A case of infant botulism infection due to consumption of untreated well-water.

A 7-week-old boy with flaccid paralysis was diagnosed with infant botulism caused by Clostridium botulinum toxin type A. In this case of infant botulism, untreated well-water was identified as a potential source of this infection.

The open conformation of WASP regulates its nuclear localization and gene transcription in myeloid cells.

Mutations in the gene encoding the Wiskott-Aldrich syndrome protein (WASP) are responsible for Wiskott-Aldrich syndrome and WASP is a major actin regulator in the cytoplasm. Although rare gain-of-function mutations in the WASP gene are known to result in X-linked neutropenia (XLN), the molecular pathogenesis of XLN is not fully understood. In this study, we showed that all reported constitutively activating mutants (L270P, S272P and I294T) of WASP were hyperphosphorylated by Src family tyrosine kinases and demonstrated higher actin polymerization activities compared with wild-type (WT) WASP. Further analysis showed a tendency of activating WASP mutants to localize in the nucleus compared with WT or the Y291F mutant of WASP. In addition, we found that WASP could form a complex with nuclear RNA-binding protein, 54 kDa (p54nrb) and RNA polymerase II (RNAP II). ChIP assays revealed that WASP associated with DNA, although the affinity was relatively weaker than RNAP II. To determine whether gene transcription was affected by WASP mutation in myeloid cells, we performed microarray analysis and found different expression profiles between WT and L270P WASP-transfected K562 cells. Among the genes affected, granulocyte colony-stimulating factor receptor, Runx1, and protein tyrosine phosphatase receptor c were included. ChIP on chip analysis of genomic DNA showed WT and L270P WASP had a highly similar DNA-binding pattern but differed in binding affinity at the same locus. Therefore, our results suggest that the open conformation of WASP regulates its nuclear localization and plays requisite roles in regulating gene transcription that would contribute to the outcome in the nucleus of myeloid cells.

Selective expansion of donor-derived regulatory T cells after allogeneic bone marrow transplantation in a patient with IPEX syndrome.

IPEX syndrome is a rare and fatal disorder caused by absence of regulatory T cells (Tregs) due to congenital mutations in the Forkhead box protein 3 gene. Here, we report a patient with IPEX syndrome treated with RIC followed by allogeneic BMT from an HLA-matched sibling donor. We could achieve engraftment and regimen-related toxicity was well tolerated. Although the patient was in mixed chimera and the ratio of donor cells in whole peripheral blood remained relatively low, selective and sustained expansion of Tregs determined as CD4+CD25+Foxp3+ cells was observed. Improvement in clinical symptoms was correlated with expansion of donor-derived Tregs and disappearance of anti-villin autoantibody, which was involved in the pathogenesis of gastrointestinal symptoms in IPEX syndrome. This clinical observation suggests that donor-derived Tregs have selective growth advantage in patients with IPEX syndrome even in mixed chimera after allogeneic BMT and contribute to the control of clinical symptoms caused by the defect of Tregs.

Effect of a blackout in pediatric patients with home medical devices during the 2011 eastern Japan earthquake.

BACKGROUND: during the eastern Japan earthquake in 2011 and the following prolonged blackout, pediatric patients with home medical devices sought electricity at the pediatric department. We retrospectively studied the effect of this earthquake and the following blackout. METHODS: we hand-reviewed pediatric admission records in Tohoku University Hospital for new inpatients attributed to the earthquake from March 11, 2011 to April 12, 2011. A survey by questionnaire regarding the situation during the earthquake was performed for parents of technology-assisted patients. RESULTS: during the study period, 24 pediatric patients were admitted to the pediatric department. Eighteen technology-assisted pediatric patients, including those with home respirators, accounted for 75% of new pediatric admissions. Patients who were admitted for electricity shortage stayed in the hospital for a mean of 11.0days (3-25days). The questionnaire survey showed that 55% of technology-assisted patients were admitted to medical centers for evacuation. The majority of patients (89%) with ventilators were eventually admitted to medical centers during the earthquake. Most of the parents of technology-assisted patients experienced a prolonged petrol shortage and difficulty in communications with medical centers. CONCLUSION: the current study suggests that technology-assisted pediatric patients with neurological disorders as the primary disease can overwhelm the capacity of hospital inpatient facilities in certain situations. Disaster preparedness should consider assuring power requirements in healthcare facilities and preparing backup power generators lasting for at least 24h for these patients. Preparing alternative measures for emergent electricity and communications could remedy serious conditions during a disaster.

