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T Lion

Publications and source records attributed to T Lion.

66 records · Page 4Linked to original sources
PubMed1991

Pure red cell aplasia in a case of Ph negative BCR/ABL rearranged CML with t(12;14)(q23;p11).

A patient with chronic myelogenous leukemia (CML) associated with pure red cell aplasia (PRCA) is reported. The occurrence of PRCA has been described previously in sporadic cases of Philadelphia chromosome (Ph) positive CML. In this patient, however, the Ph-chromosome was not detected; cytogenetic analysis revealed a t(12;14)(q23;p11) as the sole abnormality. Molecular studies by Southern and PCR analyses showed the rearrangement of the BCR and ABL sequences and expression of the chimeric bcr/abl mRNA, thus confirming the diagnosis of CML. To our knowledge, this is the first report on a case of PRCA associated with Ph negative CML at diagnosis. The possible connection between CML and PRCA is discussed.

Aged↗
PubMed1991

Non-radioactive detection of the rearranged BCR/ABL sequences amplified by polymerase chain reaction.

The polymerase chain reaction (PCR) is a powerful technique for the detection of the bcr/abl rearrangement in chronic myelogenous leukemia (CML). It allows the exponential amplification of the rearranged region, thus facilitating its detection. The specificity of the bcr/abl cDNA sequence amplified by PCR is most commonly verified by hybridization to a 32P-labeled probe. In this paper, an assay for the colorimetric detection of the amplified bcr/abl fragment is described, which offers several advantages over the use of radioactive probes. We adapted the PCR for synthesis and simultaneous labeling of DNA fragments with a non-radioactive steroid compound called digoxigenin. This labeling procedure was used to generate a digoxigenin-labeled internal probe for the chimeric bcr/abl mRNA. The assay described is based on the hybridization of the amplified bcr/abl sequence to the non-radioactively labeled probe and on the subsequent detection by an enzyme-linked immunoassay and enzyme-catalyzed color reaction. Using this protocol, we investigated 20 patients with CML along with six healthy individuals and two cell lines derived from patients with CML for the presence of the bcr/abl rearrangement. It is shown that the assay is both highly sensitive and specific and that it is readily applicable to the routine diagnosis of CML. In addition, the assay could be adapted to a number of clinical diagnostic uses.

Colorimetry↗
PubMed1990

Nonradioactive labeling of probe with digoxigenin by polymerase chain reaction.

Probes nonradioactively labeled with the steroid hapten digoxigenin have several intriguing properties, including a high sensitivity equivalent to that of radioactive probes, speed in detection, low hazard potential in handling, and possibility of long-term storage. The use of polymerase chain reaction for labeling probe has been demonstrated to offer various advantages including efficient labeling of fragments as small as 100 bp, direct labeling of genomic DNA, and labeling with subnanogram amounts of input DNA. We therefore investigated whether this technique could be adapted for labeling with a relatively large molecule such as digoxigenin. In this report, we show that the polymerase chain reaction is a very efficient technique for synthesis of digoxigenin-labeled DNA and we present an extremely simple procedure for purification of the non-isotopically labeled fragments.

Base Sequence↗
PubMed1989

Rapid dot blot quantitation of viral DNA and amplified genes in less than 1,000 human cells.

The copy number of intracellular DNA sequences can be quantitated rapidly with great sensitivity in 100 to 1,000 cells as starting material. The method applies DNA from lysed cells to a charged nylon membrane that permits successive hybridizations with probes for different genes or DNA sequences. This method was tested with eight types of human cells, including leukemic cells, and has detected Epstein-Barr virus (DNA virus) in immortalized cells, integrated HTLV-I (RNA retrovirus) in infected cells, and determined copy numbers of the amplified multiple drug-resistant gene in human cells resistant to various cytotoxic agents. It could also be used for estimating copy number of transfected DNA in human or other mammalian cells. The described method is not as sensitive as polymerase chain reaction may potentially prove, but is easily quantitated for accurate clinical diagnosis where sensitive and quantitative assays must be carried out on a limited number of cells. Examples of the method's clinical application are the staging of human neuroblastomas and the evaluation of oncogene amplification, which has prognostic value for both overall survival and relapse time in breast cancer patients.

