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Biomedical subjects

A Chybicka

Publications and source records attributed to A Chybicka.

At least 19 recordsLinked to original sources
PubMed2005

Twenty years of Polish experience with three consecutive protocols for treatment of childhood acute myelogenous leukemia.

Until 1983, results of treatment of acute myelogenous leukemia (AML) in Poland with different regimens were very poor. In 1983, the Polish Pediatric Leukemia/Lymphoma Study Group introduced a unified treatment protocol--a modified version of BFM-83 protocol. This led to an increase in the curability of AML from 15% to approximately 32%. In 1994, a modification was made: the high-risk patients (>5% blasts in bone marrow on day 15 of therapy and all M5 cases) received two additional cycles with intermediate-dose cytarabine (ID-ARAC). This led to a nonsignificant improvement in the 5-year event-free survival (EFS) rate from 32 to 36%. A new treatment protocol employing idarubicin in place of daunorubicin was introduced in 1998 and produced better initial responses, increase in the number of patients attaining remission after induction therapy and proportional increase of standard-risk patients. The probability of 5-year EFS (pEFS) for the whole group of patients increased from 36 to 47%. In standard- and high-risk groups, the 5-year pEFS was 62 and 33%, respectively. The probability of 5-year disease-free survival was 58% in the whole group, and there were no differences between risk groups. Unsatisfactory treatment results in children classified into the high-risk group are principally due to the low remission rate.

Acute Disease↗
PubMed2004

Allogeneic hematopoietic cell transplantation from alternative donors in children with myelodysplastic syndrome: is that an alternative?

Allogeneic hematopoietic cell transplantation (HCT) in children with myelodysplastic syndrome (MDS) remains a challenge due to the toxic conditioning regimens administered to minimize the risk of relapse in the HLA-matched or of graft rejection in the HLA-mismatched settings. In the absence of matched sibling donors, alternative donors such as unrelated and/or partially matched family sources remain risky, yet the only available, options. Herein we report the results of HCT from alternative donors in 14 children with different subtypes of MDS (juvenile myelomonocytic leukemia [JMML] n = 9; myelodysplastic syndrome [MDS] refractory anemia n = 3; MDS refractory anemia with excess of blasts in transformation n = 2) transplanted at our institution. The median time from diagnosis to HCT was 9 months (range 4 to 90 months). The variety of HCT types included: unrelated peripheral blood progenitor cell transplantation (PBPCT) (n = 2), partially matched family donor T-cell-repleted BMT/PBPCT (n = 6), and haploidentical T-cell-depleted PBPCT (n = 6). Five of 14 patients remain alive at 7 to 37 months posttransplant (including two patients after partially matched family donor BMT, two patients after haploidentical T-cell-depleted-PBPCT, and one after unrelated-PBPCT, respectively). The major complications were: primary graft failure in the haploidentical T-cell-depleted-setting or graft-versus-host disease (GvHD) in T-cell-repleted partially matched family or unrelated settings, respectively. Despite the high transplant-related mortality rate in this series, allogeneic HCT from alternative donors remains an interesting solution for children with MDS who lack matched sibling donors. Due to improved immune reconstitution, despite an increased risk of GvHD, T-cell-repleted transplants from single HLA-mismatched family donors remain a valuable option for children without matched donors. Splenectomy prior to HCT may positively affect the posttransplant course in patients with overt splenomegaly for example those afflicted with JMML.

Adolescent↗
PubMed2004

Prompt initiation of immunotherapy in children with an increasing number of autologous cells after allogeneic HCT can induce complete donor-type chimerism: a report of 14 children.

Immunotherapy consisting of withdrawal of immunosuppression and/or donor lymphocyte infusions was initiated in 14 children (10 acute lymphoblastic leukemia, three acute myeloblastic leukemia and one myelodysplastic syndrome) with an increasing amount of autologous DNA (increasing mixed chimerism, inMC) detected after allogeneic hematopoietic cell transplantation (HCT). Two children were in relapse when inMC was detected, 12 remained in CR. Children with overt relapse at the time of cessation of cyclosporine A (CsA) received "debulking" chemotherapy. One of them developed acute grade III graft-versus-host disease, converted to complete donor chimerism (CC) and achieved remission. Another patient did not respond and died due to disease progression. Among 12 children treated in remission, 11 responded with conversion to CC, seven after CsA withdrawal and four after DLI. One patient did not respond, rejected the graft and died due to pulmonary aspergillosis. In one patient, the response was transient, inMC reappeared and frank relapse occurred. One patient developed isolated CNS relapse despite conversion to CC, but achieved CR after conventional treatment. One child died in CC due to infection. No graft-versus-host disease (GvHD)-related death occurred. A total of 10 patients are alive in remission with median follow-up of 338 days. Our results support the hypothesis that chimerism-guided immunotherapy after alloHCT may prevent progression to hematological relapse.

