Showing papers in "European Journal of Clinical Investigation in 2007"

Standards and standardization in mastocytosis: consensus statements on diagnostics, treatment recommendations and response criteria.

Abstract: Although a classification for mastocytosis and diagnostic criteria are available, there remains a need to define standards for the application of diagnostic tests, clinical evaluations, and treatment responses. To address these demands, leading experts discussed current issues and standards in mastocytosis in a Working Conference. The present article provides the resulting outcome with consensus statements, which focus on the appropriate application of clinical and laboratory tests, patient selection for interventional therapy, and the selection of appropriate drugs. In addition, treatment response criteria for the various clinical conditions, disease-specific symptoms, and specific pathologies are provided. Resulting recommendations and algorithms should greatly facilitate the management of patients with mastocytosis in clinical practice, selection of patients for therapies, and the conduct of clinical trials.

Glucose transporter expression on the plasma membrane of resting and activated white blood cells

Abstract: Background In white blood cells (WBC), the increase in glucose utilization is a prominent feature during immune response and this depends on the function of specific glucose transporter (GLUT) isoforms. The objective was to examine the effects of activation by Phorbol 12-myristate 13-acetate (PMA) or lipopolysaccharide (LPS) and insulin on the expression of GLUT isoforms in all subpopulations of WBC. Materials and methods Blood was withdrawn from 27 healthy subjects. The expression of GLUT1, GLUT3 and GLUT4 on the plasma membrane of resting and activated monocytes, T- and B-lymphocytes and polymorphonuclear cells (PMNs) was determined in the absence and presence of physiological concentrations of insulin, by flow cytometry. Results GLUT1 did not respond to insulin in either resting or PMA/LPS activated state. In the resting state, monocytes and B-lymphocytes increased the abundance of GLUT3 and GLUT4 on their plasma membrane in response to insulin; in contrast, T-lymphocytes and PMNs were unresponsive to insulin. In the activated state, monocytes, B- and T- lymphocytes increased the expression of all three GLUT isoforms on their plasma membrane, whilst PMNs increased only GLUT1 and GLUT3; in all WBC, insulin augmented the expression of GLUT4 and GLUT3 isoforms in addition to the stimulation provided by the PMA or LPS treatment alone. Conclusion Activation of WBC leads to increased expression of GLUT1, GLUT3 and GLUT4 isoforms on their plasma membrane; this process was further augmented by insulin. During infection, these mechanisms may help to redistribute glucose as a potential source of energy away from peripheral tissues and direct it towards cells that mediate the immune response and are therefore crucial to survival.

Assessing risk of myocardial infarction and stroke: new data from the Prospective Cardiovascular Münster (PROCAM) study.

Abstract: Objectives Based on the data of the Prospective Cardiovascular Munster (PROCAM) study, a prospective study of men and women at work in the north-west of Germany, we aimed (i) to develop a refined scoring scheme for calculating the risk of acute coronary events among adult and elderly men and women; and (ii) to generate a new scoring scheme for calculating the risk of ischaemic stroke or transient ischaemic attack (TIA). Methods The coronary risk score was derived from a Weibull function using data from 18 460 men and 8515 women who were recruited before 1996 and had a mean follow-up period of 12 ± 6 years. The stroke score was derived using a Cox proportional hazards model using data of 5905 men and 2225 women aged 35‐65 years with at least 10 years of unbroken follow-up. Results The coronary risk score was based on 511 major coronary events, 462 (168 fatal, 294 non-fatal) in men and 49 (18 fatal, 31 non-fatal) in women and included the risk factors LDL cholesterol, HDL cholesterol, systolic blood pressure, smoking status, triglycerides and diabetes mellitus status. It was accurate in both sexes over an age range from 20 to 75 years with an area under the receiver-operating characteristics (ROC) curve of 0·82. The stroke score was based on 85 cerebral ischaemic events (21 TIAs, 64 ischaemic strokes) and included the risk factors age, sex, diabetes mellitus status, smoking status and systolic blood pressure. It had an area under the ROC curve of 0·78 and identified a high-risk group comprising only 4% of the study population that contained 31% of all cerebral ischaemic events.

Circulating levels of copeptin, a novel biomarker, in lower respiratory tract infections

Abstract: Background Vasopressin has haemodynamic as well as osmoregulatory effects, and reflects the individual stress response. Copeptin is cosynthesized with vasopressin, directly mirroring vasopressin levels, but is more stable in plasma and serum. Both levels are increased in patients with septic shock. Lower respiratory tract infections (LRTI) are a precursor of sepsis. Thus, we investigated circulating levels and the prognostic use of copeptin for the severity and outcome in patients with LRTI. Materials and methods Five hundred and forty-five consecutive patients with LRTI and 50 healthy controls were evaluated. Serum copeptin levels were measured with a new chemiluminescens sandwich immunoassay. Results Of the 545 patients, 373 had community-acquired pneumonia (CAP), 60 acute exacerbations of chronic obstructive pulmonary disease (COPD), 59 acute bronchitis, 13 exacerbations of asthma and 40 other final diagnoses. Copeptin levels were significantly higher in patients with LRTI as compared to controls (P < 0·001) with highest levels in patients with CAP. Copeptin levels increased with increasing severity of CAP, as classified by the pneumonia severity index (PSI) (P < 0·001). In patients who died, copeptin levels on admission were significantly higher as compared to levels in survivors [70·0 (28·8–149·0) vs. 24·3 (10·8–43·8) pmol L−1, P < 0·001]. The area under the receiver operating curve (AUC) for survival was 0·75 for copeptin, which was significantly higher as compared to C-reactive protein (AUC 0·61, P = 0·01), leukocyte count (AUC 0·59, P = 0·01) and similar to procalcitonin (AUC 0·68, P = 0·21). Conclusions Copeptin levels are increased with increasing severity of LRTI namely in patients with CAP and unfavourable outcome. Copeptin levels, as a novel biomarker, might be a useful tool in the risk stratification of patients with LRTI.

Expression of the target receptor CD33 in CD34+/CD38-/CD123+ AML stem cells.

