Análise do efeito de nanopartículas de prata contra células aderidas e biofilmes de Candida albicans e Candida glabrata

O aumento na resistência dos biofilmes de Candida à terapia antifúngica convencional tem despertado o interesse no uso da prata como um agente antimicrobiano. Assim, o objetivo deste trabalho foi avaliar a eficácia antifúngica de nanopartículas de prata (NPs) contra células aderidas e biofilmes de Candida albicans e Candida glabrata. Métodos: NPs esféricas (5 nm) foram sintetizadas através da redução do nitrato de prata pelo citrato de sódio. Testes de mínima concentração inibitória (MCI) foram realizados para as duas espécies de Candida de acordo com o método da microdiluição. NPs foram aplicadas sobre células aderidas (2 hrs) e biofilmes (48 hrs), e após 24 horas de contato os biofilmes resultantes foram caracterizados através da contagem do número de unidades formadoras de colônias (UFCs) e quantificação da biomassa total. Resultados: Os valores de MCI para C. glabrata foram maiores (0,4 – 3,3 µg/mL) do que para C. albicans (0,4 – 1,6 µg/mL). NPs foram mais efetivas na redução da biomassa total quando aplicadas sobre células aderidas do que sobre biofilmes pré-formados. NPs também foram altamente efetivas na redução das UFCs quando aplicadas sobre as células aderidas de C. glabrata (~70%) e respectivos biofilmes (~50%). Para as cepas de C. albicans o efeito não foi tão notório, mas também existiu uma redução no número de UFCs. Conclusão: NPs apresentam potencial como agente antifúngico alternativo no controle de infecções por espécies de Candida

Sigmund Exner's (1887) einige beobachtungen über bewegungsnachbilder (some observations on movement aftereffects):an illustrated translation with commentary

In his original contribution, Exner’s principal concern was a comparison between the properties of different aftereffects, and particularly to determine whether aftereffects of motion were similar to those of color and whether they could be encompassed within a unified physiological framework. Despite the fact that he was unable to answer his main question, there are some excellent—so far unknown—contributions in Exner’s paper. For example, he describes observations that can be related to binocular interaction, not only in motion aftereffects but also in rivalry. To the best of our knowledge, Exner provides the first description of binocular rivalry induced by differently moving patterns in each eye, for motion as well as for their aftereffects. Moreover, apart from several known, but beautifully addressed, phenomena he makes a clear distinction between motion in depth based on stimulus properties and motion in depth based on the interpretation of motion. That is, the experience of movement, as distinct from the perception of movement. The experience, unlike the perception, did not result in a motion aftereffect in depth

Silver colloidal nanoparticle stability: influence on Candida biofilms formed on denture acrylic

Our aim in this study was to evaluate how the chemical stability of silver nanoparticles (SNs) influences their efficacy against Candida albicans and C. glabrata biofilms. Several parameters of SN stability were tested, namely, temperature (50ºC, 70ºC, and 100ºC), pH (5.0 and 9.0), and time of contact (5 h and 24 h) with biofilms. The control was defined as SNs without temperature treatment, pH 7, and 24 h of contact. These colloidal suspensions at 54 mg/L were used to treat mature Candida biofilms (48 h) formed on acrylic. Their efficacy was determined by total biomass and colony-forming unit quantification. Data were analyzed using analysis of variance and the Bonferroni post hoc test (=0.05). The temperature and pH variations of SNs did not affect their efficacy against the viable cells of Candida biofilms (P > 0.05). Moreover, the treatment periods were not decisive in terms of the susceptibility of Candida biofilms to SNs. These findings provide an important advantage of SNs that may be useful in the treatment of Candida-associated denture stomatitis.We thank Dr David Williams, Cardiff University, Cardiff, UK, for providing the strain 324LA/94. The authors also thank Sao Paulo Research Foundation (FAPESP, process 2009/15146-5), Brazil, for supporting the work of D. R. M. The authors are indebted to Laboratorio Interdisciplinar de Eletroquimica e Ceramica, Federal University of Sao Carlos, Brazil, in the name of Andressa Kubo, for preparing and characterizing the colloidal suspensions of silver nanoparticles

TTC5 syndrome: Clinical and molecular spectrum of a severe and recognizable condition.

