Showing papers by "St. Jude Children's Research Hospital published in 1989"

Avian-to-human transmission of the PB1 gene of influenza A viruses in the 1957 and 1968 pandemics.

Abstract: We determined the origin and evolutionary pathways of the PB1 genes of influenza A viruses responsible for the 1957 and 1968 human pandemics and obtained information on the variable or conserved region of the PB1 protein. The evolutionary tree constructed from nucleotide sequences suggested the following: (i) the PB1 gene of the 1957 human pandemic strain, A/Singapore/1/57 (H2N2), was probably introduced from avian species and was maintained in humans until 1968; (ii) in the 1968 pandemic strain, A/NT/60/68 (H3N2), the PB1 gene was not derived from the previously circulating virus in humans but probably from another avian virus; and (iii) a current human H3N2 virus inherited the PB1 gene from an A/NT/60/68-like virus. Nucleotide sequence analysis also showed that the avian PB1 gene was introduced into pigs. Hence, transmission of the PB1 gene from avian to mammalian species is a relatively frequent event. Comparative analysis of deduced amino acid sequences disclosed highly conserved regions in PB1 proteins, which may be key structures required for PB1 activities.

Purification and complementary DNA cloning of a receptor for basic fibroblast growth factor

Abstract: Basic fibroblast growth factor (bFGF) participates in many processes including early developmental events, angiogenesis, wound healing, and maintenance of neuronal cell viability. A 130-kilodalton protein was isolated on the basis of its ability to specifically bind to bFGF. A complementary DNA clone was isolated with an oligonucleotide probe corresponding to determined amino acid sequences of tryptic peptide fragments of the purified protein. The putative bFGF receptor encoded by this complementary DNA is a transmembrane protein that contains three extracellular immunoglobulin-like domains, an unusual acidic region, and an intracellular tyrosine kinase domain. These domains are arranged in a pattern that is different from that of any growth factor receptor described.

Human myeloid plasma membrane glycoprotein CD13 (gp150) is identical to aminopeptidase N.

Abstract: To determine the primary structure of CD13, a 150-kD cell surface glycoprotein originally identified on subsets of normal and malignant human myeloid cells, we isolated the complete sequences encoding the polypeptide in overlapping complementary DNA (cDNA) clones. The authenticity of our cDNA clones was demonstrated by the ability of the coding sequences, subcloned in a retroviral expression vector, to mediate expression of bona fide CD13 molecules at the surface of transfected mouse fibroblasts. The nucleotide sequence predicts a 967 amino acid integral membrane protein with a single, 24 amino acid hydrophobic segment near the amino terminus. Amino-terminal protein sequence analysis of CD13 molecules indicated that the hydrophobic segment is not cleaved, but rather serves as both a signal for membrane insertion and as a stable membrane-spanning segment. The remainder of the molecule consists of a large extracellular carboxyterminal domain, which contains a pentapeptide consensus sequence characteristic of members of the zinc-binding metalloprotease superfamily. Sequence comparisons with known enzymes of this class revealed that CD13 is identical to aminopeptidase N, a membrane-bound glycoprotein thought to be involved in the metabolism of regulatory peptides by diverse cell types, including small intestinal and renal tubular epithelial cells, macrophages, granulocytes, and synaptic membranes prepared from cells of the central nervous system.

Secondary acute myeloid leukemia in children treated for acute lymphoid leukemia.

Abstract: We studied the risk of the development of acute myeloid leukemia (AML) during initial remission in 733 consecutive children with acute lymphoid leukemia (ALL) who were treated with intensive chemotherapy. This complication was identified according to standard morphologic and cytochemical criteria in 13 patients 1.2 to 6 years (median, 3.0) after the diagnosis of ALL. At three years of follow-up, the cumulative risk of secondary AML during the first bone marrow remission was 1.6 percent (95 percent confidence limits, 0.7 and 3.5 percent); at six years, it was 4.7 percent (2 and 10 percent). The development of secondary AML was much more likely among patients with a T-cell than a non-T-cell immunophenotype (cumulative risk, 19.1 percent [6 and 47 percent] at six years). Sequential cytogenetic studies in 10 patients revealed entirely different karyotypes in 9, suggesting the induction of a second neoplasm. In eight of these patients, the blast cells had abnormalities of the 11 q23 chromosomal region...

