Histopathological and Ultrastructural Changes after Electroporation in Pig Liver Using Parallel-Plate Electrodes and High-Performance Generator.

Irreversible electroporation (IRE) has gained attention as a new non-thermal therapy for ablation with important benefits in terms of homogeneous treatment and fast recovery. In this study, a new concept of high voltage generator is used, enabling irreversible electroporation treatment in large tissue volume using parallel plates. Unlike currently available generators, the proposed versatile structure enables delivering high-voltage high-current pulses. To obtain homogeneous results, 3-cm parallel-plates electrodes have also been designed and implemented. IRE ablation was performed on six female pigs at 2000 V/cm electric field, and the results were analysed after sacrifice three hours, three days and seven days after ablation. Histopathological and ultrastructural studies, including transmission and scanning electron microscopy, were carried out. The developed high-voltage generator has proved to be effective for homogeneous IRE treatment using parallel plates. The destruction of the membrane of the hepatocytes and the alterations of the membranes of the cellular organelles seem incompatible with cell death by apoptosis. Although endothelial cells also die with electroporation, the maintenance of vascular scaffold allows repairing processes to begin from the third day after IRE as long as the blood flow has not been interrupted. This study has opened new direction for IRE using high performance generators and highlighted the importance of taking into account ultrastructural changes after IRE by using electron microscopy analysis.

Analysis of tissue bioimpedance as a measurement of liver steatosis: experimental model in large animals.

BACKGROUND: Electrical bioimpedance (BI) has been used to indirectly measure steatosis. This method has not yet been established in the clinics thus experimental studies are needed in big animals. We assessed BI to measure liver steatosis in porcine animals. METHODS: Twelve large-white × Landrace pigs weighing 35 kg were allocated to a study (n = 9) and a control group (n = 3). A special diet was used to promote steatosis among the study group: methionine deficient and choline-restricted diet that contains supplements of cholesterol, collate and excess of saturated fat. Control group animals were fed a normal diet. A new tetrapolar electrode model was used for BI measurement, which were performed during open laparotomy by inserting a probe into one of the lobes. Measurements were done in the third and fourth segments of the pig liver, placing the probe either on the surface or inserted into the parenchyma of the liver. Open biopsies were obtained at the end of the measurements. Histological samples were processed and stained with hematoxylin-eosin to estimate macrosteatosis. Pearson correlation coefficient between BI and percentage steatosis were calculated at different frequencies. RESULTS: After 4 months of the special diet all the animals in the study group developed steatosis (90% to 20%), whereas none of the control group was affected. Pearson correlation coefficients between BI and percentage of steatosis were significant (0.877-0.878) with the best correlations obtained with a probe placed on the fourth segment of the liver surface and the best frequency to perform the measurements being 50 and 75 kHz. CONCLUSIONS: BI is an accurate, fast method for steatosis measurements, that is easier and cheaper than either open or needle biopsy.

Infantile convulsions with mild gastroenteritis: a retrospective study of 25 patients.

BACKGROUND: The aim of this study was to analyze the epidemiologic, clinical, and evolutional characteristics in patients who presented convulsions with mild gastroenteritis (CwG) to facilitate the diagnosis in daily clinical practice. METHODS: Twenty-five medical records of patients diagnosed with CwG were reviewed, and the epidemiological and clinical features, results of complementary studies, and evolutional data were collected. RESULTS: Age of onset ranged between 12 and 24 months in 76% of patients. Female/male ratio was 2.6 (18 women and seven men). Seizures were mostly brief (<5 min) and apparently generalized, and often repetitive occurring in cluster (2.2 seizures per episode). One patient with status epilepticus was recorded. The average interval between the onset of gastroenteritis and seizures was 3.8 days, even though seizure preceded diarrhea in three cases. Mean rectal temperature at the moment of seizure was 37.1°C. Rotavirus antigen was positive in stool in 17 episodes (55.8%). There were no abnormalities in serum biochemistry tests and cerebrospinal fluid studies. Four patients showed anomalies in the interictal electroencephalogram. The period of follow-up was 4.2 years. Five patients (20%) experienced recurrences when suffering a new gastroenteritis episode. One patient developed epilepsy during the follow-up period. CONCLUSIONS: CwG would constitute a well-differentiated convulsive syndrome. Prognosis is excellent, but a relatively important percentage of patients relapse when suffering a new diarrhea episode.

