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Allergic transfusion reactions (ATRs) and febrile non-haemolytic transfusion reactions (FNHTRs) are common, although their mechanisms remain unclear. Immunoglobulin E (IgE)-mediated type I hypersensitivity may be involved in the pathogenesis of ATR. A basophil activation test (BAT) may help elucidate this process.The BAT was based on peripheral blood samples from paediatric patients with a haematological or oncological disease and on samples of residual blood products transfused in each case. Dasatinib was used to evaluate whether basophil activation was mediated by an IgE-dependent pathway.Twenty-seven patients with and 19 patients without ATR/FNHTR were included in this study, respectively. The median BAT values associated with ATR- (n = 41) and FNHTR-causing (n = 5) blood products were 22.1% (range = 6.1%-77.0%) and 27.8% (range = 15.2%-47.8%), respectively, which were higher than the median value of 8.5% (range = 1.1%-40.9%) observed in blood products without a transfusion reaction. Dasatinib suppressed basophil activity. BAT values were comparable in patients with ATR regardless of severity. Meanwhile, BAT values analysed with blood products non-causal for ATR/FNHTR were higher in patients with ATR/FNHTR than in those without.The IgE-mediated type I hypersensitivity may be involved in the pathogenesis of ATR and FNHTR. BAT analyses may help elucidate the underlying mechanisms and identify patients at risk.

Histiocytic sarcoma (HS) is a rare disease with a poor prognosis. The efficacy of immune checkpoint inhibitors for this disease has not been established. A 13-year-old boy with HS refractory to conventional chemotherapy was treated with pembrolizumab, an immune checkpoint inhibitor. After treatment, the primary lesion and the bone metastases showed improvement; however, new metastatic lesions also occurred. This case suggests that the effect of immune checkpoint inhibitors might depend not only on programmed death ligand-1 expression and the ratio of tumor mutational burden, but also on other factors, such as the tumor microenvironment. Evaluation of more cases is required to identify biomarkers that define the efficacy of immune checkpoint inhibitors.

Treating patients with hemophilia and inhibitors is often problematic. The presence of inhibitors negatively impacts the effectiveness of treatment to achieve hemostasis especially in patients with hemophilia B, owing mainly to allergic reactions to factor IX (FIX) concentrates and the low success rate of immune tolerance therapy. A 9-month-old boy had intracranial hemorrhage and was diagnosed with hemophilia B. After replacement therapy, he developed inhibitors and an allergic reaction to FIX. Prophylactic therapy was initiated with recombinant activated factor VII (rFVIIa) and later switched to pdFVIIa/factor X (FX; 120 μg/kg as the FVII dose, every other day) because of a recurrence of intracranial hemorrhage. Since then, he remained well without life-threatening bleeding for more than 2 years. Our case suggests that pdFVIIa/FX may be useful for prophylactic therapy in hemophilia B complicated by inhibitors and allergic reaction to FIX concentrates.

Allergic transfusion reactions (ATRs) manifest frequently as transfusion reactions, and their onset may be related to a patient's allergic predisposition. Moreover, although pediatric patients with hematological/oncological disease are more susceptible to ATRs, the relationship between allergic predisposition and ATRs remains to be fully clarified.Patients who were diagnosed with pediatric hematological/oncological disease and received transfusion at the study institutions were included. We determined patient background information related to their allergy history, measured the levels of allergen-specific immunoglobulin E (IgE) using sera obtained on diagnosis, and analyzed their associations with ATR onset.Of the 363 patients analyzed, 144 developed ATRs. Multivariate analysis identified cases with high basophils in the peripheral blood, and Dermatophagoides pteronyssinus- and egg white-specific IgEs were involved in the development of ATR in all age groups. Meanwhile, a history of food allergies, and positivity for Japanese cypress- and D. pteronyssinus-specific IgEs were risk factors for developing ATRs in the5 years age group. Moreover, patients aged 5-10 years with a history of asthma, allergic rhinitis, pollinosis, or atopic dermatitis, and those aged ≥10 years with positivity for dog dander-specific IgE were at risk for developing ATRs.The allergic constitution of patients plays a role in ATR onset even in pediatric hematological/oncological diseases. Therefore, advance confirmation of a patient's allergic constitution may partly predict the onset of ATRs. However, since multiple allergic predispositions within complex mechanisms may be involved in the onset of ATRs, further verification is required.

