Concentrations Of Several Components Research Articles

Effect of protein-free diet on the uptake of amino acids by the brain in vivo

Diet that is low in essential amino acids results in lowered protein metabolism and protein content in the developing brain; adult brain is affected less. To learn more about the mechanisms responsible for these alterations, we studied cerebral amino acid uptake in malnourished mice. Protein-free diet resulted in changes in the concentration of several components in the free amino acid pool of the brain. Histidine and homocarnosine concentration greatly increased; other changes observed in young and adult brain were an increase in phenylalanine and some decreases, especially in valine, isoleucine, tyrosine, and lysine. In adult brain ornithine and arginine also decreased. The gross amino acid composition of proteins was not changed under these conditions. In young mice changes in amino acid uptake in the instances we measured were parallel to changes of concentrations of these amino acids in brain. Without amino acid administration histidine increased, lysine decreased, and leucine was unchanged in the malnourished animal. Similarly, histidine uptake increased, lysine uptake decreased, and leucine uptake was unchanged in the malnourished animals compared to controls; α-aminoisobutyrate uptake was also unaffected. We conclude that malnutrition affects cerebral transport processes in a complex way: uptake of some compounds is increased, of some others decreased. These changes in turn result in changes in the concentration of cerebral metabolites, and in the rate of their metabolism.

Distribution of pollutants from a new paper plant in southern Lake Champlain, Vermont and New York

From November of 1973 to May of 1974, 15 arrays of sediment traps were placed along 33 km of southern Lake Champlain to sample the distribution of effluent from a large paper plant located on the western shore which had commenced operation in 1971. In the arrays located near the effluent diffuser pipeline as much as 2.3 cm of sediment accumulated, whereas elsewhere in the lake less than 1 cm accumulated. In the area of accelerated accumulation, sediments contained high concentrations of several components used in or derived from paper manufacturing. Values for kaolinite, expressed as the ratio of kaolinite to chlorite, for example, were as high as 1.4, anatase (TiO2) concentrations were as high as 0.8%, organic carbon 8.7%, and phosphorus 254 µg/g; all were more abundant than in sediments collected in traps to the south or north. In surficial bottom sediments collected near each array organic carbon and phosphorus were also higher (4.2% and 127 µg/g respectively) near the diffuser than elsewhere. Thus, the new plant after three years of production measurably affected the composition of suspended sediment and surficial bottom sediment despite the construction and use of extensive facilities to reduce the flow of pollutants to the lake.

Environmental isotopes in geothermal studies

The variations in the 18O/ 16O, D/H, 13C/ 12C, 34S/ 32S isotopic ratios and in the tritium concentrations of several components of geothermal fluids have been used widely in the hydrological study of thermal systems. The recharge areas, as well as the mixing phenomena between different fluids and the circulation times, can all be evaluated satisfactorily with the help of these techniques. Of great diagnostic value are the effects of the high temperatures at depth in the geothermal fields on the isotopic exchange reactions between the fluids and the reservoir rocks and on the fractionation factors between the compounds that coexist in the fluid. The latter phenomenon in particular has permitted us to use many isotopic geothermometers that provide useful indications on the temperatures of the main reservoirs. This paper gives a detailed description of their main applications and present limits, together with some indications as to future development of field research with regard to isotopic methods applied to exploration and study of geothermal areas.

Coronary heart disease and drinking water: A search in two Finnish male cohorts for epidemiologic evidence of a water factor

A search for the hypothetical factor in drinking water that might influence the mortality from C.H.D. was made in two rural areas in western and eastern Finland. A 10-yr follow-up of the resident males had shown a higher death rate from C.H.D. in the eastern area. The difference is only partly explained by the currently known risk factors of C.H.D. The levels of 22 water characteristics were investigated in 327 wells and six tap-water samples. In both areas the water used for drinking is soft but the mean concentrations of several components differ. In general, the concentrations are lower in the eastern area. The difference is significant for pH, F, Ca, Mg, Na, and Cr. The concentrations of NO 3, K, Cu, Co, Ni, and Ba are significantly higher in the eastern area. In both populations there were indications that death from, or the development of, C.H.D. was connected with the quality of the water, particularly with low concentrations of constituents. Assuming that a single water constituent is responsible for the difference in mortality from C.H.D. between the cohorts, the elements most suspect were chromium and, to a lesser degree, copper. C.H.D. was associated with low concentrations of chromium and high concentrations of copper in drinking water. Findings on magnesium were equivocal, and no association was observed with calcium. The relationships of the components of drinking water to the following risk factors of death from C.H.D. were also investigated: systolic blood pressure, serum cholesterol, extrasystoles in ECG, and cigarette smoking. In the eastern area the concentration of serum cholesterol correlated negatively with the concentration of chromium in drinking water.

EXTRAPIGMENTARY EFFECTS OF MELANOCYTE-STIMULATING HORMONE IN AMENORRHŒIC WOMEN

Highly purified melanocyte-stimulating hormone (M.S.H.) was administered to six women with secondary amenorrhœa. Menstrual bleeding occurred in five of the patients approximately 13 days later. Transient electroencephalographic changes and akathisia-like symptoms developed in at least three of the women. The aqueous-flare phenomenon and increased visual dark adaptation were not observed, but statistically significant changes occurred in the concentrations of several components of serum.

Effect of diet on amino acid profiles during metamorphosis of the blowfly Phormia regina Meigen

To examine the effects of change in diet, a quantitative comparison has been made of the individual ninhydrin-positive substances of non-sterile meat-raised Phormia regina larvae, pupae, and adults with the corresponding stages raised on a sterile semi-defined casein diet. Despite considerable changes in the concentration of several components in the larva, it is concluded that in the biological, and not statistical, sense only taurine and possibly methionine and methionine sulphoxide titres are significantly altered by the change in dietary regimen.

榛名湖湖氷に含まれる若干の化学成分

Ice and water samples were collected from Lake Haruna, Gumma Prefecture, in the winter, 1962. The vertical change of the concentration of several components (UV-absorbance, COD, Cl, and Ca+Mg) at the lake surface was investigated with the following results.1. All the components are less concentrated in ice than in water which bordered it.2. The degree of concentration from water to ice in regards to each component is expressed in the ratio (concentration in ice) / (concentration in water).The ratio is is larger for Cl than for the other components. This fact means that in the course of freezing of lake water the desalting effect is less for Cl than for the others.3. The ratio is found to be minimum in the deepest layer of ice contacting with lake water the ratios for E220, COD, Cl and Ca+Mg are 1/10, 1/10, 1/3 and 1/20 times those of lake water respectively.