Biomedical subjects

J M Trujillo

Publications and source records attributed to J M Trujillo.

At least 55 records · Page 3Linked to original sources

PubMed1990

Biological characterization of multidrug-resistant human colon carcinoma sublines induced/selected by two methods.

Two independent multidrug-resistant (MDR) sublines, AdR1.2 and SRA1.2, were developed from the established human colon carcinoma cell line LoVo. AdR1.2 was developed by a long-term continuous exposure of LoVo cells to Adriamycin in stepwise increments of concentration; SRA1.2 was selected/induced by pulse treatments by using a single concentration of Adriamycin. The two resistant sublines were cross-resistant and cross-sensitive to a similar spectrum of cytotoxic agents. However, AdR1.2 was most resistant to Adriamycin among the nine agents tested, and SRA1.2 was most resistant to Vinca alkaloids. Although SRA1.2 had biological characteristics similar to those of LoVo, AdR1.2 had remarkably altered biological properties, including no detectable carcinoembryonic antigen secretion, a smaller proportion of proliferating cells and a lower growth rate, lower fraction of cells in S phase, a lower colony-forming ability, and smaller colonies. In addition, the resistant phenotype of AdR1.2 was reversed when the cells were grown in a drug-free medium, whereas SRA1.2 maintained its resistance for at least 10 months under similar conditions. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis of the plasma membrane proteins demonstrated overproduction of an Mr 130,000 protein in both the resistant sublines. The Mr 130,000 protein was not immunoreactive with C219 monoclonal antibody against p170, but the absence of Mr 130,000 protein in an AdR1.2 revertant and the parental LoVo suggests that it is an MDR-related plasma membrane protein. The absence of a 46-kDa cytosolic protein and the presence of a Mr 150,000 plasma membrane protein were found in AdR1.2 but not in SRA1.2. This Mr 150,000 protein immunoreacted with C219. This protein was also present, although in a reduced amount, in an AdR1.2 revertant that retained three times the MDR of LoVo cells and was thus comparable to SRA1.2. The two MDR sublines thus may represent two independent subclones which may serve as two different models for the study of multidrug resistance in human colon cancer.

Adenocarcinoma↗

PubMed1990

Strategy for breakpoint cluster region analysis in chronic myelocytic leukemia in a routine clinical laboratory.

Despite the increasing reliance on breakpoint cluster region (bcr) determinations in diagnosis of chronic myelocytic leukemia (CML), few reports have dealt with the practical aspects of specimen analysis. In the setting of a routine molecular diagnostics laboratory, samples from 68 patients with active CML were evaluated for bcr rearrangements, with the use of a variety of enzymes and two probes. The data have been used to develop an efficient strategy for bcr screening and breakpoint determination. Screening with the universal bcr (UBCR) probe on Xba I and BgI II digests yielded bcr rearrangements in 100% of the Ph1-positive patients and three of the seven Ph1-negative patients, giving bcr analysis a sensitivity of 100%. A single-enzyme screen using the UBCR probe would have resulted in a false negative rate of 10%. The false negative rate was determined during the breakpoint site analysis from additional digests hybridized to both the 3' and UBCR probes. The false negative rate for the 3' probe was 26.5%, because of deletions or 5' rearrangements. The method of breakpoint site determination was dependent on screening results. In 78% of cases, one additional hybridization with two enzyme digests was required. During breakpoint site analysis, a rare false negative result was also demonstrated with Bam HI and Eco RI. This screening strategy has made bcr analysis competitive with cytogenetic analysis at the authors' institution; although turnaround time may be slightly longer, bcr analysis can yield information (such as detecting bcr-positive/Ph1-negative patients and determining breakpoint site) that cannot be obtained by cytogenetics.

Chromosome Mapping↗

PubMed1990

Alpha interferon dose-dependent suppression of secondary clones in a patient with Philadelphia-positive chronic myelogenous leukemia.

A patient whose chronic myelogenous leukemia (CML) was treated with interferon alpha (IFN-alpha) is described. The disease showed karyotypic evolution during the chronic phase and the later myeloid acceleration. Both of these secondary clonal phenomena responded to IFN-alpha dose escalation. The case illustrates the dose dependence of CML responses to IFN-alpha. The phenomenon of clonal evolution is discussed in the context of this patient's disease.

