Pancreatic duct ligation reduces premalignant pancreatic lesions in a Kras model of pancreatic adenocarcinoma in mice.

Pancreatic duct ligation (PDL) in the murine model has been described as an exocrine pancreatic atrophy-inducing procedure. However, its influence has scarcely been described on premalignant lesions. This study describes the histological changes of premalignant lesions and the gene expression in a well-defined model of pancreatic ductal adenocarcinoma by PDL. Selective ligation of the splenic lobe of the pancreas was performed in Ptf1a-Cre(+/ki); K-ras LSLG12Vgeo(+/ki) mice (PDL-Kras mice). Three experimental groups were evaluated: PDL group, controls and shams. The presence and number of premalignant lesions (PanIN 1-3 and Atypical Flat Lesions-AFL) in proximal (PP) and distal (DP) pancreas were studied for each group over time. Microarray analysis was performed to find differentially expressed genes (DEG) between PP and PD. Clinical human specimens after pancreaticoduodenectomy with ductal occlusion were also evaluated. PDL-Kras mice showed an intense pattern of atrophy in DP which was shrunk to a minimal portion of tissue. Mice in control and sham groups had a 7 and 10-time increase respectively of risk of high-grade PanIN 2 and 3 and AFL in their DP than PDL-Kras mice. Furthermore, PDL-Kras mice had significantly less PanIN 1 and 2 and AFL lesions in DP compared to PP. We identified 38 DEGs comparing PP and PD. Among them, several mapped to protein secretion and digestion while others such as Nupr1 have been previously associated with PanIN and PDAC. PDL in Ptf1a-Cre(+/ki); K-ras LSLG12Vgeo(+/ki) mice induces a decrease in the presence of premalignant lesions in the ligated DP. This could be a potential line of research of interest in some cancerous risk patients.

Medial temporal lobe atrophy is independently associated with behavioural and psychological symptoms in Alzheimer's disease.

AIM: Evidence describing the contribution of cerebral white matter disease and medial temporal atrophy (MTA) to behavioural and psychological symptoms of dementia (BPSD) has been conflicting. The aim of this study was to assess the relationship of white matter hyperintensities (WMH) and MTA observed on magnetic resonance imaging with BPSD among patients with Alzheimer's disease. METHODS: In a cross-sectional study of a prospective cohort of patients attending a memory clinic, 46 patients with probable Alzheimer's disease (mean age: 72.38 ± 7.05 years) were studied. Sociodemographic, cognitive, and BPSD data were collected. BPSD were assessed using the Neuropsychiatric Inventory. Magnetic resonance imaging, WMH, and MTA were rated using the Scheltens scales for the assessment of signal hyperintensities and atrophy of medial temporal lobes. For multivariate analysis, two binary logistic regression analyses were carried out, with presence or absence of each BPSD as the dependent variable and with WMH or MTA as the predictor variable. Results of the logistic regression were analyzed to see if the significance of the WMH or MTA score was maintained in a model that factored in other possible confounding variables identified in univariate analysis. RESULTS: The results of binary logistic regression analysis showed that in models that accounted for confounding variables, increased total MTA was significantly associated with apathy (odds ratio = 1.605, adjusted P = 0.042) and disinhibition (odds ratio = 0.607, adjusted P = 0.042). WMH measures did not significantly predict any BPSD item. CONCLUSIONS: These findings indicate that MTA potentially contributes to the aetiology of BPSD, and they provide evidence to support the hypothesis that Alzheimer's disease pathology itself can contribute to BPSD.

Carcinoma epidermoide oral alrededor de implantes osteointegrados: a propósito de un caso y revisión bibliográfica / Squamous cell carcinoma surrounding osseointegrated dental implants: clinical case and references review

Resumen Introducción La rehabilitación oral con implantes es en la actualidad la mejor opción para el tratamiento de pacientes parcial o totalmente edéntulos. Sin embargo, no es un procedimiento exento de complicaciones. La aparición de carcinoma epidermoide en la encía circundante de los implantes, aunque infrecuente puede ser una de ellas y aunque no hay muchos casos descritos en la literatura, sería conveniente establecer qué relación, si es que existiera, pueden tener los implantes en el desarrollo de esta enfermedad. Caso clínico Presentamos el caso de una mujer de 85 años de edad con antecedentes personales de liquen plano oral, exfumadora y portadora de implantes osteointegrados colocados en las áreas correspondientes a 34, 45 y 46, que desarrolló un carcinoma epidermoide en la encía periimplantaria.

