Search

Epilepsy is a common neurological disorder that affects approximately 1% of the world’s pop7u-lation. About one third of those patients suffer from treatment-resistant epilepsy (TRE8), defined as failure to stop seizures despite adequate trials of at least two medications at therapeutic dosa-ges. There has been a growing interest in the development of novel antiepileptic drugs with diffe-rent mechanisms of action. This narrative review, based on 42 references retrieved from Scopus and Medline, discusses the scientific data from human and animal studies regarding the efficacy of cannabis-based treatment for epilepsy. Benefits have been described in pre-clinical and cli-nical studies in children, but ongoing research will clarify the real role of cannabinoids in TRE.

Cercariae of Plagiorchis spp. are frequently reported in European freshwater snails, but their true diversity is difficult to estimate due to subtle differences in morphology. We molecularly characterized 67 isolates of Plagiorchis cercariae collected from four lymnaeid snail hosts, Ampullaceana balthica, Ampullaceana lagotis, Radix auricularia and Lymnaea stagnalis in freshwater ecosystems in the Czech Republic and Poland. Based on mitochondrial cox1 and nuclear 28S sequences, ten species or species-level lineages were identified, including the first molecular evidence of P. vespertilionis from snail hosts and two species-level lineages reported for the first time. Previously undescribed species and species-level lineages are characterized morphometrically. We confirm the overlapping spatial distribution of Plagiorchis spp. in their snail hosts from Central Europe with those from Western and sub-Arctic Europe. Our results increase the known diversity of Plagiorchis spp. in Europe to 25 species/lineages in snails, but further research is needed to establish links between life cycle stages and to assess the host specificity of these parasites. [ABSTRACT FROM AUTHOR]

Although some parasitological efforts have focused on the frigate tuna Auxis thazard (Lacepède) (Scombriformes, Scombridae) in Brazil, its digenean fauna remains poorly known. Combining morphological and molecular methods, we investigated the diversity of digenean trematodes of A. thazard collected from the coastal waters off the state of Rio de Janeiro, Brazil in 2021. Six species belonging to four families were recorded: the bucephalid Rhipidocotyle cf. angusticolle Chandler, 1941, the didymozoid Didymocystis sp. 6 sensu Louvard et al. (2022), the fellodistomid Tergestia sp., and three hemiurids, Dinurus euthynni Yamaguti, 1934, Lecithochirium floridense (Manter, 1934), and L. synodi Manter, 1931. The current study brings the total number of digenean trematode species parasitising A. thazard in Brazil up to eight, with hemiuroid trematodes being most diverse. Auxis thazard is a new host record for L. floridense, L. synodi and potentially for R. angusticolle. The geographic distribution of several species found in our study appeared to be wider than previously known. Our study is the first to apply a DNA-based approach to digenean diversity in marine fishes in Brazil and we believe that both morphological descriptions and molecular sequence data provided in our study will aid future research assessing the diversity of digenean trematodes of A. thazard and other marine fishes in Brazil.

Despite recent advances in the molecular knowledge of amphistome trematodes, most genera known from fish remain to be genetically characterized. This is the case for Kalitrema, a genus of the speciose family Cladorchiidae and the type of Kalitrematinae. The type and only species of this genus, Kalitrema kalitrema Travassos, 1933, was originally proposed based on two specimens found in an armored suckermouth catfish from Brazil, and its phylogenetic position has not been evaluated. In this study, paramphistomes found in Hypostomus alatus (2/9; 22.2%) and Hypostomus francisci (4/143; 2.8%) from the Paraobepa River (São Francisco River basin), Minas Gerais, Brazil, between December 2019 and November 2021, were subjected to morphological study. The parasites were identified in low intensity of infection [1.2 (1–2)] and redescribed as K. kalitrema. This species exhibits unique features such as a linguiform body with a circular ridge near the anterior end and a deep, median notch present at the posterior extremity of the body, apparently dividing the body into two lobes. A subset of specimens was further subject to phylogenetic analyses based on the most densely sampled markers, the nuclear ribosomal RNA (28S and ITS2) and mitochondrial cox1, which revealed the inclusion of K. kalitrema in a Neotropical clade of fish paramphistomes. The most comprehensive phylogenetic tree, based on the 28S dataset, confirmed K. kalitrema as an independent, early diverging lineage among Neotropical fish cladorchiids. However, the monophyly of Kalitrematinae was not sustained, given that species of the other kalitrematine genera Pseudocladorchis and Iquitostrema included in the phylogenetic analysis fell in a distinct clade with other fish cladorchiids. As a result, we propose here a narrower concept for Kalitrematinae sensu stricto, accommodating only Kalitrema (type genus) until a more natural subfamilial or familial classification is provided. [ABSTRACT FROM AUTHOR]

