PubMed Health⌕ Search

Biomedical subjects

J Czyz

Publications and source records attributed to J Czyz.

17 recordsLinked to original sources
PubMed2004

Treatment for primary refractory Hodgkin's disease: a comparison of high-dose chemotherapy followed by ASCT with conventional therapy.

Our previously published study showed promising results of autologous stem cell transplantation (ASCT) in patients with primary resistant Hodgkin's disease (HD). Probabilities of overall survival (OS) and progression-free survival (PFS) at 3 years were 55 and 36%, respectively. The present study was undertaken to compare these results with conventionally treated patients and thus evaluate therapeutic options. Retrospective data on 76 adult patients who underwent ASCT were matched with 76 conventionally treated patients from 17 centers. Comparison of clinical characteristics in both groups showed that ASCT patients were younger (24 vs 31.5 years, P=0.001), more frequently presented with 'B' symptoms (P=0.03) and that more patients treated with chemotherapy (CT) had elevated LDH (P=0.03). In univariate analyses, bulky disease (P=0.0043) and complete resistance to standard CT (P=0.051) were found to be risk factors for OS. In a multivariate survival analysis only bulky disease was found to an independent prognostic factor (P=0.005). There was no difference in survival between the treatment groups with 5 years OS 33.7 (CI: 23-46) in the ASCT group and 35.6% (CI: 25-50) for the CT group (P=0.92). We conclude that ASCT is not superior to standard CT for treatment of patients with primary refractory HD.

Adolescent↗
PubMed2004

Outcome and prognostic factors in advanced Hodgkin's disease treated with high-dose chemotherapy and autologous stem cell transplantation: a study of 341 patients.

BACKGROUND: The reported probability of survival of patients with Hodgkin's disease (HD) following high-dose chemotherapy with autologous stem cell transplantation (HDC/ASCT) is 35-65% at 5 years. The Polish Lymphoma Research Group investigated retrospectively prognostic factors for overall survival (OS) and event-free survival (EFS), and the risk of secondary malignancies in a large series of patients who underwent HDC/ASCT. PATIENTS AND METHODS: The data of 341 consecutive patients treated in 10 centers from 1990 to 2002 were collected and analyzed. RESULTS: The actuarial 5-year OS and EFS were 64% [95% confidence interval (CI) 57% to 71%] and 45% (95% CI 39% to 51%), respectively. In the multivariate model, unfavorable prognostic factors for EFS were less than partial response at the time of ASCT [relative risk (RR), 2.92 (95% CI 1.68-5.08); P<0.001] and three or more previous chemotherapy lines (RR, 2.16; 95% CI 1.42-3.30; P<0.001). These two factors were also associated with unfavorable OS (RR, 3.32; 95% CI 1.90-5.79; P<0.001 and RR, 2.34, 95% CI 1.51-3.64; P<0.001). Five-year cumulative risk of secondary malignancy was 8.4% (95% CI 2% to 13%) and the only identified risk factor was splenectomy (P=0.02). CONCLUSIONS: HDC/ASCT should be considered early in the course of disease for patients with a response after standard therapy.

Adolescent↗
PubMed2002

High-dose chemotherapy with autologous stem cell transplantation is an effective treatment of primary refractory Hodgkin's disease. Retrospective study of the Polish Lymphoma Research Group.

We analysed the treatment outcome of primary refractory HD patients managed with high-dose chemotherapy and haematopoietic cell transplantation. Data of 65 adult patients who underwent HDC/ASCT in nine Polish centres for primary resistant Hodgkin's disease between June 1991 and July 2000 were collected retrospectively. Response rate to HDC/ASC: CR, 54%; PR, 20%; less than PR, 15%; early deaths, 11%. Actuarial 3-year OS and PFS were 55% and 36%, respectively. In multivariate analysis, lack of bulky lymph nodes and use of immunotherapy were favourable factors for both OS and PFS. IPF <3 at the time of transplantation was predictive for PFS. However, the prognostic impact of immunotherapy should be interpreted with caution since this group included more patients who achieved CR after HDC/ASCT. The results of HDC/ASCT are encouraging and confirm earlier findings. The role of immunotherapy should be further investigated in prospective trials.

