[Vascular injury associated with knee dislocation]. / La lesión vascular asociada a la luxación de rodilla.

INTRODUCTION: Knee dislocation is a rare injury but considered serious clinically since it can be accompanied by vascular and neurological injuries that if they do not have a timely diagnosis and treatment can lead to the loss of the limb. Regarding vascular injury, the optimal diagnostic method for the identification of this type of lesion is of the utmost importance. OBJECTIVE: To present the literature review on the epidemiology, classification and diagnostic approach of knee dislocation with or without associated vascular injury. METHODS: Report of the literature found in databases and analyses based on clinical experience and synthesis of these documents. CONCLUSION: Vascular injury is not an uncommon finding in the context of knee dislocation, with a high risk of complications and even amputation if an early diagnosis is not made, the authors recommend angio-CT to confirm the suspected diagnosis and not delay treatment.

INTRODUCCIÓN: La luxación de rodilla es una lesión poco común, pero considerada grave clínicamente, ya que puede acompañarse de lesiones vasculares y neurológicas que si no tienen un diagnóstico y tratamiento oportuno pueden llegar a la pérdida de la extremidad. Respecto a la lesión vascular es de suma importancia el método diagnóstico óptimo para la identificación de este tipo de lesiones. OBJETIVO: Presentar la revisión bibliográfica sobre la epidemiología, clasificación y aproximación diagnóstica de la luxación de rodilla con o sin lesión vascular asociada. MÉTODOS: Reporte de la literatura encontrada en bases de datos y análisis basados en experiencia clínica y síntesis de estos documentos. CONCLUSIÓN: La lesión vascular no es un hallazgo infrecuente en el contexto de una luxación de rodilla, tiene un riesgo elevado de complicaciones e incluso de amputación si no se realiza un diagnóstico temprano, los autores recomiendan la angio-TAC para confirmar la sospecha diagnóstica y no retrasar el tratamiento.

[«Man-in-the-barrel¼ syndrome: atypical manifestation of giant cell arteritis]. / Sindrome del hombre en el barril: manifestacion atipica de la arteritis de celulas gigantes.

INTRODUCTION: «Man-in-the-barrel¼ syndrome refers to diplegia of the upper extremities in which mobility of the head and lower limbs is preserved. Brachial plexitis that presents as «man-in-the-barrel¼ syndrome is an unusual manifestation of giant cell arteritis. We report a case of C5-C6 plexitis as part of the clinical features of a patient with giant cell arteritis. CASE REPORT: A 70-year-old male with a two-month history of weight loss, headache, facial pain and jaw claudication, associated with a persistent elevation of acute phase reactants and bilateral brachial plexopathy, with no evidence of neck or brain injuries or occult neoplasm and with negative autoimmunity tests. Results of the biopsy study of the temporal artery were compatible with giant cell arteritis, and the positron emission tomography scan revealed extensive vascular involvement of the aorta and its branches. CONCLUSIONS: Although the typical clinical manifestations of giant cell arteritis are headache, jaw claudication, loss of sight, constitutional symptoms and polymyalgia rheumatica, its presence must be suspected in patients over the age of 50 who manifest alterations affecting the peripheral nerve, including brachial diplegia with no other demonstrable cause.

TITLE: Sindrome del hombre en el barril: manifestacion atipica de la arteritis de celulas gigantes.Introduccion. El sindrome del hombre en el barril hace referencia a la diplejia de los miembros superiores con movilidad preservada de la cabeza y los miembros inferiores. La plexitis braquial que se presenta como sindrome del hombre en el barril es una manifestacion inusual de la arteritis de celulas gigantes. Se comunica un caso de plexitis C5-C6 como parte del cuadro clinico de un paciente con arteritis de celulas gigantes. Caso clinico. Varon de 70 años con dos meses de evolucion de perdida de peso, cefalea, dolor facial y claudicacion mandibular, asociados a elevacion persistente de reactantes de fase aguda y plexopatia braquial bilateral, sin evidencia de lesiones cervicales o cerebrales, neoplasia oculta y con pruebas de autoinmunidad negativas; la biopsia de la arteria temporal fue compatible con arteritis de celulas gigantes y la tomografia por emision de positrones demostro una extensa afeccion vascular de la aorta y sus ramas. Conclusiones. Si bien las manifestaciones clinicas tipicas de la arteritis de celulas gigantes son cefalea, claudicacion mandibular, perdida visual, sintomas constitucionales y polimialgia reumatica, se debe sospechar su presencia en pacientes mayores de 50 años que manifiesten alteraciones del nervio periferico, entre ellas, diplejia braquial sin otra causa demostrable.