B-cell function after unrelated umbilical cord blood transplantation using a minimal-intensity conditioning regimen in patients with X-SCID.

Patients with X-linked severe combined immunodeficiency (X-SCID) suffer from severe and persistent infections, and usually die early in life unless treated by hematopoietic stem cell transplantation. If a patient has an HLA-identical sibling donor, preparative conditioning is not necessary for T-cell engraftment and B-cell function. However, in the absence of such a donor, long-term reconstitution of full B-cell function is often problematic, leading in many cases to a lifetime requirement for immunoglobulin replacement therapy. Preparative myeloablative conditioning has been shown to improve long-term B-cell function, but may aggravate pre-existing infection and transplant-related toxicity. It is thus important to determine the minimum intensity of conditioning that assures immunoglobulin production. In the present study, we performed reduced-intensity conditioning (RIC), consisting of fludarabine 125 mg/m(2) and melphalan 80 mg/m(2), prior to unrelated umbilical cord blood transplantation (UCBT) for five patients with X-SCID, none of them had an HLA-identical donor. Four patients survived more than 4 years without sequelae, and none required long-term immunoglobulin replacement therapy. One patient succumbed to sepsis in conjunction with severe GVHD. Our result demonstrates that the RIC regimen described above in combination with UCBT is an effective and less toxic conditioning to correct B-cell function in patients with X-SCID.

Gene therapy model of X-linked severe combined immunodeficiency using a modified foamy virus vector.

X-linked severe combined immunodeficiency (SCID-X1) is an inherited genetic immunodeficiency associated with mutations in the common cytokine receptor γ chain (γc) gene, and characterized by a complete defect of T and natural killer (NK) cells. Gene therapy for SCID-X1 using conventional retroviral (RV) vectors carrying the γc gene results in the successful reconstitution of T cell immunity. However, the high incidence of vector-mediated T cell leukemia, caused by vector insertion near or within cancer-related genes has been a serious problem. In this study, we established a gene therapy model of mouse SCID-X1 using a modified foamy virus (FV) vector expressing human γc. Analysis of vector integration in a human T cell line demonstrated that the FV vector integration sites were significantly less likely to be located within or near transcriptional start sites than RV vector integration sites. To evaluate the therapeutic efficacy, bone marrow cells from γc-knockout (γc-KO) mice were infected with the FV vector and transplanted into γc-KO mice. Transplantation of the FV-treated cells resulted in the successful reconstitution of functionally active T and B cells. These data suggest that FV vectors can be effective and may be safer than conventional RV vectors for gene therapy for SCID-X1.

A case series of CAEBV of children and young adults treated with reduced-intensity conditioning and allogeneic bone marrow transplantation: a single-center study.

BACKGROUND: Epstein-Barr virus (EBV)-infected T or NK cells cause chronic active EBV infection (CAEBV). Allogeneic hematopoietic stem cell transplantation (HSCT) is curative treatment for CAEBV patients. However, chemotherapy prior to HSCT and optimal conditioning regimen for allogeneic HSCT are still controversial. PATIENTS AND METHODS: We retrospectively analyzed five patients with CAEBV treated with reduced-intensity conditioning (RIC) consisted of fludarabine, cyclophosphamide, and low-dose total-body irradiation followed by allogeneic bone marrow transplantation in a single institute. Only one of five patients received chemotherapy prior to transplantation. We analyzed EBV-infected cells in a patient whose EBV load increased after HSCT by T-cell repertoire assay, separation of T-cell subpopulations, in situ hybridization and microsatellite analysis. RESULTS: All five patients achieved engraftment, complete chimera, and eradication of EBV load. All patients have been alive without any serious regimen-related toxicity for more than 16 months following HSCT. However, one patient transplanted from HLA-matched sibling donor developed clonal proliferation of CD4+ Vß3+ T cells caused by monoclonal EBV infection on day 99 after transplantation. Further analysis revealed that the CD4+ Vß3+ T cells selectively harbored EBV genome, and these infected cells were derived from donor T cells. CONCLUSIONS: Allogeneic HSCT with RIC is a safe and effective treatment for better overall survival and less regimen-related toxicity in patients with CAEBV. Our first pediatric case reported in the literature suggests that we should consider the possibility of persistent EBV infection in donor T cells as well as the relapse in recipient cells if EBV load increases after allogeneic HSCT.