Introduction Currently, dental implants is considered as the best choice for edentulism partial or complete treatment. However, this treatment has some associated medical complications such as surrounding gum squamous cell carcinoma. Even though there are not that many cases described in medical literature, it could be appropriated to determine whether there is any relation between this neoplasic disease and the dental implants. Clinical case Presenting a 85-year-old women with PMH of lichen planus, ex-smoker and osseointegrated dental implant in areas 34, 45 and 46, with surrounding implant gum area Squamous cell carcinoma.

Radiofrequency-induced heating versus mechanical stapler for pancreatic stump closure: in vivo comparative study.

PURPOSE: The aim of this study was to assess the capacity of two methods of surgical pancreatic stump closure in terms of reducing the risk of pancreatic fistula formation (POPF): radiofrequency-induced heating versus mechanical stapler. MATERIALS AND METHODS: Sixteen pigs underwent a laparoscopic transection of the neck of the pancreas. Pancreatic anastomosis was always avoided in order to work with an experimental model prone to POPF. Pancreatic stump closure was conducted either by stapler (ST group, n = 8) or radiofrequency energy (RF group, n = 8). Both groups were compared for incidence of POPF and histopathological alterations of the pancreatic remnant. RESULTS: Six animals (75%) in the ST group and one (14%) in the RF group were diagnosed with POPF (p = 0.019). One animal in the RF group and three animals in the ST group had a pseudocyst in close contact with both pancreas stumps. On day 30 post-operation (PO), almost complete atrophy of the exocrine distal pancreas was observed when the main pancreatic duct was efficiently sealed. CONCLUSIONS: Our findings suggest that RF-induced heating is more effective at closing the pancreatic stump than mechanical stapler and leads to the complete atrophy of the distal remnant pancreas.

Long-term evolution of acinar-to-ductal metaplasia and ß-cell mass after radiofrequency-assisted transection of the pancreas in a controlled large animal model.

BACKGROUND: Pancreatic duct ligation (PDL) has been used as a model of chronic pancreatitis and as a model to increase ß-cell mass. However, studies in mice have demonstrated acinar regeneration after PDL, questioning the long-term validity of the model. We aim to elucidate whether RF-assisted transection (RFAT) of the main pancreatic duct is a reliable PDL model, both in short (ST, 1-month) and long-term (LT, 6-months) follow-ups. METHODS: Eleven pigs were subjected to RFAT. Biochemical (serum/peripancreatic amylase and glucose) and histological changes (including a semiautomatic morphometric study of over 1000 images/pancreas and IHC analysis) were evaluated after ST or LT follow-up and also in fresh pancreas specimens that were used as controls for 1 (n = 4) and 6 months (n = 6). RESULTS: The distal pancreas in the ST was characterized by areas of acinar-to-ductal metaplasia (56%) which were significantly reduced at LT (21%) by fibrotic replacement and adipose tissue. The endocrine mass showed a normal increase. CONCLUSION: RFAT in the pig seems to be an appropriate PDL model without restoration of pancreatic drainage or reduction of endocrine mass.

Radiofrequency pancreatic ablation and section of the main pancreatic duct does not lead to necrotizing pancreatitis.

OBJECTIVE: The aim of this study was to determine whether radiofrequency ablation (RFA) of the pancreas and subsequent transection of the main pancreatic duct may avoid the risk of both necrotizing pancreatitis and postoperative pancreatic fistula (POPF) formation. METHODS: Thirty-two rats were subjected to RFA and section of the pancreas over their portal vein. Animals were killed at 3, 7, 15, and 21 days (groups 0-3, respectively). Two additional control groups (sham operation and user manipulation only, respectively) of 15 days of postoperative period were considered. Postoperative complications, histological changes (including morphometric and immunohistochemical analysis), and incidence of POPF were evaluated. RESULTS: A significant increase in serum amylase levels (P < 0.05) on the third postoperative day, which return to baseline levels in the following weeks, was noted in groups 0 to 3. Those groups showed a rapid atrophy of the distal pancreas by apoptosis with no signs of necrotizing pancreatitis or POPF. The distal pancreas in groups 1 to 3 compared with group 0 and control groups showed a significant increase of small islets (<1000 µm). CONCLUSIONS: The rapid acinar atrophy of the distal pancreas after RFA and section of the pancreatic ducts in this model does not lead to necrotizing pancreatitis.

