A case of juvenile myelomonocytic leukemia with concomitant cytomegalovirus infection

Infantile cytomegalovirus (CMV)-associated disease and juvenile myelomonocytic leukemia (JMML) frequently present with similar clinical features, and thus the differential diagnosis is often difficult. An early and definite diagnosis of these disorders is required because their therapeutic approaches are very different. The authors describe a 2-month-old Japanese girl with JMML and CMV infection. The CMV antigen was detected by immunologic staining of leukocytes using the peroxidase-labeled monoclonal antibody HRP-C7. To assess clonality, the X-chromosome inactivation pattern was evaluated using polymerase chain reaction analysis of the human androgen receptor gene with or without predigestion of chromosomal DNA with HhaI or HpaII. The patient showed evidence of monoclonal origin of mononuclear cells at diagnosis. Although CMV infection mimicking JMML has previously been reported in two patients, to the authors' knowledge this is the first report describing a firm and definitive diagnosis of JMML based on the study of X-chromosome inactivation patterns.

Strategy for the treatment of unresectable hepatoblastoma: neoadjuvant chemotherapy followed by delayed primary operation or liver transplantation

We present our experience in using neoadjuvant regional and systemic chemotherapy together with surgical resection as a strategy for the treatment of unresectable hepatoblastoma. Neoadjuvant chemotherapy was given prior to surgical treatment in six children with unresectable hepatoblastoma. Furthermore, the neoadjuvant chemotherapy was intensified according to response to the initial treatment. Surgical resection was performed when the tumor was judged to be resectable. The adjuvant chemotherapy was given after delayed primary operation. Five of six children receiving neoadjuvant chemotherapy responded to the treatment and subsequently received delayed primary operation or living donor liver transplantation. All five children who had successful surgery have completed treatment and show no evidence of disease to date (27-115 months after surgery). It is concluded that neoadjuvant chemotherapy given as a combination of regional and systemic chemotherapy was effective for tumor reduction in cases with early stage or stage III disease. Also, to increase the cure rate of children with localized disease that was still unresectable after chemotherapy, living donor liver transplantation, which offers some advantage in timing of transplant compared with cadaveric liver transplantation, seems to be a possible procedure.

Fever as a risk factor causing delayed elimination of methotrexate in pediatric patients receiving high doses of cancer chemotherapy

PURPOSE

Delayed elimination of methotrexate (MTX) has been reported to be caused by a number of factors. In order to identify these causes, we retrospectively investigated the risk factors for delayed elimination in pediatric patients who received high doses of MTX.

SUBJECTS AND METHODS

The study included 69 courses of therapy involving 22 patients who received more than 1000 mg/m(2) of MTX. Plasma MTX concentrations 48 h (C48) and 72 h (C72) after infusion were used as indices of MTX elimination.

RESULTS

Neither C48 nor C72 was directly proportional to the dose of MTX infused. Both C48 and C72 were significantly higher in patients who developed fever of above 38 degrees C within a 10-day period (i.e., from 7 days before to 3 days after infusion) than in patients with no fever. Subgroup analysis revealed that C72 was significantly higher in patients who either developed fever and received antipyretics or developed fever but did not receive antipyretics than in patients who did not develop fever and did not receive antipyretics. Changes in the serum creatinine concentrations before and after MTX infusion revealed that renal function was significantly decreased in patients who developed fever compared to patients without fever.

CONCLUSIONS

The present results suggest that the development of fever is one of the main risk factors for the delayed elimination of MTX.

