Factors predictive of the successful treatment of choledocholithiasis.

BACKGROUND: Choledocholithiasis is a common complication of cholelithiasis, occurring in up to 18% of patients. Multiple treatments are often performed during the course of the management of choledocholithiasis, sometimes without success. Our study was performed identify the factors predictive of the success of treatment with retrograde endoscopic cholangiopancreatography (ERCP). METHODS: This was a retrospective, case-control study that used data from a biliary disease database at Hospital de Clínicas de Porto Alegre (HCPA). Demographic, clinical, radiological and procedure-related variables were compared between patients with successful biliary clearance after one ERCP procedure (Group 1) and those with unsuccessful biliary clearance after one ERCP procedure (Group 2). RESULTS: Three hundred twenty patients were included in Group 1, while 254 were included in Group 2. Multivariate analysis showed that older age, previous biliary exploration, elevated serum total bilirubin, choledocholithiasis above the level of the confluence of the hepatic ducts, stones retained in the cystic duct or Mirizzi syndrome, dilatation of the bile duct diagnosed during ERCP, and the need for suprapapillary opening were independently associated with the failure of the first ERCP to achieve bile duct clearance. The performance of imaging at the same institution prior to the procedure and the retention of stones in the duodenal papilla were associated with the success of endoscopic treatment. CONCLUSIONS: The variables identified in this study, when considered in conjunction with the results of previously published studies, can be used to guide the choice of therapeutic methods for patients with choledocholithiasis in the future, given the significant difference in outcomes between the two groups. In the future, a prospective study should be performed to determine whether the same factors are predictive of the success of other methods of treatment (surgical or percutaneous).

A systematic review and meta-analysis of the aetiology of acute pancreatitis.

BACKGROUND: Gallstones and alcohol are currently the most frequent aetiologies of acute pancreatitis (AP). The aim of this study is to quantify these aetiologies worldwide, by geographic region and by diagnostic method. METHODS: A systematic review of observational studies published from January 2006 to October 2017 was performed. The studies provided objective criteria for establishing the diagnosis and aetiology of AP for at least biliary and alcoholic causes. A random-effects meta-analysis was used to assess the frequency of biliary (ABP), alcoholic (AAP) and idiopathic AP (IAP) worldwide and to perform 6 subgroup analyses: 2 compared diagnostic methods for AP aetiology and the other 4 compared geographic regions. RESULTS: Forty-six studies representing 2,341,007 patients of AP in 36 countries were included. The global estimate of proportion (95% CI) of aetiologies was 42 (39-44)% for ABP, 21 (17-25)% for AAP and 18 (15-22)% for IAP. In studies that used discharge code diagnoses and in those from the US, IAP was the most frequent aetiology. ABP was more frequent in Latin America than in other regions. CONCLUSION: Gallstones represent the main aetiology of AP globally, and this aetiology is twice as frequent as the second most common aetiology.

Encapsulated platelets modulate kupffer cell activation and reduce oxidative stress in a model of acute liver failure.

Acute liver failure (ALF) is characterized by massive hepatocyte cell death. Kupffer cells (KC) are the first cells to be activated after liver injury. They secrete cytokines and produce reactive oxygen species, leading to apoptosis of hepatocytes. In a previous study, we showed that encapsulated platelets (PLTs) increase survival in a model of ALF. Here, we investigate how PLTs exert their beneficial effect. Wistar rats submitted to 90% hepatectomy were treated with PLTs encapsulated in sodium alginate or empty capsules. Animals were euthanized at 6, 12, 24, 48, and 72 hours after hepatectomy, and livers were collected to assess oxidative stress, caspase activity, and gene expression related to oxidative stress or liver function. The number of KCs in the remnant liver was evaluated. Interaction of encapsulated PLTs and KCs was investigated using a coculture system. PLTs increase superoxide dismutase and catalase activity and reduce lipid peroxidation. In addition, caspase 3 activity was reduced in animals receiving encapsulated PLTs at 48 and 72 hours. Gene expression of endothelial nitric oxide synthase and nuclear factor kappa B were elevated in the PLT group at each time point analyzed. Gene expression of albumin and factor V also increased in the PLT group. The number of KCs in the PLT group returned to normal levels at 12 hours but remained elevated in the control group until 72 hours. Finally, PLTs modulate interleukin (IL) 6 and IL10 expression in KCs after 24 hours of coculture. In conclusion, these results indicate that PLTs interact with KCs in this model and exert their beneficial effect through reduction of oxidative stress that results in healthier hepatocytes and decreased apoptosis. Liver Transplantation 22 1562-1572 2016 AASLD.

