Polymerase chain reaction: the molecular microscope of residual disease.
Explore the source record for details and available documents.
DNA, Neoplasm↗
Biomedical subjects
J Sklar
Publications and source records attributed to J Sklar.
Quantitation of T-cell DNA in cutaneous lymphoid infiltrates.
A method is described that allows the quantitation of T-cell DNA within a tissue biopsy specimen. This method is based on the densitometric evaluation of the multiband pattern of TCR-gamma gene rearrangements detectable in Southern blot analyses of polyclonal T-cell DNA digested with HindIII. These rearrangements can be detected down to a limit of approximately 5% T-cell DNA. The information derived from this type of analysis can be used to roughly assess the total T-cell content of lesional tissue specimens expressed as a percentage of total tissue DNA, and can be correlated with the pattern of T-cell infiltration visualized by immunohistology. This assessment can be used also to determine the threshold, expressed as a percentage of total lesional T-cell DNA instead of total tissue DNA, required for the detection of a monoclonal T-cell population by Southern blot analysis. These quantitative relationships may prove useful for studying cutaneous T-cell lymphoma and associated precursor conditions.
DNA↗
Nasal lymphoma. A clinicopathologic study with immunophenotypic and genotypic analysis.
We studied 13 cases of malignant lymphoma involving the nasal cavity, in six men and seven women, from 27 to 92 years of age (mean, 56 years; median, 55 years). All lymphomas had a diffuse pattern, with 10 of large-cell type (six immunoblastic polymorphous, one immunoblastic, three large cleaved cell), one of mixed small- and large-cell type and one of small cleaved-cell type. One case could not be subclassified. Angioinvasion and prominent necrosis were seen in 10 cases. Pseudoepitheliomatous hyperplasia of the overlying epithelium was present in five cases. Immunohistochemical studies on frozen or paraffin sections in nine cases revealed that the atypical cells were T cells in four cases (CD8+ in two cases) and B cells with monotypic immunoglobulin in two cases. In three cases, the findings were suggestive but not diagnostic of T lineage. Genotypic analysis in one of two cases of T-cell lymphoma revealed clonal rearrangement of the genes for beta and gamma chains of the T-cell receptor. Patients were treated initially with local radiation therapy (10 cases) or with radiation and chemotherapy (three cases). Eight patients (62%) had no relapse and were free of disease between 9 months and 23 years (mean, 6 years 5 months; median 2 years 1 month) after diagnosis. Five patients developed recurrent disease, three of whom were successfully salvaged. One patient was alive with tumor at the time of last follow-up and one died with tumor. Among cases of malignant lymphoma presenting with involvement of the nasal cavity, we find a high proportion of angioinvasive, diffuse large-cell lymphomas, with a predominance of T-cell type, and a relatively good prognosis when treated with radiation therapy.
Adult↗
Maintenance treatment of patients with myelodysplastic syndromes using recombinant human granulocyte colony-stimulating factor.
Myelodysplastic syndromes (MDS) are characterized by chronic refractory cytopenias resulting in increased risk of infection, bleeding, and conversion to acute leukemia. In an effort to improve these cytopenias we have treated 18 patients over a 6- to 8-week period with increasing daily subcutaneous doses of recombinant human granulocyte colony-stimulating factor (G-CSF). Sixteen patients responded with improvement in neutrophil counts. On cessation of treatment these counts returned to baseline values over a 2- to 4-week period. To maintain these improved blood counts 11 patients were treated with G-CSF for more prolonged periods. Ten patients again responded with an increase in total leukocyte counts (1.6- to 6.4-fold) and absolute neutrophil counts (ANC) (3.6- to 16.3-fold), with responses persisting for 3 to 16 months. A significantly decreased risk of developing bacterial infections was noted during periods with ANC greater than 1,500/mm3 as compared with periods of time with ANC less than 1,500/mm3. Two anemic patients had a greater than 20% rise in hematocrit over the study period, and 2 additional patients had a decrease in red blood cell transfusion requirements during G-CSF treatment. Bone marrow myeloid maturation improved in 7 of 9 maintenance phase patients. Three patients progressed to acute myeloid leukemia during treatment. The drug was generally well-tolerated and no severe toxicities were noted. These data demonstrated that G-CSF administered to MDS patients by daily subcutaneous administration was well-tolerated and effective in causing persistent improvement of the neutrophil levels and marrow myeloid maturation. These effects were associated with a decreased risk of infection and, in some patients, with decreased red blood cell transfusion requirements.
