Absence of REM rebound after barbiturate withdrawal.

Administration of three different barbiturates reduced rapid eye movement (REM) sleep. Drug withdrawal led to a return to baseline REM] values without significant overshoot. Similar results are observed with administration of benzodiazepines in pharmacologically equivalent dosages; therefore, a distinction between these two drug classes on the basis of withdrawal effects on the sleep electroencephalogram appears unwarranted. Further investigation is required determine why high REM levels are sometimes associated with the withdrawal of sedative-hypnotic agents.

Allogeneic stem cell transplantation in children with acute lymphoblastic leukemia after isolated central nervous system relapse: our experiences and review of the literature.

The prognosis of patients with acute lymphoblastic leukemia (ALL) and central nervous system (CNS) relapse has historically been very poor. Although chemo-radiotherapy has improved outcomes, some patients still have a poor prognosis after CNS relapse. Therefore, allogeneic hematopoietic stem cell transplantation (allo-SCT) has recently become an option for treatment of CNS leukemia; however, information, particularly on the long-term outcome of transplant recipients, is limited. We performed allo-SCT in eight pediatric patients with ALL (n=7) or T-cell type non-Hodgkin's lymphoma (n=1), who had isolated CNS relapse. All patients survived for a median of 70.5 (range, 13-153) months after SCT. Sequelae developed late in some patients: mental retardation (IQ=47) in one patient, severe alopecia in two patients, limited chronic graft-versus-host-disease in three patients, and amenorrhea and/or hypothyroidism in three patients. Except for a pre-school child with post transplant CNS relapse, six out of seven patients show normal school/social performance. Our results clearly indicate a high cure rate of isolated CNS relapse by allo-SCT in pediatric lymphoid malignancies; however, there needs to be further studies to determine which are the appropriate candidates for transplantation and what is the best transplant regimen to achieve high cure rate and maintain good quality of life.

Isolation and characterization of a human thiamine pyrophosphokinase cDNA.

A human thiamine pyrophosphokinase cDNA clone (hTPK1) was isolated and sequenced. When the intact hTPK1 open reading frame was expressed as a histidine-tag fusion protein in Escherichia coli, marked enzyme activity was detected in the bacterial cells. The hTPK1 mRNA was widely expressed in various human tissues at a very low level, and the mRNA content in cultured fibroblasts was unaffected by the thiamine concentration of the medium. The chromosome localization of the hTPK1 gene was assigned to 7q34.

Requirement for etoposide in the treatment of Epstein-Barr virus-associated hemophagocytic lymphohistiocytosis.

PURPOSE: We sought to identify the clinical variables most critical to successful treatment of Epstein-Barr virus (EBV)-associated hemophagocytic lymphohistiocytosis (HLH). PATIENTS AND METHODS: Among the factors tested were age at diagnosis (< 2 years or > or = 2 years), time from diagnosis to initiation of treatment with or without etoposide-containing regimens, timing of cyclosporin A (CSA) administration during induction therapy, and the presence or absence of etoposide. RESULTS: By Kaplan-Meier analysis, the overall survival rate for the entire cohort of 47 patients, most of whom had moderately severe to severe disease, was 78.3% +/- 6.7% (SE) at 4 years. The probability of long-term survival was significantly higher when etoposide treatment was begun less than 4 weeks from diagnosis (90.2% +/- 6.9% v 56.5% +/- 12.6% for patients receiving this agent later or not at all; P <.01, log-rank test). Multivariate analysis with the Cox proportional hazards model demonstrated the independent prognostic significance of a short interval from EBV-HLH diagnosis to etoposide administration (relative risk of death for patients lacking this feature, 14.1; 95% confidence interval, 1.16 to 166.7; P =.04). None of the competing variables analyzed had significant predictive strength in the Cox model. However, concomitant use of CSA with etoposide in a subset of patients appears to have prevented serious complications from neutropenia during the first year of treatment. CONCLUSION: We conclude that early administration of etoposide, preferably with CSA, is the treatment of choice for patients with EBV-HLH.

Numerous nonclonal chromosomal aberrations arising in residual recipient hematopoietic cells following allogeneic bone marrow transplantation.

