Search PubMed⌕ Search

Biomedical subjects

J Radich

Publications and source records attributed to J Radich.

26 records · Page 2Linked to original sources
PubMed1995

Multiplex PCR of bcr-abl fusion transcripts in Philadelphia positive acute lymphoblastic leukemia.

We describe a multiplex PCR assay for the detection of bcr-abl fusion mRNA in Philadelphia chromosome positive acute lymphoblastic leukemia (Ph + ALL). The assay provides a quick method for screening p190 (e1:a2) and p210 (b2:a2 or b3:a2) bcr-abl mRNAs simultaneously. The assay proves to be highly sensitive with detection of as little as one positive bcr-abl-expressing cell in a background of 10(5) negative bcr-abl cells. Bone marrow and peripheral blood specimens from six patients were in total accordance when run by multiplex PCR and by the single primer PCR approach. The multiplex bcr-abl assay may prove to be highly useful for screening newly diagnosed patients with ALL for the bcr-abl fusion transcript and in following the course of disease during therapy.

Base Sequence↗
PubMed1995

Bone marrow transplantation for chronic myelogenous leukemia.

Based on our understanding of CML, we recommend that patients age 65 or less with newly diagnosed CML should be evaluated to determine the stage of their disease and should be human lymphocyte antigen-typed along with their siblings. Patients age 55 years and younger who have matched or single antigen mismatched siblings should be advised to undergo BMT as soon as possible and patients up to age 65 should be considered for BMT early in their disease course if in good health. Patients age 55 years or younger without appropriately matched family member donors should have a search for an unrelated donor initiated and should be offered BMT if an appropriate donor is found. Patients for whom no donor is found and older patients without family matches can be considered for entry onto clinical trials evaluating autologous BMT or other experimental approaches.

Aged↗
PubMed1995

Polymerase chain reaction-based detection of minimal residual disease in acute lymphoblastic leukemia predicts relapse after allogeneic BMT.

We studied 20 patients who had received allogeneic bone marrow transplants for acute lymphoblastic leukemia. Using the polymerase chain reaction (PCR), we examined them for the presence of immunoglobulin heavy chain variable-diversity-junctional (IgH V-D-J) gene rearrangements as a marker of minimal residual disease (MRD). Seventeen of the patients were transplanted in relapse or for primary refractory disease, and three were transplanted in "high risk" remission. Thirteen patients had at least one positive PCR assay for MRD in the first 100 days after transplant; two died of nonleukemic causes, while all the remaining 11 relapsed. Seven patients had all negative PCR assays; two died of nonleukemic causes, four remain alive and well, and one patient with consistently negative PCR assays relapsed 47 days after his last negative test. Considering PCR status as a time-dependent covariate, the relative risk of relapse for PCR-positive patients compared to PCR-negative patients is 6.4 (p = 0.0067; 95% CI, 1.6-24.4), and the relative risk of relapse or death is 4.8 (p = 0.0052; 95% CI, 1.6-14.2). The Kaplan-Meier estimate of relapse at 1 year for PCR-positive patients is 100% compared to 33% for PCR-negative patients. The estimate for disease-free survival at 1 year for PCR-positive patients is 0% compared to 44% at 3 years for the PCR-negative group. The PCR assay for MRD appears to be a sensitive and specific test, identifying patients at high risk of relapse following allogeneic BMT who might benefit from further therapeutic interventions.

Adolescent↗
PubMed1994

Rapid RT-PCR amplification from limited cell numbers.

We describe a rapid and efficient RT-PCR method particularly suited to procedures involving limited cell and target gene copy numbers. Purified leukocytes and myeloid colonies derived from patients with chronic myelogenous leukemia (CML) in chronic phase were used for direct RT-PCR. Purified cells and colonies were lysed using a small quantity of DEPC-treated water containing RNasin as an RNA inhibitor. The untreated lysate was either used immediately for RT-PCR or frozen at -70 degrees C for later use. By this method we were able to consistently amplify bcr-abl transcripts from as few as 10 cells. No noticeable difference was observed between products amplified from fresh and frozen samples.

Base Sequence↗
PubMed1993

PCR cloning of an orphan homeobox gene (PRH) preferentially expressed in myeloid and liver cells.

Homeobox genes are members of a family of transcription factors that regulate tissue development in many different organisms. We set out to identify homeobox genes that might play a role in hematopoiesis. Using degenerate oligonucleotide primers corresponding to conserved homeobox sequences in the polymerase chain reaction (PCR), we cloned from the HL60 promyelocytic cell line a homeobox gene we now designate PRH. We mapped this gene, which was not homologous to any of the previously described homeobox genes, to chromosome 10, a region outside of the known genomic homeobox clusters. Northern blot hybridization indicates that PRH is preferentially expressed in myeloid and liver cells. The structure, chromosomal location, and pattern of expression of PRH indicate that it represents an orphan homeobox gene that may regulate the lineage development of certain hematopoietic cells.

Amino Acid Sequence↗
PubMed1989

Rare occurrence of N-ras point mutations in Philadelphia chromosome positive chronic myeloid leukemia.

Point mutations of the N-ras oncogene are relatively common in acute myelogenous leukemia (AML) cells, occurring in some 25% to 50% of patient samples. We used a technique involving the direct nucleotide sequencing of in vitro amplified N-ras genomic fragments to determine the frequency of N-ras point mutations in chronic myeloid leukemia (CML) cells at various stages of the disease. This approach will detect N-ras point mutations in a mixed population of cells if the mutation is present in 25% or more of the cells. We could not demonstrate any point mutation at N-ras codons 12,13 or 59-63 in any of the 44 CML cases analyzed, which included 21 blast crisis samples. In contrast with AML N-ras point mutations are exceedingly rare in CML.

Gene Rearrangement↗
PubMedDate not supplied

Hairy cell leukemia has a B-cell genotype.

The phenotype and, by inference, the cell of origin of some lymphocytic neoplasms has been defined by surface marker studies; however, the precise cellular origin of other neoplasms of the lymphoid system is still unknown. For example, with reference to hairy cell leukemia (HCL), cell marker data has been used in support of a monocytic, a T cell, or a B cell origin. If hairy cell leukemia is a B cell-derived neoplasm, the controversy may be resolved by genotyping the cells, using the rearrangement of immunoglobulin genes as a marker of the B cell nature of the process. Rearrangement of these genes is detected using the Southern blot technique and cloned probes specific for the JH segment of the immunoglobulin genes. In this study, the arrangement of the immunoglobulin genes was analysed in normal tissue, in two accepted B cell lymphomas and in nine cases of hairy cell leukemia. DNA from peripheral blood leukocytes (two patients) and from the spleen (seven patients) revealed a discrete new JH restriction fragment length in the leukocytes of hairy cell leukemia cases. The presence of rearranged restriction fragments is interpreted as evidence of the existence of clonal B cell populations. Three of six samples had rearranged kappa light chain fragments. We conclude that most cases of hairy cell leukemia have a B cell genotype. The use of genotyping has wider application in the analysis of hematological malignancies.

B-Lymphocytes↗