Incidencia y pronóstico de las lesiones cardíacas en el politraumatizado pediátrico / Incidence and prognosis of cardiac lesions in the paediatric polytraumatised patient

Objetivos: Conocer la incidencia y pronóstico de las lesiones cardíacas en el politraumatizado pediátrico. Conocer la trascendencia de un correcto diagnóstico, especialmente cuando el paciente no va a ser susceptible de cuidados intensivos. Métodos: Revisión bibliográfica. Selección de los artículos que respondían a una o varias de las siguientes cuestiones: 1. ¿Cuál es la incidencia de lesión cardíaca en el politrauma pediátrico? 2. ¿Diagnosticamos las lesiones cardíacas? 3. ¿Hacemos seguimiento de las lesiones cardíacas diagnosticadas? 4. Pronóstico. Resultados y conclusiones: 1. No hay datos suficientes sobre la frecuencia de lesión cardíaca diagnosticada en el seno del traumatismo torácico infantil. 2. Es posible que la lesión cardíaca esté infradiagnosticada, cobrando relevancia el diagnóstico de sospecha. 3. La decisión de monitorizar a un paciente depende de la situación clínica y del resultado de las pruebas complementarias. 4. El pronóstico de la lesión cardíaca en el niño politraumatizado es favorable si estamos ante una contusión cardíaca, sin olvidar que la condición de politraumatizado puede resultar definitiva en cuanto a mortalidad se refiere (AU)

Aims and objectives: To assess and establish the incidence and prognosis of cardiac lesions in the paediatric polytraumatised patient. To assess the significance of a correct diagnosis, particularly when the patient will not be amenable to intensive care. Methods: Bibliographic review, with selection of those papers responding to one or more of the following questions: (1) Which is the incidence of cardiac lesion in paediatric polytraumatised patients? (2) Do we diagnosed cardiac lesions? (3) Do we follow up the already diagnosed cardiac lesions? (4) What is the prognosis? Results and Conclusions: [to (1)]: There are no sufficient data regarding the diagnosis and frequency of cardiac lesion diagnosed in the context of paediatric thoracic traumatism. [to (2)]: It is quite possible that cardiac lesions are underdiagnosed, whereby the "suspicion" diagnosis becomes relevant. [to (3)] The decision to monitor a given patient depends on the clinical situation and on the results of complementary tests and analyses. [to 4]: Prognosis in the polytraumatised child is quite favourable in the presence of cardiac contusion; however, the "polytraumatised" condition may become definitory as regards mortality (AU)

Intervención psicológica en sujetos durante la reanimación de su parada cardiorrespiratoria / Psychological intervention with patients subject to cardiopulmonary resucitation

En esta investigación se estudian los aspectos psicológicos y fisiológicos relacionados con la muerte y con la parada cardiorrespiratoria. Se aporta un protocolo psicológico de estimulación verbal para aplicarlo al sujeto, durante la reanimación de su parada cardiorrespiratoria y los datos preliminares sobre la eficacia de dicha intervención, con una muestra de 30 pacientes, que presentaban una parada cardiorrespiratoria extrahospitalaria. Los resultados obtenidos aconsejan continuar con la investigación aumentando la muestra de sujetos. (AU)

Entry, dispersion and differentiation of microglia in the developing central nervous system.

Microglial cells within the developing central nervous system (CNS) originate from mesodermic precursors of hematopoietic lineage that enter the nervous parenchyma from the meninges, ventricular space and/or blood stream. Once in the nervous parenchyma, microglial cells increase in number and disperse throughout the CNS; these cells finally differentiate to become fully ramified microglial cells. In this article we review present knowledge on these phases of microglial development and the factors that probably influence them.

Proliferation of actively migrating ameboid microglia in the developing quail retina.

Sheets containing the inner limiting membrane covered by a carpet of Müller cell endfeet were used to show that ameboid microglial cells migrating tangentially in the vitreal part of the developing retina of quail embryos underwent mitosis. Double labeling with anti-beta-tubulin/QH1 or Hoechst 33342/QH1 revealed that some migroglial cells with morphological features typical of active migration were in early prophase. By anaphase and early telophase, microglial cells had retracted their lamellipodia and were ovoid in shape. Later in telophase, but well before completion of cytokinesis, both daughter cells again emitted lamellipodia, thus regaining the typical morphology of migrating cells. We concluded that ameboid microglial cells go through cycles in which migration and mitosis alternate, and that both mechanisms contribute to the spread of microglia throughout the developing retina. The mitotic spindle of dividing microglial cells showed different orientations, which probably influenced the course of subsequent migration. The expression of the proliferating cell nuclear antigen in the nucleus of most tangentially migrating ameboid microglial cells at E9-E10 confirmed their proliferative capability. However, the rate of proliferation of these cells decreased during embryonic development, and was nearly zero at E14.

Circumferential migration of ameboid microglia in the margin of the developing quail retina.