Cell Line↗
PubMed1989

Duration of first remission as an indicator of long-term survival in chronic myelogenous leukaemia.

Approximately 31 patients with chronic myelogenous leukaemia (CML) are documented in the literature who survived more than 10 years after diagnosis. We present a CML-patient whose survival of 27 years is probably the longest reported so far. The analysis of the course of disease in these patients revealed that the duration of unmaintained first remission after chemotherapy is of high prognostic significance. In 17 of 24 evaluable patients the remission lasted more than 1 year and in another five at least 6 months (mean 73.8 months, range 0-240 months). In most patients busulfan was used as initial therapy. There was no correlation between the amount of drug given and the duration of remission or survival. Other parameters such as sex, age, initial leucocyte counts, differential count, haemoglobin, platelet count or spleen size seemed to have no prognostic relevance. While approximately 25% of CML patients with typical duration of survival exhibit a Ph1 chromosome mosaicism only, this finding was present in nearly half of the long-term survivers.

Adult↗
PubMed1989

Beta 2-microglobulin. A reliable parameter for differentiating between graft rejection and severe infection after cardiac transplantation.

We investigated the role of beta 2-microglobulin as a noninvasive parameter to monitor acute rejection and severe infection in 45 consecutive heart transplant recipients. Endomyocardial biopsy revealed moderate (41 patients) or severe (three patients) rejection in 44 patients. Severe infections of bacterial septicemia (11 patients), bronchopneumonia (two patients), and viral infection (seven patients) were detected by a meticulous schedule of various clinical and laboratory tests. beta 2-Microglobulin levels in serum, generally corrected for serum creatinine, were significantly elevated in patients with infections (median, 6.3 mg/l; range Q10-Q90, 3.47-10.27 mg/l) compared with levels in patients with rejection (p less than 0.0001) or in patients in obviously good condition (p less than 0.0001). At the onset of acute rejection, the median corrected beta 2-microglobulin serum level was 1.56 mg/l (range Q10-Q90, -0.05-3.46 mg/l) and was significantly different from the control group (p less than 0.01). In addition, density function and empirical quantile analyses allowed us to define ranges of beta 2-microglobulin levels that would differentiate between rejection (2.05-3.46 mg/l) and infection (greater than 3.46 mg/l). With these values, sensitivity and specificity were 0.9 and 0.938 for detection of infection and 0.23 and 0.925 for detection of rejection, respectively. By means of beta 2-microglobulin, two cases of infection were misinterpreted as rejection (10%), and four of 44 rejections were mistaken for infections (9%). We conclude that measurements of beta 2-microglobulin may improve the management of heart transplant patients.

Adult↗
PubMed1988

B-lymphocytic hairy cells contain no HTLV-II DNA sequences.

HTLV-II has been found in some cases of the rare T-cell form of hairy-cell leukemia (HCL) and in a leukopenic chronic T-cell leukemia mimicking HCL. We asked whether the virus is implicated in the more frequent B-cell form of HCL. DNA extracted from the mononuclear cells derived from spleen (eight cases) or peripheral blood (eight cases) of 16 patients with the B-cell form of HCL was probed. No viral sequences were detected at levels of sensitivity as low as one viral genome in five cells. Therefore HTLV-II may not be involved in the B-cell form of HCL.

B-Lymphocytes↗
PubMed1987

[Recombinant (IFN-alpha 2b) therapy in hairy cell leukemia].

