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Biomedical subjects

M Petrovecki

Publications and source records attributed to M Petrovecki.

48 records · Page 3Linked to original sources
PubMed1992

AgNORs predictive value of prognosis in non-Hodgkin's lymphoma: comparison with flow cytometric cell cycle analysis.

Paraffin-embedded histopathologic specimens, taken before the commencement of therapy from 14 low-grade and 21 high-grade malignant lymphoma patients, and 9 normal lymph nodes were utilized to analyze six cell DNA-related parameters. The flow cytometry technique was used to determine cell-cycle G0/G1, S and G2/M phases, and silver staining to enumerate nuclear organized regions (AgNORs); nucleus surface area was determined by an image-analyzing system. The six parameters and natural logarithm of cell proportion in the S-phase (LS) were determined according to the histologic tumor type and achievement of the first complete remission (CR). All parameters except cell proportion in G1/M cycle phase differed significantly with respect to histologic cell type, but were not related to the achievement of first CR. Inasmuch as the parameters significantly correlated with each other, multivariate discriminant analysis and proportional hazard regression were applied to estimate their discriminant/predictive values with respect to tumor malignancy. AgNORs proved to be far superior in all three clinical parameters, S-phase was significantly predictive for the achievement of first CR, and LS for tumor histology type. The statistical model applied narrowed down the analysis of seven parameters to two with respect to tumor histology type (AgNORs and LS) and achievement of first CR (AgNORs and S), but only to one for overall patient survival (AgNORs). Only the model for tumor histology type discrimination was statistically significant (R2 = 0.904, p < 0.001). It appears that AgNORs may be of utmost predictive importance for the clinical outcome in NHL.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1991

T cell subset composition in remission phase of systemic connective tissue diseases.

The proportions and numbers of peripheral blood mononuclear cells bearing T-cell markers (CD3/HLA-DR, CD4/CD29, CD4/CD45, CD8/CD56) were analyzed using two-color flow cytometric analysis in patients with systemic lupus erythematosus (SLE), rheumatoid arthritis (RA) and Sjögren's syndrome (SS) in the remission phase of the diseases. The number of T cells (CD3+) in the blood was significantly decreased in SLE patients only; in these patients, but also in RA patients, an increased number of activated T cells (CD3+ HLA-DR+) was found. The number and proportion of helper T cells (CD4+) were decreased in SLE and SS, and normal in RA patients. In contrast, helper-inducer (CD4+ CD29+) and suppression-inducer (CD4+ CD45+) cells were both significantly increased in RA patients, decreased in SLE (only CD4+ CD45+ significantly) and unchanged in SS patients. Interestingly, however, the proportions of helper-inducer cells relative to total helper (CD4+) cell pool were significantly increased in all three groups of patients, whereas the proportion of suppression-inducer (CD4+ CD45+) cells was significantly decreased, but in SLE patients only. It is thus possible that this parameter is most pertinent to the disease status in the model studied. The population of CD8+ cells appeared more abundant in SLE patients, and the pool of CD8+ CD56+ cell was significantly enlarged in RA patients. It appears that the remission phase of disease in RA, SLE and SS patients still contains a substantial activation of the immune system, but the respective mechanisms are quite different in RA patients on one side, and SLE and SS patients on the other side.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

Natural killer cell number and activity in remission phase of systemic connective tissue diseases.

The proportions and numbers of peripheral blood mononuclear cell markers and peripheral blood NK cell activity were analyzed and correlated in systemic lupus erythematosus (SLE), rheumatoid arthritis (RA) and Sjögren's syndrome (SS) patients in the remission phase of the diseases. In comparison to the control data, the number of CD56+ cells was significantly increased in RA patients only; the same held true for double-positive cells, i.e., the alterations did not distinguish various subpopulations of NK cells. NK cell activity was significantly decreased in all the three groups of patients, with the complete lack of correlation between the NK cell number and their activity. It is possible that a significantly diminished NK cell activity in these diseases provokes a compensatory production of nonfunctional NK cells.

Adult↗
PubMedDate not supplied

Mutual predictive value of c-erbB-2 overexpression and various prognostic factors in ductal invasive breast carcinoma.

AIMS AND BACKGROUND: Breast carcinoma is a heterogeneous disease, the prognosis of which correlates with various prognostic factors. The aim of this study was to assess the prognostic significance of c-erbB-2 overexpression in breast carcinoma patients in association with other known prognostic factors. METHODS & STUDY DESIGN: The relationship between immunohistochemical expression of the c-erbB-2 oncoprotein and various established prognostic factors such as tumor size, axillary node status, estrogen and progesterone receptor status, DNA ploidy, proliferation index, cathepsin D expression and histological grade in invasive ductal breast carcinoma is presented in this study. RESULTS: Of the 93 ductal invasive carcinomas 22 (23.7%) were grade I, 51 (54.8%) grade II, and 20 (21.5%) grade III, and the majority (78: 83.9%) were 2-5 cm in diameter. Tumor metastases were identified in one or more lymph nodes in 55 (59.1%) patients, the remaining 38 (40.9%) patients being lymph node negative. According to the DNA histograms 40 (43.0%) tumors were aneuploid and 53 (57.0%) were diploid, and the majority of tumors had more than 4% of cells in the S phase of the cell cycle (83.9%). Expression of c-erbB-2 as shown by immunohistochemical intense membrane staining was present in 49 (52.7%) tumors. Cathepsin D-positive cytoplasmic granular staining and cathepsin D-positive stromal macrophages were found in 60 (64.5%) and 72 (77.4%) tumors, respectively. Univariate analysis showed that overall survival correlated significantly with axillary lymph node involvement and with estrogen and progesterone receptor status for each of the receptors separately and for their coexpression, and only marginally with c-erbB-2 overexpression. In mulitivariate analysis only axillary lymph node metastases and coexpression of estrogen and progesterone receptors were found to be independent and significant prognostic factors. CONCLUSIONS: When patients were stratified according to c-erbB-2 expression it was shown that those with c-erbB-2 overexpression and grade II tumors, tumor size greater than 2 cm, high content of aneuploid cells and cathepsin D-positive stromal macrophages had a shorter long-term survival than c-erbB-2 negative patients.

