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D Huhn

Publications and source records attributed to D Huhn.

At least 37 records · Page 2Linked to original sources
PubMed2000

Establishment and characterization of colon carcinoma and renal cell carcinoma primary cultures.

Patients with metastatic renal and colon carcinoma have a very poor prognosis. In many cases, the tumor recurs after surgical excision and chemotherapy. Therefore, it might be beneficial for cancer patients to induce an immune attack against the tumor by inserting a cytokine gene into the tumor cells. Here, two different techniques for isolation of single tumor cells were compared. An enzymatic solution was superior to an EDTA/DTT isolation solution for establishing tumor primary cultures. In total, 18 primary cell cultures could be established from 68 patients with colon and renal cell carcinoma. Cells were further characterized concerning fibroblast contamination, cell proliferation and HLA-typing. These primary tumor cells might be of value for cytokine gene transfer and in vaccination protocols for cancer patients.

Adenocarcinoma↗
PubMed2000

Paclitaxel as weekly second-line therapy in patients with advanced pancreatic carcinoma.

Although the prognosis for patients with pancreatic adenocarcinoma is still poor, gemcitabine has shown significant impact upon survival and quality of life. Our aim was to examine the potential effectiveness of a second- or third-line therapy with paclitaxel (Taxol) after confirmed progression with a gemcitabine-containing schedule for patients remaining in good clinical condition. Eighteen patients with stage IVb disease participated in this study. Pretreatment with gemcitabine was performed either as monotherapy and/or in combination with 5-fluorouracil (5-FU) and folic acid (FA). Paclitaxel was administered at weekly intervals on an outpatient basis. We observed 238 weekly treatments with a median number per patient of 12 treatments. The median dosage was 73 mg/m2 paclitaxel (range 55-88 mg/m2). Regarding toxicity, only one patient each presented with anemia and leukocytopenia of WHO grade III. Hepatotoxicity with a temporary increase in aminotransferase of WHO grade II occurred in three patients. Higher-grade symptomatic toxicity was rare, except alopecia. At this time, the median survival time is 17.5 weeks (range 7-88 weeks) since the start of therapy. Stable disease was observed in five patients. One patient achieved complete remission within 37 weeks. At this time, he has survived for more than 56 weeks after confirmed progression under first-line therapy. In conclusion, this schedule demonstrates that weekly therapy with paclitaxel after pretreatment can be effective with a low toxicity profile. This opens up an additional therapeutic option for a selected patient group with a poor prognosis so far.

Aged↗
PubMed2000

Increased sensitivity of myeloid leukemia cell lines: potential of lovastatin as bone-marrow-purging agent.

Lovastatin reduces the isoprenylation of p21ras via suppression of mevalonic acid generation. Lovastatin has been shown to reduce tumor cell proliferation in a dose-dependent manner. Here, the potential of lovastatin for purging leukemia cells from bone marrow was investigated using the myeloblastic cell lines K562 and KG-1 as a model system, derived from an erythroleukemia and an acute myelogenous leukemia, respectively. Optimal purging conditions were determined using an MTT proliferation and a leukemia colony assay. Elimination of leukemia cells was time- and dose-dependent. Depletion of K562 was 2.5 logs for 100 microM of lovastatin at 72 h of incubation. Compared to another purging agent, 100 microg/ml mafosfamide had an activity comparable to 100 mM lovastatin. Interestingly, KG-1 acute myelogenous leukemia cells were even more sensitive to lovastatin than K562 cells. In clonogenic assays, 100 microM of lovastatin resulted in a 3- to 4-log reduction of K562 colonies. Lovastatin had a progressive effect on normal hematopoietic progenitor cells. At a concentration of 100 microM of lovastatin, CFU-GM colonies were reduced by 1-2 logs. In conclusion, a differential effect on leukemia and normal progenitor cells could be detected in a clonogenic assay. These results suggest that lovastatin deserves further study as an agent for ex vivo marrow purging.

Bone Marrow Cells↗
PubMed2000

Detection of germ-cell tumor cells in peripheral blood progenitor cell harvests: impact on clinical outcome.

