Brachytherapy: An emblematic example of extreme hypofractionated regimen

In order to provide more convenient irradiation regimens for patient comfort, radiation facility organization and health expenses, new hypofractionated protocols have been evaluated. Moderately (dose/fraction: 2.3 to 3 Gy), then ultra (dose/fraction: 5.2 to 6.1 Gy) hypofractionated irradiations were first validated. The current question is: is it possible to go forward using extreme hypofractionated regimens (EHR) based on 1 to 3 fractions. Different irradiation techniques are under investigation. However, brachytherapy remains the smartest way to deliver a high dose in a small volume. We report prospective and retrospective study results which evaluated EHR for breast and prostate brachytherapy. While oncological outcome and toxicity profile appear extremely encouraging for low-risk breast cancer after a 1 to 4 fractions (6.25 to 20 Gy/fraction), the use of a single fraction of 19 to 23 Gy appears debatable for prostate cancer. Brachytherapy represents an emblematic example of EHR but longer follow-up and more mature results are awaited in order to specify the right indications and refine the EQD2 calculation method including new biological and technical factors.     

胃癌穿孔24例治疗分析

目的 :探讨胃癌穿孔的临床特点 ,指导临床诊治和提高疗效。方法 :对本院 2 4例胃癌穿孔病人采用不同手术方式治疗。其中 8例行单纯修补术 ,2例在穿孔修补术后 3周早期施行二期根治性手术 ,3例行穿孔修补加胃空肠吻合术 ,7例行姑息性胃大部切除术 ,4例行胃癌根治术。结果 :本组死亡 4例 ,其余病例中位生存期分别为 7,13 .2 ,2 5 .1个月。结论 :采取积极的治疗措施 ,可望延长患者的生存时间和提高生存质量     

Cutaneous afferent activity in the median nerve during grasping in the primate

Neural activity was recorded from the median nerve of a monkey during grasping and lifting, using a chronically implanted cuff electrode. At the onset of lifting, there was an initial dynamic response during which the intensity of the neural signal increased rapidly. This neural response attained its peak value well before the displacement, the load force or the grip force. The time course and peak of the rectified, integrated neurogram were best correlated with the rate of change of grip force. The neural activity declined exponentially to a steady value following the initial peak. During steady holding the mean amplitude of the neurogram was best correlated with the mean grip force. At the end of the holding phase there was a short burst of neural activity as the monkey relaxed the grip force and released the object. During some blocks of trials pulse perturbations were applied to the object. When the monkey did not increase the grip force in advance of the perturbation, the perturbation produced a relatively large displacement of the object and a burst of neural activity whose onset coincided with the onset of displacement. When the monkey anticipated the perturbation by increasing the grip force during the holding period preceding the perturbation, the perturbation produced a relatively small displacement and relatively little increase in neural activity.     

酸枣仁提取物急性毒性实验研究

目的 观察酸枣仁醇提取物的急性毒性反应.方法 ①小鼠尾静脉注射不同剂量的酸枣仁醇提取物,连续观察14 d,记录小鼠的急性毒性反应,并计算LD50及LD50 95%可信限;②小鼠灌胃给药,测定一次给予酸枣仁醇提取物的安全剂量.结果 ①静脉注射酸枣仁醇提取物后,部分小鼠出现中毒反应并死亡,测得LD50为27.5 g·kg-1,LD50 95%可信限为25.1～30.1 g·kg-1,死亡动物尸检,其主要脏器未见病理改变.14 d后存活小鼠体重平均增加20.4%,略高于生理盐水组(18.2%).②小鼠灌胃给药(340 g·kg-1,相当于成人一次用量的326倍)后,连续观察14 d,小鼠全部存活,无明显毒性反应,小鼠体重平均增长17.2%.结论 酸枣仁醇提取物毒性很低,临床给药安全可靠.     