Amplification of the gli Gene in Childhood Sarcomas

Abstract: The gli gene, originally identified by its amplified copy number in cells from a human malignant glioma, has a predicted translation product that contains five tandem DNA-binding zinc finger motifs related to those of Kruppel , a developmentally important Drosophila segmentation gene. Because of the potential importance of overproduction of this protein in neoplastic development, we examined DNAs from 29 cases of childhood sarcoma for evidence of amplification of the gli gene. In one of the 13 rhabdomyosarcomas studied, genomic DNA restriction fragments containing the gli gene were amplified approximately 30-fold, and expression of the 4.0-kilobase gli mRNA transcript was identified. The tumor with gli gene amplification lacked the usual histological features of alveolar or embryonal rhabdomyosarcoma; however, ultrastructural analysis of tumor cells established in culture revealed attenuated sarcomeres, resembling those found in primitive rhabdomyoblasts. Cytogenetic analysis of this cell line disclosed double-minute chromatin bodies, with no apparent rearrangements in the region of the gli locus on the long arm of chromosome 12, bands q13 to q14.3. A 15-fold level of gli amplification and gli mRNA transcripts were also detected in an established cell line from a patient with a rare form of osteosarcoma characterized by multipotential histological features. A similar level of gli gene amplification was observed in cryopreserved primary tumor cells from this patient, confirming that gene amplification took place during tumor development and not during in vitro cell culture. Amplified gli sequences were cytogenetically localized by in situ hybridization to a homogeneously staining region contained on a derivative chromosome 7. Of eight osteosarcomas and seven Ewing's sarcomas with typical histopathological features, none had detectable rearrangements or amplification of gli sequences. Thus, gli gene amplification in childhood sarcomas appears restricted to tumors with primitive histopathological features, perhaps reflecting overproduction of a gene product able to influence gene expression during early mesenchymal cell development.

Social competence and behavioral adjustment of children who are long-term survivors of cancer.

Abstract: Relatively little is known about the special needs of long-term survivors of childhood cancer or the factors that make this growing population vulnerable to chronic psychologic disorders. We therefore surveyed 183 children who had been treated for cancer at St Jude Children's Research Hospital and were free of the disease for greater than or equal to 2 years after completing therapy. Parental responses to the Child Behavior Checklist, a standardized inventory of social competence and behavioral problems, were analyzed in relation to demographic and medical variables, as well as the children's appearance and functional status. School-related problems and somatic complaints of undetermined origin were increased fourfold relative to age- and gender-adjusted rates for peer groups in the general population. The presence of functional but not cosmetic impairments increased the risk of academic and adjustment problems. An older age at evaluation, treatment with cranial irradiation, and residence in a single-parent household were also associated with an increased risk of psychologic problems. General pediatricians must eventually assume responsibility for the extended follow-up care of children who have survived a malignancy. Their awareness of the high-risk groups described in this report should facilitate more timely identification of problems and referral of the children to appropriate services.

Ligand and protein kinase C downmodulate the colony-stimulating factor 1 receptor by independent mechanisms.

Abstract: The turnover of the colony-stimulating factor 1 receptor (CSF-1R), the c-fms proto-oncogene product, is accelerated by ligand binding or by activators of protein kinase C (PKC), such as the phorbol ester 12-O-tetradecanoylphorbol-13-acetate (TPA). The mechanisms of ligand- and TPA-induced downmodulation were shown to differ by the following criteria. First, in cells in which PKC was downmodulated, CSF-1R reexpressed at the cell surface remained sensitive to ligand but was refractory to TPA-induced degradation. Second, a kinase-defective receptor containing a methionine-for-lysine substitution at amino acid 616 at its ATP-binding site failed to undergo ligand-induced downmodulation but remained responsive to TPA. Following CSF-1 stimulation, no intermediates of receptor degradation could be immunoprecipitated with polyvalent antisera to CSF-1R. In contrast, TPA induced specific proteolytic cleavage of the receptor near its transmembrane segment, resulting in the release of the extracellular ligand-binding domain from the cell and the generation of an intracellular fragment containing the kinase domain. Two-dimensional phosphopeptide mapping demonstrated no new sites of phosphorylation in response to TPA in either the residual intact receptor or the intracellular proteolytic fragment. Therefore, PKC appears not to trigger downmodulation by directly phosphorylating the receptor but, rather, activates a protease which recognizes CSF-1R as a substrate.

