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)

The toxic effects of environmental factors at work places on the hematopoietic and immune systems are of basic importance due to the time of exposure, lasting on average 8 hours daily during one week. Porphyrinurias and porphyrias have been observed after exposure to hexachlorobenzene, chlorinated dibenzodioxins, polychlorinated biphenyls, polybrominated biphenyls, vinyl chloride and lead. Aplastic anemia may occur after exposure to benzene, pesticides, arsenic, cadmium and copper compounds. Megaloblastic anemia has been noted in subjects exposed to arsenic, chlordane, benzene and nitrous oxide. Methemoglobinemia is induced by aromatic nitro and amino compounds. Hemolytic reactions caused by arsenic, methyl chloride, naphthalene, lead, cadmium and mercury compounds represent a separate problem. Immunodeficiencies resulting in decreased antitumor and antiinfectious immunity have been reported in subjects exposed to asbestos, ozone, dimethylsulphoxide, vinilidene chloride, and benzene homologues. Lymphocytopenia may be induced by manganese, lead, toluene and industrial noise. Neutropenia was marked after exposure to carbon disulphide, arsenic compounds, benzene and electromagnetic fields. Only a few reports concern the lymphocyte T3, T4 and T8 subpopulations. Electromagnetic fields (microwaves) cause an imbalance of that subpopulation, consisting of a decrease in the T8 cell count. The neutrophil enzymes, such as myeloperoxidase and alkaline phosphatase, decrease in their activity after exposure to polychlorinated biphenyls, carbon disulphide, chlorobenzene and DDT. A majority of agents cited include genotoxic effects reflected in chromosome aberrations and increased sister chromatid exchange and abnormal unscheduled DNA synthesis. Leukemia or lymphoma risk is increased after exposure to pesticides, electromagnetic fields, benzene and irradiation.
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PMID:Immunotoxic and hematotoxic effects of occupational exposures. 817 62

Uracil derivatives bearing substituted or unsubstituted vinyl groups at position C6 and alkyl- or arylthio groups at position C5 were synthesized and tested in vitro for antiviral and antiproliferative activity. None of the compounds were active against HIV-1. However, some of them inhibited the proliferation of leukemia, lymphoma and solid tumor-derived cell lines at micromolar concentrations. The maximum potency of antiproliferative activity correlates with the presence of unsubstituted vinyl groups and alkyl- or arylthio substituents.
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PMID:Synthesis, antiviral and antiproliferative activity of a new class of 5-(alkyl or arylthio)-6-vinyl uracils. 902 48

A useful synthetic methodology was developed to synthesize and radiolabel a series of (E)-5-(2-[125I]iodovinyl)uracil nucleoside substrates for herpes simplex virus type-1 thymidine kinase (HSV-1 TK). (E)-5-(2-[125I]Iodovinyl)-2'-deoxyuridine ([125I]IVDU, 10), (E)-5-(2-[125I]iodovinyl)-2'-fluoro-2'-deoxyuridine ([125I]IVFRU, 11), (E)-5-(2-[125I]iodovinyl)-2'-fluoro-2'-deoxyarabinouridine ([125I]IVFAU, 12), and (E)-5-(2-[125I]iodovinyl)arabinouridine ([125I]IVAU, 13) were synthesized in 63-83% radiochemical yield by reaction of the unprotected (E)-5-(2-(trimethylsilyl)vinyl) precursors (6-9) with [125I]ICl. Cellular uptake of these labeled compounds (10-13) was evaluated in vitro. All compounds showed minimal uptake in the KBALB cell line. However, increased uptake was observed for all compounds in KBALB-STK cells which are transduced with a replication incompetent Moloney murine leukemia virus vector encoding the HSV-1 TK gene. The results indicate that uptake of these compounds in KBALB-STK cells is variable and highly dependent on the nature of the sugar 2'-substituent. When a fluoro (12) or a hydroxy (13) substituent is present in the arabinofuranosyl (up) configuration at the 2'-position, there is diminished cellular uptake in KBALB-STK cells relative to hydrogen (10) or fluorine (11) in the ribofuranosyl (down) configuration at the 2'-position. Our results indicate that radiolabeled IVFRU (11) is most promising for further in vivo studies.
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PMID:Synthesis and cellular uptake of 2'-substituted analogues of (E)-5-(2-[125I]iodovinyl)-2'-deoxyuridine in tumor cells transduced with the herpes simplex type-1 thymidine kinase gene. Evaluation as probes for monitoring gene therapy. 921 37

