Quantification of microplastic by particle size down to 1.1 μm in surface road dust in an urban city, Japan

The impact of microplastics (MPs, plastic particles ≤5 mm) on ecosystems is of great concern. Road surfaces represent a significant source of MPs where plastic fragments are physically and chemically reduced to MPs. However, the literature lacks information on fragmentation tendencies below 11 μm. This study aimed to characterize the occurrence of MPs in road dust in different size fractions down to 1.1 μm. Road dust was collected at five sites near a major road in Kusatsu city, Japan, and partitioned by size into 13 fractions (1.1–850 μm). The coarser fractions accounted for a greater proportion of the dust. The percentage of organic matter, determined by loss on ignition, increased as the fractions became finer. Pyrolysis-gas chromatography-mass spectrometry was used to quantify 12 types of polymers in each fraction. The dust was found to contain nine types of MP, namely, polyethylene (PE), polypropylene (PP), polyvinylchloride (PVC), polystyrene (PS), styrene/butadiene rubber (SBR), acrylonitrile/butadiene/styrene resin (ABS), polycarbonate (PC), polymethylmethacrylate (PMMA), and polyamide 66 (PA66). The total MP concentration in road dust particles by particle size fraction (concentrationf) began to increase from the 125–250 μm fraction and remained elevated in finer fractions down to 1.1 μm, indicating that MPs in the road dust micronized to at least 1.1 μm. However, for individual polymer types, the tendency for concentrationf to increase or decrease with particle size fraction varied: the concentrationf of some polymers, such as PE and PVC, remained elevated in fractions down to 1.1 μm; the concentrationf of SBR, a rubber-MP, showed a stable or decreasing trend in fractions of 7.0–11 μm and finer. Particles of PE, PVC, and some other plastics might become increasingly finer, even down to 1.1 μm. Further research is needed to understand the comminution limits of these polymers under pertinent environmental conditions

Serum amyloid A-induced IL-6 production by rheumatoid synoviocytes

AbstractIn this study, we investigated the role of serum amyloid A protein (SAA) in the production of interleukin-6 (IL-6) using rheumatoid arthritis fibroblast-like synoviocytes (RA-FLS). Recombinant SAA stimulation induced the production of pro-inflammatory cytokine, IL-6, from RA-FLS. The signaling events induced by SAA included the activation of the mitogen-activated protein kineases, p38 and JNK1/2 and the activation of nuclear factor-kappa B (NF-κB). Inhibitor studies have shown SAA-induced IL-6 production to be down-regulated by NF-κB inhibition and partially inhibited by p38 or JNK inhibitors. Our findings demonstrate that SAA is a significant inducer of IL-6, which is critically involved in RA pathogenesis

Serum amyloid A triggers the mosodium urate -mediated mature interleukin-1β production from human synovial fibroblasts

Background: Monosodium urate (MSU) has been shown to promote inflammasome activation and interleukin-1β (IL-1β) secretion in monocyte/macrophages, but the cellular pathway and nod-like receptor family, pyrin domain containing 3 (NLRP3) inflammasome activation in synovial tissues, remain elusive. In this study, we investigated the effects of MSU on synovial fibroblasts to elucidate the process of MSU-mediated synovial inflammation.Methods: Human synovial fibroblasts were stimulated with MSU in the presence or absence of serum amyloid A (SAA). The cellular supernatants were analyzed by immunoblotting using anti-IL-1β or anti-caspase-1 antibodies. IL-1β or NLRP3 mRNA expressions were analyzed by real-time PCR or reverse transcription-PCR (RT-PCR) method.Results: Neither SAA nor MSU stimulation resulted in IL-1β or interleukin-1α (IL-1α) secretions and pro-IL-1β processing in synovial fibroblasts. However, in SAA-primed synovial fibroblasts, MSU stimulation resulted in the activation of caspase-1 and production of active IL-1β and IL-1α. The effect of SAA on IL-1β induction was impaired in cells by silencing NLRP3 using siRNA or treating with caspase-1 inhibitor. In addition, SAA induced the secretion of cathepsin B and NLRP3 mRNA expression in synovial fibroblasts.Conclusions: Our data demonstrate that exposure of human synovial fibroblasts to SAA promotes MSU-mediated caspase-1 activation and IL-1β secretion in the absence of microbial stimulation. These findings provide insight into the molecular processes underlying the synovial inflammatory condition of gout

