Effects of fluconazole treatment of mice infected with fluconazole-susceptible and -resistant Candida tropicalis on fungal cell surface hydrophobicity, adhesion and biofilm formation.

Background: The incidence of Candida tropicalis less susceptible to fl uconazole (FLC) has been reported in many parts of the world. Objectives: The aim of this study was to examine the changes of putative virulence attributes of Candida tropicalis accompanying the development of resistance to FLC in vitro and in vivo. Materials and Methods: A FLC-resistant strain (FLC-R) was obtained after sequential exposure of a clinical isolate FLC-sensitive (FLC-S) to increasing concentrations of the antifungal. The course of infection by both strains was analyzed in BALB/c mice. Analyses of gene expression were performed by real-time polymerase chain reaction PCR. The cell surface hydrophobicity, adhesion and biofi lm formation were also determined. Results: Development of resistance to FLC could be observed after 15 days of subculture in azole-containing medium. Overexpression of MDR1 and ERG11 genes were observed in FLC-R, and this strain exhibited enhanced virulence in mice, as assessed by the mortality rate. All mice challenged with the FLC-R died and FLC-treatment caused earlier death in mice infected with this strain. All animals challenged with FLC-S survived the experiment, regardless of FLC-treatment. Overall, FLC-R derivatives strains were signifi cantly more hydrophobic than FLC-S strains and showed greater adherence and higher capacity to form biofi lm on polystyrene surface. Conclusions: The expression of virulence factors was higher in FLC-R-C. tropicalis and it was enhanced after FLC-exposure. These data alert us to the importance of identifying microorganisms that show resistance to the antifungals to establish an appropriate management of candidiasis therapy.

Tratamento com andrógenos como possibilidade de melhoria do prognóstico reprodutivo em mulheres com envelhecimento ovariano / Treatment with androgens as a possibility to improve the reproductive outcome of women with ovarian aging

Justificativa: A resposta ao estímulo ovariano é uma peça-chave na reprodução assistida. Apesar dos recentes avanços das técnicas, pacientes com baixa reserva ovariana apresentam mau prognóstico e representam um desafio na medicina reprodutiva. Objetivo: Propor estratégia de melhoria do prognóstico reprodutivo em mulheres com idades superiores a 38 anos ou jovens com baixa contagem de folículos antrais, por meio do uso de testosterona previamente ao estímulo ovariano. Material e métodos: Levantamento de dados da literatura científica na área da medicina reprodutiva. Resultados e conclusões: O uso de androgênios em fases que antecedem a estimulação ovariana em ciclos de fertilização in vitro parece ser ótima ferramenta de melhoria da resposta à estimulação oocitária controlada em pacientes com mais de 38 anos ou com reserva ovariana diminuída. Melhora tanto a quantidade quanto a qualidade oocitária e aumenta as taxas de gestação e de nascido vivos.

Justification: The response to ovarian stimulation is a keyelement in assisted reproduction (AR). Despite recent advances in the techniques, patients with low ovarian reserve havepoor prognosis and represent a challenge in reproductive medicine.Objective: To propose a strategy to improve reproductive prognosis of women older than 38years or young women with low antral follicle count, through the use of testosterone prior to ovarian stimulus.Material and methods: Survey data from the scientific literature in the field of reproductive medicine. Results and conclusions: The use of androgens in stages preceding ovarian stimulation in IVF cycles seems to be great tool for improving oocyte response in oocyte controlled stimulation of patients older than 38 years or with diminished ovarian reserve, improving both quantityand quality of oocytes and increasing rates of pregnancy and live-born.

Molecular epidemiology of type 1 and 2 dengue viruses in Brazil from 1988 to 2001

Dengue is a mosquito-borne viral infection that in recent decades has become a major international public health concern. Epidemic dengue fever reemerged in Brazil in 1981. Since 1990 more than one dengue virus serotype has been circulating in this tropical country and increasing rates of dengue hemorrhagic fever and dengue shock syndrome have been detected every year. Some evidence supports the association between the introduction of a new serotype and/or genotype in a region and the appearance of dengue hemorrhagic fever. In order to study the evolutionary relationships and possible detection of the introduction of new dengue virus genotypes in Brazil in the last years, we analyzed partial nucleotide sequences of 52 Brazilian samples of both dengue type 1 and dengue type 2 isolated from 1988 to 2001 from highly endemic regions. A 240-nucleotide-long sequence from the envelope/nonstructural protein 1 gene junction was used for phylogenetic analysis. After comparing the nucleotide sequences originally obtained in this study to those previously studied by others, and analyzing the phylogenetic trees, we conclude that, after the initial introduction of the currently circulating dengue-1 and dengue-2 genotypes in Brazil, there has been no evidence of introduction of new genotypes since 1988. The increasing number of dengue hemorrhagic fever cases seen in Brazil in the last years is probably associated with secondary infections or with the introduction of new serotypes but not with the introduction of new genotypes.

Opiatergic participation in the thirst-inhibiting effect of acute third ventricle injections of cadmium (Cd 2+ ) and lead (Pb 2+ )

We have previously demonstrated that acute third ventricle injections of both lead and cadmium prevent the dipsogenic response elicited by dehydration or by central injections of dipsogenic agents such as angiotensin II, carbachol and isoproterenol in rats. We have also shown that the antidipsogenic action of cadmium may be due, at least in part, to activation of thirst-inhibitory central serotonergic pathways. In the present paper we show that in Wistar male rats the antidipsogenic effect of both lead acetate (3.0 nmol/rat) and cadmium chloride (3.0 nmol/rat) may be partially dependent on the activation of brain opiatergic pathways since central injections of naloxone (82.5 nmol/rat), a non-selective opioid antagonist, blunt the thirst-inhibiting effect of these metals. One hundred and twenty minutes after the second third ventricle injections, dehydrated animals (14 h overnight) receiving saline + sodium acetate displayed a high water intake (7.90 ñ 0.47 ml/100 g body weight) whereas animals receiving saline + lead acetate drank 3.24 ñ 0.47 ml/100 g body weight. Animals receiving naloxone + lead acetate drank 6.94 ñ 0.60 ml/100 g body weight. Animals receiving saline + saline drank 8.16 ñ 0.66 ml/100 g body weight whilst animals receiving saline + cadmium chloride drank 1.63 ñ 0.37 ml/100 g body weight. Animals receiving naloxone + cadmium chloride drank 8.01 ñ 0.94 ml/100 g body weight. It is suggested that acute third ventricle injections of both lead and cadmium exert their antidipsogenic effect by activating thirst-inhibiting opioid pathways in the brain