The somatic white-ivory eye spot test does not detect the same spectrum of genotoxic events as the wing somatic mutation and recombination test in Drosophila melanogaster

A groups of six chemical compounds was tested in parallel in two different somatic genotoxicity assays in Drosophila melanogaster, the wing somatic mutation and recombination test (SMART) and the white-ivory eye spot test. The wing spot test makes use of the wing cell markers multiple wing hairs (mwh) and flare (flr) and detects both mitotic recombination and various types of mutational events. The white-ivory eye spot test makes use of the white-ivory (wi) quadruplication and detects the somatic reversion of the recessive eye color mutation wi to the wild-type (w+). Three- or two-day-old larvae were fed chronically with the compounds ethylnitrosourea (ENU), N-nitrosopyrrolidine (NNP), caffeine (CAF), chromium (VI) oxide (CRO), potassium chromate (POC), and 2,4-dichlorophenoxyacetic acid (2,4-D). All six compounds are genotoxic to various degrees in the wing spot test. The percentage of the genotoxic activity that is due to mitotic recombination was between 84% and 91% for the hexavalent chromium compounds CRO and POC and about 68% for 2,4-D. In contrast, ENU and NNP showed only 46% and 25% recombinagenic activity, respectively. In the white-ivory eye spot test, the three compounds (CRO, POC, and 2,4-D) with high recombinagenic activity and CAF were clearly nongenotoxic, whereas only ENU and NNP gave a positive response. From these results, it is concluded that the spectrum of genotoxic events detected by the two assays is different. In particular, the white-ivory eye spot test appears not to detect mitotic recombination the way the wing spot test does.

Protection by coffee against somatic genotoxicity in Drosophila: role of bioactivation capacity

The protective effects of coffee against somatic mutation and mitotic recombination induced by cyclophosphamide (CPH), mitomycin C (MMC) and urethane (URE) were evaluated in the standard (ST) and high bioactivation (HB) crosses of the wing spot test in Drosophila melanogaster. These two crosses are characterized by different constitutive levels of cytochrome )-450-dependent enzyme activities. 3-day old larvae transheterozygous for the wing cell markers mwh (multiple wing hairs) and flr3 (flare3) were fed until pupation on medium containing a genotoxin alone or its combination with different concentrations of instant coffee. subsequently, the wings of the resulting adult flies were analysed for detecting single spots (mwh or flr3) originating from mutational or recombinational events as well as twin spots (mwh and flr3) originating exclusively from recombination. The results showed high sensitivity of the HB cross to URE. Co-administration of instant coffee was effective in exerting significant dose-related inhibitory effects on the genotoxicity of URE in the ST and the genetically susceptible HB cross. Similarly, coffee showed significant dose-related inhibitory effects on the genotoxicity of MMC in both crosses. The same protective effect was also observed with one concentration of coffee in combination with CPH. Pretreatment of 2-day-old HB larvae with coffee for 24 hr followed by treatment with URE was also effective in significantly reducing the induction of mutation and recombination. The magnitude of the protective effects of coffee against these three genotoxins was independent of the genotype of the larvae used for treatment, that is it was independent of the bioactivation capacity of these larvae. The study demonstrates the suitability of this assay for obtaining qualitative and quantitative data on the result of interactions among a genotoxin, an inhibitor of genotoxicity and bioactivation capacity of the host.

[Neurolinguistic programming in physician-patient communication. Basic principles of the procedure--examples for application in surgery]

Neurolinguistic programming (NLP) is a means of improving physician-patient communication that can be learned by any doctor. The present article first describes some of the fundamentals of NLP and then provides examples taken from the field of surgery-in the first instance dealing with the treatment of painful conditions by means of trance or dissociation and, secondly, on the influencing of expectations and the restructuring (reframing) of doctrines in a patient with malignant disease.

Tannic acid is not mutagenic in germ cells but weakly genotoxic in somatic cells of Drosophila melanogaster

Tannic acid (TA) was tested for genotoxic activity in three different assays (1-3) in Drosophila melanogaster by feeding of larvae or adult flies. TA did not induce sex-linked recessive lethals (1) nor sex-chromosome loss, mosaicism or non-disjunction (2) in male germ cells. In the wing somatic mutation and recombination test (SMART) (3) TA was found to be toxic for larvae of the high bioactivation cross and produced a weak positive response. These results suggest that this compound, when administered orally to larvae or adults of D. melanogaster, is not mutagenic and clastogenic in male germ cells, but weakly genotoxic in somatic cells of the wing imaginal disk.