A young female patient in a second remission of acute lymphoblastic leukemia underwent bone marrow transplantation after total body irradiation and high-dose cytarabine from her HLA-matched brother. Following successful engraftment, mixed chimerism was seen 75 days post transplant. The karyotype contained numerous abnormalities in residual recipient cells. Chromosomes 1, 7, 13, and X were significantly more affected than other chromosomes. The high-frequency breakpoints identified were 1p22.2, 5q31.2, and 13q14.2. Some karyotypes specific for leukemia, such as t(9;22)(q34.1;q11.2) and t(8;21)(q22.2;q22.2), not seen with the original disease, were also present. As the frequency of aberrant chromosomes increased markedly with time, donor leukocytes were infused 14 months after BMT, which effectively eradicated the abnormal karyotypes.

A novel infant acute lymphoblastic leukemia cell line with MLL-AF5q31 fusion transcript.

Infant acute lymphoblastic leukemia (ALL) is characterized by the presence of the proB phenotype (CD10(-)/CD19(+)), poor prognosis and frequent rearrangement of the mixed lineage leukemia (MLL) gene. The most frequent rearrangement is t(4;11)(q21;q23), the role of whose product, the MLL-AF4 fusion transcript, has been extensively studied in leukemogenesis. In a cell line of infant leukemia with MLL rearrangement denoted KP-L-RY, panhandle PCR amplification of cDNA revealed the presence of a fusion transcript, MLL-AF5q31, indicating that AF5q31 is also a partner gene of MLL. In this fusion transcript the MLL exon 6 is fused in frame to the 5' side of the putative transactivation domain of AF5q31. The AF5q31 protein is a member of the AF4/LAF4/FMR2-related family of proteins, which have been suggested to play a role in hematopoietic cell growth and differentiation. The MLL-AF5q31 fusion transcript, although probably rare, appears to be associated with the pathogenesis of infant ALL like MLL-AF4. Co-expression of HoxA9 and Meis1 genes in the KP-L-RY cell line indicated possible functional similarity between MLL-AF4 and MLL-AF5q31. Further understanding of the function of AF5q31 as well as the specific leukemogenic mechanism of MLL-AF5q31 awaits future studies.

Myelodysplastic syndrome in childhood: a retrospective study of 189 patients in Japan.

We report a retrospective analysis of children with myelodysplastic syndrome (MDS) diagnosed between 1990 and 1997 in Japan. In total, 189 patients were enrolled: 122 cases of primary MDS (26 RA, 18 RAEB, 25 RAEBt, 53 CMML/JMML), 24 cases with constitutional predisposition to MDS, and 43 cases of therapy-related MDS (t-MDS). The frequency of pediatric MDS was estimated to be 7.7% of all leukemias. Cytogenetic abnormalities were observed in 41% of primary MDS and 90% of t-MDS cases. The 4-year survival rate, estimated by Kaplan-Meier analysis, for primary RA was 78.9%, while other types of MDS and JMML had rates lower than 40%, and t-MDS showed an even more unfavorable prognosis. In primary MDS, the survival rate of patients with cytogenetic abnormalities was significantly lower. Among prognostic variables by IPSS, only the cytogenetic pattern was useful for predicting outcome in childhood MDS. There was no apparent advantage to chemotherapy for RA, and the survival rate in patients with primary RA, JMML, or t-MDS receiving stem cell transplantation was significantly higher. More precise designs of our diagnostic and classification systems, as well as therapeutic trials in large-scale prospective studies, are necessary for further improvements in MDS outcome.

Syntheses and structure-activity relationships of 5,6,7, 8-tetrahydro-5,5,8,8-tetramethyl-2-quinoxaline derivatives with retinoic acid receptor alpha agonistic activity.

In the course of our studies on retinoic acid receptor (RAR) agonists, we have designed and synthesized a series of quinoxaline derivatives. One of them, 4-[5-(5,6,7,8-tetrahydro-5,5,8, 8-tetramethyl-2-quinoxalinyl)-1H-2-pyrrolyl]benzoic acid (3a), which possesses a 2,5-disubstituted pyrrole moiety, showed selectivity for the RARalpha receptor and exerted highly potent cell-differentiating activity on HL-60 cells.

Syntheses and structure-activity relationships of novel retinoid X receptor agonists.

