3,146 research outputs found

    Growth and growth hormone secretion in children with cancer treated with chemotherapy

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    To evaluate the effect of chemotherapy on growth and growth hormone (GH) secretion. METHODS: We analyzed growth and GH secretion in 60 children in complete remission after treatment by chemotherapy and surgery for malignant solid tumors. None of them received cranial radiotherapy. Growth hormone reserve was assessed by at least two stimulation tests (clonidine, L-dopa, growth hormone-releasing hormone). In 12 children the reserve of GH pretreatment was also evaluated. RESULTS: Growth hormone deficiency (GHD) was observed in 27 of 60 patients (45%). At diagnosis, mean standing height was +0.23 +/- 0.11 standard deviation score (SDS) in the GHD group and +0.16 +/- 0.10 SDS in the non-GHD group. After chemotherapy, mean standing height in the GHD group was -0.28 +/- 0.15 SDS and -0.14 +/- 0.11 in the non-GHD group (p < 0.05), and the growth rate was +0.13 +/- 0.07 SDS in the GHD group and +0.22 +/- 0.18 SDS in the non-GHD group. For a mean follow-up of 30 months, the mean standing height was -0.46 +/- 0.29 SDS in the GHD group and -0.24 +/- 0.16 SDS for the non-GHD group (p < 0.05), and the growth rate was -0.27 +/- 0.19 SDS in the GHD group and -0.16 +/- 0.12 SDS in the non-GHD group (p < 0.05). The GH response to clonidine was significantly less than that found with the other stimuli. There was correlation between the dose intensity of some drugs and the subsequent GH response to stimulation tests. The GHD group was found to have received significantly higher doses of actinomycin D than the non-GHD group (p < 0.05). Growth impairment and GHD were not found to be correlated with duration of treatment and follow-up, tumor type, sex, or age. CONCLUSIONS: Chemotherapy as the sole form of treatment in children with cancer interferes with growth. The observed impairment of growth depends, at least in part, on a GHD related to chemotherapy. The growth rate in conjunction with the GH response to clonidine provides a sensitive measure of GHD associated with chemotherapy

    Osteocondroma lumbar sintomático

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    Se presenta un caso de osteocondroma solitario espinal localizado en la zona para-articular de la lámina izquierda de L4 y que producía una lumbociática secundaria a la estenosis del receso lateral. El osteocondroma espinal sintomático es una lesión neoplásica benigna poco frecuente y cuyo tratamiento de elección es la extirpación quirúrgica.A case of solitary spinal osteochondroma growing from the left L4 lamina, close to the facet joint, is presented. The tumor produced a stenosis of the left lateral recess and the patient suffered from low-back and sciatic pain. Symptomatic spinal osteochondroma is a rare beningn tumor, surgical removal being the most useful treatment

    Coste de la limpieza “cotidiana” de playas

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    Más de 90.000 buques mercantes al año cruzan el Estrecho de Gibraltar de los que aproximadamente un 5% son petroleros. Ello, conjuntamente con la existencia de varios puertos con refinerías y polígonos industriales petroquímicos y la práctica del bunkering para aprovisionamiento de combustible, hace a la costa gaditana un punto de riesgo para la contaminación por hidrocarburos (Carmona et al., 2009). La Demarcación de Costas de Andalucía-Atlántico (DCAA), dependiente del Ministerio de Agricultura, Alimentación y Medio Ambiente, ha realizado en numerosas ocasiones la limpieza de su litoral debido a la polución producida por ese tipo de vertidos (Carmona et al., 2012), existiendo ya alguna bibliografía sobre cómo abordar la retirada de alquitrán y otros derivados similares de las playas (e.g. DGC 2005, CEPRECO 2006a, CEPRECO 2006b). Sin embargo, además de la fracción no volátil de los hidrocarburos, existe otro tipo de desechos, naturales y/o antrópicos, que llegan a nuestras playas y que, debido sobre todo al carácter turístico de nuestro litoral, deben ser recogidos. Por ley, esta limpieza corresponde a las autoridades locales. No obstante, debido a la escasez de su presupuesto, los municipios suelen atender prioritariamente a la limpieza de las playas más urbanas y de máxima utilización. Es por este motivo que, dentro de un espíritu de colaboración entre Administraciones, la DCAA, mediante su partida de conservación y mantenimiento, ha apoyado las tareas de los Ayuntamientos, reforzando la labor municipal en las playas más concurridas y limpiando aquellas que son menos visitadas ya sea por su lejanía del casco urbano o por su escasez de servicios. En esta ponencia se presentarán los medios humanos y materiales con los que se cuenta para esta tarea, aportando cifras de toneladas de basura retiradas y coste del trabajo, junto con una comparación superficial con los datos de otros organismos y alguna sugerencia de posibles mejoras de la productividad

