二十碳五烯酸对白蛋白诱导肾小管上皮细胞转分化的影响

目的 探讨二十碳五烯酸(eicosapentaenoic acid,EPA)对人白蛋白诱导的人近端肾小管上皮细胞(HK-2)发生转分化的干预作用.方法 体外培养人HK-2细胞,随机分为6组:A组,空白对照组(未加任何刺激物);B组,单纯EPA组(加入30 μmol/L EPA);C组,血白蛋白(albumin,Alb)诱导组(加入5 mg/ml Alb);D组,低剂量EPA干预组(5mg/ml Alb+ 10 μmol/L EPA);E组,中剂量EPA干预组(5mg/ml Alb+ 30 μmol/L EPA);F组,高剂量EPA干预组(5 mg/ml Alb+ 50μmol/L EPA).细胞免疫荧光检测E钙黏蛋白(E-cadherin)、α平滑肌肌动蛋白(α-smooth muscle ac-tin,α-SMA)的表达;ELISA法检测纤维连接蛋白(fibronectin,FN)的水平;采用RT-PCR检测转化生长因子β1(transforming growth factor β1,TGF-β1)的mRNA表达.结果 与A组比较,B组TGF-β1mRNA、α-SMA、FN、E-cadherin表达均无统计学差异(P＞0.05);C组TGF-β1 mRNA、α-SMA、FN较其他各组表达明显增高(P＜0.05),而E-cadherin表达明显下降(P＜0.05).与C组比较,D组、E组、F组TGF-β1 mRNA、α-SMA、FN表达逐渐下降,两组间比较差异有统计学意义(P＜0.05);E-cadherin的表达逐渐增高,各组间比较差异有统计学意义(P＜0.05).提示EPA可显著抑制Alb刺激人肾小管上皮细胞表达E-cadherin、α-SMA,同时下调上清液中FN水平,且其抑制作用的强弱与EPA浓度密切相关.EPA还明显下调了Alb刺激后TGF-β1的表达.结论 一定浓度的人白蛋白可以诱导体外培养的HK-2细胞发生转分化;EPA可一定程度上抑制白蛋白诱导HK-2发生转分化过程,且呈剂量依赖性.     

Human papillomavirus‐related basaloid squamous cell carcinoma of the bladder associated with genital tract human papillomavirus infection

Basaloid squamous cell carcinoma is a biologically aggressive neoplasm mainly found in the head and neck region. Recently, four cases of basaloid squamous cell carcinoma of the bladder have been reported, and three of them occurred in patients with neurogenic bladder, repeated catheterizations and human papillomavirus infection of the urinary tract. To the best of our knowledge, none of the patients affected by basaloid squamous cell carcinoma of the bladder described in the literature had documented genital involvement by human papillomavirus. Herein, we describe the case of a woman with neurogenic bladder affected by basaloid squamous cell carcinoma of the bladder and by a concomitant genital tract human papillomavirus infection.     

环孢素A对积水肾脏急性压力灌注损伤的保护

目的 在不同程度肾脏积水的前提下,观察线粒体渗透性转换孔(MPTP)抑制剂环孢素A(CsA)对于急性压力灌注所致损伤的保护作用.方法 健康新西兰大白兔20只,随机分为轻度积水组(M组,n=10)和重度积水组(S组,n=10),肾脏轻度积水及重度积水模型采用输尿管套扎法构建.M组及S组分为M1、M2、S1、S24个亚组,分别予以60、100、20、60 mmHg(1mmHg=0.133 kPa)压力灌注.灌注前M组及S组均给予CsA灌胃1周.灌注后48 h取标本,检测标本中超氧化物歧化酶(SOD)及丙二醛(MDA)的含量,JC-1染色检测线粒体膜电位(MMP)的变化.结果 M1、M2、S1、S2各组SOD活力分别为(30.11±2.23)、(28.41 ±2.26)、(44.82±6.61)、(40.31±5.21) U/mg,M1与M2之间SOD活力差异无统计学意义(P＞0.05),S1与S2之间SOD活力差异无统计学意义(P＞0.05);MDA的含量分别为(0.61 ±0.17)、(0.60±0.15)、(0.95 ±0.26)、(0.80±0.32) nmol/mg,M1与M2之间MDA含量差异无统计学意义(P＞0.05),S1与S2之间MDA含量差异无统计学意义(P＞0.05).JC-1染色橙红色阳性细胞百分比分别为(67.16±9.47)％、(60.75±11.89)％、(41.08 ±4.50)％、(42.36 ±3.44)％.M1与M2比较,S1与S2比较,阳性细胞百分比差异均无统计学意义(P＞0.05).结论 CsA对于积水肾脏因急性压力灌注所致的损伤有一定的保护作用.在经皮肾镜及输尿管镜治疗结石前给予MPTP抑制剂可有效减轻压力灌注所致损伤.     

