Measurement of contact impedance of electrodes used for deep brain stimulation

High frequency electrical stimulation by means of electrodes implanted into the brain has become an accepted technique for treatment of Parkinson's disease. The electrical field distribution normally inserted into the sub thalamic nucleus minimise abnormal brain activity. Square wave pulses of 1–3.6 V with duration of 60–90 μs at a frequency range of 130–185 pps are generally used. Every electrode unit consists of four cylindrical electrodes positioned in a row and can be switched on independently. This paper determines the contact impedance of the electrodes for different frequencies and proposes improvement to reduce the contact impedance between the electrodes and the brain. Measurements were performed by placing the electrodes in a tank filled with saline. Different frequencies were applied on two electrodes via a resistor. The current was measured through the resistor and the voltage was registered between one of the electrodes and a third non current carrying electrode. The obtained values were used to calculate the contact impedance. The result shows large contact impedance for the used frequency compared to the impedance of the treated tissue, which means that variation in contact impedance can result in variation in the electrical field applied to the tissue.     

人工全髋置换术中拉钩对下肢深静脉血栓影响的研究

目的：通过对髂外动静脉及股动静脉与髋臼解剖学与临床的研究，探讨在全髋臼置换术中拉钩在髋放置位置对下肢深静脉血栓的影响。方法：通过解剖学研究56具成年骨盆标本中髂外动静脉及股动静脉来源及走行、与髋臼的关系进行测量分析；并通过临床观察22例（股骨颈骨折12例、股骨头缺血性坏死6例、类风湿性关节炎4例）在人工全髋置换术（THR）中拉钩放置安全区，经下肢静脉超声多普勒检查观察下肢深静脉血栓发病率。结果：在左侧3-5点间、右侧7-9点、左侧9点、右侧3点使用拉钩用力要适度，牵拉时间过长，会造成臀下血管、股动脉的牵拉过度或时间过长，易引起下肢深静脉血栓；通过临床22例THR拉钩放置安全区的观察，无一例下肢深静脉血栓，仅有2例轻度深静脉血流缓慢、但无明显的症状体征，经过口服活血通络中药后消失。结论：通过解剖学与临床观察研究，确定在THR中拉钩放置位置、深度是避免下肢深静脉血栓的重要因素。     

The use of deep inspiration preceding the valsalva maneuver and rapid expiration in color doppler imaging of the lower extremity veins

Deep inspiration preceding Valsalva maneuver and rapid expiration immediately following it (DIVE) enhance venous blood flow on color Doppler flow imaging (CDI). The effect of DIVE was assessed in 115 consecutive lower extremity examinations. Of these, 95 or 115 (83%) had negative CDI sonograms, and 20 of 115 (17%) had partially (six of 115) or completely (14 of 115) occluding deep vein thrombosis. DIVE enhanced venous blood flow in 68% of the negative cases, resulting in transient venous distention, and/or more complete color filling, and/or greater spectral flow velocities. The 14 cases with completely occluding thrombi showed no response to DIVE. Six cases with partially occluding thrombi showed moderate to mild response to DIVE, with improved color delineation of the residual patent lumen around the thrombus. The authors conclude that DIVE facilitates deep venous CDI, especially when compression cannot be used to augment venous flow.     

基于雨课堂的护理教育学课程教学改革实践效果分析

目的 探讨基于雨课堂的混合式教学在护理教育学课程教学中的应用效果。方法 将2019年开课的护理本科教学班设为观察组（n=20）,采用课堂教学与雨课堂平台线上学习相结合的混合式教学;将2018年同期开课、学生数量相同、实施传统课堂教学模式的教学班设为对照组（n=20）。应用SPSS 22.0进行统计学处理,采用独立样本t检验对两个班次学生的研讨课、模拟授课和课终理论考核成绩及对课程教学效果的评价进行分析。结果 两组学生的模拟授课成绩比较差异无统计学意义（t=0.21,P=0.834）,观察组学生的研讨课成绩[91.18±1.20]（t=3.09,P<0.05）和课终理论考试成绩[78.63±6.28]（t=3.33,P<0.05）高于对照组,且信息检索和处理能力（t=-3.33,P<0.05）、发现问题能力（t=-2.17,P<0.05）、独立思考能力（t=-2.53,P<0.05）、知识整合能力（t=-3.86,P<0.001）、自主学习能力（t=-3.12,P<0.05）及对护理教师角色功能的认同感（t=-2.53,P<0.05）、主动学习的意识（t=-3.13,P<0.05）和终身学习的态度（t=-4.46,P<0.001）得分高于对照组。结论 基于雨课堂的混合式教学有利于学生探究学习能力的培养和对理论知识的深度学习,促进课程教学目标的有效达成。     

肝脏子宫内膜异位症一例

肝脏子宫内膜异位症是以肝内存在异位子宫内膜为特征的一种罕见子宫内膜异位症类型,因其缺乏典型临床症状且影像学诊断困难,易被误诊,组织学检查目前仍是肝脏子宫内膜异位症诊断的金标准。现报告1例海军军医大学第三附属医院收治的患者,反复经期右上腹疼痛,经超声检查发现右肝占位性病变,术后病理证实为肝脏子宫内膜异位症。     

Polypeptide composition of normal and neoplastic human breast tissues and cells analyzed by two-dimensional gel electrophoresis

Summary The protein populations of epithelial cells cultured from two neoplastic and five non-neoplastic human breast tissues were resolved and displayed by two-dimensional polyacrylamide gel electrophoresis and silverstaining. With a computer-based image analysis system, we identified eight polypeptides which are present in both of the neoplastic cell lines, but absent from all five of the cultures of non-neoplastic breast cells. The eight polypeptides are not unique to cells cultured from neoplastic breast, because they are also found in cells cultured from non-breast tissues, both neoplastic and non-neoplastic. Two of the eight polypeptides ( M_r 25,000/pI 4.4 and M_r 31,000/pI 5.5) are present in the patterns of whole tissue samples from infiltrating ductal carcinomas and absent in most normal breast tissue.     

