Search for the Majorana Nature of Neutrinos in the Inverted Mass Ordering Region with KamLAND-Zen.

The KamLAND-Zen experiment has provided stringent constraints on the neutrinoless double-beta (0νßß) decay half-life in ^{136}Xe using a xenon-loaded liquid scintillator. We report an improved search using an upgraded detector with almost double the amount of xenon and an ultralow radioactivity container, corresponding to an exposure of 970 kg yr of ^{136}Xe. These new data provide valuable insight into backgrounds, especially from cosmic muon spallation of xenon, and have required the use of novel background rejection techniques. We obtain a lower limit for the 0νßß decay half-life of T_{1/2}^{0ν}>2.3×10^{26} yr at 90% C.L., corresponding to upper limits on the effective Majorana neutrino mass of 36-156 meV using commonly adopted nuclear matrix element calculations.

CD146 is a novel marker for highly tumorigenic cells and a potential therapeutic target in malignant rhabdoid tumor.

Malignant rhabdoid tumor (MRT) is a rare, highly aggressive pediatric malignancy that primarily develops during infancy and early childhood. Despite the existing standard of intensive multimodal therapy, the prognosis of patients with MRT is dismal; therefore, a greater understanding of the biology of this disease is required to establish novel therapies. In this study, we identified a highly tumorigenic sub-population in MRT, based on the expression of CD146 (also known as melanoma cell adhesion molecule), a cell adhesion molecule expressed by neural crest cells and various derivatives. CD146+ cells isolated from four MRT cell lines by cell sorting exhibited enhanced self-renewal and invasive potential in vitro. In a xenograft model using immunodeficient NOD/Shi-scid IL-2Rγ-null mice, purified CD146+ cells obtained from MRT cell lines or a primary tumor exhibited the exclusive ability to form tumors in vivo. Blocking of CD146-related mechanisms, either by short hairpin RNA knockdown or treatment with a polyclonal antibody against CD146, effectively suppressed tumor growth of MRT cells both in vitro and in vivo via induction of apoptosis by inactivating Akt. Furthermore, CD146 positivity in immunohistological analysis of 11 MRT patient samples was associated with poor patient outcomes. These results suggest that CD146 defines a distinct sub-population in MRT with high tumorigenic capacity and that this marker represents a promising therapeutic target.

In vitro expansion of CD34(+)CD38(-) cells under stimulation with hematopoietic growth factors on AGM-S3 cells in juvenile myelomonocytic leukemia.

Using serum-containing culture, we examined whether AGM-S3 stromal cells, alone or in combination with hematopoietic growth factor(s), stimulated the proliferation of CD34(+) cells from patients with juvenile myelomonocytic leukemia (JMML). AGM-S3 cells in concert with stem cell factor plus thrombopoietin increased the numbers of peripheral blood CD34(+) cells to approximately 20-fold of the input value after 2 weeks in nine JMML patients with either PTPN11 mutations or RAS mutations, who received allogeneic hematopoietic transplantation. Granulocyte-macrophage colony-stimulating factor (GM-CSF) also augmented the proliferation of JMML CD34(+) cells on AGM-S3 cells. The expansion potential of CD34(+) cells was markedly low in four patients who achieved spontaneous hematological improvement. A large proportion of day-14-cultured CD34(+) cells were negative for CD38 and cryopreservable. Cultured JMML CD34(+)CD38(-) cells expressed CD117, CD116, c-mpl, CD123, CD90, but not CXCR4, and formed GM and erythroid colonies. Day-7-cultured CD34(+) cells from two of three JMML patients injected intrafemorally into immunodeficient mice stimulated with human GM-CSF after transplantation displayed significant hematopoietic reconstitution. The abilities of OP9 cells and MS-5 cells were one-third and one-tenth, respectively, of the value obtained with AGM-S3 cells. Our culture system may provide a useful tool for elucidating leukemogenesis and for therapeutic approaches in JMML.

PBSC collection from family donors in Japan: a prospective survey.

