4,158 research outputs found

    New steroidal aromatase inhibitors: Suppression of estrogen-dependent breast cancer cell proliferation and induction of cell death

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Aromatase, the cytochrome P-450 enzyme (CYP19) responsible for estrogen biosynthesis, is an important target for the treatment of estrogen-dependent breast cancer. In fact, the use of synthetic aromatase inhibitors (AI), which induce suppression of estrogen synthesis, has shown to be an effective alternative to the classical tamoxifen for the treatment of postmenopausal patients with ER-positive breast cancer. New AIs obtained, in our laboratory, by modification of the A and D-rings of the natural substrate of aromatase, compounds <b>3a </b>and <b>4a</b>, showed previously to efficiently suppress aromatase activity in placental microsomes. In the present study we have investigated the effects of these compounds on cell proliferation, cell cycle progression and induction of cell death using the estrogen-dependent human breast cancer cell line stably transfected with the aromatase gene, MCF-7 aro cells.</p> <p>Results</p> <p>The new steroids inhibit hormone-dependent proliferation of MCF-7aro cells in a time and dose-dependent manner, causing cell cycle arrest in G<sub>0</sub>/G<sub>1 </sub>phase and inducing cell death with features of apoptosis and autophagic cell death.</p> <p>Conclusion</p> <p>Our <it>in vitro </it>studies showed that the two steroidal AIs, <b>3a </b>and <b>4a</b>, are potent inhibitors of breast cancer cell proliferation. Moreover, it was also shown that the antiproliferative effects of these two steroids on MCF-7aro cells are mediated by disrupting cell cycle progression, through cell cycle arrest in G<sub>0</sub>/G<sub>1 </sub>phase and induction of cell death, being the dominant mechanism autophagic cell death. Our results are important for the elucidation of the cellular effects of steroidal AIs on breast cancer.</p

    Improved growth and morphological plasticity of <i>Haloferax volcanii</i>.

    Full text link
    Some microbes display pleomorphism, showing variable cell shapes in a single culture, whereas others differentiate to adapt to changed environmental conditions. The pleomorphic archaeon Haloferax volcanii commonly forms discoid-shaped ('plate') cells in culture, but may also be present as rods, and can develop into motile rods in soft agar, or longer filaments in certain biofilms. Here we report improvement of H. volcanii growth in both semi-defined and complex media by supplementing with eight trace element micronutrients. With these supplemented media, transient development of plate cells into uniformly shaped rods was clearly observed during the early log phase of growth; cells then reverted to plates for the late log and stationary phases. In media prepared with high-purity water and reagents, without supplemental trace elements, rods and other complex elongated morphologies ('pleomorphic rods') were observed at all growth stages of the culture; the highly elongated cells sometimes displayed a substantial tubule at one or less frequently both poles, as well as unusual tapered and highly curved forms. Polar tubules were observed forming by initial mid-cell narrowing or tubulation, causing a dumbbell-like shape, followed by cell division towards one end. Formation of the uniform early log-phase rods, as well as the pleomorphic rods and tubules were dependent on the function of the tubulin-like cytoskeletal protein, CetZ1. Our results reveal the remarkable morphological plasticity of H. volcanii cells in response to multiple culture conditions, and should facilitate the use of this species in further studies of archaeal biology

    p518, a small floR plasmid from a South American isolate of Actinobacillus pleuropneumoniae

    Get PDF
    A small (3.9 kb) plasmid (p518), conferring resistance to florfenicol (MIC >8 μg/mL) and chloramphenicol (MIC >8 μg/mL) was isolated from an Actinobacillus pleuropneumoniae clinical isolate from Southeastern Brazil. To date, this is the smallest florfenicol resistance plasmid isolated from a member of the Pasteurellaceae. The complete nucleotide of this plasmid revealed a unique gene arrangement compared to previously reported florfenicol resistance plasmids found in other members of the Pasteurellaceae. In addition to the floR gene and a lysR gene, common to various florfenicol resistance plasmids, p518 also encodes strA and a partial strB sequence. An origin of replication (oriV) similar to that in the broad host range plasmid, pLS88, was identified in p518, and transformation into Escherichia coli MFDpir confirmed the ability to replicate in other species. Mobilisation genes appear to have been lost, with only a partial mobC sequence remaining, and attempts to transfer p518 from a conjugal donor strain (E. coli MFDpir) were not successful, suggesting this plasmid is not mobilisable. Similarly, attempts to transfer p518 into a competent A. pleuropneumoniae strain, MIDG2331, by natural transformation were also not successful. These results suggest that p518 may be only transferred by vertical descent

    Mapping of Alternative Oilseeds from the Brazilian Caatinga and Assessment of Catalytic Pathways toward Biofuels Production

