Mechanisms and consequences of mutation induction in mammalian cells.

Mutations have been studied for several decades in order to understand biological processes of great significance and the selection of better-adapted species. Our knowledge both of mutation spectra induced by genotoxic agents and the mechanisms involved in DNA damage processing is more advanced in bacteria than in animal cells. However, the use of new technologies such as shuttle vectors or the polymerase chain reaction will undoubtedly allow rapid progress in the next few years.

High recombination rate of an Epstein-Barr virus-simian virus 40 hybrid shuttle vector in human cells.

The stability of an Epstein-Barr virus (EBV)-simian virus 40 (SV40) hybrid shuttle vector, the p205-GTI plasmid, was analyzed in human cells during EBV- or SV40-type replication mode. When the p205-GTI plasmid was maintained as an episomal EBV vector in the human 293 cell line, no rearrangement was detected. To induce the SV40 replication mode, cells containing the episomal p205-GTI plasmid were either transfected with vectors carrying the T antigen gene or infected with SV40.

Comparison of saphenous vein patch, polytetrafluoroethylene patch, and direct arteriotomy closure after carotid endarterectomy. Part I. Perioperative results.

To evaluate the perioperative outcomes and the immediate increases in size after patch closure, 140 carotid endarterectomies were randomized into one of three groups: direct no-patch closure, saphenous vein patch closure, and polytetrafluoroethylene patch closure. Seven patients (4.4%) experienced signs of cerebral ischemia in the immediate postoperative period.

Chlamydia trachomatis and pregnancy: a cross-sectional study in pregnant Viennese women.

To identify the epidemiologic role of Chlamydia trachomatis in Vienna and its incidence in the first and third trimesters of pregnancy, 1116 pregnant women (age range 16-43 years, medium age 26) were screened. Of 459 women applying for legal abortion in the first trimester of pregnancy, Chlamydia trachomatis was detected from the cervices of 24 (5.2%).

Structure of the two related elastase genes expressed in the rat pancreas.

We have isolated and characterized rat genomic DNA fragments bearing the two secretory elastase genes that are expressed in the exocrine pancreas. The complete exonic sequences for each of the genes as well as considerable intronic and flanking sequences are reported. Each elastase gene is interrupted by seven intervening sequences which are located at corresponding positions within the two genes, with one exception: the third intron of the elastase II gene has shifted one codon in the 5' direction.

Rat pancreatic ribonuclease messenger RNA. The nucleotide sequence of the entire mRNA and the derived amino acid sequence of the pre-enzyme.

We have cloned via recombinant DNA technology the mRNA sequence of rat pancreatic ribonuclease, and have determined the entire nucleotide sequence of the mature message. Clones bearing RNase sequences within a double-stranded complementary DNA library of rat pancreatic mRNA were initially detected by hybridization with size-fractionated rat pancreatic polyadenylated RNA that included mRNA 0.85 to 1.

The cumulation of chromium and arsenic species in fish (Poecilia reticulata).

Chromium-51 and arsenic-74 were used for the investigation of the uptake and the release of different chromium and arsenic species in fish. It has been found that only trimethylarsine can be rapidly taken up directly from water. The release of chromium(III), consumed by fish in food, is very rapid: about 99.

Two similar but nonallelic rat pancreatic trypsinogens. Nucleotide sequences of the cloned cDNAs.

We have cloned and identified mRNA sequences for two rat pancreatic trypsinogens. Nucleotide sequence analysis of the cloned sequences revealed two mRNAs that encode similar, though noallelic, pretrypsinogens. Trypsinogen I mRNA is 804 nucleotides in length, plus an estimated poly(A) tract of 100 nucleotides, and contains a short (13 nucleotide) 5' noncoding region and a 3' noncoding region of 54 nucleotides.

The cumulation of zinc and cadmium in fish (Poecilia reticulata).

Zinc-65 and cadmium-115 m were used for the investigation of the uptake and the release of zinc and cadmium in fish. It has been found that the uptake of these elements directly from water is relatively low. Zinc and cadmium, consumed by fish in food, are released with the biological half-time 0.

[Gamma-glutamyltransferase in the blood of cattle].

Information is given on a long-term observation of gMT activities in the blood of cattle, aimed at using the results to interpret metabolic tests, especially tests of the function of liver. Dynamics of changes in the gMT activities was studied in the year seasons and the per cent activities in the decades (from 20 to 100 U per 1) in different groups of cows according to their reproduction cycle. In the part discussion relationships are given between the gMT activities and other findings obtained from metabolic tests.

The cumulation of methylmercury in fish (Poecilia reticulata).

Methylmercury labelled with mercury-203 was used for the investigation of the uptake and the release of methylmercury in fish. It has been found that methylmercury compounds adsorbed on fish food remain completely in fish and that they are released with the biological half-time of 110 +/- 20 days. The cumulation of methylmercury from water is very rapid: the cumulation constant is 237 +/- 67 days-1.