ABSTRACT Introduction: CEA and CA 19-9 are the most common tumor associated antigens used in the staging of patients with rectal cancer and other parts of the colon. Goal: of this study was to evaluate the value of CEA and CA 19-9 in serum of patients with colon cancer and prove its place in the diagnostic staging. Material and Methods: The study was retrospective-prospective performed at the Gastroenterohepatology Clinic, Clinical Center of Sarajevo University. The study included 91 hospitalized patients who had histologically confirmed diagnosis of colon adenocarcinoma in 98% of cases. All patients underwent colonoscopy, targeted biopsy and measurement of CEA and CA 19-9 levels in serum. All of them underwent abdominal CT and MRI of the pelvis in case of rectal cancer. Results: The study analyzed 58 men and 33 women, mean age 66.6 years, with the youngest patient at age of 35 and the oldest at age of 89 years. The largest number of patients was aged 56-75 years. According to localization 77 patients had carcinoma located in the area of the rectum and sigma 37.4 and 37.4 in the rectostigmoid area and sigma. Metastases were observed in 37 patients, with predominance in the liver (22 cases) and both liver and lungs (5 cases). CEA and CA 19-9 were determined in all cases but patients with metastases had high values, especially in the two cases of cecoascendent colon cancer where detected values were extremely high (1789ng/ml and 10780U/ml). Values of CA19 -9 were significantly higher (p<0.05). CEA mean values were highest in patients aged over 75 years. In case of CA 19-9 high mean values have been recorded in patients aged over 75 years with statistically significant differences between the age groups (p<0.05). Conclusion: CEA and CA19-9 are cancer antigens that are late markers of carcinogenesis, with significantly elevated serum concentrations in case of colon cancer with already developed metastases. Older age group of patient has significantly elevated levels of both antigens. Cancer was twice more common in men than in women.

Introduction: Gastric cancer is one of the most common tumors in humans and is on the 14th place by frequency in the United States and it is at the 8th place by the mortality rate. In the world it takes seventh place by incidence. Today prevail the opinion and the surveys show, that it is twice as common in men as compared to women. Although there are advancements in diagnostics it must be noted that gastric cancer is still discovered late and when it already has metastasized, so that the therapeutic approach is limited and low survival rate. Patients and Methods: The study was retrospective-prospective, which covered the period from 2011 to 2012 and was performed at the Clinic of Gastroenterohepatology, Clinical Center of Sarajevo University. The study included 50 patients with gastric cancer, 34 men and 16 women. All patients underwent gastroscopy and according to tumor lesions localization divided into 3 regions: cardia, corpus and antropyloric region. Tumor lesions were biopted with histologically confirmation of gastric wall cancer. All patients underwent CT of gastric wall, CT of the abdomen and in some cases EUS was performed also. Goal: To prove by available diagnostic methods (endoscopy, CT and EUS) the presence of gastric cancer, histologically validate it and determine localization according to regions. To determine by CT the thickness of the stomach wall or the penetration of tumor lesions, the presence of enlarged lymph nodes and possible metastases. Record by EUS the progression of malignant processes in depth to layers of the wall, surrounding tissue metastases and enlarged lymph nodes. Determine the correlation between the measured parameters. Results: Our study showed that the localization of tumors at the cardia was represented in 15.31%, corpus in 17.36% and antropyloric region 16.33%. Median age he was 65.5 years with a standard deviation of 11.04. We failed to demonstrate a statistically significant difference in verified findings by EUS and age as well as endoscopic findings and age. Also there is no statistically significant difference between the CT scan and endoscopy XT = 5.99 and α = 0.05 = 0.63 XE, XE XT) and endoscopic findings and age (XT = 3.84 at α = 0.01, = 0.01 XE, XE> XT). Conclusion: Our study showed that gastric cancer are more common in men than women, metastases were more common in the elderly population, there were no significant deviations from the endoscopic findings and CT findings. EUS was performed in a small number of patients and showed as a good method because it gave accurate information about the penetration depth. Endoscopy, EUS and CT are ideal methods in diagnostic and staging of gastric cancer before the surgery.

Introduction: Colorectal cancer is the third most common tumor which causes high percentage of mortality in the general population. Etiologic factors which cause this disease are various, while diagnostic methods involve very complex protocols from detection of tumor markers to a combination of endoscopic and imaging methods. Goal: To determine the number of patients suffering from colon cancer for a period of two years and with endoscopic methods to verify and localize the tumor and its spread. Histopathological determination of the tumor type. Determine the concentration of CEA and CA 19-9 in the serum. Depending on the tumor location asses its progression, severity and extent by radiological imaging methods. Material and Methods: The study was prospective and retrospective, performed at the Gastroenterohepatology Clinic of the Clinical Center of Sarajevo University. During the two-year follow-up, 91 patients were hospitalized underwent endoscopy, targeted biopsy and histologically proven adenocarcinoma of the colon in which a pathologist determined grade of the cancers. Samples were eosin stained and underwent pathological histological analyzes. All patients according to tumor localization underwent CT scan and MRI of the rectum and pelvis. Results: The most common location of the cancer regardless of sex was in the recto sigmoid colon. Prevalence of colorectal cancer spread to other organs was not related to location. No significant dependence of the localization of the tumor by gender was found (p-value = 0.313). Ca 19-9 had the highest value in localization of tumors in the rectum. There was no statistically significant difference in age between men and women. The largest number of patients has adenocarcinoma grade 2 and the localization at the rectum. Conclusion: The combination of laboratory parameters (CEA and CA 19-9) with endoscopic and radiological imaging methods is essential in diagnosis of colorectal cancer and assessment of the process progression. There is a need to impose additional diagnostic parameters to detect the disease at an earlier stage.

Abstract The use of Social Network Analysis (SNA) for online learning communities’ analysis is common and usually performed after the ending of semester. Yet, even if such analysis is very useful, it is costly, and cannot be performed many times during the semester. In this paper, we present a model of automated SNA based inference, for a large- scale community, taking into account specific environment of developing higher education system. The model is designed so to send automated reminders to all users, according their activity in the period of two weeks. One additional analysis after the mid-term exams checks if activity matches performance. It has crucial role in directing both students and educators towards the common goal: success at the final exams. The presented model enables inference on user attributes, which are stored in student model ontology. As such, the model is a step in the development of semantic and adaptive learning environment.

Abstract FIT has a large virtual community, developed for DL students, but including the growing number of in-situ students. Through the last five years, most of the students have accepted and used FIT Community Server (FITCS) for interactions, but the extent of knowledge sharing was never measured. It was determined that FITCS is a small-world scale-free network, with several hubs: some administrators and some spammers. Now we determined characteristics of the social network, such as density, centrality, degree, closeness and betweenness, for overall communication in first two semesters and for two subjects in order to estimate knowledge sharing.