External Carotid Artery Shunting During Carotid Endarterectomy: An Alternative for Cerebral Protection?

AbstractObjectives: to assess the application of external carotid artery (ECA) shunting in cerebral protection during carotid endarterectomy (CEA). Design: prospective study. Materials and Methods: the study comprised 137 consecutive patients who underwent CEA under locoregional anaesthesia. Transcranial Doppler was used to monitor the mean velocity of the middle cerebral artery (mv-MCA): (1) before carotid clamping; (2) after clamping both the common and external carotid arteries; (3) after clamping the internal carotid artery alone (“ECA test”). The decision to shunt was based on the occurrence of neurological deficit during carotid clamping. If the ECA test revealed mv-MCA approaching the pre-clamping values ECA shunting was used, whereas the remaining patients in need of a shunt had a standard internal carotid artery (ICA) shunt. Results: shunting was necessary in 12/137 cases (9%). The ECA test indicated that in four cases – 3% of the whole series or 33% of the shunted cases. In these four patients ECA shunting reversed the neurological deficit, and CEA was successfully performed without any complications. Conclusions: ECA shunting could be considered as an alternative to standard ICA shunting. Suitable cases can be identified on the basis of the ECA test

Metronomic ceramide analogs inhibit angiogenesis in pancreatic cancer through up-regulation of caveolin-1 and thrombospondin-1 and down-regulation of cyclin D1

Aims. The aims of this study were to evaluate the antitumor and antiangiogenic activity of metronomic ceramide analogs and to investigate their relevant molecular mechanisms. Methods. Human endothelial cells (HMVEC-d, HUVEC) and pancreatic cancer cells (Capan-1, MIAPaCa-2) were treated with the ceramide analogs (C2, AL6, C6 and C8), at low concentrations for 144h to evaluate any antiproliferative and pro-apoptotic effects, inhibition of migration, and to measure the expression of caveolin-1 (CAV-1) and thrombospondin-1 (TSP-1) mRNAs by real time RT-PCR. Assessment of ERK1/2 and Akt phosphorylation, and of CAV-1 and cyclin-D1 protein expression was performed by ELISA. Maximum tolerated dose (MTD) gemcitabine was compared against metronomic doses of the ceramide analogs by evaluating the inhibition of MIAPaCA-2 subcutaneous tumor growth in nude mice. Results. Metronomic ceramide analogs preferentially inhibited cell proliferation and enhanced apoptosis in endothelial cells. Low concentrations of AL6 and C2 caused a significant inhibition of HUVEC cell migration. ERK1/2 and Akt phosphorylation were significantly decreased after metronomic ceramide analog treatment. Such treatment caused the over-expression of CAV-1 and TSP-1 mRNA and protein in endothelial cells, whereas cyclin-D1 protein levels were reduced significantly. The antiangiogenic and antitumor impact in vivo of metronomic C2 and AL6 regimens was similar to that caused by MTD gemcitabine. C6 and C8 did not show any significant in vivo antitumor effects. Conclusions. Metronomic C2 and AL6 analogs have antitumor and antiangiogenic activity, determining the upregulation of CAV-1 and TSP-1 and the suppression of cyclin-D1

Risk factors associated to hospital mortality in patients with acute kidney injury on hemodialysis.

