New Gland Type Discovered in Cestodes: Neurosecretory Neurons Release a Secret into the Fish Host.

Free endings of peripheral neurosecretory neurons (NNs) were found in the tegument of plerocercoids of five species of parasitic cestodes of fish in an ultrastructural study. The free terminals secreted vesicles on the tegument surface and into the host body. Secretion was experimentally shown to increase in response to the host fish blood serum.

The neuro-exocrine secretion: A new type of gland in tapeworms?

The phenomenon of exocrine secretion via nervous cells into the host tissue has been discovered in cestodes. In five cestode species of different orders specialized "cup-shaped" free nerve endings located in the tegument have been found. Their ultrastructure is characterized by the presence of a septate junction, a thin support ring and neurosecretory vesicles 90-110 nm in diameter, which are secreted onto the surface of the tegument through a thin pore.

Comparative transcriptomic analysis of the larval and adult stages of Dibothriocephalus dendriticus (Cestoda: Diphyllobothriidea).

Tapeworms of the genus Dibothriocephalus are widely distributed throughout the world, some of which are agents of human diphyllobothriasis, one of the most important fish-borne zoonoses caused by a cestode parasite. Genomic and transcriptomic data can be used to develop future diagnostic tools and epidemiological studies. The present work focuses on a comparative analysis of the transcriptomes of adult and plerocercoid D.

Efficient delivery of Echinococcus multilocularis miRNAs using chitosan nanoparticles.

Alveolar echinococcosis caused by Echinococcus multilocularis is an important zoonotic disease, a great threat to human health due to limited interventions. microRNAs are a type of small non-coding RNA that plays a key role in many diseases and is considered as a potential therapeutic target for control of parasitic diseases. However, naked miRNAs are difficult to enter into cells and are easily degraded in both external and internal environments.

Population genetic structure of diphyllobothriid tapeworms (Cestoda: Diphyllobothriidea) parasitising fish in the Baikal Rift Zone.

Tapeworms of the genus Dibothriocephalus are widely distributed throughout the world, and some are agents of human diphyllobothriasis, one of the most important fish-borne zoonoses caused by a cestode parasite. Until now, the population genetic structure of diphyllobothriid tapeworms in the Baikal Rift Zone (BRZ) has remained unexplored. The major aim of this study was to analyse the population genetic structure of D.

Experimental study of ultrastructural mechanisms and kinetics of tegumental secretion in cestodes parasitizing fish (Cestoda: Diphyllobothriidea).

The structural response and plasticity of the cestode tegument in response to the influence of the host organism is not yet well understood. The main aims of our in vitro study were to analyse the ultrastructural mechanisms and kinetics of tegumental secretion in two cestode species, Dibothriocephalus dendriticus and Ligula interrupta, in response to the influence of fish host blood serum. The incubation of plerocercoids in the culture medium, which contained fish host blood serum, resulted in an increased number of secretory products on the tegumental surface.

Comparative analysis of different extracellular vesicles secreted by Echinococcus granulosus protoscoleces.

Extracellular vesicles (EVs) are heterogeneous populations of different membrane-wrapped vesicles in size and encapsulated cargo and have recently emerged as a crucial carrier with the functions in intercellular communication, being involved in host-parasite interactions. However, Echinococcus granulosus EVs are not fully described. To separate EVs with a different size, the culture supernatant of E.

miRNA-seq of Extracellular Vesicles and Immunomodulatory Effects of miR-4989.

Alveolar echinococcosis caused by is an important zoonotic disease. In the infected mice, emu-miR-4989-3p is present in sera, but its role remains unknown. Using high-throughput sequencing and qPCR, emu-miR-4989-3p was herein confirmed to be encapsulated into extracellular vesicles.

High-throughput identification of microRNAs in Taenia hydatigena, a cestode threatening livestock breeding industry.

Infection of Cysticercus tenuicollis, the larval stage of Taenia hydatigena, is extensively found in sheep and pigs and jeopardizes the breeding and meat industry. miRNAs are a subclass of small noncoding regulatory RNAs and closely associated with the pathogenesis and biology of parasites. Here, using HiSeq sequencing we identified 49 known and 2 potential novel miRNAs in C.