Testing the performance of superhydrophobic aluminum surfaces.

The analysis of wetting properties of superhydrophobic surfaces may be a difficult task due to the restless behavior of drops on this type of surfaces and the limitations of goniometry for high contact angles. A method to validate the performance of superhydrophobic surfaces, rather than standard goniometry, is required. In this work, we used bouncing drop dynamics as a useful tool to predict the water repellency of different superhydrophobic surfaces. From bouncing drop experiments conducted over a wide range of superhydrophobic surfaces, we found that those surfaces with a proper roughness degree and homogeneous chemical composition showed higher water-repellency. We also conducted a drop condensation study at saturating conditions aimed to determine whether there is direct correlation between water repellency and condensation delay. We found that the drop condensation process is strongly related to the surface topography, as well as the intrinsic wettability. The condensation is promoted on rough surfaces but it is delayed on intrinsically hydrophobic surfaces. However, the differences found in condensation delay between the superhydrophobic surfaces explored in this study cannot be justified by their chemical homogeneity nor their efficiency as water repellent surfaces, separately.

Supplementation with bypass fat in silvopastoral systems diminishes the ratio of milk saturated/unsaturated fatty acids.

This study was conducted to evaluate if supplementing bypass fat to cows under silvopastoral systems, increases the concentration of unsaturated fatty acids in milk, thus improving the saturated/ unsaturated ratio without a negative effect on total milk yield in fat or protein. Two concentrations of two different sources of bypass fat were evaluated for 40 days, each in a group of 24 multiparous Lucerna (Colombian breed) cows. A cross-over design of 8 Latin squares 3 x 3 was used. The variables submitted to analysis were body condition, daily milk production and milk composition. Body condition, milk yield and milk quality were not different but there was a significant decrease in the amount of saturated fatty acid in both experiments while the unsaturated fat increased significantly in experiment 1 and remained stable in experiment 2. Results, such as these have as far as we know, not been reported previously and they provide an approach for the improvement of milk as a "functional food".

Neuregulin and laminin stimulate phosphorylation of the NF2 tumor suppressor in Schwann cells by distinct protein kinase A and p21-activated kinase-dependent pathways.

Mutations in the neurofibromatosis type 2 (NF2) gene cause formation of schwannomas and other tumors in the nervous system. The NF2 protein, Schwannomin/Merlin, is a cytoskeleton-associated tumor suppressor regulated by phosphorylation at serine 518 (S518). Unphosphorylated Schwannomin restricts cell proliferation in part by inhibiting Rac- and p21-activated kinase (Pak). In a negative-feedback loop, Pak phosphorylates Schwannomin inactivating its ability to inhibit Pak. Little is known about receptor mechanisms that promote Pak activity and Schwannomin phosphorylation. Here we demonstrate in primary Schwann cells (SCs) that Schwannomin is rapidly phosphorylated on S518 by Pak following laminin-1 binding to beta1 integrin, and by protein kinase A following neuregulin-1beta (NRG1beta) binding to ErbB2/ErbB3 receptors. These receptors, together with phosphorylated Schwannomin, P-Pak, Cdc42 and paxillin are enriched at the distal tips of SC processes, and can be isolated as a complex using beta1 integrin antibody. Dual stimulation with laminin-1 and NRG1beta does not synergistically increase Schwannomin phosphorylation because ErbB2 kinase partially antagonizes integrin-dependent activation of Pak. These results identify two parallel, but interactive pathways that inactivate the tumor suppressor activity of Schwannomin to allow proliferation of subconfluent SCs. Moreover, they identify ErbB2, ErbB3 and beta1 integrins as potential therapeutic targets for NF2.

