Zilvinas Dambrauskas

Inhibition of Heme Oxygenase-1 Increases Responsiveness of Pancreatic Cancer Cells to Anticancer Treatment

Heme oxygenase-1 (HO-1) is believed to represent a key enzyme for the protection of cells against “stress.” Its overexpression in different types of human cancers supports the notion that HO-1 provides a growth advantage and contributes to cellular resistance against chemotherapy and radiotherapy. Given the poor survival rates of patients with pancreatic cancer due to its aggressive growth behavior and its exceptional resistance to all known forms of anticancer treatment, we have investigated the expression of HO-1 in human pancreatic cancer cells growth behavior and prognosis. Expression of HO-1 was analyzed in human pancreatic cancer samples in comparison with normal pancreas by quantitative PCR, Western blot, and confocal microscopy. The influence of radiotherapy and chemotherapy on HO-1 expression in pancreatic cancer cell lines was evaluated. Furthermore, HO-1 expression was specifically suppressed by small interfering RNA transfection and subsequently the alterations of growth behavior and resistance to anticancer treatment were tested. Human pancreatic cancer showed a 6-fold and 3.5-fold HO-1 up-regulation in comparison to normal pancreas based on mRNA and protein level, respectively (P < 0.05). Cancer tissues revealed marked HO-1 immunoreactivity in tumor cells and in tumor associated immunocytes. Treatment of the pancreatic cancer cell lines with gemcitabine or radiation strongly induced HO-1 expression. Targeted knockdown of HO-1 expression led to pronounced growth inhibition of the pancreatic cancer cells and made tumor cells significantly more sensitive to radiotherapy and chemotherapy. Therefore, specific inhibition of HO-1 expression may be a new option in pancreatic cancer therapy and may be used as sensitizer to chemotherapy and radiotherapy.

Value of the different prognostic systems and biological markers for predicting severity and progression of acute pancreatitis

Abstract Objective. Several tools have been developed for severity stratification in acute pancreatitis (AP). They include single biochemical markers and complex scoring systems, all of which aim at an early detection of severe AP to optimize monitoring and treatment of these patients. The aim of this study was to reassess and compare the value of some known and newly-introduced prognostic markers in the clinical context. Material and Methods. We have conducted a prospective observational study. One hundred and eight patients with a diagnosis of AP and onset of the disease within last 72 h were included in this study. Clinical data and expression results of some serum biochemical markers were used for statistical analysis. The diagnostic performance of scores predicting severity and progression of AP, cut-off values, specificity, and sensitivity were established using receiver operating characteristic curve analysis. Results. Among single biochemical markers, C-reactive protein remains the most useful. Despite its delayed increase, it is accurate, cheap, and widely available. Interleukin-6 and macrophage migration inhibitory factor seem to be new promising parameters for use in clinical routine. Pancreas specific scores (Imrie-Glasgow, pancreatitis outcome prediction) and scores assessing organ dysfunction (acute physiology and chronic health evaluation II, multiple organ dysfunction score, and Marshall score) remain of value in determining the severity, complications, and possible outcome of AP. Conclusions. Indication, timing, and consequences of the methods applied need to be carefully considered and incorporated into clinical assessments. Currently, there is no single prognostic marker that would cover the whole range of problems associated with the treatment of AP. The prediction of severity and progression of AP can be achieved using a series of accurate methods. The decision to undertake interventional or surgical treatment is the most complex task requiring both clinical judgment and meticulous monitoring of the patient.

Early course of microcirculatory perfusion in eye and digestive tract during hypodynamic sepsis

