Surface modification of poly (L-lactide) by atmospheric pressure plasma treatment and cell response

This study investigated the influence of atmospheric pressure plasma treatment on the surface properties and cell response of poly(L-lactide) (PLLA) samples. The samples were analyzed by means of X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), micro- and nanosurface roughness, water contact angle, and zeta potential. Furthermore, cell adhesion assay and cell proliferation assay on the samples were carried out using MC3T3-E1 cells. Plasma treatment significantly increased the oxygen content of the samples and decreased the contact angle and zeta potential of the samples, resulting in hydrophilic surfaces. Further, plasma treatment of the samples also enhanced the number and growth of adhering MC3T3-E1 cells. These results therefore indicate that plasma treatment is effective for surface modification and cell responses.     

Degradation of arginine by Slackia exigua ATCC 700122 and Cryptobacterium curtum ATCC 700683

Slackia exigua ATCC 700122(T) and Cryptobacterium curtum ATCC 700683(T) were our isolates from infected root canal and human periodontal pocket, respectively; they are asaccharolytic anaerobic gram-positive rods, which are predominant in the oral cavity. They utilize arginine, so our aim was to investigate the pathway of arginine degradation. Metabolic end products were determined with high-performance liquid chromatography. The related enzymatic activities in cell-free extract were also assayed. Both S. exigua and C. curtum degraded arginine and produced substantial amounts of citrulline, ornithine and ammonia. Arginine and citrulline supported the growth of both strains. As the related enzymatic activities, arginine deiminase, ornithine carbamoyltransferase and carbamate kinase activities were detected in the cell-free extract of S. exigua and C. curtum. Arginase and urease activities were not detected in either organism. These results suggest that arginine was metabolized by the arginine deiminase pathway. Both S. exigua and C. curtum degrade arginine via the arginine deiminase pathway.     

Defects in aortic fusion and craniofacial vasculature in the holoprosencephalic mouse embryo under inhibition of sonic hedgehog signaling

Sonic hedgehog (Shh) is a well-known morphogen indispensable in facial and nervous development, and recently it has also garnered much attention as a potent angiogenic factor. We previously created an animal model of holoprosencephaly by administration of cyclopamine, a specific inhibitor of hedgehog signaling, to the mouse embryos cultured in vitro, and found several types of angiogenic defects. In this study, we focused on other angiogenic phenotypes in the same model. When cyclopamine was added for embryonic day (E) 8.0-9.5, a pair of immature dorsal aortae, which normally fuse to form the single aorta by E9.5, remained to be separated. Expressions of vascular endothelial growth factor and bone morphogenetic protein 4, putative mediators of aortic fusion, were also reduced around the aorta by blockade of Shh signaling. When cyclopamine was added for E8.5-10.5, vessels on the surface of craniofacial region (possibly external cardinal veins) were extended and malformed. These results suggest that Shh signaling is essential for some aspects of embryonic angiogenesis, and that pathophysiology of holoprosencephaly may involve, at least in part, the Shh-dependent angiogenesis.     

Day care service use is associated with lower mortality in community-dwelling frail older people

OBJECTIVES: To clarify the association between day care service use and 21-month mortality in community-dwelling frail older people. DESIGN: Prospective cohort study (the Nagoya Longitudinal Study for Frail Elderly). SETTING: Community-based. PARTICIPANTS: One thousand six hundred seventy-three community-dwelling older people (540 men, 1,133 women). MEASUREMENTS: Data included the clients' demographic characteristics; depression as assessed using the short version of the Geriatric Depression Scale; a rating for basic activities of daily living (ADLs); comorbidity; number of prescribed medications and physician-diagnosed chronic diseases; use of home-care services, including day care, visiting nurse, and home-help services; and number of regular medical checkups. Survival analysis of 21-month mortality was conducted using Kaplan-Meier curves and multivariate Cox proportional hazards models. RESULTS: Of the 1,673 participants, 726 were day care service users at baseline, and 268 (94 day care service users, 174 nonusers) died during the 21-month follow-up. Multivariate Cox regression models adjusting for potential confounders showed that day care service use was associated with reduction in mortality. Subgroup analysis demonstrated that day care service use was associated with less risk of mortality in subjects who were female; were in the youngest age group (65-74); had higher ADL scores, lower comorbidity, depression, no dementia; and used a visiting nurse service. Participants using day care service two and three times or more a week had 63% or 44% lower relative hazard ratios, respectively, than participants not using the service. CONCLUSION: Among community-dwelling frail older people, day care service use two or more times per week was associated with 44% to 63% lower 21-month mortality.     

Cre/loxP-mediated CTLA4IgG gene transfer induces clinically relevant immunosuppression via on-off gene recombination in vivo

OBJECTIVE: Transfer of the CTLA4IgG gene induces long-term and high levels of CTLA4IgG expression, which can result in generalized immunosuppression. In this study, we utilized Cre/loxP-mediated on-off switch recombination to eliminate transgene expression of CTLA4IgG following acceptance of murine cardiac allografts. METHODS: Fully MHC-mismatched hearts from BALB/c donor mice were transplanted into C3H/He recipient mice. Adenovirus-containing CTLA4IgG flanked between two loxP sites was administered via a recipient tail vein immediately after transplantation. Cre-recombinase gene was subsequently transferred at day 30 posttransplantation. RESULTS: Long-term allograft survival was observed in recipients that received the CTLA4IgG gene. Cre-mediated recombination reduced CTLA4IgG gene expression without any adverse effect on the graft survival. Secondary skin grafts of donor type and of third party were promptly rejected in the recipients that accepted cardiac allografts. In addition, the B cell response against ovalbumin was suppressed during high levels of serum CTLA4IgG, but recovered after Cre-mediated inactivation of CTLA4IgG gene. CONCLUSION: CTLA4IgG gene transfer promoted long-term survival of murine cardiac allografts; however, this was not sufficient to induce tolerance. Cre/loxP-mediated on-off switch recombination was useful to inactivate the CTLA4IgG gene so that recipients' immune responses against neoantigens were restored without an influence on the allograft survival. This system may open novel strategies to orchestrate clinically relevant immunosuppression.     

Granulocyte colony-stimulating factor (G-CSF) accelerates reendothelialization and reduces neointimal formation after vascular injury in mice

OBJECTIVE: Neointimal formation following percutaneous coronary intervention (PCI), termed restenosis, limits therapeutic revascularization. Since reendothelialization is one of the determinant factors for the development of neointimal formation, we examined the effects of granulocyte colony-stimulating factor (G-CSF) on reendothelialization and neointimal formation after vascular injury in mice. METHODS AND RESULTS: Wire-mediated vascular injury was produced in the femoral artery of C57BL/6 mice. G-CSF pretreatment significantly accelerated reendothelialization and decreased neointimal formation following vascular injury; however, this inhibitory effect of G-CSF was diminished when G-CSF was started following the injury. Flow cytometry analysis revealed that G-CSF treatment increased the number of endothelial progenitor cells (EPCs: CD34+/Flk-1+) in the peripheral circulation. Vascular injury was also produced in 2 types of mice whose bone marrow was replaced with that of enhanced green fluorescent protein- and Tie2/LacZ-transgenic mice. In the reendothelialized artery of these mice, few bone marrow-derived EPCs were detected. Furthermore, G-CSF treatment reduced the serum level of interleukin (IL)-6. CONCLUSION: G-CSF treatment accelerated reendothelialization and decreased neointimal formation following vascular injury, although there was little contribution of bone marrow-derived EPCs to the reendothelialization of the artery. These results suggest that G-CSF pretreatment has a therapeutic potential for prevention of restenosis following PCI.