Clone Cells↗

PubMed1990

[Vascular pathology of the temporal bone].

In a review of our cases over the last twenty years a series of patients from the E.N.T. clinic has been selected, all of which exhibit a clinical history of tinnitus and vertigo, and in some cases hearing loss. Neuroradiological exploration was able to show that a vascular aetiology was responsible in every case. In the literature concerning this type of otological pathology these procedures are seldom found. This study presents our cases and draws attention to the high risk which surgical intervention entails if there is an undiagnosed vascular mass in the middle ear.

Angiography↗

PubMed1990

Developmental and differential regulation of human MPO gene in leukemic cells.

Northern blot analysis of RNA isolated from HL-60 cells before and after differentiation induction by TPA and DMSO showed that four MPO mRNA species (3.3, 3.1, 2.7, and 2.5 kb, respectively designated alpha 1, beta 1, alpha 2, and beta 2) are expressed in HL-60 cells. However, alpha 2 and beta 2 lack part of the 3' end sequence due to different polyadenylation sites. The steady state levels of alpha 2 and beta 2 MPO mRNA increase significantly after 1 hr of induction, while all four MPO mRNA species decrease dramatically after 10 hr of induction. Our results demonstrate that MPO gene expression is developmentally and differentially regulated. Northern blot analysis of RNA isolated from blast samples of acute myelogenous leukemia (M0-M5) and chronic lymphocytic leukemia (CLL) patients indicate that four MPO mRNA species are expressed in M1-M4 but are undetectable in M5 and CLL. Primer extension and S1 nuclease protection analysis of the MPO mRNA revealed a single transcription initiation site for the MPO gene.

Base Sequence↗

PubMed1989

Molecular heterogeneity in acute leukemia lineage switch.

Six cases of acute leukemia that underwent lineage switch from acute lymphocytic leukemia to acute myelogenous leukemia are reported. The mean age of the patients was 24 years, time to conversion was 36 months, and survival after conversion was only 3 months. Of the three cases which showed abnormal metaphases at both diagnosis and conversion, two (cases 2, 5) showed related cytogenetic abnormalities, and the third showed (case 3) independent chromosomal changes. Molecular analysis for immunoglobulin heavy chain and T-cell receptor beta chain genes showed that five of the six cases had rearrangement of at least one of these lymphoid associated genes at conversion to acute myelogenous leukemia. The single case (case 3) in which there were no lymphoid gene rearrangements at conversion was also the only case in which independent karyotypic abnormalities at diagnosis and conversion were demonstrated. Our findings suggest that lineage switch can represent either relapse of the original clone with heterogeneity at the molecular level or the emergence of a second new leukemic clone without molecular heterogeneity.

Antigens, CD↗

PubMed1989

Studies of BCR and ABL gene rearrangements in chronic myelogenous leukemia patients by conventional and pulsed-field gel electrophoresis using gel inserts.

Continual monitoring of the presence of the Philadelphia (Ph) chromosome in patients with chronic myelogenous leukemia (CML) is important for diagnosis as well as evaluation of therapy response of these patients. Because the Ph chromosome has been characterized molecularly to involve a reciprocal translocation between the ABL and BCR genes, there is an increasing interest in the use of molecular probes to detect chromosomal rearrangements in this disease. While rearrangements involving the bcr region of the BCR gene can be detected by conventional gel electrophoresis (CGE), detection of those involving ABL generally requires pulsed-field gel electrophoresis (PFGE). Currently, however, CGE and PFGE require different methods of cell preparation, with isolated DNA used in CGE and gel inserts containing whole cells used in PFGE. In this study, we show that the gel-insert method of DNA preparation can be adapted for use in CGE with slight modification of the gel-running conditions. The advantages of this method are demonstrated by studying both bcr and ABL rearrangements in bone marrow and peripheral blood samples of CML patients. Furthermore, we report a novel finding that chromosomal breakpoints in the ABL gene of CML patients occur predominantly between exons 1b and 1a.

Bone Marrow↗

PubMed1989

Mutagen sensitivity and cancer susceptibility. Report of a cancer-prone family.