Unusual Mott transition in multiferroic PbCrO3

The Mott insulator in correlated electron systems arises from classical Coulomb repulsion between carriers to provide a powerful force for electron localization. Turning such an insulator into a metal, the so-called Mott transition, is commonly achieved by “bandwidth” control or “band filling.” However, both mechanisms deviate from the original concept of Mott, which attributes such a transition to the screening of Coulomb potential and associated lattice contraction. Here, we report a pressure-induced isostructural Mott transition in cubic perovskite PbCrO₃. At the transition pressure of ∼3 GPa, PbCrO₃ exhibits significant collapse in both lattice volume and Coulomb potential. Concurrent with the collapse, it transforms from a hybrid multiferroic insulator to a metal. For the first time to our knowledge, these findings validate the scenario conceived by Mott. Close to the Mott criticality at ∼300 K, fluctuations of the lattice and charge give rise to elastic anomalies and Laudau critical behaviors resembling the classic liquid–gas transition. The anomalously large lattice volume and Coulomb potential in the low-pressure insulating phase are largely associated with the ferroelectric distortion, which is substantially suppressed at high pressures, leading to the first-order phase transition without symmetry breaking.Early transition-metal (TM) oxides with partially filled d electrons are strongly correlated (1, 2). Such correlated systems often present exciting new physics and technologically useful electronic and magnetic properties. Mott transition, characterized by delocalization of d electrons, is an attractive phenomenon for exploring the correlated nature of electrons (2, 3). Since the early failure of band theory in the 1930s, the Coulomb repulsion (U) has been proposed to be a strong force that causes electron localization (4, 5). In such electrostatic interaction, the repulsion energy decreases with the compressed lattice because of the screening effect (5–7). Consequently, as originally predicted by Mott (5), the Mott transition is controlled by U at pressures (P).Despite several decades of intensive study, it is still challenging to experimentally validate this view of Mott transition, because U is experimentally difficult to determine, and for most correlated materials it is independent of the pressure. For the known Mott systems, they are found to be controlled by either the bandwidth [e.g., the organic compound κ-Cl (8–10) and Cr-doped V₂O₃ (11, 12)] or band filling (i.e., doping of charge carriers into the parent insulator) (2). Recently, electronic transitions have frequently been reported in late 3d TM oxides (e.g., MnO) (13–16), which are theoretically attributed to bandwidth control (15) or crystal-field splitting (17). For those oxides, a U-controlled mechanism has also been proposed by Gavriliuk et al. (14) and Gavriliuk and coworkers (18); however, the spin cross-over, instead of the screening effect, is believed to contribute to the decreased U (14, 18). Complicating matter further is that the U of (Mg_1–xFe_x)O was computed to increase with pressures (13).TM oxides with a perovskite structure (ABO₃) often exhibit intriguing structural, magnetic, and electronic properties for the study of correlated systems. Among them, PbCrO₃ is such a material that can only be synthesized at high pressures. At ambient pressure, it adopts a paramagnetic (PM), cubic structure at room temperature (T) with an anomalously large unit-cell volume and transforms to an antiferromagnetic (AFM) ground state at low temperatures (19, 20). The magnetic properties arise from unpaired 3d electrons in Cr (i.e., nominally 3d²) with a large U value of 8.28 eV (19–21). Under high pressures, an isostructural phase transition (i.e., no symmetry breaking) has recently been reported in PbCrO₃ with ∼9.8% volume reduction at ∼1.6 GPa; it is the largest volume reduction known in transition-metal oxides (22). Compared with the low-P phase, the high-P phase possesses a more “normal” unit-cell volume (see refs. 21 and 22) and a moderate U of ∼3 eV (23), suggesting a collapse of Coulomb repulsion energy at the phase transition. Because of the reduced U, the mobility of 3d electrons at high pressures is energetically more favorable, which would lead to d-electron delocalization. Apparently, this is a U-driven Mott transition in PbCrO₃ as conceived by Mott. However, to date, the electronic properties of both PbCrO₃ phases have only poorly been explored. In particular, controversial electronic states, including semiconductor (24, 25), half-metal (21), or insulator (20), have been reported for the low-P phase. Besides, the crystal structure and elastic and magnetic properties, as well as the underlying mechanism for the isostructural transition, are still unsettled issues, calling for rigorous investigation into this material.With these aims, in this work we present a comprehensive study on PbCrO₃ with a focus on the P-induced electronic transition. Our findings unveil a unique Mott transition in this perovskite and a new mechanism underlying the isostructural transition.     