As part of our studies to develop novel retinoids with increased affinity and selectivity for the retinoid X receptor (RXR) subfamily, we have designed and synthesized a series of (E,E,E)-7-(1,2,3, 4-tetrahydroquinolin-6-yl)-7-alkyl-6-fluoro-3-methylhepta-2, 4, 6-trienoic acid derivatives. These tetrahydroquinolines, generated by introducing a polar N atom into the hydrophobic part of the retinoid skeleton, showed high binding affinity to RXRs. Addition of fluorine at the 6-position of the 2,4,6-trienoic acid moiety afforded compounds which elicit potent and selective transactivation of the RXRs. Compound 14b (ER-35794), which possesses an ethyl substituent at the 7-position and fluorine at the 6-position of the triene moiety, is one of the most potent and selective RXR agonists reported to date.

A novel orally active inhibitor of IL-1 generation: synthesis and structure-activity relationships of 3-(4-hydroxy-1-naphthalenyl)-2-propenoic acid derivatives.

A new series of 3-(4-hydroxy-1-naphthalenyl)-2-propenoic acids was prepared and the inhibitory activities of its members on IL-1 generation were evaluated both by in vitro systems using human monocytes and/or rat exudated macrophages stimulated with LPS, and by an in vivo system using the rat CMC-LPS air-pouch model. Many compounds in this series were found to be potent inhibitors of IL-1 generation both in vitro and in vivo. Structure-activity relationships indicated that in the rat CMC-LPS air-pouch model by oral administration the (Z)-2-substituted propenoic acids with 3-alkoxy, 5-alkyl, and 4-hydroxy substituents on the naphthalene ring exhibit optimal inhibition. Among the compounds evaluated, (Z)-3-(5-ethyl-4-hydroxy-3-methoxy-1-naphthalenyl)-2-methyl-2-propeno ic acid (20a), which inhibited IL-1 generation from human monocytes with an IC50 value of 3.0 microM and had an IC50 value of 1.4 microM for rat exudated macrophages, showed the most potent inhibitory activity in the rat CMC-LPS model by oral administration. Compound 20a also showed antiinflammatory effects in animal models of inflammation.

A novel type of retinoic acid receptor antagonist: synthesis and structure-activity relationships of heterocyclic ring-containing benzoic acid derivatives.

A new series of heterocyclic ring-containing benzoic acids was prepared, and the binding affinity and antagonism of its members against all-trans-retinoic acid were evaluated by in vitro assay systems using human promyelocytic leukemia (HL-60) cells. Structure-activity relationships indicated that both an N-substituted pyrrole or pyrazole (1-position) and a hydrophobic region, with these linked by a ring system, were indispensable for effective antagonism. Among the compounds evaluated, optimal antagonism was exhibited by 4-[4,5,7,8,9,10-hexahydro-7,7,10,-10-tetramethyl-1-(3- pyridylmethyl)anthra[1,2-b]pyrrol-3-yl]benzoic acid (31), 4-[4,5,7,8,9,10-hexahydro-7,7,10,10-tetramethyl-1-(3-pyridylmethyl)-5- thiaanthral[1,2-b]pyrrol-3-yl]benzoic acid (40), and 4-[4,5,7,8,9,10-hexahydro-7,7,10,10-tetramethyl-1-(3- pyridylmethyl)anthra[2,1-d]pyrazol-3-yl]benzoic acid (55), all of which possess a 3-pyridylmethyl group at the five-membered ring nitrogen atom.

Novel dual inhibitors of 5-lipoxygenase and thromboxane A2 synthetase: synthesis and structure-activity relationships of 3-pyridylmethyl-substituted 2-amino-6-hydroxybenzothiazole derivatives.

