On the interaction of chromomycin A3 with calf thymus DNA in the presence of metal cations at different pH values.
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Biomedical subjects
Publications and source records attributed to E Berman.
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Male F344 rats were exposed by gavage to samples of complex mixtures and evaluated 24 hr later. Seven of the 10 samples caused death at doses ranging from 1 to 5 ml/kg body wt. Eight of the 10 samples were hepatotoxic based on histopathologic evaluation; 6 were centrilobular and 2 were periportal hepatotoxicants. The waste samples exerted toxicity through different mechanisms, as indicated by differences in the severity and lobular location of the tissue damage. Nine of the 10 samples caused an increase in the ratio of liver weight to body weight (relative liver weight). With histopathological evaluation as the criterion, relative liver weight was the single best indicator of hepatotoxicity. Exposure to several of the waste samples increased serum total bilirubin and serum enzyme activities of alanine aminotransferase, aspartate aminotransferase, lactate dehydrogenase, alkaline phosphatase, and ornithine carbamyl transferase. As a battery, but not individually, the serum indicators separated the 8 hepatotoxic samples from the 2 nonhepatotoxic samples. In general, the hepatotoxicity of the waste samples did not appear to be readily predicted from (partial) chemical characterization data. An approach that includes both chemical characterization and biological testing should provide valuable information regarding the hazardous nature of complex wastes.
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Results of a multivariable analysis of prognostic factors are reported for 199 previously untreated adults with acute lymphoblastic leukemia (ALL). These patients have long-term follow-up, and the probability of cure is estimated at approximately 35%. The cause-specific hazard rate analysis found lower rates of achieving complete remission (CR) in patients with WBC greater than 10,000/microL, AUL (undifferentiated) morphology, and older age. Since these patients required additional time to respond, fewer of them actually achieved CR. Characteristics directly associated with a higher rate of death during induction therapy due to severe bone marrow suppression were low serum albumin concentration (less than or equal to 3.5 g/dL), age greater than 50 years, acute undifferentiated leukemia (AUL) morphology, low Karnofsky performance status, and weight loss greater than 5%. Factors associated with a higher rate of relapse were WBC greater than 20,000/microL, non-T cell ALL, age greater than 60 years, Ph' + ALL, and time to achieve CR greater than 5 weeks. These criteria were used to identify patients at high risk of relapse. In addition, the predictive value of high WBC was found to disappear by 18 months of continuous CR. Finally, the rate of death following first relapse was higher in patients with a short first remission duration, high percentage weight loss at initial diagnosis, and older age. In summary, factors associated with a higher rate of death during attempted induction (ie, low albumin, high percent weight loss, and poor performance status) had no association with the patient's ability to remain relapse-free. Conversely, factors correlating with more extensive or resistant disease (ie, high WBC, null or B cell ALL, or Ph' + ALL) showed no association with the ability to tolerate therapy. Thus, a less toxic but more effective induction regimen is needed for patients with a poor clinical status, whereas a more intensive form of therapy appears warranted for patients presenting with more extensive or resistant disease.
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The binding of the tide compounds to soybean agglutinin was investigated using 13C-NMR spectroscopy. The equilibrium constant for the binding of N-acetyllactosamine was found to be smaller than that obtained for the binding of ovalbumin (1.1 X 10(3) vs. 7.4 X 10(3) M-1). Only two binding sites per lectin tetramer were determined for the binding of ovalbumin, which is half the number of binding sites reported for the binding of small ligands to the lectin. Steric interference between the bulky ovalbumin molecules is believed to be the reason for the observed decrease in the apparent number of binding sites on the lectin.
Useful structural and conformational information was obtained from a detailed analysis of the fine structure of cross peaks that appears in the phase-sensitive homonuclear correlated two-dimensional spectra of complex large glycopeptides. The small chemical shift range observed for the oligosaccharide part results in a variety of cross-peak patterns. A catalogue of cross-peak fine structures and patterns expected for common carbohydrates are presented which can help in making some, all-important and crucial, proton resonance assignments. Analysis of the vicinal coupling constants extracted from the cross peaks corresponding to the hydroxymethyl protons of the inner core carbohydrates of glycopeptides derived from calf fetuin, has yielded information regarding the time-averaged solution conformation of this triantennary structure. It was shown that in solution the Man(alpha 1-6) arm of the core pentasaccharide unit, which carries a single antenna, adopts for an appreciable part of the time a conformation which brings it close to the arm that is attached to the peptide part. A similar conformation for the Man(alpha 1-6) arm was previously observed for the biantennary oligosaccharide chain. Therefore, we concluded that the presence of an additional antenna on the Man(alpha 1-3) arm of the core unit in the triantennary structure does not alter the basic biantennary conformation.
