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Notch is a transmembrane protein involved in cell fate determination. In the present study, we observed temporally and spatially restricted expression of Notch1 in developing cartilage. Notch1 was localized starting from the mesenchymal condensation stage of embryonic mouse forelimbs. Interestingly, although localization could not be detected in the proliferating chondrocytes, obvious immunoreactivity indicating its expression was retained in the perichondrial region. Next, we investigated the expression of Notch1 and related molecules in a chondrogenic cell line, ATDC5 cells. Notch1, Delta-like (Dll)1, Deltex2, and Deltex3 were coexpressed after 6-day insulin treatment. Expression of Hairy and Enhancer of split homologue (HES)-1 followed thereafter. These results suggest that Notch may have a role in the early stage of chondrogenesis. To assess the effect of Notch activation, we cultured ATDC5 cells with a myeloma clone constitutively expressing Dll1, a ligand of Notch. We also used an adenovirus vector to express the constitutively active Notch1 intracellular domain (NIC). Activating either the endogenous or exogenous Notch receptor dramatically inhibited chondrogenic cell differentiation of ATDC5 cells, as assessed by Alcian blue staining of the cells and chondrocyte differentiation markers. Last, we investigated the effect of NIC on the proliferation of the ATDC5 cells. Expression of NIC by the adenovirus strongly suppressed thymidine incorporation. These results indicate that Notch is expressed in the initial stage of chondrogenic cell differentiation and has a strong inhibitory effect on both differentiation and proliferation of the cells when activated. The expression of Notch decreases as chondrogenic differentiation proceeds; however, a population of the cells with sustained expression of Notch1 become perichondrial cells. Considering that the perichondrium acts as a stem cell source of osteoblasts and chondrocytes, Notch1 may have a role in the formation of these cells by suppressing both differentiation and proliferation.

Aim Sarcopenia has been increasingly reported as a prognostic factor for outcome in settings such as cirrhosis, liver transplantation, and emergent surgery. We aimed to elucidate the significance of sarcopenia in severe blunt trauma patients. Methods We retrospectively analyzed 84 patients emergently admitted to the intensive care unit at Kyushu University Hospital (Fukuoka, Japan) from May 2012 to April 2015. We assessed the amount of skeletal muscle present according to computed tomography and its relevance to ventilation‐free days, patients' length of stay in the intensive care unit, and 28‐day mortality. Results Twenty‐five (29.7%) patients were defined as sarcopenic. Sixteen (19.7%) patients required 15 days or more in the intensive care unit. The major reason was a prolonged ventilation requirement due to flail chest (n = 7) or pneumonia (n = 3). Sarcopenic patients' stays in intensive care were significantly longer than those of non‐sarcopenic patients (18.7 versus 6.4 days, respectively; P < 0.001). Univariate and multivariate analyses showed sarcopenia to be a significant risk factor for prolonged intensive care unit stay. Conclusion Sarcopenia is a risk factor that predicts prolonged intensive care unit stay in high‐energy blunt trauma patients.

These findings suggested that cyclin B1 protein overexpression is closely associated with less aggressive tumor behavior. Therefore, G2/M cyclin alternatives and the possible role of cyclins in cancer development warrants further attention.

Cell adhesion molecules are involved in a number of biological functions, such as cell survival, cell differentiation, tissue repair, and development. A novel molecule, POEM (preosteoblast epidermal growth factor-like repeat protein with meprin, A5 protein, and receptor protein-tyrosine phosphatase domain), was isolated by reverse transcription-polymerase chain reaction using a set of degenerate primers designed after other known epidermal growth factor (EGF)-like motifs. From its structure, POEM was suggested to be a novel adhesion molecule with five EGF-like domains, an Arg-GlyAsp (RGD) cell binding motif, and a meprin, A5 protein, and receptor protein-tyrosine phosphatase (MAM) domain. By in situ hybridization using embryonic day 16.5 (E16.5) mouse embryos, strong expression of POEM mRNA was observed in developing kidney renal tubules, parathyroid and thyroid glands, developing bone, tooth germ, and endocrine organs of the brain. The inner ear, skeletal muscle, smooth muscle (except for the vascular system), and skin were also positive for POEM expression. Bacterial recombinant POEM protein containing the RGD sequence and MAM domain showed strong cell adhesion, spreading, and survival-promoting activities. By mutating the RGD sequence to RGE, the cell spreading and survival activities were significantly decreased, but the MAM domain was shown to contribute only to cell adhesion and not to cell spreading and survival-promoting activities. The distribution of POEM in several tissues was close to that of ␣ 8 ␤ 1 integrin. Therefore, we conducted cell adhesion assays using KA8 cells, a K562 leukemia clone stably expressing ␣ 8 integrin. Parental K562 cells, which expressed ␣ 5 ␤ 1 integrin, bound to fibronectin but not to POEM. On the other hand, KA8 cells showed strong binding and spreading on both fibronectin and POEM. These results suggest that POEM is a novel ligand for ␣ 8 ␤ 1 integrin and that POEM may be involved in the development and function of various tissues, such as kidney, bone, muscles, and endocrine organs.