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.

Lytic to temperate switching of viral communities.

Microbial viruses can control host abundances via density-dependent lytic predator-prey dynamics. Less clear is how temperate viruses, which coexist and replicate with their host, influence microbial communities. Here we show that virus-like particles are relatively less abundant at high host densities. This suggests suppressed lysis where established models predict lytic dynamics are favoured. Meta-analysis of published viral and microbial densities showed that this trend was widespread in diverse ecosystems ranging from soil to freshwater to human lungs. Experimental manipulations showed viral densities more consistent with temperate than lytic life cycles at increasing microbial abundance. An analysis of 24 coral reef viromes showed a relative increase in the abundance of hallmark genes encoded by temperate viruses with increased microbial abundance. Based on these four lines of evidence, we propose the Piggyback-the-Winner model wherein temperate dynamics become increasingly important in ecosystems with high microbial densities; thus 'more microbes, fewer viruses'.

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.

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.

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.

Tecnologías emergentes en ablación por radiofrecuencia de tumores hepáticos / No disponible

No disponible

Preservation of the liver graft with Celsior solution.

INTRODUCTION: We studied the evolution of the liver graft with preservation in Celsior (CS) compared with University of Wisconsin solution (UW). MATERIAL AND METHODS: A randomized prospective clinical study in 80 liver transplants (OLTs) from May 2001 to October 2003, compared CS (group I; n = 40) and UW (group II; n = 40). The characteristics of the donors were homogeneous, with no significant differences in 15 variables. CS was perfused with 4 L through the aorta, 2 L through the portal vein, and 1 L, through the portal vein on the back table; and the UW, as 3 L, 2 L, and 1 L, respectively. All OLTs were performed using the piggyback technique. RESULTS: Group I experienced reperfusion syndrome (n = 2; 5.9%), primary graft nonfunction (n = 0); vascular complications (n = 0); biliary anastomosis stenosis (n = 8; 22.9%), intensive care unit (ICU) days (n = 4.1 +/- 1), death within 30 days (n = 1; 3.1%). The patient and graft survivals at 1, 3, 6, 12, and 24 months were 93.7%, 93.7%, 90.2%, 85.7%, 85.7%, and 94.3%, 88.5%, 85.2%, 78%, 78%, respectively. For group II; the reperfusion syndrome occured in 6 patients (17.6%); primary graft nonfunction (n = 0); vascular complications (n = 0), biliary anastomosis stenosis (n = 3; 8.6%), ICU days (n = 4.9 +/- 2.4) and death within 30 days (n = 1; 3.1%); The patient and graft survival at 1, 3, 6, 12, and 24 months were 96.9%, 93.5%, 89.8%, 79.8%, 79.8% and 94.3%, 88.3%, 84.9%, 75.5%, 66.1%, respectively. CONCLUSIONS: CS offers the similar safety to UW for preservation of liver grafts within these ischemia times.

Liver transplant, in emergency 0 (UNOS Status 1).

INTRODUCTION: The emergency 0 (UNOS status 1) liver transplant (OLT) constitutes a challenge to the transplant team. The precarious condition of the patient and the use, sometimes forced by the instability of the patients, of marginal or different blood type grafts leads to worse results than in nonemergency OLT. Herein we have presented our experience with emergency 0 OLT in the first 5 years of our program. PATIENTS AND METHODS: Among the 167 OLTs performed in the first 5 years of our program, 10 were emergency 0 OLTs. The patients were transplanted within 72 hours of inclusion on the waiting list, seven within 24 hours. The indications for emergency OLT were fulminant liver failure (FLF) in six and graft failure in the first week post-OLT in four. RESULTS: All OLTs were performed with preservation of the vena cava (piggyback) and without venovenous bypass. There was 100% patient survival of those who required an emergency 0 OLT (follow-up period of 3 to 7 years). The graft survival in FLF was 50%. Emergency retransplant was necessary because of acute rejection due to ABO incompatibility in two patients, and due to arterial ischemia in another patient. The emergency retransplants were all successful. CONCLUSION: In our experience the emergency 0 OLT is a formidable challenge for the team, but we achieved a patient survival comparable to or even better than that of OLT for chronic liver disease.