A cancer-prone family was studied to determine if certain chromosomal abnormalities might have predisposed members to develop diverse types of malignancies. The types of neoplasia that occurred in this family included cancers of the breast and stomach, multiple myeloma, dermatofibrosarcoma, Wilm's tumor, and leukemia; the latter three occurred in children at an early age. Peripheral lymphocytes from 13 family members were examined for the presence of constitutional chromosomal abnormalities, fragile sites, and mutagen sensitivity. Our data shows that all living members of this family who had cancers were hypersensitive to chromosome breakage induced by bleomycin. In contrast, neither constitutional chromosomal abnormality nor heritable type of folate-sensitive fragile site was observed in any member. The above findings suggest that genetic defects affecting chromosomal breakage and repair may be contributing factors for cancer development in several members of this family.

Adult↗

PubMed1989

Environmental exposures in cytogenetically defined subsets of acute nonlymphocytic leukemia.

Three previous investigations have reported a relationship between clonal chromosome abnormalities in marrow of patients with acute nonlymphocytic leukemia and employment in occupations involving mutagenic chemicals, but the effects of other exposures were not described. Environmental exposure profiles, gathered by questionnaire, were therefore compared using a case-control study design in 235 newly diagnosed patients with acute nonlymphocytic leukemia: 126 with abnormal and 109 with normal karyotypes. The univariate odds ratio for occupation at diagnosis was 4.6, which, when adjusted for demographic and other exposures by logistic regression, was reduced to 2.5 (95% confidence interval, 0.5 to 12.8). Adjusted point estimates for other exposures were 4.3 (1.4 to 13.3) for prior cytotoxic therapy, 1.7 (0.9 to 3.1) for cigarette smoking, and 1.9 (1.0 to 3.4) for alcohol use. Dose-response relationships were present for both tobacco and alcohol consumption. Associations between specific abnormalities (+8, -7I-7q, [corrected] inv16, t[8;21]) and certain exposures were also present. These results suggest that life-style exposures may be associated with cytogenetic lesions in persons with acute nonlymphocytic leukemia.

Alcohol Drinking↗

PubMed1989

Ras oncogene mutations are rare late stage events in chronic myelogenous leukemia.

DNA from bone marrow and peripheral blood samples of 44 chronic myelogenous leukemia (CML) patients were analyzed for the presence of mutations of codons 12, 13 or 61 of the N-ras, H-ras, or K-ras genes. In seven patients, samples were available from both their chronic phase and blast crisis. A total of 29 samples examined were at chronic phase and 22 were at blast crisis (eight lymphoid, eight myeloid, and six undifferentiated). No mutations were identified in N-ras or H-ras. Two patients in myeloid blast crisis had K-ras mutations, one patient at codon 12, the other at codon 13. In the former patient the mutation was not present and the latter patient was not tested in chronic phase. Our findings indicate ras mutations are an infrequent late stage event in CML that occur in myeloid blast crisis.

Genes, ras↗

PubMed1989

Stimulation of nonclonal hematopoiesis and suppression of the neoplastic clone after treatment with recombinant human granulocyte-macrophage colony-stimulating factor in a patient with therapy-related myelodysplastic syndrome.

A complete hematologic remission was achieved in a patient with therapy-related preleukemia and transfusion-dependent pancytopenia after treatment with recombinant human granulocyte-macrophage colony-stimulating factor (GM-CSF). The patient remained in remission for nearly 1 year despite the discontinuation of GM-CSF treatment. Several lines of evidence suggest that normal hematopoiesis was restored after GM-CSF treatment. First, the cytogenetic anomaly, which was present before GM-CSF, completely disappeared after three cycles of treatment. Cytogenetic conversion was documented by conventional karyotypic evaluation of mitotic bone marrow cell preparations as well as by premature chromosome condensation analysis of the nonmitotic cells of bone marrow and peripheral blood. Second, the growth pattern and cycle status of bone marrow granulocyte-macrophage (CFU-GM) and erythroid (BFU-E) progenitor cells were found to be normal during remission. Third, X chromosome-linked restriction fragment length polymorphism-methylation analysis of DNA from mononuclear cells (greater than 80% lymphocytes) and mature myeloid elements showed a polyclonal pattern. These findings suggest that restoration of hematopoiesis in this patient after GM-CSF treatment may have resulted from suppression of the abnormal clone and a selective growth advantage of normal elements.