Colony-Stimulating Factors↗
Detection of non-Hodgkin's lymphoma in the peripheral blood by analysis of antigen receptor gene rearrangements: results of a prospective study.
Analysis of immunoglobulin (Ig) and T-cell receptor gene rearrangements, using Southern blot hybridization, has been applied to peripheral blood lymphocytes (PBL) in 335 samples from patients with non-Hodgkin's lymphoma. The incidence of circulating lymphoma cells detected by gene rearrangement analyses is related to the histologic subtype, clinical stage of disease, and clinical status. Among 104 patients studied at diagnosis, the incidence of positive analyses was 34% in low-grade lymphoma and only 8% in intermediate-grade lymphoma. Clonal Ig gene rearrangements were detected nearly universally in the small lymphocytic histologic subtype. PBL studies were related to the initial stage of disease: positive studies were seen in 35% of patients with stage IV disease, 29% of patients with stage III disease, and 12% of patients with stages I-II disease. The incidence of PBL rearrangements at the time of disease recurrence in 32 patients requiring cytoreductive therapy was 48%, somewhat greater than at initial diagnosis. A group of patients with low-grade lymphoma, who had treatment deferred after diagnosis or recurrence, was also studied; the incidence of PBL rearrangements was 38% in this population. Among 157 patients clinically free of disease, DNA analyses of the PBL were positive in only 10%. Subsequent relapse of disease in 26 patients was antedated by PBL rearrangement in only one patient. Clonal rearrangements detected in 15 patients have been followed by recurrence of clinical disease in only one patient over a median of 24 months from the time of analysis. The lack of detectable rearrangements in the peripheral blood in the majority of patients may be due to methodology or the biology of the disease. These issues may be further addressed with alternative methods for assessment of minimal disease. However, rigorous testing of any new molecular tool requires an adequate patient population in which disease status is closely monitored over a sufficient period of time.
Blotting, Southern↗
Rapid, nonradioactive detection of clonal T-cell receptor gene rearrangements in lymphoid neoplasms.
Southern blot hybridization analysis of clonal antigen receptor gene rearrangements has proved to be a valuable adjunct to conventional methods for diagnosing lymphoid neoplasia. However, Southern blot analysis suffers from a number of technical disadvantages, including the time necessary to obtain results, the use of radioactivity, and the susceptibility of the method to various artifacts. We have investigated an alternative approach for assessing the clonality of antigen receptor gene rearrangements in lymphoid tissue biopsy specimens. This approach involves the amplification of rearranged gamma T-cell receptor genes by the polymerase chain reaction and analysis of the polymerase chain reaction products by denaturing gradient gel electrophoresis. By use of this approach, clonal rearrangements from neoplastic lymphocytes constituting as little as 0.1-1% of the total cells in the tissue are detected as discrete bands in the denaturing gel after the gel is stained with ethidium bromide and viewed under ultraviolet light. In contrast, polyclonal rearrangements from reactive lymphocytes appear as a diffuse smear along the length of the gel. Our findings suggest that polymerase chain reaction combined with denaturing gradient gel electrophoresis may offer a rapid, nonradioactive, and sensitive alternative to Southern blot analysis for the diagnostic evaluation of lymphoid tissue biopsy specimens.
Base Sequence↗
What can DNA rearrangements tell us about solid hematolymphoid neoplasms?
Studies of DNA rearrangements in antigen receptor genes and at sites of chromosomal translocations are having an increasing impact on the diagnostic evaluation of lymphoid tissue biopsy specimens. Such rearrangements represent clonal molecular markers that can be very easily detected by Southern blot hybridization or polymerase chain reaction amplification. Detection of these markers can be useful in the diagnosis or subclassification of lymphoid neoplasms, particularly when morphologic or immunophenotypic findings alone are ambiguous. At the same time, application of DNA rearrangement to the evaluation of tissue specimens also has certain shortcomings and limitations, some of which may be overcome by current research methods or advances expected in the near future.
Antigens↗
Chromosomal translocations in lymphoid neoplasia: a reappraisal of the recombinase model.
