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Results 451 - 500 of 634
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Mandal A - - 1990
Free and total amino sugar levels were determined in human prostatic fluid, vasectomized semen, presumably fertile semen, and in ejaculates having different degrees of coagulation. About 87% of the total amino sugar in seminal plasma was found in the bound form. The seminal vesicles were the richest source for seminal ...
Ekholm S - - 1990
Cardiovascular effects have been attributed to the amino acids which are precursors of catecholamines or other neurotransmitters. To study if even other amino acids may exert cardiovascular or ventilatory effects, a number of various acidic, basic and neutral L-amino acids were injected intravenously to anaesthetised normotensive rats at the doses ...
Gabrielian A E - - 1990
To determine whether hypotheses about the complementarity of amino acids based on the genetic code reflect the amino acid contact preferences found in natural proteins, the average contact probabilities for hypothetical complementary amino acid pairs were compared with those for all possible remaining pairs of the corresponding subset. A statistically ...
Ekeke G I - - 1990
Amino acid analysis showed that solvent extracts of Cajanus cajan L. Millsp. (Fabaceae) seeds (white species) contain, as free amino acid, as much as 26.3% phenylalanine. Antisickling experiments based on the estimated amount of free phenylalanine in the methanol (water-soluble) extract of the seeds showed that the presence of this ...
Jaffe K - - 1990
The involvement of certain amino acids in the memory consolidation process was investigated in the cricket Pteronemobius sp. Thirsty crickets were trained to constantly turn to one side of a symmetrical Y-shaped maze using reinforcement with water. Controls were trained to turn to both sides of the maze according to ...
Kusser W - - 1990
The ability to induce the ampicillin-mediated lysis of amino acid-deprived Escherichia coli by relaxing the stringent response decreased progressively during the course of amino acid deprivation, apparently because of a time-dependent decay in a key lysis event. The decay of this labile activity was not apparent when ampicillin treatment was ...
Tsuda T - - 1990
1. Accumulation of 2,4,6-trichlorophenyl-4'-aminophenyl ether (CNP-amino) in carp was investigated for 14 days. CNP-amino in carp could be divided into free CNP-amino [CNP-amino(I)] and bound CNP-amino [CNP-amino(II)]. 2. The bioconcentration factors (BCF) of CNP-amino(I + II) in carp were 90 +/- 38 (mean +/- SD, n = 3) for muscle, ...
Horii I - - 1989
The relationship between clinical severity, the hydration state of the skin surface as assessed by a conductance with a 3.5 MHz high frequency impedance meter, and the amino acid content of the stratum corneum (SC) of six patients with ichthyosis vulgaris and 30 elderly persons with varying degrees of xerosis ...
Di Giulio M - - 1989
In this paper, I define a measure of the relative position of each amino acid in the genetic code by means of a 21-dimensional vector describing its potential for mutation, in a single step, to each of the other amino acids, or to a chain termination codon. This measure allows ...
Schreurs W J - - 1989
Hyphae of Achlya bisexualis growing on lean media orient their extension towards a source of amino acids, and also put forth branches. Micropipettes were used to generate gradients of amino acids in the vicinity of individual hyphae. Phenylalanine and methionine were the most powerful attractants: 0.04 mM amino acid in ...
Sitaramam V - - 1989
The physical properties of amino acids were investigated in order to evaluate their possible relationship to the assignment of codons for amino acids in the genetic code. A comparison of the interconversion probability between amino acids and the distances between the amino acids for individual physical properties revealed a striking ...
Lonergan G - - 1989
A general and efficient method for the quantitative isolation of free amino acids from natural sources and their identification as crystalline N-t-butyloxycarbonyl amino acid phenacyl esters is described. The applicability of this method is illustrated in the isolation and characterization of major free amino acids from the Mediterranean fruit fly ...
Miseta A - - 1989
A better understanding of the origin and organization of genetic codons is possible based on the metabolic relatedness of amino acids. Amino acids with similar codons (anticodons) usually have the same or similar precursor molecule, even if the amino acids are not related physico-chemically. These observations suggest, that amino acid ...
