Relationship between follow-up periods and the low-dose ranges with statistically significant radiation-induced risk of all solid cancers in the Russian cohort of Chernobyl emergency workers.

Radiation-induced risks for all solid cancer incidence and mortality were studied in the cohort of Russian Chernobyl emergency workers. The cohort included 69,440 persons with documented individual radiation dose accrued over the time of working in the Chernobyl zone. The mean age at entry into the zone of recovery operations was 33.9 years and accumulated radiation dose was 132.9 mGy. A total of 6981 solid cancer incident cases and 4272 deaths occurred in this cohort from 1992 to 2017. Three follow-up periods were studied: 1992-2009, 1992-2013, and 1992-2017. For each follow-up period, the lowest dose range with statistically significant (p < 0.05) radiation-induced risk of all solid cancer incidence and mortality were obtained. For the incidence of all solid cancer during the follow-up period 1992-2009, this lowest dose range was estimated to be 0-250 mGy with an excess relative risk per dose of ERR Gy-1 = 0.51 and 95% confidence interval (CI) (0.02; 1.05) Gy-1. For the period 1992-2013, the lowest dose range was 0-175 mGy with ERR Gy-1 = 0.85 (95% CI 0.03; 1.78), while for the whole follow-up period 1992-2017, it was 0-175 mGy with ERR Gy-1 = 0.81 (95% CI 0.08; 1.62). For mortality from all solid cancers during the follow-up period 1992-2009, the lowest dose range with statistically significant radiation-induced risk was estimated to be 0-225 mGy with ERR Gy-1 = 1.07 (95% CI 0.31; 0.97). For the period 1992-2013, the lowest dose range was 0-225 mGy with ERR Gy-1 = 0.86 (95% CI 0.23; 1.58), while for the whole follow-up period 1992-2017, the lowest dose range was 0-200 mGy with ERR Gy-1 = 0.82 (95% CI 0.10; 1.65). Thus, it was found that the minimal level of significant exposure (Dmin), for which a statistically significant radiation-induced risk of all solid cancers was obtained for Russian emergency workers (with individual doses of 0 - Dmin), decreases with increasing duration of cohort observation, both for cancer incidence and mortality.

Radiation Risk of Cardiovascular Diseases in the Cohort of Russian Emergency Workers of the Chernobyl Accident.

This paper continues a series of publications that analyze the impact of radiation on incidence of circulatory system diseases in the cohort of Russian recovery operation workers (liquidators) and presents the results of the analysis of cardiovascular disease (CVD) incidence. The studied cohort consists of 53,772 liquidators who arrived in the Chernobyl accident zone within the first year after the accident (26 April 1986 to 26 April 1987). The individual doses varied from 0.0001 Gy to 1.42 Gy, and the mean external whole body dose in the cohort was 0.161 Gy. A total of 27,456 cases of CVD were diagnosed during the follow-up period 1986-2012 as a result of annual health examinations. A Poisson regression model was applied to estimate radiation risks and other risk factors associated with CVD. The following factors were identified as risk factors for CVD: the dose, duration of the liquidators' work in the Chernobyl zone, and concomitant diseases (diabetes mellitus, hypertension, overweight, and alcohol dependence). The baseline incidence of CVD is statistically significantly (p < 0.001) associated with all studied concomitant diseases. The incidence of CVD has revealed a statistically significant dose response with the lack of a latent period and with the average ERR Gy = 0.47, 95% CI = 0.31, 0.63, p < 0.001. Radiation risks of CVD statistically significantly (p = 0.01) varied with the duration of liquidators' stay in the Chernobyl zone; for those who stayed in the Chernobyl zone less than 6 wk, ERR/Gy = 0.80, 95% CI = 0.53; 1.08, p < 0.001.

Radiation-epidemiological Study of Cerebrovascular Diseases in the Cohort of Russian Recovery Operation Workers of the Chernobyl Accident.

The paper presents an analysis of the incidence of cerebrovascular diseases (CeVD) in the cohort of Russian workers involved in recovery tasks after the Chernobyl accident. The studied cohort consists of 53,772 recovery operation workers (liquidators) who arrived in the zone of the Chernobyl accident within the first year after this accident (26 April 1986-26 April 1987). The mean external whole body dose in the cohort was 0.161 Gy, while individual doses varied from 0.0001 Gy to 1.42 Gy. During the follow-up period 1986-2012, a total of 23,264 cases of CeVD were diagnosed as a result of annual health examinations. A Poisson regression model was applied for estimation of radiation risks and for an assessment of other risk factors of CeVD. The following factors were considered as risk factors for CeVD: the dose, duration of the liquidators' work in the Chernobyl zone, and the concomitant diseases (hypertension, ischemic heart disease, atherosclerosis, and diabetes). The baseline incidence of CeVD is statistically significantly (p < 0.001) associated with all studied concomitant diseases. The incidence of CeVD has revealed a statistically significant dose response with the lack of a latent period and with the average ERR/Gy = 0.45, 95% CI: (0.28, 0.62), p < 0.001. Radiation risks of CeVD statistically significantly (p = 0.03) varied with the duration of liquidators' stay in the Chernobyl zone; for those who stayed in the Chernobyl zone less than 6 wk, ERR/Gy = 0.64, 95% CI = (0.38; 0.93), p < 0.001. Among studied concomitant diseases, diabetes mellitus statistically significantly (p = 0.002) increases the radiation risk of CeVD: for liquidators with diagnosed diabetes, ERR/Gy = 1.29.

