A procedure for comprehensive two-dimensional gas chromatography retention time locked dual detection.

In this paper, a novel, and easy to perform, retention time locking procedure for locking primary and secondary retention times of detector signals in comprehensive two-dimensional gas chromatography (GCxGC) dual-detection is proposed and its advantages are demonstrated and discussed. The dual detection retention time locking procedure is a 2-step process for a GCxGC system in which the effluent of the primary column is split, by using a pressure regulated splitter, towards the GCxGC modulator using two identical secondary GC columns of which one is installed in the main GC oven and the other is installed in a secondary GC oven. The first step of the locking procedure is to minimize the secondary retention time difference between both detectors of a compound, which has a retention factor (k) close to 0.

Growth hormone treatment improves vitality and behavioural issues in children with Prader-Willi syndrome.

Aim: Prader-Willi syndrome is a neurogenetic disorder, with characteristics such as obesity, short stature, muscular weakness, intellectual deficiencies and deviant social behaviour. This study evaluated whether growth hormone treatment of children with Prader-Willi syndrome resulted in possible and lasting effects on their cognition and behaviour.

Methods: We randomised six girls and 13 boys to either a treatment group or a control group.

Cryptorchidism: a clinical perspective.

Incomplete descent of the testes is the most common genital anomaly in newborn boys. The prevalence varies with apparent geographical differences. The etiology of cryptorchidism is considered to be multifactorial (genetic, maternal, and environmental factors), and it occurs most often as an isolated disorder with no obvious cause.

Penile size in healthy Nigerian newborns: country-based reference values and international comparisons.

Aim: To establish normal reference values for penile size in Nigerian newborn boys and to compare those values with standards from other populations.

Methods: A total number of 261 healthy newborn boys delivered at gestational ages of 28 weeks or more were enrolled in the study. Penile lengths and widths were measured within 72 h of birth.

Quantitative analysis of morphine in dried blood spots by using morphine-d3 pre-impregnated dried blood spot cards.

Two different internal standard dried blood spot (DBS) pre-impregnation procedures (prior to blood spotting) were investigated. In the first procedure DBS pre-impregnation is performed by immersing the DBS card fully into an internal standard solution. In the second procedure pre-impregnation is performed by pipetting a certain volume of an internal standard solution onto the DBS card.