Search

Melatonin (MT) and sirtuins (SIRT) are geroprotective molecules that hold back the aging process and the development of age-related diseases, including cardiovascular pathologies. Buccal epithelium (BE) sampling is a non-invasive procedure, yielding highly informative material for evaluating the expression of genes and proteins as well as the synthesis of molecules. Among these, MT and SIRTs are valuable markers of the aging process and age-related pathologies. The purpose of this study was to examine age-related expression patterns of these signaling molecules, in particular MT, SIRT1, SIRT3, and SIRT6 in BE of subjects of different ages with and without arterial hypertension (AH). We used real-time polymerase chain reaction (RT-PCR) and immunofluorescence analysis by confocal microscopy. We found that MT immunofluorescence intensity in BE decreases with aging, more evidently in AH patients. SIRT3 and SIRT6 genes expression and immunofluorescence intensity in BE was decreased in aging controls. In AH patients, SIRT1, SIRT3, and SIRT6 gene expression and immunofluorescence intensity in BE was decreased in relation to age and in comparison with age-matched controls. In conclusion, the evaluation of MT and sirtuins in BE could provide a non-invasive method for appraising the aging process, also when accompanied by AH.

The article concerns biological effects of non-ionized electromagnetic irradiation which is considered in modern world as a serious ecological factor. Influence of decimetric microwave irradiation (460 MHz) on free radical processes in the rat brain tissues--visual cortex and hypothalamus--were investigated. Oxidative effects of both lipid peroxidation and specific activity of glutathione reductase were determined. It is shown that whole body irradiation for up to 4 weeks results in considerable changes of the above indices dependent on the irradiation intensity and age of the animals. Decimetric microwaves have oxidant effects at high intensity irradiation (SAR--15 mW/kg), while these effects are antioxidant at low intensity (SAR--5 mW/kg). Physiological implications of different oxidative metabolic responses of the hypothalamus and the cortex to microwaves irradiation are discussed.

Theoretical small-angle diffuse scattering curves from muscle thin filament models have been calculated. The curves reveal a maximum at 115' scattering angle. It has been shown that the maximum is due to the pitch of F-actin helix. Theoretical curves are in good agreement with the earlier obtained curves of small-angle diffuse scattering from F-actin dilute solutions.

Changes in the intensity of ascorbate- and NADPN2-dependent induced lipid peroxidation (LPO) were studied in exposure of the visual analyzer and hypothalamus of 3- and 12-month-old rats to radiation with microwaves of high and low intensity. The exposure to microwaves of high intensity stimulated basal LPO but suppressed activity of LPO-inducing systems. This suggests disturbances in the activity of different sources of active oxygen forms. Microwaves of low intensity activated systems of induced LPO. This is accompanied with synchronous activity of the antioxidant defense system maintaining a normal oxidation-reduction balance of the cell. The conclusion is that, depending on their intensity, microwaves can be either beneficial to health or be a factor of oxidative stress.

The results of applying linear position sensitive proportional counters to diffuse small-angle synchrotron radiation scattering to biopolymer solutions are presented. Synchrotron radiation of the VEPP-3 storage ring (Institute of Nuclear Physics, Novosibirsk) was used. On the basis of small-angle scattering curve obtained from protein pepsinogen it has been shown that the exposure is about 100 times less than with conventional X-ray technique.