Activity Of AAP Research Articles

How Can Storage Time and Temperature Affect Enzymic Activities in Urines?

We measured a tubular brush-border enzyme (alanine aminopeptidase, AAP) and a lysosomal hydrolase (N-acetyl-beta-D-glucosaminidase, NAG) in morning urines from 15 healthy normal subjects to check if different storage times and temperatures could modify enzyme concentrations. Short-term (24 h) storage time at room temperature or 4 degrees C does not affect AAP and NAG activities. Both enzymes are well preserved at -70 degrees C. AAP dramatically falls after 1 month at -20 degrees C, lowering to about 8% of the initial value after only 4 days of storage. On the contrary, NAG is well preserved at these storage conditions. Centrifugation has revealed not critical for measurement of these two enzymes.

Clinical investigation of urinary activity of NAG and AAP in patients with various types of primary glomerulonephritis

Clinical investigation of urinary activity of NAG and AAP in patients with various types of primary glomerulonephritis

Alanine aminopeptidase in serum: biological variations and reference limits.

We studied the effect of various factors on the biological variation of alanine aminopeptidase (AAP, EC 3.4.11.2) in serum in a population of 2178 apparently healthy subjects and in subjects taking specific drugs. To measure AAP, we used an automated assay, with alanyl-4-nitroanilide as substrate. AAP activity concentrations were significantly higher in males than in females in all age groups between 10 and 55 years. The highest mean AAP values were found for children between 10 and 14 years. In male heavy smokers, AAP values were 8% higher than in moderate or nonsmokers (P less than 0.001); in females, this effect was less pronounced. AAP concentrations were higher in subjects consuming over 44 g of ethanol a day than in those consuming less (P less than 0.01 for men, P less than 0.05 for women). The use of oral contraceptives increased AAP values by 12% (P less than 0.001). Hypolipidemic drugs caused lower values for AAP in men (P less than 0.001). Subjects showing induction of gamma-glutamyltransferase (EC 2.3.2.2) by anticonvulsant drugs had also higher AAP activities (by 23%). Taking these data into account, we established reference limits for AAP in serum.

Alanine aminopeptidase in serum: automated optimized assay, and effects of age, sex, smoking, and alcohol consumption in a selected population.

In the diagnosis of chronic (as opposed to acute) liver diseases, combinations of indicators are needed to improve specificity. Alanine aminopeptidase (AAP; microsomal aminopeptidase, EC 3.4.11.2) activity in serum reportedly is a very sensitive indicator of intrahepatic cholestasis and biliary obstruction; it is also particularly useful in diagnosing chronic liver disease when combined with an indicator of hepatocyte damage such as aspartate aminotransferase or alanine aminotransferase. We optimized the assay of AAP in serum, automated the assay by using a centrifugal analyzer, then used this automated assay to determine activity in 202 individuals, ages one to 73 years. The preliminary results were analyzed in terms of the effects of age, sex, smoking, and alcohol consumption on AAP activity in serum. Striking sex-related differences were observed: AAP activity in males declined 2.5 times more rapidly with age than did that in females; indeed, activity in adult females remained essentially constant. Moreover, AAP values were higher in men who smoked than in those who did not, the difference being of borderline significance by analysis of covariance (p = 0.0865) but significant by partial correlations (p = 0.02). No similar differences were seen for women smokers and non-smokers. When the effects of other variables were held constant, alcohol consumption alone did not significantly correlate with AAP activity in men or women.

Serum aminopeptidase A (AAP) in normal pregnancy and pregnancy complicated by pre-eclampsia

Serum aminopeptidase A (AAP) activity was measured in normal pregnancy and pre-eclampsia. The AAP activity in normal pregnancy increased progressively with advancing gestation, reaching the highest value at the end of pregnancy. The AAP activity in pregnancy complicated by pre-eclampsia was lower than in normal pregnancy.