Background Leukoreduced blood components have been widely implemented to prevent transfusion-transmitted cytomegalovirus (TT-CMV) in transplantation. Recent progress in leukoreduction technology has helped reduce the risk of TT-CMV in hematopoietic stem cell transplantation; however, its efficacy in umbilical cord blood transplantation (CBT) has not been systematically studied. Study design and methods We retrospectively analyzed the incidence of CMV infection in patients treated with CBT who received prestorage leukoreduced, CMV-unselected blood components between 2007 and 2017 in a single Japanese pediatric center. Patients were monitored for CMV antigenemia at least once weekly. Results In total, 71 patients treated with CBT were identified. Two patients were excluded because of unknown CMV serostatus or early death after CBT. Of the remaining 69 patients, 24 developed CMV antigenemia. Among them, 3 received granulocyte transfusions (3 of 3; 100%), 2 were infants with severe combined immunodeficiency who had been infected with CMV before CBT (2 of 2; 100%), and 19 were CMV-seropositive patients (19 of 23, 82.6%). Conversely, of the remaining 45 patients in whom CMV antigenemia did not develop, 41 were seronegative (0 of 41; 0%) and were transfused with a total of 925 leukoreduced, CMV-unselected blood components. Among the 41 patients, 9 (22%) received in vivo T-cell depletion with antithymocyte globulin. None of the patients in the seronegative group has subsequently shown evidence of CMV infection or developed CMV disease. Conclusion Using prestorage leukoreduction, no cases of CMV infection were detected in seronegative CBT patients. Our findings showed the safety of leukoreduction in preventing TT-CMV in this patient group.

For relapsed/refractory (r/r) acute lymphocytic leukemia (ALL), there is a clinical question on how to combine blinatumomab and inotuzumab ozogamicin (InO), which are newly emerging immunotherapeutic agents, with conventional treatment. We report the case of an 11-year-old boy with B-cell ALL, who had a failed primary treatment and achieved molecular complete remission treated with a sequence therapy of InO and blinatumomab. Later, hematopoietic stem cell transplantation could be performed without major complications. Our case may suggest that the sequence therapy of InO and blinatumomab as a bridge-to hematopoietic stem cell transplantation could be effective in the treatment of pediatric r/r ALL.

We report on a Japanese female infant as the fourth patient with the constitutional pure duplication 1q41-qter confirmed by chromosomal microarray and as the first who developed myelodysplastic syndrome (MDS) among those with the constitutional 1q duplication. Common clinical features of the constitutional pure duplication 1q41-qter include developmental delay, craniofacial characteristics, foot malformation, hypertrichosis, and respiratory insufficiency. The association between MDS and the duplication of the genes in the 1q41-qter region remains unknown.

Background Prophylactic antibiotics decrease mortality and morbidity in patients with hematological malignancies following intensive chemotherapy. However, the efficacy of prophylactic antibiotics for pediatric patients with solid tumors remains unclear. Methods We retrospectively assessed 103 neutropenic periods from 26 patients with neuroblastoma or brain tumors following three different intensity chemotherapy regimens (05A3, A, and B). While piperacillin was intravenously administered as prophylaxis (PIPC prophylaxis group), the historical control group received no prophylaxis. As patients exhibited a variable degree of myelosuppression based on the intensity of the chemotherapy regimen, we separately evaluated the frequency and severity of febrile neutropenia (FN) in each regimen. Results Following intensive chemotherapy, we observed a significantly lower frequency of FN in the PIPC prophylaxis group compared with the historical control group in both regimen 05A3 (20% vs 65%; P = 0.01) and regimen A (56% vs 93%; P = 0.02). We also observed a shorter duration of fever, lower maximum fever, and lower C-reactive protein levels in the PIPC prophylaxis group compared with the historical control group after regimens 05A3 and A. Conversely, the frequency and severity of FN were not different between the two groups after moderate-intensity chemotherapy (regimen B). However, a longitudinal routine surveillance study of Pseudomonas aeruginosa also indicated a reduction in the susceptibility to PIPC throughout the study period. Conclusions Although PIPC prophylaxis might provide an advantage for severe neutropenia in pediatric patients with solid tumors, there is concern regarding bacterial resistance to antibiotics. Therefore, further careful examination is necessary for adaptation.

