[EPIZOOTOLOGICAL CHARACTERIZATION OF TREMATODIASIS FOCI IN THE ECOSYSTEM OF THE AMUR RIVER IN THE KHABAROVSK TERRITORY].

Investigations were conducted in late June to early June 2013. The population density of mollusks of the genus Juga in the shoreline and littoral covered by meadow waters was 10 to 30 specimens/m2; there were solitary specimens of the genus Parafossarulus. Fourteen out of 39 fish species were invaded by metacercariae of Clonorchis. Manchurian spiny loaches (Leptobotia) and Light's bitterling (Rhodeus lighti) are first registered to be hosts of Clonorchis. The metacercariae of Metagonimus yokogawai were detected in silver carp (Hypophthalmichthys molitrix) and those of Nanophyetus salmincola schikhobalowi were in the kidneys, fin muscles, and gills of taimen (Hucho) and lenok (Brachymystax lenok) from the Khor River. The invasion rate for the taimen was greater than 1000 metacercariae and that for the lenok was not more than 720 metacercariae per fish.

[Social bases for the functioning of nanophyetiasis foci in the Amur region].

Parasitological examination of the population of the Amur Region has revealed that the nanophyetiasis foci affecting as high as 28.4% of the people are being preserved and functioning now; at the same time the highest rates of infection with the trematode Nanophyetus salmincola schikhobalowi are seen in the dwellers of the populated areas situated on the banks of the mountain Amur tributaries. It has been ascertained that the major season when the population is infected with Nanophyetus is summer and its highest incidence are noted in autumn (November) after the active fishing season is completed. It has been found that infection occurs in infants and the maximum incidence is in the age group of 21-30 years (45.5%) and remains virtually the same in a middle-aged population [31-50 years (37.0-42.2%)], by decreasing slightly in the older age groups (18.2-21.7%). According to the questionnaire survey data, fish (90% of its species are an intermediate host for Nanophyetus) is a staple food in the population of the highest incidence rural areas. The major causes of Nanophyetus infection are the wide consumption of raw and low-salt fish and a low population awareness of measures to prevent helminthiasis, the transmission factor of which is fish.

[Entomological monitoring of an area to assess Dirofilaria transmission risk].

As the basis for entomological monitoring, the authors first propose to investigate the structure of a season of D. repens invasion transmission in the carrier in relation to the ambient temperature, such as onset of a transmission season, terminaton of mosquito infection, the number of invasion circulations. A calculating procedure has been developed. It is shown that there is a need for entomological monitoring of each specific area irrespective of the latitude to study a risk for local dirofilariasis cases.

[Results of studies of human dirofilariasis in Russia].

Human dirofilariasis is a pressing health problem in Russia. By 2014, there have been as many as 850 Dirofilaria repens-infested people living in 42 subjects of the Russian Federation. One of the favorable factors for circulation and spread of invasion is a temperature of above +20-24 degrees C; when the latter is maintained during at least 20 days there may be 1.-1.5 circulations of invasion in the carrier and a 2.8-fold increase in transmission intensity. The border ofa dirofilariasis area with a temperate climate is southward to 58 degrees N in European Russia and West Siberia and southward to 50 degrees N in the Far East. The conditions in the human body have been found to be more favorable for the development of Dirofilaria than considered before and allow the helminth to achieve sexual maturity and to propagate. If man has microfilaremia, he may be a source of invasion. It is necessary to examine venous blood by the enrichment method and, if possible, polymerase chain reaction and enzyme immunoassay, which make it possible to establish a diagnosis in occult invasion and to identify a pathogen species.

[A new method of comparative analysis of gene expression and identification of differentially expressed mRNA]. / Novyi metod sravnitel'nogo analiza ékspressii genov i identifikatsii differentsial'no ékspressiruiushchikhsiia mRNK.

A novel method of comparative gene expression analysis is proposed which is based on representing a population of expressed mRNA sequences in the form of a set of discrete cDNA restriction fragments. By means of selective isolation of 3' terminal cDNA fragments, each mRNA species is represented by no more than one cDNA fragment of specific length and sequence. Populations of cDNA fragments from different cell types are separated by high-resolution gel electrophoresis, and the separation patterns are compared. Using the proposed approach, fragments of two genes differentially expressed in murine thymus and spleen were identified and cloned. One of the genes was found to encode the terminal deoxynucleotidyltransferase, the there is apparently a heretofore unknown gene.