INTRODUCTION: The worldwide incidence of acute kidney injury is 18% and the overall hospital mortality can rise above 50%. In Peru, there are few series about mortality of acute kidney injury in hemodialysis patients. OBJECTIVES: To identify risk factors associated to hospital mortality of acute kidney injury in hemodialysis patients. METHODS: This is a retrospective cohort of patients with acute kidney injury in hemodialysis of Hospital Nacional Edgardo Rebagliati Martins gathered between January 2013 and December 2015. The sample size was 154 patients which allowed a power of 80% and a CI of 95%. ICD-10 codes were used to identify medical records of patients with acute kidney injury (N.17) and hemodialysis (Z.49). The independent variable was oliguria, and the primary outcome was hospital mortality. Poisson regression was used for multivariate analysis. RESULTS: We identified a total of 285 patients; 212 medical records were analyzed and 44 were excluded. Out of the 168 medical records, 129 belonged to living patients and 39 to deceased ones. The overall mortality incidence was 17.2%. The principal etiologies of acute kidney injury while in hemodialysis were sepsis (39.2%), and severe dehydration (10.8%). In the adjusted model, the risk factors associated to hospital mortality of acute kidney injury while in hemodialysis were elevated serum lactate (RR 1.09), elevated serum potassium (RR 0.93), and mean arterial pressure (RR 0.97). CONCLUSIONS: Lactate is an objective parameter that can predict prognosis and contributes to a better management of acute kidney injury in hemodialysis patients. INTRODUCCIÓN: La incidencia de insuficiencia renal aguda a nivel mundial es 18% y la mortalidad intrahospitalaria puede alcanzar más del 50%. En Perú, existen escasos estudios acerca de la mortalidad en pacientes con insuficiencia renal aguda en hemodiálisis. OBJETIVOS: Identificar los factores de riesgo asociados a mortalidad intrahospitalaria en pacientes con insuficiencia renal aguda en hemodiálisis. MÉTODOS: Es una cohorte retrospectiva, en la cual se estudió a los pacientes con insuficiencia renal aguda en hemodiálisis en el Hospital Nacional Edgardo Rebagliati Martins entre enero de 2013 y diciembre de 2015. Se halló un tamaño de muestra de 154 pacientes con una potencia de 80%, y un intervalo de confianza de 95%. Se utilizaron los códigos de la Clasificación Internacional de Enfermedades-10 para identificar las historias clínicas de pacientes con insuficiencia renal aguda (N.17) y hemodiálisis (Z.49). La variable independiente fue oliguria y la variable dependiente fue mortalidad intrahospitalaria. Para el análisis multivariado, se utilizó regresión de Poisson. RESULTADOS: El universo fue de 285 pacientes. Se revisaron 212 historias clínicas y se excluyeron 44. De las 168 historias clínicas estudiadas, 129 pertenecían a pacientes vivos y 39 a fallecidos. La incidencia de mortalidad fue de 17,2%. Las principales causas de insuficiencia renal aguda en hemodiálisis fueron sepsis (39,2%) y deshidratación severa (10,8%). En el modelo ajustado, los factores de riesgo asociados a mortalidad intrahospitalaria de insuficiencia renal aguda en hemodiálisis fueron lactato (riesgo relativo 1,09), potasio (riesgo relativo 0,93), y presión arterial media (riesgo relativo 0,97). CONCLUSIONES: El lactato es un parámetro objetivo que permite predecir el pronóstico y contribuye a un mejor manejo de los pacientes con insuficiencia renal aguda en hemodiálisis.Revisión por paresRevisión por pare

Desarrollo de un modelo de simulación para terminales terrestres. Caso: Mejoramiento o reubicación de los terminales terrestres nacional e internacional de la ciudad de Arica

El presente trabajo de investigación tiene por objetivo principal determinar si las actuales instalaciones de los terminales terrestres nacional e internacional de la ciudad de Arica debe mejorarse, conservando su ubicación actual o deben ser reubicados. Para el logro de este objetivo se desarrolla un modelo de simulación que representa, bajo algunos supuestos, el funcionamiento de los terminales terrestres de la ciudad de Arica, de modo tal que permita analizar sus comportamientos frente a distintas condiciones de operación.En primer lugar, se examinan los síntomas y problemas que dan origen al trabajo de investigación. Luego se analiza el marco teórico, el cual proporciona las definiciones y teorías sobre sistemas, simulación, números y variables aleatorias y líneas de espera. Por otro lado, se realiza una descripción física y operacional de los terminales terrestres de la ciudad de Arica, base teórica en la que se fundamenta el modelo de simulación.El modelo de simulación se desarrolla formulando, en primer lugar, el sistema que se desea simular, e identificando la información necesaria para poder formular el modelo matemático. Luego se evalúan las características de la información procesada identificando su distribución de probabilidad. Posteriormente, se elabora un diagrama de flujo que representa en forma secuencial las actividades del modelo ejecutadas en un programa computacional desarrollado en lenguaje Visual Basic para Aplicaciones. Los datos entregados por este programa que corresponden a la simulación de los terminales terrestres son validados para verificar su semejanza con la realidad.Se realizan cuatro experimentos de simulación, para observar el funcionamiento de los terminales terrestres en periodos futuros, encontrar problemas operacionales o de congestionamiento e identificar el momento en que estos ocurren.Finalmente se exponen las conclusiones y recomendaciones para la solución de los problemas operativos identificados en el desarrollo de la investigación

