Drivers of archaeal ammonia-oxidizing communities in soil

Soil ammonia-oxidizing archaea (AOA) are highly abundant and play an important role in the nitrogen cycle. In addition, AOA have a significant impact on soil quality. Nitrite produced by AOA and further oxidized to nitrate can cause nitrogen loss from soils, surface and groundwater contamination, and water eutrophication. The AOA discovered to date are classified in the phylum Thaumarchaeota. Only a few archaeal genomes are available in databases. As a result, AOA genes are not well annotated, and it is difficult to mine and identify archaeal genes within metagenomic libraries. Nevertheless, 16S rRNA and comparative analysis of ammonia monooxygenase sequences show that soils can vary greatly in the relative abundance of AOA. In some soils, AOA can comprise more than 10% of the total prokaryotic community. In other soils, AOA comprise less than 0.5% of the community. Many approaches have been used to measure the abundance and diversity of this group including DGGE, T-RFLP, q-PCR, and DNA sequencing. AOA have been studied across different soil types and various ecosystems from the Antarctic dry valleys to the tropical forests of South America to the soils near Mount Everest. Different studies have identified multiple soil factors that trigger the abundance of AOA. These factors include pH, concentration of available ammonia, organic matter content, moisture content, nitrogen content, clay content, as well as other triggers. Land use management appears to have a major effect on the abundance of AOA in soil, which may be the result of nitrogen fertilizer used in agricultural soils. This review summarizes the published results on this topic and suggests future work that will increase our understanding of how soil management and edaphoclimatic factors influence AOA

EXAME PREVENTIVO PAPANICOLAOU: ADESÃO DO EXAME EM ACADÊMICAS DE ENFERMAGEM DE UMA UNIVERSIDADE DO MEIO-OESTE CATARINENSE

Nesta pesquisa teve-se o propósito de identificar a adesão à prevenção do câncer cérvico-uterino, por meio do exame Papanicolaou, reconhecer o perfil das alunas, reconhecer o índice de adesão à realização do exame preventivo, identificar as razões para a não adesão à realização do exame e identificar o conhecimento das acadêmicas quanto à realização do exame Papanicolaou. Priorizou-se o estudo com as acadêmicas do Curso de Graduação em Enfermagem da Universidade do Oeste de Santa Catarina, matriculadas no semestre 1/2013; o número de acadêmicas matriculadas no Curso é de 173, desse número, 111 acadêmicas participaram da entrevista focalizada, o que corresponde a 64,16% de participantes, com faixa etária entre 17 e 49 anos. Para a análise, os dados foram categorizados em 15 perguntas fechadas e 1 aberta. A maioria das entrevistadas encontra-se em um relacionamento estável, heterossexuais, manteve relações sexuais apenas com um parceiro. A faixa etária de 21 anos se sobressai na entrevista, representada também pela raça branca. Das entrevistadas, 79% possuem renda familiar acima de R$ 1.000,00. O questionário foi respondido por alunas das cinco fases, sendo a primeira fase com maior número de participantes. A maioria das acadêmicas sabe o que é exame Papanicolaou, e 83,7% delas realizam o exame anualmente; destas, 71,4% realizaram em consultórios particulares e com médico. Em relação aos riscos em decorrência do fator genético, somente 9 entrevistadas relataram possuir histórico de CA Uterino na família, sendo esse o fator de risco mais citado pelas acadêmicas. Sabe-se que é o enfermeiro quem contribui para a prevenção do câncer de colo uterino, destacando-se e participando no controle de fatores de risco, na realização da consulta ginecológica e do exame Papanicolaou, influindo para um maior e melhor atendimento à demanda, efetivando um sistema de registro de qualidade; por isso é importante que esse profissional, já desde o período de graduação, utilize seus conhecimentos e métodos preventivos em sua vida pessoal, cuidando da própria saúde. Observou-se que o conhecimento adquirido no decurso da graduação, tendo como disciplina Saúde Da Mulher, impõe nas acadêmicas a aderência de na prática cuidar da própria prevenção, revelou que a maioria das participantes adere ao que é de seu aprendizado, e preconizado, porém, não é aderido por outras acadêmicas, o que não deixa de ser preocupante. É um tema amplo e apresenta subsídios para novos questionamentos.Palavras-chave: Acadêmicas. Aprendizado. Preventivo.

