Determination of histidine alpha-deaminase in human stratum corneum and its absence in histidinaemia.

Simultaneous determination of urocanic acid isomers and histidine in human stratum corneum by high-performance liquid chromatography.

Factors controlling the expressed activity of histidine ammonia-lyase in the epidermis and the resulting accumulation of urocanic acid.

The synthesis of urocanic acid by histidine ammonia-lyase in guinea-pig epidermis was investigated in various ways. 1. In epidermal homogenates the enzyme obeys Michaelis-Menten kinetics and shows marked dependence of its activity of pH, such that below pH 6 it is inactive. 2. Part-thickness skin samples cultured with radioactive histidine do not accumulate detectable radioactive urocanic acid ...

بی‌خطری دو فرآورده‌ی مرطوب‌کننده: کارآزمایی بالینی دارای گروه شاهد فاز I

Background and Aim: Moisturizers have important roles in the treatment of dry skin. Their safety has to be evaluated on human volunteers in order to assess their potential skin irritation. Measurements of skin biophysical parameters can be used as fast and noninvasive methods to assess any harmful effect of cosmetic formulations on the skin sites where those products are applied. Methods: Tw...

Histidinaemia: a child and his family.

Histidinaemia, an inherited disorder of histidine metabolism, was first described by Ghadimi, Partington, and Hunter in 1961. The principal metabolic pathway for histidine is through urocanic acid and formiminoglutamic acid (FIGLU) to glutamic acid (Fig. 1). Zannoni and La Du (1963) demonstrated that histidase, the enzyme necessary for the conversion of histidine to urocanic acid, was absent fr...

ارزیابی بی‌خطری محلول موضعی مینوکسیدیل 5% + بابونه‌ی 7%

Background and Aim: Androgenetic alopecia (AGA) is the most common form of alopecia in men, worldwide and topical minoxidil appears to be the most effective and safe treatment for AGA beside oral finasteride. Safety assessment of topical minoxidil formulation could be conducted using in vivo studies on human volunteers. Using skin biophysical parameters is a fast and noninvasive method for safe...