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At least 19 recordsLinked to original sources
PubMed1978

The waste-product theory of aging: waste dilution by cell division.

When cells divide, the quantity of waste material per cell decreases because the wastes are "diluted" by apportionment between the daughters which result from the division. The quantity of waste present in a symmetrically or asymmetrically dividing population of cells is governed by a first-order non-linear differential equation. In the derivation of the equation, it is assumed (a) that waste is created at a rate which is either constant or proportional to the amount of waste already formed, (b) that waste is neither destroyed nor transported across cell walls, and (c) that the rate of cell division at large values of time is inversely proportional to the amount of waste per cell raised to a power. Relations among the parameters of the differential equation specify conditions under which its solutions rise to a critical value. If the amount of waste per cell given by a solution of the differential equation exceeds this value, it is assumed that deleterious effects become evident and that cell death follows. Decreases in the cell division rate leading to a cessation of population growth may occur at lower levels of waste accumulation.

Cell Division↗
PubMed1977

Mutagenicity of waste products from vinyl chloride industries.

The by-product from vinyl chloride production, EDC-tar, is a complex mixture of mainly short-chained chlorinated aliphatic hydrocarbons. This mixture has been tested for mutagenicity by means of Ames' Salmonella/mammalian microsome method. Since most of the components in the tar are poorly soluble in water, three agents were used as solvents or emulsifier: ethanol, DMSO, and Tween 80. The results with all these agents showed that EDC-tar contains direct as well as indirect mutagenic constitutents. It could be concluded that the mutagenic effect observed in the test could not be due to any significant extent to one of the main components, ethylene dichloride (1,2-dichloroethane). This substance showed a weak mutagenic effect, but only at higher concentrations than could be available in the highest concentration tested of the tar. Although the microsomal system enhanced the mutagenicity both of the EDC-tar and of 1,2-dichloroethane, this enhancement was dependent on NADPH in the case of EDC-tar but independent of NADPH with 1,2-dichloroethane. The Salmonella/mammalian microsome method seems to be a suitable tool for both mutagenicity screening of complex chemical mixtures and identification of mutagenic constituents in such mixtures.

Animals↗
PubMed1977

Thermophilic methane production from cattle waste.

Methane production from waste of cattle fed a finishing diet was investigated, using four 3-liter-working volume anaerobic digestors at 60 degrees C. At 55 degrees C a start-up culture, in which waste was the only source of bacteria, was generated within 8 days and readily adapted to 60 degrees C, where efficiency of methanogenesis was greater. Increasing the temperature from 60 to 65 degrees C tended to drastically lower efficiency. When feed concentrations of volatile solids (VS, organic matter) were increased in steps of 2% after holding for 1 months at a given concentration, the maximum concentrations for efficient fermentation were 8.2, 10.0, 11.6, and 11.6% for the retention times (RT) of 3, 6, 9, and 12 days, respectively. The VS destructions for these and lower feed concentrations were 31 to 37, 36 to 40, 47 to 49 and 51 to 53% for the 3-, 6-, 9-, and 12-day RT digestors, respectively, and the corresponding methane production rates were about 0.16, 0.18, 0.20, and 0.22 liters/day per g of VS in the feed. Gas contained 52 to 57% methane. At the above RT and feed concentrations, alkalinity rose to 5,000 to 7,700 mg of CaCo3 per liter (pH to 7.5 to 7.8), NH3 plus NH4+ to 64 to 90 mM, and total volatile acids to 850 to 2,050 mg/liter as acetate. The 3-day RT digestor was quite stable up to 8.2% feed VS and at this feed concentration produced methane at the very high rate of 4.5 liters/day per liter of digestor. Increasing the percentage of feed VS beyond those values indicated above resulted in greatly decreased organic matter destruction and methane production, variable decrease in pH, and increased alkalinity, ammonia, and total volatile acid concentrations, with propionate being the first to accumulate in large amounts. In a second experiment with another lot of waste, the results were similar. These studies indicate that loading rates can be much higher than those previously thought useful for maximizing methanogenesis from cattle waste.

Anaerobiosis↗
PubMed1976

Determination of hexachloro-1,3-butadiene in spinach, eggs, fish, and milk by electron capture gas-liquid chromatography.

