Diagnostic significance of selected serum enzymes in a rat heatstroke model

1979 ◽  
Vol 46 (2) ◽  
pp. 334-339 ◽  
Author(s):  
R. W. Hubbard ◽  
R. E. Criss ◽  
L. P. Elliott ◽  
C. Kelly ◽  
W. T. Matthew ◽  
...  

A total of 171 untrained, unacclimatized, and unanesthetized rats were either exercised to exhaustion at one of four ambient temperatures (5, 20, 26, or 30 degrees C), or were restrained and heated at an ambient temperature of 41.5 degrees C until their core temperatures reached a preselected end point between 41.0 and 43.3 degrees C. The serum levels of creatine phosphokinase (CRK) and two transaminases (SGOT and SGPT) were determined at 30 min, 24, 48, 72, and 96 h posttreatment. Peak enzyme activity for CPK was noted primarily at the 30-min sampling period and at 24 h for the transaminases. The data indicated that under these conditions a) the transaminase SGOT was elevated in the serum as a consequence of the extent and duration of prior hyperthermia, b) the transaminase SGOT was released in moderate amounts after exhaustive exercise but reached its greatest activity levels following hyperthermia, and c) the activity of CPK was increased by the duration of exhaustive exercise and was less sensitive than either transaminase to prior hyperthermia. As a result, each of the three experimental conditions: a) exercise without hyperthermia, b) exercise with hyperthermia, and c) sedentary hyperthermia, produced a unique pattern of serum enzyme activity that would appear useful in diagnosing a variety of heat- and/or work-induced disorders.

1989 ◽  
Vol 121 (3) ◽  
pp. 374-382 ◽  
Author(s):  
Donald C. Johnson ◽  
Mitra Sen

Abstract. The in vivo regulatory action of LH on the ovarian androgen synthesizing enzyme cytochrome P45017α (17α-hydroxylase/C17, 20-lyase) was studied in cyclic golden hamsters. Immunohistochemical studies using anti-porcine testicular cytochrome P45017α antibody indicated that the enzyme was limited to thecal cells. Transient removal of the negative feedback action of endogenous steroids by use of aminoglutethimide phosphate produced an increase in endogenous gonadotropins. A single dose (30 mg) of aminoglutethimide on days 1, 2 or 3 of the estrous cycle (day 1 = estrus), increased serum levels of LH, but only for about 12 h. Increases in enzyme activities, which persisted for at least 24 h, followed. Two doses of aminoglutethimide, 12 h apart, maintained elevated levels of serum LH for about 36 h, and enzyme activites for at least 48 h. However, when the drug was given after the pre-ovulatory surge of LH on proestrus, and again on the morning of estrus, neither serum LH nor enzyme activity levels increased within 24 h. Induced increases in enzyme activity had no effect upon ovulation rate, as determined by the number of oviductal eggs present on the morning of estrus. The results demonstrate clearly a close correlation between serum concentrations of LH and ovarian androgen synthesizing enzyme activity.


1997 ◽  
Vol 46 (2) ◽  
pp. 189-199 ◽  
Author(s):  
TAKASHI KUMAE ◽  
HATSUKO ARAKAWA ◽  
KAZUHIRO SUZUKAWA ◽  
KAORI ISHIZAKI ◽  
IWAO UCHIYAMA

2021 ◽  
Vol 7 (2) ◽  
pp. 28
Author(s):  
Camille S. Corre ◽  
Dietrich Matern ◽  
Joan E. Pellegrino ◽  
Carlos A. Saavedra-Matiz ◽  
Joseph J. Orsini ◽  
...  

Krabbe disease (KD) is a rare inherited neurodegenerative disorder caused by a deficiency in galactocerebrosidase enzyme activity, which can present in early infancy, requiring an urgent referral for hematopoietic stem cell transplantation, or later in life. Newborn screening (NBS) for KD requires identification and risk-stratification of patients based on laboratory values to predict disease onset in early infancy or later in life. The biomarker psychosine plays a key role in NBS algorithms to ascertain probability of early-onset disease. This report describes a patient who was screened positive for KD in New York State, had a likely pathogenic genotype, and showed markedly reduced enzyme activity but surprisingly low psychosine levels. The patient ultimately developed KD in late infancy, an outcome not clearly predicted by existing NBS algorithms. It remains critical that psychosine levels be evaluated alongside genotype, enzyme activity levels, and the patient’s evolving clinical presentation, ideally in consultation with experts in KD, in order to guide diagnosis and plans for monitoring.