Central-to-peripheral migration of QH1-positive microglial precursors occurs in the vitrealmost part of the developing quail retina. This study shows that some QH1-positive ameboid cells with morphological features of migrating cells are already present in the margin of the retina before microglial precursors migrating centrally to peripherally arrive in this zone. Because the earlier cells are oriented parallel to the ora serrata, we deduce that some microglial cells migrate circumferentially in the margin of the retina, whereas other microglial precursors migrate from central to peripheral zones. Microglial cells that migrate circumferentially are first seen on embryonic day 6 (E6) and advance in a temporal-to-dorsal-to-nasal direction from the temporoventral quadrant of the retina. When cells migrating centrally to peripherally reach the retinal margin, they meet those migrating circumferentially. From E6 on, some QH1-positive dendritic cells in the ciliary body bear processes that penetrate the retina, where they are oriented circumferentially. These observations suggest that microglial cells that migrate circumferentially in the retinal margin share a common origin with dendritic cells of the ciliary body. Therefore, microglial cells of the quail retina appear to make up a heterogeneous population, with some cells originating from the pecten/optic nerve head area and others from the ciliary body.

Naturally occurring cell death and migration of microglial precursors in the quail retina during normal development.

We compared chronotopographical patterns of distribution of naturally occurring neuronal death in the ganglion cell layer (GCL) and the inner nuclear layer (INL) with patterns of tangential and radial migration of microglial precursors during quail retinal development. Apoptotic cells were identified by the terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end labeling technique, and microglial precursors were identified by immunocytochemistry with an antibody recognizing quail microglial cells (QH1 antibody). Apoptotic cells were first detectable in the GCL at the seventh day of incubation (E7), were most abundant at E10, and were absent after E13. In the INL, apoptotic cells first appeared at E7, were most abundant at E12, and disappeared entirely after the third posthatching day (P3). In both retinal layers, cell death first appeared in a small central area of the retina and subsequently spread along three gradients: central-to-peripheral, temporal-to-nasal, and dorsal-to-ventral. The chronology of tangential (between E7 and E16) and radial migration (between E8 and P3) of microglial precursors was highly coincident with that of cell death in the GCL and INL. Comparison of the chronotopographical pattern of distribution of apoptotic nuclei in the GCL with the patterns of tangential and radial migration of microglial precursors neither supported nor refuted the hypothesis that ganglion cell death is the stimulus that triggers the entry and migration of microglial precursors in the developing retina. However, microglial cells in most of the retina traversed the INL only after cell death had ceased in this layer, suggesting that cell death in the INL does not attract microglial precursors migrating radially. Dead cell debris in this layer was phagocytosed by Müller cells, whereas migrating microglial cells were seen phagocytosing apoptotic bodies in the nerve fiber layer and GCL but not in the INL.

Tangential migration of ameboid microglia in the developing quail retina: mechanism of migration and migratory behavior.

Long distance migration of microglial precursors within the central nervous system is essential for microglial colonization of the nervous parenchyma. We studied morphological features of ameboid microglial cells migrating tangentially in the developing quail retina to shed light on the mechanism of migration and migratory behavior of microglial precursors. Many microglial precursors remained attached on retinal sheets containing the inner limiting membrane covered by a carpet of Müller cell endfeet. This demonstrates that most ameboid microglial cells migrate tangentially on Müller cell endfeet. Many of these cells showed a central-to-peripheral polarized morphology, with extensive lamellipodia spreading through grooves flanked by Müller cell radial processes, to which they were frequently anchored. Low protuberances from the vitreal face of microglial precursors were firmly attached to the subjacent basal lamina, which was accessible through gaps in the carpet of Müller cell endfeet. These results suggest a mechanism of migration involving polarized extension of lamellipodia at the leading edge of the cell, strong cell-to-substrate attachment, translocation of the cell body forward, and retraction of the rear of the cell. Other ameboid cells were multipolar, with lamellipodial projections radiating in all directions from the cell body, suggesting that microglial precursors explore the surrounding environment to orient their movement. Central-to-peripheral migration of microglial precursors in the retina does not follow a straight path; instead, these cells perform forward, backward, and sideways movements, as suggested by the occurrence of (a) V-shaped bipolar ameboid cells with their vertex pointing toward either the center or the periphery of the retina, and (b) threadlike processes projecting from either the periphery-facing edge or the center-facing edge of ameboid microglial cells.

Microglia development in the quail cerebellum.