1H and 31P NMR spectral analysis of a chromomycin/d(ATGCAT)2 complex provides strong evidence for a nonintercalative mode of drug binding. Investigation of the imino proton region of the duplex suggests a protection of one of the two guanine imino protons from fast exchange with the bulk water up to at least 45 degrees C by the drug. Subsequent one-dimensional nuclear Overhauser enhancement experiments place the exchangeable chromomycin chromophoric hydroxyl proton less than 0.45 nm from this guanine imino proton and the chromophore 7-methyl less than 0.45 from the internal thymine 6-proton and/or the guanine 8-proton. 1H two-dimensional NMR reveals that the duplex retains a right-handed B conformation but there are distortions at the TGC region of one chain and large deviations in the chemical shift of protons relative to the uncomplexed duplex in the other chain in the same TGC region. The data suggest that the chromomycin chromophore is oriented such that the hydrophilic side of the ring system is proximal to the helix center in the major groove near the TG region while the aromatic side of the ring is oriented away from the helix but is partially protected from the solvent by the aliphatic chain, which bends back over the two aromatic protons. Changes in the 31P spectrum of the duplex on binding of the drug are different from the effect of either actinomycin or netropsin on nucleic acid fragments.
15 hazardous industrial waste samples were evaluated for mutagenicity in the Salmonella plate-incorporation assay using strains TA98 and TA100 in the presence and absence of Aroclor 1254-induced rat liver S9. Dichloromethane/methanol extracts of the crude wastes were also evaluated. 7 of the crude wastes were mutagenic, but only 2 of the extracts of these 7 wastes were mutagenic; extracts of 2 additional wastes also were mutagenic. In addition, 10 of the crude wastes were administered by gavage to F-344 rats, and 24-h urine samples were collected. Of the 10 raw urines evaluated, 3 were mutagenic in strain TA98 in the presence of S9 and beta-glucuronidase. The 3 crude wastes that produced these 3 mutagenic urines were, themselves, mutagenic. Adequate volumes of 6 of the 10 raw urines were available for extraction/concentration. These 6 urines were incubated with beta-glucuronidase and eluted through Sep-Pak C18 columns; the methanol eluates of 3 of the urines were mutagenic, and these were the same 3 whose raw urines also were mutagenic. In general, the C18/methanol extraction procedure reduced the cytotoxicity and increased the mutagenic potency of the urines. To our knowledge, this is the first report of the mutagenicity of urine from rodents exposed to hazardous wastes. Based on the present results, the use of only strain TA98 in the presence of S9 might be adequate for general screening of hazardous wastes or waste extracts for genotoxicity. The urinary mutagenesis assay does not appear to be a useful adjunct to the Salmonella assay for screening hazardous wastes. The problems associated with chemically fractionating diverse types of hazardous wastes for bioassay are also discussed.
An adolescent patient with a history of progressively more severe seasonal depression subsequently developed a refractory manic-depressive psychosis with rapid cycling after the initiation of treatment with trimipramine. A complete remission was obtained after a course of six electroconvulsive therapy (ECT) treatments. This unusual case and its outcome are discussed in terms of apparent drug-induced rapid cycling and the treatment of this condition. It is suggested that ECT can be successfully used as an alternative therapeutic option for patients with intractable rapid-cycling manic-depressive disorder.
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NE-19550, N-(3-methoxy-4-hydroxybenzyl)oleamide, is a capsaicin analogue that has been shown to possess oral activity in the 55 degrees C rat hot-plate and mouse phenylquinone abdominal constriction analgesia tests. The compound also displayed anti-inflammatory activity orally in the carrageenan-inflamed rat-paw test and topically in the croton oil-inflamed mouse-ear test. NE-19550 activity in the thermal analgesia assay was not blocked by the opioid antagonist naloxone, and no inhibition of prostanoid synthesis in rat platelets or tissues was seen following a high analgesic and anti-inflammatory oral dose (300 mg/kg). A wide variety of known neuronal antagonists (adrenergic, serotonergic, dopaminergic, cholinergic, GABA-ergic, histaminergic) were found not to inhibit NE-19550 analgesia, further indicating a lack of involvement of known drug receptors mediating analgesic responses. Analgesic doses of NE-19550 were also found to lack the acute toxicity and thermoregulatory desensitization characteristics of the parent natural product capsaicin. It appears to represent a new class of potent-acting, non-narcotic, anti-inflammatory analgesic agents.
Timolol iontophoresis into the eye can induce herpes simplex virus type 1 (HSV-1) shedding in rabbits latently infected with HSV-1 strain McKrae. Anodal iontophoresis of 0.01% timolol was done at 0.8 mAmp for 8 min once a day for 3 consecutive days. Viral shedding was determined by the presence of HSV-1 in the preocular tear film obtained by eye swabs. In two experiments, iontophoresis of 0.01% timolol resulted in all eyes (18/18) shedding HSV-1 for an average duration of 4.3 days. When 5.0% timolol was applied topically to rabbit eyes supersensitized by iontophoresis of 6-hydroxydopamine (6-HD), all eyes (10/10) shed virus for an average duration of 2.9 days. All eyes (12/12) receiving iontophoresis of 6-HD, pre- and posttreatment with topical application of 5.0% timolol, and posttreatment with topical application of 1.0% epinephrine shed virus for an average duration of 3.6 days. Eyes treated with topical application of 5.0% timolol alone showed no difference in HSV-1 ocular shedding, compared with untreated eyes. We concluded that both iontophoresis of 0.01% timolol and topical application of 5.0% timolol to adrenergically supersensitized eyes induced HSV-1 shedding reliably and with a high frequency, and that topically applied timolol does not block the HSV-1 ocular shedding induced by epinephrine in adrenergically supersensitized eyes.