Abstract: Background CD33 (Siglec-3) is becoming increasingly important as a target of antibody-mediated therapy in acute myeloid leukaemia (AML). In normal myelopoiesis, expression of CD33 is restricted to advanced stages of differentiation, whereas primitive stem cells do not express CD33. In the present study, we asked whether leukaemic stem cells in patients with AML express CD33. Materials and methods A multicolour-staining technique was applied in 11 patients with AML, and leukaemic progenitors defined as CD34+/CD38−/CD123+ cells. AML stem cells were purified by cell sorting and were examined for expression of CD33 mRNA by reverse transcriptase–polymerase chain reaction (RT–PCR). Results In all patients in whom the majority of myeloblasts expressed CD33 (n = 8), AML progenitors reacted with the CD33 antibody P67·6. Repopulation experiments utilizing irradiated NOD/SCID mice confirmed that AML stem cells in these patients reside within the CD33+ subpopulation of the leukaemic clone. Moreover, highly purified AML stem cells (> 98% purity) from patients with CD33+ AML were found to express CD33 mRNA in RT–PCR analyses. CD33 was neither detectable on CD34+/CD38− cells in normal bone marrow nor on leukaemic stem cells in patients with CD33-negative AML. Conclusions Leukaemic stem cells in patients with CD33+ AML express CD33. This observation is in favour of novel treatment concepts employing CD33-targeting antibodies in AML.

The quantitative analysis of peripheral blood FOXP3-expressing T cells in systemic lupus erythematosus and rheumatoid arthritis patients

Abstract: Background Expressed in naturally occurring CD4 + CD25 + regulatory T cells, FoxP3 plays an important role in maintaining immune tolerance. We therefore evaluated the possibility that the peripheral blood FOXP3 + T-cell deficiency is associated with systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA). Materials and methods The FOXP3 expression in peripheral blood T cells were evaluated and correlated to the CD4 and CD25 expression by flow cytometric analysis. Cell frequencies of FOXP3 + T cells among CD4 + T cells and absolute FOXP3 + T cell counts in SLE and RA patients were determined for the statistical comparison with those in normal controls, and their correlation with disease activities in SLE patients was evaluated. The FOXP3 transcript levels in peripheral blood mononuclear cells (PBMCs) were also determined to correlate the FOXP3 + T-cell quantity and to evaluate the possible dysregulation in the expression of two FOXP3 mRNA variants in patients. Results SLE patients had the higher FOXP3 + T-cell frequency and absolute CD4 + CD25 - FOXP3 + cell count than normal individuals, and the frequencies of CD4 + CD25 + FOXP3 + and CD4 + FOXP3 + cells were positively correlated with the disease activities in SLE patients. In contrast, the differences in frequencies and absolute counts of FOXP3 + T cells between normal controls and RA patients were found to be insignificant. Moreover, SLE and RA patients appear to express two FOXP3 transcript variants in peripheral blood mononuclear cells at the levels similar to normal individuals. Conclusions The peripheral blood FOXP3 + T-cell frequency among CD4 + T cells is altered in SLE patients with the active disease activity. Therefore, the analysis on peripheral blood FOXP3 + T cells may be useful for the evaluation of lupus disease activity.

Markers of inflammation and disuse in vastus lateralis of chronic obstructive pulmonary disease patients.

Abstract: BACKGROUND: Disuse and/or local inflammation in the muscle cannot be excluded as potential influences for the decreased muscle force in patients hospitalised due to an acute chronic obstructive pulmonary disease (COPD) exacerbation. This study aims to compare expression levels of markers of disuse (insulin-like growth factor-1 (IGF-I), MyoD and myogenin) and inflammation [interleukin-6 (IL-6), IL-8 and tumour necrosis factor-alpha (TNF-alpha)] in the muscle of hospitalised and stable COPD patients and healthy elderly. MATERIAL AND METHODS: Muscle biopsies (m. vastus lateralis) were taken in 14 hospitalised COPD patients (aged 68 +/- 8), 11 clinically stable COPD patients (aged 68 +/- 9) and seven healthy subjects (aged 70 +/- 7) to analyse local mRNA expression levels of IL-6, IL-8, TNF-alpha, IGF-I and protein expression levels of IGF-I, MyoD and myogenin. Relationships of these expression levels with lung and skeletal muscle function were investigated. RESULTS: IGF-I mRNA and MyoD protein levels were significantly lower in hospitalised patients compared to healthy subjects. MyoD protein levels were positively related to quadriceps force. Muscle IL-6 and IL-8 expression in hospitalised patients was similar compared to stable patients and healthy subjects and was not related to expression levels of muscle markers of disuse or quadriceps force. Muscle TNF-alpha and myogenin were not detected. CONCLUSION: Decreased expression levels of muscle IGF-I and MyoD in hospitalised patients suggest a potential influence of disuse in the increased muscle weakness during an acute COPD exacerbation. This study did not find any evidence supporting local inflammation via IL-6, IL-8 and/or TNF-alpha in the vastus lateralis muscle of COPD patients.

Leisure time but not occupational physical activity significantly affects cardiovascular risk factors in an adult population

Abstract: Background A large number of studies have demonstrated that regular physical activity during leisure time (LTPA) accounts for a significant protection against cardiovascular diseases (CVD). On the other hand, conflicting findings on the beneficial effects of occupational physical activity (OPA) have been reported. The aim of this study is to evaluate the possible influence of different amounts of LTPA and OPA on circulating levels of several parameters associated with an increased risk of CVD. Materials and methods We studied 932 individuals (365 M; 567 F, with a mean age of 54 years) living in Florence, Italy, who were enrolled in a population study conducted between 2002 and 2004. Subjects were divided into three classes of LTPA and OPA according to a score derived from a questionnaire that assessed the amount of physical activity performed. Results LTPA was inversely related to body mass index (BMI), hip circumference, diastolic blood pressure and triglycerides, as well as directly correlated with high-density lipoprotein (HDL) cholesterol. Likewise, a higher OPA was found to be associated with higher HDL cholesterol levels. Moreover, a multivariate logistical regression analysis, adjusted for possible confounders, showed that a moderate-to-high intensity of LTPA was able to confer a significant protection against having abnormal levels of BMI, waist circumference and triglycerides, main features of the metabolic syndrome, whereas no associations between these parameters and OPA were observed. Conclusions A moderate-to-high LTPA was found to be significantly associated with a more favourable cardiovascular risk profile in terms of anthropometric, metabolic and lipid parameters among an Italian population. In addition, a relationship between OPA and HDL-cholesterol was reported.

