Platelet-activating factor acetylhydrolase and haemophagocytosis in the sepsis syndrome

Sepsis syndrome (SS) is associated with depressed PAF acetylhydrolase, the enzyme responsible for the degradation of platelet activating factor. PAF acetylhydrolase is in a large part produced by macrophages, whose inadequate activation with haemophagocytosis is frequent in patients with SS. The aim of this study was to test the hypothesis that PAF acetylhydrolase levels could be affected in these critically ill patients, because of the large amounts produced by activated macrophages in vitro and in vivo in animal models. The levels of serum PAF acetylhydrolase were assessed in 90 SS patients, who were divided into three groups: patients with (n = 34) or without haemophagocytosis (n = 31), and patients without thrombocytopenia (n = 25) who were used as a control group. The number of organ dysfunctions was matched between patients with haemophagocytosis and controls. Normal reference values were obtained in 59 randomly selected blood donors. Circulating levels of PAF acetylhydrolase were significantly (p = 0.0001) decreased in patients with SS (57+/-3 nmol/ml/min, n = 90) when compared with healthy subjects (69+/-3 nmol/ml/min, n = 59). PAF acetylhydrolase levels were greater in the presence of a haemophagocytosis but without statistical significance (64.2+/-6.5 vs. 50.1+/-2.8:p = 0.25). Despite the fact that macrophagic activation stimulates the in vitro release of PAF acetylhydrolase, no difference was found between patients with or without haemophagocytosis. The mechanism and the role of the PAF acetylhydrolase reduction in SS patients remain to be determined.     

Increased activity of the platelet-activating factor acetylhydrolase in plasma low density lipoprotein from patients with essential hypertension

We have measured activity of platelet-activating factor (PAF) acetylhydrolase, an enzyme that specifically inactivates PAF, in plasma from patients with essential hypertension and healthy controls. The average activities in 34 patients and 22 controls were 113 +/- 60 and 79 +/- 32 nmol/ml/min, respectively, and the difference was significant (p less than 0.05). Approximately three fourths of the total plasma activity was recovered in LDL, with the remainder in HDL; and there was a significant difference in the activity associated with the LDL between patients and controls. The relative distribution of the activity among lipoproteins was almost equal in the two groups, and there was no difference in plasma lipids or apoproteins between them. In patients there was a tendency for plasma PAF acetylhydrolase activity to increase with the length of the history of hypertension. Further studies are needed to distinguish between a number of reasons for increased levels of plasma PAF acetylhydrolase in essential hypertension.     

Serum PAF acetylhydrolase increases during neonatal maturation

Acetylhydrolase is an acid-labile, 43 kd protein that catalyzes the degradation of platelet activating factor (PAF), a potent phospholipid inflammatory mediator, to its biologically inactive metabolite lysoPAF. PAF has a short half-life, thus acetylhydrolase plays an important role in its regulation. Since previous work suggests that PAF may be involved in certain neonatal diseases such as necrotizing enterocolitis, we studied the effect of age on acetylhydrolase activity. Serum acetylhydrolase activity was quantified using radio-labelled PAF and measuring reaction products. Serum samples were obtained prospectively from 70 subjects ranging in age from 4 hr to 48 yr. Acetylhydrolase activity was lower for newborns (less than 3 wk) than all other age ranges (8.2 +/- 1.4 nmole/ml/min vs 30.0 +/- 1.6 nmole/ml/min, p less than .01). Furthermore, enzyme activity increased linearly with respect to the natural logarithm of age from 0 days to 6 weeks (r = 0.65, p less than .001). By 6 weeks of life acetylhydrolase activity approached values of older children and adults. Newborn acetylhydrolase activity was similar between term and preterm infants (8.6 +/- 1.9 nmole/ml/min vs 7.2 +/- 2.4 nmole/ml/min, p = NS). We conclude that acetylhydrolase activity is low in human neonates and increases during the first 6 weeks of life. These results suggest that newborn infants may be at increased risk for pathophysiologic processes mediated by PAF.     

