238 research outputs found

    Infraspinatus scapular retraction test: a reliable and practical method to assess infraspinatus strength in overhead athletes with scapular dyskinesis

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    Background Alteration of normal scapulohumeral rhythm due to the fatigue of scapular-stabilizing muscles induces decrease of rotator cuff strength. In this study we analyzed the interobserver and intraobserver realibility of the infraspinatus strength test (IST) and infraspinatus scapular retraction test (ISRT) in 29 overhead athletes with scapular dykinesis, before and after 6 months of scapular musculature rehabilitation. Materials and methods Subjects with magnetic resonance imaging (MRI) findings of labral injuries (2 cases, 5%) and cuff tears (4 cases, 11%) were excluded. Scapular dyskinesis patterns were evaluated according to Kibler et al. (J Shoulder Elbow Surg 11:550-556, 2002). We found a type I dyskinesis in 24 cases (83%) and a type II in 5 cases (17%). Patients were tested by using IST and ISRT and the maximum infraspinatus strength (kg) was registered by a handheld dynamometer. Changes in shoulder IR were measured by using a standard goniometry. Rehabilitation continued for 6 months and was focused on the restoration of scapular muscular control and balance. We used a paired Student t test for the significance of the force values (alpha = 0.01). Intraclass correlation coefficient (ICC) and standard error (SE) were applied to determine the realibility of repeated values collected within testers and between testers. Results Values of ICC close to 1 at baseline and at 6 months indicated a higher interexaminer and intraexaminer realibility. IST force values registered a significant increase at 6 months for both examiners (P<0.01). The mean difference between IST and ISRT values were not significant at 6 months (P>0.01). The increase of glenohumeral internal rotation was significant at 6 months (P<0.01). Conclusion The good realibility and the easy reproducibility make the ISRT an excellent test to assess patients with infraspinatus weakness due to scapular dyskinesis and address them toward an appropriate program of rehabilitation aimed to restore scapular musculature balance and control. \ua9 The Author(s) 2010

    MinerΓ­a de datos para el descubrimiento de patrones en enfermedades respiratorias en BogotΓ‘, Colombia

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    Trabajo de InvestigaciΓ³nEl presente proyecto se basa en la aplicaciΓ³n de minerΓ­a de datos mediante el algoritmo de clustering K- means que permita la generaciΓ³n de un modelo descriptivo con el anΓ‘lisis de los datos y con el objetivo de identificar posibles comportamientos en enfermedades respiratorias en la ciudad de BogotΓ‘. El conjunto de clΓΊsteres generados por la herramienta RapidMiner es la recopilaciΓ³n de datos de un periodo de cinco aΓ±os de 2012 a 2016, en donde se contemplan el nΓΊmero de casos asociados a 184 diagnΓ³sticos de enfermedades respiratorias y la edad de los pacientes corresponde de 0 a 5 aΓ±os.Trabajo de InvestigaciΓ³n1. GENERALIDADES 2. OBJETIVOS 3. JUSTIFICACIΓ“N 4. DELIMITACIΓ“N 5. MARCO REFERENCIAL 6. METODOLOGÍA 7. FUENTES DE EXTRACCIΓ“N Y SUS VARIABLES 8. DISEΓ‘O 9. SELECCIΓ“N DE ALGORITMOS DE CLUSTERING 10. RECONOCER PATRONES A PARTIR DE LA INFORMACIΓ“N RECOPILADA 11. CONCLUSIONES 12. TRABAJOS FUTUROS 13. REFERENCIAS BIBLIOGRÁFICAS 14. ANEXOSPregradoIngeniero de Sistema

    Functional Interactions between Retinoblastoma and c-MYC in a Mouse Model of Hepatocellular Carcinoma

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    Inactivation of the RB tumor suppressor and activation of the MYC family of oncogenes are frequent events in a large spectrum of human cancers. Loss of RB function and MYC activation are thought to control both overlapping and distinct cellular processes during cell cycle progression. However, how these two major cancer genes functionally interact during tumorigenesis is still unclear. Here, we sought to test whether loss of RB function would affect cancer development in a mouse model of c-MYC-induced hepatocellular carcinoma (HCC), a deadly cancer type in which RB is frequently inactivated and c-MYC often activated. We found that RB inactivation has minimal effects on the cell cycle, cell death, and differentiation features of liver tumors driven by increased levels of c-MYC. However, combined loss of RB and activation of c-MYC led to an increase in polyploidy in mature hepatocytes before the development of tumors. There was a trend for decreased survival in double mutant animals compared to mice developing c-MYC-induced tumors. Thus, loss of RB function does not provide a proliferative advantage to c-MYC-expressing HCC cells but the RB and c-MYC pathways may cooperate to control the polyploidy of mature hepatocytes

    Wind anisotropies and GRB progenitors

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    We study the effect of wind anisotropies on the stellar evolution leading to collapsars. Rotating models of a 60 MβŠ™_\odot star with Ξ©/Ξ©crit=0.75\Omega/\Omega_{\rm crit}=0.75 on the ZAMS, accounting for shellular rotation and a magnetic field, with and without wind anisotropies, are computed at ZZ=0.002 until the end of the core He-burning phase. Only the models accounting for the effects of the wind anisotropies retain enough angular momentum in their core to produce a Gamma Ray Burst (GRB). The chemical composition is such that a type Ic supernova event occurs. Wind anisotropies appear to be a key physical ingredient in the scenario leading to long GRBs.Comment: 5 pages, 4 figures, accepted for publication in A&A Lette

    The Histone Demethylase Jarid1b (Kdm5b) Is a Novel Component of the Rb Pathway and Associates with E2f-Target Genes in MEFs during Senescence

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    Senescence is a robust cell cycle arrest controlled by the p53 and Rb pathways that acts as an important barrier to tumorigenesis. Senescence is associated with profound alterations in gene expression, including stable suppression of E2f-target genes by heterochromatin formation. Some of these changes in chromatin composition are orchestrated by Rb. In complex with E2f, Rb recruits chromatin modifying enzymes to E2f target genes, leading to their transcriptional repression. To identify novel chromatin remodeling enzymes that specifically function in the Rb pathway, we used a functional genetic screening model for bypass of senescence in murine cells. We identified the H3K4-demethylase Jarid1b as novel component of the Rb pathway in this screening model. We find that depletion of Jarid1b phenocopies knockdown of Rb1 and that Jarid1b associates with E2f-target genes during cellular senescence. These results suggest a role for Jarid1b in Rb-mediated repression of cell cycle genes during senescence
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