Biomedical subjects

N Yokose

Publications and source records attributed to N Yokose.

28 records · Page 2Linked to original sources

PubMed1995

Acute gastric mucosal lesions associated with cytomegalovirus infection in a non-immunocompromised host.

A 75-year-old woman with epigastric pain and tarry stool was admitted to our hospital, where upper gastrointestinal endoscopic study revealed multiple gastric ulcers. The endoscopic biopsy specimens obtained on the seventh hospital day disclosed a few typical intranuclear cytomegalovirus inclusions. Cytomegalovirus-DNA was detected using polymerase chain reaction in a biopsy specimen. No immunologic abnormalities were demonstrated by any laboratory tests. While only a few cases of cytomegalovirus-associated gastric ulcer in non-immunocompromised hosts have been reported, this entity may be more frequently detected when careful histological examination is performed in the active stage rather than postponed until after healing of the ulcer.

Acute Disease↗

PubMed1995

Interleukin-2 therapy for myelodysplastic syndrome: does it work?

Recent clinical studies suggested that interleukin-2 (IL-2) has therapeutic potential for some hematologic malignancies, but the therapeutic role of IL-2 for myelodysplastic syndrome (MDS) is still unclear. MDS is a clonal malignant disorder which often involves a variety of immunologic abnormalities. Examination of the effects of IL-2 on MDS in vitro yielded the following results: (1) IL-2 did not induce the proliferation of blasts in most MDS cases. (2) The cytotoxicity of IL-2-induced lymphokine-activated killer (LAK) cells for cell lines and MDS blasts was reduced in the high-risk MDS group (refractory anemia with excess blasts (RAEB), RAEB in transformation and MDS transformed to acute leukemia), but it was still preserved in the low-risk MDS group (refractory anemia (RA) and RA with ringed sideroblasts). However, considerable variation in LAK cell cytotoxicity was noted in each group. (3) The reduced LAK cell cytotoxicity observed in MDS was explained, at least in part, by the presence of a reduced of number of natural killer (NK) cells amongst the LAK cells. (4) MDS patients who have a high blood soluble IL-2 receptor (sIL-2R) level often had defects in NK and CD8+ T cells. These in vitro findings suggest that the response to IL-2 is heterogeneous in MDS patients, and those who have a low-risk MDS subtype and/or a low blood sIL-2R level, may be prone to respond to IL-2 therapy. Clinical trials are mandatory in order to elucidate the efficacy of IL-2 therapy in the treatment of MDS.

Anemia, Refractory↗

PubMed1994

Elevated plasma soluble interleukin 2 receptor level correlates with defective natural killer and CD8+ T-cells in myelodysplastic syndromes.

The plasma soluble interleukin 2 receptor (sIL-2R) level and its relationships with haematologic and immunologic data were examined in 40 patients with myelodysplastic syndromes (MDS). The plasma sIL-2R level was significantly higher in the high-risk MDS group (refractory anaemia with excess blasts (RAEB), RAEB in transformation and chronic myelomonocytic leukaemia) than in the low-risk MDS group (refractory anaemia (RA) and RA with ringed sideroblasts) or in normal subjects, although there was considerable variation in the plasma sIL-2R level within each MDS group. The plasma sIL-2R level correlated positively with the bone marrow cellularity and bone marrow blast mass, but not with the absolute number of CD25+ lymphocytes. This may support the idea that plasma sIL-2R is derived from malignant MDS cells in the bone marrow. The plasma sIL-2R level correlated negatively with the absolute numbers of the CD8+, CD3-CD16+, and CD3-CD56+ cell populations in freshly isolated lymphocytes, the percentage of CD3-CD56+ cells in lymphokine (interleukin 2)-activated killer (LAK) cells, and the cytotoxicity of LAK cells. We conclude that MDS patients having a high plasma sIL-2R level often have a defect in natural killer and CD8+ T-cells.

Adult↗

PubMed1994

Assessment of therapeutic potential of interleukin 2 for myelodysplastic syndromes.

