Sistema nacional de procuración de órganos y tejidos para trasplante

El sistema nacional de procuración de órganos, tejidos y células para trasplante en la Argentina es impulsado, normatizado, coordinado y fiscalizado por el Incucai (Instituto Nacional Central Único Coordinador de Ablación e Implante). Hoy, el sistema de salud cuenta con más de 4000 profesionales capacitados, 300 centros de trasplante, 50 bancos de tejidos y 30 laboratorios de histocompatibilidad habilitados por el Incucai en todo el país. La conciencia sobre la importancia de la donación ha crecido y actualmente cerca de 2.300.000 personas han manifestado la decisión de donar sus órganos y tejidos y otras 40.000 se han inscripto como donantes de células de la médula ósea. En el presente trabajo se analizarán los siguientes puntos: situación actual, logros y avances; principios de definen la distribución de órganos; retos de la donación y el trasplante en la Argentina.

El poder judicial en la organización constitucional

Resumen: La potestad judicial en el principio del constitucionalismo moderno aparece diseñada de modo impreciso y sin función clara. Ella adquiere entidad en el derecho norteamericano cuando la propia jurisprudencia diseña el control de constitucionalidad. Este es resistido por el derecho continental europeo, aunque finalmente aceptado, con otras modalidades, luego de la Segunda Guerra Mundial. Con el tiempo ese poder excede el mero control de las leyes, para transformarse a través de sus sentencias en órgano que compite en la creación del derecho con los poderes políticos encargados de la función de gobierno. El autor considera que esa función basada en principios de normas internacionales de discutible vigencia y sin el freno de la consideración, por el nominalismo que la anima, de la existencia de un orden objetivo termina originando un poder incontrolable con riesgo de destrucción social.

El proceso de donación trasplante : una mirada interdisciplinaria

El trasplante de órganos es hoy un tratamiento habitual pero que tiene su limitación más importante en el total de órganos donados, que si bien va aumentando año tras año, no alcanza para satisfacer las demandas cada vez más crecientes, tornándose en un problema sanitario mundial. No es redundante precisar que el proceso de donación trasplante es sumamente complejo y que requiere la actuación de un número importante de sujetos, de las instituciones asistenciales y de la sociedad en general. En este artículo se intenta realizar un resumen esquemático de un proceso de donación a corazón batiente, que inicia con la llamada de detección; pasando por el diagnóstico de muerte bajo criterios neurológicos; selección, evaluación y mantenimiento del potencial donante; distribución de órganos y tejidos; y finalmente el punto más complejo que es el abordaje familiar en un contexto de altísima crisis.

Extracción de órganos de cadáveres con fines de trasplante. Voluntariedad y consentimiento presunto

El tema del llamado “consentimiento presunto” a los fines de habilitar la extracción de órganos cadavéricos ha suscitado debate e interés en ámbitos bioéticos y biojurídicos. Cuestiones como la del valor y significado del cuerpo y el cadáver, la relación entre el individuo y la comunidad, el papel de la voluntad y la libertad en las decisiones relacionadas con el propio cuerpo, tienen aquí especial relevancia. Varias leyes han tratado estos temas y distintos países se rigen por diferentes sistemas. La gran pregunta que recorrerá este trabajo se remite al papel y relevancia que se considera debe darse a la voluntad del difunto a la hora de disponer de sus órganos para trasplante.