Ottersen O P - - 1989
Amino acids are of crucial importance in brain function, not only as metabolic intermediates and building blocks of proteins, but also as mediators of interneuronal communication. This dual role of the amino acids distinguishes them from other neurotransmitter candidates, and implies that they are unlikely to be restricted to neurons ...
Mantagos S - - 1989
Normal newborns show a diurnal variation of blood amino acid concentration, with lower values at 04.00 h and higher at 12.00 h. Three groups of infants, each consisting of 10 normal, full-term neonates, remained under different lighting conditions for 24 h and blood amino acids were determined at 04.00 and ...
Gordon R - - 1989
The polyamine and amino acid composition of the mermithid nematode, Romanomermis culicivorax, and its host, Aedes aegypti, was determined. Putrescine, spermidine, spermine, cadaverine and two acetylated spermidine derivatives were present in parasitic juveniles, newly-emerged post-parasites, and eggs of R. culicivorax. Whole insect homogenates of fourth-instar A. aegypti contained the same ...
Imura K - - 1988
In 97 neonates receiving total parenteral nutrition in the postoperative period, clinical assessment was made for a newly devised amino acid solution (PF-I-III) from the standpoint of plasma amino acid profile and nutritional effect. These amino acid solutions prepared are characterized by the high concentration of branched-chain amino acids up ...
Klingensmith P M - - 1988
The amino acid composition of shell membranes from hard-shelled (HS), soft-shelled (SS), and shell-less (SL) eggs produced by 62-wk-old hens was analyzed by gas chromatography using N-acetyl n-propyl ester derivatives. This technique succeeded in identifying tryptophane and ornithine as shell membrane components. There were no significant differences in the concentrations ...
Taylor M A - - 1987
The sizes of amino acid pools in growing Xenopus laevis oocytes have been measured. The total free amino acid content per oocyte increases nearly 25-fold during oocyte growth. Together, glutamic acid and aspartic acid account for approximately 59-75% of the total amino acid pool in Xenopus oocytes. On the other ...
Porter G A - - 1987
Sugar, amino acid, and (14)C-assimilate release from attached maize (Zea mays L.) pedicels was studied following treatment with several chemical inhibitors. In the absence of these agents, sugar release was nearly linear over a 7-hour period. At least 13 amino acids were released with glutamine comprising over 30% of the ...
Nanda S - - 1987
A total of 21 amino acids were detected in the present investigations on three species of Gangesia (Cestoda: Proteocephalata) viz. G. bengalensis Woodland, 1924, G. hanumanthai Seth & Capoor, 1982 and G sanehensis Malhotra et al., 1981. The study was conducted in a sub-humid region around Allahabad, India. The implications ...
Albert V R - - 1987
We have sought to determine whether aromatic L-amino acid decarboxylase which functions as a neurotransmitter biosynthetic enzyme in neuronal cells can be distinguished from an enzyme with similar activity found in peripheral tissues where no neurotransmitters are synthesized. Aromatic L-amino acid decarboxylase was purified to electrophoretic homogeneity from bovine adrenal ...
Connolly B A - - 1987
Oligonucleotides containing a primary amino group at their 5'-termini have been prepared and further derivatised with amino specific probes. The sequence required is prepared using standard solid phase phosphoramidite techniques and an extra round of synthesis is then performed with N-monomethoxytrityl-0-methoxydiisopropylaminophosphinyl 3-aminopropan(1)ol. After cleavage from the resin, removal of the ...
McClendon J H - - 1987
The genetic code could not have been fixed until the means for biosynthesis of the amino acids was at hand. The biosynthetic enzymes could not be optimized until the genetic code ceased to be rearranged. Therefore the development of the code and the development of the biosynthesis of the amino ...
Kasahara T - - 1987
To measure the hedonic effectiveness of some D-amino acids two-bottle preference tests were carried out on ddy mice, and subsequently conditioned taste aversion (CTA) experiments were performed to determine to what degree hedonic responses to D- and L-amino acids are related to sweet taste in mice. Mice showed preferences for ...
