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31.
The hypothesis that platelet-activating factor (PAF) plays a role in the modulation of the vasomotor tone and blood pressure was put forward by our group in previous in vivo studies in anaesthetised rabbits. The present study was undertaken to investigate the putative role of this lipid mediator in the vascular reactivity of the renal circulation, using the experimental model of the isolated perfused rabbit kidney. Dose-response curves to noradrenaline-induced vasoconstriction were performed before and after continuous infusions of two different PAF-receptor antagonists (WEB 2086 and yangambin) and of the phospholipase A2 inhibitor mepacrine. The increases in renal perfusion pressure elicited by noradrenaline were potentiated by all the above-mentioned treatments in a dose-dependent manner. Moreover, prostaglandin F-induced vasoconstriction was also potentiated by the administration of the PAF receptor antagonists and mepacrine. Furthermore, the administration of PAF into the renal circulation induced dose-related and long-lasting vasodilator responses, which were blocked by the PAF receptor antagonists. Nevertheless, PAF-induced renal vasodilation was also abolished by a pretreatment with mepacrine or with the cyclooxygenase inhibitor indomethacin, suggesting that it enhances the secondary formation of vasodilator arachidonic acid metabolites. The data indicate that PAF is involved in the modulation of the vasomotor tone in the renal circulation, through the release of cyclooxygenase products, constituting an additional mechanism of modulation of smooth muscle cell contractility to the ones exerted by well-known vasoactive substances of endothelial origin such as nitric oxide. Received: 20 April 1998 / Accepted: 5 March 1999  相似文献   
32.
We report five patients with atypical parkinsonism characterized by freezing phenomenon, akinesia and axial rigidity without limb rigidity or tremor. These patients were selected from 252 patients with parkinsonism who were referred to our clinic from 1986 to 1993. They have common clinical features consisting of freezing phenomena involving all four extremities, especially in the initiation of walking, and marked axial rigidity; otherwise, neither supranuclear ophthalmoparesis nor nuchal dystonia was noted. Their clinical features did not change over several years except in one patient who later developed typical manifestations of progressive supranuclear palsy (PSP). Levodopa was of no effect on their symptoms. After excluding other possibilities, it is our conclusion that they represent an atypical form of PSP lying between the pure akinesia of Imai and Narabayashi and the typical form of PSP.  相似文献   
33.
目的 确定老年性痴呆患者 (seniledementiaoftheAlzheimer′sdisease ,AD)有无周围性听功能障碍及其与认知障碍的关系。方法 利用纯音测听、言语识别率、声导抗、听觉脑干反应检测AD患者 43例 ,健康老年人 50例 ,评定受试者测听可信度 ,统计测试结果 ,并将上述结果同受试者简易精神状态量表 (mini mentalscaleofequastionnaire ,MMSE)得分进行对照分析 ,寻找二者之间的关系。结果 受试者两耳间周围听力差异无显著性 ,以右耳听力结果 ( x±s)进行统计。AD组纯音听阈为 (2 6 3± 8 5)dBHL和 (2 9 1± 8 7)dBHL ,言语识别率为 (85 5± 5 5) % ;对照组纯音听阈为 (2 3 2± 1 0 6)dBHL和 (2 6 2± 1 1 8)dBHL ,言语识别率为 (87 6± 6 8) %。虽然AD组周围听功能检查结果低于对照组 ,但无统计学意义 (P >0 0 5)。测听可信度、声导抗和ABR阈值两组间差异无显著性 (P >0 0 5)。结论 老年性痴呆患者纯音听阈和言语识别率与老年聋相似 ,其周围听功能障碍与MMSE认知量表得分无关。  相似文献   
34.
A型肉毒毒素治疗脑中风和脑外伤后下肢痉挛的临床研究   总被引:6,自引:0,他引:6  
目的 探讨A型肉毒毒素 (botulinumtoxinA ,BTXa)能否有效、安全地治疗下肢肌痉挛 ,改善步行能力及步行速度。方法  2 7例中风、脑外伤患者 ,选择下肢肌肉局部注射国产BTXa。每个病人每次选择 3~ 5块肌肉 ,每块肌肉总的注射剂量介于 5 0~ 10 0U ,每次病人接受的注射总量小于或等于 40 0U。所有病人同时接受步态训练等康复治疗。注射前、注射后 2、4wk按改良式Ashworth量表 (ModifiedAsh worthScale ,MAS)评定肌张力 ,足印分析法 (footprintanaly sis)测量并记录步行时的时间距离参数的变化 ,研究各肌群肌张力变化与步态参数的关系。结果 整体比较 ,注射后 2wk(股直肌除外 )、4wk与注射前相比 ,各肌群肌张力降低 ,差异有显著性 (P <0 0 5 ) ,步态时间距离参数值 (T D值 )除步角外 ,各参数均有不同程度改善 (P <0 0 1或 <0 0 5 )。注射前与注射后 4wk比较 ,步长、步宽、步速差异均有显著性(P <0 0 5 )。注射后 2wk与 4wk比较 ,步长、步速有改善(P <0 0 5 )而步宽、步角变化不大。spearman相关分析表明各肌群肌张力降低与步长具有较好的相关性。结论 BTXa下肢肌肉局部注射结合步态训练 ,可以明显改善中风、脑外伤的痉挛步态 ,由此显示局部的化学去神经方法与康复训练相结合 ,可以使特定的功能改?  相似文献   
35.
