Phylogeny and morphology of some European cyathocotylid digeneans (Trematoda: Diplostomoidea).

The Cyathocotylidae Mühling, 1898 is a family of primitive diplostomoid trematodes important for understanding the evolution of the superfamily Diplostomoidea. However, cyathocotylids remain poorly studied with the use of molecular techniques. In this study we sequenced the 5.8S + ITS2 region, 28S rRNA, and cox1 genes of two cyathocotylid species and obtained new morphological data on them. We propose Georduboisia nom. nov. instead of the preoccupied name Duboisia Szidat, 1936 (junior homonym of Duboisia Stremme, 1911). Adults of Georduboisia cf. teganuma (Ishii, 1935) and Paracoenogonimus ovatus Katsurada, 1914 were collected from fish-eating birds in the south of the European part of Russia. Georduboisia cf. teganuma was very similar to G.teganuma but differed from it in the shape of the testes. The 28S rRNA gene dataset provided the best-resolved phylogeny of the Cyathocotylidae to date. In the phylogram based on partial sequences of this gene, P. ovatus was close to members of Holostephanoides Dubois, 1983, Neogogatea Chandler & Rausch, 1947 and Gogatea Szidat, 1936. Georduboisia cf. teganuma clustered with members of Cyathocotyle Mühling, 1896 and Holostephanus Szidat, 1936. Phylogenetic analysis based on the 5.8S + ITS2 dataset showed that adults of P. ovatus examined in our study were conspecific with the metacercariae from the musculature of fish collected in Hungary and Italy. It also revealed probable misidentifications of larvae and adults of cyathocotylids whose sequences are deposited in GenBank NCBI.

No strict host specificity: Brain metacercariae Diplostomum petromyzifluviatilis Müller (Diesing, 1850) are conspecific with Diplostomum sp. Lineage 4 of Blasco-Costa et al. (2014).

Metacercariae of Diplostomum petromyzifluviatilis (Digenea, Diplostomidae) from the brain of European river lamprey Lampetra fluviatilis from the Baltic Sea basin and Arctic lamprey Lethenteron camtschaticum from the White Sea basin were studied with the use of genetic and morphological methods. Phylogenetic analysis based on cox1 marker showed that the parasites of both lamprey species were conspecific with Diplostomum sp. Lineage 4 of Blasco-Costa et al. (2014). The name Diplostomum petromyzifluviatilis Müller (Diesing, 1850) has historical precedence as a species described from the brain of lampreys and should be used in genus nomenclature. There were no morphological qualitative differences between the metacercariae from the two lamprey species but those from L. fluviatilis were larger than those from L. camtschaticum. We expanded the data on the second intermediate hosts and the localization of D. petromyzifluviatilis, showing that its metacercariae occur not only in the brain of lampreys but also in the brain and the retina of three-spined stickleback Gasterosteus aculeatus and the vitreous humour of the perch Perca fluviatilis across the European part of the Palearctic.

[The second stage of rehabilitation of post-infectious myelopathy after a new coronavirus infection]. / Vtoroi etap reabilitatsii postinfektsionnoi mielopatii posle perenesennoi novoi koronavirusnoi infektsii.

After suffering a new coronavirus infection (COVID-19), patients develop damage to various organs and systems, including the central nervous system. One of the rare and little-described complications is spinal cord injury. PURPOSE OF THE STUDY: Description of a clinical case of post-infectious myelopathy in a young patient after a new coronavirus infection. MATERIAL AND METHODS: Patient L., 28 years old, was admitted for rehabilitation treatment at the Regional Medical and Rehabilitation Center with a diagnosis of post-infectious myelopathy, acute period, lower central paraplegia. The patient underwent a comprehensive clinical and instrumental monitoring, including an assessment of the anamnesis, complaints, physical condition, and neurological status. The dynamics of the patient's condition was assessed using the rehabilitation routing scale, as well as the Rivermead mobility index, functional categories of walking, the Hauser walking index, the Berg balance scale, and the Frenchay hand test. RESULTS: After completion of the rehabilitation course, the patient showed positive dynamics in the form of an increase in exercise tolerance up to 40 minutes; increase in strength and volume of active movements in the lower extremities. Positive dynamics was revealed on all scales assessed. CONCLUSION: Due to the fact that the number of complications of COVID-19 is growing, it is necessary to inform doctors about the possibility of such a complication as myelopathy in order to timely diagnosis and effective treatment, which will reduce the incidence associated with spinal cord dysfunction.

[The disorder of cerebral circulation in patients of able-bodied age].

