RESUMO
Due to the high incidence of fungal infections caused by Candida species and their increasing resistance to antimicrobial treatments, alternative therapies such as probiotics have been studied. It has been show that several species of the genus Lactobacillus have anti-Candida activity, probably by direct inhibition, through competition for adhesion sites or production of secondary metabolites, and by indirect inhibition, through stimulation of the immune system of their host. However, the mechanisms of inhibition of these probiotics on Candida species have not yet been fully elucidated since this effect is related to more than one inhibition pathway. In the literature, several in vitro and in vivo studies have been developed seeking to elucidate the probiotics mechanisms of action. These studies have been focused on C. albicans inhibition assays, including analysis of antimicrobial activity, adherence capacity, biofilms formation, filamentation and interference on virulence genes, as well as assays of experimental candidiasis in invertebrate and vertebrate models. In this context, the purpose of this review was to gather different studies focused on the action mechanism of probiotic strains on Candida sp. and to discuss their impact on the candidiasis prevention.
Assuntos
Antifúngicos/farmacologia , Candida/efeitos dos fármacos , Candidíase/prevenção & controle , Probióticos/farmacologia , Animais , Antifúngicos/uso terapêutico , Biofilmes/efeitos dos fármacos , Candida/patogenicidade , Modelos Animais de Doenças , Lactobacillus/fisiologia , Probióticos/uso terapêutico , VirulênciaRESUMO
Located in the south-western part of Brazil, the state of Rio de Janeiro is geotectonically contained within a complex structural province that resulted in the amalgamation of the Western Gondwana Paleocontinent. To undertake an extensive radiological characterization of this complex geological province and investigate the influence of bedrock, soil type and soil chemical-physical characteristics on natural radionuclide levels in soils, 259 surface soil samples were collected that encompassed the main soil types and geological formations throughout the state. Gamma spectrometry analysis of the samples resulted in median values of 114 Bq.kg-1for 40K, 32 Bq.kg-1 for 226Ra and 74 Bq.kg-1 for 228Ra. The median value for 226Ra was similar to the world median value for soils, the 40K value was well below the worldwide value, and that for 228Ra exceeded the world median value. The intense weathering caused by the high rainfall rates and high temperatures may be responsible for the low levels of 40K in the soils, of which the strongly acidic and clayey soils are markedly K-depleted. A soil from a high-grade metamorphic rock (granulite) presented the lowest 226Ra (18 Bq.kg-1) content, whereas the highest levels for 226Ra (92 Bq.kg-1) and 228Ra (139 Bq.kg-1) were observed in a young soil enriched in primary minerals (Leptsol). A lowland soil (Gleysol) showed the highest median of 40K (301 Bq.kg-1). Strongly acidic soils tended to present high amounts of 226Ra, and sandy soils tended to contain low levels of 228Ra. The external radiation dose indicates that the state has a background radiation level within the natural range.
Assuntos
Monitoramento de Radiação , Poluentes Radioativos do Solo/análise , Solo/química , Radiação de Fundo , Brasil , Radioisótopos de Potássio/análise , Radioatividade , Rádio (Elemento)/análise , Tório/análiseRESUMO
AIM: The aim of this study was to evaluate the potential anti-Candida effects of Lactobacillus rhamnosus ATCC 9595 on Candida albicans ATCC 18804 using in vitro and in vivo models. METHODS AND RESULTS: The in vitro analysis evaluated the effects of L. rhamnosus on C. albicans's biofilm formation by CFU count and metabolic activity, filamentation capacity, and adhesion (ALS3 and HWP1) and transcriptional regulatory gene (BCR1 and CPH1) expression. The in vitro results showed that both the L. rhamnosus cells and supernatant reduced C. albicans biofilm formation, filamentation and gene expression. In the in vivo study, the treatment with L. rhamnosus supernatant increased 80% the survival of Galleria mellonella larvae infected with C. albicans. Furthermore, the supernatant of L. rhamnosus recruited haemocytes into the haemolymph (2·1-fold increase). CONCLUSIONS: Lactobacillus rhamnosus reduced the biofilm formation and filamentation of C. albicans in vitro by negatively regulating all studied C. albicans genes. Lactobacillus rhamnosus protected G. mellonella against experimental candidiasis in vivo. SIGNIFICANCE AND IMPACT OF THE STUDY: This study is the first study to report the anti-Candida properties of L. rhamnosus ATCC 9595. The supernatant of this strain has immunomodulatory effects on the G. mellonella model and protects the larvae against pathogens.
