心率及重建相位窗对多层螺旋CT冠状动脉造影图像质量的影响

目的 探讨心率及重建相位窗对多层螺旋CT冠状动脉造影图像质量的影响。方法 80例健康体检者行16层螺旋CT回顾性心电门控条件下冠状动脉造影。结果 每位患者的4条冠状动脉分支(左冠状动脉主干、左前降支、左回旋支、右冠状动脉)分别用于图像质量分析。心率≤60次／min者，有82．1％(46／56支)的图像可用于诊断；心率61～70次／min者，有63．4％(104／164支)的图像可用于诊断；心率71～80次/min者，有41．20h，(28／68支)的图像可用于诊断；心率80次／min以上者有31．2％(10／32支)的图像可用于诊断。左冠状动脉前降支在60％～70％的重建相位窗时图像质量最佳，左冠状动脉回旋支在50％～60％时最佳，右冠状动脉重建相位窗为50％～70％较满意。结论心率及重建相位窗对多层螺旋CT冠状动脉造影图像质量有重要影响作用。     

大鼠慢性应激性水浸溃疡模型的复制

本文复制了慢性、应激性水浸溃疡模型,23℃每天拘束水浸4小时,4天后所得溃疡病变明显,溃疡指数是13.8士4.5mm~2,且再现性良好,是一个较好的慢性、应激性溃疡模型。哌哌西平对此溃疡具有较强的防治作用。     

高渗氯化钠高氧液对失血性休克家兔血乳酸和动脉血气的影响

目的:观察高渗氯化钠高氧液对失血性休克家兔动脉血气和血乳酸值的影响，评价其对失血性休克的早期救治效果。方法:制备高渗氯化钠溶液(HS)、生理盐水高氧液（NSO）和高渗氯化钠高氧液(HSO)。30只雄性家兔制备失血性休克模型［于10min内使平均动脉压（MAP）降至40mmHg（1mmHg＝0.133kPa），维持60min］，随机分为NSO，HS，HSO组3个治疗组。分别按6mL/kg剂量5min内静脉输入NSO,HS和HSO。记录休克前后及给药后心率（HR）、呼吸（RR）、MAP及尿滴（UD），测定休克前、休克60min，给药后30，60，120min时血乳酸（BL）和动脉血气值。最后观察尸肺，测定肺系数。结果:HS和HSO组均显著地改善MAP，HR和UD，降低BL，改善代谢性酸中毒,肺系数明显低于NSO组。HSO与NSO及HS比较，能更显著地降低血BL，提高动脉血氧饱和度（SaO2）和动脉血氧分压（PaO2）。结论:HSO较HS和NSO能更显著地降低血BL,提高SaO2和PaO2，对失血性休克的早期救治具有较高的使用价值。     

Poly-l-aspartic acid protects cultured human proximal tubule cells against aminoglycoside-induced electrophysiological alterations

Cultured human proximal tubule cell monolayers maintained on permeable supports were treated simultaneously with the aminoglycoside antibiotic, gentamicin, and poly- -aspartic acid (PAA), an inhibitor of aminoglycoside nephrotoxicity. Following 4 days of exposure, cell monolayers were placed into Ussing chambers to allow monitoring of transepithelial electrical properties. For each of the three cell isolatation examined, aminoglycoside-induced alterations in electrogenic transport, reflected by changes in short-circuit current (Isc), as well as alterations in paracellular properties, indicated by changes in transepithelial electrical resistance (R_T), were diminished in the presence of PAA. Alterations resulting from selective basolateral exposure to gentamicin were unchanged in the case of apically applied PAA and attenuated only when PAA acid was added basolaterally. This is the first demonstration of PAA inhibition of aminoglycoside-induced cellular alterations involving human cells.     

胃癌10和11组淋巴结转移及其清扫

目的：研究胃癌脾门淋巴结(No．10)和脾动脉周围淋巴结(No．11)转移规律，进一步探讨No．10和11清扫的必要性和方法。方法：1991年-2000年132例行全胃切除，D2以上淋巴结清扫的胃癌患者，回顾性研究临床病理资料，包括性别、年龄、肿瘤部位、大小、浸润深度、病理类型、其他淋巴结转移等对No．10和11转移的影响，比较全胃切除和全胃联合脏器切除的并发症发生率。结果：胃癌具有较高的No．10或11淋巴结转移率(18．9％)，Logistic回归分析表明，胃癌部位、病理类型、浸润深度和大小弯淋巴结转移五项临床病理指标影响No．10和U转移率。联合脏器切除的并发症发生率(32％)明显高于单纯全胃切除(11．2％)，联合肢体尾切除增加肠下脓肿发生率，而脾切除并不增加全胃切除的危险性。结论：No．10和11在胃癌有较高的转移率和特定的转移规律，预防性和治疗性的清扫实属必要，联合左侧肢体尾加脾切除增加手术危险性，应严格掌握的适应证。而保留胰腺，切除脾血管和脾清扫No．10．和ll淋巴结合理可靠。     

