可生物降解共聚膜修复兔桡骨节段性缺损

目的：探讨在引导性骨再生中生物降解材料聚已内酯（ｐｏｌｙ ε ｃａｐｒｏｌａｃｔｏｎｅ, Ｐ Ｃ Ｌ）和聚乳酸（ｐｏｌｙ ｌａｃｔｉｃ ａｃｉｄ, Ｐ Ｌ Ａ）共聚物的作用及其生物相容性和生物降解性。方法：采用兔桡骨中段１２ ｃｍ节段性骨缺损（保留骨膜）动物模型,共２４只分两组进行对照研究,每组１２只,双侧处理方法相同, Ａ组骨缺损区用膜包绕骨缺损区, Ｂ 组为空白对照。分别于３、６、１２周后处死,进行 Ｘ 线、大体、组织学及电镜观察,检测生化及免疫指标。结果：实验组（ Ａ）骨生长明显优于对照组（ Ｂ）;材料呈明显的降解趋势;血清中 Ｃａ、 Ｐ、 Ｉｇ Ｇ、 Ｉｇ Ｍ 、 Ｃ４值与正常及空白对照均无明显差异。结论：生物降解材料（ Ｐ Ｃ Ｌ／ Ｐ Ｌ Ａ）在引导骨性组织再生中有良好的屏障作用,促进骨缺损的愈合。证明新型骨生物降解材料有良好的生物降解性和生物相容性。     

Internally and externally guided voluntary saccades in unmedicated and medicated schizophrenic patients. Part I. Saccadic velocity

Saccadic eye movements were elicited in 30 schizophrenic patients before and in 17 of these 30 during antipsychotic treatment with neuroleptics, and compared with those of 12 age-matched controls under three different conditions: (a) the gap paradigm, which tests the visually triggered and visually guided saccades; (b) the anti-task paradigm, which tests the internally guided, visually triggered saccades; and (c) the memory paradigm, which tests the internally triggered and guided saccades. Eye movements were recorded by DC electro-oculography, and the peak eye velocities for the different saccades were calculated. We found that antipsychotic treatment with neuroleptics reduces the peak saccadic eye velocity. This effect is larger for internally guided saccades than for externally triggered and guided eye movements. The saccadic velocity of the unmedicated schizophrenic patients did not differ from that of the controls. Since patients with diseases of the basal ganglia primarily show abnormalities of the internally guided and triggered saccades, our findings indicate that neuroleptics influence the oculomotor loop through the basal ganglia and that this loop, by means of neuroleptic influence on the brainstem saccadic burst generator, also influences the peak velocity of the internally guided saccades. This contradicts the current idea of the role of the cortical input to the brainstem saccadic burst generator, which is thought to not be involved in the determination of saccadic velocity. Received: 20 December 1997 / Accepted: 15 September 1998     

Electrophysiological determination of the refractive state of the eye of the opossum

The refractive state of the eye of the South American opossum Didelphis marsupialis aurita was investigated with electrophysiological techniques. Using adult specimens, trapped from the wild, averaged cortical evoked responses were recorded from the region of projection of the central visual field. Stimuli consisted of a phase reversal of a square wave grating generated on a CRO screen, with luminance of 2.4 cd/m2 and contrast 0.84. The refractive state of the eye was altered by means of trial lenses and the amplitude of the cortical responses thus obtained compared to those obtained with no lens (control values). Refraction "tuning curves" were determined for each animal. The average refractive state was found to be -2.27 D indicating that this species when raised in its habitat shows, at low ambient luminosity, some degree of myopia. Determination of the Contrast Sensitivity Function indicate that induced ametropias lead to a reduction of the cut-off value of the spatial frequency and a loss of contrast sensitivity.     

Immunocontraceptive activity guided fractionation and characterization of active constituents of neem (Azadirachta indica) seed extracts

A novel approach for immunocontraception by intervention of local cell mediated immunity in the reproductive system by using single intrauterine application of neem oil has been described earlier. The reversible block in fertility was reported to last for 107–180 days in female Wistar rats (Upadhyay et al., 1990. Antifertility effects of neem oil by single intrauterine administration: A novel method of contraception. Proceedings Of The Royal Society Of London B 242, 175–180) and 7–11 months in monkeys (Upadhyay et al., 1994. Long term contraceptive effects of intrauterine neem treatment (IUNT) in bonnet monkeys: An alternative to intrauterine contraceptive devices. Contraception 49, 161–167). The present study, describes the identification and characterization of the biologically active fraction from neem seeds (Azadirachta indica A. Juss. Family Meliaceae), responsible for the above activity in adult female Wistar rats. Initial studies with the mechanically extracted oil and solvent extracts of neem seeds have revealed that the antifertility activity was present in constituents of low to intermediate polarity. A hexane extract of neem seeds was reported to be biologically active (Garg et al., 1994. Comparison of extraction procedures on the immunocontraceptive activity of neem seed extracts. Journal of Ethnopharmacology 22, 87–92). Subsequently, hexane extract was sequentially fractionated through the last active fraction using various separation techniques and tested for antifertility activity at each step. Preparative HPLC was used for isolating individual components of the active fraction in quantities, sufficient for characterization. An analytical HPLC method was developed for standardization of the fraction. The active fraction was identified to be a mixture of six components, which comprises of saturated, mono and di-unsaturated free fatty acids and their methyl esters. Dose response study was performed with the last active fractions. The antifertility activity with the active fraction was reversible in nature and it was completely active until 5% concentration. There was no systemic toxic effect following the administration of the active fraction. This study, for the first time, proposes an active fraction from neem seeds, responsible for long term and reversible blocking of fertility after a single intrauterine administration with high efficacy.     

