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1.
运用酶组织化学方法结合计算机图像分析,对自发性高血压大鼠(SHR)和正常血压的SD大鼠在大脑中动脉迅速阻断之后皮质细胞的代谢变化进行了比较观察。实验结果显示在缺血15min,皮质细胞的细胞色素C氧化酶(CCO)和乳酸脱氢酶(LDH)的活性即已发生变化,而且随缺血时间的延长而更加明显,SHR酶活性的变化更为显著,提示SHR皮质细胞对缺血缺氧更为敏感。  相似文献   

2.
扩散性抑制对脑缺血后海马迟发性神经元死亡的影响   总被引:3,自引:0,他引:3  
目的为了研究阻断大鼠局灶性脑缺血诱导的扩散性抑制对同侧海马迟发性神经元死亡的影响。方法颈内动脉插线法制备大鼠大脑中动脉缺血再灌注模型,采用电生理学方法记录扩散性抑制波,尼氏染色和TUNEL染色检测海马迟发性神经元死亡;观察阻断局灶性脑缺血再灌注诱导的扩散性抑制对海马迟发性神经元死亡的影响。结果不给予SD阻断剂,大脑中动脉缺血模型有39%的动物出现海马迟发性神经元死亡;用MK-801阻断扩散性抑制后仅10%的动物出现海马迟发性神经元死亡,机率明显减小。结论局灶性脑缺血引起的海马迟发性神经元死亡可能与扩散性抑制由缺血区不断向远隔部位播散有关。  相似文献   

3.
QS激光治疗面部雀斑临床疗效观察   总被引:2,自引:0,他引:2  
用QSND YAG倍频532nm及QS翠绿宝石755nm波长激光一次治疗面部雀斑。研究:观察哪些波长组合及用何方法在临床应用既能达到美容效果、又能缩短疗程、节约费用。在将近选患者面部色素密度均匀部位分左、中、右区域进行治疗观察后,发现:(1)QS532nm治疗组6个月疗效达40.5%(P〈0.05),(2)QS755nm治疗组6个月疗效达12%(P〈0.05),(3)QS532nm+QS75nm治疗组疗效达72%(P〈0.01)。说明采用两种波长激光同时复合治疗疗效好,而且起到了美容效果,临床值得推广。  相似文献   

4.
目的:应用人外周血单个核细胞移植治疗新生大鼠缺血缺氧性脑病,探讨干细胞移植治疗神经系统损伤性疾病的有效性和安全性。方法:7 d龄SD大鼠随机分为3组(n=12),即正常组、手术组、细胞移植组;在征得同意的情况下利用粒细胞集落刺激因子(G-CSF)对捐献者的外周血进行动员,采用血细胞分离仪分离外周血单个核细胞,并进行鉴定及荧光标记;通过尾静脉注射的方法将标记细胞植入经免疫抑制剂处理的大鼠体内,利用HE染色法观察模型建立后大鼠大脑的损伤情况,利用荧光显微镜观察移植细胞在宿主体内的存活、迁移及分化情况,利用斜板实验明确细胞移植对宿主神经功能损伤情况的影响。结果:移植细胞可在宿主脑内存活,向损伤部位迁移,细胞移植可显著改善缺血缺氧引发的大脑功能损伤;细胞移植后,动物未现不良反应。结论:外周血单个核细胞移植治疗中枢系统损伤性疾病具有较高的安全性与有效性,有望成为一种临床治疗方案。  相似文献   

5.
桐麦间作系统辐射光谱成分变化规律的研究   总被引:7,自引:0,他引:7  
对系统内对外太阳辐射的3个波段:紫外辐射(UVR300-400nm),光合有效辐射(PAR400-700nm)和近红外辐射(NIR700-1100nm)进行了分析,对比研究表明,试验期间系统内的光谱成分UVR:PAR:NIR:为5.2:48.2:46.6,系统外对照区为5.1:52.4:42.5。其中,小麦开花期系统内外分别为5.2:51.5:43.2和5.0:51.9:43.1,小麦灌浆期分别为  相似文献   

6.
目的观察局灶性脑缺血后缺血边缘区海马和皮层NG2细胞的动态表达,探讨其在脑缺血神经损伤与修复过程中所起的作用。方法将大鼠随机分为假手术组(sham)和脑缺血再灌注组,脑缺血再灌注组采用线栓法制备大鼠大脑中动脉阻塞再灌流模型(MCAO),假手术组不插入线栓,采用免疫荧光组织化学法结合共聚焦显微镜成像观察sham组及脑缺血后3d,7d,30d不同时间点缺血边缘区的海马CA1区和皮层区NG2的动态表达情况。结果脑缺血再灌注后缺血边缘区海马和皮层NG2胶质细胞表达增加,缺血后7d最明显。结论脑缺血后缺血边缘区存在NG2细胞的增生和形态变化可能与脑缺血后损伤修复密切相关。  相似文献   