Analysis of the relationship between age of larvae at mutagen treatment and frequency and size of spots in the wing somatic mutation and recombination test in Drosophila melanogaster

The relationship between the induction of mutant clones and the time of mutagen treatment was studied in the somatic mutation and recombination test (SMART) in wing cells of Drosophila melanogaster. Larvae trans-heterozygous for the recessive marker mutations multiple wing hairs (mwh) and flare (flr) were produced. Batches of these larvae were then treated with mutagen at different ages spanning all three larval instars. Methyl methanesulfonate was fed acutely for 2 h by immersing the larvae in a solution of the mutagen mixed with powdered cellulose. Wings of the surviving adult flies were mounted and scored for the presence of spots. The frequency and size of single and twin spots were recorded separately. Twin spots are produced exclusively by mitotic recombination, whereas single spots can result from various types of mutational and exchange events. There exists a clear correlation between time of induction and frequency as well as size of the single spots. In young larvae only few but very large spots are induced, whereas in older larvae the frequencies are considerably increased but the sizes are smaller. The twin spots show a different relationship. Practically no twin spots are found in very young and in very old larvae. The results demonstrate that in the wing spot test the optimal age of the larvae for mutagen treatment is 72 h.

Genotoxic activity of environmentally important polycyclic aromatic hydrocarbons and their nitro derivatives in the wing spot test of Drosophila melanogaster

The genotoxicity of three polycyclic aromatic hydrocarbons (PAHs) and of three of their nitro derivatives was evaluated in the wing Somatic Mutation And Recombination Test (SMART) in Drosophila melanogaster. Two crosses were used, i.e. the standard cross (ST) and the improved high bioactivation cross (HB) which is characterised by an increased sensitivity to the genotoxic effects of promutagens and procarcinogens. Larvae trans-heterozygous for the two recessive wing cell markers multiple wing hairs (mwh) and flare (flr3) were fed with the test compounds for 48 h. The wings of the surviving flies were analysed for the occurrence of single and twin spots. Naphthalene, 1-nitronaphthalene and 1,5-dinitronaphthalene proved to be more genotoxic in the HB cross than in the ST cross. Anthracene showed a clear genotoxic activity only in the HB cross whereas it was negative in the ST cross. 9-Nitroanthracene gave inconsistent results in both crosses. Phenanthrene was negative in the ST cross, but weakly positive in the HB cross. These results demonstrate that the genotoxic activity of these PAHs and their nitro derivatives can be detected with the somatic cells of the wing imaginal discs of larvae with high bioactivation capacity.

Time-resolved flow cytometry for the measurement of lanthanide chelate fluorescence: II. Instrument design and experimental results

A time-resolved flow cytometer capable of measuring a luminescence with a decay time in the range of 10 microseconds to 2 ms, typical for some lanthanide chelates, is presented. The instrument permits acquisition of conventional light scatter and prompt fluorescence signals as well as detection of slowly decaying luminescence by a photon counting unit for a selectable time period of 1 microsecond to 1 ms. During photon counting, the laser beam is turned off by an acoustooptic deflector. The design of a flow chamber with an average geometrical light collection efficiency of 35% over a distance of 1.7 mm is presented and analyzed by ray tracing. A pulse processing system featuring digital integration of the conventional signals and a transputer system for the acquisition and the transfer of the measured parameter values to a host computer is described. Instrument function is verified with lyophilized human lymphocytes stained for the CD8 antigen with dye-loaded liposomes. Quantitation of cell-associated europium chelate fluorescence, displaying a decay time of 1.6 ms, is demonstrated. Elimination of fast decaying background emission generated by DNA-associated ethidium bromide is shown. The background generated by instrument components in the time-gated measurement channel is characterized, and measures for its complete elimination are discussed.

Genotoxicity testing of different types of beverages in the Drosophila wing Somatic Mutation And Recombination Test

Five wines and one brandy of Spanish origin as well as three herbal teas and ordinary black tea were tested for genotoxicity in the wing Somatic Mutation And Recombination Test (SMART) which makes use of the two recessive wing cell markers multiple wing hairs (mwh) and flare (flr3) on the left arm of chromosome 3 of Drosophila melanogaster. 3-day-old larvae trans-heterozygous for these two markers were fed the beverages at different concentrations and for different feeding periods using Drosophila instant medium. Somatic mutations or mitotic recombinations induced in the cells of the wing imaginal discs give rise to mutant single or twin spots on the wing blade of the emerging adult flies showing either the mwh phenotype or/and the flr phenotype. One of the red wines showed a clear genotoxic activity that was not due to its ethanol content. Two herbal teas (Urtica dioica, Achillea millefolium) and black tea (Camellia sinensis) proved to be weakly genotoxic as well. Furthermore, it was shown that quercetin and rutin, two flavonols present in beverages of plant origin, also exhibited weak genotoxic activity in the somatic cells of Drosophila. These results demonstrate that Drosophila in vivo somatic assays can detect the genotoxicity of complex mixtures such as beverages. In particular, it is possible to administer these test materials in the same form as that in which they are normally consumed.