IntroductionThe aim of the study was to evaluate and compare the microcirculatory perfusion during experimental sepsis in different potentially available parts of the body, such as sublingual mucosa, conjunctiva of the eye, and mucosa of jejunum and rectum.MethodsPigs were randomly assigned to sepsis (n = 9) and sham (n = 4) groups. The sepsis group received a fixed dose of live Escherichia coli infusion over a 1-hour period (1.8 × 109/kg colony-forming units). Animals were observed 5 hours after the start of E. coli infusion. In addition to systemic hemodynamic assessment, we performed conjunctival, sublingual, jejunal, and rectal evaluation of microcirculation by using Sidestream Dark Field (SDF) videomicroscopy at the same time points: at baseline, and at 3 and 5 hours after the start of live E. coli infusion. Assessment of microcirculatory parameters of convective oxygen transport (microvascular flow index (MFI) and proportion of perfused vessels (PPV)), and diffusion distance (perfused vessel density (PVD) and total vessel density (TVD)) was done by using a semiquantitative method.ResultsInfusion of E. coli resulted in a hypodynamic state of sepsis associated with low cardiac output and increased systemic vascular resistance despite fluid administration. Significant decreases in MFI and PPV of small vessels were observed in sublingual, conjunctival, jejunal, and rectal locations 3 and 5 hours after the start of E. coli infusion in comparison with baseline variables. Correlation between sublingual and conjunctival (r = 0.80; P = 0.036), sublingual and jejunal (r = 0.80; P = 0.044), and sublingual and rectal (r = 0.79; P = 0.03) MFI was observed 3 hours after onset of sepsis. However, this strong correlation between the sublingual and other regions disappeared 5 hours after the start of E. coli infusion. Overall, the sublingual mucosa exhibited the most-pronounced alterations of microcirculatory flow in comparison with conjunctival, jejunal, and rectal microvasculature (P < 0.05).ConclusionsIn this pig model, a time-dependent correlation exists between sublingual and microvascular beds during the course of a hypodynamic state of sepsis.

Value of adipokines in predicting the severity of acute pancreatitis: Comprehensive review

AIM To analyze the prognostic value of adipokines in predicting the course, complications and fatal outcome of acute pancreatitis (AP). METHODS We performed the search of PubMed database and the systemic analysis of the literature for both experimental and human studies on prognostic value of adipokines in AP for period 2002-2012. Only the papers that described the use of adipokines for prediction of severity and/or complications of AP were selected for further analysis. Each article had to contain information about the levels of measured adipokines, diagnosis and verification of AP, to specify presence of pancreatic necrosis, organ dysfunction and/or mortality rates. From the very beginning, study was carried out adhering to the PRISMA checklist and flowchart for systemic reviews. To assess quality of all included human studies, the Quality Assessment of Diagnostic Accuracy Studies tool was used. Because of the high heterogeneity between the studies, it was decided to refrain from the statistical processing or meta-analysis of the available data. RESULTS Nine human and three experimental studies were included into review. In experimental studies significant differences between leptin concentrations at 24 and 48 h in control, acute edematous and acute necrotizing pancreatitis groups were found (P = 0.027 and P < 0.001). In human studies significant differences between leptin and resitin concentrations in control and acute pancreatitis groups were found. 1-3 d serum adiponectin threshold of 4.5 μg/mL correctly classified the severity of 81% of patients with AP. This threshold yielded a sensitivity of 70%, specificity 85%, positive predictive value 64%, negative predictive value88% (area under curve 0.75). Resistin and visfatin concentrations differ significantly between mild and severe acute pancreatitis groups, they correlate with severity of disease, need for interventions and outcome. Both adipokines are good markers for parapancreatic necrosis and the cut-off values of 11.9 ng/mL and 1.8 ng/mL respectively predict the high ranges of radiological scores. However, the review revealed that all nine human studies with adipokines are very different in terms of methodology and objectives, so it is difficult to generalize their results. It seems that concentrations of the leptin and resistin increases significantly in patients with acute pancreatitis compared with controls. Serum levels of adiponectin, visfatin and especially resitin (positive correlation with Acute Physiology and Chronic Health Evaluation II, Ranson and C-reactive protein) are significantly different in mild acute pancreatitis and severe acute pancreatitis patients, so, they can serve as a markers for the disease severity prediction. Resistin and visfatin can also be used for pancreatic and parapancreatic necrosis prediction, interventions needs and possible, outcome. CONCLUSION High levels of adipokines could allow for prediction of a severe disease course and outcome even in small pancreatic lesions on computed tomography scans.

Value of routine clinical tests in predicting the development of infected pancreatic necrosis in severe acute pancreatitis.

