Changes in blood ammonia induced by a maximum effort in trained and untrained subjects

Abstract Background The maximum oxygen uptake (VO2max) during cardiopulmonary exercise testing (CPET) is considered the best measure of cardiorespiratory fitness. Aim To provide up-to-date reference values for the VO2max per kilogram of body mass (VO2max/kg) obtained by CPET in the Netherlands and Flanders. Methods The Lowlands Fitness Registry contains data from health checks among different professions and was used for this study. Data from 4612 apparently healthy subjects, 3671 males and 941 females, who performed maximum effort during cycle ergometry were analysed. Reference values for the VO2max/kg and corresponding centile curves were created according to the LMS method. Results Age had a negative significant effect (p < .001) and males had higher values of VO2max/kg with an overall difference of 18.0% compared to females. Formulas for reference values were developed: Males: VO2max/kg = − 0.0049 × age2 + 0.0884 × age + 48.263 (R2 = 0.9859; SEE = 1.4364) Females: VO2max/kg = − 0.0021 × age2 − 0.1407 × age + 43.066 (R2 = 0.9989; SEE = 0.5775). Cross-validation showed no relevant statistical mean difference between measured and predicted values for males and a small but significant mean difference for females. We found remarkable higher VO2max/kg values compared to previously published studies. Conclusions This is the first study to provide reference values for the VO2max/kg based on a Dutch/Flemish cohort. Our reference values can be used for a more accurate interpretation of the VO2max in the West-European population.

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Muscle fatigue modelling: Solving for fatigue and recovery parameter values using fewer maximum effort assessments

International Journal of Industrial Ergonomics ◽

10.1016/j.ergon.2021.103104 ◽

2021 ◽

Vol 82 ◽

pp. 103104

Author(s):

Laura A. Frey-Law ◽

Mitchell Schaffer ◽

Frank K. Urban

Keyword(s):

Muscle Fatigue ◽

Maximum Effort ◽

Parameter Values

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Biomechanical movement strategies in maximum effort change-of-direction

Journal of Science and Medicine in Sport ◽

10.1016/j.jsams.2017.01.168 ◽

2017 ◽

Vol 20 ◽

pp. e63-e64

Author(s):

C. Richter ◽

A. Franklyn-Miller ◽

E. King ◽

E. Falvey

Keyword(s):

Change Of Direction ◽

Movement Strategies ◽

Maximum Effort

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Recommendation of Repeated Ammonia Tests for Intrahepatic Portal-Systemic Shunt Without Cirrhosis in Elderly Patients With Psychiatric Symptoms

Japanese Clinical Medicine ◽

10.1177/1179066017693597 ◽

2017 ◽

Vol 8 ◽

pp. 117906601769359

Author(s):

Michiaki Abe ◽

Temma Soga ◽

Nobuya Obana ◽

Kazumasa Seiji ◽

Masao Tabata ◽

...

Keyword(s):

Computed Tomography ◽

Elderly Patients ◽

Psychiatric Disorder ◽

Male Patient ◽

Psychiatric Symptoms ◽

Blood Ammonia ◽

Elderly Male ◽

Blood Tests ◽

Portal Systemic Shunt

We report an elderly male patient with hyperammonemia induced by intrahepatic portal-systemic shunt without cirrhosis (IPSSwoC). The occasional emergence of his erratic behaviors was misdiagnosed as a psychiatric disorder. Regardless of his uneven symptoms, IPSSwoC was suspected due to his hyperammonemia. The contrast computed tomography of the abdomen revealed a congenital type of IPSSwoC. As blood ammonia levels are inconstant, repeated blood tests are recommended when this disease is suspected in elderly patients with psychiatric symptoms.

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Diagnostic Criteria for Influenza B-Associated Reye's Syndrome: Clinical vs. Pathologic Criteria

PEDIATRICS ◽

10.1542/peds.60.5.702 ◽

1977 ◽

Vol 60 (5) ◽

pp. 702-708

Author(s):

Lawrence Corey ◽

Robert J. Rubin ◽

Dennis Bregman ◽

Michael B. Gregg

Keyword(s):

Disease Control ◽

Diagnostic Criteria ◽

Hepatic Dysfunction ◽

Elevated Serum ◽

Acute Onset ◽

Demographic Characteristics ◽

Influenza B ◽

Elevated Blood ◽

Blood Ammonia ◽

Reye's Syndrome

Between December 15, 1973, and June 30, 1974, a total of 379 cases of Reye's syndrome was reported to the Center for Disease Control. One hundred forty-seven (40%) were confirmed by either autopsy or biopsy, while 232 were diagnosed by clinical and laboratory parameters. Comparisons of the epidemiologic and demographic characteristics, the hospital course, the outcome, and the laboratory abnormalities of the clinically diagnosed and the pathologically confirmed cases revealed no significant differences. In the epidemiologic setting of influenza B outbreaks, children who have the acute onset of noninflammatory encephalopathy associated with elevated serum transaminase levels, hypoprothrombinemia, and elevated blood ammonia levels should be considered to have Reye's syndrome. Further evaluation of diagnostic criteria is needed, however, for sporadically occurring, nonepidemic cases of noninflammatory encephalopathy associated with hepatic dysfunction.

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HYPERAMMONEMIA DUE TO A MUTANT ENZYME OF ORNITHINE TRANSCARBAMYLASE

PEDIATRICS ◽

10.1542/peds.48.4.595 ◽

1971 ◽

Vol 48 (4) ◽

pp. 595-600

Author(s):

Ichiro Matsuda ◽

Shinichiro Arashima ◽

Haruo Nambu ◽

Yasuo Takekoshi ◽

Michiya Anakura

Keyword(s):

In Vitro Study ◽

Ornithine Transcarbamylase ◽

Vitro Study ◽

Mutant Enzyme ◽

Elevated Blood ◽

Blood Ammonia ◽

Carbamyl Phosphate

In a case of congenital hyperammonemia described in an 8½-month-old girl, elevated blood ammonia was shown to result from a mutant enzyme of ornithine transcarbamylase. An in vitro study indicated a decrease in affinity of the enzyme for carbamyl phosphate but not for ornithine.

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