Efeito da sistematização sobre atributos físicos, químicos e biológicos de um solo de várzea no Rio Grande do Sul.

bitstream/item/110873/1/Boletim-189-web.pd

Steroid-free medium discloses oestrogenic effects of the bisphosphonate clodronate on breast cancer cells

SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Additive growth inhibitory effects of ibandronate and antiestrogens in estrogen receptor-positive breast cancer cell lines

INTRODUCTION: Bisphosphonates are inhibitors of osteoclast-mediated tumor-stimulated osteolysis, and they have become standard therapy for the management of bone metastases from breast cancer. These drugs can also directly induce growth inhibition and apoptosis of osteotropic cancer cells, including estrogen receptor-positive (ER+) breast cancer cells. METHODS: We examined the anti-proliferative properties of ibandronate on two ER+ breast cancer cell lines (MCF-7 and IBEP-2), and on one ER negative (ER-) cell line (MDA-MB-231). Experiments were performed in steroid-free medium to assess ER regulation and the effect of ibandronate in combination with estrogen or antiestrogens. RESULTS: Ibandronate inhibited cancer cell growth in a dose- and time-dependent manner (approximate IC(50): 10(-4 )M for MCF-7 and IBEP-2 cells; 3 × 10(-4 )M for MDA-MB-231 cells), partly through apoptosis induction. It completely abolished the mitogenic effect induced by 17β-estradiol in ER+ breast cancer cells, but affected neither ER regulation nor estrogen-induced progesterone receptor expression, as documented in MCF-7 cells. Moreover, ibandronate enhanced the growth inhibitory action of partial (4-hydroxytamoxifen) and pure (ICI 182,780, now called fluvestrant or Faslodex™) antiestrogens in estrogen-sensitive breast cancer cells. Combination analysis identified additive interactions between ibandronate and ER antagonists. CONCLUSION: These data constitute the first in vitro evidence for additive effects between ibandronate and antiestrogens, supporting their combined use for the treatment of bone metastases from breast cancer

Comparison of the sensitivity of Pseudomonas aeruginosa to disinfectants according to the growth conditions

During the evaluation of the bactericidal effect of some disinfectants, the authors observed major differences of sensitivity in the case of Pseudomonas aeruginosa depending on the culture medium used for the preparation of the inoculum. In particular for chloroxylenol the results were much more favourable when the culture was made in brain heart infusion (Difco) than in tryptic soy broth (Difco). © 1984.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

The Frasnian/Famennian boundary interval in the South Polish-Moravian shelf basins: integrated event-stratigraphical approach

The Late Devonian mass extinction event near the Frasnian/Famennian (F/F) boundary has been analysed using conodont biostratigraphy and biofacies, sedimentology, magnetic susceptibility and geochemistry in reference sections of the South Polish-Moravian shelf (Holy Cross Mountains, Cracow and Brno areas). High-resolution biostratigraphic study revealed difficulties in the precise recognition of this 'natural' stage boundary, but confirmed the occurrence of a major (third-order) sequence boundary in the F/F transition in an active synsedimentary tectonic setting, marked by erosional discontinuities, hardgrounds and brecciation or omission surfaces. Conclusive evidence of an extraterrestrial impact has not been found. Among Earth-bound factors, the main devastating role in the shelf habitats is ascribed to fluctuating anoxia and/or nutrient dynamics in a disturbed greenhouse climatic setting. The long-term facies changes were determined by a conspicuous break in carbonate production, accompanied by replacement of mature stromatoporoid-coral reefs by pioneer shelly-crinoid banks, microbial mounds and localised oolitic bars. The key OF passage interval was marked by intermittent but generally accelerated periplatform ooze/debris input and severe storm events, as well as by probably highly fluctuating oxygenation and biological overproduction, best manifested in radiolarian-silicisponge and cephalopod acmes. Eutrophication phenomena, at least partly stimulated by various hydrothermal and volcanic processes, were one of the major biogeochemical processes during this climax of the Late Devonian biotic crisis. However, significant oceanographic perturbations were also linked with the onset of the transgressive-hypoxic Upper Kellwasser Event, still within the latest Frasnian linguiformis Zone, i.e., well before the F/F conodont collapse. Implied variations in the redox state of seawater through the Kellwasser timespan, probably in regionally highly variable temporal scales, are in agreement with recent palaeoecological and biogeochemical inferences, in particular suggesting recovering oxygenation just prior to the F/F boundary in the other Laurussian intrashelf basins. All the data support a long-time, multicausal Earth-bound crisis instead a worldwide cosmic catastrophe

Difference of Pseudomonas aeruginosa sensitivity to chloroxylenol according to the culture medium

The authors recorded notable difference of sensitivity of Pseudomonas aeruginosa to chloroxylenol according to the growth medium; the amount of magnesium of the culture medium and the growth phase were not major factors. This difference, which can be extended to various strains, is due to a difference of permeability of the outer membrane. It is suggested that adsorption of medium components on the surface of the bacteria could participate in the phenomenon. Similar results were obtained with phenol and crystal violet. © 1986.SCOPUS: ar.jinfo:eu-repo/semantics/publishe