Biomedical subjects
Publications and source records attributed to Mladen Petrovecki.
Disturbed eating attitudes and behaviors among elementary school children were evaluated using the Children's Eating Attitude Test. Our findings demonstrate that students in early adolescence have disturbed eating attitudes and behaviors. We recommend screening for eating disorders in this group in order to provide primary and secondary prevention.
Correlation and regression are statistical methods that help us determine interactions of variables. Both are being used in statistical analysis of basic and clinical research. Correlation (r) is a measure of linear relationship between two numerical measurements made on the same set of subjects and it is represented by correlation coefficient. Values of correlation coefficient range between -1 and 1. Pearson's and Spearman's coefficients of correlation are the most often used correlation coefficients. Correlation can be linear and non-linear. We calculate the significance of correlation (P) in an effort to determine significance of correlation coefficient. Regression is a statistical method that allows us to predict values of one variable from another. The simplest regression is linear regression. The success of regression equation is valued by analysis of residuals. Multiple regression is used to predict one variable from several known variables.
The role of trace elements in the pathogenesis of liver cirrhosis and its complications is still not clearly understood. Serum concentrations of zinc, copper, manganese and magnesium were determined in 105 patients with alcoholic liver cirrhosis and 50 healthy subjects by means of plasma sequential spectrophotometer. Serum concentrations of zinc were significantly lower (median 0.82 vs. 11.22 micromol/L, p < 0.001) in patients with liver cirrhosis in comparison to controls. Serum concentrations of copper were significantly higher in patients with liver cirrhosis (median 21.56 vs. 13.09 micromol/L, p < 0.001) as well as manganese (2.50 vs. 0.02 micromol/L, p < 0.001). The concentration of magnesium was not significantly different between patients with liver cirrhosis and controls (0.94 vs. 0.88 mmol/L, p = 0.132). There were no differences in the concentrations of zinc, copper, manganese and magnesium between male and female patients with liver cirrhosis. Only manganese concentration was significantly different between Child-Pugh groups (p = 0.036). Zinc concentration was significantly lower in patients with hepatic encephalopathy in comparison to cirrhotic patients without encephalopathy (0.54 vs. 0.96 micromol/L, p = 0.002). The correction of trace elements concentrations might have a beneficial effect on complications and maybe progression of liver cirrhosis. It would be recommendable to provide analysis of trace elements as a routine.
Recently, skin-sparing mastectomy (SSM) with nipple-areola complex (NAC) preservation has been promoted as an oncologically safe procedure in practice for selected patients. The criteria of selection have not been yet defined precisely. The focus of this study was to investigate predictive factors of NAC-base neoplastic involvement to define the indications for NAC preservation. A prospective clinical study was conducted of 108 randomly selected female patients with invasive breast cancer. Analyzed markers of NAC involvement were tumor-nipple distance (TND), tumor size, localization, histologic type, grade, lymphovascular invasion (LVI), site, and axillary lymph-node status. The definitive histologic findings of the NAC base were compared with analyzed markers and the frozen section results. NAC base was positive in 23.15% patients at definitive histology with false-negative results in 4.63% patients at intraoperative frozen section. Significant differences were found in TND, tumor size, axillary lymph-node status, and LVI. There were no significant differences in tumor grade and site and not enough cases for statistical evaluation in histologic type and localization. Clinical indications for NAC preservation, according to this study, include tumors < or =2.5 cm, TND >4 cm, negative axillary lymph node status, and no LVI. Considering the possibility of pre- or intraoperative measurement, tumor size, and TND evaluation will result in the lowest possible mistakes in NAC preservation. Frozen section analyses of the NAC base, because of the "false-negative" possibility, could be deemed as a relative prognostic factor until definitive histologic findings. The presence of an extensive intraductal component (EIC) in the "borderline" cases of these criteria could be an additional argument for NAC removal.
AIM: To estimate the attitudes of hospital nurses towards computers and the influence of gender, age, education, and computer usage on these attitudes. METHODS: The study was conducted in two Croatian hospitals where integrated hospital information system is being implemented. There were 1,081 nurses surveyed by an anonymous questionnaire consisting of 8 questions about demographic data, education, and computer usage, and 30 statements on attitudes towards computers. The statements were adapted to a Likert type scale. Differences in attitudes towards computers were compared using one-way ANOVA and Tukey-b post-hoc test. RESULTS: The total score was 120+/-15 (mean+/-standard deviation) out of maximal 150. Nurses younger than 30 years had a higher total score than those older than 30 years (124+/-13 vs 119+/-16 for 30-39 age groups and 117+/-15 for>39 age groups, P<0.001). Nurses with a bachelor's degree (119+/-16 vs 122+/-14, P=0.002) and nurses who had attended computer science courses had a higher total score compared to the others (124+/-13 vs 118+/-16, P<0.001). Nurses using computers more than 5 hours per week had higher total score than those who used computers less than 5 hours (127+/-13 vs 124+/-12 for 1-5 h and and 119+/-14 for <1 hour per day, P<0.001, post-hoc test). CONCLUSION: Nurses in general have positive attitudes towards computers. These results are important for the planning and implementing an integrated hospital information system.
