Hematologic pathology最新文献

p21 is induced by and mediates the effects of p53 in response to DNA damage arresting the cell in G1 or G2, by inhibiting multiple cyclin-cyclin-dependent kinases (CDK) or binding to proliferating-cell nuclear antigen (PCNA), respectively. To determine whether p21 mutants occur in tumors we examined DNA from 188 primary non-Hodgkin's B-cell lymphoma (NHL) tumors and 84 chronic myelogenous leukemia samples for mutational changes in the coding region of p21 by single-strand conformation polymorphism (SSCP) analysis and direct sequencing of polymerase chain reaction (PCR)-amplified DNA. We did not find mutations in the coding region in these two tumor types. We identified a polymorphic nucleotide change in codon 31 in which a transversion from C to A substituted amino acid arginine for serine. Three of 188 NHL tumors were homozygous for this change, but they were not identified in 84 CMLs or in 97 normal controls. On the other hand, in one CML case a transition from G to A in codon 64 substituted amino acid threonine for alanine. These data do not indicate that derangements in the coding region of p21 contribute to the initiation and/or progression of these tumors.

Sequential bone marrow aspirates and sections from patients with acute myeloid leukemia (AML) were examined to determine if a correlation exists between bone marrow morphology during induction phase of therapy and outcome. Of 95 patients of AML diagnosed between July 1987 and December 1991, 53 uniformly treated patients (induction therapy with cytosine arabinoside and daunorubicin) had sequential bone marrow examinations performed in the 2- to 5-week period following initiation of induction therapy. Four morphologic patterns were recognized in these 53 patients: Group I (22 patients)--hypocellularity or normal regeneration (> or = 15% cellularity and < 5% blasts) on the initial 2-week marrow followed by marrows showing normal regeneration; Group II (10 patients)--hypocellularity followed by "reactive myeloblastosis" (> or = 15% cellularity, 5% to 34% blasts, with promyelocytes = or > blasts); Group III (12 patients)--residual blasts (> or = 5% blasts with blasts >> promyelocytes) in the initial posttherapy marrow; Group IV (9 patients)--atypical patterns not fitting any of the other categories. Complete remission was achieved in all 32 patients in Groups I and II without additional induction therapy, but was achieved eventually in only 10 of 21 patients in Groups III and IV combined (p < 0.005), 15 of whom received additional induction therapy. Remission duration and actuarial survival for each group were as follows: Group I: 344/596 days; Group II: 443 days/> 660 days; Group III and IV combined: 351/311 days (p = 0.017 for actuarial survival). Seven of 21 patients in Groups III and IV had unfavorable initial morphology (MO, hypoplastic AML and AML preceded by myelodysplasia) compared to only 3 of 32 patients in Groups I and II (p = 0.039). It was thus observed that "reactive myeloblastosis" with up to 34% blasts on the third or fourth week bone marrow following an initial hypocellular marrow does not require additional induction therapy to achieve durable remissions or favorable survival. Also, residual blasts that outnumber promyelocytes, and atypical patterns of regeneration correlate with lower remission induction rates, shortened survival, and unfavorable morphology on the initial diagnostic bone marrow.

Paraffin wax sections of lymph node biopsies from a total of thirteen patients with the morphologic and clinical features of Castleman's disease were analyzed for the presence of the Epstein-Barr virus (EBV) by in situ hybridization for the noncoding EBV early RNAs (EBERs) and by immunohistochemistry for the EBV-encoded latent membrane protein-1 (LMP-1). Of twelve cases of localized Castleman's disease EBER-positive cells were identified in five, and in these cases were only rarely found and were always confined to the interfollicular regions. LMP-1 was not detected in any of these cases, either alone or after dual staining for EBERs and LMP-1. (A similar pattern of EBER expression is seen in nonneoplastic lymphoid tissue from EBV-positive individuals.) No EBER-positive or LMP-1 positive cells were identified in a single case of multicentric Castleman's disease. In two additional patients initially diagnosed with Castleman's disease of localized plasma cell type, repeat biopsy showed Hodgkin's disease. In both cases Reed-Sternberg cells and their variants were identified in the original biopsy on which the diagnosis of Castleman's disease was made. In one of these cases these cells showed expression of EBERs and LMP-1, indicating latent infection with EBV. The results suggest that EBV is not generally associated with Castleman's disease. Further analysis of a series of cases of multicentric Castleman's disease is indicated.

Polymorphonuclear leukocytes (PMNL) from chronic myeloid leukemia (CML) patients are defective for chemotaxis in response to the synthetic chemotactic peptide n-formyl-methionyl-leucyl-phenylalanine (fMLP) as compared to normal PMNL. The present study investigated whether the defective chemotactic response was mediated through altered actin polymerization induced with fMLP. Granulocytes isolated from seven normal subjects and seven CML patients were stimulated with fMLP and lysed with Triton containing buffer at time points of 0, 30 seconds, and 1, 2, and 10 minutes. The Triton insoluble cytoskeleton containing polymerized actin was analyzed by SDS-PAGE and densitometry. The CML PMNL polymerized significantly lesser actin than normal PMNL on stimulation with 10 nM (p > 0.05) and 1 nM (p > 0.01) fMLP. This lower actin polymerization observed in fMLP-stimulated CML PMNL may be responsible for the defective chemotaxis seen in these cells.