Primary central nervous system lymphoma (PCNSL) is a very rare type of non-Hodgkin lymphoma. Although pediatric and adolescent PCNSL patients generally respond well to intensive chemotherapy, the salvage treatment for this condition remains uncertain for patients exhibiting a poor/suboptimal response to primary therapy. Proton beam therapy (PBT) is being increasingly employed especially for pediatric oncology cases. However, the safety and feasibility of PBT for PCNSL patients have not been addressed. We encountered an adolescent patient with PCNSL exhibiting 4 of 5 adverse prognostic factors at diagnosis and a residual tumor adjacent to the pituitary gland with gadolinium enhancement on brain magnetic resonance imaging after 7 courses of intensive chemotherapy. We selected local PBT at a dose of 30.6 Gy (relative biological effectiveness) as a salvage treatment for the residual tumor. After PBT, gadolinium enhancement of the residual lesion rapidly disappeared with no acute adverse effects. Moreover, during 30 months of follow-up, no neurological or endocrinological adverse effects have been observed despite the location of the tumor. The patient is now healthy and has shown no evidence of relapse. PBT deserves further investigation as a salvage treatment option for PCNSL patients exhibiting a suboptimal response to primary chemotherapy.

Post-transplant early immune disorders and engraftment failure/delay are major issues in unrelated umbilical cord blood transplantation (UCBT). We evaluated graft-versus-host disease (GVHD) prophylaxis approaches after UCBT by comparing UCBT outcomes with GVHD prophylaxis using tacrolimus plus methylprednisolone (Tac/mPSL, n = 32) to that with Tac plus methotrexate (Tac/MTX, n = 31) at a single pediatric transplantation center. The 30-day cumulative incidence rates of neutrophil engraftment and median neutrophil engraftment times in the Tac/mPSL and Tac/MTX groups were 70.1% and 90.3% and 19 and 17 days, respectively (p = 0.09). Pre-engraftment immune reactions (PIR) and acute GVHD were improved with Tac/MTX; PIR incidence (p = 0.020) and cumulative incidence of 100-day acute GVHD (grade II–IV, 38.7% vs 68.8%, p = 0.045; grade III–IV, 9.7% vs 34.4%, p = 0.021) were significantly lower in the Tac/MTX group than in the Tac/mPSL group. However, the incidence rates of relapse (p = 0.921) and cytomegalovirus reactivation (p = 0.908), and the estimated overall (p = 0.87) and event-free survival (p = 0.88) were comparable between the two groups. These data indicate that GVHD prophylaxis with Tac/MTX is associated with favorable results, including reduced PIR and acute GVHD incidence after UCBT, without adverse effects.

We established mutated and non-mutated induced pluripotent stem cell (iPSC) clones from a patient with PTPN11 (c.226G>A)-mutated juvenile myelomonocytic leukaemia (JMML). Both types of iPSCs fulfilled the quality criteria. Mutated iPSC colonies generated significantly more CD34+ and CD34+ CD45+ cells compared to non-mutated iPSC colonies in a culture coated with irradiated AGM-S3 cells to which four growth factors were added sequentially or simultaneously. The haematopoietic differentiation potential of non-mutated JMML iPSC colonies was similar to or lower than that of iPSC colonies from a healthy individual. The PTPN11 mutation coexisted with the OSBP2 c.389C>T mutation. Zinc-finger nuclease-mediated homologous recombination revealed that correction of PTPN11 mutation in iPSCs with PTPN11 and OSBP2 mutations resulted in reduced CD34+ cell generation to a level similar to that obtained with JMML iPSC colonies with the wild-type of both genes, and interestingly, to that obtained with normal iPSC colonies. Transduction of the PTPN11 mutation into JMML iPSCs with the wild-type of both genes increased CD34+ cell production to a level comparable to that obtained with JMML iPSC colonies harbouring the two genetic mutations. Thus, PTPN11 mutation may be the most essential abnormality to confer an aberrant haematopoietic differentiation potential in this disorder.