AIM: To determine the prevalence of plagiarism among medical students in writing essays. METHODS: During two academic years, 198 second year medical students attending Medical Informatics course wrote an essay on one of four offered articles. Two of the source articles were available in an electronic form and two in printed form. Two (one electronic and one paper article) were considered less complex and the other two more complex. The essays were examined using plagiarism detection software "WCopyfind," which counted the number of matching phrases with six or more words. Plagiarism rate, expressed as the percentage of the plagiarized text, was calculated as a ratio of the absolute number of matching words and the total number of words in the essay. RESULTS: Only 17 (9%) of students did not plagiarize at all and 68 (34%) plagiarized less than 10% of the text. The average plagiarism rate (% of plagiarized text) was 19% (5-95% percentile=0-88). Students who were strictly warned not to plagiarize had a higher total word count in their essays than students who were not warned (P=0.002) but there was no difference between them in the rate of plagiarism. Students with higher grades in Medical Informatics exam plagiarized less than those with lower grades (P=0.015). Gender, subject source, and complexity had no influence on the plagiarism rate. CONCLUSIONS: Plagiarism in writing essays is common among medical students. An explicit warning is not enough to deter students from plagiarism. Detection software can be used to trace and evaluate the rate of plagiarism in written student assays.
AIM: To investigate prognostic significance of several clinicopathologic parameters in patients with adenocarcinoma of the uterine cervix. METHODS: We retrospectively studied 36 patients treated at the Department of Gynecology and Obstetrics, Zagreb University School of Medicine, Croatia, in the period from 1978-1998. Cox proportional hazard analysis was performed to examine the prognostic significance of menstrual status, clinical stage, architectural grade, nuclear grade, DNA ploidy, proliferative activity, and mode of therapy. RESULTS: The 5-year survival for this group of patients was 75%. The following parameters proved to be statistically significant in a univariate analysis: clinical stage (P=0.042), architectural grade (P=0.009), and nuclear grade (P=0.002). In the multivariate analysis, the nuclear grade (P=0.007) turned out to be the only statistically significant parameter. According to the nuclear grade, the five-year survival was 80% in the prognostically favorable and only 30% in the unfavorable group of patients. CONCLUSION: Our data showed that in patients with adenocarcinoma of the uterine cervix the nuclear grade, clinical stage, and architectural grade of the tumor represent the most important prognostic parameters. The analysis of DNA ploidy and proliferative activity had no prognostic significance.
In the modern hospital information systems govern extremely important functions such as patient management, control of work flows, administration, etc., with a great variety of recommended standards used in functional integration of healthcare information systems. The main parts of the original idea of the integrated Hospital Information System have been implemented at Dubrava University Hospital in Zagreb through several phases, resulting in data production covering distinct areas of hospital administration. This paper describes the basic idea of information, organization problems and steps taken in the implementation. International standards in communication have been implemented in the system.
Before starting the implementation of integrated hospital information systems, the physicians' and nurses' attitudes towards computers were measured by means of a questionnaire. The study was conducted in Dubrava University Hospital, Zagreb in Croatia. Out of 194 respondents, 141 were nurses and 53 physicians, randomly selected. They surveyed by an anonymous questionnaire consisting of 8 closed questions about demographic data, computer science education and computer usage, and 30 statements on attitudes towards computers. The statements were adapted to a Likert type scale. Differences in attitudes towards computers between groups were compared using Kruskal-Wallis and Mann Whitney test for post-hoc analysis. The total score presented attitudes toward computers. Physicians' total score was 130 (97-144), while nurses' total score was 123 (88-141). It points that the average answer to all statements was between "agree" and "strongly agree", and these high total scores indicated their positive attitudes. Age, computer science education and computer usage were important factors witch enhances the total score. Younger physicians and nurses with computer science education and with previous computer experience had more positive attitudes towards computers than others. Our results are important for planning and implementation of integrated hospital information systems in Croatia.
