50 research outputs found

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

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    Background: Pancreatic duct ligation (PDL) has been used as a model of chronic pancreatitis and as a model to increase β-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."This work was supported by the Spanish "Plan Estatal de Investigacion, Desarrollo e Innovacion Orientada a los Retos de la Sociedad" under Grant TEC2014-52383-C3 (TEC2014-52383-C3-3-R). RQ, EB, FB declare stock ownership in Apeiron Medical S.L., a company that has a license for the patent US 8.303.584.B2, on which the device have been employed.Quesada-Diez, R.; Andaluz, A.; Cáceres, M.; Moll, X.; Iglesias, M.; Dorcaratto, D.; Poves, I.... (2016). Long-term evolution of acinar-to-ductal metaplasia and b-cell mass after radiofrequency-assisted transection of the pancreas in a controlled large animal model. Pancreatology. 16:38-43. https://doi.org/10.1016/j.pan.2015.10.014S38431

    Ectopic Expression of E2F1 Stimulates β-Cell Proliferation and Function

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    OBJECTIVE-Generating functional beta-cells by inducing their proliferation may provide new perspectives for cell therapy in diabetes. Transcription factor E2F1 controls G(1)- to S-phase transition during the cycling of many cell types and is required for pancreatic beta-cell growth and function. However, the consequences of overexpression of E2F1 in beta-cells are unknown. RESEARCH DESIGN AND METHODS-The effects of E2F1 overexpression on beta-cell proliferation and function were analyzed in isolated rat beta-cells and in transgenic mice. RESULTS-Adenovirus AdE2F1-mediated overexpression of E2F1 increased the proliferation of isolated primary rat beta-cells 20-fold but also enhanced beta-cell death. Coinfection with adenovirus Ad Akt expressing a constitutively active form of Akt (protein kinase B) suppressed beta-cell death to control levels. At 48 h after infection, the total beta-cell number and insulin content were, respectively, 46 and 79% higher in AdE2F1+AdAkt-infected cultures compared with untreated. Conditional overexpression of E2F1 in mice resulted in a twofold increase of beta-cell proliferation and a 70% increase of pancreatic insulin content, but did not increase beta-cell mass. Glucose-challenged insulin release was increased, and the mice showed protection against toxin-induced diabetes. CONCLUSIONS-Overexpression of E2F1, either in vitro or in vivo, can stimulate beta-cell proliferation activity. In vivo E2F1 expression significantly increases the insulin content and function of adult beta-cells, making it a strategic target for therapeutic manipulation of beta-cell function. Diabetes 59:1435-1444, 201

    Beta cell count instead of beta cell mass to assess and localize growth in beta cell population following pancreatic duct ligation in mice.

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    BACKGROUND: Pancreatic-tail duct ligation (PDL) in adult rodents has been reported to induce beta cell generation and increase beta cell mass but increases in beta cell number have not been demonstrated. This study examines whether PDL increases beta cell number and whether this is caused by neogenesis of small clusters and/or their growth to larger aggregates. METHODOLOGY: Total beta cell number and its distribution over small (100 µm) clusters was determined in pancreatic tails of 10-week-old mice, 2 weeks after PDL or sham. PRINCIPAL FINDINGS: PDL increased total beta cell mass but not total beta cell number. It induced neogenesis of small beta cell clusters (2.2-fold higher number) which contained a higher percent proliferating beta cells (1.9% Ki67+cells) than sham tails (<0.2%); their higher beta cell number represented <5% of total beta cell number and was associated with a similar increase in alpha cell number. It is unknown whether the regenerative process is causally related to the inflammatory infiltration in PDL-tails. Human pancreases with inflammatory infiltration also exhibited activation of proliferation in small beta cell clusters. CONCLUSIONS/SIGNIFICANCE: The PDL model illustrates the advantage of direct beta cell counts over beta cell mass measurements when assessing and localizing beta cell regeneration in the pancreas. It demonstrates the ability of the adult mouse pancreas for neogenesis of small beta cell clusters with activated beta cell proliferation. Further studies should investigate conditions under which neoformed small beta cell clusters grow to larger aggregates and hence to higher total beta cell numbers

    Near-Infrared Fluorescence Imaging of Breast Cancer and Axillary Lymph Nodes After Intravenous Injection of Free Indocyanine Green

