112 research outputs found

    Origen de todos los poemas

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    196 p. Libro físico y digitalCiego y frágil, en sus últimas décadas, Borges continuó reclamando un parentesco con el sabio de Camden. “Whitman fue el primer poeta que experimentó las posibilidades del verso libre, sirviéndose para ello de un lenguaje sencillo y cercano a la prosa, a la vez que creaba una nueva mitología para la joven nación estadounidense. El individualismo, los relatos de sus propias experiencias, un tratamiento revolucionario del impulso erótico y la creencia en los valores universales de la democracia son los rasgos novedosos de su poética”. Whitman concibe la democracia como la liberación de la restricción, como la libertad de hacer lo que uno quiera. La idea misma de la democracia no es para la política, sino para las personas mismas en todo lo que hacen, dicen o, incluso, sienten. Walt Whitman es, a menudo, descrito como el poeta nacional de Estados UnidosPrimera edició

    Characterization of a naturally-occurring p27 mutation predisposing to multiple endocrine tumors

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    <p>Abstract</p> <p>Background</p> <p>p27Kip1 (p27) is an important negative regulator of the cell cycle and a putative tumor suppressor. The finding that a spontaneous germline frameshift mutation in <it>Cdkn1b </it>(encoding p27) causes the MENX multiple endocrine neoplasia syndrome in the rat provided the first evidence that <it>Cdkn1b </it>is a tumor susceptibility gene for endocrine tumors. Noteworthy, germline p27 mutations were also identified in human patients presenting with endocrine tumors. At present, it is not clear which features of p27 are crucial for this tissue-specific tumor predisposition in both rats and humans. It was shown that the MENX-associated <it>Cdkn1b </it>mutation causes reduced expression of the encoded protein, but the molecular mechanisms are unknown. To better understand the role of p27 in tumor predisposition and to characterize the MENX animal model at the molecular level, a prerequisite for future preclinical studies, we set out to assess the functional properties of the MENX-associated p27 mutant protein (named p27fs177) <it>in vitro </it>and <it>in vivo</it>.</p> <p>Results</p> <p><it>In vitro</it>, p27fs177 retains some properties of the wild-type p27 (p27wt) protein: it localizes to the nucleus; it interacts with cyclin-dependent kinases and, to lower extent, with cyclins. In contrast to p27wt, p27fs177 is highly unstable and rapidly degraded in every phase of the cell-cycle, including quiescence. It is in part degraded by Skp2-dependent proteasomal proteolysis, similarly to p27wt. Photobleaching studies showed reduced motility of p27fs177 in the nucleus compared to p27wt, suggesting that in this compartment p27fs177 is part of a multi-protein complex, likely together with the degradation machinery. Studies of primary rat newborn fibroblasts (RNF) established from normal and MENX-affected littermates confirmed the rapid degradation of p27fs177 <it>in vivo </it>which can be rescued by Bortezomib (proteasome inhibitor drug). Overexpression of the negative regulators microRNA-221/222 plays no role in regulating the amount of p27fs177 in RNFs and rat tissues.</p> <p>Conclusion</p> <p>Our findings show that reduced p27 levels, not newly acquired properties, trigger tumor formation in rats, similarly to what has been observed in mice. The molecular characteristics of p27fs177 establish MENX as a useful preclinical model to evaluate compounds that inhibit p27 degradation for their efficacy against endocrine tumors.</p

    Functional Imaging of Pheochromocytoma with 68Ga-DOTATOC and 68C-HED in a Genetically Defined Rat Model of Multiple Endocrine Neoplasia

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    Rats affected by the MENX multitumor syndrome develop pheochromocytoma (100%). Pheochromocytomas are uncommon tumors and animal models are scarce, hence the interest in MENX rats to identify and preclinically evaluate novel targeted therapies. A prerequisite for such studies is a sensitive and noninvasive detection of MENXassociated pheochromocytoma. We performed positron emission tomography (PET) to determine whether rat pheochromocytomas are detected by tracers used in clinical practice, such as 68Ga-DOTATOC (somatostatin analogue) or 11C-Hydroxyephedrine (HED), a norepinephrine analogue. We analyzed four affected and three unaffected rats. The PET scan findings were correlated to histopathology and immunophenotype of the tumors, their proliferative index, and the expression of genes coding for somatostatin receptors or the norepinephrine transporter. We observed that mean 68Ga-DOTATOC standard uptake value (SUV) in adrenals of affected animals was 23.3 ± 3.9, significantly higher than in control rats (15.4 ± 7.9; P = .03). The increase in mean tumor-to-liver ratio of 11C-HED in the MENX-affected animals (1.6 ± 0.5) compared to controls (0.7 ± 0.1) was even more significant (P = .0016). In a unique animal model, functional imaging depicting two pathways important in pheochromocytoma biology discriminated affected animals from controls, thus providing the basis for future preclinical work with MENX rats

    Feasibility and Acceptability of a Real-Time Telerehabilitation Intervention for Children and Young Adults with Acquired Brain Injury During the COVID-19 Pandemic: An Experience Report