Gabrys J - - 1987
Size and composition of the amino acid pool in the cell cytosol of atrial and ventricular heart muscle of 6-8 week old human embryos was evaluated by gas-liquid chromatography. It was found that the free amino acid pool in the ventricular heart muscle is about 50% higher than in the ...
Williams A P - - 1986
Some of the general problems commonly encountered with the analysis of amino acids have been described. These include problems associated with the preparation and storage of samples prior to analysis and those associated with the analytical stage itself. The effects on the accuracy of the determination of amino acids have ...
Minuk G Y - - 1986
Individual amino acids and amino acid mixtures caused a dose-dependent increase in chemiluminescence generated by peripheral blood polymorphonuclear leukocytes. A visual assay for opsonophagocytosis, however, failed to identify any quantitative differences between leukocytes incubated with amino acids and those incubated in amino-acid-free solutions. The results of this study suggest that ...
Cieslak D G - - 1986
The effect of lysine or threonine deficiency with or without excesses of all other amino acids was evaluated in a 21-d feeding study with male rats. Four amino acid mixtures were designed to be first limiting for the rat in lysine or threonine and contained either 0 or 50% excess ...
Mezl V A - - 1986
Amino acid analyses show that while the free amino acids found in the rabbit reticulocyte translation system do not increase during nuclease treatment or during prolonged storage, the endogenous levels of many amino acids are so high that the choice of a radioactive precursor for a translation should be based ...
Francis D H - - 1986
Various common L-amino acids differed in their ability to suppress K99 production in E. coli. Strains of E. coli also varied in their sensitivity to amino acid-mediated suppression of K99. Alanine, methionine, leucine, and valine were the most suppressive amino acids. However, when compared to single amino acids, mixtures of ...
Cronin J R - - 1986
All of the eighteen possible seven-carbon acyclic primary alpha-amino alkanoic acids have been positively identified in a hot-water extract of the Murchison meteorite by the combined use of gas chromatography-mass spectrometry, ion exchange chromatography and reversed-phase chromatography. None of these amino acids has previously been found in meteorites or in ...
Pulich W M - - 1986
A survey of leaf soluble amino acids was conducted for four subtropical seagrasses grown at several salinities. Proline functioned as an organic osmoticum in Halodule wrightii Aschers., Thallasia testudinum Banks ex Koenig, and Ruppia maritima L., while alanine functioned in an osmoregulatory capacity in Halophila engelmanni Aschers. When light-and salinity-induced ...
Welti M - - 1986
The laws governing degeneration of the genetic code are discussed below. Of fundamental importance in this context is the classification of the amino acids into groups on the basis of the physicochemical behaviour of their residues. From this, it is possible to formulate arithmetic relationships between the number of amino ...
Heger J - - 1985
Nitrogen balance was studied in growing male SPF-rats fed on diets in which each essential amino acid was varied from zero to about 120% of optimum requirement. From the balance results, optimum and maintenance requirements were estimated as well as the efficiency of utilization of amino acids for growth and ...
Liu Y - - 1985
When whole unripe green tomato fruits (Lycopersicon esculentum Mill, cv T(3)) were treated with ethylene (10 microliters per liter) for 18 hours, the fruit's ability to convert 1-aminocyclopropane-1-carboxylic acid (ACC) to N-malonyl-ACC (MACC) increased markedly and such an effect was also observed in fruits of mutant nor, which cannot ripen ...
Iwasaki K - - 1985
Neural responses to L- and D-amino acids were recorded from the chorda tympani in the ddy mouse and their preferences were measured using the two-bottle choice technique. Most of the D- and L-amino acids elicited neural responses above 10-30 mM, but amino acids with basic side chains and their HCl ...
Wallis I R - - 1985
Small, varying improvements in apparent ileal amino acid digestibilities were obtained when wheat was combined with certain other cereals in broiler diets. Synergistic interactions, sometimes resulting in large improvements in the apparent metabolisable energy (AME) contents of the diets, were also observed with certain cereal combinations. Combining wheat with maize ...
