表达PD-L1/PD-L2的人胎盘间充质干细胞对外周血T细胞分泌IL-17的拮抗作用

目的 探讨程序性死亡因子配体1(PD-L1)和PD-L2在人胎盘源性间充质干细胞(hPMSCs)上表达对外周血T细胞分泌IL-17的影响.方法 应用酶消化法分离人胎盘间充质干细胞(hPMSCs),并进行表型及分化鉴定;RT-PCR、激光扫描共聚焦显微镜技术(LSCM)及流式细胞术(FCM)检测hPMSCs上PD-L1及PD-L2的表达;应用化学合成的PD-L1 siRNA、PD-L2 siRNA沉默hPMSCs上PD-L1及PD-L2表达;密度梯度离心法分离纯化人外周血T细胞;细胞胞内因子染色法分析沉默PD-L1或PD-L2后hPMSCs对PMA活化的T细胞分泌IL-17的影响.结果 除PD-L1外,hPMSCs高表达PD-L2;siRNA能够有效阻断PD-L1和PD-L2在hPMSCs上的表达;胞内染色结果显示,hPMSCs能够上调T细胞IL-17的分泌,阻断PD-L1或PD-L2后,T细胞IL-17的分泌被进一步上调,且PD-L1和PD-L2具有叠加作用.结论 PD-L1和PD-L2在hPMSCs上表达,可拮抗hPMSCs刺激外周血T细胞分泌IL-17的作用.     

动态18F-FDG PET/CT显像在恶性肿瘤中的研究进展

18F-FDG PET/CT已广泛应用于恶性肿瘤的诊断、分期、疗效监测及预后评价。最大标准化摄取值是最常用的半定量评估指标,但它只是单点估计,忽略了18F-FDG摄取分布的变化,且易受多种因素影响。动态18F-FDG PET/CT检查是一个连续采集过程,可以利用动力学模型定量分析肿瘤组织对FDG的净摄取率,与传统的SUV相比,动态扫描可以对肿瘤微小代谢变化做出早期评估,更直接、有效地反映示踪剂的摄取。但因其扫描时间长、参数分析复杂等因素限制了临床应用,目前,随着多种简化扫描协议的开发,动态18F-FDG扫描已在多种恶性肿瘤中取得了初步研究成果。本文主要从动态18F-FDG PET/CT显像局限性及简化方案及动态18F-FDG PET/CT显像在肺癌、乳腺癌、胰腺癌、淋巴瘤、骨髓瘤、胶质母细胞瘤、软组织肉瘤恶性肿瘤中的应用中进行综述。      

乳腺癌MRI影像组学的研究进展

乳腺癌是全世界女性最常见的恶性肿瘤之一,也是患癌女性的主要死因。提高诊断准确性、早期评估乳腺癌预后及治疗效果是临床实践中的关键问题。MRI因其较高的软组织分辨率,目前仍是诊断乳腺癌的常用成像方式。相对于乳房X线摄影和超声,MRI可以提供更全面的诊断信息。影像组学是一个高通量提取和定量分析影像特征的新研究领域,近年来受到广泛关注并应用于肿瘤领域。作者就乳腺癌MRI影像组学方面的研究进展进行综述。     

高度浓缩生长因子对MC3T3-E1成骨细胞生物学性能的影响

目的：观察高度浓缩生长因子（concentrated growth factor,CGF）对成骨细胞生物学性能的影响。方法：将MC3T3-E1细胞在CGF环境下进行培养,并设立空白对照组。扫描电镜观察成骨细胞在CGF表面的附着;培养1、4、7 d后,检测细胞增殖情况以及碱性磷酸酶（ALP）活性;茜素红染色观察矿化结节和成骨相关基因Runx2的表达。CGF浸出液培养细胞24 h后,以鬼笔环肽染色观察细胞骨架的形态变化。采用 SPSS 21.0软件包对数据进行统计学分析。结果：CCK-8比色显示,培养1、4、7 d,在相同时间点,实验组与对照组相比,CGF细胞增殖活性显著增强（P< 0.05）。ALP活性检测显示,培养1 d后,实验组与对照组无显著差异（P>0.05）;培养4、7 d后,实验组与对照组相比,ALP活性具有显著差异（P<0.05)。茜素红染色显示,CGF组钙化结节数量增多且面积较大。鬼笔环肽染色和DAPI染色可见,CGF组中细胞数量增多,细胞铺展面增大,肌动蛋白形态更为清晰。CGF可促进Runx2 mRNA表达（P<0.05）。结论：CGF可促进MC3T3-E1细胞的增殖、分化以及Runx2的表达。     

