Biomedical subjects
B Kasper
Publications and source records attributed to B Kasper.
High-dose chemotherapy with autologous peripheral blood stem cell transplantation for bone and soft-tissue sarcomas.
The role of high-dose chemotherapy (HDCT) with PBSCT in the treatment of bone and soft-tissue sarcomas is not established. In total, 27 patients (15 female, median age at TPL 30.6 years (range: 13-59)) were analyzed (Ewing sarcoma family n=8, osteosarcoma n=6, MPNST (malignant peripheral nerve sheath tumor) n=4, synovial sarcoma n=3, liposarcoma n=2, leiomyosarcoma n=2, rhabdomyosarcoma n=1, meningosarcoma n=1). Following chemotherapy and surgery complete remission (CR) (n=9), partial remission (PR) (n=10), stable disease (SD) (n=2) and progressive disease (PD) (n=6) were reached prior HDCT. Different HDCT conditioning regimens were used. One patient died due to cardiac arrest after HDCT. Except hematologic side effects, no WHO grade III-IV complications were observed. Four patients died within 6 months due to PD, disease recurred in another seven patients and led to death, 15 patients are alive with/without disease. The median progression-free survival (PFS) is 12.0 months (range: 0-58), in nine CR patients median PFS is 25.8 months (range: 3-58). Although the role of HDCT in the treatment of sarcomas is not defined, a subgroup of patients who achieved CR before HDCT could benefit from this therapy.
Combination therapy of Thalidomide and Peginterferon in patients with progressive multiple myeloma.
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[Diagnostic imaging in refractory temporal lobe epilepsy. A comparison of MR volumetry and multivoxel-MR-spectroscopy for assessment of postoperative prognosis].
While the importance of magnetic resonance (MR) spectroscopy, volumetry, and T2-relaxometry for preoperative localization has already been verified, the question arises as to what extent the individual techniques are useful for assessing postoperative prognosis with respect to seizures and neuropsychological outcome. In a prospective comparative study, 26 patients were examined preoperatively with a 1.5 T whole-body scanner. The MR spectroscopy was taken by high resolution 1 H proton spectroscopy, the volumetry with MP rage technique. The postoperative outcome was laid down using Engel's classification. Our results show that the metabolic changes can be divided into three groups using MR spectroscopy: unilateral, slightly bilateral, and severely bilateral to contralateral. In case of bilateral changes, the severity of metabolic changes in the nonoperated, contralateral side was decisive for postoperative outcome. The results from volumetry did not correlate with postoperative outcome.
Differential expression and regulation of GTPases (RhoA and Rac2) and GDIs (LyGDI and RhoGDI) in neutrophils from patients with severe congenital neutropenia.
Severe congenital neutropenia (SCN) or Kostmann syndrome is a disorder of myelopoiesis characterized by a maturation arrest at the stage of promyelocytes or myelocytes in bone marrow and absolute neutrophil counts less than 200/microL in peripheral blood. Treatment of these patients with granulocyte colony-stimulating factor (G-CSF) leads to a significant increase in circulating neutrophils and a reduction in infection-related events in more than 95% of the patients. To date, little is known regarding the underlying pathomechanism of SCN. G-CSF-induced neutrophils of patients with SCN are functionally defective (eg, chemotaxis, superoxide anion generation, Ca(++ )mobilization). Two guanosine triphosphatases (GTPases), Rac2 and RhoA, were described to be involved in many neutrophil functions. The expression of these GTPases and their regulation in patients' neutrophils were of interest. This study determined that the guanosine diphosphate (GDP)-dissociation inhibitor RhoGDI is overexpressed at the protein level in patients' neutrophils and that overexpression is a result of G-CSF treatment. RhoA and LyGDI are expressed at similar levels, whereas Rac2 shows a decreased expression. In addition, association of Rac2 and RhoGDI or LyGDI is abrogated or not detectable based on the low Rac2 expression in patients' neutrophils. (Blood. 2000;95:2947-2953)
Granulocyte colony-stimulating factor receptor expression and 11q23/MLL genotype in childhood acute lymphoblastic leukemia developing during the first 18 months of life.
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Favorable therapeutic index of a p210(BCR-ABL)-specific tyrosine kinase inhibitor; activity on lineage-committed and primitive chronic myelogenous leukemia progenitors.
