scholarly journals Branched-Chain Keto-Acids and Pyruvate in Blood: Measurement by HPLC with Fluorimetric Detection and Changes in Older Subjects

2000 ◽  
Vol 46 (6) ◽  
pp. 848-853 ◽  
Author(s):  
Karine Pailla ◽  
Françoise Blonde-Cynober ◽  
Christian Aussel ◽  
Jean-Pascal De Bandt ◽  
Luc Cynober
Keyword(s):  
Young Adults ◽  
Age Groups ◽  
Reversed Phase ◽  
Fluorometric Detection ◽  
Institutionalized Elderly ◽  
Keto Acids ◽  
Significant Difference ◽  
Branched Chain ◽  
Branched Chain Keto Acids

Abstract Background: Measurement of keto-acids is important in various clinical situations. The aim of the present work was to develop a rapid HPLC method for the determination of keto-acids in human serum and to assess the concentrations of these acids in young adults and institutionalized elderly adults. This method was applied to the determination of blood keto-acid concentrations of young adults and institutionalized elderly people, divided into age groups Methods: Four keto-acids (α-ketoisocaproate, α-ketoisovalerate, α-keto-β-methylvalerate, and pyruvate) were derivatized with o-phenylenediamine to give fluorescent derivatives. After the sample preparation step (75 min to prepare 20 samples), the derivatives were separated chromatographically on a reversed-phase column using a binary gradient. Results: The fluorometric detection of the four keto-acids was rapid, <12 min. The method is repeatable and reproducible: the CVs were <6% and <11%, respectively, for each of the keto-acids. We found no significant difference between males and females. Concentrations of the branched-chain keto-acids decreased after age 60 years, especially α-ketoisocaproate, which decreased ∼40%. Conclusions: The proposed method allows rapid and reliable measurement of keto-acids. The data demonstrate that changes in branched-chain keto-acids concentrations in serum occur with age.

scholarly journals Determination of the Trans-resveratrol content of Champagne wines by reversed-phase HPLC

OENO One ◽  
2006 ◽  
Vol 40 (2) ◽  
pp. 117 ◽  
Author(s):  
Philippe Jeandet ◽  
David Chaudruc ◽  
Bertrand Robillard ◽  
F. Peters ◽  
Dominique Tusseau ◽  
...  
Keyword(s):  
Ethyl Acetate ◽  
Reversed Phase ◽  
Liquid Extraction ◽  
Fluorometric Detection ◽  
Reversed Phase Hplc ◽  
Liquid Liquid Extraction

<p style="text-align: justify;">Levels of trans-resveratrol in Champagne wines were determined by the use of reversed-phase HPLC with UV and fluorometric detection after liquid-liquid extraction with ethyl acetate. Resveratrol concentrations in Champagne wines range from 20 to 77 μg/L except for the Champagne rosé in which resveratrol reaches several hundred micrograms per litre. The resveratrol content of Champagne wines was also shown to decrease with aging on lees.</p>

Influence of branched-chain amino acids and branched-chain keto acids on protein synthesis in isolated hepatocytes

Hepatology ◽  
1987 ◽  
Vol 7 (2) ◽  
pp. 324-329 ◽  
Author(s):  
Wolfgang Base ◽  
Carl Barsigian ◽  
Alisa Schaeffer ◽  
Ellen Shaw ◽  
Jose Martinez ◽  
...  
Keyword(s):  
Amino Acids ◽  
Protein Synthesis ◽  
Isolated Hepatocytes ◽  
Branched Chain Amino Acids ◽  
Keto Acids ◽  
Branched Chain ◽  
Branched Chain Keto Acids

scholarly journals Development of a Solid-Phase Extraction Method for Determination of Pheophorbide a and Pyropheophorbide a in Health Foods by Liquid Chromatography