Chromosomal translocations are common in tumors and are considered to represent one of the major classes of genetic alterations productive of the malignant phenotype. Although the molecular mechanisms leading to translocations are unknown, structural analysis of translocations in tumors derived from lymphocytes and their precursors has suggested the involvement of the lymphocyte recombinase, a normal cellular enzyme (or enzyme complex) that is essential for antigen receptor gene rearrangement. Recent observations of frequent recombinase-mediated interchromosomal exchanges between separate antigen receptor genes in normal lymphocyte precursors have provided clear examples of the ability of the recombinase to catalyze chromosomal translocation events, some of which may actually contribute to increased diversity of antigen receptor proteins. These findings have established that, even in the normal setting, the recombinase is not constrained to act only on gene segments linked in cis, but can also function in trans. Certain tumor-associated chromosomal translocations can be explained as subversions of this enzymatic capability.
Base Sequence↗
T cell receptor gene trans-rearrangements: chimeric gamma-delta genes in normal lymphoid tissues.
Joining of V-, D-, and J-region gene segments during DNA rearrangements within all antigen receptor genes involves recognition of the same highly conserved heptamernonamer sequences flanking each segment. In order to investigate the possibility that recognition of these conserved sequences may sometimes permit intergenic joining of segments among different antigen receptor genes, DNA of normal human lymphoid tissues was examined by polymerase chain reaction amplification for the presence of chimeric gamma-delta T cell receptor gene rearrangements. These studies detected V gamma-(D delta)-J delta and V delta-(D delta)-J gamma rearrangements in thymus, peripheral blood, and tonsil. Analysis of thymus RNA indicated that many of these rearrangements are expressed as V gamma-(D delta)-J delta-C delta and V delta-(D delta)-J gamma-C gamma transcripts. Most transcripts (19 of 20 complementary DNA clones studied) are appropriately spliced and show correct open translational reading frames across the V-(D)-J junctions. Thus, chimeric antigen receptor genes are generated in a subset of normal lymphoid cells, probably as a result of chromosomal translocations, and such genes may possibly contribute to increased diversity within the antigen receptor repertoire.
Base Sequence↗
Usefulness of nicardipine as monotherapy for chronic, stable angina.
Using a double-blind, Latin square protocol designed to detect dose response, nicardipine hydrochloride, a new calcium antagonist, was studied as monotherapy for stable exertional angina. Eighty-one patients were enrolled in the trial and 62 patients were included in greater than or equal to 1 primary efficacy analyses. Patients received 1 to 2 weeks of placebo run-in, then 5 weeks of treatment with placebo and with 10, 20 and 30 mg of nicardipine given 3 times daily. Patients completed symptom diaries, were monitored with 24-hour electrocardiographic Holter monitors and underwent serial exercise treadmill tests. By 1 hour, 10, 20 and 30 mg of nicardipine administered 3 times daily produced statistically significant, dose-related improvements in all key exercise parameters, which persisted at the 4-hour evaluation. The systolic blood pressure at rest and during exercise decreased, but the pulse slightly increased. The peak rate-pressure product was unchanged. The side effects were not severe. Nicardipine hydrochloride is an effective, well-tolerated medication for the treatment of stable exertional angina, and is a good alternative to currently available calcium antagonists.
Adult↗
Detection of Epstein-Barr viral genomes in Reed-Sternberg cells of Hodgkin's disease.
We used slot blot hybridization, Southern blot hybridization, and in situ hybridization to investigate the presence of Epstein-Barr virus (EBV) genomes in biopsy tissues from patients with Hodgkin's disease. Slot blot hybridization performed on DNA of tissue specimens from 16 patients revealed that biopsy tissue from 3 (19 percent) contained EBV DNA. Southern blot hybridization with a DNA probe containing the 500-base-pair tandem repeated sequences located at the termini of the EBV genome confirmed the findings of the slot blot hybridization in the three positive tissue specimens and indicated the monoclonality of the EBV-infected cells in such tissues. In situ hybridization performed on the three positive specimens and on two from a previous study localized EBV nucleic acid to the Reed-Sternberg cells and variants in all specimens, with intense hybridization to Reed-Sternberg cells in two, less intense but consistent hybridization to Reed-Sternberg cells in two, and focal hybridization to Reed-Sternberg cells in one. We conclude that EBV genomes are present within Reed-Sternberg cells and variants in some patients with Hodgkin's disease and that the infected cells are monoclonal.
