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Biomedical subjects

B Büki

Publications and source records attributed to B Büki.

At least 37 records · Page 2Linked to original sources
PubMed1989

[False positive results of HIV virus tests in patients undergoing chronic hemodialysis].

The sera of 173 haemodialysis patients treated in two dialysis centers in Hungary were tested for the presence of HIV (HTLV III/LAV) antibodies. Four different commercial enzyme immunoassay (EIA) kits and two types (CEM/LAV, and H9/HTLV III) of indirect immunofluorescence assay (IFA) were used. The Western blot technique was applied as confirmatory test in the study. No confirmed positive results were found in any of the cases. However, in 15 patients (8.7%) false positive (not confirmable by the Western blot assay) results were obtained in at least one but mostly in all of the three type 1 EIA kits (ORGANON, ELECTRONUCLEONICS, SORIN) applied. In 4 patients, the IFA assay also gave false positive results which could be repeated in sequential samples taken from the same patients. Increased reactivity in the control plate (coated with a concentrate of cellular material shed by uninfected H9 cell line) of the SORIN kit was found only in a few false positive samples and no fluorescence with the uninfected H9 or CEM cells was observed in any of the sera showing a false positive IFA. These results indicate that the false positive anti-HIV results frequently observable in haemodialysis patients are not simply the consequence of the presence of antibodies reacting with the uninfected H9 and/or CEM cells but they are most probably due to antibodies against antigens expressed on these cells only after infection with the human immunodeficiency virus.

False Positive Reactions↗
PubMed1989

Different types of false positive anti-HIV reactions in patients on haemodialysis.

Serum samples of 589 haemodialysis patients were screened for HIV antibody by ELISA methods. Of these, 36 samples were found to be repeatedly reactive. None of the 36, however, could be confirmed by competitive enzyme immunoassays and Western blot; therefore, they were considered to be false positive. The sera could be divided in two groups. The sera of Group 1 were designated as the usual type of false positivity, caused most probably by anti-lymphocyte antibodies. In 19 sera, however, a special type of false positivity was found. These sera reacted strongly with the plates coated with the supernatants of HIV-infected cells but not with those of uninfected H9 cells. Three and two sera showed, respectively, positive immunofluorescence reaction with the HIV-infected, but not with the uninfected, H9 and CEM cells. Reactivity to HIV-infected H9 cells could be adsorbed from a part of these samples with lesser amounts of HIV-infected than uninfected H9 cells. This special type of false positivity was observed frequently (7/65) in patients who rejected a kidney graft. These findings suggest that this type of anti-HIV false positivity is due to antibodies reacting with cellular antigens present in HIV-infected but not in uninfected lymphocytes. Their appearance seems to be associated with the immunological activation occurring at graft rejection.

Blotting, Western↗
PubMed1988

Alterations of vasoconstrictor and sodium-regulating hormone systems in vascularly decompensated liver cirrhosis.

Plasma levels of atrial natriuretic peptide (ANP), aldosterone (PA), vasopressin (AVP), and the plasma renin activity (PRA) were examined in 15 vascularly decompensated patients suffering from liver cirrhosis, before and after administration of albumin and after a subsequent administration of furosemide. The initial ANP level was lower in 9 patients (group "A") and higher in 6 patients (group "B") than in healthy controls (Group "A": 19.5 +/- 3.0 fmol/ml; group "B": 36.7 +/- 3.9 fmol/ml; control: 25.8 +/- 2.4 fmol/ml). The initial PRA (4.4 +/- 1.0 ng AngI/ml/h) and AVP (8.5 +/- 1.5 pg/ml) activity in group "A" increased significantly compared to group "B" (PRA: 0.44 +/- 0.09; AVP: 4.1 +/- 0.5), indicating an intravascular volume depletion in group "A". Albumin infusion raised the urine and sodium excretion and the plasma concentration of ANP in group "A" but lowered in plasma levels of renin and vasopressin. The same parameters were not changed by albumin in group "B". Furosemide equally raised the urine flow rate and sodium excretion in both groups. Plasma ANP level depends on the intravascular volume, and the secondary change in its plasma concentration plays a considerable role in the retention of fluid and electrolytes in patients with cirrhosis. The increased intravascular volume in these patients depletes the fluid and electrolyte retention via the increase in ANP level.

Adult↗
PubMed1987

A simple method for detecting HIV antibodies hidden in circulating immune complexes.

A method previously used for studying the specificity of antibody components of circulating immune complexes in different diseases has been applied to analyse circulating immune complexes in HIV-infected patients. Antibodies against HIV antigens hidden in circulating immune complexes were studied in 14 sera from 13 patients with asymptomatic HIV infection (group 1) and in 11 sera from seven patients with HIV symptoms (group 2). HIV antigen-coated wells from the Vironostika kit as well as core and envelope antigen-coated beads from the Abbott confirmatory kit were used as solid-phase antigen. Using the Vironostika plates, HIV antibodies were demonstrated in circulating immune complexes in three and five sera in groups 1 and 2, respectively. Anti-core antibodies hidden in circulating immune complexes were present in three out of eight and two out of nine sera, respectively, in groups 1 and 2, whereas anti-envelope antibodies were present in circulating immune complexes in one out of eight and six out of nine sera in the same groups. These findings demonstrate that not only core-anti-core but also envelope-anti-envelope immune complexes are present in the sera of HIV infected patients.

Acquired Immunodeficiency Syndrome↗
PubMed1985

Polyphosphoinositide metabolism in adrenal glomerulosa cells.

We examined the effect of angiotensin II, a calcium-mobilizing hormone on polyphosphoinositide metabolism in isolated rat adrenal glomerulosa cells. In cells preloaded with [32P]phosphate or with [3H]inositol, stimulation with angiotensin resulted in an approx. 40% reduction in the radioactivity of triphosphoinositide (PtdIns4,5P2) within 15 s. Only a slight increase in radioactivity was observed in the subsequent 30 min. Changes in labelling of diphosphoinositide (PtdIns4P) showed similar kinetics. Incorporation studies also showed a reduction in the pool size of [32P]PtdIns4P and [32P]PtdIns4,5P2 in response to angiotensin. Production of inositol phosphates in the absence or presence of lithium, a cation-inhibiting myo-inositol-1-phosphatase, was examined in cells preloaded with [3H]inositol. The results indicate that the production rate of inositol tris- and bisphosphate shows a manifold increase in the first seconds of stimulation and remains enhanced for at least several minutes. The present data suggest that the rate of resynthesis of polyphosphoinositides also increases shortly after the activation of PtdIns4,5P2 phosphodiesterase. Corticotropin, a hormone acting via cyclic AMP, neither affected polyphosphoinositide metabolism nor modified the action of angiotensin II.

Adrenal Glands↗