Coffee inhibition of CYP3A4 in vitro was not translated to a grapefruit-like pharmacokinetic interaction clinically.

Grapefruit can augment oral medication bioavailability through irreversible (mechanism-based) inhibition of intestinal CYP3A4. Supplementary data from our recent coffee-drug interaction clinical study showed some subjects had higher area under the plasma drug concentration - time curve (AUC) and plasma peak drug concentration (Cmax) of the CYP3A4 probe felodipine compared to aqueous control. It was hypothesized that coffee might interact like grapefruit in responsive individuals.

Coffee-Antihypertensive Drug Interaction: A Hemodynamic and Pharmacokinetic Study With Felodipine.

Objectives: A period of abstinence from coffee to permit caffeine elimination appears to enable increased blood pressure on subsequent exposure. We hypothesized that this would offset the antihypertensive effect of the dihydropyridine calcium channel blocker felodipine.

Methods: A randomized, single-dose, crossover study assessed hemodynamic and pharmacokinetic effects following 2 days without coffee and caffeine-containing foods.

Plantar forces in flexor hallucis longus versus flexor digitorum longus transfer in adult acquired flatfoot deformity.

Background: Flexor hallucis longus (FHL) and flexor digitorum longus (FDL) tendon transfers are frequently used to restore the function of a deficient tibialis posterior tendon in stage II adult acquired flatfoot deformity (AAFD). Either transfer causes some loss in toe flexion force, although the decision to tenodese the cut tendon to restore associated function remains controversial. This study quantified changes in plantar force before and after tendon transfer and with or without distal tenodesis in a cadaveric model.

High frequency optoelectronic oscillators based on the optical feedback of semiconductor mode-locked laser diodes.

Optical self seeding feedback techniques can be used to improve the noise characteristics of passively mode-locked laser diodes. External cavities such as fiber optic cables can increase the memory of the phase and subsequently improve the timing jitter. In this work, an improved optical feedback architecture is proposed using an optical fiber loop delay as a cavity extension of the mode-locked laser.

ULTRASTRUCTURE OF A CEPHALOPOD PHOTOPHORE. II. IRIDOPHORES AS REFLECTORS AND TRANSMITTERS.

The iridophores of one type of photophore of the deep sea squid, Pterygioteuthis microlampas were examined with the electron microscope and four different types were found. Three of these types have not been previously described. The regular iridophores of the posterior cup appear to be one-fourth wave length reflectors and redirect the light produced by the photogenic tissue outward.

ULTRASTRUCTURE OF A CEPHALOPOD PHOTOPHORE. I. STRUCTURE OF THE PHOTOGENIC TISSUE.

One type of photophore of the deep sea squid Pterygioteuthis microlampas was examined with the electron microscope and its fine structure described. The photogenic tissue is composed of four cell types each with distinctive morphology which suggests their function. The photocytes branch and ramify throughout the central region of the photophore and have an extensive system of microvilli (the photogenic organelle) which are arranged about a central blood filled lumen.