T-cell receptor ligation causes Wiskott-Aldrich syndrome protein degradation and F-actin assembly downregulation.

BACKGROUND: Wiskott-Aldrich syndrome protein (WASP) links T-cell receptor (TCR) signaling to the actin cytoskeleton. WASP is normally protected from degradation by the Ca(++)-dependent protease calpain and by the proteasome because of its interaction with the WASP-interacting protein. OBJECTIVE: We investigated whether WASP is degraded after TCR ligation and whether its degradation downregulates F-actin assembly caused by TCR ligation. METHODS: Primary T cells, Jurkat T cells, and transfected 293T cells were used in immunoprecipitation experiments. Intracellular F-actin content was measured in splenic T cells from wild-type, WASP-deficient, and c-Casitas B-lineage lymphoma (Cbl)-b-deficient mice by using flow cytometry. Calpeptin and MG-132 were used to inhibit calpain and the proteasome, respectively. RESULTS: A fraction of WASP in T cells was degraded by calpain and by the ubiquitin-proteasome pathway after TCR ligation. The Cbl-b and c-Cbl E3 ubiquitin ligases associated with WASP after TCR signaling and caused its ubiquitination. Inhibition of calpain and lack of Cbl-b resulted in a significantly more sustained increase in F-actin content after TCR ligation in wild-type T cells but not in WASP-deficient T cells. CONCLUSION: TCR ligation causes WASP to be degraded by calpain and to be ubiquitinated by Cbl family E3 ligases, which targets it for destruction by the proteasome. WASP degradation might provide a mechanism for regulating WASP-dependent TCR-driven assembly of F-actin.

Utility of thallium-201 scintigraphy in Tolosa-Hunt syndrome.

Tolosa-Hunt syndrome (THS) is a rare disorder, especially in the pediatric population, characterized by unilateral painful ophthalmoplegia with a relapsing-remitting course. Because the diagnosis of THS is based on the exclusion of other causes of painful ophthalmoplegia, attention should be paid to possible alternative diagnoses. Thallium-201 chloride ((201)Tl) scintigraphy has been used to evaluate tissue histology in clinical oncology with a marker, the retention index (RI). A higher value indicates histological malignancy. Although its utility in pediatric THS has not been discussed, we suggest that (201)Tl scintigraphy may be informative as a marker in the diagnosis. We present an 11-year-old boy with THS who was evaluated with (201)Tl scintigraphy before treatment with corticosteroids, when he had headache, photophobia, and diplopia. The RI of (201)Tl indicated that the lesion would be benign. Although his clinical symptoms did not fulfill the THS criteria completely, his eye symptoms disappeared 2 weeks after corticosteroid treatment, which was not within the 72 h as in the diagnostic criteria of THS. He has been symptom-free for more than 2 years with only an initial 4-week corticosteroid therapy. This report not only shows the potential of (201)Tl scintigraphy to contribute to the correct diagnosis of pediatric THS but also suggests the possibility that the diagnosis of THS could be supported uniquely even in a pediatric THS-suspicious patient who did not fulfill the current THS criteria completely. In conclusion, we suggest that (201)Tl scintigraphy may be useful for making the diagnosis of THS, especially in pediatric patients.

A homozygous mutation of voltage-gated sodium channel ß(I) gene SCN1B in a patient with Dravet syndrome.

Dravet syndrome is a severe form of epileptic encephalopathy characterized by early onset epileptic seizures followed by ataxia and cognitive decline. Approximately 80% of patients with Dravet syndrome have been associated with heterozygous mutations in SCN1A gene encoding voltage-gated sodium channel (VGSC) α(I) subunit, whereas a homozygous mutation (p.Arg125Cys) of SCN1B gene encoding VGSC ß(I) subunit was recently described in a patient with Dravet syndrome. To further examine the involvement of homozygous SCN1B mutations in the etiology of Dravet syndrome, we performed mutational analyses on SCN1B in 286 patients with epileptic disorders, including 67 patients with Dravet syndrome who have been negative for SCN1A and SCN2A mutations. In the cohort, we found one additional homozygous mutation (p.Ile106Phe) in a patient with Dravet syndrome. The identified homozygous SCN1B mutations indicate that SCN1B is an etiologic candidate underlying Dravet syndrome.