La educación, la sociedad y los trasplantes: una solución a demostrar

Resumen: La grave consecuencia del comportamiento renuente de la sociedad respecto de la donación es la “muerte injusta de pacientes” en listas de espera. La escasez de órganos y el incremento de estas listas han alentado la búsqueda de soluciones. El público necesita educación e información sin ambigüedades. Además, la parcial formación universitaria sobre este tema es también responsable de una inadecuada acción médica. Para lograr esto, sería necesaria la incorporación de programas de educación en trasplantes en los planes de estudios escolares, el apoyo de las comunidades trasplantológicas nacionales e internacionales y el activo sostén del Estado y de los distintos credos religiosos. Es nuestro deber generar una solución para evitar que políticas racionalistas dirigidas a modificar la escasez de órganos no resulten ineficaces y aun contraproducentes debido a una atención inadecuada a los complejos rasgos antropológicos, psicológicos y ético-sociales del ser humano

Aspectos bioéticos del trasplante con donantes vivos

Resumen: El 4 de junio de 2010 se solicita al Comité de Bioética del Hospital Privado de Córdoba, Argentina, una consulta para que se analicen los aspectos éticos de un trasplante pulmonar lobar bilateral, con donante vivo relacionado para dos hermanas gemelas de 17 años con diagnóstico de fibrosis quística (Acta 172). Este caso nos permite revisar dos ejes esenciales de la constitución de la Bioética como son las funciones y actuación de los comités de Bioética en las instituciones hospitalarias, y la licitud de los trasplantes de órganos cuando hay donantes vivos. Se justificará la actuación del Comité de Bioética en este caso, analizando los puntos a tener en cuenta y los recaudos y recomendaciones que habrían de considerarse frente a esta situación planteada.

Tutela de la vida y trasplantes : fundamentos filosóficos de la bioética contemporánea

Los problemas bioéticos que surgen en relación con los temas de la tutela de la vida y de los trasplantes tendrán respuestas diversas, a veces incluso contrarias, según sea el fundamento filosófico del que se parta. Se analiza así, en primer lugar, la filosofía subyacente en los principios de la Bioética anglosajona. A continuación se examina la corriente bioética que aparece como opuesta al “Principismo anglosajón” y se ofrece como una alternativa desde la Europa continental, a saber, el “Personalismo”, analizando las corrientes filosófico-antropológicas que le sirven de fundamento a las diversas formas de personalismo. Finalmente, en una evaluación críticofilosófica se concluye que ni el personalismo relacional, ni el personalismo hermenéutico, ni el personalismo “a secas” son la respuesta bioética adecuada para sostener la cultura de la vida. Solamente el Personalismo ontológicamente fundado puede dar una respuesta a las cuestiones bioéticas más comprometidas, como las que se refieren a la vida o a la muerte de personas cualquiera sea su madurez, su capacidad operativa y relacional.

O Colégio de Líderes : surgimento e evolução

Discute o funcionamento do Colégio de Líderes e seus efeitos sobre a atividade legislativa da Câmara dos Deputados. Para isso, a pesquisa se baseou em artigos científicos sobre o tema e documentos que demonstram o que motivou a criação do colegiado, como ele se reúne e de que modo ele colabora para a definição da pauta de votações do Plenário. Inclui entrevistas com figuras que participaram ativamente da criação e da evolução do Colégio de Líderes no cenário político. Descreve, ainda, de que forma a sua atuação limita a representatividade parlamentar e que soluções poderiam ser adotadas para amenizar esse conflito, já que, apesar de colaborar para a concentração de poderes no Congresso Nacional, esse órgão se tornou indispensável para a organização e agilidade dos trabalhos legislativos. Para ilustrar como se dá na prática a atuação do colegiado, procedeu-se a uma análise das reuniões realizadas no primeiro período da sessão legislativa ordinária de 2009, tudo com base em dados fornecidos pela Secretaria-Geral da Mesa da Câmara dos Deputados e em notícias da Agência Câmara divulgadas naquele semestre.

Flow pattern in chandler loop - the artificial thrombus formation

In this paper a hydrodynamic approach is used to analyse carefully the flow field inChandler loop--the artificial thrombus formation. The results obtained show that near thelower meniscus where the thrombus is formed, there is a back flow accompanied with asecondary flow and its mainflow is toward the meniscus, thus providing a favourable condi-tion for corpuscle aggregation. Our finding is valuable for studying the mechanism ofthrombus formation in artificial organ and in vivo.