Serum levels of TNF-alpha,sIL-2R,IL-6, and IL-8 are increased and associated with elevated lipid peroxidation in patients with Behçet's disease

AIM: Behçet''s disease (BD) is asystemic immunoinflammatory disorder and the aetiopathogenesis is to be specified. Cytokines play a role in immune response and in many inflammatory diseases. The aim of this case-control study is to investigate serum pro-inflammatory cytokine tumour necrosis factor (TNF)-alpha, interleukin-1beta (IL-1beta), soluble IL-2 receptor (sIL-2R), IL-6, and chemokine IL-8 levels in patients with BD. We also determined the end product of lipid peroxidation (malondialdehyde (MDA)) in BD patients as an index for oxidative stress. METHODS: A total of 37 patients (19 men, 18 women) with BD (active, n = 17; inactive, n = 20) and 20 age-matched and sex-matched healthy control subjects (11 men, nine women) included in this cross-sectional, blinded study. Serum TNF-alpha, IL-1beta, sIL-2R, IL-6 and IL-8 levels were determined by a spectrophotometer technique using the immulite chemiluminescent immunometric assay. Lipid peroxidation was evaluated by Wasowicz et aL The levels of cytokines and lipid peroxidation in the active period were compared with the inactive period of the disease. Results are expressed as mean +/- standard error. RESULTS: IL-1beta levels were below the detection limits of the assay (< 5 pg/ml) in all samples. Mean levels of MDA (8.1+/-0.7 micromol/l), sIL-2R (800+/-38 U/ml), IL-6 (12.6+/-1.1 pg/ml), IL-8 (7.2+/-0.4 pg/ml), and TNF-alpha (7.9+/-0.5 pg/ml) in active BD patients were significantly higher than those in inactive patients (4.3+/-0.5 micromol/l, p < 0.01; 447+/-16 U/ml, p < 0.001; 8.3+/-0.6 pg/ml, p = 0.006; 5.3+/-0.1 pg/ml, p < 0.001; and 5.1 0.2 pg/ml, p < 0.001; respectively) or control subjects (2.1+/-0.2 micromol/l, p < 0.001; 446+/-20 U/ml, p < 0.001; 6.4+/-0.2 pg/ml, p < 0.001; 5.4+/-0.1 pg/ml, p < 0.001; and 4.7+/-0.1 pg/ml, p < 0.001, respectively). On the contrary, only the mean IL-6 level was significantly different between inactive BD and control subjects (p = 0.02). All acute phase reactants were significantly higher in active BD than in inactive period (for each, p < 0.01). Conclusions: High levels of sIL-2R, IL-6, IL-8 and TNF-alpha indicate the activation of immune system in BD. Serum sIL-2R, IL-6, IL-8 and TNF-alpha seem to be related to disease activity. Increased lipid peroxidation suggests oxidative stress in BD and therefore tissue damage in such patients. Amelioration of clinical manifestations would be envisaged by targeting these cytokines, chemokines and lipid peroxidation with pharmacological agents.     

Vascular endothelial growth factor and its soluble receptors VEGFR-1 and VEGFR-2 in the serum of patients with systemic lupus erythematosus

We investigated the serum concentration of vascular endothelial growth factor (VEGF) and its two soluble receptors, sVEGFR-1 and sVEGFR-2, in a group of 60 patients with systemic lupus erythematosus (SLE), and 20 healthy controls, using an enzyme-linked immunosorbent assay. We examined a possible association between serum levels of these proteins and certain clinical and laboratory parameters as well as SLE activity. VEGF, sVEGFR-1 and sVEGFR-2 were detectable in all patients with SLE and in all normal individuals. The VEGF level was higher in active SLE (mean, 300.8 pg/ml) than in inactive SLE (mean, 165.9 pg/ml) (p < 0.05) or in the control group (mean, 124.7 pg/ml) (p < 0.04). The highest sVEGFR-1 concentrations were also detected in active SLE patients (mean, 42.2 pg/ml) and the lowest in inactive disease (mean, 32.0 pg/ml) (p < 0.01). In contrast, the levels of sVEGFR-2 were lower in SLE (mean, 12557.6 pg/ml) than in the control group (mean, 15025.3 pg/ml) (p < 0.05). We found a positive correlation between sVEGFR-1 concentration and the SLE activity score p = 0.375 (p < 0.004) and a negative, but statistically insignificant correlation between sVEGFR-2 and SLE activity (p = -0.190, p > 0.05). Treatment with steroids and cytotoxic agents did not influence VEGF or its soluble receptors levels. In conclusion, in SLE patients the levels of VEGF and sVEGFR-1 are higher in patients with active SLE than in inactive disease or healthy persons. In contrast, the level of sVEGFR-2 is lower in active SLE than in inactive disease. The imbalance between VEGF and its soluble receptors may be important in SLE pathogenesis.     