To the Editor:Pazopanib is a multikinase inhibitor, inhibiting the signal transduction pathways of vascular endothelial growth factor receptors (VEGFRs), platelet-derived growth factor receptors, and the stem cell factor receptor.1 Pazopanib monotherapy improved progression-free survival in adult pa

Background The spectrum of late sequelae after hematopoietic stem cell transplantation (HSCT) includes infertility, which is the most frequent complication. Some reports suggested that ovarian function may be better preserved in females undergoing HSCT with reduced-intensity conditioning (RIC) than with conventional myeloablative conditioning (MAC). However, the impact of HSCT after 8-Gy TBI-based reduced-toxicity MAC (RTMAC), whose efficacy is between those of conventional MAC and RIC, on ovarian function remains unclear. Procedure A single-center retrospective analysis of data derived from patient information for all the children who underwent transplantation at the Shinshu University Hospital was carried out. Patients who underwent 8-Gy total body irradiation (TBI)-based RTMAC before HSCT were analyzed. Results A total of 36% (five of 14) of the patients developed primary ovarian insufficiency (POI) during the observation period, but serum follicle-stimulating hormone levels reduced to normal range with spontaneous menstruation in two, implying the reversal of POI. Furthermore, only one (10%) of the 10 prepubertal patients (71%; 10/14) at the time of HSCT suffered from POI at the last observation, but all three post-pubertal patients developed POI (100%), and two (67%) continued to suffer from POI at the last observation. Conclusions Taken together, 8-Gy TBI-based RTMAC before HSCT may decrease the possibility of POI compared with conventional MAC, especially in prepubertal patients. A longer follow-up will be required to ascertain whether a normal pregnancy and delivery can occur in such patients.

A 15-year-old girl with acute lymphoblastic leukemia received allogeneic dendritic cell vaccination, pulsed with Wilms tumor 1 (WT1) peptide, after her third hematopoietic stem cell transplantation (HSCT). The vaccines were generated from the third HSCT donor, who was her younger sister, age 12 years. The patient received 14 vaccines and had no graft-versus-host disease or systemic adverse effect, aside from grade 2 skin reaction at the injection site. WT1-specific immune responses were detected after vaccination by both WT1-tetramer analysis and enzyme-linked immunosorbent spot assay. This strategy may be safe, tolerable and even feasible for patients with a relapse after HSCT.

Poly(methyl methacrylate)s with high stereoregularity and clickable end-groups were synthesized via terminating reactions with α-(halomethyl)acrylates in stereospecific living anionic polymerization. The terminating reaction was efficient and tolerant to the reaction conditions to such an extent that almost quantitative end-functionalization was achieved in isotactic- and syndiotactic-specific polymerization systems. The terminating reactions were also achieved in polymerizations of vinyl methacrylate and trimethylsilyl methacrylate. For the polymerization of butyl acrylate, however, the termination efficiency was limited to less than 69%. Furthermore, the quantitative end-functionalization of the incorporated C[double bond, length as m-dash]C double bond at ω-end was achieved with various thiols catalyzed by Et3N. The base-catalysed thiol–ene reaction of the stereoregular poly(vinyl methacrylate) with a ω-end C[double bond, length as m-dash]C double bond selectively proceeded to retain vinyl ester functions, and the subsequent hydrolysis afforded ω-functional stereoregular poly(methacrylic acid). A combination of the terminating agent with a protected lithium amide afforded stereoregular poly(methyl methacrylates) with orthogonally clickable α- and ω-ends., Article, Polymer Chemistry.6(7):1078-1087(2015)

Severe combined immunodeficiency (SCID) is a defect in the differentiation and function of T cells. An increased malignancy risk, mainly lymphatic malignancy, has been described in patients with SCID. We report a patient with X-linked SCID who developed acute myeloid leukemia, derived from the recipient with somatic NRAS mutation 4 months after cord blood transplantation (CBT). Loss of heterozygosity phenomenon of the recipient at 6q14 locus was observed at 2 months post-CBT and progressed to 6q deletion (6q-) chromosome abnormality. Somatic NRAS mutation was detected at 3 months post-CBT. Thus, 6q- and NRAS mutation were strongly associated with the leukemic transformation in our patient.