Genetics ◽  
1998 ◽  
Vol 149 (2) ◽  
pp. 739-747 ◽  
Author(s):  
Thomas Mitchell-Olds ◽  
Deana Pedersen

Abstract To find the genes controlling quantitative variation, we need model systems where functional information on physiology, development, and gene regulation can guide evolutionary inferences. We mapped quantitative trait loci (QTLs) influencing quantitative levels of enzyme activity in primary and secondary metabolism in Arabidopsis. All 10 enzymes showed highly significant quantitative genetic variation. Strong positive genetic correlations were found among activity levels of 5 glycolytic enzymes, PGI, PGM, GPD, FBP, and G6P, suggesting that enzymes with closely related metabolic functions are coregulated. Significant QTLs were found influencing activity of most enzymes. Some enzyme activity QTLs mapped very close to known enzyme-encoding loci (e.g., hexokinase, PGI, and PGM). A hexokinase QTL is attributable to cis-acting regulatory variation at the AtHXK1 locus or a closely linked regulatory locus, rather than polypeptide sequence differences. We also found a QTL on chromosome IV that may be a joint regulator of GPD, PGI, and G6P activity. In addition, a QTL affecting PGM activity maps within 700 kb of the PGM-encoding locus. This QTL is predicted to alter starch biosynthesis by 3.4%, corresponding with theoretical models, suggesting that QTLs reflect pleiotropic effects of mutant alleles.


1980 ◽  
Vol 89 (3_suppl) ◽  
pp. 178-184 ◽  
Author(s):  
Krishna G. Murti ◽  
Erdem I. Cantekin ◽  
Richard M. Stern ◽  
Charles D. Bluestone

New measurements of acoustical transmission through the eustachian tube (ET) have been obtained in a series of experiments directed toward the development of a clinical instrument to assess ET function behind an intact tympanic membrane (TM). Using a sound conduction method, a sound source was placed in one nostril, and the acoustical energy that was transmitted through the ET was measured by a microphone placed in the ear canal. The present study used a broadband noise as the acoustical stimulus, in contrast to the tonal stimuli employed in previous investigations. This stimulus was chosen because it is believed to reduce the variability in the data due to intersubject differences in the acoustics of the nasopharynx and ET, and to avoid any a priori assumptions concerning the specific frequencies that would be of greatest diagnostic significance. Averaged spectra of the sound transmitted to the ear canal were obtained for three experimental conditions: acoustical source present during subject swallowing, source present with no swallowing, and subject swallowing with source absent. A Bayesian classification scheme based on the statistics of these spectra was used in classifying subjects into one of two possible categories, normal and abnormal ET function. A comparison was made between sonometric classification and classification based on a tympanometric ET function test. Correlation between the two methods was 87.1%.


2020 ◽  
Vol 42 ◽  
Author(s):  
Marcone Moreira Santos ◽  
Eduardo Euclydes de Lima e Borges ◽  
Glauciana da Mata Ataíde ◽  
Raquel Maria de Oliveira Pires ◽  
Debora Kelli Rocha

Abstract: Recent studies indicate that global temperatures will rise substantially in the 21st century, leading to the extinction of several plant species, as plant metabolism and germination are greatly affected by temperature. Melanoxylon brauna, a tree species native to the Atlantic Forest that occurs from northeastern to southeastern Brazil, is one of the many species threatened by global warming. Despite the economic and ecological importance of M. brauna, studies investigating the influence of heat stress on seed germination and biochemical responses are still incipient. This study aimed to evaluate enzyme activity in the micropylar region of M. brauna seeds during germination under heat stress conditions. Endo-β-mannanase, α-galactosidase, polygalacturonase, pectin methylesterase, pectin lyase, total cellulase, 1,3-β-glucosidase, and 1,4-β-glucosidase activities were determined in micropyles of seeds imbibed for 24, 48 and 72 h at 25, 35 and 45 °C. Seed germination was highest at 25 °C. Endo-β-mannanase activity was not detected under any of the experimental conditions, but imbibition temperature had a significant effect on the activity of all other enzymes.


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