Acute Disease↗
PubMed2004

Remaining problems and controversies in the management of childhood head and neck soft tissue sarcomas: Retrospective (national) Multicenter Study of the Polish Pediatric Solid Tumors Group.

Soft tissue sarcomas in children are a heterogeneous group of malignant diseases. Among these, tumors localized in the head and neck region are especially difficult to treat. While multidisciplinary care has dramatically improved the prognosis of sarcoma patients, their treatment remains uncertain because of demand on radical surgical resection of the tumor. Achieving cure without deforming or mutilating the child remains the primary goal of treatment. This study is the multicenter (nationwide, 11 Polish centers) retrospective analysis of the treatment results in children having soft tissue sarcoma in the head and neck region during the previous decade (from 1991 to 2001). Late effects of the treatment are documented in long-term survivals. Eighty-five children from 1 to 212 months of age were included. Different multimodal treatment protocols were utilized (CWS-91, SIOP-MMT-91, and CWS-96). The median observation time was 25 months. Data on long-term effects were collected in 34 long-term survivals. Complete remission was achieved in 68 (80%) patients. Primary treatment failure occurred in 13 (15.3%) patients, all of whom succumbed in disease progression. Relapse occurred in 21 (30.9%) patients primarily achieving complete remission. Second primary neoplasm occurred in 3 children. The estimated 5-year event-free survival and the 5-year total survival rates for the whole group are 0.38 and 0.55, respectively. The main late effect documented in long-term survivals were cosmetic defects in 12 (35.3%) and visual field deficit or blindness in 8 (26.5%). Despite substantial improvement of the prognosis of pediatric soft tissue sarcomas, the multimodal treatment of head and neck region tumors remains controversial. Improved long-term outcome and focusing on psychosocial difficulties raise the important and difficult problem of functional results and cosmesis. Tumors localized in the orbit carry an excellent prognosis. However, the main late sequela is vision impairment and cosmetic defect due to the therapy given many years earlier. Two other tumor localizations--the parameningeal and nonparameningeal ones--still have bad prognosis. The observations made in this study confirm that main prognostic factors are the size of the primary tumor and the tumor stage. The worst prognosis remains invasive tumor (T2-stage) with a size over 5 cm. Individually adjusted multimodal therapy, which imperatively needs to be radical, though not mutilating, might minimize the late effects. Psychosocial problems in long-term survivors need to be focused on at the national level and better support must be provided in the future, involving a team of different medical and paramedical profiles.

Adolescent↗
PubMed2004

The role of nuclear morphometry in prediction of prognosis for rhabdomyosarcoma in children.

AIMS: To determine whether nuclear morphometry can be used in pretreatment diagnostic procedures to guide the therapy of childhood rhabdomyosarcoma (RMS). MATERIALS AND METHODS: Biopsy specimens obtained from 108 patients with rhabdomyosarcoma aged between 1 and 217 months treated in 12 paediatric oncology departments in Poland were evaluated. There were 65 (60.2%) specimens of embryonal rhabdomyosarcoma (RME), 32 (29.6%) of alveolar RMS (RMA) and 11 (10.2%) cases of undifferentiated RMS (RMU). The clinical data from all analysed patients were evaluated. Nuclear morphometry was performed semiautomatically on haematoxylin-eosin-stained sections using the MultiScan v.8.08 Computer Scanning System and an Olympus BX 50 microscope with a x 40 magnification lens. RESULTS: In the RMA subtype cells with spindle-shape nuclei were less common (P = 0.013) and cell nuclei were generally more round in comparison with RME (P = 0.033). The clinical outcome was better if the nuclei seen in biopsies of RMS were more spindle-shaped (event-free survival 0.51 and 0.23, respectively; P = 0.04) or more cells with spindle-shaped nuclei were observed (event-free survival 0.5 and 0.28, P = 0.035). RME patients with small nuclei had a better outcome then patients with large nuclei (P = 0.014). In the RMA/RMU group, patients with small tumour cell nuclei had a worse prognosis than patients with larg tumour cell nuclei (P = 0.046). CONCLUSIONS: Nuclear morphometry is a useful tool in the assessment of children with RMS. Additionally, certain morphometric parameters could be easily applied in a selection of patients with good prognosis.

