Track topics on Twitter Track topics that are important to you
The aim of the present study was to demonstrate the applicability of a yeast androgen and estrogen bioassay in the detection of steroid esters in hair samples of animals treated with a hormone ester cocktail. The outcome of the activity screenings was critically compared with the results previously obtained with LC-MS/MS analysis. Hair samples of one pour-on treated animal, 10 ml DMSO containing 25 mg estradiol benzoate (EB), 60 mg testosterone decanoate (TD) and 60 mg testosterone cypionate (TC), were selected and analyzed with the androgen and estrogen yeast bioassay. Results showed that by the introduction of a hydrolysis step, bioassays can be used to screen for the presence of hormone esters in hair samples. Based on the difference in fluorescence responses between the non-hydrolyzed and the hydrolyzed hair samples, it was possible to detect the presence of EB up to at least 56 days after a single pour-on treatment and to detect the presence of TC and TD up to at least 14 days after the treatment. Although the LC-MS/MS analysis could detect TC and TD up to 49 days after treatment, bioassays have the advantage that they can also detect any (un)known steroid ester.
Laboratory of Food Analysis, Ghent University, Harelbekestraat 72, 9000, Ghent, Belgium, I.Becue@UGent.be.
This article was published in the following journal.
Name: Analytical and bioanalytical chemistry
Hair cortisol concentrations (hairF) are considered to be relatively robust to various confounding influences. However, a potentially important covariate factor that has received little attention in t...
Tetracyclines are used for the prevention and control of dairy cattle diseases. Residues of these drugs can be excreted into milk. Thus, the aim of this study was to develop a microbiological method u...
Relationships between the hypothalamic-pituitary adrenal and hypothalamic-pituitary gonadal axes and social behaviour in primates are complex. By using hair to quantify steroid hormones, one can obtai...
Woolly hair nevus is a mosaic disorder characterized by unruly, tightly curled hair in a circumscribed area of the scalp. This condition may be associated with epidermal nevi. We describe an 11-year-o...
Hair sprays apply fixative ingredients to provide hold to a hair style as well as weather resistance and optical properties such as shine. Generally, sprays distribute fine particles containing polyme...
Hair samples from subjects on antiretroviral therapy, both HIV- and HIV+ patients with HIV RNA 6 months will be analyzed to investigate the influence of race, hair color and hair treatment...
The objective of this study was to investigate whether there is a link between clinical and biological variables and bioassay high xaban in elderly patients as part of an unscheduled hospi...
The purpose of this study is to learn more about how hair removal with lasers achieves, what appears to be, permanent hair reduction. Laser hair removal has become one of the most popular...
A large body of evidence confirm the cholesterol lowering effect of phytosterols and red yeast rice. Because their mechanisms of action mime the ones of chemical statins and cholesterol ab...
The purpose of this research study is to better understand African American hair and scalp, its biologic appearance and how this relates to African Americans' perceptions of their hair and...
Proteins found usually in the cytoplasm or nucleus that specifically bind steroid hormones and trigger changes influencing the behavior of cells. The steroid receptor-steroid hormone complex regulates the transcription of specific genes.
Protein factors released from one species of YEAST that are selectively toxic to another species of yeast.
Detection of drugs that have been abused, overused, or misused, including legal and illegal drugs. Urine screening is the usual method of detection.
Hair grooming and cleansing aids or other products meant for topical application to hair, usually human. They include sprays, bleaches, conditioners, rinses, shampoos, nutrient lotions, etc.
A 21-carbon steroid, derived from CHOLESTEROL and found in steroid hormone-producing tissues. Pregnenolone is the precursor to GONADAL STEROID HORMONES and the adrenal CORTICOSTEROIDS.
Endocrine disorders are grouped into two categories: hormone imbalance - when a gland produces too much or too little of an endocrine hormone development of lesions (such as nodules or tumors) in the endocrine system, which may or may not affect...
Diabetes Diabetes Endocrine Obesity Oxycontin Renal Disease Thyroid Disorders Endocrinology is the study of the endocrine glands and the hormones that they secrete (Oxford Medical Dictionary). There are several groups of h...