The biodiversity of freshwater ecosystems globally still leaves much to be discovered, not least in the trematode parasite fauna they support. Echinostome trematode parasites have complex, multiple-host life-cycles, often involving migratory bird definitive hosts, thus leading to widespread distributions. Here, we examined the echinostome diversity in freshwater ecosystems at high latitude locations in Iceland, Finland, Ireland and Alaska (USA). We report 14 echinostome species identified morphologically and molecularly from analyses of nad1 and 28S rDNA sequence data. We found echinostomes parasitising snails of 11 species from the families Lymnaeidae, Planorbidae, Physidae and Valvatidae. The number of echinostome species in different hosts did not vary greatly and ranged from one to three species. Of these 14 trematode species, we discovered four species (Echinoparyphium sp. 1, Echinoparyphium sp. 2, Neopetasiger sp. 5, and Echinostomatidae gen. sp.) as novel in Europe; we provide descriptions for the newly recorded species and those not previously associated with DNA sequences. Two species from Iceland (Neopetasiger islandicus and Echinoparyphium sp. 2) were recorded in both Iceland and North America. All species found in Ireland are new records for this country. Via an integrative taxonomic approach taken, both morphological and molecular data are provided for comparison with future studies to elucidate many of the unknown parasite life cycles and transmission routes. Our reports of species distributions spanning Europe and North America highlight the need for parasite biodiversity assessments across large geographical areas.

Simple Summary: Brazil, with its remarkably diverse marine habitats, harbour one of the world's richest fish diversities. Consequently, the diversity of their trematode parasites is also expected to be extremely rich. However, our current knowledge on this group of animals is incomplete and there are many unknown trematode species that await discovery and genetic characterisation. The Hemiuridae (Digenea) is the second most speciose trematode family in marine fishes from Brazil; however, to date, it remains understudied. We examined forty-three specimens of nine fish species belonging to eight families (Carangidae, Clupeidae, Haemulidae, Muraenidae, Percophidae, Pinguipedidae, Trichiuridae, and Triglidae) collected from the coastal zone off Rio de Janeiro, Brazil and found hemiurid trematodes in the stomach of 14 fishes. Using morphological and molecular analyses, we identified eight species from four genera of the family Hemiuridae. One of these species is reported in Brazil for the first time, four are reported from new fish hosts, and four were genetically characterised for the first time. Our novel data contributes to the knowledge on marine biodiversity in Brazil and will further contribute to the classification of the family Hemiuridae. Brazil is a tropical country with remarkably diverse marine habitats that harbour a rich diversity of fish. Only a small portion of this fish diversity has been investigated for parasites, and thus the diversity of their trematode parasites remains unexplored. Moreover, only 5 out of 184 known digenean trematode species of marine fish in Brazil have been genetically characterised. The Hemiuridae Looss, 1899 is the second most speciose trematode family in marine fishes from Brazil but, in many ways, it remains a neglected group. Forty-three trematode specimens from nine fish species were collected from the coastal zone off Rio de Janeiro, Brazil. Trematodes were found in the stomach of 14 specimens of 9 fish species belonging to 8 families (Carangidae, Clupeidae, Haemulidae, Muraenidae, Percophidae, Pinguipedidae, Trichiuridae, and Triglidae). Trematode specimens were studied using morphological and molecular genetic analyses. A total of eight hemiurid species from four genera, Ectenurus, Lecithochirium, Myosaccium, and Parahemiurus were identified. This paper reports on new host records for four species of hemiurids, adds a new record on the geographical distribution for one species, and provides the first DNA sequence data supplemented with the detailed description of morphology for five species. Phylogenetic analyses supported that the subfamily classifications of the Hemiuridae—based entirely on morphological characters—needs to be reconsidered, taking into account a wider range of information sources. [ABSTRACT FROM AUTHOR]

