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41.
A new device to prevent erroneously focused shock waves to the renal parenchyma during extracorporeal shock wave lithotripsy (ESWL) has been developed; an anti-miss-shot control device (AMCD) and experiments have been conducted to evaluate its effectiveness. For shock wave generation and stone localization, piezoceramic elements (PSE) and ultrasound localization, respectively were used. After stone localization, probing ultrasounds (PU) were emmitted from the PSE towards the focal region and the reflected sound levels (RSL) were monitored by the PSE which also functioned as a microphone. A direct hit by the PU to the stone or a miss was judged from the RSL, i.e. a high RSL indicates a direct hit and a low RSL indicates a miss. Shock waves were generated only when the RSL exceeded the level which indicated a direct hit. The experimental results showed that the injury to the renal parenchyma was decreased by using the AMCD. Clinical application of the AMCD is expected to increase the safety of ESWL.This article was processed using Springer-Verlag TEX Shock Waves macro package 1990.  相似文献   
42.
目的评价冠状动脉造影的形态学特征对经皮室间隔心肌化学消融(PTSMA)术治疗肥厚型梗阻性心肌病(HOCM)的指导意义.方法选择32例药物疗效欠佳并行PTSMA手术的HOCM患者,研究其冠状动脉造影特点,并与30例年龄、性别相匹配的冠状动脉造影正常的患者(对照组)进行比较.根据定量冠状动脉造影(QCA)测定目标消融间隔支的直径,分为≤1.5mm(小间隔支组)和>1.5mm组(大间隔支组),比较两组PTSMA术前、术后心导管测量左心室流出道压差(LVOTG)的变化.结果冠状动脉造影显示HOCM组的左主干、左前降支、左回旋支及左间隔支内径均显著大于对照组(均P<0.05),HOCM组左前降支肌桥的发生率较对照组亦明显增加(P<0.05);23例消融成功,PTSMA术前、术后导管测量LVOTG分别为(85.8±31.1)、(37.25±31.9)mmHg(P<0.01),其中大间隔支组PTSMA成功率明显高于小间隔支组(P<0.05),大间隔支组LVOTG的下降程度明显大于小间隔支组(P<0.05),两组间无水乙醇用量差异无统计学意义(P>0.05).结论 HOCM患者的左前降支肌桥发生率增加,且左冠状动脉内径较粗大,尤其是左间隔支粗大;间隔支>1.5mm的HOCM患者是PTSMA手术成功的重要预测因素,这对PTSMA目标消融间隔支的选择具有重要指导意义.  相似文献   
43.
目的研究颅脑损伤后水通道蛋白4(AQP-4)在脑组织中表达的变化及其临床意义。方法对27例颅脑损伤患者行开颅手术,将术中取得的挫伤水肿脑组织(损伤组)和颞极减压获得的相对正常脑组织(对照组)进行AQP-4的免疫组化和re-al- time PCR检测。结果损伤组各时点挫伤水肿脑组织AQP-4的表达量均明显高于对照组(均P<0.05);损伤24h后周围水肿脑组织中的AQP-4表达量显著升高。结论颅脑损伤后脑水肿的形成和发展与AQP-4的异常表达密切相关。  相似文献   
44.

Objective

To determine the accuracy of magnetic resonance spectroscopy (MRS), perfusion MR imaging (MRP), or volume modeling in distinguishing tumor progression from radiation injury following radiotherapy for brain metastasis.

Methods

Twenty-six patients with 33 intra-axial metastatic lesions who underwent MRS (n=41) with or without MRP (n=32) after cranial irradiation were retrospectively studied. The final diagnosis was based on histopathology (n=4) or magnetic resonance imaging (MRI) follow-up with clinical correlation (n=29). Cho/Cr (choline/creatinine), Cho/NAA (choline/N-acetylaspartate), Cho/nCho (choline/contralateral normal brain choline) ratios were retrospectively calculated for the multi-voxel MRS. Relative cerebral blood volume (rCBV), relative peak height (rPH) and percentage of signal-intensity recovery (PSR) were also retrospectively derived for the MRPs. Tumor volumes were determined using manual segmentation method and analyzed using different volume progression modeling. Different ratios or models were tested and plotted on the receiver operating characteristic curve (ROC), with their performances quantified as area under the ROC curve (AUC). MRI follow-up time was calculated from the date of initial radiotherapy until the last MRI or the last MRI before surgical diagnosis.

