Alfredo Aguilera

Epithelial-to-mesenchymal transition of mesothelial cells is an early event during peritoneal dialysis and is associated with high peritoneal transport.

Ultrafiltration (UF) failure is a consequence of long-term peritoneal dialysis (PD). Fibrosis, angiogenesis, and vasculopathy are causes of this functional disorder after 3-8 years on PD. Epithelial-to-mesenchymal transition (EMT) of mesothelial cell (MC) is a key process leading to peritoneal fibrosis with functional deterioration. Our purpose was to study the peritoneal anatomical changes during the first months on PD, and to correlate them with peritoneal functional parameters. We studied 35 stable PD patients for up to 2 years on PD, with a mean age of 45.3+/-14.5 years. Seventy-four percent of patients presented loss of the mesothelial layer, 46% fibrosis (>150 microm) and 17% in situ evidence of EMT (submesothelial cytokeratin staining), which increased over time. All patients with EMT showed myofibroblasts, while only 36% of patients without EMT had myofibroblasts. The number of peritoneal vessels did not vary when we compared different times on PD. Vasculopathy was present in 17% of the samples. Functional studies were used to define the peritoneal transport status. Patients in the highest quartile of mass transfer area coefficient of creatinine (Cr-MTAC) (>11.8 ml min(-1)) showed significantly higher EMT prevalence (P=0.016) but similar number of peritoneal vessels. In the multivariate analysis, the highest quartile of Cr-MTAC remained as an independent factor predicting the presence of EMT (odds ratio 12.4; confidence interval: 1.6-92; P=0.013) after adjusting for fibrosis (P=0.018). We concluded that, during the first 2 PD years, EMT of MCs is a frequent morphological change in the peritoneal membrane. High solute transport status is associated with its presence but not with increased number of peritoneal vessels.

In Situ Kidney Insonation With Microbubble Contrast Agents Does Not Cause Renal Tissue Damage in a Porcine Model

Objective. Knowledge and quantification of the microcirculation are very important for estimating the status of an organ. Real‐time contrast‐enhanced sonography assesses microvascular tissue perfusion. This technique has been proposed as innocuous; however, data from experimental animals (rats) have shown renal interstitial microhemorrhage after the procedure. Therefore, we developed a porcine model to explore potential renal damage that in situ exposure might cause. Methods. Kidneys from 8 anesthetized pigs were surgically exposed. An ultrasound contrast agent (sulfur hexafluoride) was infused through the femoral vein in a continuous perfusion. Destructive ultrasonic flashes were applied with a high mechanical index over only 1 kidney (the contralateral kidney was used as a control). Blinded histologic and laboratory analyses were performed to reveal any lesions. Results. Histologic analysis of the kidney samples showed no evidence of renal damage. Biochemical parameters that could represent renal tissue damage and hemoglobin levels did not change after the microbubble‐ultrasound interaction. Conclusions. The ultrasound contrast agent‐ultrasound interaction in anesthetized pig kidneys under the output level for the imaging visualization and microbubble destruction used did not cause tissue damage. Our results suggest that this procedure could be used in humans for regular analysis of the kidney microcirculation with minimal risk of tissue damage.

Human recombinant erythropoietin does not promote cancer growth in presence of functional receptors expressed in cancer cells.

Human recombinant erythropoietin (hrEPO) therapy might be associated with tumor progression and death. This effect has been suggested to be secondary to rhEPO binding to its receptor (EPOR) expressed on cancer cells. However, there are several concerns about EPOR functionality when expressed on cancer cells. In this paper we have provided evidence that EPOR expressed in cancer cells could be implicated in proliferation events because a transfection of EPOR siRNA to EPOR-expressing bladder cancer cells resulted in a marked reduction in cell growth. However, these cell lines do not grow in the presence of hrEPO. Furthermore, bladder cancer patients that expressed EPOR in tumor samples had a reduced survival in absence of rhEPO treatment. Therefore, EPOR is implicated in bladder cancer growth but this effect appears to be independent from rhEPO supplementation. Reports which suggest that rhEPO promotes cancer growth due to the expression of EPOR in cancer cells must be observed with caution since in the presence of functional EPOR rhEPO does not promote growth.

Nefroureterectomía abierta y laparoscópica en tumores uroteliales del tracto urinario superior: experiencia inicial

Resumen Objetivo El desarrollo de la laparoscopia en urologia permite el abordaje de tumores del tracto urinario superior con una seguridad oncologica cada vez mayor, aunque todavia se sigue considerando el abordaje abierto como la tecnica de eleccion. Presentamos nuestra experiencia laparoscopica en los ultimos 4 anos frente a la tecnica abierta. Material y metodos Entre 1995 y 2009 se ha realizado un total de 95 nefroureterectomias por tumor, 70 por via abierta y 25 laparoscopicas. El abordaje por lumbotomia con desinsercion endoscopica del ureter ha sido el mas frecuente en cirugia abierta, y en laparoscopia, se ha realizado en todos los casos un acceso transperitoneal, con rodete vesical en la mayoria de los casos (56%). Resultados En las nefroureterectomias abiertas la media de tiempo quirurgico fue 205 (130-300) min, con una media de sangrado de 525 (100-1.800) ml y transfusion en 17 (24,2%) ocasiones. La media de estancia fue 8,4 (3-30) dias. En las nefroureterectomias laparoscopicas, la media de tiempo quirurgico fue 189 (120-270) min, con una media de sangrado de 130 (100-400) ml y transfusion en 4 (16%) ocasiones. La media de estancia fue 4,5 (2-28) dias. Conclusiones Los pacientes intervenidos por laparoscopia presentaron una menor tasa de transfusion y una estancia hospitalaria mas corta. El control oncologico fue similar con ambas tecnicas, si bien la laparoscopia precisa de un mayor seguimiento y mayor numero de casos.