Excessive water production in mature heavy oil fields causes incremental costs, energy consumption, and inefficiency. Understanding multiphase flows near the wellbore is an alternative to improve production efficiency. Therefore, this study conducts a series of numerical experiments based on the full set of the Navier-Stokes equations in 3D to simulate multiphase flows in porous media for heavy oil production horizontal wells. The solution given by this advanced mathematical formulation led to the description of the movement of the fluids near the wellbore with unprecedented detail. A sensitivity analysis was conducted on different rock and fluid properties such as permeability and oil viscosity, assuming homogeneous porous media. The influence of these parameters on the prediction of the breakthrough time, aquifer movement, and the severity of water production was noticed. Finally, the numerical model was verified against field data using two approaches. The first one was conducting a history match assuming homogeneous rock properties. In contrast, the second one used heterogeneous rock properties measured from well logging, achieving a lower deviation than field data, about 20%. The homogeneous numerical experiments showed that the breakthrough occurs at the heel with a subsequent crestation along the horizontal well. Moreover, at adverse mobility ratios, excessive water production tends to happen in water connings at the heel with an inflow area less than 1% of the total inflow area of the completion liner. Different aquifer movement dynamics were found for the heterogeneous case, like the breakthrough through multiple locations along the horizontal well. Finally, critical hydraulic data in the well, such as the pressure and velocity profiles, were obtained, which could be used to improve production efficiency. The numerical model presented in this study is proposed as an alternative to conducting subsurface modeling and well designs. [ABSTRACT FROM AUTHOR]

Parasites are important components of ecosystems, thus identifying patterns of their diversity is crucial for studies investigating ecosystem functioning, food web structure, trophic interactions and epidemiological parameters. Via an integrative taxonomic approach, we studied the diversity and distribution of trematodes of the genus Plagiorchis Lühe, 1899 in snails in the sub‐Arctic freshwater ecosystems of Iceland and for comparative purposes in West and North Europe (Ireland and Finland, respectively), supplemented by data from Alaska, USA, all regions with remarkably few data on trematode diversity. Molecular genetic and morphological analyses of 68 samples of cercarial isolates of Plagiorchis collected from 3,069 snails belonging to six species revealed a total of 16 species/species‐level lineages of Plagiorchis with five found in Iceland, six in Finland, nine in Ireland and five in Alaska. Two species‐level lineages found in Iceland, Finland and Ireland were reported for the first time; for all species/species‐level lineages identified by DNA sequences we provide the first morphological characterization. Our analysis of the diversity of Plagiorchis and their snail host spectrum in Europe provides evidence for Radix balthica and Lymnaea stagnalis as primary first intermediate hosts. By comparing DNA sequence data for Plagiorchis spp. from this and previous studies, we demonstrate no overlapping spatial distribution for members of the genus in our material between the continents of Europe and North America. We infer that the spatial distribution of Plagiorchis spp. is constrained mainly by migratory birds' ranges. Finally, in Europe, further research is needed to evaluate whether the diversity of Plagiorchis spp. in R. balthica is unique to high latitude ecosystems. [ABSTRACT FROM AUTHOR]