Perioperative synbiotics decrease postoperative complications in periampullary neoplasms: a randomized, double-blind clinical trial.

Periampullary neoplasms are rapidly progressive tumors with a poor prognosis and high morbidity and mortality rates, which have a negative influence on patient outcomes. Some probiotics and prebiotics have the ability to protect the intestinal barrier and prevent bacterial translocation, infection, and postoperative complications. We evaluated the use of synbiotics in a prospective, double-blind study of patients undergoing surgery for periampullary neoplasms (PNs) and assessed the effect of these agents on nutritional status, postoperative complications, antibiotic use, length of hospital stay, and mortality. Patients were randomized to receive probiotics and prebiotics-synbiotics--group S [Lactobacillus acidophilus 10, 1 × 10(9)CFU, Lactobacillus rhamnosus HS 111, 1 × 10(9) CFU, Lactobacillus casei 10, 1 × 10(9) CFU, Bifidobacterium bifidum, 1 × 10(9)CFU, and fructooligosaccharides (FOS) 100 mg]--or placebo-controls--group C, twice daily, for a total of 14 days. Risk, clinical status, and postoperative complication rates were assessed. Twenty-three patients were allocated to each group. The incidence of postoperative infection was significantly lower in group S (6 of 23 patients, 26.1%) than in group C (16 of 23 patients, 69.6%) (P = 0.00). Duration of antibiotic therapy was also shorter in group S (mean = 9 days vs. 15 days in group C; P = 0.01). Noninfectious complications were less common in group S (6 of 23 vs. 14 of 23 patients in group C; P = 0.03). Mean length of hospital stay was 12 ± 5 days in group S vs. 23 ± 14 days in group C (P = 0.00). No deaths occurred in group S, whereas 6 deaths occurred in group C (P = 0.02). Perioperative administration of synbiotics reduces postoperative mortality and complication rates in patients undergoing surgery for PNs.

PRIMA-1, a mutant p53 reactivator, induces apoptosis and enhances chemotherapeutic cytotoxicity in pancreatic cancer cell lines.

TP53 mutation is a common event in many cancers, including pancreatic adenocarcinoma, where it occurs in 50-70 % of cases. In an effort to reactivate mutant p53 protein, several new drugs are being developed, including PRIMA-1 and PRIMA-1(Met)/APR-246 (p53 reactivation and induction of massive apoptosis). PRIMA-1 has been shown to induce apoptosis in tumor cells by reactivating p53 mutants, but its effect in pancreatic cancer remains unclear. Here we investigated the effects of PRIMA-1 on cell viability, cell cycle and expression of p53-regulated proteins in PANC-1 and BxPC-3 (mutant TP53), and CAPAN-2 (wild-type TP53) pancreatic cell lines. Treatment with PRIMA-1 selectively induced apoptosis and cell cycle arrest in p53 mutant cells compared to CAPAN-2 cells. The growth suppressive effect of PRIMA-1 was markedly reduced in p53 mutant cell lines transfected with p53 siRNA, supporting the role of mutant p53 in PRIMA-1 induced cell death. Moreover, treatment with the thiol group donor N-acetylcysteine completely blocked PRIMA-1-induced apoptosis and reinforced the hypothesis that thiol modifications are important for PRIMA-1 biological activity. In combination treatments, PRIMA-1 enhanced the anti-tumor activity of several chemotherapic drugs against pancreatic cancer cells and also exhibited a pronounced synergistic effect in association with the Mdm2 inhibitor Nutlin-3. Taken together, our data indicate that PRIMA-1 induces apoptosis in p53 mutant pancreatic cancer cells by promoting the re-activation of p53 and inducing proapoptotic signaling pathways, providing in vitro evidence for a potential therapeutic approach in pancreatic cancer.

