Comparative genotoxicity of halogenated acetic acids found in drinking water.

Three short-term assays (SOS chromotest, Ames fluctuation test and newt micronucleus test) were performed to detect the genotoxic activity of organohalides, compounds likely to be found in chlorinated and/or ozonated drinking water: monochloro-, dichloro- and trichloroacetic acids and monobromo-, dibromo- and tribromoacetic acids. With the SOS chromotest, only three of the chemicals studied (dichloroacetic acid, dibromo- and tribromoacetic acids) were found to induce primary DNA damage in Escherichia coli PQ 37. In the Ames fluctuation test, all the compounds except monochloroacetic acid showed mutagenic activity in Salmonella typhimurium strain TA100. In these two in vitro tests, a good correlation between increasing number of substituents and decreasing mutagenicity was observed. Namely, the toxicity of brominated and chlorinated acetic acids decreased when the number of substituents increased. The newt micronucleus test detected a weak clastogenic effect on the peripheral blood erythrocytes of Pleurodeles waltl larvae for trichloroacetic acid only.

Genotoxicity assay of chloral hydrate and chloropicrine.

The chlorination by-products chloral hydrate and chloropicrine were assayed for genotoxicity in three short-term tests. Chloropicrine was 100-fold more potent than chloral in inducing mutations in strain TA100 of S. typhimurium (fluctuation test) and, at variance with chloral, was positive in the SOS chromotest using strain PQ37 of E. coli. On the other hand, only chloral caused a significant increase in the frequency of micronucleated erythrocytes following in vivo exposure of the amphibian Pleurodeles waltl newt larvae.

Study of the genotoxic activity of six halogenated acetonitriles, using the SOS chromotest, the Ames-fluctuation test and the newt micronucleus test.

Three short-term assays (the SOS chromotest, the Ames-fluctuation test and the newt micronucleus test) were carried out to evaluate the genotoxicity of six halogenated acetonitriles identified in chlorinated waters (monochloro-, dichloro-, trichloro-, monobromo-, dibromo- and bromochloroacetonitrile). With the SOS chromotest, three of the chemicals studied (dichloro-, dibromo- and bromochloroacetonitrile) were found to induce primary DNA damage in Escherichia coli PQ37. In the Ames-fluctuation test, all the compounds except dibromoacetonitrile showed mutagenic activity on Salmonella typhimurium strain TA100. The newt micronucleus assay detected a clastogenic effect on the peripheral blood erythrocytes of Pleurodeles waltl larvae for all the six haloacetonitriles studied. Moreover, two structure-activity relationships were noted: (1) the genotoxic activity of haloacetonitriles containing bromine substituents appeared higher than the corresponding chlorinated acetonitriles and (2) the clastogenic activity of the chlorinated acetonitriles increased with the number of chlorine substituents.

Five-day 4'-(9-acridinylamino)methanesulphon-m-anisidide and intermediate-dose cytosine arabinoside in high-risk relapsing or refractory acute myeloid leukemia.

Twenty-two patients with acute myeloid leukemia (AML), having a median age of 48.3 years (range 26-70; 10 male, 12 female), were treated with 4'-(9-acridinylamino) methanesulphon-m-anisidide (m-AMSA) 100 mg/m2 and cytosine arabinoside (AraC) 2 x 1000 mg/m2i.v. on days 1-5. There were 2M1,8 M2, 9 M4, 2M4 Eo, and 1 M5a. Of these, 12 achieved a complete remission, 3 a partial remission and 6 did not respond. The median remission duration was 9.0 months and the median overall survival 8.1 months. Side-effects of induction consisted mainly of haematological toxicity and infections with a median duration of WHO-grade-4 granulopenia and thrombopenia of 20 and 28 days respectively. Organ toxicity was mild with mucositis and cutaneous and liver toxicity being experienced by only a few patients. There was one treatment-related death. Five-day m-AMSA and intermediate-dose AraC is an easy-to-handle condensed treatment schedule with tolerable toxicity. Its effectiveness in relapsed and refractory AML is comparable to combinations of high-dose AraC with m-AMSA, anthracyclines or etoposide.

Amphotericin B causes aggregation of neutrophils and enhances pulmonary leukostasis.