Gordon K D - - 1985
Integrated taste recordings of the glossopharyngeal (IX) nerve innervating the tongue of the southern leopard frog were studied in response to various amino acids and quinine hydrochloride. Amino acids and quinine hydrochloride elicited primarily phasic taste responses. Acidic (L-aspartic and L-glutamic) and basic (L-lysine and L-arginine) amino acids, adjusted to ...
Balasubramanian R - - 1985
Detailed calculations of the conformational characteristics of a primitive decoding system are presented. A penta-nucleotide serves as the primitive tRNA (PIT) with a triplet of primitive anticodon (PAC) in a helical conformation. This molecular moiety has a cleft in the middle. An amino acid can comfortably nestle into the cleft. ...
Jarrousse C - - 1985
The work presented here aims at investigating the in vitro relationship between amino acids and pancreatic hormonal release in the suckling rat. Among the 20 most usual amino acids, 12 of them were tested on perifused pieces of pancreas in 5.5-day-old rats at a low glucose concentration. Their effects were ...
Sjöström M - - 1985
The 20 naturally occurring amino acids are characterized by 20 variables: pKNH2, pKCOOH, pI, molecular weight, substituent van der Waals volume, seven 1H and 13C nuclear magnetic resonance shift variables, and eight hydrophobicity-hydrophilicity scales. The 20-dimensional data set is reduced to a few new dimensions by principal components analysis. The ...
Slagter P J - - 1984
Published equations for estimating the daily energy needs of laying hens were combined with published equations for estimating the daily amino acid needs to derive estimated energy:amino acid ratios for laying hens at different stages of production and environmental temperatures. Two feeding trials were conducted using various percentages of the ...
Carlucci A F - - 1984
Diel patterns of dissolved free amino acid (DFAA) concentration and microheterotrophic utilization were examined in the spring and fall of 1981 in euphotic waters from the base of the mixed layer off the southern California coast. The average depths of the isotherms sampled were 19.2 m for spring and 9.0 ...
Wallis I R - - 1984
The ability of the broiler chicken to metabolise energy and to digest and absorb amino acids increased from 30 to 50 d of age. Although sex had no major effect on metabolisable energy or amino acid digestibilities at these ages, the influence of environmental temperature on amino acid digestibilities appeared ...
Blalock J E - - 1984
An interesting pattern in the genetic code has been discovered. Codons for hydrophilic and hydrophobic amino acids on one strand of DNA are complemented by codons for hydrophobic and hydrophilic amino acids on the other DNA strand, respectively. The average tendency of codons for "uncharged" (slightly hydrophilic) amino acids is ...
Barber J R - - 1984
The pathophysiology, etiology, and metabolic alterations of severe hepatic failure and nutritional support of patients with this condition are reviewed. Hepatic failure encompasses a broad range of acute and chronic processes; complications may be fatal or quite minimal. Cirrhosis refers to all types of chronic diffuse liver disease. While hepatocytes ...
Levine R L - - 1984
Mixtures of amino acid phenylthiohydantoins ( PTHs ) can be identified and quantitated by multicomponent analysis of their ultraviolet spectra. For this analysis, the direct absorbance spectra were converted to their first derivatives. Then the multicomponent analysis routine resident in the spectrophotometer was used. The entire process requires less than ...
Yuasa S - - 1984
Two studies on the abiotic formation of amino acids are presented. The first study demonstrates the role of hydrogen cyanide as a precursor of amino acids detected in extracts of lunar samples. The formation of several amino acids, including glycine, alanine, aspartic acid, and glutamic acid, under conditions similar to ...
Pieber M - - 1983
The frequency of amino acid replacements in families of typical proteins has been elegantly analyzed by Argyle (1980) showing that the most frequent replacements involve a conservation of the amino acid chemical properties. The cyclic arrangement of the twenty amino acids resulting from the most frequent replacements has been described ...
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