Biomarkers, Tumor↗
PubMed2004

Antitumor activity of bacteriophages in murine experimental cancer models caused possibly by inhibition of beta3 integrin signaling pathway.

Bacteriophages (phages) as bacterial viruses are generally believed to have no intrinsic tropism for mammalian cells. In this study the interactions between phages and various eukaryotic cells were investigated. Binding of phages to the membranes of cancer and normal blood cells was observed. Moreover, it was shown that the wild-type phage T4 (wtT4) and its substrain HAP1 with enhanced affinity for melanoma cells inhibit markedly and significantly experimental lung metastasis of murine B16 melanoma cells by 47% and 80%, respectively. A possible molecular mechanism of these effects, namely a specific interaction between the Lys-Gly-Asp motif of the phage protein 24 and beta3-integrin receptors on target cells is proposed. It was also shown that anti-beta3 antibodies and synthetic peptides mimicking natural beta3 ligands inhibit the phage binding to cancer cells. This is in line with the well-described beta3 integrin-dependent mechanism of tumor metastasis. It is concluded that the blocking of beta3 integrins by phage preparations results in a significant decrease in tumor invasiveness.

Animals↗
PubMed2003

A prospective analysis of immune recovery in children following allogeneic transplantation of t-cell-depleted or non-T-cell-depleted hematopoietic cells from HLA-disparate family donors.

Transplantation of HLA-disparate hematopoietic stem cells from related donors is an alternative for the treatment of patients lacking an HLA-matched family or unrelated donor. In the cases of a single HLA antigen disparity, extensive T-cell depletion (TCD) is not required, yet antithymocyte globulin (ATG) must be administered to prevent GvHD or graft rejection. The major concern after HLA-mismatched transplants remains immune reconstitution. Therefore, we prospectively studied the recovery of lymphocyte subsets among 22 children transplanted from partially HLA-matched family donors. We compared two groups of patients: (1) the TCD group included children (n = 1.3) who received grafts after TCD (MACS) due to an HLA disparity for more than one antigen; (2) The non-TCD group included children with either one HLA-mismatched antigen, n = 7; or more than one disparate antigen (n = 2) who received T-cell-repleted grafts and ATG. The study demonstrated rapid NK cell reconstitution among the TCD group. TCD compromised T-cell reconstitution, thus preventing GvHD, but resulting in a higher incidence of severe infectious complications, graft rejection, and disease relapse. Increasing mixed chimerism required the application of donor T-cell addbacks, thus potentiating the risk of GvHD. Primary graft rejection occurred in eight children, who required further transplants. In the non-TCD group faster T-cell reconstitution (predominantly CD3+CD8+ cells) resulted in a lower rate of relapse and infection, yet a higher rate of GvHD, including two fatal cases. Due to improved immune reconstitution, in spite of an increased risk of GvHD, non-TCD transplants from single HLA-mismatched family donors remain a valuable option for children without matched donors.

Adolescent↗
PubMed2003

Clinical value of the flow cytometric method for measuring lymphocyte subset activation: spontaneous activation of T-cell subpopulations is associated with acute GvHD.

Thymidine ((3)H-TdR) incorporation remains the most commonly used method to quantifying T-cell proliferation. This method, however, does not provide information about specific lymphocyte subpopulations responding to different stimuli. In our study, we modified previously described nonradioactive flow-cytometric T-cell activation assay measuring the expression of a CD69+ antigen on T-cell subsets and applied it to analysis of lymphocyte subsets activation/proliferation in children after allogeneic hematopoietic cell transplantation (HCT). We compared the percentage of spontaneously activated lymphocyte subpopulations (background) and the percentage of PHA-P, PWM, and SEB-stimulated cell subsets from two groups of patients: group 1, children with Graft versus Host Disease (GvHD) and group 2, children without any signs of GvHD at the time of analysis. High rate of spontaneous T-cell subset activation was found in group 1 with CD3+CD8+Ts cells being the most affected cell population. High background activation of Th and B cells correlated with the occurrence of autoimmune phenomena posttransplant. Rapid quantification of CD69+ expression on unstimulated and stimulated T-cell subsets proved to be a valuable method for monitoring children after allogeneic HCT. High proportion of activated, unstimulated Ts cells observed in the GvHD group may underline the critical role of CD3+CD8+ cells in the pathogenesis of GvHD. Thus in future immunosuppressive therapy may be adjusted according to the proportion of activated Ts cells.

