Identification of a novel HLA-A33 subtype (A*3303) and correction of the A*3301 sequence.
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Alleles↗
Biomedical subjects
D Huhn
Publications and source records attributed to D Huhn.
A novel HLA-A24 allele (A*2405) identified by single-strand conformation polymorphism analysis and confirmed by solid-phase sequencing and isoelectric focusing.
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Alleles↗
Complete subtyping of the HLA-A locus by sequence-specific amplification followed by direct sequencing or single-strand conformation polymorphism analysis.
A variety of reasons related to the HLA class I system has complicated the application of molecular approaches to HLA class I typing. Here we present a PCR-based HLA-A typing strategy considering the sequence variations of the two most polymorphic exons which allows complete subtyping of the HLA-A locus. The method is based on a sequence-specific amplification identifying the serologically defined HLA-A specificities. The PCR products generated by these group-specific primers bear the sequence information necessary for a postamplification specificity step. The primer pairs are located within one exon, either exon 2 or exon 3, which avoids amplification of polymorphic intron sequences allowing subsequent single-strand conformation polymorphism analysis and facilitating direct sequencing. Using this method we investigated 48 cell lines and 153 clinical samples. 23 PCR reactions are performed per individual for the assignment of the serological specificities A1-A80. The reproducibility was 100% in all cell lines and 85 clinical samples typed on two separate occasions. With the exception of 13 out of 231 possible serological combinations all homozygous and heterozygous combinations of A1-A80 can be distinguished by specific amplification patterns. Comparing the PCR based typing results with those of serology in 12% a discrepancy was found. Solid-phase sequencing or SSCP analysis of the group-specific PCR fragments allowed complete subtyping of the HLA-A locus. This strategy can identify all 48 HLA-A alleles based on the sequence variations of the 2nd and 3rd exon. 1128 homozygous and heterozygous allele combinations are possible for the HLA-A locus. Only 4 out of these 1128 allele combinations remained unresolved.
Alleles↗
A novel HLA-A30 allele (A*3004) identified by single-strand conformation polymorphism analysis and confirmed by solid-phase sequencing.
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Alleles↗
Hematopoietic rescue after high-dose chemotherapy using autologous peripheral-blood progenitor cells or bone marrow: a randomized comparison.
PURPOSE: To compare autologous bone marrow (BM) with peripheral-blood progenitor cells (PBPC) as hematopoietic rescue after high-dose chemotherapy (HDCT). PATIENTS AND METHODS: From January 1991 until April 1993, 47 consecutive patients with relapsed or refractory germ cell tumors were randomized to either BM harvest or collection of PBPC mobilized by chemotherapy plus granulocyte colony-stimulating factor (G-CSF). After additional conventional-dose salvage treatment, all patients received HDCT with carboplatin 1,500 mg/m2, etoposide 2,400 mg/m2, and ifosfamide 10 g/m2 with either BM or PBPC rescue. RESULTS: Forty-six patients were assessable for hematologic reconstitution, and one patient died on day +4 before engraftment. Rescue using PBPC resulted in a significantly shorter recovery time to neutrophil counts more than 500/microL (10.0 v 11.0 days, P < .01), neutrophil counts more than 1,000/microL (10.0 v 12.0 days, P = .001), and platelet counts more than 20,000/microL (10.0 v 17.0 days, P < .01), as well as in fewer days to transfusion independence from RBCs (8.0 v 12.0, P < .05) and platelets (9.0 v 12.0, P < .01) and fewer days of intravenous (IV) antibiotics (9.0 v 11.0, P < .05). However, no statistical differences in transfusion requirements or in other clinical outcome variables were observed. Overall survival and event-free survival also were not different in the two study arms. CONCLUSION: We conclude that the use of PBPC mobilized by chemotherapy plus G-CSF results in sustained trilineage reconstitution after HDCT, which occurs more rapidly as compared with BM. The earlier hematologic reconstitution in patients with PBPC rescue significantly reduces the time to transfusion independence.
Adolescent↗
Alterations of the retinoblastoma a susceptibility gene in chronic lymphocytic leukemia.
Research in recent years has shown that malignant transformation is a genetic multistep process. This holds true not only for in-vitro model systems, but has also been elegantly shown in-vivo, as in colorectal cancer. Chronic lymphocytic leukemia (CLL) is the most frequent leukemia in Western countries and occurs mainly in elderly patients, suggesting that in this form of leukemia, cumulative molecular lesions may be necessary for transformation. However, the molecular background is unknown in most cases. Cytogenetic aberrations may be used as markers for genes involved in the process of malignant transformation. In CLL, the most frequently observed structural cytogenetic lesion is a deletion/translocation involving the long arm of chromosome 13, a region where the retinoblastoma susceptibility gene (Rb-gene) has been mapped (13q14). Many groups have studied the question as to whether alterations of the Rb-gene play a causal role in the pathogenesis of CLL. This review deals with recent data indicating that i) the Rb-gene may be altered in a minority of CLL cases, and ii) there may be another gene localized on chromosome 13q14 that may be important in the molecular biology of CLL.
