动物瘢痕模型的相关研究进展

皮肤损伤后的异常愈合会导致病理性瘢痕的产生。病理性瘢痕的出现不仅影响美观,严重时还会造成心理和生理功能障碍。病理性瘢痕的机制研究对于瘢痕治疗有极为重要的意义。其中,动物瘢痕模型是目前研究病理性瘢痕的重要模型手段之一。理想的动物瘢痕模型应该在组织学、细胞学等层面尽可能接近于人类的病理性瘢痕。该文分别从传统技术动物瘢痕中的啮齿类动物模型、兔耳模型和猪模型,以及新技术动物瘢痕模型这两个方面,结合近年来在瘢痕领域应用较多的研究,进行了相应系统的阐述。     

白藜芦醇对酒精诱导雄性大鼠骨量减少和骨强度降低的保护作用

目的探索白藜芦醇对酒精诱导雄性大鼠骨量减少和骨强度降低的影响。方法 30只12周雄性大鼠随机分为对照组、模型组和治疗组3组,每组10只。模型组和治疗组大鼠给予0.4 mL/100 g的20%乙醇溶液,每周3次。治疗组接受白藜芦醇40 mg/kg治疗,每日一次,治疗为期12周。治疗结束时收集血清和股骨对治疗结果进行评价。结果治疗12周后,治疗组的股骨骨密度较模型组显著升高,差异有统计学意义(P0.05);Mircro-CT显示治疗组大鼠股骨干骺端较模型组具有更多骨小梁以及更佳的骨微观参数,差异有统计学意义(P0.05);生物力学结果显示治疗组股骨的极限载荷和峰值负荷较模型组显著升高,差异有统计学意义(P0.05);而血清检测结果表明治疗组的碱性磷酸酶和骨钙素较模型组明显降低,差异有统计学意义(P0.05)。结论白藜芦醇对酒精诱导雄性大鼠骨量减少和骨强度降低有一定的保护作用。     

How structural and functional MRI can inform dual-site tACS parameters: A case study in a clinical population and its pragmatic implications

BackgroundAbnormalities in frontoparietal network (FPN) were observed in many neuropsychiatric diseases including substance use disorders. A growing number of studies are using dual-site-tACS with frontoparietal synchronization to engage this network. However, a computational pathway to inform and optimize parameter space for frontoparietal synchronization is still lacking. In this case study, in a group of participants with methamphetamine use disorders, we proposed a computational pathway to extract optimal electrode montage while accounting for stimulation intensity using structural and functional MRI.MethodsSixty methamphetamine users completed an fMRI drug cue-reactivity task. Four main steps were taken to define electrode montage and adjust stimulation intensity using 4x1 high-definition (HD) electrodes for a dual-site-tACS; (1) Frontal seed was defined based on the maximum electric fields (EF) predicted by simulation of HD montage over DLPFC (F3/F4 in EEG 10–10), (2) frontal seed-to-whole brain context-dependent correlation was calculated to determine connected regions to frontal seeds, (3) center of connected cluster in parietal cortex was selected as a location for placing the second set of HD electrodes to shape the informed montage, (4) individualized head models were used to determine optimal stimulation intensity considering underlying brain structure. The informed montage was compared to montages with large electrodes and classic frontoparietal HD montages (F3-P3/F4-P4) in terms of tACS-induced EF and ROI-to-ROI task-based/resting-state connectivity.ResultsCompared to the large electrodes, HD frontoparietal montages allow for a finer control of the spatial peak fields in the main nodes of the FPN at the cost of lower maximum EF (large-pad/HD: max EF[V/m] = 0.37/0.11, number of cortical sub-regions that EF exceeds 50% of the max = 77/13). For defining stimulation targets based on EF patterns, using group-level head models compared to a single standard head model results in comparable but significantly different seed locations (6.43 mm Euclidean distance between the locations of the frontal maximum EF in standard-space). As expected, significant task-based/resting-state connections were only found between frontal-parietal locations in the informed montage. Cue-induced craving score was correlated with frontoparietal connectivity only in the informed montage (r = ?0.24). Stimulation intensity in the informed montage, and not in the classic HD montage, needs 40% reduction in the parietal site to reduce the disparity in EF between stimulation sites.ConclusionThis study provides some empirical insights to montage and dose selection in dual-site-tACS using individual brain structures and functions and proposes a computational pathway to use head models and functional MRI to define (1) optimum electrode montage for targeting FPN in a context of interest (drug-cue-reactivity) and (2) proper transcranial stimulation intensity.     

