Regression and inhibition of sarcoma growth by interference with a radiosensitive T-cell population.

BALB/c mice were inoculated subcutaneously with 10(6) cells from either of two syngeneic sarcomas 1315 and 1425. 6--8 days later, the mice were randomized into groups which were left untreated or given 400 rads of whole body irradiation. Irradiation significantly retarded the growth of both sarcomas, and complete regressions were seen of approximately equal to 30% of the small, established 1315 tumors. The anti-tumor effect of irradiation was abolished if the irradiated mice were inoculated with a T-cell-enriched (but not with a T-cell deprived) suspension of syngeneic spleen cells, suggesting that the irradiation inhibited tumor growth by affecting a radiosensitive population of host suppressor T cells.

Retroviral activation of interleukin 2 gene in a gibbon ape T cell lymphoma line.

The gibbon ape leukemia virus (GaLVSF)-infected T cell line, MLA 144, was established from the lymphoma of a gibbon ape. The cell line constitutively expresses IL-2 and its receptor, implying that an autocrine mechanism could be responsible for or contribute toward its growth. To explore the mechanism of constitutive IL-2 expression in MLA 144, we have isolated and characterized cosmid clones representing a normal and a doubly inserted IL-2 allele in this cell line. The map of the normal MLA 144 IL-2 allele closely resembles that of the normal human IL-2 gene. The abnormal allele contains a 3' insertion that is a GaLVSF provirus with two long terminal repeats (LTR) and an internal 3.25 kb deletion. At the 5' end of the abnormal allele is a second insertion that DNA sequencing showed to be an isolated GaLVSF LTR with a transcriptional orientation opposing that of the IL-2 gene. We demonstrate by Northern blotting analysis that the vast majority of transcripts are from the abnormal allele, implying that one or both retroviral insertions are responsible for constitutive expression of the allele.

Single-copy inverted repeats associated with regional genetic duplications in gamma fibrinogen and immunoglobulin genes.

We have found that a portion (150 base pairs) of the seventh exon of the human gamma fibrinogen gene is duplicated in the preceding intron. This duplicated sequence, termed a "pseudoexon," is flanked on each side by a single-copy inverted repeat sequence consisting of 102 base pairs. Frequencies of point substitutions indicate that both the pseudoexon and the inverted repeat sequence arose approximately 10 to 20 million years ago. The generality of this type of duplication is suggested by the occurrence of a similar duplication in the mouse immunoglobulin mu-delta region. As in the fibrinogen pseudoexon, the portion of the immunoglobulin mu-delta region containing the duplication and the inverted repeat was reported to be single-copy in the mouse genome. Since both of the first two single-copy inverted repeats to be sequenced are associated with regional duplications, it is likely that many of the single-copy inverted repeat sequences, which make up 1 to 2 percent of the genome, are also associated with regional duplications.

Identification of a zinc finger protein that inhibits IL-2 gene expression.

Transient activation of the interleukin-2 (IL-2) gene after antigen recognition by T lymphocytes is crucial for subsequent T cell proliferation and differentiation. Several IL-2 gene regulatory elements and binding factors necessary for activation of the IL-2 gene have been defined. However, little is known about negative regulation of IL-2 expression, which is likely to be important in the rapid shut-off of IL-2 transcription. A nucleotide sequence element (NRE-A) that negatively regulates IL-2 expression has been identified within the IL-2 gene. T cell nuclear extracts contained an NRE-A binding activity. A complementary DNA was isolated that encodes a zinc finger-containing protein that suppressed IL-2 gene expression. The observation of negative regulation of the immunoglobulin heavy chain gene enhancer by an element similar to NRE-A suggests that related proteins may regulate multiple immune response genes.

Promoter region of interleukin-2 gene undergoes chromatin structure changes and confers inducibility on chloramphenicol acetyltransferase gene during activation of T cells.

The chromatin structure of the interleukin-2 (IL-2) gene was probed by DNase I treatment of isolated nuclei. The 5' region of the IL-2 gene contains three regions of hypersensitivity to DNase I. When peripheral blood T cells or Jurkat T cells are stimulated with mitogens, IL-2 message is induced, and the promoter region of the IL-2 gene develops an additional hypersensitive site. This suggests that a DNA sequence close to the transcriptional start site is involved in the transduction of the extracellular signal. Such a conclusion is further supported by DNA transfection experiments. A short segment of DNA, which includes the region of induced hypersensitivity, confers inducibility on the linked chloramphenicol acetyltransferase gene in transiently transfected Jurkat cells. In addition, cells of nonhematopoietic origins exhibit a strikingly different chromatin pattern of IL-2, suggesting a role during differentiation for some of the hypersensitive sites.