During the last decade, many morphotypes of larval forms of Hysterothylacium have been proposed; however, their boundaries are taxonomically unclear. We compare newly collected material with data available for Hysterothylacium larvae, based on genetics and morphology, in order to evaluate their relationships and simplify their classification. The previously described Hysterothylacium larval type IV, type V, and type X were found in several marine fishes from Brazil. A new Hysterothylacium larval type XV, parasitic in Elops saurus from State of Sergipe, north-eastern Brazil, was proposed based on its genetic singularity and the presence of numerous spines throughout the body. Based upon phylogenetic reconstruction using the ribosomal DNA (rDNA) ITS2 sequences along with morphological traits, the following third stage larvae were considered valid (synonyms are inside parenthesis) type III (= types VII and VIII), type V (= types VI, XII, and XIII), and type X (= type XIV). Despite the lack of molecular data, Hysterothylacium larval type II is considered as synonym of type I because of their identical morphology. The morphometry of Hysterothylacium third stage larvae proved to be weak as a diagnostic tool due to its high rates of variation. Phylogenetic reconstruction using the concatenated sequences of rDNA ITS1-5.8S-ITS2 and the mitochondrion DNA (mtDNA) cox2 revealed that the sampled Hysterothylacium larval types V may represent three different species and H. deardorffovestreetorum may represent two different taxa. Furthermore, H. deardorffovestreetorum is considered species inquirenda due to its problematic description and diagnosis which are based only on larvae. A key to Hysterothylacium larvae from marine fishes is provided. [ABSTRACT FROM AUTHOR]

Copyright of Revista Brasileira de Saúde e Produção Animal (RBSPA) is the property of Revista Brasileira de Saude e Producao Animal (RBSPA) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Parasites might represent a helpful tool in understanding the historical dispersion and phylogeography of their hosts. In order to reveal whether the migration routes and diversification of hosts can be traceable in the genetic structures of their parasites, we investigated the diversity of paramphistomoid trematodes of Pelophylax frogs in 2 geographically distant European regions. Water frogs belonging to the genus Pelophylax represent a striking example of a species with a high variety of ecological adaptations and a rich evolutionary history. The parasites were collected from 2 Balkan endemic species, P. epeiroticus and P. kurtmuelleri , and 2 species in Slovakia, P. esculentus and P. ridibundus . While in Slovakia, Pelophylax frogs harboured 2 species, the diplodiscid Diplodiscus subclavatus and the cladorchiid Opisthodiscus diplodiscoides , only the former was recorded in the south-western Balkans. Remarkably high genetic diversity (16 unique mitochondrial cox 1 haplotypes, recognized among 60 novel sequences) was observed in D. subclavatus , and subsequent phylogenetic analyses revealed a strong population-genetic structure associated with geographical distribution. We also evidenced the existence of 2 divergent D. subclavatus cox 1 haplogroups in the south-western Balkans, which might be associated with the historical diversification of endemic water frogs in the regional glacial microrefugia.

DNA sequence data became an integral part of species characterization and identification. Still, specimens associated with a particular DNA sequence must be identified by the use of traditional morphology-based analysis and correct linking of sequence and identification must be ensured. Only a small part of DNA sequences of the genus Diplostomum (Diplostomidae) is based on adult isolates which are essential for accurate identification. In this study, we provide species identification with an aid of morphological and molecular (cox1, ITS-5.8S-ITS2 and 28S) characterization of adults of Diplostomum baeri Dubois, 1937 from naturally infected Larus canus Linnaeus in Karelia, Russia. Furthermore, we reveal that the DNA sequences of our isolates of D. baeri are identical with those of the lineage Diplostomum sp. clade Q , while other sequences labelled as the ‘D. baeri’ complex do not represent lineages of D. baeri. Our new material of cercariae from Radix balthica (Linnaeus) in Ireland is also linked to Diplostomum sp. clade Q. We reveal that D. baeri is widely distributed in Europe; as first intermediate hosts lymnaeid snails (Radix auricularia (Linnaeus), R. balthica) are used; metacercariae occur in eye lens of cyprinid fishes. In light of the convoluted taxonomy of D. baeri and other Diplostomum spp., we extend the recommendations of Blasco-Costa et al. (2016, Systematic Parasitology 93, 295–306) for the ‘best practice’ in molecular approaches to trematode systematics. The current study is another step in elucidating the species spectrum of Diplostomum based on integrative taxonomy with well-described morphology of adults linked to sequences.