Structure-activity relationships of tricyclic antidepressants and related compounds in the wing somatic mutation and recombination test of Drosophila melanogaster

Four antidepressants and one neuroleptic drug were tested for genotoxicity using the somatic mutation and recombination test (SMART) in wing cells of Drosophila melanogaster. Three-day-old larvae trans-heterozygous for two linked recessive wing hair mutations (multiple wing hairs and flare) were fed the test compounds in water or solvents mixed with a standard dry food for 48 h. Wings of the emerging adult flies were scored for the presence of spots of mutant cells which can result from either somatic mutation or mitotic recombination. The tricyclic antidepressant clomipramine, which is closely related to imipramine (previously shown to be genotoxic in somatic cells of Drosophila), was clearly genotoxic at concentrations above 10 mM. The structurally related antidepressants lofepramine and mianserin were positive only at 100 mM which is the maximum tolerated dose. The antidepressant maprotiline and the antipsychotic chlorpromazine, which are distinguished from the other compounds by a 6-membered central ring instead of a 7-membered one, were not genotoxic in the same dose range. These results lend further support for the hypothesis that an N atom in the heterocyclic 7-membered ring of the tricyclic molecule is responsible for the genotoxic property of the compounds in Drosophila.

The potential genotoxicity of sorbates: effects on cell cycle in vitro in V79 cells and somatic mutations in Drosophila

Sodium sorbate, potassium sorbate and an oxidation product of sodium sorbate, 4,5-epoxy-2-hexenoic acid, were tested for their genotoxic potential in cultured V79 Chinese hamster cells and in somatic cells of Drosophila melanogaster (wing spot test, SMART). In Drosophila only the epoxide showed a weak genotoxic effect. In V79 cells, freshly prepared sodium sorbate solutions at the highest concentrations only (2.5 mg/ml, 24 hr exposure) arrested mitosis at the G2/M cell cycle phase and potassium sorbate (2.5 mg/ml) had no effect. This arrest was reversible after a 24-hr recovery interval. Sodium sorbate solutions stored for up to 208 days were cytotoxic at 2.5 mg/ml, induced cell cycle arrest in the G2/M phase and increased cellular protein content, indicating an action similar to spindle poisoning and a chemical stress reaction (adaptation processes, modification of transcription). Potassium sorbate solutions stored for 28 days were also cytotoxic. With 4,5-epoxy-2-hexenoic acid at concentrations up to 0.01 mg/ml no effects were seen. At higher concentrations (at least 0.1 mg/ml) cell killing was observed, which probably resulted from unphysiologically lowered pH in the culture medium. Overall, the results are interpreted as an indication of a weak genotoxic potential of stored sodium sorbate solutions. Thus, sorbic acid and its potassium salt at the concentrations used for food preservation can still be considered as safe for human consumption.

The genotoxicity of chromium(VI) oxide in the wing spot test of Drosophila melanogaster is over 90% due to mitotic recombination

Chromium(VI) oxide and chromium(III) chloride were tested in the wing somatic mutation and recombination test (SMART) in Drosophila melanogaster according to standard procedures. The hexavalent compound was highly genotoxic in both chronic and acute treatments whereas the trivalent one was clearly negative. Further analysis of wings carrying an inversion chromosome which eliminates all recombination events showed that over 90% of the spots induced by chromium(VI) oxide are due to mitotic recombination.

Genotoxicity of 2-amino-3-methylimidazo[4,5-f]quinoline (IQ) and related compounds in Drosophila

The potent food mutagen and carcinogen 2-amino-3-methylimidazo[4,5- f]quinoline (IQ) and the structurally related heterocyclic aromatic amines 2-aminoimidazo[4,5-f]quinoline (demethyl-IQ) and 2-amino-1-methylimidazo[4,5-f]quinoline (iso-IQ) were assayed for genotoxicity in the wing somatic mutation and recombination test (SMART) as well as in the sex-linked recessive lethal (SLRL) test in Drosophila melanogaster. In addition, 3-methyl-2-nitroimidazo[4,5-f]quinoline (nitro-IQ), 2-nitrofluorene and 1,8-dinitropyrene were also assayed in the wing spot test. IQ was clearly mutagenic in the SLRL test with highest activity in spermatids. Iso-IQ was more active than IQ whereas demethyl-IQ was inactive in this test. The same pattern of results was obtained in the wing SMART: iso-IQ produced greater than 2-fold higher frequencies of spots than IQ and demethyl-IQ was clearly negative. In addition, nitro-IQ exhibited an approximately equal genotoxic activity as IQ. 2-Nitrofluorene and 1,8-dinitropyrene were both inactive in the wing spot test. These data provide good evidence for a correlation of genotoxic effects in germinal and somatic cells, and for the practical advantage of the wing spot test in Drosophila. Moreover, the results show structure-activity relationships among the heterocyclic aromatic amines and nitro compounds similar to those found in Salmonella.

