277 research outputs found

    Cholangiocarcinoma: from molecular biology to treatment

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    Cholangiocarcinoma is a rare tumor originating in the bile ducts, which, according to their anatomical location, is classified as intrahepatic, extrahepatic and hilar. Nevertheless, incidence rates have increased markedly in recent decades. With respect to tumor biology, several genetic alterations correlated with resistance to chemotherapy and radiotherapy have been identified. Here, we highlight changes in KRAS and TP53 genes that are normally associated with a more aggressive phenotype. Also IL-6 and some proteins of the BCL-2 family appear to be involved in the resistance that the cholangiocarcinoma presents toward conventional therapies. With regard to diagnosis, tumor markers most commonly used are CEA and CA 19-9, and although its use isolated appears controversial, their combined value has been increasingly advocated. In imaging terms, various methods are needed, such as abdominal ultrasound, computed tomography and cholangiopancreatography. Regarding therapy, surgical modalities are the only ones that offer chance of cure; however, due to late diagnosis, most patients cannot take advantage of them. Thus, the majority of patients are directed to other therapeutic modalities like chemotherapy, which, in this context, assumes a purely palliative role. Thus, it becomes urgent to investigate new therapeutic options for this highly aggressive type of tumor

    Intermittent Pringle Maneuver and Hepatic Function: Perioperative Monitoring by Noninvasive ICG-Clearance

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    BACKGROUND: Intermittent Pringle maneuver or selective portal clamping often are used to control inflow during parenchymal liver transection. This study was designed to determinate whether these maneuvers are associated with adverse hepatic function. METHODS: Resection was performed without portal clamping in 17 patients (group 1). Selective continuous portal clamping was performed in 11 patients (group 2) and the remaining 33 patients (group 3) had intermittent nonselective portal clamping (occlusion of the main portal trunk). The centers' protocol for total portal occlusion is 15-min occlusion alternated with 5-min reperfusion in patients with normal liver parenchyma or 10 min alternated with 5 min in patients with abnormal parenchyma. ICG elimination tests were conducted concurrently using a noninvasive monitor that tracks the plasma disappearance rate (PDR-ICG-%/min) and 15-min retention rate after administration (ICG-R15-%). RESULTS: There was no statistically difference between the three studied groups in terms of sequential changes of ICG-PDR (p < 0.625) or ICG-R15 (p < 0.398). CONCLUSIONS: Our study indicates that 15 min of intermittent Pringle maneuver or selective hemihepatic continuous portal clamping are safe methods of vascular control during liver resection, with no adverse effects on hepatocellular function

    Hepatectomy and liver regeneration: from experimental research to clinical application

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    BACKGROUND: The mechanisms and kinetics of hepatic growth have continuously been investigated. This study concerns liver regeneration in animal and patients who underwent partial hepatectomy evaluated by the hepatic extraction fraction (HEF) calculated through radioisotopic methods. METHODS: Thirty normal Wistar rats were submitted to an 85% hepatectomy, and 95 patients with primary and secondary liver tumours were included. In animal study, the liver regeneration kinetics was assessed by HEF using 99mTc-mebrofenin, the ratio liver/bodyweight and by using bromodeoxyuridine deoxyribonucleic acid incorporation. In patient study, the liver regeneration was evaluated by calculation of HEF before surgery, 5 and 30 days after hepatectomy. RESULTS: In animal, we verified a positive correlation between HEF kinetics and liver/bodyweight ratio or hepatocyte proliferation evaluated by bromodeoxyuridine deoxyribonucleic acid staining after 85% hepatectomy. In the clinical arm, no statistical differences of the HEF before hepatectomy, 5 and 30 days after hepatectomy, were observed. CONCLUSIONS: Our results support the view that human liver regeneration commences early, is fast, non-anatomical and functionally complete 5 days after hepatectomy. The fast functional liver regeneration may have a high clinical impact particularly concerning the post-operative oncological therapeutic approaches.info:eu-repo/semantics/publishedVersio

    Perioperative tumor cell dissemination in patients with primary or metastatic colorectal cancer

