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1.
Int J Clin Pharm ; 46(3): 755-760, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38416349

RESUMO

In the era of personalized medicine, pharmacovigilance faces new challenges and opportunities, demanding a shift from traditional approaches. This article delves into the evolving landscape of drug safety monitoring in the context of personalized treatments. We aim to provide a succinct reflection on the intersection of tailored therapeutic strategies and vigilant pharmacovigilance practices. We discuss the integration of pharmacogenetics in enhancing drug safety, illustrating how genetic profiling aids in predicting drug responses and adverse reactions. Emphasizing the importance of phase IV-post-marketing surveillance, we explore the limitations of pre-marketing trials and the necessity for a comprehensive approach to drug safety. The article discusses the pivotal role of pharmacogenetics in pre-exposure risk management and the redefinition of pharmacoepidemiological methods for post-exposure surveillance. We highlight the significance of integrating patient-specific genetic profiles in creating personalized medication leaflets and the use of advanced computational methods in data analysis. Additionally, we examine the ethical, privacy, and data security challenges inherent in precision medicine, emphasizing their implications for patient consent and data management.


Assuntos
Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos , Farmacogenética , Farmacovigilância , Medicina de Precisão , Medicina de Precisão/métodos , Humanos , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos/prevenção & controle , Farmacogenética/métodos , Vigilância de Produtos Comercializados/métodos
2.
Vaccine ; 41(12): 2084-2092, 2023 03 17.
Artigo em Inglês | MEDLINE | ID: mdl-36813665

RESUMO

The uptake ofCOVID-19 vaccines has varied considerably across European countries. This study investigates people's decision-making process regarding vaccination by analyzing qualitative interviews (n = 214) with residents from five European countries: Austria, Germany, Italy, Portugal, and Switzerland. We identify three factors that shape vaccination decision-making: individual experiences and pre-existing attitudes towards vaccination, social environment, and socio-political context. Based on this analysis, we present a typology of decision-making regarding COVID-19 vaccines, where some types present stable stances towards vaccines and others change over time. Trust in government and relevant stakeholders, broader social factors, and people's direct social environment were particularly relevant to these dynamics. We conclude that vaccination campaigns should be considered long-term projects (also outside of pandemics) in need of regular adjustment, communication and fine-tuning to ensure public trust. This is particularly pertinent for booster vaccinations, such as COVID-19 or influenza.


Assuntos
COVID-19 , Vacinas contra Influenza , Vacinas , Humanos , Vacinas contra COVID-19 , COVID-19/prevenção & controle , Vacinação , Pesquisa Qualitativa , Europa (Continente)
3.
Cytokine ; 111: 72-83, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30118915

RESUMO

Helminth infection can reduce the severity of inflammatory bowel disease. However, the modulatory mechanisms elicited by helminth infection are not yet fully understood and vary depending on the experimental model. Herein we evaluated the effect of acute infection of BALB/c mice with Strongyloides venezuelensis on the clinical course of ulcerative colitis induced by Dextran Sulfate Sodium (DSS) treatment of these animals. For the experiments, S. venezuelensis-infected BALB/c mice were treated orally with 4% DSS solution for seven days. As controls, we used untreated S. venezuelensis infected, DSS-treated uninfected, and untreated/uninfected BALB/c mice. During DSS treatment, mice from the different groups were compared with regards to the clinical signs related to the severity of colitis and intestinal inflammation. Mice acutely infected with S. venezulensis and treated with DSS had reduced clinical score, shortening of the colon, and tissue inflammation. Moreover, DSS-treated and infected mice showed reduced IL-4, INF-γ, and IL-17 levels and increase of IL-10 production in the colon and/or in the supernatant of mesenteric lymph nodes cell cultures that resulted in lower eosinophil peroxidase and myeloperoxidase activity in colon homogenates, when compared with DSS-treated uninfected mice. DSS-treated infected mice also preserved the intestine architecture and had normal differentiation of goblet cells and mucus production in the colon mucosa. In conclusion, the data indicate that the clinical improvement reported in DSS-treated infected mice was accompanied by the lower production of Th1/Th2/Th17 pro-inflammatory cytokines, stimulation of IL-10, and induction of mucosal repair mechanisms.