Non-Hodgkin's lymphomas of childhood: an analysis of the histology, staging, and response to treatment of 338 cases at a single institution.

Abstract: Between 1962 and 1986, a total of 338 consecutive newly diagnosed children and adolescents with non-Hodgkin's lymphomas (NHLs) were evaluated and treated at St Jude Children's Research Hospital (SJCRH). Median follow-up is 6.6 years (range, 1.8 to 23 years). The patients ranged in age from 7 months to 21 years (median, 10 years), and 71% were males. All cases were staged (I to IV) by a clinical staging system. Eighteen percent were stage I, 21% stage II, 43% stage III, and 18% stage IV. Cases frankly leukemic at diagnosis (ie, greater than 25% marrow blasts) were excluded from the analysis. Pathologic material from all cases was reviewed and classified according to the Working Formulation. The histologic distribution of cases was as follows: 38.8% diffuse small non-cleaved cell (undifferentiated, Burkitt's and non-Burkitt's); 26.3% diffuse large-cell, mainly immunoblastic; 28.1% lymphoblastic; and 6.8% other. Treatment policy evolved over time to a stage- and histology-specific strategy for treatment assi...

Hearing loss in children and young adults receiving cisplatin with or without prior cranial irradiation.

Abstract: One hundred seventy-seven children and young adults with various malignant neoplasms were prospectively tested for hearing loss after they had received cisplatin (n = 146), cranial irradiation (n = 18), or both (n = 13). Adequate renal function, no history of treatment with ototoxic drugs other than cisplatin, and availability for repeated audiometric testing were requirements for enrollment. Substantial hearing loss, defined as a hearing threshold of 50 dB or greater, was noted in only 11% of the cohort on tests conducted at the common speech frequencies (500 to 3,000 Hz). About half the patients had substantial deficits at higher frequencies (4,000 to 8,000 Hz). The probability of substantial hearing loss was directly related to the cumulative dose of cisplatin. In nonirradiated patients tested at the speech frequencies, there was a negligible risk of substantial deficits over the dose range of 90 to 360 mg/m2. As the dose increased to 720 mg/m2, the risk increased to 22%. In irradiated patients who later received cisplatin, cumulative drug doses as low as 270 mg/m2 were associated with a high probability of substantial hearing loss, suggesting potentiation of ototoxicity when these therapies are used together. Hearing acuity was either not affected or only minimally decreased in the irradiation-only group. Younger age, prior irradiation, and the presence of a CNS tumor each contributed significantly to the severity of hearing deficits at given cisplatin dose levels. We conclude that early increases in hearing threshold at a stimulus frequency of 4,000 Hz indicate probable subsequent deficits at lower frequencies, especially in young children with CNS tumors who have received cranial irradiation. The probability charts derived from this analysis should provide a useful tool for predicting hearing loss in the speech frequencies.

Molecular differential pathology of rhabdomyosarcoma

Abstract: Tumors of the soft tissues are classified histogenetically according to their phenotypic resemblance to normal adult tissue. Here we describe molecular approaches that make it possible to distinguish between one class of these tumors, rhabdomyosarcoma, and other small-, round-cell tumors. We show that the ascertainment of specific genotypic changes can be used to distinguish further between the embryonal and alveolar subtypes of rhabdomyosarcoma. We tested our model in two ways: first, in a retrospective analysis of diagnostically problematic cases of undifferentiated, small-cell tumors and, second, in a blind study of pediatric tumors. Rhabdomyosarcoma was correctly identified in all cases using this strategy alone. The underlying simplicity of the strategy used to define rhabdomyosarcoma subtypes with molecular markers suggests a model by which tumors can be unequivocally identified, which may apply equally well to other human solid tumors.

Phosphorylation of 2',3'-dideoxyinosine by cytosolic 5'-nucleotidase of human lymphoid cells.

