Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 9 de 9
Mais filtros

Intervalo de ano de publicação
Front Microbiol ; 13: 833655, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35450285


Candida albicans, an important fungal pathogen of humans, displays different morphologies, such as yeast, pseudo-hyphae and hyphae, which are recognized unequally by phagocytic cells of the innate immune response. Once C. albicans cells invade host tissues, immune cells such as macrophages are attracted to the site of infection and activated to recognize, engulf and kill the pathogen. We have investigated this fungal cell-macrophage interface by using high-throughput screening of the C. albicans GRACE library to identify genes that can influence this interaction and modify the kinetics of engulfment. Compared with the wild-type (WT) strain, we identified generally faster rates of engulfment for those fungal strains with constitutive pseudo-hyphal and hyphal phenotypes, whereas yeast-form-locked strains showed a reduced and delayed recognition and internalization by macrophages. We identified a number of GRACE strains that showed normal morphological development but exhibited different recognition and engulfment kinetics by cultured macrophages and characterized two mutants that modified interactions with the murine and human-derived macrophages. One mutant inactivated an uncharacterized C. albicans open reading frame that is the ortholog of S. cerevisiae OPY1, the other inactivated CaKRE1. The modified interaction was monitored during a 4 h co-culture. Early in the interaction, both opy1 and kre1 mutant strains showed reduced recognition and engulfment rates by macrophages when compared with WT cells. At fungal germ tube initiation, the engulfment kinetics increased for both mutants and WT cells, however the WT cells still showed a higher internalization by macrophages up to 2 h of interaction. Subsequently, between 2 and 4 h of the interaction, when most macrophages contain engulfed fungal cells, the engulfment kinetics increased for the opy1 mutant and further decreased for the kre1 mutant compared with Ca-WT. It appears that fungal morphology influences macrophage association with C. albicans cells and that both OPY1 and KRE1 play roles in the interaction of the fungal cells with phagocytes.

Front Cell Infect Microbiol ; 12: 764711, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35350439


SAGA (Spt-Ada-Gcn5-acetyltransferase) is a highly conserved, multiprotein co-activator complex that consists of five distinct modules. It has two enzymatic functions, a histone acetyltransferase (HAT) and a deubiquitinase (DUB) and plays a central role in processes such as transcription initiation, elongation, protein stability, and telomere maintenance. We analyzed conditional and null mutants of the SAGA complex module components in the fungal pathogen Candida albicans; Ngg1, (the HAT module); Ubp8, (the DUB module); Tra1, (the recruitment module), Spt7, (the architecture module) and Spt8, (the TBP interaction unit), and assessed their roles in a variety of cellular processes. We observed that spt7Δ/Δ and spt8Δ/Δ strains have a filamentous phenotype, and both are highly invasive in yeast growing conditions as compared to the wild type, while ngg1Δ/Δ and ubp8Δ/Δ are in yeast-locked state and non-invasive in both YPD media and filamentous induced conditions compared to wild type. RNA-sequencing-based transcriptional profiling of SAGA mutants reveals upregulation of hyphal specific genes in spt7Δ/Δ and spt8Δ/Δ strains and downregulation of ergosterol metabolism pathway. As well, spt7Δ/Δ and spt8Δ/Δ confer susceptibility to antifungal drugs, to acidic and alkaline pH, to high temperature, and to osmotic, oxidative, cell wall, and DNA damage stresses, indicating that these proteins are important for genotoxic and cellular stress responses. Despite having similar morphological phenotypes (constitutively filamentous and invasive) spt7 and spt8 mutants displayed variation in nuclear distribution where spt7Δ/Δ cells were frequently binucleate and spt8Δ/Δ cells were consistently mononucleate. We also observed that spt7Δ/Δ and spt8Δ/Δ mutants were quickly engulfed by macrophages compared to ngg1Δ/Δ and ubp8Δ/Δ strains. All these findings suggest that the SAGA complex modules can have contrasting functions where loss of Spt7 or Spt8 enhances filamentation and invasiveness while loss of Ngg1 or Ubp8 blocks these processes.

Candida albicans , Fatores de Transcrição , Biofilmes , Candida albicans/genética , Candida albicans/metabolismo , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Histona Acetiltransferases/genética , Histona Acetiltransferases/metabolismo , Fatores de Transcrição/metabolismo
Complement Ther Clin Pract ; 46: 101516, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34837806


BACKGROUND: Inhalation aromatherapy is a complementary therapy in different clinical settings, but there is little evidence about its effectiveness in childcare. OBJECTIVE: To assess the effectiveness of inhalational aromatherapy in the care of hospitalized pediatric patients. METHODS: Systematic review of clinical trials and quasi-experimental studies, based on PRISMA recommendations, searching Medline, Web of Science, Scopus, SciELO, LILACS, CINAHL, Science Direct, EBSCO, and updated databases. The Down and Black 2020, RoB 2020 CLARITY, and ROBINS-I 2020 scales were used through the Distiller SR software to verify the studies' internal validity and risk of bias. RESULTS: From 446 articles identified, 9 fulfilled the inclusion criteria. Seven were randomized controlled trials (RCTs), one pilot RCT, and one non-randomized quasi-experimental trial. Different outcomes were analyzed, with pain being the most frequently measured variable. None of the 6 studies that evaluated pain showed significant effects with inhalation aromatherapy. Additionally, non-significant effects were found regarding nausea, vomiting, and behavioral/emotional variables. CONCLUSIONS: The findings are still inconclusive, and more evidence is required from future studies with high methodological quality, blinding, and adequate sample sizes.