正中神经与肌皮神经的交通支及其临床意义

目的观察正中神经与肌皮神经之间的交通支，探讨其临床意义。方法对72侧防腐固定尸体解剖，对正中神经、肌皮神经之间的交通支进行测量与观察，并对不同类型交通支的结果进行比较。结果13人，16侧肢体存在18支交通支，出现率22．2％，男性与女性相比出现率高且差异显著，左右肢体的出现率无显著差异。其中肌皮神经从正中神经低位发出的有2支，正中神经-肌皮神经的交通支（Ⅰ型）与肌皮神经-正中神经的交通支（Ⅱ型）相比起、止点低，交通支较长，但直径细（Ⅰ型14．2～23．0cm，止点为11．0～21．5cm，长度为2．5～10．7cm，直径为0．55～2．15mm；Ⅱ型起点为0～17．ocm，止点为12．0～24．0cm，长度为1．9～8．4cm，直径为0．76～2．60mm）但两者差异无统计学意义（P〉0．05）。结论正中神经与肌皮神经之间存在着交通支，并起着一定的功能，手术时应注意加以保护，避免损伤。     

Anterior thoracic corpectomy without sternotomy: A strategy for malignant disease of the upper thoracic spine

SummaryBackground With increasing frequency, spine surgeons are being asked to provide decompression and stabilization in patients with spinal metastases. While no region of the spine is easily treated, the upper thoracic spine is perhaps the least accessible. Traditional approaches to this region involve either thoracotomy or at least limited sternotomy. The authors present an approach to anterior pathology of the upper thoracic spine that obviates the need for sternotomy.Methods Within the past two years, two patients with cervicothoracic metastases underwent anterior decompression and fusion without sternotomy. In both patients, the bodies of C7, T1, and T2 were removed. While both patients were prepared and draped for sternotomy, each required a neck dissection only. In both patients, left-sided incisions were made along the leading edge of the sternocleidomastoid. The platysma was divided with the overlying skin. With further dissection, the strap muscles were tagged and divided approximately one centimeter above their sternal attachments. The loose areolar tissue of the superior mediastinum was then bluntly dissected. Along the entire length of the incision, the vascular plane medial to the carotid sheath was developed to facilitate exposure of the anterior spine. A Farley-Thompson retractor system was then employed to retract and protect the superior mediastinal structures. With this exposure, corpectomies were carried out using a high speed drill. Fusion was accomplished through insertion of Steinmann pins into the adjacent intact bodies above and below. This was followed by application of methyl methacrylate. Both patients had immediate postoperative stability with preservation of spinal cord function. Both patients subsequently underwent removal of dorsally located tumor with posterior fusion.Conclusions The goal of cancer surgery is to provide for increased functional survival without undue morbidity. The authors feel that when possible, the pain of sternal and clavicular osteotomies should be avoided. The described approach works well in conjunction with a methyl methacrylate/Steinmann pin construct. Because of the intact sternum, the surgeon has a downward angle to access the superior endplate of T3. With adequate soft tissue dissection and retraction as described, however, T3 and perhaps even T4 are easily accessible. While this downward angle would likely not permit an anterior plating procedure, it lends itself nicely to Steinmann pin/methyl methacrylate fusion and spares the patient the pain and potential morbidity of sternotomy.     

High postovariectomy LH levels are not due to decreased opioid inhibition of GnRH

It has been proposed that endogenous opioid peptide (EOP) inhibition of hypothalamic GnRH secretion mediates and is dependent upon gonadal steroid feedback of LH secretion, although considerable conflicting data have been reported. Accordingly, a well-characterized replacement regimen was used to approximate physiological stimulation by estradiol (E2) and progesterone (P4) in adult rats 10 days after ovariectomy (OVX), followed by in vitro incubation of the isolated median eminence to evaluate the role of E2 and P4 in modifying GnRH release in response to the opiate receptor antagonist, naloxone (NAL). Basal (control) GnRH release from median eminences of OVX, OVX + E2, and OVX + E2 + P4 rats was similar, and NAL treatment elicited a comparable increase in GnRH release under all three gonadal steroid conditions. Thus, EOP suppression of median eminence GnRH secretion does not appear to mediate or be dependent upon negative feedback regulation of LH secretion by physiological concentrations of gonadal steroids.     

