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1.
J Fish Dis ; : e13979, 2024 Jun 16.
Article de Anglais | MEDLINE | ID: mdl-38879867

RÉSUMÉ

The increasing significance of the aquaculture sector and commercially valuable species underscores the need to develop alternatives for controlling diseases such as Ichthyophthirius multifiliis-induced ichthyophthiriasis. This ciliated protozoan parasite threatens nearly all freshwater fish species, causing substantial losses in the fishery industry. Despite this, effective large-scale treatments are lacking, emphasizing the necessity of adopting preventive strategies. While the pathogenesis of ichthyophthiriasis and its immune stimulation allows for vaccination strategies, precise adjustments are crucial to ensure the production of an effective vaccine compound. Therefore, this study aimed to evaluate the impact of immunizing Astyanax lacustris with a genetic vaccine containing IAG52A from I. multifiliis and the molecular adjuvant IL-8 from A. lacustris. Transcript analysis in immunized A. lacustris indicated mRNA production in fish muscles, demonstrating an expression of this mRNA. Fish were divided into five groups, receiving different vaccine formulations, and all groups received a booster dose 14 days after the initial immunization. Samples from vaccinated fish showed increased IL-1ß mRNA expression in the spleen within 6 h post the second dose and after 14 days. In the head kidney, IL-1ß mRNA expression showed no significant difference at 6 and 24 h but an increase was noted in fish injected with IAG and IAG + IL-8 after 14 days. IL-8 mRNA expression in the spleen and kidney did not significantly differ from the control group. Histological analysis revealed no variation in leukocyte concentration at 6 and 24 h post-vaccination; however, after 14 days, the groups injected with IAG and IAG + IL-8 exhibited a higher leukocyte density at the application sites than the control. The obtained data suggest that the used vaccine is transcribed, indicating its potential to stimulate innate immune response parameters through mRNA cytokine expression and leukocyte migration.

2.
Parasitol Int ; 97: 102796, 2023 Dec.
Article de Anglais | MEDLINE | ID: mdl-37595832

RÉSUMÉ

Myxozoans of Ceratomyxidae Doflein, 1899 are common coelozoic parasites of marine life, and are also found less frequently in freshwater fish. The present study describes Ceratomyxa ranunculiformis n. sp. as a new freshwater myxosporean species infecting the gall bladder of the Amazonian sciaenid Plagioscion squamosissimus. The new Ceratomyxa was described based on its host, myxospore morphology, ribosomal rDNA gene sequencing, parasite distribution, and phylogenetic analysis. Immature and mature plasmodia were tadpole-shaped or pyriform, and exhibited slow undulatory motility. The myxospores were elongated and crescent-shaped in the frontal view, with a sutural line between two valves, which had rounded ends. The measurements of the formalin-fixed myxospores were: average length 4.9 (4.0-6.6) µm, average thickness 37.6 (32.4-43.9) µm, average posterior angle 165° (154°-173°). Two ovoid polar capsules of equal size, average length 2.0 (1.4-3.0) µm and average width 1.9 (1.4-2.4) µm, were located adjacent to the suture and contained polar filaments with 2-3 coils. The integrated comparative analysis of the morphological characteristics and molecular analyses of the ribosomal rDNA genes supported the identification of a new species of coelozoic Ceratomyxa. Maximum likelihood analyses showed the new species clustering within a well-supported clade, together with all the other Amazonian freshwater ceratomyxids.


Sujet(s)
Myxozoa , Animaux , Myxozoa/génétique , Brésil , Phylogenèse , Poissons , ADN ribosomique/génétique , Eau douce
3.
Clin Imaging ; 98: 26-35, 2023 Jun.
Article de Anglais | MEDLINE | ID: mdl-36996597

RÉSUMÉ

Vasculitis is a complication of several infectious diseases affecting the central nervous system, which may result in ischemic and/or hemorrhagic stroke, transient ischemic attack, and aneurysm formation. The infectious agent may directly infect the endothelium, causing vasculitis, or indirectly affect the vessel wall through an immunological mechanism. The clinical manifestations of these complications usually overlap with those of non-infectious vascular diseases, making diagnosis challenging. Intracranial vessel wall magnetic resonance imaging (VWI) enables the evaluation of the vessel wall and the diseases that affect it, providing diagnostic data beyond luminal changes and enabling the identification of inflammatory changes in cerebral vasculitis. This technique demonstrates concentric vessel wall thickening and gadolinium enhancement, associated or not with adjacent brain parenchymal enhancement, in patients with vasculitis of any origin. It permits the detection of early alterations, even before a stenosis occurs. In this article, we review the intracranial vessel wall imaging features of infectious vasculitis of bacterial, viral, and fungal etiologies.


