Constituents of the roots of Melochia chamaedrys.

The cyclic peptide alkaloid, chamaedrine, was isolated from the roots of Melochia chamaedris (Sterculiaceae), along with four known cyclic peptide alkaloids (adouetine X, frangulaline, scutianine B and scutianine C), and waltherione A, parasorbic acid, propacine, and (-)-epicatequine. Their structures were elucidated on the basis of spectroscopic analysis, especially by 2D NMR ((1)H-(1)H-COSY, NOESY, HMQC, HMBC).

Occurrence of the common acute lymphoblastic leukemia antigen on blast cells of a patient with chronic myelomonocytic leukemia in non-lymphoid blastic phase.

Leukemias showing a conspicuous lymphoid phenotype, ie, those that are HLA-DR positive, common acute lymphoblastic antigen (cALLA) positive, terminal deoxynucleotidyl transferase (TdT) negative, as well as myeloperoxidase positive (MPO), could be considered so-called mixed leukemias. Leukemias with biphenotypic blasts have to be distinguished from cases comprising two separate subpopulations that express different lineage-associated characteristics. By use of a simple new method (Immunogold Staining) we examined a case of chronic myelomonocytic leukemia in blastic phase and demonstrated simultaneous staining for MPO/alpha-naphthyl-esterase and expression of the HLA-DR-positive, cALLA-positive, and TdT-negative phenotype. The cALL antigen was detected only on mono- and myelo-monoblasts; its expression was inversely related to the MPO positivity, and it disappeared together with these types of blasts after chemotherapy. On the basis of our findings it remains obscure whether the cALL antigen at the initial presentation was due to the immature monocytic features of the leukemic cells or disclosed on additional lymphoid differentiation pattern of the blasts.

Modulation of the expression of major histocompatibility antigens on splenic hairy cells--differential effect upon in vitro treatment with alpha-2b-interferon, gamma-interferon, and interleukin-2.

The mechanism of action responsible for the beneficial effect of alpha-interferon (alpha-IFN) in patients with hairy cell leukemia (HCL) is still unknown. Direct antineoplastic and immunomodulating effects on both the host immune system and the hairy cells themselves have been implicated. To evaluate whether lymphokines have any regulatory effect on antigens of the major histocompatibility complex (MHC) on hairy cells and whether this corresponds to prognostic clinical parameters, we studied splenic hairy cells from ten previously untreated patients. The samples were incubated with recombinant human alpha-IFN, gamma-IFN (gamma-IFN), and interleukin-2 (IL-2). In an indirect staining procedure, cells were labeled with monoclonal antibodies (MoAb) to HLA ABC and HLA DR surface structures and subjected to cytofluorimetric analysis. Results concerning the expression of MHC class I and HLA DR antigens were mixed for incubation of hairy cells with gamma-IFN and IL-2, whereas alpha-IFN had a distinct effect on HLA DR antigen expression. alpha-IFN strongly enhanced the intensity of staining with HLA DR MoAb in six patients, and it increased the percentage of MoAb-positive cells in five of these samples. In contrast, the staining intensity in samples from four patients was reduced considerably on alpha-IFN treatment. In this group, two samples showed a sharp alpha-IFN-induced decrease in the number of HLA DR MoAb-positive cells from originally high values, and in one sample the very low percentage of positive cells was unaffected by alpha-IFN exposure. These two groups of patients whose hairy cells displayed contrasting HLA DR expression on incubation with alpha-IFN in vitro, were found to differ in their subsequent clinical course.

Is there a direct differentiation-inducing effect of human recombinant interferon on hairy cell leukemia in vitro?

We used a panel of monoclonal antibodies (moAb) to label splenic hairy cells from eight patients to determine the membrane phenotypes, the presence of cytoplasmic immunoglobulin (cIg), and the expression of maturation-associated antigens. All eight patients had responded clinically to splenectomy either alone or in combination with alpha-2b-interferon (alpha-IFN) therapy. For each sample, cytofluorimetric analysis showed distinct, and in six cases multiple, heavy chain isotypes. After short-term culture in the presence of alpha-IFN or gamma-interferon (gamma-IFN), samples from four patients displayed characteristic changes in surface immunoglobulin (sIg) expression. When compared with untreated cells, cells co-cultured with alpha-IFN or gamma-IFN showed in four and three patients, respectively, changes that were consistent with a shift to the more mature stage in B-cell ontogeny. However, in parallel with the changes in the sIg isotypes, treatment with IFN did not induce the appearance of cIg nor did the staining patterns for moAb to CD5, CD19, CD20, and CD22 antigens indicate the induction of terminal maturation. These data suggest that hairy cell leukemia (HCL), a neoplasm of "mature" B-cells, is potentially susceptible to maturation stimuli. Based on these findings, it might be of interest to examine whether co-factors, which have proved to play a role in HCL (e.g., B-cell growth factor [BCGF]), are capable of further enhancing IFN-induced differentiation.