Biallelic mutations in the TTC5 gene have been associated with autosomal recessive intellectual disability (ARID) and subsequently with an ID syndrome including severe speech impairment, cerebral atrophy, and hypotonia as clinical cornerstones. A TTC5 role in IDs has been proposed based on the physical interaction of TTC5 with p300, and possibly reducing p300 co-activator complex activity, similarly to what was observed in Menke-Hennekam 1 and 2 patients (MKHK1 and 2) carrying, respectively, mutations in exon 30 and 31 of CREBBP and EP300, which code for the TTC5-binding region. Recently, TTC5-related brain malformation has been linked to tubulinopathies due to the function of TTC5 in tubulins' dynamics. We reported seven new patients with novel or recurrent TTC5 variants. The deep characterization of the molecular and phenotypic spectrum confirmed TTC5-related disorder as a recognizable, very severe neurodevelopmental syndrome. In addition, other relevant clinical aspects, including a severe pre- and postnatal growth retardation, cryptorchidism, and epilepsy, have emerged from the reversal phenotype approach and the review of already published TTC5 cases. Microcephaly and facial dysmorphism resulted in being less variable than that documented before. The TTC5 clinical features have been compared with MKHK1 published cases in the hypothesis that clinical overlap in some characteristics of the two conditions was related to the common p300 molecular pathway

Análise de associação quanto à produtividade e seus caracteres componentes em linhagens e cultivares de arroz de terras altas

O objetivo deste trabalho foi identificar, por meio da análise de mapeamento associativo, os marcadores moleculares relacionados à produtividade do arroz de terras altas e aos seus caracteres componentes. Foram usadas 113 linhagens e cultivares de arroz de terras altas, da Coleção Nuclear de Arroz da Embrapa, com reduzido vínculo genético entre si. Os seguintes caracteres componentes da produtividade foram avaliados: número de panículas por metro, número de grãos por panícula e peso de 100 grãos. Dos 115 marcadores utilizados, 25 (21,7%) associaram-se significativamente a um ou mais caracteres. Entre os 29 SSR ("simple sequence repeats") colocalizados em QTL ("quantitative trait loci") de produtividade de arroz, 12 foram associados aos caracteres avaliados e considerados como candidatos para uso na seleção assistida por marcadores. Os marcadores NP914540, Q6ZGD1 e Q69JE3, associados ao número de grãos por panícula, ainda não foram anotados no arroz e podem constituir o ponto de partida para estudos de genômica funcional. Entre os marcadores derivados de sequências transcritas, NP914526 e NP914533 destacam-se por pertencer a rotas metabólicas relacionadas ao aumento do potencial produtivo de arroz

Differential and shared genetic effects on kidney function between diabetic and non-diabetic individuals

A large-scale GWAS provides insight on diabetes-dependent genetic effects on the glomerular filtration rate, a common metric to monitor kidney health in disease.Reduced glomerular filtration rate (GFR) can progress to kidney failure. Risk factors include genetics and diabetes mellitus (DM), but little is known about their interaction. We conducted genome-wide association meta-analyses for estimated GFR based on serum creatinine (eGFR), separately for individuals with or without DM (nDM = 178,691, nnoDM = 1,296,113). Our genome-wide searches identified (i) seven eGFR loci with significant DM/noDM-difference, (ii) four additional novel loci with suggestive difference and (iii) 28 further novel loci (including CUBN) by allowing for potential difference. GWAS on eGFR among DM individuals identified 2 known and 27 potentially responsible loci for diabetic kidney disease. Gene prioritization highlighted 18 genes that may inform reno-protective drug development. We highlight the existence of DM-only and noDM-only effects, which can inform about the target group, if respective genes are advanced as drug targets. Largely shared effects suggest that most drug interventions to alter eGFR should be effective in DM and noDM.</p