Role of circulating soluble CD40 as an apoptotic marker in liver disease

OBJECTIVES: To measure levels of soluble CD40, a laboratory marker of apoptosis in patients with liver disease, determine its origin, and correlate the findings with disease activity and histology. DESIGN: Laboratory research study with comparison group. SETTING: Liver Institute, Laboratory of HLA Typing and Histopathology Department, Rabin Medical Center, Israel. SUBJECTS: One hundred ten patients with liver disease and 20 healthy controls. METHODS: Serum samples were collected from all patients; in addition, paired hepatic and portal vein samples were collected from 23 patients, and bile samples from 5 patients. Soluble CD40 was measured with an enzyme-linked immunosorbent assay. Apoptotic cells in liver tissue were identified by morphological criteria and quantified with the TUNEL assay. RESULTS: Soluble CD40 concentration was significantly higher in patients with liver disease than controls (mean 112.9 +/- 197.2 pg/ml vs. 24.2 +/- 9.1 pg/ml, p = 0.0001), with highest levels in the chronic viral hepatitis group (mean 131.7 +/- 137.5 pg/ml, p = 0.0001). Levels of sCD40 were correlated with serum creatinine, alkaline phosphatase, alpha-feto protein, and the apoptotic index. In the 23 paired samples, CD40 level was higher in the hepatic vein (mean 74.9 +/- 114.5 pg/ml) than the portal vein (mean 51.6 +/- 67.9 pg/ml); it was highly detectable in bile (mean 115.6 +/- 119.6 pg/ml, p = 0.0123). Untreated patients with chronic viral hepatitis (B and C) had higher levels (mean 106.2 +/- 76.5 pg/ml) than treated patients (mean 59.3 +/- 68.6 pg/ml, p = 0.049). CONCLUSIONS: Levels of soluble CD40 increase in different types of liver disease. It probably derives from the liver and is secreted into the bile. Levels correlate with the apoptotic index and are affected by antiviral treatment. Soluble CD40 may serve as a serum marker of apoptosis in liver disease.     

Proinflammatory interferon-gamma--inducing monokines (interleukin-12, interleukin-18, interleukin-15)--serum profile in patients with systemic lupus erythematosus

Concentrations of three interferon-gamma - inducing monokines, IL-12, IL-18 and IL-15, were investigated in the serum of 60 patients with systemic lupus erythematosus (SLE) and 20 healthy subjects. IL-12 and IL-18 were detectable in the serum of all patients with SLE and in all healthy controls. The level of IL-12 was significantly higher in SLE patients (median 264.9 pg/ml) than in the control group (median 163.6 pg/ml, p < 0.02). Similar differences were observed in the level of IL-18 (median values 602.2 pg/ml and 252.7 pg/ml, respectively, p < 0.001). Correlations between serum levels of IL-12 and IL-18 and SLE activity were not statistically significant (p > 0.05). We found a significant, positive correlation between IL-12 and IL-18 (rh? = 0.419, p < 0.001) in SLE patients. The level of IL-18 was higher in the SLE patients with antinuclear antibodies (ANA) (median 660.0 pg/ml) than in ANA-negative patients (median 326.5 pg/ml, p < 0.03), as well as in patients with immunoglobulin deposits at the dermal-epidermal junction (median 746.0 pg/ml and 444.0 pg/ml respectively, p < 0.04). The level of IL-12 was also higher in patients with skin immunoglobulin deposits (328.9 pg/ml) than those without this phenomenon (257.0 pg/ml, p < 0.05). The levels of both cytokines in the patients treated with immunosuppressive drugs and those patients not treated were similar. The serum levels of IL-15 were low and not significant both in SLE patients (median 2.9 pg/ml), and in healthy controls (median 1.6 pg/ml). In conclusion, serum levels of IL-12 and IL-18 are higher in SLE patients than in healthy controls which may indicate a role in the disease pathogenesis. However, they do not correlate with disease activity and seem to be unresponsive to immunosuppressive treatment.     

Lung production of platelet-activating factor acetylhydrolase in oleic acid-induced acute lung injury

Platelet-activating factor (PAF) is a proinflammatory mediator that plays a central role in acute lung injury (ALI). PAF- acetylhydrolases (PAF-AHs) terminate PAF's signals and regulate inflammation. In this study, we describe the kinetics of plasma and bronchoalveolar lavage (BAL) PAF-AH in the early phase of ALI. Six pigs with oleic acid induced ALI and two healthy controls were studied. Plasma and BAL samples were collected every 2h and immunohistochemical analysis of PAF-AH was performed in lung tissues. PAF-AH activity in BAL was increased at the end of the experiment (BAL PAF-AH Time 0=0.001+/-0.001 nmol/ml/min/g vs Time 6=0.031+/-0.018 nmol/ml/min/g, p=0.04) while plasma activity was not altered. We observed increased PAF-AH staining of macrophages and epithelial cells in the lungs of animals with ALI but not in healthy controls. Our data suggest that increases in PAF-AH levels are, in part, a result of alveolar production. PAF-AH may represent a modulatory strategy to counteract the excessive pro-inflammatory effects of PAF and PAF-like lipids in lung inflammation.     

