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Biomedical subjects

E Kiss

Publications and source records attributed to E Kiss.

At least 145 records · Page 8Linked to original sources

Influence of various parameters on benzo(a)pyrene enhancement of adenovirus SA7 transformation of Syrian hamster embryo cells.

Several of the major variable factors in the Syrian hamster embryo/simian adenovirus SA7 (SHE/SA7) viral enhancement assay were identified and the effects of these parameters on assay sensitivity were assessed. The extent of dose-dependent cytotoxicity and enhancement of SA7 transformation of primary SHE target cells by benzo(a)pyrene was examined through analysis of data obtained from 37 assays performed over a 2-year period. The variables analyzed for contribution to assay sensitivity included the number of SA7-induced transformed SHE cell foci enumerated in ten replicate dishes in the negative control condition (background focus count) (range: 26-139); the age of the SHE cell cultures at the time of exposure to benzo(a)pyrene (range: 72-144 hr postseeding); and the source of the pregnant hamsters used to prepare the primary SHE cells (Wilmington colony vs Lakeview colony, Charles River Laboratories, Inc., Wilmington, MA). The benzo(a)pyrene-induced cytotoxicity and enhancement of SA7 transformation responses were found to be independent of each of these variables, within the range of values tested.

Adenoviridae↗

Changes of serum lipids and lipoproteins during haemodialysis treatment in dialysed chronic uraemic patients.

Changes of serum lipids and lipoproteins were determined quantitatively before and after haemodialysis in chronic uraemic patients. Serum beta-lipoprotein significantly decreased due to haemodialysis, while alpha-lipoprotein and the FFA level significantly increased. Slight correlations were observed between the applied transmembrane pressure and the serum concentration of FFA, HDL-cholesterol or total cholesterol levels. Hyper-beta-lipoproteinemia was found in 70.9 per cent and Frederickson-HLP in 33.3% of the haemodialyzed chronic uraemic patients.

Adult↗

The immunosuppressive effect of methimazole on cell-mediated immunity is mediated by its capacity to inhibit peroxidase and to scavenge free oxygen radicals.

We have investigated the effect of methimazole (MMI) on cell-mediated immunity and ascertained the mechanisms of immunosuppression produced by the drug. Methimazole (greater than or equal to 10(-5) M) produced a dose-dependent inhibition in 'active' (early) rosette formation with sheep red cells and in phytohaemagglutinin (PHA)-induced lymphocyte transformation. A concentration of 10(-4) M MMI inhibited the immediate rise in intracellular cAMP triggered by PHA and the subsequent time dependent decrement over 24 h. The drug (10(-3) M) also exerted a significant inhibitory effect on antibody-dependent cell-mediated cytotoxicity (ADCC) over six-fold difference in target/effector cell ratios. At a concentration of 10(-5) M, MMI inhibited zymosan-induced respiratory burst (determined by change in the chemiluminescence of oxidized luminol) in polymorphonuclear and mononuclear cell preparations. Ninety-five per cent of the chemiluminescence in the latter preparation was due to monocytes. At concentrations between 10(-7) and 10(-6) M, MMI significantly inhibited (in cell-free systems) horseradish peroxidase-dependent generation of chemiluminescence as well as the oxidation of luminol by hydrogen peroxide. Methimazole exerts its inhibitory effects on measures of cell-mediated immunity by at least two mechanisms: inhibition of peroxidase and scavenging free oxygen radicals. Insensitivity of the test systems or poor access of MMI to leucocytes may account for the need for greater than or equal to 10(-5) M MMI to inhibit cell-mediated immunity significantly.

Animals↗

Steroid sensitivity of chronic uraemic and renal transplant patients measured by the antibody dependent cellular cytotoxicity reaction.

The steroid (methylprednisolone) sensitivity of chronic uraemic and renal transplant patients was examined on the basis of the extent of inhibition of the antibody-dependent cellular cytotoxicity (ADCC) reaction, and via the effect on the ADCC capacity test (ADCC-C). Individuals with an inhibition of 30% or more were classified as steroid-sensitive. Immunopharmacological tests and the clinical picture showed 67%, 12 of the 18 renal transplant patients to be steroid-sensitive. In 92% of the cases the transplanted kidney was functioning well one year or more postoperatively. In 5 of the 6 steroid-resistant patients rejection necessitated removal of the transplanted kidney. The method is simple to perform and gives reproducible results, and appears suitable for application in clinical practice.

Adolescent↗

Identification of four SB antigens by cloned cells. Population studies of Norwegians.

By priming in vitro with allogeneic HLA-DR compatible and also HLA-A,B mostly compatible lymphoid cells, PLT cells resulted in recognizing a group of non D/DR allelic antigens provisionally named K, L, M and N. To improve discrimination these bulk primed typing reagents were cloned and expanded. By typing of previously SB typed lymphoblastoid B cell lines (LCL) the provisional specificities could be identified as SB1, 4, 3 and 2, respectively. Typing of 186 unrelated Norwegians gave the following gene frequences: SB1: 0.05, SB2: 0.16, SB3: 0.13, SB4: 0.42 and SB blank: 0.24. No triplets were found, the calculated gene frequencies fit with Hardy-Weinberg equilibrium, and typing of a B-DR recombinant family confirmed that the SB locus is situated centromeric to B. Associations between SB and A, B, DR antigens in the same material were generally weak, the most significant associations found were between SB1-DR3 and SB4-DR2.

B-Lymphocytes↗

Induction of neoplastic transformation and DNA single-strand breaks in C3H/10T1/2 clone 8 cells by polycyclic hydrocarbons and alkylating agents.

The standard C3H/10T1/2 clone 8 (C3H/10T1/2 CL8) cell transformation assay was tested for its ability to identify a variety of polycyclic hydrocarbons and alkylating agents. Dose-dependent morphologic transformation occurred with benzo[a]pyrene (BaP), 3-methylcholanthrene (MCA), 7,12-dimethylbenz[a]anthracene, BaP-7,8-dihydroxy-7,8-dihydrodiol (BaP-7,8-diol), as well as with the relatively weak in vivo carcinogen benzo[e]pyrene. Dibenz[a,h]anthracene yielded a relatively weak response, whereas anthracene and phenanthrene were negative. In contrast, treatment of C3H/10T1/2 CL8 cells with two directly acting alkylating agents, N-nitroso-N-methylnitroguanidine (MNNG) and styrene oxide, gave no transformation, whereas a third alkylating agent, ethyl methanesulfonate (EMS), gave a weak response. Treatment with MCA (2.5 micrograms/ml) yielded a reproducible positive response and, therefore, served as a positive control for routine use of the C3H/10T1/2 CL8 assay. When cells treated with the hydrocarbons BaP, BaP-7,8-diol, or MCA were analyzed for nonspecific DNA damage (single-strand breaks or alkaline-labile sites) by alkaline elution techniques, little if any DNA damage was observed. In contrast, the alkylating agents MNNG, styrene oxide, and EMS yielded substantial numbers of single-strand breaks.

Alkylating Agents↗

Continuous monitoring of the efficiency of haemodialysis by recording the UV transmittance of the dialysis solution.

The efficiency of haemodialysis, the elimination of uraemic retention substances of low and medium molecular weight can be continuously monitored by recording the UV transmittance at 254 nm of the dialysing solution. The method for controlling the efficiency of haemodialysis is optimal if it complies with the following requirements: No or little blood sample is needed. The elimination process can be continuously monitored. The degree of eliminating the hardly dialysable organic compounds and toxic materials can be well measured. Our method was devised to fulfil the above requirements [1]. The results obtained during routine application of the method are reported in this publication.

Adolescent↗