scholarly journals John Conrad Waterlow. 13 June 1916—19 October 2010

2018 ◽  
Vol 65 ◽  
pp. 429-448
Author(s):  
D. Joe Millward
Keyword(s):  
Heat Stroke ◽  
Research Unit ◽  
Whole Body ◽  
London School ◽  
Body Protein ◽  
Scientific Disciplines ◽  
Wide Range ◽  
Isotope Ratio Mass Spectrometer ◽  
N Enrichment ◽  
Second World

John Waterlow was an inspiring clinical and laboratory-based nutritional scientist, who was recognized as paterfamilias of a large, international and influential group of distinguished acolytes. His early work was characterized by study of the nature and clinical management of infantile malnutrition, notably as director of the MRC's Tropical Metabolism Research Unit, which he established in Jamaica in 1954. His London period, from 1970 until and beyond his official retirement in 1982, involved him as Head of the Nutrition Department at the London School of Hygiene & Tropical Medicine. Here he established a Clinical Nutrition and Metabolism Unit to continue his experimental animal and human studies researching protein metabolism; he also assumed the role of the the UK's most influential public health nutritionist, becoming President of the Nutrition Society. Like all great scientists, his work encompassed a very wide range of scientific disciplines, although he modestly described himself as a physiologist, consistent with his primary Cambridge training. Above all, throughout his career, he was happiest as an experimentalist at the bench, from his first assignment studying heat stroke of British troops in the Iraq desert during the Second World War to his measurement of [ 15 N] enrichment in urea as part of his study of whole-body protein turnover just prior to his retirement, working with an isotope ratio mass spectrometer which, like much of the equipment he used, he had largely assembled himself.

Glutamine Production Rate and its Contribution to Urinary Ammonia in Normal Man

1982 ◽  
Vol 62 (3) ◽  
pp. 299-305 ◽  
Author(s):  
M. H. N. Golden ◽  
P. Jahoor ◽  
A. A. Jackson
Keyword(s):  
Production Rate ◽  
Ammonia Excretion ◽  
Whole Body ◽  
Acid Base ◽  
Male Adult ◽  
Body Protein ◽  
Acid Base Status ◽  
N Enrichment ◽  
Glutamine Production ◽  
Normal Acid

1. Glutamine [15N]amide was infused at a steady rate of 33.34 μmol/h into seven male adult volunteers who were in the fed state and normal acid-base status. 2. Plasma glutamine amide N enrichment and urinary ammonia N enrichment rose to a constant value within 3 h. 3. The glutamine production rate was 51.8 ± 7.9 mmol/h. 4. The total ammonia excretion rate was 0.87 mmol/h. Of this excreted ammonia 62.6 ± 9% was derived from the amide N atom of glutamine. 5. The excreted glutamine amide N (0.53 mmol/h) was only 1% of the glutamine production. If half the ammonia formed by the kidney is excreted in urine and half liberated into the renal vein in subjects with normal acid-base status [E. E. Owen & R. R. Robinson (1963) Journal of Clinical Investigation, 42, 263–276], then the kidney accounts for only 2% of glutamine disposal. 6. Whole body protein turnover, measured from the urinary [15N]ammonia enrichment, was 30.3 ± 7.7 g of N/day (2.8 g of protein day−1 kg−1).

Diurnal variation in urine [15N]urea content, estimates of whole body protein turnover, and isotope recycling in healthy meal-fed children with cystic fibrosis

1983 ◽  
Vol 61 (1) ◽  
pp. 72-80 ◽  
Author(s):  
H. G. Parsons ◽  
M. M. Wood ◽  
P. B. Pencharz
Keyword(s):  
Cystic Fibrosis ◽  
Diurnal Variation ◽  
Amino Nitrogen ◽  
Whole Body ◽  
Diurnal Changes ◽  
Nitrogen Flux ◽  
Body Protein ◽  
Urea Excretion ◽  
Breakdown Rates ◽  
Wide Range

The pattern of urinary urea excretion and labelling with 15N was examined in eight meal-fed 6 to 9 year old children, over a 3-day period using a simulated constant infusion of the label. The children had cystic fibrosis but were healthy and in a good nutritional status at the time of the study. Reciprocal diurnal patterns of urea excretion and [15N]urea enrichment were noted and found to be suitable for mathematical description. Urea excretion was maximal in the evening at approximately 2000 and minimal at 0800, whereas the [15N]urea enrichment was maximal at about 0800 and minimal at 2000. In addition to the diurnal variation the [15N]urea enrichment increased exponentially to a plateau or isotopic steady state. The diurnal variation in [15N]urea enrichment resulted in large diurnal changes in the calculated rates of whole body amino nitrogen flux, synthesis, and breakdown. Flux rates were approximately 44% higher in the evening than in the morning. Synthesis rates were 19% higher in the evening, whereas breakdown rates were 27% greater in the morning. Mean amino nitrogen flux rates were 1.28 (SD 0.13) g N∙kg−1∙day−1. Isotope recycling was estimated from the slope of the [15N]urea enrichment curve between 30 and 54 h from the start of the study. There was a wide range in recycling, 2.9–19.4% (mean 11.4, SD 5.4). Some of the biological and pharmacological importance of the diurnal variation in the protein metabolism is discussed.