2004 ◽  
Vol 87 (4) ◽  
pp. 937-942 ◽  
Author(s):  
Harumi Oshima ◽  
Eiji Ueno ◽  
Isao Saito ◽  
Hiroshi Matsumoto
Keyword(s):  
Liquid Chromatography ◽  
Solid Phase Extraction ◽  
Solid Phase ◽  
Reversed Phase ◽  
Official Method ◽  
Phase Extraction ◽  
Pheophorbide A ◽  
Significant Difference ◽  
Spe Method

Abstract A simple solid-phase extraction (SPE) method was developed for the liquid chromatography (LC) determination of pheophorbide (Phor) a and pyropheophorbide (Pyro) a in health foods such as chlorella, spirulina, etc. The food sample was extracted with 85% (v/v) acetone. The extract was acidified with hydrochloric acid and loaded on a C18 cartridge. After washing with water, Phor a and Pyro a were eluted with the LC mobile phase. Phor a and Pyro a were separated by isocratic reversed-phase LC and quantitated by fluorescence detection. The recoveries for spiked samples of chlorella and the extract were 87.1–102.0%. Commercial health foods (chlorella, spirulina, aloe, kale, Jews mallow, and green tea leaves) were analyzed using the SPE method. The values found for Phor a and Pyro a ranged from 2 to 788 μg/g and from &lt;1 to 24 μg/g, respectively. There was no significant difference between the SPE method and the official method in Japan (spectrophotometry after liquid–liquid extraction). The advantages of the SPE method are the short extraction times, lack of emulsions, and reduced consumption of organic solvents compared with the official method in Japan. The SPE method is considered to be useful for the screening of Phor a and Pyro a in health foods.

scholarly journals Determination of Vitamin K1 in Medical Foods by Liquid Chromatography with Postcolumn Reduction and Fluorometric Detection

2000 ◽  
Vol 83 (4) ◽  
pp. 957-962 ◽  
Author(s):  
George M Ware ◽  
G William Chase ◽  
Ronald R Eitenmiller ◽  
Austin R Long
Keyword(s):  
Limit Of Detection ◽  
Solid Phase ◽  
Sodium Bicarbonate Solution ◽  
Reversed Phase ◽  
Mean Value ◽  
Fluorometric Detection ◽  
Vitamin K1 ◽  
Limit Of Quantitation ◽  
Medical Foods

Abstract A liquid chromatographic (LC) method is described for the determination of vitamin K1 in medical foods. The sample is enzymatically digested with lipase and α-amylase and extracted with 1% sodium bicarbonate solution–isopropanol (1 + 1). After C18 solid-phase extraction, vitamin K1 is separated by nonaqueous reversed-phase LC, converted to the hydroquinone by postcolumn zinc reduction, and quantitated by fluorescence detection. The limit of detection is 8 pg (3 σ), and the limit of quantitation is 27 pg (10 σ) on column. Linear response ranged from 0.1 to 1.0 ng vitamin K1 (r = 0.9999). The mean recovery (n = 38) for all spiking levels was 101.6 ± 2.85%. Analysis of Standard Reference Material 1846, Infant Formula, gave a mean value of 0.95 ± 0.088 mg vitamin K/kg (K or K1?)(n = 31) with a coefficient of variation of 9.26.

scholarly journals Rapid Method for the Determination of Coumarin, Vanillin, and Ethyl Vanillin in Vanilla Extract by Reversed-Phase Liquid Chromatography with Ultraviolet Detection

2008 ◽  
Vol 91 (2) ◽  
pp. 383-386 ◽  
Author(s):  
Laila Ali ◽  
Gracia Perfetti ◽  
Gregory Diachenko
Keyword(s):  
Liquid Chromatography ◽  
Reversed Phase ◽  
Aqueous Acetic Acid ◽  
Reversed Phase Liquid Chromatography ◽  
Uv Detector ◽  
Ultraviolet Detection ◽  
Ethyl Vanillin ◽  
Significant Difference ◽  
Phase Liquid

