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排序方式: 共有2598条查询结果,搜索用时 15 毫秒
81.
Carmen García-Ibarbia Jesús Delgado-Calle Iñigo Casafont Javier Velasco Jana Arozamena María I. Pérez-Núñez María A. Alonso María T. Berciano Fernando Ortiz José L. Pérez-Castrillón Agustín F. Fernández Mario F. Fraga María T. Zarrabeitia José A. Riancho 《Gene》2013
We reported previously that the expression of Wnt-related genes is lower in osteoporotic hip fractures than in osteoarthritis. We aimed to confirm those results by analyzing β-catenin levels and explored potential genetic and epigenetic mechanisms involved. 相似文献
82.
Kacy Richmond Patrick Masterson Juan Felipe Ortiz 《Journal of biomolecular structure & dynamics》2013,31(7):1074-1084
Despite high sequence identity among mammalian prion proteins (PrPs), mammals have varying rates of susceptibility to prion disease resulting in a so-called species barrier. The species barrier follows no clear pattern, with closely related species or similar sequences being no more likely to infect each other, and remains an unresolved enigma. Variation of the conformationally flexible regions may alter the thermodynamics of the conformational change, commonly referred to as the conformational conversion, which occurs in the pathogenic process of the mammalian prion protein. A conformational ensemble scenario is supported by the species barrier in prion disease and evidence that there are strains of pathogenic prion with different conformations within species. To study how conformational flexibility has evolved in the prion protein, an investigation was undertaken on the evolutionary dynamics of structurally disordered regions in the mammalian prion protein, non-mammalian prion protein that is not vulnerable to prion disease, and remote homologs Doppel and Shadoo. Structural disorder prediction analyzed in an evolutionary context revealed that the occurrence of increased or altered conformational flexibility in mammalian PrPs coincides with key events among PrP, Doppel, and Shadoo. Comparatively rapid evolutionary dynamics of conformational flexibility in the prion protein suggest that the species barrier is not a static phenomenon. A small number of amino acid substitutions can repopulate the conformational ensemble and have a disproportionately large effect on pathogenesis. 相似文献
83.
Juan José Ortiz Guzmán Arcos‐García José Luis Germán D. Mendoza Martínez Fernando Xicoténcatl Plata Pérez Gisela Fuentes Mascorro Gabriela Ruelas Inzunza 《Zoo biology》2013,32(3):277-280
The effects of the addition of lysine to commercial feed given to captive black iguana (Ctenosaura pectinata) were evaluated in terms of growth and feed digestibility. Twenty‐eight‐day‐old black iguana with an initial weight of 5.5 ± 0.3 g were housed individually in cages measuring 45 × 45 × 45 cm. The experiment lasted 150 days. The ambient temperature ranged from 28 to 35°C with a relative humidity of 60 to 95%. Treatments consisted of the addition of different percentages of lysine to the feed (0.0, 0.1, 0.2, and 0.3%, dry matter [DM] base). There was a linear response (P < 0.01) in daily gain (68, 112, 118, and 151 mg/d) and daily intake (251, 289, 297, and 337 mg/d) for levels from 0 to 0.3%, respectively, as well in the growth in head size, snout–vent length, and total length. The digestibility of DM, neutral detergent fiber, and acid detergent fiber were reduced linearly (P < 0.01) as lysine levels increased. Intake and digestibility were negatively correlated (r = –0.74; P < 0.001). It is concluded that the addition of lysine to the black iguana diet in the first months of life is important to stimulate growth and intake. Zoo Biol 32:277–280, 2013. © 2012 Wiley Periodicals, Inc. 相似文献
84.
85.