Eighty-five patients with hairy-cell leukemia were treated in a multicentric "open label" study with IFN-alpha 2b and evaluated. Induction therapy was 2 X 10(6) U IFN-alpha 2b/m2, 3 times a week, s.c. The results show this regimen to be highly effective with only a few tolerable and transient side effects consisting mainly of flu-like symptoms. After 6 months of therapy 4% CR, 69% PR, and 16% MR, were noted. In a small group of four patients who had achieved CR or PR, we tested the effect of varying doses for maintenance therapy. Our preliminary results indicate that a relapse caused by interruption of IFN therapy or dose reduction to 3 X 10(6) U given once a week, o.c. could be successfully treated by readministration, or escalating the dosage of IFN. It seems that remission maintenance requires long-term treatment with IFN. In a short-term in vitro test we studied the effect of IFN-alpha 2 on the incorporation of 3H-thymidine and 3H-uridine into hairy cells of five patients. Fort both precursors no appreciable effect was detected. However, after prolonged incubation for 48 h, a significant enhancement of 3H-uridine incorporation was observed, while 3H-thymidine incorporation remained unaffected. Cell marker analysis performed with monoclonal antibodies before and after incubation of hairy cells with IFN-alpha 2 for up to 7 days did not reveal any change of the phenotype of hairy cells.

Clinical Trials as Topic↗
PubMed1987

Interferon alpha-2 for hairy cell leukemia: evidence for induction of RNA synthesis in hairy cells and failure to correlate enhancement of natural killer cells with elimination of hairy cells.

The effect of human recombinant interferon alpha 2 (IFN alpha 2) on hairy cells obtained from 16 patients was evaluated. All patients promptly responded to induction of remission with 2 X 10(6) U/m2 interferon alpha 2 b, three times a week, sc. In order to achieve a more detailed insight into the mode of action of interferon in this disease, we determined the influence of IFN alpha 2 on the incorporation of radiolabeled thymidine and uridine into hairy cells. While both 3H-thymidine and 3H-uridine incorporation were unaffected by IFN alpha 2 in a 3-hour incubation period, a significant increase in uridine incorporation into hairy cells, but not CLL cells, was observed after 24 h. Cell surface marker analysis performed with monoclonal antibodies did not reveal a quantitative alteration of the immunophenotype of hairy cells in vitro. In addition, natural killer cells, assessed by monoclonal antibodies and a cytotoxicity assay against K 562 cells, were found to be decreased in 9 out of 10 patients prior to therapy. Although IFN alpha 2 could stimulate natural killer cells in vivo, we did not find a consistent correlation between the activation of these cells and the response to therapy. We conclude, therefore, that NK cells play no major role in the regression of hairy cells. Furthermore, IFN alpha 2 does not alter antigenic determinants in vitro, but leads to an enhanced incorporation of 3H-uridine into hairy cells in vitro, thus indicating a possible role for the induction of RNA synthesis in vivo.

Adult↗
PubMedDate not supplied

[Treatment of chronic myeloid leukemia in children and adolescents--concept of the multicenter pilot study CML-ped].

CML is a rare malignancy in childhood not yet being treated by an established protocol of the Society of Pediatric Oncology and Hematology (GPOH). Up to now only allogeneic bone marrow transplantation (BMT) offers a curative treatment option. After being enrolled into the study "CML-päd" patients with a matched sibling donor should undergo BMT within six months after diagnosis and within one year if an unrelated donor can be identified. Progress in palliative therapy results from the experience in adult patients: Hydroxyurea in combination with interferon alpha (IFN) is the treatment of choice. One aim of the study is to monitor quantitatively in bone marrow aspirates the activity of the disease in all patients on treatment every three months by performing cytogenetics and molecular analysis. As a pilot protocol intensification of treatment by idarubicine and cytarabine is scheduled one year after diagnosis for those patients not undergoing BMT and exhibiting after IFN treatment less than partial response. After progress to the accelerated phase of the disease a decision has to be made on an individual basis whether the patient should undergo new experimental treatment approaches.

Adolescent↗
PubMedDate not supplied

Successful carboxypeptidase G2 rescue in delayed methotrexate elimination due to renal failure.

We report on an 18.5-year-old woman with osteosarcoma and delayed methotrexate (MTX) elimination due to renal failure after high-dose MTX, in whom rescue with high doses of folinic acid caused intolerable side effects. In this life-threatening clinical situation, the patients was rescued by the administration of recombinant carboxypeptidase G2, a bacterial enzyme that rapidly hydrolyzes MTX into inactive metabolites. This is the first report on the successful clinical use of this alternative catabolic route for the elimination of MTX.

Adolescent↗