Platelet increases survival in a model of 90% hepatectomy in rats.

BACKGROUND & AIMS: Ninety per cent hepatectomy in rodents is a model for acute liver failure. It has been reported that platelets have a strong effect enhancing liver regeneration, because of the production of several growth factors such as serotonin. The aim of this study was to investigate the role of microencapsulated platelets on 90% hepatectomy in rats. METHODS: Platelets (PLT) were microencapsulated in sodium alginate and implanted in the peritoneum of rats after 90% partial hepatectomy (PH). Control group received empty capsules (EC). Animals were euthanized at 6, 12, 24, 48 and 72 h post PH (n=9-12/group/time) to evaluate liver regeneration rate, mitotic index, liver content, serum and tissue levels of Interleukin 6 (IL-6) and serotonin and its receptor 5-hydroxytryptamine type 2B (5Ht2b). Survival rate in 10 days was evaluated in a different set of animals (n=20/group). RESULTS: Platelets group showed the highest survival rate despite the lowest liver regeneration rate at any time point. Mitotic and BrdU index showed no difference between groups. However, the number of hepatocytes was higher and the internuclear distance was shorter for PLT group. Liver dry weight was similar in both groups indicating that water was the main responsible factor for the weight difference. Gene expression of IL-6 in the liver was significantly higher in EC group 6 h after PH, whereas 5Ht2b was up-regulated at 72 h in PLT group. CONCLUSIONS: Platelets enhance survival of animals with 90% PH, probably by an early protective effect on hepatocytes and the increase in growth factor receptors.

Telomere length assessment and molecular characterization of TERT gene promoter in periampullary carcinomas.

Genetic and epigenetic alterations of the telomere maintenance machinery like telomere length and telomerase reverse transcriptase (encoded by TERT gene) are reported in several human malignancies. However, there is limited knowledge on the status of the telomere machinery in periampullary carcinomas (PAC) which are rare and heterogeneous groups of cancers arising from different anatomic sites around the ampulla of Vater. In the current study, we investigated the relative telomere length (RTL) and the most frequent genetic and epigenetic alterations in the TERT promoter in PAC and compared it with tumor-adjacent nonpathological duodenum (NDu). We found shorter RTLs (1.27 vs 1.33, P = 0.01) and lower TERT protein expression (p = 0.04) in PAC tissues as compared to the NDu. Although we did not find any mutation at two reactivating hotspot mutation sites of the TERT promoter, we detected polymorphism in 45% (9/20) of the cases at rs2853669 (T > C). Also, we found a hypermethylated region in the TERT promoter of PACs consisting of four CpGs (cg10896616 with Δß 7%; cg02545192 with Δß 9%; cg03323598 with Δß 19%; and cg07285213 with Δß 15%). In conclusion, we identified shorter telomeres with DNA hypermethylation in the TERT promoter region and lower TERT protein expression in PAC tissues. These results could be used further to investigate molecular pathology and develop theranostics for PAC.

Sarcina ventriculi a rare pathogen.

Sarcina ventriculi is a gram-positive bacterium, able to survive in extreme low pH environment. It's first description dates from 1842, by John Goodsir. Since then, just a few cases have been reported. In veterinary medicine, especially in ruminants, it causes bloating, vomiting, gastric perforation and death of the animal. It is commonly associated with delayed gastric emptying or obstruction to gastric outlet, although it's pathogenicity in humans is not fully understood. We report two cases with identification of the bacteria in gastric specimens stained with hematoxylin-eosin staining, in different clinical settings. The first patient is a young female patient, presenting cardiac arrest and death after gastric perforation and the second patient an adult male presenting with gastric adenocarcinoma, treated with partial gastrectomy followed by adjuvant chemoradiation. In our literature review, we identified forty-five cases reporting Sarcina ventriculi appearance, with a sudden increase since 2010.

Prognostic Factors of Long-term Survival Following Radical Resection for Ampullary Carcinoma.