Improved high bioactivation cross for the wing somatic mutation and recombination test in Drosophila melanogaster

The two tester strains of the high bioactivation (HB) cross for the wing somatic mutation and recombination test (SMART) in Drosophila melanogaster developed by Frölich and Würgler possess high metabolic capacity to activate promutagens. These strains contain chromosomes 1 and 2 of the DDT-resistant stock Oregon R(R) which exhibits a high constitutive level of cytochrome P450. However, they show several disadvantages for routine application, such as disturbed wing hair patterns in certain areas of the wing, making spot classification difficult, and a delay in development of the larvae. We have established and evaluated an improved HB cross (ORR; flr3 females and mwh males) producing ORR heterozygous individuals. These develop normally and have a normal, undisturbed wing hair pattern while exhibiting high bioactivation. The hybrid larvae of the improved HB cross show P450-dependent bioactivation capacity equal to or even slightly higher than those of the original HB cross. This was demonstrated by measuring the genotoxic activity of the promutagens diethylnitrosamine, 7,12-dimethylbenz[a]anthracene, N-nitrosopyrrolidine, and urethane. In addition, the improved HB cross has a sensitivity to the direct-acting alkylating agent ethyl nitrosourea equal to that of the standard cross. The main advantage of the improved HB cross is to combine the high bioactivation capacity with the ease of scoring the wings using the same criteria as for the standard cross.

[Environmental chemicals: their clinical significance in rheumatology]

Over the past years, various illnesses including features of connective tissue disorders (e.g. systemic sclerosis, systemic lupus erythematosus, mixed connective tissue disease), and rheumatoid arthritis, seemingly related to exposure to environmental materials have been reported. This paper presents some typical case reports and review major environmental associations seen in rheumatology, along with their epidemiology, clinical and laboratory features, possible pathogenesis, prognosis, and potential therapy.

Genotoxicity evaluation of five tricyclic antidepressants in the wing somatic mutation and recombination test in Drosophila melanogaster

Five tricyclic antidepressants were tested for genotoxicity using the somatic mutation and recombination test (SMART) in wing cells of Drosophila melanogaster. Three-day-old larvae trans-heterozygous for 2 linked recessive wing hair mutants (multiple wing hairs and flare) were fed the test compounds in water mixed with a standard dry food for 48 h. Wings of the emerging adult flies were scored for the presence of spots of mutant cells which can be the consequence of either somatic mutation or mitotic recombination. Desipramine and imipramine were clearly genotoxic at concentrations above 1 mM whereas amitriptyline, nortriptyline and protriptyline were not genotoxic at concentrations up to 100 mM. This seems to implicate the nitrogen atom at position 5 in the 7-membered ring of the tricyclic molecule as being responsible for the genotoxic property of the compounds in Drosophila.

The genotoxicity of nitrilotriacetic acid (NTA) in a somatic mutation and recombination test in Drosophila melanogaster

The genotoxicity of a chelating agent, the trisodium salt of nitrilotriacetic acid (NTA), was assessed in a somatic mutation and recombination test (SMART) in Drosophila melanogaster employing the wing hair markers mwh and flr3. The experiments were performed in parallel in two different laboratories (Padua, Italy and Schwerzenbach, Switzerland). The effectively absorbed doses of NTA, which was administered by feeding to larvae, were determined by a sensitive method employing [3H]leucine which allowed individual consumption levels to be measured. The particular pattern of clone induction produced by this compound suggests that NTA is active in inducing mitotic recombination and possibly aneuploidy in somatic cells of Drosophila. This is discussed in relation to the data present in the literature regarding the genotoxicity of NTA in a variety of experimental systems.

[The OFFER self concept questionnaire for adolescents and the success of inpatient psychotherapy]

The OFFER-Self-Image-Questionnaire reflect psychotherapeutic effects under special conditions. The OFFER-Self-Image-Questionnaire was used to evaluate outcome of in-patient psychotherapy in 15 adolescents. An increase of 8 or more points on the standard scale between the first and fourth week was associated with favourable outcome while an increase of 7 or less points indicated less favourable outcome.