Vólvulo yeyunal incompleto por linfangioma quístico mesentérico / Partial jejunal volvulus due to a mesenteric cystic lymphangioma

Los quistes mesentéricos son tumoraciones benignas poco frecuentes entre las que se encuentran los linfangiomas. Su presentación clínica es variable y pueden producir síntomas agudos debido a complicaciones. Se diagnostican sobre todo en edad pediátrica y su pronóstico, tras exéresis completa, suele ser excelente. Presentamos el caso de una paciente de 15 años con dolor abdominal postprandial y palpación de masa blanda en hipogastrio. Los estudios radiológicos mostraron una gran masa polilobulada de contenido quístico que englobaba un asa de yeyuno con volvulación incompleta. El tratamiento fue la exéresis del quiste y del asa de yeyuno y el diagnóstico anatomopatológico fue de linfangiomaquístico mesentérico. La paciente está asintomática después de más de 3 años de la intervención (AU)

Mesenteric cysts are unusual benign tumours thatinclude lymphangioma. Their clinical presentation is variable and acute symptoms can be produced due to complications. This tumour appears especially in childhood, and its prognosis after surgical removal is excellent. We present the case of a 15 year old female patient with symptoms of postprandial abdominal pain and palpation of smooth mass in hypogastrium. Radiological studies showed a big polilobular mass of cystic substance that included a portion of jejune within complete volvulus. The treatment was the removal of the cyst and a je junal portion and the pathological diagnosis was mesenteric cyst lymphangioma. The patient is asymptomatic more than three years after the intervention (AU)

Influencia del concentrado de plaquetas sobre la reconstrucción de defectos de cartílago articular en la rodilla de cordero / Influence of concentrated platelets on the reconstruction of cartilage defects in the lamb knee joint

Objetivo. Analizar el efecto de las plaquetas sobre el crecimiento de cartílago en los defectos articulares provocados en la rodilla ovina. Material y método. Se provocó un defecto de 4mm de diámetro y 3mm de profundidad en la tróclea femoral de ambas rodillas en corderos macho de 6 meses de edad. La distribución de los grupos fue: grupo A (n=6): el defecto de la rodilla derecha se rellenó con concentrado de plaquetas 5min después de ser activado con ClCa. Grupo B (n=6): el defecto se rellenó con colágeno y plaquetas. Material y método. Las plaquetas se obtuvieron por centrifugación de 10ml de sangre arterial obtenida de cada animal antes de la cirugía. En los defectos de la rodilla izquierda no se administraron plaquetas. Las ovejas fueron sacrificadas 10 semanas después de la cirugía. Se realizaron estudios macro y microscópicos. Resultados. En el grupo A, se observó cartílago hialino en 4 de los defectos de la rodilla derecha a las 10 semanas de la cirugía. Ninguno de los defectos de la rodilla izquierda mostró crecimiento de cartílago hialino. En el grupo B, no se observó cartílago hialino en nigún defecto. No obstante, todos los defectos presentaron mejor celularidad condral y menor fibrosis en los defectos tratados con plaquetas que en los no tratados. Conclusiones. Esta técnica para la reconstrucción con plaquetas de defectos articulares de oveja ha mostrado en nuestro estudio resultados esperanzadores que empeoran combinadas con un andamiaje de colágeno (AU)

Objective. To study the influence of platelets on cartilage growth in articular defects in the sheep knee. Material and methods. Male Rasa Aragonesa sheep (6 months) were operated under general anaesthesia. A 4mm diameter and 3mm deep defect was made in the femoral trochlea in both knees. The right knee defect was filled with platelet concentrate 5min after being activated with ClCa in group A (n=6), and similarly activated platelets + collagen scaffold in group B (n=6). Platelets were obtained by centrifuging 10ml arterial blood from the sheep prior to the surgical procedure. The left knee defect was not filled. The sheep were sacrificed 10 weeks after surgery. Macroscopic and microscopic studies were performed. Results. In group A, hyaline cartilage was observed in the right knee defect at the end of the experiment in four cases. None of the defects of the left knees showed hyaline cartilage growth. In group B, hyaline cartilage was not observed in any right knee defect. However, in group B, all sheep showed better chondral cellularity and regeneration and lower fibrosis in the defects treated with platelets than in non-treated ones. Conclusions. This technique for articular defect reconstruction with platelets has shown satisfactory results in our study. However, collagen scaffolds may decrease this positive effect (AU)

[Partial jejunal volvulus due to a mesenteric cystic lymphangioma]. / Vólvulo yeyunal incompleto por linfangioma quístico mesentérico.

Mesenteric cysts are unusual benign tumours that include lymphangioma. Their clinical presentation is variable and acute symptoms can be produced due to complications. This tumour appears especially in childhood, and its prognosis after surgical removal is excellent. We present the case of a 15 year old female patient with symptoms of postprandial abdominal pain and palpation of smooth mass in hypogastrium. Radiological studies showed a big polilobular mass of cystic substance that included a portion of jejune with incomplete volvulus. The treatment was the removal of the cyst and a jejunal portion and the pathological diagnosis was mesenteric cyst lymphangioma. The patient is asymptomatic more than three years after the intervention.