Precision and Accuracy of Measurements on CT Scout View

ObjectivesThe purposes of this study were to (1) investigate the limits of measurements on scout view in three computed tomography axes, x, y and z and (2) develop a model to provide better understanding of measurement accuracy.MethodsFor the first objective, anteroposterior and lateral scout views of a Catphan phantom 200 mm in diameter and length were acquired with a GE scanner at 21 different table heights. Phantom measurements on scout view were performed by two experienced readers. The comparison of their measures provided estimation of precision. The accuracy was assessed by determining the bias, calculated as the difference between the values measured on scout view and the real phantom size. Second, a model was developed investigating the relationship between the dimensions of the object, its image, and the table height. This relationship was tested on our data.ResultsScout view measurements were precise, with less than 0.53% difference between readers. In addition, small biases of about 1 mm were detected in the z-axis, whatever the table height. In the other axes, serious biases from −13 to +73 mm were measured. Furthermore, at isocentre, overestimations up to 7 mm were shown. The results also indicated that biases in scout view measurements are because of the geometrical projection related to the object-detector distance.ConclusionsMeasurements in the table movement axis are precise and accurate, conferring to scout views an added value for preoperative planning in orthopedic surgery.     

颞下颌关节强直动物模型中最大张口度与强直严重程度关系研究

目的　研究主、被动最大张口度（AMMO、PMMO）与颞下颌关节强直严重程度的关系。方法　选取28只健康雄性绵羊随机分为实验组和对照组，每组各14只。实验组绵羊双侧颞下颌关节模拟髁突矢状骨折，其中左侧翼外肌被切断以阻断其功能；对照组绵羊未进行手术。于术前及术后12、24周对所有绵羊体重、AMMO、PMMO、颞下颌关节形态学特点进行测量评估。结果　实验组只有右侧保留翼外肌功能的颞下颌关节发生了骨强直。术后12、24周，实验组绵羊AMMO、PMMO、极限距离均显著低于对照组，差异均有统计学意义（均P < 0.05）。实验组绵羊AMMO和PMMO与骨融合区宽度、长度、面积及钙化程度均呈负相关（均P < 0.05），其中骨融合区面积为主要影响因素（术后12、24周相关系数r分别为-0.94、-0.95）。结论　颞下颌关节强直动物模型中阻断翼外肌功能可阻止骨强直的发生；对于早期髁突矢状骨折，可通过牙合垫或牙合板进行张口训练，进而阻断翼外肌功能。当颞下颌关节发生骨强直时，骨融合区面积越大，张口受限越明显。     

Animal Models of Barrett's Esophagus and Esophageal Adenocarcinoma–Past,Present, and Future

Esophageal adenocarcinoma is the fastest rising cancer in the United States. It develops from long‐standing gastroesophageal reflux disease which affects >20% of the general population. It carries a very poor prognosis with 5‐year survival <20%. The disease is known to sequentially progress from reflux esophagitis to a metaplastic precursor, Barrett''s esophagus and then onto dysplasia and esophageal adenocarcinoma. However, only few patients with reflux develop Barrett''s esophagus and only a minority of these turn malignant. The reason for this heterogeneity in clinical progression is unknown. To improve patient management, molecular changes which facilitate disease progression must be identified. Animal models can provide a comprehensive functional and anatomic platform for such a study. Rats and mice have been the most widely studied but disease homology with humans has been questioned. No animal model naturally simulates the inflammation to adenocarcinoma progression as in humans, with all models requiring surgical bypass or destruction of existing antireflux mechanisms. Valuable properties of individual models could be utilized to holistically evaluate disease progression. In this review paper, we critically examined the current animal models of Barrett''s esophagus, their differences and homologies with human disease and how they have shaped our current understanding of Barrett''s carcinogenesis.     

Daily coping moderates the relations between stress and actigraphic sleep: a daily intensive longitudinal study with ecological momentary assessments

BackgroundTheoretical models argue that coping reduces stress responses, yet no studies have tested whether coping moderates the prospective stress effects on sleep in daily life.PurposeThis study tested if coping moderates the stress-sleep association using a daily, intensive longitudinal design across 7–12 days.Methods326 young adults (M_age = 23.24 ± 5.46) reported perceived stress and coping (problem-focused, emotional-approach, and avoidance) every evening between 20:00–02:00, providing over 2400 nights of sleep data and 3000 stress surveys from all participants. Actigraphy and sleep diaries measured total-sleep-time and sleep efficiency. Multilevel models tested the interaction effects of within- and between-person stress and coping on sleep.ResultsWithin-person problem-focused and emotional-approach coping moderated the within-person stress effects on actigraphic total-sleep-time (both p = 0.02); higher stress predicted shorter total-sleep-time only during high use of problem-focused or emotional-approach coping (both p = 0.01). Between-person avoidance moderated the between-person stress effect on actigraphic total-sleep-time (p = 0.04); higher stress predicted shorter total-sleep-time for high avoidance coping (p = 0.02). Within-person emotional-approach coping buffered the between-person stress effect on actigraphic sleep efficiency (p = 0.02); higher stress predicted higher sleep efficiency for high emotional-approach coping (p = 0.04).ConclusionsThis study showed that daily coping moderates the effects of evening stress on sleep that night. More efforts to cope with stress before bedtime had a short-term cost of shorter sleep that night. However, high use of emotional-approach coping buffered the impact of stress to promote sleep efficiency.