Search PubMed⌕ Search

Biomedical subjects

M Petrovecki

Publications and source records attributed to M Petrovecki.

At least 19 recordsLinked to original sources
PubMed1998

Indirect demonstration of the lifetime function of human thymus.

The aim of this study was to test the hypothesis that human thymus maintains its function as the site of early T cell development throughout life, but to a progressively diminishing extent. Mononuclear cell suspensions prepared from the samples of 39 human thymuses were analysed for the total number of cells per gram of thymus tissue, percentage of single marker-positive CD2, CD4 and CD8 cells, percentages of double-positive CD4CD8 and CD2CD8 cells, double-negative CD4CD8 cells, absolute numbers of these cells per gram of tissue, and extent of the in vitro proliferation upon stimulation with concanavalin A (Con A), phytohaemagglutinin (PHA) and pokeweed mitogen (PWM) mitogens. The main outcome measures were flow cytometric data on thymus lymphoid cell composition (according to CD classification), expressed as percentages and numbers of cells per gram of thymus tissue. The total number of mononuclear cells expressed per gram of thymus tissue exponentially decreased with age. The slope of none of the analysed cell subpopulations differed from the slope of the line constructed for age-related decline of the total number of mononuclear cells (-0.024 on a semilogarithmic scale). The thymuses of all ages contained all analysed cell subpopulations in approximately the same proportions: percentages of these cell subpopulations did not change with age, except for all CD4+ (P=0.017) and double-positive CD4+CD8+ (P=0.016) cells, which tended to decrease with age. The extent of proliferation of thymus cells upon stimulation with T and B cell mitogens was unrelated to age. We conclude that the thymus retains its function as the site of differentiation of T lymphocytes throughout life. With respect to the number of involved lymphoid cells, the function exponentially decreases with age.

Adolescent↗
PubMed1998

Peer review in the Croatian Medical Journal from 1992 to 1996.

We analyzed the peer review process in the Croatian Medical Journal (CMJ) from 1992 to 1996 by a retrospective analysis of review forms for 319 manuscripts. The forms asked about manuscript's structure (7 questions), its scientific value (7-item scale), clarity and length, and final recommendation (5-item scale). An international manuscript had at least one author affiliated with a non-Croatian institution. The overall rejection rate of manuscripts was 23.5%. National and international manuscripts had similar rejection rates except for original research manuscripts in clinical sciences (34.7% vs. 18.9%, p=0.046). Out-door peer review was asked for 77.4% of the manuscripts; other manuscripts were commissioned and passed an in-house review. Over the years, the number of international reviewers increased, and that of national reviewers decreased. National reviewers more often did not fill in the review form, and international reviewers more often asked for a major revision. The agreement between reviewers ranged from 34.1% (scientific value) to 90.7% (reference citations). Kappa for inter-rater agreement was poor to fair, without difference between national and international manuscripts. International manuscripts had shorter median review time (from receipt to decision) and publishing time (from acceptance to publication) than national manuscripts: 58 vs. 112 days (p<0.001), and 116 vs. 140 days (p<0.009), respectively. Our analysis shows that peer review can be introduced and sustained in a small journal from the scientific periphery. It can be fair both to national and international manuscripts, although work with the authors of national manuscripts may be needed to improve the quality of data presentation.

Croatia↗
PubMed1998

Prognostic significance of cell cycle parameters in infiltrative ductal breast carcinoma.

Flow-cytometric DNA analysis was performed retrospectively from paraffin-embedded blocks in 158 consecutive ductal infiltrative breast carcinoma patients grades I-III. Normal breast tissue was used as control. Tumor proliferative activity, cell ploidy, and DNA index (DI) were related to age of patients, histological grade of tumor, tumor size, axillary lymph node status, estrogen and progesterone receptor status, menopausal status,TNM clinical classification, and survival. There was a significant association between DNA aneuploidy and a high cellular proliferative activity, increased DI, poor differentiation of tumor, primary tumor size, number of positive lymph nodes, and postmenopausal state. Increased proportion of cells in S-phase was associated with positive lymph node status and higher number of positive lymph nodes. The cell cycle parameters had no prognostic value either for overall survival of disease-free survival of the patients.