DNA Probes↗
Consistent breakage between consensus recombinase heptamers of chromosome 9 DNA in a recurrent chromosomal translocation of human T cell leukemia.
Chromosomal translocations in lymphoid tumors frequently result from recombination between a normally rearranging antigen receptor gene and a normally non-rearranging second locus. The possibility that the lymphocyte recombinase apparatus plays a role in determining the position of breakage at the second locus has been a matter of controversy because of the inconsistent presence of heptamer-like recognition sequences adjoining breakpoints at this site. To further investigate this issue, sites of DNA recombination were analyzed in both the der(9) and der(7) products of t(7;9)(q34;q32), a recurrent translocation of human acute lymphoblastic leukemias (T-ALL). In each of three separate cases, the translocation has divided the TCR-beta locus, juxtaposing chromosome 9 DNA 5' to a J-region in the der(9) product and 3' to a D-region in the der(7) product, with variably sized N-insertions and small deletions detectable at the junctions. All three cases contain breakpoints in chromosome 9 DNA tightly clustered between two closely spaced, and oppositely oriented heptamer sequences, CAC(A/T)GTG, which perfectly match the consensus heptamer sequence recognized by the lymphocyte recombinase apparatus in normal antigen receptor gene rearrangement. In no case was there evidence of directly duplicated sequences in the two reciprocal products, as is often associated with recombination involving random staggered breakage of DNA. Taken together, these results support a mechanism for this particular translocation proceeding by recombinase-mediated breakage of both participating chromosomes.
Base Sequence↗
Detection of clonal T-cell receptor gene rearrangements in the peripheral blood of patients with mycosis fungoides/Sezary syndrome.
Involvement of the peripheral blood in mycosis fungoides/Sezary syndrome (MF/SS) has a significant impact upon prognosis, but it is often difficult to distinguish circulating cells of MF/SS from atypical reactive lymphocytes. We compared the standard morphologic method of identifying leukemic cells, the Sezary preparation, to a genotypic method using Southern blot analysis of T-cell receptor gene rearrangements in concurrent blood samples. We studied 26 MF/SS patients, five of them in remission, together with five controls from cases of various non-MF/SS skin diseases. Six of 26 MF/SS patients had morphologically atypical circulating leukocytes (3%, 4%, 5%, 14%, 16%, 19%). Seven of 26 MF/SS patients had clonal T-cell receptor gene rearrangements, including the four patients with the greatest percentages of atypical cells and three patients lacking atypical cells. Six of seven patients had skin disease at the time of sampling, including three with erythroderma, two with generalized thick plaques, and one with generalized patches, while one patient was in clinical remission. All five controls lacked morphologic and genotypic evidence of atypical or clonal T-cells. Relative to genotyping, in our series the Sezary preparation was less sensitive and less specific. There were three apparent false negative results in the Sezary preparations, and two potential false positive (patients with 3% and 4% atypical leukocytes); however, there was agreement between the two techniques in most cases. We conclude that gene rearrangement studies may provide an effective test with which to assess the peripheral blood of MF/SS patients.
Blotting, Southern↗
Clonal rearrangements of immunoglobulin genes and progression to B cell lymphoma in cutaneous lymphoid hyperplasia.
Cutaneous lymphoid hyperplasia (CLH) is a disorder characterized by the development of one or more skin lesions containing dense lymphoid infiltrates that exhibit the histopathologic features of a benign, reactive process. Nevertheless, some cases have been associated with the subsequent development of clinically overt lymphomas. This suggests that monoclonal populations may exist in some cases of CLH and that these cases may represent a subset more likely to evolve into lymphoma. To determine if such a subset of CLH can be distinguished, Southern blot analysis of DNA was used to study the immunogenotypic features of lesions from 14 patients with clinical, histopathologic, and immunopathologic findings characteristic of CLH. Five cases exhibited detectable clonal rearrangements of immunoglobulin genes. Furthermore, one of these five cases evolved into overt diffuse large cell lymphoma of B cell lineage during a 2-year follow-up of recurrent disease at the original cutaneous site. The immunoglobulin gene rearrangements of this lymphoma were identical to those of the prior CLH lesion. There was no evidence of detectable t(14;18) chromosomal translocations or clonal rearrangements of the beta gene of the T cell receptor in any case. It was concluded that CLH can be divided into two subsets based on the presence or absence of a clonal B cell population, and that overt lymphoma can arise from the former subset and contain the same B cell clone identified in the pre-existent CLH lesion.
