Plasma TNF-alpha Research Articles

Systemic levels of tumor necrosis factor alpha during hemodialysis with cellulosic membranes: no effect of the sterilization procedure.

Extractable constituents of dialyzer membranes (e.g., monomers and beta-glucans) may induce the production of cytokines in vitro. We therefore studied circulating tumor necrosis factor alpha (TNF alpha) levels in 23 stable hemodialysis patients during treatment with dry Cuprophan membranes (ETO-sterilized n = 10, steam-sterilized n = 13) longitudinally over a period of 4 weeks. After 4 weeks, those 5 patients of each group showing the highest TNF alpha levels were switched to steam-sterilized, wet Cuprophan membranes. No significant increase in plasma TNF alpha was observed during hemodialysis with either ETO- or steam-sterilized dry Cuprophan membranes. A substantial TNF alpha increase (> or = 100% compared to pre-HD values), however, was observed during 14 of 84 treatment sessions. In 5 selected patients with ETO-sterilized, dry Cuprophan dialyzers, TNF alpha rose from (mean +/- SEM) 17.2 +/- 3.0 (pre-HD) to 20.9 +/- 6.2 (120 min) and 21.9 +/- 4.5 pg/ml (240 min). Corresponding levels in patients with steam-sterilized, dry Cuprophan were 16.2 +/- 5.4 (pre-HD), 21.9 +/- 6.8 (120 min), and 16.0 +/- 3.7 pg/ml (240 min), respectively. There was no difference between ETO- and steam-sterilized dialyzers. No significant reduction in mean TNF alpha plasma levels or in frequency of elevated peak levels was achieved when these patients were switched to wet Cuprophan dialyzers for another 4 weeks. It is suggested that an induction of elevated TNF alpha levels during hemodialysis is possible but is not observed regularly during treatment with Cuprophan membranes.(ABSTRACT TRUNCATED AT 250 WORDS)

Activation and Overexpression of PARP-1 in Circulating Mononuclear Cells Promote TNF-α and IL-6 Expression in Patients with Unstable Angina

Proinflammatory cytokines are involved in the development of unstable angina (UA). Poly(ADP-ribose) polymerase-1 (PARP-1) contributes importantly to regulating the transcription of inflammatory cytokines. This study aims to investigate the relationship of PARP-1 in circulating mononuclear cells (MNCs) and plasma TNF-alpha and IL-6 in UA patients and to elucidate the mechanism that PARP-1 promotes TNF-alpha and IL-6 expression via NF-kappaB pathway. Twenty six Braunwald class IIIB UA patients, 25 stable angina patients and 25 healthy volunteers were enrolled in this study. Plasma TNF-alpha and IL-6 were determined with ELISA. Circulating MNCs were analyzed for PARP activity, PARP-1 expression and NF-kappaB DNA binding activity. MNCs from healthy subjects were cultured to investigate the direct effects of PARP-1 on NF-kappaB DNA binding activity and the expression of TNF-alpha and IL-6. PARP activity and PARP-1 expression in circulating MNCs were increased and positively correlated with plasma TNF-alpha and IL-6, respectively, in UA patients. Spontaneous NF-kappaB activation in MNCs was demonstrated in UA patients. In cultured MNCs from healthy subjects, inhibition of PARP-1 prevented lipopolysaccharide-induced increase in DNA binding activity of NF-kappaB and the expression of TNF-alpha and IL-6. Supershift assay demonstrated that PARP-1 was a component of NF-kappaB/DNA complex. Addition of recombinant human PARP-1 protein to nuclear extracts of MNCs significantly increased the DNA binding activity of NF-kappaB. Activation and overexpression of PARP-1 are demonstrated in circulating MNCs of UA patients. Overexpressed PARP-1 promotes PARP-1/NF-kappaB/DNA complex formation, thereby enhancing the expression of TNF-alpha and IL-6 in circulating MNCs of UA patients.