The pathologic and clinical heterogeneity of lymphocyte-depleted Hodgkin's disease.

Patients with Hodgkin's disease of the lymphocyte-depleted subtype (LDHD) have been said to have a poor prognosis. However, reports of this subtype are complicated by the fact that the histologic diagnosis of LDHD is often not straightforward, and its distinction from aggressive non-Hodgkin's lymphomas (NHL) can be difficult. We have reviewed our patients with LDHD at the National Cancer Institute (NCI) in light of an additional decade of experience with neoplastic and non-neoplastic conditions mimicking Hodgkin's disease. Of 198 patients who received MOPP (mechlorethamine, vincristine, procarbazine, prednisone) treatment at the NCI for Hodgkin's disease between 1964 and 1976, 43 (22%) were originally classified as LDHD. The initial diagnostic biopsies from 39 of these patients were reviewed and revealed ten with NHL, nine with LDHD, and 13 with nodular sclerosing Hodgkin's disease of the lymphocyte-depleted subtype (NSLD). The other seven patients had Hodgkin's disease without a lymphocyte-depleted component. The NHL patients were further subclassified as diffuse, large-cell (two cases) and large-cell, immunoblastic (eight cases). The pathologic review was done without knowledge of clinical features which were examined after review in the three major subgroups. Of ten patients with NHL, only three had a complete remission (CR), and median survival was 7 months. Nine of the NHL patients presented with features that are unusual for patients with Hodgkin's disease, such as bulky abdominal disease, epitrochlear lymphade-nopathy, or hypercalcemia. CRs were attained by 67% and 85% of patients in the LDHD and NSLD groups, respectively: median survival had not been reached in either group with a median of 14 years of follow-up. Lymphocyte-depleted Hodgkin's disease, adequately treated, is in our limited group of patients no worse than other histopathologic subtypes of Hodgkin's disease. The erroneous inclusion of patients with high-grade NHLs into this subtype of Hodgkin's disease may be one reason for earlier literature reports of its more aggressive nature. The diagnosis of LDHD should be made cautiously, particularly in patients with clinical features that are unusual for Hodgkin's disease at presentation.

Evolution and structure of the fibrinogen genes. Random insertion of introns or selective loss?

Chromosomal linkage as well as sequence homologies provide unequivocal evidence that the genes for the alpha, beta and gamma chains of fibrinogen arose by successive duplication of a single ancestral gene. Yet, when the three fibrinogen chains are aligned by amino acid homology, the positions of intervening sequences coincide at only two positions for all three chains. While one additional intron occurs at a homologous site in the beta and gamma chains, none of the positions of the remaining 11 introns in the three genes is shared. This arrangement of introns in the three fibrinogen genes suggests that either introns were selectively lost, implying that there is essential information in the retained introns, or the common introns were present in the ancestral fibrinogen gene and introns have been randomly inserted since the triplication of the original gene. The more likely possibility of selective loss of introns implies that the ancestral gene, as it existed about one billion years ago, must have been composed of numerous small exons.

Richter's syndrome associated with loss of response to transforming growth factor-beta.

A patient with chronic lymphocytic leukemia developed a large cell lymphoma apparently derived from the same neoplastic B-cell clone (Richter's syndrome). At the same time, mitogen-stimulated proliferation of the patient's circulating leukemic B-cells was no longer inhibited by the regulatory cytokine transforming growth factor-beta (TGF-beta), suggesting that such loss of inhibition might be contributing to the clinical and biological progression of the disease.

A tale of two systems: Pathology resident recruitment in and out of the National Resident Matching Program.

The recruitment of most first-year pathology residents currently occurs via 2 systems: the National Resident Matching Program (NRMP), known as the Match, and an underground Out-of-Match process. Out-of-Match recruitment is not a sanctioned option for American medical school seniors. Recent declines in American seniors choosing pathology has intensified pressures to recruit good international medical graduates (IMGs). Pressures by programs on IMGs and by IMGs on programs result in the Out-of-Match recruitment of many IMGs who initially enroll in the NRMP. IMGs may be offered unsolicited Out-of-Match positions with a decision deadline even though they are still interviewing. Some are told if they decline an offer, they will not be ranked by that program in the NRMP process. To enhance apparent recruitment success, programs also feel pressured to participate in the Out-of-Match process, as well as offer positions before they have interviewed all applicants. Coercion of applicants and programs contravenes the spirit of the NRMP, compromises the ability of applicants and programs to best match needs, taints constructive interactions among program directors, and does not enhance pathology's image among applicants or in the broader medical community.

Hepatosplenic gammadelta T-cell lymphoma: ultrastructural, immunophenotypic, and functional evidence for cytotoxic T lymphocyte differentiation.