Molecular basis for treating endometriosis with aromatase inhibitors

Although treatment of one unusually aggressive case of postmenopausal endometriosis with an aromatase inhibitor has been strikingly successful, large clinical trials are required to establish whether aromatase inhibitors will have a significant role in the medical management of endometriosis. Introduction of aromatase inhibitors into the treatment of endometriosis underscores the importance of basic research leading to the development of novel strategies in reproductive disorders. It was shown earlier that aromatase activity was not detectable in normal endometrium. Aromatase, however, is expressed inappropriately in endometriosis and stimulated by prostaglandin E2. Aromatase activity gives rise to local biosynthesis of oestrogen, which, in turn, stimulates prostaglandin E2 production, thus establishing a positive feedback cycle. This favours accumulation of oestrogen and prostaglandins in endometriosis, which is an inflammatory disorder dependent on oestrogen for growth.     

Stromal changes in early invasive and non-invasive breast carcinoma: an ultrastructural study

Six examples of histologically diagnosed, non-invasive breast carcinomas were studied by electron microscopy to elucidate the ultrastructural features for an accurate diagnosis of in situ carcinoma. The results obtained revealed two patterns of basal lamina/stromal cells relationship. One pattern showed intact basal lamina with associated periductal stromal cells consisting entirely of fibroblasts, the other pattern showed disruption of basal lamina by gaps and malignant cell protrusions with associated stromal cells consisting of both fibroblasts and myofibroblasts. As myofibroblasts are not a component of normal breast stroma but are known to be a prominent feature in the stroma of infiltrating breast carcinoma, the present observations suggest that myofibroblastic proliferation around in situ carcinoma represents an early sign of carcinomatous infiltration. Hence the definitive diagnosis of non-invasive carcinoma of the breast requires an intact basal lamina and a complete absence of a myofibroblastic reaction.     

Activation of protease-activated receptor 2 stimulates proliferation and interleukin (IL)-6 and IL-8 secretion of endometriotic stromal cells

BACKGROUND: Inflammation has been proposed to play essential roles in the pathophysiology of endometriosis, in which neutrophils and mast cells have been suggested to be involved. We studied whether the protease-activated receptor 2 (PAR2), which is activated by enzymes from neutrophils and mast cells, in endometriotic stromal cells (ESC) has any implication in the development of the disease. METHODS: Cultured ESC were stimulated with various concentrations of a specific PAR2 agonist peptide. Proliferating activity of the cells was determined using immunostaining of proliferating cell nuclear antigen (a cell proliferation marker), 5-bromo-2'-deoxyuridine incorporation into DNA and cell count. The concentrations of interleukin (IL)-6 and IL-8 were measured using specific enzyme-linked immunosorbent assay kits. The phosphorylation of three mitogen-activated protein kinases (MAPK), i.e. p38 MAPK, p42/44 MAPK and stress-activated protein Kinase/c-jun N terminal Kinase, in ESC was examined with Western blot analysis. RESULTS: Activation of PAR2 stimulated the proliferation of ESC and the secretion of IL-6 and IL-8 from ESC in a dose-dependent manner. Activation of PAR2 stimulated the phosphorylation of all three MAPK, and inhibitors of each MAPK suppressed the PAR2 activation-induced proliferation of ESC. CONCLUSIONS: The activation of PAR2 in ESC may be involved in the pathophysiology of endometriosis by inducing the growth and inflammation of endometriotic lesions.     

The middle collateral artery: anatomic basis for the “extreme” lateral arm flap

The vascularization of the posterolateral area of the arm is supplied by the terminal branches of the deep brachial artery [middle collateral artery (MCA) and posterior radial collateral artery]. Their anatomy has been a field of confusion for a long time. An extended lateral arm flap, named the extreme lateral arm flap, supplied by these branches and dissected as a retrograde island flap has been proposed as an alternative for large compound defects of the distal forearm. We carried out an extensive anatomic study of the extreme lateral arm flap on 69 upper limbs: 54 fresh injected with colored latex, 10 embalmed and 5 radiographed after Micropaque injection. Two origin levels of the MCA were found: a proximal one (37%) above the radial groove, and a distal one (63%) at the level of the groove. The deep brachial artery always bifurcated after the origin of the MCA into a posterior radial collateral artery (PRCA) and anterior radial collateral artery (ARCA). Indeed in our dissections, after the origin of the MCA from the deep brachial artery, there was always a common trunk named the radial collateral artery (RCA) which bifurcated into the ARCA and PRCA. In all dissected arms we always found the MCA anastomosed in a transverse pattern with the inferior ulnar collateral artery (IUCA), contributing to the anastomotic circle of the elbow. This circle represents the unique vascularization source of the reverse extreme lateral arm flap.