[Cerebrovascular disease in children with sickle cell anaemia]. / Enfermedad cerebrovascular en niños con anemia de células falciformes.

INTRODUCTION: Cerebrovascular disease (CVD) is one of the most clinically devastating complications in children with sickle cell anaemia (SCA) and an important cause of death in this population. AIMS: To determine the incidence of CVD in children with SCA and to characterise the risk factors and other related clinical and imaging aspects. PATIENTS AND METHODS: We conducted a retrospective, cross sectional, descriptive study of paediatric patients with SCA and CVD that covered the period between January 1992 and February 2002. RESULTS: A total of 131 children with SCA were registered in the period between January 1992 and February 2002, during which five children suffered some kind of CVD event. This figure corresponds to 3.81% of the patients with SCA and 7.69% of the total number of children with CVD. The most frequent clinical presentation of the CVD is bouts of seizures and the most frequently observed type of CVD is ischemic, chiefly located in the middle cerebral artery. Of the different predictors that exist for ischemic CVD, haemoglobin count was found to be lower than in haemorrhagic CVD. CONCLUSION: CVD is a common complication in the progress of patients with SCA with a high percentage of neurological sequelae.

Enfermedad cerebrovascular en niños con anemia de células falciformes / Cerebrovascular disease in children with sickle cell anemia

Introducción. La enfermedad cerebrovascular (ECV) es una de las complicaciones más devastadoras clínicamente en los niños con anemia de células falciformes (ACF) y una causa importante de muerte en esta población. Objetivo. Determinar la incidencia de ECV en los niños con ACF y caracterizar los factores de riesgo y demás aspectos clínicos e imaginológicos relacionados. Pacientes y métodos. Estudio retrospectivo, transversal y descriptivo, durante el período comprendido entre enero de 1992 y febrero de 2002, de los pacientes pediátricos con ACF y ECV. Resultados. Se registraron 131 niños con ACF en un período comprendido entre enero de 1992 y febrero de 2002, durante el cual cinco niños tuvieron algún evento de ECV; correspondió al 3,81 por ciento de los pacientes con ACF y al 7,69 por ciento del total de niños con ECV. La presentación clínica más frecuente del ECV es la convulsión, y el tipo de ECV es el isquémico, con localización anatómica en la arteria cerebral media. Dentro de los predictores existentes para la ECV isquémica, se encontró una hemoglobina más baja que en la ECV hemorrágica. Conclusión. La ECV es una complicación frecuente en la evolución del paciente con ACF, y deja un alto porcentaje de secuelas neurológicas (AU)

Introduction. Cerebrovascular disease (CVD) is one of the most clinically devastating complications in children with sickle cell anaemia (SCA) and an important cause of death in this population. Aims. To determine the incidence of CVD in children with SCA and to characterise the risk factors and other related clinical and imaging aspects. Patients and methods. We conducted a retrospective, cross-sectional, descriptive study of paediatric patients with SCA and CVD that covered the period between January 1992 and February 2002. Results. A total of 131 children with SCA were registered in the period between January 1992 and February 2002, during which five children suffered some kind of CVD event. This figure corresponds to 3.81% of the patients with SCA and 7.69% of the total number of children with CVD. The most frequent clinical presentation of the CVD is bouts of seizures and the most frequently observed type of CVD is ischemic, chiefly located in the middle cerebral artery. Of the different predictors that exist for ischemic CVD, haemoglobin count was found to be lower than in haemorrhagic CVD. Conclusion. CVD is a common complication in the progress of patients with SCA with a high percentage of neurological sequelae (AU)

Predictive value of (99m)Tc sestamibi scintigraphy in the evaluation of doxorubicin based chemotherapy response in patients with advanced breast cancer.