Lifestyle intervention in individuals with normal versus impaired glucose tolerance

Abstract: Background Lifestyle intervention is effective in the prevention of type 2 diabetes in individuals with impaired glucose tolerance (IGT). It is currently unknown whether it has beneficial effects on metabolism to a similar extent, in individuals with normal glucose tolerance (NGT) compared to individuals with IGT. Materials and methods Data from 181 subjects (133 with NGT and at risk for type 2 diabetes and 48 with IGT) who participated in the Tuebingen Lifestyle Intervention Program with increase in physical activity and decrease in caloric intake were included into this study. Body fat distribution was quantified by whole-body magnetic resonance (MR) tomography and liver fat and intramyocellular fat by 1H-MR spectroscopy. Insulin sensitivity was estimated from an oral glucose tolerance test (OGTT). Results After 9 ± 2 months of follow-up, the diagnosis of IGT was reversed in 24 out of 48 individuals. Only 14 out of 133 participants with NGT developed IGT. Body weight decreased in both groups by 3% (both P < 0·0001). Two-hour glucose concentrations during an OGTT decreased in individuals with IGT (–14%, P < 0·0001) but not with NGT (+2%, P = 0·66). Insulin sensitivity increased both in individuals with IGT (+9%, P = 0·04) and NGT (+17%, P < 0·0001). Visceral fat (–8%, P = 0·006), liver fat (–28%, P < 0·0001) and intramyocellular fat (–15%, P = 0·006) decreased in participants with IGT. In participants with NGT these changes were significant for visceral fat (–16%, P < 0·0001) and liver fat (–35%, P < 0·0001). Conclusions Moderate weight loss under a lifestyle intervention with reduction in total, visceral and ectopic fat and increase in insulin sensitivity improves glucose tolerance in individuals with IGT but not with NGT. In individuals with NGT, the beneficial effects of a lifestyle intervention on fat distribution and insulin sensitivity possibly prevent future deterioration in glucose tolerance.

Cardiac biomarkers and survival in haemodialysis patients.

Abstract: Background In dialysis patients, cardiac troponin T (cTNT) is often elevated despite the absence of acute myocardial ischaemia, and amino-terminal pro-B-natriuretic peptide (NT-proBNP) is markedly higher compared to non-haemodialysis patients. In a longitudinal observation, we evaluated the association of cTNT and NT-proBNP on cardiovascular morbidity and mortality in haemodialysis patients with and without fluid overload. Materials and methods Plasma cTNT levels of 134 haemodialysis patients were measured before and after a dialysis session by 3rd generation electro-chemoluminiscence immunoassay. NT-proBNP was determined using a polyclonal antibody recognizing the N-terminal fragment of BNP (Elecsys autoanalyzer 2010, Roche Diagnostics, Mannheim, Germany). Volume status was determined by a clinical score system. Cardiovascular morbidity and mortality were assessed over a follow-up period of 36 months. Results Plasma cTNT > 0·03 ng mL−1 was found in 39·6% of all patients. Patients with hypervolaemia had significantly higher cTNT levels compared to euvolaemic patients (median 0·054 ng mL−1, interquartile range 0·019–0·153 vs. 0·005 ng mL−1, 0·026 ng mL−1 and NT-proBNP > 5300 pg mL−1 as predictors of hypervolaemia. Asymptomatic chronic haemodialysis patients with cTNT > 0·026 ng mL−1 and NT-proBNP > 5300 pg mL−1 were more likely to die due to cardiac events in the follow-up period. Multivariate analysis documented that elevated cTNT and NT-proBNP levels were highly predictive for cardiovascular events. Conclusions Plasma levels of cTNT are elevated in approximately 40% and NT-proBNP levels in 100% of asymptomatic chronic haemodialysis patients. Both parameters depend on volume status. Increased NT-proBNP and cTNT are strongly associated with adverse outcome in end-stage renal disease patients undergoing haemodialysis, and are a useful tool for risk stratification in chronic haemodialysis patients.

Risk management of renal biopsy: 1387 cases over 30 years in a single centre.

Abstract: Background Although renal biopsy is largely employed, even in old patients with systemic diseases, few clinical studies have addressed its risk management. We aimed to obtain a comprehensive assessment of safety/utility ratio of percutaneous renal biopsy. Patients and methods Retrospective review of all the 1387 patients who consecutively underwent renal biopsy in a single centre over three decades (1973–2002) was made, with calculation of complications, multivariate logistical analyses to evaluate risk factors of complications, and rate of alteration of clinical hypotheses by pathological diagnosis. Results There were no deaths and five major complications, (0·36%). One nephrectomy (0·07%), two surgical revisions (0·1%) and two arterial-venous fistulae (0·1%). There were also 337 minor bleeding complications (24·2%) (16·4% gross haematuria and 7·8% clinically relevant haematomas needing at least prolonged bed rest). Multivariate analyses demonstrated that the risk for complications was significantly increased by systemic autoimmune diseases with odds ratio (OR) 2·06, 95% confidence interval (CI) = 1·40–3·01, end-stage kidney/acute-tubular necrosis (OR 2·96, 95% CI = 1·19–7·30), and prolonged bleeding time test (BTT) (OR 1·87, 95% CI = 1·17–2·83). Among the 1288 cases in which a clinical hypothesis before renal biopsy was recorded, renal pathology changed previous diagnoses in 423/1,288 (32·8%) of cases. Conclusions Risk assessment demonstrates that renal biopsy is a useful procedure with a low incidence of serious complications. Platelet function is the only modifiable factor significantly related to bleeding complications, suggesting the need for a more standardized alternative to the BTT. Platelet function should be evaluated to select low-risk patients for renal biopsy as ‘a day case procedure’, in order to build adequate risk management strategies.

Low triiodothyronine: a strong predictor of outcome in acute stroke patients.