Adult↗
PubMed1997

Correlation of two methods for determination of cathepsin D in breast carcinoma (immunohistochemistry and ELISA in cytosol).

We have studied the correlation of two methods (immunohistology and ELISA in cytosol) of cathepsin D (CD) determination in breast carcinoma patients. Fifty six specimens of tumor tissue were collected consecutively, and CD expression in tumor tissue and tissue macrophages was determined by standard immunohistochemistry using the aNCL-CDm anti-cathepsin D mouse monoclonal antibody (Novocastra Laboratories Ltd., Newcastle, UK). Additionally, CD concentration was determined by ELISA in cytosol of the same breast carcinoma specimens. CD positivity was correlated with tumor size, histological grade of tumor, and the cytosol progesterone adn estrogen receptor concentrations. There was no statistically significant correlation between examined parameters and either CD positivity by immunohistochemistry or cytosol CD concentration. The correlation between CD expression in tumor cells of breast carcinoma by immunohistochemistry and cytosol CD positivity was not found either. However, there was a significant association between abundance of CD positive stromal macrophages and cytosol CD concentration in all histological tumor types (p < 0.05). CD positive macrophages were abundant in most of cytosol CD positive specimens. These results suggest that breast cancer cytosol CD concentration is the cumulative result of CD content in both carcinoma cells and stromal macrophages.

Animals↗
PubMed1996

Prognostic parameters for survival of patients with malignant mesenchymal tumors of the uterus.

BACKGROUND: Malignant mesenchymal uterine neoplasms are the most aggressive type of primary uterine tumors, with most patients dying within a few years of diagnosis. Thus, it would be very important to define prognostic factors for predicting the malignancy potential of at least some of their subtypes. METHODS: Flow cytometric cell cycle analysis (proliferative activity, DNA ploidy, and DNA index) was performed on archival paraffin embedded blocks from 80 patients with malignant mesenchymal uterine neoplasms (endometrial stromal sarcomas, malignant smooth muscle tumors, and malignant Müllerian mixed tumors). The Cox proportional hazards regression model was used to assess relative effects of the following factors on patient survival: clinical stage, mode of therapy, DNA+proliferative activity, DNA index, histologic type, cellularity, degree of atypia, mitotic activity, and depth of myometrial invasion. RESULTS: There were 9 low grade stromal sarcomas, 17 high grade stromal sarcomas, 8 smooth muscle neoplasms with uncertain malignant potential, 23 leiomyosarcomas, and 16 homologous and 7 heterologous malignant Müllerian mixed tumors. In univariate analysis for stromal sarcomas, statistical significance was found for DNA ploidy+proliferative activity (P < 0.001), histologic type (P = 0.005), and DNA index (P < 0.001). In multivariate analysis, DNA index appeared to be the only significant parameter influencing patient survival (P = 0.005). In univariate analysis for malignant smooth muscle neoplasms, statistical significance was detected for mitotic activity (P = 0.049) and International Federation of Gynecology and Obstetrics classification (P = 0.021), but in multivariate analysis, clinical stage appeared to be the only significant parameter influencing patient survival (P = 0.032). In univariate analysis for malignant Müllerian mixed tumors, statistical significance was found for the depth of myometrial invasion (P = 0.039), DNA index (P = 0.037), and clinical stage (P = 0.013), but in multivariate analysis, only the depth of myometrial invasion (P = 0.036) and clinical stage (P = 0.025) were of statistical significance. CONCLUSIONS: The most powerful prognostic indicator for stromal sarcomas was the DNA index, for malignant smooth muscle neoplasms it was the clinical stage, and for malignant Müllerian mixed tumors it was the depth of myometrial invasion.

Analysis of Variance↗
PubMed1996

Analysis of data on leukocyte surface markers for recognition of leukemia/lymphoma phenotype pattern.