Tumor necrosis factor alpha production as a possible predictor of relapse in patients with multiple sclerosis.

No biological parameter is currently available as a specific marker of multiple sclerosis (MS) activity. The aim of this study was to determine whether an evolution of the neurological disability is associated with a modified profile of cytokine production. Clinical disease activity was quantitated by the Kurtzke's expanded disability status scale (EDSS). Whole blood was stimulated with phytohemagglutinin (PHA) for 2 hours at 37 degrees C and the activated plasma was assayed for Tumor necrosis factor alpha (TNF-alpha) and Interleukin-1 beta (IL-1 beta). Relapsing-remitting MS patients enduring a relapse (RRMS, in relapse) (721 +/- 58 pg/ml, n = 27) and chronic progressive MS (CPMS) patients (516 +/- 33 pg/ml, n = 17) had an higher TNF-alpha production capacity as compared to healthy subjects (143 +/- 25 pg/ml, n = 17), RRMS, stable patients, (123 +/- 11 pg/ml, n = 26) or other neurological diseases (OND) without immunological or inflammatory disease in the peripheral immune compartment (131 +/- 24 pg/ml, n = 14) (t test: p < 0.0001). IL-1 beta production was also significantly higher but to a lesser extent in the same conditions. Concentration of TNF-alpha was also found to be significantly higher in the cerebrospinal fluid (CSF) of CPMS patients (199 +/- 7.8 pg/ml, n = 7, p < 0.0001) but also in RRMS, in relapse (149 +/- 5.7 pg/ml, n = 11, p < 0.05) as compared to RRMS, stable (130 +/- 4.4 pg/ml, n = 7) or OND without inflammatory or immunological disease of the central nervous system (CNS) (142 +/- 6.2 pg/ml, n = 8).(ABSTRACT TRUNCATED AT 250 WORDS)     

Tumour necrosis factor alpha, lipid peroxidation and NO* are increased and associated with decreased free-radical scavenging enzymes in patients with Weill-Marchesani syndrome

AIM: Weill-Marchesani syndrome (WMS) is a rare systemic disorder with both autosomal recessive and dominant inheritances. Accumulation of reactive oxygen species such as O2*-, H2O2 and OH* causes lipid peroxidation (LPO), whereas antioxidant enzymes (superoxide dismutase (SOD), glutathione peroxidase (GSHPx)) mediate defence against oxidative stress. Excess tumour necrosis factor (TNF)-alpha and NO* react with O2*- and cause further antioxidant depletion with an increase in mutation frequency by H2O2. This study investigated the levels of SOD, GSHPx, catalase (CAT), TNF-alpha, NO and LPO in patients with WMS. METHODS: A group of 10 WMS patients (four males, six females; age, 26.5+/-19.0 years) and 10 age-matched and sex-matched controls (five males, five females; age, 27.3+/-18.2 years) were included. Serum TNF-alpha levels were determined by a spectrophotometer technique using immulite chemiluminescent immunometric assay. Malondialdehyde (MDA) was determined in plasma; CAT in red blood cells (RBCs), and SOD and GSHPx in both plasma and RBCs. Total serum NO* levels were evaluated by Griess reaction. RESULTS: Mean levels of TNF-alpha (8.3+/-0.6 pg/ml) in WMS patients were significantly (p<0.001) higher than controls (4.3+/-0.2 pg/ml). Plasma MDA levels in patients and controls were 5.4+/-0.8 and 1.8+/-0.6 micromol/l, respectively, and the difference was significant (p=0.0002). SOD and GSHPx activities were significantly lower in both RBCs and plasma of WMS than in controls (RBC-SOD, 3981.9+/-626.6 versus 5261.6+/-523.0 U/g haemoglobin (Hb), p=0.0005; plasma-SOD, 529.4+/-49.3 versus 713.4+/-55.7 U/g protein, p=0.0002; RBC-GSHPx, 682.7+/-42.0 versus 756.5+/-47.6 U/g Hb, p=0.0011; plasma-GSHPx, 107.3+/-15.0 versus 131.4+/-19.7 U/g protein, p=0.0113). In addition, serum NO (NO*-2 + NO*-3) levels were also significantly (p = 0.0002) increased in WMS patients (54.4+/-5.7 versus 26.9+/-6.7 micromol/l). RBC-CAT levels were similar between groups (125.6+/-21.3 versus 131.0+/-21.5 k/g Hb, p = 0.8798). CONCLUSIONS: The elevated LPO, TNF-alpha and NO* with decreased antioxidant enzyme activities indicated impaired antioxidative defence mechanisms with an oxidative injury and cell toxicity in WMS patients. The use of multiple antioxidants and free radical scavengers might be helpful in this genetic disorder.     

Vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF) and soluble interleukin-2 receptor (sIL-2R) concentrations in peripheral blood as markers of pituitary tumours

Vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), and soluble interleukin-2 receptor (sIL-2R) are important cytokines. They are secreted by normal pituitary glands and those with all types of adenomas and may be involved in pituitary tissue growth. The peripheral blood concentrations of VEGF, bFGF and sIL-2R in nineteen patients (17-70 years) with pituitary tumours and ten healthy subjects (23-34 years) were studied. Hypersecretion of prolactin (five cases), human growth hormone (four cases), and thyroid stimulating hormone (one case) was recorded in some patients, and the remaining subjects were diagnosed as having nonfunctional pituitary tumours. Increased peripheral blood plasma levels of VEGF (310.82 +/- 59.17 pg/ml) compared with controls (40.32 +/- 11.80 pg/ml; p < 0.01), as well as bFGF (87.27 +/- 7.58 pg/ml) versus controls (11.14 +/- 2.43 pg/ml; p < 0.001) were recorded. The levels of sIL-2R did not differ between the pituitary tumour patients (4,490.58 +/- 581.50 pg/ml) and control subjects (3,617.01 +/- 1,397.18 pg/ml; p > 0.05). The concentrations of VEGF and bFGF in the peripheral blood are useful additional markers of the presence of tumours.     

Changes and Relationship of PAF and TNF in Rats with Myocardial Ischaemia and Reperfusion Injury

IN THIS STUDY IT IS REPORTED THAT: (1) the levels of blood platelet-activating factor and serum tumour necrosis factor significantly increased after coronary ligation and reperfusion, compared with sham-ligated controls, in an anaesthetized rat model; (2) compared with vehicle controls, pretreatment with the PAF antagonist BN 50739 (10 mg/kg, i.v.) produced significant decreases in infarct size (from 29.6 +/- 4.0% to 22.4 +/- 2.1%, p < 0.05 after 3 h ligation, and from 28.5 +/- 9.5% to 10.5 +/- 4.5%, p < 0.01 after 4 h reperfusion) and the level of serum TNF (from 10.4 +/- 7.7 U/ml to 3.9 +/- 4.8 U/ml, p < 0.05); and (3) a significan positive correlation was found between the level of blood PAF or serum TNF and infarct size. The present results indicate that PAF and TNF may be important mediators involved in myocardial ischaemia and reperfusion injury, and that PAF antagonists may exert a protective effect on ischaemic or reperfused myocardium by inhibiting the interaction of PAF and TNF.     

Adenosine deaminase enzyme activity is increased and negatively correlates with catalase,superoxide dismutase and glutathione peroxidase in patients with Behçet's disease: original contributions/clinical and laboratory investigations