Liposome-encapsulated hemoglobin (hemoglobin-vesicle) is not transferred from mother to fetus at the late stage of pregnancy in the rat model.

AIMS: Liposome-encapsulated hemoglobin (hemoglobin vesicles: HbV; diameter 250 nm) is reconstructed from human hemoglobin and developed as an artificial oxygen carrier for use as a transfusion alternative. Previous studies using rodent models closely investigated the safety of daily repeated infusions (DRI) of HbV and reported that the reticuloendothelial system was physiologically capable of degrading HbV to maintain plasma clinical chemistry within normal ranges. The present study examined the effect of DRI of HbV on the pregnant rat mother and fetal development, focusing on placental transfer of HbV in pregnancy. MAIN METHODS: Pregnant rats intravenously received HbV bolus injections at 2 ml/kg/day for the last 7 consecutive days till term. The cumulative infusion volume (14 ml/kg) was equal to 25% of the whole blood volume (56 ml/kg). KEY FINDINGS: Maternal DRI of HbV had no obvious side effects on the pregnant mother or on fetal development. Maternal vital signs, plasma clinical chemistry, and blood gas parameters were overall normal after DRI of HbV. In addition, maternal/fetal transfer of HbV was limited to the placenta and HbV did not reach the fetus. Histopathological examination with human hemoglobin antibody detected HbV accumulation in the maternal spleen, liver, kidney, and placenta, but not in the fetuses. These results were also confirmed by a pharmacokinetic study using (125)I-labeled HbV. SIGNIFICANCE: This safety study of HbV use in the pregnant mother and fetus will contribute to a possible application of HbV as a potential treatment for fetal hypoxia by supplying oxygen through the placenta.

Development of a multi-step leukemogenesis model of MLL-rearranged leukemia using humanized mice.

Mixed-lineage-leukemia (MLL) fusion oncogenes are intimately involved in acute leukemia and secondary therapy-related acute leukemia. To understand MLL-rearranged leukemia, several murine models for this disease have been established. However, the mouse leukemia derived from mouse hematopoietic stem cells (HSCs) may not be fully comparable with human leukemia. Here we developed a humanized mouse model for human leukemia by transplanting human cord blood-derived HSCs transduced with an MLL-AF10 oncogene into a supra-immunodeficient mouse strain, NOD/Shi-scid, IL-2Rγ(-/-) (NOG) mice. Injection of the MLL-AF10-transduced HSCs into the liver of NOG mice enhanced multilineage hematopoiesis, but did not induce leukemia. Because active mutations in ras genes are often found in MLL-related leukemia, we next transduced the gene for a constitutively active form of K-ras along with the MLL-AF10 oncogene. Eight weeks after transplantation, all the recipient mice had developed acute monoblastic leukemia (the M5 phenotype in French-American-British classification). We thus successfully established a human MLL-rearranged leukemia that was derived in vivo from human HSCs. In addition, since the enforced expression of the mutant K-ras alone was insufficient to induce leukemia, the present model may also be a useful experimental platform for the multi-step leukemogenesis model of human leukemia.

Two novel mutations in the lactase gene in a Japanese infant with congenital lactase deficiency.

Intestinal lactase is required for the hydrolysis of lactose that is the most essential carbohydrate in milk and the primary diet source of newborn. Congenital lactase deficiency [CLD (MIM 223000)] is a severe gastrointestinal disorder and is characterized by watery diarrhea due to an extremely low or the lack of lactase activity in the intestinal wall from birth. CLD is a rare disease and occurs more frequently in Finland. Recent studies have shown that mutations in the coding region of the lactase (LCT) gene underlie CLD in patients from Finland and other European countries. Here, we report two novel mutations in the LCT gene in a Japanese female infant with clinical features consistent with those of CLD. She suffered from severe watery diarrhea from the age of 2 days on breast milk/lactose containing cow's milk formula. With the lactose-free hydrolyzed cow's milk formula, diarrhea was stopped, and she has now developed well on a lactose-free diet. She shows a lactose-intolerance pattern on the lactose challenge test. Sequence analysis revealed the two mutations in her LCT gene: c.4419C>G (p.Y1473X) in exon 10 transmitted from her mother and c.5387delA (p.D1796fs) in exon 16 transmitted from her father. Both mutations cause premature truncation of lactase polypeptide and are supposed to be responsible for CLD. To our knowledge, this is the first report on mutations in the LCT gene in Japan. We suggest that an increased awareness is required regarding CLD.

