The Keio Journal of Medicine
Online ISSN : 1880-1293
Print ISSN : 0022-9717
ISSN-L : 0022-9717
Volume 54, Issue 4
Displaying 1-6 of 6 articles from this issue
REVIEWS
  • Thomas Schwarz
    2005 Volume 54 Issue 4 Pages 165-171
    Published: 2005
    Released on J-STAGE: June 20, 2006
    JOURNAL FREE ACCESS
    Ultraviolet radiation (UV), in particular the UVB range, suppresses the immune system in several ways. UVB inhibits antigen presentation, induces the release of immunosuppressive cytokines and causes apoptosis of leukocytes. UVB, however, does not cause general immunosuppression but rather inhibits immune reactions in an antigen-specific fashion. Application of contact allergens onto UV-exposed skin does not cause sensitization but induces antigen-specific tolerance since such an individual cannot be sensitized against the very same allergen later, although sensitization against other allergens is not impaired. This specific immunosuppression is mediated by antigen-specific suppressor/regulatory T cells. UVB-induced DNA damage is a major molecular trigger of UV-mediated immunosuppression. Reduction of DNA damage mitigates UV-induced immunosuppression. Likewise interleukin-12 which exhibits the capacity to reduce DNA damage can prevent UV-induced immunosuppression and even break tolerance. Presentation of the antigen by UV-damaged Langerhans cells in the lymph nodes appears to be an essential requirement for the development of regulatory T cells. Studies addressing the molecular mechanisms underlying UV-induced immunosuppression will contribute to a better understanding how UV acts as a pathogen but on the other hand can be also used as a therapeutic tool.
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  • Federico Brugnami, Cristiano Caleffi
    2005 Volume 54 Issue 4 Pages 172-178
    Published: 2005
    Released on J-STAGE: June 20, 2006
    JOURNAL FREE ACCESS
    Dental implants are established alternatives for replacing missing teeth. Tooth loss for different reasons may leads to alveolar resorption. Shortage of bone can prevent proper positioning of dental implants according to prosthetic needs and treatment planning, unless the volume of hard and soft tissues is increased before implantation. In the esthetic area it is essential not only to achieve well-anchored implants but also sufficient soft and hard tissue in order to obtain natural looking result. This article will present several treatment modalities to augment the soft and hard tissues in order to obtain proper insertion of implants according to prosthetic needs and patient satisfaction.
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  • Shane E. Hendon, Jack A. DiPalma
    2005 Volume 54 Issue 4 Pages 179-183
    Published: 2005
    Released on J-STAGE: June 20, 2006
    JOURNAL FREE ACCESS
    As the prevalence of gastric carcinoma decreases in Japan, the prevalence of colon cancer has been increasing. Examination of the screening practices for colon cancer in the United States can offer insight into practices that may be useful in Japan. This paper will review the epidemiology and risk factors for colon cancer, the genetics ofcolon cancer, prevention issues, screening modalities, and current recommendations in U.S. practice.
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  • Qing Lu, Elizabeth O. Harrington, Sharon Rounds
    2005 Volume 54 Issue 4 Pages 184-189
    Published: 2005
    Released on J-STAGE: June 20, 2006
    JOURNAL FREE ACCESS
    Apoptosis is important in developmental biology and in remodeling of tissues during repair. Apoptosis also plays important roles in the progression of many diseases. The cellular and molecular mechanisms of apoptosis, in general, have been extensively demonstrated. However, the causes and the roles of apoptosis of various cell types in the lung are not well understood. We have determined that adenosine/homocysteine causes lung vascular endothelial cell apoptosis by inhibition of carboxyl methylation of the small GTPase, Ras, through inhibition of isoprenylcysteine carboxyl methyltransferase (ICMT) activity, leading to inactivation of Ras and the subsequent disruption of focal adhesion complexes, resulting in cell-extracellular matrix detachment and anoikis. Apoptosis can either ameliorate or exacerbate lung injury, depending upon the cell type. Although apoptosis of polymorphonuclear leukocytes in the lung prevents inflammation and the development of acute respiratory distress syndrome during acute lung injury, Fas/FasL-mediated alveolar epithelial cell apoptosis promotes acute lung injury and pulmonary fibrosis. Lung epithelial and endothelial cell apoptosis also contributes to the development of emphysema. This article focuses on elucidating the mechanisms of adenosine/homocysteine-induced endothelial cell apoptosis. We also review the current understanding of the role of lung cell apoptosis in acute lung injury, pulmonary fibrosis and emphysema.