Ca. Nitrososphaera and Bradyrhizobium are inversely correlated and related to agricultural practices in long-term field experiments

Agricultural land management, such as fertilization, liming, and tillage affects soil properties, including pH, organic matter content, nitrification rates, and the microbial community. Three different study sites were used to identify microorganisms that correlate with agricultural land use and to determine which factors regulate the relative abundance of the microbial signatures of the agricultural land-use. The three sites included in this study are the Broadbalk Experiment at Rothamsted Research, UK, the Everglades Agricultural Area, Florida, USA, and the Kellogg Biological Station, Michigan, USA. The effects of agricultural management on the abundance and diversity of bacteria and archaea were determined using high throughput, barcoded 16S rRNA sequencing. In addition, the relative abundance of these organisms was correlated with soil features. Two groups of microorganisms involved in nitrogen cycle were highly correlated with land use at all three sites. The ammonia oxidizing-archaea, dominated by Ca. Nitrososphaera, were positively correlated with agriculture while a ubiquitous group of soil bacteria closely related to the diazotrophic symbiont, Bradyrhizobium, was negatively correlated with agricultural management. Analysis of successional plots showed that the abundance of ammonia oxidizing-archaea declined and the abundance of bradyrhizobia increased with time away from agriculture. This observation suggests that the effect of agriculture on the relative abundance of these genera is reversible. Soil pH and NH(3) concentrations were positively correlated with archaeal abundance but negatively correlated with the abundance of Bradyrhizobium. The high correlations of Ca. Nitrososphaera and Bradyrhizobium abundances with agricultural management at three long-term experiments with different edaphoclimatic conditions allowed us to suggest these two genera as signature microorganisms for agricultural land use

Metal-resistant rhizobacteria change soluble-exchangeable fraction in multi-metal-contaminated soil samples

There is a complex interaction between various components of the soil ecosystem, including microbial biomass and soil chemical contaminants such as heavy metals and radionuclides, which may greatly affect the efficiency of bioremediation techniques. The aim of this study was to investigate microbial capacity to change pH, changes in the metal soluble-exchangeable fraction, and effects of initial heavy metal contents on soil samples in microbial solubilization/immobilization capacity. The soil samples used in this study were collected at a known metal-contaminated site. Three highly metal-resistant bacteria were isolated from rhizosphere soil samples collected on weed species identified as Senecio brasiliensis, Senecio leptolobus, and Baccharis trimera. A completely randomized experimental design in a factorial arrangement was used, with three replicates. In general, with an acid pH, the isolates neutralized the contaminated growth media. In a neutral or basic initial pH, increases in pH were observed in the media, so these bacteria have an alkalizing effect on the growth media. Soluble metal contents were quite different and depend on the microbial species and heavy metal contents in the soil samples. The soluble-exchangeable fraction of metal such as Cu, Zn, Ni, Cr, Cd, Pb, and Ba may be unavailable after inoculation with heavy metalresistant rhizobacteria. A promising approach seems to be the application of inoculants with metal-resistant bacteria in bioremediation of multi-metal-polluted environments to improve the efficiency of this environmentally friendly technology

Valvuloplastia pulmonar percutânea em síndrome de Noonan

Os autores descrevem o casa de uma menina de 14 anos portadora de Syndrome de Noonan e estenose pulmonar severa submetida a valvuloplastia pulmonar percutanea com cateter-balgo House melhora sintomftica importante ap6s o procedimento, que transcorreu sem complicag6es. No entanto, permaneceu obstrugao residual na via de saida do ventrfculo direito por hipertrofia infundibular, que regrediu apes um ano e meio de acompanhamento O faso 6 ilustrativo de alguns pontos controversos do uso da valvuloplastia pulmonar percutanea, coma seu emprego em pacientes com vflvulas displasicas e estenose importante, o tempo correta da indicagao, o uso de betabloqueadores após o procedimento, a técnica utilizada e o tamanho do balio a ser empregado e suas repercussões a médio e longo prazo.The authors report the case of a fourteen years-old girl with Noonan's Syndrome and severe pulmonary stenosis who underwent a percutaneous pulmonary balloon valvuloplasty. There was symptomatic improvement after the procedure and no complications. However, moderate residual stenosis remained due to infundibular obstruction, which decreased significantly in one and a half years of follow up. This case illustrates some controversial issues of percutaneous pulmonary balloon valvuloplasty: its application on dysplasic valves with severe stenosis, the correct timing of intervention, the use of betablockers after the procedure, technical aspects and the size of the balloon used and medium to long term result