Assuntos
Colite/imunologia , Colo/imunologia , Sulfato de Dextrana/toxicidade , Interleucina-10/imunologia , Strongyloides/imunologia , Estrongiloidíase/imunologia , Células Th1/imunologia , Células Th17/imunologia , Células Th2/imunologia , Doença Aguda , Animais , Colite/induzido quimicamente , Colite/parasitologia , Colite/patologia , Colo/parasitologia , Colo/patologia , Feminino , Células Caliciformes/imunologia , Células Caliciformes/patologia , Camundongos , Camundongos Endogâmicos BALB C , Estrongiloidíase/induzido quimicamente , Estrongiloidíase/patologia , Células Th1/patologia , Células Th17/patologia , Células Th2/patologia
4.
Pain Res Manag ; 2016: 2020915, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27445601

RESUMO

Serotonin is a monoamine neurotransmitter that plays a major role in both nociception and mood regulation. Alterations in the 5-hydroxytryptophan (5HT) system have been reported in chronic pain patients. In recent years, Selective Serotonin Reuptake Inhibitors (SSRIs) have been suggested as an alternative treatment for chronic pain due to the fact that they are better tolerated presenting less secondary effects than other antidepressants such as tricyclic antidepressants. Although several clinical trials have been published, the effectiveness of SSRI as treatment for pain conditions is inconclusive. This review aims to summarise what is known, regarding the effectiveness of SSRI as a treatment for chronic pain conditions in adults. A total of 36 studies involving a total of 1898 participants were included in this review. Of the 36 trials included in the review, 2 used zimelidine as treatment, 3 used escitalopram, 4 used fluvoxamine, 4 used sertraline, 6 used citalopram, 8 used paroxetine, 9 used fluoxetine, and one used both citalopram and paroxetine. Because the trials included in this review are quite heterogeneous, only qualitative analyses were performed. SSRI seems to have an effect on most of chronic pain conditions; however, further clinical trials with good methodology leading to low risk of bias are needed in order to conclude once and for all the effect of this drug class as treatment for chronic pain conditions.


Assuntos
Dor Crônica/tratamento farmacológico , Inibidores Seletivos de Recaptação de Serotonina/uso terapêutico , Bases de Dados Factuais/estatística & dados numéricos , Método Duplo-Cego , Humanos , Ensaios Clínicos Controlados Aleatórios como Assunto , Resultado do Tratamento
5.
Parasitol Res ; 115(8): 3107-17, 2016 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-27102638

RESUMO

Strongyloidiasis is a neglected chronic nematode infection, in which the control of autoinfection rate and severity of disease is dependent on type 2 immune responses. Strongyloides also causes Th2 responses in the lung of infected animals and changes in airway function, including airway hyperresponsiveness (AHR). Mechanisms of AHR during Strongyloides venezuelensis infection are not entirely known, and we investigate here the role of IL-4, eosinophils, and IL-33/ST2. AHR was evaluated in infected mice by determining changes in lung function after increasing doses of methacholine. Balb/C, but no C57Bl/6, mice developed AHR, tissue eosinophilia, and increased local IL-4 and IL-5 production. Functional changes peaked at day 4 and 7, after the larva had left the lungs. AHR was clearly dependent on IL-4 but not on eosinophils, as evaluated by experiments in IL-4 and Gata-1-deficient mice. Experiments in ST2-deficient mice showed that this pathway was not needed for induction of AHR but was necessary for the maintenance of AHR and for Th2 responses in the lung. These studies clearly show a crucial role for IL-4 in the induction of AHR following S. venezuelensis infection and for IL-33/ST2 in maintaining AHR and lung Th2 responses.


Assuntos
Eosinófilos/imunologia , Proteína 1 Semelhante a Receptor de Interleucina-1/imunologia , Interleucina-33/imunologia , Interleucina-4/imunologia , Hipersensibilidade Respiratória/imunologia , Strongyloides/imunologia , Estrongiloidíase/imunologia , Alérgenos/imunologia , Animais , Eosinofilia/imunologia , Eosinofilia/parasitologia , Fator de Transcrição GATA1/genética , Proteína 1 Semelhante a Receptor de Interleucina-1/genética , Interleucina-4/biossíntese , Interleucina-4/genética , Interleucina-5/biossíntese , Interleucina-5/imunologia , Contagem de Leucócitos , Pulmão/imunologia , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Hipersensibilidade Respiratória/parasitologia , Estrongiloidíase/parasitologia , Células Th2/imunologia
6.
J Ethnopharmacol ; 180: 114-23, 2016 Mar 02.
Artigo em Inglês | MEDLINE | ID: mdl-26806570