Osteopontin might be involved in bone remodelling rather than in inflammation in ankylosing spondylitis

To determine whether osteopontin (OPN) is increased in patients with AS and to investigate its relationship to inflammatory disease activity and bone remodelling process. This cross-sectional study included 30 patients with AS and 23 age- and sex-matched healthy controls. We assessed clinical characteristics and laboratory parameters including the ESR, CRP, lipid profiles, the Bath AS disease activity index (BASDAI) and the Bath AS radiographic index (BASRI). To evaluate bone metabolism, we tested ALP, OCN and C-telopeptide of type I collagen (CTX-I). Plasma levels of OPN, TNF-alpha and IL-6 were measured by ELISA, and mRNA expression in peripheral blood mononuclear cells (PBMCs) was performed by RT-PCR. Changes in OPN level were also evaluated in eight patients after the treatment with a TNF-alpha blocker. Patients with AS had significantly higher plasma OPN, TNF-alpha and IL-6 levels and more mRNA expression than healthy controls. Plasma OPN levels were correlated with serum ALP, OCN and CTX-I levels, but not with ESR, CRP, lipid profiles, BASDAI or BASRI. Treatment with a TNF-alpha blocker did not alter OPN levels, although it reduced the disease activity. Patients with AS had higher levels of OPN compared with controls. The plasma OPN level was correlated with serum ALP, OCN and CTX-I levels, but not with disease activity in AS. OPN might be involved in bone remodelling rather than in inflammation in AS.

THE PROTECTIVE EFFECT OF THE CHOLINERGIC ANTI-INFLAMMATORY PATHWAY AGAINST SEPTIC SHOCK IN RATS

To investigate the effects of the cholinergic anti-inflammatory pathway on hemodynamics, blood biochemistry, the plasma TNF-alpha level, and the nuclear factor-kappaB (NF-kappaB) activation during septic shock, male Sprague-Dawley rats were subjected to cecal ligation and puncture (CLP, a model of polymicrobial sepsis) or sham operation. Forty-eight rats were randomly assigned into six equal groups: sham CLP group; CLP group; VGX group was subjected to bilateral cervical vagotomy after CLP; STM group was subjected to bilateral cervical vagotomy after CLP plus the left vagus nerve trunk electrical stimulation; THA group was administered tetrahydroaminoacridine after CLP and bilateral cervical vagotomy; and alpha-BGT group was administered alpha-bungarotoxin before electrical stimulation of the vagus nerve. The right carotid artery was cannulated to monitor MAP. The plasma TNF-alpha level was measured using enzyme-linked immunosorbent assays. The hepatic NF-kappaB activation was determined by Western blotting. Cecal ligation and puncture produced progressive hypotension. Serum aspartate transaminase and alanine transaminase levels significantly increased after CLP challenge. The plasma TNF-alpha level and the hepatic NF-kappaB activation significantly increased after CLP alone or with bilateral cervical vagotomy compared with sham-operated group. Application of constant voltage pulses to the caudal vagus trunk significantly prevented the development of CLP-induced hypotension, alleviated the hepatic damage, and reduced the plasma TNF-alpha production, but electrical stimulation had no effect on the hepatic NF-kappaB activation. Tetrahydroaminoacridine administration after bilateral cervical vagotomy reversed hypotension and attenuated the plasma TNF-alpha response; in addition, it had no effect on the hepatic NF-kappaB activation. alpha-Bungarotoxin pretreatment significantly reversed the inhibitory effect of vagal electrical stimulation, but it had no effect on the hepatic NF-kappaB activation. Our results showed that the cholinergic anti-inflammatory pathway might produce a potential protective effect on polymicrobial sepsis in rats.

Protective effects of the combination of α-helical antimicrobial peptides and rifampicin in three rat models of Pseudomonas aeruginosa infection