Abstract: BACKGROUND: Low triiodothyronine (T3) has been associated with increased short-term mortality in intensive care unit patients and long-term mortality in patients with heart disease. The objective of this study was to investigate possible associations of thyroid hormone status with clinical outcome in patients admitted for acute stroke. MATERIALS AND METHODS: A total of 737 consecutive patients with acute first ever stroke who presented within 24 h from symptoms' onset were studied. Total T3, thyroxin (T4) and thyroid-stimulating hormone (TSH) levels were assessed in the morning following admission. Cases with T3 values < or = 78 ng dL(-1) (1.2 nmol L(-1)) (median) were characterized as 'low T3'. Cases with T4 values < or = 4.66 microg dL(-1) (60 nmol L(-1)) were characterized as 'low T4'. Basic and clinical characteristics, stroke risk factors, and brain imaging were evaluated. Neurological impairment was assessed using the Scandinavian Stroke Scale. RESULTS: Four hundred and seventeen (56%) patients had T3 values < or = 78 ng dL(-1) and 320 had normal T3 values. The 1-year mortality was 27.34% for low T3 and 19.37% for normal T3 cases (P = 0.006). A smaller percentage of patients with low T3 values were independent at 1 year compared to those with normal T3 values [54.2% vs. 68.7%, chi(2) = 12.09, P < 0.001, odds ratio (OR) = 0.53, 95% confidence interval (CI) 0.37-0.76]. Cox regression analysis revealed that increased age, haemorrhagic stroke, low Scandinavian Stroke Scale score, increased glucose and low T3 values (hazards ratio 0.69, CI = 0.48-0.98, P = 0.041) were significant predictors of 1-year mortality. CONCLUSIONS: A high proportion of patients with acute stroke were found soon after the event with low T3 values. The low-T3 syndrome is an independent predictor of early and late survival in patients with acute stroke, and predicts handicap at 1 year.

The metabolic syndrome: metabolic changes with vascular consequences

Abstract: Despite criticism regarding its clinical relevance, the concept of the metabolic syndrome improves our understanding of both the pathophysiology of insulin resistance and its associated metabolic changes and vascular consequences. Free fatty acids (FFA) and tumour necrosis factor-alpha (TNF-alpha) play prominent roles in the development of insulin resistance by impairing the intracellular insulin signalling transduction pathway. Obesity is an independent risk factor for cardiovascular disease and strongly related to insulin resistance. In case of obesity, FFAs and TNF-alpha are produced in abundance by adipocytes, whereas the production of adiponectin, an anti-inflammatory adipokine, is reduced. This imbalanced production of pro- and anti-inflammatory adipokines, as observed in adipocyte dysfunction, is thought to be the driving force behind insulin resistance. The role of several recently discovered adipokines such as resistin, visfatin and retinol-binding protein (RBP)-4 in the pathogenesis of insulin resistance is increasingly understood. Insulin resistance induces several metabolic changes, including hyperglycaemia, dyslipidaemia and hypertension, all leading to increased cardiovascular risk. In addition, the dysfunctional adipocyte, reflected largely by low adiponectin levels and a high TNF-alpha concentration, directly influences the vascular endothelium, causing endothelial dysfunction and atherosclerosis. Adipocyte dysfunction could therefore be regarded as the common antecedent of both insulin resistance and atherosclerosis and functions as the link between obesity and cardiovascular disease. Targeting the dysfunctional adipocyte may reduce the risk for both cardiovascular disease and the development of type 2 diabetes. Although lifestyle intervention remains the cornerstone of therapy in improving insulin sensitivity and its associated metabolic changes, medical treatment might prove to be important as well.

Increased plasma visfatin levels in subjects with the metabolic syndrome

Abstract: Editor – The presence of the metabolic syndrome (MetS) increases the risk for cardiovascular disease (CVD) and type 2 diabetes mellitus [1]. A ‘new’ adipocytokine named ‘visfatin’ (pre-B cell colony-enhancing factor) is a cytokine highly expressed in visceral fat that exhibits insulin-mimetic properties [2]. We investigated the possible differences in plasma visfatin levels between subjects with and without MetS. Consecutive patients (n = 186, 81 men/105 women) without known CVD or diabetes mellitus attending the Outpatient Lipid Clinic of the University Hospital of Ioannina participated in the present study. Ninety of them fulfilled the National Cholesterol Educational Program Adult Treatment Panel III (NCEP ATP III) criteria for the diagnosis of MetS [3] and the remaining 96 subjects served as a control group (non-MetS). Plasma visfatin concentrations were measured using an enzyme-linked immunoabsorbent assay (EIA) kit (Phoenix Pharmaceuticals, Belmont, California, USA). Plasma visfatin concentrations were higher in MetS subjects compared with non-MetS individuals [24·6 (9·1–56·6) ng mL vs. 16·1 (6·7–48·7) ng mL, P < 0·01], even after adjustment for age, sex and body mass index. Visfatin levels increased proportionally to the number of MetS components (P for trend < 0·01) (Fig. 1). Plasma visfatin concentrations were correlated with waist circumference (rho = 0·3, P < 0·001), triglycerides (rho = 0·35, P < 0·001), systolic (rho = 0·28, P < 0·001) and diastolic (rho = 0·27, P < 0·001) blood pressure but not with high-density lipoprotein cholesterol levels. Plasma visfatin levels were marginally correlated with fasting glucose (rho = 0·144, P = 0·055) and insulin levels (rho 0·165, P = 0·035), as well as with the homeostasis model assessment (HOMA) index (rho = 0·16, P = 0·041). In conclusion, plasma visfatin levels are increased in patients with MetS compared with individuals that do not fulfil the criteria for this syndrome. Visfatin concentrations elevate in parallel with the number of MetS components. Gene expression of visfatin was recently found to be enhanced in macrophages of human unstable carotid and coronary atherosclerotic lesions; this finding suggests a potential role for visfatin as an inflammatory mediator and in plaque destabilisation process [4]. Larger clinical studies are needed in order to assess if the observed increase in visfatin levels in MetS subjects is a consequence of the involvement of the molecule in the pathogenesis of this syndrome, or it is just an epiphenomenon that might be a useful marker of abdominal fat deposition and cardiovascular risk.

Arteriogenesis: basic mechanisms and therapeutic stimulation.

