Expression and pharmacological inhibition of TrkB and EGFR in glioblastoma

Molecular Biology Reports - A member of the Trk family of neurotrophin receptors, tropomyosin receptor kinase B (TrkB, encoded by the NTRK2 gene) is an increasingly important target in various...     

Donepezil Prevents Inhibition of Cerebral Energetic Metabolism Without Altering Behavioral Parameters in Animal Model of Obesity

Neurochemical Research - Obesity is characterized by chronic inflammation of low grade. The cholinergic anti-inflammatory pathway favors the reduction of the inflammatory response. In this work the...     

On the release of fluoride from biofilm reservoirs during a cariogenic challenge: an in situ study

Abstract

Biofilm fluoride reservoirs may be a source of fluoride to the fluid phase during a sugar challenge reducing tooth mineral loss. However, the evidence for that is conflicting and has not been studied in biofilms containing different fluoride levels. In order to test fluoride release from biofilms with distinct fluoride concentrations, biofilms were grown in situ exposed to a combination of placebo, calcium and fluoride rinses forming biofilms with no (fluoride-free rinses), low (fluoride-only rinses) or high (calcium followed by fluoride rinses) fluoride concentrations, and collected before and 5?min after a sucrose challenge. Rinsing with fluoride increased fluoride concentration in the biofilm (p?<?0.05), mainly when a calcium pre-rinse was used before the fluoride (p?<?0.05). However, after a sugar challenge, no significant increase in the biofilm fluid fluoride concentration was observed, even in the fluoride-rich biofilms (p?>?0.05). Fluoride-rich biofilms do not release fluoride to the fluid phase during a sugar challenge.     

Organic Codes: A Unifying Concept for Life

Although the knowledge about biological systems has advanced exponentially in recent decades, it is surprising to realize that the very definition of Life keeps presenting theoretical challenges. Even if several lines of reasoning seek to identify the essence of life phenomenon, most of these thoughts contain fundamental problem in their basic conceptual structure. Most concepts fail to identify either necessary or sufficient features to define life. Here, we analyzed the main conceptual frameworks regarding theoretical aspects that have been supporting the most accepted concepts of life, such as (i) the physical, (ii) the cellular and (iii) the molecular approaches. Based on an ontological analysis, we propose that Life should not be positioned under the ontological category of Matter. Yet, life should be better understood under the top-level ontology of “Process”. Exercising an epistemological approach, we propose that the essential characteristic that pervades each and every living being is the presence of organic codes. Therefore, we explore theories in biosemiotics and code biology in order to propose a clear concept of life as a macrocode composed by multiple inter-related coding layers. This way, as life is a sort of metaphysical process of encoding, the living beings became the molecular materialization of that process. From the proposed concept, we show that the evolutionary process is a fundamental characteristic for life’s maintenance but it is not necessary to define life, as many organisms are clearly alive but they do not participate in the evolutionary process (such as infertile hybrids). The current proposition opens a fertile field of debate in astrobiology, epistemology, biosemiotics, code biology and robotics.

     

Ewing Sarcoma: influence of TP53 Arg72Pro and MDM2 T309G SNPs

The Ewing Sarcoma is an important tumor of bone and soft tissue. The SNPs Arg72Pro of TP53 and T309G of MDM2 have been associated with many cancer types and have been differently distributed among populations worldwide. Based on a case–control design, this study aimed to assess the role of these SNPs in 24 Ewing Sarcoma patients, compared to 91 control individuals. DNA samples were extracted from blood and genotyped for both SNPs by PCR–RFLP and confirmed by DNA sequencing. The results showed an association between the G allele of the T309G and Ewing Sarcoma (P = 0.02). Comparing to the TT carriers, the risk of G allele carriers was 3.35 (95 % CI = 1.22–9.21) with P = 0.02. At the genotypic level, an association of the TT genotype with the control group (P = 0.03) was found. Comparing to the TT genotype, the risk of TG and GG was 2.97 (95 % CI = 1.03–8.58) with P = 0.04 and 5.00 (95 % CI = 1.23–20.34) with P = 0.02, respectively. No associations regarding the Arg72Pro SNP were found. Considering that the T309G has been associated with several types of cancer, including sarcomas, our results indicate that this SNP may also be important to Ewing Sarcoma predisposition.     

Virulence and pathogenicity of Candida albicans is enhanced in biofilms containing oral bacteria

This study examined the influence of bacteria on the virulence and pathogenicity of candidal biofilms. Mature biofilms (Candida albicans-only, bacteria-only, C. albicans with bacteria) were generated on acrylic and either analysed directly, or used to infect a reconstituted human oral epithelium (RHOE). Analyses included Candida hyphae enumeration and assessment of Candida virulence gene expression. Lactate dehydrogenase (LDH) activity and Candida tissue invasion following biofilm infection of the RHOE were also measured. Candida hyphae were more prevalent (p < 0.05) in acrylic biofilms also containing bacteria, with genes encoding secreted aspartyl-proteinases (SAP4/SAP6) and hyphal-wall protein (HWP1) up-regulated (p < 0.05). Candida adhesin genes (ALS3/EPA1), SAP6 and HWP1 were up-regulated in mixed-species biofilm infections of RHOE. Multi-species infections exhibited higher hyphal proportions (p < 0.05), up-regulation of IL-18, higher LDH activity and tissue invasion. As the presence of bacteria in acrylic biofilms promoted Candida virulence, consideration should be given to the bacterial component when managing denture biofilm associated candidoses.     