OBJECTIVE: This study was designed to test the algorithm for the recognition of leukemia/lymphoma pattern, based on cell immunophenotype assessed using specific monoclonal antibodies and measured using flow cytometry. DESIGN AND METHOD: Analysis was performed by comparing phenotyping data with reference data, followed by scoring of such comparisons. Output of the recognition was designed as a report list of possible diagnoses (defined as objects in the informatic system). Reference data were compiled from the respective literature. RESULTS: From 57 blood and bone marrow samples tested in this study, accurate recognition of the real diagnosis (object) appeared on the first four places of the report list in 54 (94.7%) samples. CONCLUSION: The list of the objects recognized by the use of algorithm appeared to be helpful in making a differential diagnosis, occasionally pointing to the states that the physician had not in mind at the start of the analysis.

Algorithms↗
PubMed1995

Granulocyte-monocyte colony forming unit content of autologous bone marrow transplants in patients with haematological malignancy.

Cell viability and number of granulocyte-monocyte colony forming units (CFU-GM) were systematically assessed in 57 patients who had undergone transplantation of the autologous bone marrow for treatment of haematologic malignancies. Bone marrow cell cultivation in agarose with feeder layers appeared inferior to that performed in agarose with recombinant human granulocyte-monocyte colony stimulating factor and methylcellulose with phytohaemaglutinin leukocyte-conditioned medium. Since the transplant cells were frozen in liquid nitrogen between harvesting and reinfusion, the following samples were tested: buffy coat cells, buffy coat cells immediately after addition of dimethylsulphoxide, cell sample that had been frozen for 24 hours, and frozen transplant cells at the time of thawing and transplantation. Each procedural step decreased both cell viability and the number of CFU-GM, but since the lymphohaematologic recovery in all patients followed the pattern reported in the literature for high-quality transplants, we concluded that our transplants retained the necessary number of progenitor cells. It appears that the best strategy for dynamic assessment of the transplant quality would be to perform tests after every step of the transplant processing. Cell viability and number of progenitors per body weight in transplants were also found to be associated with probability of neutrophil reconstitution after bone marrow reinfusion.

Adolescent↗
PubMed1995

Autologous bone marrow transplantation for haematological malignancies--experiences of the centre of Zagreb.

From April 1988 to May 1993, 71 patients (32 acute myelogenous leukaemia [AML], 24 acute lymphoblastic leukaemia [ALL], 7 Hodgkin's disease [HD], 5 non-Hodgkin lymphoma [NHL], 2 neuroblastoma, 1 chronic myelogenous leukaemia [CML]) were treated with myeloablative therapy followed by reinfusion of cryopreserved autologous bone marrow (ABMT). The majority of patients with acute leukaemia were in first complete remission (CR), while 11 AML patients and 9 ALL patients were in advanced stage of the disease (> I CR or relapse). The BM was reinfused without purging. The conditioning regimen for all ALL and proportion of AML patients consisted of cyclophosphamide (CY) 120 mg/kg and fractionated total body irradiation (TB) in a total dose of 12 Gy. 18 AML patients received busulfan 16 mg/kg instead of TBI. Leukaemia-free survival (LFS) for first CR AML patients was 48% at 43 months with the median follow-up of 17 months. Probability of relapse was 44%. LFS for advanced AML was only 9% and the probability of relapse 89%. LFS for first CR ALL patients was 72% at 53 months with the median follow-up of 15 months, while probability of relapse was only 23%. For advanced ALL, LFS was 32% at 33 months and probability of relapse 64%. Probability of toxic death for first CR patients was 11%. We found a predictive value of viability testing and in vitro CFU-GM assay for haematologic recovery after ABMT. We conclude that ABMT with cryopreserved BM is a relatively safe method for consolidation therapy of AL. The results of treatment are encouraging.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1995

AgNORs predictive value of prognosis in non-Hodgkin's lymphoma according to the Kiel classification.

Application of the colloidal silver method for demonstration of argyrophilic proteins of nucleolar organizer regions (AgNORs) in histological sections of non-Hodgkin's lymphomas (NHLs) has been shown to be a helpful method for the discrimination of high- and low-grade NHL. In this study correlation between the mean number of AgNORs and other morphological and clinical parameters with survival in 58 patients with NHL, classified according to the Kiel classification, was investigated. It was shown that the mean number of AgNORs differed between the low- and high-grade group of NHLs (P < 0.001), as did survival (P < 0.0001). The mean number of AgNORs was also highly significant when describing actuarial survival. The value of 2.9 NORs per nuclei was the cut-point for separating the whole group into two subgroups, which differed the most when related to survival of patients with NHL.