Sujet(s)
Maladies transmissibles , Vascularite du système nerveux central , Humains , Angiographie par résonance magnétique/méthodes , Produits de contraste , Angiographie cérébrale/méthodes , Gadolinium , Imagerie par résonance magnétique , Vascularite du système nerveux central/imagerie diagnostique , Vascularite du système nerveux central/anatomopathologie
4.
Acta Parasitol ; 67(4): 1644-1656, 2022 Dec.
Article de Anglais | MEDLINE | ID: mdl-36107329

RÉSUMÉ

PURPOSE: Henneguya Thélohan, 1892 is one of the most species-rich genera of myxosporean parasites and infects fish around the world. The present study describes a new species infecting the gill filaments, fins, and kidneys of Plagioscion squamosissimus (Heckel, 1840), an economically important freshwater fish distributed in watersheds in the north of South America. METHODS: A total of 108 P. squamosissimus specimens were examined from three geographic localities in the Amazon basin: the Lago Grande do Curuai, a marginal lake of the Amazon River; the Tapajós River, in the state of Pará; and the Solimões River, in the state of Amazonas, Brazil. The analyses were based on the myxospore morphology, ribosomal DNA sequencing, phylogeny, prevalence, and geographic distribution of the host and its parasite. RESULTS: Parasite prevalences were 50% in both the Tapajós and Solimões rivers, and 35.4% in the Lago Grande do Curuai. In terms of the site of infection, the prevalence total was 23.1% in the gill filament, 29.6% in the fins, and 1.8% in the kidney. Regarding gender, the prevalence was 59.5% for males, 32.5% for females, and 21.7% for undetermined sex. The specimens found here were both morphologically and molecularly identical regardless of the infected organ and geographic locality, but distinct from all other Henneguya species, revealing that the parasite reported represents a novel species named Henneguya longisporoplasma n. sp. Despite the sampling being carried out in three different geographic localities of the Amazon basin, no population-level genetic variation was observed, even in the typically more variable ITS-1 region, revealing a panmictic population of H. longisporoplasma n. sp. in this large watershed. Maximum likelihood and Bayesian analyses showed the novel Henneguya clustered as a sister branch of the subclade formed of Henneguya that infect fish belonging to the family Cichlidae. CONCLUSIONS: A novel Henneguya species was identified parasitizing P. squamosissimus. The parasite presented wide geographic distribution in the Amazon basin and genetic analyses showed it as revealing a panmictic population.


Sujet(s)
Cichlides , Cnidaria , Maladies des poissons , Myxozoa , Parasites , Animaux , Femelle , Mâle , Théorème de Bayes , Maladies des poissons/épidémiologie , Maladies des poissons/parasitologie , Cichlides/parasitologie , Brésil/épidémiologie
5.
Microb Pathog ; 162: 105370, 2022 Jan.
Article de Anglais | MEDLINE | ID: mdl-34954045

RÉSUMÉ

Although species of the genus Ceratomyxa Thélohan, 1892 mostly parasitize marine fish around the world, a surprising diversity of the genus has recently been reported from Amazonian freshwater fish. In this study, we report a freshwater Ceratomyxa species parasitizing Hemiodus orthonops (Hemiodontidae) from the Paraná River (La Plata Basin) in a watershed flowing into the southern part of South America, which expands the geographic distribution of this fish parasite in the freshwater resources of the continent. We applied a combination of morphological, small subunit ribosomal DNA (SSU rDNA), and phylogenetic analyses, and vermiform-shaped plasmodia endowed with motility were found swimming in the bile of the fish. The characteristics of the plasmodia and myxospores of the Ceratomyxa species found in the Paraná River resembled those of Ceratomyxa fonsecai, a parasite of the congeneric host Hemiodus unimaculatus from the Tocantins River basin in northern Brazil. Due to the close morphological and morphometric resemblances and the impossibility of genetic comparison, the parasite found in H. orthonops from the Paraná River was designated as Ceratomyxa cf. fonsecai, and the definition of its taxonomic status was left for further study. Maximum likelihood and Bayesian analyses showed Ceratomyxa cf. fonsecai clustering within a well-supported clade, together with other Amazonian freshwater ceratomyxids. The present study suggests that shifts of the complex host/parasite between marine and freshwater environments were facilitated by marine incursions into South America in the Early Miocene.


