equilibrium may be displaced and lead to enhanced clot formation and a prothrombotic state. df may therefore have the potential to not only quantify hypercoagulability, but may also be useful in screening these individuals.

Application of ROTEM to assess hypercoagulability in patients with lung cancer.

BACKGROUND: Venous thromboembolism (VTE) is common in patients with cancer, contributing significantly to morbidity and mortality Currently, no test reliably identifies patients at increased risk of developing VTE who would therefore benefit from prophylactic intervention. The aim of the current study was to evaluate rotational thromboelastometry (ROTEM) in identifying VTE risk in patients with lung cancer. We also compared parameters of ROTEM in patients with limited and extensive disease. METHODS: Parameters of ROTEM were measured in 67 patients with lung cancer and 72 age-matched healthy controls and compared with conventional markers of haemostasis. Patients were followed up for 12 months and VTE incidence recorded. RESULTS: Lung cancer patients had a reduced clotting time (CT), increased maximum clot firmness (MCF) and increased alpha angle compared with controls. Patients also had significantly higher levels of fibrinogen and PAI-1 than controls and in the former group there was a strong correlation between fibrinogen and both MCF and alpha angle. Six patients developed a VTE during the follow-up period and all had values for MCF at or above the upper limit of normal for EXTEM. CONCLUSIONS: This study demonstrates that several ROTEM parameters are significantly different in lung cancer patients compared to healthy age-matched controls, whereas only one of the parameters measured is significantly different between extensive compared to limited disease. No differences were observed between patients who developed a VTE compared to those who did not, highlighting the limitations of ROTEM use in patients with lung cancer.

The contributions of oxidative stress, oxidised lipoproteins and AMPK towards exercise-associated PPARγ signalling within human monocytic cells.

Peroxisome proliferator-activated receptor gamma (PPARγ) is known to be activated via exercise-associated transient increases in oxidative stress. However, the precise mechanism(s) triggering PPARγ activation in monocytes during/following exercise remain to be confirmed. Here, two cohorts of five healthy male individuals undertook exercise bouts (cycling; 70% VO2max; 45 min) in the presence/absence of dietary antioxidant supplementation (vitamins C (1000 mg/day) and E (400IU/day) for four weeks before exercise); monocytic 5' adenosine monophosphate-activated protein kinase (AMPK)/PPARγ co-activator-1alpha (PGC-1α)/PPARγ signalling was investigated in samples obtained before exercise and up to 24 h after exercise, while THP-1 cells were cultured as an in vitro monocyte model. In THP-1 cells, AMPKα1 was phosphorylated within 1h of menadione (15 µM)-triggered increases in [reactive oxygen species (ROS)]cyto, an effect which was followed by upregulation of PPARγ and several of its target genes (PGC-1α, liver X receptor alpha [LXRα] and ATP-binding cassette subfamily A, member 1 [ABCA1]; 24-72 h), with these effects being blunted by co-administration of vitamin C (62.5 µM). Conversely, treatment with oxidised low-density lipoprotein (oxLDL) (1 µg/mL; 24-72 h), but not non-oxidised LDL, upregulated the above PPARγ-regulated genes without affecting AMPKα1 phosphorylation. In vivo, dietary antioxidant supplementation (which is known to prevent exercise-triggered increases in oxLDL levels) blunted exercise-associated upregulation of the above PPARγ-regulated genes, but had no effect on exercise-associated transient [ROS]cyto increases, or on AMPK phosphorylation. These data suggest that exercise-associated PPARγ signalling effects appear, at least in monocytes, to be mediated by increased generation of PPARγ ligands via oxidation of lipoproteins (following exercise-associated transient increases in oxidative stress), rather than via [ROS]cyto-mediated AMPK activation. These findings may be of clinical relevance, as PPARγ activation in monocytes is associated with beneficial effects related to type-2 diabetes and its cardiovascular complications.

Impact of training on outcomes following incisional hernia repair.

