Surgical resection of retrohepatic inferior vena cava leiomyosarcoma without vascular reconstruction: case report.

Inferior vena cava leiomyosarcoma (IVCL) is a rare malignant mesenchymal tumor. Surgical treatment is a challenge because it must combine free surgical margins with vascular reconstruction, using prosthetic or autologous grafts, primary suture, or simple ligation without vein reconstruction. The ligation option is possible thanks to the slow growth of the tumor, allowing collateral venous circulation to develop. We present a case of an IVCL treated with radical resection without vascular reconstruction. The patient was a 48-year-old female with abdominal pain in the right upper quadrant, asthenia, and postprandial dyspeptic symptoms. Abdominal tomography revealed a mass with an expansive formation located in the infrahepatic segment of the inferior vena cava and reduced vessel lumen. During surgery, vein clamping did not provoke hemodynamic repercussions, suggesting sufficient collateral circulation formation. It was decided to perform a radical resection of the entire portion of the retrohepatic vena cava and ligate the vena cava without vascular reconstruction. The patient recovered without complications.

Ressecção cirúrgica de leiomiossarcoma de veia cava inferior retro-hepática sem reconstrução vascular: relato de caso / Surgical resection of retrohepatic inferior vena cava leiomyosarcoma without vascular reconstruction: case report

Resumo O leiomiossarcoma de veia cava inferior (LVCI) é um raro tumor maligno mesenquimal. Seu tratamento cirúrgico é um desafio, pois necessita combinar margens cirúrgicas livres com reconstrução vascular, usando prótese ou enxerto autólogo, sutura primária ou ligadura simples sem reconstrução da veia. A ligadura é possível graças ao lento crescimento do tumor, permitindo o desenvolvimento de circulação venosa colateral. Apresentamos um caso de LVCI tratado por ressecção radical sem reconstrução vascular. Paciente feminina, 48 anos, com dor abdominal em hipocôndrio direito, astenia e sintomas dispépticos pós-prandiais. Tomografia de abdome revelou massa de formação expansiva localizada no segmento infra-hepático da veia cava inferior com redução da luz do vaso. Na cirurgia, o clampeamento da veia não indicou repercussões hemodinâmicas, sugerindo formação de circulação colateral suficiente. Decidiu-se pela ressecção radical em toda a porção da veia cava retro-hepática e ligadura da veia cava sem reconstrução vascular. A paciente evoluiu sem intercorrências.

Abstract Inferior vena cava leiomyosarcoma (IVCL) is a rare malignant mesenchymal tumor. Surgical treatment is a challenge because it must combine free surgical margins with vascular reconstruction, using prosthetic or autologous grafts, primary suture, or simple ligation without vein reconstruction. The ligation option is possible thanks to the slow growth of the tumor, allowing collateral venous circulation to develop. We present a case of an IVCL treated with radical resection without vascular reconstruction. The patient was a 48-year-old female with abdominal pain in the right upper quadrant, asthenia, and postprandial dyspeptic symptoms. Abdominal tomography revealed a mass with an expansive formation located in the infrahepatic segment of the inferior vena cava and reduced vessel lumen. During surgery, vein clamping did not provoke hemodynamic repercussions, suggesting sufficient collateral circulation formation. It was decided to perform a radical resection of the entire portion of the retrohepatic vena cava and ligate the vena cava without vascular reconstruction. The patient recovered without complications.

Isotopic evidence for niche partitioning and the influence of anthropogenic disturbance on endemic and introduced rodents in central Madagascar.