Cell Division↗
Potential of autologous immunologic effector cells for bone marrow purging in patients with chronic myeloid leukemia.
Relapse is a major concern in autologous bone marrow transplantation (BMT). Therefore, purging of bone marrow to reduce the amount of tumor cells reinfused into the patient is widely used. Immunologic effector cells such as lymphokine activated killer (LAK) cells are attractive for purging of bone marrow since these cells might have an additional in vivo effect on tumor cells in contrast to other purging protocols. In patients with chronic myelogenous leukemia (CML), LAK cells can only be used in some patients for purging bone marrow since LAK cells possess no or only limited cytolytic activity against autologous CML tumor cells in most cases. In this study, we investigated the effect of autologous and allogeneic cytokine-induced killer (CIK) cells on tumor cells from patients with CML. CIK cells have been generated from peripheral blood lymphocytes by incubation with interferon-gamma on day 0, interleukin-1, interleukin-2 and a monoclonal antibody against CD3 on day 1. In contrast to LAK cells, CIK cells were able to lyse both autologous and allogeneic cells from patients with CML as determined by a 51Cr release and a tumor colony assay. The cytotoxicity of CIK cells against CML cells was confined to the CD56+ population. CIK cells showed no major toxic effect on hematopoietic progenitor cells when tested in CFU-GM assays. CIK cells eliminated three orders of magnitude of K562 cells and less than one order of magnitude of progenitor cells (25% reduction). This represents a differential effect of CIK cells on tumor and progenitor cells.(ABSTRACT TRUNCATED AT 250 WORDS)
Base Sequence↗
Detection of DNA methylation in the calcitonin gene in human leukemias using differential polymerase chain reaction.
One of the earliest events in the multistep process of malignant transformation is a change in the methylation pattern of certain genes. DNA methylation is usually detected by Southern blotting after restriction digest with methylation-sensitive endonucleases. Calcitonin gene hypermethylation has been described in a variety of human malignancies including lymphomas and leukemias. Here we report a technique based on the semi-quantitative differential polymerase chain reaction (PCR) which is capable of detecting subtle changes in the methylation pattern of the human calcitonin gene. This technique is based on two principles: (i) simultaneous coamplification of the target gene (5'-region of the calcitonin gene) and a reference gene for quantitative purposes; and (ii) simultaneous coamplification of a competitor with identical primer-binding sites as the target gene to control for proper restriction digest. Using this technique, we investigated calcitonin gene methylation in a variety of human cell lines, primary leukemias and normal human blood donors. The data revealed good correlation with standard Southern blotting. Weak calcitonin gene methylation was found in all normal blood donors tested (n = 14). In contrast, strong calcitonin gene methylation was detected in most acute leukemias (five of 10 acute myeloid leukemias (AML); six of seven acute lymphoblastic leukemias (ALL)). These data show that this technique can reliably be used to quantitate gene methylation and indicate that there exists heterogeneity with regard to methylation status in different leukemias, suggesting that hypermethylation of the calcitonin gene may play a role in the transformation process of some, but not all, human leukemias. Furthermore, differential PCR may facilitate determination of calcitonin gene methylation in clinical or archival tumor samples.
Base Sequence↗
Expression of axl, a transforming receptor tyrosine kinase, in normal and malignant hematopoiesis.
We previously reported the cloning, and characterization of a receptor tyrosine kinase, axl, from two patients with chronic myelogenous leukemia. Herein, we describe the expression pattern of axl in normal and malignant hematopoietic tissue axl message is detected in normal human bone marrow but not significantly in normal blood leukocytes. Cell separation experiments showed that axl is expressed in hematopoietic CD34+ progenitor and marrow stromal cells, at low levels in peripheral monocytes, but not in lymphocytes or granulocytes. Consistent with the normal pattern of axl expression, axl RNA was found predominantly in diseases of the myeloid lineage: 39 of 66 (59%) patients with myeloproliferative disorders (acute myeloid leukemia, chronic myeloid leukemia (CML) in chronic phase, CML in myeloid blast crisis, and myelodysplasia) showed significant axl transcription, as compared with 1 of 45 (2%) lymphoid leukemias (chronic lymphocytic leukemia, acute lymphocytic leukemia, and CML in lymphoid blast crisis). Treatment of K562 cells with the phorbol ester, 12-O-tetradecanoylphorbol-13-acetate (TPA), administration of interferon alpha (IFN alpha) to normal monocytes, and treatment of U937 cells with TPA and IFN tau significantly induced axl expression, supporting a role for this kinase in the intracellular signaling of myeloid cells through a variety of biochemical pathways. These results suggest that the axl kinase may be operative in normal and malignant myeloid biology.