Hepatosplenic gammadelta T cell lymphoma (TCL) is a rare, aggressive subset of peripheral TCL that presents with hepatosplenomegaly and cytopenias. Detailed clinicopathological, ultrastructural, and cytogenetic analyses of these lymphomas are limited; functional characteristics of these lymphomas are unknown. We have undertaken a clinicopathological, immunophenotypic, ultrastructural, cytogenetic, and functional analysis of three hepatosplenic gammadelta TCLs. All patients presented with massive hepatosplenomegaly and anemia, thrombocytopenia, or severe neutropenia; terminal blastlike transformation occurred in one patient. Combination chemotherapy had no response in two patients, but induced complete remission in one. gammadelta T cell receptor (TCR) expression and clonal TCRdelta gene rearrangements were documented in each case. Two different subsets of gammadelta TCL were identified based on delta chain variable region usage; two lymphomas were Vdelta1+, whereas the third was negative for both Vdelta1 and Vdelta2. Cytogenetic analysis was performed on two lymphomas; isochromosome 7q and probable trisomy 8 was shown in one of the Vdelta1+ lymphomas, whereas the Vdelta1 negative lymphoma had 14p+ with t(1;14)(q21;p13). NK cell-associated antigens (CD11c, CD16, or CD56) and cytotoxic T lymphocyte (CTL) effector proteins (perforin, granzyme B, TIA-1, and Fas ligand) were expressed by each lymphoma; dense core cytolytic granules were observed by electron microscopy in both lymphomas studied. Functional studies performed in two cases showed TCR-mediated cytolysis of P815 x 2 FcR+ cells induced by anti-CD3 in a redirected cytolysis assay in one of the CD56+, Vdelta1+ lymphomas, whereas IFNgamma secretion was induced by anti-CD3 in the CD56-, Vdelta1 negative lymphoma. These studies show that hepatosplenic gammadelta TCLs have CTL differentiation, retain functional activity in vitro, and are derived from at least two gammadelta T cell subsets.

Diagnosis of posttransplantation lymphoproliferative disorder by endomyocardial biopsy in a cardiac allograft recipient.

Posttransplantation lymphoproliferative disorder is a serious complication of organ transplantation. This disorder has been linked to Epstein-Barr virus infections and can involve the transplanted organ. In the past the diagnosis of posttransplantation lymphoproliferative disorder in heart transplant recipients involving the transplanted organ was made primarily at autopsy. A case of a patient with posttransplantation lymphoproliferative disorder in whom the diagnosis was made initially by endomyocardial biopsy with confirmation by application of molecular techniques on mediastinal lymph node tissue and who was subsequently treated successfully is reported.

Myeloperoxidase-positive acute megakaryoblastic leukemia.

Acute megakaryoblastic leukemia (FABM7) is an unusual but well recognized form of acute myelogenous leukemia in which the bone marrow blast cells are phenotypically recognized by the demonstration of cytoplasmic platelet peroxidase or surface staining for the IIb/IIIa platelet-specific glycoprotein. Herein, the authors report a case of acute megakaryoblastic leukemia that satisfies the accepted French-American-British criteria and in which the blast cells also exhibit evidence of myeloid differentiation, including surface MY7 (CD13) by flow cytometry and immunocytochemical positivity for myeloperoxidase. These findings suggest that megakaryoblasts may be closely related to myelomonoblasts, that they have the potential to partially differentiate along multiple phenotypic lines, and that aberrant phenotypes can occur that do not correspond to known stages of normal maturation. The authors illustrate the difficulty in classification of these aberrant phenotypes by standard cytochemical and morphologic criteria.

DNA typing of the human MN and Ss blood group antigens in amniotic fluid and following massive transfusion.

Although red blood cell (RBC) antigen typing by agglutination is generally useful, several situations exist where this approach is difficult or impossible. For example, following a massive transfusion, a patient's residual RBCs are mixed with transfused normal donor RBCs. In this case, typing by hemagglutination primarily detects the antigens on the heterogeneous population of transfused RBCs. Agglutination testing is also of limited use for determining the phenotype of a fetus at risk for hemolytic disease of the newborn because fetal RBCs must be obtained by periumbilical blood sampling. Determining the genotype of an individual by analyzing genomic DNA isolated from peripheral blood nucleated cells or amniocytes is an alternative approach for determining the RBC antigen type. In this report, the allele specific polymerase chain reaction (AS-PCR) was used to identify the alleles at the MN and Ss loci that encode the corresponding antigens on glycophorin A (GPA) and glycophorin B (GPB), respectively. This method was used to type these alleles in peripheral blood samples obtained from normal individuals and from patients following massive transfusion. Of 23 peripheral blood specimens analyzed, all were correctly typed by this method. The allele specific polymerase chain reaction was also used to determine these alleles using amniotic fluid samples. Of 11 amniotic fluid specimens analyzed, 8 were correctly typed at both loci. Mistyping of three amniotic fluid specimens was explained by possible maternal blood contamination.