PURPOSE: In order to assess the effect of the tyrosine kinase inhibitor CGP57148B on lineage-committed and primitive chronic myelogenous leukemia (CML) progenitor cells, peripheral blood progenitor cells (PBPC) mobilized in chronic phase CML were exposed to this compound in vitro. METHODS: Both short-term (</=1 week) and long-term exposure (>/=2 weeks) to CGP57148B were investigated using suspension culture, semisolid (methylcellulose) assay or stroma-dependent long-term culture (LTC). The proportion of bcr/abl-positive progenitors was determined after direct plating [2 weeks in colony-forming cell (CFC) assay] as well as after 2 or 6 weeks LTC (LTC always followed by CFC replates). RESULTS: Incubation of CML PBPC over 48 h in suspension culture with 100 microM CGP57148B reduced the proportion of bcr/abl-positive colonies to 4.4 +/- 4.3% (n = 5) after direct plating, 6.6 +/- 4.2% (n = 5) after 2 weeks LTC and 5 +/- 5.6% (n = 2) after 6 weeks LTC. At this dose, survival of drug-exposed normal PBPC was 53 +/- 4.2%, 51 +/- 2.8% and 54.5 +/- 4.9% (n = 2), respectively. Incubation with CGP57148B at a concentration of 10 microM over 1 week under LTC conditions reduced the number of bcr/abl-positive colonies to 11.8 +/- 6.1% (n = 5) after direct plating, 12 +/- 6.4% (n = 4) after 2 weeks LTC and 14.3 +/- 11.4% (n = 3) after 6 weeks LTC; survival of normal PBPC was 84.5 +/- 2.1%, 93 +/- 4.2% and 86 +/- 1.4% (n = 2), respectively. Following long-term exposure to CGP57148B at a concentration of 1 microM, the proportion of remaining bcr/abl-positive colonies was 35%, 9% and 25% of untreated CML samples after direct plating as well as after 2 and 6 weeks LTC, respectively. The respective values for 10 microM CGP57148B were 10%, 11% and 19%. Long-term exposure of normal progenitors to CGP57148B yielded a survival of 98%, 100% and 93% (1 microM) or 77%, 86% and 80% (10 microM), respectively. CONCLUSION: The results support the use of CGP57148B either for short-term exposure in vitro (e.g. purging) or for continuous treatment of CML in vivo.
SH2-containing protein tyrosine phosphatases SHP-1 and SHP-2 are dramatically increased at the protein level in neutrophils from patients with severe congenital neutropenia (Kostmann's syndrome).
Severe congenital neutropenia (SCN) or Kostmann's syndrome is characterized by a stop in differentiation of myeloid progenitor cells at the myelocytic or promyelocytic stage. The pathophysiology of SCN is still unclear. We previously showed that the tyrosine kinase JAK2 is phosphorylated and activated in neutrophils from patients with severe congential neutropenia. We investigated the role of tyrosine phosphatases in this disease. Expression of the SH2 domain-containing tyrosine phosphatases SHP-1 and SHP-2 was analyzed in myeloid cells from patients with SCN in comparison to healthy donors. We investigated tyrosine phosphatase expression in myeloid cells at the protein level by Western blot analysis using polyclonal antisera against SHP-1 and SHP-2. Whereas SHP-1 and SHP-2 were hardly detectable in neutrophils from healthy donors, neutrophils from patients with SCN revealed high amounts of these two proteins in Western blot analyses. Reverse transcriptase-polymerase chain reaction and Northern blot analyses demonstrated no dramatic differences of SHP-1 mRNA in neutrophils from congenital neutropenia patients as compared to healthy donors. SHP-2 mRNA was hardly detectable in the neutrophils from patients and in normal neutrophils. Increased expression of SHP protein correlated with elevated activity of both SHP-1 and SHP-2 in neutrophils of patients with SCN. Taken together, these data indicate differential regulation for SHP-1 and SHP-2 at the protein level in neutrophils from SCN patients in comparison to healthy donors. We suggest that overexpression of SHP-1 and SHP-2 protein in neutrophils and not in mononuclear cells from patients with SCN might be related to the disease, e.g., by defective dephosphorylation of proteins involved in intracellular signaling pathways.
Association of src-kinase Lyn and non-src-kinase Syk with the granulocyte colony-stimulating factor receptor (G-CSFR) is not abrogated in neutrophils from severe congenital neutropenia patients with point mutations in the G-CSFR mRNA.