Base Sequence↗
[Current status of treatment for chronic viral hepatitis using recombinant interferon alpha].
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Chronic Disease↗
CD 34 immunotyping of blasts in myelodysplasia.
We studied the expression of the hematopoietic progenitor cell antigen CD 34 in six patients with refractory anemia with excess of blasts (RAEB), five patients with RAEB in transformation (RAEB-T), and seven patients with chronic myelomonocytic leukemia (CMML). Immunocytochemical labeling of bone marrow cells was performed by an indirect immunoperoxidase method with preservation of morphological details. The cells were stained with May-Grünwald-Giemsa, photographed, destained, and immunolabeled by the immunoperoxidase technique. We found 1.5 +/- 0.5% blasts and 0.8 +/- 0.4% CD 34+ blasts in normal bone marrow. The CD 34 positivity of blasts was 53 +/- 9%. The patients with RAEB showed 1.7 +/- 1.4% CD 34+ blasts. The CD 34 positivity of blasts (11.8 +/- 5.6%) was lower than in normal bone marrow. The patients with RAEB-T had a higher percentage of CD 34+ blasts (7.3 +/- 3.4) and a higher CD 34 positivity of blasts (28.2 +/- 14.6%) than patients with RAEB. The CMML patients showed a percentage of CD 34+ blasts and a CD 34 positivity of blasts in the range of RAEB. We found an increase of promonocytes (PMC) in 5/7 patients. In some patients the PMC were CD 34 positive. Our results indicate that the increase of blasts in REAB is related to CD 34-negative blasts. With progression to RAEB-T the percentage of CD 34-positive blasts increased. Some of the CMML patients also showed a population of CD 34-positive PMC. A clone of undifferentiated CD 34-positive cells is characteristic for patients with these types of myelodysplasia.
Anemia, Refractory, with Excess of Blasts↗
Detection of allelic loss within the beta 1-interferon gene in childhood acute lymphoblastic leukemia using differential PCR.
Deletion of the short arm of chromosome 9p involving the beta 1-interferon (IFN) gene has been implicated in the process of malignant transformation in lymphomas and acute lymphoblastic leukemias. Since cytogenetic analysis is frequently unsuccessful in clinical samples, we used a recently described differential PCR technique to detect losses within the beta 1-IFN gene in 86 acute leukemias. Using differential PCR, no beta 1-IFN deletion was detected in 44 acute myeloid leukemia (AML) and eight control samples. However, five of 42 acute lymphoblastic leukemia (ALL) probes (12%) exhibited loss of the beta 1-IFN gene (three common ALL, two T-ALL). Cytogenetic analysis was performed independently in three of these five cases and revealed abnormalities of chromosome 9p in two samples. Two of five T-ALL cases exhibited a loss within the beta 1-IFN gene, compared with 3/29 c-ALLs, suggesting a predominance of IFN gene loss in T-ALLs. These data indicate that PCR can be used for rapid detection of gene dosage phenomena in clinical leukemia samples.
Acute Disease↗
Overexpression of the Raf-1 proto-oncogene in human myeloid leukemia.
The Raf-1 protein, a cytoplasmic serine/threonine kinase, plays an important role in signal transduction pathways. In order to examine the role of Raf-1 in human myeloid leukemia, we determined raf-1 mRNA expression by Northern blot analysis in blast cell samples from 27 acute myeloid leukemia (AML) cases and peripheral blood mononuclear cells from six healthy donors. A normal raf-1 transcript size was detected in all cases investigated. However, overexpression of raf-1 mRNA was found in 2 of 27 AML cases, both of which were erythroleukemias (AML, FAB M6).
Acute Disease↗
Expression and mutational analysis of Nm23-H1 in liver metastases of colorectal cancer.
It has been proposed that nm23-H1, a candidate suppressor gene for metastasis, plays an important role in metastasis formation of human tumours. In order to investigate its role in the progression of colorectal cancer, we analysed 22 liver metastases of this malignancy with respect to mutational changes, loss of heterozygosity and expression levels of nm23-H1. Although genetic alterations in nm23-H1 have recently been described in those colorectal adenocarcinomas which give rise to distant metastases, we were unable to detect any mutation in the coding sequence of nm23-H1 in the metastatic tissue itself. We further analysed the metastases with respect to allelic deletions at the chromosomal locus of nm23. However, no loss of heterozygosity could be detected in ten informative cases. Moreover, the mRNA expression levels of nm23-H1 in the metastatic tissues were not significantly different from those in normal colon mucosa. Thus, although nm23-H1 might be involved in metastasis suppression of certain tumour types, in colorectal tumour progression its role remains to be determined.