Long-term surviving recipients of allogeneic hematopoietic stem cell transplantation (HSCT) often suffer from diabetes mellitus (DM). We sought to identify risk factors for the development of post-transplant DM and impaired glucose tolerance (IGT) in pediatric HSCT patients. Glucose tolerance statuses were evaluated in 22 patients aged 6.3-21.8 years who had received allogeneic HSCT between the ages of 0.8-13.5 years. Five patients were diagnosed as having type 2 DM, and treated with insulin or oral hypoglycemic agents. Five patients were included in the IGT group, and the remaining 12 children were in the normal glucose tolerance (NGT) group. The cumulative incidence of DM plus IGT was 11.6 % at 5 years and 69.3 % at 10 years. None of the patients were obese/overweight and none had a family history of DM. There were no significant differences in serum levels of leptin and adiponectin between the DM + IGT and the NGT groups. An average preprandial glucose levels in the DM + IGT group were significantly higher than those in the NGT group from preparative conditioning to 60 days after HSCT. In multivariate analysis, an age of ≥6 years at the time of HSCT was significantly associated with the development of DM + IGT. Additionally, careful follow-up is necessary, even for NGT patients.

advance online publication, February 25, 2014, Juvenile myelomonocytic leukemia (JMML) is a fatal, mixed myeloproliferative and myelodysplastic disorder occurring in infancy and early childhood. Children with JMML have mutually exclusive genetic abnormalities in granulocyte-macrophage colony-stimulating factor (GM-CSF) signaling pathways, inactivation of the NF1 or mutations in PTPN11, NRAS, KRAS and CBL. A whole-exome sequencing study, performed by Sakaguchi et al.,3 has recently demonstrated that in addition to the high frequency of RAS pathway mutations, mutations in SETBP1 and JAK3 are common recurrent secondary events, and that these events may be involved in tumor progression, and are associated with poor clinical outcomes., Article, LEUKEMIA. 28(7):1545-1548 (2014)

Mechanisms of relapse of acute lymphoblastic leukemia (ALL) after human leukocyte antigen (HLA) class II mismatched hematopoietic stem cell transplantation (HSCT) remain unclear. We report two children with relapsed ALL after HSCT from related donors with HLA-DRB1 and -DQB1 mismatches in the graft versus host direction. One lost HLA-DRB1, DQB1, and DPB1 alleles, and the other lost one HLA haplotype of the leukemic blasts at relapse. HLA class II loss may be a triggering event for ALL relapse after partially HLA-mismatched-related HSCT. In addition, HLA typing of relapsed leukemic blasts could be vital in the selection of retransplant donors.

To the Editor, Severe combined immunodeficiency (SCID) is a primary immunodeficiency with profound impairment of cellular immunity due to diminished numbers or absence of T cells. SCID patients typically succumb to severe and recurrent infections early in life unless they receive suitable treatment [1, 2]. Hematopoietic stem cell transplantation (HSCT) is the curative option for patients with SCID; however, the outcome is poor in those with ongoing cytomegalovirus (CMV) infection [3]. CMV central nervous system (CNS) disease is reported to be rare but fatal (>90 %) in patients undergoing HSCT [4, 5]. This is the first report of a patient with SCID who developed CMV encephalitis after umbilical cord blood transplantation (CBT) but survived. A 2-month-old boy was admitted to our hospital for the investigation of persistent fever and poor sucking. Immunological investigation showed hypogammaglobulinemia and lymphopenia with a marked decrease in the number of CD4 (1 %) and CD56 cells (5 %) in the blood. DNA sequencing showed a point mutation of the IL2RG gene [6]. He was diagnosed with X-linked SCID. He was scheduled to undergo CBT. CMV antigenemia assay usingmonoclonal antibody HRP-C7 revealed 252 positive cells per 50,000 cells in blood. CMV DNA was detected by PCR in cerebrospinal fluid (CSF). Brain MRI showed no significant abnormalities. CMV antigenemiapositive cells decreased to