Sujet(s)
Characiformes , Cnidaria , Maladies des poissons , Myxozoa , Parasites , Parasitoses animales , Animaux , Théorème de Bayes , Brésil , Cnidaria/génétique , ADN ribosomique/génétique , Eau douce , Vésicule biliaire , Myxozoa/génétique , Phylogenèse
6.
Microb Pathog ; 158: 105077, 2021 Sep.
Article de Anglais | MEDLINE | ID: mdl-34216741

RÉSUMÉ

In this study, integrative taxonomy is applied to describe a new dactylogyrid species, Ameloblastella pirarara sp. n. from the gills of Phractocephalus hemioliopterus, a commercially and ecologically important Amazonian catfish. Ameloblastella pirarara sp. n. can be distinguished from its congeners mainly by the morphology of the male copulatory organ (MCO), accessory piece, and anchors. The new species most resembles Ameloblastella unapi, from the Peruvian Amazon, but differs from it by the number of MCO rings, morphology of the vaginal canal and sclerotized structures of the haptor. Phylogenetic analyses based on sequences of the partial 28S rDNA (D1-D2 domains) gene placed the new species in a well-supported subclade of Ameloblastella spp. parasites of Neotropical siluriform fish, as a sister taxon to Ameloblastella unapioides. Thus, the new species described herein expands our knowledge of the diversity of monogenoid parasites from Amazonian freshwater fish.


Sujet(s)
Poissons-chats , Maladies des poissons , Trematoda , Animaux , Brésil , Femelle , Branchies , Mâle , Phylogenèse
7.
Fish Shellfish Immunol ; 116: 12-18, 2021 Sep.
Article de Anglais | MEDLINE | ID: mdl-33965526

RÉSUMÉ

Triploid induction is a promising biotechnique that could be used to enhance aquaculture yields in the near future. However, studies conducted with several fish species have demonstrated that the presence of an extra set of chromosomes may result in deleterious health effects. Furthermore, studies of fish immune responses still need to be conducted before these specimens can be readily commercialized. In the study presented herein, we evaluated the effects of triploid induction on hematology, erythrocyte morphometry and morphology, phagocytosis, and the expression levels of IL-1ß and TGF-ß using specimens of the Neotropical species, Astyanax altiparanae. In general, the cell counts of erythrocytes, leukocytes, and neutrophils in triploid fish were lower than those in diploid fish. The erythrocytes of triploid fish were larger than those found in diploid fish, but also demonstrated considerably higher frequencies of cellular and nuclear abnormalities. Although not statistically significant, triploid induction resulted in a phagocytic capacity (PC) 20% lower than that found with diploid fish. No notable differences were observed in phagocytic index (PI). Gene expression levels for the cytokine IL-1 were lower in tissues from the head kidney, liver, and spleen of triploid fish with respect to diploid fish. Gene expression levels of TGF-ß were lower only in the spleen of triploids compared to diploids. In conclusion, triploid induction resulted in A. altiparanae specimens with immune impairments and potentially lower resistances to disease and low-quality environments.


Sujet(s)
Characidae , Immunité innée , Triploïdie , Animaux , Characidae/sang , Characidae/génétique , Characidae/immunologie , Érythrocytes , Femelle , Protéines de poisson/génétique , Tests hématologiques , Interleukine-1 bêta/génétique , Leucocytes/immunologie , Mâle , Phagocytose , Saccharomyces cerevisiae , Facteur de croissance transformant bêta/génétique
8.
Microb Pathog ; 150: 104718, 2021 Jan.
Article de Anglais | MEDLINE | ID: mdl-33385492

RÉSUMÉ

A new cnidarian myxosporean infecting the spleen of an economic and ecological important bryconid fish (Salminus franciscanus) is described based on integrative taxonomic approach including morphological, ultrastructural, biological traits, geography, molecular data and phylogenetic analysis. In a total of thirty specimens examined, nineteen (63.3%) were infected by an undescribed parasite species belonging to the genus Myxobolus. Plasmodial development was asynchronous, with young development in the periphery and mature myxospores in the central area and without projections and microvilli in the plasmodial wall. Mature myxospores were ovoid in shape and measured 7.9 ± 0.2 µm (7.6-8.1 µm) in length and 5.4 ± 0.1 µm (5.0-5.6 µm) in width. The two polar capsules were equal in size, occupying a little more than half of the myxospore body, measuring 4.0 ± 0.2 µm (3.9-4.1 µm) in length and 1.7 ± 0.1 µm (1.5-1.8 µm) in width. The polar tubules coiled in six turns, perpendicular to the long axis of polar capsule. Phylogenetic analysis placed the new species within a clade containing nine myxobolid species from South American characiforms fish and appears as a close species of Myxobolus pantanalis. Nevertheless, the sequences of the new species and M. pantanalis have a large genetic divergence of 13.5% in their SSU rDNA. In light of the differences observed from the integrative taxonomy, we confidently considered that this isolate is a new species of cnidarian myxosporean, M. douradae n. sp., increasing the knowledge of diversity of this enigmatic group of cnidarians.