Psicología Evolutiva y Psicología Evolucionista. Claves para la discusión

[Es] La teoría creacionista, universalmente en vigor antes de Darwin (y aún hoy sostenida por más de uno) sostenía que había habido una mente (divina), encargada de diseñar al hombre; que le puso ojos para que viera, oídos, mente para que pensara...Desde Darwin, por el contrario, se opina que la necesidad de enfrentarse a problemas diversos hizo que la mente fuera diversificándose, a través de sucesivas selecciones de las mentes más adaptativas. Según esto: 1.-¿Existen maquinarias biológicas “especializadas” en nuestro cerebro?. Y si existieran, 2.-¿Se desarrollan de forma espontánea?; es decir, sin esfuerzo ni instrucción formal? 3.-¿Se despliegan de forma inconsciente, autónoma y similar en todos los seres humanos? En definitiva: ¿Existe algo (facultad psicológica, órgano mental, sistema neurológico, módulo computacional…) que permita decir que las personas saben esto… o aquello… en el mismo sentido que las arañas saben tejer o los pájaros construir sus nidos?

Cell Reprogramming, IPS Limitations, and Overcoming Strategies in Dental Bioengineering

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O colégio de líderes : surgimento e evolução

Discute o funcionamento do Colégio de Líderes e seus efeitos sobre a atividade legislativa da Câmara dos Deputados. Para isso, a pesquisa se baseou em artigos científicos sobre o tema e documentos que demonstram o que motivou a criação do colegiado, como ele se reúne e de que modo ele colabora para a definição da pauta de votações do plenário. Incluindo entrevistas com figuras que participaram ativamente da criação e da evolução do Colégio de Líderes no cenário político, este trabalho descreve de que forma a sua atuação limita a representatividade parlamentar e que soluções poderiam ser adotadas para amenizar esse conflito, já que, apesar de colaborar para a concentração de poderes no Congresso Nacional, esse órgão se tornou indispensável para a organização e agilidade dos trabalhos legislativos. Para ilustrar como se dá, na prática, a atuação do colegiado, procedeu-se a uma análise acerca das reuniões realizadas no primeiro período da sessão legislativa ordinária de 2009, tudo com base em dados fornecidos pela Secretaria-Geral da Mesa e em notícias da Agência Câmara divulgadas naquele semestre.

Report on Marine Mammal Unusual Mortality Event UMESE0501Sp: Multispecies Mass Stranding of Pilot Whales (Globicephala macrorhynchus), Minke Whale (Balaenoptera acutorostrata), and Dwarf Sperm Whales (Kogia sima) in North Carolina on 15-16 January 2005

