三维伪连续动脉自旋标记评价症状性大脑中动脉慢性闭塞后脑灌注状态的临床价值

目的探讨三维伪连续动脉自旋标记(3D-pCASL)在症状性大脑中动脉(MCA)慢性闭塞后脑灌注状态的评价价值。方法前瞻性选择收集我院2017年8月至2020年3月具有临床症状而就诊的MCA慢性闭塞患者42例,进行常规MRI、MRA及3D-pCASL检查,3D-pCASL采用两个标记延迟时间(PLD=1.5 s、2.5 s)。分别测量患侧、镜像侧MCA感兴趣区(ROI)脑白质血流量(CBF),并计算患侧与镜像侧比值,比较分析患侧与镜像侧双时相脑灌注CBF值的差异。结果 42例单侧MCA慢性狭窄患者,脑内DWI均未见扩散受限信号灶。患侧和镜像侧PLD=1.5 s时CBF为[(32.94±9.99)/(41.72±8.46)],均较PLD 2.5 s[(40.29±8.97)/(45.69±9.09)]降低,且患侧PLD较镜像侧降低更明显,差异有统计学意义(P0.05)。患侧CBF较镜像侧呈低灌注状态31例(73.81%),其中严重缺血后失代偿5例(11.90%),CBF正常灌注7例(16.67%),CBF高灌注4例(9.52%),患侧侧支循环完全代偿。结论全脑3D-pCASL评估症状性大脑中动脉慢性闭塞患者脑白质CBF可信度高,可作为常规序列,为临床诊疗提供量化依据。     

A spheroid-based 3-D culture model for pancreatic cancer drug testing,using the acid phosphatase assay

Current therapy for pancreatic cancer is multimodal, involving surgery and chemotherapy. However, development of pancreatic cancer therapies requires a thorough evaluation of drug efficacy in vitro before animal testing and subsequent clinical trials. Compared to two-dimensional culture of cell monolayer, three-dimensional (3-D) models more closely mimic native tissues, since the tumor microenvironment established in 3-D models often plays a significant role in cancer progression and cellular responses to the drugs. Accumulating evidence has highlighted the benefits of 3-D in vitro models of various cancers. In the present study, we have developed a spheroid-based, 3-D culture of pancreatic cancer cell lines MIAPaCa-2 and PANC-1 for pancreatic drug testing, using the acid phosphatase assay. Drug efficacy testing showed that spheroids had much higher drug resistance than monolayers. This model, which is characteristically reproducible and easy and offers rapid handling, is the preferred choice for filling the gap between monolayer cell cultures and in vivo models in the process of drug development and testing for pancreatic cancer.     

The roles of actin cytoskeleton and actin-associated protein Crn1p in trap formation of Arthrobotrys oligospora

Nematode-trapping fungi include a variety of species capable of generating specific trapping devices to capture nematodes and the production of devices is also an indicator of a switch from saprophytic to predacious lifestyles. Traps are developed from vegetative mycelia, but they are quite different from hyphae in both morphological and physiological characteristics. Therefore, the molecular mechanisms underlying their formation have attracted much attention. In this investigation, Arthrobotrys oligospora, a nematode-trapping fungus, has three-dimensional networks and genomics and proteomics were recently performed, so as to reveal the relationship between actin cytoskeleton and trap formation. Both actin staining via FITC-phalloidin and treatment of actin polymerization inhibitor Lat-B illustrated that the actin cytoskeleton played an important role in trap development. Furthermore, absence of the conserved actin-associated protein Crn1p caused a structural defect of traps and failure to infect nematodes. It was observed that mutant Δcrn1 represented a reduced number of rings and a lower complexity of three-dimensional networks, likely due to the disturbance of actin branching. Collectively, our study confirmed the involvement of the actin cytoskeleton as well as the conserved actin-associated protein Crn1p in trap formation. It further suggested the manners in which Crn1p influences the development of three-dimensional networks in A. oligospora.     