Our study was conducted to evaluate the impact of tumor cell contamination in peripheral blood progenitor cell (PBPC) harvests on the clinical outcome of patients with germ-cell tumors undergoing high-dose chemotherapy (HDCT) and autologous PBPC reinfusion. Samples of mononuclear cells from progenitor cell harvests of 57 patients with advanced or recurrent germ-cell tumors were retrospectively screened for contaminating tumor cells using immunocytochemical staining for cytokeratin filaments and reverse transcription-PCR (RT-PCR) testing for germ-cell alkaline phosphatase mRNA. The results were correlated to clinical prognostic variables as well as to the overall and event-free survival of these patients. Tumor cell contamination was detected in PBPC harvests of 16 of 57 enrolled patients (28%), and, among these, in 14 of 51 (27%) who underwent HDCT. The presence of contaminating tumor cells as detected by either immunocytochemical staining, RT-PCR, or both was strongly associated with a reduced overall survival (43% versus 71%, P = 0.0037) and event-free survival (0% versus 52%, P = 0.0005) after 1 year. In multivariate analysis, the demonstration of contaminating tumor cells had a higher predictive value for a poor event-free survival than other known prognostic variables. The presence of contaminating tumor cells in PBPC harvests of patients with germ-cell tumors seems to predict a poor overall and event-free survival in patients undergoing HDCT and autologous PBPC reinfusion.

Adult↗
PubMed1999

Elevated reticulocyte count--a clue to the diagnosis of haemolytic-uraemic syndrome (HUS) associated with gemcitabine therapy for metastatic duodenal papillary carcinoma: a case report.

In adults, the haemolytic-uraemic syndrome (HUS) is associated with probable causative factors in the minority of all cases. Cytotoxic drugs are one of these potential causative agents. Although metastatic cancer by itself is a recognized risk-factor for the development of HUS, therapy with mitomycin-C, with cis-platinum, and with bleomycin carries a significant, albeit extremely small, risk for the development of HUS, compared with all other cytotoxic drugs. Gemcitabine is a novel cytotoxic drug with promising activity against pancreatic adenocarcinoma. We are reporting on one patient with metastatic duodenal papillary carcinoma developing HUS while on weekly gemcitabine therapy. The presenting features in this patient were non-cardiac pulmonary oedema, renal failure, thrombocytopenia and haemolytic anaemia. The diagnosis of HUS was made on the day of admission of the patient to this institution. Upon aggressive therapy, including one single haemodialysis and five plasmaphereses, the patient recovered uneventfully, with modestly elevated creatinine-values as a remnant of the acute illness. Re-exposure to gemcitabine 6 months after the episode of HUS instituted for progressive carcinoma, thus far has not caused another episode of HUS.

Adult↗
PubMed1999

Phase I clinical study applying autologous immunological effector cells transfected with the interleukin-2 gene in patients with metastatic renal cancer, colorectal cancer and lymphoma.

Natural killer-like T lymphocytes termed cytokine-induced killer (CIK) cells have been shown to eradicate established tumours in a severe combined immune deficient (SCID) mouse/human lymphoma model. Recently, we demonstrated that CIK cells transfected with cytokine genes possess an improved proliferation rate and a significantly higher cytotoxic activity as compared to non-transfected cells. Here, in a phase I clinical protocol, autologous CIK cells were generated from peripheral blood obtained by leukapheresis in patients with metastatic renal cell carcinoma, colorectal carcinoma and lymphoma. CIK cells were transfected with a plasmid containing the interleukin-2 (IL-2) gene via electroporation. Transfected cells generated IL-2 in the range of 330-1800 pg 10(-6) cells 24 h(-1) with a mean of 836 pg 10(-6) cells 24 h(-1). Ten patients received 1-5 intravenous infusions of IL-2-transfected CIK cells; five infusions with transfected CIK cells were given. In addition, the same patients received five infusions with untransfected CIK cells for control reasons. In three patients, WHO grade 2 fever was observed. Based on polymerase chain reaction of peripheral blood transfected cells could be detected for up to 2 weeks after infusion. There was a significant increase in serum levels of interferon gamma (IFN-gamma), granulocyte-macrophage colony-stimulating factor (GM-CSF) and transforming growth factor beta (TGF-beta) during treatment. Interestingly, there was also an increase in CD3+ lymphocytes in the blood of patients during therapy. In accordance, a partial increase in cytotoxic activity in peripheral blood lymphocytes (PBLs) was documented when patient samples before and after therapy were compared. Concerning clinical outcome, six patients remained in progressive disease, three patients showed no change by treatment, and one patient with lymphoma developed a complete response. In conclusion, we were able to demonstrate that CIK cells transfected with the IL-2 gene can be administered without major side-effects and are promising for future therapeutic trials.

Adolescent↗
PubMed1999

Efficacy and toxicity of IFN-alpha2b combined with cytarabine in chronic myelogenous leukaemia.