Adult↗
PubMedDate not supplied

An algorithm for leukaemia immunophenotype pattern recognition.

Since leukaemia-specific leucocyte antigen has not been identified to date, the immunological diagnosis of leukaemia is achieved through the application of a wide set of monoclonal antibodies specific for surface markers on leukaemic cells. Thus, the interpretation of leukaemia immunophenotype seems to be a mathematically determined comparison of 'what we found' and 'what we know' about it. The objective of this study was to establish an algorithm for transformation of empirical rules into mathematical values to achieve proper decisions. Recognition of leukaemia phenotype was performed by comparison of phenotyping data with reference data, followed by scoring of such comparisons. Systematic scoring resulted in the formation of new numerical variables allocated to each state, whereas a most significant variable was described as a complex measure of compatibility. A system of recognized states was described by mathematical variables measuring the confidence of information systems, i.e. maximal, total and relative entropy. The entire algorithm was derived by matrix algebra and coded in a high-level program language. The list of the states recognized appeared to be especially helpful in differential diagnosis, occasionally pointing to states that had not been in the scientist's mind at the start of the analysis.

Algorithms↗
PubMedDate not supplied

[Analysis of lymphocyte immunophenotypes in neonates].

Immune system development is not completed at the end of gestation, so newborns are not fully immunocompetent. In order to evaluate the neonatal immune system status and investigate the reasons for increased neonatal susceptibility to infections, the major lymphocytes subpopulations were studied in newborns comparing the results to adult controls. The cord blood from 21 term-newborns and the peripheral blood from 23 adults were analyzed using fluorochrome labelled monoclonal antibodies and two-color flow cytometry. The percentage of T lymphocytes was lower in newborns (64.9 versus 72.8% in adults), as well as the percentage of NK cells (4.8 versus 15.5%). On the contrary, the proportions of unlabelled cells were increased in term cord blood. The percentage of cytotoxic T lymphocytes was significantly lower in term-newborns as compared to the adult controls (17.8 versus 30.3%), and so were the percentages of activated T lymphocytes (0.3 versus 3.7%) and cytotoxic non-MHC restricted T lymphocytes (0.2 versus 1.8%). The expression of CD45R0 marker on neonatal lymphocytes was very low (1%). These characteristics of newborn lymphocytes phenotype are the result of inexperienced and partly undeveloped immune system.

Adult↗
PubMedDate not supplied

[The chemical war in Croatia].

During the present war against the Republic of Croatia, chemical weapons have been used by the Yugoslav Federal Army (YFA) against both civilians and Croatian Army soldiers. The use of irritants was suspected (Vukovar, Bogdanovci and Vinkovci, October-November, 1991; Solin in the Split area, September, 1991) and proved (Velika Gorica in the Zagreb area, September, 1991; Cakovec, November, 1991) in many cases. The use of psychochemical incapacitating agents (Bilje near Osijek, July, 1991), as well as of psychostimulants in YFA own soldiers (Zadar, August, 1991) has been suspected on clinical findings or laboratory tests. The use of acetylcholnesterase inhibitors was proved in one aggressor's diversion (Zadar, Krusevo, July, 1991). Phosphorus from projectiles and fuming boxes caused poisoning and skin burns due to incineration (Vukovar, November, 1991). YFA used the civilian's fear of chemical and biological weapons, throwing untoxic substances all over the Croatian territory. Great ecocide problems have occurred with massive industry devastation (Sisak, Osijek, October, 1991-January, 1992), with enumerous amounts of toxic substances released into the soil and river aquatoria.

Chemical Warfare↗
PubMedDate not supplied

[Autologous blood transfusion in orthopedic surgery patients].

During a 16-month period, blood for autologous transfusion treatment was taken in 186/788 (23.6%) orthopedic patients. Vasovagal reactions during blood withdrawal were observed in 8.6% of patients. Transfusiologic treatment with autologous blood alone was carried out in 134 (72%) patients. In 36 (19.4%) patients, homologous blood was given in addition to autologous blood. Withdrawal of the required blood unites could not be completed in 33 (17.7%) patients. In this group of patients, the need of homologous blood transfusion was highest (39.3%). In 98.3% of patients, mean values of hemoglobin and hematocrit immediately before the surgical procedure exceeded 100 g/L and 30%, respectively.

Adolescent↗
PubMedDate not supplied

Proliferating cell nuclear antigen (PCNA) as a prognostic factor for colorectal cancer.

PCNA (proliferating cell nuclear antigen) is a cell cycle related protein that is maximally elevated in late G1 and S-phase of proliferating cells. 114 biopsy specimens of colorectal cancer were immunolabeled with PC 10 which specifically recognizes PCNA; Dukes' staging and histological grading were estimated for each case. All patients were followed-up for at least 60 months or to death. All data were analysed by the computer program NCSS (Number Cruncher Statistical System). According to the results, PCNA-index may be considered an independent prognostic factor for colorectal cancer; it may also be helpful in supporting the therapeutic strategies based only on Dukes' stage.

Colorectal Neoplasms↗