An experimental study has been performed to compare the in vitro activity and the in vivo efficacy of magainin II and cecropin A with or without rifampicin against control and multidrug-resistant Pseudomonas aeruginosa strains. In vitro experiments included MIC determinations and synergy studies. For in vivo studies, animals were given an intraperitoneal injection of P. aeruginosa lipopolysaccharide, P. aeruginosa ATCC 27853 and one clinical multiresistant P. aeruginosa strain. Groups of animals received intravenously isotonic sodium chloride solution, 10 mg/kg rifampicin, 1 mg/kg magainin II or 1 mg/kg cecropin A. Two groups of animals received a combined treatment with magainin II + rifampicin or cecropin A + rifampicin at the same dosages as the singly treated groups. In addition, a further group was treated with tazobactam/piperacillin (120 mg/kg). Lethality, bacterial growth in blood and peritoneum, and endotoxin and TNF-alpha concentrations in plasma were evaluated. Combinations of alpha-helical antimicrobial peptides showed in vitro synergistic interaction. Magainin II and cecropin A exerted strong antimicrobial activity and achieved a significant reduction in plasma endotoxin and TNF-alpha concentrations when compared with control and rifampicin-treated groups. Rifampicin exhibited no anti-P. aeruginosa activity and good substantial impact on endotoxin and TNF-alpha plasma concentrations. Combined treatment groups had significant reductions in bacterial count, positive blood cultures and mortality rates when compared with singly treated and control groups. Our results highlight the potential usefulness of these combinations that provide future therapeutic alternatives in P. aeruginosa infections.

High percentage of apoptotic spermatozoa in ejaculates from men with chronic genital tract inflammation

Silent chronic inflammation of genital tract (CIGT) is considered as a major contributing factor to male fertility disorders. Within CIGT, inflammatory cytokines such as TNF-alpha might induce spermatozoal apoptosis, which in turn has been shown to have a negative influence on the sperm-oocyte penetration capacity. Thus, the aim of this study was to investigate spermatozoal apoptosis in patients with fertility disorders and signs of CIGT. Apoptosis of spermatozoa was determined by expression of annexin V using flow cytometry. Apoptotic spermatozoa were further discriminated from necrotic spermatozoa by 7-amino-actinomycin (7AAD). Ejaculates of patients showing signs of CIGT (P-CIGT) such as high polymorphonuclear (PMN) elastase were compared to control ejaculates of patients lacking signs of CIGT (CON). Thereby we detected a significant correlation between PMN elastase and TNF-alpha in the seminal plasma and apoptotic spermatozoa. Furthermore, we demonstrated a significantly higher percentage of apoptotic spermatozoa in the ejaculate of P-CIGT compared to CON. Interestingly, a significantly higher percentage of apoptotic spermatozoa was detected in the swim-up fraction demonstrating motility of apoptotic spermatozoa. This is in line with the missing correlation of apoptotic spermatozoa and motility. In conclusion, patients with signs of CIGT display high numbers of apoptotic spermatozoa with progressive motility, which might have an impact on reproductive techniques such as intrauterine insemination or in-vitro fertilisation.

Stress and Body Mass Index Each Contributes Independently to Tumor Necrosis Factor-α Production in Prepubescent Latino Children

This investigation extended prior work by determining if stress and body mass index (BMI) contributed independently to tumor necrosis factor-alpha (TNF-alpha) levels among prepubescent Latino children and if sex and family history of type 2 diabetes mellitus (T2DM) modified these relationships. Data were collected in South Florida from 112 nondiabetic school-aged Hispanic children, of whom 43.8% were obese (BMI >/= 95th percentile) and 51.8% presented with a family history of T2DM. Stressful life events were assessed via parental report using a life events scale. Plasma TNF-alpha levels were determined with enzyme-linked immunosorbent assay. The relative contributions of stress and BMI with TNF-alpha levels and the potential interaction effects of sex and family history of T2DM were analyzed with multiple linear regression analyses. Stress and BMI each accounted for a significant proportion of the unique variance associated with TNF-alpha. The association between stress and TNF-alpha was not modified by sex or family history of T2DM. These findings implicate BMI and stress as independent determinants of TNF-alpha (an inflammatory cytokine and adipocytokine) among Latino children. Future investigations should examine the potential roles of exercise, nutritional status, age, and growth hormone in explicating the relationship between TNF-alpha production and psychosocial distress and risk for infection among obese children.