Phosphatidylinositol 3-kinase/AKT pathway inhibition by doxazosin promotes glioblastoma cells death, upregulation of p53 and triggers low neurotoxicity

Glioblastoma is the most frequent and malignant brain tumor. Treatment includes chemotherapy with temozolomide concomitant with surgical resection and/or irradiation. However, a number of cases are resistant to temozolomide, as well as the human glioblastoma cell line U138-MG. We investigated doxazosin’s (an antihypertensive drug) activity against glioblastoma cells (C6 and U138-MG) and its neurotoxicity on primary astrocytes and organoptypic hippocampal cultures. For this study, the following methods were used: citotoxicity assays, flow cytometry, western-blotting and confocal microscopy. We showed that doxazosin induces cell death on C6 and U138-MG cells. We observed that doxazosin’s effects on the PI3K/Akt pathway were similar as LY294002 (PI3K specific inhibitor). In glioblastoma cells treated with doxasozin, Akt levels were greatly reduced. Upon examination of activities of proteins downstream of Akt we observed upregulation of GSK-3β and p53. This led to cell proliferation inhibition, cell death induction via caspase-3 activation and cell cycle arrest at G0/G1 phase in glioblastoma cells. We used in this study Lapatinib, a tyrosine kinase inhibitor, as a comparison with doxazosin because they present similar chemical structure. We also tested the neurocitotoxicity of doxazosin in primary astrocytes and organotypic cultures and observed that doxazosin induced cell death on a small percentage of non-tumor cells. Aggressiveness of glioblastoma tumors and dismal prognosis require development of new treatment agents. This includes less toxic drugs, more selective towards tumor cells, causing less damage to the patient. Therefore, our results confirm the potential of doxazosin as an attractive therapeutic antiglioma agent

Ca. Nitrososphaera and Bradyrhizobium are inversely correlated and related to agricultural practices in long-term field experiments

Agricultural land management, such as fertilization, liming, and tillage affects soil properties, including pH, organic matter content, nitrification rates, and the microbial community. Three different study sites were used to identify microorganisms that correlate with agricultural land use and to determine which factors regulate the relative abundance of the microbial signatures of the agricultural land-use. The three sites included in this study are the Broadbalk Experiment at Rothamsted Research, UK, the Everglades Agricultural Area, Florida, USA, and the Kellogg Biological Station, Michigan, USA. The effects of agricultural management on the abundance and diversity of bacteria and archaea were determined using high throughput, barcoded 16S rRNA sequencing. In addition, the relative abundance of these organisms was correlated with soil features. Two groups of microorganisms involved in nitrogen cycle were highly correlated with land use at all three sites. The ammonia oxidizing-archaea, dominated by Ca. Nitrososphaera, were positively correlated with agriculture while a ubiquitous group of soil bacteria closely related to the diazotrophic symbiont, Bradyrhizobium, was negatively correlated with agricultural management. Analysis of successional plots showed that the abundance of ammonia oxidizing-archaea declined and the abundance of bradyrhizobia increased with time away from agriculture. This observation suggests that the effect of agriculture on the relative abundance of these genera is reversible. Soil pH and NH₃ concentrations were positively correlated with archaeal abundance but negatively correlated with the abundance of Bradyrhizobium. The high correlations of Ca. Nitrososphaera and Bradyrhizobium abundances with agricultural management at three long-term experiments with different edaphoclimatic conditions allowed us to suggest these two genera as signature microorganisms for agricultural land use.This is the publisher’s final pdf. The published article is copyrighted by the author(s) and published by the Frontiers Research Foundation. The published article can be found at: http://www.frontiersin.org/Microbiology.Keywords: Ca. Nitrososphaera, Agricultural land use, Bradyrhizobium, Ammonia-oxidizing archaea, Soil properties, DiazotrophsKeywords: Ca. Nitrososphaera, Agricultural land use, Bradyrhizobium, Ammonia-oxidizing archaea, Soil properties, Diazotroph