Recycling of glucose and determination of the Cori Cycle and gluconeogenesis

1999 ◽  
Vol 277 (3) ◽  
pp. E401-E407 ◽  
Author(s):  
Joseph Katz ◽  
John A. Tayek
Keyword(s):  
Glucose Metabolism ◽  
Theoretical Analysis ◽  
Mathematical Analysis ◽  
Glycogen Synthesis ◽  
Numerical Examples ◽  
Cori Cycle ◽  
Isotopomer Analysis ◽  
The Difference ◽  
Glucose Recycling

We have derived equations, by employing [U-13C]glucose and mass isotopomer analysis, to determine the pathways of glycogen synthesis (J. Katz, W. P. Lee, P. A. Wals, and E. A. Bergner. J. Biol. Chem. 264: 12994–13004, 1989). More recently, by use of these methods we have derived equations to determine the rate of glucose recycling and of gluconeogenesis [Tayek and Katz. Am. J. Physiol.270 ( Endocrinol. Metab. 33): E709–E717, 1996 and 272 ( Endocrinol. Metab. 35): E476–E484, 1997, and Katz and Tayek. Am. J. Physiol. 275 ( Endocrinol. Metab. 38): E537–E542, 1988]. The former equations have been criticized and challenged by C. Des Rosiers, B. R. Landau, and H. Brunengraber [ Am. J. Physiol. 259 ( Endocrinol. Metab. 22): E757–E762, 1990], and the latter recently by B. R. Landau, J. Wahren, S. F. Previs, G. K. Ekberg, D. Yang, and H. Brunengraber [ Am. J. Physiol. 274 ( Endocrinol. Metab. 37): E954–E961, 1998]. Landau et al. claimed that our equations were in error and “corrected” them. Their analysis, and their values for recycling and gluconeogenesis (GNG) differ markedly from ours. We show here our equations and estimates of recycling and GNG to be correct. We present here a theoretical analysis of recycling and discuss the determination of the Cori Cycle and GNG. We illustrate by numerical examples the difference in parameters of glucose metabolism calculated by the methods of Katz and Landau. J. Radziuk and W. N. P. Lee [ Am. J. Physiol. 277 ( Endocrinol Metab. 40): E199–E207, 1999] and J. K. Kelleher [ Am. J. Physiol. 277 ( Endocrinol. Metab. 40): E395–E400, 1999] present a mathematical analysis that, although differing in some respects from Landau’s, supports his equation for GNG. We show in theappendix that their derivation of the equation for GNG is incorrect.

Application of mass isotopomer analysis for determination of pathways of glycogen synthesis

1991 ◽  
Vol 261 (3) ◽  
pp. E332-E336
Author(s):  
J. Katz ◽  
W. N. Lee
Keyword(s):  
Blood Glucose ◽  
Mass Spectroscopy ◽  
Specific Activity ◽  
Glycogen Synthesis ◽  
Natural Abundance ◽  
Hepatic Glycogen ◽  
Direct Path ◽  
Isotopomer Analysis ◽  
Mass Isotopomer

An elementary exposition of the application of mass spectroscopy to studies with substrates labeled uniformly with 13C is presented. A procedure to obtain mass isotopomer spectra, corrected for natural abundance, of products labeled with 13C in several positions is outlined. The calculation for enrichment, a term equivalent to specific activity with radioisotopes, is shown. Examples of mass isotopomer patterns of blood glucose and glycogen are presented, and calculations of the contribution of the direct path to hepatic glycogen synthesis and the dilution of glucose-derived pyruvate are shown. The analysis of mass isotopomer patterns recently offered by C. Des Rosiers, B. R. Landau, and H. Brunengraber [Am. J. Physiol. 259 (Endocrinol. Metab. 22): E757-E762, 1990] is critically examined.

