Hitoshi Okochi

Tokyo Women's Medical University, Edo, Tokyo, Japan

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Publications (96)371.72 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: Interleukin (IL)-21 is regarded as a potent antitumor agent, which increases the cytotoxicity of both natural killer (NK) and CD8+ T cells. In this study, we investigated the role of IL-21 in mycosis fungoides (MF). IL-21 mRNA expression levels in patch and plaque MF were significantly higher than those in normal skin. IL-21 mRNA expression levels in tumor MF were significantly decreased compared with those in patch and plaque MF. Interestingly, mRNA expression levels of IL-21 in MF lesional skin significantly correlated with those of T-helper type-1 cytokines/chemokines such as CXCL10, CXCL11 and γ-interferon. Immunohistochemistry showed that IL-21 was expressed by keratinocytes in patch and plaque MF. Furthermore, serum IL-21 levels in patients with tumor MF were significantly lower than those of healthy controls and plaque MF. Thus, IL-21 expression was significantly downregulated in skin and blood of patients with tumor MF, which may contribute to progression of MF. Our study suggests that recombinant IL-21 would be a promising therapy for MF.
    No preview · Article · Jan 2016 · The Journal of Dermatology
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    ABSTRACT: The injection of endothelial progenitor cells and mononuclear cells derived from bone marrow at the ischemic region of peripheral artery disease patients is reported to be effective for therapeutic angiogenesis; however, these cell therapies require large amounts of bone marrow to obtain sufficient numbers of cells. To solve this problem, we attempted to culture bone-marrow-derived mesenchymal stem cells (BM-MSC), which are supposed to secrete several cytokines that promote angiogenesis. We also focused on using platelet-rich plasma (PRP) as a supplement for cell culture instead of fetal bovine serum. Human BM-MSC obtained from healthy volunteers expanded rapidly when cultured with 10% PRP prepared from their own blood. FACS analysis revealed that these cultured human MSC were homogeneous populations, and chromosomal analysis showed a normal karyotype. Moreover, the angiogenetic effect was apparent two weeks after human BM-MSC were injected into the ischemic muscle in SCID mice. Tumor formation was not detected three months after injection into SCID mice either subcutaneously or intramuscularly. To simulate clinical settings, canine BM-MSC were grown with canine PRP and injected into their ischemic muscles. We confirmed that donor cells existed in situ two and six weeks after operation without any side effects. These results suggest that cultured human BM-MSC can be a promising cell source for therapeutic angiogenesis.
    Preview · Article · Jun 2015
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    ABSTRACT: Tumor growth and metastasis of cancer involve autonomous tumor cell growth and host-tumor interactions. While tumor-specific immunity has been intensively studied in vitro, dynamic roles of lymphatic transport on tumor immunity in vivo have not been fully elucidated. In this study, we examined tumor growth and anti-tumor immune responses using kCYC mice, which demonstrate severe lymphatic dysfunction. Primary tumor growth was augmented in kCYC mice (compared to wild-type mice) when B16 melanoma or EL-4 lymphoma cells were subcutaneously injected. Expression of inflammatory cytokines such as IFN-γ, TNF-α, and IL-2 as well as IL-10 expression in draining lymph nodes (LNs) was significantly reduced in kCYC mice after tumor inoculation. Moreover, decreased levels of tumor-associated antigens were detected in draining LNs in kCYC mice, together with impaired antigen presentation. CD8+ T cells in draining LNs derived from kCYC mice bearing B16 melanoma also showed significantly decreased cytotoxic activity in vitro. Finally, tumor suppression activity of CD8+ T cells derived from kCYC mice bearing B16 melanoma was reduced when adoptively transferred to naive wild-type mice. In summary, these findings suggest that lymphatic transport is essential in generating optimal tumor-specific immune responses mediated by CD8+ T cells.
