Peptide Regulation of Skin Fibroblast Functions during Their Aging In Vitro.

The effect peptides KE, KED, AED and AEDG on proliferation (Ki-67), regeneration and aging (CD98hc), apoptosis (caspase-3), and extracellular matrix remodeling (MMP-9) in skin fibroblasts during their aging in culture were studied by immunofluorescent confocal microscopy. All studied peptides inhibited MMP-9 synthesis that increases during aging of skin fibroblasts and enhanced the expression of Ki-67 and CD98hc that are less intensively synthesized during cell aging. Peptides AED and AEDG suppressed caspase-dependent apoptosis that increases during aging of cell cultures.

[Quality of operator's performance and associated physiological reactions in relation to stress-tolerance].

The purpose was to study operator's stress-resistance by correlating the results of work with its physiological effects associated with the sympathetic system reactions. Hard- and software Neurolab-200M was used to test 10 subjects in two experiments with different stressful conditions. Work efficiency was assessed by time for completion and accuracy of the "Manometers test" challenging the ability to perceive information and to take decision under severe time limitation. Heart rate per a minute, systolic and diastolic blood pressure were measured immediately before and during the test. According to the results of the experiments, two subjects demonstrated low stress-resistance when doing the operator's tests. Comparison of the physiological data of these and the rest subjects showed good agreement with the hypothesis that weak stress-resistance, unlike the strong one, is associated with less pronounced stress-induced sympathetic reactions.

[Evaluation of operator's quality using test "Manometers" implemented with the use of hard- and software Neurolab-2000M].

Purpose of the work was to correlate the quality parameters (speed and accuracy) of test Manometers implementation with the use of hard- and software Neurolab-2000M. The operator's quality parameters were latent reaction time (LRT) as a speed criterion, number of errors as an accuracy criterion, and speed and accuracy dependent time of task presentation (TP). The parameters were related by evaluation of statistical significance of calculated linear correlation coefficients Correlations between TP and LRT as well as between LRT and the number of errors were neither unique nor significant. On the opposite, TP and the number of errors were in direct correlation on the level of proximity and high statistical significance. These results suggest that, like the number of errors, TP can serve as a criterion of test completion accuracy. Regarding LRT, the parameter is not suitable for evaluation of accuracy of the Manometers test completion.

[Job quality evaluation with regard to individual stress tolerance of operators].

Male test-subjects (n = 8, 25 to 36 years of age) were kept awake and working for 67 hrs. in an anechoic room. Every 1-2 hours the test-subjects performed eye-tracking of rhythmic light points with an abrupt and unexpected change of frequency. The task was to strike the key the moment the frequency was noticed to have changed. One test session took 10 to 15 minutes; depending on test duration, the number of frequency change could be from 38 up to 59-60. The moments of frequency change and keystroke were registered. Latent reaction time was determined (LRT). Individual LRT values and variations (SD) were evaluated. A statistically significant correlation between individual LRT values and variations was established, i.e. high SD corresponded to high LRT values and visa versa. Thus the worst test results were associated with high LRT values and variations, whereas, on the contrary, the best test results were characterized by low LRT values and variations. Data of the investigation are subject to analysis with regard to their relation to operator's stress tolerance; possible neurophysiological mechanisms of this relation are discussed.

[The correlation between the heart contraction rate and the operator's stress-resistance].

There is factual confirmation of the correlation between operator's stress-resistance and heart rate (HR). HR data alone without assessment of the job quality in a group of operators were enough to rank the operators by their resistance to stress. However, there are several requirements to be met. To begin with, operators should experience a weak or moderate mental stress that will modify HR. Secondly, other sympathetic influences should be reduced to a minimum, as they may mask the emotion-driven effects (motor activity, elevated tone of posture muscles, meals). With this in view, HR measurements are advisable during night sleep to escape, in addition, the endogenous sympathetic activation associated with ergotrophic metabolism. In the day time, HR should be measured after 10 to 15 minutes in recumbent position.

[Heart rate of operators with various levels of stress-tolerance].

The paper presents results of the investigation with 8 male subjects 25 to 36 y.o. attesting the existence of relation between stress tolerance evidenced from the data about tracking function during extended continuous wakefulness and the sympathetic activity assessed by heart rate values. Based on there results, the higher stress tolerance, the lower baseline sympathicotonia and the stronger sympathetic reactions to adequate stimuli.

[Clinical and x-ray diagnosis and diagnosis and classification of occupational fluorosis]. / Kliniko-rentgenologicheskaia diagnostika i klassifikatsiia professional'nogo fliuoroza.

The authors summarize longstanding experience in studies of chronic occupational intoxication caused by fluoric compounds. Findings are that diagnosis and clinical classification of occupational fluorosis should base on osteosclerotic changes in compact substance of peripheral bones, primarily of forearms and legs. The authors give clinical classification of occupational fluorosis.