Impairment of IL-12-Dependent STAT4 Nuclear Translocation in a Patient with RecurrentMycobacterium aviumInfection

We examined the immunological abnormality in a patient with recurrent Mycobacterium avium infection. T cells from the patient showed decreased ability both to produce IFN-gamma and to proliferate in response to IL-12. Despite decreased expression of IL-12R beta1 and beta2 chains in the patient's PHA-activated T cells, there was no difference in IL-12-induced tyrosine and serine phosphorylation of STAT4 in PHA-activated T cells between the patient and healthy subjects, suggesting that IL-12R signals are transmitted to STAT4 in the patient's PHA-activated T cells. Using EMSA, confocal laser microscopy, and Western blotting, we demonstrated that the nuclear translocation of STAT4 in response to IL-12 is reduced in PHA-activated T cells from the patient when compared with those from healthy subjects. Leptomycin B was used to examine whether nuclear export of STAT4 is increased in the patient's T cells. However, leptomycin B treatment did not reverse impaired IL-12-induced nuclear accumulation of STAT4. Although the exact mechanism responsible for the impaired STAT4 nuclear translocation in this patient remains unclear, the absence of mutation in the IL-12Rbeta1, IL-12Rbeta2, STAT4, and STAT4-binding sequence of the IFN-gamma gene and preservation of STAT4 tyrosine and serine phosphorylation suggest the existence of a defective STAT4 nuclear translocation. This defect is likely responsible for the impaired STAT4 nuclear translocation in IL-12-stimulated T cells, leading to impairment of both IFN-gamma production and cell proliferation. To the best of our knowledge, this is the first report of a patient with atypical mycobacterial infection associated with impairment of STAT4 nuclear translocation.

electrophysiology and immunohistochemistry in the hippocampal ca1 and the dentate gyrus of rats chronically exposed to 1-bromopropane, a substitute for specific chlorofluorocarbons

1-Bromopropane is a newly introduced substitute for specific chlorofluorocarbons whose production was prohibited because of depletion of ozone layers. In this study, we analyzed disinhibitory effects induced by repetitive inhalation of 1-bromopropane for 12 weeks in the hippocampal CA1 and the dentate gyrus. In addition, reversal of the disinhibitory effects was examined 4 weeks after 1-bromopropane inhalation ceased. Exposure rats were placed in a stainless steel inhalation chamber at a concentration of 700 ppm, while the control group was provided only room air in the same type of chamber. Paired-pulse inhibition of population spike was considerably decreased (P<0.05) at 5 ms interpulse intervals in the CA1, and at 10 and 20 ms (P<0.05) interpulse intervals in the dentate gyrus in slices obtained from exposed rats following 4-, 8- and 12-week inhalation periods. The paired-pulse inhibition was decreased at 5 ms interpulse intervals in the dentate gyrus after 12 weeks of inhalation. These changes were not associated with the paired-pulse ratio of field excitatory postsynaptic potentials, suggesting a reduction of recurrent inhibition. The disinhibition was counteracted with the N-methyl-d-aspartate receptor antagonist dl-2-amino-5-phosphonopentameric acid in the dentate gyrus, whereas it was unchanged in the CA1. Tiagabine, a selective inhibitor of GABA transporter GAT1, increased the paired-pulse inhibition in the dentate gyrus, and the increase was less in the exposed rats compared with control rats (P<0.0003). The changes in both areas recovered to control levels 4 weeks after cessation of inhalation. Our electrophysiological studies suggest differential and reversible disinhibitory effects in the dentate gyrus and the CA1. 1-Bromopropane-induced disinhibition was further analyzed by immunohistochemical methods. There were no apparent morphological defects in either excitatory or inhibitory neuronal components, supporting the reversibility of physiological changes. In conclusion, chronic inhalation of 1-bromopropane induces a disinhibition in the CA1 and dentate gyrus that is reversible following cessation of exposure.

Experimental treatment of human neuroblastoma using live-attenuated poliovirus

Neuroblastoma, originated from neural crest cells, is the most common extracranial solid tumor in childhood. In the present study, we evaluated in vitro the oncolytic effect of live-attenuated poliovirus on human neuroblastoma cell lines, and in vivo its therapeutic efficacy in human neuroblastoma-bearing athymic mice. Live-attenuated poliovirus killed 27 (93%) of 29 established neuroblastoma cell lines in vitro. It induced cleavage of eukaryotic translation initiation factor 4G, leading to cell death through a mechanism involving activation of caspase-9, caspase-3 and poly(ADP-ribose)polymerase. For the in vivo experiments, an animal model was established using athymic mice xenotransplanted with SJ-N-JF neuroblastoma cells on both flanks. Inoculation of live-attenuated poliovirus into one of the two tumors caused a dramatic and complete regression of both the inoculated and contralateral tumors. Live-attenuated poliovirus has potent oncolytic activity against human neuroblastomas in vitro and in vivo and it may be useful for the treatment of advanced and refractory neuroblastomas, however, further studies are necessary to evaluate the safety of method.