[On the species independence of Mathevolepis larbicus Karpenko, 1982 (Cyclophyllidea, Hymenolepididae, Ditestolepidini)].

The cestode species Mathevolepis larbicus Karpenko, 1982 parasitizing shrews in Russian Far East is restored. As the holotype was lost, the neotype is selected. The redescription and differential diagnosis of the species are given.

[The population dynamics of the water shrew Neomys fodiens (Mammalia, Soricidae) and its helminthes fauna in the Northern Baraba]. / Dinamika populiatsii kutory obyknovennoi--Neomys fodiens (Mammalia: Soricidae) i ee gel'mintofauny v Severnoi Barabe.

The water shrew population was studied in Ust-Urgulca (Novosibirsk Province) in 1978-1990; abundance, sex and age structure, reproduction rate of this animal and its helminth fauna were examined. It was found that the abiotic factors (in particular the water level of habitat areas) influenced on the water shrew populations. The number of water shrews increased when the high water level increased. In these conditions, the population of the water shrew rejuvenated and the numbers of females increased with some increasing their fertility. In the helminthes fauna associated with the water shrew, predominated the parasite species developing in water invertebrates or ones living near water basins. When water habitats dried out, the number of water shrews decreased and individuals retained only in some areas and the population became old.

[Brachylepis gen. n.--a new genus of cestodes (Cyclophyllidea: Hymenolepididae) from shrews in Siberia and the Far East]. / Brachylepis gen. n.--novyi rod tsestod (Cyclophyllidea: Hymenolepididae) ot zemleroek Sibiri i Dal'nego Vostoka.

A new genus Brachylepis gen. n. hymenolepididean cestodes associated with common shrews (Sorex) in Siberia and Russian Far East is created. These genus includes three species removed from the genus Mathevolepis: Brachylepis morosovi (Karpenko, 1994) comb. n. (type species), B. sorextscherskii (Morosov, 1957) comb. n. and B. triovaria Karpenko, 1990) comb. n. The new genus is characterized by the gradual strobila with a little number of segments, unarmed scolex with apical glandular organ, by lack of internal seminal vesicle and differential seminal receptacle, by form of uterus as horse shoe in young worms and buble-like in mature worms. A tendency of inverse proportional dependence between the number of uterus segments in the strobila and the number of hexacanths in the uterus has been noticed. The table of differential characters for the species of the genus Brachylepis is proposed.

[A redescription of Hepatocestus hepaticus (Cestoda: Dilepididae) from shrews in western Siberia]. / Pereopisanie Hepatocestus hepaticus (Cestoda: Dilepididae) ot zemleroek Zapadnoi Sibiri.

The redescription of the cestoda Hepatocestus hepaticus (Baer, 1932) was made on the original material from the Western Siberia shrews in connection with the first registration this species at shrews within the east palearctic. The analysis of the morphology of the H. hepaticus from the western Siberian populations of shrews hadn't reveal essential morphological distinctions as compared with their western palearctic populations except that we didn't found the uterine capsules in the specimens studied by us. Crocidura sibirica Dukelsky was been registered as the definite host of this cestoda at first.

[The role of the owsianka Leucaspius delineatus in maintaining opisthorchiasis foci in Novosibirsk Province]. / Rol' verkhovki Leucaspius delineatus v podderzhanii ochagov opistorkhoza v Novosibirskoi oblasti.

Materials reflecting opisthorchiasis infection in fish in the Novosibirsk region were analyzed. On the basis of fish population estimation and studies on its invasion with Opisthorchis felineus (Rivolta, 1884) it was shown that a considerable part in maintaining opisthorchiasis foci is played by Leucaspius delineatus. It is numerous, can easily acclimatize itself in natural water bodies, inaccessible for predatory animals, easily infected with Opisthorchis larvae, and therefore can play an important role in formation of new opisthorchiasis foci during amelioration of Kulunda and Baraba forest-steppe.