High-order algorithms for riesz derivative and their applications (IV)

2019 ◽  
Vol 22 (6) ◽  
pp. 1537-1560
Author(s):  
Hengfei Ding ◽  
Changpin Li
Keyword(s):  
Finite Difference ◽  
Theoretical Analysis ◽  
Difference Scheme ◽  
Riesz Space ◽  
Unconditionally Stable ◽  
Numerical Convergence ◽  
Numerical Examples ◽  
Advection Dispersion ◽  
The Difference ◽  
Convergence Orders

Abstract The main goal of this article is to establish a new 4th-order numerical differential formula to approximate Riesz derivatives which is obtained by means of a newly established generating function. Then the derived formula is used to solve the Riesz space fractional advection-dispersion equation. Meanwhile, by the energy method, it is proved that the difference scheme is unconditionally stable and convergent with order 𝓞(τ2 + h4). Finally, several numerical examples are given to show that the numerical convergence orders of the numerical differential formulas and the finite difference scheme are in line with the theoretical analysis.

Interpretation of isotopomer patterns in tracing glycogen synthesis and glucose recycling using [13C6]glucose

1990 ◽  
Vol 259 (5) ◽  
pp. E757-E762
Author(s):  
C. Des Rosiers ◽  
B. R. Landau ◽  
H. Brunengraber
Keyword(s):  
Glycogen Synthesis ◽  
Indirect Pathway ◽  
Direct Pathway ◽  
Glucose Recycling ◽  
Arterial Glucose

Tracing glycogen synthesis with [U-13C]glucose involves determination of isotopomer patterns in precursors and products. The contribution of the direct pathway to glycogen synthesis has been estimated from the ratio (R) of the number of glycogen glucose molecules having six 13C atoms to the total number of glucose molecules having one to six 13C atoms. Using theoretical examples, we show that the equation to calculate R underestimates the contribution of the direct pathway. We derive a correct stoichiometric expression for R. Also, we show how to correct these estimates for 1) recondensation of two M+3 three-carbon intermediates into M+6 glucose 6-phosphate, and 2) the increasing enrichment of arterial glucose in various isotopomers arising from the indirect pathway. Finally, using the developed formulas we recalculate data from the literature. Similar considerations apply to investigations of glucose recycling using [U-13C6]glucose.

FRACTIONAL DETERMINATIONS OF URINARY 17-KETOSTEROIDS IN HYPEREMESIS GRAVIDARUM

1962 ◽  
Vol 41 (1) ◽  
pp. 123-128 ◽  
Author(s):  
Pentti A. Järvinen ◽  
Sykkö Pesonen ◽  
Pirkko Väänänen
Keyword(s):  
Hyperemesis Gravidarum ◽  
First Trimester ◽  
Control Group ◽  
Before And After ◽  
Daily Urine ◽  
First Trimester Of Pregnancy ◽  
The Difference

ABSTRACT The fractional determination of 17-ketosteroids in the daily urine was performed in nine cases of hyperemesis gravidarum and in four control cases, in the first trimester of pregnancy both before and after corticotrophin administration. The excretion of total 17-KS is similar in the two groups. Only in the hyperemesis group does the excretion of total 17-KS increase significantly after corticotrophin administration. The fractional determination reveals no difference between the two groups of patients with regard to the values of the fractions U (unidentified 17-KS), A (androsterone) and Rest (11-oxygenated 17-KS). The excretion of dehydroepiandrosterone is significantly higher in the hyperemesis group than in the control group. The excretion of androstanolone seems to be lower in the hyperemesis group than in the control group, but the difference is not statistically significant. The differences in the correlation between dehydroepiandrosterone and androstanolone in the two groups is significant. The high excretion of dehydroepiandrosterone and low excretion of androstanolone in cases of hyperemesis gravidarum is a sign of adrenal dysfunction.

