Osteocyte lacunar density and area in newly formed bone of the augmented sinus

OBJECTIVES Osteocytes, the most common cells of the bone, are buried in lacunae. Density and area of the osteocyte lacunae change with increasing maturation of the newly formed bone. Evaluation of osteocyte lacunae can therefore provide insights into the process of graft consolidation. MATERIALS AND METHODS Here, we determined the osteocyte lacunar density (number of osteocyte lacunae per bone area; N.Ot/BAr) and the osteocyte lacunar area in μm(2) (Lac.Ar) in histological specimens 6 and 12 weeks after the sinuses of 10 minipigs were augmented with Bio-Oss(®) , a deproteinized bovine bone mineral, and Ostim(®) , an aqueous paste of synthetic nanoparticular hydroxyapatite. The region of interest was defined by the following criteria: (i) >1 mm from the host bone, (ii) >0.5 mm from the sinus mucosa, (iii) minimum area of 0.2 mm(2) , and (iv) bone tissue spanning at least two bone substitute particles. RESULTS The overall osteocyte lacunar density was significantly higher in the Bio-Oss(®) group than in the Ostim(®) group and decreased during the observation period at a similar range in both groups. The osteocyte lacunar area was smaller in the Bio-Oss(®) group than the Ostim(®) group but there was no significant change within the groups over time. CONCLUSIONS These results suggest that bone substitutes affect the osteocyte lacunar density and the osteocyte lacunar area in the newly formed bone within the augmented sinus in this particular model situation. These measures can provide insights into the maturation of newly formed bone in the augmented sinus.

Learning curve for robotic-assisted laparoscopic colorectal surgery.

BACKGROUND: Robotic-assisted laparoscopic surgery (RALS) is evolving as an important surgical approach in the field of colorectal surgery. We aimed to evaluate the learning curve for RALS procedures involving resections of the rectum and rectosigmoid. METHODS: A series of 50 consecutive RALS procedures were performed between August 2008 and September 2009. Data were entered into a retrospective database and later abstracted for analysis. The surgical procedures included abdominoperineal resection (APR), anterior rectosigmoidectomy (AR), low anterior resection (LAR), and rectopexy (RP). Demographic data and intraoperative parameters including docking time (DT), surgeon console time (SCT), and total operative time (OT) were analyzed. The learning curve was evaluated using the cumulative sum (CUSUM) method. RESULTS: The procedures performed for 50 patients (54% male) included 25 AR (50%), 15 LAR (30%), 6 APR (12%), and 4 RP (8%). The mean age of the patients was 54.4 years, the mean BMI was 27.8 kg/m(2), and the median American Society of Anesthesiologists (ASA) classification was 2. The series had a mean DT of 14 min, a mean SCT of 115.1 min, and a mean OT of 246.1 min. The DT and SCT accounted for 6.3% and 46.8% of the OT, respectively. The SCT learning curve was analyzed. The CUSUM(SCT) learning curve was best modeled as a parabola, with equation CUSUM(SCT) in minutes equal to 0.73 × case number(2) - 31.54 × case number - 107.72 (R = 0.93). The learning curve consisted of three unique phases: phase 1 (the initial 15 cases), phase 2 (the middle 10 cases), and phase 3 (the subsequent cases). Phase 1 represented the initial learning curve, which spanned 15 cases. The phase 2 plateau represented increased competence with the robotic technology. Phase 3 was achieved after 25 cases and represented the mastery phase in which more challenging cases were managed. CONCLUSIONS: The three phases identified with CUSUM analysis of surgeon console time represented characteristic stages of the learning curve for robotic colorectal procedures. The data suggest that the learning phase was achieved after 15 to 25 cases.

