Papers by Klara Dubravcic
Aim To evaluate the clinical utility of incorporating a novel heavy/light chain immunoassay (HLC)... more Aim To evaluate the clinical utility of incorporating a novel heavy/light chain immunoassay (HLC) into the existing methods for the assessment of multiple myeloma (MM) patients.
Croatian medical journal, Jan 19, 2015
To evaluate the clinical utility of incorporating a novel heavy/light chain immunoassay (HLC) int... more To evaluate the clinical utility of incorporating a novel heavy/light chain immunoassay (HLC) into the existing methods for the assessment of multiple myeloma (MM) patients. Convenience sera samples from 90 previously treated IgG and IgA MM patients in different disease stages were analyzed. The study was conducted in Clinical Hospital Center Zagreb between 2011 and 2013. The collected sera were analyzed by standard laboratory techniques (serum protein electrophoresis, quantification of total immunoglobulins, serum immunofixation, serum free light chain [FLC] assay) and HLC assay. HLC ratios outside the normal range were found in 58 of 90 patients, including 28 out of 61 patients with total immunoglobulin measurements within the normal range and 5 out of 23 patients in complete response. Both elevated HLC isotype level and abnormal HLC ratio correlated with the parameters of tumor burden, including percentage of plasma cells in the bone marrow (P<0.001 and P=0.002, respectively) ...
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Lijec̆nic̆ki vjesnik
Hairy cell leukemia is a chronic B-cell lymphoproliferative disorder characterized by clonal prol... more Hairy cell leukemia is a chronic B-cell lymphoproliferative disorder characterized by clonal proliferation of hairy cells. Treatments of choice are purine analogues, particularly cladribine. We treated thirty patients with cladribine either by continuous 7-day infusion at a daily dose of 0.1 mg/kg or by 2-h infusion for 5 consecutive days at a daily dose of 0.14 mg/kg. Remission was achieved in 90% of the patients. After a median follow-up of 44 months overall survival is 93% and time to treatment failure more than 6 years. Two patients did not respond, one patient died of infection shortly after the treatment. Side-effects resulted mainly from hematological toxicity, 23% of the patients had neutropenic fever while 20% required platelets or packed red cell transfusions. Our results show that cladribine is safe and effective in the treatment of hairy cell leukemia. There were no significant differences in toxicity and response between 7-day continuous infusion and 5-day intermittent ...
Large volume leukapheresis: Efficacy and safety of processing patient's total blood volume six ti... more Large volume leukapheresis: Efficacy and safety of processing patient's total blood volume six times Large-volume leukapheresis (LVL) differs from standard leukapheresis by increased blood flow and altered anticoagulation regimen. An open issue is to what degree a further increase in processed blood volume is reasonable in terms of higher yields and safety. In 30 LVL performed in patients with haematologic malignancies, 6 total blood volumes were processed. LVL resulted in a higher CD34+ cell yield, without change in graft quality. Although a marked platelet decrease can be expected, LVL is safe and can be recommended as the standard procedure for patients who mobilize low numbers of CD34+ cells and when high number of CD34+ cells are required.
Transfusion and Apheresis Science, 2011
Large volume leukapheresis: Efficacy and safety of processing patient's total blood volume six ti... more Large volume leukapheresis: Efficacy and safety of processing patient's total blood volume six times Large-volume leukapheresis (LVL) differs from standard leukapheresis by increased blood flow and altered anticoagulation regimen. An open issue is to what degree a further increase in processed blood volume is reasonable in terms of higher yields and safety. In 30 LVL performed in patients with haematologic malignancies, 6 total blood volumes were processed. LVL resulted in a higher CD34+ cell yield, without change in graft quality. Although a marked platelet decrease can be expected, LVL is safe and can be recommended as the standard procedure for patients who mobilize low numbers of CD34+ cells and when high number of CD34+ cells are required.
Toxicology in Vitro, 2006
Diazene N-phenyl-2-(2-pyridinyl)diazenecarboxamide (JK-279) is a newly synthesized compound, cyto... more Diazene N-phenyl-2-(2-pyridinyl)diazenecarboxamide (JK-279) is a newly synthesized compound, cytotoxic for several tumor cell lines and their drug-resistant sublines. In human cervical carcinoma cells (HeLa), this compound reduced intracellular glutathione content and increased sensitivity to cisplatin. The aim of the present study was to elucidate the molecular mechanisms involved in the cytotoxic effect of diazene JK-279 on HeLa cells. Cytotoxicity was determined by the MTT method. Flow cytometry analysis showed that diazene JK-279 induces G 2 /M phase arrest, mediated by the increase in p21 expression, and accompanied by an alteration in the expression of survivin. The highest concentration of JK-279 altered nuclear morphology in intact cells, showing ''apoptosis-like'' features. No cleavage of procaspase-3, procaspase-9 and PARP, or altered expression of apoptotic proteins Bcl-2 and Bax were detected. At the same time, PS externalization and internucleosomal DNA cleavage were observed. Partial necrosis was detected as well. Our results demonstrate that cytotoxicity of diazene JK-279 is mostly the consequence of caspase-independent cell death, which is in some aspects ''apoptosis-like''. Taking into account the multiplicity of mechanisms used by cancer cells to prevent apoptosis, the drugs (like diazene JK-279) that would activate alternative cell death pathways could provide a useful tool for new types of cancer therapy.