Effects of surgical treatment in thymoma with myasthenia gravis: our experience in 103 patients.

A retrospective study of 103 thymectomies examines the effects of the integration of surgical and medical therapy in patients affected by myasthenia gravis accompanied by thymoma. An extended thymectomy via a median longitudinal sternotomy was used in 102 patients. The operative mortality was 4.85% (5/103 patients), the 10-year survival rate was 78% with a recurrence rate of 3.06% (3/98). Neoplastic infiltration and postoperative radiotherapy did not influence the survival rate. There was no correlation between a preoperative Osserman's class better than III and postoperative outcome. The improvement of medical treatment, and anaesthesiological and intensive care techniques resulted in a decrease of the operative mortality and long-term death rate during the last 10 years of our 20-year series. Extended thymectomy via sternotomy is the best intervention in patients with myasthenia gravis associated with thymoma judged by the low operative mortality and the favorable 10-year survival rates.     

The effects of voluntary contraction effort on quadriceps femoris electromyogram median frequency in humans: a muscle and sex comparison

The purpose of this study was to examine the effect of voluntary contraction efforts on the median frequency (f _med) of the electromyogram (EMG) recorded from the quadriceps femoris muscle in healthy men and women. A group of 30 healthy volunteers (15 men, 15 women) were assessed for EMG activity of the vastus medialis (VM), vastus lateralis (VL), and rectus femoris (RF) muscles during isometric contractions with the knee at 60° flexion. Subjects performed a series of 5 s maximal voluntary isometric contractions that anchored the perceptual range with a "10" on a 10-point scale. Sub-maximal isometric contractions were then separately performed at the following perceived effort levels on the 10-point scale: 1, 2, 3, 4, 5, 6, 7, 8 and 9, in a random order. Subjects were instructed to maintain the contraction at each perceived level of effort for 5 s. The f _med of the three muscles was assessed using a power spectrum analysis performed over 11 consecutive, 512 ms, epochs overlapping each other by half their length during the middle 3 s of each contraction. The f _med for each of the 11 epochs was then determined for each muscle, followed by calculation of the means and normalized coefficients of variation [(standard deviation/mean)×100%] for each contraction. The results demonstrated that the mean f _med of VL was significantly greater than those of the other two muscles, and that f _med of RF was significantly greater than that of VM. The VL muscle demonstrated a significant increase in mean f _med across the contraction efforts, compared to the VM and RF muscles that displayed a significant decrease. The men displayed significantly higher f _med values for the VM muscle than did the women, as well as showing a significantly greater increase across the contraction efforts for the VL muscle. The variability of f _med was shown to be significantly higher for the VM muscle, compared to the VL and RF muscles. The findings of this study suggest that the f _med statistic is most sensitive to contraction intensity efforts for the VL muscle, and that men display significantly higher values for the VL and VM muscles, compared to women. Electronic Publication     

模拟脑电节律的调制磁场对中缝核神经元放电影响的研究

用数值计算和动物实验的方法研究模拟脑电节律的调制磁场对与睡眠有关的中缝核神经元放电的影响 ,从而探讨其对睡眠的影响。通过数字仿真 ,研究了神经纤维对调制磁场刺激作用的响应特性 ,发现了神经纤维具有对低频调制包络信号响应敏感 ,对高频载波不响应的特性。依据睡眠全过程脑电节律的变化 ,研制了模拟 EEG信号发生器。采用高频磁脉冲作为载波调制模拟脑电节律信号 ,用所得的调制磁场诱导兔脑 ,观察磁刺激对中缝核5 -羟色胺能神经元放电的影响。动物实验结果表明 ,中缝核经磁刺激后放电频率发生显著改变 ,其放电变慢。这说明磁刺激能抑制 5 -羟色胺能神经元神经电活动水平 ,将为改善失眠症提供新的途径