BACKGROUND: The purpose of this study was to quantify the effect of training on clinical outcomes following elective incisional hernia repair. METHODS: The case notes of 100 consecutive elective open and laparoscopic incisional hernia repair procedures performed between January 2004 and July 2008 were reviewed retrospectively. Cases were performed either by consultant surgeons or trainees operating under direct supervision. The proportion of cases performed by trainees was recorded and the seniority of the operating surgeon related to peri- and post-operative outcomes as well as long-term recurrence rates. RESULTS: Of the 100 cases, 61 were performed by consultants and 39 by trainees. There were no significant demographic differences between the two groups. Trainees undertook a similar proportion of laparoscopic cases as compared with consultants (44% vs. 44%). In addition, the operating time (60 +/- 4 mins vs. 58 +/- 4 mins), length of hospital stay (3.0 +/- 0.3 days vs. 3.3 +/- 0.3 days) and post-operative morbidity rates (18 % vs 10%) were similar between the two groups. At a mean follow-up period of 2.82 +/- 0.17 years, the incidence of recurrent herniae was lower in the trainee group, however this was not statistically significant (8% vs 16% ; p = 0.22). CONCLUSIONS: Supervised trainees can successfully undertake both open and laparoscopic incisional hernia repairs with no detrimental effects on overall hospital costs, post-operative morbidity and long-term recurrence rates.

Exercise-associated generation of PPARγ ligands activates PPARγ signaling events and upregulates genes related to lipid metabolism.

The aim of the present study was to test the hypotheses that exercise is associated with generation of peroxisome proliferator-activated receptor-γ (PPARγ) ligands in the plasma and that this may activate PPARγ signaling within circulating monocytes, thus providing a mechanism to underpin the exercise-induced antiatherogenic benefits observed in previous studies. A cohort of healthy individuals undertook an 8-wk exercise-training program; samples were obtained before (Pre) and after (Post) standardized submaximal exercise bouts (45 min of cycling at 70% of maximal O(2) uptake, determined at baseline) at weeks 0, 4, and 8. Addition of plasma samples to PPARγ response element (PPRE)-luciferase reporter gene assays showed increased PPARγ activity following standardized exercise bouts (Post/Pre = 1.23 ± 0.10 at week 0, P < 0.05), suggesting that PPARγ ligands were generated during exercise. However, increases in PPARγ/PPRE-luciferase activity in response to the same standardized exercise bout were blunted during the training program (Post/Pre = 1.18 ± 0.14 and 1.10 ± 0.10 at weeks 4 and 8, respectively, P > 0.05 for both), suggesting that the relative intensity of the exercise may affect PPARγ ligand generation. In untrained individuals, specific transient increases in monocyte expression of PPARγ-regulated genes were observed within 1.5-3 h of exercise (1.7 ± 0.4, 2.6 ± 0.4, and 1.4 ± 0.1 fold for CD36, liver X receptor-α, and ATP-binding cassette subfamily A member 1, respectively, P < 0.05), with expression returning to basal levels within 24 h. In contrast, by the end of the exercise program, expression at the protein level of PPARγ target genes had undergone sustained increases that were not associated with an individual exercise bout (e.g., week 8 Pre/week 0 Pre = 2.79 ± 0.61 for CD36, P < 0.05). Exercise is known to upregulate PPARγ-controlled genes to induce beneficial effects in skeletal muscle (e.g., mitochondrial biogenesis and aerobic respiration). We suggest that parallel exercise-induced benefits may occur in monocytes, as monocyte PPARγ activation has been linked to beneficial antidiabetic effects (e.g., exercise-induced upregulation of monocytic PPARγ-controlled genes is associated with reverse cholesterol transport and anti-inflammatory effects). Thus, exercise-triggered monocyte PPARγ activation may constitute an additional rationale for prescribing exercise to type 2 diabetes patients.

Role of Toll-like receptors 2, 4, and 9 in mediating neutrophil dysfunction in alcoholic hepatitis.