RESUMO

ETHNOPHARMACOLOGICAL RELEVANCE: Sida pilosa Retz (Malvaceae) is a plant used in Africa for the treatment of intestinal helminthiasis, lower abdominal pains and dysmenorrhea. AIM OF THE STUDY: In order to determine the potential use of S. pilosa in the treatment of schistosomiasis mansoni, we evaluated the schistosomicidal, antioxidant and anti-fibrotic properties of the aqueous extract and the n-butanol fraction of its aerial parts. MATERIAL AND METHODS: S. pilosa aqueous extract (SpAE) at 100, 200 and 400mg/kg and n-butanol fraction (SpBF) at 50, 100 and 200mg/kg were administered per os to Schistosoma mansoni-infected mice for 4 weeks. Praziquantel (100mg/kg × 5 days) was used as reference drug. After sacrifice, worm burden and egg count, transaminases and proteins levels were evaluated. Malondialdehyde (MDA), lipid hydroperoxydes (LOOH), catalase (CAT), superoxide dismutase (SOD), eosinophil peroxidase (EPO) and myeloperoxidase (MPO) were also measured. The anti-fibrotic effect of the plant was evaluated by the determination of hydroxyproline and γ-interferon (IFN-γ). RESULTS: The treatment of S. mansoni-infected mice by SpAE or SpBF resulted in a moderate reduction of worm burden and egg load in the liver and intestine. Both SpAE and SpBF significantly reversed the increasing liver proteins, MDA, LOOH and CAT levels induced by the infection. Moreover, SOD activity was improved by SpAE and SpBF. Schistosomiasis mansoni considerably increased the EPO (p<0.001) and MPO activities (p<0.001). SpAE treatment significantly reduced EPO and MPO activities at all doses. SpBF failed to reduce the increasing MPO and decreased EPO only at the highest dose. S. mansoni-infection induced an increase in hydroxyproline content (p<0.001) and a decrease in IFN-γ level (p<0.001). Both SpAE and SpBF significantly reduced hepatic hydroxyproline content, while only SpAE (p<0.05) improved IFN-γ level. CONCLUSION: These results suggest that the liver pathology in schistosomiasis mansoni is improved by S. pilosa aqueous extract, which disclosed a moderate schistosomicidal, but strong antioxidant and anti-fibrotic activities. The n-butanol fraction was however less active than the aqueous extract.


Assuntos
Anti-Helmínticos/uso terapêutico , Antioxidantes/uso terapêutico , Cirrose Hepática/tratamento farmacológico , Malvaceae , Extratos Vegetais/uso terapêutico , Esquistossomose mansoni/tratamento farmacológico , 1-Butanol/química , Animais , Anti-Helmínticos/farmacologia , Antioxidantes/farmacologia , Catalase/metabolismo , Fezes/parasitologia , Feminino , Interferon gama/metabolismo , Fígado/efeitos dos fármacos , Fígado/metabolismo , Fígado/parasitologia , Fígado/patologia , Cirrose Hepática/metabolismo , Cirrose Hepática/parasitologia , Cirrose Hepática/patologia , Malondialdeído/metabolismo , Camundongos , Fitoterapia , Componentes Aéreos da Planta , Extratos Vegetais/farmacologia , Schistosoma mansoni/efeitos dos fármacos , Esquistossomose mansoni/metabolismo , Esquistossomose mansoni/parasitologia , Esquistossomose mansoni/patologia , Solventes/química , Superóxido Dismutase/metabolismo , Água/química
7.
Parasitol Res ; 114(12): 4601-16, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26350380