    Full-text · Article · May 2015 · Oncotarget
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    ABSTRACT: The dermal papilla is composed of a small clump of mesenchymal cells, called dermal papilla cells (DPCs). DPCs closely interact with epidermal cells to give rise to hair follicles and shafts during hair follicle development and the hair cycle. DPCs are promising cell sources for hair regeneration therapy for alopecia patients. However, once DPCs are put into conventional two-dimensional culture conditions, they quickly lose their capability to produce hair follicles. We aimed to expand a sufficiently large population of DPCs that retain their hair inductive activity. Murine DPCs were cultured in the presence of platelet-derived growth factor-AA (PDGF-AA) and fibroblast growth factor 2 (FGF2). Expressions of follicular-related genes were analyzed by real time PCR and hair inductive activity was determined by patch assay and chamber assay in vivo. FGF2 significantly increased the expression of platelet-derived growth factor receptor alpha (PDGFRα) in cultured vibrissal DPCs. PDGF-AA, a ligand of PDGFRα, promoted proliferation of DPCs synergistically when utilized with FGF2 and enhanced the expression of several follicular-related genes in DPCs. Hair reconstitution assays revealed that DPCs treated with both PDGF-AA and FGF-2 were able to maintain their hair inductive activity better than those treated with FGF2 alone. Both cell proliferation and hair inductive activity in murine DPCs are maintained by the synergistic effect of FGF2 and PDGF-AA. Copyright © 2015. Published by Elsevier Ireland Ltd.
    No preview · Article · Apr 2015 · Journal of Dermatological Science
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    ABSTRACT: Maturity-onset diabetes of the young (MODY) is a heterozygous monogenic diabetes; more than 13 disease genes have been identified. However, the pathogenesis of MODY isn't fully understood because the pancreatic beta cells of the patients are inaccessable. Therefore, we attempted to establish MODY patient-derived iPS (MODY-iPS) cells to investigate the pathogenic mechanism of MODY by inducing pancreatic beta cells. We established MODY5-iPS cells from Japanese patient with MODY5 (R177X) and confirmed MODY5-iPS cells possessed the characteristics of pluripotent stem cells. In the course of differentiation from MODY5-iPS cells into pancreatic beta cells, we examined the disease gene, HNF1B mRNA. We found that the amount of R177X mutant transcripts was much less than that of wild ones, but they increased after adding cycloheximide to the medium. These results suggest that these R177X mutant mRNAs are disrupted by nonsense-mediated mRNA decay in MODY-iPS cells during the developmental stages of pancreatic beta cells.This article is protected by copyright. All rights reserved.
    Full-text · Article · Mar 2015
  • Rie R. Yotsu · Shotaro Hagiwara · Hitoshi Okochi · Takeshi Tamaki
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    ABSTRACT: Treatment for patients with chronic wounds is entering a new era, and autologous platelet-rich plasma (PRP) is among the most promising treatments. PRP contains a concentration of platelets obtained by centrifuging the patient's blood. Because it contains fibrin and high concentrations of growth factors, PRP is known to promote wound healing. In this study, we present five patients with chronic foot ulcers successfully treated with PRP in our institution. The patients had various underlying diseases: diabetes (n = 2), peripheral arterial disease (n = 1), both diabetes and peripheral arterial disease (n = 1), and cutaneous polyarteritis nodosa (n = 1). Also, we provide a description of PRP's mechanisms, advantages, and limitations.