Bone Marrow Transplantation↗
PubMed2002

In vitro comparative antileukemic activity of various glucocorticoids in childhood acute leukemia.

Resistance to glucocorticoids is nowadays one of the strongest adverse risk factors in the treatment of childhood acute lymphoblastic leukemia (ALL). Differential in vitro antileukemic activity of various glucocorticoids and their cross-resistance pattern in childhood acute lymphoblastic and myeloblastic leukemia was determined by means of the MTT assay in 49 successfully tested samples of childhood acute leukemia. The equivalent antileukemic concentrations of respective drugs against lymphoblasts in de novo ALL samples were: 35 microM of hydrocortisone; 8 microM of prednisolone; 1.6 microM of methylprednisolone; 0.47 microM of dexamethasone and 0.23 microM of betamethasone. In comparison to initial ALL samples, the group of relapsed ALL was more resistant to: prednisolone (38-fold, p=0.004), dexamethasone (>32-fold, p=0.004), methylprednisolone (37-fold, p=0.039), betamethasone (38-fold, p=0.018) and hydrocortisone (33-fold, p=0.030). The group of acute myeloid leukemia (AML) samples were resistant to: prednisolone (>83-fold, p<0.001), dexamethasone (>32-fold, p<0.004), methylprednisolone (>65-fold, p=0.003), betamethasone (>66-fold, p=0.004) and hydrocortisone (61-fold, p=0.007), when compared to ALL at presentation. A significant cross-resistance between all used glucocorticoids as well as between glucocorticoids and other tested anti-leukemic drugs was found. In some individual cases in vitro glucocorticoid cross-resistance was less pronounced and relatively good antileukemic activity of betamethasone was observed.

Antineoplastic Agents↗
PubMed2000

[Preliminary results of BFM 96 protocol in treatment of childhood ALL relapse in the experience of the Polish Paediatric Leukaemia /Lymphoma Study Group].

Between 1998 and 1999, 36 children aged from 3 months to 18 years (10 girls and 26 boys) with first relapse of acute lymphoblastic leukaemia were included in the study. The children were treated according to the BFM 96 relapse protocol. There were 24 cases with early (including 9 children with very early) and 12 cases with late relapse ( BM-20, local extra BM-6, combined 10). The overall second complete remission (CR) rate was 83,33%. The probability of overall EFS after 2 years was 73,3%. The results obtained with BFM 96 chemotherapy in children with first late relapse are acceptable. For children with early relapses, megachemotherapy with BMT in second remission should be used.

Adolescent↗
PubMed2000

[Results of treatment of children with chronic myelogenous leukaemia (CML) obtained by the Polish Paediatric Leukaemia/Lymphoma Study Group].

Retrospective analysis of 102 children with CML from 9 paediatric centres in Poland has been performed. A total number of 102 children: 58 boys and 44 girls aged 1-17 years (median 9.4 years old) with CML, treated in the period 1975-1999 were included in the study. Forty eight of 102 (47.1 %) children were treated with cytostatic drugs without IFN alpha: busulfan, hydroxyurea, 6-mercaptopurine or etoposide (VP-16). Fifty four of 102 (52.9%) patients were treated with interferon alpha (IFN alpha) after cytoreductive pretreatment. Thirty out of 102 (29.4%) patients underwent stem cell transplantation (SCT): 24 - matched related donor allo-BMT, 2 - matched unrelated donor allo-BMT, 1 - partially matched related donor T-cell depleted allo-PBPCT, 1 - syngeneic allo-BMT and 2 - autologous PBPCT. Overall survival analysis revealed that 46 of the 102 (45.1%) children remained alive: 5/35 (14.3%) children treated with cytostatics alone, 22/37 (59.5%) children treated with IFN alpha and 19/30 (63.3%) children treated with SCT. Among SCT survivors there are 10/17 (58.8%) children treated with IFN alpha prior to SCT and 9/13 (69.2%) children treated with cytostatics alone prior to SCT. The probability of 5-year survival is 0.51 in the group treated with SCT (median follow-up 58 months); 0.43 in the group treated with IFN alpha (median follow-up 53 months) and 0.23 in the group treated with cytostatics (median follow-up 31 months). Our data show, that BMT is the treatment of choice in CML in children. IFN alpha could be successfully applied as an alternative treatment for those, who do not have a suitable donor for allogeneic SCT. Better outcome in post BMT children, who were not treated with IFN alpha prior to SCT requires confirmation by studies on larger groups of patients. However, it seems to be justified to stop IFN alpha therapy at least 3 months before SCT. The main reason for unsuccessful treatment outcome in patients with CML in Poland remains the still insufficient access to MUD-BMT.