Assuntos
Antibiose , Candida albicans/genética , Lacticaseibacillus rhamnosus/fisiologia , Mariposas/imunologia , Fatores de Virulência/genética , Animais , Biofilmes , Candida albicans/fisiologia , Sistema Imunitário/imunologia , Larva/imunologia , Larva/microbiologia , Mariposas/microbiologia , Fatores de Virulência/metabolismoRESUMO
Liposomes are nanosystems that allow a sustained release of entrapped substances. Gamma-aminobutyric acid (GABA) is the most prevalent inhibitory neurotransmitter of the central nervous system (CNS). We developed a liposomal formulation of GABA for application in long-term CNS functional studies. Two days after liposome-entrapped GABA was injected intracerebroventricularly (ICV), Wistar rats were submitted to the following evaluations: (1) changes in mean arterial pressure (MAP), heart rate (HR) and renal sympathetic nerve activity (RSNA) to ICV injection of bicuculline methiodide (BMI) in anesthetized rats; (2) changes in cardiovascular reactivity to air jet stress in conscious rats; and (3) anxiety-like behavior in conscious rats. GABA and saline-containing pegylated liposomes were prepared with a mean diameter of 200 nm. Rats with implanted cannulas targeted to lateral cerebral ventricle (n = 5-8/group) received either GABA solution (GS), empty liposomes (EL) or GABA-containing liposomes (GL). Following (48 h) central microinjection (2 µL, 0.09 M and 99 g/L) of liposomes, animals were submitted to the different protocols. Animals that received GL demonstrated attenuated response of RSNA to BMI microinjection (GS 48 ± 9, EL 43 ± 9, GL 11 ± 8%; P < 0.05), blunted tachycardia in the stress trial (ΔHR: GS 115 ± 14, EL 117 ± 10, GL 74 ± 9 bpm; P<0.05) and spent more time in the open arms of elevated plus maze (EL 6 ± 2 vs. GL 18 ± 5%; P = 0.028) compared with GS and EL groups. These results indicate that liposome-entrapped GABA can be a potential tool for exploring the chronic effects of GABA in specific regions and pathways of the central nervous system.
Assuntos
Fármacos Cardiovasculares/administração & dosagem , Fármacos do Sistema Nervoso Central/administração & dosagem , GABAérgicos/administração & dosagem , Lipossomos/administração & dosagem , Ácido gama-Aminobutírico/administração & dosagem , Animais , Ansiedade/tratamento farmacológico , Ansiedade/fisiopatologia , Pressão Arterial/efeitos dos fármacos , Bicuculina/administração & dosagem , Bicuculina/análogos & derivados , Cateteres de Demora , Comportamento Exploratório/efeitos dos fármacos , Comportamento Exploratório/fisiologia , Frequência Cardíaca/efeitos dos fármacos , Infusões Intraventriculares , Rim/inervação , Masculino , Microinjeções , Ratos Wistar , Estresse Fisiológico/efeitos dos fármacos , Estresse Fisiológico/fisiologia , Sistema Nervoso Simpático/efeitos dos fármacos , Sistema Nervoso Simpático/fisiologia , Taquicardia/tratamento farmacológico , Taquicardia/fisiopatologiaAssuntos
Peptídeos beta-Amiloides/toxicidade , Transtornos Cognitivos/induzido quimicamente , Depressão/induzido quimicamente , Doença de Alzheimer , Peptídeos beta-Amiloides/administração & dosagem , Peptídeos beta-Amiloides/farmacocinética , Anedonia/efeitos dos fármacos , Animais , Química Encefálica/efeitos dos fármacos , Transtornos Cognitivos/metabolismo , Citocinas/análise , Depressão/metabolismo , Modelos Animais de Doenças , Comportamento de Ingestão de Líquido , Fluoxetina/administração & dosagem , Fluoxetina/uso terapêutico , Gliose/induzido quimicamente , Gliose/prevenção & controle , Hipocampo/efeitos dos fármacos , Hipocampo/metabolismo , Resposta de Imobilidade Tônica , Inflamação , Injeções Intraventriculares , Transtornos da Memória/induzido quimicamente , Transtornos da Memória/metabolismo , Camundongos , Resistência Física , Pré-Medicação , Reconhecimento Psicológico/efeitos dos fármacos , Sacarose , NataçãoRESUMO
The lead (Pb) isotopes ²°6Pb and ²°8Pb are the final products of the radioactive decay of ²³8U and ²³²Th, respectively. Soils in the municipalities of Pedra and Venturosa, Brazil, present high levels of these radionuclides. We hypothesized that forage plants growing in these soils may take up high amounts of Pb and, consequently, intoxicate dairy cows. To test this, we quantified Pb concentrations in 23 forage samples from this region. Pb concentrations varied from 5 to 344 mg kg⻹. The highest values are one order of magnitude above the reported limit, therefore, indicating high risk of Pb contamination for dairy cows.