On 15-16 January 2005, three offshore species of cetaceans (33 short-finned pilot whales, Globicephala macrorhynchus, one minke whale, Balaenoptera acutorostrata, and two dwarf sperm whales, Kogia sima) stranded alive on the beaches of North Carolina. The pilot whales stranded near Oregon Inlet, the minke whale in northern North Carolina, and the dwarf sperm whales near Cape Hatteras. Live strandings of three species in one weekend was unique in North Carolina and qualified as an Unusual Mortality Event. Gross necropsies were conducted on 16-17 January 2005 on 27 pilot whales, two dwarf sperm whales, and the minke whale. Samples were collected for clinical pathology, parasitology, gross pathology, histopathology, microbiology and serology. There was variation in the number of animals sampled for each collection type, however, due to carcasses washing off the beach or degradation in carcass condition during the course of the response. Comprehensive histologic examination was conducted on 16 pilot whales, both dwarf sperm whales, and the minke whale. Limited organ or only head tissue suites were obtained from nine pilot whales. Histologic examination of tissues began in February 2005 and concluded in December 2005 when final sampling was concluded. Neither the pilot whales nor dwarf sperm whales were emaciated although none had recently ingested prey in their stomachs. The minke whale was emaciated; it was likely a dependent calf that became separated from the female. Most serum biochemistry abnormalities appear to have resulted from the stranding and indicated deteriorating condition from being on land for an extended period. Three pilot whales had clinical evidence of pre-existing systemic inflammation, which was supported by histopathologic findings. Although gross and histologic lesions involving all organ systems were noted, consistent lesions were not observed across species. Verminous pterygoid sinusitis and healed fishery interactions were seen in pilot whales but neither of these changes were causes of debilitation or death. In three pilot whales and one dwarf sperm whale there was evidence of clinically significant disease in postcranial tissues which led to chronic debilitation. Cardiovascular disease was present in one pilot whale and one dwarf sperm whale; musculoskeletal disease and intra-abdominal granulomas were present in two pilot whales. These lesions were possible, but not definitive, causal factors in the stranding. Remaining lesions were incidental or post-stranding. The minke whale and three of five tested pilot whales had positive morbillivirus titers (≥1:8 with one at >1:256), but there was no histologic evidence of active viral infection. Parasites (nematodes, cestodes, and trematodes) were collected from 26 pilot whales and two dwarf sperm whales. Sites of collection included stomach, nasal/pterygoid, peribullar sinuses, blubber, and abdominal cavity. Parasite species, locations and loads were within normal limits for free-ranging cetaceans and were not considered causative for the stranding event. Gas emboli lesions which were considered consistent with or diagnostic of sonarassociated strandings of beaked whales or small cetaceans were not found in the whales stranded as part of UMESE0501Sp. Twenty-five heads were examined with nine specific anatomic locations of interest: extramandibular fat, intramandibular fat, auditory meatus, peribullar acoustic fat, peribullar soft tissue, peribullar sinus, pterygoid sinus, melon, and brain. The common finding in all examined heads was verminous pterygoid sinusitis. Intramandibular adipose tissue reddening, typically adjacent to the vascular plexus, was observed in some individuals and could represent localized hemorrhage resulting from vascular rete rupture, hypostatic congestion, or erythrocyte rupture during the freeze/thaw cycle. One cetacean had peracute to acute subdural hemorrhage that likely occurred from thrashing on the beach post-stranding, although its occurrence prior to stranding cannot be excluded. Information provided to NMFS by the U.S. Navy indicated routine tactical mid-frequency sonar operations from individual surface vessels over relatively short durations and small spatial scales within the area and time period investigated. No marine mammals were detected by marine mammal observers on operational vessels; standard operating procedure for surface naval vessels operating mid-frequency sonar is the use of trained visual lookouts using high-powered binoculars. Sound propagation modeling using information provided to NMFS indicated that acoustic conditions in the vicinity likely depended heavily on position of the receivers (e.g., range, bearing, depth) relative to that of the sources. Absent explicit information on the location of animals meant that it was not possible to estimate received acoustic exposures from active sonar transmissions. Nonetheless, the event was associated in time and space with naval activity using mid-frequency active sonar. It also had a number of features in common (e.g., the “atypical” distribution of strandings involving multiple offshore species, all stranding alive, and without evidence of common infectious or other disease process) with other sonar-related cetacean mass stranding events. Given that this event was the only stranding of offshore species to occur within a 2-3 day period in the region on record (i.e., a very rare event), and given the occurrence of the event simultaneously in time and space with a naval exercise using active sonar, the association between the naval sonar activity and the location and timing of the event could be a causal rather than a coincidental relationship. However, evidence supporting a definitive association is lacking, and, in particular, there are differences in operational/environmental characteristics between this event and previous events where sonar has apparently played a role in marine mammal strandings. This does not preclude behavorial avoidance of noise exposure. No harmful algal blooms were present along the Atlantic coast south of the Chesapeake Bay during the months prior to the event. Environmental conditions, including strong winds, changes in upwelling- to downwelling-favorable conditions, and gently sloping bathymetry, were consistent with conditions which have been correlated with other mass strandings. In summary, we did not find commonality in gross and histologic lesions that would indicate a single cause for this stranding event. Three pilot whales and one dwarf sperm whale had debilitating conditions identified that could have contributed to stranding, one pilot whale had a debilitating condition (subdural hemorrhage) that could have been present prior to or resulting from stranding. While the pilot and dwarf sperm whale strandings may have had a common cause, the minke whale stranding was probably just coincidental. On the basis of examination of physical evidence in the affected whales, however, we cannot definitively conclude that there was or was not a causal link between anthropogenic sonar activity or environmental conditions (or a combination of these factors) and the strandings. Overall, the cause of UMESE0501Sp in North Carolina is not and likely will not be definitively known. (PDF contains 240 pages)