子宮に発生した炎症性筋線維芽細胞性腫瘍のMRI所見

炎症性筋線維芽細胞性腫瘍は,筋線維芽細胞や線維芽細胞に分化する細胞を含み,炎症細胞の浸潤が加わった稀な腫瘍である.様々な臓器に発生しうるが,子宮における報告は極めて稀である.今回我々は,組織学的に診断された子宮炎症性筋線維芽細胞性腫瘍の症例を経験したのでMRI所見を中心に報告する.症例は63歳女性.全身倦怠感,発熱,体重減少および下腹部痛を主訴に精査目的にて当院産婦人科に入院となった.MRIで腫大した子容体部にT2強調像で不均一な信号上昇を示す造影効果の低い腫瘤を認め,周囲の子宮体部筋層は瀰漫性に高信号を示し,強い造影効果を呈し,膿瘍形成が疑われた.抗生剤治療により臨床症状の改善を認めた.再度MRIが施行され,子宮体部腫大は改善,子容体部腫瘍も縮小し,T2強調像ではやや信号が低下し,ほぼ均一で強い造影効果を示すように所見の変化を認めた.しかし,患者の強い希望により,再発予防目的で子宮全摘術および両側子宮付属器切除術が施行された.病理組織学的にはcompact spindle cell subtypeの子宮炎症性筋線維芽細胞性腫瘍と診断された.子宮炎症性筋線維芽細胞性腫瘍は良性病変であるものの再発の可能性が高く,転移や血管浸潤も報告されており,外科的切除の適応がある.子宮病変の報告は11例しかなく,中でもMRIにおける画像所見を報告したものは1例のみである.抗生剤治療に反応する特徴的な臨床経過とMRIを中心とした画像診断により本症の術前診断の可能性が示唆される.We describe the case of a 63-year-old woman with a rare uterine inflammatory myofibroblastic tumor. Magnetic resonance imaging revealed a heterogeneous mass of increased T_2 signal and poor gadolinium enhancement in the enlarged uterine corpus, surrounded by diffusely increased T_2 signal and gadolinium enhancement in the myometrium. Following antibiotic therapy for suspected abscess, the tumor appeared smaller, decreased T_2 signal, and increased gadolinium enhancement on magnetic resonance imaging. Thereafter, the patient requested to undergo total hysterectomy. The predominant pattern of the present tumor may be altered from the myxoid-vascular to compact spindle cell subtype by the medical therapy according to magnetic resonance features reported on extra-uterine inflammatory myofibroblastic tumors, although only the latter subtype was histogically confirmed. We correlate radiologic and pathologic findings in this tumor

子宮に発生した炎症性筋線維芽細胞性腫瘍のMRI所見

炎症性筋線維芽細胞性腫瘍は,筋線維芽細胞や線維芽細胞に分化する細胞を含み,炎症細胞の浸潤が加わった稀な腫瘍である.様々な臓器に発生しうるが,子宮における報告は極めて稀である.今回我々は,組織学的に診断された子宮炎症性筋線維芽細胞性腫瘍の症例を経験したのでMRI所見を中心に報告する.症例は63歳女性.全身倦怠感,発熱,体重減少および下腹部痛を主訴に精査目的にて当院産婦人科に入院となった.MRIで腫大した子容体部にT2強調像で不均一な信号上昇を示す造影効果の低い腫瘤を認め,周囲の子宮体部筋層は瀰漫性に高信号を示し,強い造影効果を呈し,膿瘍形成が疑われた.抗生剤治療により臨床症状の改善を認めた.再度MRIが施行され,子宮体部腫大は改善,子容体部腫瘍も縮小し,T2強調像ではやや信号が低下し,ほぼ均一で強い造影効果を示すように所見の変化を認めた.しかし,患者の強い希望により,再発予防目的で子宮全摘術および両側子宮付属器切除術が施行された.病理組織学的にはcompact spindle cell subtypeの子宮炎症性筋線維芽細胞性腫瘍と診断された.子宮炎症性筋線維芽細胞性腫瘍は良性病変であるものの再発の可能性が高く,転移や血管浸潤も報告されており,外科的切除の適応がある.子宮病変の報告は11例しかなく,中でもMRIにおける画像所見を報告したものは1例のみである.抗生剤治療に反応する特徴的な臨床経過とMRIを中心とした画像診断により本症の術前診断の可能性が示唆される.We describe the case of a 63-year-old woman with a rare uterine inflammatory myofibroblastic tumor. Magnetic resonance imaging revealed a heterogeneous mass of increased T_2 signal and poor gadolinium enhancement in the enlarged uterine corpus, surrounded by diffusely increased T_2 signal and gadolinium enhancement in the myometrium. Following antibiotic therapy for suspected abscess, the tumor appeared smaller, decreased T_2 signal, and increased gadolinium enhancement on magnetic resonance imaging. Thereafter, the patient requested to undergo total hysterectomy. The predominant pattern of the present tumor may be altered from the myxoid-vascular to compact spindle cell subtype by the medical therapy according to magnetic resonance features reported on extra-uterine inflammatory myofibroblastic tumors, although only the latter subtype was histogically confirmed. We correlate radiologic and pathologic findings in this tumor