7.
内源性阿片物质参与大鼠缺血预处理的心肌保护作用   总被引:13,自引:2,他引:11  
Fu LL  Xia Q  Shen YL  Wong TM 《生理学报》1998,50(6):603-610
实验以离体灌流的SD大鼠心脏为模型,用k特异性拮抗剂的MR2266研究k阿片受体的阻断与缺血预处理的关系,用放射免疫分析法研究IP及长时间缺血对心肌强啡肽A1-13浓度的影响,探索K阿片物质在IP过程中的作用和地位。  相似文献   

8.
目的 观察局灶性脑缺血后海马和缺血边缘区星形胶质细胞过度增殖对微循环的影响。方法将大鼠随机分为假手术组、缺血组和干预组,缺血组和干预组采用线栓法制备大脑中动脉栓塞模型,缺血组侧脑室采用ALZET微渗透泵给予0.2%DMSO,干预组给予细胞周期抑制剂roscovitine,假手术组不插入线栓,不给与任何药物干预。缺血7d后于股静脉注入FITC标记的葡聚糖标记血管,小鼠抗大鼠单克隆抗胶质纤维酸性蛋白(glial fibrillary acidic protein,GFAP)抗体标记星形胶质细胞;激光共聚焦三维成像显示胶质细胞于微循环之间的关系。结果缺血同侧海马和缺血边缘区在GFAP阳性细胞增多的同时,局部微血管血流灌注明显减少,应用细胞周期抑制剂roscovitine抑制星形胶质细胞增生可以明显增加局部微血管的血流灌注。结论脑缺血后缺血边缘区和海马的反应性星形胶质细胞增生与微循环灌注减少密切相关。  相似文献   

9.
当归注射液对脑缺血/再灌注神经元代谢物的影响   总被引:6,自引:1,他引:5  
目的:研究当归注射液对脑缺血/再灌注时神经元代谢物及血流速度的作用,阐明当归对脑缺血损伤神经修复过程的影响。方法:雄性SD大鼠69只,体重150~170g,随机分成假手术组(n=4)、缺血损伤组(n=30)和当归治疗组(n=35)。制作右大脑中动脉血供阻断(MCA0)模型。缺血2h后,当归治疗组立即腹腔注射当归注射液(5g/kgbw)。在再灌注后3~4h和5~6h,以磁共振成像(MRI)技术研究大脑T2加权成像(T2WI)和局域质子谱(^1H MRS)的变化,观察当归对成像和神经元代谢物N-乙酰天门冬氨酸(NAA)、肌酸/磷酸肌酸(Cr/PCr)和胆碱(Cho)的影响。激光多普勒血流仪观察当归注射液对血流速度的影响,测定脑表面血管密度。结果:与缺血损伤组比较,当归治疗组的高信号强度区信号减弱、体积小,NAA值大,Cr/NAA和Cho/NAA比值小,再灌注时的血流速度显著加快,单位面积内的血管长度增加。结论:当归注射液加快缺血脑组织的血液循环,改善神经元的代谢。  相似文献   

10.
大鼠视网膜缺血后一氧化氮合酶阳性神经元的变化   总被引:3,自引:2,他引:1  
本文用前房加压灌注视网膜缺血模型、β-NADPH脱氢酶组化方法研究了SD大鼠视网膜内含一氧化氮合酶(NOS)神经元的分布及其变化。实验动物依缺血时间分四组,分别为缺血10min、15min、30min及60min组。将NOS阳性细胞进行计数统计,做自身配对t检验及方差分析。实验结果表明正常及缺血视网膜NOS阳性神经元。大多数位于内核层,少数位于节细胞层;NOS阳性细胞在视网膜中央区密度高于周边区,而各象限的平均密度分布无明显差别。缺血15min后内核层的NOS阳性细胞开始减少,随缺血时间的延长细胞减少更为明显。各组均以视网膜中央区变化较为显著,提示视网膜缺血15min后即可出现神经生物学变化,视网膜中央区对缺血比周围区更为敏感。  相似文献   