Lipid peroxidation in ischemia-reperfusion oxidative injury of the graft preserved in Celsior and University of Wisconsin solutions on a pig pancreas transplantation model.

BACKGROUND: Graft pancreatitis (GP) is one the main technical problems associated with pancreas transplant (PT). It occurs in 20% of patients representing a risk factor for thrombosis and cause of graft loss. GP is related to oxidative effects from oxygen-derived free radicals (OFR) in ischemia-reperfusion injury. We evaluated lipid peroxidation by the OFR in the PT of pig organs preserved with either Celsior or Wisconsin solutions. METHODS: In Landrace pigs we performed 24 pancreas allografts, which were preserved 18 or 24 hours: 12 with Celsior solution (CS) and 12 with Wisconsin solution (UW). No immunosuppression was administered. The oxidative effects were determined by quantification of malondialdehyde (MDA) and 4-hydroxyalkenals (4-HDA) and of the carbonyl groups of proteins in our pancreatic tissue samples and measured at different times: (A) baseline in the donor, (B) after perfusion of the graft, (C) after the ischemia period, and (D) 30 minutes after ischemia-reperfusion of the graft. RESULTS: The MDA and 4-HDA values were similar in conditions A, B, and C, but showed an extraordinary increase after ischemia-reperfusion in D, among both the 18- or 24-hour preserved grafts and in the same proportion with CS and UW. The carbonyl groups of the proteins rose in conditions B and C (cold ischemia), but less so in state D (reperfusion). CONCLUSIONS: The oxidative injury of a pancreatic graft preserved for 18 or 24 hours occurs during reperfusion, with an extraordinary intensity, but similarly with CS and UW, an observation that may help to explain graft pancreatitis.

Prognostic factors in maxillary sinus and nasal cavity carcinoma.

AIMS: The aim of the present study is to define prognostic factors, particularly the impact of treatment on paranasal sinus and nasal cavity malignancies. MATERIAL AND METHODS: Retrospective study of patients with maxillary antrum and nasal fossae malignancies. A maxillectomy classification as performed to treat malignancies in our institution is described. Multivariate analysis of prognostic factors was done using the Cox's model. RESULTS: One hundred and nine patients were evaluated. Squamous cell carcinoma was found in 62 cases and in 95 patients the epicentre of the tumour was located in the maxillary antrum. Ten patients were treated with surgery only, 39 patients with surgery and adjuvant radiation therapy, 37 cases received only radiotherapy, and 18 received radiotherapy followed by surgery; in five cases a combination of chemo-radiotherapy was used. Multivariate analysis identified T classification, orbit invasion, N classification, site of origin of tumour in nasal fossae, and no surgical resection as independent prognostic factors (p=0.0001). CONCLUSION: T4 tumours with orbit invasion present bad prognosis as compared to other T4 tumours. Surgical resection should be included in the treatment strategy. Because of the high frequency of lymph-node metastasis, neck treatment should be considered in T4 tumours.

Mastectomía bilateral profiláctica en paciente portadora de la mutación BRCA-1 / Prophylactic bilateral mastectomy in a BRCA-1 mutation carrier

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Aspectos psicosomáticos de la hipertrofia mamaria / Psychosomatics aspects of mammary hypertrophy

El tratamiento de la hipertrofia mamaria constituye, en la actualidad, una de las prácticas quirúrgicas más comunes del trabajo de los cirujanos plásticos. En estas pacientes, además de confirmarse una sintomatología física evidente, como es dolor de espalda y/o cuello, lesiones cutáneas y adormecimiento en las manos, las repercusiones estéticas asociadas condicionan una evaluación negativa de la autoimagen corporal que, junto a vivencias de ansiedad y depresión, producen diversos grados de malestar psicosocial. Es por esto que la mamoplastia de reducción, además de disminuir significativamente el volumen mamario, proporciona grandes beneficios, según todas las series revisadas, mejorando los síntomas físicos asociados a la macromastia y aumentando la calidad de vida, nivel de salud y autoestima de las pacientes (AU)

Apoptosis and CD8 and CD54 cell expression in rat small bowel transplantation.