Tratamiento del cáncer colorrectal con metástasis irresecables con quimioterapia sin resección del primario: análisis de las complicaciones relacionadas con el tumor / Treatment of colorectal cancer with unresectable metastasis with chemotherapy without primary tumor resection: Analysis of tumor-related complications

INTRODUCCIÓN: Aunque el tratamiento convencional de los pacientes con cáncer colorrectal en estadio IV ha consistido en la resección del tumor primario seguida de quimioterapia, varios estudios defienden que en pacientes poco sintomáticos el primer y único tratamiento debe ser quimioterapia. El objetivo es analizar las complicaciones relacionadas con el tumor primario en una serie consecutiva de pacientes con cáncer colorrectal y metástasis irresecables tratados con quimioterapia sin cirugía. MATERIAL Y MÉTODOS: Estudio descriptivo retrospectivo. Se ha incluido a todos los pacientes con cáncer colorrectal y metástasis irresecables en los que se decidió realizar quimioterapia sin resección del tumor primario durante el periodo enero 2007-febrero 2011. RESULTADOS: La edad media de los 61 pacientes analizados era de 67 ± 13 años. Veinte (33%) pacientes presentaron alguna complicación durante el seguimiento. La complicación más frecuente fue la obstrucción intestinal en 15 (25%) seguida de la perforación. Las complicaciones precisaron cirugía en 6 (10%). No hemos encontrado diferencias estadísticamente significativas en las características de los pacientes entre aquellos que presentaron una complicación y los que no, aunque el porcentaje de complicaciones entre los portadores de prótesis colónica (53%) dobló el del resto de pacientes (26%). CONCLUSIONES: La quimioterapia sin cirugía es una buena opción en la mayoría de los pacientes con cáncer colorrectal y metástasis irresecables. Sin embargo, aunque el porcentaje de pacientes que precisan cirugía es bajo, el número de complicaciones relacionadas con el tumor primario no es despreciable. Se necesitan estudios que permitan identificar a aquellos pacientes en los que estaría indicada una colectomía profiláctica

INTRODUCTION: Although the conventional treatment of patients with stage IV colorectal cancer involves resection of the primary tumor followed by chemotherapy, several studies suggest that in patients with few symptoms the first and only treatment should be chemotherapy. The objective of this study is to analyze the complications related to the primary tumor in a series of patients with unresectable metastatic colorectal cancer treated with chemotherapy without surgery. MATERIAL AND METHODS: Retrospective descriptive study. The study included all patients with unresectable metastatic colorectal cancer treated with chemotherapy without resection of the primary tumor (January 2007-February 2011). RESULTS: The mean age of the 61 patients analyzed was 67 ± 13 years and the performance status was 0-1 in 53 (87%). Twenty (33%) patients developed complications during follow-up. The most common complication was intestinal obstruction in 15 (25%) patients followed by perforation. Complications required surgery in 6 (10%) cases. We did not find differences in patient characteristics between those who had a complication and those without, although the complication rate in patients with a colonic stent (53%) was twice that of other patients (26%). CONCLUSIONS: Chemotherapy without surgery is a good option in most patients with unresectable metastatic colorectal cancer. However, although the percentage of patients requiring surgery is low, the total number of complications related to the primary tumor is not negligible. Studies are needed to identify those patients in whom a prophylactic colectomy could be indicated

[Treatment of colorectal cancer with unresectable metastasis with chemotherapy without primary tumor resection: analysis of tumor-related complications]. / Tratamiento del cáncer colorrectal con metástasis irresecables con quimioterapia sin resección del primario: análisis de las complicaciones relacionadas con el tumor.

INTRODUCTION: Although the conventional treatment of patients with stage iv colorectal cancer involves resection of the primary tumor followed by chemotherapy, several studies suggest that in patients with few symptoms the first and only treatment should be chemotherapy. The objective of this study is to analyze the complications related to the primary tumor in a series of patients with unresectable metastatic colorectal cancer treated with chemotherapy without surgery. MATERIAL AND METHODS: Retrospective descriptive study. The study included all patients with unresectable metastatic colorectal cancer treated with chemotherapy without resection of the primary tumor (January 2007-February 2011). RESULTS: The mean age of the 61 patients analyzed was 67±13 years and the performance status was 0-1 in 53 (87%). Twenty (33%) patients developed complications during follow-up. The most common complication was intestinal obstruction in 15 (25%) patients followed by perforation. Complications required surgery in 6 (10%) cases. We did not find differences in patient characteristics between those who had a complication and those without, although the complication rate in patients with a colonic stent (53%) was twice that of other patients (26%). CONCLUSIONS: Chemotherapy without surgery is a good option in most patients with unresectable metastatic colorectal cancer. However, although the percentage of patients requiring surgery is low, the total number of complications related to the primary tumor is not negligible. Studies are needed to identify those patients in whom a prophylactic colectomy could be indicated.