RESUMO

Multiple schistosome and soil-transmitted nematode infections are frequently reported in human populations living in tropical areas of developing countries. In addition to exposure factors, the host immune response plays an important role in helminth control and morbidity in hosts with multiple infections; however, these aspects are difficult to evaluate in human populations. In the current study, female Swiss mice were simultaneously co-infected with Strongyloides venezuelensis and Schistosoma mansoni or infected with St. venezuelensis at 2, 4, or 14 weeks after Sc. mansoni infection. The simultaneously infected mice showed a similar parasite burden for St. venezuelensis compared with mono-infected mice. In contrast, there was a significant reduction of St. venezuelensis burden (primarily during the migration of the larvae) in mice that were previously infected with Sc. mansoni at the acute or chronic phase. Independent of the stage of Sc. mansoni infection, the St. venezuelensis co-infection was capable of inducing IL-4 production in the small intestine, increasing the IgE concentration in the serum and increasing eosinophilia in the lungs and intestine. This result suggests that the nematode infection stimulates local type 2 immune responses independently of the schistosomiasis stage. Moreover, previous Sc. mansoni infection stimulated early granulocyte infiltration in the lungs and trematode-specific IgM and IgG1 production that recognized antigens from St. venezuelensis infective larvae; these immune responses would act in the early control of St. venezuelensis larvae. Our data suggest that the effect of multiple helminth infections on host susceptibility and morbidity largely depends on the species of parasite and the immune response.


Assuntos
Coinfecção/imunologia , Schistosoma mansoni/crescimento & desenvolvimento , Esquistossomose mansoni/imunologia , Strongyloides/crescimento & desenvolvimento , Estrongiloidíase/imunologia , Animais , Coinfecção/parasitologia , Citocinas/imunologia , Feminino , Humanos , Interleucina-4/imunologia , Intestino Delgado/imunologia , Intestino Delgado/parasitologia , Pulmão/imunologia , Pulmão/parasitologia , Camundongos , Schistosoma mansoni/imunologia , Esquistossomose mansoni/parasitologia , Strongyloides/imunologia , Estrongiloidíase/parasitologia
8.
Pain ; 156(6): 1101-1111, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25782365

RESUMO

The thermal grill illusion, where interlaced warm and cold bars cause an unusual burning sensation, and paradoxical heat sensations (PHS), where cold is perceived as warm when alternating warm and cold, are examples of a complex integration of thermal sensations. Here, we investigated the effect of sensitization of heat-sensitive neurons on cold and warm integration. We examined thermal thresholds, PHS, and warm, cold, and pain sensations to alternating cold (10°C) and warm (40°C) bars (the thermal grill [TG]) in the primary area (application site) after topical application with capsaicin and vehicle control (ethanol) on the volar forearms in randomized order in 80 healthy participants. As expected, capsaicin induced heat allodynia and hyperalgesia and decreased cold and cold pain sensation. In addition, we found that after capsaicin application, the TG caused less pain and burning than the 40°C bars alone in contrast to the control side where the TG caused more pain and burning, consistent with the thermal grill illusion. In both situations, the pain intensity during the TG correlated inversely with both cold and warm pain thresholds but not with detection thresholds. Paradoxical heat sensation was only seen in 3 participants after control application but in 19 participants after capsaicin. Those with PHS after capsaicin application had higher detection thresholds to both cold and warm than those without PHS, but there was no difference in thermal pain threshold. These results suggest that a complex cross talk among several cold and warm sensitive pathways shapes thermal perception.


Assuntos
Ansiedade/fisiopatologia , Capsaicina/administração & dosagem , Hiperalgesia/fisiopatologia , Limiar da Dor/efeitos dos fármacos , Fármacos do Sistema Sensorial/administração & dosagem , Sensação Térmica/efeitos dos fármacos , Adolescente , Adulto , Feminino , Humanos , Masculino , Medição da Dor , Estatísticas não Paramétricas , Inquéritos e Questionários , Adulto Jovem
9.
Biomed Res Int ; 2015: 349584, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25699274

RESUMO

It is suggested that genetic variations explain a significant portion of the variability in pain perception; therefore, increased understanding of pain-related genetic influences may identify new targets for therapies and treatments. The relative contribution of the different genes to the variance in clinical and experimental pain responses remains unknown. It is suggested that the genetic contributions to pain perception vary across pain modalities. For example, it has been suggested that more than 60% of the variance in cold pressor responses can be explained by genetic factors; in comparison, only 26% of the variance in heat pain responses is explained by these variations. Thus, the selection of pain model might markedly influence the magnitude of the association between the pain phenotype and genetic variability. Thermal pain sensation is complex with multiple molecular and cellular mechanisms operating alone and in combination within the peripheral and central nervous system. It is thus highly probable that the thermal pain experience is affected by genetic variants in one or more of the pathways involved in the thermal pain signaling. This review aims to present and discuss some of the genetic variations that have previously been associated with different experimental thermal pain models.