CX3CR1+ cells facilitate the activation of CD4 T cells in the colonic lamina propria during antigen-driven colitis

Dendritic cells (DCs) and macrophages populate the intestinal lamina propria to initiate immune responses required for the maintenance of intestinal homeostasis. To investigate whether CX3CR1(+) phagocytes communicate with CD4 T cells during the development of transfer colitis, we established an antigen-driven colitis model induced by the adoptive transfer of DsRed OT-II cells in CX3CR1(GFP/+) × RAG(-/-) recipients challenged with Escherichia coli expressing ovalbumin (OVA) fused to a cyan fluorescent protein (CFP). After colonization of CX3CR1(GFP/+) × RAG(-/-) animals with red fluorescent E. coli pCherry-OVA, colonic CX3CR1(+) cells but not CD103(+) DCs phagocytosed E. coli pCherry-OVA. Degraded bacterial-derived antigens are transported by CD103(+) DCs to mesenteric lymph nodes (MLNs), where CD103(+) DCs prime naive T cells. In RAG(-/-) recipients reconstituted with OT II cells and gavaged with OVA-expressing E. coli, colonic CX3CR1(+) phagocytes are in close contact with CD4 T cells and presented bacterial-derived antigens to CD4 T cells to activate and expand effector T cells.

The Early Activation Marker CD69 Regulates the Expression of Chemokines and CD4 T Cell Accumulation in Intestine

Migration of naïve and activated lymphocytes is regulated by the expression of various molecules such as chemokine receptors and ligands. CD69, the early activation marker of C-type lectin domain family, is also shown to regulate the lymphocyte migration by affecting their egress from the thymus and secondary lymphoid organs. Here, we aimed to investigate the role of CD69 in accumulation of CD4 T cells in intestine using murine models of inflammatory bowel disease. We found that genetic deletion of CD69 in mice increases the expression of the chemokines CCL-1, CXCL-10 and CCL-19 in CD4(+) T cells and/or CD4(-) cells. Efficient in vitro migration of CD69-deficient CD4 T cells toward the chemokine stimuli was the result of increased expression and/or affinity of chemokine receptors. In vivo CD69(-/-) CD4 T cells accumulate in the intestine in higher numbers than B6 CD4 T cells as observed in competitive homing assay, dextran sodium sulphate (DSS)-induced colitis and antigen-specific transfer colitis. In DSS colitis CD69(-/-) CD4 T cell accumulation in colonic lamina propria (cLP) was associated with increased expression of CCL-1, CXCL-10 and CCL-19 genes. Furthermore, treatment of DSS-administrated CD69(-/-) mice with the mixture of CCL-1, CXCL-10 and CCL-19 neutralizing Abs significantly decreased the histopathological signs of colitis. Transfer of OT-II×CD69(-/-) CD45RB(high) CD4 T cells into RAG(-/-) hosts induced CD4 T cell accumulation in cLP. This study showed CD69 as negative regulator of inflammatory responses in intestine as it decreases the expression of chemotactic receptors and ligands and reduces the accumulation of CD4 T cells in cLP during colitis.

Luaḥ ha-Ittim : Zeittafel der biblischen und nachbiblischen Geschichte der Juden von der Erschaffung der Welt bis zum Jahre 5560, (dem Anfange des 19. Jahrhunderts üblicher Zeitrechnung) ; in 2 Abth.

von H. Schlesinger

Prima pars Ebreae grammatices pro indipientibus ...

Johanne Auenario Egrano. Cum praef. Philippi Melanthonis

Characterization of tumor-associated Foxp3+ regulatory T cells and de-novo induction by the tumor microenvironment