In vivo cytochrome P 450 interactions of the newly developed H+/K(+)-ATPase inhibitor pantoprazole (BY 1023/SK&F 96022) compared to other antiulcer drugs

Almost 10% of adverse drug reactions observed in clinical patients are due to interactions of two or more therapeutic agents (18). The aim of the present study was to investigate in vivo interactions of the H2-blocker cimetidine and three newly developed H+/K(+)-ATPase inhibitors, omeprazole, lansoprazole and pantoprazole (BY 1023/SK&F 96022) with cytochrome P 450 in rats. Because diazepam is a drug used very often as comedication in ulcer patients, the duration of the effects of diazepam on muscle coordination were used to evaluate the drug interactions on metabolic enzymes. The present data indicate a clear rank order of the antiulcer drugs' potency for interaction with diazepam: 1) lansoprazole with a 50% prolongation of diazepam effect at 170 mumol/kg, 2) cimetidine and omeprazole at 281 and 288 mumol/kg, respectively and 3) pantoprazole at greater than 1000 mumol/kg. Because the three H+/K(+)-ATPase inhibitors are approximately equipotent with respect to inhibition of gastric acid secretion, it can be concluded that pantoprazole is superior to omeprazole and lansoprazole when unwanted adverse effects with drug metabolizing enzymes are considered. This may be an advantage in clinical use of the drug.

[F-waves and H-reflexes in hemispastic syndrome]

Canalized F-waves and H-reflexes occurring on small hand and foot muscles are to be considered symptoms of central disinhibition. Occurrence of these waves and reflexes in patients with hemispastic syndrome is analyzed and correlated with clinical aspects.

Thirty compounds tested in the Drosophila wing spot test

The Drosophila wing somatic mutation and recombination test (SMART) was evaluated for its suitability in genotoxicity screening by testing 30 chemicals. Of the 2 crosses used, the mwh-flr3 cross turned out to be more convenient than the previously used mwh-flr cross. Based on the experience gained with both acute exposures and chronic exposures of different duration, we suggest that the optimal strategy in genotoxicity screening is to start with chronic exposure of 3-day-old larvae for 48 h (that is, until pupation). Only for unstable compounds and very volatile compounds and gases are acute treatments, including inhalation, recommended. In general, a qualitative evaluation of the genotoxicity of a compound in the wing assay is possible with as few as 1-2 different exposure concentrations. A more quantitative evaluation of genotoxicity, based upon dose-response data, can often be achieved with as few as 3-4 concentrations. The results reported here were obtained in 2 different laboratories, demonstrating that the wing spot test is easily transferable to other laboratories. The experience gained indicates that the assay has now been developed to an extent that a coordinated international comparative validation study is desirable.

Genotoxicity of aniline derivatives in various short-term tests

Various substituted aniline derivatives were tested for genotoxicity in several short-term tests in order to examine the hypothesis that a substitution at both ortho positions (2,6-disubstitution) could prevent genotoxicity due to steric hindrance of an enzymatic activation to electrophilic intermediates. In the Salmonella/microsome assay, 2,6-dialkylsubstituted anilines and 2,4,6-trimethylaniline (2,4,6-TMA) were weakly mutagenic in strain TA100 when 20% S9 mix was used, although effects were small compared to those of 2,4-dimethylaniline and 2,4,5-trimethylaniline (2,4,5-TMA). In Drosophila melanogaster, however, 2,4,6-TMA and 2,4,6-trichloroaniline (TCA) were mutagenic in the wing spot test at 2-3 times lower doses than 2,4,5-TMA. In the 6-thioguanine resistance test in cultured fibroblasts, 2,4,6-TMA was again mutagenic at lower doses than 2,4,5-TMA. Two methylene-bis-aniline derivatives were also tested with the above methods: 4,4'-methylene-bis-(2-chloroaniline) (MOCA) was moderately genotoxic in all 3 test systems whereas 4,4'-methylene-bis-(2-ethyl-6-methylaniline) (MMEA) showed no genotoxicity at all. DNA binding studies in rats, however, revealed that both MOCA and MMEA produced DNA adducts in the liver at levels typically found for moderately strong genotoxic carcinogens. These results indicate that the predictive value of the in vitro test systems and particularly the Salmonella/microsome assay is inadequate to detect genotoxicity in aromatic amines. Genotoxicity seems to be a general property of aniline derivatives and does not seem to be greatly influenced by substitution at both ortho positions.