We applied a multi-isotope approach to examine aspects of niche partitioning, competition, and mobility for rodents in the Central Highlands of Madagascar. Specifically, we used carbon (δ13C), nitrogen (δ15N), and strontium (87Sr/86Sr) isotope ratios in bone to investigate diet and mobility for endemic tufted tail rats (Eliurus spp.), and introduced black rats (Rattus rattus) and house mice (Mus musculus) within and outside a fragment of montane humid forest in the Ambohitantely Special Reserve. There was a clear spatial segregation in trapping success for different species: Eliurus was only in the forest interior and edge, Mus only outside of the fragment in a marsh and park housing complex, and Rattus in all habitats except the housing complex. We find only moderate support for mobility of rodents among habitats. Mus may routinely move between the marsh and housing complex. However, regular movement between the forest edge and interior, or between the forest fragment and surrounding grassland is not supported. Taxa appear to target different foods: Rattus tends to feed at a higher trophic level than Eliurus, and Mus consumes some C4 resources. To date, strontium isotopes have been underutilized in ecological research. Here, we show that they are highly complementary to carbon and nitrogen isotope data. Even in localities with relatively uniform underlying geology, it may be possible to distinguish individuals that regularly forage in different habitats.

Scalar Fluxes Near a Tall Building in an Aligned Array of Rectangular Buildings.

Scalar dispersion from ground-level sources in arrays of buildings is investigated using wind-tunnel measurements and large-eddy simulation (LES). An array of uniform-height buildings of equal dimensions and an array with an additional single tall building (wind tunnel) or a periodically repeated tall building (LES) are considered. The buildings in the array are aligned and form long streets. The sensitivity of the dispersion pattern to small changes in wind direction is demonstrated. Vertical scalar fluxes are decomposed into the advective and turbulent parts and the influences of wind direction and of the presence of the tall building on the scalar flux components are evaluated. In the uniform-height array turbulent scalar fluxes are dominant, whereas the tall building produces an increase of the magnitude of advective scalar fluxes that yields the largest component. The presence of the tall building causes either an increase or a decrease to the total vertical scalar flux depending on the position of the source with respect to the tall building. The results of the simulations can be used to develop parametrizations for street-canyon dispersion models and enhance their capabilities in areas with tall buildings.

Are Urban-Canopy Velocity Profiles Exponential?

Using analyses of data from extant direct numerical simulations and large-eddy simulations of boundary-layer and channel flows over and within urban-type canopies, sectional drag forces, Reynolds and dispersive shear stresses are examined for a range of roughness densities. Using the spatially-averaged mean velocity profiles these quantities allow deduction of the canopy mixing length and sectional drag coefficient. It is shown that the common assumptions about the behaviour of these quantities, needed to produce an analytical model for the canopy velocity profile, are usually invalid, in contrast to what is found in typical vegetative (e.g. forest) canopies. The consequence is that an exponential shape of the spatially-averaged mean velocity profile within the canopy cannot normally be expected, as indeed the data demonstrate. Nonetheless, recent canopy models that allow prediction of the roughness length appropriate for the inertial layer's logarithmic profile above the canopy do not seem to depend crucially on their (invalid) assumption of an exponential profile within the canopy.

Neutralización del efecto hemorrágico inducido por veneno de Bothrops asper (Serpientes : Viperidae) por extractos de plantas tropicales / Neutralization of hemorrhagic effect inducid by venom of Bothrops asper (Serpentes: Viperidae) for extracts of tropical plants

Se evaluó la capacidad de extractos orgánicos de 48 especies de plantas costarricense para neutralizar la actividad hemorrágica del veneno de la serpiente Bothrops asper (terciopelo). Los extractos se evaluaron mediante un bioensayo basado en inyecciones intradérmicas de veneno en ratones, o de mezclas veneno-extracto, seguidas de la cuantificación macroscópica de la hemorragia. Se observó una inhibición total de la hemorragia con los extractos etanólicos, de acetato de etilo y acuoso de Bursera simaruba, Clusia torresii, C. palmana, Croton draco, Persea americana, Phoebe brenesii, Pimenta dioica, Sapindus saponaria, Smilax cuculmeca y Virola koschnyi. El análisis químico de estos extractos permitió identificar catequinas, flavonas, antocianinas y taninos condensados, los cuales podrían jugar un papel en la inhibición del efecto hemorrágico debido a la capacidad de quelar el ion zinc requerido por las metaloproteínas hemorrágicas para su acción