Severe congenital neutropenia (SCN) is characterized by a maturation arrest of myeloid progenitor cells at the stage of promyelocytes in bone marrow and low levels of mature neutrophils in peripheral blood. To date, little is known regarding the underlying pathomechanism of SCN. A defective response of neutrophil precursors to granulocyte colony-stimulating factor (G-CSF) is a suggested mechanism. In the last few years, we and others described point mutations in the cytoplasmic domain of the G-CSF receptor (G-CSFR) mRNA in a subgroup of SCN patients. In one allele of the G-CSFR gene, a C to T substitution resulted in a change from a glutamine codon to a stop codon. The expected G-CSFR proteins were truncated by 83 to 98 amino acids. In this study, we show that the Lyn and Syk kinases are associated with the G-CSFR in neutrophils from SCN patients with point mutations in the cytoplasmic domain of the G-CSFR mRNA. These findings provide additional proof of the expression of normal G-CSFRs in these patients, because the possible Syk binding motif is located between amino acid 727 and 747 in the G-CSFR.
Clinical implications of G-CSF receptor mutations.
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Severe congenital neutropenia patients with point mutations in the granulocyte colony-stimulating factor (G-CSF) receptor mRNA express a normal G-CSF receptor protein.
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Clinical relevance of point mutations in the cytoplasmic domain of the granulocyte colony-stimulating factor receptor gene in patients with severe congenital neutropenia.
Recently, point mutations in the gene of the granulocyte colony-stimulating factor (G-CSF) receptor have been reported in two patients with severe congenital neutropenia who developed acute myeloid leukemia (AML). We investigated the frequency of these specific G-CSF receptor mutations in patients with congenital neutropenia undergoing treatment with r-metHuG-CSF (Filgrastim) and the clinical relevance of these mutations. Nucleotides 2306 to 2561 including the critical region (nucleotides 2384-2429) from the intracellular domain of the G-CSF receptor gene were amplified by reverse transcriptase-polymerase chain reaction. Detection of point mutations was performed with specific restriction enzyme analysis, as well as sequencing of PCR products. Both genomic DNA and cDNA from neutrophils and mononuclear cells were analyzed from 28 patients with severe congenital neutropenia. Four of 28 patients with congenital neutropenia displayed a point mutation in the tested cytoplasmic region of the G-CSF receptor gene. The point mutations replace a glutamine codon by a stop codon of the G-CSF receptor gene. Among these four congenital neutropenia patients with a mutated G-CSF receptor, two developed AML. All four patients were investigated regularly and no correlation between occurrence of G-CSF receptor mutation and time or dose of r-metHuG-CSF treatment was found. No point mutations in the G-CSF receptor critical domain could be detected in cells from the other 24 congenital neutropenia patients. Furthermore, we tested six family members of the two patients with AML including mothers and fathers, one sister, and one brother who suffers from congenital neutropenia, as well. All family members displayed a normal G-CSF receptor gene. After the acquisition of the G-CSF receptor mutations, the congenital neutropenia patients continued to respond to G-CSF therapy with an increase in absolute neutrophils in the peripheral blood. We conclude that the point mutations in the critical region of the intracellular part of the G-CSF receptor occur spontaneously and are not inherited. From our data, we suggest that the described G-CSF receptor point mutations do not alter the response to treatment with r-metHuG-CSF and are not the cause of severe congenital neutropenia.
Cytosolic proteins from neutrophilic granulocytes: a comparison between patients with severe chronic neutropenia and healthy donors.
A modified technique of two-dimensional gel electrophoresis (2-DE) was used to investigate differences in the pattern of cytosolic proteins of neutrophilic granulocytes from patients with severe congenital neutropenia, cyclic neutropenia, and idiopathic neutropenia in comparison with healthy donors. At the time of study, all patients tested received treatment with a recombinant human granulocyte colony-stimulating factor (r-metHuG-CSF; Filgrastim, Amgen). Using the Investigator 2-D Electrophoresis System (Millipore) we were able to detect more than 1000 protein spots in the cytosol of neutrophilic granulocytes from both patients and healthy controls. We investigated six patients with severe congenital neutropenia, five patients with cyclic neutropenia, four patients with idiopathic neutropenia, and 13 healthy donors. In the cytosol of neutrophilic granulocytes from patients we found an additional protein spot. This protein spot (molecular mass approximately 32.4 kDa, pI about 5.5) could be identified by internal sequencing after in-gel digestion with endoproteinase Lys-C as tropomyosin. The importance of the overexpression of tropomyosin in neutrophilic granulocytes from patients with severe chronic neutropenia is not yet understood.
