Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0023418 (leukemia)
 93,477 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Tartrate-resistant acid phosphatase (TRAcP) is a reliable cytochemical marker for the diagnosis of hairy cell leukemia (HCL). The enzyme has been the subject of much biochemical investigation yet its function in the hairy cells (HC) is still unknown. Two TRAcPs have been purified from HCL spleen tissues by a series of chromatographic separations. The two enzymes, provisionally called peak 1 and peak 2, had specific activities of greater than 600 U/mg and 800 U/mg respectively when p-nitrophenyl phosphate (p-NPP) was used as substrate and had Km values in the range of 1 to 5 mM p-NPP. The two TRAcPs had the same substrate specificities and inhibitor sensitivities, therefore could be isoforms of the same enzyme. Their pH optima were between 5 and 6 for all substrates tested including the phosphotyrosine-containing peptide, Raytide, which was still hydrolyzed efficiently at neutral pH. Neither phosphoserine nor phosphoserine-containing casein were hydrolyzed by either enzyme. The TRAcPs of HC may thus be capable of functioning as protein-tyrosine phosphatases (PTP). High activity of a PTP could regulate the activities of protein-tyrosine kinases and thereby influence the growth and differentiation of the hairy cells.
Leukemia 1992 Mar
PMID:Protein-tyrosine phosphatase activity of hairy cell tartrate-resistant acid phosphatase. 156 56

Treatment of an organism with UVB light or PUVA (8-methoxypsoralen + UVA light) not only leads to alterations in the irradiated skin but also to systemic immunomodulation, due to the release of several chemical mediators of immunosuppression like prostaglandins, acute-phase proteins, IL-1 inhibitor, alpha-melanocyte-stimulating hormone, propiomelanocorticotropin or other cytokines. A recently described mediator is urocanic acid, which is transformed by UV light in the skin from the trans- to the cis-isomer and that exerts a systemic immunomodulatory effect. In our experiments, treatment with PUVA or with cis-urocanic acid prevents the rejection of rat heart allografts in 50% and 40% of cases, respectively. Control grafts are rejected in fewer than 10 days. PUVA treatment of donor leukocytes before transfusion into the prospective recipient inhibits only their sensitizing, not their graft-protecting, effect on subsequent skin grafts in mice. PUVA treatment also prevents acute lethal GVH disease in mice after irradiation with a sublethal dose of x-rays and transfusion of semiallogeneic spleen cells. Treatment of recipient mice with cis-urocanic acid has the same effect. The humoral immune response to sheep erythrocytes is not influenced by cis-urocanic acid. These results demonstrate that PUVA treatment or its chemical mediator, cis-urocanic acid, may be used in transplantation and hematology as naturally occurring immunosuppressive agents, especially for the control and manipulation of GVH leukemia reaction.
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PMID:Cis-urocanic acid as a mediator of ultraviolet-light-induced immunosuppression. 159 41

Seven young cats were injected with feline leukemia virus (FeLV); six of them became viremic. All of the viremic cats developed AIDS-related symptoms, i.e. lymphopenia, neutropenia, thymic atrophy, and wasting syndrome, along with an altered pituitary and adrenocortical function. These symptoms closely resemble human AIDS induced by HIV. It was discovered that, after 2 weeks of infection, the average amount of plasma adrenocorticotropic hormone (ACTH) detected in the infected cats was reduced by 29% in comparison with that before the infection. In contrast to the second week, the fifth week of infection showed a 94% increase of plasma ACTH which then dropped back down to 38% after the sixth and seventh weeks. This opposing biphasic pattern of change was also observed in the plasma cortisol content of the infected cats. The amount of change in plasma cortisol did not correlate with the detected increase in plasma ACTH, indicating a weak adrenal response to pituitary action.
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PMID:Induction of feline immunodeficiency syndrome by feline leukemia virus: pituitary and adrenocortical dysfunctions. 196 24