Encouraging responses to histone deacetylase inhibitors have been reported for hematologic malignancies. Here, we report effects of panobinostat and 5-azacytidine on the proliferation of juvenile myelomonocytic leukemia (JMML) CD34We previously reported that stimulation of JMML CD34Panobinostat dose dependently reduced the numbers of day 7 CD34These results demonstrate that panobinostat directly suppresses the growth of JMML CD34

We describe successful treatment of 3 cases of human herpesvirus 6 (HHV-6) encephalitis/myelitis following cord blood transplantation (CBT). Ganciclovir (GCV) (10 mg/kg/day) reduced HHV-6 load to undetectable levels in cerebrospinal fluid (CSF). Early dose reduction in the presence of HHV-6 detectable in CSF resulted in an increased HHV-6 load. GCV was capably shifted to valganciclovir (VGCV) with an almost equivalent concentration. GCV/VGCV may be effective for HHV-6 encephalitis/myelitis after CBT, although HHV-6 load in CSF should be monitored.

Background The outcome of approximately 20% of patients with acute lymphoblastic leukemia (ALL) remains poor because of disease recurrence. We examined whether DNA methylation of cadherin superfamily genes is a useful biomarker for ALL relapse. Procedure We used Infinium Methylation 450K Arrays to assess genome-wide DNA methylation status. The methylation status of each individual gene was then determined by a combination of bisulfite restriction analysis and genome bisulfite sequencing. mRNA expression was evaluated by reverse-transcriptase PCR (RT-PCR) and quantitative real-time PCR. Results Cadherin superfamily genes including cadherin (CDH) 1, protocadherin (PCDH) 8, and PCDH17 were selected for analysis of methylation status. In 40 patient samples with B-cell precursor (BCP) ALL at diagnosis, the methylation frequencies of CDH1, PCDH8, and PCDH17 were 62.5, 55, and 30%, respectively. CDH1 and PCDH8 methylation was also detected in 80 and 20% of control bone marrow (BM) samples, respectively. On the contrary, PCDH17 was unmethylated in all control BM samples. There was a significant correlation between the methylation status of PCDH17 (but not CDH1 and PCDH8) and event-free survival or overall survival. Univariate and multivariate analyses showed that only PCDH17 methylation was associated with an increased risk for relapse and mortality in patients with BCP ALL. Conclusion PCDH17 methylation at diagnosis was closely related to poor prognosis and thus could be used as a new biomarker to predict relapse in patients with BCP ALL.

The limit state design method has been introduced into the design criteria for geotechnical structures. The current paper attempts to apply the reliability-based design method, at Level II, to the bearing capacity of the foundations of open channels from the viewpoint of the limit state design. To examine the applicability of the proposed procedure for practical structures, the reliability index is computed for evaluating the stability of the foundations of existing open channels designed by the conventional method. The conventional design procedure makes excessively safe side design. We applied the FORM to the existing open channels designed by the conventional design procedure, and consequently, large values of reliability index, 3 and 5 were obtained for clayey and sandy soils, respectively. Finally, the partial factors for the soil parameters have been determined, corresponding to the target reliability indices β t =1, 3 and 4.

