Aphidicolin, an inhibitor of DNA replication, blocks the TPA-induced differentiation of a human megakaryoblastic cell line, MEG-O1.

The commitment process of a human megakaryoblastic cell line (MEG-O1) induced with phorbol ester, TPA, was investigated with special reference to glycoprotein (GP) IIb/IIIa expression, multinuclear formation, and DNA replication. TPA (10(-7) mol/L) completely inhibited cellular division in MEG-O1, but did not suppress de novo DNA synthesis. Two days' culture with 10(-7) mol/L TPA was sufficient for MEG-O1 cells to initiate an irreversible commitment process. These cells could not resume cell growth and expressed GP IIb/IIIa antigen; some of them showed multinuclear form and DNA polyploidy even after removal of TPA from the culture medium. DNA histogram analysis showed that, upon treatment with TPA, the percentage of cells whose DNA ploidy was more than 8N was 5 to 10 times higher than that of control cells. Precise analysis using cell size fractionation by centrifugal elutriation method showed that there was strong correlation between the percentage of multinuclear cells and DNA polyploidy in TPA-treated cells. The percentage and staining intensity of GP IIb/IIIa and other megakaryocytic phenotypes such as von Willebrand factor and PAS staining were highest in large multinuclear cell populations, suggesting that these cells are the most differentiated population in this system. In TPA-treated cells, the activity of DNA polymerase alpha, a marker for cell growth, remained at the same level as in control cells. Aphidicolin, a specific inhibitor of DNA polymerase alpha, completely inhibited the differentiation induction of MEG-O1 cells with TPA measured by either GP IIb/IIIa expression or multinuclear cell formation. Therefore, DNA replication appears to be involved in the process of phenotypic expression as well as endomitosis in megakaryocyte differentiation of MEG-O1 cells. Aphidicolin was also effective in inhibiting megakaryocytic differentiation of other leukemia cell lines such as human erythroleukemia (HEL) and K562 cell lines induced with TPA, suggesting the close interplay of DNA replication and phenotypic expression in megakaryopoiesis.     

Leukemic relapse in the central nervous system after allogeneic stem cell transplantation with complete remission in the bone marrow and donor-type chimerism: report of two cases

We studied two cases with leukemia that relapsed in the central nervous system (CNS) after allogeneic stem cell transplantation. One patient underwent peripheral blood stem cell transplantation (SCT) from a related, yet haplotype-mismatched, donor for chronic myelomonocytic leukemia. She was kept in complete remission (CR) in the bone marrow (BM) for 7 months, until relapse in the cerebrospinal fluid (CSF) was evident. In the other patient, with acute lymphoblastic leukemia, systemic relapse occurred when he was still on immunosuppression 6 months after SCT from an unrelated donor. After induction chemotherapy following cessation of immunosuppression, the BM examination proved CR. During consolidation chemotherapy, however, he developed leukemic dissemination in the CSF, despite the fact that the BM was in CR. Chimerism status in the BM mononuclear cells and fractionated peripheral blood (PB) cells (granulocytes, T-lymphocytes, and the others) was assessed by short tandem repeat analysis. In both patients, the BM cells and all the fractions of the PB cells proved donor-type chimeras. These results seem to suggest that the graft-versus-leukemia effects might not be as effective in the CNS as in the BM, even when complete T-lymphoid chimerism is achieved.     

Disruption of tumor necrosis factor-alpha gene diminishes the development of atherosclerosis in ApoE-deficient mice

Inflammatory cytokines, including tumor necrosis factor-alpha (TNF-alpha) have been implicated in atherogenesis. However, the precise role of TNF-alpha in atherogenesis is still unclear. To examine the effect of TNF-alpha on atherogenesis, we generated compound-deficient mice in apolipoprotein E (apoE) and TNF-alpha (apoE-/-/TNF-alpha-/-) and compared them with apoE-/- mice. Although serum total cholesterol levels were markedly elevated in both apoE-/-/TNF-alpha-/- and apoE-/- mice compared to wild-type mice, no differences were observed between apoE-/-/TNF-alpha-/- and apoE-/- mice. The atherosclerotic plaque area in the aortic luminal surface of apoE-/-/TNF-alpha-/- mice (n=8, 3.1+/-0.4%) was significantly smaller than that of apoE-/- mice (n=7, 4.7+/-0.4%, p<0.001) despite the lack of difference in serum cholesterol levels. The atherosclerotic lesion size in the aortic sinus of apoE-/-/TNF-alpha-/- mice (n=10, 5.1+/-0.3 x 10(5)microm(2)) was also significantly smaller than that of apoE-/- mice (n=11, 7.0+/-0.3 x 10(5)microm(2), p<0.0001). RT-PCR analysis indicated that the expression levels of intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1) and monocyte chemoattractant protein-1 (MCP-1) were significantly higher in apoE-/- than apoE-/-/TNF-alpha-/- mice. Macrophages from apoE(-/-) mice showed higher uptake level of oxidized LDL and increased expression level of scavenger receptor class A (SRA) compared to those from apoE-/-/TNF-alpha-/- mice. These results indicate that TNF-alpha plays an atherogenic role by upregulating the expressions of ICAM-1, VCAM-1 and MCP-1 in the vascular wall, and by inducing SRA expression and oxidized LDL uptake in macrophages.     