    No preview · Article · Jan 2015 · The Journal of Dermatology

  • No preview · Article · Jul 2014
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    ABSTRACT: Background Cilostazol, an inhibitor of phosphodiesterase type III, is an antiplatelet agent and vasodilator. Some clinical reports have suggested that this drug can improve progressive and refractory lymphedema. Objective In this study, we investigated whether cilostazol has the potential to proliferate lymphatic vessels and to improve lymphatic function using human lymphatic endothelial cells (LECs) and mouse lymphedema models. Methods Human LECs were counted at several time points while they were cultured in the presence of cilostazol and/or protein kinase A inhibitor. After receiving a diet including 0.1% cilostazol or control diet, skin tissue and lymphatic function of k-cyclin transgenic (kCYC + /-) mice, which have pernicious lymphatic dysfunction, was analyzed. A different lymphedema model was generated in wild type mice by excising circumferential tail skin to remove the superficial lymphatics. After oral administration of cilostazol, tail lymphedema was examined in this mouse model. Results Proliferation of LECs was promoted in a dose-dependent manner, which was partially inhibited by a protein kinase A inhibitor. Lymphatic vessel count increased in the cilostazol-treated kCYC+/− mice over that in the non-treated mice. Lymph flow improved in cilostazol-fed kCYC+/− mice as assessed by subcutaneous injection of Evans blue dye into the footpad. Oral administration of cilostazol also decreased lymphedema in a tail of wild type mice. Conclusion Cilostazol promoted growth of human LECs and improved lymph flow and lymphedema in two different mouse lymphedema models. These results suggest that cilostazol would be a promising agent for the treatment of lymphedema.
    No preview · Article · May 2014 · Journal of dermatological science
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    ABSTRACT: Sensitization and challenge using dinitrofluorobenzene (DNFB) induce contact hypersensitivity (CHS) with Th1 cell infiltration, whereas those using FITC generate CHS with Th2 cell infiltration. In this study, we attempted to determine the role of CXCR3, a chemokine receptor, in Th1- and Th2-type CHS induced by DNFB or FITC using CXCR3-deficient (CXCR3(-/-)) mice. Ear swelling was prolonged after DNFB challenge in CXCR3(-/-) mice, which was accompanied by increased Th1 cytokines and decreased TGF-β and IL-10 expression at a late time point of CHS, whereas there was no significant difference between wild-type and CXCR3(-/-) mice in FITC-induced CHS. In Th1-type CHS, the number of regulatory T cells (Tregs) was decreased in the challenged ear of CXCR3(-/-) mice compared with that of wild-type mice, suggesting that CXCR3 would be important in migration of Tregs into the site of inflammation. Moreover, we examined the characteristics of CXCR3(+) Tregs both in vitro and in vivo, revealing that CXCR3(+) Tregs expressed high levels of TGF-β and IL-10 as well as IFN-γ compared with CXCR3(-) Tregs. When CXCR3(-/-) mice were injected with CXCR3(+) Tregs, the prolonged ear swelling induced by DNFB was normalized. Taken together, our results suggest that CXCR3(+) Tregs play a key role for quenching Th1-type CHS.
    No preview · Article · May 2013 · The Journal of Immunology
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    ABSTRACT: Skin wound healing is an interactive process involving soluble mediators, ECM, resident cells, and infiltrating cells. Little is known about wound healing in the presence of lymphedema. In this study, we investigated wound healing using kCYC(+/-) mice, which demonstrate severe lymphatic dysfunction. Wound healing was delayed significantly in kCYC(+/-) mice when compared with WT mice. In wounded skin of kCYC(+/-) mice, mast cell numbers were increased compared with WT mice, whereas macrophage numbers were decreased. Moreover, IL-10 expression by mast cells was increased, and expression of bFGF, mainly produced by macrophages, was decreased in wounded skin of kCYC(+/-) mice compared with WT mice. We next crossed kCYC(+/-) mice with IL-10(-/-) mice, which were reported to show accelerated wound closure. In kCYC(+/-) IL-10(+/-) mice, time course of wound healing, numbers of macrophages, and IL-10 mRNA expression levels in wounded skin were comparable with WT IL-10(+/-) mice. Similar results were obtained using a different lymphedema model, in which circumferential skin excision was performed on the tails of mice to remove the superficial lymphatics. In summary, these findings suggest that IL-10 plays an important role in delayed wound healing in the setting of lymphatic dysfunction.