Adolescent↗
PubMed2000

[Results of the treatment of myelodysplastic syndrome (MDS)obtained by the Polish Paediatric Leukaemia /Lymphoma Study Group].

Sixty children with MDS treated in six centres of the Polish Paediatric Leukaemia/Lymphoma Study Group in the period 1975-1999 were included in the study. In 20 children RAEB-T, in 13 RA, in 21 RAEB and in 6 CMML were diagnosed. Our own and literature data showed that BMT is the best therapy for children with MDS. We need a new comprehensive protocol for the diagnosis and treatment of children with MDS in Poland.

Adolescent↗
PubMed2000

[Results of treatment of osteosarcoma in children according to the SFOP-94 protocol in the experience of the Polish Paediatric Solid Tumour Study Group].

Between April 1994 and December 1999, 34 children aged from 5 to 20 years (23 females and 11 males) suffering from osteosarcoma, were treated according to the SFOP-94 protocol. The primary preoperative chemotherapy consists of adriamycin and high-dose methotrexate administration. There were 28 patients with non-metastatic tumours of the extremities and 6 children presented disseminated disease with pulmonary metastases. The primary localization included femur - 20 patients, tibia - 9 patients and humerus - 5 patients. In 26 patients limb-salvage surgery was applied. The programme of chemotherapy was changed in 4 children because of toxicity of methotrexate (1 patient) and progression of disease (3 patients). 26 out of 34 (76,5 %) children are alive including 24 out of 28 patients with localized disease. EFS calculated according to Kaplan-Meier analysis was 60 % at 67 months.

Adolescent↗
PubMed2000

[G-CSF and GM-CSF in treatment of neutropaenia after chemotherapy in children with neoplasms].

A total number of 608 cycles of G-CSF and/or GM-CSF was applied in 280 patients aged from 6 months to 20 years during neutropaenia associated with chemotherapy of children's neoplasms (NHL-124, NBL-42, RMS-36, Nephroblastoma-18, Osteosarcoma-17, Ewing's Sarcoma-14, Hepatoblastoma-6, Neurofibrosarcoma-6, PNET-5, Medulloblastoma-3, Fibrohistiocytoma-3, Angiosarcoma-2, other - 4). G-CSF - Neupogen (Filgastrim, Hoffman La Roche - 492 cycles) and GM-CSF - Leucomax (Molgramostim, Shering Plough - 116 cycles) were administered 5 mg/kg/day s.c. Forty one children with malignancies (NHL -21 cases, solid tumours -17) treated before cytokines were in use served as a control group. Our study demonstrated that G-CSF and GM-CSF therapy, gives a shorter period of neutropaenia, reduction of the number of febrile days, decreased frequency of infection and shortened its duration.

Adolescent↗
PubMed1998

[The efficacy of BFM-90 program in the treatment of acute lymphoblastic leukemia in children in the studies of Polish pediatric leukemia/lymphoma group].

Between years 1993 and 1998, 113 children aged from 6 months to 18 years (41 girls and 72 boys) with first relapse of acute lymphoblastic leukaemia (ALL) were included in the study. All children were treated according to BFM-90 relapse protocol. Thirty-two cases were classified as very early relapses, 56 as early and 25 as late relapses. Sixty-one children had isolated bone marrow relapse, in 30 children extramedullary relapse occurred (in 21 children in central nervous system and in 16 children in testes). There were 23 combined relapses. Remission was achieved in 12 children with very early relapse (78.12%), 32 children with early relapse (85.71) and 19 children with late relapse (96%). Event-free survival in 30 months of follow-up was 29.2%, 59.0% and 73.2% for very early, early and late relapses, respectively. Sixteen children with relapsed ALL after chemotherapy according to BFM-90 relapse protocol underwent high-dose therapy with hematopoietic stem cell transplantation (in 3 cases autologous and in 13 cases allogeneic). In 6 children isolated bone marrow relapse occurred after transplantation, all of them died during subsequent chemotherapy. Ten children is alive and well from 2 to 43 months after transplantation. The results obtained with BFM-90 chemotherapy in children with first early relapses are not acceptable. Such patients require high-dose chemotherapy and transplantation of hematopoietic progenitor cells.

Adolescent↗