A Practical Procedure for Analysis of Lead Isotopes in Bivalve Shells Using Laser Ablation Multicollector Inductively Coupled Plasma Mass Spectrometry (LA-MC-ICP-MS).

Lead, like other trace elements, is incorporated in the growing bands of bivalve shells. The chemicals stored into the shells can provide valuable information about seawater conditions during the period of shell formation. In this study, we present a practical approach to determine Pb isotopic signatures in bivalve shells as a tool for evaluating lead pollution in coastal waters. To demonstrate the applicability of the method, Pb isotopic fingerprinting in bivalve shell layers were investigated using laser ablation multicollector inductively coupled plasma mass spectrometry (LA-MC-ICP-MS). Lead isotope ratios (208Pb/206Pb and 206Pb/207Pb) were measured along distinct sections of the maximum growth axis of the shells. Calibration and quantification of Pb isotopes were performed using NIST 612 as reference material. Our results demonstrated that Pb isotope ratios in the shells ranged from 1.143 to 1.201 for 206Pb/207Pb and from 2.061 to 2.161 for 208Pb/206Pb. The isotopic signatures recorded in the sample shells correspond to similar ranges of Pb signatures reported for marine sediments from the same study area. In general, this work shows that LA-MC-ICP-MS is a suitable technique for determining spatially resolved lead isotopic signatures in bivalve shells and that it can be used to estimate the origin of Pb pollution in aquatic environments.

Evaluation of seeds ethanolic extracts of Triplaris gardneriana Wedd. using in vitro and in vivo toxicological methods.

Triplaris gardneriana Wedd. is a tree used in folk medicine to treat venereal diseases and inflammation as well as a source of biological compounds with antioxidant capacity. In order to assess the safety of these bioactive compounds, the present study aimed to determine the toxicity of an ethanolic extract of T. gardneriana, (EETg). Toxicological tests included hemolytic activity, toxicity toward the brine shrimp Artemia, cytotoxicity against breast cancer cells (MCF7) and acute oral toxicity in rodents. In addition, toxicogenomics techniques were used to determine genome expression in MCF7 cells exposed to EETg. The results showed that the extract exhibits approximately 60% of hemolytic activity at the highest tested concentration (64 µg/ml) and toxicity against nauplii of Artemia sp. (LC50 of 67.85 µg/ml). Further, EETg appears to be cytotoxic to MCF7 (cell viability reduced to 40% at 250 µg/ml after 24 hr). Genomic data demonstrated differential expression of 14 genes. Data analysis indicated possible altered pathways (e.g., xenobiotic metabolism), possible adverse health risks (e.g., hepatotoxicity), and drugs with similar gene expression profile (e.g., antimicrobials). The investigation provides important information on potentially adverse aspects of EETg, which need to be considered prior to the therapeutic utilization of this plant.Abbreviations: EETg: ethanolic extract of T. gardneriana seeds; MCF7: michigan cancer foundation-7 which refers to a human breast cell line (adenocarcinoma); NGS: next-generation sequencing; edgeR: empirical analysis of digital gene expression data in R; Consensus: consensus path database; FDR: false discovery rate; NCBI: national center for biotechnology information; KEGG: kyoto encyclopedia of genes and genomes; Ingenuity: ingenuity pathway analysis software; CMAP: connectivity map; OECD: organization for economic co-operation and development; HL-60: human promyelocytic leukemia cells; PC3: prostate cancer cells.

Detection and Correlation of Single and Concomitant TP53, PTEN, and CDKN2A Alterations in Gliomas.

Gliomas are the most frequent primary tumors of central nervous system and represent a heterogeneous group of tumors that originates from the glial cells. TP53, PTEN, and CDKN2A are important tumor suppressor genes that encode proteins involved in sustaining cellular homeostasis by different signaling pathways. Though genetic alterations in these genes play a significant role in tumorigenesis, few studies are available regarding the incidence and relation of concomitant TP53, PTEN, and CDKN2A alterations in gliomas. The purpose of this study was to evaluate the occurrence of mutation and deletion in these genes, through single-strand conformational polymorphism, array-comparative genomic hybridization, and fluorescence in situ hybridization techniques, in 69 gliomas samples. Molecular results demonstrated a significant higher prevalence of TP53, PTEN, and CDKN2A alterations in astrocytoma than other tumor subtypes, and heterozygous deletion was the most frequent event. In addition, a significant association was observed between TP53 and CDKN2A alterations (p = 0.0424), which tend to coexist in low grade astrocytomas (5/46 cases (10.9%)), suggesting that they are early events in development of these tumors, and PTEN and CDKN2A deletions (p = 0.0022), which occurred concomitantly in 9/50 (18%) patients, with CDKN2A changes preceding PTEN deletions, present preferably in high-grade gliomas.