    Full-text · Article · May 2013 · Journal of leukocyte biology
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    ABSTRACT: Transcription factors (TFs) are able to regulate differentiation-related processes, including dedifferentiation and direct conversion, through the regulation of cell type-specific transcriptional profiles. However, the functional interactions between the TFs regulating different transcriptional profiles are not well understood. Here, we show that the TFs capable of inducing cell type-specific transcriptional profiles prevent the dedifferentiation induced by TFs for pluripotency. Of the large number of TFs expressed in a neural-lineage cell line, we identified a subset of TFs that, when overexpressed, strongly interfered with the dedifferentiation triggered by the procedure to generate induced pluripotent stem cells. This interference occurred through a maintenance mechanism of the cell type-specific transcriptional profile. Strikingly, the maintenance activity of the interfering TF set was strong enough to induce the cell line-specific transcriptional profile when overexpressed in a heterologous cell type. In addition, the TFs that interfered with dedifferentiation in hepatic-lineage cells involved TFs with known induction activity for hepatic-lineage cells. Our results suggest that dedifferentiation suppresses a cell type-specific transcriptional profile, which is primarily maintained by a small subset of TFs capable of inducing direct conversion. We anticipate that this functional correlation might be applicable in various cell types and might facilitate the identification of TFs with induction activity in efforts to understand differentiation.
    Full-text · Article · Apr 2013 · Proceedings of the National Academy of Sciences

  • No preview · Article · Feb 2013 · Journal of Dermatological Science
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    ABSTRACT: Classically activated macrophages produce IL-12, IL-23, and TNF-α, whereas alternatively activated macrophages (M2 cells) produce IL-10 and express several receptors such as mannose receptor and CD163. Tumor-associated macrophages exhibit M2 phenotype, whose presence has been associated with poor prognosis in various tumors. To investigate distribution of CD163(+) cells in lesional skin and serum levels of soluble CD163 (sCD163) in patients with cutaneous T cell lymphoma (CTCL), atopic dermatitis (AD), or psoriasis. The numbers of CD163(+) and CD68(+) cells in lesional skin of CTCL, AD, or psoriasis, and in normal skin were examined by immunohistochemistry. Serum soluble CD163 (sCD163) levels were quantified by enzyme-linked immunosorbent assay. The numbers of CD163(+) cells in lesional skin of CTCL, AD, or psoriasis were significantly larger than in normal skin. In CTCL, the numbers of CD163(+) or CD68(+) cells increased as more tumor cells infiltrated and they decreased after treatment with topical steroid and ultraviolet light. Moreover, CTCL patients with an increased number of CD163(+) cells showed worse prognosis. Serum sCD163 levels in patients with CTCL, AD, or psoriasis were significantly higher than those in normal controls. In CTCL patients, serum sCD163 levels significantly correlated with serum soluble interleukin-2 receptor and CCL17 levels. In AD patients, serum sCD163 levels correlated with serum IgE levels. The numbers of CD163(+) cells in lesional skin and serum sCD163 levels were associated with disease progression of CTCL. Further study focusing on CD163(+) cells in CTCL lesional skin would be an interesting research field.
    No preview · Article · Jul 2012 · Journal of dermatological science
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    ABSTRACT: The lymph transports tissue-resident dendritic cells (DCs) to regional lymph nodes (LNs), having important roles in immune function. The biological effects on tissue inflammation following lymphatic flow obstruction in vivo, however, are not fully known. In this study, we investigated the role of the lymphatic system in contact hypersensitivity (CHS) responses using k-cyclin transgenic (kCYC(+/-)) mice, which demonstrate severe lymphatic dysfunction. kCYC(+/-) mice showed enhanced ear swelling to both DNFB and FITC, as well as stronger irritant responses to croton oil compared with wild-type littermates. Consistently, challenged ears of kCYC(+/-) mice exhibited massive infiltrates of inflammatory cells. In contrast, DC migration to regional LNs, drainage of cell-free antigen to LNs, antigen-specific IFN-γ production, and lymphocyte proliferation were impaired during the sensitization phase of CHS in kCYC(+/-) mice. Transfer experiments using lymphocytes from sensitized mice and real-time PCR analysis of cytokine expression using challenged ear revealed that ear swelling was enhanced because of impaired lymphatic flow. Collectively, we conclude that insufficient lymphatic drainage augments apparent inflammation to topically applied allergens and irritants. The findings add insight into the clinical problem of allergic and irritant contact dermatitis that commonly occurs in humans with peripheral edema of the lower legs.
