Of matrices and men

Matrices used in modern electrokinetic techniques are surveyed. They are essentially three: cellulose acetate, agarose and polyacrylamide gels. The use of cellulose acetate is confined mostly to analyses in clinical chemistry labs. The properties of agarose are discussed, in particular its capacity of forming large-pore structures via supercoiling, i.e. formation of suprafibers with average radii of approximately 20-25 nm. Several modified agaroses are reviewed, in particular the SeaPlaque, SeaPrep, NuSieve, NuFix, Seakem and Isogel brands and a composite agarose-polyacrylamide matrix, quite popular in the seventies for DNA and RNA separations. The field of polyacrylamide gels seems to be bursting, with the large number of crosslinkers described, imparting special properties to such matrices. The properties of new, modified acrylamide monomers, little known in the field of electrophoresis, are evaluated; in particular: trisacryl gels, hydroxyalkyl methacrylate gels and acryloylmorpholine-bisacrylylpiperazine gels, the latter formed by amphiphilic monomers, highly resistant to alkaline hydrolysis. The properties and formulas of a host of acidic and basic acrylamido derivatives (11 of them) used as buffers and titrants for isoelectric focusing in immobilized pH gradients are reviewed here for the first time. The review culminates with a glimpse at a new generation of amphiphatic matrices, such as HydroLink and 'shielded hydrophobic phase' gels, which appear to be the latest developments in the fields of electrophoresis and chromatography, respectively.     

All the queen's men

Humans have an ancient and intimate relationship with honey bees--from the development of beekeeping in prehistoric times up to the recent sequencing of the honey bee genome. Yet, the intimacies of bee sexuality remained obscure and contentious until relatively recently. Their stepwise unravelling is a tale of advances and misconception that, in part, may have stemmed from an all too humanised view of bees.     

Estrogen metabolism in men

In studies of men's capacity for estrogen inactivation in health and disease, it was observed that patients with prostatic cancer had enhanced ability to inactivate estrogenic hormones. This ability might well lead to excessive androgen stimulation, thereby providing favorable hormonal environment for the development of prostatic cancer. Extension or regression of the malignant process did not affect this peculiar pattern of estrogen metabolism. It is possible, therefore, that the pattern may not be related to the cancer process itself but to some inherent tendency in the individual. Upon speculation as to whether or not this tendency is found in the liver, which is known to be the principal site of estrogen inactivation, studies of patients with liver damage were carried out and the results indicated that the liver possesses a tremendous reserve for inactivation of the estrogens in men. Studies on estrogen concentration in the bile indicated that estrogens are not eliminated rapidly from the human body through the biliary tract. However, this does not hold true for experimental animals. Observations on endogenous estrogen excretion in men did not support the concept that benign prostatic hypertrophy is due to an elevated estrogen-androgen ratio.     

Of rats and men

A report on the third biannual 'Rat Genomics and Models' meeting, Cold Spring Harbor, USA, 11-14 December 2003.