scholarly journals The Effect of Noise in Raman Spectra on the Reconstruction of the Concentration of Amino Acids in the Mixture by Multivariate Curve Resolution (MCR) Analysis

2021 ◽  
Vol 7 (2) ◽  
pp. 020309
Author(s):  
Irina Matveeva ◽  
Lyudmila Bratchenko ◽  
Oleg Myakinin ◽  
Elena Tupikova ◽  
Valery Zakharov
Keyword(s):  
Amino Acids ◽  
Raman Spectrum ◽  
Amino Acid ◽  
Raman Spectra ◽  
Biological Tissues ◽  
Amino Acid Mixture ◽  
Multivariate Curve Resolution ◽  
Acid Mixture ◽  
Curve Resolution ◽  
Negative Effect

Changes in the concentration of free amino acids in biological tissues is a sign of impaired protein metabolism in patients with cancer. Recently, Raman spectroscopy has been used for early diagnostics of oncological diseases. The concentrations of individual components of biological tissue (for instance, the concentrations of amino acids) can be obtained by decomposing the tissue Raman spectrum. This study was designed to evaluate the effect of noise in the Raman spectra of individual amino acids on the result of the decomposition of the spectra of an amino acid mixture. As a decomposition method, we used Multivariate Curve Resolution-Alternating Least Squares (MCR–ALS) analysis and investigate experimental Raman spectra of amino acids and mathematically simulated Raman spectra of amino acid mixtures. Noise with different signal-to-noise ratios (SNR) was artificially added to both the experimental spectra of pure amino acids and the spectra of the mixtures. Concentration values for each amino acid obtained as a result of applying the MCR–ALS analysis have been compared with the corresponding true values and the correlation coefficients have been calculated. The results show a less pronounced negative effect of noise in the case when the spectra of pure amino acids (which were used as a basis for the MCR–ALS analysis) are noisy, and a more pronounced negative effect when the spectrum of the mixture is noisy. The accuracy of reconstruction of an amino acid is also negatively affected by strong background fluorescence in the amino acid spectrum. Moreover, the results indicate that using the basis spectra with a high SNR (SNR = 5) makes it possible to successfully estimate the amino acid concentrations in a mixture even when the Raman spectrum of the mixture is noisy and has a low SNR (SNR < 5).

scholarly journals Effect of co-ingestion of amino acids with rice on glycaemic and insulinaemic response

2015 ◽  
Vol 114 (11) ◽  
pp. 1845-1851 ◽  
Author(s):  
Yean Yean Soong ◽  
Joseph Lim ◽  
Lijuan Sun ◽  
Christiani Jeyakumar Henry
Keyword(s):  
Amino Acids ◽  
Blood Glucose ◽  
Amino Acid ◽  
Glycaemic Index ◽  
Amino Acid Mixture ◽  
Postprandial Blood Glucose ◽  
Acid Mixture ◽  
White Rice ◽  
Amino Acid Mixtures

AbstractConsumption of high glycaemic index (GI) and glycaemic response (GR) food such as white rice has been implicated in the development of type 2 diabetes. Previous studies have reported the ability of individual amino acids to reduce GR of carbohydrate-rich foods. Because of the bitter flavour of amino acids, they have rarely been used to reduce GR. We now report the use of a palatable, preformed amino acid mixture in the form of essence of chicken. In all, sixteen healthy male Chinese were served 68 or 136 ml amino acid mixture together with rice, or 15 or 30 min before consumption of white rice. Postprandial blood glucose and plasma insulin concentrations were measured at fasting and every 15 min after consumption of the meal until 60 min after the consumption of the white rice. Subsequent blood samples were taken at 30-min intervals until 210 min. The co-ingestion of 68 ml of amino acid mixture with white rice produced the best results in reducing the peak blood glucose and GR of white rice without increasing the insulinaemic response. It is postulated that amino acid mixtures prime β-cell insulin secretion and peripheral tissue uptake of glucose. The use of ready-to-drink amino acid mixtures may be a useful strategy for lowering the high-GI rice diets consumed in Asia.

Liver extract and its free amino acids equally stimulate gastric acid secretion

1980 ◽  
Vol 239 (6) ◽  
pp. G493-G496 ◽  
Author(s):  
E. J. Feldman ◽  
M. I. Grossman
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Acid Secretion ◽  
Gastric Acid Secretion ◽  
Free Amino Acid ◽  
Free Amino Acids ◽  
Free Amino ◽  
Liver Extract ◽  
Amino Acid Mixture ◽  
Acid Mixture

Using intragastric titration in dogs with gastric fistulas, dose-response studies were carried out with liver extract and with a mixture of amino acids that matched the free amino acids found in liver extract. All solutions were adjusted to pH 7.0 and osmolality to 290 mosmol x kg-1. Doses are expressed as the sum of the concentrations of all free amino acids. At each dose studied (free amino acid concentration: 2.8, 5.6, 11, 23, and 45 mM), acid secretion in response to the free amino acid mixture was not significantly different from that of liver extract. The peak response to both liver extract and the free amino acid mixture occurred with the 23-mM dose and represented about 60% of the maximal response to histamine. The serum concentrations of gastrin after liver extract and the amino acid mixture were not significantly different. It is concluded that in dogs with gastric fistula, gastric acid secretion and release of gastrin were not significantly different in response to liver extract and to a mixture of amino acids that simulated the free amino acid content of liver extract.

