To assess the effect of pancreas transplantation on free fatty acid (FFA) and glucose metabolism, we studied seven uremic IDDM patients (HbA1c 9.1%), nine IDDM patients after combined kidney-pancreas ...transplantation (HbA1c 5.8%), seven patients with chronic uveitis (HbA1c 5.6%), and nine normal control subjects (HbA1c 5.5%) by means of the 3(- 3)Hglucose and 1(-14)Cpalmitate infusion techniques combined with indirect calorimetry and euglycemic insulin clamp. In the postabsorptive state, pancreas-transplant patients had similar plasma glucose and FFA concentrations and non-statistically different rates of hepatic glucose production (HGP) and FFA turnover, while demonstrating a reduced rate of FFA oxidation (42 +/- 5 vs. 73 +/- 10 micromol x m-2 x min-1; P < 0.05) compared with control subjects. After 180 min of tracer equilibration, all subjects underwent a low-dose (100 min, 8 mU x m-2 x min-1) followed by a high-dose (100 min, 40 mU x m-2 x min-1) euglycemic insulin infusion. During insulin infusion, pancreas-transplant patients showed a greater inhibition of FFA concentration (609 +/- 76 to 58 +/- 15 micromol/l) compared with healthy subjects (681 +/- 90 to 187 +/- 25 micromol/l; P < 0.01 vs. pancreas-transplant patients). FFA turnover and oxidation rates during both low-dose and high-dose insulin infusions were lower in pancreas-transplant patients compared with healthy subjects (P < 0.03 and P < 0.01, for turnover and oxidation, respectively). Uremic IDDM patients demonstration altered basal and insulin-mediated glucose metabolism. Pancreas transplantation normalized only insulin-mediated glucose oxidation, leaving the stimulation of non-oxidative glucose disposal still markedly defective. In conclusion, patients after pancreas transplantation have normal basal FFA turnover and reduced basal FFA oxidation rates. During hyperinsulinemia, pancreas-transplant patients show a normal inhibition of FFA turnover and FFA oxidation. Insulin-mediated glucose metabolism remained abnormal after pancreas transplantation. Our findings may be related to the effect of chronic immunosuppressive therapy on glucose and FFA metabolism.
There is increasing evidence that a fine-tuned integrin cross talk can generate a high degree of specificity in cell adhesion, suggesting that spatially and temporally coordinated expression and ...activation of integrins are more important for regulated cell adhesive functions than the intrinsic specificity of individual receptors. However, little is known concerning the molecular mechanisms of integrin cross talk. With the use of beta(1)-null GD25 cells ectopically expressing the beta(1)A integrin subunit, we provide evidence for the existence of a cross talk between beta(1) and alpha(V) integrins that affects the ratio of alpha(V)beta(3) and alpha(V)beta(5) integrin cell surface levels. In particular, we demonstrate that a down-regulation of alpha(V)beta(3) and an up-regulation of alpha(V)beta(5) occur as a consequence of beta(1)A expression. Moreover, with the use of GD25 cells expressing the integrin isoforms beta(1)B and beta(1)D, as well as two beta(1) cytoplasmic domain deletion mutants lacking either the entire cytoplasmic domain (beta(1)TR) or only its "variable" region (beta(1)COM), we show that the effects of beta(1) over alpha(V) integrins take place irrespective of the type of beta(1) isoform, but require the presence of the "common" region of the beta(1) cytoplasmic domain. In an attempt to establish the regulatory mechanism(s) whereby beta(1) integrins exert their trans-acting functions, we have found that the down-regulation of alpha(V)beta(3) is due to a decreased beta(3) subunit mRNA stability, whereas the up-regulation of alpha(V)beta(5) is mainly due to translational or posttranslational events. These findings provide the first evidence for an integrin cross talk based on the regulation of mRNA stability.
In the recent past, MnTe has proven to be a crucial component of the intrinsic magnetic topological insulator (IMTI) family MnTemBi2Te3n, which hosts a wide range of magneto-topological properties ...depending on the choice of m and n. However, bulk crystal growth allows only a few combinations of m and n for these IMTIs due to the strict limitations of the thermodynamic growth conditions. One way to overcome this challenge is to utilize atomic layer-by-layer molecular beam epitaxy (MBE) technique, which allows arbitrary sequences of MnTem and Bi2Te3n to be formed beyond the thermodynamic limit. For such MBE growth, finding optimal growth templates and conditions for the parent building block, MnTe, is a key requirement. Here, we report that two different hexagonal phases of MnTe-nickeline (NC) and zinc-blende/wurtzite (ZB-WZ) structures, with distinct in-plane lattice constants of 4.20 +/- 0.04 A and 4.39 +/- 0.04 A, respectively-can be selectively grown on c-plane Al2O3 substrates using different buffer layers and growth temperatures. Moreover, we provide the first comparative studies of different MnTe phases using atomic-resolution scanning transmission electron microscopy and show that ZB and WZ-like stacking sequences can easily alternate between the two. Surprisingly, In2Se3 buffer layer, despite its lattice constant (4.02 A) being closer to that of the NC phase, fosters the ZB-WZ instead, whereas Bi2Te3, sharing the same lattice constant (4.39 A) with the ZB-WZ phase, fosters the NC phase. These discoveries suggest that lattice matching is not always the most critical factor determining the preferred phase during epitaxial growth. Overall, this will deepen our understanding of epitaxial growth modes for chalcogenide materials and accelerate progress toward new IMTI phases as well as other magneto-topological applications.
