Biomedical subjects

Tamás Fenyvesi

Publications and source records attributed to Tamás Fenyvesi.

3 recordsLinked to original sources

PubMed2004

Endothelins: a possible mechanism of cytostatics-induced cardiomyopathy.

Endothelium responds to physical and chemical stimuli by synthesis and release of a variety of vasoactive and signal molecules. Cardiac performance is regulated by cardiac endothelial cells in a paracrine manner, analogous to vascular endothelial control of vascular tone. Endothelin-1 (ET-1), one of the most potent vasoconstrictor peptides, which is synthetized and released by endothelial cells. The role of ET-1 in some special pathological state is still unclear. Authors have investigated the effect of anthracyclines (maximal dose: 450 mg/bodysurface m2) on left ventricular systolic and diastolic function and on the level of plasma ET-1, in 31 (13 male, aged 19-70 years, mean: 38.9) patients suffered from Hodgkin (24) and Non-Hodgkin (7) lymphomas. They have also studied the association between plasma ET-1 concentration and echocardiographic parameters. Serum ET-1 was measured by ELISA method. Left ventricular function analyzed by echocardiography: ejection fraction (EF), time velocity integral (VTI), E and A waves, E/A ratio, deceleration time (DT), Doppler index were assessed. Statistical analysis was made by the Wilcoxon rank test. ET-1 plasma level decreased significantly after therapy (5.6 +/- 3.5 vs. 3.1 +/- 0.9 pg/ml, P < 0.0006). EF (56.4 +/- 5.0% vs. 48.7 +/- 5.1%, P < 0.0001) decreased, and DT (168.1 +/- 36.8 ms vs. 206.5 +/- 58.8 ms, P < 0.0073) increased significantly after administration of anthracycline, showing that both systolic and diastolic left ventricular performance was deteriorated. There was no difference in other echocardiographic parameters before and after therapy. In conclusion, decrease of serum ET-1 concentration might be a result of anthracyclin's direct cytotoxic effect and the decreasing level of ET-1 may play a role in the reduction of the EF. More studies are needed to evaluate the presence and severity of endothelial damage, and long-term follow-up may reveal the importance of low ET-1 level and may show the time is needed for the restoration of the ET-1 concentration to the basic level after cessation of cytostatic therapy.

Adult↗

PubMed2004

Endothelin-1 and cardiac function in anthracycline-treated patients: a 1-year follow-up.

Anthracyclines are widely used chemotherapeutic agents in the treatment of lymphomas known to induce cardiomyopathy in more than 20% of patients. There is increasing experimental evidence that cardiac endothelial cells regulate cardiac performance and that endothelin-1 (ET-1) is a central substance in this regulatory mechanism. Twenty (seven male, aged 20-68 years) patients with Hodgkin's or non-Hodgkin's lymphoma treated with anthracycline were followed-up for 1 year. At baseline, after cessation of anthracycline treatment and at 1 year, the plasma ET-1 level was measured by enzyme-linked immunosorbent assay and cardiac function was estimated by echocardiographic measurement of the ejection fraction, the E/A ratio and the deceleration time. The ET-1 level decreased significantly after therapy (5.47 +/- 3.34 pg/mL versus 3.44 +/- 0.69 pg/mL, P < 0.02), and remained significant at 1 year (3.43 +/- 0.57 pg/mL, P < 0.008). The ejection fraction (57.80 +/- 4.73% versus 48.05 +/- 5.65%, P < 0.0001) and the E/A ratio (1.35 +/- 0.40 versus 1.15 +/- 0.40, P < 0.01) decreased, and the deceleration time (177.00 +/- 44.96 ms versus 209.50 +/- 66.25 ms, P < 0.04) increased significantly after therapy, showing that both systolic and diastolic left ventricular performance were deteriorated. Compared with the baseline, the same significant changes were found at 1 year (ejection fraction, 50.65 +/- 8.87%, P < 0.0007; E/A ratio, 1.10 +/- 0.34, P < 0.003; deceleration time, 223.25 +/- 46.85 ms, P < 0.002). The decrease of the ET-1 concentration might be a result of anthracyclines' direct cytotoxic effect and the decreasing level of ET-1 may play a role in the ejection fraction reduction. The results of 1-year follow-up suggest that, although anthracycline toxicity occurs shortly after treatment, the undesirable effect remains.

Adult↗

PubMed2002

[Double-blind peer review].

The peer review process in medical sciences is much debated. The method is not yet evidence based. Who are the reviewers and how do they perform? They are "independent" experts. As such they are bound to be involved in research similar to that outlined in the manuscript. Very often they are contestant in the same race. That is why the author consider the double blind method, where the author is blinded and the reviewer masked from each other's identity, the best choice. Nevertheless in very many scientific journals of high quality and envied impact factors do not blind the identity of the authors. Science is a race for fame, self accomplishment and also a means to get grants for pursuing the scientific research. Only success is able to provide resources for expensive scientific research. There is no fail-safe method against bias in grant giving and editorial process. In the tidal wave of electronic information it is mandatory to help in differentiating between signal and noise in science. Peer review is the best method to protect readers from the trash of uncontrolled publications in medical science.

Double-Blind Method↗