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71.
Ferrari G Pastorelli R Buchi F Spinelli E Gozzini A Bosi A Santini V 《Journal of proteome research》2007,6(1):367-375
Imatinib is the first molecular targeted therapy that has shown clinical success, but imatinib acquired resistance, although a rare event, is critical during the therapy of chronic myelogenous leukaemia (CML). With the aim of better understanding the molecular mechanisms accompanying acquisition of resistance to this drug, a comparative proteomic approach was undertaken on CML cell lines LAMA 84 S (imatinib sensitive) and LAMA 84 R (imatinib resistant). Forty-four differentially expressed proteins were identified and categorized into five main functional classes: (I) heat shock proteins and chaperones; (II) nucleic acid interacting proteins (binding/synthesis/stability); (III) structural proteins, (IV) cell signaling, and (V) metabolic enzymes. Several heat shock proteins known to complex Bcr-Abl were overexpressed in imatinib resistant cells, showing a possible involvement of these proteins in the mechanism of resistance. HnRNPs also resulted in being up-regulated in imatinib resistant cells. These proteins have been shown to be strongly and directly related to Bcr-Abl activity. To our knowledge, this is the first direct proteomic comparison of imatinib sensitive/resistant CML cell lines. 相似文献
72.
Population size and distribution of Otaria flavescens in central and southern Chubut, Patagonia were determined by aerial censuses conducted during the breeding season in 1989 and 1995 and outside the season. Pup numbers were corrected by means of a linear regression between pup and adult male (AM) numbers obtained from terrestrial censuses carried out in 1994 and 1996. During the 1989 breeding season, 10,557 sea lions occurred at 29 locations; 2,800 (26.3%) were pups. During the 1995 breeding season, 14,887 animals were censused at 32 sites; 3,311 (22.2%) were pups. The corrected pup number increased to 4,852, indicating that around 32% is lost when counting from photographs. The corrected total number increased to 16,483; this fell to less than one half between breeding seasons (November 1990 and 1995). The 1995 breeding season census represents the highest number since 1972 (8,800) and the widest historical dispersion (37 sites year round contrasting with 13 in the late 1940s and 1972). However, the present number is about one half of the 33,000 censused about 50 yr ago. Using a correction factor developed for the north Paragonian population (1.8 × censused number) the present population size in the area can be estimated at around 29,669 individuals. 相似文献
73.
Notomista E Pennacchio F Cafaro V Smaldone G Izzo V Troncone L Varcamonti M Di Donato A 《Microbial ecology》2011,61(3):582-594
Novosphingobium sp. PP1Y, isolated from a surface seawater sample collected from a closed bay in the harbour of Pozzuoli (Naples, Italy),
uses fuels as its sole carbon and energy source. Like some other Sphingomonads, this strain can grow as either planktonic
free cells or sessile-aggregated flocks. In addition, this strain was found to grow as biofilm on several types of solid and
liquid hydrophobic surfaces including polystyrene, polypropylene and diesel oil. Strain PP1Y is not able to grow on pure alkanes
or alkane mixtures but is able to grow on a surprisingly wide range of aromatic compounds including mono, bi, tri and tetracyclic
aromatic hydrocarbons and heterocyclic compounds. During growth on diesel oil, the organic layer is emulsified resulting in
the formation of small biofilm-coated drops, whereas during growth on aromatic hydrocarbons dissolved in paraffin the oil
layer is emulsified but the drops are coated only if the mixtures contain selected aromatic compounds, like pyrene, propylbenzene,
tetrahydronaphthalene and heterocyclic compounds. These peculiar characteristics suggest strain PP1Y has adapted to efficiently
grow at the water/fuel interface using the aromatic fraction of fuels as the sole carbon and energy source. 相似文献
74.
The most important bile acids, in the form of glycine and taurine conjugates, have been ordered in terms of relative acidity scale. The measurements have been carried out using mass spectrometric techniques. The group of taurine conjugates confirm the superior acidity over the glycine derivatives. Rationale of the differences found in gas-phase and comparison with the data reported in solution-phase are discussed with the support of theoretical calculations. The study has been completed with the acidity sequence of mixed oxo-hydroxy bile acids. 相似文献
75.
76.
P. Guicherd J. P. Peltier E. Gout R. Bligny G. Marigo 《Trees - Structure and Function》1997,11(3):155-161
In leaves of Fraxinus excelsior L., malate and mannitol were characterized by 13C NMR spectroscopy and enzymatic specific assays as the major constituents of a soluble carbon fraction involved in an osmotic
adjustment. During a summer drought where predawn leaf water potential of adult trees growing in a mesoxerophilic stand fell
to – 4 MPa in August, malate and mannitol leaf contents increased by a factor of 1.8 and 2.2 respectively, compared to control
trees growing on a flood plain. This drought stress led to concentrations as high as 280 mM and 600 mM for mannitol and malate,
respectively. The effects of gradually developing water deficit were also studied in a semi-controlled environment in 3-year-old
seedlings. When predawn leaf water potential reached -6 MPa, leaves displayed a low turgor pressure but stomatal conductance
was still measurable. Malate and mannitol were also the main osmoticum involved. After rewatering, gas exchange capacities
were largely restored. Altogether, these results show that the strong water-stress tolerance of Fraxinus excelsior is in part related to an accumulation of malate and mannitol.
Received: 3 January 1996 / Accepted: 19 March 1996 相似文献
77.
Marzola E Camarda V Batuwangala M Lambert DG Calo' G Guerrini R Trapella C Regoli D Tomatis R Salvadori S 《Peptides》2008,29(5):674-679
In the present study we describe the synthesis and biological evaluation of 24 analogues of the urotensin II (U-II) fragment U-II(4-11) substituted in position 4 with coded and non-coded aromatic amino acids. All of the new analogues behaved as full U-II receptor (UT) agonists. Our results indicated that aromaticity is well tolerated, size, length and chirality of the side chain are not important, while substituents with a nitrogen atom are preferred. Thus acylation of U-II(5-11) with small groups bearing nitrogen atoms could be instrumental in future studies for the identification of novel potent UT receptor ligands. 相似文献
78.
79.
80.
Samuele Raccosta Mauro Manno Donatella Bulone Daniela Giacomazza Valeria Militello Vincenzo Martorana Pier Luigi San Biagio 《European biophysics journal : EBJ》2010,39(6):1007-1017
The formation of protein aggregates is important in many fields of life science and technology. The morphological and mechanical
properties of protein solutions depend upon the molecular conformation and thermodynamic and environmental conditions. Non-native
or unfolded proteins may be kinetically trapped into irreversible aggregates and undergo precipitation or gelation. Here,
we study the thermal aggregation of lysozyme in neutral solutions. We characterise the irreversible unfolding of lysozyme
by differential scanning calorimetry. The structural properties of aggregates and their mechanisms of formation with the eventual
gelation are studied at high temperature by spectroscopic, rheological and scattering techniques. The experiments show that
irreversible micron-sized aggregates are organised into larger clusters according to a classical mechanism of diffusion and
coagulation, which leads to a percolative transition at high concentrations. At a smaller length scale, optical and atomic
force microscopy images reveal the existence of compact aggregates, which are the origin of the aggregation irreversibility. 相似文献