A CCAAT/enhancer binding protein beta isoform, liver-enriched inhibitory protein, regulates commitment of osteoblasts and adipocytes.

Although both osteoblasts and adipocytes have a common origin, i.e., mesenchymal cells, the molecular mechanisms that define the direction of two different lineages are presently unknown. In this study, we investigated the role of a transcription factor, CCAAT/enhancer binding protein beta (C/EBPbeta), and its isoform in the regulation of balance between osteoblast and adipocyte differentiation. We found that C/EBPbeta, which is induced along with osteoblast differentiation, promotes the differentiation of mesenchymal cells into an osteoblast lineage in cooperation with Runx2, an essential transcription factor for osteogenesis. Surprisingly, an isoform of C/EBPbeta, liver-enriched inhibitory protein (LIP), which lacks the transcriptional activation domain, stimulates transcriptional activity and the osteogenic action of Runx2, although LIP inhibits adipogenesis in a dominant-negative fashion. Furthermore, LIP physically associates with Runx2 and binds to the C/EBP binding element present in the osteocalcin gene promoter. These data indicate that LIP functions as a coactivator for Runx2 and preferentially promotes the osteoblast differentiation of mesenchymal cells. Thus, identification of a novel role of the C/EBPbeta isoform provides insight into the molecular basis of the regulation of osteoblast and adipocyte commitment.

The effect of small dose of topiroxostat on serum uric acid in patients receiving hemodialysis.

INTRODUCTION: Topiroxostat, a recently developed xanthine oxidase inhibitor, is expected to have fewer adverse effects than allopurinol because it has different mechanism of action from alloprinol. However, its dosage, usage and safety have not been established in patients with impaired renal function or those undergoing dialysis at the development since no studies was conducted in these patients. METHODS: Cross over clinical trial using 3 months of allopurinol and topiroxostat on 27 maintain Japanese HD patients were carried out. The effects on oxidative stress status of both drugs were also evaluated by measuring oxidation reduction potential. FINDINGS: Twenty-five of twenty-seven patients completed study. The mean serum uric acid levels in the topiroxostat-treated arm was significantly lower than it in the allopurinol-treated arm time-dependently (P < 0.0001). Corrected oxidative stress ratio defined as biological antioxidant potential/diacron reactive oxygen metabolites was significantly increased in topiroxostat-arm (*P = 0.0035), but not in allopurinol-arm (P = 0.1429). No significant difference was seen in diacron reactive oxygen metabolites, biological antioxidant potential, static oxidation-reduction potential, and capacity oxidation-reduction potential between pre and post treatment of both drugs. DISCUSSION: It is suggested that a low dose of topiroxostat decreased serum uric acid sufficiently to maintain it below 7.0 mg/dL in patients receiving hemodialysis.

[A case of recurrent breast cancer with chronic renal failure treated on an outpatient basis].

We report a case of recurrent breast cancer with chronic renal failure in a 58-year-old female. She could be treated on an outpatient basis under good general condition for most of her remaining life by chemoradiotherapy in combination with hemodialysis. Modification of the chemoradiotherapy procedures and collaboration of medical staff including the doctor in charge of home medical care and her family was indispensable in keeping her hospital stay as short as possible.