Nicholas Francella Sarah E. Gwyn Yanjie Yi Bing Li Peng Xiao Sarah T. C. Elliott Alexandra M. Ortiz James A. Hoxie Mirko Paiardini Guido Silvestri Cynthia A. Derdeyn Ronald G. Collman 《Journal of virology》2013,87(17):9719-9732
CD4+ T cells rather than macrophages are the principal cells infected by human immunodeficiency virus type 1 (HIV-1) and simian immunodeficiency virus (SIV) in vivo. Macrophage tropism has been linked to the ability to enter cells through CCR5 in conjunction with limiting CD4 levels, which are much lower on macrophages than on T cells. We recently reported that rhesus macaques (RM) experimentally depleted of CD4+ T cells before SIV infection exhibit extensive macrophage infection as well as high chronic viral loads and rapid progression to AIDS. Here we show that early-time-point and control Envs were strictly CD4 dependent but that, by day 42 postinfection, plasma virus of CD4+ T cell-depleted RM was dominated by Envs that mediate efficient infection using RM CCR5 independently of CD4. Early-time-point and control RM Envs were resistant to neutralization by SIV-positive (SIV+) plasma but became sensitive if preincubated with sCD4. In contrast, CD4-independent Envs were highly sensitive to SIV+ plasma neutralization. However, plasma from SIV-infected CD4+ T cell-depleted animals lacked this CD4-inducible neutralizing activity and failed to neutralize any Envs regardless of sCD4 pre-exposure status. Enhanced sensitivity of CD4-independent Envs from day 42 CD4+ T cell-depleted RM was also seen with monoclonal antibodies that target both known CD4-inducible and other Env epitopes. CD4 independence and neutralization sensitivity were both conferred by Env amino acid changes E84K and D470N that arose independently in multiple animals, with the latter introducing a potential N-linked glycosylation site within a predicted CD4-binding pocket of gp120. Thus, the absence of CD4 T cells results in failure to produce antibodies that neutralize CD4-independent Envs and CD4-pretriggered control Envs. In the absence of this constraint and with a relative paucity of CD4+ target cells, widespread macrophage infection occurs in vivo accompanied by emergence of variants carrying structural changes that enable entry independently of CD4. 相似文献
86.
87.
Rafael Bielza Galindo Alejandro Ortiz Espada Estefanía Arias Muñana Rocío Velasco Guzmán de Lázaro Asunción Mora Casado Ricardo Moreno Martín Blanca Tapia Salinas Javier Escalera Alonso Jorge Gómez Cerezo 《Revista espa?ola de geriatría y gerontología》2013
Background
Patients with hip fracture (HF), due to their characteristics, require a specific support. The Acute Orthogeriatric Unit (OGU) has been shown to be one of the most beneficial.Objective
To evaluate the main variables of HF patients treated at an OGU and compare them with the previous referral model (RC).Material and methods
A prospective observational study with retrospective control was conducted on 169 patients, split into two groups. In the RC group, patients were admitted to conventional trauma ward. In the OGU group, an early geriatric assessment was performed, and patients were simultaneously attended daily by the orthopaedic surgeon, nurse and geriatrician, and the surgery times, work load, discharge and destination, were planned in a weekly meeting with the rest of professionals.Results
A total of 71 patients were included in the RC group and 96 in the OGU group. The preoperative characteristics were similar, except for a slightly higher comorbidity in the OGU group. The OGU patients were operated on earlier (3.82±2.08 vs 4.61±2.5 days; P<.32), and overall hospital stay was reduced by 28% (11.84±4.04 vs 16.46±8.4 days; P<.001). The functional efficiency (Barthel Index at discharge-Barthel Index at admission/overall stay - stay before surgery) was higher in the OGU group (1.56±0.7 vs 2.61±1.1; P<.05). There were no differences in functional status, mortality or discharge location.Conclusions
The OGU is a level of care that provides effective medical care in HF patients in general hospitals. 相似文献88.