Immunofluorescent staining of peripheral blood mononuclear cells with the monoclonal antibody anti-HC2 combined with phase microscopic examination identified leukemic hairy cells in nine of 13 patients (69%) evaluated at Memorial Hospital prior to treatment with recombinant alpha-interferon (rIFN-alpha A). The remaining four patients required further studies of bone marrow or peripheral blood cytospin samples for diagnosis. In some cases a low percentage of cells staining with anti-HC2 could be significantly increased by depleting T cells from the sample using sheep red blood cell rosetting. These 13 patients represent a subgroup of patients treated on a phase II rIFN-alpha A study at Memorial Hospital. Ten patients (77%) achieved a partial response in a median of 128 days (range, 64-234). One patient achieved a minor response and two patients failed treatment. Nonhematologic toxicity, consisting of fever and malaise, was transient in all patients. Serial determinations of HC2-positive cells in the peripheral blood closely paralleled disease activity in the bone marrow in one patient treated for 4 years with various therapeutic modalities. The antibody anti-HC2 may play a significant role in the diagnosis and monitoring of hairy cell leukemia using peripheral blood sampling.
A study of the equilibrium binding of glycoproteins to lectins was undertaken using the titled compounds as a model system for such interactions. The binding of hen ovalbumin, enriched in galactose specifically 13C-labelled at C1, to Erythrina cristagalli agglutinin was studied by 13C-NMR spectroscopy. The lectin was shown to be bivalent for ovalbumin with an apparent estimated association constant, at infinite dilution, of about 10(4) M-1. The observed association is similar to that found for the corresponding disaccharide, Gal(beta 1-4)GlcNAc. The results strongly suggest that only the N-acetyllactosamine moiety in the carbohydrate side chain of galactose-enriched ovalbumin participates in the binding to the lectin with little, if any, interactions from other parts of either the side chain or the polypeptide backbone of ovalbumin.
The triantennary structure of the N-linked oligosaccharide side-chain of fetuin, elucidated by a combination of 13C-n.m.r. spectroscopy and enzymic degradations, accords with that reported earlier with respect to the branching pattern, but the ratio of the N-acetylneuraminic acid linkages to the galactose residues [alpha-(2----3) vs. alpha-(2----6)] was found to be 1:1, indicating structural heterogeneity of the side chains. Also, one out of nine galactosyl residues is linked to 2-acetamido-2-deoxy-beta-D-glucose by a (1----3) rather than a (1----4) linkage. The chemical shifts reported are in excellent agreement with those for the intact glycoprotein. Unusual chemical shift effects lead to the conclusion that the alpha-NeuAc-(2----6) residues interact with other parts of the oligosaccharide side-chain. The action of beta-D-galactosidase from Aspergillus niger on desialylated fetuin removed approximately 85% of the beta-Gal residues (1----4)-linked to GlcNAc and 65% of the beta-Gal residues (1----3)-linked to GalNAc, but none of the beta-Gal residues (1----3)-linked to GlcNAc.
Complete assignments of all anomeric resonances in the proton and carbon spectra of the N-linked oligosaccharide units of fetuin were made using one- and two-dimensional NMR spectroscopy. We are able to confirm the presence of microheterogeneity in the N-acetylneuraminic acid linkages to the galactose residues and the presence of a unique triantennary structure which carries a side chain: NeuAc alpha(1-3)Gal beta(1-3)GlcNac beta(1-4)-. Anomeric carbon chemical shifts changes resulting from long-range conformational effects were observed.
Twenty-four patients with blastic-phase chronic myelogenous leukemia (CML) were treated with mitoxantrone. The patients included 19 whose cells were Philadelphia chromosome (Ph1+) and 5 who were either Ph1- or in whom cytogenetics were not available. Six of the 19 whose cells were Ph1+ responded and one of those who were Ph1- responded. The patients were further characterized into lymphoid or nonlymphoid on the basis of terminal deoxynucleotidyl transferase or morphology. Two of the patients with lymphoid transformation and 3 of those with nonlymphoid transformation responded. In 3 patients post-treatment cytogenetic evaluation revealed the presence of Ph1- metaphases. We conclude that mitoxantrone has modest activity in blCML and that the cytogenetic responses suggest the possibility of greater efficacy in chronic-phase CML.