PROBLEM: Huge physiologic changes during parturition involve immune cells. Alterations in maternal and neonatal lymphocytes postpartum might ascertain the subpopulations that are most affected and may possibly be of importance in the process. METHOD OF STUDY: Peripheral blood was taken from 20 healthy women at vaginal delivery and 3 days later, concomitantly with cord and peripheral blood from their newborns. Lymphocyte immunophenotyping was done by three-color flow-cytometry. RESULTS: Maternal T helper cells were decreased and natural killer (NK) cells were significantly increased during labor. Percentage of CD4(+) and percentage and absolute count of CD8(+) cells coexpressing CD45RA and CD45RO antigens were higher than 3 days later. In cord blood NK cells were considerably increased and more CD4(+) cells expressed CD45RO antigen. CONCLUSION: Coexpression of CD45RA and CD45RO molecules indicates activation of maternal CD4(+) and CD8(+) lymphocytes. NK cells increase suggests their possible association with parturition processes. Lymphocyte subsets in cord blood correspond to maternal subsets to some extent.
Interleukin-2 (IL-2) is a lymphokine produced by activated T-cells. Its receptor, IL-2R, is expressed on T-cells. Several clinical and experimental findings point towards IL-2 as a crucial mediator inducing immunologic reaction against human follicle in alopecia areata. The objective of our study was to analyze the expression of IL-2R as a sign of T-cell activation in scalp biopsies of patients suffering from alopecia areata. An immunohistochemical analysis was used to determine the difference in cytokine-regulated expression of IL-2R between 45 patients with active and stable phase of alopecia areata and 23 healthy control subjects. In the patients with alopecia areata in active phase, the expression of IL-2R in scalp biopsies was significantly stronger than that in the patients with stable disease and in controls. The increase of IL-2R+ cells in early phase of the disease could suggest that T-lymphocyte activation with IL-2 secretion and IL-2R expression may initiate the immune inflammatory mechanism of alopecia areata.
The aim of this paper is to present the post mortem dental evidence and dental health of the victims exhumed throughout the territories of Croatia that was temporarily occupied during the war. A total number of 62,432 teeth out of 1,253 human bodies exhumed from 5 different counties were analyzed. The majority of victims inhabited those areas before 1991. Post mortem dental characteristics were analyzed according to the American Board of Forensic Odontology and WHO methodology. The results show the highest level of the dental health before 1991 in the Vukovarsko-Srijemska County. The decayed (D), missing (M), filling (F), teeth (T), DMFT of that County was at the lowest level i.e. at 5.2. In all of the other counties, it was always between 6 and 12. The material most frequently used for the dental fillings was amalgam. Its highest frequency level was recorded in the County 4 (8%) and lowest in the County 1 (1.5%), p<0.001. The most frequent prosthodontic appliances were acrylic dentures. Their frequency was lowest in the County 5 (1.3%) and highest in the County 3 (11.6%), p<0.001. Determination of sex and dental age showed that victims were mostly men (79%) of middle and elderly age (89%). Teeth were useful also for monitoring of the quality of exhumations--taking into consideration number of empty dental sockets. The highest number of empty dental sockets was recorded in the County 3 (40.4%) and lowest in the County 1 (13.5%), p<0.001. Even after many years in the soil, teeth proved to be the most preserved human organs and valuable indicators of identity as well as of the way of life before death.
This study was undertaken to evaluate the effect of galanthamine, a new cholinesterase inhibitor on cognitive performances in 84 patients with various apoE genotype and Alzheimer's disease (AD) during the six-month treatment. The diagnosis of AD was made on the basis of NINCDS/ADRDN criteria. ApoE4 genotype was determined by PCR procedure. The cognitive performance was assessed MMSE at baseline and six months later. The difference among the groups was statistically analyzed by ANOVA model and Pearson's chi2-test. The MMSE at baseline in all completes was 18.0 +/- 3.73, whereas the mean value of MMSE after 6 months was 16.4 +/- 5.61 indicating significant deterioration (p < 0.01). Of the 84 patients, 14 (169%) were apoE4 homozygous, 41 (49%) were heterozygous, whereas 29 (35%) were apoE4 negative. The significant number of responders was observed among apoE4 homozygous patients (71%; chi2 = 6.89; p = 0.032). The subgroup of apoE4 homozygous patients with AD in its mild to moderate stage may be considered as responders to galanthamine.
We evaluate the efficacy of PEIT in patients with HCC using duplex color Doppler US. The study included 27 HCC patients admitted to the University Hospital Centre Zagreb, between 1993 and 1997. PEIT was performed for ablation of tumor supplying vessels in HCCs of < 5 cm in diameter, and as a palliative measure for tumor feeding vessel obliteration in larger tumors. The efficacy of PEIT was evaluated with duplex color Doppler US, and controlled by dynamic CT scan (16 patients) or selective angiography of hepatic artery (11 patients). All patients had well vascularized tumors before PEIT, and after therapy 25 of them showed absent or minimal tumor vascularization. Recanalization of the tumor feeding vessel was detected with Doppler US within 9 months after therapy. Study results suggested that duplex color Doppler US should be the method of choice in the evaluation of PEIT as well as in the follow-up of HCC patients after PEIT.
