958 resultados para Axis patterning
Resumo:
Our aim was to assess the clinical outcome of patients who were subjected to long-axis sacroplasty for the treatment of sacral insufficiency fractures. Nineteen patients with unilateral (n = 3) or bilateral (n = 16) sacral fractures were involved. Under local anaesthesia, each patient was subjected to CT-guided sacroplasty using the long-axis approach through a single entry point. An average of 6 ml of polymethylmethacrylate (PMMA) was delivered along the path of each sacral fracture. For each individual patient, the Visual Analogue pain Scale (VAS) before sacroplasty and at 1, 4, 24 and 48 weeks after the procedure was obtained. Furthermore, the use of analgesics (narcotic/non-narcotic) along with the evolution of post-interventional patient mobility before and after sacroplasty was also recorded. The mean pre-procedure VAS was 8 +/- 1.9 (range, 2 to 10). This rapidly and significantly (P < 0.001) declined in the first week after the procedure (mean 4 +/- 1.4; range, 1 to 7) followed by a gradual and significant (P < 0.001) decrease along the rest of the follow-up period at 4 weeks (mean 3 +/- 1.1; range, 1 to 5), 24 weeks (mean 2.2 +/- 1.1; range, 1 to 5) and 48 weeks (mean 1.6 +/- 1.1; range, 1 to 5). Eleven (58%) patients were under narcotic analgesia before sacroplasty, whereas 8 (42%) patients were using non-narcotics. Corresponding values after the procedure were 2/19 (10%; narcotic, one of them was on reserve) and 10/19 (53%; non-narcotic). The remaining 7 (37%) patients did not address post-procedure analgesic use. The evolution of post-interventional mobility was favourable in the study group as they revealed a significant improvement in their mobility point scale (P < 0.001). Long-axis percutaneous sacroplasty is a suitable, minimally invasive treatment option for patients who present with sacral insufficiency fractures. More studies with larger patient numbers are needed to explore any unrecognised limitations of this therapeutic approach.
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An example of the relationship that exist between the preferred crystaliografic orientation of quartz grains and the attitude of the mylonite foliation of quartz-feldspar mylonites is described. These rocks are the result of the inhomogeneous deformation under low-grade metamorphic conditions of a late Hercynian granodiorite, intruded into the gneisses of the slopes of the Canig massif (Eastern Pyrenees). The Costabona mylonites have a quartz c-axis fabric in pseudo-twogirdles symmetrical with respect to the mylonite foliation and perpendicular to the shearband systems which produce an extensional crenulation of the mylonite foliation.
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The Nrf2 transcription factor controls the expression of genes involved in the antioxidant defense system. Here, we identified Nrf2 as a novel regulator of desmosomes in the epidermis through the regulation of microRNAs. On Nrf2 activation, expression of miR-29a and miR-29b increases in cultured human keratinocytes and in mouse epidermis. Chromatin immunoprecipitation identified the Mir29ab1 and Mir29b2c genes as direct Nrf2 targets in keratinocytes. While binding of Nrf2 to the Mir29ab1 gene activates expression of miR-29a and -b, the Mir29b2c gene is silenced by DNA methylation. We identified desmocollin-2 (Dsc2) as a major target of Nrf2-induced miR-29s. This is functionally important, since Nrf2 activation in keratinocytes of transgenic mice causes structural alterations of epidermal desmosomes. Furthermore, the overexpression of miR-29a/b or knockdown of Dsc2 impairs the formation of hyper-adhesive desmosomes in keratinocytes, whereas Dsc2 overexpression has the opposite effect. These results demonstrate that a novel Nrf2-miR-29-Dsc2 axis controls desmosome function and cutaneous homeostasis.