BACKGROUND: It was the aim of this study to elucidate the influence of opioids on coronary vascular tone using the model of isolated porcine coronary artery segments. METHODs: We studied the effects of fentanyl (0.01, 0.1, 1.0 microg ml(-1)), alfentanil (0.1, 1.0, 10 microg ml(-1)), and sufentanil (0.01, 0.1, 1.0 microg ml(-1)) on the contractile response to three vasoconstrictors, acetylcholine, histamine and serotonin. RESULTS: Fentanyl (0.1, 1.0 microg x ml(-1)) dose-dependently attenuated the contractile response to acetylcholine, but not to histamine and serotonin. There were no differences in fentanyl's vasorelaxing potency between rings with intact and denuded endothelium. Alfentanil and sufentanil did not exert any significant influence on any of the vasoconstrictors tested. CONCLUSION: It is concluded that, in isolated porcine coronary artery rings, fentanyl at high concentrations has an attenuating effect on acetylcholine-induced contractions, which is independent of endothelial function, whereas alfentanil and sufentanil do not influence coronary vascular tone.  相似文献   
36.
听力正常成年人同时多频听觉稳态诱发反应研究   总被引:10,自引:3,他引:10  
目的 了解正常听力成人同时多频听觉稳态诱发反应的特性。方法  32名受试者 (6 4耳 ) ,年龄 2 2~ 32岁 ,平均 2 8.3岁 ,男 12名 ,女 2 0名 ,双耳纯音听阈测试各频率听阈在 2 0dB以内。以载波频率为 0 .5、1、2和 4kHz的纯音 ,调制频率分别为 77、85、93和 10 1Hz(左耳 )以及 79、87、95、10 3Hz(右耳 )的调幅声作为测试信号 ,双耳 8个频率同时给声刺激 ,同时自动判定并记录反应。各载波频率的阈值、反应幅度等数据采用SPSS统计软件分析。结果 ①同时多频听觉稳态诱发反应阈高于纯音听阈 7~ 19dB。②反应阈经双因素方差分析 (侧别×频率 ) ,左右耳之间无显著性差异 (F =1.94 2 ;μ 1,179;P =0 .16 5 ) ,但各频率之间有显著性差异 (F =31.2 5 4 ;μ 3,179;P =0 .0 0 0 ) ,各频率反应阈均值之间进一步的两两比较显示 0 .5kHz反应阈与其它频率之间存在显著性差异。③以 6 0dBSPL作为分析强度 ,男女受试者在各个频率的反应幅度的差异经双因素方差分析 (性别×频率 )有显著性差异 (F =2 .94 8;μ 3,175 ;P =0 .0 34) ,0 .5kHz反应幅度最低 ,4kHz最高。性别之间有显著性差异 (F =16 .4 90 ;μ 1,175 ;P=0 .0 0 0 ) ,男性反应幅度高于女性。④各频率不同状态下背景噪声的差异经双因素方差分析 ,提示清醒状  相似文献   
37.
 目的 探讨纯系LEW大鼠及裸小鼠膀胱灌注给药方法。方法 显微镜下解剖雌性LEW大鼠及裸小鼠尿道并根据解剖特征改造套管针。通过插入尿道的套管针膀胱灌注墨水,同时观察插管及膀胱充盈和染色情况。持续观察小鼠和大鼠生存状况及尿道损伤情况。结果 显微镜下可见雌性LEW大鼠及裸小鼠尿道与人存在明显差异。经尿道插管成功率高(100%),动物生活状况没有明显受到插管灌注影响。结论 裸鼠膀胱灌注给药治疗是一种成功率高而可行的给药手段,动物膀胱灌注化疗模型可能为研究膀胱肿瘤治疗提供更为有效的工具。  相似文献   
38.