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    INTRODUCTION: Although there is general correlation between the TNM stage of colorectal cancer (CRC) and its prognosis, there is often significant variability of tumor behaviour and individual patient outcome, which is unaccounted for by pathologic factors alone. Our aim was to estimate perioperative tumor cell dissemination in patients with primary or CRC liver metastases as a possible factor influencing the outcome. METHODS: Forty patients were prospectively enrolled in the study from the year 2007 to 2008. Eighteen patients had histologically proven CRC (50% rectal, 44% colonic, 6% colonic and rectal). Sixteen patients (47%) had CRC liver metastases only. The remaining six patients who underwent colon or liver resection for benign conditions, acted as the control group. All patients with malignant pathologies had R0 resections. Blood samples were taken before the surgical incision (T0), immediately after tumor resection (T1) and at the end of the surgical intervention (T2). Data acquisition was performed using a dual-laser FACSCalibur flow cytometer. Circulating malignant cells were identified as being CD45-/cytokeratin+. RESULTS: The analysis of patients overall (CRC resection subgroup and hepatectomy subgroup) revealed that there was no statistically significant difference of the tumoral cell count in the blood per million of hematopoietic cells at T0, T1 and T2. CONCLUSIONS: This study demonstrates no differences in the detected circulating numbers of tumor cells at different stages of surgical intervention

    Influence of P53 on the radiotherapy response of hepatocellular carcinoma

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    Hepatocellular carcinoma (HCC) is one of the most common cancers worldwide, and it has a poor prognosis and few therapeutic options. Radiotherapy is one of the most effective forms of cancer treatment, and P53 protein is one of the key molecules determining how a cell responds to radiotherapy. The aim of this study was to determine the therapeutic efficacy of iodine-131 in three human HCC cell lines

    Oxidative Stress, DNA, Cell Cycle/Cell Cycle Associated Proteins and Multidrug Resistance Proteins: Targets of Human Amniotic Membrane in Hepatocellular Carcinoma

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    The anticancer effects of human amniotic membrane (hAM) have been studied over the last decade. However, the action mechanisms responsible for these effects are not fully understood until now. Previously results reported by our team proved that hAM is able to induce cytotoxicity and cell death in hepatocellular carcinoma (HCC), a worldwide high incident and mortal cancer. Therefore, this experimental study aimed to investigate the cellular targets of hAM protein extracts (hAMPE) in HCC through in vitro studies. Our results showed that hAMPE is able to modify oxidative stress environment in all HCC cell lines, as well as its cell cycle. hAMPE differently targets deoxyribonucleic acid (DNA), P21, P53, β-catenin and multidrug resistance (MDR) proteins in HCC cell lines. In conclusion, hAMPE has several targets in HCC, being clear that the success of this treatment depends of a personalized therapy based on the biological and genetic characteristics of the tumor

    Manganese pigmented anodized copper as solar selective absorber

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    The study concerns the optical and structural properties of layers obtained by a new efficient surface treatment totally free of chromium species. The process is made up of an anodic oxidation of copper in an alkaline solution followed by an alkaline potassium permanganate dipping post-treatment. Coatings, obtained at the lab and pilot scales, are stable up to 220 °C in air and vacuum, present low emissivity (0.14 at 70 °C) and high solar absorptivity (0.96), i.e. a suitable thermal efficiency (0.84 at 70 °C)

    Impact of splenic artery ligation after major hepatectomy on liver function, regeneration and viability

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    It was reported that prevention of acute portal overpressure in small-for-size livers by inflow modulation results in a better postoperative outcome. The aim is to investigate the impact of portal blood flow reduction by splenic artery ligation after major hepatectomy in a murine model. Forty-eight rats were subjected to an 85% hepatectomy or 85% hepatectomy and splenic artery ligation. Both groups were evaluated at 24, 48, 72 and 120 post-operative hours: liver function, regeneration and viability. All methods and experiments were carried out in accordance with Coimbra University guidelines. Splenic artery ligation produces viability increase after 24 h, induces a relative decrease in oxidative stress during the first 48 hours, allows antioxidant capacity increment after 24 h, which is reflected in a decrease of half-time normalized liver curve at 48 h and at 72 h and in an increase of mitotic index between 48 h and 72 h. Splenic artery ligation combined with 85% hepatectomy in a murine model, allows portal inflow modulation, promoting an increase in hepatocellular viability and regeneration, without impairing the function, probably by inducing a less marked elevation of oxidative stress at first 48 hours
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