The mortality experience of a cohort of Italian plastic-ware workers exposed to radiofrequency (RF)-electromagnetic fields generated by dielectric heat sealers was investigated. Follow-up extended from 1962 to 1992. The standardised mortality ratio (SMR) analysis was restricted to 481 women workers, representing 78% of the total person-years at risk. Mortality from malignant neoplasms was slightly elevated, and increased risks of leukemia and accidents were detected. The all-cancer SMR was higher among women employed in the sealing department, where exposure to RF occurred, than in the whole cohort. This study raises interest in a possible association between exposure to RF radiation and cancer risk. However, the study power was very small, and the possible confounding effects of exposure to solvents and vinyl chloride monomer (VCM) could not be ruled out. The hypothesis of an increased risk of cancer after radiofrequency exposure should be further explored by means of analytical studies characterised by adequate power and more accurate exposure assessment.
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PMID:Mortality of plastic-ware workers exposed to radiofrequencies. 926 38

Hexadecylphosphocholine (HePC) is a new ether lipid analogue with remarkable antineoplastic activity in vitro and in vivo. As the precise molecular mechanism by which this substance and probably other ether lipids exert their biological effects is still not defined, we tried to approach this problem by generating a cell line resistant to the antiproliferative properties of HePC. This was successfully accomplished by slow adaptation over a period of 14 months, of the very sensitive human leukemia cell line HL60. HePC resistant HL60 cells (HL60R) tolerate 8- to 10-fold higher doses of HePC and are continuously cultured in medium containing 10 micrograms/ml of HePC. An immunophenotypic and karyotypic characterization of HL60 and HL60R cells showed only marginal differences between the two cell lines. Total phospholipids, total cholesterol, protein and vinyl ether lipid content were equal in both cells. A down-regulation of the ether lipid mass in HL60R of about 40% could reflect one mechanism of tolerance induction. Though HePC uptake in HL60R cells was significantly lower than in the parental line, steady state measurements of cellular HePC content revealed similar HePC content in the membranes at HePC concentrations that were cytotoxic for HL60 but did not affect HL60R. This observation indicates that uptake and cellular accumulation of HePC do not determine HePC resistance. The resistant HL60R cells also showed a considerable degree of cross-resistance to ether phospholipids ET-18-OCH3 and BM 41.440, suggesting a common mode of action for HePC and other ether lipid analogues.
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PMID:Induction of resistance in the human leukemia cell line HL60 towards hexadecylphosphocholine and other ether phospholipid analogues. 941 27

Epidemiologic evidence on the relation between reactive chemicals and cancer is reviewed. These highly reactive chemicals (acrylonitrile; bis[chloromethyl]ether and chloromethyl methyl ether; 1,3-butadiene, ethylene oxide; formaldehyde; mustard gas; sulfuric acid; and vinyl chloride) vary in use and exposure. All are animal carcinogens that also have received considerable epidemiologic attention. Acrylonitrile is a chemical of current economic importance. The epidemiologic evidence is quite weak, but the available studies were very small. Epidemiologic studies clearly demonstrate that bis (chloromethyl) ether and chloromethyl methyl ether cause lung cancer. Continued follow-up of exposed workers is encouraged to provide information on risks for other cancers. Results from epidemiologic studies of butadiene-exposed workers are somewhat inconsistent, but the largest study with the best exposure assessment found the largest relative risk for leukemia. The failure of several larger studies to replicate the early Swedish findings of a very strong association between leukemia and ethylene oxide has not been adequately explained. Epidemiologic studies of formaldehyde provide limited evidence for an association with cancer of the nasopharynx and possibly with nasal cancer. These very rare tumors, however, are difficult to study epidemiologically. Mustard gas is a well-established lung carcinogen, but a recent follow-up of the English cohort suggests that other sites also may be affected. Sulfuric acid appears to cause laryngeal cancer. A suggested relationship with lung cancer in a few studies is of concern because of the widespread opportunity for exposure from ambient air pollution. Vinyl chloride causes angiosarcoma of the liver, but a large, multi-country study provided no clear evidence that other sites are affected.
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PMID:Reactive chemicals and cancer. 949 5