The importance of activated CD8 cells expressing IL-2R in small bowel and other organ rejection has been reported. Some authors even consider that a positive correlation might be demonstrated between the number of apoptotic enterocytes and the degree of graft rejection. In addition, moderate to intense activation of endothelial molecules in small bowel allograft in rats has been reported in chronic rejection. The aim of the present paper is to ascertain, in a heterotopic small bowel transplantation (HSBT) in rats, whether CD3, CD4, CD8, and CD54 cell expression in the allograft infiltrates shows some relationship with allograft enterocyte apoptosis when rejection is present. Wistar Furth male rats were allotted to two groups: group A was the control group without transplantation; group B received a heterotopic small bowel allograft from Fisher rats and an im dose of FK506 (0.25 mg/kg/day). A significant increase of CD8, CD54 cell receptor expression, and apoptosis in the group undergoing HSBT showed rejection. No significant differences have been observed in the variables under study between the control and HSBT without rejection groups or in CD3 and CD4 among the three groups. We observed a significant correlation between apoptosis and rejection, between CD8 and CD54 with apoptosis and with rejection, and between CD8 and CD54. This indicates that the activation of endothelial molecules and cells may play an important role in established HSBT chronic rejection. We consider that this study may contribute to the knowledge of small bowel allograft chronic rejection and its immunomodulation.

Hidatidosis muscular primaria recidivante de vasto interno / Recurrent primary muscle echinococcosis of the vastus medialis

La hidatidosis por Equinococcus granulossus es una parasitosis que afecta principalmente a hígado y pulmón y que en una mínima proporción implica de forma primaria al músculo. Presentamos el caso de una paciente de 60 años intervenida en tres ocasiones de una masa en la cara interna del muslo derecho y que tras llegar al diagnóstico de hidatidosis fue tratada con antihelmínticos durante un largo período, reapareciendo la tumoración al suspenderlos. En este momento acudió a nuestro servicio donde se diagnosticó hidatosis muscular recidivada con fístula a piel. Se practicó intervención radical resecando en bloque la periquística y el trayecto fistuloso. En el seguimiento postoperatorio se apreciaron imágenes quísticas compatibles con reaparición de la enfermedad siendo necesarias nuevas intervenciones que hasta el momento no han logrado una resolución definitiva de la enfermedad. El tratamiento de elección de la hidatidosis en cualquier localización es la resección quirúrgica radical (quistoperiquistectomía), lo que requiere un diagnóstico previo adecuado. Ante una masa quística muscular no se debe olvidar esta localización de la hidatosis, ya que el primer tratamiento que se realice determinará la evolución de una patología benigna que, como en nuestro caso, puede evolucionar con recurrencias múltiples, muy invalidantes y de difícil resolución (AU)

Autologous blood transfusion as an immunomodulator in experimental sepsis.

BACKGROUND: Homologous blood transfusion is associated with immunosuppressive consequences. Some clinical and experimental studies have suggested an immunostimulating action of autologous blood transfusion. The aim of this paper is to ascertain the effects of either homologous blood transfusion or autologous blood transfusion on the lymphocyte subsets and cytokines in a model of intra-abdominal sepsis. MATERIALS AND METHODS: There were three study groups. Group A: 10 Wistar-Furth (WF) rats underwent cecal ligation and puncture (CLP) aimed at causing an intra-abdomial sepsis; Group B: 10 WF rats underwent CLP plus 1 ml homologous blood perioperative transfusion obtained from Fisher-344 rat while Group C: 10 WF rats underwent CLP plus 1 ml autologous blood perioperative transfusion. Changes of peripheral lymphocyte subsets, percentages of total T-lymphocytes (CD3), Helper T-lymphocytes (CD4), supressor/cytotoxic T-lymphocytes (CD8), CD4/CD8 ratio, Interleukin-2 receptor expression (IL-2R) and cytokines IL-1 and TNF-alpha were measured in peripheral blood on the preoperative, 1st, 3rd and 7th postsepsis (PO) days. RESULTS: Rats in homologous transfused group showed a decrease of %CD4 on the 3rd PO (from preoperative to 3rd PO;p < 0.01; and from 1st to 3rd PO; p < 0.05) and on the 7th PO (from preoperative to 7th PO; p < 0.05); %CD8 increased from preoperative to 3rd PO (p < 0.05), from 1st to 3rd PO (p < 0.01) and from 1st to 7th PO (p < 0.05). An initial decrease on day 1 (p < 0.01) followed by an increase on the 3rd PO (p < 0.01) with regard to IL-2R and a significant increase of IL-1 levels within the first 24h (p < 0.01). Rats in autologous transfused group showed an increase of %CD3 from preoperative to 7th PO (p < 0.05), and from 3rd to 7th PO (p < 0.01). CONCLUSIONS: We observed that homologous blood transfusions induce a greater alteration in the cellular immune response and of the cascade of cytokines than autologous transfusions. This modulates the variations of the immune response induced by sepsis.