Candida albicans Increases Tumor Cell Adhesion to Endothelial Cells In Vitro: Intraspecific Differences and Importance of the Mannose Receptor

The dimorphic fungus Candida albicans is able to trigger a cytokine-mediated pro-inflammatory response that increases tumor cell adhesion to hepatic endothelium and metastasis. To check the intraspecific differences in this effect, we used an in vitro murine model of hepatic response against C. albicans, which made clear that tumor cells adhered more to endothelium incubated with blastoconidia, both live and killed, than germ tubes. This finding was related to the higher carbohydrate/protein ratio found in blastoconidia. In fact, destruction of mannose ligand residues on the cell surface by metaperiodate treatment significantly reduced tumor cell adhesion induced. Moreover, we also noticed that the effect of clinical strains was greater than that of the reference one. This finding could not be explained by the carbohydrate/protein data, but to explain these differences between strains, we analyzed the expression level of ten genes (ADH1, APE3, IDH2, ENO1, FBA1, ILV5, PDI1, PGK1, QCR2 and TUF1) that code for the proteins identified previously in a mannoprotein-enriched pro-metastatic fraction of C. albicans. The results corroborated that their expression was higher in clinical strains than the reference one. To confirm the importance of the mannoprotein fraction, we also demonstrate that blocking the mannose receptor decreases the effect of C. albicans and its mannoproteins, inhibiting IL-18 synthesis and tumor cell adhesion increase by around 60%. These findings could be the first step towards a new treatment for solid organ cancers based on the role of the mannose receptor in C. albicans-induced tumor progression and metastasis.

The electric field of a weakly electric fish

Freshwater fish of the genus Apteronotus (family Gymnotidae) generate a weak, high frequency electric field (< 100 mV/cm, 0.5-10 kHz) which permeates their local environment. These nocturnal fish are acutely sensitive to perturbations in their electric field caused by other electric fish, and nearby objects whose impedance is different from the surrounding water. This thesis presents high temporal and spatial resolution maps of the electric potential and field on and near Apteronotus. The fish's electric field is a complicated and highly stable function of space and time. Its characteristics, such as spectral composition, timing, and rate of attenuation, are examined in terms of physical constraints, and their possible functional roles in electroreception.

Temporal jitter of the periodic field is less than 1 µsec. However, electrocyte activity is not globally synchronous along the fish 's electric organ. The propagation of electrocyte activation down the fish's body produces a rotation of the electric field vector in the caudal part of the fish. This may assist the fish in identifying nonsymmetrical objects, and could also confuse electrosensory predators that try to locate Apteronotus by following its fieldlines. The propagation also results in a complex spatiotemporal pattern of the EOD potential near the fish. Visualizing the potential on the same and different fish over timescales of several months suggests that it is stable and could serve as a unique signature for individual fish.

Measurements of the electric field were used to calculate the effects of simple objects on the fish's electric field. The shape of the perturbation or "electric image" on the fish's skin is relatively independent of a simple object's size, conductivity, and rostrocaudal location, and therefore could unambiguously determine object distance. The range of electrolocation may depend on both the size of objects and their rostrocaudal location. Only objects with very large dielectric constants cause appreciable phase shifts, and these are strongly dependent on the water conductivity.