[Divergence of Chlorophyll Dynamics in the Naroch Lakes].

We present results of the analysis of long-term chlorophyll a dynamics in the Naroch lakes. It has been shown that an increase in nutrient load in the 1970s resulted in progressive eutrophication of Naroch lakes. Then, starting in the mid-1980s, the increase in water transparency and decreases in concentrations of phosphorus and nitrogen have been occurring due to the environmental improvement program. In the 1980s, the Naroch lakes experienced a strong factor as an invasion by zebra mussel (Dreissena polymorpha Pallas). Our analysis shows that responses of all three lakes to the intensive nutrient load and further decrease in the nutrient concentration as a result of the environmental protection measures have been correlated. At the same time, different degrees of the influence of the zebra mussel invasion on the lakes are shown to lead to divergence in chlorophyll dynamics. This divergence was observed as a drastic decline in correlations between variations in chlorophyll concentrations in every Naroch lakes.

[Optimization of accounting for radiation exposure of patients as a basis for assessing the risk of stochastic effects due to medical X-ray diagnostic irradiation].

The work is devoted to optimization of the control and accounting for radiation exposure of patients in the X-ray examinations by means of improving existing forms of state statistical survey (form #3-DOZ.). The analysis of the radiation exposure of patients in medical institutions of the Rostov region for the period of 2005-2011 was carried out. It is proposed to exclude the information about the individual patient doses received by calculation; differentiate a group of "adult patients' on age and gender, selecting the reproductive age, discriminate as a separate category of dose-generating, intervention methods of research that will allow to more accurately calculate the risk of the development of stochastic effects of the medical radiation exposure to population.

[Optimization of the health level assessment of healthy individuals in the system of primary health care in the relation with social and hygienic monitoring of population health].

It is proposed to extend the program of social and hygienic monitoring of public health by virtue of inclusion of risk factors for diseases according both to lifestyle and corresponding periodic health examination groups. Information can be obtained on the basis of materials of "Health centers".

[Polymorphism of the coxl mtDNA gene from cercarian isolates of the avian schistosome Bilharziella polonica (Trematoda: Schistosomatidae) from Belarussian lakes].

We have studied the phylogeographic structure of avian schistosomes Bilharziella polonica (class Trematoda, family Schistosomatidae), parasites of 18 molluscs Planorbius corneus (family Planorbidae) from three Belarussian lakes. Low nucleotide (pi<0.5%) and high haplotype (h=85.6%) diversity of the gene encoding the cytochrome C oxidase first subunit (coxl) was found on the part of the species range studied. The phylogeographic reconstructions showed that the sample examined consists of at least two lineages ofhaplotypes A and C. Haplotype diversity was somewhat higher in lineage C. The genetic divergence between these genealogical lines reached 0.55%, while the time of possible divergence was 180,000-270,000 years. Possible evolutionary scenarios for differentiation of the B. polonica lines and effectiveness of using coxl for barcoding trematode populations and finding coevolutionary parasite-host relationships are discussed.

[Estimation of morbidity rates in relation to living conditions].

The scientific and practical evaluation of the cumulative influence of environmental factors on human health presents certain difficulties as the establishment of the level of individual health is methodologically inadequately developed. By employing the clinical studies only, the existing prophylactic medical examination system enables one to detect only the early signs of diseases. Estimating the level of human health should be complemented with criteria for prenosological diagnosis along with the assessment of individual living conditions to enhance the objectivity of determining the population's health status and to elaborate hygienically founded prophylactic measures.

[Patient radiation safety in the development of the medical standards "patient management protocols"].

The aim of the study was to develop a procedure for substantiating the control irradiation levels during medical irradiation. Two databases on the controlled parameters of R-equipment and on the individual patient doses from outpatient cards were analyzed.

[Human cercariasis caused by schistosomatid larvae from aquatic birds in the Narochanka River recreational area of Byelarus]. / Tserkariozy cheloveka, vyzyvaemye lichinkami shistosomatid vodoplavaiushchikh ptits, v Narochanskoi rekreatsionnoi zone Belarusi.

The reasons of the dramatically aggravated cercarial situation were examined in the Naroch Lake area (Minsk Province, Byelorussia). The incidence of infection with cercariae of the family Schistosomatidae trematodes in 8 mollusk species of the genera Lymnaea, Planorbarius, Planorbis, Anisus which were nonuniformly distributed in the upper littoral were studied. The snails form mosaic congestions of various density (from solitary individuals in a 50-100 m2 area to hundreds per m2), which is associated with the nature of aquaphytocenoses and the degree of plant overgrowth. The snails infected with Trichobilharzia ocellata and Bilharziella polonica cercariae accounted for 18.8%. Schistosoma cercariae affected L. stagnalis, L. ovata, and L.p. corvus to the greatest extent. The proportion of ducks (Anas platyrhyncha) infected with the two Schistosomatidae is 30.0% in the area in question with the average infestation rate of as many as 20 trematodes of both sexes per duck. High-risk areas for human infestation (with the number of Schistosoma cercariae exceeding 10 larvae in 10 liters of water) were recorded in the upper littorals in the beach zones of all recreation institutions such as sanatoria, rest homes, camping, etc.). The fact that Schistosoma cercariae can be active in attacking man under the conditions of the Naroch Lake littoral was verified by the self-infestation of one of the authors (S.A. Be'er). Schistosome dermatitis showing its typical clinical manifestations developed after 120-130 cercariae had penetrated into the arms and legs.(ABSTRACT TRUNCATED AT 250 WORDS)

[Adenylate cyclase and cAMP-dependent protein kinase activity in the adrenal glands of animals after chronic administration of ACTH]. / Izuchenie aktivnosti adenilattsiklazy i cAMP-zavisimykh proteinkinaz v nadpochechnikakh zhivotnykh pri khronicheskom vvedenii AKTG.