Genotoxicity testing of antiparasitic nitrofurans in the Drosophila wing somatic mutation and recombination test

Nifurtimox and eight structurally related 5-nitrofuran compounds active against Trypanosoma cruzi were tested for genotoxicity in the wing somatic mutation and recombination test in Drosophila melanogaster. Nifurtimox, compound ada and compound 1B were clearly mutagenic and recombinogenic whereas the remaining six compounds were negative. In contrast to the situation in bacterial mutagenicity tests, nitroreductase activity is probably not decisive for the genotoxicity of these compounds in Drosophila. The three non-genotoxic nitrofurans with high antiparasitic activity are promising candidates for the replacement of nifurtimox. However, these compounds require further genotoxicity testing in eukaryotic assay systems for a final evaluation.

Investigation of coffee in Drosophila genotoxicity tests

Two preparations of coffee (instant coffee and freeze-dried home-brew coffee) were tested in different mutagenicity assays in germ cells as well as in somatic cells of Drosophila melanogaster. The three end-points assayed in germ cells were sex-linked recessive lethals (mainly gene mutations and small chromosome aberrations), dominant lethals (cytotoxic effects as well as genotoxic effects) and sex-chromosome losses (chromosome breakage and non-disjunction). The aqueous coffee solutions were fed either to adult male flies for 3 days or to growing larvae during the whole larval development. Treated males were crossed with appropriately marked females, and the different genetic end-points were analysed in the F1 or F2 generation. The test concentrations (instant coffee 4% (w/v), home-brew coffee 3%) were acutely toxic in adult males (killing approximately 75 and 90% of the exposed flies, respectively). No increase in deaths was caused in larvae by the same concentrations. Only cytotoxic effects were observed in the test for dominant lethals. No conclusive genotoxic effects could be detected in any of the three germ cell assays. The coffee preparations were also tested for induction of mutation and mitotic recombination in somatic cells of the wing imaginal disc. Larvae trans-heterozygous for two recessive wing hair markers were fed high concentrations of the coffees for varying periods of time. Wings of surviving adult flies were analysed for mosaic spots. Twin spots exhibiting both mutant phenotypes are produced by mitotic recombination; single spots showing one or the other phenotype are the result of somatic mutation, such as gene mutation or deletion, or of mitotic recombination. Both coffees had weak effects on normal (repair-proficient) cells as well as on excision repair-defective cells in this assay. Additional experiments with pure caffeine and decaffeinated coffee show that these weak effects in somatic cells were most probably caused by the caffeine present in the two coffees.

Aristolochic acid is mutagenic and recombinogenic in Drosophila genotoxicity tests

Aristolochic acid (AA) has been tested for genotoxic activity in three different assays with Drosophila melanogaster (i-iii). AA induced sex-linked recessive lethals (i) and chromosome losses (ii) in male germ cells. In a newly developed fast assay with somatic cells of larvae (iii), AA induced mutant single spots as well as twin spots. The data indicate that in addition to the mutagenic activity, AA also possesses recombinogenic activity leading to somatic recombination in mitotically active cells. The experimental labor involved to detect the genotoxic activity of AA was lowest with the somatic cell assay.

Mutagenic activity of the pyrrolizidine alkaloids seneciphylline and senkirkine in Drosophila and their transfer into rat milk

Seneciphylline and senkirkine, two pyrrolizidine alkaloids that occur in animal feeds and medicinal herbs, respectively, have been tested for their ability to produce sex-linked recessive lethals in males of Drosophila melanogaster using the Basc test (3-day feeding method). Seneciphylline was found to be mutagenic at concentrations of 10(-5), 10(-4) and 10(-3)M, which produced 3.8% sex-linked recessive lethals (983 chromosomes tested). 9.0% (708) and 15.3% (327), respectively. Senkirkine (10(-5)M) produced 4.4% sex-linked recessive lethals (2541 chromosomes tested) against 0.17% (9081) in controls. Brood pattern analysis with senkirkine showed maximum sensitivity in the late spermatid stage of spermatogenesis, which agrees with evidence that pyrrolizidine alkaloids act as indirect mutagens. Flies fed with milk from lactating rats given an oral dose of 25 mg seneciphylline/kg showed 1.2% sex-linked recessive lethals (1477 chromosomes tested), against 0.3% (1533) in controls.