AIM: To investigate whether and to what extent various parameters, such as individual characteristics, computer habits, situational factors, and pseudoscientific variables, influence Medical Informatics examination grade, and how inadequate statistical analysis can lead to wrong conclusions. METHODS: The study included a total of 382 second-year undergraduate students at the Rijeka University School of Medicine in the period from 1996/97 to 2000/01 academic year. After passing the Medical Informatics exam, students filled out an anonymous questionnaire about their attitude toward learning medical informatics. They were asked to grade the course organization and curriculum content, and provide their date of birth; sex; study year; high school grades; Medical Informatics examination grade, type, and term; and describe their computer habits. From these data, we determined their zodiac signs and biorhythm. Data were compared by the use of t-test, one-way ANOVA with Tukey's honest significance difference test, and randomized complete block design ANOVA. RESULTS: Out of 21 variables analyzed, only 10 correlated with the average grade. Students taking Medical Informatics examination in the 1998/99 academic year earned lower average grade than any other generation. Significantly higher Medical Informatics exam grade was earned by students who finished a grammar high school; owned and regularly used a computer, Internet, and e-mail (p< or =0.002 for all items); passed an oral exam without taking a written test (p=0.004), or did not repeat the exam (p<0.001). Better high-school students and students with better grades from high-school informatics course also scored significantly better (p=0.032 and p<0.001, respectively). Grade in high-school mathematics, student's sex, and time of year when the examination was taken were not related to the grade, and neither were pseudoscientific parameters, such as student zodiac sign, zodiac sign quality, or biorhythm cycles, except when intentionally inadequate statistics was used for data analysis. CONCLUSION: Medical Informatics examination grades correlated with general learning capacity and computer habits of students, but showed no relation to other investigated parameters, such as examination term or pseudoscientific parameters. Inadequate statistical analysis can always confirm false conclusions.
Explore the source record for details and available documents.
The use of immunosuppressive therapy may be associated with significant toxicity. The aim of this study was to investigate the effect of cyclosporine A (CsA) in murine model of experimental colitis. Experimental colitis was induced in NMRI mice using an enema of 0.2% solution of dinitrofluorobenzene, combined with skin sensitization. After inducing colitis, experimental groups of animals were treated with CsA (1, 3, 5, 10, 25, 50 mg/kg/day) intraperitoneally (i.p.) or intracolonically (i.c.), and control groups were treated with phosphate-buffered saline intraperitoneally or intracolonically, respectively. Colonic inflammatory changes were assessed using a histopathologic score of 0-30, and pooled whole blood samples were processed with monoclonal antibodies for cyclosporine concentration. In addition, two groups of animals with experimental colitis were treated intraperitoneally or intracolonically with 3 mg/kg/day of CsA, and the colons were also taken for immunohistochemistry for CD25. CsA diminished the extent of colitis in groups treated with 3, 5, 10, or 25 mg/kg intraperitoneally or intracolonically, and in groups treated with 1 and 50 mg/kg intracolonically (P < 0.05). The effect of intracolonic application of CsA was not related to whole blood cyclosporine concentrations. In addition, the effect of CsA at 3 mg/kg, applied intraperitoneally or intracolonically was, in part, expressed in decreasing the numbers of CD25+ cells within colonic mucosa/submucosa (P < 0.05). In conclusions, the results of this study indicate the possibility of intracolonic application of cyclosporine in order to widen the therapeutic window for effective, but possibly toxic drug, such as cyclosporine.
The nm23 gene/protein is a putative metastatic suppressor identified a decade ago in a melanoma cell line. A number of laboratory, clinical and pathological studies have been carried out to define its real biological and biochemical function as a step in a complex metastatic process. In our study we examined the significance of nm23 expression in 164 breast cancer patients, aged 35 to 74 years, in comparison to other parameters such as age, menopausal status, histological grade, tumor size, lymph node status, and hormone receptor status. Overall survival (OS) and disease-free survival (DFS) were analyzed. The median follow-up was 84 months. Significant changes in OS were found for tumor size, nodal involvement and histological grade but there was no convincing correlation with nm23 expression. When patients were stratified according to nm23 expression, it was shown that overall survival in nm23-positive patients was no longer than that in nm23 negative patients. It was also shown that patients who were lymph node negative and older than 50 years had longer OS than nm23-negative patients. A statistical analysis shows that there is a correlation between axillary node status and nm23 expression (p = 0.018) as well as between patients' ages and nm23 expression (p = 0.043). There was no statistically significant correlation between nm23 expression, lymph node status and their combination on DFS.