Assuntos
Doenças dos Bovinos/epidemiologia , Intoxicação por Chumbo/veterinária , Chumbo/análise , Poluentes do Solo/análise , Animais , Brasil/epidemiologia , Bovinos , Clima , Indústria de Laticínios , Dieta/estatística & dados numéricos , Exposição Ambiental/análise , Exposição Ambiental/estatística & dados numéricos , Monitoramento Ambiental , Monitoramento Epidemiológico , Intoxicação por Chumbo/epidemiologia , Plantas/química , Solo/químicaRESUMO
(210)Pb is widely distributed in the environment. In this context, the aim of this research has been: (1) to determine (210)Pb concentrations in milk and dairy products from farms located in the cities of Pedra and Venturosa in Pernambuco, Brazil; and (2) to calculate the dose due to the ingestion of (210)Pb in these products. The ion exchange resin method was used and the concentration of (210)Pb varied from 62 to 650 mBq l(-1) in fresh milk, from 202 to 1,494 mBq kg(-1) in curdled cheese and from 11 to 253 mBq l(-1) in milk whey. The estimated dose due to ingestion of milk and dairy products in this region was 0.2 Sv, which is at least two orders of magnitude above the maximum recommended levels.
Assuntos
Exposição Ambiental/análise , Poluentes Ambientais/análise , Contaminação de Alimentos/análise , Radioisótopos de Chumbo/análise , Leite/química , Animais , Brasil , Bovinos , Cromatografia por Troca Iônica , Clima , Indústria de Laticínios , Monitoramento Ambiental/métodos , Feminino , Resinas de Troca IônicaRESUMO
This study compared the effect of using two different concentrations of sodium hydroxide (NaOH) in the N-acetyl-L-cysteine-sodium hydroxide (NALC-NaOH) method for sputum decontamination on smear and culture positivity and the proportion of contaminated cultures: 14% of cultures were contaminated using the standard final 1% NaOH concentration during processing compared to 11% contaminated cultures using a final 1.25% NaOH concentration (P < 0.008). The proportion of cultures positive for mycobacteria decreased from 21% to 11% for sputum processed with 1% and 1.25% final NaOH concentrations, respectively (P < 0.001). Our findings suggest that a small reduction in culture contamination did not justify the considerable loss of positive cultures.
Assuntos
Descontaminação/métodos , Hidróxido de Sódio/química , Escarro/microbiologia , Acetilcisteína/química , Técnicas Bacteriológicas , Humanos , Mycobacterium/isolamento & purificação , Estudos Prospectivos , Manejo de Espécimes , Tuberculose/diagnóstico , Tuberculose/microbiologiaRESUMO
The aim of this research was to determine (210)Pb concentrations in forage from farms located in the municipalities of Pedra and Venturosa, in the Brazilian state of Pernambuco, where rolled blocks of mafic rock with a high percentage of U(3)O(8) were found. The concentrations of (210)Pb varied from 2 to 503 Bq kg(-1) in the forage dry matter samples evaluated. Due to the elevated levels of (210)Pb in the forage samples, it is concluded that this radionuclide is highly available to be ingested by dairy cows and this could represent a hazard to the human population due to possible milk contamination.
Assuntos
Indústria de Laticínios , Exposição Ambiental/análise , Radioisótopos de Chumbo/análise , Leite/química , Poluentes Radioativos/análise , Animais , Bovinos , Dieta/estatística & dados numéricos , Plantas/química , Monitoramento de RadiaçãoRESUMO
Vegetables grown with phosphate fertilizer (conventional management), with bovine manure fertilization (organic management) and in a mineral nutrient solution (hydroponic) were analyzed and the concentrations of (238)U, (226)Ra and (228)Ra in lettuce, carrots, and beans were compared. Lettuce from hydroponic farming system showed the lowest concentration of radionuclides 0.51 for (226)Ra, 0.55 for (228)Ra and 0.24 for (238)U (Bq kg(-1) dry). Vegetables from organically and conventionally grown farming systems showed no differences in the concentration of radium and uranium. Relationships between uranium content in plants and exchangeable Ca and Mg in soil were found, whereas Ra in vegetables was inversely correlated to the cation exchange capacity of soil, leading to the assumption that by supplying carbonate and cations to soil, liming may cause an increase of U and a decrease of radium uptake by plants. The soil to plant transfer varied from 10(-4) to 10(-2) for (238)U and from 10(-2) to 10(-1) for (228)Ra.