Características ultraestructurales de células precursoras neurales en intestino de rata / No disponible

No disponible

Correlación clinicomorfológica de distintas formas de demencia asociada a enfermedad de neurona motora / No disponible

No disponible

Células madre neurales positivas a la nestina en el Sistema Nervioso Entéricco / No disponible

No disponible

Tumor miofibroblástico en la edad pediátrica. A propósito de 3 casos / Paediatric myofibroblastic tumours. A presentation of three cases

El tumor miofibroblástico inflamatorio es una enfermedad poco frecuente en la edad pediátrica, en general benigna, aunque con posible evolución a malignidad. Se presentan 3 pacientes con tumor miofibroblástico en edad pediátrica, en diferentes localizaciones: pulmonar, gástrica e intestinal. Las características clínicas dependen del lugar en el que esté ubicado el tumor. Generalmente, hay fiebre prolongada en todos, sin gran afectación del estado general. En el primer caso, la hematemesis era su primer síntoma, mientras que en el segundo la anemia y la fiebre obligaron a la realización de una imagen abdominal. En el tercer caso fueron la fiebre, la tos y los síntomas respiratorios los que alertaban acerca de una posible tumoración pulmonar. En este caso se obtuvo un cultivo positivo para una micobacteria atípica: Mycobacterium avium. Todos los casos cursan con aumento de proteína C reactiva, velocidad de sedimentación globular, anemia, trombocitosis y aumento de gammaglobulinas. La evolución es favorable; la cirugía es curativa siempre y cuando la resección sea total; el diagnóstico es anatomopatológico. Los autores quieren destacar la precocidad en el diagnóstico de uno de los pacientes (3 meses), dato no hallado en la literatura médica (AU)

There cases of paediatric inflammatory myofibroblastic tumours in different locations are presented. This a rare benign disease, that can develop into malignant forms. Clinical features are associated with the location. Fever was the main symptom in all our cases. The symptoms that indicated the location of the tumour were, haematemesis in the first case, and respiratory disease in the third. ,In the third case our patient was diagnosed with tuberculosis due to mycobacterium avium. All cases had increased CRP, ESR, thrombocytosis and high levels of gamma globulins. Surgery is curative if total resection is possible, and the diagnosis is made by histopathology. We would like to emphasise the early development in the second case as this was a 3 months-old infant (AU)

[Paediatric myofibroblastic tumours. A presentation of three cases]. / Tumor miofibroblástico en la edad pediátrica. A propósito de 3 casos.

There cases of paediatric inflammatory myofibroblastic tumours in different locations are presented. This a rare benign disease, that can develop into malignant forms. Clinical features are associated with the location. Fever was the main symptom in all our cases. The symptoms that indicated the location of the tumour were, haematemesis in the first case, and respiratory disease in the third. In the third case our patient was diagnosed with tuberculosis due to mycobacterium avium. All cases had increased CRP, ESR, thrombocytosis and high levels of gamma globulins Surgery is curative if total resection is possible, and the diagnosis is made by histopathology. We would like to emphasise the early development in the second case as this was a 3 months-old infant.

[Reversible posterior leukoencephalopathy: report of two cases after vincristine treatment]. / Leucoencefalopatía posterior reversible: descripción de dos casos asociados a vincristina.

Reversible posterior leukoencephalopathy syndrome is a clinical-radiological phenomenon associated with headache, vomiting, lethargy, visual disturbances and seizures, concomitant with radiological abnormalities predominantly within posterior cerebral white matter due to cerebral edema. There are multiple triggers as acute hypertension, cancer, hematological disease, renal pathology, red cells transfusions and different drugs. We present two patients with reversible posterior leukoencephalopathy under treatment for acute lymphoblastic leukemia because of the probable association with vinca alkaloids.