Adolescent↗
PubMed2001

Expression and cellular distribution of alpha(v)integrins in beta(1)integrin-deficient embryonic stem cell-derived cardiac cells.

beta(1)integrin-deficient (beta(1)-/-) ES cells showed increased differentiation of cardiac cells characterized by reduced adhesion and high beating frequency. Whereas in whole embryoid body outgrowths of beta(1)-/- cells maximum levels of alpha(v), beta(3)and beta(5)integrin mRNA were delayed and transiently upregulated, in cardiac clusters isolated from beta(1)-/- cells, only beta(3)integrin mRNA levels were enhanced in comparison to wild-type (wt) cells. To answer the question, whether alpha(v)and beta(3)integrins may compensate, at least partially, the loss of beta(1)integrin function during cardiac differentiation, the distribution of alpha(v)and beta(3)integrins in beta(1)-/- and wt pacemaker-like cardiac cells was analyzed. A different distribution of alpha(v)and beta(3)integrins in beta(1)-/- v wt cardiac cells was found. In wt cardiac cells, beta(1)integrin was localized in specialized subsarcolemmal regions, in particular, at focal contacts and costameres, but alpha(v)integrin was diffusely distributed. In contrast, in beta(1)-/- cardiac cells, alpha(v)integrin was preponderantly localized at cell membranes, focal contacts and costameres. beta(3)integrin displayed a diffuse pattern both in wt and in beta(1)-/- pacemaker-like cells at early differentiation stages, whereas at terminal stages, beta(3)was colocalized with sarcomeres in wt, but not in beta(1)-/- pacemaker-like cells. Quantitative immunofluorescence analysis revealed increased alpha(v)and beta(3)integrin levels in beta(1)-/- pacemaker-like cardiac cells. Our results led us to conclude that altered cellular distribution of alpha(v)integrin and upregulation of beta(3)integrin correlate with growth and survival of beta(1)-/- cardiac pacemaker-like cells at an early developmental state. However, alpha(v)and beta(3)integrins cannot functionally compensate the loss of beta(1)integrin during terminal differentiation of cardiac cells implicating that cardiomyocytes require specific beta(1)integrin functions for cardiac specialization.

Animals↗
PubMed2001

Differentiation of embryonic stem cell-derived dopaminergic neurons is enhanced by survival-promoting factors.

Here, we describe the generation of viable and dopamine-producing neurons derived from pluripotent mouse embryonic stem cells. Neurotrophic factors in combination with survival-promoting factors, such as interleukin-1beta, glial cell line-derived neurotrophic factor, neurturin, transforming growth factor-beta(3) and dibutyryl-cyclic AMP, significantly enhanced Nurr1 and tyrosine hydroxylase (TH) mRNA levels, whereas En-1, mash-1 and dopamine-2-receptor mRNA levels were not upregulated. In parallel, mRNA levels of the anti-apoptotic gene bcl-2 were found to be upregulated at terminal stages. Double immunofluorescence analysis revealed increased numbers of TH- and dopamine transporter-, but not gamma-aminobutyric acid- and serotonin-positive neurons in relation to synaptophysin-labeled cells by survival-promoting factors. Moreover, high-performance liquid chromatography analysis showed detectable levels of intracellular dopamine. We conclude that survival-promoting factors enhance differentiation, survival and maintenance of dopaminergic neurons derived from embryonic stem cells.

1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine↗
PubMed2001

Embryonic stem cell differentiation: the role of extracellular factors.

Embryonic stem (ES) cells have the capacity to self renew and to differentiate into cellular derivatives of the endodermal, ectodermal, and mesodermal lineages. Therefore, ES cells have been used to analyse the effects of exogenous factors on the developmental pattern during in vitro differentiation. By using an in vitro loss-of-function approach based on beta1 integrin-deficient ES cells, it was found that integrin-dependent mechanisms are involved in the regulation of Wnt-1 and BMP-4 expression. Antagonistic effects of the signalling molecules Wnt-1 and BMP-4, morphogens involved in early differentiation events, have been observed in vivo and in vitro: BMP-4 acts as a potent mesoderm inducer, whereas Wnt-1 plays a critical role in the determination of neuroectoderm. Here, we summarise data of ES cell-derived cardiac, myogenic, and neuronal differentiation of wild type and beta1 integrin-deficient ES cells. We present evidence that the interaction of cells with the extracellular matrix via integrins determines the expression of the signalling molecules BMP-4 and Wnt-1, resulting in the activation of the mesodermal and neuroectodermal lineage, respectively. The results support the idea that the influence of the extracellular 'niche' on the developmental fate of pluripotent stem cells is determined not only by soluble factors, but also by the extracellular matrix.