Adolescent↗
PubMed1994

Tumor cell cycle in patients with stage I endometrial carcinoma.

Flow cytometric cell cycle analysis was performed on paraffin-embedded blocks from 49 patients with stage I endometrial carcinoma. Care was taken to separate tumor tissue from normal tissue in each specimen; normal tissue was used as a control for each individual specimen. DNA index, proliferative activity, and cell DNA aneuploidy were correlated with known parameters of tumor malignancy. Increased DNA index corresponded well with the DNA aneuploid tumors, poor tumor differentiation (G3), myometrial invasion of more than one-third, more malignant histologic type of tumor, and low concentration of estrogen (< or = 10 fmole/mg) and progesterone (< or = 25 fmole/mg) receptors. Similar results were obtained for tumor cell proliferative activity (percentage of cells in S + G2/M phases) and for DNA aneuploid tumors. Since more than 90% of patients with stage I endometrial carcinoma survived the 5-year postoperation period, analyzed parameters could not be checked for survival-related prognostic significance. However, our data indicate that cell cycle analysis may be instrumental for objective ranking of several known prognostic parameters.

Adult↗
PubMed1994

Age-dependent haematological disturbances in anaesthetic personnel chronically exposed to high occupational concentrations of halothane and nitrous oxide.

Anaesthetic staff chronically exposed to high occupational concentrations of halothane and nitrous oxide were tested for numerous haematological and cellular function parameters at the peak of the working season and after 3 weeks vacation. The analysis of data was performed to compare differences in subjects younger and older than the age of 40 years, respectively when compared with normal controls. The analysis revealed a higher recovery of erythrocyte count in the blood of older staff, and stronger disturbance of leucocyte formation in younger staff. In contrast, monocytes appeared to be more stable in the younger staff as were the T and B lymphocyte counts. After stimulation with PHA, Con A and PWM mitogens, lymphocytes from the older age group incorporated a significantly higher amount of tritiated thymidine, but stimulation indices did not differ. Natural killer cell numbers appeared equally affected; natural killer cell activity was unaffected, but there was an increase in activity in the younger staff after the vacation. Serum immunoglobulin concentrations tended to be more affected in older individuals at the peak of the working season.

Adult↗
PubMed1994

Prognostic value of steroid hormone receptors concentration in patients with endometrial carcinoma.

The concentrations of progesterone receptors in endometrial tumors of 160 patients were analyzed with respect to survival and presence of clinicopathologic prognostic factors. The concentration of 25 fmol/mg of proteins for progesterone receptors appeared to be most powerful for prediction of survival. The survival was also significantly correlated to age, depth of myometrial invasion and clinical stage of the tumor. Concentration of estrogen receptors could not be correlated with the probability of patients' actuarial survival.

Actuarial Analysis↗
PubMed1994

Relationships between DNA damage and the survival of murine bone marrow cells irradiated in situ.

The relationships between DNA damage and the survival of murine bone marrow cells irradiated in situ were examined. Cell survival was assayed by the ability of bone marrow cells from irradiated mice to form colonies in vitro (CFU-C). DNA double-strand breaks (DSBs) were measured by neutral (nondenaturing) filter elution and pulsed-field gel electrophoresis (PFGE). Double-strand breaks were measured in the proliferating bone marrow cells, identified by injecting the mice with [3H]dThd at various times before gamma irradiation, as a model of the behavior of the radiosensitive target cells. To assess how the DNA lesions measured using these techniques correlated with cell killing, the effect of the radioprotective agent WR-2721 on the induction of DSBs in proliferating bone marrow cells was compared with its effect on CFU-C survival. WR-2721 protected against the killing of both granulocyte-macrophage and erythroid burst-forming CFU-C by a factor of about 2. In contrast, little (1.2-fold) protection was observed in the PFGE assay at radiation doses between 5 and 20 Gy. Similarly, at the lowest dose studied (5 Gy) there was little protection against DSBs as measured by neutral elution; only after doses of between 10 and 30 Gy was significant protection observed. Thus the previously reported predictive relationship between DSBs and cell survival in vitro does not appear to extend directly to murine bone marrow cells irradiated in vivo.