Neutrophil dysfunction in alcoholic hepatitis is associated with endotoxemia and an increased incidence of infection, but the mechanism is unclear. We aimed to investigate the role of Toll-like-receptors (TLR)2, 4, and 9 in mediating neutrophil dysfunction in alcoholic hepatitis. Neutrophils from healthy volunteers were incubated with alcoholic hepatitis patients' plasma (n = 12) with and without TLR2, 4, or 9 antagonists and with and without human albumin. TLR2, 4, and 9 expression, neutrophil oxidative burst, phagocytosis, and CXCR1+2 expression were measured by FACS analysis. Patients' plasma increased oxidative burst, decreased CXCR1+2 expression, and decreased phagocytosis of normal neutrophils in association with increased expression of TLR2, 4, and 9 and depletion of ATP. Inhibition of TLR2, 4, and 9 prevented the increase in oxidative burst and the decrease in CXCR1 and CXCR2 expression but did not prevent phagocytic dysfunction. Incubation with albumin completely prevented the patient plasma induced neutrophil dysfunction. Increased expression of TLR2, 4, and 9 is associated with neutrophil dysfunction, endotoxemia, and energy depletion. TLR2, 4, and 9 inhibition does not improve phagocytosis, indicating that TLR overexpression may be the result and not the cause of neutrophil activation. Albumin, an endotoxin scavenger, prevents the deleterious effect of patients' plasma on neutrophil phagocytosis, resting burst, and TLR expression.

L-Ornithine phenylacetate (OP): a novel treatment for hyperammonemia and hepatic encephalopathy.

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.

Remote ischaemic preconditioning of the hind limb reduces experimental liver warm ischaemia-reperfusion injury.

BACKGROUND: Direct ischaemic preconditioning of the liver reduces ischaemia-reperfusion injury (IRI). Remote ischaemic preconditioning (RIPC) of a limb has been shown to reduce IRI to the heart. This study determined the effect of brief remote ischaemia to the limb in reducing early liver warm IRI. METHODS: Twenty-eight male rabbits were allocated to four groups: sham operated, RIPC alone, IRI alone, and RIPC plus IRI. RIPC was induced in the leg with a tourniquet, before liver IRI, by three alternate cycles of 10 min ischaemia followed by 10 min reperfusion. Liver IRI was produced by total inflow occlusion for 25 min. Markers of liver injury and systemic and hepatic haemodynamics were measured for 2 h after reperfusion. RESULTS: At 2 h, IRI alone was associated with increased serum levels of aminotransferases, and reduced mean arterial blood pressure, hepatic blood flow and peripheral oxygen saturation. There was significant improvement in these variables in animals that had RIPC before liver IRI, and hepatic venous nitrate/nitrite levels were also significantly higher. CONCLUSION: In this experimental model RIPC appeared to reduce liver IRI.

A model to study total hepatic ischemia-reperfusion injury.

BACKGROUND: Most experimental animal models for studying hepatic ischemia-reperfusion injury (IRI) involve partial or segmental ischemia of the liver or a portocaval shunt procedure to avoid mesenteric congestion. However, these do not reflect the global ischemia that occurs during liver transplantation. A rabbit model of total hepatic ischemia without a portocaval shunt is described. METHODS: Twenty male New Zealand white rabbits (3.5 +/- 0.3 kg) were allocated to four groups: group 1 (n = 5), sham-operated; group 2 (n = 5), 20-minute total hepatic ischemia; group 3 (n = 5), 25-minute total hepatic ischemia; and group 4 (n = 5), 30-minute total hepatic ischemia. Total hepatic ischemia was induced by occluding the portal inflow vessels (portal vein and artery) with an atraumatic vascular loop and were measurements taken for 2 hours during reperfusion. RESULTS: A total hepatic ischemia of 30 minutes caused severe liver injury resulting in cardiac arrest at 2 hours of reperfusion in all five animals due to metabolic acidosis. Twenty minutes of total ischemia was tolerated and did not produce significant liver injury. Twenty-five minutes of total ischemia was tolerated but at 2 hours of reperfusion, resulted in significant liver injury (68 +/- 41, 283.0 +/- 20.5, and 835.2 +/- 52.7 U/L) compared with the sham-operated group (serum ALT, 25.4 +/- 2.7; serum AST, 47.4 +/- 3.0; serum LDH, 307.6 +/- 44.4 U/L; P < .003). CONCLUSIONS: Rabbits can tolerate 25 minutes of total hepatic ischemia without a portosystemic shunt. This 25-minute ischemia model simulates operative conditions during liver transplantation and will be valuable in studies modulating IRI.

