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V Mayer

Publications and source records attributed to V Mayer.

At least 37 records · Page 2Linked to original sources
PubMed1992

HPLC-monitoring of AZT in HIV-infected patient's plasma: a critical study.

3'-azido-2', 3'-deoxythymidine (AZT) concentrations in spiked human plasma were determined by means of reversed-phase high performance liquid chromatography (RP-HPLC). Samples were first cleaned-up for analysis using solid-phase extraction (SPE) columns filled with Silipore C18. In the concentration range comprising usual peak plasma concentrations during AZT therapy (0.1-20 mumol/l, i.e. 0.026-5.34 micrograms/ml) mean efficiency of the extraction procedure reached as high as 75.3% of original AZT concentrations in standard unextracted aqueous solutions. Replicate analyses in this range gave satisfactory intra-assay precision and reproducibility with coefficient of variation less than 11.3%. Calibration curves both in water and plasma showed good linearity (r > 0.999). The detection limit in plasma was 2 mumol/l, i.e. 5.3 ng per a 20 microliter of sample injected to the HPLC column. Plasma levels of AZT after a single dose administration, determined by HPLC and RIA showed rather poor correlation (r = 0.8900). In RIA about 1.7-4.5 times higher concentration values were obtained in a relatively short time, and, consequently, this method may better fulfil the needs of routine drug monitoring.

Calibration↗
PubMed1991

Enhanced chemiluminescence-based hybridization analysis for PCR-mediated HIV-1 DNA detection offers an alternative to 32P-labelled probes.

The efficiency of enhanced chemiluminescence based on a novel generation substrate for alkaline phosphatase, adamantyl-1,2-dioxetane phosphate, was compared with that of 32P-labelled probe for visualization of human immunodeficiency virus type 1 (HTV-1)-specific DNA-DNA hybrids. The probe used for nonisotopic detection was digoxigenin labelled and targeted by anti-digoxigenin antibody Fab-fragments conjugated to alkaline phosphatase. The dot-blot hybridization analysis performed on a dilution series of HIV-1 proviral DNA demonstrated a lower sensitivity limit of 0.5 pg with the nonisotopic method. However, one order of magnitude less DNA could still be detected by a random-primed 32P-labelled probe. The ability of nonradioactive and radioactive probes to detect 590-bp gag gene-specific target sequences generated by the polymerase chain reaction (PCR)-mediated amplification of HIV-1 DNA was also compared. Analysis of 20 samples from individuals at increased risk for HIV infection by using the two assayed systems produced virtually equivalent signal images on corresponding specimens. Furthermore, complete concordance in the performance was found when HIV-1 proviral DNA was investigated by PCR in additional 50 samples of human blood mononuclear cells.

Adamantane↗
PubMed1991

HTLV-I virus in Europeans: the continuous spread. A meta-analysis.

Published and unpublished data on the HTLV-I seroprevalence in 13 European countries (sample a total of 79.549 persons) was subject to meta-analysis. HTLV-I infection was significantly associated with intravenous drug use, HIV-I seropositivity, geographical area and immigration from endemic areas outside of Europe. Significant percentage of HTLV-I seropositivity was observed in all groups of HIV-I seropositive individuals studies. The overall HTLV-I seroprevalence was 4.16% in intravenous drug abusers, 0.66% in male homosexuals, 0.62% in immigrants from HTLV-I endemic areas and 0.015% in the general population. A major problem in these epidemiological considerations is the uncertain delineation of the serology of HTLV-I versus that of HTLV-II. There have, been no reports from Europe of the specific leukaemic and neurologic indicator diseases associated with the HTLV-I seropositivity. Presently, the HTLV-I/HIV-I co-infected individuals represent an urgent medical problem. The information available shows a need for self-exclusion of all blood donor groups at risk for HTLV-I infection and for active seroepidemiological surveillance in all parts of Europe. However, improvements in diagnostic methods, increased knowledge about the pathogenesis of infection by HTLV-I or HTLV-II virus and the probable detection of new human retroviruses may markedly influence the future requirements for preventive measures.

Europe↗
PubMed1991

Failure of azidothymidine to inhibit human immunodeficiency virus (HIV) replication in a promonocytic cell line (U937).

The inhibitory effect of azidothymidine (AZT) on HIV replication in the promonocytic cell line U937 was investigated. After infection with HIV-1/LAV virus, U937 cells were cultured for prolonged period in the presence of the drug at a final concentrations of 20 mumol/l or 50 mumol/l, respectively. The antiviral activity was determined according to the inhibition of viral reverse transcriptase activity, and of viral antigen production (immunofluorescence assay). We conclude that virus production was not efficiently influenced during long term passage even at high drug concentrations.

Depression, Chemical↗
PubMed1990

Human immunodeficiency virus inhibition by lysed leukocyte ultrafiltrate.

The in vitro effect of partially purified lysed leukocyte ultrafiltrate (LLU) on LAV 1 strain of the human immunodeficiency virus (HIV) was investigated. Decrease of virus production as a function of LLU concentration was observed while the phenotype of cultured lymphocytes has remained unchanged. We observed the same depletion of helper-inducer T-cells in samples treated with LLU as well as in infected controls. LLU did not influence significantly the growth of cultured lymphocytes. Following the effect of LLU on RNA-dependent DNA polymerase, inhibition of the LAV 1 reverse transcriptase by LLU was observed. This inhibition was shown to be LLU dose-dependent, considering its content of proteins and orcinol-reactive material. Kinetic studies revealed that inhibition is reversible and competitive with the substrate (3HTTP) but not with template-primer (poly rA-oligo dT).

Binding, Competitive↗
PubMed1990

Amino acid analysis of selected reversed-phase high performance liquid chromatographic peaks of crude and partially purified lysed human leukocyte ultrafiltrate.

