Detection of polycyclic aromatic hydrocarbon exposure damage using different methods in laboratory animals.

Benzo[a]pyrene, benzo[b]fluoroanthene and dibenzo[a,h]anthracene dissolved in a 1:2 mixture of dimethylsulphoxide (DMSO) and water were administered to two groups of female mice, each group containing 15 mice. The doses were administered orally (via gavage) at the respective rates of 1 and 100 micrograms kg-1 body weight five times per week for a period of 9 weeks. The influence of the polycyclic aromatic hydrocarbons (PAHs) was determined using the following methods: determination of DNA-PAH adducts, of chromosome injuries (micronucleus test), of induction of repair using the unscheduled DNA synthesis (UDS) test, and by examination of the DNA structure after nucleoid sedimentation. All the methods investigated provided evidence of a significant effect resulting from exposure to PAHs on the parameters examined. Following chronic exposure to PAHs, the formation of DNA-PAH adducts and injury to the genetic material, as well as the appearance of micronuclei (micronucleus test), the induction of unscheduled DNA synthesis (UDS test) and mutation of the DNA structure (nucleoid sedimentation), were demonstrated. The described methods therefore provide a means for the detection of genetic damage caused by PAH exposure in humans.

Abnormal epidermal changes after argon laser treatment.

A 26-year-old woman with a congenital port-wine stain on the forehead was treated three times at 2-month intervals with an argon laser. Six months after the last treatment, moderate blanching and mild scaling confined to the treated area was observed. A biopsy specimen of the treated area revealed a significant decrease in ectatic vessels. However, epidermal changes similar to those of actinic keratosis with disorganized cell layers and marked cytologic abnormalities were seen. Analysis of peripheral blood lymphocytes for a defect in DNA repair was negative. Multiple, argon laser-induced photothermal effects may be responsible for the changes observed in our case and may lead to premalignant epidermal transformation.

Continuous induction of unscheduled DNA synthesis by gamma irradiation.

The induction of DNA-synthesis in non-S-phase cells is a very sensitive measure of a preceding damage of DNA. Usually, in an in vivo-in vitro test (treatment of an animal, incorporation of H3-thymidine in a cell suspension) the damaging of DNA takes place hours to days before the evaluation. In this case, the time course of the UDS-induction after a single dose of 1 Gy gamma irradiation was observed over a long period of time (21 months). C57 black mice served as test animals. In an age of about 80 days they were irradiated and the induction of unscheduled DNA synthesis was measured at ten time intervals during the whole life-span of the animals. Although the repair in this gamma radiation damage in DNA is a very quick process--with centrifugation in alkaline sucrose a half-life of some minutes is found--an induction of unscheduled DNA synthesis could be seen at the irradiated animals until the end of their life (640 days). The reason for this could be permanent disorders in cellular regulation caused by the gamma irradiation.

Pharmacogenetic differences in the inhibitory effect of cimetidine on the metabolism of antipyrine.

The relationship between acetylator phenotype and the inhibitory effect of cimetidine on the hepatic metabolism of antipyrine has been studied in 20 subjects. Cimetidine, 1,0 g/day resulted in a significant decrease in the metabolic clearance rate of antipyrine, but only in slow acetylators, as fast acetylators were less affected. No sex difference was observed. No major change occurred in the urinary excretion of D-glucaric acid, which means that cimetidine had not-affected that Phase II reaction. It did significantly decrease the urinary partial clearance rate of norantipyrine, leaving that of antipyrine and 4-OH-antipyrine unchanged, which suggests that cimetidine had preferentially inhibited the P450 isozyme that catalyses norantipyrine formation.

[DNA metabolism in lymphocytes of experimental subjects during thermotherapy (sauna, Turkish bath)]. / DNA-Metabolismus in Lymphozyten von Versuchspersonen unter Thermotherapie (Sauna, Dampfbad).

The unprogrammed DNA synthesis (UDS) in the lymphocytes of the peripheral blood was significantly higher in regular sauna-users than in those who had not had a sauna for some time. Sedimentation velocity of the supercoiled DNA in the lymphocytes was decreased 1 h and 24 h after Turkish bath, but the difference from values before the bath was not statistically significant.

[Studies on the possible influence of oxamethacin upon DNA synthesis, DNA reparation and the supercoiled structure of DNA is spleen cells of mice]. / Untersuchungen über einen möglichen Einfluss von Oxametacin auf DNA Synthese, DNA Reparatur und die Supercoiled Struktur der DNA in Mausmilzzellen.

The action of Oxamethacin on the DNA metabolism in spleen cells of mice was investigated with "in vitro" and "in vivo" experiments. An in vitro incubation of cells with 1 microgram Oxamethacin/ml did not influence the replicative DNA synthesis. 10 micrograms/ml however inhibited 50% of DNA synthesis. Oxamethacin dispensed in vivo did not show this inhibition. DNA repair after UV as well as after gamma irradiation was not influenced by this substance. Also the reconstitution of the supercoiled form of the DNA after different damages was not affected by Oxamethacin.

The influence of some prostaglandins on DNA synthesis and DNA excision repair in mouse spleen cells in vitro.