Leucoencefalopatía posterior reversible: descripción de dos casos asociados a vincristina / Reversible posterior leukoencephalopathy: report of two cases after vincristine treatment

La leucoencefalopatía posterior reversible (LEPR) es un síndrome clínico-radiológico caracterizado por cefalea, vómitos, alteración de conciencia, problemas visuales y convulsiones, que presenta de forma concomitante lesiones radiológicas, fundamentalmente en las regiones posteriores de la sustancia blanca debido al edema cerebral existente. Este cuadro se asocia a múltiples situaciones médicas, como hipertensión arterial aguda, cáncer, enfermedades hematológicas, enfermedad renal, transfusión de glóbulos rojos y múltiples fármacos, como inmunosupresores, y citostáticos, entre otras causas. Presentamos dos casos en niños con leucemia aguda linfoblástica (LLA), asociados probablemente a utilización de vincristina (AU)

Reversible posterior leukoencephalopathy syndrome is a clinical-radiological phenomenon associated with headache, vomiting, lethargy, visual disturbances and seizures, concomitant with radiological abnormalities predominantly within posterior cerebral white matter due to cerebral edema. There are multiple triggers as acute hypertension, cancer, hematological disease, renal pathology, red cells transfusions and different drugs. We present two patients with reversible posterior leukoencephalopathy under treatment for acute lymphoblastic leukemia because of the probable association with vinca alkaloids (AU)

A radiofrequency-assisted device for bloodless rapid transection of the liver: a comparative study in a pig liver model.

BACKGROUND: Efficient and safe liver parenchymal transection is dependent on the ability to address both parenchymal division and hemostasis simultaneously. In this article we describe and compare with a saline-linked instrument a new radiofrequency (RF)-assisted device specifically designed for tissue thermocoagulation and division of the liver used on an in vivo pig liver model. METHODS: In total, 20 partial hepatectomies were performed on pigs through laparotomy. Two groups were studied: group A (n=8) with hepatectomy performed using only the proposed RF-assisted device and group B (n=8) with hepatectomy performed using only a saline-linked device. Main outcome measures were: transection time, blood loss during transection, transection area, transection speed and blood loss per transection area. Secondary measures were: risk of biliary leakage, tissue coagulation depth and the need for hemostatic stitches. Tissue viability was evaluated in selected samples by staining of tissue NADH. RESULTS: In group A both blood loss and blood loss per transection area were lower (p=0.001) than in group B (70+/-74 ml and 2+/-2 ml/cm(2) vs. 527+/-273 ml and 13+/-6 ml/cm(2), for groups A and B, respectively). An increase in mean transection speed when using the proposed device over the saline-linked device group was also demonstrated (3+/-0 and 2+/-1cm(2)/min for group A and B, respectively) (p=0.002). Tissue coagulation depth was greater (p=0.005) in group A than in group B (6+/-2 mm and 3+/-1 mm, for groups A and B, respectively). Neither macroscopic nor microscopic differences were encountered in transection surfaces between both groups. CONCLUSIONS: The proposed RF-assisted device was shown to address parenchymal division and hemostasis simultaneously, with less blood loss and faster transection time than saline-linked technology in this experimental model.

Radiofrequency hepatic ablation with internally cooled electrodes and hybrid applicators with distant saline infusion using an in vivo porcine model.

AIMS: Radiofrequency ablation (RFA) of tumors by means of internally cooled (ICE) or multitined expandable electrodes combined with infusion of saline into the tissue may improve results. Our aim was to determine the efficacy of a previously optimized hybrid ICE system (ICE combined with infusion of saline into the tissue at a distance of 2mm) in comparison with a conventional ICE cluster electrode in porcine liver in vivo. METHODS: A total of 32 RFA were performed on a total of 10 farm pigs using two RFA systems: Group A (n=16): Cluster electrode. Group B (n=16): Hybrid system (with continuous infusion of 100ml/h of 20% NaCl at 2mm distance from the electrode shaft by an independent isolated needle). Livers were removed for macroscopic and histological assessment after the procedure. Coagulation volume, coagulation diameters, coefficient of variability (CV) of coagulation volume, sphericity ratio (SR), deposited power (DP), deposited energy (DE), deposited energy per coagulation volume (DEV) and rise of animal temperature during the procedure were compared and correlated among groups. Additionally, linear regression analysis was modeled to study the relationship between deposited energy and either coagulation volume and rise of animal temperature during the procedure in both groups. RESULTS: Both coagulation volume and short diameter of coagulation were significantly greater (p<0.05) in group B compared to group A (22.7+/-11.0 cm(3) and 3.1+/-0.7 cm vs. 13.5+/-7.7 cm(3) and 2.5+/-0.5 cm, respectively). A similar CV and SR was observed among groups (57.1% and 1.4+/-0.3 vs. 48.6% and 1.3+/-0.2 for groups B and A, respectively). In group B, DE and DP were more than double group A, but DEV was nearly twice as high (9782 J/cm(3) vs. 5342 J/cm(3), for groups B and A, respectively). No significant relationship between DE and coagulation volume was encountered. CONCLUSION: Efficacy of a single ICE may be improved with continuous infusion of saline at around 2 mm from the electrode shaft. Coagulation volume obtained with this improved system may be even greater than that obtained with a cluster electrode.