The therapeutic potential of interleukin 2 (IL-2) for myelodsplastic syndromes (MDS) was evaluated in vitro. IL-2-induced lymphokine-activated killer (LAK) cells were prepared from 38 MDS patients and 20 normal subjects. The cytotoxicity of LAK cells against K562 and Raji cell lines and MDS blasts was significantly reduced in high-risk MDS (refractory anaemia with excess blasts (RAEB), RAEB in transformation, and leukaemic transformation of MDS), but was relatively well-preserved in low-risk MDS (refractory anaemia (RA) and RA with ringed sideroblasts). Examination of the immunophenotypes of freshly-isolated lymphocytes showed that the percentage of CD4+ cells in low-risk MDS and the percentage of CD3+, CD4+ and CD8+ cell populations in high-risk MDS was significantly reduced compared with these populations in normal subjects. After cultivation with IL-2, these three cell populations were still reduced in the corresponding MDS groups and the percentage of CD3-CD56+ cells were significantly reduced in high-risk MDS. There was a positive correlation between the percentage of K562 cells lysed by MDS LAK cells and the percentage of CD3-CD56+ lymphocytes in MDS LAK cells. These aberrant lymphocyte subpopulations appeared to explain, at least in part, the reduced LAK cell cytotoxicity in MDS. These results present a possibility that IL-2 and LAK therapies are ineffective for most high-risk MDS patients, whereas they have potential value for low-risk MDS patients whose lymphocyte cytotoxicity is usually preserved.

Adult↗

PubMed1994

Defective natural killer (NK) cell-mediated cytotoxicity does not imply clonal involvement of NK cells in myelodysplastic syndromes.

The clonality of purified cells was examined in 10 myelodysplastic syndromes (MDS) patients by analysing the restriction fragment length polymorphism and methylation pattern of the phosphoglycerate-kinase gene. Natural killer (NK) cell-mediated cytotoxicity was also examined. The granulocytes and monocytes were monoclonal or oligoclonal in all cases, except for the monocytes in one case. Conversely, the NK and T cells had a polyclonal pattern in most cases, including all cases who had defective NK cell-mediated cytotoxicity. The hypothesis that reduced NK cell-mediated cytotoxicity in MDS is caused by a clonal involvement of NK cells was not supported by the present study.

Adult↗

PubMed1994

Aplastic anemia with circulating erythroblasts.

Since the presence of erythroblasts (Ebl) in the peripheral blood of patients suspected to have aplastic anemia (AA) has been thought to suggest an error in diagnosis, such patients may not receive appropriate therapy promptly, with potentially fatal results. However, we recently experienced patients who had the typical features of AA except for circulating Ebl, and responded well to therapy for AA. In this study, we examined 55 untreated AA patients for the presence of circulating Ebl. Seven patients (12.7%) had circulating Ebl (at least one Ebl per 200 leukocytes counted). These seven patients showed the typical features of AA. There were no significant differences in age or hematologic parameters, including the morphology of bone marrow Ebl, between the AA patients having circulating Ebl (Ebl(+) AA) and the AA patients without Ebl. All but one of the Ebl(+) AA patients responded well to the therapy for AA. During 12.0-110.4 months of follow-up, transformation to other diseases did not occur, and all seven patients were alive. We conclude that circulating Ebl are not rare in patients who have otherwise typical features of AA, and that if such Ebl(+) AA patients are severely cytopenic, they should receive treatment for AA without delay.

Adolescent↗

PubMed1993

Chemotherapy for minimally differentiated acute myeloid leukemia (AML-M0). A report on five cases and review of the literature.

With the objective of establishing the optimal therapy for minimally differentiated acute myeloid leukemia (AML-M0), we examined the therapeutic results of five AML-M0 cases and reviewed the literature. In a series of 63 patients with newly diagnosed acute leukemia who were admitted to the Main Hospital of Nippon Medical School, five patients fit the criteria for AML-M0: negative myeloperoxidase (MPO) and Sudan black B reaction by light microscopy, negative for B- and T-lineage markers, and positive for myeloid markers. They were treated by means of AdVP [adriamycin, vincristine, and prednisolone (PSL)] therapy and/or BHAC-DMP [behenoylcytosine arabinoside (BHAC), daunorubicin (DNR), 6-mercaptopurine (6-MP), and PSL] therapy. The AdVP therapy was unsuccessful in the two patients who received it, while a complete remission (CR) was achieved with the BHAC-DMP therapy in three of four patients. Although one patient treated with BHAC-DMP did not achieve CR, his blasts were apparently sensitive to the therapy. In assessable cases in the literature where leukemic blasts were MPO-negative, myeloid marker-positive and B- and T-lineage marker-negative, CR was achieved in 54.5% and 44.4% with anti-acute myeloid leukemia therapy and anti-acute lymphocytic leukemia therapy, respectively. Five cases in the literature were treated with a chemotherapeutic regimen containing BHAC [or cytosine arabinoside (Ara-C)], DNR, and 6-MP, and all achieved CR. The regimen containing BHAC (or Ara-C), DNR, and 6-MP may be useful as induction chemotherapy for AML-M0.