Professional identity in nursing: A mixed method research study

Professional identity is developed through a self-understanding as a nurse along with experience in clinical practice and understanding of their role. Personal and professional factors can influence its development. A recent integrative literature review synthesised factors that influenced registered nurse’s perceptions of their professional identity into three categories of the self, the role and the context of nursing practice. This review recommended that further research was needed into professional identity and how factors and perceptions changed over time. The aims of this study were to explore registered nurses’ understanding of professional identity and establish if it changed over time. A mixed-methods study using a two-stage design with an on-line survey and focus groups was implemented with registered nurses who were studying nursing at a postgraduate level in Australia or Scotland. The reported influences on professional identity related to the nurse, the nursing role, patient care, the environment, the health care team and the perceptions of nursing. Professional development and time working in the profession were drivers of changes in thinking about nursing, their role and working context and their professional identity. Additionally, participants sought validation of their professional identity from others external to the profession.     

多体素磁共振频谱技术在海马硬化中的应用

目的评价磁共振多体素频谱技术在早期海马硬化中的应用价值。方法对28例单侧颞叶癫痫患者行常规MR及双侧海马区多体素频谱检查,测量双侧海马区域N-乙酰天门冬氨酸、胆碱、肌酸的信号强度,分析双侧海马区代谢物的分布情况。结果 1常规MR检查示4例单侧海马萎缩,4例诊断侧别不一致,20例海马形态学未见改变;2患侧NAA、NAA/Cho、NAA/Cr、NAA/(Cho+Cr)值较对侧均明显降低,差异有统计学意义。结论多体素磁共振频谱技术能够早期发现海马硬化,进而可对癫痫灶进行准确定位。     

Dorsal root ganglion neurons promote proliferation and osteogenic differentiation of bone marrow mesenchymal stem cells

Preliminary animal experiments have confirmed that sensory nerve fibers promote osteoblast differentiation, but motor nerve fibers have no promotion effect. Whether sensory neurons promote the proliferation and osteogenic differentiation of bone marrow mesenchymal stem cells remains unclear. No results at the cellular level have been reported. In this study, dorsal root ganglion neurons(sensory neurons) from Sprague-Dawley fetal rats were co-cultured with bone marrow mesenchymal stem cells transfected with green fluorescent protein 3 weeks after osteogenic differentiation in vitro, while osteoblasts derived from bone marrow mesenchymal stem cells served as the control group. The rat dorsal root ganglion neurons promoted the proliferation of bone marrow mesenchymal stem cell-derived osteoblasts at 3 and 5 days of co-culture, as observed by fluorescence microscopy. The levels of m RNAs for osteogenic differentiation-related factors(including alkaline phosphatase, osteocalcin, osteopontin and bone morphogenetic protein 2) in the co-culture group were higher than those in the control group, as detected by real-time quantitative PCR. Our findings indicate that dorsal root ganglion neurons promote the proliferation and osteogenic differentiation of bone marrow mesenchymal stem cells, which provides a theoretical basis for in vitro experiments aimed at constructing tissue-engineered bone.     

Assessment of Diffuse Thyroid Disease by Strain Ratio in Ultrasound Elastography

The goal of this study was to explore the value of strain ratio from real-time elastography in the semi-quantitative assessment of diffuse thyroid disease. Fifty-one patients with primary hyperthyroidism, 70 with Hashimoto's thyroiditis, 8 with subacute thyroiditis and 43 with normal healthy thyroids were recruited to measure the strain ratio (SR) of thyroid tissue and sternocleidomastoid muscle (on the same side of the thyroid). SR values of all groups were subjected to statistical analysis. The SRs (mean ± standard deviation) of patients with hyperthyroidism, Hashimoto's thyroiditis and subacute thyroiditis were 2.30 ± 1.08, 7.04 ± 7.74 and 24.09 ± 13.56, respectively. The SR of the control group was 1.76 ± 0.54. SR values ranked in ascending order were control group < hyperthyroidism group < Hashimoto's thyroiditis group < subacute thyroiditis group. There were statistically significant (p < 0.05) differences in thyroid hardness between groups with different diffuse thyroid diseases. SR values of the hyperthyroidism and control groups did not statistically differ (p > 0.05). It is feasible to assess diffuse thyroid disease with strain ratios obtained with ultrasound elastography.