11.
nm23、EGFR和Bcl-2蛋白在肺癌组织中的表达及临床意义   总被引:1,自引:1,他引:0  
目的:观察nm23、EGFR和Bcl-2在人肺癌中的表达,探讨其与肺癌临床生物学行为的关系。方法:采用免疫组化检测了49例肺癌及癌旁组织中nm23、EGFR和Bcl-2蛋白的表达情况,并对其与肺癌临床生物学行为进行相关分析。结果:在49例肺癌中,EGFR和Bel-2蛋白的阳性表达率分别为51.0%和34.7%,均高于正常肺组织17.5%和12.5%(p<0.05),nm23蛋白的阳性表达率为55.1%,则显著低于正常肺组织87.5%(p<0.01)。在病理分级的高一中分化、低分化和未分化中nm23的阳性表达率分别为82.6%、41.2%和11.1%(p<0.01)。EGFR在非小细胞肺癌(NSCLC)组为61.5%,在小细胞肺癌(SCLC)组为10.0%(p<0.01)。在NSCLC TNM分期中,Ⅰ期 Ⅱ期与Ⅲ P<0.01)期中EGFR的阳性表达率分别为39.3%和81.8%(p<0.01);病理分级的高-中分化和低分化中EGFR的阳性表达率分别为39.1%和88.2%(p<0.01);在淋巴结转移组为57.9%,无淋巴结转移组为27.3%(p<0.05)。Bcl-2的阳性表达率在NSCLC组为25.6%,在SCLC组为70%,统计学分析差异有统计学意义(p<0.01);在NSCLC组病理分级的高分化、中分化和低分化中Bcl-2阳性表达率分别为62.5%、26.7%和5.89%(p<0.01)。结论:癌基因EGFR、凋亡抑制基因Bcl-2与抑癌基因nm23在肺癌的发生、发展中存在着相互促进作用。  相似文献   

12.
2009-2013年测量了中国11个汉语方言族群26954例汉族人的身高、体重值,计算了身体质量指数(I_(bm)),将汉族人的I_(bm)与经度、纬度进行相关分析。研究结果表明:总的说来,随年龄增长,11个方言族群I_(bm)值均呈线性增大,并且年龄组间差异均具有统计学意义。11个族群中,北方话族群I_(bm)值明显大于南方各族群。乡村男性(r=0.671; p0.05)、城市女性(r=0.043; p=0.820>0.05)I_(bm)与经度无相关。按照I_(bm)均数大于24.0、I_(bm)均数在23.1~24.0之间、I_(bm)均数小于23.0,可以将中国方言族群分成3个层次,中国北方话族群均分布在第1、2层次,南方族群主要分布在第2、3层次,也就是说11个族群大致按照纬度高低顺序依次分布在第1、2、3层次。遗传、环境、饮食、劳作强度等因素都不同程度影响身高、体重,也影响中国人的I_(bm)值。  相似文献   

13.
本文报道了昆明市8148例儿童恒牙(第三磨牙除外)萌出时间的横断面调查,对恒牙萌出与年龄、身高、体重和月经初潮的关系进行了探讨。经相关分析,恒牙萌出数与年龄高度相关,与身高和体重低度相关,并建立了由年龄、身高或体重推算萌牙数的回归方程。还发现恒牙萌出与青少年性成熟也有一定的联系。提示恒牙萌出也能反映儿童的生长发育状况,故可作为衡量儿童生长发育的一项指标。  相似文献   

14.
以全自动生化分析仪测定结果为参考值,采用傅利叶变换近红外透射光谱技术,结合偏最小二乘法,建立人血清中胆固醇和甘油三酯的定标模型。利用内部交叉验证和自动优化功能对预测模型进行了优化,确定了最优建模参数。模型对人血清中胆固醇和甘油三酯定标样品集的预测值与参考值的相关系数r分别为0.9011、0.9593,预测校正标准误RMSECV分别为15.0mg/dL,21.6mg/dL。表明利用近红外光谱分析技术实现血清中胆固醇和甘油三酯快速检测是可行的。  相似文献   

15.
A study was undertaken to examine a range of sample preparation and near infrared reflectance spectroscopy (NIRS) methodologies, using undried samples, for predicting organic matter digestibility (OMD g kg−1) and ad libitum intake (g kg−1 W0.75) of grass silages. A total of eight sample preparation/NIRS scanning methods were examined involving three extents of silage comminution, two liquid extracts and scanning via either external probe (1100-2200 nm) or internal cell (1100-2500 nm). The spectral data (log 1/R) for each of eight methods were examined by three regression techniques each with a range of data transformations. The 136 silages used in the study were obtained from farms across Northern Ireland, over a two year period, and had in vivo OMD (sheep) and ad libitum intake (cattle) determined under uniform conditions. In the comparisons of the eight sample preparation/scanning methods, and the differing mathematical treatments of the spectral data, the sample population was divided into calibration (n = 91) and validation (n = 45) sets. The standard error of performance (SEP) on the validation set was used in comparisons of prediction accuracy. Across all 8 sample preparation/scanning methods, the modified partial least squares (MPLS) technique, generally minimized SEP's for both OMD and intake. The accuracy of prediction also increased with degree of comminution of the forage and with scanning by internal cell rather than external probe. The system providing the lowest SEP used the MPLS regression technique on spectra from the finely milled material scanned through the internal cell. This resulted in SEP and R2 (variance accounted for in validation set) values of 24 (g/kg OM) and 0.88 (OMD) and 5.37 (g/kg W0.75) and 0.77 (intake) respectively. These data indicate that with appropriate techniques NIRS scanning of undried samples of grass silage can produce predictions of intake and digestibility with accuracies similar to those achieved previously using NIRS with dried samples.  相似文献   