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MINIREVIEW
  • Hide Tsukamoto
    2005 Volume 54 Issue 4 Pages 190-192
    Published: 2005
    Released on J-STAGE: June 20, 2006
    JOURNAL FREE ACCESS
    Alcoholic liver disease (ALD) is characterized by accumulation of neutral lipids in hepatocytes leading to micro and macro-vesicular steatosis and balloon cell degeneration. Hypercaloric alimentation and resultant obesity also cause similar changes as evident in non-alcoholic fatty liver disease (NAFLD). Thus, accumulation of lipids in hepatocytes is a pathologic hallmark of ALD and NAFLD. In contrast, quiescent hepatic stellate cells (HSC) are characterized by the intracellular content of not only vitamin A but also triglycerides, and HSC activation is associated with depletion of these lipids. In fact, our recent work demonstrates that adipogenic/lipogenic transcriptional regulation rendered by PPARγ, LXRα, and SREBP-1c is essential for the maintenance of the fat-storing, quiescence phenotype of HSC. Expression of these adipogenic transcription factors is lost in activated HSC and the treatment of the cells with the adipocyte differentiation cocktail or ectopic expression of PPARγ or SREBP-1c causes a reversal of activated cells to the quiescent phenotype. In steatotic livers from ALD and NAFLD mouse models, the expression of these adipogenic transcription factors is induced while the normal control livers lack such expression. Thus, adipogenic regulation is essential for HSC quiescence while it makes hepatocytes steatotic. Interestingly, under the adipogenic conditions of ALD and NAFLD, HSC are still activated to cause fibrosis. This fat paradox in hepatocytes and HSC highlights contrasted significance of fat in these two cell types that depend on each other for their homeostatic control. It further suggests, activated HSC in steatotic livers may have defective insulin signaling or lipogenic regulation.
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SPECIAL CONTRIBUTION
  • Meigen Liu, Kimitaka Hase, Tetsuya Tsuji, Toshiyuki Fujiwara, Shin Yam ...
    2005 Volume 54 Issue 4 Pages 193-196
    Published: 2005
    Released on J-STAGE: June 20, 2006
    JOURNAL FREE ACCESS
    Although electromyography and electrodiagnosis (EMG-EDX) is one of the most fundamental skills in rehabilitation medicine, the number of residency programs that can provide comprehensive postgraduate EMG-EDX training is still limited in Japan. Under these circumstances, we started a 2-day primer course in EMG-EDX at Keio University Hospital in 1998. To review our 7-year experience with the course, we analyzed the number and specialty of the participants, their appraisal of the lectures and practical sessions, and the score distribution of the final examination. The number of participants totaled 288 during the past 7 years, and the mean number for each year was 41. The distribution by specialty for the whole period was 64.0% for rehabilitation medicine, 25.4% for orthopedic surgery, 5.1% for neurology, 1.0% for pediatrics, 0.5% for gerontology and 4.1% for physical therapists and occupational therapists. The difficulty levels of the lectures were judged as appropriate by 81 to 95.5% of the participants, and the presentation was judged as good by 34 to 67% of them. For the practice sessions, the difficulty levels were judged as appropriate by 88% of the participants, and the quality of the supervisors was judged as good by 64% of them. The mean score for the final examination was 56.0 (SD 15.2, median 60). In conclusion, our course has played an important role to promote EMG-EDX in our country by providing compact introductory exposure to EMG-EDX for beginners. A follow-up system for the course graduates is planned to support their EMG-EDX practice.
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