Visual Outcomes from Shunting for Idiopathic Intracranial Hypertension

ABSTRACT

A retrospective notes review was conducted for 50 consecutive patients who underwent shunt surgery for idiopathic intracranial hypertension (IIH). The decimal visual acuity and the mean radial degrees (MRD) of the I4e isopter of the Goldmann visual field were measured pre-operatively and after a mean follow-up period of 1123 days (range: 13–3551 days). A ventriculo-peritoneal shunt was the first procedure in 38 patients and a lumbo-peritoneal shunt in 12. The mean decimal visual acuity of the worse affected eye improved from 0.75 to 0.84, p?=?0.011. The MRD score of the worse affected eye improved on average from 25.6° to 35.5°, p?<?0.0001. In those with significant pre-operative visual impairment in their worse affected eye (defined as an MRD score ≤30°), the MRD score improved on average from 10.3° to 26.5°, p?=?0.0008. The mean number of surgical procedures for each patient was 2.8 (range: 1–15). Taking all surgical procedures into account, post-operative complications were experienced by 30 patients. At last follow-up, 28 patients still complained of headache, 8 of whom had the intervention performed primarily for headache. Shunting can improve visual function in patients with IIH. There is significant post-operative morbidity and often the need for repeated procedures. Headache also commonly remains in these patients. There is a need for a randomised controlled trial of operative interventions in IIH. Sample size calculations for such a trial to treat significant vision loss are presented.     

Red Light Facilitates the Sensed Presence Elicited by Application of Weak,Burst-Firing Magnetic Fields Over the Temporal Lobes

To test the hypothesis that the wavelength (color) of ambient lightning should modulate experiences of a sensed presence when the right hemisphere was stimulated by weak, burst-firing magnetic fields, volunteers were exposed for 30 min to this condition or to a sham field while they sat (eyes opened) in either dim red, green, or white light. Subjects exposed to the magnetic field reported significantly more visual sensations along the left side in red light and along the right side in green light. The significant interaction between ambient color and the field treatment was due to the marked increase in experiences of dizziness, sensed presence, “ego-alien” thoughts, and detachment from the body and “being somewhere else” for subjects exposed to the magnetic field while sitting in red light. The concurrence of entoptic images experienced within the upper left peripheral visual field and the sensed presence supported the hypothesis that both are associated with the intrusion of right hemispheric processes into left hemispheric awareness.     

Magnetic-field Exposures in the Workplace: Reference Distribution and Exposures in Occupational Groups

Abstract

Exposures to extremely-low-frequency magnetic fields were assessed by taking personal measurements with a dosimeter calibrated at 50 Hz with a bandwidth of 40—400 Hz. The study group was a population-based random sample of 1,098 Swedish men. Exposures were determined as workday mean, median, maximum, and standard deviation, and the time fraction of the day when exposures exceeded 0.20 μT. For workday means, the 50th percentile was 0.17 μT, and the 75th percentile was 0.27 μT. For median values, the 50th percentile was 0.11 μT and the 75th percentile was 0.16 μT. The strongest correlation (Spearman rank correlation = r_s) found was between the workday mean and the fraction of time above 0.20 μT (r_s = 0.89). The authors used the same data to estimate exposures for the 100 most common occupations according to the 1990 Swedish census. A minimum of four independent measurements for each occupation was required. Among occupations with low workday mean values were earth-moving machine operator, health care worker, and concrete worker. Among occupations with high workday mean exposures were welder and electrical or electronics engineer or technician. High exposure levels were also found in occupations outside the study base, such as train engine driver and glass, ceramic, or brick worker. Exposures to magnetic fields vary widely, since levels of exposure are strongly affected by factors such as duration of exposure and distance from the source. Large variations often found between individuals within occupations could reflect variations in tasks across different workdays for the particular occupations and/ or local conditions such as tools and installations, and/or how the work is organized and performed.     

超低频电磁场对硝普钠诱导的软骨细胞凋亡的影响

目的:研究超低频电磁场对硝普钠诱导的SD大鼠肋骨骨骺软骨细胞凋亡的影响。方法:不同浓度硝普钠诱导软骨细胞凋亡,检测不同时间软骨细胞半数致死量(LD50)的硝普钠浓度;观察超低频电磁场对软骨细胞凋亡的影响。结果:半数软骨细胞致死的硝普钠浓度呈时间依赖性下降;经超低频电磁场和硝普钠同时作用后的细胞凋亡率明显低于单纯硝普钠作用的细胞凋亡率(P<0.05);单纯硝普钠诱导的细胞在超微结构上有典型的凋亡改变,超低频电磁场能在一定程度上恢复软骨细胞的正常结构。结论:超低频电磁场能抑制硝普钠诱导体外培养的大鼠软骨细胞的凋亡。     

永磁体磁共振电特性成像方法研究

磁共振电特性成像,是利用磁共振原始数据对被测生物组织的电特性进行重建的一种成像方法。利用有限元仿真软件,建立0.4 T主磁场下的射频线圈模型,测量仿真中射频场的分布情况。通过射频场空载和负载下射频场的均匀性,证明电特性的不同影响射频场的分布。用0.4 T永磁体磁共振设备对仿体和人体头部进行实验,并根据仿真数据和实验数据对电特性进行重建。结果表明,低场磁共振电特性在有无负载下,感兴趣区域的磁通密度均匀性相差将近4倍,磁通密度模值明显增加,这为磁共振电特性低场下发展提供一定的参考。     