Assuntos
Percepção da Dor , Limiar da Dor , Dor/genética , Temperatura Alta , Humanos , Modelos Teóricos , Dor/fisiopatologia
10.
Mol Pain ; 10: 76, 2014 Dec 04.
Artigo em Inglês | MEDLINE | ID: mdl-25472558

RESUMO

BACKGROUND: Recent studies have suggested an association between genotypes affecting the expression of the serotonin transporter and thermal pain perception and the thermal grill. The aim of this study was to investigate differences in thermal and mechanical pain perception and the thermal grill in two groups of healthy volunteers according to their genotype, associated with either high (n = 40) or low (n = 40) expression of the serotonin transporter and according to gender. Cold and warm detection and pain thresholds, pressure pain threshold and cold, warm and pain sensations to single or alternating stimuli with cold (20°C) and warm (40°C) temperatures (known as the thermal grill) were determined. In addition, intensity of ongoing pain and area and intensity of pinprick hyperalgesia in the secondary hyperalgesic area following topical application of capsaicin and vehicle control (ethanol) were determined. RESULTS: No significant differences in detection and pain thresholds for cold and warm temperatures, presence of paradoxical heat sensation, pressure pain threshold and pain responses to suprathreshold thermal stimuli were observed. There was also no difference in capsaicin-evoked ongoing pain and secondary hyperalgesia between the two genotype groups (p >0.4), also when subdivided by gender (p >0.17). In addition, there were no significant differences in the perception of the thermal grill between the two genotypes (p >0.5), also when subdivided by gender. CONCLUSIONS: Genotypes associated with high or low expression of the serotonin transporter were not associated with thermal pain thresholds, pressure pain threshold, pain after capsaicin application or responses to the thermal grill.The present results do not support that the investigated genotypes play a major role in thermal pain perception among healthy individuals.


Assuntos
Capsaicina/química , Limiar da Dor/fisiologia , Dor/genética , Polimorfismo Genético , Receptor 5-HT1A de Serotonina/genética , Adulto , Etanol/química , Feminino , Interação Gene-Ambiente , Genótipo , Voluntários Saudáveis , Temperatura Alta , Humanos , Masculino , Manejo da Dor , Receptor 5-HT1A de Serotonina/fisiologia , Temperatura , Adulto Jovem
11.
PLoS One ; 8(11): e78889, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24244382

RESUMO

Pain catastrophizing, a coping style characterized by excessively negative thoughts and emotions in relation to pain, is one of the psychological factors that most markedly predicts variability in the perception of pain; however, only little is known about the underlying neurobiology. The aim of this study was to test for associations between psychological variables, such as pain catastrophizing, anxiety and depression, and selected polymorphisms in genes related to monoaminergic neurotransmission, in particular serotonin pathway genes. Three hundred seventy-nine healthy participants completed a set of psychological questionnaires: the Pain Catastrophizing Scale (PCS), the State-Trait Anxiety Inventory and Beck's Depression Inventory, and were genotyped for 15 single nucleotide polymorphisms (SNPs) in nine genes. The SNP rs1176744 located in the serotonin receptor 3B gene (5-HTR3B) was found to be associated with pain catastrophizing scores: both the global score and the subscales of magnification and helplessness. This is the first study to show an association between 5-HTR3B and PCS scores, thus suggesting a role of the serotonin pathway in pain catastrophizing. Since 5-HTR3B has previously been associated with descending pain modulation pathways, future studies will be of great interest to elucidate the molecular pathways involved in the relation between serotonin, its receptors and pain catastrophizing.


Assuntos
Catastrofização/genética , Medição da Dor , Polimorfismo Genético , Receptores 5-HT3 de Serotonina/genética , Inquéritos e Questionários , Catastrofização/metabolismo , Catastrofização/psicologia , Feminino , Humanos , Masculino , Receptores 5-HT3 de Serotonina/metabolismo , Serotonina/genética , Serotonina/metabolismo
12.
Pain ; 154(8): 1469-76, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23707290