Abstract: Pharmacological attempts to stimulate the growth of collateral arteries (arteriogenesis) are evolving towards a new treatment option for patients with vascular occlusive diseases. This enlargement of small pre-existing anastomoses towards large conductance arteries takes place independent of local oxygen tension and is driven by changes in luminal shear stress and infiltration of circulating cells. With the increasing knowledge regarding the distinct differences between capillary sprouting (angiogenesis) and arteriogenesis, several cytokines and growth factors have been demonstrated to stimulate the growth of arterial blood vessels in preclinical models of vascular disease. However, the translation towards clinical practice remains difficult and first in-man trials show limited success. Intensive research especially regarding new drug delivery platforms and the potentially serious side effects of pro-arteriogenic therapeutics is warranted before stimulation of arteriogenesis could become a significant treatment option for vascular occlusive diseases. This review focuses on the recent advances in the field of collateral artery growth. In addition, possible means to overcome the hurdles that have hampered the clinical implementation of pro-arteriogenic therapies will be discussed.

Activated VEGFR2/KDR pathway in tumour cells and tumour associated vessels of colorectal cancer.

Abstract: Background Vascular endothelial cell growth factor (VEGF) acts by phosphorylating specific tyrosine kinase receptors on endothelial cell membrane promoting angiogenesis. The study of the activation status of VEGF receptors in human malignancies has recently become feasible by means of specific monoclonal antibodies recognising the phosphorylated form of these receptors. Materials and methods In the current study, we investigate the expression of the phosphorylated VEGFR2/KDR receptor in normal colon and colorectal adenocarcinomas in parallel with histopathological parameters, prognosis and the expression of the ‘hypoxia inducible factor’ HIF1α. Results pVEGFR2/KDR was weakly expressed in the normal colon, but it was expressed strongly in the cytoplasm and nuclei of cancer cells and in the tumour associated vasculature, mainly at the invading tumour edge. pVEGFR2/KDR expression in cancer cells was significantly associated with a tumour diameter > 6 cm (P = 0·04), poor histological differentiation (P = 0·004) and with high CEF1α expression (P = 0·05). High pVEGFR2/KDR expressing vascular density was significantly related with a high VEGF and HIF1α expression in cancer cells (P = 0·02 and 0·03, respectively). This was also related significantly to high pVEGFR2/KDR expression in cancer cells. In multivariate analysis, the most significant predictors for death were lympho-vascular invasion (P < 0·001) followed by VEGF (P = 0·014), node status (P = 0·015), standard vascular density (P = 0·022) and necrosis (P = 0·032). Conclusions pVEGFR2 receptors are largely expressed in colon cancer cells and intratumoural vasculature. As VEGF targeting agents enter the clinical practice, the role of monoclonal antibodies recognising the phosphorylated form of VEGF receptors as predictors of response to targeted therapies should be sought in clinicopathological trials.

Pathogenesis of hepatic encephalopathy: the tumour necrosis factor-alpha theory.

Abstract: Hepatic encephalopathy (HE) is a major complication for acute and chronic liver failure. Despite several decades of intensive clinical and basic research, the pathogenesis of HE is still incompletely understood, and the precise mechanisms causing brain dysfunction in liver failure are still not fully established. Several theories concerning the pathogenesis of HE have been previously suggested, including the ammonia theory, which received the most attention. These theories are not mutually exclusive and the validity of none of them has been definitely proved experimentally. In this review article, an attractive theory concerning the pathogenesis of HE, the tumour necrosis factor-alpha (TNF) theory, is presented and comprehensively discussed after accumulation of sufficient data which indicate that the pro-inflammatory cytokine, TNF, is strongly involved in the pathogenesis of HE associated with both acute and chronic liver failure. This theory seems to be superior to all other previous theories in the pathogenesis of HE, and may induce development of other beneficial therapeutical modalities for HE directed towards inhibition of TNF production and/or action, and towards enhancement of its degradation.

The PPARδ agonist GW501516 suppresses interleukin‐6‐mediated hepatocyte acute phase reaction via STAT3 inhibition

Abstract: Background Interleukin-6 and downstream liver effectors acute phase reactants are implicated in the systemic inflammatory reaction. Peroxisome proliferator-activated receptor δ (PPAR δ ), which binds to and is activated by a variety of fatty acids, was recently shown to have anti-inflammatory actions.

Interaction between cytokines and sCD40L in patients with stable and unstable coronary syndromes

Abstract: BACKGROUND: Evidence suggests that soluble CD40-ligand (sCD40L) is elevated in coronary artery disease (CAD) and is released from activated platelets during the acute myocardial infarction (AMI). Although sCD40L is part of immune response, the mechanisms regulating its release in different disease states remain unknown. MATERIALS AND METHODS: This study enrolled 596 subjects: 201 patients with stable CAD, 109 patients with AMI and 286 healthy controls. Circulating levels of sCD40L, interleukin-6 (IL-6), soluble vascular cell adhesion molecule-a (sVCAM-1) and soluble intercellular adhesion molecule-1 (sICAM-1) were determined by enzyme-linked immunosorbent assay (ELISA). RESULTS: Patients with AMI (n = 109) had higher levels of sCD40L and IL-6 compared to both CAD (n = 201) (P < 0.01) and controls (n = 286) (P < 0.01), while CAD also had higher levels of sCD40L and IL-6 compared to controls (P < 0.01). Similarly, sICAM-1 and sVCAM-1 levels were higher in CAD and AMI compared to controls (P < 0.05). IL-6 was the only parameter independently associated with sCD40L in healthy individuals [beta (SE):0.491(0.096), P = 0.0001]. However, in CAD or AMI, only diabetes mellitus [beta (SE): 2.689 (1.082), P = 0.044 and beta (SE): 10.406 (3.215), P = 0.002, respectively] and smoking [beta (SE): 3.470 (1.111), P = 0.002 and beta (SE): 9.694 (2.478), P = 0.0001, respectively] (but not IL-6), were independently associated with sCD40L levels. CONCLUSIONS: Both CAD and AMI are accompanied by increased levels of sCD40L in parallel with an elevation of proinflammatory cytokine IL-6 and adhesion molecules sVCAM-1 and sICAM-1. Diabetes mellitus and smoking (but not IL-6 or adhesion molecules) were the only factors independently associated with sCD40L levels in CAD and AMI patients.

The role of calcimimetics in the treatment of hyperparathyroidism.