Sujet(s)
Cnidaria , Maladies des poissons , Parasitoses animales , Animaux , Brésil , Branchies , Phylogenèse , Rate
9.
Genet Mol Biol ; 43(4): e20200006, 2020.
Article de Anglais | MEDLINE | ID: mdl-33174977

RÉSUMÉ

In the present study, the complete characterization of cDNA and genomic sequences of IL-1ß and IL-8, as well as the expression profile of these genes in the South American fish pacu (Piaractus mesopotamicus) is provided. The full-length pmIL-1ß cDNA was composed of 1208 nucleotides that would produce a precursor peptide with 273 amino acid residues. A putative caspase-1 cleavage site, similar to what is found in mammalian IL-1ß, was identified producing a mature peptide with a theoretical molecular weight of 17.21 kDa. The pmIL-8 cDNA sequence consisted of 1019 nucleotides which encoded a 95-amino acid protein with a theoretical molecular weight of 10.43 kDa that showed all typical CXC chemokine features, including a 20-residue signal peptide and four conserved cysteine residues. Constitutive mRNA expression was detected for both genes in the liver, head kidney, gill, intestine, skin and spleen. After a bacterial challenge, up-regulation was detected for both pmIL-1ß and pmIL-8 in the spleen and head kidney at 12 h post-infection. At 24 h post-infection there was a decrease in the expression of both genes, with pmIL-8 showing a significant down-regulation in the liver and head kidney when compared to the control groups.

10.
Parasitol Res ; 119(11): 3627-3637, 2020 Nov.
Article de Anglais | MEDLINE | ID: mdl-32852620

RÉSUMÉ

This study increases the known biodiversity of cnidarian parasites in neotropical bryconid fishes. Two novel Myxobolus species are described based on morphology, ultrastructure and small subunit ribosomal DNA (ssrDNA) sequencing: Myxobolus vetuschicanus n. sp. infecting fins of Salminus franciscanus and Myxobolus mineirus n. sp. infecting the mesentery of Brycon orthotaenia from the São Francisco River basin, Minas Gerais State, Brazil. Ultrastructural analysis of the two species revealed an asynchronous sporogenesis process, with germinative cells and young developmental stages of myxospores in the periphery of the plasmodia. In M. vetuschicanus n. sp., the plasmodia were surrounded by a layer of fibroblasts and in M. mineirus n. sp., the plasmodial membrane had direct contact with the host tissue. The phylogenetic analysis based on the ssrDNA of Henneguya/Myxobolus species showed that the two novel Myxobolus species grouped in subclades together with other parasite species of bryconid fishes.


Sujet(s)
Biodiversité , Characiformes/parasitologie , Maladies des poissons/parasitologie , Myxobolus/isolement et purification , Parasitoses animales/parasitologie , Nageoires animales/parasitologie , Animaux , Brésil , ADN ribosomique , Branchies/parasitologie , Myxobolus/classification , Phylogenèse , Petite sous-unité du ribosome des eucaryotes , Rivières/parasitologie
11.
Acta Trop ; 211: 105616, 2020 Nov.
Article de Anglais | MEDLINE | ID: mdl-32621932