Age- and sex-related bone uptake of Tc-99m-HDP measured by whole-body bone scanning

2000 ◽  
Vol 39 (05) ◽  
pp. 127-132 ◽  
Author(s):  
Nicole Sieweke ◽  
K. H. Bohuslavizki ◽  
W. U. Kampen ◽  
M. Zuhayra ◽  
M. Clausen ◽  
...  
Keyword(s):  
Whole Body ◽  
Bone Lesions ◽  
Men And Women ◽  
Bone Uptake ◽  
Normal Bone ◽  
Age Related ◽  
Number Of Patients ◽  
Wide Range ◽  
Bone Scans ◽  
Body Bone

Summary Aim of this study was to validate a recently introduced new and easy-to-perform method for quantifying bone uptake of Tc-99m-labelled diphosphonate in a routine clinical setting and to establish a normal data base for bone uptake depending on age and gender. Methods: In 49 women (14-79 years) and 47 men (6-89 years) with normal bone scans as well as in 49 women (33-81 years) and 37 men (27-88 years) with metastatic bone disease whole-body bone scans were acquired at 3 min and 3-4 hours p.i. to calculate bone uptake after correction for both urinary excretion and soft tissue retention. Results: Bone uptake values of various age-related subgroups showed no significant differences between men and women (p >0.05 ). Furthermore, no differences could be proven between age-matched subgroups of normals and patients with less than 10 metastatic bone lesions, while patients with wide-spread bone metastases revealed significantly increased uptake values. In both men and women highest bone uptake was obtained (p <0.05 ) in subjects younger than 20 years with active epiphyseal growth plates. In men, bone uptake slowly decreased with age up to 60 years and then showed a tendency towards increasing uptake values. In women, the mean uptake reached a minimun in the decade 20-29 years and then slowly increased with a positive linear correlation of age and uptake in subjects older than 55 years (r = 0.57). Conclusion: Since the results proposed in this study are in good agreement with data from literature, the new method used for quantification could be validated in a large number of patients. Furthermore, age- and sexrelated normal bone uptake values of Tc-99m-HDP covering a wide range of age could be presented for this method as a basis for further studies on bone uptake.

scholarly journals Whole-body arginine dimethylation is associated with all-cause mortality in adult renal transplant recipients

Amino Acids ◽  
2021 ◽  
Author(s):  
Adrian Post ◽  
Alexander Bollenbach ◽  
Stephan J. L. Bakker ◽  
Dimitrios Tsikas
Keyword(s):  
Renal Transplant ◽  
Excretion Rate ◽  
Whole Body ◽  
Renal Transplant Recipients ◽  
Transplant Recipients ◽  
Kidney Donors ◽  
Body Protein ◽  
All Cause Mortality ◽  
Arginine Residues ◽  
Excretion Rates

AbstractArginine residues in proteins can be singly or doubly methylated post-translationally. Proteolysis of arginine-methylated proteins provides monomethyl arginine, asymmetric dimethylarginine (ADMA) and symmetric dimethylarginine (SDMA). ADMA and SDMA are considered cardiovascular risk factors, with the underlying mechanisms being not yet fully understood. SDMA lacks appreciable metabolism and is almost completely eliminated by the kidney, whereas ADMA is extensively metabolized to dimethylamine (DMA), with a minor ADMA fraction of about 10% being excreted unchanged in the urine. Urinary DMA and ADMA are useful measures of whole-body asymmetric arginine-dimethylation, while urinary SDMA serves as a whole-body measure of symmetric arginine-dimethylation. In renal transplant recipients (RTR), we previously found that higher plasma ADMA concentrations and lower urinary ADMA and SDMA concentrations were associated with a higher risk of all-cause mortality. Yet, in this RTR collective, no data were available for urinary DMA. For the present study, we additionally measured the excretion rate of DMA in 24-h collected urine samples of the RTR and of healthy kidney donors in the cohort, with the aim to quantitate whole-body asymmetric (ADMA, DMA) and symmetric (SDMA) arginine-dimethylation. We found that lower DMA excretion rates were associated with higher all-cause mortality, yet not with cardiovascular mortality. In the healthy donors, kidney donation was associated with considerable decreases in ADMA (by − 39%, P < 0.0001) and SDMA (by − 21%, P < 0.0001) excretion rates, yet there was no significant change in DMA (by − 9%, P = 0.226) excretion rate. Our results suggest that protein-arginine dimethylation is altered in RTR compared to healthy kidney donors and that it is pronouncedly shifted from symmetric to asymmetric arginine-dimethylation, with whole-body protein-arginine dimethylation being almost unaffected.