Hexachloro-1,3-butadiene (HCBD), a waste product formed in the manufacture of perchloroethylene and trichloroethylene, has been found in fish from the lower Mississippi River basin. The AOAC official method for organochlorine pesticide residues in fatty and nonfatty foods has been modified for the determination of HCBD residues in selected food commodities. Acetonitrile extracts of nonfatty foods, or the combined acetonitrile extracts obtained in acetonitrile-petroleum ether partitioning of fat isolated from fatty foods, are diluted with water and extracted with petroleum ether. The petroleum ether extracts are chromatographed on Florisil and HCBD is eluted with petroleum ether. The elute is analyzed by gas-liquid chromatography with an electron capture detector. Average recoveries of HCBD from fortified samples of fatty and nonfatty foods were greater than 90% in the interlaboratory trials of the method.

Animals↗
PubMed1976

Progress in biochemical engineering.

Biochemical engineering is one of the answers to some of the challenges of the present age: hunger, shortage in raw material and energy supply and contamination of environment. Its contribution to the solution of these problems is the industrial production of protein, the use of raw materials (incl. waste products) not used up to now, the accomplishment of chemical reactions at ambient temperatures as well as the degradation or utilization of widely different waste materials.

Biochemical Phenomena↗
PubMed1978

Chlorinated tyrosine in municipal waste treatment plant products after superchlorination.

Previous work has shown that 3, 5-dibromotyrosine acts as a thyroxine production/secretion inhibitor which may imply a similar response to chlorotyrosine derivatives. Chloro- and dichlorotyrosine have been produced in the laboratory by the action of aqueous chlorine upon tyrosine at low pH, and have been found in the effluent from superchlorination facilities in use at three municipal waste treatment plants. The extent to which these and other possible chlorinated amino acids occur in superchlorinated waste products, and their fate in receiving streams is not known, and is under investigation by this laboratory.

Amino Acids↗
PubMed1978

Retention of fluoride from diets containing materials produced during aluminium smelting.

1. Using male rats, the availability of fluoride from five by products of the aluminium smelting industry was tested. This was done by considering the balance between fluoride administered in controlled diets and the total fluoride content of waste products eliminated over an experimental period of 1 week. 2. Results indicated that yields of available fluoride expressed as percentage weight of original material were cryolite (Na3ALF6), 45.9%; sodium fluoride (NaF), 41.7%; aluminium fluoride (AFL3.H20), 9.1%; mist eliminator grid solids (with CaF2), 9.4%; reclaimed alumina with adsorbed F, 0.27%. 3. Of the various tissues analysed for fluoride content, only the kidney and femur showed any significant correlation with the amounts of fluoride absorbed or retained.

Aluminum↗
PubMed1976

[Determination of the toxicity of industrial waste by means of a bacterial test (author's transl)].

The decision on whether industrial waste should be deposited on general or special dumps depends upon the toxicity of the waste and thus upon the risk of ground-water pollution and the killing off of micro-organisms responsible for breaking down waste products. Since chemical analyses that are to provide information on toxicity are frequently very costly, an attempt was made to determine the toxicity of solid or semi-solid waste with the aid of a bacterial test. As in the perforated-plate test, here, too, the formation and size of inhibition zones were used to determine the toxicity after diffusion of substances contained in industrial waste. About 30 different types of industrial waste were examined with this method. For almost all substances a positive correlation of the (known) constituents of waste to the formation of inhibition zones was found to exist. The influence exercised by solubility and diffusibility and other problems are dealt with.

Hydrogen-Ion Concentration↗
PubMed1979

[Nutritive antibiotic additives in animal feeding stuffs--a further form of environmental pollution (author's transl)].

Feeding domestic animals with mycelia, a by-product of vitamine production, gave rise to the side effect of markedly improved utilization of the fodder. This effect is not due to the vitamine and protein content but to the antibiotic content of this waste product. The nutritive effect was brought about by a larger number of different antibiotics in concentrations which were considerably lower than the therapeutically required doses. Therefore we speak, in this connection, of a nutritive addition of antibiotics to animal fodder. Since at the time of introducing this feeding method only the mutational resistance to antibiotics of pathogens was known and since the nutritive dosaging cannot select such therapeutically relevant degrees of resistance of the germs, no importance was attached to the development of the resistance and its effect on human medicine. However, during the last decade it has been found that the feeding of antibiotics is indeed capable of selecting the plasmidic resistance to antibiotics of the gram-negative intestinal bacteria in the faeces of the animals. For pigs, calves and hens--to quote only the most important animals--now contain a coliflora almost completely studded with R-factors. Owing to the transmissibility of the plasmids and the epidemiologically short path from animal to man, dangers emerge for the human medicine from this nutritive selection. Therefore the use of all antibiotics which select resistance plasmids, should be avoided in animal feed stuffs. It would be best, if antibiotics used in human medicine were not used in veterinary practice.