Some six or so physiological systems, essential to normal mammalian life, are involved in poisoning; an intoxication that causes severe injury to any one of them could be life threatening. Reversible chemical reactions showing Scatchard-type binding are exemplified by CO, CN- and cyclodiene neurotoxin insecticide intoxications, and by antigen-antibody complex formation. Haemoglobin (Hb) molecular biology accounts for the allosteric co-operativity and other characteristics of CO poisoning, CN- acts as a powerful cytochrome oxidase inhibitor, and antigen binding in a deep antibody cleft between two domains equipped with epitopes for antigen-binding groups explains hapten-specific immune reactions. Covalent chemical reactions with second-order (SN2) kinetics characterize Hg and Cd poisonings, the reactions of organophosphates and phosphonates with acetylcholinesterase and neurotoxic esterase and the reaction sequence whereby Paraquat accepts electrons and generates superoxide under aerobic conditions. Indirect carcinogens require cytochrome P450 activation to form DNA adducts in target-organ DNA and cause cancer, but a battery of detoxifying enzymes clustered with the P450 system must be overcome. Thus, S-metabolism competes ineffectively with target DNA for reactive vinyl chloride (VC) metabolites, epoxide hydrolase is important to the metabolism and carcinogenicity of alfatoxins and polycyclic aromatic hydrocarbons (benzo[a]pyrene, etc.), and the non-toxic 2-naphthylhydroxylamine N-glucuronide acts as a transport form in 2-naphthylamine bladder cancer. VC liver-cancer pathogenesis is explicable in terms of the presence of the glutathione S-transferase detoxifying system in hepatocytes and its absence from the fibroblastic elements, and of the VC concentrations reaching the liver by different administrative routes. In VC carcinogenicity, chemical reactions give imidazo-cyclization products with nucleoside residues of target DNA, and in benzene leukaemia, Z,Z-muconaldehyde forms cyclic products containing a pyrrole residue linked to purine. Increased HbCO concentrations reduce the O2-carrying capacity of the blood, and the changed shape of the O2-Hb dissociation curve parallels disturbance in O2 unloading. CN- acts on electron transport and paralyses respiration. In telodrin poisoning, preconvulsive glutamine formation abstracts tricarboxylic acid intermediates incommensurately with normal cerebral respiration. Antigen-antibody complexing depletes the antibody titre, available against infection. At high doses of Cd, Cd-thionein filtered through the kidneys is reabsorbed and tubular lesions produced. Some organophosphate insecticides promote irreversible acetylcholinesterase phosphorylation and blockade nerve function, and others react with neurotoxic esterase to cause delayed neuropathy. The evidence for Paraquat pulmonary poisoning suggests a radical mechanism involving three interrelated cyclic reaction stages. The action of N- and O8 (O substituent in 6-position of the purine) demethylases explains deletion mechanisms for DNA-alkyl adducts. DNA-directed synthesis in the presence of ultimate carcinogens provides for an estimation of misincorporations, which implicate the same transversions as those found by direct mutagenicity testing. Chemical carcinogens recognize tissue-sensitive cells and modify their heritable genetic complement. Oncoproteins encoded by activated oncogenes signal the transformation of normal cells into cancer cells. The importance of the H-ras oncogene and p53 tumour-suppressor gene is stressed. Antidotal action is analysed; for example, parenteral glutamine administration to telodrin-intoxicated rats restores the depleted cerebral glutamate level and prevents seizures. Glutamate acts as anticonvulsant in petit mal epilepsy. In general, therefore, the reaction of the toxicant-related substance with the relevant target-tissue macromolecule accounts for the biochemical/biological events at a cellular level a
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PMID:Toxic action/toxicity. 1074 Aug 94