CT导引注射胶原酶治疗腰椎间盘突出症的临床研究

目的：探讨ＣＴ引导下椎间盘突出的髓核内和突出物表面注射胶原酶治疗椎间盘突出 的效果。方法：对９０例椎间盘突出的患者在ＣＴ导引下分别于椎间盘突出的髓核内和突出物的表达注射胶原酶,所有患者随访３个月￣２年,其中３０例行ＣＴ复查。结果：穿刺成功率１００％,术后随访３个月￣２年,优良率为９５．６％,２９例ＣＴ随访突出物 部分缩小或消失（９６．７％）,本组无并发症。结论”腰椎间盘突出的髓核内和突出物的表面共     

3种配准方式下肺癌图像引导放射治疗摆位误差的比较

目的研究滑轨CT不同配准方式对肺癌大分割调强放疗摆位误差的影响。方法选取2016年10月至2017年10月在安徽医科大学第一附属医院放疗科就诊的肺癌患者24例,每周行滑轨CT扫描所得图像与原计划图像行灰度、骨性、手动3种模式在线配准,得出X、Y、Z轴3个方向平移误差,并进行统计分析。结果灰度配准、骨性配准和手动配准方式测量的X、Y、Z轴摆位误差分别为(0. 21±0. 16)、(0. 29±0. 15)、(0. 37±0. 22) cm,(0. 27±0. 16)、(0. 35±0. 25)、(0. 29±0. 19) cm,(0. 18±0. 12)、(0. 28±0. 16)、(0. 23±0. 14) cm,结果显示Y轴平移误差最大,其次为X轴,Z轴最小,且3组数据的差异有统计学意义(P <0. 05)。其中灰度模式在X、Y、Z轴上平移误差较骨性模式均缩小,灰度模式在X、Z轴上平移误差较手动模式有所缩小,差异有统计学意义(P <0. 05)。结论肺癌患者行图像引导大分割调强放疗时,应用滑轨CT中的灰度模式可缩小摆位误差。     

Atornillado anterior de la odontoides empleando tomografía computarizada de haz cónico intraoperatorio y navegación

ObjectiveThe purpose of this study was to asses the value of intraoperative cone-beam CT (O-arm) and stereotactic navigation for the insertion of anterior odontoid screws.Materials and methodsthis was a retrospective review of patients receiving surgical treatment for traumatic odontoid fractures during a period of 18 months.Procedures were guided with O-arm assistance in all cases. The screw position was verified with an intraoperative CT scan. Intraoperative and clinical parameters were evaluated. Odontoid fracture fusion was assessed on postoperative CT scans obtained at 3 and 6 months’ follow-upResultsFive patients were included in this series; 4 patients (80%) were male. Mean age was 63.6 years (range 35-83 years). All fractures were acute type ii odontoid fractures. The mean operative time was 116 minutes (range 60-160 minutes). Successful screw placement, judged by intraoperative computed tomography, was attained in all 5 patients (100%). The average preoperative and postoperative times were 8.6 (range 2-22 days) and 4.2 days (range 3-7 days) respectively. No neurological deterioration occurred after surgery. The rate of bone fusion was 80% (4/5).ConclusionAlthough this initial study evaluated a small number of patients, anterior odontoid screw fixation utilizing the O-arm appears to be safe and accurate. This system allows immediate CT imaging in the operating room to verify screw position.     

Effects of latex membrane on guided regeneration of long bones

Abstract

Natural latex extracted from Hevea brasiliensis is one of the materials pointed out as potential tissue regenerators. The use of latex-based membranes in bone regeneration might be an alternative to stimulate bone formation. The aim of this study was to evaluate the effects of latex membranes in guided bone regeneration of defects produced in long bones of rats. Sixty rats were equally divided into latex and control groups, and each group was subdivided into two subgroups according to treatment duration of 1 and 4 weeks. Bone defects with 2.5?mm in diameter were surgically made in the left tibia. In the animals of the latex group, a latex membrane was placed over the bone defect. The samples underwent quantitative histological analysis of bone formation and collagen matrix, immunohistochemical analysis of osteogenic protein markers, assessment of bone mechanical properties and bone densitometry, and radiological assessment. The osteocalcin immunostaining data were submitted to the generalized linear model test with two independent factors. For the other data, the multivariate ANOVA with two independent factors was performed. The use of the latex membrane significantly improved (p?<?0.005) the volume of newly formed bone, collagen type I matrix, expression of osteopontin, and bone stiffness, both in the early and late stages of regeneration. In conclusion, the latex membrane was able to promote bone regeneration in long bones.