5,739 research outputs found
Clinical and magnetic resonance imaging characteristics of thoracolumbar intervertenral disk extrusions and protrusions in large breed dogs
Clinical and magnetic resonance imaging characteristics of thoracolumbar intervertenral disk extrusions and protrusions in large breed dogs
It has recently been shown that the fat-derived hormone adiponectin has the ability to decrease hyperglycemia and to reverse insulin resistance. However, bacterially produced full-length adiponectin is functionally inactive. Here, we show that endogenous adiponectin secreted by adipocytes is post-translationally modified into eight different isoforms, as shown by two-dimensional gel electrophoresis. Carbohydrate detection revealed that six of the adiponectin isoforms are glycosylated. The glycosylation sites were mapped to several lysines (residues 68, 71, 80, and 104) located in the collagenous domain of adiponectin, each having the surrounding motif of GXKGE(D). These four lysines were found to be hydroxylated and subsequently glycosylated. The glycosides attached to each of these four hydroxylated lysines are possibly glucosylgalactosyl groups. Functional analysis revealed that full-length adiponectin produced by mammalian cells is much more potent than bacterially generated adiponectin in enhancing the ability of subphysiological concentrations of insulin to inhibit gluconeogenesis in primary rat hepatocytes, whereas this insulin-sensitizing ability was significantly attenuated when the four glycosylated lysines were substituted with arginines. These results indicate that full-length adiponectin produced by mammalian cells is functionally active as an insulin sensitizer and that hydroxylation and glycosylation of the four lysines in the collagenous domain might contribute to this activity.link_to_subscribed_fulltex
Impact of facial conformation on canine health: Brachycephalic Obstructive Airway Syndrome
The domestic dog may be the most morphologically diverse terrestrial mammalian species known to man; pedigree dogs are artificially selected for extreme aesthetics dictated by formal Breed Standards, and breed-related disorders linked to conformation are ubiquitous and diverse. Brachycephaly–foreshortening of the facial skeleton–is a discrete mutation that has been selected for in many popular dog breeds e.g. the Bulldog, Pug, and French Bulldog. A chronic, debilitating respiratory syndrome, whereby soft tissue blocks the airways, predominantly affects dogs with this conformation, and thus is labelled Brachycephalic Obstructive Airway Syndrome (BOAS). Despite the name of the syndrome, scientific evidence quantitatively linking brachycephaly with BOAS is lacking, but it could aid efforts to select for healthier conformations. Here we show, in (1) an exploratory study of 700 dogs of diverse breeds and conformations, and (2) a confirmatory study of 154 brachycephalic dogs, that BOAS risk increases sharply in a non-linear manner as relative muzzle length shortens. BOAS only occurred in dogs whose muzzles comprised less than half their cranial lengths. Thicker neck girths also increased BOAS risk in both populations: a risk factor for human sleep apnoea and not previously realised in dogs; and obesity was found to further increase BOAS risk. This study provides evidence that breeding for brachycephaly leads to an increased risk of BOAS in dogs, with risk increasing as the morphology becomes more exaggerated. As such, dog breeders and buyers should be aware of this risk when selecting dogs, and breeding organisations should actively discourage exaggeration of this high-risk conformation in breed standards and the show ring
A molecular biology and phase II trial of lapatinib in children with refractory CNS malignancies: a pediatric brain tumor consortium study.