The design, synthesis and biological evaluation of novel seco-iso-cyclopropylfurano[2,3-e]indoline (seco-iso-CFI) and the seco-cyclopropyltetrahydrofurano[2,3-f]quinoline (seco-CFQ) analogues of the duocarmycins are described. These novel analogues (4-7) were designed on the premise that the lone pair of electrons on the furano-oxygen atom could enter into conjugation with the isocyclopropylfurano[e]indolone (iso-CFI) alkylating moiety, formed from the loss of HCl in compounds 4-7. The seco-iso-CFI DNA alkylating pharmacophore was synthesized through a well precedented approach of 5-exo-trig aryl radical cyclization with a vinyl chloride. In our studies, in addition to the formation of the seco-iso-CFI product, an equal amount of an unexpected seco-CFQ product was also generated during the radical cyclization reaction. Like CC-1065 and adozelesin, using Taq DNA polymerase stop and thermal cleavage assays, the seco-iso-CFI compounds (4 and 6) and the seco-CFQ compounds (5 and 7) were shown to preferentially alkylate the adenine-N3 position within the minor groove of long stretches of A residues. A MM2 energy optimized molecular model of a 1:1 complex of compound 6 with DNA reveals that the iso-CFI compound fits snugly within the minor groove. Using a MTT based experiment, the cytotoxicity of compounds 4-7 were determined against the growth of murine leukemia (L1210), mastocytoma (P815) and melanoma (B16) cell lines. The concentrations of compounds required to inhibit the growth of these tumor cells by 50% is in the range of 10(-8)M. These compounds were also tested against a panel of human cancer cells by the National Cancer Institute, demonstrating that the compounds exhibited a high level of activity against selected solid tumors. At a concentration of 0.0084 microM (based on the IC(50) of compound 17 (seco-CBI-TMI) against the growth L1210 cells), while compounds 4 and 17 were toxic against murine bone marrow cells as judged by a colony forming study of freshly isolated murine progenitor hematopoeitic cells, compound 5, a seco-CFQ compound, was significantly less toxic. Flow cytometric analysis of P815 cells that had been incubated for 24h with compounds 4 and 5 at their cytotoxic IC(50) concentrations indicated the induction of apoptosis in a large percentage of cells, thereby suggesting that this might be the mechanism by which the iso-CFI compounds kill cells.
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PMID:Novel furano analogues of duocarmycin C1 and C2: design, synthesis, and biological evaluation of seco-iso-cyclopropylfurano[2,3-e]indoline (seco-iso-CFI) and seco-cyclopropyltetrahydrofurano[2,3-f]quinoline (seco-CFQ) analogues. 1211 Mar 16