In vitro effects of the neuroactive substances serotonin and γ-aminobutyric acid on leucocytes from sticklebacks (Gasterosteus aculeatus).

The majority of parasites have evolved strategies to evade the immune responses of their hosts. Neuroactive substances produced by cestodes are possible candidate molecules for regulating host immune responses. The neurons of helminths can synthesize a wide range of molecules that are identical to the ones functioning in their host organisms, and host lymphocytes have receptors for these neuroactive substances.

Identification of emu-TegP11, an EF-hand domain-containing tegumental protein of Echinococcus multilocularis.

Tegumental proteins (TegPs) are a group of proteins that coat on the surface of worms, mainly being involved in ion uptake and immune evasion. Echinococcus species have many TegPs, but none of them have been characterized and their role remains unclear. The genome-wide analysis revealed that there were at least 14 tegp genes (tegp1 - 14) in Echinococcus species, the majority of which were found to contain an EF-hand domain or a dynein light chain-like domain or both.

Dataset of proinflammatory cytokine and cytokine receptor gene expression in rainbow trout () measured using a novel GeXP multiplex, RT-PCR assay.

A GeXP multiplex, RT-PCR assay was developed and optimized that simultaneously measures expression of a suite of immune-relevant genes in rainbow trout (), concentrating on tumor necrosis factor and interleukin-1 ligand/receptor systems and acute phase response genes. The dataset includes expression values for , , , , , (e3-5), (e9-11), , , , , , , , , , , , and . Gene expression was measured at four time-points post-challenge in both a resistant line (ARS-Fp-R) and a susceptible line (ARS-Fp-S) of rainbow trout.

Prostaglandins E and D-regulators of host immunity in the model parasite Diphyllobothrium dendriticum: An immunocytochemical and biochemical study.

The spectrum of immunomodulating molecules produced by tapeworms is not yet well understood. The aims of this study, on the tapeworm Diphyllobothrium dendriticum, were: 1) detection and quantification of prostaglandins (PGs) E and D by high performance liquid chromatography; 2) visualization of PGE and PGD in specific cells, using methods of immunocytochemistry and confocal laser scanning microscopy; and 3) investigation of the ultrastructure of the cells potentially producing PGE and PGD. The PGE immunoreaction (IR) was found in the apical terminals of the frontal glands and sensory organs in the tegument and in small neurons belonging to the main cords and commissures.

Proinflammatory cytokine and cytokine receptor gene expression kinetics following challenge with Flavobacterium psychrophilum in resistant and susceptible lines of rainbow trout (Oncorhynchus mykiss).

Flavobacterium psychrophilum (Fp) is the causative agent of bacterial cold water disease (BCWD) which causes appreciable economic losses in rainbow trout aquaculture. We previously reported development of a genetic line, designated ARS-Fp-R that exhibits higher survival relative to a susceptible line, designated ARS-Fp-S, following either laboratory or natural on-farm challenge. The objectives of this study were to determine the temporal kinetics of gene expression between experimentally-challenged ARS-Fp-R and ARS-Fp-S fish and the correlation between gene expression and pathogen load.

[Localization of prostaglandin E2, γ-aminobutyric acid, and other potential immunomodulators in the plerocercoid Diphyllobothrium dendriticum (Cestoda)].

For the first time, the potential immunomodulators prostaglandin E2 and γ-aminobutyric acid (GABA) have been revealed in the plerocercoid Diphyllobothrium dendriticum, which is a parasite in the tissues and abdominal cavity of the Baikal omul Coregonus migratorius. The localization of immunomodulators in parasite tissues was compared with the location of typical markers of the nervous system (serotonin (5-HT) and FMRF-amide) and a marker of microtubules (α-tubulin). Prostaglandin E2 was revealed in the cells that are immunoreactive to α-tubulin and are situated in the cortical parenchyma outside the central nervous system (CNS).