The study was organized to evaluate influence of risk factors on hospital mortality in patients with acute stroke because incidence of stroke in patients of able-bodied age is increasing. All cases of in-patient care of patients of able-bodied age with acute stroke (n=4118) in the Tyumen Oblast clinical hospital № 2 during 2010-2018 were analyzed. The study was based on sampling data from hospital medical records. During the analyzed period, decreasing of in-patient lethality up to 34.9% in patients of able-bodied age was observed. During the period of "therapeutic window" 60% of patients of able-bodied age admitted died. The multivariate analysis was applied to assess influence of different factors on in-patient mortality. The presence of coronary heart disease increases risk of mortality up to 47.5%, Exp(Beta)=1.475, employment - up to 66.8%, Exp(Beta)=1.668 as compared to baseline risk. The presence of arterial hypertension and remoteness of symptom onset in ln (hours) (hospital admission) decreases mortality risk up to approximately 39.7%, Exp (Beta)=0.603 and up to 24.0%, Exp (Beta)=0.760, respectively (specificity - 75.86%, sensitivity - 72.18%; overall diagnostic accuracy - 75.23%). In patients of working age the presence of coronary heart disease and elder age are risk factors of stroke. The presence of coronary heart disease and employment are risk factors of in-patient mortality. Whereas presence of hypertension and employment decreases risk of lethal outcome.

[The efficiency of functioning of regional vascular center in case of acute disorder of cerebral blood circulation].

The acute stroke is one of leading causes of mortality and disability both in Russia Federation and worldwide. The specialized vascular centers and units proved to be effective in improving diagnostics, treatment and functional outcome inpatients in various countries. The purpose of article is to evaluate efficacy of regional vascular center (RVC) in Tyumen. The functioning of RVC in 2011-2017 was assessed using purposefully developed and implemented score card of medical care quality assessment in vascular centers. The epidemiological data for 2007-2017 was obtained from statistical materials of the Department of Health of Tyumen oblast. The epidemiological parameters were calculated both in absolute units by simple summing up of cases of illness and in relative units per number of population. It was established that all diagnostic and treatment procedures in RVC were implemented according actual medical standards. The significant increase of the percentage of patients hospitalized during first three hours after the onset of stroke symptoms was established. The patients receiving thrombolytic therapy was observed, with an improvement of functional status of patients upon discharge. The significant improvement of early diagnosis of cerebrovascular diseases (CVD) in the service area of RVC was demonstrated. The development and implementation of the plan of a regional vascular center placement and stroke patient routing enabled optimization of medical care accessibility to this group of patients and increased identification of CVD.

Morphology and phylogeny of Henneguya oviperda infecting oocytes of Esox lucius, with description of parasite-induced histopathology.

Henneguya oviperda (Cohn, 1895) (Myxozoa: Myxobolidae) is a parasite infecting oocytes of the northern pike Esox lucius Linnaeus, 1758 (Actinopterygii: Esocidae). Infected oocytes are surrounded by all oocyte layers, some of them thinner and less visible than intact oocytes. A mature plasmodium of H. oviperda fills the entire internal space of the oocytes at the secondary growth phase, rendering the nucleus and organelles of the latter undetectable. Apart from the observed degradation of internal structures, alterations in the envelopes of the infected oocytes, and the deformation of the intact oocytes adjacent to them, no other developmental anomalies have been found in the reproductive products of female northern pike. Mature spores of H. oviperda have oval bodies with polar capsules of almost equal size and caudal projections that are on average equal to the spore body length. Phylogenetic analysis comparing 18S rDNA sequences placed H. oviperda into a clade of esocid-infecting species of the genus Henneguya and also supported H. psorospermica as a sister species.

[A regional experience of the optimization of neurological care for the rural population]. / Regional'nyi opyt optimizatsii nevrologicheskoi pomoshchi sel'skomu naseleniiu.

At present, the problem of disparity of healthcare, including neurological care, in urban and rural settings is highly relevant. Medical care after acute stroke or other chronic disabling diseases (epilepsy, Parkinson's disease) in rural settings is quite challenging due to the lack of access to specialized medical treatment facilities, low level of resources in medical and obstetric centers, low quality of healthcare, personnel turnover in rural healthcare and insufficient coverage of population with outpatient follow-up services. The most promising optimization approaches, which proved to be effective both abroad and in the Russian Federation, including Tyumen district, are the development of multidisciplinary mobile teams and telemedicine. Introduction of these approaches provides an increased access of rural population to specialized medical care, which leads to improvement in overall population health status.

[Ecological and Biochemical Aspects of Parasite-Host Interactions in Transformed Aquatic Bodies: A Case Study of the Cestode Triaenophorus nodulosus and Its Host, the Northern Pike Esox lucius].