MR image segmentation using vector decomposition and probability techniques: A general model and its application to dual-echo images

A general model is developed for segmenting magnetic resonance images using vector decomposition and probabilfty techniques. Each voxel is assigned fractional volumes of q tissues from p differently weighted images (q ≤ p + 1) in the presence of partial-volume mixing, random noise, and other tissues. Compared wtth the eigenimage method, fewer differently weighted images are needed for segmenting the q tissues, and the contrast-to-noise ratio in the calculated fractional volumes is improved. The model can produce com-posrte tissue-type images similar to that of the probability methods, by comparing the fractional volumes assigned to different tissues on each voxel. A three-tissue (p = 2, q = 3) model is illustrated for segmenting three tissues from dual-echo images. M provides statistical analysis to the algebraic method. A three-compartment phantom is segmented for validation. Two clinical examples are presented.     

Effect of chronic oral domperidone therapy on gastrointestinal symptoms and gastric emptying in patients with parkinson's disease

This study investigated whether domperidone could improve gastrointestinal symptoms in patients with Parkinson's disease who were receiving levodopa therapy. A total of 11 patients were studied. Following a baseline gastric emptying test, patients were treated with a starting dose of domperidone 20 mg p.o. q.i.d. A follow-up gastric emptying test was repeated at least 4 months after starting domperidone therapy. At the beginning and at each 3-month follow-up visit, symptoms of nausea, vomiting, anorexia, abdominal bloating, heartburn, regurgitation, dysphagia, and constipation were evaluated and scored on a scale of 0–3. The overall mean follow-up period was 3 years. Compared with their baseline evaluation, patients experienced a significant improvement in all symptoms (p < 0.05) except dysphagia and constipation. Gastric emptying of an isotope-labeled solid meal was significantly faster, with a baseline result of 60.2 ± 6.4% retention of isotope 2 h after the meal compared with 37.0 ± 2.2% retention during domperidone therapy (p < 0.05). Patients' global assessment of Parkinson's disease remained stable or improved. Serum prolactin was elevated in all patients after domperidone therapy (p < 0.05). Domperidone therapy significantly reduces upper gastrointestinal symptoms and accelerates gastric emptying of a solid meal, but does not interfere with response to antiparkinsonism treatment.     

The Effect of Quisqualic Acid-Induced Lesions of the Nucleus Basalis Magnocellularis on Latent Inhibition

Latent inhibition (LI) is a reduction in the rate of acquisition of a Pavlovian conditioned response that results from prior nonreinforced preexposure to a conditioned stimulus (CS). LI has been suggested to reflect the operation of mechanisms involved in stimulus selection for subsequent cognitive processing. The present experiment was conducted to assess the effect of bilateral lesions of the nucleus basalis magnocellularis (NBM) on LI employing a conditioned emotional response paradigm. Bilateral lesions of the NBM were produced by administration of 0.12 M quisqualic acid and resulted in decreased cortical acetylcholinesterase staining, as well as a 40% reduction in cortical choline acetyltransferase activity. Following lever press training, preexposed animals received 40 presentations of a 60-s tone CS. Nonpreexposed animals received no tone presentations. Acquisition of conditioned suppression was then assessed over the course of 4 tone-shock (0.6 mA, 0.5 s) pairings. Control, preexposed animals displayed a retarded rate of acquisition in comparison to nonpreexposed controls, thereby demonstrating that the parameters used in the present experiment produced LI. In contrast, lesioned animals preexposed to the CS acquired conditioned suppression as readily as non-preexposed lesioned animals. However, the acquisition of conditioned suppression in both lesioned groups was found to be similar to that displayed in the preexposed control group. This pattern of results was interpreted as being attributable to a lesion-induced impairment in the ability to maintain stimulus processing, rather than a deficit in the ability to filter a stimulus. Copyright © 1996 Elsevier Science Inc.     

Advances in processing of surface myoelectric signals: Part 1

During sustained voluntary or electrically elicted muscle contractions the surface myoelectric signal is nonstationary and it undergoes progressive changes reflecting the modifications of the motor unit action potentials and their propagation velocity. In particular, during sustained electrical stimulation, the evoked signals show progressive amplitude, time scaling and shape modification. The quantitative evaluation of these changes is important for non-invasive muscle characterisation and may be performed in either the time or frequency domain using parametric and nonparametric spectral analysis as well as alternative methodologies. The paper introduces the detection techniques, reviews and compares the methods of spectral estimation based on FFT and autoregressive models, and discusses their applications and limitations in extracting information from the surface myoelectric signal with particular regard to myoelectric manifestations of localised muscle fatigue during sustained contractions.     

老年人上消化道出血104例临床分析

分析104例60岁以上的老年人上消化道出血的病因,依次为急性胃粘膜病变,上消化道肿瘤,消化性溃疡及门脉高压。手术治疗效果优于内科保守治疗,而保守治疗又以甲氰咪胍效果较好。