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PURPOSE: Local breast cancer relapse after breast-saving surgery and radiotherapy is associated with increased risk of distant metastasis formation. The mechanisms involved remain largely elusive. We used the well-characterized 4T1 syngeneic, orthotopic breast cancer model to identify novel mechanisms of postradiation metastasis. EXPERIMENTAL DESIGN: 4T1 cells were injected in 20 Gy preirradiated mammary tissue to mimic postradiation relapses, or in nonirradiated mammary tissue, as control, of immunocompetent BALB/c mice. Molecular, biochemical, cellular, histologic analyses, adoptive cell transfer, genetic, and pharmacologic interventions were carried out. RESULTS: Tumors growing in preirradiated mammary tissue had reduced angiogenesis and were more hypoxic, invasive, and metastatic to lung and lymph nodes compared with control tumors. Increased metastasis involved the mobilization of CD11b(+)c-Kit(+)Ly6G(high)Ly6C(low)(Gr1(+)) myeloid cells through the HIF1-dependent expression of Kit ligand (KitL) by hypoxic tumor cells. KitL-mobilized myeloid cells homed to primary tumors and premetastatic lungs, to give rise to CD11b(+)c-Kit(-) cells. Pharmacologic inhibition of HIF1, silencing of KitL expression in tumor cells, and inhibition of c-Kit with an anti-c-Kit-blocking antibody or with a tyrosine kinase inhibitor prevented the mobilization of CD11b(+)c-Kit(+) cells and attenuated metastasis. C-Kit inhibition was also effective in reducing mobilization of CD11b(+)c-Kit(+) cells and inhibiting lung metastasis after irradiation of established tumors. CONCLUSIONS: Our work defines KitL/c-Kit as a previously unidentified axis critically involved in promoting metastasis of 4T1 tumors growing in preirradiated mammary tissue. Pharmacologic inhibition of this axis represents a potential therapeutic strategy to prevent metastasis in breast cancer patients with local relapses after radiotherapy. Clin Cancer Res; 18(16); 4365-74. ©2012 AACR.
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A large body of data gathered over the last decades has delineated the neuronal pathways that link the central nervous system with the autonomic innervation of the endocrine pancreas, which controls alpha- and beta-cell secretion activity and mass. These are important regulatory functions that are certainly keys for preserving the capacity of the endocrine pancreas to control glucose homeostasis over a lifetime. Identifying the cells involved in controlling the autonomic innervation of the endocrine pancreas, in response to nutrient, hormonal and environmental cues and how these cues are detected to activate neuronal activity are important goals of current research. Elucidation of these questions may possibly lead to new means for preserving or restoring defects in insulin and glucagon secretion associated with type 2 diabetes.
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Myc family members play crucial roles in regulating cell proliferation, size, and differentiation during organogenesis. Both N-myc and c-myc are expressed throughout inner ear development. To address their function in the mouse inner ear, we generated mice with conditional deletions in either N-myc or c-myc. Loss of c-myc in the inner ear causes no apparent defects, whereas inactivation of N-myc results in reduced growth caused by a lack of proliferation. Reciprocally, the misexpression of N-myc in the inner ear increases proliferation. Morphogenesis of the inner ear in N-myc mouse mutants is severely disturbed, including loss of the lateral canal, fusion of the cochlea with the sacculus and utriculus, and stunted outgrowth of the cochlea. Mutant cochleas are characterized by an increased number of cells exiting the cell cycle that express the cyclin-dependent kinase inhibitor p27Kip1 and lack cyclin D1, both of which control the postmitotic state of hair cells. Analysis of different molecular markers in N-myc mutant ears reveals the development of a rudimentary organ of Corti containing hair cells and the underlying supporting cells. Differentiated cells, however, fail to form the highly ordered structure characteristic for the organ of Corti but appear as rows or clusters with an excess number of hair cells. The Kölliker's organ, a transient structure neighboring the organ of Corti and a potential source of ectopic hair cells, is absent in the mutant ears. Collectively, our data suggest that N-myc regulates growth, morphogenesis, and pattern formation during the development of the inner ear.
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Status signals function in a number of species to communicate competitive ability to conspecific rivals during competition for resources. In the paper wasp Polistes dominulus, variable black clypeal patterns are thought to be important in mediating competition among females. Results of previous behavioral experiments in the lab indicate that P dominulus clypeal patterns provide information about an individual's competitive ability to rivals during agonistic interactions. To date, however, there has been no detailed examination of the adaptive value of clypeal patterns in the wild. To address this, we looked for correlations between clypeal patterning and various fitness measures, including reproductive success, hierarchical rank, and survival, in a large, free-living population of P. dominulus in southern Spain. Reproductive success over the nesting season was not correlated with clypeal patterning. Furthermore, there was no relationship between a female's clypeal patterning and the rank she achieved within the hierarchy or her survival during nest founding. Overall, we found no evidence that P dominulus clypeal patterns are related to competitive ability or other aspects of quality in our population. This result is consistent with geographical variation in the adaptive value of clypeal patterns between P. dominulus populations; however, data on the relationship between patterning and fitness from other populations are required to test this hypothesis.