AIM: Behçet''s disease (BD) is an inflammatory vasculitis with immunologic, endothelial and neutrophil alterations. Adenosine deaminase (AD) is a marker of T-cell activation and is related to the production of reactive oxygen species by neutrophils with the production of NO(*), O(2)(*-), H(2)O(2) and OH(*). We reported increased tumour necrosis factor-alpha, soluble interleukin-2 receptor, interleukin-6, interleukin-8 and NO(*) in active BD. As there is a relation between cytokines, T cells and oxidative stress in inflammatory diseases, this study further evaluated: (1) plasma AD activity and its correlation with acute phase reactants; (2) thiobarbituric acid-reactive substances (TBARS) as an indicator for lipid peroxidation; and (3) antioxidant enzymes superoxide dismutase (SOD), glutathione peroxidase (GSHPx) and catalase in patients with BD. The effect of disease activity and correlations between the measured parameters were explored. METHODS: A total of 35 active (n=17) or inactive (n=18) patients with BD (16 men, 19 women) satisfying International Study Group criteria, and 20 age-matched and sex-matched controls (nine men, 11 women) were included in this cross-sectional case-control study. AD and TBARS were measured in plasma, catalase in red blood cells (RBC), and SOD and GSHPx in both plasma and RBC in both groups. Acute phase reactants (alpha(1)-antitrypsin, alpha(2)-macroglobulin, neutrophils, erythrocyte sedimentation rate) were used to classify patients as active or inactive. RESULTS: Plasma AD (mean+/-standard error of the mean, 36.1+/-0.7 U/l) and TBARS (4.2+/-0.1 nmol/ml) levels were significantly (for each, p<0.001) higher in BD than in controls (24.1+/-0.8 U/l and 1.6+/-0.1 nmol/ml, respectively). RBC catalase activity was significantly (p<0.001) lower in BD than in controls (120.9+/-3.8 versus 160.3+/-4.1 k/g haemoglobin). SOD and GSHPx activities were significantly lower in both plasma and erythrocytes of patients with BD than in controls (plasma SOD, 442.4+/-8.6 versus 636.4+/-9.2 U/ml, p<0.001; RBC SOD, 3719.2+/-66.0 versus 4849.7+/-49.0 U/g haemoglobin, p<0.001; plasma GSHPx, 73.1+/-1.5 versus 90.6+/-2.9 U/ml, p<0.001; RBC GSHPx, 600.7+/-8.0 versus 670.6+/-10.1 U/g haemoglobin, p<0.001). Active BD patients had significantly lower antioxidant enzymes (except RBC catalase) and higher AD and TBARS levels than inactive subjects (for each, p<0.01). When considering all BD patients, a significant positive correlation was present between AD and TBARS (p<0.001) whereas both AD and TBARS were negatively correlated with antioxidant enzymes (for each, p<0.05). CONCLUSIONS: AD and lipid peroxidation are increased and associated with defective antioxidants in BD, suggesting interactions between activated T cells and neutrophil hyperfunction. Measures of pro-oxidative stress and antioxidative defence with AD activity as an indicator of T-cell activation can be considered as significant supportive diagnostic indicators, especially in active disease. In addition, strengthening the antioxidant defence may contribute to treatment modalities.     

Platelet-activating factor acetylhydrolase and transacetylase activities in human aorta and mammary artery

Platelet-activating factor (PAF), the potent phospholipid mediator of inflammation, is involved in atherosclerosis. Platelet-activating factor-acetylhydrolase (PAF-AH), the enzyme that inactivates PAF bioactivity, possesses both acetylhydrolase and transacetylase activities. In the present study, we measured acetylhydrolase and transacetylase activities in human atherogenic aorta and nonatherogenic mammary arteries. Immunohistochemistry analysis showed PAF-AH expression in the intima and the media of the aorta and in the media of mammary arteries. Acetylhydrolase and transacetylase activities were (mean +/- SE, n = 38): acetylhydrolase of aorta, 2.8 +/- 0.5 pmol/min/mg of tissue; transacetylase of aorta, 3.3 +/- 0.7 pmol/min/mg of tissue; acetylhydrolase of mammary artery, 1.4 +/- 0.3 pmol/min/mg of tissue (P < 0.004 as compared with acetylhydrolase of aorta); transacetylase of mammary artery, 0.8 +/- 0.2 pmol/min/mg of tissue (P < 0.03 as compared with acetylhydrolase of mammary artery). Lyso-PAF accumulation and an increase in PAF bioactivity were observed in the aorta of some patients. Reverse-phase HPLC and electrospray ionization mass spectrometry analysis revealed that 1-O-hexadecyl-2 acetyl-sn glycero-3-phosphocholine accounted for 60% of the PAF bioactivity and 1-O-hexadecyl-2-butanoyl-sn-glycerol-3-phosphocholine for 40% of the PAF bioactivity. The nonatherogenic properties of mammary arteries may in part be due to low PAF formation regulated by PAF-AH activity. In atherogenic aortas, an imbalance between PAF-AH and transacetylase activity, as well as lyso-PAF accumulation, may lead to unregulated PAF formation and to progression of atherosclerosis.     

Oxytocin and bovine parturition: a steep rise in endometrial oxytocin receptors precedes onset of labor.