Adenocarcinoma↗

PubMed1989

Detection of two alternative bcr/abl mRNA junctions and minimal residual disease in Philadelphia chromosome positive chronic myelogenous leukemia by polymerase chain reaction.

The Philadelphia (Ph') chromosome in chronic myelogenous leukemia (CML) results in fusion of the bcr gene and c-abl oncogene, which transcribes into two types of chimeric bcr/abl mRNAs: the L-6 junction and the K-28 junction. By means of a highly sensitive assay, combination of reverse transcription and polymerase chain reaction (RT/PCR), we analyzed 38 blood samples obtained from 31 patients with Ph'-positive CML and two patients with Ph'-negative bcr rearranged CML. Among the 21 samples obtained in chronic phase, eight patients had the L-6 mRNA, 11 had the K-28 mRNA, and two had both the L-6 and K-28 mRNAs. Among the nine samples obtained in blast crisis, four contained the L-6 mRNA, two contained the K-28 mRNA, and three contained both the K-28 and L-6 mRNAs. This finding supports the concept of alternative splicing of bcr/abl mRNAs transcribed in Ph'-positive CML. However, it appears to be a rare event. Of the eight samples obtained from eight patients who had achieved complete cytogenetic remission and negativity for bcr region rearrangement for 6 months to 3 years after recombinant alpha interferon (r alpha-IFN) therapy, all of them showed evidence of minimal residual Ph'-positive clones as detected by the RT/PCR assay. This finding suggests that interferon therapy suppresses the proliferation of the Ph'-positive clones, but it does not completely eradicate the Ph'-positive stem cells.

DNA-Directed DNA Polymerase↗

PubMed1989

Peripheral acute leukemia: high peripheral but low-marrow blast count.

We report five patients who had greater than 30% peripheral blasts and less than 30% marrow blasts. By the current standards these cases would be classified as myelodysplastic syndrome. Four of five patients progressed to acute leukemia within approximately 1 1/2 months of developing greater than 30% peripheral blasts. Two of these four patients had evidence of acute leukemia by criteria other than marrow involvement at the time of presentation: one patient had evidence of multifocal dermal involvement; and the other patient had a cytogenetic abnormality, t(8;21), found predominantly in acute leukemia. The fifth patient developed acute leukemia 2 years after initial presentation with greater than 30% peripheral blasts. Although our series of patients is small, it does suggest that patients who have greater than 30% peripheral blasts should be considered an acute leukemia, even with less than 30% marrow blasts.

Acute Disease↗

PubMed1989

Myeloid surface antigen-positive acute lymphoblastic leukemia (My+ ALL): immunophenotypic, ultrastructural, cytogenetic, and molecular characteristics.

Leukemic blasts from 40 consecutively admitted adults with untreated acute lymphoblastic leukemia (ALL) were examined for myeloid surface antigen expression. Of these, 14 (35%) were reactive with one or more myeloid monoclonal antibodies. Each example of myeloid surface antigen-positive (My+ ALL) met the standard morphologic and cytochemical criteria for ALL. In addition, none of the 13 samples studied for ultrastructural evidence of myeloperoxidase met the criteria for acute myelocytic leukemia (AML). All patient samples reacted with lymphoid monoclonal antibodies: CD10+ (8 patients), CD19+ CD10- (2 patients), T cell+ (2 patients), and T cell+ CD10+ (2 patients). Coexpression of myeloid and lymphoid determinants was established by two-color immunofluorescence studies using flow cytometry in five of five samples analyzed. Cytogenetic abnormalities that have been associated with myeloid and mixed leukemias were common, including t(9;22), 7q-, abnormalities of 11q with or without a translocation, 20q-, and -5. Blasts from seven patients were studied at the molecular level. Immunoglobulin heavy chain gene rearrangements were detected in five of five samples with B cell+ T cell- phenotypes. One sample that was T cell+ CD10+ was germline for the immunoglobulin heavy chain and the T cell receptor gamma- and beta-chain genes. The other patient with T cell+ CD10+ blasts relapsed with AML following allogeneic bone marrow transplantation. The leukemia cells at the time of diagnosis and the cells at relapse demonstrated similar cytogenetics and the same immunoglobulin gene rearrangement, suggesting a clonal relationship. As a group, the My+ ALL patients had a significantly decreased complete remission rate when compared to My- ALL patients. Further studies at the molecular level will be required to determine the significance of karyotype abnormalities in My+ ALL.