Base Sequence↗
The effect of methylene blue phototreatment on plasma proteins and in vitro coagulation capability of single-donor fresh-frozen plasma.
BACKGROUND: Photodynamic virus inactivation of fresh-frozen plasma (FFP) may result in its impaired coagulation capability. STUDY DESIGN AND METHODS: Double-volume plasmapheresis samples from 11 donors were divided in pairs of 250 mL. One group underwent methylene blue (MB) phototreatment (MB-FFP). The other group was treated according to the standards of the American Association of Blood Banks for preparation and storage of FFP. Parameters of hemostasis and clinically important plasma proteins were tested in native plasma, thawed MB-FFP, thawed FFP, and twice-frozen and thawed FFP (FFP-II). RESULTS: Mean activities of factor V (73.4 vs. 94.5%; p < 0.01), factor VIII (58.1 vs. 86.7%; p < 0.001), and fibrinogen (1.8 vs. 2.8 g/L; p < 0.001) were reduced in MB-FFP as compared to those in FFP. The comparison of MB-FFP to FFP-II revealed reduced activities of factor VIII (58.1 vs. 85.2%; p < 0.001) and fibrinogen (1.8 vs. 2.8 g/L; p < 0.001) but no changes in factor V. Activated partial thromboplastin time in MB-FFP was prolonged beyond the upper normal range (+5.3 sec; p < 0.001) and prothrombin time increased in MB-FFP versus FFP (+0.96 sec; p < 0.001). CONCLUSION: MB phototreatment reduces the in vitro coagulation capacity of FFP, most likely as a result of the effects of an additional freezing and thawing procedure and photooxidation-induced protein damage.
Blood Coagulation↗
Interleukin-7 gene transfer in patients with metastatic colon carcinoma, renal cell carcinoma, melanoma, or with lymphoma.
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Adolescent↗
Cytokine efficiency in the treatment of high-grade malignant non-Hodgkin's lymphomas: results of a randomized double-blind placebo-controlled study with intensified COP-BLAM +/- rhGM-CSF.
In high-grade malignant non-Hodgkin's lymphomas (hNHL) recombinant human granulocyte-macrophage colony-stimulating factor (rhGM-CSF) was evaluated as support to chemotherapy. In a phase III trial, 172 patients (age 18-73 years, stage II-IV) were risk-stratified according to LDH levels and lymphoma size and randomized to receive rhGM-CSF (400 micrograms) (87 patients) or placebo (85 patients) subcutaneously days 8-14 of each cycle of an intensified COP-BLAM regimen. RhGM-CSF significantly reduced the length and nadir of neutropenia, the length of fever episodes, the frequency of all and of severe infections, and of hospitalization and antibiotic requirements. Complete response rates were 63% for all patients and 64% vs. 61% (n.s.) in the rhGM-CSF vs. the control group. Deviations from protocol in applied dosages of myelotoxic drugs and in cycle intervals maintained differed slightly in favor of the rhGM-CSF arm. However, there were no significant differences in overall survival between the GM-CSF treatment and control groups (21 vs. 23 months). Early relapse rates were markedly lower than in the standard-dose COP-BLAM/IMVP-16 regimen. Thus, GM-CSF abates toxic side effects of chemotherapy and may help to maintain dose intensity in high-risk hNHL.
Adolescent↗
Propagation of large numbers of T cells with natural killer cell markers.
Previously, a subset of T cells co-expressing the NK cell antigen CD56 has been described. These CD3+CD56+ cells are rare in peripheral blood collections and have been poorly characterized. We have developed culture conditions which allow for the rapid expansion of CD3+CD56+ cells. The protocol for cellular expansion includes the addition of interferon-gamma on day 0, interleukin-1, interleukin-2 and a monoclonal antibody against CD3 on day 1 to peripheral blood lymphocytes. Cells of the CD3+CD56+ phenotype increased up to 6000-fold using this protocol after 16 d in culture. These cells have been characterized by flow cytometry and have been found to express the alpha, beta T cell receptor, co-express the CD5 and CD8 antigens and do not express the CD16 antigen. Morphologically, these cells cannot be distinguished from NK cells. CD3+CD56+ killer cells lyse a variety of tumour cells with intermediate activity between CD3-CD56+ NK cells and CD3+CD56- T cells.
Antigens, CD↗