The present disclosure provides novel methods for determining an effective dosage of a PAA prodrug and for treating a UCD that incorporate body surface area and urinary PAGN concentration. The disclosure further provides novel methods for assessing compliance with PAA prodrug administration that incorporate urinary PAGN concentration, and the subject's current dosing regimen, BSA, or age. The disclosure further provides novel methods of treating a UCD in a subject in need thereof that incorporate urinary PAGN concentration, and the subject's current dosing regimen, BSA, and/or age.

Nitrogen scavenging drugs such as glycerol phenylbutyrate can be administered safely to infants and toddlers with urea cycle disorders by adjusting the dosage based on one or more biomarkers selected from the group consisting of urinary-PAGN and plasma PAA:PAGN ratio.

The present disclosure provides novel methods for determining an effective dosage of a PAA prodrug and for treating a UCD that incorporate body surface area and urinary PAGN concentration. The disclosure further provides novel methods for assessing compliance with PAA prodrug administration that incorporate urinary PAGN concentration, and the subject's current dosing regimen, BSA, or age. The disclosure further provides novel methods of treating a UCD in a subject in need thereof that incorporate urinary PAGN concentration, and the subject's current dosing regimen, BSA, and/or age.

Nitrogen scavenging drugs such as glycerol phenylbutyrate can be administered safely to infants and toddlers with urea cycle disorders by adjusting the dosage based on one or more biomarkers selected from the group consisting of urinary-PAGN and plasma PAA:PAGN ratio.

The present invention relates to a method for assessing mitochondrial function in a tissue or organ other than the kidney in a test subject, including: a step of calculating a ratio (BUN/CRE) of blood urea nitrogen (BUN) concentration to blood creatinine (CRE) concentration in a test subject; and a step of estimating mitochondrial activity in a tissue or organ other than the kidney in the test subject using the calculated ratio (BUN/CRE).

Provided is a non-human animal that is highly practical as a hyperuricenia model, the non-human animal being the following: (a) a non-human animal obtained by producing a primary chimeric non-human animal by transplantation of human hepatocytes to an immunodeficient non-human animal with liver dysfunction; and subsequently administering a purine base-containing substance to the primary chimeric non-human animal, or (b) a non-human animal obtained by producing a serially transplanted chimeric non-human animal via two steps, a first step being a step of producing a primary chimeric non-human animal by transplantation of human hepatocytes to an immunodeficient non-human animal with liver dysfunction, a second step being a step of transplanting the human hepatocytes grown in the body of the primary chimeric non-human animal to an immunodeficient non-human animal with liver dysfunction, the second step being performed one or more times; and subsequently administering a purine base-containing substance to the serially transplanted chimeric non-human animal.

Nitrogen scavenging drugs such as glycerol phenylbutyrate can be administered safely to infants and toddlers with urea cycle disorders by adjusting the dosage based on one or more biomarkers selected from the group consisting of urinary-PAGN and plasma PAA:PAGN ratio.

The present disclosure provides novel methods for determining an effective dosage of a PAA prodrug and for treating a UCD that incorporate body surface area and urinary PAGN concentration. The disclosure further provides novel methods for assessing compliance with PAA prodrug administration that incorporate urinary PAGN concentration, and the subject's current dosing regimen, BSA, or age. The disclosure further provides novel methods of treating a UCD in a subject in need thereof that incorporate urinary PAGN concentration, and the subject's current dosing regimen, BSA, and/or age.

The present disclosure provides novel methods for determining an effective dosage of a PAA prodrug and for treating a UCD that incorporate body surface area and urinary PAGN concentration. The disclosure further provides novel methods for assessing compliance with PAA prodrug administration that incorporate urinary PAGN concentration, and the subject's current dosing regimen, BSA, or age. The disclosure further provides novel methods of treating a UCD in a subject in need thereof that incorporate urinary PAGN concentration, and the subject's current dosing regimen, BSA, and/or age.

The present disclosure provides novel methods for determining an effective dosage of a PAA prodrug and for treating a UCD that incorporate body surface area and urinary PAGN concentration. The disclosure further provides novel methods for assessing compliance with PAA prodrug administration that incorporate urinary PAGN concentration, and the subject's current dosing regimen, BSA, or age. The disclosure further provides novel methods of treating a UCD in a subject in need thereof that incorporate urinary PAGN concentration, and the subject's current dosing regimen, BSA, and/or age.