Abstract: Calcimimetics reduce serum levels of parathyroid hormone (PTH) and calcium, with a leftward shift in the set-point for calcium-regulated PTH secretion. The aim of this publication is to review the data available for calcimimetics in primary, secondary and tertiary hyperparathyroidism (HPT). Parathyroidectomy (PTX) is currently the only curative treatment for primary HPT, and recommended for patients with moderate-to-severe disease, as defined by a 2002 National Institute's of Health summary statement. In general, patients with primary HPT not meeting these surgical criteria, as well as those with contraindication or refusal for surgery, are monitored for signs and symptoms of primary HPT. There are currently no non-surgical therapies approved for use in primary HPT, although bisphosphonates are used in some patients, in an effort to control serum calcium levels. Calcimimetics decrease PTH and calcium levels and are a potential alternative for patients contraindicated for PTX, or who have failed previous PTX and have recurrent primary HPT. Secondary HPT develops early in chronic kidney disease and is present virtually in all patients with end-stage renal disease (ESRD). Secondary HPT is a progressive disease and is associated with several systemic complications, including renal osteodystrophy, soft tissue and vascular calcifications, and adverse cardiovascular outcomes. In ESRD patients, calcimimetics were shown to simultaneously reduce PTH, calcium, phosphate and calcium x phosphate product. In addition, observational analyses of use of calcimimetics in the ESRD population have shown a reduction of important clinical outcomes. In renal allograft recipients with tertiary HPT and hypercalcaemia, calcimimetics are a promising treatment option to control the parameters of calcium phosphate metabolism and may be a valid alternative to PTX. Based on its unique mechanism of action, the calcimimetic cinacalcet may play a role in the medical treatment of primary and tertiary forms of HPT, in addition to the registered indication for the treatment of secondary HPT.

Evaluation of antileukaemic effects of rapamycin in patients with imatinib-resistant chronic myeloid leukaemia.

Abstract: Background Recent data suggest that the mammalian target of rapamycin (mTOR) is involved in the regulation of growth of neoplastic cells in chronic myeloid leukaemia (CML). Patients and methods We treated six patients with imatinib-resistant CML in haematological relapse (leukocytes > 20 000 µL−1) with rapamycin at 2 mg per os daily for 14 consecutive days, with dose-adjustment allowed to reach a target rapamycin serum concentration of 10–20 pg mL−1. Results A major leukocyte response with decrease to less than 10 000 µL−1 was obtained in two patients, and a minor transient response was seen in two other patients. In responding patients, we also observed a decrease in vascular endothelial growth factor (VEGF) mRNA levels in circulating leukaemic cells. Side effects during rapamycin treatment were mild in most patients. In one patient, pneumonia developed. Rapamycin was also found to counteract growth of CML cells in vitro as determined by 3H-thymidine incorporation. Moreover, rapamycin inhibited the growth of Ba/F3 cells exhibiting various imatinib-resistant mutants of BCR/ABL, including the T315I variant that exhibits resistance against most currently available BCR/ABL kinase inhibitors. Conclusions Rapamycin shows antileukaemic effects in imatinib-resistant CML in vitro and in vivo. Larger trials with rapamycin or rapamycin-derivatives in combination with other targeted drugs are warranted to further determine clinical efficacy in CML.

Mitochondrial function and endocrine diseases

Abstract: Mitochondria are fundamental for oxidative energy production and impairment of their functionality can lead to reduced ATP synthesis and contribute to initiation of apoptosis. Endocrine tissues critically rely on oxidative phosphorylation so that mitochondrial abnormalities may either be causes or consequences of diminished hormone production or action. Abnormalities typical for diseases caused by mitochondrial DNA mutations such as Kearns-Sayre syndrome or mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes syndrome are also seen in certain endocrine diseases. Lack or excess of thyroid hormones, major ubiquitous regulators of mitochondrial content and activity, cause muscular abnormalities and multisystem disorders. Mitochondria are a further prerequisite for steroidogenesis as well as insulin secretion and action. Recent studies showed that reduced mitochondrial ATP synthesis in skeletal muscle is a feature of certain hereditary and acquired forms of insulin resistance and diabetes mellitus. Finally, ageing is not only accompanied by various degrees of hormonal deficiency and insulin resistance but is also associated with a progressive decline of mitochondrial number and function. Future research is needed to examine whether mitochondrial abnormalities are the cause or consequence of ageing and frequent metabolic diseases such as obesity and type 2 diabetes mellitus, and to address mitochondria as a target for novel therapeutic regimes.

Treatment with atorvastatin reduces serum adipocyte-fatty acid binding protein value in patients with hyperlipidaemia

Abstract: Background Adipocyte-fatty acid binding protein (A-FABP) is a circulating protein expressed in adipocytes and macrophages. Several recent studies demonstrated that A-FABP might be involved in the pathogenesis of metabolic syndrome, particularly in dyslipidaemia, insulin resistance and atherosclerosis. The aim of this study was to investigate the influence of atorvastatin treatment (20 mg day−1 for 3 months) on serum A-FABP value in subjects with hyperlipidaemia. Materials and methods Anthropometric and serum analyses were performed for body mass index, A-FABP, triglycerides, total cholesterol, high-density lipoprotein (HDL) cholesterol, low-density lipoprotein (LDL) cholesterol, uric acid, alanine aminotransferase (ALT), aspartate aminotransferase (AST), high sensitive C-reactive protein (hs-CRP), creatine kinase (CK) and glucose on 26 subjects (BMI 30·3 ± 6·0, mean age 62 ± 10 years) with hyperlipidaemia who met the criteria: total cholesterol > 5·2 mmol L−1, LDL cholesterol > 3·3 mmol L−1 and triglycerides < 3 mmol L−1. Results After the 3-month therapy, a significant reduction in total cholesterol (P < 0·001), LDL cholesterol (P < 0·001), glucose (P < 0·001), A-FABP (from 44·6 ± 26·2 to 38·6 ± 19·3 g L−1, P < 0·01), uric acid (P < 0·05), AST (P < 0·05) and triglycerides (P < 0·05) values was observed. No difference was found in BMI, CK, ALT, hs-CRP, or HDL cholesterol values. A significant difference in the serum A-FABP value before and after the therapy remains after the correction for total cholesterol value (P < 0·001). A positive correlation between serum A-FABP and glucose was found (P < 0·05). Conclusions In conclusion, our study confirmed in vivo that atorvastatin reduces serum A-FABP by a pleiotropic mechanism and supports the hypothesis that A-FABP is involved in atherosclerotic actions.

Anakinra in two adolescent female patients suffering from colchicine-resistant familial Mediterranean fever: effective but risky.

