PubMed Health⌕ Search

Biomedical subjects

V Burek

Publications and source records attributed to V Burek.

At least 19 recordsLinked to original sources
PubMed1998

The role of complement and gp120-specific antibodies in virus lysis and CD4+ T cell depletion in HIV-1-infected patients.

The substantial virus lysis was induced by HIV-1-infected patient serum and normal human complement serum in the presence of purified patient IgG. Non-infected CD4+ T cells coated with the whole virus or with a recombinant HIV-1 envelope gp120 and sensitised with patient IgG were also shown to be susceptible to complement-dependent lysis. The serum level of complement regulatory protein in a fluid phase, the C1-esterase inhibitor, was significantly correlated with serum concentration of C1q-circulating immune complexes (P=0.0062), but inversely with CD4+ T cell count (P < 0.0001). Accordingly, the disease progression in HIV-1-infected patients was significantly correlated with the level of complement activation as determined by serum level of C1-esterase inhibitor (P=0.0001), and inversely correlated with CD4+ cell count (P < 0. 0001) and gp120-specific antibody titre (P=0.0086). These results strongly suggest that the complement activation by gp120-specific antibodies play a very important role in virus clearance, but also in depletion of infected as well as gp120-coated non-infected CD4+ bystander T cells during the course of HIV-1 infection.

Animals↗
PubMed1996

Inhibition of classical complement activation by sera from HIV-1-positive patients.

It was shown that gp120/160-coupled CD4+ T cells could be lysed by complement activation, but the target cell lysis was strongly inhibited by the majority of HIV-1-positive sera. Significantly more sera from HIV-1-infected patients with CD4+ T cell count higher than 500 microl (N = 38) as well as from patients with 200-500/microl (N = 32) showed strong inhibition of complement activation as compared to sera from those with less than 200 CD4+ T cells/microl (N = 28) (P = 0.0064 and 0.0012, respectively). Consequently, highly significant correlation between CDL inhibitory activity and CD4+ T cell count in HIV-1-infected patients was found by Spearman's rank order analysis (R = 0.399, P < 0.001). CH50 titer and functional C1-inhibitor level were significantly lower in inhibitory as compared to the noninhibitory sera (P < 0.001) and to controls (P < 0.001). The C3 activation products-C3-circulating immune complexes were not increased in inhibitory sera (P = 0.014) suggesting that inhibition of complement activation occurred at or before C3 activation level. C4d fragments and antigenic C1-INH concentration were significantly increased in both categories of HIV-1-positive sera, P < 0.001. These findings indicate that persistent and massive stimulation of complement system with HIV-1 envelope glycoproteins during all stages of the disease induced impairment of classical pathway activation by an inhibitory factor in a majority of patients, which might contribute to the onset of opportunistic infections and AIDS.

Complement Activation↗
PubMed1992

Antibodies to Borrelia burgdorferi in various population groups in Croatia.

The purpose of the present study was to investigate the prevalence of antibody to Borrelia burgdorferi in Croatia in various population groups. The study comprised 263 individuals: 93 healthy subjects (travellers); 100 controls separated into 2 subgroups, 50 from high risk zone (endemic) and 50 from low risk zone (non-endemic); and 70 members of a high risk population (forestry workers). Antibody to B. burgdorferi of IgM and IgG class were analysed by an ELISA technique using mixed antigen made of strain B31 (ATCC 35210). IgG antibodies were detected in 9/93 (9.7%) in general population; 22/50 (44.0%) in the control group from high risk zone and 4/50 (8.0%) from low risk zone; and 30/70 (42.9%) among forestry workers. In all tested groups low numbers of IgM positive were found.

Adult↗
PubMed1988

Local xenogeneic graft-versus-host reaction: a measure of T-cell function in asymptomatic HBsAg carriers.

The local xenogeneic graft-versus-host reaction was used as a bioassay to assess T lymphocyte function in 31 asymptomatic HBsAg carriers and 40 healthy controls. Positive local gvh reaction was found in all normal subjects and in only 12 of the carriers tested. Analysis of persistence of HBsAg positivity demonstrated that patients with protracted carrier state (1-5.5 years) mostly exhibited negative local gvh reaction. Controversely, patients with a short duration of carrier state (6-12 months) showed positive local gvh reaction, similar to the range of the healthy subjects. Also, no correlation was observed between the magnitude of local gvh reaction and T-rosette percentage.

Adolescent↗
PubMed1985

Prevalence of antibodies to hepatitis A virus among urban children aged 0-7 years in Yugoslavia.

In a study of the prevalence of hepatitis A virus antibody in urban Yugoslav children aged 0-7 years, 18.2% were positive; most of them were only a few months old. The maternal origin of antibody in these very young children could be inferred from the rapid decrease of antibody during the first 5-7 months of life, following which period until the age of 7 years, there was no significant increase in the proportion with antibody. It was concluded that the age range included in this study (0-7 years) does not represent a time of life when most urban Yugoslav children come into contact with hepatitis A virus.

Child↗
PubMedDate not supplied

Azithromycin: single 1.5 g dose in the treatment of patients with atypical pneumonia syndrome--a randomized study.

An open comparative study was undertaken in order to assess the efficacy and safety of a single dose of azithromycin in the treatment of community-acquired atypical pneumonia. A total of 100 adult patients with atypical pneumonia syndrome were randomized to receive 1.5 g of azithromycin as a single dose, or 500 mg once daily for 3 days. The presence of Mycoplasma pneumoniae, Chlamydia pneumoniae, Chlamydia psittaci, Coxiella burnetii, and Legionella pneumophila infection was diagnosed by serological tests. Control clinical examinations were performed 72 h, 10-12 days and 4 weeks after treatment initiation. Among 96 patients (48 in each group) who were evaluable for clinical efficacy M. pneumoniae infection was confirmed in 24, C. pneumoniae in nine, C. psittaci in five, C. burnetii in six, and L. pneumophila in five. Forty-seven patients (97.9%) in each group were cured. Side effects were observed in two patients in the single-dose group, and one patient in the 3-day group. In conclusion, a single 1.5 g dose of azithromycin may be an alternative to the standard 3-day azithromycin regimen in the treatment of outpatients with atypical pneumonia syndrome.

Adult↗
PubMedDate not supplied

[Presence of Chlamydia pneumoniae antibodies in patients with ischemic heart disease and acute myocardial infarct].

Numerous seroepidemiological studies that suggest an association of C. pneumoniae infection and atherosclerosis have been published in last decade. The aim of this study was to assess a prevalence of C. pneumoniae antibodies in population of Zagreb area, and to investigate possible differences in prevalence of antibodies in patients with atherosclerosis and healthy controls. Forty-seven patients with coronary artery disease or myocardial infarction and 54 controls without any previous history of atherosclerosis were enrolled in the study. Sera were examined by microimmunofluorescence test. Persons with IgA antibody titers > or = 1:32, and/or IgG antibody titers > or = 1:64 were considered as seropositive. We found 75% seropositive in a total number of subjects, although number of seropositive and higher titers of antibodies were found more often in patients with atherosclerosis compared to control group: 74.5% of IgA seropositive patients versus 33.3% seropositive in control group, and 89.4% of IgG seropositive patients compared to 63% seropositive controls. Chronic (persistent) infections with C. pneumoniae were noted in 74.5% of patients and 33.3% controls.

Adult↗