Identification of Thermus thermophilus HB8 tRNA (Gm18) methyltransferase gene

For the purpose of identification of the gene for Thermus thermophilus tRNA (Gm18) methyltransferase [tRNA (guanosine-2'-)-methyltransferase, EC 2.1.1.34], the purified enzyme from native source was analyzed by the peptide-mass mapping. The target gene encoded the amino acid sequences of the obtained peptides was searched in data from Thermus thermophilus HB8 genome-sequencing project. We found the target gene AB05130, which was expected to encode a protein composed of 194 amino acid residues and the molecular mass of this protein was calculated as 22083. The recombinant protein was expressed in E. coli as an active form. The Gm18 formation activity of the purified recombinant protein was confirmed by in vitro methylation followed by two-dimensional thin layer chromatography and Liquid Chromatography/Mass Spectrum analysis of substrate tRNA.

Identification of essential amino acid residues of tRNA (Gm18)methyltransferase for methyl-transfer activity

Recent computation analyses have pointed out an existence of conserved amino acid motifs among RNA ribose 2'-O-methyltransferases. However, the functions of these motifs are unclear yet. We carried out the site-directed mutagenesis studies systematically on Thermus thermophilus HB8 tRNA (Gm18) methyltransferase gene. Subsequent biochemical analyses with purified variant enzymes clearly revealed that five conserved amino acid residues (Asn35, Arg41, Glu124, Ser150, and Asn152) are involved in S-adenosyl-L-methionine binding. This is for the first time reporting the function of the conserved motifs among RNA ribose 2'-O-methyltransferases.

Allelic association of the neuronal nitric oxide synthase (NOS1) gene with schizophrenia

Nitric oxide (NO) has been identified as a widespread and multifunctional biological messenger molecule in the central nervous system (CNS), with possible roles in neurotransmission, neurosecretion, synaptic plasticity, and tissue injury in many neurological disorders, including schizophrenia. Neuronal NO is widely produced in the brain from L-arginine catalyzed by neuronal NO synthase (NOS1). We therefore hypothesized that the NOS1 gene may play a role in the pathophysiology of schizophrenia. In the present study, we examined the genetic association between a novel single nucleotide polymorphism (SNP: a C-->T transition located 276 base pairs downstream from the translation termination site) of the human NOS1 gene, which is located in chromosome 12q24, and schizophrenia (215 Japanese patients with schizophrenia and 182 healthy controls). The allele frequencies of the polymorphism in exon 29 of the NOS1 gene differed significantly between patients with schizophrenia and controls (chi(2) = 20.10, df = 1, P = 0.000007; relative risk = 1.92; 95% confidence interval = 1.44-2.55). Our results suggest that the NOS1 gene polymorphism may confer increased susceptibility to schizophrenia.

A novel hypoxia-dependent 2-nitroimidazole KIN-841 inhibits tumour-specific angiogenesis by blocking production of angiogenic factors

