Visualization of the left extraperitoneal space and spatial relationships to its related spaces by the visible human project

Background

The major hindrance to multidetector CT imaging of the left extraperitoneal space (LES), and the detailed spatial relationships to its related spaces, is that there is no obvious density difference between them. Traditional gross anatomy and thick-slice sectional anatomy imagery are also insufficient to show the anatomic features of this narrow space in three-dimensions (3D). To overcome these obstacles, we used a new method to visualize the anatomic features of the LES and its spatial associations with related spaces, in random sections and in 3D.

Methods

In conjunction with Mimics® and Amira® software, we used thin-slice cross-sectional images of the upper abdomen, retrieved from the Chinese and American Visible Human dataset and the Chinese Virtual Human dataset, to display anatomic features of the LES and spatial relationships of the LES to its related spaces, especially the gastric bare area. The anatomic location of the LES was presented on 3D sections reconstructed from CVH2 images and CT images.

Principal Findings

What calls for special attention of our results is the LES consists of the left sub-diaphragmatic fat space and gastric bare area. The appearance of the fat pad at the cardiac notch contributes to converting the shape of the anteroexternal surface of the LES from triangular to trapezoidal. Moreover, the LES is adjacent to the lesser omentum and the hepatic bare area in the anterointernal and right rear direction, respectively.

Conclusion

The LES and its related spaces were imaged in 3D using visualization technique for the first time. This technique is a promising new method for exploring detailed communication relationships among other abdominal spaces, and will promote research on the dynamic extension of abdominal diseases, such as acute pancreatitis and intra-abdominal carcinomatosis.     

Negative Emotion Regulation in Patients with Posttraumatic Stress Disorder

Objective

To explore the neural mechanisms of negative emotion regulation in patients with post-traumatic stress disorder (PTSD).

Methods

Twenty PTSD patients and 20 healthy subjects were recruited. Event-related functional magnetic resonance imaging (fMRI) was used to investigate the modification of emotional responses to negative stimuli. Participants were required to regulate their emotional reactions according to the auditory regulation instructions via headphones, to maintain, enhance or diminish responses to negative stimuli during fMRI scans.

Results

The PTSD group showed poorer modification performance than the control group when diminishing responses to negative stimuli. On fMRI, the PTSD group showed decreased activation in the inferior frontal cortex, inferior parietal lobule, insula and putamen, and increased activation in posterior cingulate cortex and amygdala during up-regulation of negative emotion. Similar decreased activation regions were found during down-regulation of negative emotion, but no increased activation was found.

Conclusion

Trauma exposure might impair the ability to down-regulate negative emotion. The present findings will improve our understanding of the neural mechanisms of emotion regulation underlying PTSD.     

Validation of a low-dose hybrid RSA and fluoroscopy technique: Determination of accuracy, bias and precision

Analyzing skeletal kinematics with radiostereometric analysis (RSA) following corrective orthopedic surgery allows the quantitative comparison of different implant designs. The purpose of this study was to validate a technique for dynamically estimating the relative position and orientation of skeletal segments using RSA and single plane X-ray fluoroscopy. Two micrometer-based in vitro phantom models of the skeletal segments in the hip and knee joints were used. The spatial positions of tantalum markers that were implanted into each skeletal segment were reconstructed using RSA. The position and orientation of each segment were determined in fluoroscopy images by minimizing the difference between the markers measured and projected in the image plane. Accuracy was determined in terms of bias and precision by analyzing the deviation between the applied displacement protocol and measured pose estimates. Measured translational accuracy was less than 100 microm parallel to the image plane and less than 700 microm in the direction orthogonal to the image plane. The measured rotational error was less than 1 degrees . Measured translational and rotational bias was not statistically significant at the 95% level of confidence. The technique allows real-time kinematic skeletal measurements to be performed on human subjects implanted with tantalum markers for quantitatively measuring the motion of normal joints and different implant designs.     