A novel tissue engineered three-dimensional in vitro colorectal cancer model

The interactions of cancer cells within a solid mass with the surrounding reactive stroma are critical for growth and progression. The surrounding vasculature is recruited into the periphery of the growing tumour to supply cancer cells with nutrients and O₂. This study focuses on developing a novel three-dimensional (3-D) in vitro biomimetic colorectal cancer model using colorectal cancer cells and connective tissue cells. The 3-D model comprises a dense artificial cancer mass, created by partial plastic compression of collagen type I containing HT29 colorectal cancer cells, nested in a non-dense collagen type I gel populated by fibroblasts and/or endothelial cells. HT29 cells within the dense mass proliferate slower than when cultured in a two-dimensional system. These cells form tumour spheroids which invade the surrounding matrix, away from the hypoxic conditions in the core of the construct, measured using real time O₂ probes. This model is also characterized by the release of vascular endothelial growth factor (VEGF) by HT29 cells, mainly at the invading edge of the artificial cancer mass. This characterization is fundamental in establishing a reproducible, complex model that could be used to advance our understanding of cancer pathology and will facilitate therapeutic drug testing.     

Review of brachytherapy complications – Upper gastrointestinal tract

While brachytherapy applications are not widely used for cancer diagnoses in the upper GI tract (including the esophagus, liver, stomach, and pancreas), they have a clear role in palliation and symptom management and occasionally definitive locoregional treatment. With the increasing use of image-guided techniques, the incidence of side effects and complications has shown to be lower than many other alternative treatment modalities, making brachytherapy approaches a preferred treatment option. This review examines procedural complications and acute and chronic adverse effects from radiation associated with esophageal, hepatobiliary, and pancreatic brachytherapy and their management.     

Three-dimensional periorbital asymmetry assessment of congenital microphthalmia children with a structured light 3D scanning system

Congenital microphthalmia is a rare phenotype characterized by eye growth retardation. Due to the lack of eyeball stimulation, children suffering from congenital microphthalmia always have bony orbital maldevelopment, which leads to facial asymmetry. In the present study, a structured light 3D scanning system was used as a novel method to measure the three-dimensional periorbital asymmetry in children with congenital microphthalmia.Children with unilateral congenital microphthalmia of 0–6 years old were enrolled in the present study. All participants underwent an ultrasound scan to measure the axial length, and accepted the structured light 3D scanning system for their periorbital appearance. The degree of periorbital asymmetry was evaluated using 17 facial landmarks within a three-dimensional cartesian coordinate system (the X-axis represented the horizontal direction, the Y-axis represented the vertical direction, and the Z-axis represented the sagittal direction). Paired student t-test and ANOVA were used in the present study. A three-dimensional periorbital topography was also established to further illustrate the periorbital asymmetry.A total of 67 children were recruited, which included 31 boys and 34 girls. The axial length on the affected side (12.28 ± 3.35 mm) was generally smaller than that on the unaffected side (20.54 ± 1.65 mm, P < 0.001). When grouped by age, the periorbital asymmetry mainly manifested in the Y-axis and Z-axis directions. The unaffected side had a higher orbitale superior (5.09 ± 0.35 vs. 3.02 ± 0.30, P < 0.001) and a lower orbitale inferior (?19.52 ± 0.51 vs. ?16.90 ± 0.53, P < 0.001) in 0–1 year old group. Same performances were also found in the 1–3 and 3–6 age groups. When grouped according to the proportion of axial length on the bilateral sides, seven of the 12 Y-values and all 12 Z-values had statistical differences.The structured Light 3D scanning system may serve as a beneficial complementary tool for computed tomography, in order to better understand the periorbital deformities caused by congenital microphthalmia.     

Iodine-125 brachytherapy alone for advanced primary parotid gland carcinoma

This study aimed to evaluate the efficacy of iodine-125 (¹²⁵I) brachytherapy alone for the treatment of advanced parotid gland carcinoma and to identify predictors of tumour control and patient survival. Primary parotid gland carcinoma patients (n = 23) treated with ¹²⁵I brachytherapy alone between 1 October 2005 and 31 July 2013 at Peking University Stomatology Hospital were enrolled in this retrospective study. All had clinical stage IV disease. The prescribed dose was 60–160 Gy. The local control rate, survival rate, and predictors of the prognosis were evaluated. Adverse events related to treatment were also noted. The average follow-up time was 29 months (range 9–74 months). Among the 23 patients, six had local failure and 11 died during the follow-up period. The 1-, 3-, and 5-year overall survival rates were 87.0%, 55.4%, and 47.5%, respectively. The 1-, 3-, and 5-year progression-free survival rates were 73.9%, 47.0%, and 39.2%, respectively. The 1-, 3-, and 5-year local control rates were 82.1%, 73.9%, and 73.9%, respectively. Age and distant metastasis were independent predictors of survival, while the preoperative duration of the disease was an independent predictor of local control. The use of ¹²⁵I seed brachytherapy alone for the treatment of primary parotid gland carcinoma can provide good short-term results without causing any severe side effects.