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Biomedical subjects

J Kadar

Publications and source records attributed to J Kadar.

13 recordsLinked to original sources
PubMed2000

Competitive cytokeratin 19 RT-PCR for quantification of breast cancer cells in blood cell suspensions.

Detection of residual tumor cells in BM and PBPC products has been correlated with worse outcome of breast cancer patients. Still, there is a considerable demand for studies investigating the influence of the actual tumor cell number on prognosis, as quantification routinely has been cumbersome and time consuming and, thus, was evaded. We developed and evaluated a competitive RT-PCR-ELISA assay for cytokeratin 19 (CK19) with standard curve quantification that allows quantification of multiple samples within a working day; mRNA isolation, RT-PCR reaction, and automated ELISA detection were carried out using commercial kits. Results were expressed as OD420nm ratios of CK19 and an internal competitor. Values were then converted into tumor cell numbers using a standard curve of MCF-7 tumor cells. The assay had high specificity because of primers and capture probes with great heterogeneity to both published pseudogenes, which was confirmed by BLAST sequence alignment. We achieved a sensitivity of detecting 1 tumor cell per 10(6) mononuclear cells (MNC). Between-batch precision (n = 8) for quantification was consistent and reasonable, with a coefficient of variation around 25%. Therefore, this assay should be suitable and sufficient for routine quantification of tumor cell numbers in BM or PBPC samples.

Antibodies↗
PubMed1998

Sustained decrease of peripheral lymphocytes after allogeneic blood stem cell aphereses.

48 healthy donors underwent peripheral blood stem cell (PBSC) apheresis for allogeneic transplantation beginning on day 4 of G-CSF (2 x 5 microg/kg) mobilization. In one to four (median two) large-volume mononuclear cell aphereses, a median of 55.9 x 10(9) of lymphocytes (range 21.0-109.2 x 10[9]) were collected, an amount comparable to lymphocyte numbers removed by therapeutic lymphaphereses in autoimmune diseases. Mean peripheral lymphocyte counts decreased from premobilization values of 2.31 x 10(9)/l to 1.31 x 10(9)/l at a median of 34 d (1 month) and 1.53 x 10(9)/l at a median of 327 d (11 months). The decrease in peripheral lymphocyte counts was significantly correlated with the number of lymphocytes removed and the number of aphereses. Neutrophil and platelet counts returned to normal values after 1 month whereas monocyte counts and haemoglobin concentrations were significantly decreased at 1 month but not at 11 months.

Female↗
PubMed1997

Detection of melanoma cells in peripheral blood stem cell harvests of patients with progressive metastatic malignant melanoma.

The detection of melanocyte-specific messenger RNA in patients with malignant melanoma suggests the potential contamination of peripheral blood stem cell (PBSC) harvests by neoplastic cells. In this study, the melanocyte-specific transcripts of tyrosinase and Melan-A/MART-1 were used to detect neoplastic cells in PBSC harvests of nine metastatic malignant melanoma patients. Only one patient's PBSC harvest tested positive for tyrosinase. All harvests were negative for Melan-A/MART-1. Our results suggest that contamination of PBSC harvests with neoplastic cells may not contribute to disease progression following high-dose chemotherapy in advanced malignant melanoma.

Adult↗
PubMed1996

[10 years transplantation of bone marrow and hematopoietic stem cells in adults at the Hannover Medical School].

PATIENTS AND METHODS: From January 1986 until August 1995 230 adult patients received an allogeneic or autologous transplantation of bone marrow or hematopoietic blood stem cells. The conditioning and myeloablative treatment regimens were chosen according to the underlying disease and type of transplant. RESULTS: The observation period comprises 1 to 115 months after transplantation. After allogeneic transplantation from HLA-identical family donors, the probabilities of disease-free survival were for acute myeloid leukemia in first complete remission (CR) (n = 35) 77%, for acute lymphoid leukemia in 1st CR (n = 7) 72% and in 2nd CR (n = 10) 40%, in first chronic phase of chronic myeloid leukemia (n = 34) 50% and in severe aplastic anemia (n = 7) 100%. Following myeloablative therapy and autologous transplantation the probabilities of disease-free survival were 47% in relapsed Hodgkin's disease (n = 22) and 42% for relapsed high-grade non-Hodgkin's lymphoma (n = 12). Eight of 10 patients with acute myeloid and 7 of 8 with acute lymphoid leukemia suffered a leukemic relapse after autologous bone marrow transplantation. Three of 8 patients with relapsed testicular cancer survived relapse-free. Treatment failures were due to more advanced acute graft versus host disease after allogeneic transplantation and caused by relapse after autologous transplantation. Current protocols evaluate the allogeneic transplantation of enriched CD34+ blood stem cells. In chronic myeloid leukemia the autologous transplantation of blood stem cells after myeloablative therapy is being studied.

Adolescent↗
PubMed1994

Biocompatibility studies of the single-needle technique in plateletpheresis with the Fresenius AS 104 blood cell separator.