Biochemical recurrence risk factors in surgically treated high and very high-risk prostate tumors.

Introduction High and very high-risk prostate cancers are tumors that display great variation in their progression, making their behaviour and consequent prognosis difficult to predict. We analyse preoperative and postoperative risk factors that could influence biochemical recurrence of these tumors. Material and methods We carried out univariate and multivariate analyses in an attempt to establish statistically significant preoperative (age, rectal examination, PSA, biopsy Gleason score, uni/bilateral tumor, affected cylinder percentage) and postoperative (pT stage, pN lymph node affectation, Gleason score, positive surgical margins, percentage of tumor affectation, perineural infiltration) risk factors, as well as their relationship with biochemical recurrence (PSA >0.2 ng/mL). Results We analysed 276 patients with high and very high-risk prostate cancer that were treated with laparoscopic radical prostatectomy (LRP) between 2003-2007, with a mean follow-up of 84 months. Incidence of biochemical recurrence is 37.3%. Preoperative factors with the greatest impact on recurrence are suspicious rectal exam (OR 2.2) and the bilateralism of the tumor in the biopsy (OR 1.8). Among the postoperative factors, the presence of a LRP positive surgical margins (OR 3.4) showed the greatest impact, followed by the first grade of the Gleason score (OR 3.3). Conclusions The factor with the greatest influence on biochemical recurrence when it comes to surgery and high and very high-risk prostate cancer is the presence of a positive margin, followed by the Gleason score. Preoperative factors (PSA, biopsy Gleason score, rectal examination, number of affected cylinders) offered no guidance concerning the incidence of BCR.

Ganglioneuroma adrenal: dilema clínico-quirúrgico acerca de un hallazgo fortuito

Ganglioneuroma is a benign neoplasm derived from the neural crest consisting of mature ganglionic cells and Schwann cells. The posterior mediastinum is its most common location, followed by the retroperitoneum. Only a small proportion of ganglioneuromas arise from the adrenal medulla (15--30%). The routine use of imaging tests has increased the frequency of diagnosis of adrenal incidentalomas. Most of these lesions are nonfunctional benign adenomas. Other less common lesions include cortisol-secretin adenoma, metastases, adrenal carcinoma, and myelolipoma. Lesions such as cysts, inflammatory or infectious lesions, bilateral adrenal bleeding or, as in the case reported here, ganglioneuroma are less frequently found. Our clinical case was a 61-year-old with a history of pemphigus vulgaris in 1998 who required high-dose corticosteroid therapy. She reported no known allergic reactions to drugs, and had no history of high blood pressure, diabetes mellitus, or dyslipidemia. A computed tomography (CT) scan of the chest performed for chronic cough revealed a left adrenal mass 61 mm × 47 mm × 37 mm in size with lobulated contours and attenuation values of 20--30 Hounsfield units (HUs) in basal slices (Fig. 1; oral and intravenous contrast was not used because the radiologist suspected pheochromocytoma based on basal images). The patient was referred to the endocrinology department to work-up a left adrenal incidentaloma. The patient reported pain at rest in the left lumbar region. Upon specific questioning, she reported no constitutional symptoms or evidence of hypercortisolism (central obesity, striae, muscle weakness, bruising, mood changes, hirsutism, acne), hyperandrogenism, or hyperaldosteronism (HBP, muscle weakness, nocturia, urinary

Neurofibroma de la túnica albugínea: hallazgos en ecografía y resonancia magnética con correlación patológica

OBJETIVO: Comunicar el segundo caso descrito en la literatura de neurofibroma solitario con origen en la tunica albuginea testicular y los hallazgos radiologicos. METODO/RESULTADOS: Presentamos un neurofibroma de la tunica albuginea en un paciente adulto no afectado por neurofibromatosis. Se describen los hallazgos de este tumor en ecografia-doppler y resonancia magnetica (RM) con correlacion histopatologica, asi como una breve revision de la literatura. CONCLUSION: La RM puede ser una tecnica util para ayudar en la caracterizacion prequirurgica de las lesiones paratesticulares. El neurofibroma debe ser incluido en el diagnostico diferencial de masas escrotales cuando estan bien delimitadas y muestran hiperintensidad de senal en T2 y realce intenso tras la administracion de gadolinio.

Open and Laparoscopic Partial Nephrectomy: Experience at La Paz University Hospital

Objective: Partial nephrectomy is a safe procedure in renal tumors less than 4 cm. The laparoscopic technique is one of the most complex surgeries in urology. We present our experience in 12 years with open and laparoscopic technique. Material and Methods: The analyzed period covers from 1995 to 2006, during which 96 parenchymal sparing renal surgical procedures were performed, 75 of them open (1995–2004) and 21 laparoscopic (2004–2006). Absolute contraindications for laparoscopic surgery were solitary kidney, tumor size greater than 4 cm and location of the tumor close to the hilus. Results: There are statistically significant differences in operating time (shorter in laparoscopy), intraoperative bleeding and transfusion (greater in open surgery), and hospital stay (3.3 d in laparoscopic vs. 7.5 d in open). The positive margins are greater (not statistically significant) in laparoscopic procedure because the learning curve. Conclusion: Conservative renal surgery is a common approach for tumors less than 4 cm. The laparoscopic procedure is a difficult surgery and should be performed by surgeons with expertise in laparoscopy. The development of both laparoscopic instruments and new biological sealants allows for an easier implementation of this minimally invasive procedure.