Copper-trafficking efficacy of copper-pyruvaldehyde bis(N4- methylthiosemicarbazone) on the macular mouse, an animal model of Menkes disease.

BACKGROUND: Menkes disease (MD) is a disorder of copper transport caused by ATP7A mutations. Although parenteral copper supplements are partly effective in treating MD, the copper level in the brain remains insufficient, whereas copper accumulates in the kidney. We investigated the copper-trafficking efficacy of copper-pyruvaldehyde bis(N4-methylthiosemicarbazone) (Cu-PTSM), a lipophilic copper complex, in macular mice, an animal model of MD. METHODS: Macular mice were treated with cupric chloride (CuCl2) or Cu-PTSM on postnatal days 4, 10, and 17. At 4 wk of age, the copper levels in major organs and cytochrome oxidase (CO) activity in brain tissue were measured. Hematology, blood biochemistry, and urinary ß2-microglobulin (ß2-M) secretion were also assessed. RESULTS: The copper levels in the brains of the Cu-PTSM-treated group remained low, but CO activity in the cerebral and cerebellar cortices in the Cu-PTSM-treated group were higher than those in the CuCl2-treated group. There were no significant differences in hematological or biochemical findings or in urinary ß2-M secretion among the groups. CONCLUSION: Although the copper-trafficking efficacy of Cu-PTSM was limited, the improved CO activity in the brain suggests that Cu-PTSM delivered copper more effectively to neuronal CO than did CuCl2. Reduced renal copper accumulation may be beneficial in prolonged copper supplementation.

Casitas B-cell lymphoma mutation in childhood T-cell acute lymphoblastic leukemia.

Somatic CBL mutations have been reported in a variety of myeloid neoplasms but are rare in acute lymphoblastic leukemia (ALL). We analyzed 77 samples from hematologic malignancies, identifying a somatic mutation in CBL (p.C381R) in one patient with T-ALL that was associated with a uniparental disomy at the CBL locus and a germline heterozygous mutation in one patient with JMML. Two NOTCH1 mutations and homozygous deletions in LEF1 and CDKN2A were identified in T-ALL cells. The activation of the RAS pathway was enhanced, and activation of the NOTCH1 pathway was inhibited in NIH 3T3 cells that expressed p.C381R. This study appears to be the first to identify a CBL mutation in T-ALL.

Unusual ribbon-like periventricular heterotopia with congenital cataracts in a Japanese girl.

Periventricular heterotopia (PH), clumps of neurons mislocated beside the ventricle, is caused by failure to initiate migration during embryogenesis. We report on a 32-month-old Japanese girl with a unique subtype of PH, namely ribbon-like PH. The patient presented with severe psychomotor developmental delay, intractable epilepsy, and congenital cataracts and developed West syndrome phenotype. Brain magnetic resonance imaging revealed a unique undulating form of PH, categorized as ribbon-like PH, and other brain malformations including simplified gyri and dysgenesis of the corpus callosum. There was no evidence of prenatal TORCH infection or associated syndrome. Array-based comparative genomic hybridization revealed no chromosomal rearrangements. Genetic analyses of the FLNA, DCX, ARX, LIS1, and TUBA1A genes showed no mutations. Although little is known about ribbon-like PH, the clinical manifestations in our patient clearly differed from those in other reported patients.

Post-transplantation lymphoproliferative disorder in living-donor liver transplantation: a single-center experience.

