Asian Science Citation Index is committed to provide an authoritative, trusted and significant information by the coverage of the most important and influential journals to meet the needs of the global scientific community.  
ASCI Database
308-Lasani Town,
Sargodha Road,
Faisalabad, Pakistan
Fax: +92-41-8815544
Contact Via Web
Suggest a Journal
 
Articles by A Yokoyama
Total Records ( 3 ) for A Yokoyama
  M Ii , H Nishimura , H Sekiguchi , N Kamei , A Yokoyama , M Horii and T. Asahara
 

Rationale: Recent reports have demonstrated that signals from vascular endothelial cells are necessary for organogenesis that may precede vasculogenesis. However, the origin of these neovascular cells in regenerating tissue has not been clarified.

Objective: Here we tested the hypothesis that adult neural stem cells (NSCs) can differentiate into vascular lineage, as well as neural lineage, in the process of collaborative organogenesis.

Methods and Results: NSCs, clonally isolated from mouse brain, were shown to develop endothelial and smooth muscle phenotypes in vitro. To elucidate whether NSCs can simultaneously differentiate into vascular and neural cells in vivo, genetically labeled NSCs were administered to mice with unilateral sciatic nerve crush injury or operatively induced brain and myocardial ischemia. Two weeks later, necropsy examination disclosed recruitment of the labeled NSCs to sites of injury differentiating into vascular cells (endothelial cells and vascular smooth muscle cells) and Schwann cells in regenerating nerve. Similarly, NSC-derived vascular cells/astrocytes and endothelial cells were identified in ischemic brain tissue and capillaries in myocardium 2 weeks following transplantation, respectively.

Conclusions: These findings, concurrent vasculogenesis and neurogenesis from a common stem cell, suggest that certain somatic stem cells are capable of differentiating into not only somatic cells of identity but also into vascular cells for tissue regeneration.

  T Fujii , H Kunikane , H Okamoto , K Watanabe , H Kunitoh , K Mori , A Yokoyama , H Fukuda , T Tamura and N. Saijo
  Objective

It is important to find optimal regimens of cisplatin (CDDP)-based third-generation chemotherapy and radiotherapy for patients with unresectable Stage III non-small cell lung cancer (NSCLC).

Methods

This Phase II study was designed to determine the toxicity and efficacy of two courses of chemotherapy (CDDP 80 mg/m2 on day 1 and irinotecan 60 mg/m2 on days 1 and 8) followed by accelerated hyperfractionated thoracic radiotherapy (60 Gy/40 fractions in 4 weeks) combined with daily carboplatin (CBDCA) administration. CBDCA was administered at a target area under the plasma level–time curve of 0.4 x (24 h creatinine clearance + 25), according to Calvert's formula.

Results

Twenty-six patients were enrolled in the study. The patients' median age was 63 years (range 40–74 years) and included 22 males and 4 females. Seven patients were Stage IIIA and 19 were Stage IIIB. Twenty had a performance status (PS) of 1 versus six with a PS of 0. There was one treatment-related death due to sepsis and pneumonia associated with Grade 4 neutropenia and diarrhea during chemotherapy. Grade 3 or 4 neutropenia and diarrhea were observed in 14 and 5 patients, respectively. Toxicity of the radiotherapy was mild. There were 0 complete response and 13 partial responses, giving a response rate of 50.0%. Median survival time and 2-year survival were 16.4 months and 21.5%, respectively. This study was designed with Simon's two-stage design, and the response rate did not meet the criteria to proceed to the second stage and the study was terminated early.

Conclusions

This regimen might be inactive for patients with unresectable Stage III NSCLC.

  T Matsumoto , M Ii , H Nishimura , T Shoji , Y Mifune , A Kawamoto , R Kuroda , T Fukui , Y Kawakami , T Kuroda , S. M Kwon , H Iwasaki , M Horii , A Yokoyama , A Oyamada , S. Y Lee , S Hayashi , M Kurosaka , S Takaki and T. Asahara
 

The therapeutic potential of hematopoietic stem cells/endothelial progenitor cells (HSCs/EPCs) for fracture healing has been demonstrated with evidence for enhanced vasculogenesis/angiogenesis and osteogenesis at the site of fracture. The adaptor protein Lnk has recently been identified as an essential inhibitor of stem cell factor (SCF)–cKit signaling during stem cell self-renewal, and Lnk-deficient mice demonstrate enhanced hematopoietic reconstitution. In this study, we investigated whether the loss of Lnk signaling enhances the regenerative response during fracture healing. Radiological and histological examination showed accelerated fracture healing and remodeling in Lnk-deficient mice compared with wild-type mice. Molecular, physiological, and morphological approaches showed that vasculogenesis/angiogenesis and osteogenesis were promoted in Lnk-deficient mice by the mobilization and recruitment of HSCs/EPCs via activation of the SCF–cKit signaling pathway in the perifracture zone, which established a favorable environment for bone healing and remodeling. In addition, osteoblasts (OBs) from Lnk-deficient mice had a greater potential for terminal differentiation in response to SCF–cKit signaling in vitro. These findings suggest that inhibition of Lnk may have therapeutic potential by promoting an environment conducive to vasculogenesis/angiogenesis and osteogenesis and by facilitating OB terminal differentiation, leading to enhanced fracture healing.

 
 
 
Copyright   |   Desclaimer   |    Privacy Policy   |   Browsers   |   Accessibility