Glycidol is a viscous liquid that is used as a stabilizer in the manufacture of vinyl polymers, as an additive for oil and synthetic hydraulic fluids, and as a diluent in some epoxy resins. NTP Toxicology and Carcinogenesis studies were conducted by administering glycidol (94% pure, containing 1.2% 3-methoxy-1,2-propanediol, 0.4% 3-chloro-1,2-propanediol, 2.8% diglycidyl ether, and 1.1% 2,6-dimethanol-1,4-dioxane) in water by gavage to groups of F344/N rats and B6C3F1 mice of each sex for 16 days, 13 weeks, or 2 years. Genetic toxicology studies were conducted in Salmonella typhimurium, Chinese hamster ovary (CHO) cells, Drosophila melanogaster, and the bone marrow of male B6C3F1 mice. Sixteen-Day Studies: Glycidol doses for groups of five rats or five mice of each sex ranged from 37.5 to 600 mg/kg; vehicle controls received distilled water. All rats that received 600 mg/kg died between days 3 and 13. Edema and degeneration of the epididymal stroma, atrophy of the testis, and granulomatous inflammation of the epididymis occurred in males that received 300 mg/kg. All mice that received 600 mg/kg and two males and two females that received 300 mg/kg died by day 4 of the studies. Focal demyelination in the medulla and thalamus of the brain occurred in all female mice that received 300 mg/kg. Thirteen-Week Studies: Doses for groups of 10 rats ranged from 25 to 400 mg/kg, and doses for groups of 10 mice ranged from 19 to 300 mg/kg; vehicle controls received distilled water. All rats that received 400 mg/kg died by week 2; three males and one female that received 200 mg/kg died during weeks 11-12. Final mean body weights of male rats that received 50, 100, or 200 mg/kg were 96%-85% that of vehicle controls; final mean body weights of female rats receiving the same doses were 95%-89% that of vehicle controls. Sperm count and sperm motility were reduced in male rats that received 100 or 200 mg/kg. Necrosis of the cerebellum, demyelineation in the medulla of the brain, tubular degeneration and/or necrosis of the kidney, lymphoid necrosis of the thymus, and testicular atrophy and/or degeneration occurred in rats that received 400 mg/kg. All mice that received 300 mg/kg died by week 2; deaths of mice that received 150 mg/kg occurred during weeks 4-8 for males and weeks 1-5 for females. Mean body weights of chemically exposed mice surviving to the end of the studies were generally 90%-94% those of vehicle controls. Sperm count and sperm motility were reduced in dosed male mice. Compound-related histopathologic lesions included demyelination of the brain in males and females that received 150 or 300 mg/kg, testicular atrophy in males at all doses, and renal tubular cell degeneration in male mice that received 300 mg/kg. Based on reduced survival, reduced weight gain, and histopathologic lesions in the brain and kidney in rats that received 200 or 400 mg/kg and on reduced survival and histopathologic lesions of the brain in mice that received 150 or 300 mg/kg, doses selected for the 2-year studies of glycidol were 37.5 and 75 mg/kg for rats and 25 and 50 mg/kg for mice. Body Weights and Survival in the Two-Year Studies: Mean body weights of chemically exposed male rats generally ranged from 80% to 94% of those of vehicle controls, and mean body weights of chemically exposed female rats were from 90% to 97% those of vehicle controls. Mean body weights of chemically exposed male mice were similar to those of vehicle controls; mean body weights of chemically exposed female mice were 79%-95% of those of vehicle controls. Virtually all male and female rats that received glycidol died or were killed in a moribund condition as a result of the early induction of neoplastic disease (final survival--male: vehicle control, 16/50; low dose, 0/50; high dose, 0/50; female: 28/50; 4/50; 0/50). Survival of vehicle control male rats was lower than that usually observed; however, specific causes of deaths could not be determined. The survival of male mice and low dose female mice was similar to that of vehicle controls; survival of female mice that resurvival of male mice and low dose female mice was similar to that of vehicle controls; survival of female mice that received 50 mg/kg was lower than that of vehicle controls after week 101 (final survival--male: 33/50; 25/50; 27/50; female: 29/50; 27/50; 17/50). Nonneoplastic and Neoplastic Effects in the Two-Year Studies: Chemical-related nonneoplastic lesions in both rats and mice included hyperkeratosis and epithelial dysplasia of the forestomach. Fibrosis of the spleen was also present in rats of each sex, and cysts of the preputial gland and kidney were present in male mice. Exposure to glycidol induced dose-related increases in the incidences of neoplasms in numerous tissues in both rats and mice (see summary table on page 5 of the Technical Report). In male rats, mesotheliomas arising in the tunica vaginalis and frequently metastasizing to the peritoneum were considered the major cause of early death. Early deaths in female rats were associated with the presence of mammary gland neoplasms. Genetic Toxicology: Glycidol was mutagenic in a variety of in vitro and in vivo short-term tests. Mutagenic activity was observed in S. typhimurium strains TA97, TA98, TA100, TA1535, and TA1537 exposed to glycidol with and without exogenous metabolic activation. Glycidol was positive in the absence of exogenous metabolic activation in the mouse lymphoma assay for induction of trifluorothymidine resistance in L5178Y/TK cells; it was not tested with activation. In cytogenetic tests with CHO cells, glycidol induced both sister chromatid exchanges and chromosomal aberrations in the presence and absence of exogenous metabolic activation. Glycidol induced sex-linked recessive lethal mutations and reciprocal translocations in the germ cells of male D. melanogaster exposed by feeding. The incidence of micronucleated polychromatic erythrocytes was increased in the bone marrow of male B6C3F1 mice administered glycidol by intraperitoneal injection. Conclusions: Under the conditions of these 2-year gavage studies, there was clear evidence of carcinogenic activity of glycidol for male F344/N rats, based on increased incidences of mesotheliomas of the tunica vaginalis; fibroadenomas of the mammary gland; gliomas of the brain; and neoplasms of the forestomach, intestine, skin, Zymbal gland, and thyroid gland. There was clear evidence of carcinogenic activity for female F344/N rats, based on increased incidences of fibroadenomas and adenocarcinomas of the mammary gland; gliomas of the brain; neoplasms of the oral mucosa, forestomach, clitoral gland, and thyroid gland; and leukemia. There was clear evidence of carcinogenic activity for male B6C3F1 mice based on increased incidences of neoplasms of the harderian gland, forestomach, skin, liver, and lung. There was clear evidence of carcinogenic activity for female B6C3F1 mice, based on increased incidences of neoplasms of the harderian gland, mammary gland, uterus, subcutaneous tissue, and skin. Other neoplasms that may have been related to the administration of glycidol were fibrosarcomas of the glandular stomach in female rats and carcinomas of the urinary bladder and sarcomas of the epididymis in male mice. Synonym: 2,3-epoxy-1-propanol
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PMID:NTP Toxicology and Carcinogenesis Studies of Glycidol (CAS No. 556-52-5) In F344/N Rats and B6C3F1 Mice (Gavage Studies). 1269 47