Marrow fibrosis associated with a Philadelphia chromosome.

Three patients had marked marrow fibrosis and an apparent Philadelphia (Ph) chromosome. Hematologic, cytogenetic, and molecular studies demonstrated the heterogeneity of such cases, including the first example of clinically typical myelofibrosis (MF) associated with a bcr gene rearrangement characteristic of chronic myelogenous leukemia (CML).

Secondary Ph-positive CML with a minority monosomy 7 clone.

We report a case of Ph-positive chronic myelogenous leukemia (CML) secondary to previous treatment for a lymphoma. At the time of original diagnosis of lymphoblastic lymphoma, chromosome studies of blood and bone marrow were normal. Following therapy and a clinical remission complicated by CNS relapse, the patient presented 16 months after treatment was discontinued with a WBC of 110,000 mm-3, consistent with CML. Blood and marrow cytogenetic studies at this time showed a Ph chromosome, t(9;22)(q34;q11) translocation, without other karyotypic alteration. A separate small clone with the karyotype 45,XY, -7 was found in the blood. His disease followed an aggressive course and he died 3 months later. The autopsy findings indicated CML in blast crisis. Molecular studies performed on cells replacing a lymph node revealed a rearrangement of the breakpoint cluster region (bcr) of chromosome #22 and of the immunoglobulin heavy chain locus. Taken together, it seems most likely that the patient's CML developed as a second neoplasm following successful elimination of his lymphoblastic lymphoma by therapy.

Genetic testing. Counseling, laboratory, and regulatory issues and the EUROPAC protocol for ethical research in multicenter studies of inherited pancreatic diseases.

This article highlights several of the important issues and illustrates a European protocol that should be considered when offering genetic testing on a research or clinical basis for HP, as well as for other inherited disorders of the pancreas.

Molecular diagnosis of cystic fibrosis.

The clinical and pathologic features of patients with cystic fibrosis are summarized, and generalized genotype or phenotype correlations are discussed in this article. Incorporation of modern molecular biologic techniques into a rapid, cost-efficient, and specific diagnostic laboratory test is outlined. The protocol for the multiplex polymerase chain reaction detection of five common cystic fibrosis transmembrane conductance regulator (CFTR) mutations by ASO hybridization is detailed. Neonatal screening and issues involved in the genetic counseling of families at risk for cystic fibrosis are presented. Recommendations for molecular diagnostic testing in cystic fibrosis are made.

Carrier screening for cystic fibrosis: costs and clinical outcomes.

OBJECTIVES: To evaluate the costs and clinical effects of 16 alternative strategies for cystic fibrosis (CF) carrier screening in the reproductive setting; and to test the sensitivity of the results to assumptions about cost and detection rate, stakeholder perspective, DNA test specificity, chance of nonpaternity, and couples' reproductive plans. METHOD: Cost-effectiveness analysis. RESULTS: A sequential screening strategy had the lowest cost per CF birth avoided. In this strategy, the first partner was screened with a standard test that identifies 85% of carriers. The second partner was screened with an expanded test if the first partner's screen was positive. This strategy identified 75% of anticipated CF births at a cost of $367,000 each. This figure does not include the lifetime medical costs of caring for a patient with CF, and it assumes that couples who identify a pregnancy at risk will choose to have prenatal diagnosis and termination of affected pregnancies. The cost per CF birth identified is approximately half this figure when couples plan two children. CONCLUSIONS: The cost-effectiveness of CF carrier screening depends greatly on couples' reproductive plans. CF carrier screening is most cost-effective when it is performed sequentially, when the information is used for more than one pregnancy, and when the intention of the couple is to identify and terminate affected pregnancies. These conclusions are important for policy considerations regarding population-based screening for CF, and may also have important implications for screening for less common diseases.

Primary low-grade T-helper cell testicular lymphoma.

Non-Hodgkin's lymphoma is the most common primary testicular neoplasm of older men but is rare in young men. The vast majority of primary testicular lymphomas are intermediate- to high-grade lymphomas. Peripheral T-cell lymphomas of the testes are rare; most are large cell lymphomas. We describe an unusual case of a primary small lymphocytic, CD4+, peripheral T-cell lymphoma that presented as a Staphylococcus aureus scrotal abscess in a 30-year-old male. Clonal rearrangement of the T-cell receptor beta gene was demonstrated by Southern analysis. To our knowledge, low-grade, peripheral T-cell lymphoma of the testes has not been previously reported.