Severe adverse events (SAE) and late hematological malignancies have been reported after PBSC donation. No prospective data on incidence and risk factors have been available for family donors so far. The Japan Society for Hematopoietic Cell Transplantation (JSHCT) introduced therefore in 2000 a mandatory registration system. It defined standards for donor eligibility and asked harvest centers to report any SAE immediately. All donors were examined at day 30 and were to be contacted once each year for a period of 5 years. Acute SAEs within day 30 were reported from 47/3264 donations (1.44%) with 14 events considered as unexpected and severe (0.58%). No donor died within 30 days. Late SAEs were reported from 39/1708 donors (2.3%). The incidence of acute SAEs was significantly higher among donors not matching the JSHCT standards (P=0.0023). Late hematological malignancies in PBSC donors were not different compared with a retrospective cohort of BM donors (N:1/1708 vs N:2/5921; P=0.53). In conclusion, acute and late SAEs do occur in PBSC donors at relatively low frequency but risk factors can be defined.

Prescription trends for treatment of paediatric gastroenteritis at a Japanese hospital between 1997 and 2007.

OBJECTIVE: We aimed to investigate recent trends in prescriptions for the treatment of paediatric gastroenteritis in Japan over a 10-year period (1997-2007). METHODS: In this retrospective cohort study, we collected data for 2295 prescriptions for 1241 putative cases of paediatric gastroenteritis, which were treated between 1997 and 2007 at Hamamatsu University Hospital, Hamamatsu, Japan. RESULTS: The most frequently prescribed drugs were probiotics (n = 621), followed by anti-emetics (n = 474). In most years between 1997 and 2007, more cases were treated with probiotics than with any other drug type (30.6-63.3% of cases), with the percentage increasing between 2005 and 2007. In contrast, the frequencies of anti-emetic and antipyretic prescriptions remained fairly stable, and prescriptions for antibiotics decreased slightly over the study period. Anti-emetics were commonly used in this hospital. CONCLUSION: Although experimental evidence upon which to base recommendations is lacking, Japanese evidence-based guidelines are critical for improving the quality of treatment of paediatric gastroenteritis.

Glyoxalase-I is a novel target against Bcr-Abl+ leukemic cells acquiring stem-like characteristics in a hypoxic environment.

Abl tyrosine kinase inhibitors (TKIs) such as imatinib and dasatinib are ineffective against Bcr-Abl(+) leukemic stem cells. Thus, the identification of novel agents that are effective in eradicating quiescent Bcr-Abl(+) stem cells is needed to cure leukemias caused by Bcr-Abl(+) cells. Human Bcr-Abl(+) cells engrafted in the bone marrow of immunodeficient mice survive under severe hypoxia. We generated two hypoxia-adapted (HA)-Bcr-Abl(+) sublines by selection in long-term hypoxic cultures (1.0% O(2)). Interestingly, HA-Bcr-Abl(+) cells exhibited stem cell-like characteristics, including more cells in a dormant, increase of side population fraction, higher beta-catenin expression, resistance to Abl TKIs, and a higher transplantation efficiency. Compared with the respective parental cells, HA-Bcr-Abl(+) cells had higher levels of protein and higher enzyme activity of glyoxalase-I (Glo-I), an enzyme that detoxifies methylglyoxal, a cytotoxic by-product of glycolysis. In contrast to Abl TKIs, Glo-I inhibitors were much more effective in killing HA-Bcr-Abl(+) cells both in vitro and in vivo. These findings indicate that Glo-I is a novel molecular target for treatment of Bcr-Abl(+) leukemias, and, in particular, Abl TKI-resistant quiescent Bcr-Abl(+) leukemic cells that have acquired stem-like characteristics in the process of adapting to a hypoxic environment.

The Bcr-Abl kinase inhibitor INNO-406 induces autophagy and different modes of cell death execution in Bcr-Abl-positive leukemias.

Bcr-Abl tyrosine kinase (TK) inhibitors are promising therapeutic agents for Bcr-Abl-positive (Bcr-Abl(+)) leukemias. Although they are known to promote caspase-mediated apoptosis, it remains unclear whether caspase-independent cell death-inducing mechanisms are also triggered. Here we demonstrated that INNO-406, a second-generation Bcr-Abl TK inhibitor, induces programmed cell death (PCD) in chronic myelogenous leukemia (CML) cell lines through both caspase-mediated and caspase-independent pathways. The latter pathways include caspase-independent apoptosis (CIA) and necrosis-like cell death (CIND), and the cell lines varied regarding which mechanism was elicited upon INNO-406 treatment. We also observed that the propensity toward CIA or CIND in cells was strongly associated with cellular dependency on apoptosome-mediated caspase activity. Cells that undergo CIND have a high apoptosome activity potential whereas cells that undergo CIA tend to have a lower potential. Moreover, we found that INNO-406 promotes autophagy. When autophagy was inhibited with chloroquine or gene knockdown of beclin1 by shRNA, INNO-406-induced cell death was enhanced, which indicates that the autophagic response of the tumor cells is protective. These findings suggest new insights into the biology and therapy of Bcr-Abl(+) leukemias.