Toxicology in Vitro, 2013
Curcumin is a natural compound that exhibits a wide range of beneficial effects, among them the a... more Curcumin is a natural compound that exhibits a wide range of beneficial effects, among them the anti-tumor activity. Recently it was shown that curcumin may be efficient against drug resistant tumor cells. The goal of our investigation was to examine if human laryngeal carcinoma cells resistant to carboplatin display sensitivity to curcumin, as compared to parental cells, and if this sensitivity is altered, to determine the molecular mechanisms that are responsible for it. We found that carboplatin resistant 7T cells were also cross resistant to curcumin. After the treatment with equimolar concentration of curcumin, 7T cells exhibited lower intracellular accumulation of curcumin which coincided with reduced formation of reactive oxygen species (ROS), diminished lipid and DNA damage followed by reduced induction of apoptosis and expression of heat shock protein 70 (Hsp70), as compared to parental HEp-2 cells. However, after the treatment with equitoxic concentration of curcumin, intracellular accumulation and all the explored downstream effects were similar in both cell lines suggesting that resistance of 7T cells to curcumin was based on its reduced intracellular accumulation. Since curcumin accumulates mostly in the membranes, we explored the fatty acid composition of both cell lines, but we did not find any difference between them.
Pediatric Blood & Cancer, 2010
of 103 specimens were correctly diagnosed by FC. The predictive value of FC RD at day 15 was then... more of 103 specimens were correctly diagnosed by FC. The predictive value of FC RD at day 15 was then analyzed. In B lineage ALL, day 15 FC significantly correlated with Ig/TCR results at day 33 and/or week 12 (P < 0.01). No significant correlation was found in T lineage ALL. Conclusions. Thus, FC with preset uniform gating at day 15 predicts PCR-detectable MRD in B precursor ALL. Presented data may be used to define new polychromatic cytometric diagnostics of MRD including semiautomatic assessment. Pediatr
Haematologica, 2007
We examined whether phosphorylation of Aiolos in primary human lymphocytes is part of the maligna... more We examined whether phosphorylation of Aiolos in primary human lymphocytes is part of the malignant transformation in leukemia. By analyzing mutations at a restriction site we show here that impairment of Aiolos activity in human leukemia is not based on deficient phosphorylation as had been demonstrated in experiments in vitro.
medicina, 2011
... Terapija ciklosporinom traje oko 3 godine. U prosincu 2005. bolesnica boravi u bolnici zbog t... more ... Terapija ciklosporinom traje oko 3 godine. U prosincu 2005. bolesnica boravi u bolnici zbog tranzitorne ishemijske atake (TIA). Ova klinička slika pobudila je sumnju na PNH. Nalaz imunofenotipizacije pe-riferne krvi dokazao je prisustvo populacije stani-ca PNH. ...
Clinical Rheumatology, 2007
The objective of this report is to explore the balance between serum and synovial fluid levels of... more The objective of this report is to explore the balance between serum and synovial fluid levels of interleukin (IL)-18 in children with juvenile idiopathic arthritis (JIA). Blood samples were obtained from 81 children with JIA and 18 control children. Synovial fluid samples were collected from 16 children with oligoarticular JIA. Concentrations of IL-18 were determined using commercial kit. Patients with systemic JIA had higher serum levels of IL-18 than patients with other forms of JIA or control children, both during the active (median, range: 6,240, 1,600-78,750 pg/ml) and inactive (1,615, 513-3,270 pg/ml) phase of disease [analysis of variance (ANOVA), P<0.05). Levels of IL-18 in sera of children with oligoarticular JIA (255, 89-4,342 pg/ml) were similar to the respective synovial fluid levels (217, 89-1,245 pg/ml). Serum levels of IL-18 were proportional to the erythrocyte sedimentation rate and levels of C-reactive protein, but inversely proportional to the haemoglobin levels. IL-18 appears to be an important mediator of systemic JIA, while it seems of a lesser relevance in pathogenesis of other JIA forms. Therefore, inhibition of IL-18 might be a base for a successful biological therapy for systemic JIA.
Clinical Neurology and Neurosurgery, 2004
Recent data indicate that the apoptotic process, mediated by the CD95/Fas cell surface receptor, ... more Recent data indicate that the apoptotic process, mediated by the CD95/Fas cell surface receptor, is impaired in activated lymphocytes of patients with relapsing-remitting multiple sclerosis. Using flow cytometric-immunophenotyping, we analyzed the expression of CD95/Fas on peripheral blood CD4+ and CD8+ T lymphocytes (PBL) in 10 MS patients in relapse, and the effect of pulse corticosteroid therapy on the apoptosis of autoreactive lymphocytes. The proportions of CD8+ and CD8+CD95+ T lymphocytes were significantly higher in MS patients in relapse before than after pulse corticosteroid therapy. Conversely, the proportions of CD4+ and CD4+CD95+ T cells were significantly lower before than after therapy, but not significantly different from healthy persons. The different expression of CD95/Fas on peripheral blood CD8+ T lymphocytes in relapsing RRMS and in healthy controls suggests a possible involvement of apoptosis in the pathogenesis of MS. Our results also show that pulse corticosteroid therapy influences the CD95/Fas expression on CD8+ and CD4+ T lymphocytes in patients with RRMS.