RESUMO

The perception of pain is determined by a combination of genetic, neurobiological, cultural, and emotional factors. Recent studies have demonstrated an association between specific genotypes and pain perception. Particular focus has been given to the triallelic polymorphism in the promoter region of the serotonin transporter gene in relation to pain perception. The aim of this study was to investigate whether the modulatory effect of emotions mediated by visual stimuli on muscular pain perception is genotype dependent. A total of 150 healthy subjects were selected on the basis of their polymorphism in the serotonin transporter gene. First, visual conditioning was performed with positive, negative, and neutral pictures from the International Affective Picture System, and the unpleasantness/pleasantness of the pictures was rated. Second, visual conditioning stimuli were presented while experimental jaw muscle pain was evoked by injection of hypertonic saline into the masseter muscle, and participants continuously rated pain intensity on an electronic visual analogue scale. The pictures induced similar changes in emotions across the 3 genotype groups, and hypertonic saline evoked moderate pain levels in all participants. However, in participants with a high expression of the serotonin transporter protein, conditioning with negative pictures increased pain intensity and positive pictures decreased pain intensity when compared with neutral pictures. In contrast, there were no significant effects of the pictures on pain perception in participants with either intermediate or low expression of the protein. These results suggest that polymorphisms in the serotonin transporter gene play an important role in emotions modulation of muscle pain.


Assuntos
Mialgia/genética , Mialgia/fisiopatologia , Polimorfismo Genético/genética , Proteínas da Membrana Plasmática de Transporte de Serotonina/genética , Adolescente , Adulto , Análise de Variância , Emoções/fisiologia , Feminino , Testes Genéticos , Genótipo , Humanos , Masculino , Mialgia/psicologia , Medição da Dor , Limiar da Dor/fisiologia , Estimulação Luminosa , Escalas de Graduação Psiquiátrica , Percepção Visual/genética , Adulto Jovem
13.
Mem Inst Oswaldo Cruz ; 106(7): 884-91, 2011 11.
Artigo em Inglês | MEDLINE | ID: mdl-22124562

RESUMO

Lectin-carbohydrate binding may be involved in the recognition of Schistosoma mansoni sporocysts by haemocytes of Biomphalaria; therefore, we tested if this interaction is associated with snail resistance against Schistosoma infection. In vitro data showed that most of the S. mansoni sporocysts cultured with haemocytes from Biomphalaria glabrata BH, a highly susceptible snail strain, had a low number of cells that adhered to their tegument and a low mortality rate. Moreover, the addition of N-acetyl-D-glucosamine (GlcNAc) did not alter this pattern of adherence and mortality. Using haemocytes and haemolymph of Biomphalaria tenagophila Cabo Frio, we observed a high percentage of sporocysts with adherent cells, but complete encapsulation was not detected. Low concentrations of GlcNAc increased haemocyte binding to the sporocysts and mortality, which returned to basal levels with high concentrations of the carbohydrate. In contrast, haemocytes plus haemolymph from B. tenagophila Taim encapsulated cellular adhesion index of level 3 and destroyed over 30% of the S. mansoni sporocysts in culture. Interestingly, the addition of GlcNAc, but not mannose, to the culture medium resulted in the significant inhibition of cellular adhesion to the parasite tegument and the reduction of parasite mortality, suggesting that GlcNAc carbohydrate moieties are important to the recognition of S. mansoni by B. tenagophila Taim.


Assuntos
Acetilglucosamina/imunologia , Biomphalaria/parasitologia , Hemócitos/parasitologia , Hemolinfa/parasitologia , Oocistos/fisiologia , Schistosoma mansoni/imunologia , Animais , Biomphalaria/citologia , Carboidratos/imunologia , Interações Hospedeiro-Parasita
14.
Mem. Inst. Oswaldo Cruz ; 106(7): 884-891, Nov. 2011. ilus, graf
Artigo em Inglês | LILACS | ID: lil-606653

RESUMO

Lectin-carbohydrate binding may be involved in the recognition of Schistosoma mansoni sporocysts by haemocytes of Biomphalaria; therefore, we tested if this interaction is associated with snail resistance against Schistosoma infection. In vitro data showed that most of the S. mansoni sporocysts cultured with haemocytes from Biomphalaria glabrata BH, a highly susceptible snail strain, had a low number of cells that adhered to their tegument and a low mortality rate. Moreover, the addition of N-acetyl-D-glucosamine (GlcNAc) did not alter this pattern of adherence and mortality. Using haemocytes and haemolymph of Biomphalaria tenagophila Cabo Frio, we observed a high percentage of sporocysts with adherent cells, but complete encapsulation was not detected. Low concentrations of GlcNAc increased haemocyte binding to the sporocysts and mortality, which returned to basal levels with high concentrations of the carbohydrate. In contrast, haemocytes plus haemolymph from B. tenagophila Taim encapsulated cellular adhesion index of level 3 and destroyed over 30 percent of the S. mansoni sporocysts in culture. Interestingly, the addition of GlcNAc, but not mannose, to the culture medium resulted in the significant inhibition of cellular adhesion to the parasite tegument and the reduction of parasite mortality, suggesting that GlcNAc carbohydrate moieties are important to the recognition of S. mansoni by B. tenagophila Taim.