Somatic mutation and recombination test in Drosophila melanogaster

A novel test system for the detection of mutagenic and recombinogenic activity of chemicals is described in detail. Drosophila melanogaster larvae trans-heterozygous for the mutations multiple wing hairs (mwh) and flare (flr) are exposed to the test compounds for various periods of time ranging from 96 hr to 1 hr. Induced mutations are detected as single mosaic spots on the wing blade of surviving adults that show either the multiple wing hairs or flare phenotype. Induced recombination leads to mwh and flr twin spots and also to a certain extent, to mwh single spots. Recording of the frequency and the size of the different spots allows for a quantitative determination of the mutagenic and recombinogenic effects. This and earlier studies with a small set of well-known mutagens indicate that the test detects monofunctional and polyfunctional alkylating agents (ethyl methanesulfonate, diepoxybutane, mitomycin C, Trenimon), mutagens forming large adducts (aflatoxin B1), DNA breaking agents (bleomycin), intercalating agents (5-aminoacridine, ICR-170), spindle poisons (vinblastine), and antimetabolites (methotrexate). In addition, the test detects mutagens unstable in aqueous solution (beta-propiolactone), gaseous mutagens (1,2-dibromoethane), as well as promutagens needing various pathways of metabolic activation (aflatoxin B1, diethylnitrosamine, dimethylnitrosamine, mitomycin C, and procarbazine). The rapidity and ease of performance as well as the low costs of the test necessitate a high priority for validation of this promising Drosophila short-term test.

An investigation of the genetic toxicology of irradiated foodstuffs using short-term test systems. III--In vivo tests in small rodents and in Drosophila melanogaster

Six in vivo genetic toxicity tests were carried out on irradiated or unirradiated cooked chicken, dried dates and cooked fish. The tests were as follows: sex-linked recessive lethal mutations in Drosophila melanogaster (dried dates only), chromosome aberrations in bone marrow of Chinese hamsters, micronucleus test in rats, mice and Chinese hamsters, sister-chromatid exchange in bone marrow of mice and Chinese hamsters and in spermatogonia of mice, and DNA metabolism in spleen cells of Chinese hamsters. None of the tests provided any evidence of genetic toxicity induced by irradiation. However, dried dates, whether irradiated or not, showed evidence of some genetic toxicity in their effect on DNA metabolism in spleen cells and SCE induction in bone marrow. Feeding irradiated fish affected DNA metabolism in the spleen cells of Chinese hamsters. This effect could be interpreted as an induction of an immunoactive compound, although it could also be explained by the persistence of an immunoactive compound due to the removal by irradiation of spoilage organisms that would normally degrade it.

Mutagenesis in spermatozoa of Drosophila melanogaster by cross-linking agents depends on the mus(1)101+ gene product in the oocyte

In Drosophila melanogaster the sex-linked gene must(1)101+ is essential for mutagenesis induced by a cross-linking agent: mature sperm mutagenized by nitrogen mustard (HN2) yield high frequencies of induced sex-linked recessive lethals if tested with wild-type oocytes but practically no recessive lethals if tested with homozygous mus(1)101D1 oocytes. In the absence of mus(1)101+ at least some cross-links act as lethal lesions, whereas in the presence of mus(1)101+ some act as premutational lesions. The lack of delayed mutations in mutant oocytes indicates that the lesions are efficiently eliminated and do not lead to mutagenesis in later post-fertilization nuclear divisions. The mutation mus(1)101D1 is not a null allele because, in tests with heterozygotes, it reduces mutagenesis to a lesser extent than a deletion including the mus(1)101 locus. It is a leaky allele with such a reduced activity that, in homozygous condition, mutagenesis is practically absent. In deletion heterozygotes the mus(1)101+ gene is not dosage-compensated.

[The treatment of psoriasis-arthritis with cyclosporin A, a new immunosuppressive agent]

The treatment of psoriasis and psoriatic arthritis by cyclosporin A, a new immunosuppressive agent believed to have a largely selective action on T lymphocytes, is described. Results in 4 cases show that cyclosporin A can bring about a most impressive improvement in psoriatic lesions of the skin and its appendages, but that its effect on the arthropathy is variable. There is still little certainty about the compound's mechanism of action in these conditions. Cyclosporin A may give rise to a whole range of side effects and its use--like that of other immunosuppressants--should therefore be contemplated only in severe and progressive forms of psoriasis and psoriatic arthritis resistant to other forms of treatment except cytostatic drugs.

[Cyclosporin A--effects and side effects in the treatment of rheumatoid and psoriatic arthritis (author's transl)]

The treatment of rheumatoid arthritis and psoriatic arthritis with cyclosporin A is described. Cyslosporin A is a new selective immunosuppressant which acts primarily on the T lymphocytes. It has already been shown to be effective in preventing rejection following kidney transplantation as well as in preventing graft-versus-host disease. In rheumatoid and psoriatic arthritis, however, its effect was not satisfactory, although rather different in the two conditions; overall only about one third of the patients showed any marked improvement. By contrast, and for reasons which are as yet unexplained, it had a beneficial effect on the cutaneous symptoms of psoriasis. Cyclosporin A had little effect on immune parameters. Side effects--mainly kidney toxicity, gastro-intestinal reactions and hirsutism--were common but reversible. On present evidence its principal indication among rheumatological diseases would seem to be as a treatment for severe, intractable psoriatic arthritis.

