Dietary polyamines promote the growth of azoxymethane-induced aberrant crypt foci in rat colon

We have examined whether dietary polyamines influence the formation and initial growth of azoxymethane (AOM)-induced aberrant crypt foci (ACF) in rat colon. Effects of a combination of dietary polyamines at three dose levels (putrescine: 50, 280, 740 nmol/g; spermidine: 10, 261, 763 nmol/g; spermine: 1, 31, 91 nmol/g) in the polyamine-poor AIN-76A diet were studied in animals in two different experimental situations: animals treated with AOM alone and animals treated with AOM + difluoromethylornithine (DFMO), a specific inhibitor of endogenous polyamine synthesis. In both experimental situations, dietary polyamines enhanced the growth of ACF, expressed as the number of large ACF (foci with three or more aberrant crypts, ACF > or = 3), whereas the formation of ACF, expressed as the number of ACF, was apparently not altered. In animals treated with AOM alone, maximal growth enhancing effect on ACF was nearly obtained with the median level of dietary polyamine. In rats fed a low polyamine diet, basic AIN-76A, DFMO reduced the growth of AOM-induced ACF by 83%. This inhibitory effect of DFMO was counteracted by dietary polyamines in a dose- dependent manner, and it was abolished at the highest level of polyamines. In conclusion, it was demonstrated that dietary polyamines are able to enhance the growth of AOM-induced ACF. Further, dietary polyamines reversed the DFMO-caused inhibition of ACF growth, probably by compensating for the DFMO-reduced endogenous polyamine synthesis.      

Correction of ventricular late potentials with drug and non-drug methods in patients with essential hypertension

The aim of the work was to evaluate the effects of drug and non-drug methods of treatment of patients with essential hypertension (EH) on ventricular late potentials (VLP). One hundred and thirteen patients with I to II stage EH aged 30 to 73 (mean age 53 +/- 9.7 years) were included in the study. VLP were registered by recording signal-averaged ECG (SA-ECG) before and after treatment with antihypertensive preparations (lisinopril, nifedipine) and intravenous ozone therapy. VLP were detected in 34 (30%) of the EH patients. The study found a decrease in the frequency of VLP detection from 40% (8 patients) to 10% (2 patients) after therapy with the ACE inhibitor lisinopril. In the group of patients who received monotherapy with the calcium antagonist nifedipine the number of subjects with VLP before and after the treatment was the same, 3 patients or 20%. In the group receiving bi-component therapy with lisinopril, an ACE inhibitor, and nifedipine, a calcium antagonist, the number of patients with VLP fell from 4 subjects (28.6%) to 1 subject. These data were confirmed with significant SA-ECG parameters. The study also revealed that ozone therapy as a part of complex treatment of EH improved SA-ECG parameters, which manifested by a decrease in VLP from 29.7% to 14.1%.     

Use of metaiodobenzylguanidine for assessing status of ends of myocardial sympathetic nerves in myocardium of patients with bronchial asthma

AIM: To evaluate sympathetic nervous system activity of the heart in patients with bronchial asthma (BA) given beta-adrenomimetics (BAM). MATERIAL AND METHODS: 27 patients with moderate BA (13 patients in an acute phase and 14 patients in remission) treated with BAM and 13 healthy people were examined by using 123I-metaiodobenzylguanidine (MIBG) myocardial planar scintigraphy and estimating the washout rate, early (15-min) and late (240-min) uptake; single-photon emission computed tomography; assessment of MIBG distribution in the left ventricular myocardium, catecholamine excretion with urine. RESULTS: It was found that the MIBG washout rate was significantly higher in asthmatic patients especially in the acute period. The cardiac MIBG uptake was significantly lower in the group of patients with impaired cardiac sympathetic activity. More inhomogeneous myocardial MIBG uptake also occurred in the asthmatic group. Norepinephrine and epinephrine excretion was significantly higher in patients with bronchial asthma and cathecholamine and MIBG excretions correlated. CONCLUSION: Cardiac functional sympathetic activity impairment in asthmatic patients was shown by increased MIBG washout rate and reduced myocardial MIBG uptake, more inhomogeneous substance distribution in the left ventricular myocardium and higher catecholamine excretion levels reflecting sympathetic nervous activity intensification.     

Methodological aspects of hygienic standardization of pesticide level in food products

On the basis of a significant amount of experimental studies of toxic effect of pesticides attributed to different groups of chemical substances a rapid calculating and experimental technique for hygienic standardization of pesticide content in foodstuffs has been set forth. The proposed technique enables one to define quickly and safely the threshold and inert pesticide doses and to reduce general duration of toxicologic experiments by 35%.