Evaluation of Placentation and the Role of the Aryl Hydrocarbon Receptor Pathway in a Rat Model of Dioxin Exposure

Background: Our environment is replete with chemicals that can affect embryonic and extraembryonic development. Dioxins, such as 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), are compounds affecting development through the aryl hydrocarbon receptor (AHR).Objectives: The purpose of this investigation was to examine the effects of TCDD exposure on pregnancy and placentation and to evaluate roles for AHR and cytochrome P450 1A1 (CYP1A1) in TCDD action.Methods: Actions of TCDD were examined in wild-type and genome-edited rat models. Placenta phenotyping was assessed using morphological, biochemical, and molecular analyses.Results: TCDD exposures were shown to result in placental adaptations and at higher doses, pregnancy termination. Deep intrauterine endovascular trophoblast cell invasion was a prominent placentation site adaptation to TCDD. TCDD-mediated placental adaptations were dependent upon maternal AHR signaling but not upon placental or fetal AHR signaling nor the presence of a prominent AHR target, CYP1A1. At the placentation site, TCDD activated AHR signaling within endothelial cells but not trophoblast cells. Immune and trophoblast cell behaviors at the uterine–placental interface were guided by the actions of TCDD on endothelial cells.Discussion: We identified an AHR regulatory pathway in rats activated by dioxin affecting uterine and trophoblast cell dynamics and the formation of the hemochorial placenta. https://doi.org/10.1289/EHP9256     

Stable Vinyl Polyperoxide: Synthesis,Characteristics and Thermal Initiation Potentials of Poly(α‐phenylstyrene peroxide)

The stable vinyl polyperoxide, namely, poly(α‐phenylstyrene peroxide) (PAPSP), an alternating copolymer of α‐phenylstyrene and oxygen, has been synthesized by the oxidative polymerization of α‐phenylstyrene. It was characterized by ¹H and ¹³C NMR, FT‐IR, DSC, GC‐MS and GPC studies. The overall activation energy (E_d) for the degradation of PAPSP was found to be 45.0 kcal/mol. The stability of PAPSP was estimated from its isothermal degradation rate and compared with other related vinyl polyperoxides. Thermal initiating potentialities of PAPSP have been studied by polymerizing styrene at 80°C. The polymerization follows classical kinetics. The mechanism of polymerization has been discussed. The active polymer, which contains PAPSP segments in the polystyrene chain was confirmed by ¹H NMR study. The values of K² for PAPSP compared to that of 2,5‐dimethyl‐2,5‐dihydroperoxyhexane and di‐tert‐butyl peroxide at 80°C indicate that PAPSP can be used as an effective high temperature initiator.     

Malignant transformation of mature cystic teratoma into undifferentiated carcinoma: A case report

Malignant transformation of mature cystic teratoma (MCTO) is a rare entity. Even rarer is the transformation of MCTO into undifferentiated carcinoma. We report a case of an 80‐year‐old woman with undifferentiated carcinoma and squamous cell carcinoma component originating from mature cystic teratoma of the ovary.     

糖基化改装人脂肪来源干细胞促进其骨髓归巢及成骨的研究

目的探讨脂肪来源干细胞表达的CD44,可以被糖基化技术进行修饰,成为造血干细胞E/L选择素配体（HCELL）,进而可有效的骨髓归巢并原位分化成骨。 方法应用α-1,3-唾液盐藻糖酶：FTV以及其底物GDP-海藻糖处理人脂肪来源干细胞,使该细胞表面CD44分子糖基化为HCELL,检测其增殖、分化等细胞生物学特性。平行平板流动腔试验以及免疫荧光染色验证其小鼠体内归巢及成骨能力。 结果α-1,3-岩藻糖基化的hASC在不损害细胞活力的情况下表达HCELL,能够诱导血管内皮细胞表面E-选择素与其结合,并在剪切力条件下,使hASCs与内皮E-选择素产生强大的滚动粘附效应,促进hASCs迁移到骨髓中,并在小鼠骨髓中产生人骨样细胞。 结论本研究证明糖基化技术能够增强干细胞的骨髓归巢能力,且不对干细胞自身细胞活性产生负向作用。     

Clinicoradiological factors influencing the reversibility of posterior reversible encephalopathy syndrome: a multicenter study

Purpose The aim of this retrospective study was to clarify the relation between the reversibility of posterior reversible encephalopathy syndrome (PRES) with three factors: the anatomical region of the brain involved, the background clinical cause, and the diffusion weighted image (DWI) intensity of PRES lesions. Material and methods This multicenter study, conducted by the PRES Study Group of the Neuroradiology Workshop, involved 52 cases from 28 institutions. Initial and follow-up magnetic resonance imaging were compared regarding the reversibility of PRES lesions according to anatomical location and clinical background. Initial DWI and apparent diffusion coefficient (ADC) maps were reviewed in 20 cases. Results Reversibility was significantly lower (P < 0.01) in the brain stem (44%) and deep white matter (47%) compared to the other cortical and subcortical areas (76%–91%). The reversibility was greater in the eclampsia subgroup followed by the hypertension and chemotherapy subgroups. DWI, even with ADC maps, had limitations in predicting the outcome of PRES lesions. Conclusion The typical cortical and subcortical PRES lesions showed reversibility, whereas the brain stem and deep white matter lesions showed less reversibility. PRES due to eclampsia showed maximum reversibility compared to hypertension- and drug-related PRES. DWI, even with ADC maps, had limitations in predicting the course of PRES. Some parts of the study were used for poster presentations at the Japan Radiological Society meetings in 2005 and 2006, in Yokohama, Japan.