    Full-text · Article · Nov 2011 · Journal of Investigative Dermatology
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    ABSTRACT: Induction of a desired cell type by defined transcription factors (TFs) using iPS technology can be used for cell replacement therapy. However, to overcome problems such as tumor formation, genomic insertional mutagenesis by viral transduction in the induction process needs to be avoided using alternative approaches. One approach could be the direct delivery of TF protein by a protein transduction system, whereby a protein transduction domain (PTD) is fused to facilitate the penetration of cell membrane. However, fusion proteins, including TFs, are reported to be biologically less active through the interference of PTD with proper protein folding. Here, we report a proof-of-concept study in which TF proteins fused with PTDs could be reactivated by removal of PTDs from cells. We demonstrated that Sox2 and Oct3/4 proteins fused with PTD were less active in mouse embryonic stem cells. Removal of PTD by a site-specific protease, derived from tobacco etch virus (TEV), substantially restored the functionality of these proteins, proved by enhanced rescue ability for differentiation induced by endogenous Sox2 and Oct3/4 repression. These results suggest that, by removing a PTD inside the cells, directly delivered TF proteins may exert substantially enhanced function than presently considered.
    No preview · Article · May 2011 · Journal of Biotechnology
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    ABSTRACT: CCL21 expression by lymphatic endothelial cells (LECs) is essential for migration of CCR7+ immune cells from skin to regional lymph nodes (LNs). We investigated the importance of mitogen-activated protein kinase (MAPK) signaling in CCL21 expression by ECs in vitro and in vivo. Normal human dermal lymphatic microvascular ECs (HMVEC-dLy) stimulated in vitro with oncostatin M (OSM) expressed high amounts of CCL21 mRNA. CCL21 protein expression by HMVEC-dLy was also markedly increased by OSM compared with unstimulated cultures. Marked phosphorylation of MAPK 44/42 was detected in HMVEC-dLy stimulated by OSM. CCL21 expression by HMVEC-dLy was blocked by a JAK inhibitor 1, JAK3 inhibitor, and U0126 (a MAPK kinase inhibitor) in vitro, all of which blocked phosphorylation of MAPK 44/42. In addition, injection of U0126 into murine skin significantly decreased CCL21 mRNA and protein expression. Moreover, injection of U0126 before sensitization decreased migration of dendritic cells to draining LNs and decreased contact hypersensitivity responses. In summary, these results suggest that the MAPK pathway is important for CCL21 expression by LECs in vitro and in vivo. Blocking MAPK signaling within skin may offer a novel approach to treatment of inflammatory skin diseases.
    Full-text · Article · May 2011 · Journal of Investigative Dermatology
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    ABSTRACT: CCR3 is a specific marker of anaplastic large cell lymphoma (ALCL) cells. ALCL cells also express CCL11, a ligand for CCR3, leading to the hypothesis that CCL11 may play an autocrine role in ALCL progression. In this study, we investigated a role of CCL11 in cell survival and growth of human Ki-JK cells, established from an ALCL patient, and murine EL-4 lymphoma cells. Both Ki-JK and EL-4 cells expressed cell surface CCR3. CCL11 increased cell survival rates of Ki-JK cells in a dose-dependent manner, whereas it promoted EL-4 cell proliferation. Furthermore, CCL11 induced phosphorylation of extracellular signal-regulated kinase (ERK) 1/2 in both Ki-JK cells and EL-4 cells. Cell survival and tumor proliferation promoted by CCL11 was completely blocked by inhibition of ERK phosphorylation. CCL11 induced expression of antiapoptotic proteins, Bcl-xL and survivin, in Ki-JK cells. CCL11 also enhanced tumor growth of EL-4 and Ki-JK cells in vivo. Consistent with these results, tumor cells of cutaneous ALCL expressed CCR3 and increased levels of phosphorylated ERK1/2, Bcl-xL, and survivin in situ. Thus, our findings prompt a novel therapeutic approach to treat relapses of an aggressive form of lymphoma based on the discovery that a cell surface marker of disease functions as a critical autocrine growth receptor.