In vitro experiments were performed on mouse spleen cells to establish possible influences of some naturally occurring prostaglandins on DNA synthesis and DNA excision repair. The prostaglandins A1, B1, E1, E2 and F2alpha were tested in concentrations of lopg, 5ng and 2.5microgram per ml cell suspension. DNA synthesis was significantly increased by PgF2alpha in all the three concentrations tested, while the other tested prostaglandins were essentially ineffective. DNA excision repair was significantly inhibited by PgE1 and PgE2 at 5ng/ml and at 2.5microgram/ml but increased by PgF2alpha in the two lower concentrations. The rejoining of DNA-strand breaks after gamma-irradiation was slightly reduced by PgE1, PgE2 and PgF2alpha at 2.5microgram/ml.

[Studies on cellular protein synthesis in synovial fluid following intraarticular gold administration (author's transl)]. / Untersuchungen über die Proteinsynthese der Zellen der Synovialflüssigkeit nach intraartikulärer Goldapplikation.

Na-aurothiomalate was applied intraarticularly in the conentration range between 2 and 40 mg to joints of patients with rheumatoid arthritis. Between 2 and 20 mg a constant inhibition of 3H-aminoacids incorporation in proteins was observed. At a dosage of 40 mg of this gold salt a strong inhibition could be detected. In the low concentration range an additional degradation of structurally changed proteins could be the cause of the lower incorporation rate of 3H-aminoacids. From 40 mg on a real inhibition of protein synthesis seems to occur.

[Mode of action of D-penicillamine in chronic polyarthritis. 2. Studies on DNA repair in synovial fluid cells following intra-articular administration of D-penicillamine]. / Uber den Wirkungsmechanismus von D-Penicillamin bei chronischer Polyarthritis. 2. Untersuchungen über die DNA-Reparatur in Zellen der Synovialflüssigkeit nach intraartikulärer D-Penicillamin-Verabreichung.

6 patients with rheumatoid arthritis were treated intraarticularly with 50 or 100 mg D-Penicillamine. The influence of this substance on DNA repair in cells of synovial fluid was investigated. DNA repair was investigated by gradient centrifugation. 50 mg D-PA showed no effect, 100 mg D-PA a slight slowing of the DNA-rejoining till the native supercoiled DNA form.

[DNA--"rejoining" in lymphycytes of patients with a minifestation of rheumatoid arthritis in older age (author's transl)]. / Untersuchungen über das "Rejoining" von DNA aus Lymphozyten von Patienten mit Alters-cP.

Relations between the time of manifestation of the disease and the course of the rheumatoid arthritis were found from the clinic frequently. Patients with later first manifestation of rheumatoid arthritis show clear differences against patients with earlier manifestation of the disease at which the late first manifestation a high activity of the process of the disease exhibit. In males first manifestation of rheumatoid arthritis in middle age of 54,5 years was observed, while in a first manifestation of rheumatoid arthritis in middle age of 47 years a normal course of the disease was found. The difference between the both courses was proved as significantly. In former investigations we could prove that in patients with rheumatoid arthritis the 3H-Thymidin-build in the course of not programmed DNA-synthesis in the DNA of lymphocytes after damage with ionizing was retarded. The rate of not programmed DNA synthesis seems to be in old persons equal. The ligase reaction is possibly diminished because the number of DNA-strand breakes with the age is strong increasing.

[Effect of sodium fluoride on DNA metabolism during therapy for osteoporosis]. / Der Einfluss von Natrium-Fluorid auf den DNA-Metabolismus während einer Osteoporose-Therapie.

The influence of sodium fluoride therapy on semiconservative DNA-synthesis and DNA-excision repair was investigated in lymphocytes of the peripheral blood of 6 patients with osteoporosis. The daily dose of sodium fluoride was 25 mg in the first week, and subsequent 50 mg during a period of 15 to 37 weeks. No significant effect on the tested parameters was found in 5 subjects. One patient showed significantly inhibited DNA-repair in the lymphocytes up to the ninth week, but during subsequent therapy normal values were obtained in this patient also. In conclusion sodium fluoride seems to have no effect on DNA-metabolism in lymphocytes of patients with osteoporosis.

[Influence of some cytostatic drugs on semiconservative DNA-synthesis and DNA-repair in normal and cancer cells (author's transl)]. / Die Wirkung einiger Zytostatika auf die semikonservative DNS-Synthese und auf die DNS-Reparatur von normalen und Tumorzellen

The action of cyclophosphamide, vincristine, vinblastine and procarbacine on the enzymes of the excision repair and on the semiconservative DNA-synthesis was investigated. To get a view of the total repair enzyme complexes the incorporation of 3H-thymidine into DNA after UV- and Gamma-irradiation was measured, and sedimentation profiles in alkaline sucrose were carried out. The drugs were also tested after being metabolized. The 4 drugs had no influence in an in vitro system on DNA-repair using spleen cells. Vinblastine and procarbacine showed an inhibitory effect on semiconservative DNA-synthesis. Using Yoshida ascites cells for the investigations we found an inhibition of the exonuclease-polymerase system by cyclophosphamide and procarbacine and a supression of ligase reaction by vinblastine and vincristine. Different degrees of inhibition of DNA-synthesis in Yoshida ascites cells could be seen after use of the 4 cytostatic drugs.

Investigations into the inhibition of DNA repair processes by detergents.

The inhibition of semi-conservative DNA replication and unscheduled DNA synthesis by three different detergents was investigated in mouse spleen cells. The investigations were made by following the kinetics of the incorporation of 3H-thymidine into the DNA, as well as by autoradiographic studies. At various concentrations different inhibition patterns were found and the significance of these findings is discussed.