scholarly journals Effect of dietary protein on energy metabolism including protein synthesis in the spiny lobster Sagmariasus verreauxi

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Shuangyao Wang ◽  
Chris G. Carter ◽  
Quinn P. Fitzgibbon ◽  
Basseer M. Codabaccus ◽  
Gregory G. Smith
Keyword(s):  
Protein Synthesis ◽  
Energy Metabolism ◽  
Dietary Protein ◽  
Spiny Lobster ◽  
Ammonia Excretion ◽  
Metabolic Energy ◽  
Whole Body ◽  
Body Protein ◽  
Energy Substrate ◽  
Sagmariasus Verreauxi

AbstractThis is the first study in an aquatic ectotherm to combine a stoichiometric bioenergetic approach with an endpoint stochastic model to explore dietary macronutrient content. The combination of measuring respiratory gas (O2 and CO2) exchange, nitrogenous (ammonia and urea) excretion, specific dynamic action (SDA), metabolic energy substrate use, and whole-body protein synthesis in spiny lobster, Sagmariasus verreauxi, was examined in relation to dietary protein. Three isoenergetic feeds were formulated with varying crude protein: 40%, 50% and 60%, corresponding to CP40, CP50 and CP60 treatments, respectively. Total CO2 and ammonia excretion, SDA magnitude and coefficient, and protein synthesis in the CP60 treatment were higher compared to the CP40 treatment. These differences demonstrate dietary protein influences post-prandial energy metabolism. Metabolic use of each major energy substrate varied at different post-prandial times, indicating suitable amounts of high-quality protein with major non-protein energy-yielding nutrients, lipid and carbohydrate, are critical for lobsters. The average contribution of protein oxidation was lowest in the CP50 treatment, suggesting mechanisms underlying the most efficient retention of dietary protein and suitable dietary inclusion. This study advances understanding of how deficient and surplus dietary protein affects energy metabolism and provides approaches for fine-scale feed evaluation to support sustainable aquaculture.

Effect of dietary protein on bed-rest-related changes in whole-body-protein synthesis

1990 ◽  
Vol 52 (3) ◽  
pp. 509-514 ◽  
Author(s):  
C A Stuart ◽  
R E Shangraw ◽  
E J Peters ◽  
R R Wolfe
Keyword(s):  
Protein Synthesis ◽  
Dietary Protein ◽  
Bed Rest ◽  
Whole Body ◽  
Body Protein

scholarly journals Comprehensive assessment of post-prandial protein handling by the application of intrinsically labelled protein in vivo in human subjects

2021 ◽  
pp. 1-9
Author(s):  
Jorn Trommelen ◽  
Andrew M. Holwerda ◽  
Philippe J. M. Pinckaers ◽  
Luc J. C. van Loon
Keyword(s):  
Protein Synthesis ◽  
Amino Acid ◽  
Stable Isotope ◽  
Dietary Protein ◽  
Protein Metabolism ◽  
Muscle Protein ◽  
Human Subjects ◽  
Whole Body ◽  
Body Protein

All human tissues are in a constant state of remodelling, regulated by the balance between tissue protein synthesis and breakdown rates. It has been well-established that protein ingestion stimulates skeletal muscle and whole-body protein synthesis. Stable isotope-labelled amino acid methodologies are commonly applied to assess the various aspects of protein metabolism in vivo in human subjects. However, to achieve a more comprehensive assessment of post-prandial protein handling in vivo in human subjects, intravenous stable isotope-labelled amino acid infusions can be combined with the ingestion of intrinsically labelled protein and the collection of blood and muscle tissue samples. The combined application of ingesting intrinsically labelled protein with continuous intravenous stable isotope-labelled amino acid infusion allows the simultaneous assessment of protein digestion and amino acid absorption kinetics (e.g. release of dietary protein-derived amino acids into the circulation), whole-body protein metabolism (whole-body protein synthesis, breakdown and oxidation rates and net protein balance) and skeletal muscle metabolism (muscle protein fractional synthesis rates and dietary protein-derived amino acid incorporation into muscle protein). The purpose of this review is to provide an overview of the various aspects of post-prandial protein handling and metabolism with a focus on insights obtained from studies that have applied intrinsically labelled protein under a variety of conditions in different populations.

Contribution of Skin to Whole-Body Protein Synthesis in Rats at Different Stages of Maturity

1992 ◽  
Vol 122 (11) ◽  
pp. 2167-2173 ◽  
Author(s):  
Christiane Obled ◽  
Maurice Arnal
Keyword(s):  
Protein Synthesis ◽  
Whole Body ◽  
Body Protein
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