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71.
Paolo Cossu-Rocca Sandra Orrù Maria Rosaria Muroni Francesca Sanges Giovanni Sotgiu Sara Ena Giovanna Pira Luciano Murgia Alessandra Manca Maria Gabriela Uras Maria Giuseppina Sarobba Silvana Urru Maria Rosaria De Miglio 《PloS one》2015,10(11)
Background
Triple Negative Breast Cancer (TNBC) accounts for 12–24% of all breast carcinomas, and shows worse prognosis compared to other breast cancer subtypes. Molecular studies demonstrated that TNBCs are a heterogeneous group of tumors with different clinical and pathologic features, prognosis, genetic-molecular alterations and treatment responsivity. The PI3K/AKT is a major pathway involved in the regulation of cell survival and proliferation, and is the most frequently altered pathway in breast cancer, apparently with different biologic impact on specific cancer subtypes. The most common genetic abnormality is represented by PIK3CA gene activating mutations, with an overall frequency of 20–40%. The aims of our study were to investigate PIK3CA gene mutations on a large series of TNBC, to perform a wider analysis on genetic alterations involving PI3K/AKT and BRAF/RAS/MAPK pathways and to correlate the results with clinical-pathologic data.Materials and Methods
PIK3CA mutation analysis was performed by using cobas® PIK3CA Mutation Test. EGFR, AKT1, BRAF, and KRAS genes were analyzed by sequencing. Immunohistochemistry was carried out to identify PTEN loss and to investigate for PI3K/AKT pathways components.Results
PIK3CA mutations were detected in 23.7% of TNBC, whereas no mutations were identified in EGFR, AKT1, BRAF, and KRAS genes. Moreover, we observed PTEN loss in 11.3% of tumors. Deregulation of PI3K/AKT pathways was revealed by consistent activation of pAKT and p-p44/42 MAPK in all PIK3CA mutated TNBC.Conclusions
Our data shows that PIK3CA mutations and PI3K/AKT pathway activation are common events in TNBC. A deeper investigation on specific TNBC genomic abnormalities might be helpful in order to select patients who would benefit from current targeted therapy strategies. 相似文献72.
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74.
Tatiana F. Souto Sérgio F. Aquino Silvana Q. Silva Carlos A. L. Chernicharo 《Biodegradation》2010,21(3):411-424
The main objective of this work was to evaluate the influence of incubating conditions on the specific methanogenic activity (SMA) test in order to harmonize the test protocol. For this serum bottles were incubated with anaerobic sludge (from UASB reactor treating domestic sewage) in factorial planned experiments which assessed the influence of the temperature, substrate concentration, food/microorganism (F/M) ratio, presence of yeast extract in the medium, as well as type of carbon and nutrient solution. The results showed that the tested methane measuring methods (volumetric with biogas characterization, volumetric with gas wash in alkaline solution, and manometric by using the OxiTop® system) presented a similar performance. The maintenance of a small gaseous phase volume (e.g. 10% of the total volume) resulted in higher SMA values; and the ideal substrate concentration for the SMA test ranged from 0.5 to 3.0 gCOD/l since higher acetate concentration caused sludge inhibition. The suggested temperature for the test is 35°C and the best F/M ratio varied from 0.125 to 0.750 gCOD/gVS, and this seemed to be the most influent parameter for the SMA test. Finally tests performed with nutrient solution complemented by yeast extract resulted in the highest SMA values. 相似文献
75.
Alexandra Pavlova Faith M. Walker Rodney van der Ree Silvana Cesarini Andrea C. Taylor 《Conservation Genetics》2010,11(6):2393-2407
The squirrel glider Petaurus norfolcensis occurs across a broad Australian latitudinal range that includes gaps in distribution and potential biogeographic barriers,
creating the potential for evolution of distinct entities within this species. Because of the species’ threatened status in
the southern part of its range, we tested for the presence of geographically based independent evolutionary units among gliders
sampled from southern, and northern coastal populations, using sequences of mitochondrial cytochrome b DNA (mtDNA) and a set of five nuclear microsatellites in 258 individuals. Our analyses suggest that an initial northward
colonisation in the early- to mid-Pleistocene was followed by isolation by distance and, eventually, divergence between the
sampled coastal and southern populations in the mid- to late-Pleistocene. We propose that the previously large and diverse
southern populations have declined coincidentally with the replacement of wet forests by open sclerophyll woodlands during
the preceding few million years. By contrast coastal populations further north appear to have been expanding and at present
have an effective population size several times greater than southern populations. These results suggest that the two forms
are on different evolutionary trajectories and should be treated separately for conservation purposes. It is highly desirable
that loss of southern populations be prevented to maintain the unique genetic diversity accumulated over a considerable evolutionary
timescale. 相似文献
76.