Adolescent↗

PubMed1988

Stimulation of myelopoiesis in patients with aplastic anemia by recombinant human granulocyte-macrophage colony-stimulating factor.

Aplastic anemia is a syndrome in which pancytopenia occurs in the presence of hypocellularity of the bone marrow. To assess the biologic activities of recombinant human granulocyte-macrophage colony-stimulating factor (GM-CSF) in aplastic anemia, we gave GM-CSF (60 to 500 micrograms per square meter of body-surface area) to 10 patients with moderate or severe disease, by continuous intravenous infusion daily for two weeks, and repeated the treatment after a two-week rest period. The treatment increased the white-cell count (1.6- to 10-fold) in all patients, primarily because of an increase in the numbers of neutrophils (1.5 to 20-fold), eosinophils (12- to greater than 70-fold), and monocytes (2- to 32-fold). Rates of hydrogen peroxide production in purified granulocyte fractions increased during GM-CSF treatment. Increases in bone marrow cellularity, myeloid precursor cells, and myeloid:erythroid cell ratios accompanied the white-cell response. Despite the in vivo response of the white-cells, the concentration of colony-forming cells remained the same. Measurable concentrations of interleukin-2 (2 to 15 units per milliliter) were found in the serum of 8 patients, and high levels of erythropoietin (81 to 1200 IU per liter) were found in 10 patients. The predominant side effects were constitutional symptoms. These results indicate that recombinant human GM-CSF is effective in stimulating myelopoiesis in patients with severe aplastic anemia and may benefit some patients in whom the disorder is refractory to standard forms of therapy.

Adolescent↗

PubMed1988

The myeloperoxidase gene is translocated from chromosome 17 to 15 in a patient with acute promyelocytic leukemia.

This study demonstrates that a differentiation-specific gene, the myeloperoxidase (MPO) gene, is translocated in a patient with acute promyelocytic leukemia (APL). The MPO gene recently has been mapped to chromosome #17, close to the breakpoint involved in the t(15;17) commonly seen in APL. By in situ hybridization, we showed that this gene was translocated from chromosome #17 to #15 in an APL patient. Although the significance of this translocation remains unclear, MPO is known to be highly expressed in APL. The causal relationship between the high expression and translocation of this gene requires further investigation.

Chromosome Banding↗

PubMed1988

Chronic myelomonocytic leukemia with trisomy 8 and a related clone with trisomy 8 and t(15;17).

We describe a patient with chronic myelomonocytic leukemia who showed trisomy 8 in 100% of his bone marrow metaphases. Of interest was the finding that 20% of the Giemsa-banded metaphases also showed t(15;17)(q22;q21), with breakpoints indistinguishable from those seen in cases of acute progranulocytic leukemia (APL). The patient showed no morphologic or clinical evidence of APL, and he died after 6 months, with no evidence that the disease had progressed to acute leukemia. Although cytogenetically the breakpoints appeared to be the same as those in APL, we suspect that this patient's translocation may have differed at the molecular level from the t(15;17) commonly seen in APL.

Aged↗

PubMed1988

Detection of minimal residual bcr/abl transcripts by a modified polymerase chain reaction.

The Philadelphia (Ph1) chromosome in chronic myelogenous leukemia (CML) involves reciprocal translocation of the bcr gene and the c-abl oncogene. The fused bcr/abl gene is transcribed into two types of chimeric mRNA. By means of a combined method of S1 nuclease protection and polymerase chain reaction, we amplified sequences representative of the chimeric bcr/abl transcripts. Only 5 micrograms of total cellular RNA is needed and the chimeric bcr/abl message can be detected at a dilution of 1:100,000. We also detected residual chimeric bcr/abl transcripts in the remission samples from two Ph1-positive CML patients. This technique has the potential to identify a subpopulation of Ph1-positive CML patients in remission who are at high risk of relapse.

Base Sequence↗