An abundant supply of amino acids enhances the metabolic effect of exercise on muscle protein

1997 ◽  
Vol 273 (1) ◽  
pp. E122-E129 ◽  
Author(s):  
G. Biolo ◽  
K. D. Tipton ◽  
S. Klein ◽  
R. R. Wolfe
Keyword(s):  
Amino Acids ◽  
Blood Flow ◽  
Protein Synthesis ◽  
Amino Acid ◽  
Muscle Protein ◽  
Muscle Protein Synthesis ◽  
Amino Acid Mixture ◽  
Acid Mixture ◽  
Protein Kinetics ◽  
Amino Acid Infusion

Six normal untrained men were studied during the intravenous infusion of a balanced amino acid mixture (approximately 0.15 g.kg-1.h-1 for 3 h) at rest and after a leg resistance exercise routine to test the influence of exercise on the regulation of muscle protein kinetics by hyperaminoacidemia. Leg muscle protein kinetics and transport of selected amino acids (alanine, phenylalanine, leucine, and lysine) were isotopically determined using a model based on arteriovenous blood samples and muscle biopsy. The intravenous amino acid infusion resulted in comparable increases in arterial amino acid concentrations at rest and after exercise, whereas leg blood flow was 64 +/- 5% greater after exercise than at rest. During hyperaminoacidemia, the increases in amino acid transport above basal were 30-100% greater after exercise than at rest. Increases in muscle protein synthesis were also greater after exercise than at rest (291 +/- 42% vs. 141 +/- 45%). Muscle protein breakdown was not significantly affected by hyperminoacidemia either at rest or after exercise. We conclude that the stimulatory effect of exogenous amino acids on muscle protein synthesis is enhanced by prior exercise, perhaps in part because of enhanced blood flow. Our results imply that protein intake immediately after exercise may be more anabolic than when ingested at some later time.

Amino Acids in Premature Infants

PEDIATRICS ◽  
1988 ◽  
Vol 82 (4) ◽  
pp. 680-680
Author(s):  
NIELS C. R. RÄIHÄ
Keyword(s):  
Amino Acids ◽  
Birth Weight ◽  
Amino Acid ◽  
Parenteral Nutrition ◽  
Premature Infants ◽  
Amino Acid Mixture ◽  
Acid Mixture ◽  
Metabolic Capacity ◽  
Low Birth Weight Infants ◽  
Term Infants

To the Editor.— In a recent paper in Pediatrics, Heird et al1 reported their evaluation of the use of a new amino acid mixture for parenteral nutrition in low birth weight infants. On the basis of their results the authors made the following statement: "These observations refute the concept that the metabolic capacity of LBW infants for amino acids is limited in comparison to that of term infants, older infants, and chi1dren."1(p49) Such a conclusion is not justified on the basis of the presented data.

Effects of amino acids and gastric inhibitory polypeptide on insulin release in dogs

1982 ◽  
Vol 242 (1) ◽  
pp. E53-E58
Author(s):  
J. G. Yovos ◽  
T. M. O'Dorisio ◽  
T. N. Pappas ◽  
S. Cataland ◽  
F. B. Thomas ◽  
...  
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Insulin Release ◽  
Insulin Response ◽  
Gastric Inhibitory Polypeptide ◽  
Amino Acid Mixture ◽  
Group Iv ◽  
Acid Mixture ◽  
Group Iii ◽  
Group I

Insulin release following intravenous administration of an amino acid solution with and without a simultaneous infusion of varying amounts of porcine gastric inhibitory polypeptide (GIP) was studied in dogs. Group I received a 10-amino acid mixture (300 mosmol/kg iv) at 16.6 ml/min for 1 h; group II, amino acid mixture plus 0.5 micrograms.kg-1.h-1 porcine GIP; group III, amino acid mixture plus 1.0 micrograms.kg-1.h-1 of GIP; group IV (a and b) received either 0.5 or 1.0 micrograms.kg-1.h-1 of GIP alone. Compared to group I, groups II and III had a greater insulin response during the first 30 min of the infusion. Group] IV (a and b) showed no insulin release. Glucose concentrations showed no significant change in all groups. From these results, it is concluded that insulin release after intravenous infusion of an amino acid mixture plus GIP is greater than after amino acids or GIP alone. It appears that this effect is more pronounced in the early phase of insulin release.

