105 research outputs found

    Dependence of Spreading and Differentiation of Mesenchymal Stem Cells on Micropatterned Surface Area

    Get PDF
    Micropatterning technology is a highly advantageous approach for directly assessing and comparing the effects of different factors on stem cell functions. In this study, poly(vinyl alcohol)- (PVA-) micropatterned polystyrene surfaces were prepared using photoreactive PVA and ultraviolet photolithography with a photomask. The micropatterned surface was suitable for single-cell array formation and long-term cell culture due to the nanometer thickness of nonadhesive PVA layer. Different degrees of cell spreading with the same cell shape were established by adjusting the sizes of circular, cell-adhesive polystyrene micropatterns. Cell spreading and differentiation of mesenchymal stem cells (MSCs) on the micropatterns were investigated at the single-cell level. The assembly and organization of the cytoskeleton were regulated by the degree of cell spreading. Individual MSCs on large circular micropatterns exhibited a more highly ordered arrangement of actin filaments than did those on the small circular micropatterns. Furthermore, the differentiation of MSCs was dependent on the degree of cell spreading. Increased cell spreading facilitated the osteogenic differentiation but suppressed the adipogenic differentiation of MSCs. This micropatterning method is valuable for stem cell research in tissue engineering and regenerative medicine

    Surgery for Perforation Complicating Colon Cancers

    Get PDF
    Eleven patients with perforation complicating colon cancers were clinically analyzed with respect to perforation sites and surgical outcome. In general, perforations complicating colon cancers are divided into two categor ies, free perforation and penetration with abscess or fistula formation. It is emphasized that surgical outcome for free perforation is unsatisfactory. Therefore, two-stage operation is recommended and the aim of the treatment should be first concentrated on peritonitis. In conclusion, complete resection of carcinoma is necessary in obtaining a satisfactory result

    Functional Hydrogels With Tunable Structures and Properties for Tissue Engineering Applications

    Get PDF
    Tissue engineering (TE) has been used as an attractive and efficient process to restore the original tissue structures and functions through the combination of biodegradable scaffolds, seeded cells, and biological factors. As a unique type of scaffolds, hydrogels have been frequently used for TE because of their similar 3D structures to the native extracellular matrix (ECM), as well as their tunable biochemical and biophysical properties to control cell functions such as cell adhesion, migration, proliferation, and differentiation. Various types of hydrogels have been prepared from naturally derived biomaterials, synthetic polymers, or their combination, showing their promise in TE. This review summarizes the very recent progress of hydrogels used for TE applications. The strategies for tuning biophysical and biochemical properties, and structures of hydrogels are first introduced. Their influences on cell functions and promotive effects on tissue regeneration are then highlighted

    Influence of Cell Spreading Area on the Osteogenic Commitment and Phenotype Maintenance of Mesenchymal Stem Cells

    Get PDF
    Osteogenic differentiation and commitment of mesenchymal stem cells (MSCs) is a complex process that is induced and regulated by various biological factors and biophysical cues. Although cell spreading area, as a biophysical cue, has been demonstrated to play a critical role in the regulation of osteogenic differentiation of MSCs, it is unclear how it affects the maintenance of the committed phenotype after osteogenic differentiation of MSCs. In this study, poly (vinyl alcohol) was micropatterned on a tissue culture polystyrene surface, and the micropatterns were used to culture MSCs to control their cell spreading area. The influence of cell spreading area on osteogenic differentiation and maintenance of the differentiated phenotype of MSCs was investigated. MSCs with a larger spreading area showed a higher degree of osteogenic differentiation, slower loss of differentiated phenotype and slower re-expression of stem cell markers compared with MSCs with a smaller spreading area. A large cell spreading area was beneficial for osteogenic differentiation of MSCs and maintenance of their differentiated phenotype

    Carcinoma-containing CEA in colon cancers in primary and metastatic tumors

    Get PDF
    Carcinoma-containing CEA was measured as compared with normal tissues and metastases in the lymph nodes and the liver. The high CEA production was remarkable in the potent malignant tumors and metastases in the liver and the lymph nodes as compared with those in normal colon tissues as well as in non metastatic lymph nodes. It is reasonable to consider that high plasma CEA may well indicate advancing or highly potent malignant diseases or recurrence of colon cancers due to destruction of vascular structure by cancer invasion

    Management of Blunt Hepatic Trauma

    Get PDF
    One hundred and twelve consecutive cases with blunt hepatic trauma between January 1, 1965 and December 31, 1988 at the First Dpartment of Surgery, Nagasaki University were reviewed. Fifty-seven patients had minor injuries, 33 moderate injuries and 22 severe injuries. Sixty-five patients (58%) sustained also one of more associated injuries. Out of 43 patients over the last ten years 30 were diagnosed by US or CT. Eighty-eight patients (78.3%) underwent laparotomy ; laparotomy and drainage alone in 13, suture and packs in 57, debridement and minor liver resection in 11 and right lobectomy in 9. The results of treated patients were assessed according to the grading of liver injury and assocated injury. The overall mortality was 13.4% (15 of 112). True liver-related mortality due to hemorrhage was 26.7% (4 of 5), and the other 11 patients who died were due to refractory shock and the development of multiple organ failure (MOF). Twenty-one patients were conservatively managed with only one death, and the other 20 survivors had no complications and healed completely from 6 to 12 months after trauma. Although lobectomy or resectional debridement are advocated as an operative procedure for massive injury, a conservative management for mild or moderate ruptures is still recommended as far as possible

    Postoperative Course of Crohn\u27s Disease -In regard to Recurrence and Residual Disease at Anastomosis -

    Get PDF
    Twenty-seven patients with Crohn\u27s disease who were operated on at the First Department of Surgery, Nagasaki University School of Medicine and followed-up after surgery were reviewed. Involved portion of intestinal tract were 10 in small bowel only, 14 in both small and large bowels, and 3 in large bowel. Major indication for surgery were obstruction, fistula, peritonitis and intractability of medical therapy. Twenty-two patients underwent radical resection and the other 5 patients had the disease left behind at anastomosis. The recurrence rate was 25.9% (7 out of 22), and early recurrence was found in small bowel diseases with longitudinal ulcerations or multiple aphthoid ulcers. Initial recurrence occured near the suture line, which showed no wide spreading in subsequent periods. Two cases with both small and large bowel disease required reoperation over 5 years after initial surgery because of stenosis. Three out of five cases with residual disease at the intestinal resection margin had a good condition, but the other three cases with skip sigmoid disease were intractable for medical therapy. Most suture line recurrence and residual disease at anastomosis were sufficiently managed by postoperative medication for long periods of time. Long-term follow-up study showed a good quality of life in about 75% of these cases. In conclusion, conservative resection rather than the sacrifice of normal bowel should be recommended for an extended disease of small bowel

    Results of the search for inspiraling compact star binaries from TAMA300's observation in 2000-2004

    Get PDF
    We analyze the data of TAMA300 detector to search for gravitational waves from inspiraling compact star binaries with masses of the component stars in the range 1-3Msolar. In this analysis, 2705 hours of data, taken during the years 2000-2004, are used for the event search. We combine the results of different observation runs, and obtained a single upper limit on the rate of the coalescence of compact binaries in our Galaxy of 20 per year at a 90% confidence level. In this upper limit, the effect of various systematic errors such like the uncertainty of the background estimation and the calibration of the detector's sensitivity are included.Comment: 8 pages, 4 Postscript figures, uses revtex4.sty The author list was correcte
    corecore