Depressive mood modulates the anterior lateral CA1 and DG/CA3 during a pattern separation task in cognitively intact individuals: A functional MRI study

Although patients with major depressive disorder typically have a reduced hippocampal volume, particularly in the cornu ammonis 1 (CA1), animal studies suggest that depressive mood is related to the dentate gyrus (DG). In this study, our objective was to clarify which hippocampal subregions are functionally associated with depressive mood in humans. We conducted a functional MRI (fMRI) study on 27 cognitively intact volunteers. Subjects performed a modified version of a delayed matching‐to‐sample task in an MRI scanner to investigate pattern separation‐related activity during each phase of encoding, delay, and retrieval. In each trial, subjects learned a pair of sample cues. Functional MR images were acquired at a high spatial resolution, focusing on the hippocampus. Subjects also completed the Beck Depression Inventory (BDI), a questionnaire about depressive mood. Depending on the similarity between sample cues, activity in the DG/CA3 and medial CA1 in the anterior hippocampus changed only during encoding. Furthermore, the DG/CA3 region was more active during successful encoding trials compared to false trials. Activity in the DG/CA3 and lateral CA1 was negatively correlated with BDI scores. These results suggest that the DG/CA3 is the core region for pattern separation during the encoding phase and interacts with the medial CA1, depending on the similarity of the stimuli, to achieve effective encoding. Impaired activity in the DG/CA3, as well as in the lateral CA1, was found to be associated with depressive symptoms, even at a subclinical level. © 2013 Wiley Periodicals, Inc.     

Characteristics and Treatment Outcomes of Small-bowel Angioectasia in Systemic Sclerosis Patients: A Retrospective Observational Study

Objective Systemic sclerosis (SSc) is defined as an autoimmune disease presenting with fibrosis of various organs and vascular endothelial damage. Vascular lesions, including small-bowel angioectasias, are also frequently detected in SSc patients. Polidocanol injection (PDI) is a safe and effective hemostatic treatment for gastrointestinal bleeding. We evaluated the outcomes of PDI for small-bowel angioectasia in SSc patients. Methods We retrospectively evaluated 65 consecutive SSc patients (61 women; mean age, 64.3 years old) who underwent capsule endoscopy (CE) and/or double-balloon endoscopy at Hiroshima University Hospital between April 2012 and December 2019. Patients Patients were stratified according to the presence of small-bowel angioectasia. Among patients who underwent CE during the same period, those with small-bowel angioectasia without concomitant diseases were compared with SSc patients with small-bowel angioectasia. Clinical and endoscopic characteristics, treatment outcomes, and the incidence of metachronous small-bowel angioectasia after PDI were evaluated. Results SSc patients with small-bowel angioectasia exhibited significantly lower hemoglobin levels and a significantly higher incidence of skin telangiectasia than those without small-bowel angioectasia. On a multivariate analysis of the presence of small-bowel angioectasia, anemia and skin telangiectasia were significant independent factors. SSc patients with small-bowel angioectasia included a higher proportion of women and exhibited a significantly higher incidence of metachronous small-bowel angioectasia than X. The characteristics of small-bowel angioectasia and outcomes of PDI were not significantly different between the two groups. No post-treatment rebleeding cases or adverse events were noted. Conclusion CE should be performed for SSc patients with anemia and/or skin telangiectasia. PDI is effective for SSc patients with small-bowel angioectasia.     

The positron emission tomography with F18 17beta-estradiol has the potential to benefit diagnosis and treatment of endometrial cancer

BACKGROUND: The positron emission tomography (PET) with F18 17beta-estradiol (FES) has good imaging for assessment of estrogen receptor in breast cancer. CASE: We report on a 30-year-old woman who desired to preserve her fertility with well-differentiated endometrial adenocarcinoma. Before hormone treatment was started, FES-PET showed increased uptake of endometrium, magnetic resonance imaging (MRI) showed thickness and F-18 fluorodeoxyglucose (FDG)-PET showed increased uptake. FES-PET after 3 months showed remaining FES uptake, but there were no abnormal findings on MRI and FDG-PET. Hysteroscopy showed remaining adenocarcinoma. After additional treatment, FES-PET showed a therapeutic response, and hysteroscopy showed no abnormal finding. CONCLUSIONS: To our knowledge, this is the first report that FES-PET has the potential to provide more useful information than did FDG-PET about the hormone therapy.