Diabetes mellitus e a doença de Alzheimer / Diabetes Mellitus and Alzheimer's disease

A associação entre a Diabete Mellitus e a demência está sendo alvo de forte interesse devido a alta incidência com o aumento da expectativa de vida. A diabete, assim como doenças vasculares, apresenta forte fator de risco para o desenvolvimento de demências. Muitos fatores afetam adversamente a saúde do cérebro de indivíduos com Diabetes, incluindo a desregulação energética, inflamação, diminuição da perfusão, aumento do estresse oxidativo e deposição proteica. A diabete é uma doença metabólica complexa que pode ter efeitos devastadores sobre múltiplos sistemas orgânicos. É proposto que na fisiopatologia do déficit cognitivo no diabético sejam pela hipoglicemia crônica, efeitos acumulativos de eventos hipoglicêmicos e possíveis efeitos diretos da insulina no sistema nervoso central. Ainda não está claro se esses fatores, isoladamente, ou, em conjunto, conduzem ao desenvolvimento do déficit cognitivo. Fortes evidências demonstram que a Doença de Alzheimer, juntamente com as doenças cardiovasculares e diabetes possam ter uma mesma origem. Tendo em vista a discussão que o metabolismo energético seja enfatizado devido à hipoperfusão, não é difícil especular que a Diabetes possa ser um componente importante na patogênese da Doença de Alzheimer por reflexo da vasculopatia associada, resultando em danos ao ambiente microvascular. Com base nesta revisão foi possível perceber a forte a fluência da Diabetes sobre o quadro de declínio cognitivo o que sugere uma forte influência da Diabetes no desenvolvimento da Doença de Alzheimer e a existência de um potencial link etiológico entre as Doenças Vasculares, Diabetes e a Doença de Alzheimer.

The association between diabetes mellitus and dementia is target of strong interest due to high incidence with increasing life expectancy.Diabetes, as well as vascular diseases, presents a strong risk factor for the development of dementia. Many factors adversely affect the health of the brain in individuals with diabetes, including energy dysregulation, inflammation, decreased perfusion, increased oxidative stress and protein deposition. Diabetes is a complex metabolic disease that can have devastating effects in multiple organ systems. It is proposed that in the pathophysiology of cognitive deficit in diabetic patients is the chronic hypoglycemia, cumulative effects of hypoglycemic events and possible direct effects of insulin on the central nervous system. It is unclear whether these factors singly or together, lead to the development of cognitive deficit. Strong evidence shows that Alzheimer's disease together with cardiovascular disease and diabetes can have the same origin.In view of the discussion that energy metabolism is emphasized due to hypoperfusion, it is not difficult to speculate that diabetes may be an important component in the pathogenesis of Alzheimer's disease by reflecting the associated vasculopathy, resulting in damage to the microvascular environment. Based on this review it was revealed the strong influence of diabetes on cognitive decline framework and our conclusion supports the hypothesis of a strong influence of diabetes on the development of Alzheimer's disease and the existence of a potential etiological link between the Vascular Diseases, diabetes and Alzheimer's disease.

Phenolic compounds of Triplaris gardneriana can protect cells against oxidative stress and restore oxidative balance.

This work aimed to add value to an underexploited plant species from Brazil, Triplaris gardneriana. To that, the phenolic compounds profile of its seed ethanolic extract and fractions was examined by HPLC and the antioxidant capacity assessed using chemical assays as well as in vitro cell imaging. Twelve compounds were quantified and classified as either phenolic acids or flavonoids. The fractionation process did not generate fractions with different compositions except for chloroformic fraction, which showed only 6 out of 12 standard compounds used. DPPH assay revealed samples with a concentration-dependent radical scavenging activity, being methanolic fraction the one with the largest activity (SC50 11.45±0.02µg/mL). Lipid peroxidation assessment, in the presence and absence of stress inducer, showed that particularly the ethanol extract (IC50 26.75±0.08µg/mL) and the ethyl acetate fraction (IC50 6.14±0.03µg/mL) could inhibit lipid peroxidation. The ethyl acetate fraction performed best in chelating iron (48% complexation at 1000µg/mL). Cell imaging experiments showed that the ethanolic extract could protect cells against oxidative stress as well as restore the oxidative balance upon stress induction. In conclusion, T. gardneriana seeds showed a promising phenolic compounds profile and antioxidant activity that may be further exploited.

Polyphenol Composition, Antioxidant Activity and Cytotoxicity of Seeds from Two Underexploited Wild Licania Species: L. rigida and L. tomentosa.

Studies have shown the benefit of antioxidants in the prevention or treatment of human diseases and promoted a growing interest in new sources of plant antioxidants for pharmacological use. This study aimed to add value to two underexploited wild plant species (Licania rigida) and L. tomentosa) from Brazilian flora. Thus, the phenolic compounds profile of their seed ethanol extract and derived fractions were elucidated by HPLC, the antioxidant capacity was assessed by in vitro chemical tests and the cytotoxicity determined using the human carcinoma cell lines MCF-7 and Caco-2. Eleven phenolic compounds were identified in the extracts of each species. The extracts and fractions showed excellent antioxidant activity in the DPPH assay (SC50, ranging from 9.15 to 248.8 µg/mL). The aqueous fraction of L. rigida seeds was most effective in preventing lipid peroxidation under basal conditions (IC50 60.80 µg/mL) whereas, in the presence of stress inducer, the methanolic fraction of L. tomentosa performed best (IC50 8.55 µg/mL). None of the samples showed iron chelating capacity. Ethanolic seed extracts of both species did not reveal any cytotoxicity against MCF-7 and Caco-2 cells. Both plant species showed a promising phenolic profile with potent antioxidant capacity and deserve attention to be sustainably explored.