The lysosomal enzyme activities of the cestode Triaenophorus nodulosus and its host, the pike, in-aquatic bodies with different degrees of technogenic transformation (Northern Karelia, Russia) have been studied. As has been shown, iron-ore waste causes an increase in the acid phosphatase, nuclease, and beta-galactosidase activities of the host and a decrease in its beta-glucosidase and cathepsin D activities. As a rule, the changes in the same cestode enzyme activities are the opposite. With a decrease in the technogenic load, most of the studied characteristics display the trend of approaching the corresponding values observed in a clean lake. It is assumed that the host plays a leading role in the biochemical adaptation of the parasite and its host to mineral environmental pollution.

[MORPHOLOGICAL VARIABILITY OF PROTEOCEPHALUS PERCAE (MÜLLER 1780) PARASITIZING COREGONID FISHES].

Morphological variability of Proteocephalus percae from native host--perch Perca fluviatilis and two species of coregonids (whitefish Coregonus lavaretus and Arctic cisco C. autumnalis) from fish farms of Karelia were studied. Parasite groups from 3 host species differed by morphometric parameters. Morphological structure of P. percae from native host included three morphs, those numbers were almost equal. Parasite groups of whitefish and Arctic cisco differed from that of perch in morphological structure and dominance of different morphs. Changes of the P. percae morphological structure was related to differences in ecological niches of three hosts of parasite. This reflects the initial stages of microevolution. The results obtained allow us to estimate an adaptive response of parasitic worms to new host species settling to pond.

[HELMINTHS OF THE COMMON ROACH (RUTILUS RUTILUS LINNAEUS, 1758) AND THE EUROPEAN PERCH (PERCA FLUVIALITIS LINNAEUS, 1758) IN THE LAKE TERKHIIN TSAGAAN (MONGOLIA)].

The article provides data about helminthes of the common roach and the European perch in the Lake Terkhiin Tsagaan (Mongolia). Six parasite species were found. Data on the occurrence of the trematode species and larvae of Streptocara crassicauda are obtained for the first time. Species composition of Diplostomum spp. metacercariae parasitizing in fish eyes is updated.

[PARASITES OF THE COMMON ROACH (RUTILUS RUTILUS L.) UNDER THE IMPACT OF INDUSTRIAL POLLUTION OF A LAKE].

The consequences of man-induced transformation of Lake Kostomukshskoe (tailings dump) related to increased mineralization and entry of highly dispersed dredge material not typical for northern lakes were studied using roach parasites as the example. It was found that the roach parasite fauna has been losing rare and scant parasite species of different taxonomic groups, mainly helminthes with an indirect life cycle. Common and dominant species of myxosporidians, monogeneans, trematodes of genera Diplostomum and Tylodelphys have been preserved. The chances of survival are higher for those parasites with direct life cycle. Also the parasite species whose larvae can actively penetrate the host have been survived. The species Ligula intestinalis, Philometra rishta, Pseudocapillaria tomentosa had reported very rare. Fish are infected with these parasites by feeding of Copepoda and oligochaetes.

NEW DATA ON BIRD HELMINTHS IN MONGOLIA.

For the first time the data on helminths in piscivorous birds (the great cormorant and the Mongolian gull) in Mongolia were obtained. Surveys yielded 11 species (Cestoda--2, Trematoda--6, Nematoda--3). The cormorant hosted 5 helminth species, the herring gull--6 species.

[Morphological variability and the structure of pre-reproductive age group of the cestode Proteocephalus torulosus from Altai osman (Oreoleuciscus, Cyprinidae) in water bodies of Mongolia].

Morphological variability of immature Proteocephalus torulosus was studied for the first time. On the basis of scolex shape, three phenotypes were distinguished: clavate, rounded, and lanceolate. The clavate phenotype was found to be dominant, the rounded one is small in number, and the lanceolate one is rare. The wide ranges of morphometric variability were established. The clavate phenotype differs from the rounded one by its higher variability. The high morphologic variability of immature P. torulosus is comparable to that in adult mature parasites from Altai osman, the Central Asian endemic from the genus Oreoleuciscus. The conclusion is made on the influence of extremely changeable environmental condition in the region on the parasite and host adaptations during their co-evolution.

[Parasites of the Osprey (Pandion haliaetus) in northwestern Russia].

New data on Ospey parasites in Karelian Republic are given. One specimen was investigated. Two parasite species--Nematostrigea serpens and Diplostomum pseudospathaceum were found. Trematoda D. pseudospathaceum was recorded in Osprey parasite fauna for the first time.