Tumour angiogenesis is initiated by angiogenic factors that are produced in large amounts by hypoxic tumour cells. The inhibition of this step may lead to tumour-specific antiangiogenesis because normal tissues are not usually hypoxic. On the other hand, blocking a biological function of endothelial cells is known to result in angiogenic inhibition. To produce a tumour-specific and powerful antiangiogenesis, we determined whether potent angiogenic inhibition could be achieved by inhibiting the production of angiogenic factors by hypoxic tumour cells and simultaneously blocking certain angiogenic steps in endothelial cells under normoxia. We focused on the 2-nitroimidazole moiety, which is easily incorporated into hypoxic cells and exhibits its cytotoxicity as hypoxic cytotoxin. We designed and synthesised 2-nitroimidazole derivatives designated as KIN compounds, and investigated their antiangiogenic activities under normoxia using a chick embryo chorioallantoic membrane. KIN-841 (2-nitroimidazole 1-acetylhydroxamate) showed a potent angiogenic inhibition in a dose-dependent manner. This compound inhibited the proliferation of bovine pulmonary arterial endothelial (BPAE) cells more strongly than that of tumour cells, such as Lewis lung carcinoma (3LL) cells, under normoxia. The inhibition of cell proliferation by KIN-841 under hypoxia increased about five-fold compared to that under normoxia. Moreover, under hypoxia, KIN-841 significantly decreased the excessive production of vascular endothelial cell growth factors induced by 3LL cells as determined by tritium-labelled thymidine ([(3)H]thymidine) incorporation into BPAE cells and by ELISA. Intraperitoneal administration of KIN-841 suppressed 3LL-cell-induced in vivo angiogenesis in the mouse dorsal air sac system. These results indicate that the regulation of the production of angiogenic factors by hypoxic tumour cells is a useful target for tumour-specific angiogenesis inhibition, and that KIN-841, which causes simultaneous direct inhibition of endothelial cell function and production of angiogenic factors by hypoxic tumour cells, is a very potent inhibitor of tumour-specific angiogenesis. Thus, the potential for clinical use of KIN-841 as an antitumour drug is very high.

Gamera, a family of LINE-like repetitive sequences widely distributed in medaka and related fishes

A family of repetitive sequences, designated Gamera, has been identified in the genome of the Hainan medaka fish Oryzias curvinotus, a closely related species to the common medaka fish O. latipes. Sequencing and Southern blot analyses of this family revealed: (1) amino acid sequence similarity to reverse transcriptase domains of long interspersed nuclear elements (LINEs); (2) 5' truncation of dispersed copies; and (3) the disruption of another genetic element, indicating a past transposition event. These results suggest that Gamera belongs to the LINE superfamily. Gamera is widely distributed in the genus Oryzias, and the phylogenetic relationship might indicate its presence in the common ancestor of the genus.

A case of POEMS syndrome associated with reactive amyloidosis and Waldenström's macroglobulinaemia

A72-year-old Japanese man presented with a 5-year history of fatigue, night sweats, oedema of dorsum of foot, muscle weakness, and paresthesia of the lower extremities. On examination, the patient fulfilled the diagnostic criteria for POEMS syndrome, but was unusual in that he also had underling Waldenström's macroglobulinaemia with IgM kappa. The M protein of POEMS syndrome is usually IgG and IgA with lambda light chains. To our knowledge, there are only three cases of POEMS syndrome with IgM kappa including our case. Autopsy findings revealed that small lymphocytes were more prominent than plasma cells in the bone marrow. These plasma cells were stained with IgM kappa. Amyloid deposits identified by Congo red stain were detected predominantly in the vascular walls of the gastrointestinal tract, pancreas and kidney. This amyloid protein was classified as amyloid associated protein. This is the first case of POEMS syndrome associated with reactive amyloidosis and Waldenström's macroglobulinaemiae.

BK virus-associated fatal renal failure following late-onset hemorrhagic cystitis in an unrelated bone marrow transplantation

The human polyomavirus BK (BKV)-associated hemorrhagic cystitis (HC) has been a frequent and, seldom life-threatening complication after bone marrow transplantation (BMT). The authors report a male with melodysplastic syndrome, who developed BKV-associated late-onset HC 12 days after HLA-matched unrelated BMT. His urine contained epithelial cells with intranuclear inclusion bodies suggestive of BKV infection and was positive for BKV in polymerase chain reaction. He did not respond to any treatment for HC. In addition, he developed BKV-associated acute renal failure on day 26, followed by hepatic veno-occlusive disease on day 42. This is the first case in which BKV may be associated with fatal progressive renal failure.