The influence of amphotericin B (AmB) on the aggregation of polymorphonuclear leukocytes (PMN) was examined by means of in vitro aggregometry as well as in an in vivo model of pulmonary leukostasis (PL). The AmB caused a dose-dependent aggregation of PMN that was partially blocked by addition of serum to the drug prior to its reaction with the PMN. No aggregation of PMN was seen after the addition of nystatin, a similar polyene antibiotic. In vivo studies were conducted in rabbits, where PL was induced by an intravenous infusion of zymosan-activated plasma (ZAP) or phorbol myristate acetate (PMA), and the degree of resulting leukostasis was expressed as the number of PMN per high power field (HPF). Animals in the control group had 6 +/- 3 PMN/HPF. This number increased to 12.4 +/- 5.6 when ZAP was infused and postmortem examination was performed 1 h later and to 17.4 +/- 4 if the examination was performed after 24 h. These numbers increased more than twice when AmB (1 mg/kg) was infused together with the ZAP. Increased PL after the infusion of ZAP and AmB was not attenuated by prior administration of methylprednisolone (30 mg/kg) to the animals. Infusions of AmB per se caused no significant PL but did cause increased pinocytosis in the pulmonary endothelium. Enhancement of PL by AmB was also examined in a model of PMA-induced PL.(ABSTRACT TRUNCATED AT 250 WORDS)

Surgery in patients with hepatitis.

The results of thirteen major operations performed in twelve patients with various forms of hepatitis are reviewed. five patients succumbed shortly after surgery, four of them with acute yellow atrophy of liver and one following septic shock. In the patients with acute viral hepatitis, associated malignancy is assumed to have contributed to death. One patient with chronic active hepatitis treated by corticosteroids had an uneventful recovery, while two patients with the same disease, to whom corticosteroids were not administered, succumbed to hepatic failure.

DNA-polymerase inhibitors. Rifamycin derivatives.

Ten new derivatives of the antibiotic rifamycin with variable side chains at position 3 were synthesized. The inhibitory activity of these derivatives against DNA-polymerases isolated from avian myeloblastosis virus, E. coli and calf thymus were studied at various conditions. 3-(2,4,6-trinitrophenylhydrazone-(methyl) rifamycin SV is a strong inhibitor for all the polymerases tested and belongs to the C class inhibitors of reverse transcriptase. 3-(monoallylhydrazone-(methyl) rifamycin SV possesses a selective action on polymerases: at 0.1 mg/ml concentration it almost completely inhibits the reverse transcriptase and less than half of the bacterial and eukaryotic enzymes. A drug is found which strongly inhibits the DNA-polymerases from E. coli and calf thymus and weakly the viral enzyme. The inhibitory effect on reverse transcriptase is independent of the choice of template-primer; it could be overcome by the addition of excess enzyme but not of excess template-primer; the inhibition could be completely reversed by dilution of the drug-enzyme mixture. From Lineweaver-Burk analysis, the inhibition is noncompetitive with respect to the template-primer and, thus the drugs bind to the site different from the active site for the template-primer. From protective action of the template-primer and other data it might be suggested that the rifamycin derivatives act at an early step(s) in DNA synthesis catalyzed by reverse transcriptase. The obtained data are in agreement with the results for other derivatives of rifamycin SV described in literature.

[Stability of 6-beta-[(hexahydro-1H-azepin-l-yl)methyleneamino]-penicillanic acid in aqueous solutions]. / Ustoichivost'6-beta[(geksagidro-1H-azepin-l-il)metilenamino]penitsillanovoi kisloty v vodnykh rastvorakh

Stability of acqueous solutions of 6-beta-[(hexahydro-IH-azepin-I-yl)methylenamino] penicillanic acid at various values of pH and temperature was studied. It was found that inactivation of the antibiotic in both the acid and the alkaline medium proceeded according to the equation of the 1st order. At pH 1.3 and a temperature of 35 degrees the half life of the antibiotic was 7 hours. The activation energy calculated according to the Arrenius equation was 13.5 kcal/mol at pH 1.3 and 22.2 kcal/mol at pH 10.5. The antibiotic was inactivated in glycol and phosphate buffers. Its qualitative analysis was performed according to an improved iodometric method.

[Pharmacokinetics of dioxonium]. / Farmakokinetika dioksoniia

An investigation in the pharmacokinetics of a new peripheral muscle relaxant dioxonium and of its carbon-labeled analogue (with respect to the N-methyl groups) was carried out. An intravenous administration of dioxonium-C14 was found to bring about a biphasic change in radioactivity of the blood plasma. The stoppage of curarization, irrespective of a dioxonium dose, is seen to occur at a definite radioactivity level in the blood plasma. Major radioactivity following introduction of dioxonium-C14 is observed in the organism of the rats in the skeletal muscles and in the kidneys. The drug is eliminated from the organism through the kidneys in an unchanged and pharmacologically active form.

[Comparative study of the fate of fluorofur and 5-fluorouracil in the organism]. / Sravnitel'noe izuchenie sud'by ftorafura i 5-ftoruratsila v organizme

Fluorofur (FT) is slowly splitted in tissues releasing free 5-FU. The duration of stay in the organism of 5-FU formed from FT is longer than that of 5-FU administered solely. Moreover, FT does not result in the formation of such high 5-FU concentrations, as observed while using 5-FU itself. It seems to account for an insignificant toxicity of FT and its greater efficacy in treatment of malignant tumors.