In vitro effects of prostaglandin E2 on leucocytes from sticklebacks (Gasterosteus aculeatus) infected and not infected with the cestode Schistocephalus solidus.

Many helminth parasites have evolved strategies to evade the immune response of their hosts, which includes immunomodulation. Prostaglandin E2 (PGE2) is one of the best-described immunomodulators in mammalian helminth parasite infections. We hypothesized that also in teleost fish anti-helminthic immune responses are regulated via PGE2.

GABA in the nervous system of the cestodes Diphyllobothrium dendriticum (Diphyllobothriidea) and Caryophyllaeus laticeps (Caryophyllidea), with comparative analysis of muscle innervation.

The nervous system (NS) of the cestodes Diphyllobothrium dendriticum (Diphyllobothriidea) and Caryophyllaeus laticeps (Caryophyllidea) was investigated using immunocytochemistry. The GABA neurotransmitter was identified in the NS of both species; GABAergic neurons were detected in the main nerve cords (MC). GABA-like immunoreactive neurons were predominantly unipolar and exhibited more intensive immunoreactivity in the neurite than in the perikaryon.

[Composition of leucocytes of the head kidney of the crucian carp Carassius auratus gibelio (Cypriniformes: Cyprinidae) as affected by invasion of cestode Digramma interrupta (Cestoda; Pseudophyllidea)].

The composition of leucocytes of the head kidney is studied in the crucian carps (Carassius auratus) either contaminated or uncontaminated with Digramma interrupta. The composition of leucocytes in the pronephros of the crucian carp from Lake Baikal basin has a lymphoid character. Compared to the crucian carp from the European part of Russia, in the fish from Baikal the granulocytopoetic processes are more pronounced.

Perspectives on the use of marine and freshwater hydrobiont oils for development of drug delivery systems.

Marine foods represent a unique source of poly-unsaturated fatty acids (PUFA) of the omega-3 (n-3) family. Today it is generally accepted that fish oil is important in a healthy and balanced omnivorous human diet. This favorable health perception of fish oil is however troubled by the high level of PUFA oxidation and low absorption in the gastro-intestinal tract.

[Changes in mast cell composition in the hamster duodenum in experimental diphyllobothriosis].

The morphometric investigation was performed to study the reaction of mast cells (MC) in mucosal lamina propria of hamster duodenum to experimental infection with tapeworm Diphyllobothrium dendriticum. The invasion was found to result in a significant increase of MC cells absolute content, changes in the proportions of their functional groups, increased anaphylactic MC degranulation, enhanced MC precursor migration and their accelerated differentiation.

[Detection of arbovirus antigens in the mosquitoes and ticks inhabiting the Saratov Region].

The paper gives the results of a study dealing with the detection of the antigens of arboviruses of West Nile, Sindbis, Batai, Crimean-Congo hemorrhagic fever, a serocomplex of Californian encephalitis in the field material gathered in the Saratov Region in 2000-2006. The bloodsucking arthropods inhabiting the region were shown to be actively involved in the circulation of arboviruses in natural biotopes. The conclusion that it is expedient to organize an annual monitoring of arbovirus-induced infections in the areas where positive findings have been notified is justified.

[Cellular composition of the mesenteric lymph node cortex in Baikal nerpa during postnatal ontogenesis].

Cellular composition (relative cell content and cell density) of nodules' germinal centers, mantle zones and paracortical zones was evaluated morphometrically in mesenteric lymph nodes of 65 Baikal nerpas (Pusa sibirica Gmelin) aged 1 month-19 years. A significant decrease in the number of large and medium lymphocytes (3 and 1.9 times, respectively) and reticular cells (2.

[Structural organization of mesenteric lymph nodes in postnatal development of the Baikal seal, Pusa sibirica Gmel].

Structural organization of mesenteric lymph nodes in the Baikal seal has been studied with regard to its age-dependent changes. It has been shown that the relative area of connective tissue structures (the capsule and trabeculae) increases during postnatal development, while the areas of the cortex and medulla decrease. The proportions of secondary lymph nodes and paracortical zone in the cortex become smaller, with the corticomedullary index tending to decrease with age.