Recently, regenerative medicine focusing on tissue-engineering techniques has been developed and established as a new clinical field. In Japan, two types of cultivated mucosal epithelial transplantation have been clinically applied to ocular surface reconstruction of severe stem cell deficiencies; one is allogeneic/autologous cultivated corneal epithelial transplantation and the other is autologous cultivated oral mucosal epithelial transplantation. These new techniques enabled us to treat severe stem cell deficiencies by covering the whole damaged ocular surface with cultivated mucosal epithelial sheets. In the field of corneal endothelial research, reconstruction of damaged corneal endothelium utilizing cultivated human corneal endothelial cells or their precursors has been developed and its usefulness confirmed in animal models. This review will provide an overview of recent results, as well as an insight into the future of research on corneal regenerative medicine in Japan.

We performed a retrospective study to examine the preventive effects of newquinolones for endogenous infection in patients receiving various allogeneic hematopoietic stem cell transplantation including bone marrow transplantation (BMT), peripheral blood stem cell transplantation (PBSCT), and cord blood transplantation (CBT). Forty-nine patients were enrolled. Ciprofloxacin or norfloxacin was orally administered for intestinal sterilization from day -14 until engraftment. As a result, the period from transplantation until engraftment was significantly longer in CBT group than in BMT group. The febrile index (the ratio of the febrile (> or =38.0 degrees C) period during neutropenia (< or =500 cells/mm(3)) and C-reactive protein (CRP)-positive index (the ratio of CRP-positive (> or =2.0 mg/dl) period during neutropenia) were comparable among the three groups. In addition, no gram-negative bacteria in stool was isolated in the three groups; that is, an endogenous infection of gram-negative bacteria, a potential pathogen, was well controlled by newquinolones. We should be careful when interpreting the results of this small study; however, newquinolones are clinically effective for endogenous infection of gram-negative bacteria in patients receiving not only BMT, but also PBSCT and CBT.

A 67-years old woman was referred to our hospital in October 1992 with thrombocytopenia and splenomegaly. A bone marrow biopsy revealed decreased cellularity, with moderately increased reticulin fibrosis and discrete dysmorphic megakaryocytes but no signs of dysplasia in the erythroid or the myeloid lineages. The karyotype of the bone marrow cells was t(12;17) (q24;q11). She was diagnosed as having agnogenic myeloid metaplasia. The patient received only blood transfusions until November 1998 when leukocytosis with immature cells started to appear. The bone marrow aspiration analysis showed increased cellularity and chromosomal analysis demonstrated the presence of t(9;22) (q34;q11) without any t(12;17) (q24;q11) abnormality. Because IFN therapy and oral administration of hydroxyurea did not show any cytological effect, administration of imatinib mesylate was started from December 2001. The Ph-positive cells as demonstrated by the FISH method had decreased to 7% by April 2003. But the t(12;17)(q24;q11) positive clones, which were observed on the first admission, again appeared in the peripheral blood, whereas Ph clones were detected in only one out of 24 cells examined. During the course of treatment with imatinib mesylate for chronic myelogenous leukemia which developed from agnogenic myeloid metaplasia accompanied with t(12;17)(q24;q11) translocation, the co-existence of two clones derived from, possibly, stem cells was identified.

A 4-year-old girl with familial hemophagocytic lymphohistiocytosis (FHL) underwent unrelated cord blood stem cell transplantation (uCBSCT) using the fludarabine-based non-myeloablative conditioning regimen. Shortly after the uCBSCT, she experienced the reactivation of the FHL, and subsequent graft failure. Considering that the residual recipient lymphocytes, which survived after non-myeloablative conditioning, had a role in the FHL reactivation and in the graft rejection, myeloablative conditioning combined with horse ATG was used to eradicate the recipient lymphocytes in the second CBSCT. Furthermore, in order to prevent rejection, cord blood, the DNA type of which was completely matched in a host to graft (HVG) direction, was selected. In the second uCBSCT, FHL reactivation was noted at a limited level. Complete chimerism was achieved and the NK-cell activity recovered to the normal range. Our case suggests the necessity of the conditioning regimen to eradicate host lymphocytes in the stem cell transplantation for FHL, and the significance of HLA DNA-typing in uCBSCT for pediatric patients.

Stress urinary incontinence (SUI) is a major urologic health problem and the number of patients with SUI will rise dramatically as the population of elderly people continues to increase in Japan. This condition causes unnecessary and detrimental psychological distress, social isolation, and public expense for care. Surgery remains the cornerstone of treatment for female SUI and also in those who have failed to improve with conservative measures. Many surgical procedures, however, have been described with varying degree of success. The ideal surgical treatment for this disease should be effective in QOL improvement, minimal invasive and durable for the long-term. Based on a new understanding of the pathophysiology of SUI as well as the development of surgical techniques and devices, mid urethral sling operations such as TVT (tension-free vaginal tape) have become widely used and they provide significant short-term and long-term cure rates. However, perioperative complications, including serious problems like bowel, vascular and bladder injuries have been reported. Most complications are related to blind trocar passage in the retropubic space. The alternative procedure transobturator procedure was developed to minimize these complications, in which tape is introduced through the obturator foramen. This technique provides high short-term cure rates, similar to those achieved with TVT, but with fewer complications. A number of injectables have been used for the treatment of SUI, including collagen, coated-beeds and Teflon. Although injectable treatment is convenient and minimally invasive, efficacy and durability are lower than other surgical procedures. Modification by tissue-engineering techniques using autologous stem cells or precursors of mature cells showed regeneration and reconstitution of urinary sphincteric function. In the future this strategy may be an attractive therapy for SUI. The choice of operation should be tailored to suit each individual case based on the clinical and urodynamic findings, as well as the age and the expectations of treatment outcome.

