La enfermedad de Parkinson (EP) es la patología neurodegenerativa motora con mayor incidencia a nivel mundial, cuyas causas aún no son claras. Actualmente no existe cura, pero es posible contar con ...diferentes tratamientos que permiten aliviar algunos de sus síntomas y enlentecer su curso. Debido a la gran cantidad de informaciones, en ocasiones contradictorias sobre los llamados "factores de riesgo" (entendidos éstos como situaciones que pueden exacerbar la posibilidad de aparición de la enfermedad, incluyendo desde la predisposición familiar hasta la exposición prolongada a substancias exógenas), en esta revisión se pretende ofrecer una panorámica actual sobre factores asociados a la aparición de EP Se revisan también algunos tratamientos que buscan contrarrestar la pérdida de la función dopaminérgica de la substancia nigra (SN) y algunas de las aproximaciones terapéuticas tanto farmacológicas, como por estimulación cerebral profunda (ECP) o por implante celular. Se revisan también investigaciones sobre el potencial terapéutico de compuestos con alta especificidad a receptores colinérgicos (nAChRs) y antagonistas de receptores de adenosina, específicamente del subtipo A2A. Posiblemente durante las próximas décadas, nuestro conocimiento en epigenética pueda arrojar nuevas luces sobre esta interacción, así como sobre las relaciones entre ciertas líneas de microbios intestinales y aparición de EP. En este momento, la alternativa terapéutica que ofrece mayor eficacia es la ECP, sin embargo, a futuro se espera que el desarrollo de nuevas estrategias de implante cerebral pueda ofrecer una cura real de la EP. Palabras clave Enfermedad de Parkinson (EP); estimulación cerebral profunda (ECP); sustancia nigra (SN); núcleo subtálamico (NST); globo pálido interno (GPi) Parkinson's disease (PD) is the most prevalent neurodegenerative motor pathology worldwide, the causes of which are still unclear. Currently there is no cure, but it is possible to have different treatments that allow to alleviate some of its symptoms and slow its course. Due to the large amount of information, sometimes contradictory, about the so-called "risk factors" (understood as situations that may exacerbate the possibility of the onset of the disease, from family predisposition to prolonged exposure to exogenous substances), in this review aims to provide a current overview of factors associated with the occurrence of PD. We also review some treatments that seek to counteract the loss of the dopaminergic function of the substance nigra (SN) and some of the therapeutic approaches both pharmacologically, by deep brain stimulation (DBS) or by cellular implantation. Also reviewed investigations on the therapeutic potential of compounds with high specificity to cholinergic receptors (nAChRs) and adenosine receptor antagonists, specifically the A2A subtype. Possibly, during the next decades, our knowledge in epigenetics may shed new light on this interaction, as well as on the relationships between certain lines of intestinal microbes and onset of PD. At this time, the most effective therapeutic alternative is DBS; however, in the future it is expected that the development of new brain implant strategies may offer a real cure for PD. Keywords Parkinson Disease (PD); Deep brain stimulation (DBS); substancia nigra (SN); subthalami nucleus (NST); globo pálido interno (GPi)
The marine nematodes usually comprise free-living species, although a few are parasitic. However, several cases of free-living nematodes found accidentally in the digestive tract of certain ...vertebrates, especially fishes, have sometimes been recorded and categorized as pseudoparasites. In the present work, two species of marine fishes, the rhomboid crappie, Diapterus rhombeus, and the silvered crappie, Eucinostomus argenteus (Perciformes: Gerreidae), from Angra dos Reis on the coast of Rio de Janeiro (Brazil) were examined. Seven species of free-living marine nematodes were found in the digestive tract of these fish. Several of these species remain unknown as free-living forms in Brazil. The combination of the fish feeding strategies and the poor preservation of the body of the nematode specimens found could indicate that these nematodes are pseudoparasites, appearing in the fishes' digestive tracts through accidental ingestion and thereafter surviving for brief periods of time. Descriptions, illustrations and tables of measurements are provided for all species. Six of these species (Croconema torquens, Dorylaimopsis pellucida, Oncholaimellus labiatus, Parodontophora breviamphida, Prooncholaimus ornatus, Trissonchulus latus) have been reported for the first time from the Brazilian coast.
Cofactors, biomarkers, and the mutational status of genes such as TP53, EGFR, IDH1/2, or PIK3CA have been used for patient stratification. However, many genes exhibit recurrent mutational positions ...known as hotspots, specifically linked to varying degrees of survival outcomes. Nevertheless, few hotspots have been analyzed (e.g., TP53 and EGFR). Thus, many other genes and hotspots remain unexplored.