ACTH, a prolonged action hormone, in a dose of 2.5 mu. was injected into guinea pigs daily for 5-35 days. The adenylate cyclase activity of the crude adrenal membrane fraction and the activity of cAMP-dependent protein kinases in the cytoplasmic fraction were determined. Cyclic changes in the basal and stimulated adenylate cyclase activities occurring with 15-20-day intervals have been established for the first time. The sensitivity of adenylate cyclase to ACTH, NaF and GTP did not change in the course of two cycles. The activity of cAMP-dependent protein kinases increased during the first few days after ACTH administration and decreased after further injections of the hormone. The role of cyclic changes of the enzyme activity in the mechanism of proliferative effect of ACTH is discussed.

[Adenylate and guanylate cylase system function in human hyperplastic adrenals in Itsenko-Cushing disease]. / Sostoianie adenilat- i guanilattsiklaznoi sistem v giperplazirovannykh nadpochechnikakh cheloveka pri bolezni Itsenko-Kushinga.

The content of cyclic nucleotides and the activity of adenylate and guanylate cyclases as well as of cAMP phosphodiesterase in the human hyperplastic adrenals were determined after one- and two-step bilateral adrenalectomy for Itsenko-Cushing's disease. A decrease in cGMP concentration and a corresponding increase in cAMP/cGMP correlation were seen in the 2nd hyperplastic adrenal comparatively to those in the 1st one. An enhanced basal activity of adenylate cyclase and its lowered sensitivity to ACTH were found in the 1st and the 2nd adrenals. These changes correlate with a rise in the blood ACTH concentration in patients after the ablation of one adrenal. It is suggested that the augmented adenylate cyclase activity leads to an increased activation of steroidogenesis enzymes in the rest adrenal, ensuring the elevated rate of corticosteroid secretion. The nature of changes in guanylate cyclase activity is contrary to that of adenylate cyclase; namely, guanylate cyclase basal activity of the 2nd hyperplastic adrenal was shown to be lower than that of the 1st one. The cAMP phosphodiesterase activity in the 1st and the 2nd adrenals remained unchanged.

[Changes in cyclic nucleotide metabolism in compensatory adrenal hypertrophy (following unilateral adrenalectomy)]. / Izmeneniia v metabolizme tsiklicheskikh nukleotidov pri kompensatornoi gipertrofii nadpochechnikov (posle odnostoronnei adrenaléktomii).

The cyclic nucleotide content, adrenocortical adenylatecyclase, guanylatecyclase, cAMP and cGMP phosphodiesterase activity, as well as the blood corticosteroid content of guinea pigs were determined at the different periods after bilateral adrenalectomy. The raised basal adenylatecyclase effect was also seen during compensatory hypertrophy of the sole adrenal. The response of adenylatecyclase to ACTH and Na is also enhanced at this moment. It is suggested that a physiological increase in the blood ACTH concentration, resultant of unilateral adrenalectomy, intensifies the adenylatecyclase catalytic activity and does not induce enzyme desensitization. The guanylatecyclase activity grows. It was established that changes in both cyclase activities are dependent on the postoperative time and are equal by character. The alteration of adenylatecyclase state always leads to the rise of guanylatecyclase activity. Changes in the cAMP and cGMP phosphodiesterase activity were not observed.

[Adenylate cyclase activity and cyclic nucleotide content in human adrenal tumors under Icenko-Cushing syndrome]. / Aktivnost' adenilattsiklazy i soderzhanie tsiklicheskikh nukleotidov v opukholiakh nadpochechnikov cheloveka pri sindrome Itsenko--Kushinga.

The adenylate cyclase activity and cyclic nucleotide content in excised human adrenal tumours (Icenko-Cushing syndrome) were determined. The experimental data were compared to those obtained for hyperplastic adrenals. All adrenal tumours under study revealed a decreased cAMP level, an increased cGMP level and a resulting decrease of the cAMP/cGMP ratio. In malignant adrenal tumours the adenylate cyclase activity was sharply increased in comparison with that in hyperplastic adrenals. In the majority of malignant tumours the adenylate cyclase response to ACTH was either altogether absent or sharply decreased. In benign adrenal tumours the basal activity of the enzyme was unchanged and the enzyme response to ACTH was essentially normal. The decrease of adenylate cyclase response to ACTH in malignant tumours is apparently not due to the impaired catalytic activity of the enzyme, since its response to stimulation by sodium fluoride remains unaffected. In some tumours (one malignant and two benign ones) a non-specific stimulation of adenylate cyclase by hormones, which are not natural activators of the enzyme was observed. It was assumed that these changes are due to the damage of hormonal receptors in adrenal tumours.