12 research outputs found

    Plastics select for distinct early colonizing microbial populations with reproducible traits across environmental gradients

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    Little is known about early plastic biofilm assemblage dynamics and successional changes over time. By incubating virgin microplastics along oceanic transects and comparing adhered microbial communities with those of naturally occurring plastic litter at the same locations, we constructed gene catalogues to contrast the metabolic differences between early and mature biofilm communities. Early colonization incubations were reproducibly dominated by Alteromonadaceae and harboured significantly higher proportions of genes associated with adhesion, biofilm formation, chemotaxis, hydrocarbon degradation and motility. Comparative genomic analyses among the Alteromonadaceae metagenome assembled genomes (MAGs) highlighted the importance of the mannose-sensitive hemagglutinin (MSHA) operon, recognized as a key factor for intestinal colonization, for early colonization of hydrophobic plastic surfaces. Synteny alignments of MSHA also demonstrated positive selection for mshA alleles across all MAGs, suggesting that mshA provides a competitive advantage for surface colonization and nutrient acquisition. Large-scale genomic characteristics of early colonizers varied little, despite environmental variability. Mature plastic biofilms were composed of predominantly Rhodobacteraceae and displayed significantly higher proportions of carbohydrate hydrolysis enzymes and genes for photosynthesis and secondary metabolism. Our metagenomic analyses provide insight into early biofilm formation on plastics in the ocean and how early colonizers self-assemble, compared to mature, phylogenetically and metabolically diverse biofilms

    Pituitary adenomas : immunohistochemical study of 167 cases

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    Foram analisados 167 casos de adenomas da hipófise pelo método imuno-histo-¬ químico utilizando o Complexo da Avidina Biotina (ABC) descrito por Hsu e col. (1981). Foram usados 6 anti-hormônios hipofisários: anti-prolactina (aPRL), na diluição de 1:1.500, anti-hormônio do crescimento (aHGH), na diluição de 1:4.000, anti-hormônio adrenocortico-¬ trófico (aACTH), na diluição de 1:3.000, anti-hormônio tireotrófico (aTSH), na diluição de 1:3.000, anti-hormônio luteinizante (aLH), na diluição de 1:1.000, anti-hormônio folículo estimulante (aFSH), na diluição de 1:300. O período de incubação foi de 14 a 16 horas a 4oC. Foi realizada também a coloração pelo Orange G-PAS. O levantamento dos dados clínicos, laboratoriais, e radiológicos dos casos de adenomas da hipófise foi realizado após a leitura das lâminas pelo método imuno-histoquímico. Dos 167 casos de adenomas da hipófise, 136 (81,4%) mostraram imuno-reação positiva a um ou mais anti-hormônios, variando o índice de positividade entre 1 e 90% das células neoplásicas. A imuno-reação foi positiva exclusivamente a um anti-hormônio em 80 casos (58,8%) e para dois ou mais anti-hormônios nos 56 casos restantes (41,2%), sendo a associação mais freqüentemente encontrada aquela em aue a positividade ocorreu para o a P R L e o aHGH. A positividade à reação imuno-his-¬ toquímica distribuiu-se da seguinte forma: 100 casos foram positivos para o aPRL, em 49 pacientes de forma isolada; 65 casos foram positivos para o aHGH, em 22 pacientes de forma isolada; 31 casos foram positivos para o aACTH, em 8 pacientes de forma isolada; 5 casos foram positivos ao aTSH, em um paciente de forma isolada; um paciente apresentou adenoma positivo ao aLH; um caso foi positivo ao aFSHOne hundred and sixty seven cases of pituitary adenoma were analysed using the immunocytochemical method of the Avidin-Biotin Complex (ABC), described by Hsu et al. (1981). Six pituitary anti-hormones were utilized: anti-prolactin (aPRL») at a 1:1,500 dilution; anti-growth hormone (aHGH) at a 1:4,000 dilution; anti-adrenocorticotro-¬ phic hormone (aACTH) at a 1:3,000 dilution; anti-thyrothrophic hormone (aTSH) at a 1:3,000 dilution; anti-luteinizing hormone (aLH) at a 1:1,000 dilution; and a anti_follicle-¬ -stimulating hormone (aFSH) at a 1:300 dilution. Incubation period was 14 to 16 hours at 4°C. The survey of clinical, laboratory and radiological data of cases of pituitary adenomas was performed (after reading- the stained slides using the immunocytochemical method. Of the 167 cases of pituitary adenomas, 136 (81,4%) disclosed a positive immuno-¬ reaction to one or more anti-hormones, and the positivity index of neoplastic cells varied from 1 to 90%. The immunoreaction was positive exclusively to one anti-hormone in 80 cases (58,8%) and to two or more anti-hormones in 56 cases, and the association most frequently found was between both aPRL and aHGH. The positivity to the immunoreaction was distributed as follows; — 100 cases were positive por aPRL, exclusively in 49 cases; — 65 cases were positive for aHGH, exclusively in 22 cases; —• 31 cases were positive for aACTH, exclusively in 8 cases; — 5 cases were positive for aTSH, exclusively in one case; — one patient presented an adenoma positive to aLH and another patient to aFSH