Plasma levels of TNF-α, IL-6, and IL-10 and their relationship with left ventricular diastolic function in patients with stable angina pectoris and preserved left ventricular systolic performance

The role of inflammation--a key factor underlying coronary artery disease (CAD) and systolic heart failure--in promotion of left ventricular (LV) diastolic dysfunction has not been investigated extensively so far. The aim of this study was: (i) to evaluate plasma levels of TNF-alpha, IL-6, and IL-10 in patients with stable CAD and preserved LV systolic function and (ii) to assess their relationships with LV diastolic function. The study population consisted of 126 patients with single vessel and 58 patients with multivessel stable CAD and LV ejection fraction >50%, and 39 healthy controls. Each participant underwent echocardiographic study including estimation of LV diastolic function indices: peak velocities of early (E) and late (A) transmitral flows, deceleration time of E wave, isovolumic relaxation time, E wave (ETT) and A wave (ATT) transit time to the LV outflow tract, and flow propagation velocity of E wave (Ep). Plasma TNF-alpha, IL-6, and IL-10 levels were evaluated by radioimmunometric method. Patients with CAD presented higher TNF-alpha and IL-6 levels and higher values of IL-6/IL-10 and TNF-alpha/IL-10 ratio than the controls. IL-6 levels were higher in patients with multivessel disease than in those with single vessel disease. Significant correlations (all P<0.001) were found for TNF-alpha and Ep (r=-0.41), E/Ep (r=0.45), and ETT (r=0.38). IL-6 correlated with Ep (r=-0.39) and E/A (r=-0.33), whereas IL-10 with ETT (r=0.37), Ep (r=-0.44), and E/Ep (r=0.46). In patients with stable CAD and preserved LV systolic performance, plasma levels of TNF-alpha and IL-6 are elevated and there is association between immunoinflammatory activation reflected by plasma levels of cytokines and LV diastolic dysfunction.

Protective Effects of Caffeic Acid Phenethyl Ester on Intestinal Ischemia-Reperfusion Injury

Intestinal ischemia reperfusion (IR) causes tissue injury in two ways, starting a pro-inflammatory cascade and oxidative stress. The aim of this study was to investigate the possible protective effects of caffeic acid phenethyl ester (CAPE), which has antioxidant and anti-inflammatory properties, against intestinal IR injury in rats. Forty male Wistar-Albino rats were divided into five groups: Sham, IR, IR plus ethanol (vehicle), IR plus 10 mg/kg (IR + 10CAPE), and 30 mg/kg CAPE (IR + 30CAPE) at the 30-min ischemic period. Intestines were exteriorized and the superior mesenteric artery was occluded for 45-min ischemia and then the clamp was removed for 120-min reperfusion. After the experiment, the intestines were removed for biochemical and light microscopic examinations. Additionally, blood samples were taken for plasma TNF-alpha measurement. The TBARS levels of the IR and IR + Ethanol groups were higher than the Sham group (P < 0.05). Both CAPE treatments decreased TBARS levels in comparison with the IR group (P < 0.05). In both CAPE-treated groups, while the superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activities were increased compared to all other groups, which was similarly the case for the CAT activity compared to the Sham and IR + Ethanol groups (P < 0.05). There were no significant differences between GSH levels of all study groups. The TNF-alpha levels of the IR and IR + Ethanol groups were non-significantly increased compared to the Sham group (P > 0.05). The TNF-alpha levels of 10 and 30 mg/kg CAPE groups were non-significantly decreased compared to the IR group (P > 0.05). The tissue MPO activities of the IR and IR + Ethanol groups were higher than the Sham group (P < 0.05). The MPO activities of the IR + 10CAPE and IR + 30CAPE groups were not significantly different from the Sham group (P > 0.05). There was necrosis of mucosa in the IR and IR + Ethanol groups in light microscopic evaluations. Those changes were significantly reversed by 30 mg/kg CAPE treatment. The intestinal IR injury may be reversed by anti-inflammatory and antioxidant actions of the CAPE. However, 30 mg/kg CAPE treatment may be more efficient in preventing intestinal IR injury in rats.