AAP Activities in Border and Indian Health-Reply

In Reply .—The efforts of the AAP and associated organizations to which Eaton and colleagues refer are commendable. Last fall, as we sat to discuss some of the issues with a few colleagues during the AAP meetings, we realized again that the problems of our fellow men, women, and children in the border area indeed boggle the mind. I suggest, therefore, that the will of an entire society, more than the actions of a few, will determine how much we can do to prevent further alienation of the societies separated by the border line. I am aware of the impressive achievements of the AAP and those of many institutions along the two sides of the border, but the problem, the overwhelming health problem, remains. With no credentials to show to back up my convictions, I am willing to stand alone to express those convictions for fear that, otherwise, what I

Urinary [formula omitted] and aminopeptidase N in the diagnosis of graft rejection after live donor renal transplantation

An evaluation of the usefulness of urinary N- acetyl-β- d- glucosaminidase (NAG) and aminopeptidase N (AAP) measurements in the diagnosis and prediction of acute and chronic renal allograft rejection was made. Enzyme activities were measured in 2, 745 morning spot urine samples from 53 consecutive live donor renal allograft recipients up to 180 days after transplantation. Reference ranges of urinary enzyme activities in 14 recipients with normal graft function were higher than those established in a carefully selected group of healthy controls. 89 and 91% of 76 clinically diagnosed acute rejection episodes (ARE) in the remaining 39 graft recipients were accompanied by sharp increase over baseline of NAG and AAP respectively. All rejection episodes occurring in the early period after transplantation were characterised by high enzymuria. AAP was more sensitive than NAG as the magnitude of its increase over baseline was more, while NAG was more specific with less number of false positive elevations. Both enzymes were found to be equally good prognostic indices of graft loss and chronic graft deterioration. Regular monitoring of urinary NAG and AAP activities throughout the post transplant period would thus be valuable, in (a) diagnosis and prediction of ARE in the early as well as late post operative period and (b) prediction of eventual graft outcome.

Communication

As far as can be determined, the first medical organization was founded in the year 1518, when Dr Thomas Linacre, physician to Henry VII and Henry VIII, proposed and arranged the establishment of the College of Physicians (now the Royal College of Physicians). There is no recording as to differences of opinion among the membership, but it seems more than likely that complete accord and harmony did not always exist. According to the old adage, "That's what makes horseracing." Good communication (the exchange of information) can bridge most disagreements or differences of opinion. The most frequently discussed and the most important question faced by the Executive Board of the American Academy of Pediatrics has concerned the best means by which to develop and utilize communication. Examples indude the President's letter to the membership (December 1978) listing 32 AAP accomplishments and activities over the past five years; and still another is the Academy program for the International Year of the Child, "The AAP Speaks Up for Children." Communication, then, is the way to begin to solve most problems and that leads us to the theme of this discussion today: communication between practicing pediatricians and those engaged in academic pediatrics, and communication between those groups and both the Federal government and the public sector. Pediatric practitioners could not exist without pediatric teaching programs and research; conversely, the latter would be pragmatically useless without the practicing pediatricians. Both groups must recognize that they exist interdependently and that their mutual growth and development is equally interdependent.

Alamine aminopeptidase excretion after mercuric chloride renal failure

Within the first 24 hr after induction of acute renal failure in rats by 4.7 mg/kg body weight of mercuric chloride, there was a highly significant ( P < 0.001) increase in urine AAP activity. Enzymuria sharply declined during the next 48 hr, although did not return to baseline until Day 4. A transient secondary period of hyperenzymuria occurred 8 to 10 days after injection. In addition to the type of renal injury, timing of sample collections influences the diagnostic value of urine enzyme determinations.

Biochemische Parameter zur Feststellung der Lebensfähigkeit allogener Nierentransplantate

In 54 patients with graft failure the changes of urine sodium concentration and of urinary enzyme activities (alanine aminopeptidase, AAP) were investigated. It was found that: (1) the kidneys with irreversible acute tubular necrosis are characterised by high urine sodium level, and low AAP activities. These changes correspond to the end stage of renal insufficiency. (2) Low concentration of sodium and extremely high AAP excretion are characteristic in grafts with severe rejection episodes. (3) If kidneys lost their function due to irreversible rejection, the biochemical variables showed the same changes as in the first group. We concluded that by continuous determination of sodium levels and enzyme activities in urine and by their correlation it is possible to detect the non-functioning grafts in the early posttransplantation period.