Abstract

Objective: This study set out to provide further information on how high modulation/stimulus rates affect the auditory steady-state response (ASSR) amplitude for a 1000-Hz tone, and how this effect varies between individuals. Both sinusoidal amplitude modulated tones and tone pip stimuli were investigated. Design: Modulation/stimulus rates were 70, 80, and 90 Hz and the peak to peak stimulus levels were matched for the two different types of stimuli, at 90.5 dBSPLppe. Study sample: The study was carried out on fourteen normally-hearing adults (9 males and 5 females) Results: Overall the ASSR amplitude to the two types of stimuli was similar. In general there was an increasing response amplitude between rates of 70 and 90 Hz; The relationship between the amplitude of the response and the modulation /stimulus rate varied considerably between subjects. Conclusions: Optimum stimulus rates based on group data may not give the best rate in a significant proportion of subjects. Currently tone pip ABR is the primary method used in assessing hearing in babies. Finding a way of avoiding suboptimal stimulus rates for ‘80-Hz’ ASSR in babies will improve the likelihood of ASSR being seen as an alternative.  相似文献   
39.
Today it is possible, by the use of newly developed tests, to diagnose cases of non-organic hearing loss with reasonable certainty. Having once decided that there may be non-organic elements, it is useful to supplement routine pure-tone and speech audiometry with a neurophysiological test like an ERA by means of which the auditory threshold can be established without the patients subjective judgement. A hearing loss which is apparent by routine pure-tone audiometry, but which is not evident after ERA is almost certainly non-organic, although confirmation of this state of affairs by other reliable tests is advisable. Measurement of the acoustic reflex thresholds and delayed speech feedback tests are both useful in this respect and rarely cause any confusion, except in some cases of true hearing loss in strongly recruiting ears.  相似文献   
40.
背景 阻塞性睡眠呼吸暂停低通气综合征(OSAHS)病理改变可引起内耳和听觉系统的功能障碍,而关于OSAHS合并高脂血症对这一发生过程的影响暂无定论。目的 研究中重度OSAHS患者听觉功能检查特征及其与OSAHS、三酰甘油(TG)的相关性,并探究其可能原因。方法 选取2017年1月-2019年5月在上海交通大学医学院附属瑞金医院耳鼻咽喉科住院的中重度OSAHS患者50例,根据患者清晨空腹TG水平分为TG升高OSAHS组(25例)、TG正常OSAHS组(25例),同期选择20例健康体检者为对照组。对研究对象进行纯音听阈测定(PTA)、畸变产物耳声发射(DPOAE)检查,并记录不同频率的听阈值及信噪比(SNR),分析OSAHS患者听觉功能检查特征,探究TG是否加重听力损伤。采用Pearson相关分析探究不同频率的听阈值、SNR与OSAHS患者特征的相关性。结果 TG正常OSAHS组PTA的 2.00 、4.00 、8.00 kHz的听阈值及平均听阈值高于对照组(P<0.05),DPOAE的 4.00 kHz的SNR低于对照组(P<0.05)。TG升高OSAHS组DPOAE的1.00、2.00 、8.00 kHz的SNR低于TG正常OSAHS组(P<0.05)。PTA的0.50 kHz(r=0.227)、1.00 kHz(r=0.362)、2.00 kHz(r=0.328)、4.00 kHz(r=0.403)、8.00 kHz(r=0.463)听阈值及平均听阈值(r=0.500)与年龄呈正相关,1.00 kHz(r=0.333)、2.00 kHz(r=0.372)、4.00 kHz(r=0.464)、8.00 kHz(r=0.330)听阈值及平均听阈值(r=0.399)与呼吸暂停低通气指数(AHI)呈正相关,2 kHz(r=-0.314)听阈值与最低动脉血氧饱和度(SaO2)呈负相关,1.00 kHz(r=0.378)、2.00 kHz(r=0.444)听阈值与TG呈正相关;DPOAE的2.00 kHz(r=-0.221)、4.00 kHz(r=-0.432)、8.00 kHz(r=-0.441)的SNR与年龄呈负相关,4.00 kHz(r=-0.545)、8.00 kHz(r=-0.241)的SNR与AHI呈负相关,1.00 kHz(r=-0.507)、2.00 kHz(r=-0.385)的SNR与TG呈负相关(P<0.05)。结论 中重度OSAHS患者有不同程度的听力损伤,中重度OSAHS伴血脂升高则可加重听力损伤。OSAHS越严重,听力损伤越明显。年龄、AHI、TG水平越高,中重度OSAHS 患者的听力损伤越严重。  相似文献   
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