RÉSUMÉ

Species of the genus Ellipsomyxa Køie, 2003, parasitize mostly marine and brackish fish around the world. In the present study, we describe two novel species of Ellipsomyxa: Ellipsomyxa plagioscioni n. sp. parasitizing the gall bladder of Plagioscion squamosissimus (Sciaenidae), a freshwater fish but commonly found in brackish water in the Amazonian estuarine environment; and Ellipsomyxa paraensis n. sp. infecting Cichla monoculus (Cichlidae), a strictly freshwater fish. The host specimens were caught from the Amazon and Tapajós rivers, in the municipal region of Santarém, in the State of Pará, Brazil. The study was performed using a combination of morphological, biological, and SSU rDNA-based phylogeny, which suggested that marine transgressions of the Miocene epoch, in the central region of South America, were a pathway for the adaptation and radiation of these cnidarian parasites in the freshwater environment. Both disporic plasmodia and mature myxospores were found floating freely in the bile. Mature myxospores from both species were ellipsoidal in the valvular and sutural views, with thin smooth valves elongated in the direction perpendicular to the plane of the transverse sutural line. Ellipsomyxa plagioscioni n. sp. myxospores measured 11.1 (10.2-12.8) µm in length and 6.6 (5.6-7.6) µm in width. Two pyriform polar capsules discharging on opposite sides, some distance from both the sutural line and the spore ends, measured 3.8 (3.2-4.4) µm in length and 2.8 (2.3-3.3) µm in width, with 5-6 coil polar tubules. Ellipsomyxa paraensis n. sp. myxospores measured 11.5 (10.5-12.4) µm in length and 7.5 (6.6-8.6) µm in width. Two pyriform polar capsules which discharged on opposite sides some distance from both the sutural line and spore ends, measured 3.2 (2.1-3.9) µm in length and 2.6 (2.0-3.3) µm in width, with 2-3 coil polar tubules. Valvular protrusions were observed, associated with the tips of the polar capsules. Molecular analysis based on the SSU rDNA sequences indicated that the two novel Ellipsomyxa species were distinct from all other sequences deposited in the GenBank database. The phylogenetic trees clustered E. plagioscioni n. sp. as a basal species of a lineage of the marine/estuarine Ellipsomyxa, while E. paraensis n. sp. clustered together with other Amazonian species.


Sujet(s)
Maladies des poissons/parasitologie , Poissons/parasitologie , Myxozoa/isolement et purification , Rayonnement , Animaux , Brésil/épidémiologie , Cnidaria/génétique , Vésicule biliaire/parasitologie , Phylogenèse , Rivières , Spores
12.
Acta Trop ; 209: 105533, 2020 Sep.
Article de Anglais | MEDLINE | ID: mdl-32442433

RÉSUMÉ

The objective of this study was reports, through morphological and small subunit ribosomal DNA (SSU rDNA) sequencing, two novel myxobolid myxosporeans infecting Piaractus brachypomus, an economicaly important Amazonian fish popularly known as "pirapitinga". Of a total of 25 specimens of P. brachypomus examined 68% had the gill filament parasitized by Henneguya tapariensis n. sp. and 16% had infection of Myxobolus arapiuns n. sp. in the pyloric cecum. The morphological analysis revealed H. tapariensis n. sp. myxospores with an ellipsoid shape and caudal process larger than the length of the body. The polar capsules of same size were elongated and occupied less than half the body. Sequencing of the SSU rDNA generated a partial sequence of 1946 bp. In M. arapiuns n. sp. the myxospores had oval-shaped body and polar capsules of the same size, occupying less than half the body. Sequencing of the SSU rDNA generated a partial sequence of 1950 bp. Phylogenetic analysis revealed a cluster according to the order/family of the host, where H. tapariensis n. sp. was grouped in a subclade with Henneguya brachypomus and Henneguya piaractus and M. arapiuns grouped in a subclade with Myxobolus colossomatis, Myxobolus matosi and Myxobolus pirapitingae.


Sujet(s)
Maladies des poissons/parasitologie , Myxobolus/génétique , Parasitoses animales/parasitologie , Animaux , Poissons , Myxobolus/anatomie et histologie , Myxobolus/classification , Phylogenèse
13.
Parasitol Res ; 119(4): 1209-1220, 2020 Apr.
Article de Anglais | MEDLINE | ID: mdl-32189056

RÉSUMÉ

This paper provides morphological and phylogenetic analyses of two new myxobolid species found infecting Piaractus brachypomus from the Amazon basin. The fish were caught in the Tapajós River, in the municipality of Santarém, in the state of Pará, Brazil. The plasmodial development of Henneguya brachypomus n. sp. occurred in the gill lamellae while Myxobolus pirapitingae n. sp. developed in the pyloric cecum. Morphological analyses did not identify inflammatory infiltrate for either species, but H. brachypomus n. sp. induced stretching of the epithelium, compression of the adjacent tissues, and displacement and deformation of the neighboring lamellae. The mature myxospores of H. brachypomus n. sp. were ellipsoid, with a length of 11.7-13.8 µm, a width of 4.0-4.6 µm, and a thickness of 3.5-4.3 µm. The polar capsules were elongated, with a length of 5.6-7.3 µm and a width of 1.3-2.0 µm, and each contained a polar filament with 8-9 coils. The caudal process was 40.5-48.1 µm long and the total length of the myxospore was 52.4-61.6 µm. Myxobolus pirapitingae n. sp. exhibited rounded mature myxospores measuring 10.0-11.1 µm in length, 7.0-7.6 µm in width, and 5.4-6.3 µm in thickness. The polar capsules were of equal size and occupied less than half the myxospore, measuring 3.5-4.0 µm in length and 2.0-2.6 µm in width, with each containing a polar filament with 6-7 coils. Phylogenetic analysis based on partial small subunit ribosomal DNA (ssrDNA) sequences showed that H. brachypomus n. sp. clustered as a sister species of Henneguya piaractus, while M. pirapitingae n. sp. was grouped in a sub-clade together with Myxobolus matosi and Myxobolus colossomatis.