The first molecular assessment of phylogenetic relationships of cladorchiid digeneans (superfamily Paramphistomoidea Fischoeder, 1901) from freshwater fishes based on 28S rDNA, ITS2 and cox1 sequences reveals the subfamilies Dadayiinae Fukui, 1929 and Kalitrematinae Travassos, 1933 as non-monophyletic, whereas Dadaytrema Travassos, 1931 represented by three species is monophyletic. Fourteen species of cladorchiids were found in characiform, perciform and siluriform fishes in the Neotropical Region (Brazil and Peru), with numerous new host and geographical records. The first scanning electron micrographs of seven species are presented. Two new species of dadayiine and one new species of kalitrematine paramphistomes are described. Microrchis macrovarium sp. n. from Pimelodella cristata (Müller et Troschel) (type host), Tetranematichthys quadrifilis (Kner) and Pterodoras granulosus (Valenciennes) in Brazil and Peru differs from all three congeners in that the testes are directly tandem, not oblique, and that the ovary, between the caecal ends, is widely separated from the testes. Pronamphistoma philippei sp. n. from Heros sp. in Brazil is distinguished from the type and only species, Pronamphistoma cichlasomae Thatcher, 1992, by the absence of the anterior collar-like expansion present in the type species, the presence of extramural rather than intramural pharyngeal sacs, and the unusual development of the dorsal and ventral exterior circular muscle fibre series in the acetabulum. Pseudocladorchis romani sp. n. from P. granulosus (type host), Brachyplatystoma vaillantii (Valenciennes), Calophysus macropterus (Lichtenstein), Megalodoras uranoscopus (Eigenmann et Eigenmann) and Oxydoras niger (Valenciennes) in Brazil and Peru, is most similar to Pseudocladorchis nephrodorchis Daday, 1907 but differs in the shape of the testes (irregular, versus reniform in the latter species) and the size of the ovary (as large as, or larger than, the testes in the new species). The generic diagnosis of Pronamphistoma Thatcher, 1992 is amended. Dadaytremoides parauchenipteri Lunaschi, 1989 is transferred to Doradamphistoma Thatcher, 1979 as D. parauchenipteri (Lunaschi, 1989) comb. n. based on morphological and molecular evidence.

A taxonomic survey of six nematode species (including three new taxa) from the genus Cucullanus Müller, 1777, parasites of marine fishes off the Brazilian coast, is provided. Nematodes were studied using light and scanning electron microscopy (SEM). Cucullanus gastrophysi n. sp. parasitic in Lophius gastrophysus Miranda Ribeiro differs from its congeners by the combination of the following features: shape and number of sclerotized structures in the oesophastome (a pair of lateral elongate structures and a single small reniform one), position of deirids and excretory pore (both anterior to oesophagus base), spicule length and spicule/body length ratio (0.97-1.29 mm and 6.5-10.5%, respectively), morphology and length of gubernaculum (V-shaped, 107-135 µm long). Cucullanus protrudens n. sp. from Pagrus pagrus (Linnaeus) has the cloacal lips broadly protruded, which differentiates it from several species of Cucullanus; other features, e.g., the length of spicules and gubernaculum (400-415 µm and 91-103 µm, respectively), arrangement of caudal papillae and position of excretory pore (slightly posterior to oesophagus-intestine junction) also characterize this species. Cucullanus pseudopercis n. sp. from Pseudopercis semifasciata (Cuvier) has deirids and excretory pore posterior to the oesophagus-intestine junction, which distinguishes the species from most of the congeners; furthermore, the arrangement of caudal papillae in combination with the length of spicules and gubernaculum (1.0-1.5 mm and 178-196 µm, respectively) separate this species from other taxa. Newly collected specimens of C. cirratus Müller, 1777 (type species of the genus) from Urophycis brasiliensis (Kaup), C. pedroi from Conger orbignianus Valenciennes (type host of the species) and C. genypteri Sardella, Navone & Timi, 1997 from Genypterus brasiliensis Regan, were studied as well. Comparisons between newly collected samples and the taxonomic data available for each respective species revealed features that were not previously mentioned (e.g. presence of unpaired cloacal papilla, detailed morphology of cloacal lips), as well as negligible differences in morphometry and caudal papillae arrangement. Observations on the type material of C. carioca suggested affinities with the genus Dichelyne Jägerskiöld, 1902; however, the poor preservation of these specimens does not allow further conclusions. Cucullanus rougetae is considered to be a species inquirenda.