A carcinogenesis bioassay of butyl benzyl phthalate, a plasticizer for vinyl chloride plastics, was accomplished by feeding diets containing 6,000 or 12,000 ppm of the phthalate to groups of 50 F344/N rats and 50 B6C3F1 mice of each sex for 28 to 103 weeks. Mean body weights of dosed female rats and mice of each sex were lower than those of the control animals throughout most of the study. After week 14, an increasing number of dosed male rats died as a result of an unexplained internal hemorrhaging, and all surviving male rats were killed at week 29 to 30. Because of compound-related mortality, butyl benzyl phthalate was not adequately tested for carcinogenicity in male F344/N rats. Mononuclear cell leukemias occurred at a statistically significant (P=0.011) increased incidence in the high-dose group of female rats when compared with the control group and with a significantly (P=0.006) increasing trend (controls 7/49, 14%; low-dose 7/49, 14%; high-dose 18/50, 36%). The incidence in the high-dose group and the overall trend remained statistically significant (P=0.008 and P=0.019) when compared with the historical incidence for F344/N female rats with leukemia at this laboratory (77/ 399, 19%). Further, this leukoproliferation was generally characterized by splenomegaly and often by hepatomegaly. Administration of butyl benzyl phthalate was not associated with increased incidences of any type of tumor among male or female mice. Tumor rates were decreased in female rats for fibroadenomas of the mammary glands (20/49, 14/49, 9/50) and in male mice for lymphomas of the hematopoietic system (13/50, 11/49, 4/50) and for alveolar/bronchiolar adenomas or carcinomas (17/50, 11/49, 8/50). Under the conditions of this bioassay, butyl benzyl phthalate was probably carcinogenic for female F344/N rats, causing an increased incidence of mononuclear cell leukemias. The male F344/N rat study was considered inadequate for evaluation due to compound-related toxicity and early mortality. Butyl benzyl phthalate was not carcinogenic for B6C3F1 mice of either sex. Levels of Evidence of Carcinogenicity: Male Rats: Inadequate Study Female Rats: Positive Male Mice: Negative Female Mice: Negative Synonyms: BBP; benzyl butyl phthalate; phthalic acid; benzyl butyl ester; Santicizer 160
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PMID:Carcinogenesis Bioassay of Butyl Benzyl Phthalate (CAS No. 85-68-7) in F344/N Rats and B6C3F1 Mice (Feed Study). 1277 22


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