Animals↗
PubMed2001

Rituximab (Mabthera, Rituxan) in patients with recurrent indolent lymphoma: evaluation of safety and efficacy in a multicenter study.

The objective of this multiinstitutional study was to evaluate the safety and efficacy of rituximab at standard four weekly doses in patients with recurrent indolent lymphoma. Thirty-eight patients entered into this study, 63% had follicular lymphoma and 61% had an IPI score of 2 or more. Median disease duration was 3 yr, median number of prior treatments was three, and 66% of patients responded to the immediate past treatment with a median remission duration of 3 mo. A total of 158 antibody doses were given, including two patients who received two courses of four infusions each. One patient developed acute respiratory failure after the second dose and required assisted ventilation. There was no immediate relationship to the antibody infusion and no evidence of infection. This complication resolved and the patient successfully completed the full course of the antibody treatment. Another patient discontinued therapy after the second dose owing to intolerable fever and painful erythema. Sixty percent of the first, and 20% of subsequent rituximab infusions were associated with infusion-related reactions including mild fever, chills, and occasional skin eruptions. Complete and partial responses were achieved in 24% and 35% of 34 evaluable patients, respectively, for an overall response rate of 59%. The median time to progression/relapse in responding patients was 16 mo (95% CI, 6.4, 25.6) compared with a median of 3 mo duration of response to the immediate previous therapy in these patients. Longer response duration post rituximab monotherapy than with previous treatment in this series of heavily pretreated patients suggests a major role for the antibody in the therapy of patients with indolent lymphoma.

Adult↗
PubMed2001

Anchorage-dependent chick embryo fibroblasts synthesise DNA and proliferate when cultured in multilayered sheets suspended among glass fibres.

Chick embryo fibroblasts (CEFs) spontaneously form multicellular and multilayered sheets suspended on the network of glass fibres which are stabilized by fibronectin containing protein deposits located at cell-to-cell contacts. The cells situated within the sheets are surrounded by the neighbouring cells and their mechanical equilibrium is stabilised by intercellular "parabaric" effects. It was found that CEFs in the sheets retain relatively high mitotic activity corresponding to that observed in sparse monolayer cultures. These cells grew up to much higher local density than in confluent and contact-inhibited monolayer cultures and developed an abundance of microfilament bundles that terminated at vinculin-containing protein complexes. The results presented demonstrate that direct contact with solid substratum, cell-to-cell contacts, local cell density, and intercellular exchange of humoral factors are not directly involved in the density-dependent inhibition of growth observed in monolayer cultures. They also support the concepts concerning the role of mechanical equilibrium of cell membrane and sub-membranous cytoskeleton in the regulation of proliferation of non-transformed cells.

Actin Cytoskeleton↗
PubMed2000

Gap-junctional coupling measured by flow cytometry.

A method is described which reliably quantifies the degree of intercellular communication via gap junctions by combining a dye-loading technique with fluorescence-activated flow cytometry. Our experiments expand former measurements of other groups by analyzing the time- and density-dependent onset of coupling with a fixed ratio of donor to recipient cells. The high sensitivity of this technique provides a better resolution than the microelectrode technique and allows the detection of small changes in gap-junctional coupling by examining a large number of cells in a single experiment. Suspended cells were loaded with the membrane-permeable dye calcein AM, which is intracellularly hydrolyzed by nonspecific esterases, and the resulting polyanionic calcein is thus trapped inside these donor cells. Gap junctions, however, are permeable for this fluorescent dye, as can be observed when suspended donor cells are added to recipient cells (i.e., monolayer cultures) in which case cell-cell contact is established within less than 60 min. In addition, one of these two cell populations can also be stained with a membrane-resident dye (e.g., DiI), which facilitates the identification of different cell populations (donors, recipients, and noncoupled cells) not only by epifluorescence microscopy but also by flow cytometry. Our analyses reveal that junctional coupling depends not only on the connexin type (homo- or heterotypic junction) but also on the origin (species) of the contacting cells (homo- or heterospecific contact). We confirm earlier reports in which homotypic-homospecific coupling was demonstrated with different techniques in connexin-transfected HeLa and RIN cells as well as in BICR/M1R(k) and 3T3/SV40 cells. In contrast to other publications, we show that a significant heterotypic-homospecific coupling between Cx40- and Cx43-HeLa transfectants can be resolved, whereas no coupling was detected for heterotypic-heterospecific contacts between Cx40-HeLa transfectants and the Cx43-expressing cell lines BICR/M1R(k), 3T3/SV40, and RIN.