    Pituitary adenomas : immunohistochemical study of 167 cases

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    Foram analisados 167 casos de adenomas da hipófise pelo método imuno-histo-¬ químico utilizando o Complexo da Avidina Biotina (ABC) descrito por Hsu e col. (1981). Foram usados 6 anti-hormônios hipofisários: anti-prolactina (aPRL), na diluição de 1:1.500, anti-hormônio do crescimento (aHGH), na diluição de 1:4.000, anti-hormônio adrenocortico-¬ trófico (aACTH), na diluição de 1:3.000, anti-hormônio tireotrófico (aTSH), na diluição de 1:3.000, anti-hormônio luteinizante (aLH), na diluição de 1:1.000, anti-hormônio folículo estimulante (aFSH), na diluição de 1:300. O período de incubação foi de 14 a 16 horas a 4oC. Foi realizada também a coloração pelo Orange G-PAS. O levantamento dos dados clínicos, laboratoriais, e radiológicos dos casos de adenomas da hipófise foi realizado após a leitura das lâminas pelo método imuno-histoquímico. Dos 167 casos de adenomas da hipófise, 136 (81,4%) mostraram imuno-reação positiva a um ou mais anti-hormônios, variando o índice de positividade entre 1 e 90% das células neoplásicas. A imuno-reação foi positiva exclusivamente a um anti-hormônio em 80 casos (58,8%) e para dois ou mais anti-hormônios nos 56 casos restantes (41,2%), sendo a associação mais freqüentemente encontrada aquela em aue a positividade ocorreu para o a P R L e o aHGH. A positividade à reação imuno-his-¬ toquímica distribuiu-se da seguinte forma: 100 casos foram positivos para o aPRL, em 49 pacientes de forma isolada; 65 casos foram positivos para o aHGH, em 22 pacientes de forma isolada; 31 casos foram positivos para o aACTH, em 8 pacientes de forma isolada; 5 casos foram positivos ao aTSH, em um paciente de forma isolada; um paciente apresentou adenoma positivo ao aLH; um caso foi positivo ao aFSHOne hundred and sixty seven cases of pituitary adenoma were analysed using the immunocytochemical method of the Avidin-Biotin Complex (ABC), described by Hsu et al. (1981). Six pituitary anti-hormones were utilized: anti-prolactin (aPRL») at a 1:1,500 dilution; anti-growth hormone (aHGH) at a 1:4,000 dilution; anti-adrenocorticotro-¬ phic hormone (aACTH) at a 1:3,000 dilution; anti-thyrothrophic hormone (aTSH) at a 1:3,000 dilution; anti-luteinizing hormone (aLH) at a 1:1,000 dilution; and a anti_follicle-¬ -stimulating hormone (aFSH) at a 1:300 dilution. Incubation period was 14 to 16 hours at 4°C. The survey of clinical, laboratory and radiological data of cases of pituitary adenomas was performed (after reading- the stained slides using the immunocytochemical method. Of the 167 cases of pituitary adenomas, 136 (81,4%) disclosed a positive immuno-¬ reaction to one or more anti-hormones, and the positivity index of neoplastic cells varied from 1 to 90%. The immunoreaction was positive exclusively to one anti-hormone in 80 cases (58,8%) and to two or more anti-hormones in 56 cases, and the association most frequently found was between both aPRL and aHGH. The positivity to the immunoreaction was distributed as follows; — 100 cases were positive por aPRL, exclusively in 49 cases; — 65 cases were positive for aHGH, exclusively in 22 cases; —• 31 cases were positive for aACTH, exclusively in 8 cases; — 5 cases were positive for aTSH, exclusively in one case; — one patient presented an adenoma positive to aLH and another patient to aFSH

    Microbial population structure in a stratified, acidic pit lake in the Iberian Pyrite Belt

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    We examined the geochemistry and bacterial and archaeal community structure in the acidic (pH < 2.4) pit lake at Peña de Hierro, near the headwaters of the Río Tinto. The lake has strong vertical gradients in light, O2, pH, conductivity, and dissolved ions. Bacterial and archaeal communities between 0 and 32 m displayed low species richness and evenness. Relatives of iron cycling taxa accounted for 60-90% of the operational taxonomic units (OTUs) throughout the water column. Relatives of heterotrophic, facultative Fe(III)-reducing species made up more than a third of the bacterial and archaeal community in the photic zone. Taxa related to Fe(II) oxidizers Ferrithrix thermotolerans and Acidithix ferrooxidans were also abundant in the photic zone. Below the photic zone, relatives of the lithoautotrophic Fe(II) oxidizers Leptospirillum ferrooxidans and Ferrovum myxofaciens bloomed at different depths within or just below the oxycline. Thermoplasmatales predominated in the deep, microoxic zone of the lake. The microbial population structure of the lake appears to be influenced by the production of oxygen and organic matter by phototrophs in a narrow zone at the lake surface and by strong geochemical gradients present in the water column that create distinct niches for separate Fe(II) oxidizers
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