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    Background: Near-infrared fluorescence imaging (NIRFI) of breast cancer (BC) after the intravenous (IV) injection of free indocyanine green (fICG) has been reported to be feasible. However, some questions remained unclarified. Objective: To evaluate the distribution of fICG in BC and the axillary lymph nodes (LNs) of women undergoing surgery with complete axillary LN dissection (CALND) and/or selective lymphadenectomy (SLN) of sentinel LNs (NCT no. 01993576 and NCT no. 02027818). Methods: An intravenous injection of fICG (0.25 mg/kg) was administered to one series of 20 women undergoing treatment with mastectomy, the day before surgery in 5 (group 1) and immediately before surgery in 15 (group 2: tumor localization, 25; and pN+ CALND, 4) as well as to another series of 20 women undergoing treatment with tumorectomy (group 3). A dedicated NIR camera was used for ex vivo fluorescence imaging of the 45 BC lesions and the LNs. Results: In group 1, two of the four BC lesions and one large pN+ LN exhibited fluorescence. In contrast, 24 of the 25 tumors in group 2 and all of the tumors in group 3 were fluorescent. The sentinel LNs were all fluorescent, as well as some of the LNs in all CALND specimens. Metastatic cells were found in the fluorescent LNs of the pN+ cases. Fluorescent BC lesions could be identified ex vivo on the surface of the lumpectomy specimen in 14 of 19 cases. Conclusions: When fICG is injected intravenously just before surgery, BC can be detected using NIRFI with high sensitivity, with metastatic axillary LNs also showing fluorescence. Such a technical approach seems promising in the management of BC and merits further investigation.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

    Deep epigastric lymph nodes implication in patients' recurrence pattern after cytoreductive surgery in ovarian peritoneal metastases.

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    Although complete cytoreductive surgery (CRS) with or without hyperthermic intraperitoneal chemotherapy (HIPEC) offers a good prognosis in patients with peritoneal metastasis of ovarian cancer (PMOC), recurrences are quite common. These recurrences can be intra-abdominal or systemic in nature. Our objective was to study and illustrate the global recurrence pattern in patients operated for PMOC, shedding light on a previously overlooked lymphatic basin at the level of the epigastric artery, the deep epigastric lymph nodes (DELN) basin.info:eu-repo/semantics/publishe

    A radical approach to achieve complete cytoreductive surgery improve survival of patients with advanced ovarian cancer

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    Introduction: Cytoreductive surgery of locally advanced ovarian cancer has evolved in the last few years from surgery to remove macroscopic residual disease (< 1 cm; R2b) to macroscopic complete cytoreductive surgery with no gross residual disease (R1). The aim of this study was to evaluate the impact of the adoption of a maximalist surgical approach on postoperative complications, disease recurrence and survival. Materials and methods: This was a retrospective study using prospectively collected data on patients who received either conservative approach (CA) or radical approach (RA) surgical treatment for primary ovarian cancer stage IIIc/IVa/IVb between June 2006 and June 2013. Results: Data for 114 patients were included, 33 patients in the CA group and 68 patients in the RA group were consequently analysed. In the RA group, operative time was longer, in relation to more complex surgical procedures; with more blood losses and a higher rate of compete macroscopic resection. Totally, 77% of the patients had postoperative complications, with more grade I/II complications in the RA group but the same rates of grade III/IV complications in the both groups (P = 0.14). For all patient study population, the overall and disease-free survivals were improved in case of no macroscopic residual disease. Overall survival was improved in the RA group (P = 0.05), with no difference in terms of disease-free survival (P = 0.29) Conclusion: A radical approach in advanced ovarian cancer allows a higher rate of complete cytoreductive surgery impacting overall survival. However, a non-significant trend for increased mild complications (grade I/II) rate is observed in this group.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

    Absence of residual fluorescence in the surgical bed at near-infrared fluorescence imaging predicts negative margins at final pathology in patients treated with breast-conserving surgery for breast cancer

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    Introduction: Positive margins after breast-conserving surgery (BCS) for breast cancer (BC) remain a major concern. In this study we investigate the feasibility and accuracy of indocyanine green (ICG) fluorescence imaging (FI) for the in vivo assessment of surgical margins during BCS. Materials and methods: Patients with BC admitted for BCS from October 2015 to April 2016 were proposed to be included in the present study (NCT02027818). ICG (0.25 mg/kg) was intravenously injected at induction anesthesia and ICG-FI of the surgical beds was correlated with final pathology results. Results: Fifty patients consented to participate and thirty-five patients were retained for final analysis, 15 patients having been excluded for, respectively, incomplete video records data for signal to background ratio (SBR) calculation (11) and in situ tumors (4). The final pathological assessment of 35 breast specimens identified 5 (14.7%) positive margins. Intraoperative ICG-FI revealed hyperfluorescent signals in 15 (42.9%) patients and an absence of fluorescent signals in 20 (57.1%). Median SBR in patients with involved margins was 1.8 (SD 0.7) and was 1.25 (SD 0.6) in patients with clear margins (p = 0.05). The accuracy, specificity, positive and negative predictive value of ICG-FI for breast surgical margin assessment were 71%, 60%, 29% and 100%, respectively. Conclusion: ICG-FI of BC surgical beds has a high negative predictive value for surgical margin assessment during BCS. The absence of residual fluorescence in the surgical bed of patients with fluorescent tumors predicts negative margins at final pathology and allows the surgeon to avoid further intraoperative analysis.SCOPUS: ar.jinfo:eu-repo/semantics/publishe
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