Regulatory T cells expressing the fork-head box transcription factor 3 (Foxp3) play a central role in the dominant control of immunological tolerance. Compelling evidence obtained from both animal and clinical studies have now linked the expansion and accumulation of Foxp3+ regulatory T cells associated with tumor lesions to the failure of immune-mediated tumor rejection. However, further progress of the field is hampered by the gap of knowledge regarding their phenotypic, functional, and the developmental origins in which these tumor-associated Foxp3+ regulatory T cells are derived. Here, we have characterized the general properties of tumor-associated Foxp3+ regulatory T cells and addressed the issue of tumor microenvironment mediated de-novo induction by utilizing a well known murine tumor model MCA-205 in combination with our BAC Foxp3-GFP reporter mice and OT-II TCR transgenic mice on the RAG deficient background (RAG OT-II). De-novo induction defines a distinct mechanism of converting non-regulatory precursor cells to Foxp3+ regulatory T cells in the periphery as opposed to the expansion of pre-existing regulatory T cells formed naturally during thymic T cell development. This mechanism is of particularly importance to how tumors induce tumor-antigen-specific suppressor cells to subvert anti-tumor immune responses. Our study has found that tumor-associated Foxp3+ regulatory T cells are highly activated, undergo vigorous proliferation, are more potent by in-vitro suppression assays, and express higher levels of membrane-bound TGF-β1 than non-tumor regulatory T cells. With Foxp3-GFP reporter mice or RAG OT-II TCR transgenic mice, we show that tumor tissue can induce detectable de-novo generation of Foxp3+ regulatory T cells of both polyclonal or antigen specific naïve T cells. This process was not only limited for subcutaneous tumors but for lung tumors as well. Furthermore, this process required the inducing antigen to be co-localized within the tumor tissue. Examination of tumor tissue revealed an abundance of myeloid CD11b+ antigen-presenting cells that were capable of inducing Foxp3+ regulatory T cells. Taken together, these findings elucidate the general attributes and origins of tumor-associated Foxp3+ regulatory T cells in the tumor microenvironment and in their role in the negative regulation of tumor immunity.^

Investigation of Quaternary diatoms in sediment core CRP-1 from the Ross Sea, Antarctica

In the first season of drilling, the Cape Roberts Project (CRP) recovered one drillcore (CRP-l) from Roberts Ridge in western McMurdo Sound, Ross Sea, Antarctica Diatom biostratigraphy places the upper six lithostratigraphic units (Units 1.1, 2.1, 2.2, 2.3, 3.1, and 4.1) of CRP-l (0.0 to 43.15 mbsf) within the Quaternary. Both non-marine and marine Quaternary diatoms occur in variable abundance in the Quaternary interval of CRP- 1 Biostratigraphic data resolve two Quaternary time slices or events within CRP-1. Marine diatom assemblages in Units 4.1 and 3.1 represent sedimentation within the diatom Actinocyclus ingens Zone (1.35 to 0.66 Ma). Further refinement of the age of Unit 3.l places deposition in the interval 1.15 to 0.75 Ma based on the common occurrence of Thalassiosira elliptipora and correlation to the Southern Ocean acme of this taxon The absence of ActiActinocyclus ingens and the presence ot Thalassiosira antarctica in Unit 2.2 require a younger zonal assignment for this interval, within the diatom Thalassiosira lentiginosa Zone (0.66 to 0.0 Ma). A new diatom species. Rouxia leventerae, is described from marine assemblages of Units 2.2, 2.3, 3.1, and 4.l. Lithostratigraphic Unit 3.1 (33.82 to 31.89 mbsf) is a bryozoan-dominated skeletal-carbonate facies. Low abundance of Fragilariopsis curta and Fragilariopsis cylindrus within this unit combined with the relatively high abundance of species associated with open water indicates deposition in waters that remained ice free for much or all of the year Diatom assemblages suggest carbonate deposition in Unit 3.1 is linked to a significant early Pleistocene event in McMurdo Sound, when elevated surface-water temperatures inhibited the formation of sea ice.