Objective. Fine-needle aspiration (FNA) is the procedure of choice for accurate diagnosis of infected necrosis. However, invasive procedures increase the risk of secondary pancreatic infection and the timing of FNA is still a matter for debate. Our objective was to assess the value of routine clinical tests to determine the minimal risk for infected necrosis, thereby optimizing timing and selection of patients for image-guided FNA. Material and methods. This prospective, non-randomized study comprised 90 patients with acute necrotizing pancreatitis. The data of 52 patients were used for discriminant function analysis to determine the differences between patients with infected necrosis and those with sterile necrosis. Cut-off points for variables were established using receiver operating characteristic (ROC) curve analysis and logistic regression was performed to determine the risk of infected necrosis. The clinical relevance of the defined diagnostic system was prospectively tested in a further 38 consecutive patients with acute necrotizing pancreatitis (ANP). Results. Discriminant function analysis showed that C-reactive protein (CRP) and white blood cell (WBC) values were significant discriminators between patients with sterile necrosis and those with infected necrosis. Cut-off values of 81 mg/l for CRP and 13×109/l for WBC were established. The predicted risk for infected necrosis is approx. 1.4% if both tests are below the defined cut-off values. Consequently, we found FNA unnecessary in this subset of patients, unless otherwise indicated, as this invasive procedure per se carries a certain risk of bacterial contamination. Conclusions. Routine clinical tests are helpful in diagnosing the development of infected necrosis. Based on the application of classification functions, the timing and selection of patients for image-guided FNA can be optimized.

Tumor‐related factors and patient's age influence survival after resection for ampullary adenocarcinoma

BACKGROUND/PURPOSE The majority of surgeons agree that ampullary adenocarcinoma should be removed by partial pancreatoduodenectomy. Favoring extended resection, based on the uncertainty of the preoperative diagnosis and the higher probability of clear resection margins, we aimed to disclose the results of this surgical procedure in terms of postoperative morbidity and mortality, and to identify prognosticators of long-term survival. METHODS We documented, prospectively, 25 consecutive patients with adenocarcinoma of the papilla of Vater in whom pylorus-preserving pancreatoduodenectomy was performed. Clinical data, pathology reports, International Union Against Cancer (UICC) tumor stage, postoperative morbidity, mortality, and long-term follow-up results were evaluated. The Kaplan-Meier method and log-rank test were applied for univariate analysis. The Cox proportional hazard model was used for multivariate analysis. RESULTS Postoperative mortality was 4%, overall morbidity was 32%, and pancreas-associated morbidity was 8%. Mean survival time was 53.8 months. Tumor size, N status, UICC stage, lymphatic invasion, blood vessel infiltration, R0 resection, and age of patient at the cutoff of 70 years were independent predictors of survival on univariate analysis. Multivariate analysis, however, disclosed no independent predictors of prognosis. CONCLUSIONS Pancreatoduodenectomy for ampullary carcinoma is reasonable in terms of postoperative morbidity and mortality. Tumor-related factors, R0 resection, and advanced age appeared as the main predictors of survival.

Effects of prophylactic antibiotics in acute pancreatitis.

OBJECTIVES The use of prophylactic antibiotics in severe acute pancreatitis (SAP) is controversial. The aim of this study was to compare the effects of antibiotics administered as prophylaxis and as treatment on demand, respectively, in two prospective, non-randomized cohorts of patients. METHODS The study population consisted of 210 patients treated for SAP. In Group 1 (n= 103), patients received prophylactic antibiotics (ciprofloxacin, metronidazole). In Group 2 (n= 107), patients were treated on demand. Ultrasound-guided drainage and/or surgical debridement of infected necrosis were performed when the presence of infected pancreatic necrosis was demonstrated. The primary endpoints were infectious complication rate, need for and timing of surgical interventions, incidence of nosocomial infections and mortality rate. RESULTS Ultrasound-guided fine needle aspiration [in 18 (16.8%) vs. 13 (12.6%) patients; P= 0.714], ultrasound-guided drainage [in 15 (14.0%) vs. six (5.8%) patients; P= 0.065] and open surgical necrosectomy [in 10 (9.3%) vs. five (4.9%) patients; P= 0.206] were performed more frequently and earlier [at 16.6 ± 7.8 days vs. 17.2 ± 6.7 days (P= 0.723); at 19.5 ± 9.4 days vs. 24.5 ± 14.2 days (P= 0.498), and at 22.6 ± 13.5 days vs. 26.7 ± 18.1 days (P= 0.826), respectively] in Group 2 compared with Group 1. There were no significant differences between groups in mortality and duration of stay in the surgical ward or intensive care unit. CONCLUSIONS The results of this study support the suggestion that the use of prophylactic antibiotics does not affect mortality rate, but may decrease the need for interventional and surgical management, and lower the number of reoperations.

