Secretory immunoglobulin‐A reactivity following increases in workload intensity using the Defined Intensity Stressor Simulation (DISS)

Previous work suggests that secretory immunoglobulin‐A (S‐IgA) reactivity is inversely related to the perceived demands of the stressor. The Defined Intensity Stressor Simulation (DISS) comprises eight stressor modules, and allows for the manipulation of stress either through increasing the number of modules, or increasing the workload of the modules. The current study assessed the effect of increasing the workload of four modules upon S‐IgA reactivity and perceived demands. Participants (N = 14) attended three sessions on consecutive days where they provided a timed saliva sample immediately before and after 5 min on the DISS at low, medium and high workload. Following each session participants recorded their perceptions of the task with regard to workload and levels of stress and arousal. Perceived workload and stress, but not arousal, increased in accordance with increases in workload, however, differential S‐IgA reactivity was observed. Low workload resulted in a slight increase in S‐IgA secretion; medium workload elicited significant up‐regulation, while down‐regulation of S‐IgA occurred following high workload. As DISS is analogous to a variety of working environments it is suggested that the observed S‐IgA reactivity is indicative of how individuals react to multi‐tasking environments when faced with increases in objective or perceived workload demands. As S‐IgA levels are related to protection from illness, down‐regulation of S‐IgA in those who perceive greater demands may lead to greater vulnerability to ill‐health. Copyright © 2005 John Wiley & Sons, Ltd.     

A群脑膜炎多糖菌苗接种前后流脑流行规律的改变及今后预防对策

本文研究了在使用菌苗预防前后的流行性脑脊髓膜炎流行强度的变迁，年龄、地区及季节分布特点，人群的易感性及带菌率之间的关系，并讨论了今后的预防措施。     

Temporal prominence of auditory evoked potentials (N1 wave) in 4-8-year-old children

Cortical auditory evoked potentials (N1 wave) were studied in 24 adults (12 men, 12 women) and 20 children (12 boys, 8 girls; age: 4-8 years). In adults, this wave was recorded with maximal amplitude at frontocentral sites, peaking at about 100 ms poststimulation, whereas in children the auditory response displayed maximal amplitude at the midtemporal sites, with a positive wave at about 100 ms and a large negative wave at approximately 170 ms. Moreover, the modulatory effects of intensity on N1 amplitude were prominent at frontocentral sites in adults and at temporal sites in children. Frontocentral negative response was also recorded in children but was smaller in amplitude and longer in peak latency (around 140 ms) than in adults; responses were of greater amplitude at the frontal site than at the vertex before 6 years of age, whereas the reverse was more often found after this age. These data suggest great differences with age in the neural generators contributing to auditory evoked potentials recorded in the N1 latency range.     

基于Mapcheck2的调强放射治疗计划剂量验证分析

目的探讨基于Mapcheck2的调强放射治疗计划剂量验证与靶区均匀性指数(HI)、靶区适形指数(CI)及等中心点剂量梯度(D_Gref)的关系。方法选取2018年6月至2020年2月于医院行调强放射治疗计划的497例患者作为研究对象,采用Mapcheck2进行剂量验证,以剂量误差3%、吻合距离3 mm下的γ通过率≥90%且中心点累积剂量偏差绝对值(Dacc)≤3%为限定条件,在合格的462例计划中随机选取18例设为对照组,将不合格的35例分为A组(Dacc≤3%但γ通过率<90%,11例)、B组(γ通过率<90%且Dacc>3%,9例)、C组(γ通过率≥90%但Dacc>3%,15例),计算并比较4组的HI、CI及D_Gref值。结果 A组各指标与对照组比较,C组HI、CI值与对照组比较,差异均无统计学意义(P>0.05);B组各指标与对照组比较,C组D_Gref值与对照组比较,差异均有统计学意义(P<0.05)。对35例不合格计划进行优化设计后,经验证均合格,且优化后计划的HI、CI及D_Gref值与优化前比较,差异均无统计学意义(P>0.05)。结论调强放射治疗计划设计前,应选取合理的射野数目、方向,优化参数、算法,并尽量将射野等中心点置于靶区内剂量梯度较小的位置,以减少影响剂量验证的不良因素。     

利用独立准直器开展调强放疗算法研究

研究利用独立准直器调整射野强度分布。设计了两种递推的办法来计算射野处序列,采用模拟退火算法优化射野片的照射顺序。并以在Ｖａｒｉａｎ ６００Ｃ轲速器上实施三个临床调强射野为例,估计ＩＣ调强放疗的照射时间。照射时间一般在５至１０ｍｉｎ。它近似与机器剂量率成反比,并受调强算法,矩阵元素大小以及强度分级数的影响。     