Abstract A method is described for determining coumarin, vanillin, and ethyl vanillin in vanilla extract products. A product is diluted one-thousand-fold and then analyzed by reversed-phase liquid chromatography using a C18 column and a mobile phase consisting of 55 acetonitrile45 aqueous acetic acid (1) solution at a flow rate of 1.0 mL/min. Peaks are detected with a UV detector set at 275 nm. Vanilla extracts were spiked with 250, 500, and 1000 g/g each of coumarin, vanillin, and ethyl vanillin. Recoveries averaged 97.4, 97.8, and 99.8 for coumarin, vanillin, and ethyl vanillin, respectively, with coefficient of variation values of 1.8, 1.3, and 1.3, respectively. No significant difference was observed among the 3 spiking levels. A survey of 23 domestic and imported vanilla extract products was conducted using the method. None of the samples contained coumarin. The surveyed samples contained between 0.4 to 13.1 and 0.4 to 2.2 mg/g vanillin and ethyl vanillin, respectively.

Transamination of branched-chain keto acids by isolated perfused rat kidney.

1978 ◽  
Vol 235 (1) ◽  
pp. E47
Author(s):  
W E Mitch ◽  
W Chan
Keyword(s):  
Amino Acids ◽  
Rat Kidney ◽  
Branched Chain Amino Acids ◽  
Keto Acid ◽  
Branched Chain Amino Acid ◽  
Keto Acids ◽  
Perfused Rat Kidney ◽  
Branched Chain ◽  
Branched Chain Keto Acids ◽  
Isolated Rat

Isolated rat kidney perfused without substrate released serine, glycine, and taurine, and substantially smaller amounts of other amino acids. When branched-chain keto acids were added, the corresponding amino acids were released at rates amounting to 15-25% of keto acid disappearance. Perfusion with 2 mM alpha-keto-isovalerate or alpha-keto-beta-methylvalerate caused an increased glucose release amounting to 18-23% of keto acid disappearance. The activity of branched-chain amino acid transferase (BATase) was significantly stimulated by perfusion with the analogue of leucine, but not by perfusion with alpha-ketoglutarate, the analogues of valine or isoleucine, or with leucine itself. These findings document that the kidney converts branched-chain keto acids in part to the corresponding amino acids and suggest that the keto analogue of leucine may be involved in the control of renal BATase activity, thereby indirectly regulating the metabolism of branched-chain amino acids.

scholarly journals Analysis of measles-related hospitalizations in Tuscany from 2000 to 2014

2016 ◽  
Vol 144 (12) ◽  
pp. 2605-2612 ◽  
Author(s):  
E. BERTI ◽  
S. SOLLAI ◽  
E. ORLANDINI ◽  
L. GALLI ◽  
M. DE MARTINO ◽  
...  
Keyword(s):  
Young Adults ◽  
Age Groups ◽  
Public Health Problem ◽  
Hospitalization Rate ◽  
Measles Elimination ◽  
Hospitalization Rates ◽  
Significant Difference ◽  
Measles Outbreaks ◽  
Measles Incidence ◽  
Discharge Database

SUMMARYTo evaluate measles incidence and its relevant changes over a 14-year period (2000–2014), we analysed data from the regional hospital discharge database on children and adults hospitalized in Tuscany, Italy. A total of 181 paediatric and 413 adult cases were identified. Despite all the efforts towards regional measles elimination, we observed that the overall measles hospitalization rates for children and adults living in Tuscany globally increased from 0·45 to 0·85/100 000 during the study period (P = 0·001) showing fluctuations due to periodic measles outbreaks. Data stratified by age group showed that the hospitalization rate significantly increased in young adults over the study period, confirming an increase in susceptibility to measles in this subpopulation. Conversely, no statistically significant difference was observed in the hospitalization rate in the other age groups. However, children aged <1 year still exhibit the highest hospitalization rate. Pneumonia represented the most common complication in both the adult and children subsets. No death was reported. Measles still represents a public health problem, and national strategies should be implemented, focusing on emergent susceptible subsets, such as infants and young adults.

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