Newly diagnosed chronic myelogenous leukaemia (CML) patients (n = 65) were treated with interferon (IFN)-alpha2b (5 x 106 IU/d s.c.) combined with monthly courses of cytarabine (20 mg/d s.c. for 14 d). Median age of patients enrolled was 45 years. The endpoints of the study were clinical efficacy and toxicity. The survival rates at 3 years and 5 years were 77% and 56%, respectively. The rate of complete haematological response was 60%. Evaluation of cytogenetic response was available in 29/65 patients. A complete cytogenetic response was seen in 3/29 patients (10%). W.H.O. toxicity grade 3-4 occurred in only 22/523 evaluable treatment cycles. Since the study protocol required intermittent or definitive discontinuation of cytarabine in case of moderate leucopenia (white blood cells (WBC) <5 x 109/l), combined cytopenia (WBC < 5 x 109/l, platelets <100 x 109/l), and isolated moderate thrombocytopenia (<100 x 109/l), the drug had to be discontinued temporarily or definitively in 200 cycles and the dose of cytarabine had to be reduced in 35 cycles. Thus, only 25% of the planned dose of cytarabine could be administered. At this dosage it would appear that cytarabine had no effect on survival and did not improve remission rates. We conclude that a clinical benefit for the addition of cytarabine to the treatment of CML with IFN might only be achieved by the administration of a higher cumulative dose of cytarabine, suggesting that lower leucocyte counts of 2-4 x 109/l have to be tolerated.

Adolescent↗
PubMed1999

Phase I trial of gemcitabine (Gemzar), 24 h infusion 5-fluorouracil and folinic acid in patients with inoperable pancreatic cancer.

Gemcitabine (Gemzar) has a significant impact upon survival and quality of life for patients with pancreatic cancer, compared with 5-fluorouracil (5-FU). This phase I study was initiated to define the recommended dose of 5-FU delivered as a 24 h infusion in combination with gemcitabine (1000 mg/m2) and folinic acid (200 mg/m2) in patients with inoperable pancreatic cancer, treated on an outpatient basis. Drugs were administered weekly for 4 weeks out of 6 weeks. Sixteen chemonaive patients (median age 59 years, range 51-66) were enrolled, 15 had stage IV and one stage III disease. The median Karnofsky performance score (KPS) was 70 (range 60-80). Six patients received 5-FU 750 mg/m2, eight received 5-FU 1000 mg/m2 and two received 5-FU 1250 mg/m2. The maximum tolerated dose of 5-FU was 1000 mg/m2. Hepatotoxicity was dose limiting. One patient who received 5-FU 1250 mg/m2 died as a result of hepatorenal failure. There was one partial response, nine patients had stable disease for more than 3 months and 13 patients had improved KPS. The median time to progressive disease was 31 weeks (range 5-50 weeks). A phase 11 trial is underway to further assess the activity of this combination at the recommended dose of 750 mg/m2 5-FU.

Adult↗
PubMed1999

Classical Hodgkin's disease and follicular lymphoma originating from the same germinal center B cell.

PURPOSE: Classical Hodgkin's disease and non-Hodgkin's B-cell lymphoma occasionally occur in the same patient. To clarify whether these different diseases share a common precursor cell, we analyzed the immunoglobulin rearrangements in tumor cells of the classical Hodgkin's disease and the follicular lymphoma that developed in the same patient 2 years apart. PATIENTS AND METHODS: Polymerase chain reaction (PCR) for the detection of rearranged immunoglobulin genes was carried out on single Reed-Sternberg cells and on whole tissue DNA extracted from the follicular lymphoma. PCR products were sequenced and compared with each other and with germ line immunoglobulin variable segments. Immunoglobulin heavy- and light-chain transcripts were analyzed by radioactive in-situ hybridization. RESULTS: The same monoclonal immunoglobulin gene rearrangement was found in both neoplasms. The variable region of the immunoglobulin heavy-chain genes of the Reed-Sternberg and of the follicular lymphoma cells were differently mutated, but six somatic mutations were shared by both lymphoma cells. Although the coding capacity of the immunoglobulin genes was preserved in both neoplastic cell populations, immunoglobulin heavy- (mu) and light- (kappa) chain expression was restricted to the follicular lymphoma cells, except for small amounts of kappa light-chain mRNA in some Reed-Sternberg cells. CONCLUSIONS: The neoplastic cells of the Hodgkin's disease and the follicular lymphoma that occurred in this patient derived from a common precursor B cell. Its differentiation stage could be identified as that of a germinal center B cell. Thus, transforming events can be more important than the cell of origin in determining a disease entity.