Abstract: 29,39-Dideoxyinosine (ddlno) is a potent and selective inhibitor of human immunodeficiency virus in human lymphoid cells and monocytes/macrophages. Earlier studies [J. Biol. Chem. 263:15354 (1988)] showed that anabolism of ddlno in human lymphoid cells is mediated via an initial step of phosphorylation and subsequent amination to dideoxy-AMP via adenylosuccinate synthetase/lyase. Evidence was obtained that neither adenosine kinase nor deoxycytidine kinase is involved in the phosphorylation of this compound in human lymphoid cells. We now find that, in the presence of MgCl2, KCl, and inosine-59-monophosphate as phosphate donor, purified cytosolic 59-nucleotidase catalyzed the phosphorylation of ddlno. Although not phosphate donors, ATP, diadenosine tetraphosphate, and glycerate-2,3-bisphosphate stimulate this phosphorylation by the nucleotidase 4-5-fold. In addition to ddlno, the antiviral nucleoside analogs 29,39-dideoxyguanosine and carbovir were substrates for this enzyme. The relative phosphorylation of these compounds varied with the concentration of the phosphate donor IMP. Approximate Km values of the nucleotidase for inosine, ddlno, dideoxyguanosine, and carbovir were, respectively, 3.4, 0.5, 0.9, and 1.7 mM. Although the substrate activity of dideoxynucleosides is inefficient, it appears likely that this nucleotidase is responsible for the metabolism of these compounds to their active nucleotides, yielding antiviral activity in human lymphoid cells.

Therapy for localized Ewing's sarcoma of bone

Abstract: Fifty-two previously untreated patients with localized Ewing's sarcoma of bone were treated with nonintensive chemotherapy in combination with surgery or radiation therapy (RT). RT was delivered to limited volumes in a dose dependent on the initial response to induction chemotherapy (30 to 35 Gy v 50 to 55 Gy). Fifty of the 52 patients achieved complete or partial responses with induction chemotherapy, with one nonresponding patient rendered free of tumor with surgery. Fifty patients were evaluable for local control of tumor and overall response to protocol therapy. Seventeen relapses have occurred; three metastatic, four local plus metastatic, and ten local. Two factors predicted worse disease-free survival: high WBC count (P = .03) and size of primary tumor (P = .05). Of the 14 local recurrences, 12 occurred in 28 patients who presented with primary tumors greater than 8 cm in size while only two of 22 patients with lesions less than 8 cm had local recurrence. The Kaplan-Meier estimate of disease-free survival at 3 years is 82% for those with small lesions and 64% for those with larger lesions. Site of primary was of no prognostic value (P = .27). The 5-year survival estimate for all patients is 80% (median time on study, 3.3 years).

Peripheral primitive neuroectodermal tumor (peripheral neuroepithelioma) in children. A review of the St. Jude experience and controversies in diagnosis and management.

Abstract: All patients diagnosed with primitive neuroectodermal tumor (PNET) and extraosseous Ewing's sarcoma in one institution between 1962 and 1987 were reviewed. Of the 26 cases studied, 16 had been diagnosed originally as PNETs, seven tumors were rediagnosed as PNET or EOE by histologic review, and three tumors had an original diagnosis of extraosseous Ewing's sarcoma. To determine whether these diagnoses determine a group of tumors with unique biologic behavior and identifiable pathologic characteristics, clinical and treatment response data were compiled, and electron microscopic and immunohistochemical studies were done for those patients with adequate samples. With combined modality therapy, this group achieved a substantially shorter disease control interval than patients with disseminated osseous Ewing's sarcoma or disseminated neuroblastoma--10.8 months versus 17 months and 16 months, respectively. The pattern of relapse and distant spread also differed among these tumor types. Immunohistochemical studies (for example, neuron-specific enolase and beta 2 microglobulin) were helpful in confirming the diagnosis but were not definitive in themselves. Tentative diagnostic criteria are proposed for use in studies designed to provide further information on the nature and treatment of PNET. Some of the controversies regarding diagnosis are discussed. The authors propose a uniform approach to treatment of extraosseous Ewing's sarcoma and PNET in order to try to clarify their relation.