Sergio Scapin Silvia Leoni Silvana Spagnuolo Davide Gnocchi Paolo De Vito Paolo Luly Jens Z. Pedersen Sandra Incerpi 《Steroids》2010,75(8-9):576-584
Extranuclear or nongenomic effects of thyroid hormones are mediated by receptors located at the plasma membrane or inside cells, and are independent of protein synthesis. Recently the αVβ3 integrin was identified as a cell membrane receptor for thyroid hormones, and a wide variety of nongenomic effects have now been shown to be induced through binding of thyroid hormones to this receptor. However, also other thyroid hormone receptors can produce nongenomic effects, including the cytoplasmic TRα and TRβ receptors and probably also a G protein-coupled membrane receptor, and increasing importance is now given to thyroid hormone metabolites like 3,5-diiodothyronine and reverse T3 that can mimick some nongenomic effects of T3 and T4. Signal transduction from the αVβ3 integrin may proceed through at least three independent pathways (protein kinase C, Src or mitogen-activated kinases) but the details are still unknown. Thyroid hormones induce nongenomic effects on at least three important Na+-dependent transport systems, the Na+/K+-ATPase, the Na+/H+ exchanger, and amino acid transport System A, leading to a mitogenic response in embryo cells; but modulation of the same transport systems may have different roles in other cells and at different developmental stages. It seems that thyroid hormones in many cases can modulate nongenomically the same targets affected by the nuclear receptors through long-term mechanisms. Recent results on nongenomic effects confirm the old theory that the primary role of thyroid hormones is to keep the steady-state level of functioning of the cell, but more and more mechanisms are discovered by which this goal can be achieved. 相似文献
77.
Deyze Alencar Soares Rosângela Vieira de Andrade Simoneide Sousa Silva Anamélia Lorenzetti Bocca Sueli Maria Soares Felipe Silvana Petrofeza 《BMC microbiology》2010,10(1):241
Background
Phospholipase B (PLB) has been reported to be one of the virulence factors for human pathogenic fungi and has also been described as necessary for the early events in infection. Based on these data, we investigated the role of PLB in virulence and modulation of the alveolar pulmonary immune response during infection using an in-vitro model of host-pathogen interaction, i.e. Paracoccidioides brasiliensis yeast cells infecting alveolar macrophage (MH-S) cells. 相似文献78.
Palma Simoniello Silvana FilosaMarilisa Riggio Rosaria ScudieroStefania Tammaro Francesca TrinchellaChiara M. Motta 《Comparative biochemistry and physiology. Toxicology & pharmacology : CBP》2010,151(2):194-203
This study examined the cytological and molecular effects of cadmium, a toxic heavy metal, in the liver of the Italian wall lizard Podarcis sicula. Cadmium was administered in single dose, by diet, to induce a concentration comparable with that measured in animals living in contaminated sites. For comparison, cadmium was also administered in multiple doses by food (chronic) or in a single dose intraperitoneally (i.p.); the effects were followed at regular time intervals up to 30 days post treatments. Atomic absorption spectrometry analysis demonstrated cadmium ion uptake and accumulation in the parenchyma with an estimated half-life of approximately 8 days. Cytological analyses revealed that the metal induced oedema, activated metallothionein expression in Kupffer cells and extracellular matrix production in fat storing cells. It also caused swelling and alteration in lipid and sugar metabolism in hepatocytes. In conclusion, in the wall lizard cadmium is toxic to the liver even at very low concentrations, the response is not strictly dose and time dependent and almost no recovery occurs in short (30 days) time periods. 相似文献
79.
Search for effective natural enemies of <Emphasis Type="Italic">Tetranychus evansi</Emphasis> (Acari: Tetranychidae) in northwest Argentina 总被引:1,自引:1,他引:0
Furtado IP Toledo S de Moraes GJ Kreiter S Knapp M 《Experimental & applied acarology》2007,43(2):121-127
The mite Tetranychus evansi Baker & Pritchard (Tetranychidae) probably originated in South America. Because of its importance as a tomato pest in Africa, an extensive project has been conducted to detect potentially effective natural enemies in South America for the classical biological control of the pest in Africa. A search for the natural enemies of T. evansi was conducted in the Province of Tucumán, northwestern Argentina, in December 2004, and this report describes the results. One hundred predatory mites of the family Phytoseiidae referring to 11 species were collected on 11 examined species of solanaceous plants. The most abundant phytoseiid species collected were Neoseiulus californicus (McGregor) and Euseius concordis (Chant). Adults and immatures of those species, as well as of Neoseiulus idaeus Denmark & Muma, Phytoseiulus fragariae Denmark & Schicha and Proprioseiopsis cannaensis (Muma) were found in association with T. evansi, suggesting that they were developing on the pest. However, because of the possible biological differences between populations of a given species, biological studies evaluating T. evansi as a prey for those predators seem desirable. 相似文献
80.