Action mechanisms of probiotics on Candida spp. and candidiasis prevention: an update.

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.

Lactobacillus rhamnosus inhibits Candida albicans virulence factors in vitro and modulates immune system in Galleria mellonella.

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.

Avaliação da atividade hepatoprotetora do asiaticosídeo em modelo experimental de lesão hepática por paracetamol em ratos / Hepatoprotective activity of asiaticoside in experimental liver injury induced by paracetamol in rats

Asiaticoside is a triterpenoid present in Centella asiatica extract, responsible for the therapeutic activity of this plant in chronic liver disease. The hepatocyte is the cell responsible for the endocrine and exocrine functions of the liver, in addition to the conversion of harmful substances into non-toxic compounds that are excreted in the bile. That is why the liver is sensitive to the action of some drugs, such as paracetamol. Hence, paracetamol was used as an experimental model of liver damage, with the aim of assessing the effectiveness of asiaticoside, in a standard therapeutic dose, as a hepatoprotector in Wistar rats. In this experiment, 40 animals were used and divided into two groups: those treated with asiaticoside and the untreated control group. Animals from the first group were subjected to pretreatment with the active ingredient (1mg/kg/dia P.O.) for eight days and exposed to a toxic dose of paracetamol (3 g/kg P.O.) on the eighth day. After 24 h and 72 h, these rats were sacrificed for the collection of blood samples and liver fragments. To assess hepatoprotective activity, serum enzymes (AST, ALT and alkaline phosphatase) indicative of liver damage were measured and histological and morphological analyses of liver tissue were performed. The results obtained showed that asiaticoside exerted hepatoprotective action, since it promoted a reduction in histological lesions and a decrease in serum levels of AST and ALT. From these results, we conclude that asiaticoside, in the dose most commonly used in herbal medicine, protects the liver against acute hepatitis induced by paracetamol...

O asiaticosídeo é um triterpenóide presente no extrato da Centella asiatica, sendo responsável pela atividade terapêutica desta planta em doenças hepáticas crônicas. O hepatócito é a célula responsável pelas funções endócrinas e exócrinas do fígado, além de converter substâncias nocivas em materiais não tóxicos excretados pela bile. Por esse motivo, o fígado é sensível à ação de alguns fármacos, como, por exemplo, o paracetamol. Assim, utilizando o paracetamol como modelo experimental de lesão hepática, o objetivo deste estudo foi avaliar a ação hepatoprotetora do asiaticosídeo, na dose estabelecida como terapêutica, em ratos Wistar. Dois grupos compostos por vinte animais cada, tratados com asiaticosídeo (1mg/kg/dia v.o.) por oito dias e não tratados foram submetidos à intoxicação com elevada dose de paracetamol (3 g/kg v.o) no oitavo dia. Em seguida, os animais foram eutanasiados após 24 h ou 72 h para coleta de amostras de sangue e fragmentos de fígado. Para avaliação da atividade hepatoprotetora, foi realizada a dosagem sérica de enzimas indicativas de lesão hepática (AST, ALT e Fosfatase Alcalina) e a análise histológica e morfométrica do tecido hepático. Os resultados obtidos permitiram evidenciar que na dose utilizada, o asiaticosídeo apresenta atividade hepatoprotetora, uma vez que o grupo submetido ao tratamento prévio apresentou menos lesões histológicas e menores níveis séricos de AST e ALT quando comparado ao grupo controle. Estes resultados permitem concluir que o asiaticosídeo, na dose mais usualmente empregada na fitoterapia, apresentou atividade hepatoprotetora na hepatite aguda causada por elevada dose de paracetamol...

Desenvolvimento de uma sonda de DNA para a detecçäo do vírus da doença de Aujeszky / Development of DNA probe for detection of Aujeszky's disease virus

Uma sonda radioativa e uma outra biotinilada foram produzidas para detecçäo do vírus da doença de Aujeszky (VDA). O fragmento de Bam H I 7 do DNA genômico do VDA foi marcado por "nick translation" empregando P32dCTP e um fragmento de 196pb, resultante de uma amplificaçäo pela reaçäo em cadeia pela polimerase marcado com biotina 7-dATP. Essas sondas, de uma maneira rápida e específica, prestaram-se para a detecçäo da infecçäo aguda pelo VDA. Entretanto, näo se mostraram sensíveis o suficiente para detectar seqüências genômicas de VDA no gânglio trigêmio de suínos e camundongos com infecçäo latente

A signalling theory of excessive technological adoption.

Technology adoption has been identified as one of the main elements behind the growth of health care expenditures. It has been argued that the health insurance arrangements in the US justify, to a certain extent, the technology-driven rise in costs. Moreover, it eases the adoption of less cost-effective procedures and devices. This paper presents an additional argument by which excessive technology investments may occur: providers of care invest in technology as a way to "signal" their intrinsic (and unobservable) quality. Providers face the option of adopting a new technology. The decision of adoption in itself may convey information about his/her quality: for example, patients conjecture that providers who display newer technology are of higher quality. Providers, being aware of this, may invest in technology to reveal themselves as high quality. Thus, technology adoption could result only from the desire to attract patients. The investment is self-defeating in the sense that if all providers invest, no information about quality is transmitted to patients. We evaluate the argument in a context of demand for health care services where patients have initially no information about the quality of different providers. We show that an incentive to invest as a way to signal quality may or may not lead to overinvestment. It is also possible that only some providers invest. They reveal themselves as high quality providers. The analysis suggests that the argument is more important for some services than for others. Overall, an additional argument for overinvestment in technology in some circumstances is provided.

The black box of health care expenditure growth determinants.

In this paper, the determinants of growth of aggregate health expenditures are investigated. The study departs from previous literature in that it looks at differences across countries in growth (and not levels) of health care expenditures. Estimation is made for 24 OECD countries. Health system characteristics usually believed to influence health expenditures growth, like population ageing, the type of health system (public reimbursement, public contract or integrate) and existence of gatekeepers, are found to be non-significant. Nevertheless, there is evidence that health expenditures experienced a clear slower growth in the last decade. The explanation for this slowdown could not be found in the proposed model and should stimulate further research.