NOD/Shi-scid IL2rgamma(null) (NOG) mice more appropriate for humanized mouse models.

"Humanized mice," in which various kinds of human cells and tissues can be engrafted and retain the same functions as in humans, are extremely useful because human diseases can be studied directly. Using the newly combined immunodeficient NOD-scid IL2rgamma(null) mice and Rag2(null) IL2rgamma(null) humanized mice, it has became possible to expand applications because various hematopoietic cells can be differentiated by human hematopoietic stem cell transplantation, and the human immune system can be reconstituted to some degree. This work has attracted attention worldwide, but the development and use of immunodeficient mice in Japan are not very well known or understood. This review describes the history and characteristics of the NOD/Shi-scid IL2rgamma(null) (NOG) and BALB/cA-Rag2(null) IL2rgamma(null) mice that were established in Japan, including our unpublished data from researchers who are currently using these mice. In addition, we also describe the potential development of new immunodeficient mice that can be used as humanized mice in the future.

Outcome of risk-based therapy for infant acute lymphoblastic leukemia with or without an MLL gene rearrangement, with emphasis on late effects: a final report of two consecutive studies, MLL96 and MLL98, of the Japan Infant Leukemia Study Group.

We evaluated the efficacy of a treatment strategy in which infants with acute lymphoblastic leukemia (ALL) were stratified by their MLL gene status and then assigned to different risk-based therapies. A total of 102 patients were registered on two consecutive multicenter trials, designated MLL96 and MLL98, between 1995 and 2001. Those with a rearranged MLL gene (MLL-R, n=80) were assigned to receive intensive chemotherapy followed by hematopoietic stem cell transplantation (HSCT), while those with germline MLL (MLL-G, n=22) were treated with chemotherapy alone. The 5-year event-free survival (EFS) rate for all 102 infants was 50.9% (95% confidence interval, 41.0-60.8%). The most prominent late effect was growth impairment, observed in 58.9% of all evaluable patients in the MLL-R group. This plan of risk-based therapy appears to have improved the overall prognosis for infants with ALL, compared with previously reported results. However, over half the events in patients with MLL rearrangement occurred before the instigation of HSCT, and that HSCT-related toxic events comprised 36.3% (8/22) of post-transplantation events, suggesting that further stratification within the MLL-R group and the development of more effective early-phase intensification chemotherapy will be needed before the full potential of this strategy is realized.

C1-C2 point monitoring of low-dose cyclosporin a given as a single daily dose in children with steroid-dependent relapsing nephrotic syndrome.

AIM: It has been reported that the pharmacokinetics of cyclosporin A (CsA) in children is different from that in adults. It appears that, in general, pediatric patients metabolize CsA more rapidly than adult patients, necessitating the use of higher dose of the drug in pediatric transplant recipients. In this context, we speculated that single-dose daily administration of low-dose CsA may be associated with a higher peak blood level without associated trough blood level elevation, and thereby yield better results and allow safer use of the drug than the conventional twice daily administration dosing used for the treatment of childhood idiopathic nephrotic syndrome (INS). METHODS: A total of 10 children with steroid-dependent relapsing INS (9 with biopsy-proven minimal-change disease) who showed steroid toxicity were enrolled in the study. The initial daily dose of CsA (Neoral) used was around 2.0 mg/kg, given as a single daily dose before breakfast. The dose was subsequently adjusted to achieve a C1-C2 point blood level between 600 - 800 ng/ml. The dose of the concomitantly administered prednisolone was tapered following the commencement of CsA. RESULTS: The mean daily CsA dosage, the mean C1-C2 point blood level and the mean trough blood level in the subjects were 2.2 +/- 0.8 mg/kg, 754.0 +/- 71.9 ng/ml and 42.7 +/- 29.2 ng/ml, respectively. At the latest observation, after a mean duration of 17 months (6 - 24 months) of CsA therapy, the minimum dose of prednisolone required for maintenance of clinical remission and the calculated relapse rate were significantly decreased as compared to the respective pretreatment values (0.52 +/- 0.46 mg/kg on alternate days, vs. 0.97 +/- 0.63 mg/kg on alternate days, and 0.28 +/- 0.32 times per six months, vs. 1.06 +/- 0.41 times per six months, respectively, p = 0.005). No significant change was observed in the mean estimated GFR value as compared to the pretreatment value (183.1 +/- 35.4 ml/min/1.73 m2vs. 185.4 +/- 39.3 ml/min/1.73 m2). No evidence of CsA nephrotoxicity was observed in a repeat renal biopsy performed around 12 months after the commencement of CsA therapy in two patients. CONCLUSIONS: Despite the limitations of the study, our results suggest that administration of low-dose CsA as a single daily dose with C1-C2 point blood level monitoring might be an equally effective and safe and, therefore, more cost-beneficial, protocol for the treatment of steroid-dependent cases of relapsing INS, as conventional twice-daily administration of CsA with trough blood level monitoring. Further studies to confirm the long-term efficacy and safety of this CsA treatment protocol in larger numbers of patients are, however, needed.