Different somatic alterations of the HRPT2 gene in a patient with recurrent sporadic primary hyperparathyroidism carrying an HRPT2 germline mutation

Early onset of primary hyperparathyroidism (PHPT) and multiglandular involvement suggest a familial form in which germline mutation of a PHPT-related gene(s) and a somatic event at the same locus can be often demonstrated. We investigated the involvement of multiple endocrine neoplasia type 1 (MEN1) and HRPT2 genes in a 39-year-old man with recurrent PHPT. PHPT was firstly diagnosed at the age of 21 and the patient had two recurrences separated by extended periods of normocalcemia. This unusual history prompted us to investigate other family members and study the MEN1 and HRPT2 genes. An HRPT2 germline missense mutation in exon 3 (R91P) was found in the index case, which was associated with different HRPT2 somatic alterations in each of the three examined parathyroid tumors. These findings are consistent with Knudson's 'two hit' concept of biallelic inactivation of classical tumor suppressor genes. Screening of 15 asymptomatic relatives was negative for the R91P germline mutation. All the three abnormal parathyroid specimens showed cystic features at histology and were negative for parafibromin immunostaining. In one specimen, diffuse parafibromin staining was evident in a rim of normal parathyroid tissue surrounding the adenomatous lesion. Our study shows that different somatic genetic events at the HRPT2 locus are responsible for the asynchronous occurrence of multiple adenomas in a patient carrying an HRPT2 germline mutation. The finding of diffuse parafibromin staining in a rim of normal parathyroid tissue, but not in the contiguous adenomatous lesion, reinforces the concept that loss of parafibromin expression is responsible for the development of parathyroid tumors in this setting

Antiangiogenic and anticolorectal cancer effects of metronomic irinotecan chemotherapy alone and in combination with semaxinib

Metronomic chemotherapy refers to the administration of chemotherapy at low, nontoxic doses on a frequent schedule with no prolonged breaks. The aim of the study is to rationally develop a CPT-11 metronomic regimen in preclinical settings of colon cancer. In vitro cell proliferation, apoptosis and thrombospondin-1/vascular endothelial growth factor (TSP-1/VEGF) expression analyses were performed on endothelial (HUVEC, HMVEC-d) and colorectal cancer (HT-29, SW620) cells exposed for 144 h to metronomic concentrations of SN-38, the active metabolite of CPT-11. HT-29 human colorectal cancer xenograft model was used, and tumour growth, microvessel density and VEGF/TSP-1 quantification was performed in tumours. In vitro and in vivo combination studies with the tyrosine inhibitor semaxinib were also performed. SN-38 preferentially inhibited endothelial cell proliferation alone and interacted synergistically with semaxinib; it induced apoptosis and increased the expression and secretion of TSP-1. Metronomic CPT-11 alone and combined with semaxinib significantly inhibits tumour growth in the absence of toxicity, which was accompanied by decreases in microvessel density and increases in TSP-1 gene expression in tumour tissues. In vitro results show the antiangiogenic properties of low-concentration SN-38, suggesting a key role of TSP-1 in this effect. In vivo, the CPT-11 metronomic schedule is effective against tumour and microvessel growth without toxic effect on mice