Effects of camptothecin derivatives and topoisomerase dual inhibitors on Trypanosoma cruzi growth and ultrastructure

BACKGROUND: Trypanosoma cruzi is the etiological agent of Chagas’ disease that is an endemic disease in Latin America and affects about 8 million people. This parasite belongs to the Trypanosomatidae family which contains a single mitochondrion with an enlarged region, named kinetoplast that harbors the mitochondrial DNA (kDNA). The kinetoplast and the nucleus present a great variety of essential enzymes involved in DNA replication and topology, including DNA topoisomerases. Such enzymes are considered to be promising molecular targets for cancer treatment and for antiparasitic chemotherapy. In this work, the proliferation and ultrastructure of T. cruzi epimastigotes were evaluated after treatment with eukaryotic topoisomerase I inhibitors, such as topotecan and irinotecan, as well as with dual inhibitors (compounds that block eukaryotic topoisomerase I and topoisomerase II activities), such as baicalein, luteolin and evodiamine. Previous studies have shown that such inhibitors were able to block the growth of tumor cells, however most of them have never been tested on trypanosomatids. RESULTS: Considering the effects of topoisomerase I inhibitors, our results showed that topotecan decreased cell proliferation and caused unpacking of nuclear heterochromatin, however none of these alterations were observed after treatment with irinotecan. The dual inhibitors baicalein and evodiamine decreased cell growth; however the nuclear and kinetoplast ultrastructures were not affected. CONCLUSIONS: Taken together, our data showed that camptothecin is more efficient than its derivatives in decreasing T. cruzi proliferation. Furthermore, we conclude that drugs pertaining to a certain class of topoisomerase inhibitors may present different efficiencies as chemotherapeutical agents

Antifungal susceptibility of the endophytic fungus Rhinocladiella similis (URM 7800) isolated from the Caatinga dry forest in Brazil

The present study reports a new occurrence of Rhinocladiella similis isolated as an endophytic fungus in the Caatinga dry tropical forest in Brazil and describes its antifungal susceptibility. The isolate R. similis URM 7800 was obtained from leaves of the medicinal plant Myracrodruon urundeuva. Its morphological characterization was performed on potato dextrose agar medium and molecular analysis using the ITS rDNA sequence. The antifungal susceptibility profile was defined using the Clinical and Laboratory Standards Institute (CLSI) protocol M38-A2. The colony of isolate URM 7800 showed slow growth, with an olivaceous-gray color and powdery mycelium; in microculture, it showed the typical features of R. similis. In the antifungal susceptibility test, isolate URM 7800 showed high minimal inhibitory concentration (MIC) values for amphotericin B (>16 μg/mL), voriconazole (16 μg/mL), terbinafine (>0.5 μg/mL), and caspofungin (>8 μg/mL), among other antifungal drugs. Pathogenic melanized fungi are frequently isolated in environments where humans may be exposed, and these data show that it is essential to know if these isolates possess antifungal resistance

Reduction of Tubulin Expression in Angomonas deanei by RNAi Modifies the Ultrastructure of the Trypanosomatid Protozoan and Impairs Division of Its Endosymbiotic Bacterium

In the last two decades, RNA interference pathways have been employed as a useful tool for reverse genetics in trypanosomatids. Angomonas deanei is a non-pathogenic trypanosomatid that maintains an obligatory endosymbiosis with a bacterium related to the Alcaligenaceae family. Studies of this symbiosis can help us to understand the origin of eukaryotic organelles. The recent elucidation of both the A. deanei and the bacterium symbiont genomes revealed that the host protozoan codes for the enzymes necessary for RNAi activity in trypanosomatids. Here we tested the functionality of the RNAi machinery by transfecting cells with dsRNA to a reporter gene (green fluorescent protein), which had been previously expressed in the parasite and to α-tubulin, an endogenous gene. In both cases, protein expression was reduced by the presence of specific dsRNA, inducing, respectively, a decreased GFP fluorescence and the formation of enlarged cells with modified arrangement of subpellicular microtubules. Furthermore, symbiont division was impaired. These results indicate that the RNAi system is active in A. deanei and can be used to further explore gene function in symbiont-containing trypanosoma tids and to clarify important aspects of symbiosis and cell evolution. This article is protected by copyright. All rights reserved

