Mammalian sphingoid bases: Biophysical, physiological and pathological properties

Sphingoid bases encompass a group of long chain amino alcohols which form the essential structure of sphingolipids. Over the last years, these amphiphilic molecules were moving more and more into the focus of biomedical research due to their role as bioactive molecules. In fact, free sphingoid bases interact with specific receptors and target molecules, and have been associated with numerous biological and physiological processes. In addition, they can modulate the biophysical properties of biological membranes. Several human diseases are related to pathological changes in the structure and metabolism of sphingoid bases. Yet, the mechanisms underlying their biological and pathophysiological actions remain elusive. Within this review, we aimed to summarize the current knowledge on the biochemical and biophysical properties of the most common sphingoid bases and to discuss their importance in health and disease

Fermentation characteristics and chemical composition of elephant grass silage with ground maize and fermented juice of epiphytic lactic acid bacteria

This study aimed to evaluate the microbial populations, fermentation profile, dry matter recovery and chemical composition of elephant grass silage with ground maize (GM) and the fermented juice of epiphytic lactic acid bacteria (FJLB). A factorial design was used with four levels of GM (0 g/kg, 50 g/kg, 100 g/kg and 200 g/kg), untreated or treated with FJLB, in a completely randomized design with five replicates. A pre-experiment was undertaken to determine the optimum level of sucrose to be added to fermented juice for the development of epiphytic microflora. In this pre-experiment, a completely randomized design with three replications was used. The treatments were represented by the levels of sucrose (0 g/kg, 5 g/kg, 10 g/kg, 20 g/kg, 40 g/kg, 60 g/kg and 80 g/kg, fresh matter basis). The microbial populations, dry matter recovery, and effluent losses were affected by the interaction between GM and FJLB. Dry matter (DM) and crude protein (CP) contents increased linearly with the inclusion of GM. The addition of GM enhanced the fermentation process via a reduction in losses, and improvements were identified in the nutritional value of elephant grass silages. The use of fermented juice increased dry matter recovery, and its effect was more pronounced when ground maize was added.Keywords: dry matter recovery, lactic acid, microbiology, Pennisetum purpureu

Revisiting consistency conditions for quantum states of systems on closed timelike curves: an epistemic perspective

There has been considerable recent interest in the consequences of closed timelike curves (CTCs) for the dynamics of quantum mechanical systems. A vast majority of research into this area makes use of the dynamical equations developed by Deutsch, which were developed from a consistency condition that assumes that mixed quantum states uniquely describe the physical state of a system. We criticise this choice of consistency condition from an epistemic perspective, i.e., a perspective in which the quantum state represents a state of knowledge about a system. We demonstrate that directly applying Deutsch's condition when mixed states are treated as representing an observer's knowledge of a system can conceal time travel paradoxes from the observer, rather than resolving them. To shed further light on the appropriate dynamics for quantum systems traversing CTCs, we make use of a toy epistemic theory with a strictly classical ontology due to Spekkens and show that, in contrast to the results of Deutsch, many of the traditional paradoxical effects of time travel are present.Comment: 10 pages, 6 figures, comments welcome; v2 added references and clarified some points; v3 published versio

Emerging Role for the PERK/eIF2α/ATF4 in Human Cutaneous Leishmaniasis.

Leishmania parasites utilize adaptive evasion mechanisms in infected macrophages to overcome host defenses and proliferate. We report here that the PERK/eIF2α/ATF4 signaling branch of the integrated endoplasmic reticulum stress response (IERSR) is activated by Leishmania and this pathway is important for Leishmania amazonensis infection. Knocking down PERK or ATF4 expression or inhibiting PERK kinase activity diminished L. amazonensis infection. Knocking down ATF4 decreased NRF2 expression and its nuclear translocation, reduced HO-1 expression and increased nitric oxide production. Meanwhile, the increased expression of ATF4 and HO-1 mRNAs were observed in lesions derived from patients infected with the prevalent related species L.(V.) braziliensis. Our data demonstrates that Leishmania parasites activate the PERK/eIF2α/ATF-4 pathway in cultured macrophages and infected human tissue and that this pathway is important for parasite survival and progression of the infection

Atlantic frugivory: a plant–frugivore interaction data set for the Atlantic Forest