Grupo de discusión en línea. En: Jornadas Bibliotecolocológicas: Modalidades de acceso y trasferencia de la información en contextos actuales

Presentación del Grupo de Discusión en línea "Bibliomisioneros"

Mean cover and frequencies of vascular plant species during three decades around Abisko Scientific Research Station

Plant species distributions are expected to shift and diversity is expected to decline as a result of global climate change, particularly in the Arctic where climate warming is amplified. We have recorded the changes in richness and abundance of vascular plants at Abisko, sub-Arctic Sweden, by re-sampling five studies consisting of seven datasets; one in the mountain birch forest and six at open sites. The oldest study was initiated in 1977-1979 and the latest in 1992. Total species number increased at all sites except for the birch forest site where richness decreased. We found no general pattern in how composition of vascular plants has changed over time. Three species, Calamagrostis lapponica, Carex vaginata and Salix reticulata, showed an overall increase in cover/frequency, while two Equisetum taxa decreased. Instead, we showed that the magnitude and direction of changes in species richness and composition differ among sites.

Plan de ordenamiento territorial preliminar : litoral de Río Negro, Argentina

Para la generación de un Plan de Ordenamiento territorial preliminar del Litoral de Río Negro se requiere seguir una metodología de trabajo de acuerdo a las siguientes actividades: capacitación de técnicos y profesionales de la administración pública (especialmente dirigido a la formulación de programas y proyectos ambientales), viabilidad y utilidad de estudios de impacto ambiental e integración y coordinación ínter administrativa. En segunda instancia se determina el área de estudio, la que se describe en cuanto a sus aspectos físicos naturales y en cuanto al medio antrópico (población, asentamientos, infraestructura regional y turismo). La metodología utilizada para el Plan de OT preliminar se basa en el método sintético de identificación de unidades integrales de paisaje. Para su definición se relevan en campo datos del medio físico, biológico y antrópico. Se segmenta el área de estudio para determinar unidades ambientales y unidades del paisaje presentes, se clasifican las unidades geoambientales dando lugar a una cartografía sintética y luego a una analógica. Las unidades obtenidas permiten identificar los principales conflictos y problemáticas ambientales, que son la guía utilizada para definir los criterios de ordenamiento del territorio. Toda esta información fue finalmente introducida a un SIG, dando lugar a las bases cuali y cuantitativas para plantear el Plan de ordenamiento territorial y propuestas de normativas a seguir.

Enfoques del ordenamiento territorial en América Latina

Enfoques del Ordenamiento Territorial en América Latina." La Revista Proyección editada por el Instituto CIFOT inicia una nueva etapa. El Comité Editor decide pasar al formato digital. Lanzada en el IV Seminario de OT (2007), incorpora los tres primeros números editados. La que hoy aparece lleva el Nº 4 y presenta los últimos enfoques teóricos metodológicos sobre el binomio ambiente -territorio, planteos a nivel mundial sobre desarrollo sustentable, sostenibilidad ambiental en el desarrollo territorial y su relación con el desarrollo local. Aparecen artículos referidos a metodologías para analizar y diagnosticar problemáticas urbanas y rurales, resultados de investigaciones y experiencias que demuestran la eficacia del Ordenamiento Territorial como herramienta de planificación y de gestión que ayuda a minimizar desequilibrios socioeconómicos y el deterioro ambiental. Damos respuesta a las inquietudes del público y aprovechamos la ocasión para invitar a sumarse a quienes tengan trabajos referidos a estos temas y quieran publicarlos.

Gestión del ordenamiento territorial en América Latina : desarrollo recientes

Las principales conclusiones del estudio realizado entre los años 2001 y 2002 sobre las políticas de ordenamiento territorial que desde comienzos de los años ochenta del siglo pasado se desarrollaban en los países de América Latina muestran que hacia el año 2002 las políticas latinoamericanas de Ordenamiento Territorial (OT) se encontraban en un estado incipiente. A través del análisis de los casos de países como Argentina, El Salvador, Honduras, Nicaragua, Uruguay, México y Colombia se puede observar la complejidad de la gestión territorial en América Latina y los desafíos que enfrenta. Frente a esto es necesaria una apuesta territorial integral hacia un modelo de desarrollo en el que la política económica (global), las políticas sectoriales y las territoriales confluyan en la búsqueda de un nuevo orden territorial regionalmente armónico y equilibrado, socialmente justo y democrático, descentralizado, ambientalmente sostenible y económicamente competitivo, pero entendiendo dicha competitividad sin detrimento de los derechos sociales, ambientales y económicos de los ciudadanos. Es posible que bajo la lógica perversa de la economía de mercado esto sea una utopía, pero es lo único que le da sentido y significado socialmente aceptable a las políticas de desarrollo y ordenamiento territorial.