Implication of the peak serum level of mizoribine for control of the serum anti-dsDNA antibody titer in patients with lupus nephritis.

AIM: Mizoribine (MZR) is a novel selective inhibitor of inosine monophosphatase dehydrogenase that was developed in Japan. We previously reported the efficacy and safety of oral MZR pulse therapy, which is associated with elevated peak serum MZR levels, in selected patients with lupus nephritis. However, only limited information is available as yet on the optimal peak serum level of MZR that would yield an enhanced clinical efficacy without serious toxicity in patients with lupus nephritis. METHODS: A total of 11 patients with clinically stable lupus nephritis treated with oral MZR pulse therapy combined with low-dose prednisolone were enrolled in the cross-sectional study. The peak serum concentrations of MZR (as determined by HPLC) and the serum anti-dsDNA antibody titers (as determined by ELISA) were examined in the patients in order to evaluate the correlation between these two parameters. The correlation between the dose of MZR (mg/kg) administered orally as a single daily dose and the peak serum level of the drug was also examined. In two of the patients, serial measurements of the changes in the peak serum levels of MZR and anti-dsDNA titers could be conducted over 10 months. RESULTS: A significant inverse correlation (r = -0.596, p = 0.0116) was observed between the peak serum levels of MZR and the serum anti-dsDNA antibody titers in the study participants, while the dose of prednisolone remained unchanged. The peak level of MZR in the serum was significantly correlated with the single dose of MZR (r = 0.509, p = 0.0371). In the two patients in whom serial measurements were conducted, the first patient who showed a peak serum MZR level of less than 2.5-3.0 microg/ml eventually developed an increase of the serum anti-dsDNA titer with hypocomplementemia and proteinuria. On the other hand, in the second patient who showed a peak serum MZR level in excess of 4.0 microg/ml, persistently low serum anti-dsDNA titers with normocomplementemia were observed. CONCLUSION: Although this study is only a preliminary study conducted on a small sample, we speculate from the results that a peak serum level of MZR of at least more than 2.5-3.0 mirog/ml is necessary to achieve satisfactory clinical efficacy of the drug for the treatment of lupus nephritis. Further study is needed to confirm these preliminary findings.

Therapy-related myelodysplastic syndrome in childhood: a retrospective study of 36 patients in Japan.

We report here a retrospective analysis of 36 children with therapy-related myelodysplastic syndrome (t-MDS) diagnosed between 1990 and 1999 in Japan. Their median age was 7.7 years and the median latency period for the development of t-MDS was 38.5 months. The primary tumors were hematologic in 15 of the cases and nonhematologic in 21. Chromosomal abnormalities were detected in 32/34(94%) patients: abnormalities of chromosomes 5and/or 7 in 41% and notably, 11q23 abnormalities in 31%. The prognosis of children with t-MDS was very poor as compared to children with primary MDS (5 year survival: 16% versus 54%, p<0.0001).

Living-donor liver transplantation for propionic acidaemia.

Three patients with the severe form of propionic acidaemia were treated with living-donor liver transplantation (LDLT). The procedure was successful for all patients and the incidence of metabolic decompensation was reduced dramatically even without protein restriction. Biochemically, however, the improvement was not significant and the patients continued to excrete large amounts of propionic acid metabolites. One of the patients experienced a severe acidaemic episode 3 years after transplantation. LDLT has a beneficial effect on the care of severely affected patients since it reduces the risk of metabolic decompensation and improves the quality of life with less strict dietary control. Adequate protein restriction and medication need to be maintained even after successful transplantation.