To investigate the biocompatibility of the single-needle technique of the Fresenius AS 104 blood cell separator we analyzed coagulation, complement and hemolysis parameters prior to, during and after five thrombocytaphereses. The data were compared with results of the same parameters from identical donors in the dual-needle procedure. The analysis of bilirubin, lactate dehydrogenase, hydroxybutyrate dehydrogenase and haptoglobin showed no relevant hemolysis. However, changes of the concentrations of coagulation factors XII and XI indicated an activation of coagulation. This was confirmed by an increase of the thrombin-antithrombin III complex during apheresis. No significant change in the complement split product content of the samples obtained during apheresis was found. Complement factors, glucose, lactate, leukocytes, morphology score and thrombocytes were measured in platelet concentrates. The comparison of the platelet products showed no significant differences except for leukocyte contamination. Glucose and lactate concentrations were similar in both procedures. Levels of complement activation markers were not statistically different.

Bilirubin↗
PubMed1992

[Therapeutic thrombocytapheresis in patients with myeloproliferative diseases with the cell separators Fresenius AS 104 and Cobe Spectra: biocompatibility and safety].

We studied biocompatibility, safety and efficiency of the two cell separators AS 104 (Fresenius) and Spectra (Cobe) during therapeutic thrombocytaphereses. Although some patients have very high platelet levels and coagulation as well as circulatory equilibrium is easily disturbed, no important activation of coagulation or complement was observed. In respect to patient's safety both cell separators performed very well.

Biocompatible Materials↗
PubMed1991

[Therapeutic cytapheresis].

In myeloproliferative disorders many complications are caused by circulatory problems due to high leukocyte or platelet numbers and by hyperviscosity. With cytaphereses and mild cytostatics like Azathioprine, these problems are solved quickly and without major side effects. We report about plateletaphereses for polycythemia vera and megacaryocytic myelosis and leukocytaphereses for chronic myelogenous leukemia. In addition, erythrocytaphereses were carried out successfully in a patient with a combination of heterozygous sickle cell anemia and thalassemia minor.

Adult↗
PubMed1991

Erythrocyte apheresis in combination with elimination of fibrinogen and plasma proteins of higher molecular weight in macular disease and in uveal effusion syndrome.

Reduction of hematocrit as well as elimination of fibrinogen and plasma proteins of higher molecular weight are effective approaches in hemorheology. A combination of these therapeutical concepts was applied in one patient with uveal effusion syndrome and in 16 patients with maculopathy. The hematocrit was reduced by erythrocyte apheresis. Fibrinogen and plasma proteins were eliminated by plasma exchange. In the case of uveal effusion syndrome the filling of the scleral veins as well as the uveal effusion were reduced. Furthermore visual function was improved significantly. In 9 of the 16 patients with maculopathy a significant increase in visual acuity occurred. The therapy described lowers significantly the following parameters: hematocrit, fibrinogen, serum proteins, plasma viscosity, erythrocyte aggregation and apparent whole blood viscosity (native and standardized). In a multiple linear regression analysis we found correlations as follows: plasma viscosity correlates with fibrinogen and proteins of higher molecular weight (r = 0.82), erythrocyte aggregation with fibrinogen and proteins of higher molecular weight (r = 0.88), standardized apparent whole blood viscosity with fibrinogen and proteins of higher molecular weight (r = 0.88) and native apparent whole blood viscosity with hematocrit, fibrinogen and proteins of higher molecular weight (r = 0.91).

Blood Component Removal↗
PubMed1990

Induction of human B cell differentiation by Fc region activators. II. Stimulation of IL-6 production.

Fc region fragments derived from the enzymatic cleavage of human IgG have been shown to induce human peripheral blood-derived B cells to differentiate into Ig secreting cells (ISC). The synthetic peptide p23, corresponding to residues 335 to 357 in the Fc region of human IgG1, represents a region of the molecule responsible for stimulation of ISC formation. Fc region-induced ISC formation requires at least two signals; one supplied by Fc region activators and one supplied by a T cell-derived factor(s). In this report we show that the coculture of human PBMC with pFc' or p23, results in the release of factor(s) that resemble IL-6 in its pattern of biologic activity. This conclusion is based on the observations that supernatants from Fc region-stimulated PBMC cultures contained increased levels of elements that scored as positive in two assays for IL-6: the B9.9 hybridoma growth and the CESS cell differentiation assays. Moreover, RNA from Fc region-stimulation PBMC contained increased levels of IL-6 cDNA-hybridizable elements. Finally, it was observed that rabbit anti-IL-6 inhibited the ability of supernatants derived from Fc region-stimulated PBMC cultures to induce B9.9 cell proliferation as well as p23-induced ISC formation in intact PBMC cultures. Fc region fragments induce both monocytes and T cells to produce IL-6. Taken together, these results indicate that IL-6 is produced in Fc region-stimulated PBMC cultures and is involved in B cell activation by these activators.

Adult↗