No abstract

A total of 109 alpha-hemolytic and 104 nonhemolytic Escherichia coli isolates from children with dyspepsia and urinary tract infections were investigated for resistance to the bactericidal activity of human serum. A significantly higher proportion of serum resistance was found in alpha-hemolytic E. coli isolates than in nonhemolytic isolates (P < 0.01). An association between the titer of alpha-hemolysin produced and serum resistance was found. Escherichia coli strains causing intestinal and extraintestinal infections exhibit a number of virulence determinants that have been well established by many investigators, e.g., adhesins, O and K antigens, production of alpha-hemolysin, verotoxin, cytotoxic-necrotizing factor, enterotoxins, colicins and, iron sequestration (1, 3-5, 11, 12, 22). Resistance of E. coli to human serum is regarded as another virulence factor (28). Serum resistance can be mediated by O-antigen polysaccharide side chains (26), capsular polysaccharides (16, 24) and outer membrane lipoproteins (19). Similar to the findings of other investigators (9, 14), a correlation between alpha-hemolysin production and serum resistance in E. coli strains was suggested by the results of our previous study (25). To obtain more information, in this study serum resistance in E. coli isolates from stool and urine samples from children with dyspepsia and urinary tract infections, respectively, was investigated. A total of 109 alpha-hemolytic and 104 nonhemolytic E. coli strains were isolated predominantly from hospitalized infants younger than 2 years of age with either dyspepsia (n ϭ 106) or urinary tract infections (n ϭ 107). Isolation of the bacterium and its subsequent identification were performed by standard bacteriological methods. O serotyping was done by using 8 polyvalent and 56 monovalent antiserum samples that were available (Imuna, Šarišské Michaľan, Slovakia). Alpha-hemolysin production was quantified according the method of Tabouret et al. (27). An overnight culture of bacteria (125 l), grown in Todd-Hewitt broth (Difco) containing 10 mM CaCl 2 , was inoculated into 5 ml of the same medium and incubated in a water bath at 37ЊC with agitation for 4 h. Supernatants were collected after centrifugation (10,000 ϫ g for 10 min at 4ЊC), adjusted to pH 7.0 to 7.4 with 1 N NaOH, and assayed for hemolytic activity in polystyrene microtitration plates. Twofold dilutions (in 100-l volumes) of the culture supernatant in Tris-buffered saline (pH 7.4) containing 0.01 M CaCl 2 were made; 50 l of washed sheep erythrocytes (1% suspension) was added to each dilution, and the mixtures were incubated at 37ЊC for 2 h with occasional shaking. After incubation, 0.1 ml of saline was added, and unlysed erythrocytes

Nine children aged 2 months to 13 (mean 6.6) years with renal hypertension were treated with captopril. The treatment lasted for 1.5 to 14 months. Maintenance doses ranged between 1 and 5 mg/kg/day. Good effect was achieved with captopril in children with normal renal function and in mild renal insufficiency. In patients with end-stage renal disease when dialysis failed to maintain normal body water captopril was ineffective.

Changes of milieu interieur in nephrotic syndrome (NS) have many consequences in various organs. We have measured the electrical charge of erythrocytes (Ery) with binding of alcian blue (AB) in 18 children with relapse of NS (12 minimal changes, 3 membranous and 3 mesangioproliferative glomerulonephritis) and 15 healthy children. The most important finding was that the binding of AB to Ery in patients with minimal change nephrotic syndrome (MCNS) and other aetiologies of NS was significantly less than that in the control group (p < 0.05). In addition, we have studied the thermal denaturation of the Ery membranes by differential scanning microcalorimetry. In some children with NS we have seen the splitting of B transition. We suppose that these phenomena occur as the result of structural change, which may involve lipoprotein components of the cytoskeletal network.

There were 942 cases of glomerulonephritis classified according to WHO out of 1499 renal biopsies. Immunoglobulins IgG, IgA, IgM, C3 and fibrinogen were examined immunohistochemically in a standard way and IgD, IgE, albumin, C4 and HBsAg in a non-standard way. The results were compared with a control group. The results show that the excluding value of the negative immunohistochemical examination in glomerulonephritis is higher than the proving value of the positive examination.