Desarrollo de herramientas y estrategias para el ordenamiento territorial

El presente no es un proyecto de investigación, sino de gestión y desarrollo de herramientas para la toma de decisiones. Su objetivo es colaborar dentro del marco de la "Red Nacional de Ordenamiento y Desarrollo Territorial" (Poder Ejecutivo Nacional, 2004) propuesta por el Gobierno Nacional, con los gobiernos provinciales y otros organismos en la planificación del uso de los recursos del territorio, procurando un manejo sostenible de los mismos, a fin de reducir en forma progresiva los desequilibrios espaciales, contribuyendo a elevar la calidad de vida de todos los habitantes del país. En las últimas décadas, ante la existencia de una creciente presión antrópica sobre el medio natural y, paralelamente, un mayor grado de conocimiento de las causas y efectos de los diferentes riesgos, éstos han comenzado a tener mayor influencia en la determinación de políticas y prioridades para inversiones o emprendimientos económicos en general y en la fijación de pautas de ocupación del territorio. La planificación aparece como una herramienta adecuada para orientar y organizar el desarrollo equitativo y sustentable de un territorio y la población que lo ocupa. El Ordenamiento Territorial (OT) significa disponer, con orden, la ocupación y usos del territorio según la mayor o menor aptitud de sus diferentes elementos constitutivos. Este proyecto se considera estratégico para el Programa Nacional Ecoregiones del INTA (PNECO), ya que encara los problemas territoriales desde un punto de vista global (aspectos económicos, sociales, productivos, culturales y ambientales), tradicionalmente tratados de forma sectorial, plantea directivas a mediano y largo plazo (escenarios) y guía la planificación regional y local. El enfoque central del OT es la visión participativa, acordando intereses contrapuestos (trade-offs1) y sinérgicos, transformando amenazas en oportunidades. Es este punto central el que permitirá vincular el PNECO con todos sus Proyecto Específicos (PE), considerando el marco de políticas públicas vinculadas al medio ambiente y la producción en cada ecoregión del país, asociado al Programa Nacional de Territorios del INTA

Políticas territoriales y construcción del paisaje cultural : caso región Gran La Plata

El propósito es presentar las principales estrategias de ordenamiento territorial urbano puestas en práctica en los últimos quince años en el Gran La Plata, que han incidido en el paisaje cultural. Se observan tanto políticas de enfoques integrales como sectoriales, las que incorporan innovaciones en OT y proponen nuevos y/o renovados paisajes culturales y las políticas “centrales" desde las gestiones municipales. Se reflexiona sobre aportes y debilidades, incompatibilidades entre ellas, en el marco del desarrollo sustentable. La estrategia metodológica utilizada tiene un perfil cualitativo y de tipo exploratoria, con un diseño de naturaleza flexible. En el estudio de caso se identifican las modalidades de intervención en función de las transformaciones del paisaje resultante y su gestión. Tiene una fuerte orientación interpretativa y la estrategia general está orientada a conseguir una familiarización con hechos aun no suficientemente comprendidos para generar nuevas ideas que permitan realizar nuevas preguntas e hipótesis. En este marco, las políticas se tornan contradictorias, si bien han logrado modificar algunos microespacios. Se entienden más como el recorte y congelamiento/ restauración del paisaje previo que como la creación de otros renovados, nuevos y/o mejores y con valores sociales aggiornados. En lo ambiental, no han sido acompañadas por estrategias estructurantes como el arbolado urbano y disposición de los residuos sólidos urbanos.