Amane Tamura

ATBF1-A protein, but not ATBF1-B, is preferentially expressed in developing rat brain.

The ATBF1 gene encodes transcription factors containing four homeodomains and multiple zinc finger motifs. However, the gene products have yet to be identified and the role remains unknown in vivo. In this study, we raised an antiserum for ATBF1 and found high levels of expression of ATBF1 in developing rat brain. Western and Northern blot analyses detected a 400 kDa protein and 12.5 kb mRNA in developing rat brain, respectively; both corresponding to ATBF1‐A but not the B isoform. The protein was highly expressed in the midbrain and diencephalon and mRNA was highly expressed in the brainstem, mostly in embryo and neonatal brain. Immunohistochemistry identified postmitotic neurons in the brainstem as the major site of ATBF1 expression, and the expression levels varied depending on age of and location in the brain. Expression was transient and weak in the precursor cells at early neurogenesis. ATBF1 decreased postnatally, but remained in mature neurons, including those expressing DOPA decarboxylase (DDC). High levels of ATBF1 were expressed in precursor cells in accordance with neurogenesis and were continued to the mature neurons in specific areas such as the inferior colliculus. Expression was not significant from precursor cells to mature neurons in the cerebral cortex and hippocampus. ATBF1 and its Drosophila homolog, Zfh‐2, are known to regulate cell differentiation and proliferation via the interaction with either of the basic helix‐loop‐helix transcription factors, c‐myb, or the DDC gene. Together with these reported functions the expression features detected here suggest that ATBF1 may participate in the regulation of neuronal cell maturation or region‐specific central nervous system differentiation. J. Comp. Neurol. 465:57–71, 2003.

Successful treatment of severe cytomegalovirus retinitis with foscarnet and intraocular injection of ganciclovir in a myelosuppressed unrelated bone marrow transplant patient.

A female patient with ALL received a bone marrow transplant (BMT) from an unrelated donor with a one locus HLA mismatch. The donor was heterozygous at the HLA-A locus, while the patient was homozygous at this locus. The patient had cytomegalovirus (CMV) antigenemia on day 42 following an intensive preparative regimen that included anti-thymocyte globulin and BU+CY+TBI to prevent graft rejection. Ganciclovir was given initially for the treatment of CMV antigenemia, although the patient soon developed severe myelosuppression. The patient’s hematopoietic recovery was poor, and CMV and human herpesvirus-6 (HHV-6) were detectable in the peripheral blood. Severe CMV retinitis was treated with foscarnet and the intraocular injection of ganciclovir. The CMV retinitis improved and the marrow gradually recovered. CMV and HHV-6 were no longer detectable in the peripheral blood. Foscarnet and intraocular injection of ganciclovir appeared to be an effective treatment for CMV retinitis in this myelosuppressed BMT patient.

Acute Promyelocytic Leukemia with Marrow Fibrosis at Initial Presentation: Possible Involvement of Transforming Growth Factor-β1

Although the occurrence of marrow fibrosis in acute myeloid leukemia has been described, there have been no reports of acute promyelocytic leukemia (APL) associated with marrow fibrosis. Here we describe an APL patient with severe marrow fibrosis at initial presentation. He had the typical manifestations of APL, except for marrow fibrosis. Complete remission was achieved by treatment with all-trans retinoic acid plus chemotherapy, and his marrow fibrosis gradually improved concomitantly with the decrease in leukemic cells. To clarify the mechanism of marrow fibrosis in this patient, we investigated the expression of genes for several cytokines promoting fibrosis by the reverse transcriptase polymerase chain reaction methods. An overexpression of transforming growth factor-β1 was noted in his leukemic cells at initial presentation, whereas no increase in expression was observed at the time of relapse when he no longer had marrow fibrosis. These findings suggest that overexpression of transforming growth factor-β1 was involved in the development of marrow fibrosis in this APL patient.

Long-Term Administration of Oral Low-Dose Topoisomerase II Inhibitors, MST-16 and VP-16, for Refractory or Relapsed Non-Hodgkin’s Lymphoma

It is known that the topoisomerase II inhibitors, MST-16 (sobuzoxane) and VP-16 (etoposide), are effective for the treatment of lymphoma. Five patients with refractory or relapsed non-Hodgkin’s lymphoma (NHL) were treated with a combination of oral MST-16 and VP-16 over a long period. Two patients had severely refractory NHL. The remaining 3 patients could not be treated with intensive chemotherapy because of severe organ dysfunction or a poor hematopoietic reserve. All 5 are alive and well after MST-16 and VP-16 treatment. MST-16 and VP-16 are effective for NHL when intensive chemotherapy is ineffective or contraindicated.

Treatment of intestinal graft-versus-host disease using betamethasone enemas

Intestinal graft-versus-host disease (GVHD) can readily easily induce generalized metabolic disturbance that influences morbidity and mortality after allogeneic bone marrow transplantation. Although adding a new drug or increasing the doses of immunosuppressive agents will probably be effective for controlling intestinal GVHD, the systemic side effects of such therapy cannot be ignored. In this study, we used betamethasone retention enemas as a local treatment for eight patients with refractory and/or severe intestinal GVHD. Six of the eight patients showed improvement of diarrhea and/or abdominal pain, with a reduction in the stage of GVHD. When treatment with betamethasone enemas was continued for 10 to 27 days in the 6 responding patients, no severe toxicity was observed. One patient failed to respond to treatment and another could not tolerate the enemas. Despite some uncertainty regarding the indications and duration of treatment, betamethasone enemas seem to be a potential alternative method for the management of intestinal GVHD.