[Specific features of the numbers and structure of the population of Proteocephalus longicollis (Zeder 1800) (Cestoda: Proteocephalidea)--a mass parasite of whitefish Coregonus lavaretus L. under conditions of technogenic pollution of the water body].

The numbers, age structure, and morphological variation of the cestode Proteocephalus longicollis from whitefish of a natural water body (Kamennoe Lake) and those of Kostomuksha Lake polluted with wastes of the mining industry (Northern Karelia) have been studied. In the polluted water body, a high infestation of whitefish and domination of larval stages in the structure of the parasite population have been established. It is shown that under conditions of pollution, only one of the variations ofscolex signs dominates in the structure of phenotypic diversity. The size indices of cestodes are reliably smaller as compared with cestodes from the natural water body. The data obtained indicate that technogenic pollution determines a decrease in the intrapopulation diversity of P. longiocollis, and a decrease in the values of morphometric characters indicates inhibition of the morphophysiological state of individuals.

[Trematodes fauna of waterfowl birds in Karelia].

Trematode fauna of waterfowl birds of Karelia comprises 23 species; 8 of them are described from the region for the first time. Descriptions and figures of Urogonimus macrostomus, Neoeucotyle zakharovi, Hypoderaeum conoideum, Echinostoma robustum, Orchipedum tracheicola, Prostogonimus cuneatus P. ovatus, and P. rarus are given.

[Peculiarities of the biology and parasite fauna of juvenile Atlantic salmon (Salmo salar L.) in the Pista River (White Sea Basin), according to the Gyrodactylus salaris infestation].

Juvenile salmon Salmo salar m. sebago Girard from the Pista River system (the White Sea Basin) was investigated. The data on species composition and occurrence peculiarities of Gyrodactylus salaris Malmberg, 1957 are given. This monogenean is the alien species for the river system and it is recorded for the first time. It is shown that the distribution of the parasite abundance is can be described as the negative binomial distribution; variations of its parameters (k and p) were also characterized. Parasitological data obtained, as well as the data describing the characteristics of growth and age structure of juvenile salmon population, suggest the potential influence of G. salaris infection on the degree of survival of fishes in the lake-river system examined.

[Population biology of cestode genus Triaenophorus in natural and man-made water bodies].

A comparative study of the frequencies of occurrence and distribution of the abundances of pike parasites, tapeworms of the genus Triaenophorus, was carried out in natural lakes and water bodies contaminated by the Kostomuksha mining and concentration mill (Northern Karelia). We demonstrate that the wide presence of T. crassus and T. nodulosus in natural northern lakes is due to the diversity of aquatic organisms and the structure of trophic relations. The abundance of both species is modeled by the negative binomial distribution. Relations in the host-parasite system are stable. Estimates of the parameter k of the negative binomial distribution reflect the changes in the interactions in the host-parasite system. T. nodulosus has survived in the man-made water body storing the highly mineralized recirculated water from the mill. Disturbance-related distinctions were detected in the parameters of the T. nodulosus abundance distribution in the host population. In the Okunevoye Lake, where the water discharged from the tailings dump is more diluted, the infection rates in pike did not differ from those in undisturbed water bodies.

[Peculiarities of the parasitofauna of Atlantic salmon parr (Salmo salar L.), brown trout (Salmo truttae L.), and char (Salvelinus alpinus L.) in the Utsjoki River system (Northern Finland)].

Data on the parasite diversity in Salmonidae fish parr from different parts of the Utsjoki River obtained during 1993-1995 and 2006-2007 are presented. Three fish species, Salmo salar L., S. truttae L., and Salvelinus alpinus L., were examined on the presence of helminthes. Twenty species of salmon parasites were found, the majority of which are the parasites with complicated life cycles. Infusorians C apriniana piscium, myxosporidia Chloromyxum januaricus and Myxobolus neurobius, metacercaria of the genera Diplostomum and Apatemon, and the nematode Raphidascaris acus larvae were the most numerous in salmon parasite fauna. Brown trout had the most number of specific parasite species, whereas char was infested by protozoan parasites only.

[Trematode fauna patterns of the freshwater fish on the border of the geographical range].

The trematode fauna of the fishes inhabiting Lake Ladoga are represented by forty-six species; nine species of which are found here on the northern boudary of their geographic range. The depauperization of the trematode fauna compared to the southern pools is a result both of the decreasing impact of the Pont-Caspian group and of the introduction of the boreal piedmont species complex. The increase in the biological productivity of Lake Ladoga for the last 50-year period leads to enrichment of the species biodiversity. The same process increases the invasion extensiveness by trematodes, which use fish as an intermediate host. The Diplostomida, the presence of which is crucial for the young fish survival rate, dominate among the trematodes.