Perfluorooctane Sulfonate (PFOS) and Related Perfluorinated Compounds in Human Maternal and Cord Blood Samples: Assessment of PFOS Exposure in a Susceptible Population during Pregnancy

Fluorinated organic compounds (FOCs), such as perfluorooctane sulfonate (PFOS), perfluorooctanoate (PFOA), and perfluorooctane sulfonylamide (PFOSA), are widely used in the manufacture of plastic, electronics, textile, and construction material in the apparel, leather, and upholstery industries. FOCs have been detected in human blood samples. Studies have indicated that FOCs may be detrimental to rodent development possibly by affecting thyroid hormone levels. In the present study, we determined the concentrations of FOCs in maternal and cord blood samples. Pregnant women 17–37 years of age were enrolled as subjects. FOCs in 15 pairs of maternal and cord blood samples were analyzed by liquid chromatography–electrospray mass spectrometry coupled with online extraction. The limits of quantification of PFOS, PFOA, and PFOSA in human plasma or serum were 0.5, 0.5, and 1.0 ng/mL, respectively. The method enables the precise determination of FOCs and can be applied to the detection of FOCs in human blood samples for monitoring human exposure. PFOS concentrations in maternal samples ranged from 4.9 to 17.6 ng/mL, whereas those in fetal samples ranged from 1.6 to 5.3 ng/mL. In contrast, PFOSA was not detected in fetal or maternal samples, whereas PFOA was detected only in maternal samples (range, < 0.5 to 2.3 ng/mL, 4 of 15). Our results revealed a high correlation between PFOS concentrations in maternal and cord blood (r(2) = 0.876). However, we did not find any significant correlations between PFOS concentration in maternal and cord blood samples and age bracket, birth weight, or levels of thyroid-stimulating hormone or free thyroxine. Our study revealed that human fetuses in Japan may be exposed to relatively high levels of FOCs. Further investigation is required to determine the postnatal effects of fetal exposure to FOCs

Mechanical Properties and Histological Evaluation of Bone Grafting Materials Containing Different Ratios of Calcium Phosphate Cement and Porous β-tricalcium Phosphate Granules

Article信州医学雑誌 66(2): 139-150(2018)journal articl

Peening Natural Aging of Aluminum Alloy by Ultra-High-Temperature and High-Pressure Cavitation

The peening solution treatment was performed on AC4CH aluminum alloy by ultra-high-temperature and high-pressure cavitation (UTPC) processing, and the peening natural aging was examined. Furthermore, peening artificial aging treatment by low-temperature and low-pressure cavitation (LTPC) was performed, and the time course of peening natural aging and peening artificial aging were compared and investigated. It was found that when the AC4CH alloy is processed for an appropriate time by UTPC processing, compressive residual stress is applied and natural aging occurs. In addition, the UTPC processing conditions for peening natural aging treatment with high compressive residual stress and surface hardness were clarified. After peening artificial aging by LTPC processing, the compressive residual stress decreases slightly over time, but the compression residual stress becomes constant by peening natural aging through UTPC treatment. In contrast, it was found that neither natural nor artificial peening natural aging occurs after processing for a short time

A case of total hip arthroplasty for nonunion after femoral trochanteric fracture surgery with complete breakage of only the compression screw of the InterTAN nail

Intramedullary nails are an effective treatment for common femoral trochanteric fractures. However, one of their complications is implant breakage due to poor reduction and nonunion after surgery. We herein report a case of a 54-year-old man who underwent total hip arthroplasty for nonunion after internal fixation of a femoral trochanteric fracture. The femoral trochanteric fracture was treated by internal fixation using the Trigen InterTAN nail. The patient developed symptoms of hip pain 6 months after internal fixation. Nine months after internal fixation, hip radiographs and computed tomography scans showed breakage of only the compression screw. During total hip arthroplasty, we were unable to remove the lag screw and compression screw before the femoral head dislocation because no gap was present between the two screws. Thus, we removed these screws with the femoral head after dislocation of the femoral head. The removed nail was partially damaged at the lag screw hole. This change was retrospectively observed on the preoperative computed tomography scan. Three months after total hip arthroplasty, the patient was able to walk unaided and the hip pain had resolved. If only the compression screw is completely broken after internal fixation with the Trigen InterTAN nail, both the lag screw and compression screw will be difficult to remove with preservation of the femoral head. We effectively managed such a case by not only revision internal fixation but also total hip arthroplasty