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    This study examined the feasibility and acceptability of a telerehabilitation intervention during the COVID-19 pandemic in a sample of children and young adults with Acquired Brain Injury (ABI). Thirteen patients and/or their families agreed to participate in the speech and neuropsychological telerehabilitation sessions. The treatment was synchronous, patient centered and aimed at improving specific abilities. Sessions were held twice a week over a 10-week period. Two questionnaires were completed both by parents and therapists to assess feasibility and acceptability. Neither technical issues nor clinical obstacles were found. The quality of the therapeutic relationship played a key role in the intervention. Synchronous telerehabilitation provided several advantages both for patients and therapists. Moreover, the patient centered intervention eased the burden of the caregivers at a time of high stress. The real-time telerehabilitation treatments were deemed suitable for children and young adults with ABI. Further studies are needed to support the use of telerehabilitation as an integral part of their standard care

    Early Rehabilitation Reduces Time to Decannulation in Patients With Severe Acquired Brain Injury: A Retrospective Study

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    Purpose: Early decannulation is considered a main rehabilitative goal in tracheostomized patients. Our aim is to evaluate whether a very early rehabilitation protocol helps to reduce the tracheostomy duration in patients affected by an Acquired Brain Injury (ABI).Methods: Data about consecutive tracheostomized patients admitted in our Neuro-Rehabilitation Unit (NRU) were retrospectively collected. We defined two groups: Early Rehabilitation Group patients came from our ICU, where they started the rehabilitative treatment; Delayed Rehabilitation Group patients arrived from external ICUs and started rehabilitation in our NRU. Primary outcome was the time from tracheostomy to decannulation. Secondary outcomes were: ICU length of stay, time from NRU admission to decannulation, Glasgow Coma Scale, Coma Recovery Scale revised and Levels of Cognitive Functioning scores at NRU discharge and the re-cannulation rate.Results: We enrolled 66 patients, 40 in the Early Rehabilitation Group and 26 in the Delayed Rehabilitation Group. 70% of patients for each group could be decannulated (p = 0.73) and were analyzed. Only one patient was re-cannulated. Early Rehabilitation Group showed a shorter tracheostomy duration (61.0 vs. 94.5 days, p = 0.013), a higher probability of occurrence of decannulation (p = 0.008) and a lower ICU length of stay (30.0 vs. 52.0 days, p = 0.001). The time to decannulation in NRU was similar between groups (30.0 vs. 45.50 days, p = 0.14). All the scale scores had a significant improvement in both groups (p &lt; 0.0001 all).Conclusions: The present study shows that an early neuro-rehabilitation protocol helps to reduce the time to decannulation in tracheostomized patients affected by ABI

    Association of colorectal adenoma with other malignancies in Swedish families

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    Using the Swedish Family-Cancer Database covering over 11.5 million individuals, estimated relative risks (RRs) for colorectal adenoma were using Poisson's regression. The RR of colorectal adenoma was found to be increased among first-degree relatives of patients with colorectal cancer (2.72; 95% confidence interval=2.46–3.00) and among the offspring and siblings of patients with endometrial and prostate cancers. We also found an increased risk of colorectal adenoma for the offspring of individuals with stomach cancer and leukaemia, and for siblings of those with pancreatic cancer and multiple myeloma. Our results suggest that colorectal adenoma may share a genetic aetiology with cancer even at extracolorectal sites. Increases of colorectal adenoma in families affected by prostate cancer and acute leukaemia cannot be attributed to known cancer syndromes, although the play of chance cannot be excluded

    Role of T198 Modification in the Regulation of p27Kip1 Protein Stability and Function

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    The tumor suppressor gene p27Kip1 plays a fundamental role in human cancer progression. Its expression and/or functions are altered in almost all the different tumor histotype analyzed so far. Recently, it has been demonstrated that the tumor suppression function of p27 resides not only in the ability to inhibit Cyclins/CDKs complexes through its N-terminal domain but also in the capacity to modulate cell motility through its C-terminal portion. Particular interest has been raised by the last amino-acid, (Threonine 198) in the regulation of both protein stability and cell motility

    Murine Models and Cell Lines for the Investigation of Pheochromocytoma: Applications for Future Therapies?

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    Pheochromocytomas (PCCs) are slow-growing neuroendocrine tumors arising from adrenal chromaffin cells. Tumors arising from extra-adrenal chromaffin cells are called paragangliomas. Metastases can occur up to approximately 60% or even more in specific subgroups of patients. There are still no well-established and clinically accepted “metastatic” markers available to determine whether a primary tumor is or will become malignant. Surgical resection is the most common treatment for non-metastatic PCCs, but no standard treatment/regimen is available for metastatic PCC. To investigate what kind of therapies are suitable for the treatment of metastatic PCC, animal models or cell lines are very useful. Over the last two decades, various mouse and rat models have been created presenting with PCC, which include models presenting tumors that are to a certain degree biochemically and/or molecularly similar to human PCC, and develop metastases. To be able to investigate which chemotherapeutic options could be useful for the treatment of metastatic PCC, cell lines such as mouse pheochromocytoma (MPC) and mouse tumor tissue (MTT) cells have been recently introduced and they both showed metastatic behavior. It appears these MPC and MTT cells are biochemically and molecularly similar to some human PCCs, are easily visualized by different imaging techniques, and respond to different therapies. These studies also indicate that some mouse models and both mouse PCC cell lines are suitable for testing new therapies for metastatic PCC
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