Kinematics and dynamics of the auto-rotation of a model winged seed.

Numerical simulations of the auto-rotation of a model winged seed are presented. The calculations are performed by solving simultaneously the Navier-Stokes equations for the flow surrounding the seed and the rigid-body equations for the motion of the seed. The Reynolds number based on the descent speed and a characteristic chord length is varied in the range 80-240. Within this range, the seed attains an asymptotic state with finite amplitude auto-rotation, while for smaller values of the Reynolds number no auto-rotation is observed. The motion of the seed is characterized by the coning and pitch angles, the angular velocity and the horizontal translation of the seed. The values obtained for these quantities are qualitatively similar to those reported in the literature in experiments with real winged seeds. When increasing the Reynolds number, the seed tends to rotate at higher speeds, with less inclination with respect to the horizontal plane, and with a larger translation velocity. With respect to the aerodynamic forces, it is observed that, with increasing Reynolds number, the horizontal components decrease in magnitude while the vertical component increases. The force distribution along the wing span is characterized using both global and local characteristic speeds and chord lengths for the non-dimensionalisation of the force coefficients. It is found that the vertical component does not depend on the Reynolds number when using local scaling, while the chordwise component of the force does.

Case report of splenic artery steal syndrome: demonstration of portal hyperflow mechanism by anatomic variant of the splenic artery and correlation with Doppler rates.

We report the case of a liver transplant recipient who developed a "splenic artery steal syndrome" (SASS) successfully treated by partial splenic embolization (PSE). Interestingly, because the patient presented an anatomic variant of the splenic artery (SA) originating from the superior mesenteric artery (SMA), improvement was observed in hepatic artery (HA) flow following PSE that could only be explained by decreased portal perfusion and not by the derivation from the SA.

Toxicidad hepática recurrente secundaria a metilprednisolona intravenosa / No disponible

Las reacciones adversas hepáticas relacionadas con la administraciónde fármacos (hepatotoxicidad) son cuadros relativamentefrecuentes que presentan una amplia variabilidad clínica e histológica.La identificación precoz de estos cuadros es fundamental enla práctica clínica debido a su potencial gravedad. En la mayoríade los casos la suspensión del fármaco desencadenante es suficientepara la resolución del cuadro clínico.A pesar de que los esteroides son utilizados en una amplia variedadde situaciones clínicas, la notificación de cuadros de hepatotoxicidadsecundaria a esteroides intravenosos es excepcional.Presentamos el caso clínico de una mujer diagnosticada de esclerosismúltiple, que recibió metilprednisolona a altas dosis enforma de “pulsos” intravenosos como tratamiento de las reagudizacionesde su enfermedad y presentó 3 brotes recurrentes de hepatitisde predominio hepatocelular con un patrón clínico, analíticoe histológico compatible con toxicidad hepática agudasecundaria a metilprednisolona intravenosa. En el tercer episodiose realizó una biopsia hepática que demostró un patrón de hepatitisaguda con necrosis líticas confluentes, histología no descritapreviamente en pacientes tratados con esteroides intravenosos

Adverse drug reactions (hepatotoxicity) are a frequent cause ofacute liver injury with a wide clinical and histological spectrum. Anearly recognition of drug-related liver disease has been consideredessential in clinical practice due to potential risks. In most casesexposure discontinuation improves the clinical picture.Steroids are used in a variety of clinical settings. However, intravenoussteroids have rarely been associated with hepatotoxicity.We report the case of a middle-aged woman with multiple sclerosiswho received a bolus of methylprednisolone on threeoccasions for the management of relapsing disease, with the developmentof repeated episodes of elevated liver enzymes aftercorticoid administration. In the third episode a liver biopsy wasperformed, which showed acute hepatitis with bridging necrosis;such histological picture has not been described before in patientstreated with intravenous steroids

[Recurrent acute liver toxicity from intravenous methylprednisolone]. / Toxicidad hepática recurrente secundaria a metilprednisolona intravenosa.

Adverse drug reactions (hepatotoxicity) are a frequent cause of acute liver injury with a wide clinical and histological spectrum. An early recognition of drug-related liver disease has been considered essential in clinical practice due to potential risks. In most cases exposure discontinuation improves the clinical picture.Steroids are used in a variety of clinical settings. However, intravenous steroids have rarely been associated with hepatotoxicity. We report the case of a middle-aged woman with multiple sclerosis who received a bolus of methylprednisolone on three occasions for the management of relapsing disease, with the development of repeated episodes of elevated liver enzymes after corticoid administration. In the third episode a liver biopsy was performed, which showed acute hepatitis with bridging necrosis; such histological picture has not been described before in patients treated with intravenous steroids.

Hemobilia / Hemobilia

No disponible

[The incidence and progression of lymphoma of the cavum in AIDS]. / Incidencia y evolución del linfoma de cávum en el SIDA.

A clinical case of a woman with AIDS who developed lymphoma of the nasopharynx and paralysis of the VII, IX and XII cranial nerves is reported. The probable origin of the paralysis in relation to AIDS and lymphoma is discussed.

Lupus pernio with involvement of nasal cavity and maxillary sinus.

Histological demonstration of sarcoidosis affecting the paranasal sinus is rare in the clinical practice. In this paper, we present a case with a diagnosis of lupus pernio with extensive involvement of the nasal cavity and the right maxillary sinus. Long before being diagnosed as having lupus pernio, the patient had had a long history of nasal obstruction and had been treated surgically without success on 3 occasions. The literature on the topic is reviewed.