Frequency of point mutations in the gene for the G-CSF receptor in patients with chronic neutropenia undergoing G-CSF therapy.
Point mutations in the gene for the G-CSF receptor have been reported previously in a subgroup of patients with severe congenital neutropenia. Here, we investigated the frequency of these specific G-CSF receptor mutations in patients with neutropenic disorders undergoing treatment with recombinant human (r-metHu)G-CSF (Filgrastim). Nucleotides 2306 to 2561, including the critical region (nucleotides 2384-2429) from the intracellular domain of the G-CSF receptor gene, were amplified by reverse transcriptase-polymerase chain reaction, and DNA was sequenced directly and after transformation in E. coli. Four of 30 patients with severe congenital neutropenia displayed a point mutation in the tested cytoplasmic region of the G-CSF receptor gene. Two of the four patients with a mutated G-CSF receptor developed acute myeloid leukemia secondary to congenital neutropenia. G-CSF receptor analyses were performed in myeloid cells taken at different time points in the four patients with the mutated receptor, and no correlation between occurrence of the mutation and time or dose of r-metHuG-CSF treatment was found. No point mutations in the G-CSF receptor critical domain could be detected in cells from the other 26 congenital neutropenia patients. Additionally, no G-CSF receptor point mutations could be seen in neutrophils, blood and bone marrow mononuclear cells from patients with cyclic or idiopathic neutropenia, and bone marrow mononuclear cells from patients suffering from severe aplastic anemia. Similar results were obtained by Touw et al., demonstrating that five out of 25 patients with congenital neutropenia reveal G-CSF receptor mutations. These data show that the point mutations in the critical region of the intracellular part of the G-CSF receptor occur only in a subgroup of severe congenital neutropenia patients. Furthermore, our data suggest that the described G-CSF receptor point mutations are not correlated with the start, duration or doses of r-metHuG-CSF treatment, but might result from genetic instability in the G-CSF receptor gene in severe congenital neutropenia.
The protein tyrosine kinase JAK2 is activated in neutrophils from patients with severe congenital neutropenia.
Severe congenital neutropenia (SCN; or Kostmann syndrome) is an autosomal recessive disorder characterized by a maturation arrest of myelopoiesis at the level of promyelocytes. Myeloid precursor cells from patients with SCN require pharmacological dosages of recombinant human granulocyte colony-stimulating factor (r-metHuG-CSF; Filgrastim; Amgen, Thousand Oaks, CA) to differentiate to normal neutrophils. Thus, it is hypothesized that the underlying defect responsible for SCN is based on an abnormal G-CSF-induced signal transduction pathway. Because JAK2, a nonreceptor tyrosine kinase, is involved in the signaling pathway of G-CSF, we examined the expression and activity of JAK2 in neutrophils from SCN patients during r-metHuG-CSF treatment. The immunoprecipitated JAK2 protein showed increased tyrosine phosphorylation in neutrophils from SCN patients as compared with that in neutrophils from healthy donors, suggesting that this kinase is activated. In vitro kinase assays of immunoprecipitated JAK2 confirmed that neutrophils from SCN patients show an increased autophosphorylation of JAK2 in comparison with that of neutrophils from healthy volunteers. These findings suggest that JAK2 is activated in SCN patients.
[Ketoconazole-induced hepatitis. Case report].
Since Oct. 1981 a new systemic antifungal drug Ketoconazole is available in the Federal Republic of Germany that has proven effective even in severe cases with fungal infections. This case-study will call attention on a rare but important side effect, namely Ketoconazole induced hepatitis. As an acute icteric viral hepatitis, type Non-A-Non-B-hepatitis possibly misdiagnosed only a carefully compiled history of the recent intake of drugs points at the real cause of hepatitis. In our case-report we observed a considerable increase in serum enzymes, especially GOT, GPT and GLDH after a drug-challenge with two tablets. We recommend so-called liver functions tests 2 to 3 weeks after beginning of therapy and further-on in monthly intervals. Histologically at that time toxic hydropic changes of the liver cells and a mesenchymal reaction with portal and intralobular mainly eosinophilic infiltration could be established. The serum enzymes came to normal only after 12 weeks.
[Massive digitoxin poisoning: successful therapy by means of hemoperfusion].
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