Preoperative chemoradiation vs radiation alone for stage II and III resectable rectal cancer: a meta‐analysis

Aim  The aim of this systematic literature review and meta‐analysis was to compare preoperative radiotherapy (RT) with preoperative chemoradiotherapy (ChRT) in patients with stage II and III resectable rectal cancer.

Expression of major histocompatibility complex class I-related chain A/B (MICA/B) in pancreatic carcinoma

Major histocompatibility complex class I-related chain A and B (MICA/B) are two stress-inducible ligands that bind to the immunoreceptor NKG2D and play an important role in mediating cytotoxicity of NK and T cells. Release of MIC molecules from the cell surface is thought to constitute an immune escape mechanism of tumor cells and thus could be associated with more aggressive course of tumor growth. In this study, we investigated the expression of MICA/B in ductal pancreatic carcinoma and serum in relation to tumor stage, differentiation and survival. MICA/B expression in tumor tissues and sera from patients with pancreatic cancer were analyzed by immunohistochemical staining (IHC), western blotting and ELISA, respectively. MICA/B expression was present in 17 of 22 (77%) of the tumors but not in normal pancreatic ductal epithelial cells. Poorly differentiated tumors showed more pronounced MICA/B expression compared to differentiated tumors, but did not correlate significantly to other tumor characteristics. MICA/B-negative tumors displayed significantly lower incidence of lymph node metastases (p<0.01), and less mortality within 3 years following resection (p<0.02). In conclusion, tissue levels of MICA/B expression were elevated in pancreatic cancer cells without elevated levels in serum, despite well-recognized acute phase reactants in serum. Poorly differentiated tumors showed high MICA/B expression, which was related to extended tumor lymph node metastases and less frequent long-term survival.

Fatty acids of erythrocyte membrane in acute pancreatitis patients

AIM To evaluate changes in the fatty acid composition of erythrocyte membrane phospholipids during severe and mild acute pancreatitis (AP) of alcoholic and nonalcoholic etiology. METHODS All consecutive patients with a diagnosis of AP and onset of the disease within the last 72 h admitted to the Hospital of Lithuanian University of Health Sciences between June and December 2007 were included. According to the Acute Physiology and Chronic Health Evaluation (APACHE II) scale, the patients were subdivided into the mild (APACHE II score < 7, n = 22) and severe (APACHE II score ≥ 7, n = 17) AP groups. Healthy individuals (n = 26) were enrolled as controls. Blood samples were collected from patients on admission to the hospital. Fatty acids (FAs) were extracted from erythrocyte phospholipids and expressed as percentages of the total FAs present in the chromatogram. The concentrations of superoxide dismutase and glutathione peroxidase were measured in erythrocytes. RESULTS We found an increase in the percentages of saturated and monounsaturated FAs, a decrease in the percentages of total polyunsaturated FAs (PUFAs) and n-3 PUFAs in erythrocyte membrane phospholipids of AP patients compared with healthy controls. Palmitic (C16:0), palmitoleic (C16:1n7cis), arachidonic (C20:4n6), docosahexaenoic (DHA, C22:6n3), and docosapentaenoic (DPA, C22:5n3) acids were the major contributing factors. A decrease in the peroxidation and unsaturation indexes in AP patients as well as the severe and mild AP groups as compared with controls was observed. The concentrations of antioxidant enzymes in the mild AP group were lower than in the control group. In severe AP of nonalcoholic etiology, the percentages of arachidic (C20:0) and arachidonic (C20:4n6) acids were decreased as compared with the control group. The patients with mild AP of nonalcoholic etiology had the increased percentages of total saturated FAs and gama linoleic acid (C18:3n6) and the decreased percentages of elaidic (C18:1n9t), eicosapentaenoic acid (EPA, C20:5n3), DPA (C22:5n3), DHA (C22:6n3) as well as total and n-3 PUFAs in erythrocyte membrane phospholipids. CONCLUSION The composition of FAs in erythrocyte membranes is altered during AP. These changes are likely to be associated with alcohol consumption, inflammatory processes, and oxidative stress.