The influence of increased training volume on cytokines and ghrelin concentration in college level male rowers

The aim of this study was to investigate plasma IL-6, TNF-alpha, leptin and ghrelin concentrations during high-volume training. Eight trained male rowers participated. Fasting blood was sampled before (T1) and after (T2) increased training volume and after recovery period (T3). Two-hour rowing was performed at T1, T2 and at T3 with blood samples before, POST and POST 30'. Decrease in fasting leptin was observed at T2 (from 1.31 (0.53) to 0.93 (0.27) ng ml(-1); P < 0.05). Leptin was also significantly decreased at POST and POST 30 exercise compared to PRE test at T2. At T2 POST 30' leptin was significantly lower compared to corresponding value at T1. There were no significant post-exercise changes in ghrelin at T2 compared to T1 and T3. TNF-alpha was significantly increased POST exercise only at T2. In conclusion, high-volume training causes alterations of post exercise leptin and TNF-alpha, while increases in ghrelin are down regulated.

Cytokine blockade attenuates sympathoexcitation in heart failure: Cross‐talk between nNOS, AT‐1R and cytokines in the hypothalamic paraventricular nucleus

To investigate evidence for the interplay between cytokines, angiotensin II and nNOS in the paraventricular nucleus (PVN), for regulating sympathetic outflow in a rat model of CHF. Heart failure was induced in Sprague-Dawley rats by coronary artery ligation. One group of rats was treated with pentoxifylline (PTX, 30 mg/kg IP), a cytokine blocker, or vehicle, for 5 weeks. Another group of rats was pre-treated with PTX before coronary ligation to study prior cytokine blocking effect on survival. Both groups were combined in the analysis. Echocardiography demonstrated an increase in LV end-diastolic pressure and Tei index after 5 weeks in CHF rats. ELISA revealed a significant increase in plasma TNF-alpha and IL-1beta in CHF rats. Inducible NOS (iNOS) and angiotensin receptor-type 1 (AT-1R) mRNA expressions were increased, while neuronal NOS (nNOS) was decreased in the PVN of CHF rats; these changes were reversed by PTX. PTX treatment also decreased plasma norepinephrine and epinephrine levels and improved baroreflex control of renal sympathoexcitation in CHF rats. Immunohistochemistry revealed elevated 3-nitrotyrosine formation in the heart and the PVN of CHF rats, but not in PTX treated rats. PTX decreased both peripheral and central cytokine expression, alleviated nitric oxide dysregulation, and inhibited the formation of peroxynitrite in the PVN resulting in decreased sympathoexcitation in CHF rats.

Anti‐inflammatory effects of dimemorfan on inflammatory cells and LPS‐induced endotoxin shock in mice

Dimemorfan (a sigma1 receptor agonist) showed neuroprotective properties in animal models of inflammation-mediated neurodegenerative conditions, but its effects on inflammatory cells and systemic inflammation remain unclear. The effects of dimemorfan on phorbol-12-myristate-13-acetate (PMA)- and N-formyl-methionyl-leucyl-phenylalanine (fMLP)- induced neutrophils and lipopolysaccharide (LPS)-activated microglial cells, as well as LPS-induced endotoxin shock in mice were elucidated. Dimemorfan decreased PMA- and fMLP-induced production of reactive oxygen species (ROS) and CD11b expression in neutrophils, through mechanisms independent of sigma1 receptors, possibly by blocking ROS production and G-protein-mediated intracellular calcium increase. Dimemorfan also inhibited LPS-induced ROS and nitric oxide (NO) production, as well as that of monocyte chemoattractant protein-1 and tumour necrosis factor-alpha (TNF-alpha), by inhibition of NADPH oxidase (NOX) activity and suppression of iNOS up-regulation through interfering with nuclear factor kappa-B (NF-kappaB) signalling in microglial cells. Treatment in vivo with dimemorfan (1 and 5 mg kg(-1), i.p., at three successive times after LPS) decreased plasma TNF-alpha, and neutrophil infiltration and oxidative stress in the lung and liver. Our results suggest that dimemorfan acts via sigma1 receptor-independent mechanisms to modulate intracellular calcium increase, NOX activity, and NF-kappaB signalling, resulting in inhibition of iNOS expression and NO production, and production of pro-inflammatory cytokines. These effects may contribute its anti-inflammatory action and protective effects against endotoxin shock in mice.

Increased CD11/CD18 expression on peripheral blood leucocytes of patients with sarcoidosis.