Resistance to doxorubicin based chemotherapy is a major therapeutic problem limiting advanced breast cancer treatment. 99mTc hexakis-2-methoxyisobutylisonitrile ((99m)Tc-MIBI) has been reported to be extruded from tumour cells by the P-glycoprotein and multidrug resistance protein encoded by MDR1 and MRP1 genes, respectively. These proteins are involved in the cellular efflux of several chemotherapeutic agents including doxorubicin. The aim of this study was to investigate the clinical value of a standard (99m)Tc-MIBI scintimammography technique in the prediction of response to chemotherapy in advanced breast cancer patients. Fifty-six lesions from 33 female patients with locally advanced (n=27) or recurrent breast cancer (n=6) were included in the study. MIBI scintigraphy was performed 2-8 days prior to chemotherapy (FAC regimen). Images were acquired 10 min and 1 h post-injection of 740-1110 MBq of (99m)Tc-MIBI. Tumour-to-normal background tissue uptake ratios were calculated on each lesion in the early (T/B(e)) and delayed phase of the study (T/B(d)). Both T/B(e) and T/B(d) ratios were significantly higher (P<0.0001) in responders (n=43) than nonresponders (n=13). Diagnostic values of (99m)Tc-MIBI in the prediction of chemotherapy response were evaluated using the arbitrary cut-off values of 1.5 for T/B(e) and 1.4 forT/B(d). Sensitivity, specificity, positive and negative predictive values were 88.4%, 92.3%, 97.4%, 70.6%; and 90.7%, 100.0%, 100.0%, 76.6%, for T/B(e) and T/B(d), respectively. We conclude that (99m)Tc-MIBI scintigraphy may be a clinically valuable tool for guiding chemotherapy in advanced breast cancer patients.

Initial experience with Song's covered duodenal stent in the treatment of malignant gastroduodenal obstruction.

PURPOSE: Initial experience with use of Song's covered duodenal stent in the treatment of malignant gastroduodenal obstruction is reported. MATERIALS AND METHODS: Sixteen consecutive patients with malignant gastroduodenal obstruction were treated with peroral placement of Song's covered duodenal stent. The mean age was 58 years (range, 28-90 y). Gastroduodenal obstruction was caused by gastric (n = 8), metastatic (n = 2), gallbladder (n = 3), pancreatic (n = 2), or ampullary (n = 1) cancer. The disease was considered inoperable in all patients. With use of a flexible 20-F introducing system, seven fully covered, three uncovered, and 10 partially covered duodenal stents were placed under fluoroscopic guidance. RESULTS: The technical success rate was 94% (15 of 16) with no major complications. Symptoms of gastroduodenal obstruction improved in 14 patients. Stent migration was observed in three of seven fully covered stents. Patients with migrated stents required endoscopic stent removal and placement of uncovered duodenal stents. Tumor ingrowth was observed in two thirds of uncovered stents. In the 10 procedures with partially covered duodenal stents, no migration or tumor ingrowth was observed. All patients died 1-48 weeks (mean, 12 weeks) after stent placement. CONCLUSION: Peroral placement of Song's covered duodenal stent is a feasible and effective method of palliation in the majority of patients with malignant gastroduodenal obstruction. Migration of fully covered stents and tumor ingrowth of uncovered stents are important limitations that can be overcome with the use of a partially covered duodenal stent.

Malignant hilar and perihilar biliary obstruction: use of MR cholangiography to define the extent of biliary ductal involvement and plan percutaneous interventions.

PURPOSE: To determine the usefulness of magnetic resonance (MR) cholangiography in defining the extent of biliary ductal involvement in patients with malignant hilar and perihilar biliary obstruction and to evaluate whether findings at MR cholangiography alone are sufficient to plan percutaneous interventions in these patients. MATERIALS AND METHODS: Twenty-nine patients with malignant hilar and perihilar biliary obstruction were examined with MR cholangiography. Two radiologists evaluated MR images and determined the extent of biliary ductal involvement. A hypothetical plan for biliary drainage was established prior to any intervention. All patients underwent percutaneous cholangiography, and 27 of 29 patients also underwent biliary drainage and/or stent placement within 7 days after MR cholangiography. By using direct cholangiography as the standard of reference, the usefulness of MR cholangiography in defining the extent of biliary ductal involvement was determined. The type of drainage performed was compared with the type that had been anticipated at MR cholangiography. RESULTS: MR cholangiography was adequate in helping predict the extent of biliary ductal involvement in 28 (96%) of 29 patients and led to underestimation of the extent of the disease in one patient. The therapeutic plan anticipated with MR cholangiography matched the one actually used in 24 (83%) of 29 patients. CONCLUSION: The high accuracy of MR cholangiography for defining extent of ductal involvement in patients with malignant hilar and perihilar obstruction allows adequate planning of percutaneous interventions in a majority of patients.

