Lajos Trézl
Budapest University of Technology and Economics
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Featured researches published by Lajos Trézl.
Cancer Cell International | 2001
Béla Szende; Erno Tyihák; Lajos Trézl
Both L-arginine supplementation and deprivation influence cell proliferation. The effect of high doses on tumours is determined by the optical configuration: L-arginine is stimulatory, D-arginine inhibitory. Arginine-rich hexapeptides inhibited tumour growth. Deprivation of L-arginine from cell cultures enhanced apoptosis. The pro-apoptotic action of NO synthase inhibitors, like NG-monomethyl-L-arginine, is manifested through inhibition of the arginase pathway. NG-hydroxymethyl-L-arginines caused apoptosis in cell cultures and inhibited the growth of various transplantable mouse tumours. These diverse biological activities become manifest through formaldehyde (HCHO) because guanidine group of L-arginine in free and bound form can react rapidly with endogenous HCHO, forming NG-hydroxymethylated derivatives. L-arginine is a HCHO capturer, carrier and donor molecule in biological systems. The role of formaldehyde generated during metabolism of NG-methylated and hydroxymethylated arginines in cell proliferation and death can be shown. The supposedly anti-apoptotic homozygous Arg 72-p53 genotype may increase susceptibility of some cancers. The diverse biological effects of L-arginine and its methylated derivatives call for further careful studies on their possible application in chemoprevention and cancer therapy.
Molecular and Cellular Biochemistry | 2003
Lajos Trézl; Lehel Hullán; Zsuzsa M. Jászay; Tibor Szarvas; Imre Petneházy; Béla Szende; Jozsef Bocsi; Zoltan Takats; Károly Vékey; László Töke
Abstract1H, 13C NMR, ESMS and MS/MS investigations proved that there is an antagonism in the spontaneous reaction of formaldehyde with L-lysine and L-arginine. L-Arginine can only be hydroxymethylated on the guanidino group in a very fast reaction forming mono-, di-, and trihydroxymethyl arginines (HMA). L-Lysine can be methylated on the ε-amino group forming mono-, di-, and trimethyl lysine on physiological pH. Hydroxymethyl arginines are relative stable, isolable products, and can also be formed in biological systems, especially in plants. Significant amounts of hydroxymethyl arginines were identified in the aqueous extract of lyophilized kohlrabi, which can be formed in photosynthesis during CO2 fixation. 14C-Formaldehyde formed in a short-term (10, 30 sec) 14CO2 fixation reaction in Zea mays L. (early maturity variety: Szegedi TC 277) was captured by L-arginine, which occurs in leaves in large amount. Formaldehyde formed during photosynthesis can react not only with the arginine, but with ribulose-1,5-diphosphate present in leaves. In model reactions formaldehyde can react with the ‘ene diole’ group of ribulose-1,5-diphosphate in the absence of Rubisco enzyme, which is a similar reaction to the addition of formaldehyde to L-ascorbic acid. Hydroxymethyl arginines (HMA) are endogenous formaldehyde carrier molecules transferring the bound formaldehyde to thymidylate synthase enzyme system incorporating it into the folate cycle. HMA can also carry the bound formaldehyde to the cells especially to the tumorous cells (HT29 adenocarcinoma), and cause significant inhibition of cell proliferation and causes apoptosis.
Journal of Pharmaceutical and Biomedical Analysis | 1985
Erno Tyihák; Lajos Trézl; Pál Kolonits
Abstract From the reaction between l -lysine and formaldehyde, Nϵ-formyl- l -lysine was isolated by means of ion-exchange column chromatography. The identification of Nϵ-formyl- l -lysine was carried out by ion-exchange overpressured-layer chromatography (OPLC) and 1H NMR and 13C NMR spectroscopies. The m.p. and mixed m.p. values, the retention characteristics and the chemical shifts of the isolated product were identical with those of an authentic sample of Nϵ-formyl- l -lysine.
Biomedical optics | 2004
Jozsef Bocsi; Ed Luther; Anja Mittag; Ingo Jensen; Ulrich Sack; Dominik Lenz; Lajos Trézl; Viktor Varga; Beea Molnar; Attila Tárnok
Background: Slide based cytometry (SBC) is a technology for the rapid stoichiometric analysis of cells fixed to surfaces. Its applications are highly versatile and ranges from the clinics to high throughput drug discovery. SBC is realized in different instruments such as the Laser Scanning Cytometer (LSC) and Scanning Fluorescent Microscope (SFM) and the novel inverted microscope based iCyte image cytometer (Compucyte Corp.). Methods: Fluorochrome labeled specimens were immobilized on microscopic slides. They were placed on a conventional fluorescence microscope and analyzed by photomultiplayers or digital camera. Data comparable to flow cytometry were generated. In addition, each individual event could be visualized. Applications: The major advantage of instruments is the combination of two features: a) the minimal sample volume needed, and b) the connection of fluorescence data and morphological information. Rare cells were detected, frequency of apoptosis by myricetin formaldehyde and H2O2 mixtures was determined;. Conclusion: LSC, SFM and the novel iCyte have a wide spectrum of applicability in SBC and can be introduced as a standard technology for multiple settings. In addition, the iCyte and SFM instrument is suited for high throughput screening by automation and may be in future adapted to telepathology due to their high quality images. (This study was supported by the IZKF-Leipzig, Germany and T 034245 OTKA, Hungary)
Phosphorus Sulfur and Silicon and The Related Elements | 1999
Imre Petneházy; Lajos Trézl; Csaba Vida; Zsuzsa M. Jászay
Abstract Chemical modification of wool by means of dimethyl phoaphitc and D-glucose results in an increase in dye pickup, while colour and light fastness properties did not decrease, in fact some features bccpme more favourable. Our invesigations showed that increase in fibre diameter occurred. which could rise the rate of dye penetration. Amino acid analysis of the treated wool sample h w e d a decrease in lysine and arginim content, which allows of supposing covalent bond formation betweecl dimcthyl phosphite, D-glucose and the amino and guanidino groups of wool.
Annals of the New York Academy of Sciences | 1998
Ern}o Tyihák; Lajos Trézl; Béla Szende
Archive | 1989
Sandor Irimi; Adam Molnar; Jozsef Gabor; László Töke; Lajos Trézl; István Rusznák; Viktória Horváth; Tibor Szarvas
Acta Biologica Hungarica | 1998
Lajos Trézl; Hullán L; Szarvas T; Csiba A; Béla Szende
Acta Biologica Hungarica | 1998
Béla Szende; Ernő Tyihák; Lajos Trézl; Éva Szoke; I. László; Gy Kátay; Zs Király-Véghely
Archive | 1985
Istvan Dipl Chem Ing Bitter; Jozsef Gabor; Sandor Dipl Chem Ing Hernadi; Viktória Horváth; Sandor Irimi; Adam Molnar; István Rusznák; Lajos Trézl