[Investigation of the role of polymorphic loci RS2299941, RS1903858, RS10490920, RS2735343 of the PTEN gene in patients with prostate cancer].

Prostate cancer is a clinically heterogeneous disease, and accurate risk stratification of patients is becoming a key clinical task. This is the most common malignant neoplasm and the leading cause of cancer death in men worldwide. Genomic markers include tools and technologies that can predict the probability of an initial positive biopsy, reduce the number of unnecessary repeated biopsies, identify tumors with low, medium and high risk, classify the degree of disease, as well as predict and monitor the clinical response to intervention. Variants of the PTEN gene are of great interest as genetic markers of the risk of developing prostate malignancies.

[The role of laser Doppler flowmetry as a diagnostic criterion of impaired microcirculation of vesico-urethral segment and prostatic gland].

To study changes in microcirculation of the lower urinary tract in different diseases we used laser analyzer of capillary circulation LAKK-01. The control group consisted of 25 volunteers, the study group--of 65 patients with different vesico-urethral diseases. Normal values of microcirculation in the wall of the urinary bladder, prostatic gland and urethra were determined. These values were significantly reduced in patients with vesico-urethral disorders. Thus, alterations in microcirculation in different pathological conditions of the vesicourethral segment confirm the hypothesis of a direct involvement of microcirculation disorders in pathogenesis of many urological diseases.

[Changes in microcirculation of the urinary bladder in patients with stage II prostatic adenoma depending on the treatment method].

To determine microcirculation in the wall of the urinary bladder in prostatic adenoma, we used a laser analyzer of capillary circulation LAKK-01. Two groups participated in the trial: 105 males with stage II prostatic adenoma (the study group) and 25 volunteers (the control group). We estimated normal parameters of microcirculation in the wall of the bladder. In stage II prostatic adenoma the above microcirculation decreased to a subcritical perfusion level. Significantly earlier and complete recovery of microcirculation was observed in patients who had taken cardura (Pfizer) in a dose 2 mg/day for 3 months after transurethral resection of prostatic gland. Thus, 2 mg/day cardura (Pfizer) in patients with prostatic adenoma of stage II after TUR of the prostate promotes early and effective recovery of microcirculation.

The role of lipid and antioxidant exchanges in cell division synchronization (mathematical model).

Cell-cycle synchronization of two diffuse-coupled cells has been studied in the framework of the membrane model for the cell division cycle, proposed by Chernavskii et al. (1977). It has been shown semi-analytically (using the averaging principle) and by computer stimulation that a) if the duration of the G1-phase (TG1) for two identical cells is comparable with the duration of the remaining cycle (TS + G2 + M), the lipid (L)-exchange results in a synchronization with phase difference phi = 0. The antioxidant (A)-exchange leads to a phase-locking with phi = T0/2 (where T0 is the cell cycle period; b) if TG1 much greater than TS + G2 + M (or TG1 much less than TS + G2 + M) the L-exchange makes synchronization possible both with phi = 0 and phi = T0/2 while the A-exchange results in phase-locking with phi confined to the region 0 to T0/2; c) for non-identical cells differing in the values of kinetic parameters, the locking band narrows as the population density increases (when some model parameters are close to the bifurcation thresholds). We expect that the cells selected artificially at a definite phase of cycle might maintain the synchronous division for a long time if the lipid exchange between cells were stimulated.

[Fluctuations of cell cycle duration]. / O mekhanizme fluktuatsii dlitel'nosti kletochnogo tsikla.

The problems whether the cell cycle is a deterministic or probabilistic process is widely discussed in current literature [1, 3, 7]. Present work deals with fluctuations of the cell cycle in terms of the mathematical model of membrane regulation of cell division. The presence of white noise in the parameters describing the influxes of lipids and antioxidants into the membrane is studied by the methods of Markovian processes, as well as by direct computer simulation. The equation for the distribution function of cell generation times is obtained and the increase of dispersion and the mean cell cycle time during the change of the system parameters which can be related to the density of cell culture is calculated. The theoretical distributions qualitatively agree with experimental data.

On the distribution of cell cycle generation times.

The problem of whether the cell cycle is a deterministic or probabilistic process is widely discussed in the current literature (P. Nurse, Nature, 286, pp. 9-10, 1980). In this report the question of fluctuations of cell cycle period is treated in the limits of the membrane model of cell division regulation. The parametric analysis of the equations set both for normal and tumour cells is carried out. We describe the bifurcation parameters in the neighbourhood of which the system can amplify the small fluctuations. The presence of white noise in parameters describing the lipids and antioxidants influxes into membrane is examined by methods of Marcovian processes and also by direct stochastic computer simulation. The equation for the distribution function of generation times is obtained and the increase of dispersion and mean cycle time during the changes of those parameters which would be connected with cell culture density is calculated. The influence of parameter fluctuations upon the cycle period for both normal and tumour cells is compared in the framework of model assumptions. The ratio of dispersion of generation time distribution to mean period value for an ensemble of tumour cells is shown to be several times greater than that for normal ones. In the discussion the problem of the presence of a premitotical (G02) resting state and of the possibility of its experimental detection is considered.