Focal arterial injuries of the proximal extremities: helical CT arteriography as the initial method of diagnosis.

PURPOSE: To present our experience with helical computed tomographic (CT) arteriography as the initial diagnostic examination in patients suspected to have focal arterial injuries of the proximal extremities. MATERIALS AND METHODS: During 19 months, 142 arterial segments in the proximal portions of the extremities of 139 patients with trauma were evaluated with helical CT arteriography. CT arteriograms were interpreted on site by the radiologist in charge of emergency procedures and retrospectively with consensus interpretation between two radiologists. CT study quality and the presence of arterial injuries were noted. CT arteriographic findings were compared with those of surgery, conventional arteriography, and/or clinical follow-up. RESULTS: Five (3.6%) patients had nondiagnostic studies and underwent conventional arteriography. In the remaining 137 arterial segments in 134 patients, helical CT arteriography demonstrated arterial injuries in 61 segments and normal arteries in 76 segments. These segments were treated initially with surgery (55 segments) or endovascular intervention (four segments) or were observed (78 segments); 77 of the 78 observed segments remained stable at 3-18 months (mean follow-up, 5.2 months). There were no differences between the on-site and consensus interpretations (kappa = 1.0). The sensitivity of CT arteriography was 95.1%, and the specificity was 98.7%. CONCLUSION: Helical CT arteriography can be performed as the initial diagnostic method in most patients suspected to have focal arterial injuries of the proximal portions of the extremities.

Experiencia inicial con el stent esofagico de song para el tratamiento paliativo de la disfagia maligna benigna y fistula esofagotraqueal / Initial experience with esophageal stent, song type fot palliative treatment of bening and malignat dysphagia and tracheoesophageal fistula

Se evaluaron los resultados clínicos de la colocación de stents esofágicos autoexpandibles recubiertos tipo Song de fabricación local en el tratamiento paliativo de la disfagia tumoral, por estenosis benigna y en casos de fístula esofagotraqueal. Entre Agosto de 1998 y Mayo de 1999 se colocaron 27 stents en 24 pacientes, 20 pacientes con estenosis malignas del esófago y 4 pacientes con estenosis benignas. El stent se construyó localmente con alambre de acero inoxidable en Z, cubierto de una membrana de poliuretano. Todos los pacientes presentaban disfagia severa a líquidos o comidas blandas y se consideraron inoperables o malos candidatos quirúrgicos. La colocación del stent fue técnicamente posible en 23 pacientes. En un paciente el stent migró superiormente. Dos pacientes requirieron 2 stents cada uno. Mejoría significativa de la disfagia se observó en 23 pacientes. Las complicaciones tempranas fueron dolor severo (n=3) y sangrado que requirió transfusión (n= 1). Complicaciones tardías incluyeron migración (n = 1) y obstrucción por comida (n = 1). Síntomas de reflujo gastroesofágico severo se observaron en 3 pacientes. Stents con válvulas antirreflujos se utilizaron en 4 pacientes sin presencia de reflujo significativo ni obstrucción por comida. Los stents esofágicos autoexpandibles recubiertos ofrecen una paliación efectiva de la disfagia de origen tumoral y es el tratamiento de elección en las fístulas traqueoesofágicas en pacientes que no sean candidatos quirúrgicos. En un grupo seleccionado de pacientes con estenosis esofágicas benignas, la colocación de stents en forma temporal o permanente ofrece una alternativa al manejo no quirúrgico de la disfagia

Biliary obstruction: findings at MR cholangiography and cross-sectional MR imaging.

