Selection for longevity favors stringent metabolic control in Drosophila melanogaster.

Models of the evolution of life span predict, and gerontological studies show, a relation between nutrient use and life span. This study examines the role and comparative use of nutrients in long- and short-lived populations of D. melanogaster selectively bred for age-at-reproduction, without respect to metabolism or feeding rate. We test the hypotheses that selection for life span has favored the restriction of nutrient use and that the observed effect of low population density during development is a consequence of modifying nutrient use. The use of nutrients was measured here by the uptake of radiolabeled glucose, its incorporation into lipid and protein, and by the in vivo metabolic flux through the pentose shunt. Measurements show that uptake, incorporation, and flux are severely limited in long-lived stocks, compared to short-lived populations of the same stage and stage of development. Raising long-lived stocks at low population numbers relieves the restriction on metabolism in larvae, increasing incorporation and flux, and causes adult life span to decline. Larvae of long-lived populations appear to feed less actively, suggesting that the reduction in use of nutrients could simply be from reduced intake. Changes in total soluble protein correspond with measurements of uptake, incorporation, and flux. Soluble protein is substantially less in long-lived stocks, before pupation, but catches up in early adulthood to that in the short-lived populations. Despite different nutrient use by larval populations, only slight differences are found in development rate. They are insufficient to account for the differences observed in longevity.

Microbiological, chemical and toxicological characterization of contaminated sites in Czechoslovakia.

We investigated the contaminated area near the wood-preserving factory at the town Sobeslav in South Bohemia. The factory has been working for approximately 90 years. The soils of this area are extremely contaminated with the polyaromatic hydrocarbons (PAHs) derived from the creosote oils and heavy metals (predominantly Zn, Cu, Hg). The biological activities of sample contaminated soils are very low compared with unpolluted soil. The comparison of actual and potential activity between samples is evaluated for the prediction of the efficiency of application of a bioremediation processes. The testing of frequency of occurrence of a bacterium resistant to heavy metals (Zn and Cu) is used for prediction of possible negative effects on the biodegradation of organic pollutants at the concentrations of heavy metals in soils. A concentration of 2 mmol/l zinc in medium (according Houba-Remarcle) does not negatively influence the number of bacteria. A concentration of 2 mmol/l copper practically does not influence the number of bacteria. Several bacterial strains are able to survive concentrations of 20 mmol/l zinc, 8.5 mmol/l copper and 2 mmol/l cadmium. The preliminary results show that practically all strains which are resistant to heavy metals are able to degrade fluoranthene, as a representative PAH. The real concentrations of heavy metals in soils are below the levels where heavy metals negatively influence the growth of bacteria.

The use of the Microtox system for evaluation of toxicity of the wastes in Vítkovice Steelworks, Ostrava (Czechoslovakia).

Ostrava's Industrial Agglomeration is one of the most polluted areas in Czechoslovakia due to an enormous production of wastes and wastewaters from both industry and municipal sources. As most of the wastes are deposited in the environment in a very simple way (usually in landfills) they may cause negative environmental effects and represent a serious hazardous factor for the surroundings. Complex legislative regulations on waste treatment with respect to environmental protection are currently accepted. Many data on the character of produced and deposited wastes which are necessary for classification of wastes are, however, missing. Rapid and reliable estimates of biological effects of wastes were made in one of the biggest steelwork enterprises which belongs to the most significant producers of wastes in the Ostrava region. Typical wastes which are produced in the greatest amount were selected and the leachates of the wastes were tested using the microbial toxicity test, Microtox. The results contribute to a monitoring programme for evaluation of environmental quality.

The role of glucose-6-phosphate dehydrogenase in the evolution of longevity in Drosophila melanogaster.

Different polymorphic elements of the enzyme glucose-6-phosphate dehydrogenase (G6PD) are favoured under selection for long versus short life span. Replicate independently selected populations of short-lived individuals exhibit a more rapidly migrating and less actively staining allozyme, while long-lived populations have a slower migrating and more active allozyme. These correspond to the common ZwA and ZwB variants of the G6PD locus Zw. In vitro measurements show G6PD activity varies with allozymes and life span. Long-lived males have 64 per cent greater activity in G6PD, while females of long-lived strains are 108 per cent higher than those of short-lived strains. Previous studies of these strains have repeatedly demonstrated additivity of life span in F1 crosses. Activity of G6PD in reciprocal F1 populations is additive and intermediate between parents.

[Radiation changes of the lungs following irradiation for carcinoma]. / Radiacní zmeny plic po ozárení karcinomu

Moderately edematous lungs were ascertained in four cases of radiation pneumonitis causing death in connection with irradiating the carcinoma of the lungs by way of currently used orthovoltage actinotherapy. Histologically the most conspicuous were the findings of the hyaline alveolar membrane and the cellular atypia of endothel of the alveoles and the lymph-ducts.