Sujet(s)
Maladies des poissons/parasitologie , Myxobolus , Myxozoa , Parasitoses animales/parasitologie , Animaux , Brésil , Characiformes , Femelle , Branchies , Mâle , Typage moléculaire , Myxobolus/classification , Myxobolus/isolement et purification , Myxozoa/classification , Myxozoa/isolement et purification , Phylogenèse , Petite sous-unité du ribosome , Rivières
15.
Parasitol Int ; 76: 102061, 2020 Jun.
Article de Anglais | MEDLINE | ID: mdl-31978596

RÉSUMÉ

Two new Myxobolus species were described infecting Brycon orthotaenia from the São Francisco River, in the state of Minas Gerais, Brazil. From a total of 39 B. orthotaenia collected, two specimens (5.1%) exhibited infection of the ovary and 12 specimens (30.8%) displayed infection of the liver. The plasmodia of both Myxobolus species were white and spherical measuring around 1 mm in length. The plasmodium found in the ovary showed mature myxospores, which were oval shaped from the frontal view and measured 9.2-11.0 (9.8 ± 0.4) µm in length, 5.9-6.9 (6.5 ± 0.3) µm in width and 4.6-5 (4.9 ± 0.1) µm in diameter. The two polar capsules were the same size and measured 3.9-6.2 (4.7 ± 0.5) µm in length and 1.8-2.4 (2.1 ± 0.2) µm in width. The polar tubules had 9 coils. The plasmodium found in the liver showed mature myxospores which were ellipsoidal in shape from the frontal view and measured 10.0-11.4 (10.7 ± 0.5) µm in length, 7.3-8.6 (8.1 ± 0.4) µm in width and 5.3-7.0 (6.8 ± 0.4) µm in diameter. The two polar capsules were the same size and measured 4.2-5.4 (4.9 ± 0.3) µm in length and 1.9-2.9 (2.7 ± 0.3) µm in width. The polar tubules had 8 coils. Ultrastructural analysis revealed an asynchronous sporogenesis process, with young developmental myxospore stages more often found in the periphery of the plasmodium and mature myxospores in the centre of the plasmodium. The plasmodial wall was formed by a single membrane which was not surrounded by a layer of host tissue. A thick layer of fibrous material was found in the peripheral ectoplasm close to the plasmodial wall of the plasmodium found in the ovary. Phylogenetic analysis based on the small-subunit ribosomal DNA - ssrDNA sequences and using the closest myxozoan sequences to each one of the species studied here based on previous GenBank data and Henneguya/Myxobolus/Thelohanellus species parasitizing fish from South American, revealed that the new species are grouped in a subclade together with other Myxobolus species parasitizing bryconid hosts.


Sujet(s)
Characiformes/parasitologie , Maladies des poissons/parasitologie , Interactions hôte-parasite , Myxobolus/classification , Parasitoses animales/parasitologie , Phylogenèse , Animaux , Brésil , Microscopie électronique , Myxobolus/anatomie et histologie , Myxobolus/ultrastructure , Rivières/parasitologie
16.
Pediatr Radiol ; 50(6): 776-792, 2020 05.
Article de Anglais | MEDLINE | ID: mdl-31925460

RÉSUMÉ

Pediatric multiple sclerosis (MS) deserves special attention because of its impact on cognitive function and development. Although knowledge regarding pediatric MS has rapidly increased, understanding the peculiarities of this population remains crucial for disease management. There is limited expertise about the efficacy and safety of current disease-modifying agents. Although pathophysiology is not entirely understood, some risk factors and immunological features have been described and are discussed herein. While the revised International Pediatric MS Study Group diagnostic criteria have improved the accuracy of diagnosis, the recently revised McDonald criteria also offer some new insights into the pediatric population. It is fundamental that radiologists have strong knowledge about the vast spectrum of demyelinating disorders that can occur in childhood to ensure appropriate diagnosis and provide early treatment.