Abnormal activation of glycogen synthesis in fibroblasts from NIDDM subjects. Evidence for an abnormality specific to glucose metabolism

Diabetes ◽  
1993 ◽  
Vol 42 (4) ◽  
pp. 583-589 ◽  
Author(s):  
A. M. Wells ◽  
I. C. Sutcliffe ◽  
A. B. Johnson ◽  
R. Taylor
Keyword(s):  
Glucose Metabolism ◽  
Glycogen Synthesis

THE SUBJECT FIELD OF INSTITUTIONAL EDUCATION: THE SENSE AND PROSPECTS OF DEVELOPMENT IN UKRAINE

2020 ◽  
pp. 25-38
Author(s):  
Irina Mordous
Keyword(s):  
Decisive Role ◽  
Subject Field ◽  
National Education ◽  
Progressive Development ◽  
Separate Area ◽  
Economic Transformations ◽  
The Difference ◽  
The Individual ◽  
Political Economic

The development of modern civilization attests to its decisive role in the progressive development of institutions. They identified the difference between Western civilization and the rest of the world. Confirmation of the institutional advantages of the West was its early industrialization. The genesis and formation of institutionalism in its ideological and conceptualmethodological orientation occurs as a process alternative to neoclassic in the context of world heterodoxia, which quickly spread in social science. Highlighting institutional education as a separate area of sociocultural activity is determined by the factor of differentiation of institutional theory as a whole. A feature of institutional education is its orientation toward the individual and his/her transformation into a personality. The content of institutional education is revealed through the analysis of the institution, which includes a set of established customs, traditions, ways of thinking, behavioral stereotypes of individuals and social groups. The dynamics of socio-political, economic transformations in Ukraine requires a review of the foundations of national education and determination of the prospects for its development in the 21st century in the context of institutionalism.

scholarly journals Possibility of Human Gender Recognition Using Raman Spectra of Teeth

Molecules ◽  
2021 ◽  
Vol 26 (13) ◽  
pp. 3983
Author(s):  
Ozren Gamulin ◽  
Marko Škrabić ◽  
Kristina Serec ◽  
Matej Par ◽  
Marija Baković ◽  
...  
Keyword(s):  
Raman Spectra ◽  
Principal Component ◽  
Support Vector ◽  
Gender Recognition ◽  
Proof Of Concept ◽  
Male And Female ◽  
Tooth Type ◽  
Tooth Apex ◽  
The Difference

Gender determination of the human remains can be very challenging, especially in the case of incomplete ones. Herein, we report a proof-of-concept experiment where the possibility of gender recognition using Raman spectroscopy of teeth is investigated. Raman spectra were recorded from male and female molars and premolars on two distinct sites, tooth apex and anatomical neck. Recorded spectra were sorted into suitable datasets and initially analyzed with principal component analysis, which showed a distinction between spectra of male and female teeth. Then, reduced datasets with scores of the first 20 principal components were formed and two classification algorithms, support vector machine and artificial neural networks, were applied to form classification models for gender recognition. The obtained results showed that gender recognition with Raman spectra of teeth is possible but strongly depends both on the tooth type and spectrum recording site. The difference in classification accuracy between different tooth types and recording sites are discussed in terms of the molecular structure difference caused by the influence of masticatory loading or gender-dependent life events.

scholarly journals Influence of Erythrocytes on Direct Potentiometric Determination of Sodium and Potassium

1983 ◽  
Vol 20 (2) ◽  
pp. 116-120 ◽  
Author(s):  
P Bijster ◽  
H L Vader ◽  
C L J Vink
Keyword(s):  
Whole Blood ◽  
Potassium Concentration ◽  
Reference Electrode ◽  
Sodium Concentration ◽  
General Phenomenon ◽  
Liquid Junction ◽  
Direct Potentiometry ◽  
The Difference ◽  
Sodium And Potassium

We have shown that the sodium concentration in whole blood measured by direct potentiometry is higher than in plasma. The ‘erythrocyte-effect’, already described by Siggaard Andersen, is most pronounced for instruments equipped with a reference electrode with an open static liquid junction and is thus a general phenomenon. Instruments with a modified liquid junction show less interference. The same phenomenon appears for the determination of the potassium concentration, although the difference between whole blood and plasma, when measured with instruments equipped with a modified liquid junction, can be neglected in practice.

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