Tumour necrosis factor alpha is an important mediator of portal and systemic haemodynamic derangements in alcoholic hepatitis.

BACKGROUND: The role of proinflammatory cytokines in the pathogenesis of portal hypertension is unclear. AIMS AND METHODS: 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. RESULTS: Serum bilirubin (p<0.05), C reactive protein (p<0.001), and white cell count (p<0.01) 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; p<0.001) with a sustained reduction prior to discharge (12.8 (1.9) mm Hg; p<0.001). Mean arterial pressure and systemic vascular resistance increased significantly (p<0.001and p<0.01, respectively), mirrored by a reduction in cardiac index (5.9 (0.5) to 4.7 (0.5) l/min/m(2); p<0.05) 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. CONCLUSION: 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.

Review article: the molecular adsorbents recirculating system (MARS) in liver failure.

In recent years different artificial liver support systems are being developed for use in patients with acute decompensation of chronic liver disease or acute liver failure. The molecular adsorbents recirculating system (MARS), a device in which patient's blood is dialysed across an albumin-impregnated membrane against a recirculated albumin-containing solution, seems to be effective in removing albumin-bound toxins, such as fatty acids, bile acids and bilirubin. Although the clinical experience with MARS is scarce, some pilot studies have reported its effectiveness at improving liver function and hepatic encephalopathy in patients with acute decompensation of chronic liver disease, and renal function in patients with hepatorenal syndrome type I. Data regarding MARS experience in acute liver failure and in primary graft dysfunction are encouraging but limited. Its real usefulness in these settings is, at present, under evaluation in randomized controlled clinical trials.

Evidence of differences in the biotransformation of organic contaminants in three species of freshwater invertebrates.

Acute static bioassays were performed using three freshwater invertebrate species (the oligochaete Lumbriculus variegatus, the fingernail clam Sphaerium corneum and the larvae Chironomus riparius) exposed separately to a variety of 14C radiolabelled contaminants. The aim of this work was to investigate if the chemicals remained as parent compounds after the treatments. Chemicals used were 2,4-dichlorophenol; 2,4,5-trichlorophenol; pentachlorophenol; pyrene; Fenpropidin, and Trifluralin. Homogenates of the whole body tissue of each organism were prepared and total radioactivity was measured. Contaminants were then extracted into organic solvents and analysed by high-pressure liquid chromatography techniques. Chromatograms showed that most of the substances extracted were present as parent compounds in S. corneum and in L. variegatus. In contrast, for C. riparius a low proportion of the chemicals was recovered as parent compounds. These results suggest that different metabolic processes could take place in the different species.

The use of sediment analogues to study the uptake of pollutants by chironomid larvae.

A technique is described that uses artificial resin beads with known surface properties to investigate the factors influencing the bioaccumulation of pollutants from sediments. One advantage of this technique is that it provides a standard procedure against which it is possible to calibrate natural sediments with their diverse properties. The method has been used on third instar larvae of the midge Chironomus riparius and the results are compared with previous studies on the worm Lumbriculus variegatus. The use of a standard test using resin beads as a substitute for natural sediment allows comparisons to be made between species and substrates. Thus, the bioaccumulation factors for the midge larvae are much smaller than those of the worm and this correlates with the ability of the insect larva to detoxify many pollutants. It is also possible to use the test to identify if ingestion of the sediment increases the bioaccumulation of contaminants and whether this involves the release of pollutants by digestive processes or not.