BACKGROUND: The incidence of adenocarcinoma of the ampulla of Vater has been increasing over the past years. Nevertheless, it is still a rare disease and the prognostic factors predicting long-term survival are not sufficiently clarified. This study aims to evaluate the association between histopathological characteristics and long-term survival of patients with ampullary cancer after curative resection, as well as the efficiency of immunohistochemical expression of CK7, CK20, and CDX2 to distinguish the histopathological (intestinal or pancreaticobiliary) patterns. METHODS: Demographic, histopathological data, pTNM stage, and immunohistochemical expression patterns were collected from 65 patients with adenocarcinoma of the ampulla of Vater. Five and 10-year overall and disease-free survival rates after curative resection were determined. RESULTS: Of the 65 patients with ampullary carcinoma, 47 (72%) underwent radical resection. The 5- and 10-year overall survival rate was 46% and 37%, respectively. Our results demonstrate that the main prognostic factors were the presence and number of lymph node metastases, lymph node ratio (LNR), differentiation grade, and lymphovascular invasion. After multivariate analysis, only lymph node ratio ≥ 20% remained an independent prognostic factor of survival (HR: 2.63 95% CI: 1.05-6.61; p = 0.039). CONCLUSION: Here, we demonstrated more evidence that the lymph node metastases are associated with poor prognosis in ampullary carcinoma. Particularly, the relation between the number of metastatic lymph nodes and the number of harvested lymph node (LNR) should be considered a major prognostic factor.

Calcium Signaling Alterations Caused by Epigenetic Mechanisms in Pancreatic Cancer: From Early Markers to Prognostic Impact.

Pancreatic ductal adenocarcinoma (PDAC) is an aggressive disease with high mortality rates. PDAC initiation and progression are promoted by genetic and epigenetic dysregulation. Here, we aimed to characterize the PDAC DNA methylome in search of novel altered pathways associated with tumor development. We examined the genome-wide DNA methylation profile of PDAC in an exploratory cohort including the comparative analyses of tumoral and non-tumoral pancreatic tissues (PT). Pathway enrichment analysis was used to choose differentially methylated (DM) CpGs with potential biological relevance. Additional samples were used in a validation cohort. DNA methylation impact on gene expression and its association with overall survival (OS) was investigated from PDAC TCGA (The Cancer Genome Atlas) data. Pathway analysis revealed DM genes in the calcium signaling pathway that is linked to the key pathways in pancreatic carcinogenesis. DNA methylation was frequently correlated with expression, and a subgroup of calcium signaling genes was associated with OS, reinforcing its probable phenotypic effect. Cluster analysis of PT samples revealed that some of the methylation alterations observed in the Calcium signaling pathway seemed to occur early in the carcinogenesis process, a finding that may open new insights about PDAC tumor biology.

Synchronous Periampullary Tumors in a Patient With Pancreas Divisum and Neurofibromatosis Type 1.

INTRODUCTION: In this study, we describe for the first time a Neurofibromatosis type 1 patient with pancreas divisum, multiple periampullary tumors and germline pathogenic variants in NF1 and CFTR genes. CASE REPORT: A 62-year-old female NF1 patient presented with weakness, choluria, nausea, and diffuse abdominal pain to an emergency room service. Magnetic resonance imaging revealed an abdominal mass involving the periampullary region and pancreas divisum. After surgical resection, three synchronous neoplasms were detected including two ampullary tumors (adenocarcinoma of the major ampulla and a neuroendocrine tumor of the minor ampulla) and a gastrointestinal stromal tumor (GIST). Germline multigene panel testing (MGPT) identified two pathogenic heterozygous germline variants: NF1 c.838del and CFTR c.1210-34TG[12]T[5]. CONCLUSION: This is the first report of a Neurofibromatosis type 1 patient with pancreas divisum and multiple periampullary tumors harboring pathogenic germline variants in NF1 and CFTR genes. The identification of two germline variants and a developmental anomaly in this patient may explain the unusual and more severe findings and underscores the importance of comprehensive molecular analyses in patients with complex phenotypes.

Hyperbaric oxygen therapy effects on tissue lesions in acute pancreatitis. Experimental study in rats.