Animal Feed↗
PubMed1978

The current status of hazardous solid waste management.

Growth of the population and of industrialization, and substandard disposal of the increased waste products thus generated, have resulted in numerous documented cases of harm to human, plant, and animal health. The Resource Conservation and Recovery Act (1976), its stated goals, and its intended means of implementation, are discussed relative to hazardous waste problems. Subtitle C of this Act, and the authority granted by it to the U.S. Environmental Protection Agency, are explained. Standards and regulations have been imposed upon those responsible for generating and transporting hazardous wastes, to ensure the ultimate safe disposal of such wastes in environmentally suitable, properly licensed facilities.

Environmental Pollution↗
PubMed1978

Kinetics of growth and ectopic production of human chorionic gonadotropin by an ovarian cystadenocarcinoma cell line maintained in vitro.

An established ovarian papillary cystadenocarcinoma cell line, designated 163, released immunoreactive human chorionic gonadotropin (HCG) in vitro into the culture medium. The maximal rate of this ectopic activity (10 to 15 ng/day/10(6) cells) occurred at the onset of the logarithmic phase of cell growth and greatly exceeded the intracellular HCG content of cells approaching confluency (0.037 ng/10(6) cells). The HCG production was not detected during the plateau phase of growth. The rate of cellular proliferation and HCG release depended upon the frequency of media change in a manner suggesting that the two processes are interrelated and may be affected by such environmental factors as cell density, nutrient availability, and the accumulation of waste products. The addition of purified HCG to the cultures had no appreciable effect on either the cell growth or the accumulation of HCG. The release of HCG into the medium was greatly stimulated in the presence of sodium butyrate at concentrations from 1 to 10 mM, despite the fact that these concentrations of butyrate resulted in a marked decrease in the cell number/culture in comparison with control media. Equivalent amounts of sodium acetate had no effect on either cell growth or the release of HCG.

Butyrates↗
PubMed1976

Qualitative distribution of neutral lipids and phospholipids in Hymenolepis microstoma from the cysticercoid to the egg producing adult.

The distribution of neutral lipids and phospholipids in Hymenolepis microstoma has been studied using Fettrot, Sudan Black B, Sudan IV and copper phthalocyanin staining techniques. In the cysticercoid, neutral lipids are found in the outer membrane, the lining of the cysticercoid cavity, the tegument of the larval worm and the calcareous corpuscles. A decreasing gradient of phospholipids is found starting from the acellular layer, through the circular fibrous layer, the longitudinal fibrous layer, the adjacent dense zone and ending with the lining of the cysticercoid cavity. Phospholipids are also found in the calcareous corpuscles and the tegument of the larval worm. In the young adult (3 days p.i.) fat globules are first seen to accumulate in the last 2-3 proglottids. Until the 6th day p.i. they are found in the posterior third of the worm, surrounding developing gonads, but mostly concentrated along the transverse line. The mature proglottids contain fat, (a) in both granular and globular forms: in the folds of the uterus, sperm ducts, cirrus pouch and tegument (proximal cytoplasm), (b) in a diffuse form: in the vitellaria, ovary, testes and the tegument (distal cytoplasm). Pre-gravid and gravid proglottids show the largest fat globules. From the cleaving embryo to the fully developed oncosphere the concentrations of neutral lipids and phospholipids vary in form, intensity and location. In all strobilar forms of the parasite neutral lipids and phospholipids are found in the tegument and calcareous corpuscles. Although in H. microstoma lipid droplets are found in the excretory canals, all lipids in the proglottids are not absolutely waste products. From the results it would appear that they play a role in the maturation of gonads and transformation of the fertilized ovum to the oncosphere.

Animals↗