    Renormalization: the observable-state model

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    The usual mathematical formalism of quantum field theory is non-rigorous because it contains divergences that can only be renormalized by non-rigorous mathematical methods. The purpose of this paper is to present a method of subtraction of this divergences using the formalism of decoherence. This is achieved by replacing the standard renormalization method by a projector on a well defined Hilbert subspace. In this way a list of problems of the standard formalism disappears while the physical results of QFT remains valid. From it own nature, this formalism can be used in non-renormalizable theories.Comment: 23 page

    Turbidity and Other Effects Resulting from Trafalgar Sandbank Dredging and Palmar Beach Nourishment

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    Beach-nourishment requirements on the southwestern Spanish coast have led to a significant increase in offshore dredging. Following a new research line, assessment of changes recorded in physicochemical and biological parameters due to dredging and dumping operations was performed at the Cape of Trafalgar and Palmar Beach during June and July 2008. Turbidity, salinity, pH, dissolved oxygen, temperature, and suspended-sediment data were collected at 10 stations. At the end of the study, a three-campaign monitoring program was implemented for 1 year to assess the possible effects on biological communities and sediment properties. The relevant results, such as the average extent of the sediment plume (< 400 m) and its persistence in the environment (< 10 min), are discussed in this paper. A precise correlation between turbidity and suspended sediments and the recovery time of ecological balance were also established. Furthermore, minimal and reversible effects caused by dredging and dumping operations in this type of marine environment were identified

    A novel controlled drug-delivery system for growth hormone applied to healing skin wounds in diabetic rats

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    Controlled release systems for drugs, hormones and growth factors can be particularly useful in tissue repair processes. These systems act as a biodegradable support containing the substance to be delivered, allowing their gradual release. In the past years, the local application of growth factors has acquired special relevance as a therapeutic option for use in subjects who show de cient tissue scarring, the hormone dose being the limiting factor for its success. In this study, the in vitro biocompatibility of a copolymer formed by vinylpyrrolidone and 2-hydroxyethyl methacrylate, used as an administration vehicle for hGH, was evaluated. The system was then tested in vivo in terms of its capacity for healing incisional wounds in healthy and diabetic rats. For the in vitro studies, polymer and hormone degradation rates were determined, and polymer biocompatibility was evaluated in broblast cultures. In the in vivo experiments, an incision was made in the back of the animals, and polymers discs with/ without hGH, were introduced in the aperture. Morphological, immunohistochemical and morphometric evaluations were performed on wound tissue specimens 3¿10 days after surgery. In vitro, the polymer was found to be biodegradable and showed no toxic effects on broblasts, the hormone being slowly released to the culture medium. In untreated diabetic rats, a delayed skin scarring and cell response were observed, compared to that noted in healthy animals. Skin closure, keratinisationand brosis occurred earlier in the presence of the polymer-hGH system. The use of this co-polymer as an administrationvehicle for hGH improves the wound scarring process in the pathological setting of diabetes
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