Uptake and metabolism of amino acids by the dog liver perfused in situ

1962 ◽  
Vol 202 (3) ◽  
pp. 407-414 ◽  
Author(s):  
Rapier H. McMenamy ◽  
William C. Shoemaker ◽  
Jonas E. Richmond ◽  
David Elwyn
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Amino Acid Mixture ◽  
Acid Mixture ◽  
Sharp Rise ◽  
Dog Blood ◽  
Dog Liver ◽  
Amino Acid Concentrations ◽  
Uptake And Metabolism

Dog livers were perfused in situ for periods up to 6 hr with dog blood recycled through a pump-oxygenator. An amino acid mixture was administered for 90 min. Concentrations of amino acids were determined at intervals of 30 min or more. Rates of uptake and metabolism were calculated. After the start of perfusion, there is a fall in most plasma amino acid concentrations and a reciprocal rise in liver amino acids. Addition of amino acids causes a sharp rise in plasma amino acids. There is a rapid uptake of most of the amino acids by liver, although the concentrations of amino acids in liver fail to rise appreciably. Notable exceptions are valine, leucine, and isoleucine. Uptake of amino acids stimulates: a) an increase in the rate of synthesis of urea which ultimately accounts for 90% of the metabolized amino acids; b) a net synthesis of ornithine; and c) net noncatabolic metabolism of amino acids which may in part be protein synthesis. The results support the view that the liver temporarily stores a part of ingested amino acids as proteins, and subsequently makes them available to other organs.

Chromatographic Separation of Free Amino Acids in Table Sirups

1971 ◽  
Vol 54 (1) ◽  
pp. 61-65
Author(s):  
Arthur Russell Johnson ◽  
Richard L Corliss ◽  
Enrique Fernandez-Flores
Keyword(s):  
Amino Acids ◽  
Quantitative Analysis ◽  
Amino Acid ◽  
Ion Exchange ◽  
Free Amino Acids ◽  
Free Amino ◽  
Amino Acid Mixture ◽  
Acid Mixture ◽  
Butyl Esters ◽  
Tlc Analysis

Abstract Qualitative chromatographic methods for the separation of free amino acids in table sirups are presented to aid in the development of chemical indices of composition which may be useful in establishing the identity of sirups and detecting their adulteration. Free amino acids in 2 table sirups were isolated on ion exchange columns and eluted with dilute ammonia. The concentrated amino acid mixture in the eluate was spotted directly on silica gel G plates for TLC analysis, or the amino acids were converted to their N-trifluoroacetyl n-butyl esters for GLC analysis. As many as 16 amino acids were qualitatively separated and identified and a potential for quantitative analysis was demonstrated.

scholarly journals Conversion Percentage of Tryptophan to Nicotinamide is Higher in Rice Protein Diet than in Wheat Protein Diet in Rats

2015 ◽  
Vol 8 ◽  
pp. IJTR.S22444
Author(s):  
Katsumi Shibata ◽  
Tsutomu Fukuwatari ◽  
Tomoyo Kawamura
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Body Weight Gain ◽  
Acid Value ◽  
Amino Acid Mixture ◽  
The Body ◽  
Protein Diet ◽  
Acid Mixture ◽  
Wheat Protein ◽  
Rice Protein

We reported previously that the pellagragenic property of corn protein is not only low L-tryptophan concentration but also the lower conversion percentage of L-tryptophan to nicotinamide; the amino acid composition greatly affected the conversion percentage. The amino acid value of wheat protein is lower than that of rice protein. In the present study, we compare the conversion percentages of L-tryptophan to nicotinamide between wheat protein and rice protein diets in growing rats. The body weight gain for 28 days in rats fed with a 10% amino acid mixture diet with wheat protein was lower than that of rats fed with a 10% amino acid diet with rice protein (68.1 ± 1.6 g vs 108.4 ± 1.9 g; P < 0.05). The conversion percentage of L-tryptophan to nicotinamide was also lower for the wheat protein diet compared with the rice protein diet (1.44 ± 0.036% vs 2.84 ± 0.19%; P < 0.05). The addition of limiting amino acids (L-isoleucine, L-lysine, L-tryptophan, L-methionine, L-threonine) to the wheat protein diet improved growth and the conversion percentage. In conclusion, our result supports the thinking that the composition of amino acids affects the conversion ratio of L-tryptophan to nicotinamide.

Electrical activity in mesenteric nerves after perfusion of gut lumen

1962 ◽  
Vol 202 (4) ◽  
pp. 725-730 ◽  
Author(s):  
K. N. Sharma ◽  
E. S. Nasset
Keyword(s):  
Amino Acids ◽  
Small Intestine ◽  
Amino Acid ◽  
Electrical Activity ◽  
Constant Temperature ◽  
Amino Acid Mixture ◽  
Acid Mixture ◽  
Temperature And Pressure

Impulses from the peripheral cut end of mesenteric nerves to the intestinal loops of anesthetized cats were recorded oscilloscopically. Dogs with Thiry-Vella loops and with electrodes implanted in mesenteric nerves were used for chronic studies. The loops were perfused with different solutions at constant temperature and pressure. After glucose perfusion of the lumen the increase in frequency of firing was more marked in medium and larger fibers. After perfusion with single amino acids the increase was more conspicuous in smaller fibers. Amigen (amino acid mixture, dextrose, and salts) perfusion resulted in mixed patterns. No appreciable changes were observed with 0.9% NaCl, Tyrode's solution, and 0.025 n NaOH, but a slight increase was obtained with 0.025 n HCl. The possibility of some chemoreceptor mechanism in the small intestine is suggested. Its possible role in ingestion of food is discussed.

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