As part of our search for novel antiinflammatory drug candidates, we have designed and synthesized a series of 3-pyridylmethyl-substituted 2-amino-6- hydroxybenzothiazoles. Introduction of a 3-pyridylmethyl group into the 2-amino group (type-A) or the benzene ring (type-B) of 2-amino-6-hydroxybenzothiazoles imparted dual inhibitory activity against the production by glycogen-induced peritoneal cells of rat (in vitro) of leukotriene B4 (LTB4) and thromboxane A2 (TXA2), while not significantly inhibiting that of prostaglandin E2 (PGE2). The observed inhibition of the former two arachidonic acid metabolites was indicated to be the result of a direct action on 5-lipoxygenase and TXA2 synthetase by a cell-free in vitro assay. On the other hand, the inhibitory activities against PGE2 production were for most compounds very weak, indicating that they did not inhibit cyclooxygenase. Structure-activity relationship studies concerning the position of the 3-pyridylmethyl group revealed that type-B compounds generally showed about 10-fold stronger inhibitory activity against TXA2 synthetase than type-A compounds. The position of the 3-pyridylmethyl group played an important role in TXA2 synthetase inhibition. When some of these compounds (8, 13a, 26a (E3040), 26b, 27b, and 28b) were orally administered in the rat TNB/ethanol-induced chronic colitis model (100 mg/kg), the production of both LTB4 and TXB2 in the rat colon was reduced (ex vivo). In addition, one type-B compound, 6-hydroxy-5,7-dimethyl-2-(methylamino)-4-(3-pyridylmethyl)benzothiazole (26a), demonstrated a therapeutic effect at treatments of 100 mg/kg po once daily for 11 days and showed almost comparable activity to sulfasalazine at a dose of 500 mg/kg, the reference drug for inflammatory bowel diseases, in this in vivo model.

Structure-activity relationships of (E)-3-(1,4-benzoquinonyl)-2-[(3-pyridyl)-alkyl]-2-propenoic acid derivatives that inhibit both 5-lipoxygenase and thromboxane A2 synthetase.

As part of our research for the development of novel antiinflammatory drug candidates, we have designed and synthesized a series of (E)-3-(1,4-benzoquinonyl)-2-[(3-pyridyl)alkyl]-2-propenoic acid derivatives as dual inhibitors of 5-lipoxygenase (5-LO) and thromboxane (TX) A2 synthetase. In order to increase the absorption after oral administration, we introduced a carboxylic acid moiety into the 1,4-benzoquinone skeleton, which has 5-LO-inhibitory character. Introduction of a 3-pyridylalkyl group at the double bond of the 1,4-benzoquinonyl propenoic acid moiety afforded good to moderate inhibitory activities against the production of leukotriene (LT) B4 and TXA2 while not significantly inhibiting that of prostaglandin E2 by glycogen-induced peritoneal cells of rat (in vitro). The length of the methylene chain of the 3-pyridylalkyl group influenced the inhibition of LTB4 and TXB2 production. An increase of lipophilicity by introducing a more lipophilic alkoxy group did not markedly increase the inhibitory activity on LTB4 production. The position of alkoxy group on the 1,4-benzoquinone skeleton played an important role in TXA2 synthetase inhibition. Compounds such as 20c (E6700) with an appropriate alkoxy group and proper length of methylene side chain, together with a polar substituent (carboxylic acid), showed good inhibition of both 5-LO and TXA2 synthetase and possess a variety of pharmacologically beneficial effects.

Discovery of novel and potent retinoic acid receptor alpha agonists: syntheses and evaluation of benzofuranyl-pyrrole and benzothiophenyl-pyrrole derivatives.

In the course of our studies on retinoic acid receptor (RAR) agonists, we have designed and synthesized a series of benzofuran and benzothiophene derivatives. Some of these compounds (1a,b,e,f,j) markedly inhibited LPS-induced B-lymphocyte proliferation and exerted RARalpha selectivity. One of them, 4-[5-(4,7-dimethylbenzofuran-2-yl)pyrrol-2-yl]benzoic acid (1b), when orally administered significantly inhibited mouse antibody production and delayed type hypersensitivity (DTH) responses from a dose of 0.1 mg/kg.

Thymic localization of gallium-67 in pediatric patients with lymphoid and nonlymphoid tumors.

To determine the significance of 67Ga localization in the thymus of children, 142 67Ga photoscans from 45 children with various tumors were studied. Sixty-nine photoscans were taken for 17 cases of lymphoma, 73 photoscans were made for 28 cases of nonlymphoid tumors. Thymic localization of 67Ga was positive in 16 (36%) of the 45 patients and in 30 (21%) of the 142 photoscans. Positive thymus scans were seen in five (29%) of the 17 cases of lymphoma and 11 (39%) of the 28 solid tumors. The positive incidence was highest (90%) in ages 1-2 yr old. Of the eight grade 2 (strong positive) patients, the thymus in one case of Hodgkin's disease was diagnosed as malignant and the other seven solid tumor cases were nonmalignant. Most of the latter seven cases became positive after beginning of treatment (surgery and/or chemotherapy). Although the precise mechanism is not well understood, thymic localization of 67Ga may represent immunologic response to tumors, especially in infants with nonlymphoid neoplasms.