Structure-function investigation of the interaction of 1- and 2-substituted 3-hydroxypyridin-4-ones with 5-lipoxygenase and ribonucleotide reductase.

The structural and physiochemical properties of 3-hydroxypyridin-4-one chelators (HPOs) which influence inhibition of the iron-containing metalloenzymes ribonucleotide reductase (RR) and 5-lipoxygenase (5-LO) have been investigated. HPOs with substituents at the 1- and 2-positions of the pyridinone ring have been synthesized, and their inhibitory properties compared with those of desferrioxamine (DFO). Varying the alkyl substituents does not affect the affinity constant of these ligands for iron(III), but permits a systematic investigation of the effect of hydrophobicity and molecular shape on inhibitory properties. The inhibition of RR was monitored, indirectly by measuring tritiated thymidine incorporation into DNA and directly by the quantification of the EPR signal of the enzyme tyrosyl radical. 5-LO inhibition was examined spectrophotometrically, measuring the rate of linoleic hydroperoxide formation by soybean lipoxygenase. The results indicate that the substituent size introduced at the 2-position of the HPO ring is critical for determining inhibition of both enzymes. Large substituents on the 2-position, introduce a steric factor which interferes with accessibility to the iron centers. These studies have identified chelators such as 1,6-dimethyl-2-(N-4',N-propylsuccinamido)methyl-3-hydroxypyridin-4-one (CP358), which causes only a 10% inhibition of 5-LO after 24 h of incubation at 110 microm IBE (iron-binding equivalents) in comparison to simple dialkyl HPOs such as Deferiprone (CP20) which cause up to 70% inhibition. Using EPR spectroscopy, CP358 inhibits RR at a slower rate than CP20, while chelating intracellular iron(III) at a similar rate, a finding consistent with an indirect inhibition of the tyrosyl radical. However, hepatocellular iron is mobilized at a faster rate by CP358 (P < 0.001). These findings demonstrate that it is possible to design bidentate HPOs which access intracellular iron pools rapidly while inhibiting non-heme iron-containing enzymes relatively slowly, at rates comparable to DFO. It is anticipated that such compounds will possess a superior therapeutic safety margin to currently available bidentate HPOs.

The pH dependence of naturally occurring low-spin forms of methaemoglobin and metmyoglobin: an EPR study.

The paramagnetic species in human metHb and horse metmyoglobin (metMb) have been studied at low temperature using EPR spectroscopy. The high-spin (HS) haem signal in aquometMb has a greater rhombic distortion than the HS metHb signal. Nevertheless, the individual line width (g=6) is smaller in metMb than in metHb, consistent with non-identical signals from the alpha and beta Hb subunits. Three low-spin (LS) haem forms are present in metHb, while metMb has only two. The major LS form in both proteins is the alkaline species (with OH(-) at the sixth co-ordination position). The minor LS forms are assigned to different histidine hemichromes in equilibrium with the normal HS species at low temperature. LS forms disappear when the haem is bound by a ligand, such as fluoride, which ensures 100% occupancy of the HS state both at room temperature and at 25 K. The small differences in effective g-factors of the histidine hemichromes are interpreted in terms of different distances between the distal histidine and haem iron. The pH dependence of the inter-conversion of the different paramagnetic species is consistent with a model whereby protonation of a residue with a pK of 5.69 (metHb) or 6.12 (metMb), affects ligand binding and transformation from the HS to the LS form. Chemical and spectroscopic considerations suggest that the residue is unlikely to be the proximal or distal histidine. We therefore propose a model where protonation of this distant amino acid causes a conformational change at the iron site. Identical effects are seen in frozen human blood, suggesting that this effect may have physiological significance.