Blotting, Southern↗
Long-term growth of malignant thymocytes in vitro.
We report a new methodology for the long-term growth of malignant T-lymphoblasts from patients with T-cell acute lymphoblastic leukemia (T-ALL) and T-cell lymphoblastic lymphoma (T-LL). When malignant cells were cultured in the presence of insulin-like growth factor I under hypoxic conditions, cellular proliferation occurred that resulted in the establishment of immortal cell lines from ten of 12 patient tumors. Authenticity of each cell line was verified by a direct comparison of the immunophenotype, karyotype, and immunogenotype with the patient's tumor cells. This improved method of cell culture permits frequent establishment of cell lines from patients with T-ALL/T-LL, thereby aiding in analysis of thymocyte transformation and neoplasia.
Adolescent↗
Acute torticollis secondary to rupture of the sternocleidomastoid.
Trauma to the neck musculature and cervical spine is frequently caused by hyperextension injuries which may result in muscular spasm or rupture. Partial rupture of the sternocleidomastoid muscle with subsequent formation of a fibrotic band is an unusual cause of acute torticollis. The case of a 21-year-old man who developed an acute torticollis and cervical pain after a motor vehicle accident is presented. Computed tomography scan demonstrated 75% rupture of the left sternocleidomastoid muscle with fibrotic band replacing the absent muscle tissue. Neck range of motion was markedly decreased. The patient underwent a trial of muscle relaxants and intensive physical therapy with no significant improvement. Surgical release of the residual fibrotic band was performed, and the left deviation of the neck was reduced from 25 degrees preoperatively to 5 degrees postoperatively. With surgical release and intensive postoperative physical therapy, the patient regained full motion and strength of the cervical spine musculature.
Adult↗
Continuing rearrangement but absence of somatic hypermutation in immunoglobulin genes of human B cell precursor leukemia.
Southern blot analyses revealed that cells from nearly 30% of childhood B cell precursor acute lymphoblastic leukemias (ALLs) contained more than two rearranged, nongermline bands for Ig heavy chain genes. DNA corresponding to these bands was molecularly cloned from two cases which showed three and seven rearranged bands, respectively. Nucleotide sequence analysis of the cloned DNA demonstrated that each band represented different VDJ or DJ rearrangements. While the same DJ joints were shared by several rearrangements, different DJ joints were found in the majority of rearrangements, precluding V region substitution as an explanation for the multiplicity of heavy chain rearrangements in these leukemias. Most of the V region segments involved in these rearrangements were restricted to VH region families that have been shown previously to be preferentially rearranged in human fetal B lineage cells. Sequence analysis of multiple copies of the same VDJ rearrangements from different cells revealed no somatic mutation, a mechanism responsible for detection of extra rearranged Ig DNA bands in certain other B lineage tumors. The data suggest that in some cases of ALL Ig heavy chain genes begin and continue to rearrange de novo within the neoplastic B cell precursor populations derived from an original malignant cell transformed at a stem cell stage of differentiation.
Amino Acid Sequence↗
T-cell lymphomas containing Epstein-Barr viral DNA in patients with chronic Epstein-Barr virus infections.
Fatal T-cell lymphomas developed in three patients with a chronic illness manifested by fever, pneumonia, dysgammaglobulinemia, hematologic abnormalities, and extraordinarily high titers of antibody to the Epstein-Barr virus (EBV) capsid antigen (greater than 10,000) and early antigen (greater than 640) but low titers to the EBV nuclear antigen (less than or equal to 40). To understand the pathogenesis of these tumors better, we determined the immunophenotype of the tumor cells and analyzed tumor-cell DNA for EBV genomes and for lymphoid-cell gene rearrangements. More than 80 percent of the cells in tumors had an activated helper T-cell phenotype (T4, T11, la positive). The EBV genome was found by in situ hybridization in tumor tissue from each patient. Southern blot assay of DNA digests from one patient showed the same pattern as that of the EBV-infected marmoset line, B95-8. DNA digests from two patients showed a monoclonal proliferation of T cells determined on the basis of uniform T-cell-receptor gene rearrangements and a single band for the joined termini of the EBV genome. We conclude that EBV may infect T cells and contribute to lymphomas in selected patients with severe EBV infections.
Adult↗