The use of poultry feather to produce keratinase by Aspergillus carbonarius

O objetivo deste trabalho foi estudar a produção de queratinase por Aspergillus carbonarius URM 1546, tendo-se como substrato penas de galinha, por meio de planejamento fatorial completo 23. Todos os parâmetros estudados e as interações de segunda ordem foram estatisticamente significativos. A maior atividade queratinolítica (48,9 U mL-1) foi obtida com 120 rpm, 0,5% (p/v) de penas de galinha e sete dias de cultivo.The objective of this work was to evaluate the keratinase production by Aspergillus carbonarius URM 1546, using as substrate poultry feather in a full experimental design 23. The studied parameters and the second-order interactions were statistically significant. The maximum keratinase activity (48.9 U mL-1) was obtained using 120 rpm, with 0.5% (w/v) poultry feather and seven culture days

Filamentous fungi from AIDS patient secretions and from the environmental air in hospital

Mediante la toma de muestras de secreciones orofaríngeas, nasales y del oído externo de 50 pacientes con Síndrome de Inmunodeficiencia Adquirida (SIDA-AIDS) y del aire de las salas de tratamiento de los mismos, se obtuvieron 238 muestras: 87 de las secreciones y 151 del aire, Se aislaron 29 spp. de hongos filamentosos de los especímenes clínicos y 38 del aire. En las secreciones de los pacientes, el grupo forma: Mycelia sterilia, y Fusarium oxysporum, F. lateritium, Aspergillus parasiticus, fueron los Hyphomycetes más representativos y los géneros Aspergillus y Fusarium constituyeron el 47% de los  aislamientos en proporciones semejantes.En el ambiente hospitalario, el grupo forma Mycelia sterilia y las especies C. sphaerospermum, Aspergilus sydowii y  C. cladosporioides fueron los Hyphomycetes más representativos y los generos Aspergillus y Penicillium constituyeron el 47,7% de los aislamientos . Los taxa más comunes que se presentaron al mismo tiempo en los pacientes como en su ambiente fueron: Mycelia sterilia, C. sphaerospermum, A.sydowii, A.restrictus y P.implicatum

The perception of sleep quality in kidney transplant patients during the first year of transplantation

OBJECTIVE: Poor sleep quality is one of the factors that adversely affects patient quality of life after kidney transplantation, and sleep disorders represent a significant cardiovascular risk factor. The objective of this study was to investigate the prevalence of changes in sleep quality and their outcomes in kidney transplant recipients and analyze the variables affecting sleep quality in the first years after renal transplantation. METHODS: Kidney transplant recipients were evaluated at two time points after a successful transplantation: between three and six months (Phase 1) and between 12 and 15 months (Phase 2). The following tools were used for assessment: the Pittsburgh Sleep Quality Index; the quality of life questionnaire Short-Form-36; the Hospital Anxiety and Depression scale; the Karnofsky scale; and assessments of social and demographic data. The prevalence of poor sleep was 36.7% in Phase 1 and 38.3% in Phase 2 of the study. RESULTS: There were no significant differences between patients with and without changes in sleep quality between the two phases. We found no changes in sleep patterns throughout the study. Both the physical and mental health scores worsened from Phase 1 to Phase 2. CONCLUSION: Sleep quality in kidney transplant recipients did not change during the first year after a successful renal transplantation

Oficinas multiprofissionais:: educação em saúde para idosos de uma comunidade

Objetivos: Descrever o processo de elaboração de oficinas de promoção da saúde voltadas a um grupo de convivência para idosos e compartilhar a experiência de uma equipe de residentes multiprofissionais na construção de metodologias para se discutir saúde dentro de grupos. Métodos: Entre 2007 e 2009, a equipe de residentes multiprofissionais acompanhou um grupo de convivência, constituído de aproximadamente quarenta idosos. Foram observadas as principais demandas em saúde a serem trabalhadas junto ao grupo e desenvolvidas oficinas para promoção da saúde. Resultados: Os temas trabalhados nas oficinas foram osteoporose, diabetes mellitus, dislipidemia, planejando o futuro e relações de cuidado. Os residentes construíram materiais didáticos, como cartazes, folders, bolsas coloridas, cartões ilustrativos, que ilustraram os temas abordados de forma lúdica. As oficinas possibilitaram que os participantes fossem agentes ativos no processo de aprendizagem e de fazer saúde, o que pressupõe benefícios à saúde física, mental e social desse grupo