Efficacy of Inactivated Influenza A Virus (H3N2) Vaccines Grown in Mammalian Cells or Embryonated Eggs

Abstract: Influenza virus (H3N2) host cell variants isolated from a single infected individual were compared for their protective efficacies when used as formalin-inactivated purified whole virus vaccines in ferrets. A/Mem/12/85 virus grown in embryonated chicken eggs (egg-grown), which differs from A/Mem/12/85 grown in mammalian Madin-Darby canine kidney cells (MDCK-grown) by a single amino acid substitution in the hemagglutinin molecule, was shown to be distinguishable by immune ferret serum. Ferrets were immunized intramuscularly with intact inactivated MDCK- or egg-grown virus and were subsequently challenged with infectious virus grown in either host cell type. MDCK-grown-virus vaccine induced higher mean serum hemagglutination-inhibiting (HAI) and neutralizing antibody titers than did egg-grown-virus vaccine and induced superior protection of ferrets against subsequent challenge with infectious virus grown in either host cell type. These results suggest that human influenza viruses that are antigenically and structurally similar to viruses grown in mammalian cells may be more efficacious as vaccines than some variants selected in eggs.

A Prospective Study of Hickman/Broviac Catheters and Implantable Ports in Pediatric Oncology Patients

Abstract: We prospectively studied the continuous function and complication rates of 286 central venous catheters consecutively placed in 264 children and young adults at a single institution over a 19-month period (median follow-up, 376 days). Externalized catheters (91 Hickman [H], 113 Broviac [B]) and implantable ports (n = 82) were compared for complications, including infection and thrombosis. The most frequent major complication of all catheters was infection, although the rates of infection varied with the duration of catheter use and were generally lower than reported by others. Overall, when catheter failures (removal) for infection, obstruction, or dislodgement were considered, ports had a significantly longer failure-free duration of use (P = .0024) than did externalized catheters. Likewise, ports had a significantly longer infection-free (P less than .01) duration of use than H and B catheters. However, differences in patient age and clinical characteristics among the three catheter groups may have affe...

Biologic potential of amantadine-resistant influenza A virus in an avian model.

Abstract: Amantadine has been accepted for both the treatment and prophylaxis of influenza A virus infections. Although amantadine-resistant mutants have been shown to be readily generated both in the laboratory and in children treated with rimantadine, little is known about their biologic properties, such as genetic stability, transmissibility, or pathogenicity, compared with the parental virus. This study examined these properties using an avian influenza virus, A/chicken/Pennsylvania/1370/83 (H5N2). Variants that were amantadine-resistant, virulent, and capable of competing with wild-type virus for transmission to susceptible hosts in the absence of the drug were selected. These amantadine-resistant variants were also genetically stable, showing no reversion to wild-type after six passages in birds over a period of greater than 20 d. Thus, these virus variants had no detectable biologic impairment. The mutations conferring drug resistance were in the M2 polypeptide and were identical to mutations previously described in human amantadine-resistant virus. These results suggest that resistant mutants may have the potential to threaten the effective use of amantadine and rimantadine for the control of epidemic influenza.

Phospholipase C-gamma, a substrate for PDGF receptor kinase, is not phosphorylated on tyrosine during the mitogenic response to CSF-1.

Abstract: Quiescent mouse NIH3T3 cells expressing a transduced human c-fms gene encoding the receptor for colony stimulating factor-1 (CSF-1) were stimulated with mitogenic concentrations of platelet-derived growth factor (PDGF) or CSF-1. Immunoprecipitated phospholipase C-gamma (PLC-gamma) was phosphorylated on tyrosine and calcium was mobilized following treatment of intact cells with PDGF. In contrast, only trace amounts of phosphotyrosine were incorporated into PLC-gamma and no intracellular calcium signal was detected after CSF-1 stimulation. Similarly, CSF-1 treatment did not stimulate phosphorylation of PLC-gamma on tyrosine in a CSF-1-dependent. SV40-immortalized mouse macrophage cell line that expresses high levels of the CSF-1 receptor. In fibroblasts, antiserum to PLC-gamma co-precipitated a fraction of the tyrosine phosphorylated form of the PDGF receptor (PDGF-R) after ligand stimulation, implying that phosphorylated PDGF-R and PLC-gamma were associated in a stable complex. Pre-treatment of cells with orthovanadate also led to tyrosine phosphorylation of PLC-gamma which was significantly enhanced by PDGF, but not by CSF-1. Thus, although the PDGF and CSF-1 receptors are structurally related and appear to be derived from a single ancestor gene, only PDGF-induced mitogenesis in fibroblasts correlated with tyrosine phosphorylation of PLC-gamma.