Effect of basic fibroblast growth factor on insulin secretion from microencapsulated pancreatic islets: an in vitro study

Microencapsulation of pancreatic islets represents a potentially effective method to prevent graft rejection in allotransplantation or xenotransplantation without the need of immunosuppression. Adequate insulin secretion and glucose responsiveness of microencapsulated pancreatic islets has been regarded as a prerequisite for successful transplantation. The microencapsulated pancreatic islets were respectively cultured in bFGF+ RPMI-1640 medium (bFGF+) or bFGF- RPMI-1640 medium (bFGF-) for 21 days. The functional activities of microencapsulated pancreatic islets were assessed by measuring basal insulin secretion and stimulated insulin release at different time points. The results revealed that microencapsulated pancreatic islets in the presence of bFGF demonstrated an increase in basal insulin secretion. Furthermore, microencapsulated pancreatic islets in the presence of bFGF demonstrated a marked stimulated insulin release and relative stability of stimulation indices (SI). The results in the perifusion study showed that microencapsulated pancreatic islets in the presence of bFGF maintained good glucose responsiveness over the course of culture period as well. These results indicate that bFGF has a beneficial effect on insulin secretion from microencapsulated pancreatic islets during in vitro culture. New strategies for preserving and improving function of microencapsulated pancreatic islets prior to transplantation may be developed by application of growth factors or other factors.

Isolation, culture, and characterization of endocrine cells from 6-month-old porcine pancreas

Porcine endocrine cells were isolated from pancreas of 6-month-old pigs by two-step enzymatic digestion procedures. They were separated by the density gradient (isopycnic) centrifugation method using Histopaque-1077. Isolated cells were cultured and divided into two groups: suspension cells and adhesion cells. Suspension cells maintained their cell numbers on and after 7 days in culture. Approximately 1 x 10(7) cells were obtained from single pancreas of a 6-month-old pig. The cultured suspension cells took up dithizone (DTZ) staining 14 days after isolation in culture and indicated the presence of beta-cells. In in vitro study, the suspension cells were capable of secreting insulin into the culture medium. The suspension cells were tested for insulin and glucagon staining by Western blot analysis. These results indicated the maintenance of endocrine cell function after isolation. However, cultured adhesion cells failed to maintain their function during culture. In in vivo study, the suspension cells were transplanted into diabetes-induced nude mice. Reduction in blood glucose level was obtained after transplantation. Intraperitoneal glucose tolerance test (IPGTT) results showed a normal pattern of blood glucose clearance. After 1 week, the transplanted endocrine cells were detected with anti-insulin antibody by immunostaining and it showed the presence of viable beta-cells under the renal capsule of nude mice. Collectively, our results suggest that isolated and cultured suspension porcine endocrine cells maintained their endocrine function. These endocrine cells can be used as isolated islets for further study, including transplantation experiments.

Evaluation of insulin secretion of isolated rat islets cultured in extracellular matrix

Islet isolation involves enzymatic digestion of the interstitial matrix and mechanical disruption of the tissue. It is possible that a fundamental change of islet biology resulting from the loss of critical factors required for islet function or survival will occur. Extracellular matrix (ECM) is one of the most important components of the islet microenvironment. Reconstruction of the cell-matrix relationship seems to be effective for improving the loss of differentiated islet structure and function. The purpose of this study was to characterize and compare the effects of collagen gel mixture or Matrigel on beta-cell function and islet cell survival. After isolation by the collagenase digestion technique, rat islets were divided and cultured with various types of collagen gel mixture. They were assessed for their glucose-stimulated insulin secretion and cell viability. Glucose-induced insulin secretion of islets cultured with collagen type I gel or a mixture of collagen type I and IV was improved after 11 days in culture. In conclusion, a type of gel composed of collagen type I and/or type IV as an islet microenvironment is sufficient to maintain glucose responsiveness and may be useful for islet transplantation.