Amifostine↗
PubMed1993

Hypersensitivity to Parietaria officinalis pollen in newcomers to the area with the plant.

Hypersensitivity to Parietaria officinalis (wall pellitory) pollen and other environmental allergens was studied in pollinosis patients allergic to P. officinalis pollen who were born in areas without P. officinalis and later moved to the city of Split, where P. officinalis is responsible for some 65% of pollinosis cases. Highly significant positive correlations were found for both the intensity of skin test reaction and concentration of specific serum IgE with the length of residence in the area. In contrast, the respective data on subjects hypersensitive to P. officinalis pollen allergen, but born and living in the area of Split, revealed a tendency to negative correlation between age and intensity of hypersensitivity to P. officinalis. A number of patients from both groups were tested for presence of serum IgE antibodies specific for 14 common environmental allergens. Hypersensitivity to P. officinalis pollen was associated with hypersensitivity to olive, mugwort, and birch pollen in newcomers; hypersensitivity to birch and, to some extent, olive pollen was significantly more frequent in newcomers than in autochthonous patients who were allergic to P. officinalis pollen. Regardless of whether the patients were autochthons or newcomers to the area with P. officinalis, hypersensitivity to P. officinalis mostly excluded hypersensitivity to Dermatophagoides farinae and D. pteronyssinus, and vice versa.

Adolescent↗
PubMed1993

Nucleolar organiser regions and survival in patients with non-Hodgkin's lymphomas classified by the working formulation.

AIMS: To correlate the numbers of silver staining nuclear organiser regions (AgNORs) in non-Hodgkin's lymphoma classified by the working formulation with survival, the first complete remission, and the length of remission. METHODS: Sixty one patients were included in the study. Paraffin wax sections were stained using silver solution to visualise nucleolar organiser regions. The AgNORs were counted in 150 nuclei of each specimen. Data were examined using the Kruskal-Wallis test, multivariate discriminant analysis, and Cox's regression test. Curves were calculated by the method of Kaplan and Meier. RESULTS: Most patients who were alive had low grade lymphoma (p < 0.01). The first complete remission was obtained more frequently in the low and intermediate grade groups (p < 0.05). The longest survival was found in the low grade group (p < 0.001). The mean number of AgNORs differed significantly in all three groups (p < 0.001). This was also true for area of nuclei (p < 0.001) and length of remission (p < 0.05). In a multivariate analysis the numbers of AgNORs were highly predictive for survival, remission, and the length of remission. CONCLUSIONS: The numbers of AgNORs correlated with survival, remission, and the length of remission in patients with non-Hodgkin's lymphoma.

Adolescent↗
PubMed1992

Leukocyte membrane markers on cell populations defined by six flow cytometric bitmaps.

Peripheral blood samples from healthy adults, patients with transplanted bone marrow, and healthy children were analyzed for the proportions of cells positive for CD2, CD4, CD8, CD19, CD56, CDw65, and KiM8 cell membrane markers. Six cell gates were defined on granularity vs. cell size (L90 degrees LSx-FALS) flow cytometric display for each blood sample: large lymphocytic, small lymphocytic, monocytic, mononuclear, granulocytic, and all-cell gate, and the listed markers were determined in each of them. Considerable differences in marker-positive cell proportions were found between healthy adults and children, and particularly between healthy adults and patients with transplanted bone marrow. Marker-positive cell frequencies corresponded to biologic distribution of three leukocyte populations within the defined gates, in a general agreement with known specificities of the antibodies used. A considerable degree of variations in the positions of gates drawn for different samples and the numbers of cells counted in them was observed. Still it appeared that all six gates, otherwise commonly used in flow cytometric analysis, could be precisely defined and yielded reproducible data. large and small lymphocytic gates yielded very similar marker frequencies, revealing that in cases where three leukocyte populations were not clearly delineated on (90 degrees LSxFALS) display, a smaller lymphocytic gate could be safely drawn in order to avoid contamination with monocytes.

Adult↗