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Di(2-ethylhexyl)phthalate (DEHP) is a reproductive toxicant in male rodents. The aim of the current study was to extrapolate the pharmacokinetics and toxicokinetics of mono(2-ethylhexyl)phthalate (MEHP, a primary metabolite of DEHP) in humans by using data from oral administration of DEHP to chimeric mice transplanted with human hepatocytes. MEHP and its glucuronide were detected in plasma from control mice and chimeric mice after single oral doses of 250mg DEHP/kg body weight. Biphasic plasma concentration-time curves of MEHP and its glucuronide were seen only in control mice. MEHP and its glucuronide were extensively excreted in urine within 24h in mice with humanized liver. In contrast, fecal excretion levels of MEHP glucuronide were high in control mice compared with those with humanized liver. Adjusted animal biomonitoring equivalents from chimeric mice studies were scaled to human biomonitoring equivalents using known species allometric scaling factors and in vitro metabolic clearance data with a simple physiologically based pharmacokinetic (PBPK) model. Estimated urine MEHP concentrations in humans were consistent with reported concentrations. This research illustrates how chimeric mice transplanted with human hepatocytes in combination with a simple PBPK model can assist evaluations of pharmacokinetics or toxicokinetics of the primary or secondary metabolites of DEHP.

We have successfully grown highly strained GaInNAs/GaAs multiple quantum wells (MQWs) ranging from a single-QW (SQW) structure to a five-QW (5QW) structure without strain-compensation layers or Sb surfactant by molecular beam epitaxy (MBE). High-resolution X-ray-diffraction (HRXRD) measurements showed clear multiple reflections of GaInNAs QWs, which suggests their good structural quality. Photoluminescence (PL) measurements revealed that a triple-QW (TQW) structure had a strong PL intensity proportional to the number of QW layers, while the 5QW structure had a PL intensity that was five times less than that of the SQW structure. We fabricated GaInNAs/GaAs TQW edge-emitting lasers and demonstrated a record low-threshold current of 4.3 mA at a long wavelength of 1.29 μm