Bio‐Inspired Multiple Cycle Healing and Damage Sensing in Elastomer–Magnet Nanocomposites

Damage‐sensing and healing are biological functions which are urgently required in structural health monitoring and remediation of engineering structures. The development of a bio‐inspired multiple cycle damage sensing and triggered healing magnet–polymer nanocomposite (Magpol) is reported. Magpol is comprised of an acrylonitrile butadiene co‐polymer (NBR) matrix and a magnetic nanoparticle (MNP) filler. Magpol nanocomposites in a range of MNP filler concentrations are studied. NBR is selected as the matrix due to its extensive use in industrial coatings, for example, in the automotive industry. Mn‐Zn ferrite MNP is chosen due to its appropriate Curie temperature and good specific absorption rate. Exposure of damaged Magpol to a remote external alternating magnetic field results in MNP heating. The MNP heats the surrounding NBR matrix, resulting in triggered healing. Fractured Magpol samples are successfully healed over several cycles. Incorporation of rhodamine b mechano‐chromophore in Magpol results in multicycle damage sensing by photo‐luminescent absorption. Thus, the developed Magpol is attractive for structural health monitoring and remediation application.     

电磁辐射对大鼠海马BDNF和NCAM表达的影响

目的:研究电磁辐射前后大鼠海马脑源性神经营养因子(brain-derived neurotrophic factor,BDNF)和神经细胞粘附因子(neural cell adhesion molecule,NCAM)表达水平的变化.方法:场强为6×104V/m的电磁脉冲照射Wistar大鼠,采用免疫组织化学染色观察海马组织中BDNF和NCAM的表达.结果:BDNF和NCAM的表达均于照后1h开始升高,6h达高峰(P＜0.05).结论:电磁脉冲照射后早期,BDNF和NCAM的上调可能介导了突触可塑性的正向改变.     

Effect of pulsed electromagnetic field therapy in patients undergoing total knee arthroplasty: a randomised controlled trial

Purpose

It has been reported that even one year after total knee arthroplasty (TKA), a relevant percentage of patients does not attain complete recovery and indicate unfavourable long-term pain outcome. We compared the clinical outcome of 33 patients undergoing TKA randomly assigned to the control or the pulsed electromagnetic field group (I-ONE therapy).

Methods

I-ONE therapy was administered postoperatively four hours per day for 60 days. Patients were assessed before surgery and then at one, two and six months postoperatively using international scores.

Results

One month after TKA, pain, knee swelling and functional score were significantly better in the treated compared with the control group. Pain was still significantly lower in the treated group at the six month follow-up. Three years after surgery, severe pain and occasional walking limitations were reported in a significantly lower number of patients in the treated group.

Conclusions

Advantages deriving from early control of joint inflammation may explain the maintenance of results at follow-up. I-ONE therapy should be considered an effective completion of the TKA procedure.     

不同治疗时间的脉冲电磁场对去势大鼠股骨生物力学性能的影响

目的通过采用不同治疗时间的脉冲电磁场（PEMFs）干预去势大鼠骨质疏松模型，观察各组大鼠的股骨生物力学性能的变化，以探索PEMFs治疗骨质疏松的最适治疗时间。方法按随机分组原则用密闭信封法将雌性3个月龄SD大鼠50只分为5组：假手术对照组10只，卵巢切除对照组10只，卵巢切除Ⅰ组10只，卵巢切除Ⅱ组10只，卵巢切除Ⅲ组10只。除假手术对照组以外，对所有动物按文献方法去势造模。卵巢切除Ⅰ组、卵巢切除Ⅱ组和卵巢切除Ⅲ组大鼠每天在强度为3．8mT，频率为8Hz的电磁场环境中分别照射20，40，60min，共30d。假手术对照组和卵巢切除对照组不干预。各组动物均在满30d后，行股动脉放血处死，取右侧股骨作生物力学性能测定。结果卵巢切除对照组大鼠的股骨结构力学指标（包括最大位移、最大载荷及最大能量吸收）和材料力学指标（包括最大应力、最大应变及弹性模量）显著低于其它4组大鼠（P〈0．05或P〈0．01），而假手术对照组、卵巢切除Ⅰ组、卵巢切除Ⅱ组及卵巢切除Ⅲ组4组大鼠的股骨生物力学指标之间的差异无统计学意义（P〉0．05）。结论PEMFs能阻止大鼠在卵巢切除后的股骨生物力学性能下降，对去势大鼠的骨质疏松症有肯定的预防作用。在磁场强度（3．8mT）和脉冲频率（8Hz）相同的前提下3种治疗时间的PEMFs均能使卵巢切除大鼠股骨生物力学性能维持在接近正常的水平，但3种治疗时间之间的差异无统计学意义，说明每日用PEMFs对去势大鼠治疗20—60min，对其骨生物力学性能的维持效果相同。