BACKGROUND: Post-transplantation lymphoproliferative disorder (PTLD) is a group of life-threatening complications of organ transplantation, which occurs most frequently in pediatric patients. This retrospective study evaluates a single-institution experience of five cases of PTLD after living-donor liver transplantation (LDLT). PATIENTS AND METHOD: We reviewed the records of 78 pediatric patients (<18 years old) and 54 adult patients, who underwent LDLT between July 1991 and December 2009. RESULT: PTLD was diagnosed in five pediatric patients, yielding an overall incidence of 3.8%. There were no significant differences between the pediatric patients with and those without PTLD in terms of their age, sex, reason for transplantation, calcineurin inhibitor, Epstein-Barr virus (EBV) serostatus, ABO compatibility, lymphocyte cross-matching, or episodes of biopsy proven rejection. Two patients with abdominal lymphadenopathy and one with gastrointestinal PTLD responded to a reduction in immunosuppression. Treatment with rituximab was necessary for another gastrointestinal PTLD patient. Diffuse large-B-cell lymphoma was diagnosed in one patient with mediastinal and lung masses. This patient was treated with chemotherapy and rituximab, followed by surgical resection. All patients survived and no evidence of recurrence has been found since. CONCLUSION: Although PTLD is potentially life-threatening, it can be managed by appropriate and prompt treatment, with a good outcome.

Successful cord blood transplantation with reduced-intensity conditioning for childhood cerebral X-linked adrenoleukodystrophy at advanced and early stages.

Childhood cerebral ALD is a rapidly progressive and neurodegenerative disorder for which HSCT is the curative therapy if carried out at early stages. We successfully treated two patients of childhood cerebral ALD by CBT with RIC. The proband was a seven-yr-old boy whose brain MRI severity score (Loes score) was 14.5. Unrelated CBT was performed in five wk. To minimize conditioning regimen-related neurotoxicity, the combination of fludarabine (125 mg/m(2)), melphalan (140 mg/m(2)), and 4 Gy of brain-sparing TBI was used. The second patient was a six-yr-old brother of the proband. Four wk after the detection of a single small lesion (Loes score 1), he received unrelated CBT with the same RIC as the proband. In both patients, the engraftment was fast and stable, and severe complications were not observed. Furthermore, gadolinium-enhanced inflammation on brain MRI rapidly disappeared after CBT. Now, 20 and 13 months have passed after CBT, respectively, and both patients are neurologically stable. The RIC we used was sufficient for stable engraftment of cord blood and also tolerable even to the patient with advanced ALD. RIC-CBT should be considered for the patients with cerebral ALD at advanced stages, as well as those at early stages.

[Case of a pharyngeal-cervical-brachial variant of Guillain-Barré syndrome without pharyngeal palsy].

We report a case of a 3-year-old boy with acute muscle weakness that initially affected neck and all four limbs but later vanished from the lower limbs. Pharyngeal palsy was not observed during the course. All deep tendon reflexes were absent. Peripheral nerve conduction studies showed a demyelination pattern in each limb. The patient received intravenous high-dose corticosteroid hormone, followed by two immunoglobulin therapies. His muscle strength gradually improved after treatment and was almost completely restored four months later. We ultimately diagnosed the condition as the pharyngeal-cervical-brachial variant of Guillain-Barré syndrome, in consideration of the patient's muscle weakness of the neck and four limbs, the greater degree of weakness of the upper limbs versus the lower limbs. His clinical presentation was atypical for the pharyngeal-cervical-brachial variant of Guillain-Barré syndrome, as he presented no pharyngeal muscle weakness or anti GT1a antibodies, typical manifestations of the condition.

Differential proliferation rhythm of neural progenitor and oligodendrocyte precursor cells in the young adult hippocampus.

Oligodendrocyte precursor cells (OPCs) are a unique type of glial cells that function as oligodendrocyte progenitors while constantly proliferating in the normal condition from rodents to humans. However, the functional roles they play in the adult brain are largely unknown. In this study, we focus on the manner of OPC proliferation in the hippocampus of the young adult mice. Here we report that there are oscillatory dynamics in OPC proliferation that differ from neurogenesis in the subgranular zone (SGZ); the former showed S-phase and M-phase peaks in the resting and active periods, respectively, while the latter only exhibited M-phase peak in the active period. There is coincidence between different modes of proliferation and expression of cyclin proteins that are crucial for cell cycle; cyclin D1 is expressed in OPCs, while cyclin D2 is observed in neural stem cells. Similar to neurogenesis, the proliferation of hippocampal OPCs was enhanced by voluntary exercise that leads to an increase in neuronal activity in the hippocampus. These data suggest an intriguing control of OPC proliferation in the hippocampus.