Radiofrequency is a secure and effective method for pancreatic transection in laparoscopic distal pancreatectomy: results of a randomized, controlled trial in an experimental model.

BACKGROUND: Postoperative pancreatic fistula (PPF) is the most frequent and serious complication after laparoscopic distal pancreatectomy (LDP). Our goal was to compare the performance, in terms of PPF prevention, and safety of a radiofrequency (RF)-assisted transection device versus a stapler device in a porcine LDP model. METHODS: Thirty-two animals were randomly divided into two groups to perform LDP using a RF-assisted device (RF group; n = 16) and stapler device (ST group; n = 16) and necropsied 4 weeks after surgery. The primary endpoint was the incidence of PPF. Secondary endpoints were surgery/transection time, intra/postoperative complications/deaths, postoperative plasmatic amylase and glucose concentration, peritoneal liquid amylase and interleukin 6 (IL-6) concentrations, weight variations, and histopathological changes. RESULTS: Two clinical and one biochemical PPF were observed in the ST and RF groups respectively. Peritoneal amylase concentration was significantly higher in the RF group 4 days after surgery, but this difference was no longer present at necropsy. Both groups presented a significant decrease in peritoneal IL-6 concentration during the postoperative follow-up, with no differences between the groups. RF group animals showed a higher postoperative weight gain. In the histopathological exam, all RF group animals showed a common pattern of central coagulative necrosis of the parenchymal surface, surrounded by a thick fibrosis, which sealed main and secondary pancreatic ducts and was not found in ST group. CONCLUSIONS: The fibrosis caused by an RF-assisted device can be at least as safe and effective as stapler compression to achieve pancreatic parenchyma sealing in a porcine LDP model.

La psicología en Paraguay, contexto histórico: retos para una integración en escenarios latinoamericanos / The psychology in Paraguay: challenges for an integration in Latin American scenarios

La Psicologia en Paraguay tuvo sus origines en la Educación, desde el siglo XIX en la curricula de la secundaria se tenia la materia de Psicología. Recién en la década de los 60 surge la formación universitaria, tanto en la Universidad Nacional como la Universidad Católica. Con la apertura democrática en los años 90, se abrieron otras universidades públicas y privadas para la formación de psicólogos. Las grandes desigualdades sociales en América Latina y los problemas sociales convocan a la Psicologia a generar conocimientos acordes a la realidad latinoamericano. Se constituyen como desafíos fundamentales para la Psicología en Paraguay la formación con calidad y la investigación, estos dos temas surgen como emergentes para avanzar en la integración de la Psicología Paraguaya a la Psicologia Regional y a otros ámbitos del conocimiento.(AU)

Psychology in Paraguay has been originated in the Education area, in the Psychology subject that had developed from the century XIX in the High schol schedule. Just in the decade of the sixty arise this study at the university, as much in the National University as the Catholic University. With the democratic opening in 1990, other public and private universities were opening for the psychologists formation. The great social inequalities in Latin America and the social problems needs the Psychology tools to generate knowledge agreed to the Latin American reality. The fundamental challenges for Psychology in Paraguay are the high quality formation and the researches. These two subjects arise as necessary to advance in the integration process of Paraguayan Psychology to Regional Psychology and other areas of the knowledge.(AU)

Radiation treatment of recurrent pheochromocytoma of the bladder: case report and review of literature.

Secondary to the paucity of pheochromocytoma, very limited data exist regarding the optimal treatments of metastatic disease. Malignant pheochromocytomas are often considered unresponsive to radiotherapy, but this decision is based on the few case reports performed before 1970. There have been a handful of reports about metastatic resolution and palliation from radiation therapy. Nevertheless, radiotherapy is not considered a mainstay of pheochromocytoma treatment. In this case report, we describe a patient with a malignant extraadrenal pheochromocytoma, metastatic to the right humerus, and her treatment course of surgery and radiotherapy.