Sarcoidosis is a multisystem disease of unknown etiology characterized by non-caseating granulomata, formed mainly from macrophages surrounded by lymphocytes and plasma cells. Using a novel method for the preparation of blood leucocytes for flow cytometry, we report increased expression of LeuCAMs (CD11/CD18) on peripheral blood leucocytes of 11 Caucasian and 10 Afro-Caribbean patients with sarcoidosis compared with age-, sex- and race-matched controls. Whilst the percentages of the cells expressing CD11/CD18 were no different, the density, expressed as mean fluorescence intensity (MFI), was greater for all leucocytes in sarcoids than in normal individuals. The expression of intercellular adhesion molecule-1 (ICAM-1), a ligand for LFA-1 which is expressed on all leucocytes, was not significantly different from normal, whereas HLA-DR was expressed more intensely on sarcoid monocytes (P less than 0.01) and blood lymphocytes (P less than 0.005) than control cells. Our findings are consistent with leucocyte activation although we were unable to confirm reports of elevated tumour necrosis factor-alpha (TNF-alpha) in the patients' plasma using an ELISA. Increased expression of adhesion molecules on peripheral blood leucocytes may play a role in the cellular extravasation, aggregation, and granuloma formation seen in sarcoidosis.

Visfatin expression in subcutaneous adipose tissue of pre‐menopausal women: relation to hormones and weight reduction

A novel adipokine, visfatin, was found to be related to adiposity in humans and regulated by a number of hormonal signals. The aim of this study was to investigate the relationships of visfatin expression in adipose tissue with potential regulatory factors such as insulin, testosterone and tumor necrosis factor-alpha (TNF-alpha) and to elucidate the effect of a diet induced weight reduction on adipose tissue mRNA expression and plasma levels of visfatin. Biopsies of subcutaneous abdominal adipose tissue (SCAAT) and plasma samples were obtained at the beginning of the study from 47 pre-menopausal women (age 38.7 +/- 1.7 years, body mass index (BMI) 27.9 +/- 1.4 kg m(-2)), consisting of 15 lean, 16 overweight and 16 obese subjects. The subgroup of 32 overweight/obese women (age 42.1 +/- 1.9 years, BMI 31.2 +/- 0.9 kg m(-2)) underwent a 12 week hypocaloric weight reducing diet and samples were obtained at the end of the diet. Biopsy samples were analysed for visfatin and TNF-alpha mRNA levels and plasma was analysed for relevant metabolites and hormones. In the group of 47 subjects visfatin mRNA expression in SCAAT was negatively correlated with plasma free testosterone (r = -0. 363, P < 0.05) and BMI (r = -0.558, P < 0.01) and positively associated with adipose tissue TNF-alpha mRNA expression (r = 0.688, P < 0.01). The diet resulted in the reduction of body weight and in the decrease of plasma insulin, free testosterone and TNF-alpha levels. In the group of overweight/obese subjects visfatin mRNA in SCAAT increased after the diet and the diet induced increase was positively correlated with the magnitude of body weight loss. Visfatin mRNA expression in SCAAT is associated with TNF-alpha expression, plasma free testosterone and BMI in pre-menopausal women. A weight reducing hypocaloric diet results in the increase of visfatin mRNA in SCAAT.

Soluble IL-2 receptor and tumour necrosis factor-α in plasma of haemophilia patients infected with HIV

We measured plasma concentrations of soluble receptors for IL-2 (sIL-2R) and tumour necrosis factor-alpha (TNF-alpha) in 149 haemophilia patients. Soluble IL-2R levels were elevated in 37% of 62 HIV-seronegative patients (mean 570 +/- 27 U/ml versus 361 +/- 17 U/ml in the control group, P less than 0.0001), in 78% of 68 HIV-seropositive patients (928 +/- 49 U/ml, P less than 0.0001), and in 95% of 19 AIDS/ARC patients (1578 +/- 199 U/ml, P less than 0.0001 compared with controls and with HIV-seronegative patients; P less than 0.005 compared with HIV-seropositive asymptomatic patients). A negative correlation was observed between sIL-2R, relative and absolute numbers of CD4+ cells (P less than 0.0001), and CD4/CD8 ratios (P less than 0.0001). There was also a negative correlation between sIL-2R in plasma and the cellular expression of IL-2R (P less than 0.001). We found a significant association of sIL-2R and plasma neopterin (P less than 0.0001). With progression of the disease from HIV-seronegative to seropositive without symptoms and to full manifestation of AIDS/ARC, sIL-2R plasma levels increased. The highest levels were found at the time of diagnosis of AIDS/ARC, but the levels decreased again during the following 18 months. Eight per cent of HIV-seronegative patients, 32% of HIV-seropositive patients, and 24% of patients with AIDS/ARC had increased plasma TNF-alpha. We conclude that sIL-2R and TNF-alpha plasma levels are elevated in HIV-infected haemophilia patients and that sIL-2R is a marker for disease progression from asymptomatic HIV-seropositive to AIDS/ARC.