Binocular function and patient satisfaction after monovision induced by myopic photorefractive keratectomy.

PURPOSE: To measure binocular function and patient satisfaction with monovision induced by photorefractive keratectomy (PRK) in myopic presbyopic patients. SETTING: Refractive Department, Cleveland Clinic, Cleveland, Ohio, USA. METHODS: This study comprised 21 myopic presbyopic patients with monovision induced by PRK. Sixteen emmetropic patients who had PRK served as a control group. Monovision was induced by undercorrecting the nondominant eye by 1.25 diopters for near vision and correcting the dominant eye with emmetropia for distance vision. Monocular and binocular uncorrected Snellen visual acuities at 20 feet and 13 inches, manifest refraction, ocular dominance, stereopsis at 20 feet and 13 inches, monocular and binocular contrast sensitivities, Worth-4-Dot test at 20 feet and 1/3 of a meter, and fusional convergence amplitudes were examined in each patient. RESULTS: In the monovision group at near and distance, 20 patients (95.3%) had binocular visual acuity of 20/25 or better. No patient in the monovision group used reading glasses postoperatively; 4 of 16 patients (25.0%) in the control group used such glasses. All patients maintained binocular fusion and stereo acuity ranging from 40 to 800 seconds of arc. Mean patient satisfaction was 86% (range 40% to 100%). In the control group, 12 patients (75.0%) had binocular distance visual acuity of 20/25 or better and 11 (68.8%) had binocular near visual acuity of 20/25 or better. CONCLUSION: Monovision PRK patients had better near vision than control PRK patients, with minimal compromise in stereo acuity and overall high patient satisfaction.

Hepatic lesion ablation with bipolar saline-enhanced radiofrequency in the audible spectrum.

RATIONALE AND OBJECTIVES: The authors' purpose was to create larger and more regular liver lesions in vitro by testing a new hyperthermia approach that uses a bipolar saline-enhanced electrode for radiofrequency (RF) in the audible spectrum and a greater power supply. MATERIALS AND METHODS: The authors' hyperthermia approach (group A, n = 23) was used in excised porcine livers, and the results were compared with those of a previously described monopolar saline-enhanced electrode procedure (group B, n = 23). In each set of experiments, RF in the audible spectrum current (50 Hz) was provided for 15 minutes with a similar ablation protocol. Electrical variables (impedance, current, voltage, power, and energy), temperatures in the lesions, volume size, regularity ratio of the lesion, and microscopic findings were measured. RESULTS: In group A, the mean volume size and the mean regularity ratio values were 144.8 cm3 +/- 59.8 and 0.78 +/- 0.1, respectively. In group B, the mean volume size and regularity ratio values were 62.1 cm3 +/- 36.4 and 0.62 +/- 0.1, respectively. The values in group B were thus significantly lower than those in group A (P < .01). The lesions in group A were also more homogeneous. No significant differences were found in electrical variables. CONCLUSION: The new bipolar saline-enhanced electrode produced larger, more regular, and more homogeneous lesions ex vivo than the previously used monopolar saline-enhanced electrode method. Using a greater power supply increased the amount of coagulative necrosis.

Primary hydatid disease in lumbar muscles.

The authors report a case of primary hydatid disease in the lumbar muscles of a 40-year-old male patient. The rarity of this disease in our regions and the low incidence of this location make primary diagnosis difficult. The tumor had been treated elsewhere five years previously by means of simple excision. Recurrence of the lesion was diagnosed five years after the first surgery. Wide excision of the cyst and pericyst with a 3.5-cm security margin was performed. Six years after the last surgery, no recurrence has been detected.