3T3 Cells↗
PubMed1996

[Evaluation of treatment results in patients with polycythemia rubra vera].

The study was aimed to assess the efficacy of busulphan treatment in patients with polycythemia rubra vera (PRV). The group of 74 patients (mean age 60 years, range: 40-81) was studied, including 38 females, 36 males. The remission was achieved in all cases; the mean time of remission was 33 months (range 3-200), the mean busulphan dose necessary to reach the first PRV remission was 266 mg (range: 76-600). The associations between hemoglobin level, white blood cells, neurocytes, platelet counts at diagnosis and the mean cumulative busulphan dose necessary to obtain the first PRV remission as well as between above parameters and the mean duration of the first PRV remission was estimated. The mean duration of the first PRV remission was significantly (P < 0.03) longer in patients with neurocyte count below 9.6 G/l (9.6 x 10(3)/mm3) as compared to those with higher levels; except it, no relationship were noticed between above parameters. The results of the study confirmed that busulphan is an effective and safe drug for patients with PRV.

Adult↗
PubMed1995

[Isolated infiltration of optic nerves in the course of acute lymphoblastic leukemia].

51 years old male with acute lymphoblastic leukaemia in hematological remission was admitted to the hospital due to abrupt loss of vision. The cause of estimated complication was symmetrical infiltration of optical nerves. No other symptoms of leukaemia were observed at the time. In spite of combined radio- and chemotherapy no improvement was achieved. Two months later leukaemia relapse in the bone marrow was observed. The patient died of septic complications during reinduction treatment.

Bone Marrow Neoplasms↗
PubMed1994

Efficacy of the Frame and Hu mathematical model for the quantitative analysis of agents influencing growth of chick embryo fibroblasts.

The experiments on the effect of various sera and substratum surface area upon growth of chick embryo fibroblast-like cells in secondary cultures are described and discussed on the grounds of a mathematical model for growth of anchorage-dependent cells proposed by Frame and Hu [14]. The model and presented results demonstrate the mutual independence of the effects of agents influencing the rate of cell proliferation (i.e. accelerating or retarding growth) and the agents that modify the limitation of cell proliferation (i.e. maximum cell density at confluence). The model proposed by Frame and Hu due to its relative simplicity offers an easy mode of description and quantitative evaluation of experiments concerning cell growth regulation. It is shown that various sera added at constant concentration significantly modify the rate of cell proliferation with little effect upon the maximum cell density attainable. The cells grew much more slowly in the presence of calf serum than in the presence of chick serum and the addition of iron and zinc complexes to calf serum significantly accelerated cell growth. An increase in the substratum surface area by the addition of glass wool to culture vessels significantly increased cell density per constant volume of medium even when retardation of growth was observed. The results presented point to the need of direct cell counting for estimation of cell growth curves and discussion of effects of agents influencing parameters characterizing cell proliferation.

Aneuploidy↗
PubMedDate not supplied

A new model for the research into rhythmic contraction activity of cardiomyocytes in vitro.

Heart cells continue to contract rhythmically after isolation and in culture in vitro. We describe a model of heart preparation in vitro that permits quantitative research on the frequency of contractions of cardiomyocytes. The chick embryo heart explants placed on a network of elastic glass fibers continued beating for months, recorded and analyzed with the methods of computer-assisted image analysis. The efficacy of this experimental model for the screening of effects of various agents on the frequency of contractions was examined by following the effects of nifedipine, caffeine, ethanol, and benzamide. The reversibility of the effects and the reproducibility of results were demonstrated quantitatively. The significance of a mechanical elastic load provided by glass fibers for the preservation of long-lasting contractile activity of cardiomyocytes is discussed and the common occurrence of oscillatory contraction processes in various eucaryotic cells is noted.

Animals↗
PubMedDate not supplied

[Leukocyte doubling time as a prognostic factor in chronic lymphocytic leukemia].

The authors present clinical analysis of 57 patients with chronic lymphocytic leukaemia, observed during the first three stages of the disease according to Rai classification. The analysis of the presented material has confirmed the clinical and prognostic value of this classification, but at the same time has shown differences of clinical course of the disease in particular patient. There was no sex neither age effect on the clinical course of chronic lymphocytic leukemia. The authors confirmed that leukocyte doubling time is a very useful prognostic factor in chronic lymphocytic leukaemia.

Adult↗