We used the QH1 antibody to study changes in the morphological features and distribution of microglial cells throughout development in the quail cerebellum. Few microglial precursors were present in the cerebellar anlage before the ninth incubation day (E9), whereas many precursors apparently entered the cerebellum from the meninges in the basal region of the cerebellar peduncles between E9 and E16. From this point of entry into the nervous parenchyma, they spread through the cerebellar white matter, forming a 'stream' of labeled cells that could be seen until hatching (E16). The number of microglial cells in the cerebellar cortex increased during the last days of embryonic life and first posthatching week, whereas microglial density within the white matter decreased after hatching. As a consequence, the differences in microglial cell density observed in the cerebellar cortex and the white matter during embryonic life diminished after hatching, and microglia showed a nearly homogeneous pattern of distribution in adult cerebella. Ameboid and poorly ramified microglial cells were found in developing stages, whereas only mature microglia appeared in adult cerebella. Our observations suggest that microglial precursors enter the cerebellar anlage mainly by traversing the pial surface at the basal region of the peduncles, then migrate along the white matter, and finally move radially to the different cortical layers. Differentiation occurs after the microglial cells have reached their final position. In other brain regions the development of microglia follows similar stages, suggesting that these steps are general rules of microglial development in the central nervous system.

Quantitative alterations after long-term alcohol administration in the dorsal lateral geniculate nucleus (dLGN) in the rabbit (Oryctolagus cuniculus).

The effects of chronic excessive alcohol ingestion on the central nervous system were studied in neurons of the dorsal lateral geniculate nucleus (dLGN) in the rabbit (Oryctolagus cuniculus). In this nucleus, neuron density and other morphometric parameters such as the somatic volume of the cells have been investigated both under normal conditions and under alcohol intoxication. Special attention was given to the possibility that positive somatic heteropycnosis may be a sign of imminent cell death. In addition, the percentage volumes occupied by normal neuronal soma and by affected cells were determined. Continuous alcohol treatment for 6 months reduced the size of certain types of neurons, the alteration being specially intense in areas with an abundance of larger neurons. In these areas more intense signs of somatic heteropycnosis also appeared. We discuss the relationship between the condition of the inhibitory neurons (GABAergic interneurons), the distribution of these in the lower zone of the nucleus, and their greater resistance to the influence of alcohol. This type of stereological analysis is intended to provide a better interpretation of the different degrees of the effects of alcohol, and to give more detailed information about changes at cellular level, both for comparative purposes with other situations and to shed light on the alterations caused by alcoholism.

Morphological changes induced by colchicine in the chick optic cup in early stages of development. A stereological study.

In this study chick embryo optic cups at HH stage 13 of development were analyzed under normal conditions and after inoculation with colchicine for 1, 2, 4, and 8 h. Several changes were seen after these periods of treatment: 1) modifications of the structure, with thicker regions in the cup and a general decrease in the total volume according to the duration of exposure to the drug (about 4 times less than normal, 5,035 x 10(3) microns 3 vs 1,334 x 10(3) microns 3 after 8 h of treatment); 2) enlargement of the ventricular cavity and its closure, due to failure of approximation of retinal and pigmentary layers; 3) failure of lens development, with delay and impairment of pit formation and deformation of all structures; lens volume was less than normal (about 4 times less, 2,148 x 10(3) microns 3 vs 658 x 10(3) microns 3 after 8 h of treatment); 4) a general segregation of the cells making up the structure, principally in the more active proliferating zones. The local alterations found are described.

Morphometry and frequency of afferent synaptic terminals in the rabbit dorsal-lateral geniculate nucleus.

Morphological and morphometric features of the retinal synaptic terminals (RLP) and cortical synaptic terminals (RSD) were analyzed in the alpha E sector of the rabbit dorsal-lateral geniculate nucleus (dLGN). A methodological approach was selected which allowed us to determine volume of the neuropil and elsewhere record variations in the size and distribution of the two types of terminals found in the three zones (superior, middle, and inferior) from up to down into which the alpha E sector of the dLGN was divided. After obtaining an isotropic, uniform, and pseudorandom (IUR) sample, the terminals were examined on the basis of a set of morphometric parameters. An analysis of these data showed the retinal terminals (RLP) to be more numerous and to occupy a greater total area of the neuropil in the dorsal (superior) zone of the nucleus, whereas the number and total area occupied by cortical terminals (RSD) did not vary in the superior, middle, and inferior zones. Upon comparing the two types of terminals, the RLP were larger and more widely distributed, the greatest differences between the two appearing in the dorsal (superior) zone of the dLGN.

Stereological study on the mode of optic cup expansion and the accumulation of mitoses in the early stages of chick embryo development.

The present study was designed to contribute to our understanding of the factors that take part in the developmental transformation of the optic vesicle into the optic cup. The expansion and formation of this structure are dependent upon factors such as cellular proliferation, the space or zone occupied by the growing optic cup, and environmental influences. Our investigation in the chick embryo analyzes the relationship between retinal thickness and ventricular mitotic density. This relationship is shown in the study as PEI (proliferation-expansion index). That index varies in the superior, medial and inferior regions of the retina when the zones of the same stage are compared, as well as in the comparisons of values between the 13-14 stage and the 17-18 stage. These differences indicate a different behavior of the cells constituting the retinal regions. Also discussed is the influence of the retinal fissure on the morphological changes observed during optic cup development.