Background Encouraging responses to histone deacetylase inhibitors have been reported for hematologic malignancies. Here, we report effects of panobinostat and 5-azacytidine on the proliferation of juvenile myelomonocytic leukemia (JMML) CD34+ cells. Procedure We previously reported that stimulation of JMML CD34+ cells with stem cell factor and thrombopoietin on irradiated murine AGM-S3 cells led to substantial expansion of JMML CD34+ cells that contained leukemic stem cells capable of transplantation into immunodeficient mice. Using this culture system, we evaluated effects of panobinostat and 5-azacytidine on the proliferation of JMML CD34+ cells. Results Panobinostat dose dependently reduced the numbers of day 7 CD34+ cells generated under stimulation of hematopoietic growth factors on AGM-S3 cells in all eight patients with JMML. These patients possessed various genetic and/or karyotypic abnormalities. CD34+ CD38- cells were substantially more sensitive to panobinostat at 10 and 20 nM than CD34+ CD38+ cells. Panobinostat, however, failed to influence the ability of AGM-S3 cells to stimulate JMML CD34+ cell production. In contrast to HL60 cells, apoptosis and cell cycle arrest in panobinostat-mediated inhibition were at low levels in JMML. The inhibitor also suppressed the factor-dependent proliferation of normal CD34+ cells on AGM-S3 cells. Meanwhile, no substantial inhibitory effects of 5-azacytidine on the growth of JMML CD34+ cells were observed. Conclusions These results demonstrate that panobinostat directly suppresses the growth of JMML CD34+ cells, in particular CD34+ CD38- cells, regardless of the genetic abnormality type, suggesting that it is a useful antileukemic drug to target JMML stem cells at a pretransplant stage.

N,N-Bis(4-methoxyphenyl)-4-(1-oxyl-3-oxide-4,4,5,5-tetramethylimidazolin-2-yl)phenylamine (1) was synthesized as a durable nitronyl nitroxide radical combined with a triarylamine moiety. Cyclic voltammetry and UV–Vis absorption spectra during the electrochemical oxidation of 1 revealed that the first redox was derived from the triarylamine moiety. The ionization potential of 1 was measured by photoelectron spectroscopy to be −5.4 eV, which was appropriate as a hole-transporting material. A single-layer hole-only device was fabricated with the radical molecule 1 dispersed in polycarbonate (ITO/1:polycarbonate/Al): The radical-layer exhibited a maximum current density of 0.2 mA/cm2, which was applicable for organic electronic devices.

Poly[2-{bis(4-methoxyphenyl)amino}phenyl-5-(2-ethylhexyloxy)-1,4-phenylenevinylene] 1 was prepared via the Gilch reaction of the p-bis(chloromethyl)benzene monomer, 2-{bis(4-methoxyphenyl)aminophenyl}-α,α′-dichloro-p-xylene. The Gilch reaction facilitated the preparation of the polyphenylenevinylene with a triarylamine pendant group when compared to that via the Heck polycondensation. The molecular weight of the polymer was approximately 4.0×105, and it was soluble in common solvents and was reversibly redoxed due to the pendant arylamine moiety. Chemical oxidation of 1 afforded the corresponding aminium polyradical 1+ with the half life-time of ca. 2 weeks under ambient conditions. ESR and magnetization measurements of 1+ revealed a forbidden multiplet signal and an average spin quantum number (S) of 3/2 at low temperature, respectively. The polyradical 1+ was the first example of a high molecular weight, high-spin organic polymer with solvent-solubility and film formability. 2,3-Bis[N,N-bis(4-methoxyphenyl)aminophenyl]stilbene 2 and its aminium diradical 2+ were also prepared as the model dimer compounds; 2+ was a triplet molecule at low temperature. The effect of the π-conjugated poly(1,4-phenylenevinylene) backbone on the high-spin alignment was also discussed.

Mechanisms of relapse of acute lymphoblastic leukemia (ALL) after human leukocyte antigen (HLA) class II mismatched hematopoietic stem cell transplantation (HSCT) remain unclear. We report two children with relapsed ALL after HSCT from related donors with HLA-DRB1 and -DQB1 mismatches in the graft versus host direction. One lost HLA-DRB1, DQB1, and DPB1 alleles, and the other lost one HLA haplotype of the leukemic blasts at relapse. HLA class II loss may be a triggering event for ALL relapse after partially HLA-mismatched-related HSCT. In addition, HLA typing of relapsed leukemic blasts could be vital in the selection of retransplant donors.