Malignant histiocytosis in childhood: clinical, cytochemical, and immunohistochemical studies of seven cases.

Tissue specimens obtained at autopsy from seven childhood cases of malignant histiocytosis were studied by immunohistochemistry. Clinically, the majority of the cases showed sustained fever, hepatosplenomegaly, pancytopenia, and DIC. The pretreatment diagnosis was based on their typical clinical manifestations and bone marrow smear findings. Although three patients temporarily responded to exchange transfusion and chemotherapy, all seven patients eventually died of active disease. Postmortem examination revealed the proliferation of atypical histiocytes appearing in variable degrees of maturation in the lymph nodes, liver, spleen, bone marrow, lungs, and central nervous system. Immunohistochemical staining for lysozyme, nonspecific cross-reacting antigen (NCA), alpha 1-antitrypsin (alpha 1 AT), alpha and beta subunits of S100 protein (S100 alpha, beta), and concanavalin A receptors (ConAR) in cytoplasm demonstrated the presence of two subtypes of malignant histiocytes, ie, S100 beta+/NCA-/ConAR+ (4 cases) and S100 beta-/NCA+/ConA R+ (three cases). The results of lysozyme, alpha 1 AT, and S100 alpha staining were inconsistent. A survey of the literature disclosed that the incidence of S100 protein-positive cases in children was higher than in adults (12/21 v 5/19; chi 2, P less than .05). Further large scale investigation is necessary to confirm the independence and significance of these two subtypes of histiocytes in malignant histiocytosis.

FK506-induced intractable leukoencephalopathy following allogeneic bone marrow transplantation.

FK506-related leukoencephalopathy has been reported to be reversible and readily treated by discontinuation or reduction of FK506. We describe two pediatric cases of FK506-related leukoencephalopathy following allogeneic bone marrow transplantation, which could not be readily controlled. These cases show that FK506-related leukoencephalopathy is not always reversible, and patients may develop epilepsy. Bone Marrow Transplantation (2000) 25, 331-334.

Unsuccessful CTL transfusion in a case of post-BMT Epstein-Barr virus-associated lymphoproliferative disorder (EBV-LPD).

A patient with AML (FAB M4Eo) developed EBV-LPD 1.5 months after allogeneic BMT from his one locus-mismatched mother, the diagnosis being confirmed on day +82. Attempts to eradicate the monoclonally proliferating LPD using chemotherapy (VP16/dexamethasone) followed by two doses of EBV-specific CTL and one dose of unstimulated donor leukocytes were not successful. We assume delay of infusions (day +100, +107) and insufficient CTL cell doses (total 9.2 x 10(6)) may have been responsible for the poor outcome in this case.

Successful allogeneic bone marrow transplantation in a case with myelodysplastic syndrome which developed following Fanconi anemia.

We report the case of a 14-year-old boy with myelodysplastic syndrome (MDS/RAEB) which developed following Fanconi anemia. The patient received BMT from an HLA-identical sister. Based on the in vitro CY-sensitivity test, 100 mg/kg of CY was administered for conditioning combined with 6 Gy TBI. Mucosal symptoms such as stomatitis, diarrhea and hematuria were severe, but manageable, and engraftment was successful. The patient has maintained normal trilineage hematopoiesis with > 90% Karnofsky score for 30 months with disappearance of a clonal chromosomal abnormality (47,XY, +i(lq)) which was detected before BMT.

Chimerism analysis on mononuclear cells in the CSF after allogeneic bone marrow transplantation.

To evaluate the chimeric status of mononuclear cells in the CSF after allogeneic BMT, cells were analyzed by FISH using satellite DNA probes for human X and Y chromosomes. CSF cells were obtained from five pediatric ALL patients who received BMT from sex-mismatched donors. All patients received TBI-containing conditioning regimens. We found that CSF cells showed complete donor type in 19-97 days after BMT, when complete donor type hematopoiesis was observed. The rapid entry of the donor leukocytes into the brain may exert beneficial effects to eradicate the residual CNS leukemic cells and prevent a CNS relapse in ALL patients after BMT.