ABSTRACT
Las talasemias son un grupo heterogéneo de alteraciones congénitas, cuya característica común es un defecto en la síntesis de una o varias de las cadenas de globina. Cada talasemia recibe el nombre de la cadena que deja de sintetizarse. Las más comunes son la -talasemia, -talasemia y -talasemia. La forma más frecuente en España es la -talasemia menor, aunque su distribución es muy irregular. Son trastornos hereditarios con un patrón de herencia autosómica dominante. Es importante diagnosticar las talasemias (incluso las formas asintomáticas o con muy poca expresividad clínica), para poder hacer un adecuado consejo genético y prevenir la aparición de casos graves de talasemia
Thalassemias are a heterogeneous group of congenital disorders whose common characteristic is a defect in the synthesis of one or several globin chains. Each thalassemia receives the name of a chain that is not longer synthesized. The most common are the -thalassemias, -thalassemias and -thalassemias. The most frequent form in Spain is the -thalassemias, although its distribution is very irregular. They are hereditary disorders with an autosomal dominant inheritance. It is important to diagnose the thalassemias (even the asymptomatic forms or those with very little clinical expressivity) in order to be able to give adequate genetic advice and prevent the appearance of serious cases of thalassemias
Subject(s)
Humans , Thalassemia/diagnosis , Genetic Counseling , Primary Health Care/methods , Anemia/physiopathology , Hemoglobins/deficiency , beta-Thalassemia/physiopathology , alpha-Thalassemia/physiopathologyABSTRACT
La mayoría de las crisis de hipo son autolimitadas, y no suelen ser motivo de consulta. Cuando el hipo es persistente o recurrente, tiene gran repercusión en la calidad de vida de la persona y es entonces cuando se demanda asistencia. En la mayoría de las crisis de hipo transitorio se desconoce cuál es su etiología. La causa más frecuente de hipo persistente son las enfermedades gastroesofágicas. El hipo puede ser manifestación de alguna enfermedad subyacente o signo de alarma de alguna complicación, como por ejemplo una dehiscencia de sutura en un postoperatorio. De ahí la importancia de hacer una historia clínica detallada, una exploración física completa y pruebas complementarias dirigidas para llegar al diagnóstico. Reseño a continuación un protocolo para tener presente en la evaluación del paciente con hipo
Most of the hiccup episodes are self-limited and are not generally a cause for consultation. When hiccup is persistent or recurrent, it has an important repercussion on the person's quality of life and that is when care is requested. The etiology is unknown in most of the transient hiccup episodes. The most frequent cause of persistent hiccup is gastroesophageal diseases. Hiccup may be a manifestation of some underlying disease or sign of alarm of some complication such as suture dehiscence in a post-operative period. Thus, it is important to make a detailed clinical history, complete physical examination and complementary tests aimed at reaching a diagnosis. In present a protocol to consider in the evaluation of the patient with hiccup in the following
Subject(s)
Humans , Primary Health Care , Hiccup/diagnosis , Hiccup/etiology , Hiccup/therapyABSTRACT
La demencia es un trastorno adquirido y progresivo, caracterizado por la presencia de múltiples déficit cognoscitivos, sin alteración del nivel de conciencia, que interfieren de forma significativa en la actividad laboral y social. La demencia por la enfermedad de Pick apenas supone el 1% del total de las demencias, pertenece al grupo de las demencias frontotemporales. En las fases iniciales destacan las alteraciones de personalidad y conducta, (desinhibición, conducta antisocial y apatía) y de las capacidades ejecutivas (planificación). Son características las alteraciones en el lenguaje con tendencia a la ecolalia, coprolalia y neologismos. El deterioro cognitivo aparece más tardíamente
Dementia is an acquired and progressive disorder characterized by the presence of multiple cognitive deficits, without consciousness alteration, that significantly interferes in work and social activity. Dementia of Pick's Disease hardly accounts for 1% of all dementias and belongs to the frontotemporal dementia group. In the initial phases, personality and behavior alterations (disinhibition, antisocial behavior and apathy) and executive capacity alterations (planning) stand out. Alterations in language with tendency to echolalia, coprolalia and neologisms are characteristic. Cognitive deterioration appears later
Subject(s)
Humans , Dementia/etiology , Pick Disease of the Brain/diagnosis , Pick Disease of the Brain/complications , Diagnosis, Differential , Mental Disorders/etiologyABSTRACT
We present an experimental procedure for the determination and the verification under practical conditions of physical and computational parameters used in our proton pencil beam algorithm. The calculation of the dose delivered by a single pencil beam relies on a measured spread-out Bragg peak, and the description of its radial spread at depth features simple specific parameters accounting individually for the influence of the beam line as a whole, the beam energy modulation, the compensator, and the patient medium. For determining the experimental values of the physical parameters related to proton scattering, we utilized a simple relation between Gaussian radial spreads and the width of lateral penumbras. The contribution from the beam line has been extracted from lateral penumbra measurements in air: a linear variation with the distance collimator-point has been observed. Analytically predicted radial spreads within the patient were in good agreement with experimental values in water under various reference conditions. Results indicated no significant influence of the beam energy modulation. Using measurements in presence of Plexiglas slabs, a simple assumption on the effective source of scattering due to the compensator has been stated, leading to accurate radial spread calculations. Dose measurements in presence of complexly shaped compensators have been used to assess the performances of the algorithm supplied with the adequate physical parameters. One of these compensators has also been used, together with a reference configuration, for investigating a set of computational parameters decreasing the calculation time while maintaining a high level of accuracy. Faster dose computations have been performed for algorithm evaluation in the presence of geometrical and patient compensators, and have shown good agreement with the measured dose distributions.
Subject(s)
Algorithms , Proton Therapy , Radiotherapy Planning, Computer-Assisted/statistics & numerical data , Radiotherapy, Conformal/statistics & numerical data , Biophysical Phenomena , Biophysics , Humans , Models, Theoretical , Neoplasms/radiotherapy , Scattering, RadiationABSTRACT
While the development of inverse planning tools for optimizing dose distributions has come to a level of maturity, intensity modulation has not yet been widely implemented in clinical use because of problems related to its practical delivery and a lack of verification tools and quality assurance (QA) procedures. One of the prerequisites is a dose calculation algorithm that achieves good accuracy. The purpose of this work was twofold. A primary-scatter separation dose model has been extended to account for intensity modulation generated by a dynamic multileaf collimator (MLC). Then the calculation procedures have been tested by comparison with carefully carried out experiments. Intensity modulation is being accounted for by means of a 2D (two-dimensional) matrix of correction factors that modifies the spatial fluence distribution, incident to the patient. The dose calculation for the corresponding open field is then affected by those correction factors. They are used in order to weight separately the primary and the scatter component of the dose at a given point. In order to verify that the calculated dose distributions are in good agreement with measurements on our machine, we have designed a set of test intensity distributions and performed measurements with 6 and 20 MV photons on a Varian Clinac 2300C/D linear accelerator equipped with a 40 leaf pair dynamic MLC. Comparison between calculated and measured dose distributions for a number of representative cases shows, in general, good agreement (within 3% of the normalization in low dose gradient regions and within 3 mm distance-to-dose in high dose gradient regions). For absolute dose calculations (monitor unit calculations), comparison between calculation and measurement reveals good agreement (within 2%) for all tested cases (with the condition that the prescription point is not located on a high dose gradient region).