Oxytocin receptors were measured in myometrium and intercaruncular endometrium of cows during pregnancy and parturition. Concentrations of estradiol-17 beta, estrone, and progesterone in peripheral blood were also measured. Receptor concentrations in the endometrium rose almost 200-fold from Day 20 to term (p < 0.0001, ANOVA), from 40 +/- 11 to 7300 +/- 1430 fmol/mg protein. Myometrial receptor concentrations increased 10-fold from 180 +/- 36 fmol/mg on Day 20 to 1850 +/- 360 fmol/mg protein at term (p < 0.0001, ANOVA). During labor, endometrial receptors (6600 +/- 1300 fmol/mg) remained at prelabor values, whereas myometrial receptor concentrations had decreased to 1190 +/- 316 fmol/mg (not significant) and declined further postpartum. Plasma concentrations of progesterone declined from 4-5 ng/ml to about 2 ng/ml between Days 250 and 282 and dropped to < 0.2 ng/ml shortly before delivery. Plasma concentrations of estrone and estradiol-17 beta were below 10-20 pg/ml until Day 230. Estrone concentrations were significantly (p < 0.05) increased by Day 250 and estradiol-17 beta by Day 270, and then both rose rapidly. During labor, plasma estrone was 1135 +/- 245 pg/ml and plasma estradiol-17 beta was 226 +/- 131 pg/ml. The molar ratio of estrone and estradiol-17 beta to progesterone rose from less than 0.01 to 4.4 during labor, and was correlated with oxytocin receptor concentrations in endometrium (r = 0.5160, p < 0.001), but not those in myometrium (r = 0.0122). The regulation of oxytocin receptors by ovarian hormones in the two tissues may therefore differ.(ABSTRACT TRUNCATED AT 250 WORDS)     

Serum platelet-activating factor acetylhydrolase activity: a novel potential inflammatory marker in type 1 diabetes

Plasma activity of the platelet-activating factor acetylhydrolase (PAF-AH) plays an important role in inflammation and atherosclerotic process in chronic diseases. We aimed to evaluate the levels of PAF-AH activity and their association with the metabolic profile and chronic complications in patients with type 1 diabetes. The study included 118 outpatients (54 males) aged 27.1+/-11.3 years with disease duration of 12.3+/-8.5 years with (n=38) or without (n=80) diabetes complications and 96 control subjects (48 males) matched for age, gender, body mass index and smoking habits. The serum levels of PAF-AH activity were higher in patients either with or without chronic complications (16+/-5.3 and 14+/-5.4 nmol/(min mL), respectively) than in controls (13+/-5.1 nmol/(min mL), P=0.02). In the total population, PAF-AH activity was correlated with age, HDL-cholesterol, total cholesterol and LDL-cholesterol. In patients, PAF-AH activity was correlated with age, HbA1c, uric acid, HDL-cholesterol, cholesterol, LDL-cholesterol, cholesterol/HDL-cholesterol ratio and the LDL-cholesterol/HDL-cholesterol ratio. It is concluded that PAF-AH plasma activity could be a novel candidate for low-grade inflammatory marker in patients with type 1 diabetes.     

Endocrine changes during pregnancy, parturition and the early post-partum period in the llama (Lama glama)

Mean (+/- s.d.) pregnancy length for the 14 llamas in this study was 350 +/- 4.5 days. Plasma progesterone concentrations increased by 5 days after mating and remained elevated (greater than 2.0 ng/ml) throughout most of pregnancy. At about 2 weeks before parturition, plasma progesterone concentrations began to decline, dropped markedly during the final 24 h before parturition, and returned to basal concentrations (less than 0.5 ng/ml) by the day of parturition. The combined oestrone + oestradiol-17 beta and oestradiol-17 beta concentrations varied between 6 and 274 pg/ml and 4 and 114 pg/ml, respectively, during the first 9 months of pregnancy. Concentrations increased between 9 months after mating and the end of pregnancy with peak mean concentrations of 827 +/- 58 (s.e.m.) pg oestrone + oestradiol-17 beta/ml (range: 64-1658) and 196 +/- 10 pg oestradiol-17 beta/ml (31-294) during the last week of pregnancy. Concentrations then declined to 87 +/- 14 pg oestrone + oestradiol-17 beta/ml (7-488) and 25 +/- 5 pg oestradiol-17 beta/ml (2.5-142) during the first week post partum. Plasma cortisol concentrations varied between 2.6 and 51.9 ng/ml (14.0 +/- 0.5) from mating until 2 weeks before parturition when the concentrations began to decline. Only a slight increase in plasma cortisol concentrations was observed in association with parturition. Plasma triiodothyronine concentrations varied between 0.5 and 4.5 ng/ml (1.9 +/- 0.1) throughout pregnancy and the periparturient period.(ABSTRACT TRUNCATED AT 250 WORDS)     

