CIR - Artigos
Permanent URI for this collection
Browse
Browsing CIR - Artigos by Author "Abrantes, AM"
Now showing 1 - 9 of 9
Results Per Page
Sort Options
- Cholangiocarcinoma: from molecular biology to treatmentPublication . Brito, AF; Abrantes, AM; Encarnação, JC; Tralhão, JG; Botelho, MFCholangiocarcinoma 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.
- Estudo experimental do impacto da clampagem selectiva da veia porta na função hepatocelularPublication . Tralhão, JG; Abrantes, AM; Gonçalves, C; Carvalho, C; Portela, I; Laranjo, M; Oliveiros, B; Cardoso, D; Ribeiro, AB; Botelho, MF; Castro e Sousa, FThe influence of selective clamping of the elements of hepatic pedicle in the hepatocellular function and viability were evaluated in our department. AIM: Study the effect of selective clamping of the portal vein (CPV) in hepatocellular function in an animal model with normal liver. METHOD: Three groups of Wistar rats (males, 2 months) were subjected a CPV for 60 min: group A (n=21) submitted to a continuous inflow occlusion; group B (n=12) underwent to a CPV for 30 min with 5 min of reperfusion; group C (n=10) underwent a CPV for 15 min with 5 min of reperfusion. The group D (n=9) was not subjected to a CPV. A hepatic biopsy was done at the end of surgery. The degree of tissue injury was evaluated using: 1) blood markers: AST, ALT, total bilirubin (TB), GGT alkaline-phosphatase, LDH and hepatic extraction fraction (HEF) by radioisotopic methods three days before laparotomy (BS) and after surgery (AS); 2) apoptosis, necrosis were investigated after collagenase cell isolation from hepatectomy pieces by flow-cytometry using the followed probes: propidium-iodide and annexin-V. Statistical analysis: variance analysis, post-hoc comparisons by Turkey-test (p<0.05). RESULTS: 1) Mortality: Group A - 62%, Group B - 17%, Group C - 30%, Group D - 0% (p<0.03). 2) We observed statistical differences in these parameters: ALT (p<0,025) and LDH (p<0,002) preferentially in groups A but without differences between the A,B,C and D Groups (ns). 3) We also verified a significant decrease in HEF values (p<0,0001) preferentially in group A without differences between the groups. 4) No difference were observed when analysed apoptosis and necrosis and cell viability between the groups. CONCLUSIONS: Postoperative liver failure is the leading cause of mortality after hepatectomy, however selective clamping of the portal vein, is reflected in an increase in cell viability and a decrease in the type of cell death (necrosis ou apoptosis) compared to studies carried out previously by us and thus may be regarded as an alternative to the Pringle maneuver. However, selective clamping of the portal vein for periods above 30' should be avoided, given the high mortality verified.
- Hepatectomy and liver regeneration: from experimental research to clinical applicationPublication . Tralhão, JG; Abrantes, AM; Hoti, E; Oliveiros, B; Cardoso, D; Faitot, F; Carvalho, C; Botelho, MF; Castro e Sousa, FBACKGROUND: 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.
- Impact of splenic artery ligation after major hepatectomy on liver function, regeneration and viabilityPublication . Carrapita, J; Abrantes, AM; Campelos, S; Gonçalves, AC; Cardoso, D; Sarmento-Ribeiro, AB; Rocha, C; Santos, JN; Botelho, MF; Tralhão, JG; Farges, O; Barbosa, JMIt 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.
- Influence of P53 on the radiotherapy response of hepatocellular carcinomaPublication . Gomes, AR; Abrantes, AM; Brito, AF; Laranjo, M; Casalta-Lopes, JE; Gonçalves, AC; Sarmento-Ribeiro, AB; Botelho, MF; Tralhão, JGHepatocellular 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.
- Intermittent Pringle Maneuver and Hepatic Function: Perioperative Monitoring by Noninvasive ICG-ClearancePublication . Tralhão, JG; Hoti, E; Oliveiros, B; Abrantes, AM; Botelho, MF; Castro e Sousa, FBACKGROUND: 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.
- Perioperative tumor cell dissemination in patients with primary or metastatic colorectal cancerPublication . Tralhão, JG; Hoti, E; Serôdio, M; Laranjeiro, P; Paiva, A; Abrantes, AM; Pais, ML; Botelho, MF; Castro e Sousa, FINTRODUCTION: 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.
- Quercetin in Cancer Treatment, Alone or in Combination with Conventional Therapeutics?Publication . Brito, AF; Ribeiro, M; Abrantes, AM; Pires, AS; Teixo, RJ; Tralhão, JG; Botelho, MFCancer is a problem of global importance, since the incidence is increasing worldwide and therapeutic options are generally limited. Thus, it becomes imperative to find new therapeutic targets as well as new molecules with therapeutic potential for tumors. Flavonoids are polyphenolic compounds that may be potential therapeutic agents. Several studies have shown that these compounds have a higher anticancer potential. Among the flavonoids in the human diet, quercetin is one of the most important. In the last decades, several anticancer properties of quercetin have been described, such as cell signaling, pro-apoptotic, anti-proliferative and anti-oxidant effects, growth suppression. In fact, it is now well known that quercetin has diverse biological effects, inhibiting multiple enzymes involved in cell proliferation, as well as, in signal transduction pathways. On the other hand, there are also studies reporting potential synergistic effects when combined quercetin with chemotherapeutic agents or radiotherapy. In fact, several studies which aim to explore the anticancer potential of these combined treatments have already been published, the majority with promising results. Actually it is well known that quercetin can act on the chemosensitization and radiosensitization but also as chemoprotective and radioprotective, protecting normal cells of the side effects that results from chemotherapy and radiotherapy, which obviously provides notable advantages in their use in anticancer treatment. Thus, all these data indicate that quercetin may have a key role in anticancer treatment. In this context, this review is focused on the relationship between flavonoids and cancer, with special emphasis on the role of quercetin.
- Study of hepatocellular function in the murine model following hepatic artery selective clampingPublication . Tralhão, JG; Abrantes, AM; Gonçalves, AC; Hoti, E; Laranjo, M; Martins, R; Oliveiros, B; Cardoso, D; Sarmento-Ribeiro, AB; Botelho, MF; Castro e Sousa, FPURPOSE: To investigate the impact of selective hepatic artery clamping (SHAC) in hepatocellular function. METHODS: Three groups of Wistar male rats were subjected to SHAC ischemia period of 60min: Group A continuous SHAC were subjected to SHAC ischemia period of 60min, Group B intermittent SHAC of 30min with 5min of reperfusion and Group C intermittent SHAC of 15min with 5min of reperfusion. Animals without SHAC were included-Group D. To evaluate hepatocellular function blood markers and hepatic extraction function (HEF) using 99mTc-mebrofenin were performed before and after surgery. Flow cytometry was used to analyze oxidative stress and cell viability. RESULTS: A mortality rate of 7.6% in Group A was observed. HEF maintained normal values between the groups. Flow cytometry demonstrated no significant differences between the groups in viability, type of cell death as well as in the production of reactive oxygen species. CONCLUSIONS: The selective hepatic artery clamping compared to other clamping techniques results on increased cell viability and decreased hepatocyte death. The SHAC is a potential alternative to decrease per-operative bleeding while maintaining hepatocellular function.