Isolation and Characterization of Mercury Resistant Bacillus sp. from Soils with an Extensive History as Substrates for Mercury Extraction in Mexico

Metal phytoextraction assisted by bacteria plays an important role in bioremediation systems. In this work, mercury-resistant bacterial strains were isolated from soils with high levels of mercury (San Joaquin, Queretaro State, Mexico) and identified as Bacillus sp. based on the 16S rDNA gene sequence analysis. The bacterial strains were found to exhibit different multiple mercury-resistance and carbon source utilization characteristics. The mercury reduction ability was tested through a volatilization assay. The bacterial isolates were also evaluated for their ability to promote growth and mercury uptake in tomato plants. In a roll towel assay, the maximum vigor index of tomato plants was obtained with the inoculation of Bacillus sp. A2, A12, B11, B15 and C1, while in a pot assay, the maximum vigor index was obtained with the inoculation of Bacillus sp. A6, A7 and B20, compared with un-inoculated controls in the presence of HgCl₂. Maximum Hg accumulation in the roots and shoots of tomato plants was obtained only with Bacillus sp. A7 in the roll towel assay, whereas in the pot assay, maximum accumulation was obtained with Bacillus sp. A12 compared with un-inoculated controls. Our results show that mercury accumulation in tissue is enhanced by these plant growth promoting bacterial strains, which recommends their possible use as microbe-assisted phytoremediation systems in mercury-polluted soils.     

Standardisation of Western blotting to detect HTLV-1 antibodies synthesised in the central nervous system of HAM/TSP patients

Intrathecal synthesis of human T-lymphotropic virus type 1 (HTLV-1) antibodies (Abs) represents conclusive evidence of a specific immune response in the central nervous system of HTLV-1 associated myelopathy/tropical spastic paraparesis (HAM/TSP) patients. Western blotting (WB) for HTLV Abs in serum is a confirmatory test for HTLV-1 infection. The aim of this study was to standardise the Western blot to demonstrate the intrathecal pattern of Abs against HTLV-1 proteins in HAM/TSP patients. Paired cerebrospinal fluid (CSF) and serum samples were selected from 20 patients with definite HAM/TSP, 19 HTLV-1 seronegative patients and two HTLV-1 patients without definite HAM/TSP. The presence of reactive bands of greater intensity in the CSF compared to serum (or bands in only the CSF) indicated the intrathecal synthesis of anti-HTLV-1 Abs. All definite HAM/TSP patients presented with an intrathecal synthesis of anti-HTLV-1 Abs; these Abs were not detected in the control patients. The most frequent intrathecal targets of anti-HTLV-1 Abs were GD21, rgp46-I and p24 and, to a lesser extent, p19, p26, p28, p32, p36, p53 gp21 and gp46. The intrathecal immune response against env (GD21 and rgp46-I) and gag (p24) proteins represents the most important humoral pattern in HAM/TSP. This response may be used as a diagnostic marker, considering the frequent association of intrathecal anti-HTLV-1 Ab synthesis with HAM/TSP and the pathogenesis of this neurological disease.     

A Novel Method to Predict Genomic Islands Based on Mean Shift Clustering Algorithm

Genomic Islands (GIs) are regions of bacterial genomes that are acquired from other organisms by the phenomenon of horizontal transfer. These regions are often responsible for many important acquired adaptations of the bacteria, with great impact on their evolution and behavior. Nevertheless, these adaptations are usually associated with pathogenicity, antibiotic resistance, degradation and metabolism. Identification of such regions is of medical and industrial interest. For this reason, different approaches for genomic islands prediction have been proposed. However, none of them are capable of predicting precisely the complete repertory of GIs in a genome. The difficulties arise due to the changes in performance of different algorithms in the face of the variety of nucleotide distribution in different species. In this paper, we present a novel method to predict GIs that is built upon mean shift clustering algorithm. It does not require any information regarding the number of clusters, and the bandwidth parameter is automatically calculated based on a heuristic approach. The method was implemented in a new user-friendly tool named MSGIP—Mean Shift Genomic Island Predictor. Genomes of bacteria with GIs discussed in other papers were used to evaluate the proposed method. The application of this tool revealed the same GIs predicted by other methods and also different novel unpredicted islands. A detailed investigation of the different features related to typical GI elements inserted in these new regions confirmed its effectiveness. Stand-alone and user-friendly versions for this new methodology are available at http://msgip.integrativebioinformatics.me.