[Renal side effects of treatment with cyclosporin A in rheumatoid arthritis and after bone marrow transplantation]

Renal function was studied prospectively in 6 patients with rheumatoid arthritis and non-prospectively in 5 patients after bone marrow transplantation. Both groups were treated with cyclosporin A. Functionally and histologically the results suggest tubulotoxicity of cyclosporin A which seems to be dose-related and reversible. Also found in the urine of these patients were yellow, as yet undescribed crystalline bodies often included in casts.

Mutation induction in repair-deficient strains of Drosophila

Experimental evidence indicates a polygenic control of mutagenesis in Drosophila melanogaster. In oocytes chromosome aberrations detected as half-translocations or dominant lethals depend on a repair system which in a number of genetically nonrelated strains shows different repair capacities. Sister chromatic exchanges (SCE) are easily studied as ring chromosome losses. They develop through a genotype controlled mechanism from, premutational lesions. Stocks with particular pairs of third chromosomes were discovered in which increased sensitivity of larvae to the toxic effects of a monofunctional alkylating agent (MMS) correlates with high frequencies of x-ray induced SCE's. Sex-linked mutagen-sensitive mutants could be shown to control mutation fixation: Pronounced maternal effects were found when sperm carrying particular types of premutational lesions were introduced into different types of mutant oocytes. The mutant mus(1)101D1 was found to be unable to process lesions induced by the crosslinking agent nitrogen mustard (HN2) into point mutations (measured as sex-linked recessive lethals). Alkylation damage leads to increased point mutation frequencies in the excision repair deficient mutant mei-9L1, but to reduced frequencies in the post-replication repair deficient mutant mei-41D5. It became clear that the study of maternal effects on mutagenized sperm represents an efficient tool to analyze the genetic control of mutagenesis in the eukaryotic genome of Drosophila melanogaster.

Mutagen-sensitive mutants in Drosophila melanogaster: effects on premutational damage

Drosophila melanogaster males from a Basc stock were mutagenized with either X-rays, ethyl methanesulfonate (EMS), or nitrogen mustard (HN2). Groups of identically treated males were crossed to different types of female. Sex-linked recessive lethals were scored as a genetic end point. The females used were homozygous for X-chromosomal mutations (mus(1)101D1, mus(1)104D1, mei-9 or mei-41D5) which lead to defective DNA repair and which increase the mutagen sensitivity of larvae. Females from a white stock with normal DNA repair capacities served as controls. The premutational lesions induced in mature sperm are only processed after insemination by the maternal enzyme systems present in the oocytes. Differences in the efficiency of the processing of lesions can lead to maternal effects on the frequency of mutations recovered from mutagenized sperm. It was found that, with the exception of mus(1)104D1, all mutants analysed significantly modify the mutation fixation of one or more types of premutational lesions. The most drastic effect is found with the mus(1)101D1 stock in which HN2-induced DNA cross-links do not lead to sex-linked recessive lethals. It is assumed that mus(1)101D1 is defective in an early step of DNA cross-link repair. Our first set of data clearly demonstrates that the study of maternal effects in Drosophila is an efficient tool to analyse the in vivo function of repair mutations on chemically induced mutagenesis.

Lack of correlation between MMS-toxicity in larvae and in adults of mutagen-sensitive mutants of Drosophila melanogaster

Adult males of 20 different stocks of Drosophila melanogaster, including 16 with various X-linked mutagen-sensitive mutations, were tested for sensitivity to the lethal action of methyl methane sulfonate (MMS) in a continuous feeding experiment. It was impossible to establish a correlation between MMS-toxicity in adults and MMS-toxicity in larvae. In addition, experiments to examine the fertility of MMS-treated flies of four mutagen-sensitive strains and one wild-type strain were performed. These experiments demonstrated that the spermatogonia of mei-9L1 and mei-41D5 in larvae and in adults are more sensitive to MMS than the spermatogonia of the wild-type strain or the other two mutagen-sensitive strains.

A protective effect of caffeine on drosophila larvae treated with methyl methanesulfonate

Lethality induced in larval populations of Drosophila melanogaster was recorded after treatment with (1) caffeine, (2) MMS or (3) caffeine plus MMS. The mixture of caffeine plus MMS was less toxic than expected from the effects observed after treatment with either substance individually. It is postulated that in the combined treatment the caffeine, by inhibiting semiconservative DNA replication, allows for some additional time for repair of alkylated DNA by a repair pathway which is not sensitive to caffeine, possibly excision repair.