2,5-Bis(chloromethyl)triphenylamine 1 was prepared and polymerized via the Gilch reaction to give poly(2-diphenylamino-1,4-phenylenevinylene) 2G as a solvent-soluble Φ-conjugated polymer. 1 was also polymerized via the chemical vapor deposition to yield the precursor polymer of 2C, which was heated under vacuum to yield a yellow or brown thin film of 2C on substrates such as glass and a silicon wafer. Spectroscopies of the film supported the formation of the poly (2-diphenylamino-1,4-phenylenevinylene) 2C. The arylamine moiety of the 2C film worked as a functional group like a redox site.

Two poly(p-phenylenevinylene) derivatives, TPA-PPV and TPA-CN-PPV, bearing a triarylamine pendant were synthesized by the Wittig-Horner and Knoevenagel reactions, respectively. The optical properties of the polymers were improved by energy transfer from the triarylamine pendant to the poly(p-phenylenevinylene) main chain. Cyclic voltammetry revealed that the HOMO energy level of the pendant TPA moiety is higher than that of the PPV main chain, suggesting that the hole injection from ITO into the TPA moiety, then from the TPA moiety into PPV is more favorable than directly from ITO into the PPV main chain. A single-layer light-emitting diode using TPA-PPV as the emitting layer exhibited a maximum brightness of 790 cd/m2 at a bias of 8 V, while the control device employing commercially available MEH-PPV as the emitter showed a maximum brightness of 250 cd/m2 under 11 V. The higher brightness combined with the higher current density was attributed to the effective hole injection and/or hole transport in the TPA-PPV-based device.

An N-phenylcarbazole-containing poly(p-phenylenevinylene) (PPV), poly[(2-(4′-carbazol-9-yl-phenyl)-5-octyloxy-1,4-phenylenevinylene)-alt-(2-(2′-ethylhexyloxy)-5-methoxy-1,4-phenylenevinylene)] (Cz-PPV), was synthesized, and its optical, electrochemical, and electroluminescent properties were studied. The molecular structures of the key intermediates, the carbazole-containing boronic ester and the dialdehyde monomer, were crystallographically characterized. The polymer was soluble in common organic solvents and exhibited good thermal stability with a 5% weight loss at temperatures above 420 °C in nitrogen. A cyclic voltammogram showed the oxidation peak potentials of both the pendant carbazole group and the PPV main chain, indicating that the hole-injection ability of the polymer would be improved by the introduction of the carbazole-functional group. A single-layer light-emitting diode (LED) with a simple configuration of indium tin oxide (ITO)/Cz-PPV (80 nm)/Ca/Al exhibited a bright yellow emission with a brightness of 1560 cd/m2 at a bias of 11 V and a current density of 565 mA/cm2. A double-layer LED device with the configuration of ITO/poly(3,4-ethylenedioxy-2,5-thiophene):poly (styrenesulfonic acid) (60 nm)/Cz-PPV (80 nm)/Ca/Al gave a low turn-on voltage at 3 V and a maximum brightness of 6600 cd/m2 at a bias of 8 V. The maximum electroluminescent efficiency corresponding to the double-layer device was 1.15 cd/A, 0.42 lm/W, and 0.5%. The desired electroluminescence results demonstrated that the incorporation of hole-transporting functional groups into the PPVs was effective for enhancing the electroluminescent performance. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 5765–5773, 2005

Novel triphenylamine- and oxadiazole-substituted poly(1,4-phenylenevinylene)s (PPV) or CN-PPV ( P1 – 4 ) were synthesized by the Wittig–Horner, Knoevenagel, and Gilch type polymerization. The polymers exhibited good solubility in common organic solvents, relatively high photoluminescent (PL) efficiency, and high HOMO level for ca. −5.1 eV. The simple double-layer devices of triphenylamine-PPV ( P1 ), ITO/PEDOT: PSS/ P1 /Cs/Al, exhibited a very high luminance of 510 cd/m 2 under a low driving voltage of 3 V, demonstrating the effectiveness of triphenylamine moiety as a substituent of PPV derivatives for a light-emitting polymer. Triphenylamine-CN-PPV ( P2 ) exhibited bipolar reversible redox in CV. The bipolar type of PPVs, P2 and triphenylamine-oxadiazole-PPV ( P3 ), showed lower luminance and efficiency than those of the p -type of PPV ( P1 ).