Abstract: Sir, Mutations in the pyrin gene (MEFV) cause the inflammatory disorder familial Mediterranean fever (FMF) [1]. Most of the patients are treated with colchicine for the prevention of both attacks and secondary amyloidosis. Clinical failure of colchicine treatment is seen in 5 to 10% of patients. Patients who are non-responders suffer a lot despite taking painkillers. Quite often patients are unable to manage daily life because of the disease. No treatment recommendations exist for these cases [2]. Recently, two case reports concerning treatment of colchicine-resistant FMF patients with anakinra were published [3,4]. Anakinra is an interleukin-1 (Il-1) receptor antagonist. Il-1 is a major proinflammatory cytokine that is increased in activity by pyrin, which is shown to be elevated in FMF [5,6]. Since knowledge about the efficacy and tolerance of anakinra is rare we herein present two case studies of patients treated with it. Case 1: A 29-year old Turkish woman with positive personal and family FMF history was visiting our outpatient clinic in March 2007 because of recurrent FMF attacks associated with severe abdominal pain and fever. FMF was previously diagnosed in this patient in Turkey when she was 13 years of age. She had been taking colchicine tablets for several years but in the last year the attack rate had increased and she had typical symptoms every week. During the onset of symptoms she took a large amount of different painkillers, which had no effect. Despite an increased dosage of colchicine (1·5 mg d –1 ), she had elevated inflammation signs [C-reactive protein (CRP): 90·5 mg L –1 , normal: 0–10 mg L –1 ; serum amyloid A (SAA): 626 mg L –1 , normal: < 5 mg L –1 ]. Her serum creatinine level was 0·71 mg dL –1 and no proteinuria was detected. Because of her poor quality of life caused by the recurrent attacks we decided to try anakinra treatment. After informing the patient about the potential side effects and the empirical aspects of the therapy, treatment was started with 100 mg anakinra administered subcutaneously every day. Before administration a quantiFERON-TB Gold test was performed which showed a negative result. After eight days of anakinra treatment the patient was symptom free and after three weeks the inflammatory parameters almost normalised (Fig. 1). The administration of colchicine was not interrupted at any time point. Three weeks after the start of treatment, administration of anakinra was stopped because the patient was feeling well and it was assumed that continuing with colchicine would prolong the attack rate. After 4 days the patient came to our outpatient department again and was complaining of severe abdominal pain. The inflammation parameters were also elevated. Administration of anakrina was restarted and recovery was achieved within a few days concomitant with a decrease in the inflammation parameters. Colchicine was stopped at this time point since efficacy was missing. During the following 3 months an ‘on and off treatment’ with anakrina took place. The first time the application was stopped because the patient could not tolerate any further injections due to severe pain at the site of the injection. Her symptoms and inflammation parameters returned very quickly afterwards. The patient then decided to restart anakinra because the severity of her pain due to FMF persistently increased. Since the patient’s insurance company refused to pay for this treatment, anakinra therapy was stopped until this problem was resolved. Vienna General Hospital, Medical University of Vienna, Vienna, Austria (R. Gattringer, H. Lagler, K. B. Gattringer, S. Knapp, H. Burgmann, S. Winkler, W. Graninger, F. Thalhammer).

Mineral metabolism disturbances in patients with chronic kidney disease.

Abstract: Background Kidney disease, especially chronic kidney disease (CKD), is a worldwide public health problem with serious adverse health consequences for affected individuals. Secondary hyperparathyroidism, a disorder characterized by elevated serum parathyroid hormone levels, and alteration of calcium and phosphorus homeostasis are common metabolic complications of CKD that may impact cardiovascular health. Materials and methods Here, we systematically review published reports from recent observational studies and clinical trials that examine markers of altered mineral metabolism and clinical outcomes in patients with CKD. Results Mineral metabolism disturbances begin early during the course of chronic kidney disease, and are associated with cardiovascular disease and mortality in observational studies. Vascular calcification is one plausible mechanism connecting renal-related mineral metabolism with cardiovascular risk. Individual therapies to correct mineral metabolism disturbances have been associated with clinical benefit in some observational studies; clinical trials directed at more comprehensive control of this problem are warranted. Conclusions There exists a potential to improve outcomes for patients with CKD through increased awareness of the Bone Metabolism and Disease guidelines set forth by the National Kidney Foundation–Kidney Disease Outcomes Quality Initiative. Future studies may include more aggressive therapy with a combination of agents that address vitamin D deficiency, parathyroid hormone and phosphorus excess, as well as novel agents that modulate circulating promoters and inhibitors of calcification.

Genetic and environmental determinants of the PON‐1 phenotype

Abstract: Background Paraoxonase (PON-1) is a high-density lipoprotein (HDL)-associated enzyme that may protect against cardiovascular disease (CVD), because it hydrolyses oxidized phospholipids of low-density lipoprotein (LDL) and therefore prevents the detrimental effects on the arterial wall. The current report describes the determinants of PON-1 bioavailability and activity. Materials and methods This is the largest (n = 1527) cross-sectional evaluation performed on PON-1 genotypes (Q192R, T-107C and L55M) and environmental determinants to PON-1 catalytic activity and bioavailability in serum of postmenopausal women. PON-1 catalytic activity and PON-1 bioavailability were measured, in vitro, with a paraoxon hydrolysis assay and a phenylacetate hydrolysis assay, respectively. Results The major determinant of paraoxon hydrolytic activity is the Q192R genotype, but there was also a relation with the C-107T and L55M genotype, HDL levels and alcohol consumption. Phenylacetate hydrolytic activity was most strongly affected by the C-107T genotype followed by the L55M genotype, HDL levels, alcohol consumption and smoking. Conclusions PON-1 Q192R, C-107T and L55M genotype, alcohol consumption, smoking and HDL levels are determinants of serum PON-1 phenotype. The contributions of the genetic markers to the PON-1 phenotype are stronger than the contributions of the lifestyle determinants.

Microalbuminuria and the metabolic syndrome and its components in the Chinese population.