We systematically screened over 1400 hotspots across 33 TCGA cancer types. We compared the patients carrying a hotspot against (i) all cases, (ii) gene-mutated cases, (iii) other mutated hotspots, or (iv) specific hotspots. Due to the limited number of samples in hotspots and the inherent group imbalance, besides Cox models and the log-rank test, we employed VALORATE to estimate their association with survival precisely.
We screened 1469 hotspots in 6451 comparisons, where 314 were associated with survival. Many are discussed and linked to the current literature. Our findings demonstrate associations between known hotspots and survival while also revealing more potential hotspots. To enhance accessibility and promote further investigation, all the Kaplan-Meier curves, the log-rank tests, Cox statistics, and VALORATE-estimated null distributions are accessible on our website.
Our analysis revealed both known and putatively novel hotspots associated with survival, which can be used as biomarkers. Our web resource is a valuable tool for cancer research.
ABSTRACT In the Amazon, the growing demand for fish has been boosting the expansion of fish farms. However, the intensification of cultivation can generate disequilibrium in the parasite-host ...environment, predisposing fish to parasitic infections. The objective of this study was to evaluate the community structure of metazoan parasites in cultivation systems of piauçu, Leporinus macrocephalus, in the state of Acre, Brazil. We examined 100 specimens from a semi-intensive cultivation system (earth tanks) and 100 from an extensive system (dams). Overall 66.5% of the hosts were parasitized. We collected 1,240 parasite specimens, classified in 15 metazoan taxa (10 monogenoidean, one digenean and four nematodes). The parasite prevalence was higher by Monogenoidea in the dams, and by Nematoda in the earth tanks. The parasitic indexes were, in general, low and varied among species. Monogeneoidea had higher values for quantitative and ecological descriptors of parasitism in the dams, while Nematoda had higher values in the earth tanks. A single species of Digenea was found in the dams, with low prevalence. No taxon was classified as central. In the dams, parasite abundance was correlated only with total fish length, while in the earth tanks, it was positively correlated with total length, weight and condition factor of fish. The endoparasite and ectoparasite infracommunities presented higher richness, dominance, diversity and evenness, respectively, in the earth tanks and in the dams. This is the first study of ecological descriptors of parasites of L. macrocephalus in the Amazon.
RESUMO Na Amazônia, a crescente demanda por pescado vem impulsionando a expansão da piscicultura. No entanto, a intensificação dos cultivos pode gerar desequilíbrio no sistema parasito-hospedeiro-ambiente, predispondo os peixes a infecções parasitárias. O objetivo deste estudo foi avaliar a estrutura das comunidades de metazoários parasitos de piauçu, Leporinus macrocephalus, em sistemas de cultivo no estado do Acre, Brasil. Foram coletados 200 peixes, sendo 100 espécimes de sistema de cultivo semi-intensivo em viveiro escavado e 100 de sistema extensivo em açude. Dos 200 hospedeiros analisados 66,5% estavam parasitados. Foram coletados 1.240 espécimes de metazoários, classificados em quinze espécies (10 de Monogenoidea, uma de Digenea e quatro de Nematoda). A prevalência de parasitismo por Monogenoidea foi maior em açude e por Nematoda em viveiro. De forma geral, os índices de parasitismo foram baixos e variaram entre as espécies, com maiores valores dos descritores quantitativos e ecológicos do parasitismo por Monogenoidea em açude e Nematoda em viveiro. A única espécie de Digenea foi encontrada em açude e com baixa prevalência. Nenhum táxon foi classificado como central. Nos açudes, a abundância parasitária foi correlacionada apenas com o comprimento total dos hospedeiros, e nos viveiros com o comprimento total, peso e fator de condição dos hospedeiros. Nos viveiros, a infracomunidade de endoparasitos apresentou os maiores índices de riqueza, dominância, diversidade e equitabilidade. Nos açudes, os ectoparasitos apresentaram os maiores índices. Este foi o primeiro registro de índices parasitários de L. macrocephalus em sistemas de cultivo na Amazônia.