Adult↗
PubMed1999

TNF-alpha secretion and apoptosis of lymphocytes mediated by gene transfer.

Efficient gene transfer of lymphocytes is extremely difficult. Apoptosis may play a role in this gene transfer resistance of lymphocytes. Here we show that transfection of lymphocytes via non-viral vectors leads to induction of apoptosis in a significant proportion of cells. Since apoptosis may be mediated via tumor necrosis factor d (TNF-alpha) and the TNF-alpha receptor pathway, we studied the amount of TNF-alpha secreted by lymphocytes transfected without gene insert. TNF-alpha secretion was dependent on the gene transfer method used. High amounts were detected using receptor-mediated gene transfer and lipofection. In contrast, only low amounts of TNF-alpha were detected after electroporation and retroviral gene transfer. In receptor-mediated gene transfer, TNF-alpha secretion was due to the use of anti-CD3 antibody. Transfection of lymphocytes led to selective decrease in CD120b/TNF-alpha receptor II (TNFR-2)-positive cells. Induction of apoptosis and necrosis mediated by TNF-alpha via TNFR-2 (p80) was partially blocked using a neutralizing anti-TNF-alpha antibody. Blockage of apoptosis and necrosis could be further increased by adding anti-Fas-ligand (FasL) antibody, suggesting that induction of apoptosis via FasL and Fas receptor (Apo-1/CD95) may also play a role. This blockage led to a significant increase in the proliferation rate of lymphocytes transfected with cytokine genes. In conclusion, various gene transfer techniques led to TNF-alpha secretion, apoptosis and necrosis of lymphocytes. Apoptosis and necrosis could be partially blocked using a neutralizing anti-TNF-alpha antibody.

Antibodies, Monoclonal↗
PubMed1998

Sensitivity and specificity of indirect immunofluorescence and Grocott-technique in comparison with immunocytology (alkaline phosphatase anti alkaline phosphatase = APAAP) for the diagnosis of Pneumocystis carinii in broncho-alveolar lavage (BAL).

The purpose of the study was to compare the sensitivity and specificity of the indirect method of immunofluorescence with the immunocytological technique of alkaline phosphatase anti alkaline phosphatase complex (APAAP) for the detection of Pneumocystis carinii by bronchoalveolar lavage (BAL) in HIV-1 positive patients. - 83 HIV-1 positive patients with clinical presentations suggestive of Pneumocystis carinii pneumonia (PcP) were included in the study. 28 samples were found Pc-positive by immunofluorescence (IFT), 26 by Grocott and 29 by APAAP. In comparison to the lab results 33 patients were diagnosed as PcP according to the clinical course (i.e. therapeutic outcome, drugs used, and therapy changes). Compared to the clinical diagnoses, the following lab tests proved to be false positive and false negative: false positive: IF = 1, Grocott = 0, APAAP = 4 (3F6). false negative: IF = 5, Grocott = 7, APAAP = 4 (3F6). - Grocott stain shows insufficient correlation to the clinical diagnoses (p = 0.0156, McNemar-Test, two-tailed). - The two different detection methods (IFT and APAAP) showed no significant statistical difference with regard to their sensitivity (p = 0.3438, McNemar-Test, two tailed) and specificity. Considering cost and time the immunofluorescence technique seems to be the most suitable for the diagnosis of PcP in HIV-1 positive patients.

AIDS-Related Opportunistic Infections↗
PubMed1998

Kinetics of the graft-versus-leukemia response after donor leukocyte infusions for relapsed chronic myeloid leukemia after allogeneic bone marrow transplantation.