Abstract: Background Microalbuminuria and the metabolic syndrome (MetS) have both been linked to chronic kidney disease and cardiovascular disease. This study investigated the association between urinary albumin-to-creatinine ratio (ACR) and MetS and its components. Materials and methods A total of 2311 subjects aged 40 years and over were recruited in 2004 in a metropolitan city in Taiwan. The biochemical indices, such as fasting glucose levels, urinary albumin, urinary creatinine and anthropometric indices, were measured. We defined microalbuminuria as a urinary ACR ranging from 30 to 300 mg g−1 creatinine. MetS was defined using the American Heart Association and the National Heart, Lung and Blood Institute (AHA/NHLBI) and the International Diabetes Federation (IDF) definitions. The relationship between MetS and microalbuminuria was examined using multiple logistical regression analysis. Results Subjects with microalbuminuria had higher age, body mass index (BMI), waist circumference, blood pressure, fasting plasma glucose, triglycerides, total cholesterol (TCHOL)/high-density lipoprotein cholesterol (HDL-C) ratio, prevalence of diabetes mellitus and hypertension and lower HDL-C than subjects with normoalbuminuria. After adjusting for age and BMI, microalbuminuria was associated with the individual components of MetS, except in central obesity in women and elevated fasting glucose in men. After adjusting for age, BMI, smoking and alcohol consumption status, multiple logistical regressions revealed that microalbuminuria is strongly associated with MetS in both genders and according to both definitions. The odds ratio of having MetS using the AHA/NHLBI and IDF definition was 1·76 (1·16–2·67) and 1·73 (1·06–2·83) in men and 2·19 (1·38–3·50) and 2·09 (1·24–3·51) in women, respectively. Conclusions Microalbuminuria was strongly associated with MetS and its components. There is an increased likelihood of having MetS if subjects have microalbuminuria.

Age-related changes in bile acid synthesis and hepatic nuclear receptor expression

Abstract: BACKGROUND Recent data highlighted the role of nuclear receptors in the transcriptional regulation of the limiting enzyme of bile acid synthesis, cholesterol 7alpha-hydroxylase, in cellular and animal models. This study was designed to analyze the effects of age on cholesterol 7alpha-hydroxylase and related nuclear receptor expression in human livers. DESIGN Surgical liver biopsies were obtained in 23 patients requiring operation on the gastrointestinal tract. mRNA levels of cholesterol 7alpha-hydroxylase and related nuclear receptors and co-activators were assayed by quantitative real-time RT-PCR. Serum levels of 7alpha-hydroxy-4-cholesten-3-one, a marker of bile acid synthesis, were assayed by gas-liquid chromatography:mass spectrometry. RESULTS Ageing was inversely correlated with serum 7alpha-hydroxy-4-cholesten-3-one and with cholesterol 7alpha-hydroxylase mRNA levels (r = -0.44 and r = -0.45 on a semi-log scale, respectively, P < 0.05). Among different nuclear factors, cholesterol 7alpha-hydroxylase mRNA best correlated with hepatocyte nuclear factor-4 (r = 0.55 on a log scale, P < 0.05); hepatocyte nuclear factor-4 levels were also inversely correlated with age (r = -0.64 on a semi-log scale, P < 0.05). Age was inversely correlated with serum insulin-like growth factor-I levels, which were directly correlated with hepatocyte nuclear factor-4 and cholesterol 7alpha-hydroxylase expression. No suppressive effect of short heterodimer partner expression on cholesterol 7alpha-hydroxylase was observed. CONCLUSIONS Ageing associates with reduced bile acid synthesis, possibly related to decreased hepatic expression of hepatocyte nuclear factor-4 and consequently of cholesterol 7alpha-hydroxylase. Age-related modifications of the growth hormone/insulin-like growth factor axis might play a role. These findings may help to elucidate the pathophysiology of age-related modifications of cholesterol metabolism.

Aquaporins in the hepatobiliary tract. Which, where and what they do in health and disease

Abstract: The biological importance of the aquaporin family of water channels was recently acknowledged by the 2003 Nobel Prize for Chemistry awarded to the discovering scientist Peter Agre. Among the pleiotropic roles exerted by aquaporins in nature in both health and disease, the review addresses the latest acquisitions about the expression and regulation, as well as physiology and pathophysiology of aquaporins in the hepatobiliary tract. Of note, at least seven out of the thirteen mammalian aquaporins are expressed in the liver, bile ducts and gallbladder. Aquaporins are essential for bile water secretion and reabsorption, as well as for plasma glycerol uptake by the hepatocyte and its conversion to glucose during starvation. Novel data are emerging regarding the physio-pathological involvement of aquaporins in multiple diseases such as cholestases, liver cirrhosis, obesity and insulin resistance, fatty liver, gallstone formation and even microparasite invasion of intrahepatic bile ducts. This body of knowledge represents the mainstay of present and future research in a rapidly expanding field.

Association of oxidative stress and PON1 with LDL and HDL particle size in middle-aged subjects

Abstract: Background Alterations in plasma lipoprotein subclass distributions affect atherosclerosis risk Smaller, denser low-density lipoprotein (LDL) particles (sdLDL) are more susceptible to oxidation In contrast, most of the protective effects of high-density lipoproteins (HDL) are attributable to larger particles This study investigates the connection between LDL and HDL particle heterogeneity and oxidative stress, antioxidative defence (AOD) and paraoxonase (PON1) status in a healthy middle-aged Serbian population Materials and methods LDL and HDL particle sizes and subclass distributions were measured by gradient gel electrophoresis in 104 men and 103 women, aged 53 ± 9·4 years PON1 activities and PON1Q192R phenotypes were determined with paraoxon and diazoxon as substrates The oxidative stress/AOD status was estimated by measuring malondialdehyde (MDA) and superoxide-anion () levels and superoxide-dismutase (SOD) activity Results Subjects with sdLDL had significantly higher MDA (P < 0·001) and (P < 0·05) levels and greater diazoxonase (DZOase) activity (P < 0·05) compared to subjects with larger LDL particles A high MDA concentration was a significant predictor of the sdLDL phenotype (P < 0·005) Increased levels of and MDA were associated with smaller HDL3 subclass abundance Reduced HDL particle size was associated with lower DZOase activity (P < 0·01) Conclusions Even in the absence of symptoms of atherosclerosis, sdLDL particles are associated with increased oxidative stress, which may stimulate a compensatory rise in PON1 DZOase activity Elevated oxidative stress may significantly affect HDL subclass distribution, resulting in the accumulation of smaller, denser HDL particles with diminished antioxidative capacity