Results

Median MRI follow-up was 16 months (range: 2-33). Thirty percent of lesions (n=10) were determined to be radiation injury; 70% (n=23) were determined to be tumor progression. For the MRS, Cho/nCho had the best performance (AUC of 0.612), and Cho/nCho >1.2 had 33% sensitivity and 100% specificity in predicting tumor progression. For the MRP, rCBV had the best performance (AUC of 0.802), and rCBV >2 had 56% sensitivity and 100% specificity. The best volume model was percent increase (AUC of 0.891); 65% tumor volume increase had 100% sensitivity and 80% specificity.

Conclusion

Cho/nCho of MRS, rCBV of MRP, and percent increase of MRI volume modeling provide the best discrimination of intra-axial metastatic tumor progression from radiation injury for their respective modalities. Cho/nCho and rCBV appear to have high specificities but low sensitivities. In contrast, percent volume increase of 65% can be a highly sensitive and moderately specific predictor for tumor progression after radiotherapy. Future incorporation of 65% volume increase as a pretest selection criterion may compensate for the low sensitivities of MRS and MRP.  相似文献   
45.
紫心甘薯多糖对四氯化碳肝损伤小鼠的保护作用   总被引:3,自引:0,他引:3       下载免费PDF全文
研究紫心甘薯多糖对四氯化碳(CCl4)诱导小鼠免疫性肝损伤的保护作用及可能作用机制.以不同剂量的紫心甘薯多糖200、400、800 mg.(kg.d)-1分别给予小鼠灌胃,设立对照组,连续10 d作预处理,腹腔注射0.1%的CCl410 ml.kg-1建立CCl4诱导小鼠肝损伤模型.测定血清谷丙转氨酶(ALT)、谷草转氨酶(AST)、乳酸脱氢酶(LDH)酶活力、总胆红素(TBIL)、总蛋白(TP)含量,测定肝组织中超氧化物岐化酶(SOD)、谷胱甘肽(GSH)、丙二醛(MDA)水平,并进一步观察肝组织病理组织学变化.紫心甘薯多糖各剂量组均能明显地抑制血清中ALT、AST、LDH、TBIL的升高和TP的下降,降低肝脏中MDA的含量,提高肝组织中SOD和GSH活性,减轻CCl4对肝脏细胞的病理损伤.紫心甘薯多糖对CCl4致小鼠急性肝损伤具有明显保护作用,其作用机理可能与抗氧化作用有关.  相似文献   
46.

Purpose

The purposes of this study were to evaluate the reproducibility for measuring the cold pressor test (CPT)-induced myocardial blood flow (MBF) alteration using phase-contrast (PC) cine MRI, and to determine if this approach could detect altered MBF response to CPT in smokers.

Materials and methods

After obtaining informed consent, ten healthy male non-smokers (mean age: 28 ± 5 years) and ten age-matched male smokers (smoking duration ≥ 5 years, mean age: 28 ± 3 years) were examined in this institutional review board approved study. Breath-hold PC cine MR images of the coronary sinus were obtained with a 3 T MR imager with 32 channel coils at rest and during a CPT performed after immersing one foot in ice water. MBF was calculated as coronary sinus flow divided by the left ventricular (LV) mass which was given as a total LV myocardial volume measured on cine MRI multiplied by the specific gravity (1.05 g/mL).

Results

In non-smokers, MBF was 0.86 ± 0.25 mL/min/g at rest, with a significant increase to 1.20 ± 0.36 mL/min/g seen during CPT (percentage change of MBF (?MBF (%)); 39.2% ± 14.4%, p < 0.001). Inter-study reproducibility for ?MBF (%) measurements by different MR technologist was good, as indicated by the intraclass correlation coefficient of 0.93 and reproducibility coefficient of 10.5%. There was no significant difference between smokers and non-smokers for resting MBF (0.85 ± 0.32 mL/min/g, p = 0.91). However, ?MBF (%) in smokers was significantly reduced (-4.0 ± 32.2% vs. 39.2 ± 14.4%, p = 0.011).