Little is known about the mechanisms and the kinetics of the so-called graft-versus-leukemia (GVL) response induced by donor lymphocyte infusions (DLI) in patients with leukemic relapse after allogeneic bone marrow transplantation (BMT). We sought to elucidate this problem by sequentially studying three patients with relapsed chronic myeloid leukemia after sex-mismatched BMT from time before donor leukocyte infusion until achievement of complete molecular remission. Lineage-specific chimerism was assessed longitudinally by a combined fluorescent immunophenotyping and sex chromosome-specific in situ hybridization approach. Results were related to quantitative detection of bcr-abl transcripts by competitive differential reverse transcriptase-polymerase chain reaction (RT-PCR), qualitative bcr-abl RT-PCR, and multiplex PCR-based DNA donor/recipient chimerism. All patients had predominant donor lymphopoiesis at the time of DLI, suggesting a state of tolerance to recipient leukemic and/or normal cells. In contrast, granulopoiesis and erythropoiesis were mainly recipient derived in both patients with hematologic relapse and partly recipient derived in the patient with molecular relapse. Eighty percent, 90%, and 8% of CD34(+) cells, respectively, were found to be of recipient origin at relapse, and few donor stem cells predicted for cytopenia post-DLI. Responses were seen after a time lag of 5 to 13 weeks after DLI and resulted in reversal to full donor chimerism within a critical switch period of 4 to 5 weeks. A sudden decrease in recipient cells was paralleled by a sharp decrease in bcr-abl transcript numbers detectable several weeks before achievement of molecular remission and onset of clinical graft-versus-host disease (GVHD). This response pattern was confirmed by retrospective RT-PCR analysis in an additional five patients. Prospective monitoring of stem cell chimerism and response may enable us to individually tailor adoptive immunotherapy in the future.

Adult↗
PubMed1998

Quantitative fluorescence flow cytometry: a comparison of the three techniques for direct and indirect immunofluorescence.

Three types of microbead calibrators available for quantitative fluorescence flow cytometry have been studied in parallel using a variety of monoclonal antibodies (MoAbs). The QIFI kit is designed for indirect immunofluorescence (IF), and both the Quantum Simply Cellular (QSC) assay and the Quanti-BRITE assay are designed for direct IF. Because of the different nature of the respective ligands, epitopes on cells versus F'ab-portions on QSC beads, large differences in titration curves for a large number of CD MoAbs were noted between QSC beads and cells. Use of the QSC assay and fluorescein isothiocyanate (FITC) and phycoerythrin (PE) conjugates of the same CD reagent revealed substantially different numbers of cellular binding sites. Numbers of cellular binding sites as determined by direct IF using the Quanti-BRITE assay and by indirect IF using the QIFI kit were similar. We also found that erythrocyte (RBC)-lysing reagents cause varying and sometimes substantial reduction in the fluorescence intensity (FI) of cells stained directly with CD34 MoAb conjugates, but the RBC-lysing reagents had no effect on the FI of cells stained indirectly with the same CD34 MoAbs. This report defines a number of variables critical for standardized quantitative flow cytometry. We conclude that the choice of calibrators, fluorochrome conjugates, staining methods, and modes of sample processing can effect the determination of cellular binding sites to MoAbs. Direct immunofluorescence using the Quanti-BRITE assay and indirect IF using the QIFI kit appear to yield comparable results for the standardized determination of numbers of cellular binding sites to MoAbs.

Animals↗
PubMed1998

Granulocyte colony-stimulating factor worsens the outcome of experimental Klebsiella pneumoniae pneumonia through direct interaction with the bacteria.

Besides its well-established effects on granulocytopoiesis, granulocyte colony-stimulating factor (G-CSF) has been shown to have direct effects on the recruitment and bactericidal ability of neutrophils, resulting in improved survival of experimentally infected animals. We studied the effect of G-CSF on the course of experimental pneumonia induced by Klebsiella pneumoniae, an important gram-negative bacillary pulmonary pathogen. Using a highly reproducible murine model, we here show the paradoxical finding that mortality from infection was significantly increased when animals received G-CSF before induction of pneumonia. Administration of G-CSF promoted replication of bacteria in the liver and spleen, thus indicating an impairment rather than an enhancement of antibacterial mechanisms. By contrast, a monoclonal antibody against Klebsiella K2 capsule significantly reduced bacterial multiplication in the lung, liver, and spleen, and abrogated the increased mortality caused by G-CSF. In vitro studies showed a direct effect of G-CSF on K pneumoniae resulting in increased capsular polysaccharide (CPS) production. When bacteria were coincubated with therapeutically achievable concentrations of G-CSF, phagocytic uptake and killing by neutrophils was impaired. Western blot analysis showed three binding sites of G-CSF to K pneumoniae. Binding of 125I-G-CSF to K pneumoniae was displaced by an excess of unlabeled G-CSF, whereas an unrelated cytokine, interleukin-1alpha, did not compete with G-CSF binding to the bacteria. Thus, in this model, the direct effect of G-CSF on a bacterial virulence factor, CPS production, outweighed any beneficial effect of G-CSF on recruitment and stimulation of leukocytes.

Animals↗