Analytic reversed-phase high performance liquid chromatography (RP-HPLC) was performed to separate from the crude lysed human leukocyte ultrafiltrate (LLU) its partially purified most immunoactive subfraction P2/II in vivo. Under conditions used, the highest degree of segregation of both. LLU and P2/II could be observed in the first, as well as in the last two fifth of the water-methanol gradient. The comparison of the RP-HPLC traces of LLU and P2/II suggests that probably some hydrophilic components of LLU have been removed or--at least--diminished. The preliminary amino acid analysis (AA) of the selected peaks showed that none of them lacks Gly, Ser, and Glu. Of the basic amino acid residues Lys has been found with relatively many peaks while hydrophobic as well as aromatic amino acids have been represented very modestly. Further study is warranted in order to determine better the bearings of presented findings for the in vivo situation.

Amino Acid Sequence↗
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↗
PubMed1989

Antibodies to axonal neurofilaments in Creutzfeldt-Jakob disease and other organic dementias.

Antibodies reacting with neurofilament proteins were detected by indirect immunofluorescence in the sera from 6 out of 10 patients with verified Creutzfeldt-Jakob disease (CJD), in 4 out of 8 cases of Alzheimer's disease (AD), in a variable percentage (29.4-42.8%) of sera from patients (n = 46) with other dementias of organic or infectious origin and in 5 out of 30 asymptomatic relatives of CJD patients. The occurrence of this antibody did not correlate with the duration or with any other clinical manifestation of CJD. The applicability of the test as differential-diagnostic marker appears limited. The later development of CJD and mental or nervous disease in 3 of 5 asymptomatic relatives with positive serological reaction suggest that the method although nonspecific, may be of certain value in the search for persons at higher risk to develop a degenerative disorder of CNS.

Autoantibodies↗
PubMed1989

Semipurified human leukocyte ultrafiltrate in herpes zoster. I. Large-scale preparation and biochemical analysis.

Nine batches of lysed human leukocyte ultrafiltrate (LLU) prepared from buffy coats of random healthy donors, as well as their semipurified subfractions--P2/II--were compared in terms of protein, orcinol-reactive material (ORM) content, and ratios of the average values of their ORM and protein contents. Two-step ethanol precipitation and size exclusion chromatography on Sephadex G-15 were used for partial purification and concentration. In comparison to the starting material, approximately 4.4 - fold increase in the ORM/protein ratio of P2/II has been effected. Relatively high variation in both, protein and ORM content of the crude LLU individual batches (ranges: 365 micrograms/1 ml - 962 micrograms/1 ml; 157 micrograms/1 ml - 660 micrograms/1 ml, respectively), as well as of those of P2/II fractions (ranges: 16.5 micrograms/1 ml - 207.5 micrograms/1 ml; 150 micrograms/1 ml - 480 micrograms/1 ml, respectively) could be observed. The suggested combined purification procedure removed from the LLU about 85% proteins and 33% ORM. The removed material contained inhibitors of the cell-mediated immunity (CMI)-inducing and/or augmenting properties of LLU. This is in good agreement with the observed improved therapeutic effect of P2/II fraction in herpes zoster treatment of otherwise noncompromised adults, as described in the companion paper.

Biological Factors↗
PubMed1989

Increased migration inhibition factor production by leukocytes of patients with herpes zoster given the leukocyte ultrafiltrate.

Using the direct leukocyte migration inhibition assay, the cell-mediated immune response was followed in together 47 patients suffering from herpes zoster. Of these, 19 persons were treated with partially purified and concentrated lysed leukocyte ultrafiltrate. Enhancement and/or earlier production of the leukocyte migration inhibition factor--in the presence of varicella-zoster virus antigen--was observed by leukocytes from patients given the ultrafiltrate on days 2-3 since the onset of the vesicular stage of the disease. Highly significant (alpha = 1%, P less than 0.01) differences in the migration inhibition values were observed between non-treated patients and patients given one dose of the ultrafiltrate during the days 3-12 after appearance of the first herpes zoster vesicles; on days 13-30 these values were not significant.

Adolescent↗
PubMed1989

Rehabilitation of common athletic injuries of the hand and wrist.

Rehabilitation of athletic injuries of the hand and wrist should begin at the time of injury. Early recognition and prompt medical attention can serve to minimize the initial effects of injury. A systematic evaluation should include assessment of deformity, joint instability, active and passive motion, edema, and nerve and tendon function. In spite of initial negative findings, painful joints should be protected. Joints of the hand and wrist are particularly vulnerable to the effects of aggressive rehabilitation. Signs of reaction to exercises should be closely observed. Upgrading of activity should only occur as soft-tissue healing will allow.

Athletic Injuries↗
PubMed1988

A biometrical view on normal values of CD4 and CD8 lymphocyte counts in peripheral blood.

Statistical methods have been used to determine an optimal approach to the definition of the reference range for CD4 ("helper") and CD8 ("suppressor/cytotoxic") T cell numbers and the CD4/CD8 ratio in the peripheral blood. A graphical presentation of the absolute values for CD4 and CD8 for 85 healthy blood donors showed that a reference ellipse defined by fitting a gaussian distribution to logarithmically transformed data for absolute counts of CD4 and CD8 cells was superior to the fitting of an ellipse to untransformed data. Further analysis for another 147 subjects showed that the 95% tolerance prediction for the CD4/CD8 ratio in health could be stated with 95% confidence as 0.6 to 5.0. This approach allows clear definition of reference ranges for T cell tests in health and would also be applicable to results for patients with a disease such as HIV 1 infection in which a reference range for "well" patients exists and a change in the T cell ratio is of prognostic significance.

Biometry↗