Retinal degeneration associated with RDH12 mutations results from decreased 11-cis retinal synthesis due to disruption of the visual cycle

Human Molecular Genetics     

The aging man and woman: are the differences important?

This article celebrates the continuing differences between men and women that are present in our twilight years. Although men die earlier than women, they spend fewer years with major disability. There is increasing interest in the use of testosterone to improve the quality of life in both older men and women. Sarcopenia, osteopenia, hip fractures, and frailty are all more common in women than in men. Sexuality remains important to both men and women throughout life. Finally, it is known that cytokines play a major role in the pathophysiology of aging, a process now recognized as the cytokine-related aging process.     

The new radiology workforce: Changing expectations

The zeitgeist of the new radiology workforce can best be described by a Bob Dylan song title: “The Times They Are A-Changin’.” The new generation of physicians, although embracing the same foundations of medical practice as previous generations, places greater emphasis on personal satisfaction than its predecessors. Gone are the days when physicians operated as sole practitioners; today’s workforce member is content to function in the role of “employee” in a trade-off for more lifestyle flexibility. This change has occurred not because of one specific factor but because of a change in the profession of medicine coupled with a combination of factors; familial responsibilities, avocational activities, and personal satisfaction have surfaced as motivating factors in choosing a profession. Today’s workforce has a personal perception of success that may not be fulfilled solely by the contemporary practice of medicine. With the radiologist shortages that are now occurring and anticipated increased demand for staff radiologists, today’s radiology workforce has helped shape the specialty into one that is altering its structure to attract and retain its workforce.     

Siberian ginseng (Eleutheroccus senticosus) effects on CYP2D6 and CYP3A4 activity in normal volunteers.

Siberian ginseng ([SG]; Eleutherococcus senticosus) is a commonly used herbal preparation. The objective of this study was to assess in normal volunteers (n = 12) the influence of a standardized SG extract on the activity of cytochrome P450 CYP2D6 and 3A4. Probe substrates dextromethorphan (CYP2D6 activity) and alprazolam (CYP3A4 activity) were administered orally at baseline and again following treatment with SG (1 x 485 mg twice daily) for 14 days. Urinary concentrations of dextromethorphan and dextorphan were quantified, and dextromethorphan metabolic ratios (DMRs) were determined at baseline and after SG treatment. Likewise, plasma samples were collected (0-60 h) for alprazolam pharmacokinetics at baseline and after SG treatment to assess effects on CYP3A4 activity. Validated high performance liquid chromatography methods were used to quantify all compounds and relevant metabolites. There were no statistically significant differences between pre- and post-SG treatment DMRs indicating a lack of effect on CYP2D6 (P > 0.05). For alprazolam there also were no significant differences in the pharmacokinetic parameters determined by noncompartmental modeling (C(max), T(max), area under the curve, half-life of elimination) indicating that SG does not significantly induce or inhibit CYP3A4 (P > 0.05). Our results indicate that standardized extracts of SG at generally recommended doses for over-the-counter use are unlikely to alter the disposition of coadministered medications primarily dependent on the CYP2D6 or CYP3A4 pathways for elimination.