Antisense technology offers the potential to create compounds specific enough to support highly isotypically selective pharmacology (i.e., pharmacologic agents specific enough to affect only one isotype in a multigene family of related proteins). However, enthusiasm about the potential of the technology has been appropriately tempered by questions about its ability to deliver on its promise. The fundamental issue is: Can oligonucleotides that have acceptable drug properties be created? This review discusses recent progress that helps to define the pharmacokinetic, pharmacologic, and toxicologic properties of phosphorothioate oligonucleotides. Progress in the medicinal chemistry of oligonucleotides that has resulted in a wide range of new chemical classes is also described.

The concept of ex vivo expansion of the human stem/progenitor cell population was tested in this study. Cord blood mononuclear cells were isolated and cultured in the presence of SCF, IL-3, and either cord blood serum (CBS) or fetal calf serum (FCS). After 8 days of incubation with CBS or FCS, the number of CFU-GM was increased ninefold and four-and-a-half-fold, respectively. However, the enhancing effect lasted for only a short period. This study demonstrates that CBS could contain growth factors expanding progenitor cells. Whether the ability of CBS to enhance the CFU-GM expanding capacity is attributable to a novel factor or factors, or represents effects of other known cytokines, remains to be determined.

Heterozygotes for beta-thalassemia usually have raised levels of HbA2, but in Greece about 5% of beta-thalassemia carriers are observed to have normal or borderline levels. It is postulated that such cases have mild beta+ thalassemia mutations or coinheritance of delta-thalassemia. We selected 18 heterozygotes with the hematological phenotype of normal HbA2 (type 2) beta thalassemia who were negative for the delta beta Corfu mutation, and screened them for previously defined Mediterranean beta-thalassemia and delta-thalassemia mutations. The coinheritance of beta and delta-thalassemia was demonstrated in four cases with the following genotypes: in cis beta+ IVSII -n745/delta+ 27, beta 0NS39/delta 059(-A), beta+ IVSI-n110/delta 059(-A) and in trans beta+ IVSI-n6 and delta+ 27. A further nine heterozygotes had mild beta(+)-thalassemia mutations (eight with the beta+ IVSI-n6 mutation, one with the beta+ polyA (A-->G) mutation). In four heterozygotes with severe beta-thalassemia chromosomes (2 beta+ IVSI-n110, 1 beta 0 FSC-6, 1 beta 0 IVSI-n1) no known delta-thalassemia mutations were observed. One case had a delta beta deletion chromosome. These results indicate that the hematological phenotype of normal HbA2 (type 2) beta-thalassemia in Greece is genetically heterogeneous; it is mainly associated with the delta beta Corfu mutation or coinheritance of beta and delta thalassemia mutations or with very mild beta(+)-thalassemia mutations, mainly beta+ IVSI-n6. In the rare cases with severe beta-thalassemia mutations, the normal levels of HbA2 may be due to coinheritance of as yet undefined delta thalassemia mutations.

T cells are considered to be activated in the thymus, and it has been emphasized recently that the thymic stromal cells play an important role in the process of T-cell maturation. To clarify how the stromal cells interact with T cells a cloned stromal cell line from human thymus was established and its adhesive capacity with T cells was studied. A recombinant plasmid, pSV3gpt containing SV40 large T antigen was introduced to human thymic stroma by the calcium phosphate co-precipitation method, and the thymic stromal cell line R-3-4 was obtained. Immunohistochemical examination showed that R-3-4 possessed with HLA-class 1 antigen, laminin, fibronectin, and keratin. To determine if the R-3-4 interacts with T cells, the binding activity of R-3-4 with T cells examined by using rosette formation technique. The R-3-4 formed rosette only with the T cells, but both B cells and myeloid cells did not bind to the R-3-4. This rosette formation between R-3-4 and T cells was inhibited when T cells were pretreated with anti-CD2 antibodies, suggesting that some mechanism involving CD2 participates in this binding. Our novel established thymic stromal cell line might be useful for studying the interactions between thymic stroma and T cells in vitro.

The association of plasmacytosis and lymphocytosis with acute myeloid leukemia (AML) has been documented in isolated case reports. We examined 149 cases (134 adults, 15 children) of newly diagnosed AML and found 9 adults (6%) with > or = 5% plasma cells and 1 child and 1 adult with > or = 20% lymphocytes. Lymphocytes constituted 25% and 42% of marrow cellularity in the adult and child respectively and persisted throughout remission in the child's marrow. The percentage of morphologically normal plasma cells ranged from 5% to 13% (mean 7%). Monoclonal immunoglobulins were not detected with immunostaining or flow cytometry. Hypergammaglobulinemia was present in 3 cases, and a monoclonal increase in IgG-kappa in 1. Plasmacytosis was not seen in remission marrows from these patients (n = 4). Lymphocytosis or plasmacytosis occurs in approximately 7% of patients with AML, appears reactive in nature, and may represent an immunological response to tumor. Monoclonal paraproteins may occur without other evidence of B-cell neoplasia.