Induction of tumour necrosis factor-alpha during haemodialysis. Influence of the membrane type

Some of the secondary clinical effects induced by long-term haemodialysis in patients with end-stage renal failure have been related to an increased production of interleukin-1 (IL-1). We investigated the role of another cytokine which shares a number of biological properties with IL-1, tumour necrosis factor-alpha (TNF-alpha). In long-term haemodialysed patients, we found at the beginning of the dialysis increased plasma TNF-alpha levels and enhanced monocyte capacity to produce TNF-alpha spontaneously ex vivo. Non-haemodialysed uraemic patients also presented increased plasma TNF-alpha levels. During dialysis with cellulose acetate (CA) or polysulphone (PS) membranes, plasma TNF-alpha levels and the spontaneous and lipopolysaccharide-induced production of TNF-alpha by monocytes remained at predialysis levels. In contrast, when cuprophane membranes were used, there was a significant increase in plasma TNF-alpha levels and in both spontaneous (10-fold) and lipopolysaccharide-induced (seven-fold) ex vivo TNF-alpha production by monocytes. These results suggest that monocytes are stimulated during haemodialysis with the poorly biocompatible cuprophane membrane.

Insulin Resistance in Patients with Stroke is Related to Visceral Fat Obesity and Adipocytokines

Insulin resistance is associated with hyperglycemia and dyslipidemia and promotes atherosclerosis. Although insulin resistance is associated with adipocytokines, little is known about the association in patients with stroke without diabetes mellitus. The aim of the current study was to examine the relationship among insulin resistance, visceral fat area, and adipocytokines in patients with stroke. This study design was cross-sectional in a university hospital. We studied 60 patients with stroke and no history of diabetes mellitus who had hyperglycemia or hypertriglyceridemia or reduced fasting plasma high-density lipoprotein cholesterol. We measured insulin resistance, the plasma level of tumor necrosis factor (TNF)-alpha, adiponectin, and the visceral fat area. Insulin resistance was defined by the homeostasis model assessment and the level of insulin at 120 minutes after consuming oral glucose. We classified two groups (insulin sensitive or insulin resistant). In all, 21 of 60 patients (35.0%) had insulin resistance and 35 (58.3%) had hyperinsulinemia. Compared with insulin-sensitive patients with stroke (n = 18), insulin-resistant patients with stroke (n = 21) had significantly wider visceral fat areas and a high level of plasma TNF-alpha. The plasma level of adiponectin in insulin-resistant patients with stroke was similar to that in insulin-sensitive patients. Insulin-resistant patients with stroke in this study had a large amount of visceral fat and increased levels of TNF-alpha. We recommend that obese patients with stroke should be examined for insulin resistance to reduce the risk of the development of atherosclerosis.

Interferon-α effects on diurnal hypothalamic–pituitary–adrenal axis activity: relationship with proinflammatory cytokines and behavior