Development of a new method to induce angiogenesis at subcutaneous site of streptozotocin-induced diabetic rats for islet transplantation

The subcutaneous space is a potential site for clinical islet transplantation. Even though there are several advantages, poor blood supply at this site mainly causes failure of islet survival. In this study, angiogenesis was induced in advance at the diabetic rats subcutis for islet transplantation by implanting a polyethylene terephthalate (PET) mesh bag containing gelatin microspheres incorporating basic fibroblast growth factor (bFGF) (MS/bFGF) and a collagen sponge. The bFGF was incorporated into gelatin microspheres for controlled release of bFGF. As controls, a PET mesh bag with or without either collagen sponges or MS/bFGF was implanted at the subcutaneous site of diabetic rats. Macroscopic and microscopic examinations revealed the formation of capillary network in and around the PET mesh bag containing MS/bFGF and collagen sponges 7 days after implantation when compare with other control groups. When tissue hemoglobin level was also measured, a significantly high level of hemoglobin amount was observed compared with that of control groups. When allogeneic islets mixed with 5% agarose were transplanted into the prevascularized rat subcutis, normoglycemia was maintained for more than 40 days, while other control groups were ineffective. This study demonstrated that combination of gelatin microspheres incorporating bFGF and collagen sponges enabled the mesh to induce neovascularization even at the subcutaneous site of streptozotocin-induced diabetic rats, resulting in improved function of islet transplantation.

Polio vaccine virus-associated meningoencephalitis in an infant with transient hypogammaglobulinemia

The case of an infant with transient hypogammaglobulinemia who developed meningoencephalitis, retinitis and sensorineural hearing loss is presented. The neurovirulent variant of the Sabin type 2 oral poliovirus vaccine was detected in cerebrospinal fluid and stool.

Association between three functional polymorphisms of dopamine D2 receptor gene and tardive dyskinesia in schizophrenia

The dopamine D2 receptor (DRD2) gene is considered one of the candidate genes contributing to the development of tardive dyskinesia (TD). In the present study, we investigated the genetic association between three functional polymorphisms (Ser311Cys, -141C Ins/Del and TaqI A) in the DRD2 gene and TD (200 patients with schizophrenia: 44 with TD and 156 without TD). No significant difference in the allelic and genotypic distribution between patients with TD and those without TD was observed. However, we found a slightly significant association between the -141C Ins/Del polymorphism and the total Abnormal Involuntary Movement Scale (AIMS) score (P = 0.037). The significant association between the -141C Ins/Del polymorphism and the total AIMS score did not remain after the regression analysis was taken into account (P = 0.14). Our results suggest that that three functional polymorphisms in DRD2 may not play a major role in the occurrence of TD.

Tyrosine phosphorylation-dependent and -independent role of Shc in the regulation of IGF-1-induced mitogenesis and glycogen synthesis

To examine the functional role of Shc tyrosine phosphorylation in IGF-1 signaling, wild-type (WT)-Shc and Y239,240,317F (3F)-Shc were transiently transfected into L6 myoblasts. IGF-1 signaling was compared among the transfected cells. IGF-1-induced tyrosine phosphorylation of Shc and its subsequent association with Grb2 were increased in WT-Shc cells, whereas they were decreased in 3F-Shc cells compared with those in parental L6 cells. Consistent with their changes, IGF-1-induced MAPK activation and thymidine incorporation were enhanced in WT-Shc cells, whereas they were again decreased in 3F-Shc cells. It is possible that Shc and insulin receptor substrate (IRS)-1 can interact competitively, via their phosphotyrosine binding (PTB) domains, with the activated IGF-1 receptor. In this regard, IGF-1-induced tyrosine phosphorylation of IRS-1 was decreased by overexpressing both WT-Shc and 3F-Shc cells. Consistent with the decrease, IGF-1-induced IRS-1 association with the p85 subunit of PI3K and activation of PI3K and Akt were reduced in both WT-Shc and 3F-Shc cells. As a result, IGF-1-induced glycogen synthesis was also decreased in both cells. Furthermore, expression of Shc PTB domain alone inhibited IGF-1 stimulation of Akt and glycogen synthesis. These results indicate that tyrosine phosphorylation of Shc is important for IGF-1 stimulation of MAPK leading to mitogenesis and that Shc, via its PTB domain, negatively regulates IGF-1-induced glycogen synthesis by competing with IRS-1, which is not relevant to Shc tyrosine phosphorylation.