    No preview · Article · Mar 2011 · Cancer Research
  • Hitoshi Okochi
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    ABSTRACT: Basic and clinical research on adult stem cells is progressing rapidly. New technology that can generate iPS (induced pluripotent stem cells) cells from various types of tissue may completely change the stem cell world and regenerative medicine. In terms of clinical applications, both bone marrow and skin are very attractive sources of adult stem cells because they are highly accessible and the procedures to obtain them are minimally invasive. However, we have to seriously consider both safety issues and cost performance when we treat patients with cultured cells. We should use animal-free materials as often as possible and remember that culture stressors may induce epigenetic changes in the cultured cells. Nonetheless, there can be no doubt that stem-cell-based therapy is a promising tool in the field of regenerative medicine.
    No preview · Chapter · Dec 2010
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    ABSTRACT: Stem cells from various organs have been shown to regenerate muscle cells. Among them, skin-derived cells are promising because of their easy accessibility. We separated murine dermal cells into Sca-1 (+) and (−) fractions and investigated which of them could differentiate into muscle cells. After the cells were aggregated for 4 days and cultured on a collagen type I-coated plate for 7–10 days, the Sca-1 (−) fraction had expanded into many myoblastic cells, but the Sca-1 (+) fraction had not. Initial commitment to the myogenic lineage appeared to start during the aggregation. Sca-1 (−) cells proliferated exponentially and maintained their ability to differentiate into skeletal muscle cells within 7–10 days. About 60% of the cells showed positive staining for skeletal fast myosin heavy chain. Transplantation experiments revealed that the myoblastic cells arising after several passages were successfully engrafted into damaged host muscle. In conclusion, we have found that murine dermal Sca-1 (−) cells differentiate into muscle cells in vitro and in vivo after using an initial aggregation procedure. Their high differentiation efficiency and proliferation ability will offer substantial advantages for stem cell research.
    No preview · Article · Oct 2010 · Tissue Engineering Part A
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    ABSTRACT: Adipose tissue-derived mesenchymal stem cells (ASCs) have been reported to be multipotent and to differentiate into various cell types, including osteocytes, adipocytes, chondrocytes, and neural cells. Recently, many authors have reported that ASCs are also able to differentiate into vascular endothelial cells (VECs) in vitro. However, these reports included the use of medium containing fetal bovine serum for endothelial differentiation. In the present study, we have developed a novel method for differentiating mouse ASCs into VECs under serum-free conditions. After the differentiation culture, over 80% of the cells expressed vascular endothelial-specific marker proteins and could take up low-density lipoprotein in vitro. This protocol should be helpful in clarifying the mechanisms of ASC differentiation into the VSC lineage.
    No preview · Article · Oct 2010 · Biochemical and Biophysical Research Communications

Publication Stats

4k Citations
371.72 Total Impact Points


  • 2015
    • Tokyo Women's Medical University
      Edo, Tokyo, Japan
  • 2010-2015
    • National Center for Global Health and Medicine in Japan
      Edo, Tokyo, Japan
  • 1988-2010
    • The University of Tokyo
      • Department of Surgical Sciences
      Tokyo, Tokyo-to, Japan
  • 2008
    • Nagai Internal Medicine Clinic
      Okayama, Okayama, Japan
    • Waseda University
      • Division of Education
      Edo, Tōkyō, Japan
  • 2004
    • Nho Tokyo Medical Center
      Edo, Tōkyō, Japan
  • 2000
    • Kanto Central Hospital
      Edo, Tōkyō, Japan
  • 1996
    • University of Miami
      • Department of Medicine
      كورال غيبلز، فلوريدا, Florida, United States
  • 1994
    • University of Miami Miller School of Medicine
      • Division of Hospital Medicine
      Miami, Florida, United States
  • 1993
    • National Institute on Aging
      Baltimore, Maryland, United States