Transfer from pediatric to adult health care: effects on diabetes outcomes

The transfer from pediatric to adult diabetes health care for emerging adults with type 1 diabetes (T1D) has received increasing attention in the literature. This review analyzes the effect of this health care transfer on the outcomes of diabetes care visit attendance, glycemic control, and acute diabetes‐related complications, and assesses the methodological strength of the studies reporting observational and interventional data. Observational studies, often limited by incomplete data, report a decline in diabetes care visits but an improvement or no change in hemoglobin A1c (HbA1c) after transfer to adult care. Results from studies reporting a transition intervention are restricted by lack of appropriate control groups and the collection of data both before and after transfer of care. Very few methodologically strong studies are available to guide clinicians with the transition from pediatric to adult care, and these shortcomings should be addressed in future studies designed to facilitate and improve the care of emerging adults with T1D.     

Effects of Curcumin on Tobacco Smoke‐induced Hepatic MAPK Pathway Activation and Epithelial–Mesenchymal Transition In Vivo

Tobacco smoke is a major risk factor for hepatic cancer. Epithelial–mesenchymal transition (EMT) induced by tobacco smoke is crucially involved in the initiation and development of cancer. Mitogen‐activated protein kinase (MAPK) pathways play important roles in tobacco smoke‐associated carcinogenesis including EMT process. The chemopreventive effect of curcumin supplementation against cancers has been reported. In this study, we investigated the effects of tobacco smoke on MAPK pathway activation and EMT alterations, and then the preventive effect of curcumin was examined in the liver of BALB/c mice. Our results indicated that exposure of mice to tobacco smoke for 12 weeks led to activation of ERK1/2, JNK, p38 and ERK5 pathways as well as activator protein‐1 (AP‐1) proteins in liver tissue. Exposure of mice to tobacco smoke reduced the hepatic mRNA and protein expression of the epithelial markers, while the hepatic mRNA and protein levels of the mesenchymal markers were increased. Treatment of curcumin effectively attenuated tobacco smoke‐induced activation of ERK1/2 and JNK MAPK pathways, AP‐1 proteins and EMT alterations in the mice liver. Our data suggested the protective effect of curcumin in tobacco smoke‐triggered MAPK pathway activation and EMT in the liver of BALB/c mice, thus providing new insights into the chemoprevention of tobacco smoke‐associated hepatic cancer. Copyright © 2017 John Wiley & Sons, Ltd.     

Epithelial cells in PDL are critical in resuming the integral relation between tooth root and supporting bone after trauma--a transplantation experiment

OBJECTIVE: The aim of this study was to determine the response of the residual epithelial network following traumatic breakdown of the periodontal ligament (PDL). METHODS: Mandibular incisor sections with PDL (experimental) and sections denuded of PDL (control) from 4- to 6-week-old Wistar-Furth rats were transplanted into the defects created in the frontal bone of the recipient syngeneic rats. At intervals, the defects with implanted teeth roots were collected and processed for histological and biochemical examination. Immunolocalization of epithelial cells was performed to monitor their phenotypic changes during transplantation healing period. RESULTS: (1) Histological observation of the experimental sample revealed the sequence of cellular response characterized by an initial degeneration of PDL followed by a proliferation of granulation tissue. There was also a marked odontoblastic reaction with extensive deposition of regular dentine within the pulp chambers. In the control group, initial signs of bony fusion with dentine led to an extensive ankylosis and bone replacement between roots and defects. (2) Immunostaining indicated that, in experimental groups, the pattern of regularly spaced epithelial cells lying in close approximation to the root surface was distinct 10 days post-transplantation but became diminished afterwards. The immunoreaction against epithelial cells was negative in the control. CONCLUSION: Residual PDL is essential to prevent ankylosis after trauma and epithelial cells may facilitate the re-establishment of root-PDL-bone complex by transforming into mesenchymal cells.