An hypothesis of increased endorphinergic activity has been proposed to account for the characteristic symptoms of Rett syndrome. Cerebrospinal fluid samples from eight girls with Rett syndrome were analysed for beta-endorphin (beta-EP) immunoactivity and compared with samples from a control group of 15 children with acute leukaemia in remission. Severity of symptoms was not found to be related to beta-EP level. A group of early-treated adolescents with phenylketonuria had beta-EP levels similar to the Rett syndrome patients, but no symptoms resembling theirs. Therefore it is unlikely that increased levels of beta-EP are of primary pathogenetic significance. The conflicting findings of many earlier reports may be a result of differences between control groups.
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PMID:Cerebrospinal fluid beta-endorphin in Rett syndrome. 206 27

alpha-MSH fragments containing melphalan were tested in vivo on L1210 leukemia and on human amelanotic melanoma xenograft in mice and in vitro on human amelanotic melanoma cell lines. The compounds exhibit significant antitumor activity, but no selectivity in targeting of melanoma can be achieved. There is a difference between melphalan and the melphalyl-peptide in their action on protein synthesis. The peptide derivatives also are less mutagenic than melphalan, according to the SCE assay, furnishing further evidence for the positive effect of natural carrier molecules.
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PMID:Investigations on the antitumor effect and mutagenicity of alpha-MSH fragments containing melphalan. 217 55

We have found that preparations of rate-zonal purified Moloney murine leukemia virus originally obtained from the National Cancer Institute Resources Program, when separated by SDS-PAGE in the absence of mercaptoethanol (beta-MSH), exhibited a doublet envelope glycoprotein band of approximately 69/67 kD. When the same samples were run in the presence of beta-MSH, a single band at 70 kD (gp70) was observed. Western blot analysis with polyclonal antiserum identified both the 69- and 67-kD bands as envelope gene products. Tryptic peptide mapping of each of the gp67 and gp69 bands confirmed the serological data, with each showing conserved as well as unique peptides. These results imply that the Moloney murine leukemia virus samples examined above contain two structurally different envelope gene products. Western blot analysis using ecotropic and dualtropic specific sera suggest that gp69 is derived from an ecotropic virus, while gp67 is from a dualtropic virus. This is consistent with the results of an earlier study which showed that the majority of the cysteines (4/5) in dualtropic gp70 are lost by a single deletion relative to the ecotropic gp70 species. This would account for the difference in mobility observed in the SDS-PAGE profile in the absence of beta-MSH. It would indicate that the cysteines play an important role in defining structural differences that separate the ecotropic and dualtropic gp70s.
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PMID:Reduction-modifiable properties of Moloney murine leukemia virus gp70 as an indicator of envelope glycoprotein heterogeneity. 252 96

Neurological disorders, such as seizures, are not infrequently associated with anti-leukemic therapy. It has been hypothesized that a disrupted peptidergic transmission between neurons could be the cellular basis of the neurological dysfunction. Since endogenous opioids have been recently found to alter neuronal function and possess anticonvulsant properties, the cerebrospinal fluid (CSF) immunoreactive beta-endorphin levels in children with Acute Lymphoblastic Leukemia (ALL) during chemotherapy and cranial irradiation have been studied. Twenty-seven children, 2 at low, 20 at medium and 5 with high risk ALL, undergoing prophylactic treatment for meningeal leukemia, entered the study. Sequential lumbar punctures with introduction of MTX combined with oral prednisone therapy were performed; each lumbar puncture sample was collected and assayed for immunoreactive beta-endorphin. All the patients studied showed a biphasic profile of the peptide with the minimum levels reached during the induction (days 14-28) and the maximum levels detected at the end of the intensification chemotherapy (days 49-55). In the 3 groups the beta-endorphin decrease corresponded to the period of prednisone therapy; the increase was concomitant with the suspension of oral glucocorticoids. 3 patients showed tonic-clonic seizures which coincided with the lowest cerebrospinal fluid beta-endorphin levels and, in the follow-up, 13 out of 27 patients displayed EEG abnormalities. From these findings a relationship between cerebrospinal fluid beta-endorphin concentrations and neuronal excitability in patients with ALL can be suggested. It is also evidenced that oral glucocorticoid therapy has profound inhibitory effects on central beta-endorphin levels.
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PMID:Immunoreactive beta-endorphin levels in cerebrospinal fluid of children with acute lymphoblastic leukemia: relationship with glucocorticoid therapy and neurological complications. 253 Nov 80

