Feedback Control of the Arachidonate Cascade in Osteoblastic Cells by 15-deoxy-Δ12,14-Prostaglandin J2

15-deoxy-Δ12,14-prostaglandin J2 (15d-PGJ2) and an anti-diabetic thiazolidinedione, troglitazone (TRO) are peroxisome proliferator-activated receptor (PPAR)-γ ligands, which regulate immuno-inflammatory reactions as well as adipocyte differentiation. We previously reported that 15d-PGJ2 can suppress interleukin (IL)-1β-induced prostaglandin E2 (PGE2) synthesis in synoviocytes of rheumatoid arthritis (RA). IL-1 also stimulates PGE2 synthesis in osteoblasts by regulation of cyclooxygenase (COX)-2 and regulates osteoclastic bone resorption in various diseases such as RA and osteoporosis. In this study, we investigated the feedback mechanism of the arachidonate cascade in mouse osteoblastic cells, MC3T3-E1 cells, which differentiate into mature osteoblasts. Treatment with 15d-PGJ2 led to a significant increase in IL-1α-induced COX-2 expression and PGE2 production in a dose dependent manner. The effect of 15d-PGJ2 was stronger than that of TRO. However, it did not affect the expression of COX-1. In addition, cell viability of MC3T3-E1 cells was not changed in the condition we established. This means that 15d-PGJ2 exerts a positive feedback regulation of the arachidonate cascade of PGE2 in osteoblastic cells. These results may provide important information about the pathogenesis and treatment of bone resorption in a variety of diseases such as RA and osteoporosis

Mobile monitoring along a street canyon and stationary forest air monitoring of formaldehyde by means of a micro gas analysis system

A micro-gas analysis system (μGAS) was developed for mobile monitoring and continuous measurements of atmospheric HCHO. HCHO gas was trapped into an absorbing/reaction solution continuously using a microchannel scrubber in which the microchannels were patterned in a honeycomb structure to form a wide absorbing area with a thin absorbing solution layer. Fluorescence was monitored after reaction of the collected HCHO with 2,4-pentanedione (PD) in the presence of acetic acid/ammonium acetate. The system was portable, battery-driven, highly sensitive (limit of detection = 0.01 ppbv) and had good time resolution (response time 50 s). The results revealed that the PD chemistry was subject to interference from O3. The mechanism of this interference was investigated and the problem was addressed by incorporating a wet denuder. Mobile monitoring was performed along traffic roads, and elevated HCHO levels in a street canyon were evident upon mapping of the obtained data. The system was also applied to stationary monitoring in a forest in which HCHO formed naturally via reaction of biogenic compounds with oxidants. Concentrations of a few ppbv-HCHO and several-tens of ppbv of O3 were then simultaneously monitored with the μGAS in forest air monitoring campaigns. The obtained 1 h average data were compared with those obtained by 1 h impinger collection and offsite GC-MS analysis after derivatization with o-(2,3,4,5,6-pentafluorobenzyl)hydroxylamine (PFBOA). From the obtained data in the forest, daily variations of chemical HCHO production and loss are discussed

Spontaneous flexor tendon rupture due to an insufficiency fracture of the hamate hook in a patient with systemic lupus erythematosus: A case report

Introduction: Spontaneous flexor tendon rupture is usually caused by trauma, systemic diseases, or carpal bone and joint disorders. Here we report a case of spontaneous flexor tendon rupture occurring in a systemic lupus erythematosus (SLE) patient following nonunion of the hamate hook after an insufficiency fracture, and which was also associated with tendon degeneration caused by SLE. Case presentation: A 57-year-old woman was diagnosed with SLE 22 years ago and being treated with oral prednisolone. She became unable to flex her left little finger without any history of trauma or sporting activity. CT showed nonunion of the hamate hook. MRI showed rupture of the flexor digitorum profundus tendon of the little finger. We performed tendon transfer and excision of the hamate hook. She recovered active flexion of the little finger at 4 months postoperatively with full satisfaction. Discussion: There was no history of trauma that could have caused nonunion of the hamate hook. We considered that the insufficiency fracture of the hamate hook occurred as a result of osteoporosis caused by SLE and long-term steroid use. Nonunion of the hamate hook caused mechanical attrition of the tendons, and in combination with the tendon degeneration caused by SLE, further resulted in rupture of the flexor tendon. Conclusion: When we encounter a case of spontaneous flexor tendon rupture in a patient with systemic disease such as SLE or long-term steroid use, attention should be paid to the state of the carpal bones and joints as they sometimes accompany unexpected causes

On-site Multi Monitoring of Isoprene and Related Compounds in Forest Air

A novel analytical instrument has been developed for simple near-real time measurements of isoprene, and was applied to on-site analysis of forest air. Isoprene contained in sample air was trapped for 4 min and thermally desorbed to introduce it into a chemiluminescence cell. In this single column trapping/separation chemiluminescence (SCTS–CL) method, isoprene in ppbv level could be measured every 10 min with a limit of detection of 0.15 ppbv. In a plant chamber experiment, the isoprene concentration increased with light irradiation and decreased in the dark. The chamber experiment results by SCTS–CL agreed well with those obtained by thermal desorption-gas chromatography-mass spectrometry. In field analysis conducted in forest, isoprene concentration increased in the daytime and not found in the nighttime. On the other hand, α-pinene concentration was higher during the night compared to that in the day; probably because α-pinene emitted whole day and its decomposition was higher during the day. Other than isoprene, formaldehyde, ozone, nitrogen oxides, organic and inorganic acids were monitored simultaneously in the forest campaign, and daily variations and seasonal variations\are discussed. Model of emission and decomposition was considered and daily variation of emission rates were simulated from changes in the concentrations of isoprene and α-pinene. The amplification of oxidants by BVOCs is discussed based on the field experimental results