Assuntos
Agricultura , Rádio (Elemento)/análise , Urânio/análise , Verduras/metabolismo , Daucus carota/metabolismo , Fabaceae/metabolismo , Lactuca/metabolismo , Rádio (Elemento)/metabolismo , Urânio/químicaRESUMO
Avaliou-se a técnica da imunoperoxidase como método auxiliar para a detecção de Mycoplasma hyopneumoniae em suínos naturalmente infectados. Foram colhidos 80 fragmentos de pulmões de 40 animais provenientes de granjas consideradas negativas e 40 de granjas com diagnóstico positivo de pneumonia enzoótica. Com a utilização de soro policlonal específico (IgG de coelho anti- M. hyopneumoniae) observou-se correlação positiva de 77 por cento entre os diagnósticos microscópicos e imunoistoquímicos, enquanto que a correlação entre os diagnósticos macroscópico e imunoistoquímico foi de 49 por cento. Nas granjas consideradas negativas observou-se presença de discreta imunorreação em 22,5 por cento dos casos, o que poderia indicar a existência de reação cruzada com outros microrganismos. Nas granjas com diagnóstico positivo para pneumonia enzoótica a técnica da peroxidase-anti-peroxidase (PAP) revelou diferentes graus de intensidade, variando de fraca imunomarcação até espesso depósito amarronzado no epitélio ou na luz das vias aéreas, ou ainda no interior de macrófagos, com relação direta entre a intensidade das lesões e da imunorreação. A técnica imunoistoquímica possui sensibilidade de 95 por cento e especificidade de 77,5 por cento, podendo ser recomendada como ferramenta auxiliar, rápida e de baixo custo para o diagnóstico de pneumonia enzoótica suína em laboratórios de rotina em histopatologia.
Assuntos
Pneumonia Suína Micoplasmática/diagnóstico , Suínos , Técnicas Imunoenzimáticas/métodos , Mycoplasma hyopneumoniaeRESUMO
Avaliou-se a técnica da imunoperoxidase como método auxiliar para a detecção de Mycoplasma hyopneumoniae em suínos naturalmente infectados. Foram colhidos 80 fragmentos de pulmões de 40 animais provenientes de granjas consideradas negativas e 40 de granjas com diagnóstico positivo de pneumonia enzoótica. Com a utilização de soro policlonal específico (IgG de coelho anti- M. hyopneumoniae) observou-se correlação positiva de 77% entre os diagnósticos microscópicos e imunoistoquímicos, enquanto que a correlação entre os diagnósticos macroscópico e imunoistoquímico foi de 49%. Nas granjas consideradas negativas observou-se presença de discreta imunorreação em 22,5% dos casos, o que poderia indicar a existência de reação cruzada com outros microrganismos. Nas granjas com diagnóstico positivo para pneumonia enzoótica a técnica da peroxidase-anti-peroxidase (PAP) revelou diferentes graus de intensidade, variando de fraca imunomarcação até espesso depósito amarronzado no epitélio ou na luz das vias aéreas, ou ainda no interior de macrófagos, com relação direta entre a intensidade das lesões e da imunorreação. A técnica imunoistoquímica possui sensibilidade de 95% e especificidade de 77,5%, podendo ser recomendada como ferramenta auxiliar, rápida e de baixo custo para o diagnóstico de pneumonia enzoótica suína em laboratórios de rotina em histopatologia.(AU)
The immunoperoxidase technique as an auxiliary method for the detection of Mycoplasma hyopneumoniae in naturally infected pigs was evaluated. Eighty lung fragments of which 40 from animals of farms considered negatives and 40 of farms with positive diagnosis of enzootic pneumonia were collected. The results obtained with polyclonal specific serum (IgG of rabbit anti - M. hyopneumoniae) evidentiated a positive correlation of 77% between microscopic and immunohistochemical diagnoses, while the correlation between the macroscopic and immunohistochemical diagnoses was of 49%. In the farms considered negatives the presence of discrete immunoreaction in 22.5% of the cases, what could indicate the existence of cross reaction with other microorganisms, was observed. In the farms with positive diagnosis for enzootic pneumonia the peroxidase-anti peroxidase technique revealed different degrees of intensity, varying from weak immunomarcation to thick brownish deposit in the epithelium or in the light of the airways, or still inside macrophages, with a direct relationship among the intensity of the lesions and the immunoreaction. It was also verified that the immunohistochemistry technique presented 95% of sensibility and 77.5% of specificity, being recommended as auxiliary, fast and of low cost tool for the diagnosis of swine enzootic pneumonia in routine laboratories of histopathology.(AU)