Twenty-two patients with malignant biliary obstruction and 21 patients with suspected obstruction of biliary-enteric anastomoses were evaluated over a 12-month period with magnetic resonance (MR) cholangiography and cross-sectional MR imaging. In patients with malignant obstruction, MR cholangiography helped accurately determine the status of the biliary ductal system by identifying the exact location and extent of the obstruction and the severity of duct dilatation. In so doing, MR cholangiography helped determine whether percutaneous transhepatic cholangiography with antegrade stent placement or retrograde cholangiography with stent placement constituted the more suitable treatment. Cross-sectional MR imaging was necessary to identify the organ of tumor origin, define the tumor margins, and determine the stage of disease. This information helped evaluate the appropriateness of curative surgical therapy versus palliative drainage procedures. In patients with biliary-enteric anastomoses, MR cholangiography clearly depicted the site of the anastomosis and demonstrated the status of the intrahepatic ducts, thereby helping determine which patients would benefit from undergoing antegrade duct cannulation with a drainage procedure or perhaps balloon dilation. In some of these patients, MR cholangiography was sufficient to help plan therapeutic intervention. MR cholangiography also demonstrates the presence and size of biliary stones and associated findings such as intraductal tumor growth. In addition, MR cholangiography may obviate retrograde cholangiography, which can be technically difficult to perform.

Embolizacion arterial transcateter para el control de la hemorragia severa en pacientes con carcinoma cervical avanzado / Transcatheter arterial embolization in treatment of severe hemorrhage in patients with advanced carcinoma of the cervix

Entre 1984 y 1999 se realizaron veintiocho embolizaciones arteriales transcateter en 26 pacientes con hemorragia vaginal severa secundaria a cáncer de cérvix avanzado. El estadio del cáncer cervical fue IIIB en 24 pacientes, IIB en una paciente y IV en una paciente. Se realizó angiografía de las arterias pélvicas con embolización de las arterias hipogástricas usando Gelfoam (n= 19, espirales de alambre metálicos y Gelfoam (n= 1), partículas de alcohol polivinilo (PVA) y espirales de alambre (n=4) y partículas de PVA únicamente (n=4). El sangrado agudo fue controlado en 23 pacientes con estabilización de la condición clínica. Embolizaciones repetidas fueron necesarias en tres pacientes. Complicaciones mayores incluyeron trombosis arterial (n= 1), complicaciones neurológicas mayores secundarias a la embolización accidental de nervios de las extremidades inferiores (n=2) y necrosis de grandes miomas requiriendo histerectomía (n=1). El seguimiento fue posible en 16 pacientes. Ocho pacientes murieron entre 1-14 meses después del procedimiento. No hubo episodios significativos de resangrado tardío en ninguna de las pacientes. La embolización arterial transcateter es un método efectivo para controlar la hemorragia severa refractaria al manejo conservador en pacientes con carcinoma cervical avanzado

Treatment of popliteal artery aneurysms with uncovered Wallstents.

We report two patients with acutely thrombosed popliteal artery aneurysms that were successfully treated with a combination of thrombolytic therapy and placement of noncovered Wallstents.

Treatment of chronic iliac artery occlusions with guide wire recanalization and primary stent placement.

PURPOSE: To evaluate the results of primary stent placement without initial thrombolysis in the treatment of iliac occlusions. MATERIALS AND METHODS: During a 3-year period, 61 iliac artery occlusions were treated in 59 patients. The mean length of the occluded segment was 10 cm (range, 4-25 cm). The occluded arteries were treated with primary placement of self-expandable metallic stents. RESULTS: Successful recanalization with primary stent placement was possible in 56 of 61 occlusions (92% technical success rate). Mean Doppler ankle/brachial index increased from 0.51 to 0.90 immediately after treatment and was 0.91 on the last follow-up (P < .05). Primary patency rate at 24 months was 73%, and secondary patency rate was 88%. Procedural complications included distal embolization (n = 4) and an episode of massive intra-abdominal bleeding. Three patients developed a hematoma at the puncture site that did not require additional therapy. Late complications included stent occlusion (n = 9) and significant stenosis related to intimal hyperplasia (n = 1). Mean follow-up period was 29 months (range, 7-55 months). CONCLUSION: Primary stent placement is an effective therapeutic option for iliac artery occlusions.

Retrieval of migrated colonic stents from the rectum.

Palliative stenting of malignant colonic obstruction may be complicated by stent migration. Stents that migrate into the rectum cannot be passed with bowel movements and frequently cause obstruction. We present two simple means to retrieve stents from the rectum using fluoroscopic guidance. These techniques were used successfully without complication in four stent migrations.