Aromaterapia , Terapias Complementares , Administração por Inalação , Criança , Humanos , Náusea , Vômito
PLoS One ; 13(12): e0209917, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30596767


Little is known about how Drosophila adults behave in the wild, including mating, allocation of food and space, and escape from predators. This lack of information has negative implications for our ability to understand the capabilities of the nervous system to integrate sensory cues necessary for the adaptation of organisms in natural conditions. We characterized a set of behavioral routines of D. melanogaster and D. simulans adults in three ecologically different orchards: grape, apple and prickly pear. We also investigated how the flies identify conspecifics and aliens in the wild to better understand relationships between group formation and adaptation of Drosophila to breeding sites. We characterized the locations by recording in each orchard humidity, temperature, illumination conditions, pH of fruits, the presence/absence of other Drosophila species and the predator ant Linepithema humile. Our findings suggest that the home range of these species of Drosophila includes decaying fruits and, principally, a variety of microhabitats that surround the fruits. The ecological heterogeneity of the orchards and odors emitted by adult D. melanogaster and D. simulans influence perch preferences, cluster formation, court and mating, egg-laying site selection, and use of space. This is one of the first large examinations of the association between changing, complex environments and a set of adult behaviors of Drosophila. Therefore, our results have implications for understanding the genetic differentiation and evolution of populations of species in the genus Drosophila.

Drosophila/fisiologia , Comportamento Alimentar/fisiologia , Cadeia Alimentar , Comportamento Sexual Animal/fisiologia , Animais , Feminino , Masculino
Parasit Vectors ; 9: 52, 2016 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-26822677


BACKGROUND: The existence nematodes of veterinary importance such as Haemonchus contortus resistant to anthelmintic drugs, including the macrocyclic lactones, has become a major concern in animal health. Macrocyclic lactone resistance in H. contortus seems to be multigenic including the active efflux of these drugs by P-glycoproteins, members of the ABC transporter family, present in this parasite. The goals of the present work were to determine the activity of H. contortus P-glycoprotein 9.1 (Hco-PGP-9.1) and its interaction with the avermectins, ivermectin, abamectin, and also the milbemycin, moxidectin. Additionally, the localisation of Hco-PGP-9.1 was sought in adult worms. METHODS: Hco-Pgp-9.1 was cloned and expressed in mammalian cells and its expression profile was determined at the transcriptional and protein level by qRT-PCR and Western-blot, respectively. The nematode transport activity was assessed using the tracer dye Rhodamine 123. A ligand competition assay between different macrocyclic lactones and Rhodamine 123 was used to establish whether or not there was interaction between Hco-PGP-9.1 and the avermectins (abamectin and ivermectin) or moxidectin. In addition, immunostaining was carried out to localise Hco-PGP-9.1 expression in the transgenic cells and in adult female parasites. RESULTS: Hco-PGP-9.1 was expressed in the cell membrane of the transfected host cells and was able to extrude Rhodamine 123. Ivermectin and abamectin, but not moxidectin, had a pronounced inhibitory effect on the ability of Hco-PGP-9.1 to transport Rhodamine 123. Antibodies raised against Hco-PGP-9.1 epitopes localised to the uterus of adult female H. contortus. CONCLUSIONS: These results suggest a strong interaction of the avermectins with Hco-PGP-9.1. However, possibly due to its physico-chemical properties, moxidectin had markedly less effect on Hco-PGP-9.1. Because of the greater interaction of the avermectins than moxidectin with this transporter, it is more likely to contribute to avermectin resistance than to moxidectin resistance in H. contortus. Possible over expression of Hco-PGP-9.1 in the female reproductive system in resistant worms could reduce paralysis of the uterus by macrocyclic lactones, allowing continued egg release in drug challenged resistant worms.

