Serum and urine cytokines were analyzed in children with hemolytic uremic syndrome (HUS) and thrombotic thrombocytopenic purpura (TTP). Interleukin-6 (IL-6) was elevated in the serum of 33 of 35 children with HUS (94%) and in 2 of 2 children with recurrent TTP. Serum IL-6 was higher in children with HUS who developed anuria, extrarenal manifestations during the acute phase of illness and/or chronic renal sequelae. Tumor necrosis factor-alpha (TNF-alpha) was detected in the serum of 7 patients with HUS (20%) and 1 patient with TTP. IL-6 and TNF-alpha were elevated in the urine of 4 of 4 children with HUS and 2 of 2 children with TTP. Urinary levels were higher than serum levels, suggesting local production of cytokines in the urinary tract. Sequential serum and urine samples showed that IL-6 levels varied with disease activity. IL-6 and TNF-alpha were not detected in the serum (n = 25) and urine (n = 15) of healthy children. We conclude that IL-6 in urine may be used to monitor disease activity in HUS and TTP.

An interleukin-6 (IL-6) response was detected in 81 patients with febrile urinary tract infections (UTIs). Bacteremic patients (n=24) had higher serum IL-6 at inclusion and throughout the first 24 h (P<. 01) and higher urine IL-6 from 6 h after start of therapy (P<.01) than did nonbacteremic patients (n=57). The serum and urine IL-6 responses remained elevated longer in the bacteremic group. Patients with clinical signs of pyelonephritis had higher serum and urine IL-6 concentrations than did other patients in the study population (P=.058, P<.01, respectively). IL-6 high responders had higher temperatures (P<.05) and C-reactive protein levels (P<.05, P<.01) than did low responders. The results demonstrate that IL-6 responses accompany febrile UTIs regardless of bacteremia and that the response reflects disease severity. The results suggest that IL-6 produced in the urinary tract can trigger the systemic host response in the absence of bacteremia.

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A study of the potentiometric titration and metal ion binding properties of peat is reported. Peat is found to behave as a typical polyelectrolyte system which, especially at high pH's, can be very highly charged. One difference between peat and commonly investigated polyelectrolyte systems (like poly(acrylate)) is that a very broad spectrum of pKa values is required for the description of the titration characteristics of peat. The prime reason for this is assigned to the presence of humic acids, formed during decomposition of plant parts. The humic acids constitute a rather badly defined group of polyelectrolytes built up inter alia of carboxylic, phenolic and sugar groups. The presence of different length segments of conjugated double bonds provides conditions for light absorption at a broad range of wave-lengths, hence the black or brown colour of these compounds, as well as the stabilisation of resonance structures including carboxylate and phenolate groups. Because of large differences in double-bond segment lengths, a broad range of pKa values results.For the analysis of potentiometric titrations, a theoretical model is developed which has the following characteristics:1. The titratable groups are assumed to be evenly distributed on the peat surfaces. 2. The surfaces are assumed to be planar and no consideration of curvature effects is made.3. Only monovalent and divalent counterions and monovalent colons are assumed to be present in the aqueous medium.4. Counterions can bind to peat electrostatically in the counterion layer as well as specifically to different groups on the peat surface.5. The electrostatic potential on the surface is calculated using the Poisson-Boltzmann equation.By means of this theoretical model, a very good description of the titration characteristics of peat is obtained if peat is assumed to contain titratable surfaces with a continuous spectrum of pKa values in the interval 1-11.

Background and Objectives We investigated whether surface marker expression analysis of blood eosinophils may reflect disease activity in systemic sclerosis (SSc), since a role for eosinophils in the pathogenesis of SSc may be suggested from the observation of increased counts in bronchoalveolar lavage. Materials and Methods By flow cytometer analysis, eosinophils in whole blood were identified in 32 consecutive untreated patients using surface marker CD16 and CD9. Surface expression of markers CD11b, CD44, CD48, CD54, CD81 and HLA-DR was measured. Data were related to clinical measurements of the disease activity. Results An increased blood eosinophil population with low surface expression of CD9 was identified in patients with early SSc, i.e. a disease duration of <2 years, compared to patients with longer disease duration (P = 0.003) and controls (P = 0.029). CD81 expression was lower in SSc patients compared to healthy individuals (P = 0.003). In patients with early SSc, CD81 levels correlated inversely to degree of skin involvement (r = –0.67; P = 0.009). CD48 levels were increased in early SSc and were associated with an increased concentration of alveolar nitric oxide in these patients (r = 0.84; P < 0.001). CD16 expression on blood eosinophils was also higher in patients with early disease and was associated with loss of nailfold capillaries (r = –0.78; P < 0.001). Conclusions Blood eosinophils in patients with SSc display a diverse phenotype depending on disease duration. In early disease, surface marker expression on eosinophils is associated with disease activity and severity.