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In this communication we introduce a low or reduced coherence interferometry technique that can be used to retrieve surface topology on samples with high roughness. Moreover, we will show that the approach enables surface topology measurement also at the interface of so-called turbid media, where multiple scattering inside tissues can be a major issue, preventing accurate measurements.
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In cases of transjugular liver biopsies, the venous angle formed between the chosen hepatic vein and the vena cava main axis in a frontal plane can be large, leading to technical difficulties. In a prospective study including 139 consecutive patients who underwent transjugular liver biopsy using the Quick-Core biopsy set, the mean venous angle was equal to 49.6 degrees. For 21.1% of the patients, two attempts at hepatic venous catheterization failed because the venous angle was too large, with a mean of 69.7 degrees. In all of these patients, manual reshaping of the distal curvature of the stiffening metallic cannula, by forming a new mean angle equal to 48 degrees , allowed successful completion of the procedure in less than 10 min.
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Within a developing organism, cells require information on where they are in order to differentiate into the correct cell-type. Pattern formation is the process by which cells acquire and process positional cues and thus determine their fate. This can be achieved by the production and release of a diffusible signaling molecule, called a morphogen, which forms a concentration gradient: exposure to different morphogen levels leads to the activation of specific signaling pathways. Thus, in response to the morphogen gradient, cells start to express different sets of genes, forming domains characterized by a unique combination of differentially expressed genes. As a result, a pattern of cell fates and specification emerges.Though morphogens have been known for decades, it is not yet clear how these gradients form and are interpreted in order to yield highly robust patterns of gene expression. During my PhD thesis, I investigated the properties of Bicoid (Bcd) and Decapentaplegic (Dpp), two morphogens involved in the patterning of the anterior-posterior axis of Drosophila embryo and wing primordium, respectively. In particular, I have been interested in understanding how the pattern proportions are maintained across embryos of different sizes or within a growing tissue. This property is commonly referred to as scaling and is essential for yielding functional organs or organisms. In order to tackle these questions, I analysed fluorescence images showing the pattern of gene expression domains in the early embryo and wing imaginal disc. After characterizing the extent of these domains in a quantitative and systematic manner, I introduced and applied a new scaling measure in order to assess how well proportions are maintained. I found that scaling emerged as a universal property both in early embryos (at least far away from the Bcd source) and in wing imaginal discs (across different developmental stages). Since we were also interested in understanding the mechanisms underlying scaling and how it is transmitted from the morphogen to the target genes down in the signaling cascade, I also quantified scaling in mutant flies where this property could be disrupted. While scaling is largely conserved in embryos with altered bcd dosage, my modeling suggests that Bcd trapping by the nuclei as well as pre-steady state decoding of the morphogen gradient are essential to ensure precise and scaled patterning of the Bcd signaling cascade. In the wing imaginal disc, it appears that as the disc grows, the Dpp response expands and scales with the tissue size. Interestingly, scaling is not perfect at all positions in the field. The scaling of the target gene domains is best where they have a function; Spalt, for example, scales best at the position in the anterior compartment where it helps to form one of the anterior veins of the wing. Analysis of mutants for pentagone, a transcriptional target of Dpp that encodes a secreted feedback regulator of the pathway, indicates that Pentagone plays a key role in scaling the Dpp gradient activity.
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The let-7 tumor suppressor microRNAs are known for their regulation of oncogenes, while the RNA-binding proteins Lin28a/b promote malignancy by inhibiting let-7 biogenesis. We have uncovered unexpected roles for the Lin28/let-7 pathway in regulating metabolism. When overexpressed in mice, both Lin28a and LIN28B promote an insulin-sensitized state that resists high-fat-diet induced diabetes. Conversely, muscle-specific loss of Lin28a or overexpression of let-7 results in insulin resistance and impaired glucose tolerance. These phenomena occur, in part, through the let-7-mediated repression of multiple components of the insulin-PI3K-mTOR pathway, including IGF1R, INSR, and IRS2. In addition, the mTOR inhibitor, rapamycin, abrogates Lin28a-mediated insulin sensitivity and enhanced glucose uptake. Moreover, let-7 targets are enriched for genes containing SNPs associated with type 2 diabetes and control of fasting glucose in human genome-wide association studies. These data establish the Lin28/let-7 pathway as a central regulator of mammalian glucose metabolism.