Alteration of Brain Functional Networks in Early-Stage Parkinson’s Disease: A Resting-State fMRI Study

Although alterations of topological organization have previously been reported in the brain functional network of Parkinson’s disease (PD) patients, the topological properties of the brain network in early-stage PD patients who received antiparkinson treatment are largely unknown. This study sought to determine the topological characteristics of the large-scale functional network in early-stage PD patients. First, 26early-stage PD patients (Hoehn and Yahr stage:1-2) and 30 age-matched normal controls were scanned using resting-state functional MRI. Subsequently, graph theoretical analysis was employed to investigate the abnormal topological configuration of the brain network in early-stage PD patients. We found that both the PD patient and control groups showed small-world properties in their functional brain networks. However, compared with the controls, the early-stage PD patients exhibited abnormal global properties, characterized by lower global efficiency. Moreover, the modular structure and the hub distribution were markedly altered in early-stage PD patients. Furthermore, PD patients exhibited increased nodal centrality, primarily in the bilateral pallidum, the inferior parietal lobule, and the medial superior frontal gyrus, and decreased nodal centrality in the caudate nucleus, the supplementary motor areas, the precentral gyrus, and the middle frontal gyrus. There were significant negative correlations between the Unified Parkinson Disease Rating Scale motor scores and nodal centralities of superior parietal gyrus. These results suggest that the topological organization of the brain functional network was altered in early-stage PD patients who received antiparkinson treatment, and we speculated that the antiparkinson treatment may affect the efficiency of the brain network to effectively relieve clinical symptoms of PD.     

猪流行性腹泻mRNA疫苗的制备与免疫原性评价

猪流行性腹泻(porcine epidemic diarrhea,PED)是一种可引起仔猪高致死率的传染性疾病,尽管已有灭活疫苗和减毒活疫苗上市,但由于病毒变异频繁导致保护效力欠佳,发病率依然居高不下。本研究首次制备了PED mRNA候选疫苗,并在小鼠和妊娠母猪上评价了其免疫原性,证明了基于病毒受体结合区异源二聚体的mRNA候选疫苗具有良好的免疫原性,可在小鼠上高效诱导体液和细胞免疫应答,单次免疫血清中和抗体滴度达到1:300以上,并在妊娠母猪上诱导了与灭活疫苗相近的中和抗体水平,实现了100%抗体转阳。本研究为PED mRNA疫苗的进一步产业化奠定了基础。     

禾谷镰孢菌β-微管蛋白基因克隆及其与多菌灵抗药性关系的分析

应用3对引物,从禾谷镰孢菌(Gibberella zeae)对多菌灵(MBC)的敏感菌株(MBC^R)和田间及室内诱导抗药性菌株(MBC^R)中扩增β-微管蛋白基因。该基因全长1631bp,包含3个内含子,编码447aa,与其他常见植物病原丝状真菌β-微管蛋白基因的氨基酸同源性达95．12％～99．30％。MBC^R和MBC^R菌株核苷酸序列分析表明,MBCR菌株未发生任何位点的突变,说明G．zeae对MBC的抗药性机制并非像其他丝状真菌一样由β-微管蛋白198位氨基酸突变所致。     

辽西地区林地土壤抗蚀性分析

以半干旱的辽西地区广布的油松针叶纯林、油松针阔混交林和阔叶林林下的土壤为研究对象,通过主分量分析方法将9个抗蚀性指标分为3类：无机胶粒团聚类因子、有机胶粒团聚类因子和抗分散类因子,并以抗蚀性指数,来评价辽西地区土壤的抗蚀性,以期为辽西地区水土保持效益评价和造林树种选择提供依据。结果表明,土壤抗蚀性上坡小于下坡,阳坡半阳坡小于阴坡半阴坡;坡度越大土壤抗蚀性越差;阔叶林林下的土壤抗蚀性大于针阔混交林,大于针叶纯林。     

樟子松人工固沙林天然更新障碍因子分析

采用比较分析与野外试验的方法,对沙地樟子松人工林天然更新障碍因子进行了分析。结果表明,影响天然更新的环境因子主要有郁闭度、枯枝落叶层、植被盖度和立地条件。天然更新的障碍主要是由于引种地降雪覆盖少,温度偏高等原因,使土壤蒸发大、苗木蒸腾大,造成水分的亏缺,从而导致1－2年生更新幼苗死亡。针对樟子松人工固沙林天然更新障碍及其更新特点,提出在适宜立地上采取人工促进措施,如埋土、灌水等方法,以保证天然更新有效进行。