    Get PDF
    Biofuels are increasingly important renewable resources in the world's energy matrix that have challenged the scientific community as well as small and large farmers to develop alternatives to fossil fuels in order to achieve the aims of energy transition. In particular, Brazil's proven competitiveness in agribusiness together with its rich biodiversity put the country in a key position in the biofuels market. The semiarid Caatinga of northeastern Brazil, an exclusive biome rich in many oilseed species suitable for potential energy purposes, is of particular interest in this field. Nowadays, soybeans are the main feedstock used for the production of biodiesel, but, due to the increasing demand for biofuels, the search for alternative sources of oil from tropical flora with high productivity is crucial. Under this premise, this systematic review focuses on mapping Caatinga's vegetable oil crops that could be used as alternative raw materials for biofuels' production in Brazil, in addition to traditional soybeans and sugarcane. To gain more detailed insight into these matrices, their main properties, including oil content, fatty acid profile and physicochemical properties, are discussed. Moreover, an overview is provided of processes to synthesize different types of biofuels, particularly biodiesel and aviation biokerosene, including the routes employing homogeneous, enzymatic and mainly heterogeneous catalysts. Finally, future prospects and challenges for renewable biofuels and the Caatinga biome are addressed

    Percutaneous Occlusion of Vascular Malformations in Pediatric and Adult Patients: 20-Year Experience of a Single Center

    Get PDF
    OBJECTIVE: A case series on different vascular malformations (VM) treated with percutaneous occlusion in children and adults is presented. BACKGROUND: Percutaneous occlusion is usually the preferred treatment method for VM. Previous series have mostly focused on single types of devices and/or VM. METHODS: Retrospective analysis of all patients who underwent percutaneous occlusion of VM in a single center, from 1995 to 2014, excluding patent ductus arteriosus. Clinical and angiographic data, procedural details, implanted devices, and complications were assessed. Procedural success was defined as effective device deployment with none or minimal residual flow. Predictors of procedural failure and complications were determined by multivariate analysis. RESULTS: A total of 123 VM were intervened in 47 patients with median age of 12 years (25 days-76 years). The VM included 55 pulmonary arteriovenous fistulae, 39 aortopulmonary collaterals, 10 systemic venovenous collaterals, 8 peripheral arteriovenous fistulae, 5 Blalock-Taussig shunts, 4 coronary fistulae, and 2 Fontan fenestrations. The 143 devices used included 80 vascular plugs, 38 coils, 22 duct occluders, and 3 foramen ovale or atrial septal defect occluders. Median vessel size was 4.5 (2.0-16.0) mm and device/vessel size ratio was 1.4 (1.1-2.0). Successful occlusion was achieved in 118 (95.9%) VM, including three reinterventions. Four (3.3%) clinically relevant complications occurred, without permanent sequelae. Lower body weight was independently associated with procedural failure and complications. CONCLUSION: To our knowledge, this is the largest series on different VM occluded percutaneously in children and adults, excluding patent ductus arteriosus. Percutaneous occlusion was effective and safe, using different devices.info:eu-repo/semantics/publishedVersio

    Content of Lipids, Fatty Acids, Carbohydrates, and Proteins in Continental Cyanobacteria: A Systematic Analysis and Database Application

    Get PDF
    The lipid, fatty acid, protein, and carbohydrate contents in cyanobacterial strains and biomass can vary by orders of magnitude. Many publications (thousands of peer-reviewed articles) require more work to extract their precise concentration values (i.e., different units, inaccurate data), which makes them not easily exploitable. For this purpose, tables have been compiled from the literature data, including lipids, fatty acids, proteins, and carbohydrates composition and quantities in cyanobacteria. A lot of data (323) were collected after careful a literature search, according to selected criteria in order to distinguish separately cyanobacteria, and according to categories of genus and species and generate average values of the contents of these cell components. These data are exploited in a first systematic analysis of the content in types of strains. Our database can be a powerful tool for biologists, chemists, and environmental agencies to determine the potential concentration of high-value chemical building blocks directly from low-value bloom biomass, cell cultures, or debris in the sediment, offering the potential to minimize environmental waste and add value to the agro-industrial residues. The database can also support strategies for food manufacturers to develop new products with optimized properties for veterinarian applications

    Potential of Waste as Raw Silk Worm Biodegradable Surfactant

    Get PDF
    Silkworm pupa is byproducts of silkworm farms are not fully utilized. This study aims to assess the potential silkworm waste as a raw material surfactant "biodegradable". Silk pupa oil has 43.70% triglyceride. The characterisation by the spectra FTIR showed the degradation results in wavelength 1050-1300 cm-1 and 1690-1760 cm-1 indicated the consecutive C‒O and C=O group of alcohol/ether/carboxylic acids/esters, and the wave number 2500-2700 cm-1 indicated the presence of O‒H groups of the carboxylic acid with hydrogen bonds. GC-MS analysis showed the components of palmitic acid β-monogliseride, α-monopalmitin, palmitic chloride acid, oleic acid, linoleic acid chloride. FTIR spectra degradation products Mono-diglyceride provide distinctive peaks that appear at wavelength 1041.56 cm-1 and 3659.61 cm-1 that showed group C-OH and OH, respectively. The performance test results of surfactant to the benzene-water system showed no effect of surfactant that is as an emulsifier. Silk pupa oil contains components that can be converted into a biodegradable surfactant. Keywords: silkworm pupa, surfactant, glycerolysis, monoglyceride
    • …
    corecore