OBJECTIVE: To study the effects of hyperbaric oxygen therapy on tissue lesions in an experimental model of acute pancreatitis induced by pancreatic duct ligation. ANIMALS: Forty-eight adult female Wistar rats were randomized into two groups (n=24): control group and hyperbaric oxygen therapy group. INTERVENTION: The second group was treated with a two-hour daily session of hyperbaric oxygen therapy at 2.5 ATA started 6 hours after pancreatic duct ligation. SETTING: The two groups were divided into 3 subgroups of 8 rats each undergoing euthanasia on days 1, 3, and 7 after the acute pancreatitis induction. MAIN OUTCOME MEASURES: The pancreas was evaluated according to the following histopathologic criteria: edema, hemorrhage, acinar necrosis and leukocyte infiltration. RESULTS: Hyperbaric oxygen therapy was efficient in significantly reducing acinar necrosis on the first day (P=0.049) and the foci of hemorrhage on the seventh day (P=0.050). The edema and leukocyte infiltration did not show the expected reduction. CONCLUSION: The utilization of a daily session of hyperbaric oxygen therapy at 2.5 ATA is efficient in reducing the hemorrhage and acinar necrosis but is not sufficient to reduce edema and leukocyte infiltration.

[Early pancreatic cancer: can the methods currently available identify this disease?]. / Câncer do pâncreas em fase inicial: é possível identificá-lo através dos instrumentos científicos e propedêuticos atualmente disponíveis?

OBJECTIVES: Call attention of the gastroenterologists and surgeons on the patients with high risk of developing pancreatic carcinoma, and whether or not forms of surveillance and prevention of this disease, which can be applied to daily clinical practice. DATA SURVEY: It was used the database of PubMed (US National Library of Medicine), looked up the publications of recent years for the groups at risk, molecular biological testing and methods of image used in the identification of small tumors of the pancreas. BACKGROUND: The survival rates of adenocarcinoma of the pancreas remain negligible, even after the significant advances in diagnosis by imaging, treatment and understanding of the molecular biology of this disease. Although embryonic strategies for surveillance and prevention for people with high risk of pancreatic cancer has developed. CONCLUSIONS: This review summarizes how to identify people at high risk of developing this disease and what is the state of the art of genetic counseling and screening through techniques of image available.

THE ROLE OF IMMUNOINFLAMMATORY MARKERS IN THE PROGNOSIS AND RESECTABILITY OF PANCREATIC ADENOCARCINOMA.

BACKGROUND: Pancreatic adenocarcinoma has a high mortality rate. A prognostic tool is essential for a better risk stratification. The neutrophil/lymphocyte ratio and adaptations and the platelet/lymphocyte ratio seem promising for this purpose. AIM: Evaluate the prognostic value of neutrophil/lymphocyte ratio, derived neutrophil/lymphocyte ratio and platelet/lymphocyte ratio, analyze the ideal cutoff values and investigate their utility in predicting resectability. METHODS: Data were collected of patients with pancreatic adenocarcinoma in Hospital de Clínicas de Porto Alegre between 2003 and 2013. The studied ratios were determined by blood count collected at hospital admission and after two cycles of palliative chemotherapy. RESULTS: Basal neutrophil/lymphocyte ratio, derived neutrophil/lymphocyte ratio and platelet/lymphocyte ratio did not have prognostic impact in survival (p=0.394, p=0.152, p=0.177 respectively). In subgroup analysis of patients submitted to palliative chemotherapy, neutrophil/lymphocyte ratio, derived neutrophil/lymphocyte ratio and platelet/lymphocyte ratio determined after two cycles of chemotherapy were prognostic for overall survival (p=0.003, p=0.009, p=0.001 respectively). The ideal cutoff values found were 4,11 for neutrophil/lymphocyte ratio (sensitivity 83%, specificity 75%), 2,8 for derived neutrophil/lymphocyte ratio (sensitivity 87%, specificity 62,5%) and 362 for platelet/lymphocyte ratio (sensitivity 91%, specificity 62,5%), Neutrophil/lymphocyte ratio, derived neutrophil/lymphocyte ratio and platelet/lymphocyte ratio were not able to predict resectability (p=0.88; p=0.99; p=0.64 respectively). CONCLUSIONS: Neutrophil/lymphocyte ratio, derived neutrophil/lymphocyte ratio and platelet/lymphocyte ratio are useful as prognostic markers of overall survival in patients with pancreatic adenocarcinoma submitted to palliative chemotherapy. Its use as resectability predictor could not be demonstrated.