Adult↗

PubMed1993

Effects of interleukin 2 on myelodysplastic syndromes.

To evaluate the clinical usefulness of interleukin 2 (IL-2) on myelodysplastic syndromes (MDS), the serum IL-2 level, the effect of IL-2 on the proliferation of blasts, and the cell-mediated cytotoxic effect of IL-2 on blasts were examined in MDS patients. Of 18 patients, 2 patients had an increased serum IL-2 level. Although the proliferation of blasts in most cases, including the two patients having a high serum IL-2 level, was not stimulated by IL-2, the blasts of one case apparently proliferated in response to IL-2. It was also clearly shown that IL-2-stimulated normal peripheral blood mononuclear cells (PBMNC) showed cytotoxicity against MDS blasts, whereas the PBMNC of the advanced stages of MDS were usually defective in regard to this IL-2-dependent cytotoxicity. The therapeutic usefulness of IL-2 or lymphokine-activated killer cells for MDS was not established by the present study.

Cell Division↗

PubMed1993

A novel megakaryocyte potentiator produced by MC-1 human lung cancer cell line.

The hematopoietic stimulating activity of a human lung cancer cell line, MC-1, was investigated. The protein fraction (MC-1 protein) was prepared from the serum-free culture supernatant of MC-1 cells using hydroxyapatite and concanavalin A-agarose columns. In serum-containing cultures, MC-1 protein stimulated colony formation by megakaryocyte colony-forming units (CFU), erythroid burst-forming units and granulocyte/macrophage (GM) CFU. The stimulating effect was strongest for megakaryocyte CFU. The factor having megakaryocyte colony-stimulating activity was shown to be a protein whose molecular weight was determined to be 23,000 daltons by gel filtration. By various analyses, this protein was shown to be molecularly different from the heretofore-identified cytokines that may affect megakaryocytopoiesis, i.e., interleukin-1 (IL-1), IL-2, IL-3, IL-6, IL-7, IL-11, granulocyte colony-stimulating factor (CSF), macrophage CSF, GM-CSF, leukemia inhibitory factor, stem cell factor and tumor necrosis factor. Under serum-free conditions, MC-1 protein augmented murine megakaryocyte colony formation in the presence of murine IL-3 and increased the acetylcholinesterase activity of purified murine megakaryocytes. It was also shown that MC-1 protein stimulated human megakaryocyte colony formation. It was concluded that MC-1 cells produce a megakaryocyte potentiator which is molecularly different from any heretofore-identified cytokines.

Animals↗

PubMed1993

[Two cases of acute leukemia with t(6;9) (p23;q34)].

Two cases of acute leukemia with a t (6;9) (p23;34) chromosome abnormality are reported. The first case was a 34-year-old female who was hospitalized in October 1989. A diagnosis of FAB-M1 was made. Chromosomal analysis of the bone marrow cells showed a 46, XX, t (6;9) (p23;q34). Complete remission was achieved after two courses of BHAC-DMP therapy. In September 1991, at the time of relapse, chromosomal analysis revealed two abnormal clones consisting of a 46, XX, t (6;9) (p23;q34), -12, -17, +der (12) t (12;17) (p11.2;q11.2) with a residual normal clone. She died in February 1992. The second case was a 42-year-old male who was hospitalized in January 1990. He was diagnosed as having RAEB. Chromosomal analysis of the bone marrow cells showed 46, XY, t (6;9) (p23;q34). Three months later, the disease progressed to acute leukemia accompanied by leg ulceration with leukemic cell infiltration. Small-dose ara-C therapy was given, but with no effect. After two subsequent courses of therapy with low-dose etoposide, complete remission was achieved. Four months later, relapse occurred, and the patient died of sepsis in February 1991. In the literature, 31 cases of myeloproliferative disorders with t (6;9) have been reported.

Acute Disease↗