Evaluation of cytotoxic and antimicrobial effects of two Bt Cry proteins on a GMO safety perspective.

Studies have contested the innocuousness of Bacillus thuringiensis (Bt) Cry proteins to mammalian cells as well as to mammals microbiota. Thus, this study aimed to evaluate the cytotoxic and antimicrobial effects of two Cry proteins, Cry8Ka5 (a novel mutant protein) and Cry1Ac (a widely distributed protein in GM crops). Evaluation of cyto- and genotoxicity in human lymphocytes was performed as well as hemolytic activity coupled with cellular membrane topography analysis in mammal erythrocytes. Effects of Cry8Ka5 and Cry1Ac upon Artemia sp. nauplii and upon bacteria and yeast growth were assessed. The toxins caused no significant effects on the viability (IC50 > 1,000 µg/mL) or to the cellular DNA integrity of lymphocytes (no effects at 1,000 µg/mL). The Cry8Ka5 and Cry1Ac proteins did not cause severe damage to erythrocytes, neither with hemolysis (IC50 > 1,000 µg/mL) nor with alterations in the membrane. Likewise, the Cry8Ka5 and Cry1Ac proteins presented high LC50 (755.11 and >1,000 µg/mL, resp.) on the brine shrimp lethality assay and showed no growth inhibition of the microorganisms tested (MIC > 1,000 µg/mL). This study contributed with valuable information on the effects of Cry8Ka5 and Cry1Ac proteins on nontarget organisms, which reinforce their potential for safe biotechnological applications.

Molecular characterization of TP53 gene in human populations exposed to low-dose ionizing radiation.

Ionizing radiation, such as that emitted by uranium, may cause mutations and consequently lead to neoplasia in human cells. The TP53 gene acts to maintain genomic integrity and constitutes an important biomarker of susceptibility. The present study investigated the main alterations observed in exons 4, 5, 6, 7, and 8 of the TP53 gene and adjacent introns in Amazonian populations exposed to radioactivity. Samples were collected from 163 individuals. Occurrence of the following alterations was observed: (i) a missense exchange in exon 4 (Arg72Pro); (ii) 2 synonymous exchanges, 1 in exon 5 (His179His), and another in exon 6 (Arg213Arg); (iii) 4 intronic exchanges, 3 in intron 7 (C → T at position 13.436; C → T at position 13.491; T → G at position 13.511) and 1 in intron 8 (T → G at position 13.958). Alteration of codon 72 was found to be an important risk factor for cancer development (P = 0.024; OR = 6.48; CI: 1.29-32.64) when adjusted for age and smoking. Thus, TP53 gene may be an important biomarker for carcinogenesis susceptibility in human populations exposed to ionizing radiation.

Anti-inflammatory properties of doxycycline and minocycline in experimental models: an in vivo and in vitro comparative study.

AIMS AND METHODS: Minocycline (Mino) and doxycycline (Dox) are second generation tetracyclines known to present several other effects, which are independent from their antimicrobial activities. We studied in a comparative way the anti-inflammatory effects of Mino and Dox, on acute models of peripheral inflammation in rodents (formalin test and peritonitis in mice, and carrageenan-induced paw oedema in rats). Immunohistochemical assays for TNF-alpha and iNOS in rat paws of carrageenan-induced oedema were also carried out as well as in vitro assays for myeloperoxidase (MPO) and lactate dehydrogenase (LDH). Furthermore, antioxidant activities were evaluated by the DPPH assay. RESULTS: In the formalin test although Mino and Dox (1, 5, 10 and 25 mg/kg, i.p.) inhibited the first phase, they acted predominantly on the second phase of the test, where inhibition of the licking time close to 80% were observed. Mino and Dox were very efficacious in reducing the carrageenan-induced paw oedema in rats (10, 25 and 50 mg/kg, i.p.) and carrageenan-induced leucocyte migration (1 and 5 mg/kg, i.p.) to mice peritoneal cavities. Besides, they also significantly inhibited MPO and LDH releases at doses ranging from 0.001 to 1 µg/ml. Thus, in general, the anti-inflammatory activity of Dox was higher as compared to that of Mino, although the radical scavenging activity of Mino was of a magnitude 10 times higher. CONCLUSIONS: Our data indicate that anti-inflammatory and antioxidant effects, involve the inhibition of iNOS and TNF-alpha, among other properties, and these encourage clinical studies of these compounds for new therapeutic applications, especially those were inflammation plays a role.