Biochemical and thermodynamic characteristics of a new serine protease from Mucor subtilissimus URM 4133

A protease from the fungus Mucor subtilissimus URM 4133, capable of producing bioactive peptides from goat casein, was purified. SDS-PAGE and zymography showed a molecular mass of 30 kDa. The enzyme was active and stable in a wide pH range (6.0–10.5) and (5.0–10.5), respectively. Optimum temperature was at 45–50 °C and stability was above 80 % (40 °C/2 h). Activity was not influenced by ions or organic substances (Triton, Tween, SDS and DMSO), but was completely inhibited by PMSF, suggesting that it belongs to the serine protease family. The Km and Vmax were 2.35 mg azocasein.mL-1 and 333.33 U.mg protein-1, respectively. Thermodynamic parameters of irreversible denaturation (40–60 °C) were enthalpy 123.63 – 123.46 kJ.mol-1, entropy 120.24–122.28 kJ.mol-1 and Gibbs free energy 85.97 – 82.45 kJ.mol-1. Any peptide sequences compatible with this protease were found after analysis by MALDI-TOF, which suggests that it is a new serine protease.info:eu-repo/semantics/publishedVersio

Production of enzymes by filamentous fungus using sugarcane and sugarcane bagasse as substrate

The production of enzymes by bioprocesses is a good alternative to add value to agroindustrial waste. Sugarcane bagasse, an abundant and cheap by-product of the sugar industry, was tested as a carbon source for the production of biotechnological interesting enzymes. In this work, fungi were isolated from anatomical parts of sugarcane (root, steam and leaf) and, then, were assessed for enzyme production. The isolated and identified fungi were Fusarium sp., Penicillium sp., Trichoderma auroviride and Cladosporium cladosporioides. Trichoderma auroviride was used for enzyme production (xylanase, invertase and protease) using sugarcane as substrate. Xylanase production (2037 U) by Trichoderma auroviride was higher than invertase and protease production; thus, this enzyme was selected for the further studies. The study of the influence of variables (temperature and stirring intensity) on xylanase production by Trichoderma auroviride, using sugarcane bagasse as substrate, showed that the most favorable xylanase production conditions were observed at 25 °C, without stirring intensity and using saline and Tween for enzyme extraction, which led to a 1980 U xylanase activity.(Produção de enzimas por fungos filamentosos utilizando cana-de-açúcar e bagaço de cana-de-açúcar como substrato). A produção de enzimas por bioprocessos é uma boa alternativa para agregar valor a resíduos agroindustriais. O bagaço da cana-de-açúcar, um abundante e barato subproduto da indústria de açúcar, foi testado como fonte de carbono para a produção de enzimas de interesse biotecnológico. Neste trabalho foi realizado o isolamento e identificação de fungos a partir de peças anatômicas (caule, raiz e folha) da cana-de-açúcar e em seguida foi realizada a investigação da produção de enzimas por esses microrganismos. Fusarium sp., Penicillium sp., Trichoderma auroviride e Cladosporium cladosporioides foram os fungos isolados e identificados. Trichoderma auroviride foi utilizado para a produção de enzimas (xilanase, invertase e protease) utilizando cana-de-açúcar como substrato. A produção de xilanase (2037 U) por Trichoderma auroviride foi maior que a produção de protease e de invertase, portanto, essa enzima foi selecionada para estudos posteriores. O estudo da influência das variáveis temperatura e intensidade de agitação na produção da xilanase por Trichoderma auroviride usando bagaço da cana-de-açúcar como substrato demonstrou que a condição mais favorável para a produção de xilanase foi observada a 25 °C, sem agitação e utilizando solução salina e Tween para extração da enzima, o que levou a uma produção de xilanase de 1980 U