Membro 1 da Subfamília B de Cassetes de Ligação de ATP/genética , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/metabolismo , Anti-Helmínticos/metabolismo , Haemonchus/genética , Animais , Western Blotting , Feminino , Perfilação da Expressão Gênica , Genitália Feminina/efeitos dos fármacos , Ivermectina/análogos & derivados , Ivermectina/metabolismo , Macrolídeos/metabolismo , Ligação Proteica , Reação em Cadeia da Polimerase em Tempo Real
Int J Parasitol ; 45(1): 85-93, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25486495


Haemonchus contortus is a veterinary nematode that infects small ruminants, causing serious decreases in animal production worldwide. Effective control through anthelmintic treatment has been compromised by the development of resistance to these drugs, including the macrocyclic lactones. The mechanisms of resistance in H. contortus have yet to be established but may involve efflux of the macrocyclic lactones by nematode ATP-binding-cassette transporters such as P-glycoproteins. Here we report the expression and functional activity of H. contortus P-glycoprotein 2 expressed in mammalian cells and characterise its interaction with the macrocyclic lactones, ivermectin, abamectin and moxidectin. The ability of H. contortus P-glycoprotein 2 to transport different fluorophore substrates was markedly inhibited by ivermectin and abamectin in a dose-dependent and saturable way. The profile of transport inhibition by moxidectin was markedly different. H. contortus P-glycoprotein 2 was expressed in the pharynx, the first portion of the worm's intestine and perhaps in adjacent nervous tissue, suggesting a role for this gene in regulating the uptake of avermectins and in protecting nematode tissues from the effects of macrocyclic lactone anthelmintic drugs. H. contortus P-glycoprotein 2 may thus contribute to resistance to these drugs in H. contortus.

Subfamília B de Transportador de Cassetes de Ligação de ATP/análise , Anti-Helmínticos/metabolismo , Haemonchus/química , Haemonchus/metabolismo , Lactonas/metabolismo , Compostos Macrocíclicos/metabolismo , Estruturas Animais/química , Animais , Transporte Biológico Ativo , Resistência a Medicamentos , Perfilação da Expressão Gênica , Haemonchus/efeitos dos fármacos , Ivermectina/análogos & derivados , Ivermectina/metabolismo , Macrolídeos/metabolismo
J Cell Biochem ; 112(1): 189-99, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-21117064


Echinococcus granulosus, the agent of hydatid disease, presents an indirect life cycle, with canines (mainly dogs) as definitive hosts, and herbivores and human as intermediary ones. In intermediary hosts fertile and infertile cysts develop, but only the first ones develop protoscoleces, the parasite form infective to definitive hosts. We report the presence of bovine IgGs in the germinal layer from infertile cysts (GLIC), in an order of magnitude greater than in the germinal layer from fertile cysts (GLFC). When extracted with salt solutions, bovine IgGs from GLIC are associated with low or with high affinity (most likely corresponding to non specific and antigen specific antibodies, respectively). Specific IgGs penetrate both the cells of the germinal layer and HeLa cultured cells and recognize parasitic proteins. These results, taken together with previous ones from our laboratory, showing induction of apoptosis in the germinal layer of infertile hydatid cysts, provide the first coherent explanation of the infertility process. They also offer the possibility of identifying the parasite antigens recognized, as possible targets for immune modulation.

Doenças dos Bovinos/imunologia , Equinococose/veterinária , Echinococcus granulosus/imunologia , Infertilidade/veterinária , Animais , Bovinos , Doenças dos Bovinos/metabolismo , Doenças dos Bovinos/patologia , Equinococose/imunologia , Equinococose/metabolismo , Echinococcus granulosus/metabolismo , Células HeLa , Humanos , Imunidade Humoral , Infertilidade/imunologia , Microscopia de Fluorescência
Rev. obstet. ginecol. Venezuela ; 58(4): 217-229, dic. 1998. tab
Artigo em Espanhol | LILACS | ID: lil-301428


Indicar la importancia del asesoramiento genético para la prevención de los defectos del nacimiento y una reproducción sana, utilizando una población blanco altamente motivada, tal como la madre de alto riesgo para defectos del nacimiento. Selección de madres de alto riesgo en la consulta prenatal, la consulta de niños sanos, el servicio de ultrasonido y el registro de malformados. Hospital Chiquinquirá de Maracaibo y consultas públicas y privadas de la región. En once años, 576 pacientes, se atendieron en la consulta de genética. La ultrasonografía realizada por el genetista, demostró ser mas eficiente (38,23 por ciento) que la realizada en el servicio de ultrasonido (11,1 por ciento),(p>0,001; prueba de Z de una cola). La atención prenatal a la madre es incompleta sin el asesoramiento genético ya que a través del mismo, es posible la selección de un 10 por ciento a un 50 por ciento de embarazos de alto riesgo para defectos fetales cuya prevención de incidencia y recurrencia es posible, con beneficios económicos cuantificables para la nación

Humanos , Feminino , Gravidez , Perinatologia , Gravidez de Alto Risco , Diagnóstico Pré-Natal , Ginecologia , Obstetrícia , Venezuela
51; s.n; 1986. 156 p. ilus, tab.
Tese em Espanhol | BIMENA | ID: bim-4267

Humanos , Vasectomia