Conclusion

PC cine MRI can be used to reproducibly quantify MBF response to CPT and to detect impaired flow response in smokers. This MR approach may be useful for monitoring the sequential change of coronary blood flow in various potentially pathologic conditions and for investigating its relationship with cardiovascular risk.  相似文献   
47.
Point-of-care testing (POCT) in patients with ischemic heart disease is driven by the time-critical need for fast, specific, and accurate results to initiate therapy instantly. According to current guidelines, the results of the cardiac marker testing should be available to the physician within 30 min (“vein-to-brain” time) to initiate therapy within 60–90 min (“door-to-needle” time) after the patient has arrived at the emergency room or intensive care unit. This article reviews the current efforts to meet this goal (1) by implementing POCT of established biochemical markers such as cardiac troponins, creatine kinase MB, and myoglobin, in accelerated diagnosis and management workflow schemes, (2) by improving current POCT methods to obtain more accurate, more specific, and even faster tests through the integration of optical and electrochemical sensor technology, and (3) by identifying new markers for the very early and sensitive detection of myocardial ischemia and necrosis. Furthermore, the specific requirements for cardiac POCT in regard to analytical performance, comparability, and diagnostic sensitivity/specificity are discussed. For the future, the integration of new immunooptical and electrochemical chip technology might speed up diagnosis even further. However, every new development will have to meet the stringent method validation criteria set for corresponding central laboratory testing.  相似文献   
48.
NHE1(Na+/H+交换器1)抑制剂对于心肌缺血再灌注损伤具有较好的保护作用.以苯(或吡啶)甲酰胍为母核,利用拼合原理,在苯(或吡啶)甲酰胍母环上引入4-(2,3,4-三甲氧基苄基)哌嗪-1-甲基,设计并合成了8个未见文献报道的目标化合物.其结构经MS,IR,1H NMR和元素分析确证.体外血小板肿胀模型(PSA)试验结果表明,大部分目标化合物显示出较好的NHE1抑制活性.  相似文献   
49.
《Analytical letters》2012,45(4):735-744
Heart-type fatty acid-binding protein (H-FABP) is a small cytosolic protein abundant in heart muscle cells. It offers great potential as a sensitive biomarker for early diagnosis of acute myocardial infarction (AMI).

Ninety-one patients presented to the Emergency Department suspected of AMI with a median symptom onset of 6 h (IQR 3–20 h), of which 75 (82.4%) had AMI. The diagnostic performance of a point-of-care immunotest for H-FABP was compared with those of cardiac troponin T (cTnT), creatinine kinase MB (CK-MB), and myoglobin. The H-FABP immunotest was found to have a significant better sensitivity than the other markers and a better specificity than myoglobin and CK-MB. The H-FABP Immunotest gave the greatest area under the receiver operating characteristic (ROC) curve (0.864) for those admitted within 6 h after the onset of symptoms; whereas, cTnT gave the greatest area under the ROC curve (0.936) for those admitted 6–24 h. The H-FABP was also found to be the most efficient marker to diagnose patients suspected of AMI without ST-elevation and with a negative cTnT.

Early detection of H-FABP using the point-of-care immunotest in patients suspected of AMI may allow more accurate targeting of appropriate therapy and considerable cost savings than the current diagnostic tests.  相似文献   
50.
为探讨急性心肌梗死患者D-二聚体、肌钙蛋白及心肌酶谱联合检测的临床意义,选择30例健康者(对照组)和100例患者(病例组)进行D-二聚体、肌钙蛋白及心肌酶谱(AST、LDH、CK、CK-MB)检测,并把100例患者(病例组)分为3组,分别为36例AMI组,34例不稳定型心绞痛(UAP)组,30例稳定型心绞痛(SAP)组。结果表明,AMI组及UAP组中D-二聚体、肌钙蛋白及心肌酶谱(AST、LDH、CK、CK—MB)的升高程度较SAP组和健康对照组显著增高(P〈0.05);AMI组肌钙蛋白(cTnT)较UAP组明显增高(P〈0.05);UAP组肌钙蛋白(cTnT)较对照组明显增高(P〈0.05);D-二聚体、肌钙蛋白及心肌酶谱(AST、LDH、CK、CK—MB)的升高程度与心肌梗死的面积正相关(P〈0.01)。提示D-二聚体、肌钙蛋白及心肌酶谱(AST、LDH、CK、CK—MB)联合检测有助于急性心肌梗死诊断的提高。  相似文献   
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