Cell Biology and Toxicology, 2006
We have previously synthesized various diazenecarboxamides (subsequently referred to as diazenes)... more We have previously synthesized various diazenecarboxamides (subsequently referred to as diazenes) that were cytotoxic to several tumor cell lines. To increase their biological activity, the structure has been modified appropriately. In the present study we examined the effects of N(1)-phenyl-N(2)-(2-pyridinylmethyl)diazenedicarboxamide (RL-337) obtained from the previously examined cytotoxic compound N(1)-phenyl-N(2)-(2-pyridinyl)diazenecarboxamide (JK-279), and compared them with those of diazene JK-279. Using a modified colorimetric MTT assay, the cytotoxicity of RL-337 was determined on human cervical carcinoma HeLa cells, glioblastoma A1235 cells, and prostate adenocarcinoma PC-3 cells. The possible synergistic effect of diazene RL-337 with cisplatin, doxorubicin, and vincristine, and its influence on intracellular GSH content was examined on HeLa cells. Diazene RL-337 was cytotoxic against all three human tumor cell lines, being more cytotoxic to HeLa cells than diazene JK-279. The higher efficacy of RL-337 than of JK-279 can be connected with higher basicity of the 2-picoline moiety present in the former diazene comparing with the pyridine fragment that is a part of the latter. The diazene RL-337 acted synergistically with cisplatin, doxorubicin, and vincristine (diazene JK-279 exhibited synergistic effect only with cisplatin). Glutathione (determined by Tietze&#39;s method) was not a target molecule of diazene RL-337 (but was for JK-279, as shown earlier). After just 1 h treatment with diazene RL-337, the cells started to lose membrane integrity. There was no cleavage of caspase-3 in RL-337-treated samples, and the majority of cells died 6 h after the treatment through necrosis (previously, apoptosis-like cell death was detected for diazene JK-279). Thus, although diazenes JK-279 and RL-337 are very similar in their structure, they exhibit widely different biological activity.
Cell Biology and Toxicology, 2007
Lithium is the most widely prescribed mood stabilizer, but the precise molecular mechanisms under... more Lithium is the most widely prescribed mood stabilizer, but the precise molecular mechanisms underlying its therapeutic function are not yet fully elucidated. Recent preclinical and clinical evidence indicates its neuroprotective and neurotrophic effects. As a tight coupling of function and metabolism in the central nervous system between glial cells and neurons has recently been detected, lithium&#39;s effect on glial cells may participate also in the total beneficial effects of this drug. The aim of the present study was to analyze molecular mechanisms induced in human glioblastoma A1235 cells by the treatment with lithium, especially its influence on the expression of apoptosis-related genes. Lower levels of lithium (0.5 mmol/L and 2 mmol/L) did not cause any cytotoxicity or changes in the cell cycle phase distribution following 72 h incubation. However, a higher dose (20 mmol/L) was cytostatic for glioblastoma cells, and caused accumulation of cells in G(2)/M phase of the cell cycle. The treatment with lithium did not alter the levels of Bcl-2 or procaspase-3 and did not cleave PARP, but increased the levels of p21(WAF/Cip1) and survivin. Thus, increased expression of p21(WAF/Cip1) (a protein with antiapoptotic function), and survivin (a protein that supports the growth of cells by suppression of apoptosis and promotion of cell proliferation) may be the early events in the long-term cell response to lithium that are involved in the beneficial effects of this drug.
American Journal of Hematology, 2009
Ikaros, Aiolos, and Helios are transcription factors important in lymphocyte differentiation and ... more Ikaros, Aiolos, and Helios are transcription factors important in lymphocyte differentiation and development . One of the most interesting aspects of the Ikaros family members is that they are expressed as multiple splice variants and proteins arising from alternatively spliced transcripts may act as dominant negatives. Although expression of these short isoforms has been linked to lymphoid and myeloid leukemia the comparison of Ikaros members mRNA expression level has not been reported. Here we show, by means of real time qRT-PCR method, a quantitative distribution of Ikaros, Aiolos, and Helios mRNA in hemopoietic cells of patients with lymphocytic leukemia, represented by the most frequent B cell chronic lymphocytic leukemia (CLL) and acute lymphocytic leukemia (T cell ALL and common ALL), and compared with the acute leukemia of the myeloid lineage, acute myeloid leukemia (AML). We found that the relative quantity of Ikaros and Helios mRNA was similar in all subgroups. However, analysis of Aiolos showed a clear difference among groups because of its lower expression in all types of acute leukemia investigated. Our results associating a lower Aiolos expression with acute leukemia point to Aiolos's role in human lymphocyte development, as previously shown in mice.
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Papers by Klara Dubravcic