Assuntos
Animais , Acetilglucosamina/imunologia , Biomphalaria/parasitologia , Hemócitos/parasitologia , Hemolinfa/parasitologia , Oocistos/fisiologia , Schistosoma mansoni/imunologia , Biomphalaria/citologia , Carboidratos/imunologia , Interações Hospedeiro-Parasita
15.
Neuron ; 65(2): 217-29, 2010 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-20152128

RESUMO

The pituitary hormone, prolactin, triggers lactation in nursing mothers. Under nonlactating conditions, prolactin secretion is suppressed by powerful inhibition from hypothalamic tuberoinfundibular dopamine (TIDA) neurons. Although firing pattern has been suggested as integral to neuroendocrine control, the electrical behavior of TIDA cells remains unknown. We demonstrate that rat TIDA neurons discharge rhythmically in a robust 0.05 Hz oscillation. The oscillation is phase locked between neurons, and while it persists during chemical synaptic transmission blockade, it is abolished by gap junction antagonists. Thyrotropin-releasing hormone (TRH) potently stimulates prolactin release, an effect assumed to take place in the pituitary. In TIDA cells, TRH caused a transition from phasic to tonic firing through combined pre- and postsynaptic effects. These findings suggest a model for prolactin regulation where a TIDA network switch from oscillations to sustained discharge converts dopamine from an antagonist at high concentrations to a functional agonist as dopamine output from the network decreases.


Assuntos
Núcleo Arqueado do Hipotálamo/fisiologia , Relógios Biológicos/fisiologia , Dopamina/fisiologia , Rede Nervosa/fisiologia , Neurônios/fisiologia , Hormônio Liberador de Tireotropina/fisiologia , Animais , Masculino , Ratos , Ratos Sprague-Dawley
16.
J Physiol ; 587(Pt 6): 1179-86, 2009 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-19204048

RESUMO

Central orexin/hypocretin neurones are critical for sustaining consciousness: their firing stimulates wakefulness and their destruction causes narcolepsy. We explored whether the activity of orexin cells is modulated by thyrotropin-releasing hormone (TRH), an endogenous stimulant of wakefulness and locomotor activity whose mechanism of action is not fully understood. Living orexin neurones were identified by targeted expression of green fluorescent protein (GFP) in acute brain slices of transgenic mice. Using whole-cell patch-clamp recordings, we found that TRH robustly increased the action potential firing rate of these neurones. TRH-induced excitation persisted under conditions of synaptic isolation, and involved a Na(+)-dependent depolarization and activation of a mixed cation current in the orexin cell membrane. By double-label immunohistochemistry, we found close appositions between TRH-immunoreactive nerve terminals and orexin-A-immunoreactive cell bodies. These results identify a new physiological modulator of orexin cell firing, and suggest that orexin cell excitation may contribute to the arousal-enhancing actions of TRH.


Assuntos
Hipotálamo/fisiologia , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Neurônios/fisiologia , Neuropeptídeos/metabolismo , Hormônio Liberador de Tireotropina/farmacologia , Potenciais de Ação/efeitos dos fármacos , Animais , Proteínas de Fluorescência Verde/genética , Hipotálamo/citologia , Hipotálamo/efeitos dos fármacos , Técnicas In Vitro , Potenciais da Membrana/efeitos dos fármacos , Camundongos , Camundongos Endogâmicos , Camundongos Transgênicos , Neurônios/citologia , Neurônios/efeitos dos fármacos , Orexinas , Técnicas de Patch-Clamp , Sódio/metabolismo , Tetrodotoxina/farmacologia , Hormônio Liberador de Tireotropina/análogos & derivados , Hormônio Liberador de Tireotropina/metabolismo
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