Rodrigo Ortiz José Navarrete Claudia Oviedo Mario Párraga Ivo Carrasco Eduardo de la Vega Manuel Ortiz Robert A. Blanchette 《Antonie van Leeuwenhoek》2013,104(6):1193-1203
Wood decomposition is an important component in forest ecosystems but information about the diversity of fungi causing decay is lacking. This is especially true for the temperate rain forests in Chile. These investigations show results of a biodiversity study of white-rot fungi in wood obtained from Chiloé National Park in Los Lagos region, Chile. Culturing from white-rotted wood followed by sequencing of the complete internal transcribed spacer region of the ribosomal DNA (rDNA) or partial large subunit region of the rDNA, identified 12 different species in the Basidiomycota. All of these fungi were characterized as white rot fungi and were identified with a BLAST match of 97 % or greater to sequences in the GenBank database. Fungi obtained were species of Phlebia, Mycoacia, Hyphodontia, Bjerkandera, Phanerochaete, Stereum, Trametes, and Ceriporiopsis. This report identifies for the first time in Chile the species Ceriporiopsis subvermispora, Hyphodontia radula, Phlebia radiata, Phanerochaete affinis, Peniophora cinerea, Stereum gausapatum, Phlebia setulosa and Phanerochaete sordida. Scanning electron microscopy was used to characterize the type of decay caused by the fungi that were isolated and a combination of selective lignin degraders and simultaneous white rot fungi were found. Fungi that cause a selective degradation of lignin are of interest for bioprocessing technologies that require modification or degradation of lignin without cellulose removal. 相似文献
89.
This paper aims to assess to what degree and in what way the brood chamber affects the pollen content of the honey. Twenty-nine pieces of comb containing only honey were cut from different frames of hives. The percentage of cells in each frame occupied by the brood chamber and the distance between these cells and the cut piece were recorded. A honey sample was extracted from each comb piece, avoiding any contamination with pollen, its sediment examined under the microscope and its botanical constituents identified and counted. The results show that the pollen content of honey was higher in samples from frames containing brood or pollen cells; in these samples the pollen content was positively correlated with the amount of these cells in the frame and the proximity of the honey to them. The proportion of pollen grains from principally nectariferous plants was lower in honeys with a high pollen content. 相似文献
90.
Alvaro C. Ucero Alberto Benito-Martin Isabel Fuentes-Calvo Beatriz Santamaria Julia Blanco Jose M. Lopez-Novoa Marta Ruiz-Ortega Jesus Egido Linda C. Burkly Carlos Martinez-Salgado Alberto Ortiz 《生物化学与生物物理学报:疾病的分子基础》2013,1832(10):1744-1755
Tumor necrosis factor-like weak inducer of apoptosis (TWEAK) regulates apoptosis, proliferation and inflammation in renal epithelial cells and plays a role in acute kidney injury. However, there is little information on the chronic effects of TWEAK. We hypothesized that TWEAK may influence renal fibrosis and regulate kidney fibroblast biology, in part, through Ras pathway.We studied a chronic model of experimental unilateral ureteral obstruction in wild type and TWEAK deficient mice, and a murine model of systemic TWEAK overexpression. TWEAK actions were also explored in cultured renal and embryonic fibroblasts.TWEAK and TWEAK receptor expression was increased in the obstructed kidneys. The absence of TWEAK decreased early kidney tubular damage, inflammatory infiltrates and myofibroblast number. TWEAK deficient mice had decreased renal fibrosis 21 days after obstruction, as assessed by extracellular matrix staining. In mice without prior underlying kidney disease, systemic overexpression of TWEAK induced kidney inflammation and fibrosis. In cultured fibroblasts, TWEAK induced proliferation through activation of the Ras/ERK pathway. TWEAK also activated nuclear factor κB (NFκB)-dependent inflammatory chemokine production in murine renal fibroblasts.In conclusion, lack of TWEAK reduces renal fibrosis in a model of persistent kidney insult and overexpression of TWEAK led to renal fibrosis. TWEAK actions on renal fibroblasts may contribute to the in vivo observations, as TWEAK promotes inflammatory activity and proliferation in fibroblast cultures. 相似文献