低频超声波透皮给药的强度对皮肤组织的影响

目的　探讨不同强度下低频超声波介导透皮给药对人体皮肤组织的影响。方法　以 2 4例健康青年志愿者的双上臂作为试验区域 ,每个试验者两上臂同时涂抹 1geutecticmixtureoflocalanesthetics,10min后分别采用 0 .5、1W·cm-2 的能量进行低频超声 (2 0kHz )介导 ,介导时间 10min。每 5min测量两组镇痛起始时间 ,试验结束后观察皮肤组织的变化。结果　能量为 1W·cm-2 的低频超声组平均镇痛起始时间为 32 .75± 3.73min ,0 .5W·cm-2 组为 37.6 5± 3.2 4min。低频超声可使角质层间质增宽和疏松 ,0 .5W·cm-2 组未见组织学病理损害 ,1W·cm-2 组可见点状红疹 ,类似二度烫伤。结论　能量高可更快促进药物透过皮肤 ,但高能量可引起皮肤组织病理性损害 ,0 .5W·cm-2 组能量是比较安全的低频给药方式。     

乳腺癌旋转切线调强照射技术的研究

目的建立一种新的等中心旋转切线调强照射技术,在保持调强技术靶区剂量均匀性不变情况下,试图进一步减少患侧肺组织及心脏卷入射野的体积和剂量。方法根据等中心旋转切线照射的物理原理,使用PinnacleVersion7.4的子野优化软件做治疗计划。旋转切线野沿靶区等中心切线设置,相邻切线野的机架转角间隔5°、10°、15°,切线野的内缘和外缘分别与靶区内缘(胸壁)和靶区外缘相切,起始野和终止野处设立一对穿野,旋转等中心一般设置在与弯形靶区中心(即剂量归一点)相对应的胸壁附近。利用BEV视图设置每个切线野的形状和大小。对每个切线野预设7个子野。按临床治疗要求设置靶区、重要器官(肺和心脏)的剂量处方。结果靶区内处方剂量50Gy的体积V50为95.1%。靶处方剂量的95%、105%、110%及115%以上的相应等剂量线面包围的体积V95%、V105%、V110%、V115%分别为0.98、0.84、0.53、0.18。患、健侧肺和心脏的V10、V20、V30、V40、V50值都很低。结论旋转切线调强技术不仅能得到靶区内很好的剂量均匀性和较高的靶区剂量适合度,而且能更好地保护患侧心脏和肺组织的受量大小和受量范围。定位摆位相对简单。在任何带有子野优化的治疗计划系统上都可作为该技术的计划设计。如果配以限制或跟随胸廓运动的措施,将会更充分地发挥该技术的优点。     

高强度聚焦超声治疗肝癌16例初步疗效观察

目的：观察高强度聚焦超声（HIFU）治疗中晚期肝癌的临床疗效。方法：采用FEP—BY01型高能聚焦超声热疗机，联合肝动脉检塞化疗（TACE）、抗癌中成药及支持对症治疗，对16例不能手术的肝癌进行综合治疗。结果：治疗后患者临床症状改善，疼痛缓解评分与疗前相比，差异有显著性（P〈0．05）；B超显示回声增强，血流明显减少；AFP水平下降，无明显肝功能改变；无明显并发症发生。结论：HIFU治疗中晚期肝癌能缓解患者疼痛，改善生活质量，值得进一步研究。     

高能聚焦超声治疗子宫肌瘤300例疗效观察

目的 观察高能聚焦超声肿瘤治疗机对子宫肌瘤的治疗效果。方法 采用FEP—BY01型高能聚焦超声肿瘤治疗机对300例子宫肌瘤患者进行治疗；治疗3个月后，通过B超检验和患者临床症状对比对治疗效果进行评定。结果 子宫肌瘤体积缩小30％以上且B超回声明显增强者197例（65．67％）；瘤体缩小30％以下和（或）B超回声明显增强者94例（31．33％）；绝大多数患者临床症状改善。结论 高能聚焦超声对子宫肌瘤具有良好治疗效果。     

Use of multiplexed tandem PCR to estimate the prevalence and intensity of Theileria orientalis infections in cattle

This study employed a semi-quantitative, multiplexed tandem PCR (MT-PCR) to assess the prevalence and infection intensity of four genotypes (buffeli, chitose, ikeda and type 5) of Theileria orientalis in cattle in Australia. Genomic DNA samples from blood samples (n = 448) collected from 27 to 32 dairy cows from each of 15 dairy herds with a history of recent theileriosis outbreaks (Group 1), and from blood samples available from 24 cows with or without oriental theileriosis (Group 2) were tested using MT-PCR. Results revealed that all four genotypes were present in Group 1 cattle; genotype buffeli had the highest prevalence (80.5%), followed by genotypes ikeda (71.4%), chitose (38.6%) and type 5 (20.3%). Genotype ikeda had the highest average infection intensity in the cattle (relating to 55,277 DNA copies), followed by buffeli, chitose and type 5 (6354–51,648 copies). For Group 2, results indicated that genotype ikeda had a significantly higher average intensity of infection than buffeli in symptomatic cattle (P < 0.001), and symptomatic cattle had a higher intensity of ikeda than asymptomatic cattle (P = 0.004). Future studies should assess the utility of the present MT-PCR assay as a diagnostic and epidemiological tool in other parts of Australasia and the world.