Gerbils (Meriones unguiculatus) experimentally infected with Litomosoides chagasfilhoi were treated with a single oral dose of 40 or 80 mg of albendazole, respectively. Observation of the ...microfilaremia after the treatment showed that both single oral doses of albendazole decreased the microfilaremia in L. chagasfilhoi infection. The body wall was composed of a cuticle, a hypodermis, and a muscular layer, and treated nematodes showed no morphological alterations. The ultrastructural alterations produced by treatment with 40 mg of albendazole included a higher number of membrane invaginations in the basal labyrinth of the uterine epithelium and the presence of myelin figures in this region. Inside the uterus, most embryos and microfilariae were disintegrated. The treatment with 80 mg of albendazole did not produce alterations in the uterine wall, and the number of vesicles near the microfilariae sheath was smaller than that observed in the untreated and in the 40-mg treatment groups. However, all the microfilariae observed in the uterus were extensively damaged with cytoplasmic vacuolization and cellular degeneration. No alterations in the intestinal cells were observed after treatment with 40 or 80 mg of albendazole. The present study contributes to the knowledge of albendazole's effects in filariids and demonstrates the potential embryotoxic and microfilaricidal consequences of this drug.
A new nematode species,
Philometra nattereri
n. sp. (Philometridae), is described from female specimens found in the oculo-orbits and nasal cavity of the red piranha
Pygocentrus nattereri
Kner ...(Characiformes: Characidae) from five lakes in Central Amazonia, Brazil, collected in 2008 and 2009 (overall prevalence 12%, intensity 1–3 nematodes per fish). Based on light and scanning electron microscopical examination, the new species differs from most other congeners parasitising freshwater fishes in that its oesophageal gland extends anteriorly far anterior to the level of the nerve-ring, in the presence of 14 small cephalic papillae arranged in two circles and in having two minute caudal projections. This is the first species of
Philometra
Costa, 1845 reported from fishes of the family Characidae and the second valid species of this genus parasitic in freshwater fishes of Brazil and South America.
Two species of nematodes belonging to the genus Ichthyouris Inglis, 1962 (I. ro and I. bursata), were collected from the cichlid fish Mesonauta festivus in the central Brazilian Amazon region. Both ...species are reported in this locality for the first time. I. bursata is reported in a new host, M. festivus, and this is the first report of I. ro parasitizing its type host in Brazil. We provide a more detailed description for I. ro, including morphological aspects that were not mentioned in the original description.
Procamallanus (Spirocamallanus) halitrophus (Fusco and Overstreet, 1978) is an intestinal parasite of the flounders Syacium papillosum and Citharichthys macrops, both of which are native to waters ...off the coast of the state of Rio de Janeiro, Brazil. With transmission electron microscopy, we observed the body wall which is composed of the cuticle, hypodermis, and somatic musculature. The cuticle of P. (S.) halitrophus is composed of 5 layers: the epicuticle, cortical, median, fibrous, and basal layers. Underlying the cuticle is the hypodermis, a syncytium that contains mitochondria, glycogen granules, vesicles, inclusion bodies, and an endoplasmic reticulum. The region of hypodermal chords contains a nucleus in addition to the other organelles and there is a basal lamina surrounding each muscle cell. The use of imidazole-buffered osmium tetroxide solution revealed the presence of lipids in the epicuticle, the membrane that surrounds each muscle cell, the inclusion bodies, and the endoplasmic reticulum. The phosphotungstic-acid technique revealed basic proteins in the epicuticle and dense bodies. The use of periodic acid-thiosemicarbazide-silver proteinate for carbohydrate detection did not show any reaction products in the cuticle. However, glycogen particles were evident in the hypodermis and muscle cells.
This study provides the first investigation on acquisition of parasites in invasive O. niloticus by parasite species of native Cichlidae from the Igarapé Fortaleza basin, Northern Brazil. There were ...examined 576 specimens of 16 species of native cichlids and invasive O. niloticus collected in the main channel and the floodplain area of this tributary of Amazon River. The invasive O. niloticus was poorly parasitized having only Ichthyophthirius multifiliis, Trichodina centrostrigeata, Paratrichodina africana, Trichodina nobilis (Protozoa) and Cichlidogyrus tilapiae (Monogenoidea), and this host has not acquired any parasite species common to the native ichthyofauna region. In contrast, species of native cichlids showed rich fauna of parasites with predominance of Monogenoidea species, larvae and adults of Nematoda, Digenea, Cestoidea and Acanthocephala, besides four species of Protozoa and four Crustacea. However, only T. nobilis was acquired by native fish, the Aequidens tetramerus, which is a new host for this exotic Trichodinidae. In O. niloticus, well established in the region, the small number of helminth species may be associated with its rusticity, good adaptation in the new environment and also the presence of native parasites with relative specificity, but without ability to complete its life cycle in this invasive host of this ecosystem.
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