High expression of ERBB2 has been reported in medulloblastoma and ependymoma; EGFR is amplified and over-expressed in brainstem glioma suggesting these proteins as potential therapeutic targets. We conducted a molecular biology (MB) and phase II study to estimate inhibition of tumor ERBB signaling and sustained responses by lapatinib in children with recurrent CNS malignancies. In the MB study, patients with recurrent medulloblastoma, ependymoma, and high-grade glioma (HGG) undergoing resection were stratified and randomized to pre-resection treatment with lapatinib 900 mg/m(2) dose bid for 7-14 days or no treatment. Western blot analysis of ERBB expression and pathway activity in fresh tumor obtained at surgery estimated ERBB receptor signaling inhibition in vivo. Drug concentration was simultaneously assessed in tumor and plasma. In the phase II study, patients, stratified by histology, received lapatinib continuously, to assess sustained response. Eight patients, on the MB trial (four medulloblastomas, four ependymomas), received a median of two courses (range 1-6+). No intratumoral target inhibition by lapatinib was noted in any patient. Tumor-to-plasma ratios of lapatinib were 10-20 %. In the 34 patients (14 MB, 10 HGG, 10 ependymoma) in the phase II study, lapatinib was well-tolerated at 900 mg/m(2) dose bid. The median number of courses in the phase II trial was two (range 1-12). Seven patients (three medulloblastoma, four ependymoma) remained on therapy for at least four courses range (4-26). Lapatinib was well-tolerated in children with recurrent or CNS malignancies, but did not inhibit target in tumor and had little single agent activity.Fil: Fouladi, Maryam. St. Jude Children’s Research Hospital; Estados UnidosFil: Stewart, Clinton F.. St. Jude Children’s Research Hospital; Estados UnidosFil: Blaney, Susan M.. Baylor College of Medicine. Texas Children’s Cancer Center; Estados UnidosFil: Onar Thomas, Arzu. St. Jude Children’s Research Hospital; Estados UnidosFil: Schaiquevich, Paula Susana. St. Jude Children’s Research Hospital; Estados Unidos. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Packer, Roger J.. Children’s National Medical Center; Estados UnidosFil: Goldman, Stewart. Anne and Robert H. Lurie Children’s Hospital of Chicago; Estados UnidosFil: Geyer, J. Rusell. Children’s Hospital and Regional Medical Center; Estados UnidosFil: Gajjar, Amar. St. Jude Children’s Research Hospital; Estados UnidosFil: Kun, Larry E.. St. Jude Children’s Research Hospital; Estados UnidosFil: Boyett, James M.. St. Jude Children’s Research Hospital; Estados UnidosFil: Gilbertson, Richard J.. St. Jude Children’s Research Hospital; Estados Unido
On twisted Fourier analysis and convergence of Fourier series on discrete groups
We study norm convergence and summability of Fourier series in the setting of
reduced twisted group -algebras of discrete groups. For amenable groups,
F{\o}lner nets give the key to Fej\'er summation. We show that Abel-Poisson
summation holds for a large class of groups, including e.g. all Coxeter groups
and all Gromov hyperbolic groups. As a tool in our presentation, we introduce
notions of polynomial and subexponential H-growth for countable groups w.r.t.
proper scale functions, usually chosen as length functions. These coincide with
the classical notions of growth in the case of amenable groups.Comment: 35 pages; abridged, revised and update
Construction of Parseval wavelets from redundant filter systems
We consider wavelets in L^2(R^d) which have generalized multiresolutions.
This means that the initial resolution subspace V_0 in L^2(R^d) is not singly
generated. As a result, the representation of the integer lattice Z^d
restricted to V_0 has a nontrivial multiplicity function. We show how the
corresponding analysis and synthesis for these wavelets can be understood in
terms of unitary-matrix-valued functions on a torus acting on a certain vector
bundle. Specifically, we show how the wavelet functions on R^d can be
constructed directly from the generalized wavelet filters.Comment: 34 pages, AMS-LaTeX ("amsproc" document class) v2 changes minor typos
in Sections 1 and 4, v3 adds a number of references on GMRA theory and
wavelet multiplicity analysis; v4 adds material on pages 2, 3, 5 and 10, and
two more reference
Germinação in vitro de grãos de pólen de Vriesea spp. (Bromeliaceae).
Estudos de viabilidade polínica são fundamentais como suporte ao melhoramento genético de bromeliáceas e para tal o ajuste de meios de germinação de pólen é determinante. Este trabalho objetivou avaliar a germinação de grãos de pólen in vitro e o subsequente crescimento do tubo polínico em Vriesea carinata, V. friburgensis, V. michaelii, V. paraibica e V. simplex. Grãos de pólen coletados na antese foram inoculados em quatro meios de cultura: BM, BKM, MBKM e SM, solidificados com agar (0,8%); pH ajustado a 6,5 e mantidos a uma temperatura de 27 ± 1 ºC. O delineamento experimental foi inteiramente casualizado em esquema fatorial 5 x 4 (genótipo x meios de cultura), com 12 repetições, avaliando-se 300 grãos de pólen quanto à viabilidade e o comprimento de 25 tubos polínicos, aleatoriamente, por tratamento. Após 8 horas em cultura, verificou-se que os meios BKM e SM resultaram em maior germinação e comprimento do tubo polínico. Para as espécies V. carinata (80,33 %), V. paraibica (88,73 %), V. simplex (90,46 %) e V. michaelii (90,03 %) o melhor meio de cultura foi SM e para V. friburgensis, BKM (90,43 %) foi o melhor
- …