Sujet(s)
Sclérose en plaques/imagerie diagnostique , Âge de début , Enfant , Diagnostic différentiel , Humains
17.
J Neuroradiol ; 47(5): 369-381, 2020 Sep.
Article de Anglais | MEDLINE | ID: mdl-31279838

RÉSUMÉ

Dural arteriovenous fistulas (DAVFs) are complex vascular abnormalities that account for 10-15% of intracranial vascular malformations. DAVFs are typically encountered in middle-aged adults, with a slightly female predominance. The causative factors are still uncertain; however, abnormal local hemodynamics and neoangiogenesis related to dural sinus or venous thrombosis can contribute to DAVF occurrence. The diagnosis is dependent on a high level of clinical suspicion and high-resolution imaging techniques. Computed tomography and/or magnetic resonance imaging aid in the diagnosis, but conventional angiography remains the most accurate method for the complete characterization and classification of DAVFs. The therapeutic approach can be conservative or more aggressive, based on symptom severity, sequelae risk and patient characteristics. This article is a pictorial review of adult intracranial DAVFs that highlights some tips and tricks for recognizing useful red flags in the suspicion of DAVFs.


Sujet(s)
Malformations vasculaires du système nerveux central/imagerie diagnostique , Neuroimagerie/méthodes , Produits de contraste , Humains , Pronostic
18.
Parasitol Int ; 71: 27-36, 2019 Aug.
Article de Anglais | MEDLINE | ID: mdl-30878707

RÉSUMÉ

Twelve Myxobolus species have been previously described to parasitize Bryconidae fish in South America. Here, we describe two novel myxosporean species that parasitize economically important Bryconidae from the São Francisco River basin in Brazil. Myxospores morphometry, morphology, small-subunit ribosomal DNA - ssrDNA sequences, and other biological traits were used in the taxonomic analysis. Phylogenetic analysis was performed to assess the position of the new Myxobolus species among the closest Myxobolus/Henneguya. Myxobolus iecoris n. sp. was found infecting the liver of Salminus franciscanus (dourado). Myxospores were oval with the anterior region aculiform in frontal view and biconvex in lateral view and measured 11.4-14.2 (12.8 ±â€¯0.8) µm long, 7.7-9.9 (8.7 ±â€¯0.6) µm wide, 6.5-7.5 (6.9 ±â€¯0.4) µm thick. Two pyriform and equal-sized polar capsules measuring 4.9-7.4 (5.9 ±â€¯0.5) µm long and 2.3-3.5 (3.0 ±â€¯0.2) µm wide contained polar tubules with 8-9 turns. Myxobolus lienis n. sp. was found infecting the spleen of Brycon orthotaenia (matrinxã). Myxospores were round to oval in frontal view and biconvex in lateral view and measured 10.3-13.8 (12 ±â€¯0.6) µm long, 6.8-9.3 (8.3 ±â€¯0.5) µm wide, and 6.9-7.0 (7.0 ±â€¯0.6) µm thick. Two oval and equal-sized polar capsules measured 3.9-5.8 (4.6 ±â€¯0.5) µm long and 2.0-3.5 (2.8 ±â€¯0.3) µm wide contained polar tubules with 5-6 turns. Ultrastructural analysis revealed asynchronous sporogenesis with germinative cells and young sporogonic stages in the periphery of the plasmodia. A connective tissue capsule was observed surrounding Myxobolus lienis n. sp., but it was absent for Myxobolus iecoris n. sp. Maximum likelihood and Bayesian inferences showed the two novel species clustering in a well-supported subclade composed by Myxobolus spp. of bryconids. Myxobolus iecoris n. sp. appeared as a sister species of M. aureus and Myxobolus lienis n. sp. as sister to M. umidus.


Sujet(s)
Characiformes/parasitologie , Maladies des poissons/parasitologie , Myxobolus/classification , Phylogenèse , Animaux , Brésil , ADN ribosomique/génétique , Branchies/parasitologie , Séquençage nucléotidique à haut débit , Foie/parasitologie , Microscopie , Microscopie électronique , Parasitoses animales/parasitologie , Rivières/parasitologie
19.
Eur J Clin Nutr ; 73(3): 465-473, 2019 03.
Article de Anglais | MEDLINE | ID: mdl-29973677