Efficacy and Safety of a Biosimilar Versus Branded Enoxaparin in the Prevention of Venous Thromboembolism Following Major Abdominal Surgery: A Randomized, Prospective, Single-Blinded, Multicenter Clinical Trial.

Several biosimilar versions of enoxaparin are already approved and in use globally. Analytical characterization can establish good quality control in manufacturing, but they may not assure similarity in clinical outcomes between biosimilar and branded enoxaparin. This study evaluated the efficacy and safety of biosimilar Cristália versus branded Sanofi enoxaparin in venous thromboembolism (VTE) prevention in patients undergoing major abdominal surgery at risk for VTE. In this randomized, prospective single-blind study, we compared Cristália enoxaparin (Ce), a biosimilar version, versus branded Sanofi enoxaparin (Se; at a dose of 40 mg subcutaneously per day postoperatively from 7 to 10 days) in 243 patients submitted to major abdominal surgery at risk for VTE for VTE prevention. The primary efficacy outcome was occurrence of VTE or death related to VTE. The principal safety outcomes were a combination of major bleeding and clinically relevant non-major bleeding. Bilateral duplex scanning of the legs was performed from days 10 to 14, and follow-ups were performed up to 60 days after surgery. The incidence of VTE was 4.9% in the Cristália group and 1.1% in the Sanofi group (absolute risk difference = 3.80%, 95% confidence interval [CI]: -1.4%-9.0%) yielding noninferiority since the 95% CI does not reach the prespecified value Δ = 20%. Clinically significant bleeding occurred in 9.9% in the Cristália group and in 5.5% in the Sanofi group (n.s. ). In conclusion, this study suggests that 40 mg once daily of Ce, a biosimilar enoxaparin, is as effective and safe as the branded Sanofi enoxaparin in the prophylaxis of VTE in patients submitted to major abdominal surgery at risk for VTE.

Pancreatic intraepithelial neoplasia and ductal adenocarcinoma induced by DMBA in mice: effects of alcohol and caffeine.

PURPOSE: To evaluate the effects of alcohol and caffeine in a pancreatic carcinogenesis mouse model induced by 7,12-dimethylbenzantracene (DMBA), according to the PanIN classification system. METHODS: 120 male, Mus musculus, CF-1 mice were divided into four groups. Animals received either water or caffeine or alcohol or alcohol + caffeine in their drinking water. In all animals, 1 mg of DMBA was implanted into the head of the pancreas. After 30 days, euthanasia was performed; excised pancreata were then fixed in formalin, stained with hematoxylin-eosin and categorized as follows: normal ducts, reactive hyperplasia, PanIN-1A, PanIN-1B, PanIN-2, PanIN-3 or adenocarcinoma. RESULTS: PanIN lesions were verified in all groups. Adenocarcinoma was detected in 15% of animals in the caffeine group, 16.6% in the water group, 23.8% in the alcohol + caffeine group and 52.9% in the alcohol group (P<0.05). CONCLUSIONS: The experimental pancreatic carcinogenesis mouse model using DMBA effectively induces PanIN lesions and pancreatic adenocarcinoma. This study verified the association between alcohol use and pancreatic adenocarcinoma; caffeine did not present the same effect.

Paracrine Effects of Bone Marrow Mononuclear Cells in Survival and Cytokine Expression after 90% Partial Hepatectomy.