SJL/J mice which developed a high incidence of spontaneous reticulum cell neoplasms, developed a low rate incidence (20-25%) of myeloid leukemia (ML) after X-irradiation. The possible effect of adrenal steroid imbalance to radiation-induced ML in SJL/J mice was tested. Intact and thymectomized animals were exposed to a single dose of 300 r whole body irradiation and treated with either hydrocortisone acetate, prednisone, metyrapone and adrenocorticotropin as coleukemogenic agents. Hydrocortisone and prednisone exerted a marked coleukemogenic effect, increasing the ML incidence to a similar rate of about 50-70%, at a mean latent period of 300 days. Prominent leukemic infiltration were observed in the bone marrow, spleen, lymph nodes and liver of the leukemic animals. Results of cytological and histological studies, including cytochemistry and ultrastructure, were all consistent with the diagnosis of acute myeloid leukemia (AML). Since AML is the type of human secondary leukemia which appears increasingly in patients treated with alkylating drugs and/or irradiation and corticosteroids for Hodgkin's disease or other neoplastic diseases, the experimental model of AML induced in SJL/J mice could be used for elucidation of mechanisms of leukemogenesis in secondary leukemia.
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PMID:High incidence of acute myeloid leukemia in SJL/J mice after X-irradiation and corticosteroids. 386 24

The antitumor action of the 2-chloroethylnitrosocarbamoyl derivatives of peptides related to the 9-13 amino acid residues of alpha-MSH/ACTH and of the C-terminal tetrapeptide analogue of gastrin have been investigated. Series of 2-chloroethylnitrosoureas attached to amino acids, di-, tri-, tetra-, or pentapeptides were examined in a primary screening system. Among these compounds the Pro-Val-, Lys-Pro-Val-, and Trp-Gly-Lys-Pro-Val-containing 2-chloroethylnitrosocarbamoyl groups were the most effective in the L1210 system. The human melanoma xenograft line was also affected by these agents, while colorectal xenografts were insensitive. A combination of tripeptide-2-chloroethyl-nitrosourea with BCNU induced more than additive growth inhibition of L1210 leukemia.
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PMID:Antitumor action of N-(2-chloroethyl)-N-nitrosocarbamoyl derivatives of biologically active polypeptide hormone fragments. 394 98

Gazdar-murine sarcoma virus (Gz-MSV) particles, obtained from tissue culture fluids of chronically infected HTG-2 hamster cells are immature in morphology and contain uncleaved Pr65gag as the predominant protein (greater than 95% Coomassie blue stain) (A. Pinter and E. deHarven, 1979, Virology 99, 103-110; Y. Yoshinaka and R. B. Luftig, 1982, Virology 118, 380-388). When Gz-MSV particles are disrupted in 1% sodium dodecyl sulfate (SDS) and then analyzed by SDS-polyacrylamide gel electrophoresis (PAGE) in the absence of reducing agents, such as beta-mercaptoethanol (beta-MSH) almost half of the Pr65gag Coomassie blue-stained band is detected as a band at a Mr of 130K. Electrophoretic blotting studies with monospecific antisera against MuLV p30, p15, p12, and p10 showed that the 130K band cross-reacted with all four antigens suggesting that it was a dimer of Pr65gag. Two-dimensional (2D) SDS-PAGE where the first dimension was run under nonreducing conditions and the second with beta-MSH, supported the contention that the 130K band was a dimeric complex of Pr65gag. One also saw minor amounts of a 260K and higher polymeric forms of Pr65gag on the SDS gels, suggesting that polymeric forms may exist as well. When 32P-labeled Gz-MSV particles obtained by in vivo labeling of infected HTG-2 cells with [32P]PPi were electrophoresed on SDS-PAGE, only 10% of the 32P label was detected at the 130K position. In contrast, 30% of the Coomassie blue-stained Pr65gag material was found at 130K on the 2D gels. This suggests that unphosphorylated Pr65gag is more likely to participate in dimer formation than phosphorylated Pr65gag. Pr65gag of Moloney murine leukemia virus (M-MuLV), which is present as a minor (5% of stain) protein band on SDS-PAGE also showed 130K dimers. Further, in beta-MSH-deficient SDS preparations of Gz-MSV, electrophoresed after trypsin treatment, a 32K band that stained with p15, but not p10, p12, nor p30, antisera was observed. If beta-MSH was added, this band was no longer present. Thus Pr65gag dimerization in immature MuLV particles appears to at least involve the p15 region of the polyprotein. Since p15 is an extremely hydrophobic protein, formation of Pr65gag dimers may occur when virion precursor proteins are brought to the cell membrane during virus assembly.
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PMID:Murine retrovirus Pr65gag forms a 130K dimer in the absence of disulfide reducing agents. 608 46


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