This study evaluated aspects of population ecology and community component of mites in Pseudolynchia canariensis (Macquart) of domestic pigeons Columba livia in Juiz de Fora, Minas Gerais, Brazil. A ...total of 236 forest mites were found in 74 out of 156 fl ies (47.4% infestation). The prevalence for Myialges anchora Sergent & Trouessart was 23.7%, with average intensity 1.5 ± 0.90 and average abundance 0.4 ± 0.76, mostly (94.4%) located on the abdomen; 75.9% of the mites (n = 41) surrounded by eggs, with a mean of 16.4 ± 14.60 eggs per individual and 21.6 ± 12.90 eggs per ovigerous female. The prevalence for M.lophortyx (Furmann & Tharshis) was 13.5% (n = 21) with 62 individuals, mean intensity 3.0 ± 2.75 average abundance 0.4 ± 1.41; 41.9% (n = 26) located at the right wing and 58.1% (n = 36) were in the left wing; 72.6% (n = 45) showed ovigerous mass, with 4.56 ± 3.42 per each individual and 6.3 ± 3.04 per ovigerous female. The prevalence of Ornithocheyletia hallae Volgin was 23.7% (n = 37) with 120 individuals, with mean intensity of 3.2 ± 4.47, and mean abundance of 0.8 ± 2.56. In 28.4% (n = 21) of flies occurred simultaneous mite infestations, mainly for M.anchora and O.hallae, present in 66.7% (n = 14) of flies with mixed effect. The component communities showed an aggregate distribution. The mite species O.hallae was more agregate, while M.anchora and M.lophortyx showed the same K value.
Signal transduction targets in invasion Alessandro, Riccardo; Kohn, Elise C
Clinical & experimental metastasis,
01/2002, Letnik:
19, Številka:
3
Journal Article
Recenzirano
The processes of physiologic and malignant invasion use the same cellular pathways, albeit under differential regulation. Critical signaling messages can be initiated through cell-cell and ...cell-substratum contact, as well as using autocrine and paracrine activation. Cancer cells are known for their flexibility and autocrine functions, however, they still rely on a battery of important signaling events. The interaction between the tumor cell and the stroma provides an important signaling milieu and target zone for molecular therapeutic intervention. It is now recognized that malignant invasion requires that interaction for optimal signaling and function. New technologies are now available to allow more rapid dissection of these pathways and characterization of unique regulatory sites for therapeutic gain.
The Arcminute Microkelvin Imager Zwart, J. T. L.; Barker, R. W.; Biddulph, P. ...
Monthly Notices of the Royal Astronomical Society,
12/2008, Letnik:
391, Številka:
4
Journal Article
Recenzirano
Odprti dostop
The Arcminute Microkelvin Imager is a pair of interferometer arrays operating with six frequency channels spanning 13.9–18.2 GHz, for observations on angular scales of 30 arcsec–10 arcmin and for ...declinations greater than −15°; the Small Array has a sensitivity of 30 mJy s−1/2 and the Large Array has a sensitivity of 3 mJy s−1/2. The telescope is aimed principally at Sunyaev–Zel'dovich imaging of clusters of galaxies. We discuss the design of the telescope and describe and explain its electronic and mechanical systems.
Animal burrows in a river's earthen levee leads to water piping phenomena causing structural damage and eventual collapse during floods. Currently, the state of the art comprises case studies that ...deal with management and maintenance, while very few documents attempt at assessing possible animal-induced failure mechanisms. For the latter, detection and characterisation of the animal burrows is crucial and Electrical Resistivity Tomography (ERT) and Ground Penetrating Radar are the most employed geophysical techniques. Between 2017 and 2018 a team of physicists, engineering geologists, and geophysicists has for the first time probed the possibility of exploiting the Muon Transmission Radiography (MTR) to verify the internal conservation status of levees that were visibly damaged by animal activities. The technique is a non-invasive method, currently under development, based on the detection of muons, a highly penetrating component of atmospheric cosmic rays. MTR is capable of providing angular maps of the average density of the material present in front of the detector. A test site measurement campaign was carried out with a prototype instrument placed at the side of the levee. This new survey methodology was compared to a more traditional ERT measurement, performed with a pole-dipole and dipole-dipole configuration. Moreover, the actual burrows' distribution was mapped during the demolition works using Terrestrial Laser Scanner measurements to validate and constrain results. The comparison between ERT and MTR maps shows that, in spite of some limitations, the latter is a suitable and promising technique that could successfully complement a program of geological risk assessment.
•Exploiting Muon Transmission Radiography to verify the levees conservation status•Validation of Muon Transmission Radiography by means of geoelectrical measurements•Animal burrows reconstruction by means of Muon Radiography, ERT, and TLS
LHCf is planning to measure very forward particle emission in the LHC p-Pb collisions foreseen at the end of 2012. The measurement is expected to constrain the nuclear effect in the forward particle ...emission relevant to the CR-Air interaction. Model discrimination power of this measurement is presented together with some detail in technical feasibility.
The Large Hadron Collider forward (= LHCf) experiment has successfully finished the first phase of data taking at LHC radicals = 0.9 and 7 TeV proton-proton collisions in 2010. As current status, we ...concentrate on analyzing the obtained data. As the first result, the energy spectra of photon measured by LHCf during = 7 TeV p-p collision has been published recently. Also the study of the upgraded version of LHCf detector for future = 14TeV run scenario is developed with the GSO scintillator. Another possible plan of p-A(nuclear) collision in LHC is also studied. In this paper, as the current status of the experiment, analyses, and works for foreseen detector upgrade are summarized.
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