Acute liver failure is a complex and fatal disease. Cell-based therapies are a promising alternative therapeutic approach for liver failure due to relatively simple technique and lower cost. The use of semipermeable microcapsules has become an interesting tool for evaluating paracrine effects in vivo. In this study, we aimed to assess the paracrine effects of bone marrow mononuclear cells (BMMC) encapsulated in sodium alginate to treat acute liver failure in an animal model of 90% partial hepatectomy (90% PH). Encapsulated BMMC were able to increase 10-day survival without enhancing liver regeneration markers. Gene expression of Il-6 and Il-10 in the remnant liver was markedly reduced at 6 h after 90% PH in animals receiving encapsulated BMMC compared to controls. This difference, however, was neither reflected by changes in the number of CD68+ cells nor by serum levels of IL6. On the other hand, treated animals presented increased caspase activity and gene expression in the liver. Taken together, these results suggest that BMMC regulate immune response and promote apoptosis in the liver after 90% PH by paracrine factors. These changes ultimately may be related to the higher survival observed in treated animals, suggesting that BMMC may be a promising alternative to treat acute liver failure.

Guidelines for the management of neuroendocrine tumours by the Brazilian gastrointestinal tumour group.

Neuroendocrine tumours are a heterogeneous group of diseases with a significant variety of diagnostic tests and treatment modalities. Guidelines were developed by North American and European groups to recommend their best management. However, local particularities and relativisms found worldwide led us to create Brazilian guidelines. Our consensus considered the best feasible strategies in an environment involving more limited resources. We believe that our recommendations may be extended to other countries with similar economic standards.

Pancreatic intraepithelial neoplasia and ductal adenocarcinoma induced by DMBA in mice.

BACKGROUND: Pancreatic ductal adenocarcinoma has a poor long-term prognosis. Experimental models are necessary to understand not only its biologic behavior, but also the early pancreatic lesions known as pancreatic intraepithelial neoplasia (PanIN) and to develop new treatments. The aim of this study was to evaluate pancreatic carcinogenesis induced by 7,12-dimethyl-1,2-benzanthracene (DMBA) implantation in mice according to the PanIN classification system. METHODS: Ninety male, Mus musculus, CF-1 mice underwent a median laparotomy and 1 mg of DMBA was implanted into the proximal pancreas held in place by a purse-string suture. Mice were killed after 30 and 60 days after which the excised pancreata were fixed in formalin, embedded in paraffin, and stained with hematoxylin-eosin for histologic analysis. The specimens were evaluated blind by 2 pathologists for the presence of the following histology: normal ducts, reactive hyperplasia, PanIN-1A, PanIN-1B, PanIN-2, and PanIN-3, and adenocarcinoma. RESULTS: In the 30-day group, pathologic evaluation showed 4 (17%) reactive hyperplasia, 16 (67%) PanIN lesions, and 4 (17%) adenocarcinomas. In the 60-day group, there were 10 (27%) specimens with reactive hyperplasia, 13 (35%) with PanIN lesions, and 14 (38%) with adenocarcinomas. The difference between groups was statistically significant (P<.05). All pancreata with adenocarcinoma had concomitant PanIN lesions. CONCLUSIONS: The DMBA experimental model in mice induces PanIN lesions and ductal adenocarcinoma that have similar histology to that of human pancreatic cancer. This model may be useful for study of pancreatic carcinogenesis, particularly the molecular progression of early pancreatic ductal lesions.

Encapsulated Whole Bone Marrow Cells Improve Survival in Wistar Rats after 90% Partial Hepatectomy.

Background and Aims. The use of bone marrow cells has been suggested as an alternative treatment for acute liver failure. In this study, we investigate the effect of encapsulated whole bone marrow cells in a liver failure model. Methods. Encapsulated cells or empty capsules were implanted in rats submitted to 90% partial hepatectomy. The survival rate was assessed. Another group was euthanized at 6, 12, 24, 48, and 72 hours after hepatectomy to study expression of cytokines and growth factors. Results. Whole bone marrow group showed a higher than 10 days survival rate compared to empty capsules group. Gene expression related to early phase of liver regeneration at 6 hours after hepatectomy was decreased in encapsulated cells group, whereas genes related to regeneration were increased at 12, 24, and 48 hours. Whole bone marrow group showed lower regeneration rate at 72 hours and higher expression and activity of caspase 3. In contrast, lysosomal-ß-glucuronidase activity was elevated in empty capsules group. Conclusions. The results show that encapsulated whole bone marrow cells reduce the expression of genes involved in liver regeneration and increase those responsible for ending hepatocyte division. In addition, these cells favor apoptotic cell death and decrease necrosis, thus increasing survival.