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Neuroblastoma (NB) is one of the most deadly solid tumors of the young child, for which new efficient and targeted therapies are strongly needed. The CXCR4/CXCR7/CXCL12 chemokine axis has been involved in the progression and organ-specific dissemination of various cancers. In NB, CXCR4 expression was shown to be associated to highly aggressive undifferentiated tumors, while CXCR7 expression was detected in more differentiated and mature neuroblastic tumors. As investigated in vivo, using an orthotopic model of tumor cell implantation of chemokine receptor-overexpressing NB cells (IGR-NB8), the CXCR4/CXCR7/CXCL12 axis was shown to regulate NB primary and secondary growth, although without any apparent influence on organ selective metastasis. In the present study, we addressed the selective role of CXCR4 and CXCR7 receptors in the homing phase of metastatic dissemination using an intravenous model of tumor cell implantation. Tail vein injection into NOD-scid-gamma mice of transduced IGR-NB8 cells overexpressing CXCR4, CXCR7, or both receptors revealed that all transduced cell variants preferentially invaded the adrenal gland and typical NB metastatic target organs, such as the liver and the bone marrow. However, CXCR4 expression favored NB cell dissemination to the liver and the lungs, while CXCR7 was able to strongly promote NB cell homing to the adrenal gland and the liver. Finally, coexpression of CXCR4 and CXCR7 receptors significantly and selectively increased NB dissemination toward the bone marrow. In conclusion, CXCR4 and CXCR7 receptors may be involved in a complex and organ-dependent control of NB growth and selective homing, making these receptors and their inhibitors potential new therapeutic targets.
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Background: Nursing terminologies are designed to support nursing practice but, as with any other clinical tool, they should be evaluated. Cross-mapping is a formal method for examining the validity of the existing controlled vocabularies. Objectives: The study aims to assess the inclusiveness and expressiveness of the nursing diagnosis axis of a newly implemented interface terminology by cross-mapping with the NANDA-I taxonomy. Design/Methods: The study applied a descriptive design, using a cross-sectional, bidirectional mapping strategy. The sample included 728 concepts from both vocabularies. Concept cross-mapping was carried out to identify one-to-one, negative, and hierarchical connections. The analysis was conducted using descriptive statistics. Results: Agreement of the raters" mapping achieved 97%. More than 60% of the nursing diagnosis concepts in the NANDA-I taxonomy were mapped to concepts in the diagnosis axis of the new interface terminology; 71.1% were reversely mapped. Conclusions: Main results for outcome measures suggest that the diagnosis axis of this interface terminology meets the validity criterion of cross-mapping when mapped from and to the NANDA-I taxonomy.
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Background In most eumetazoans studied so far, Hox genes determine the identity of structures along the main body axis. They are usually linked in genomic clusters and, in the case of the vertebrate embryo, are expressed with spatial and temporal colinearity. Outside vertebrates, temporal colinearity has been reported in the cephalochordate amphioxus (the least derived living relative of the chordate ancestor) but only for anterior and central genes, namely Hox1 to Hox4 and Hox6. However, most of the Hox gene expression patterns in amphioxus have not been reported. To gain global insights into the evolution of Hox clusters in chordates, we investigated a more extended expression profile of amphioxus Hox genes. Results Here we report an extended expression profile of the European amphioxus Branchiostoma lanceolatum Hox genes and describe that all Hox genes, except Hox13, are expressed during development. Interestingly, we report the breaking of both spatial and temporal colinearity for at least Hox6 and Hox14, which thus have escaped from the classical Hox code concept. We show a previously unidentified Hox6 expression pattern and a faint expression for posterior Hox genes in structures such as the posterior mesoderm, notochord, and hindgut. Unexpectedly, we found that amphioxus Hox14 had the most divergent expression pattern. This gene is expressed in the anterior cerebral vesicle and pharyngeal endoderm. Amphioxus Hox14 expression represents the first report of Hox gene expression in the most anterior part of the central nervous system. Nevertheless, despite these divergent expression patterns, amphioxus Hox6 and Hox14 seem to be still regulated by retinoic acid. Conclusions Escape from colinearity by Hox genes is not unusual in either vertebrates or amphioxus and we suggest that those genes escaping from it are probably associated with the patterning of lineage-specific morphological traits, requiring the loss of those developmental constraints that kept them colinear.