RÉSUMÉ

BACKGROUND/OBJECTIVES: Ready-to-eat cereal (RTEC) breakfasts have been increasing in Portugal, among children. Eat Mediterranean (EM), a Portuguese comprehensive community-based intervention, proposed to improve breakfast patterns of children and adolescents and to evaluate the healthiness of RTEC according to WHO/Europe nutrient profile model (Euro-NP). SUBJECTS/METHODS: EM Program was developed during two scholar years (15/16 and 16/17) toward 2333 students (pre to secondary education). Data on breakfast was provided using a family record form. The intervention consisted of 257 educational sessions addressing the principles of Mediterranean Diet, and promoting a "healthy breakfast at home". To check for compliance with Euro-NP, RTEC package food labels' nutritional composition was used. RESULTS: After intervention 92.9% of children/adolescents had breakfast daily with no report of breakfast skippers. RTECs were one of the most frequent (66.5%) breakfasts. Statistically significant improvements were showed for: daily qualitative and complete breakfast frequency (5.6%) and fruit (11.2%). Consumption of RTEC decreased 28%. According to Euro-NP, 84.6% of the RTECs were non-compliant, regarding sugar content. Children's RTECs presented 5% more of energy and 26% more sugar than the "non-children's" RTECs. CONCLUSION: EM strategy showed to be a successful program to improve patterns and quality of breakfast of the children and adolescents, reinforcing the importance of school-based nutritional programs in changing lifestyles. Nutrient profiling can be a useful tool to provide a selection of foods to be part of a healthy diet and can be used by policy-makers to design policies to identify the foods to which marketing restrictions to children, will apply.


Sujet(s)
Petit-déjeuner/physiologie , Régime alimentaire/méthodes , Grains comestibles/métabolisme , Comportement alimentaire/physiologie , Nutriments/métabolisme , Adolescent , Enfant , Enfant d'âge préscolaire , Europe , Femelle , Humains , Mâle , Portugal
20.
Acta Trop ; 191: 17-23, 2019 Mar.
Article de Anglais | MEDLINE | ID: mdl-30579809

RÉSUMÉ

This study presents morphologic, molecular and phylogenetic data about two new species of the genus Myxobolus and of the previously described Myxobolus colossomatis, all which are found infecting the Colossoma macropomum, a fish whose natural habitat is the Amazon Basin of Brazil, from where the specimens for this study were caught. A total of 51 C. macropomum specimens were examined between October of 2014 and January of 2016. Plasmodia of the myxosporeans were found infecting several organs: Myxobolus matosi n. sp. and Myxobolus longissimus n. sp. were respectively found in the inner face of the operculum and in the wall external surface of the stomach and gill arch. M. matosi n. sp. were 9.6 ± 0.4 µm in length, 7.0 ± 0.3 µm in width and 5.0 ± 0.3 µm in thickness of the myxospore. M. longissimus n. sp. measured 19.1 ± 0.4 µm in length, 9.4 ± 0.3 µm in width and 8.3 ± 0.4 µm in thickness. The polar capsules, which were elongated, showed 4.3 ± 0.4 µm in length and 1.9 ± 0.1 µm in width for M. matosi n. sp. and 10.5 ± 0.2 µm in length and 2.5 ± 0.1 µm in width for M. longissimus n. sp. The Myxobolus colossomatis had two myxospore morphotypes: 1) Ellipsoidal myxospores measuring 11.6 ± 0.4 µm in length and 7.6 ± 0.2 µm in width. Their elongated polar capsules measured 5.6 ± 0.2 µm in length and 2.5 ± 0.2 µm in width; 2) Oval myxospores measuring 10.4 ± 0.5 µm in length and 7.7 ± 0.3 µm in width. Their polar capsules were 5.4 ± 0.2 µm in length and 2.4 ± 0.0 µm in width. The number of turns of the polar filament was 7-8 coils. The molecular comparison of the small subunit ribosomal DNA (ssrDNA) showed a genetic divergence of 10.3% between M. matosi n. sp. and M. colossomatis, 22.4% between M. matosi n. sp. and M. longissimus n. sp., and 23.2% between M. longissimus n. sp. and M. colossomatis. Myxobolus cf. colossomatis, a parasite of Piaractus mesopotamicus, showed 11.1% of genetic divergence to M. colossomatis, demonstrating them to be distinct species. Phylogenetic analysis, based on sequences of the ssrDNA, showed the M. matosi n. sp. to be a sister species of M. colossomatis, and it also showed M. longissimus n. sp. to be a sister branch in the lineage composed by Myxobolus cf. cuneus and Henneguya pellucida.


Sujet(s)
Maladies des poissons/génétique , Myxobolus/classification , Myxobolus/génétique , Myxozoa/classification , Myxozoa/génétique , Parasitoses animales/classification , Parasitoses animales/parasitologie , Animaux , Brésil , Phylogenèse
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