Non peer reviewe

Nutritional Evaluation Of Children With Chronic Cholestatic Disease

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)To evaluate the nutritional status of children with persistent cholestasis and to compare the anthropometric indices between children with and without liver cirrhosis and children with and without jaundice. Methods Children with persistent cholestasis, i.e. increased direct bilirrubin or changes in the canalicular enzyme gamma-glutamyl transferase (GGT), were included. The anthropometric measures were weight (W), height or length (H), arm circumference (AC), triceps skinfold thickness (TST), arm muscle circumference (AMC), and body mass index (BMI). Results Ninety-one children with cholestasis, with current median age of 12 months, were evaluated. W/age (A) and H/A indices below -2 Z-scores were observed in 33% and 30.8% of patients, respectively. Concerning the W/H index and BMI, only 12% and 16% of patients, respectively, were below -2 Z-scores. Regarding AC, 43.8% of 89 evaluated patients had some depletion. Observing the TST, 64% of patients had depletion, and 71.1% of the 45 evaluated patients had some degree of depletion regarding the ACM index. Conclusion Evaluation using weight in patients with chronic liver diseases may overestimate the nutritional status due to visceromegaly, subclinical edema, or ascites. Indices that correlate weight and height, such as W/H and BMI, may also not show depletion because of the chronic condition in which there are depletion of both weight and height. TST, AC, and ACM are parameters that better estimate nutritional status and should be part of the management of patients with liver diseases and cholestasis. © 2015 Sociedade Brasileira de Pediatria.922197205CNPq, Conselho Nacional de Desenvolvimento Científico e TecnológicoConselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

Cutaneous anaplastic large T-cell lymphoma in a cat - case report

ABSTRACT Lymphoma is the most common lymphoproliferative disorder in cats. However, cutaneous lymphomas are uncommon in this species and can be classified as epitheliotropic or non-epitheliotropic. Epitheliotropic lymphomas are typically of T-cells and have tropism for epidermis and/or adnexal epithelium. Non-epitheliotropic lymphomas can be of either T-cell or B-cell and involve predominantly the dermis. The present study describes a case of multifocal cutaneous anaplastic large T-cell lymphoma. The skin nodules were multiple and variable in size, alopecic and erythematous in appearance and randomly distributed. Immunohistochemistry revealed positivity for the CD3 antigen, consistent with T-lymphocytes. This neoplasm should be remembered whenever multiple cutaneous nodules are observed in cats

Protective effect of Melissa officinalis aqueous extract against Mn-induced oxidative stress in chronically exposed mice

AbstractManganese (Mn) is an essential element for biological systems; however occupational exposure to high levels of this metal may lead to neurodegenerative disorders, resembling Parkinson's disease (PD). While its mechanisms of neurotoxicity have yet to be fully understood, oxidative stress plays a critical role. Thus, the main goal of this study was to investigate the efficacy of aqueous extract of Melissa officinalis in attenuating Mn-induced brain oxidative stress in mice. Sixteen male mice were randomly divided into two groups and treated for 3 months: the first group consumed tap water (control group) and the second group was treated with Mn (50mg/kg/day for habituation during the first 15 days followed by 100mg/kg/day for additional 75 days) in the drinking water. After 3 months both groups were sub divided (n=4 per group) and treated for additional 3 months with Mn and/or M. officinalis in the drinking water. The first group (control) was treated with water and served as control; the second group (M. officinalis) was treated with M. officinalis (100mg/kg/day); the third group was treated with Mn (100mg/kg/day); the fourth group (Mn+M. officinalis) was treated with both Mn and M. officinalis (100mg/kg/day each). Mn-treated mice showed a significant increase in thiobarbituric acid reactive species (TBARS) levels (a marker of oxidative stress) in both the hippocampus and striatum. These changes were accompanied by a decrease in total thiol content in the hippocampus and a significant increase in antioxidant enzyme activity (superoxide dismutase and catalase) in the hippocampus, striatum, cortex and cerebellum. Co-treatment with M. officinalis aqueous extract in Mn-treated mice significantly inhibited the antioxidant enzyme activities and attenuated the oxidative damage (TBARS and decreased total thiol levels). These results establish that M. officinalis aqueous extract possesses potent antioxidative properties, validating its efficacy in attenuating Mn-induced oxidative stress in the mouse brain