Mechanisms of inhibition of DNA synthesis by 2-chlorodeoxyadenosine in human lymphoblastic cells.

Abstract: 2-Chloro-2'-deoxyadenosine 5'-triphosphate (CldATP) is a strong inhibitor of the reduction of ADP, CDP, UDP and GDP by ribonucleotide reductase in extracts of CCRF-CEM with 50% inhibition at concentrations of 0.1 to 0.3 microM. In cells exposed to 0.3 microM 2-chloro-2'-deoxyadenosine (CldAdo), the intracellular concentration of CldATP reaches 2 microM within 15 min, and DNA synthesis by the cells is inhibited 90% within 30 min. At concentrations of extracellular CldAdo that inhibit DNA synthesis, there is also marked inhibition of intracellular conversion of cytidine to deoxycytidine nucleotides indicating significant intracellular inhibition of ribonucleotide reductase. Exposure of cells to 0.3 microM CldAdo decreases dCTP by 63% in 30 min, dATP and dTTP by 20% and dGTP by a smaller amount. Similar decreases in these pools occur when other inhibitors of ribonucleotide reductase are present at concentrations causing similar inhibition of DNA synthesis. Deoxycytidine treatment of cells inhibited by CldAdo restores dCTP and other pools, but restoration of DNA synthesis is incomplete, indicating that there is another mechanism for inhibition of DNA synthesis in addition to depletion of deoxyribonucleotide pools. This alternate mechanism is probably related to the incorporation of CldAdo into DNA that occurs despite a 25-times lower intracellular level of CldATP than dATP.

Neurotoxicity due to central nervous system therapy for childhood leukemia.

Abstract: Therapy for occult or overt meningeal leukemia produces subclinical or clinical neurotoxicity in a variable proportion of children with acute lymphoblastic leukemia (ALL). The type, frequency, and permanence of these central nervous system (CNS) changes depend primarily on the therapy itself, although the contribution of additional factors, such as young age, may be substantial. Neurotoxicity in patients who have received 2,400 cGy cranial irradiation plus 5 concurrent doses of intrathecal methotrexate as CNS prophylaxis has been characterized more fully than the CNS changes accompanying other forms of therapy. Cross-sectional studies using cranial computed tomography scans to evaluate structural changes in the brain have shown ventricular dilatation in 15%, white matter hypodensity in 3.5%, and calcifications in 8%. The principal neuroendocrine effect is decreased growth velocity during therapy and adolescence, with significant decreases in final height in approximately one-third of children. Secondary cerebral gliomas with a poor prognosis are being reported with increasing regularity, but the true risk of this complication is still unknown. Use of parenteral methotrexate as the sole method of CNS prophylaxis is associated with transient focal white matter hypodensity. Neuroendocrine and neuropsychologic sequelae associated with this therapy are minimal; however, much of the available information is based on patients treated with regimens that had unacceptably high CNS relapse rates or whose length of follow-up was brief. With more aggressive, and hence more effective, prophylaxis with intrathecal methotrexate, spinal cord myelopathy may become a significant new area of neurotoxicity. Clinically significant CNS toxicity develops in the majority of patients who receive treatment for meningeal relapse. The leukemia itself is a prime contributing factor to this neurotoxicity. In patients who are subsequently cured of leukemia, acute neurotoxicity consists mainly of seizures; the most significant sequelae appearing after the cessation of therapy consists of significant drops in full scale IQ.

Interplay between carbohydrate in the stalk and the length of the connecting peptide determines the cleavability of influenza virus hemagglutinin.

Abstract: The ability of many viruses to replicate in host cells depends on cleavage of certain viral glycoproteins, including hemagglutinin (HA). By generating site-specific mutant HAs of two highly virulent influenza viruses, we established that the relationship between carbohydrate in the stalk and the length of the connecting peptide is a critical determinant of cleavability. HAs that lacked an oligosaccharide side chain in the stalk were cleaved regardless of the number of basic amino acids at the cleavage site, whereas those with the oligosaccharide side chain resisted cleavage unless additional basic amino acids were inserted. This finding suggests that the oligosaccharide side chain interferes with HA cleavage if the number of basic amino acids at the cleavage site is not adequate to nullify this effect. Similar interplay could influence cleavage of other viral glycoproteins, such as those of human and simian immunodeficiency viruses and paramyxoviruses.