We retrospectively investigated the clinical characteristics of reactivation of hepatitis B (HB) virus after allogeneic hematopoietic stem cell transplantation (HSCT). Of 2002 patients who received transplantation between January 1994 and December 2004, seven patients who were anti-HB surface antibody (anti-HBs) positive and HB surface antigen (HBs-Ag) negative developed reactivation of the HB virus after allogeneic HSCT. The patients' median age was 49 years, and they consisted of 5 males and 2 females. Six of 7 recipients received hematopoietic stem cells from HLA-identical sibling donors. All donors were negative for HBs-Ag. Six donors were negative for anti-HBs and one donor was not investigated for anti-HBs. HB reactivation occurred 5 to 29 (median 15) months after HSCT. Chronic graft-versus-host-disease (GVHD) was observed in 5 cases. The peak value of GPT during HB reactivation varied from 83 to 1930 (median 318) IU/l. Lamivudine was given to 5 patients. One patient was treated with supportive therapy and other one patient was observed without treatment. Two patients developed fulminant hepatitis and died of hepatic dysfunction. Clinicians should consider the possibility of HB reactivation in anti-HBs-positive patients. The establishment of a preventive method for HB reactivation would be desirable.

Many kinds of cells, including embryonic stem cells and tissue stem cells, have been considered candidates for cell transplantation therapy for muscle-degenerative diseases. Bone marrow stromal cells (MSCs) also have great potential as therapeutic agents since they are easily isolated and can be expanded from patients without serious ethical or technical problems. Recently, new methods for the highly efficient and specific induction of functional skeletal muscle cells have been found in MSCs. Induced cells differentiate into muscle fibers upon transplantation into degenerated muscles of rats and mdx-nude mice. Furthermore, the induced population contained Pax7-positive cells that contribute to subsequent regeneration of muscle upon repetitive damage without additional transplantation of cells. Here I describe the discovery of these induction systems and focus on the potential use of MSC-derived cells for "auto-cell transplantation therapy" in muscle-degenerative diseases.

A 43-year-old female was admitted with therapy-resistant pancreatitis and an abdominal tumor around the pancreatic head. Laboratory data revealed leukocytosis with a white blood cell count of 18200/microl, 25% atypical cells and an LDH of 13410 IU/l. The bone marrow was comprised of 78.4 percent lymphoblastoid cells which were positive for CD10, CD19 and CD20, and the cytogenetic study of which demonstrated the presence of t(8;14) (q24;q32) and t(14;18) (q32;q21) in the same clone. The patient was diagnosed as having Burkitt's lymphoma (BL) with t(8;14) and t(14;18). Although CODOX-M and IVAC therapy combined with rituximab achieved complete remission, she died of rapid progressive disease during whole brain irradiation before autologous peripheral blood stem cell transplantation. Even if the intensive chemotherapy with rituximab is given adequately, durable remission may not be achieved in BL with translocation of t(8;14) and t(14;18). A more effective therapy remains to be established for the treatment of this disease.

We have already reported that heart transplantation and left ventricular assist system (LVAS) are the useful surgical treatments for severe heart failure. However, these treatments have several problems such as donor limitation and complications and a novel strategy is desired. The autologous myoblast sheets attenuated the cardiac remodeling in the rat infarcted myocardium and dilated cardiomyopathy hamsters, leading to the improvement of cardiac performance. In this study, we will report the present results of heart transplantation and LVAS and also, report the development of porcine autologous myoblast sheets and hypothesized that autologous myoblast sheets regenerate the porcine infracted myocardium for clinical application. Skeletal myoblast (SM) isolated from leg muscle were cultured and detached from the dishes as single monolayer cell-sheet (tissue) at 20 degrees C using temperature-responsive culture dishes. Echocardiography demonstrated that cardiac systolic performance was significantly improved in SM group 4 weeks after operation rather than the control group. Both diastolic dysfunction and regional delayed relaxation in association with regional systolic function were recovered in the SM group, while the control group were not. Histologically, anterior wall was significantly recovered and dilatation of left ventricle was well attenuated in the SM group, while not in the other groups. SM-sheet implantation improved cardiac function by attenuating the cardiac remodeling and metabolic recovery in the impaired myocardium in the porcine ischemic myocardium, suggesting a promising strategy for clinical myocardial regeneration therapy.