Interferon (IFN)-alpha has been used to investigate pathways by which innate immune cytokines influence the brain and behavior. Accordingly, the impact of IFN-alpha on diurnal secretion of hypothalamic-pituitary-adrenal (HPA) axis hormones was assessed in 33 patients eligible for treatment with IFN-alpha plus ribavirin for hepatitis C. In addition, the relationship between IFN-alpha-induced HPA axis changes and proinflammatory cytokines and behavior was examined. Plasma ACTH and cortisol as well as tumor necrosis factor (TNF)-alpha, interleukin-6 and their soluble receptors, were measured hourly between 0900 and 2100 hours at baseline and following approximately 12 weeks of either no treatment (n=13) or treatment with IFN-alpha/ribavirin (n=20). Plasma IFN-alpha was also measured at each visit. Depression and fatigue were assessed using the Montgomery-Asberg depression rating scale and the multidimensional fatigue inventory. Compared to no treatment, IFN-alpha/ribavirin administration was associated with significant flattening of the diurnal ACTH and cortisol slope and increased evening plasma ACTH and cortisol concentrations. Flattening of the cortisol slope and increases in evening cortisol were correlated with increases in depression (r=0.38, P<0.05 and r=0.36, P<0.05, respectively) and fatigue (r=0.43, P<0.05 and r=0.49, P<0.01, respectively). No relationship was found between immune and HPA axis measures, although increases in plasma IFN-alpha, TNF-alpha and soluble TNF-alpha receptor2 were independently correlated with behavioral endpoints. These data indicate that chronic exposure to innate immune cytokines may contribute to the altered diurnal HPA axis activity and behavior found in medically ill individuals. However, given the lack of correlation between HPA axis and immune measures, the mechanism by which chronic cytokine exposure influences HPA axis function remains to be determined.

Evaluation of dimethyl sulphoxide effects on initial response to endotoxin in the horse

Endotoxaemia is one of the most severe and ubiquitous disease processes in horses. Although dimethyl sulphoxide (DMSO) is used clinically in horses, there is no study indicating its efficacy in endotoxaemic horses. DMSO ameliorates the clinical response to i.v. lipopolysaccharide (LPS) administration. Eighteen horses were assigned randomly to one of 4 groups: Normosol-LPS (0.2 mug/kg bwt, i.v.); DMSO (1 g/kg bwt, i.v.)-saline; high-dose DMSO (1 g/kg bwt, i.v.)LPS; low-dose DMSO (20 mg/kg bwt, i.v.)-LPS. Horses participating in the DMSO-saline group were later assigned randomly to one of the LPS groups. Data for physical parameters, white blood cell counts, plasma TNF-alpha, and blood lactate and glucose concentrations were examined for the effect of treatment using a repeated-measures mixed-model ANOVA. A value of P<0.05 was considered significant. Endotoxaemia occurred in all horses receiving LPS, as indicated by the clinical score, physical parameters, haemoconcentration and leucopenia. High-dose DMSO ameliorated the effect of LPS on fever. DMSO, at either dose, but did not have a significant effect on LPS-induced changes in all other evaluated parameters. In this study, DMSO had minimal effects on clinical signs of induced endotoxaemia in horses. The effects were manifested by amelioration of LPS-induced fever.

Overexpression of Lymphotoxin in T Cells Induces Fulminant Thymic Involution

Activated lymphocytes and lymphoid-tissue inducer cells express lymphotoxins (LTs), which are essential for the organogenesis and maintenance of lymphoreticular microenvironments. Here we describe that T-cell-restricted overexpression of LT induces fulminant thymic involution. This phenotype was prevented by ablation of the LT receptors tumor necrosis factor receptor (TNFR) 1 or LT beta receptor (LTbetaR), representing two non-redundant pathways. Multiple lines of transgenic Ltalphabeta and Ltalpha mice show such a phenotype, which was not observed on overexpression of LTbeta alone. Reciprocal bone marrow transfers between LT-overexpressing and receptor-ablated mice show that involution was not due to a T cell-autonomous defect but was triggered by TNFR1 and LTbetaR signaling to radioresistant stromal cells. Thymic involution was partially prevented by the removal of one allele of LTbetaR but not of TNFR1, establishing a hierarchy in these signaling events. Infection with the lymphocytic choriomeningitis virus triggered a similar thymic pathology in wt, but not in Tnfr1(-/-) mice. These mice displayed elevated TNFalpha in both thymus and plasma, as well as increased LTs on both CD8(+) and CD4(-)CD8(-) thymocytes. These findings suggest that enhanced T cell-derived LT expression helps to control the physiological size of the thymic stroma and accelerates its involution via TNFR1/LTbetaR signaling in pathological conditions and possibly also in normal aging.