Iloprost for the attenuation of ischaemia/reperfusion injury in a distant organ

The objective of this study was to investigate antioxidant and cytoprotective properties of iloprost in a distant organ after ischaemia reperfusion injury. Male Wistar rats were divided into two groups. After application of anesthaesia both hindlimbs were occluded. A 2-h reperfusion procedure was carried out after 60 min of ischemia. Study group (STU) rats (n=10) received 10 microg kg(-1) iloprost in 1 ml of saline from the tail vein 10 min before reperfusion. Control (CON) group rats (n=10) received an equal amount of saline. The rats were sacrificed by injection of a high dose of thiopentone sodium. Blood and tissue samples (right kidneys) were taken for analysis. Differences in malondialdehyde (MDA), myeloperoxidase (MPO), Na+-K+ ATPase and total antioxidant capacity (TAC) between the groups were analysed. MPO, MDA and TAC levels in the sera of CON and STU groups were 1.60+/-0.26 U l(-1), 11.42+/-5.23 nmol ml(-1), 8.30 x 10(-2)+/- 3.93 x 10(-2) nmol ml(-1) h(-1) and 1.07+/-0.11 U l(-1), 7.60+/-1.81 nmol ml(-1) and 0.15+/-3.23 x 10(-2) nmol ml(-1) h(-1) (p=0.0001, p=0.043 and p=0.0001 respectively). MPO, ATPase and MDA levels in kidneys for CON and STU groups were 1.24+/-0.58 U g(-1), 85.70+/-52.05 nmol mg(-1), 17.90+/-7.40 nmol ml(-1) and 0.78+/-0.31 U g(-1), 195.90+/-56.13 nmol mg(-1) and 10.10+/-0.99 nmol ml(-1) (p=0.046, p=0.0001 and p=0.009 respectively). When given prior to reperfusion, the positive effect of iloprost in the attenuation of distant organ reperfusion injury has been demonstrated.     

Endothelin-3 like immunoreactivity in plasma of patients with cirrhosis of the liver.

A highly specific and sensitive radioimmunoassay (RIA) has been established for determination of endothelin-3 like immunoreactivity in human plasma to investigate its possible role in hemodynamic alterations due to liver disease. Crossreactivity with other endothelin isoforms was always below 4 %, the lower detection limit following extraction on Sep-Pak C18 cartridges was 0.5 pg/ml. The concentration of endothelin-3 (mean +/- SEM) was 4.16 +/- 0.56 pg/ml (n = 13) in plasma of patients with cirrhosis of the liver, three fold higher than in age matched controls (1.35 +/- 0.27 pg/ml, n = 12, p less than 0.01). Plasma immunoreactivity was confirmed to be endothelin-3 related by reverse-phase HPLC. These data could suggest a role of plasma endothelin-3 in circulatory changes, as they occur in cirrhosis of the liver.     

Serum levels of angiogenic cytokines in systemic lupus erythematosus and their correlation with disease activity

We investigated the serum concentration of hepatocyte growth factor (HGF), vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF) and transforming growth factor beta1 (TGF-beta1) using an enzyme-linked immunosorbent assay (ELISA) in a group of 60 patients with systemic lupus erythematosus (SLE), and 20 healthy controls. We also examined the possible association between the serum concentrations of these factors and certain clinical, laboratory parameters and SLE activity. HGF, VEGF and TGF-beta1 were detectable in all patients with SLE, and in all normal individuals. bFGF was measurable in 70% of the patients with SLE and in 65% of the healthy controls. The HGF level was higher in active SLE (median 1,019.5pg/ml) than in inactive SLE (median 787.8 pg/ml) (p < 0.005) or in the control group (median 847.0 pg/ml) (p < 0.009). The level of VEGF in active SLE was also higher (203.5 pg/ml) than in inactive disease (116.1 pg/ml) (p < 0.05) or in healthy persons (133.5 pg/ml) (p < 0.04). The levels of bFGF and TGF-beta1 were similar for both the active and inactive SLE, and the control group (p > 0.05). We found a significant, positive correlation between the levels of HGF and bFGF (r = 0.268, p < 0.04), HGF and TGF-beta1 (r = 0.365, p < 0.005) and HGF and VEGF (r = 0.327, p < 0.02) as well as VEGF and TGF-beta1 (r = 0.543, p < 0.001). We found a positive correlation between VEGF serum levels and platelet counts (r = 0.272, p < 0.04), and the TGF-beta1 concentration and platelet count (r = 0.313; p < 0.02). There was also a positive correlation between HGF serum concentration and the SLE activity score (r = 0.435, p < 0.001), as well as between the level of VEGF and SLE activity (r = 0.252, p = 0.05). In conclusion, serum levels of the angiogenic factors HGF and VEGF may be relevant in SLE pathogenesis. Their concentrations seem to be markers of SLE activity.