16.
泰山丛枝菌根真菌群落结构特征   总被引:12,自引:1,他引:12  
2007年对泰山植被根围内丛枝菌根(arbuscular mycorrhiza,AM)真菌群落组成、数量、分布及其与植物多样性的关系进行了研究。从泰山傲徕峰、黑龙潭库区等样地共分离出4属16种AM真菌:球囊霉属Glomus 9种、无梗囊霉属Acaulospora 4种、巨孢囊霉属Gigaspora 2种和盾巨孢囊霉属Scutellospora1种。其中,球囊霉属Glomus及聚球囊霉Glomus fasciculatum的孢子密度、相对多度、分布频度和重要值均最高,分别为泰山植被区根围内AM真菌优势属和优势种。各样地之间Sorenson相似系数在0.60和0.85之间。植被数量与孢子密度(r=0.80,p0.01)、植物种的丰富度与AM真菌种的丰富度(r=0.77,p0.01)以及与孢子密度(r=0.59,p0.01)均呈极显著正相关关系。研究结果表明植物多样性对于提高AM真菌多样性发挥极为重要的作用。  相似文献   

17.

Background

Although Monte Carlo simulations of light propagation in full segmented three-dimensional MRI based anatomical models of the human head have been reported in many articles. To our knowledge, there is no patient-oriented simulation for individualized calibration with NIRS measurement. Thus, we offer an approach for brain modeling based on image segmentation process with in vivo MRI T1 three-dimensional image to investigate the individualized calibration for NIRS measurement with Monte Carlo simulation.

Methods

In this study, an individualized brain is modeled based on in vivo MRI 3D image as five layers structure. The behavior of photon migration was studied for this individualized brain detections based on three-dimensional time-resolved Monte Carlo algorithm. During the Monte Carlo iteration, all photon paths were traced with various source-detector separations for characterization of brain structure to provide helpful information for individualized design of NIRS system.

Results

Our results indicate that the patient-oriented simulation can provide significant characteristics on the optimal choice of source-detector separation within 3.3 cm of individualized design in this case. Significant distortions were observed around the cerebral cortex folding. The spatial sensitivity profile penetrated deeper to the brain in the case of expanded CSF. This finding suggests that the optical method may provide not only functional signal from brain activation but also structural information of brain atrophy with the expanded CSF layer. The proposed modeling method also provides multi-wavelength for NIRS simulation to approach the practical NIRS measurement.

Conclusions

In this study, the three-dimensional time-resolved brain modeling method approaches the realistic human brain that provides useful information for NIRS systematic design and calibration for individualized case with prior MRI data.  相似文献   

18.
Previous studies show that transient increases in both blood flow and magnetic resonance image signal intensity (SI) occur in human muscle after brief, single contractions, and that the SI increases are threefold larger in physically active compared with sedentary subjects. This study examined the relationship between these transient changes by measuring anterior tibial artery flow (Doppler ultrasound), anterior muscle SI (3T, one-shot echo-planar images, TR/TE = 1,000/35), and muscle blood volume and hemoglobin saturation [near-infrared spectroscopy (NIRS)] in the same subjects after 1-s-duration maximum isometric ankle dorsiflexion contractions. Arterial flow increased to a peak 5.9 ± 0.7-fold above rest (SE, n = 11, range 2.6-10.2) within 7 s and muscle SI increased to a peak 2.7 ± 0.6% (range 0.0-6.0%) above rest within 12 s after the contractions. The peak postcontractile SI change was significantly correlated with both peak postcontractile flow (r = 0.61, n = 11) and with subject activity level (r = 0.63, n = 10) estimated from 7-day accelerometer recordings. In a subset of 7 subjects in which NIRS data acquisition was successful, the peak magnitude of the postcontractile SI change agreed well with SI calculated from the NIRS blood volume and saturation changes (r = 0.80, slope = 1.02, intercept = 0.16), confirming the blood-oxygenation-level-dependent (BOLD) mechanism underlying the SI change. The magnitudes of postcontractile changes in blood saturation and SI were reproduced by a simple one-compartment muscle vascular model that incorporated the observed pattern of postcontractile flow, and which assumed muscle O(2) consumption peaks within 2 s after a brief contraction. The results show that muscle postcontractile BOLD SI changes depend critically on the balance between O(2) delivery and O(2) consumption, both of which can be altered by chronic physical activity.  相似文献   

19.
近红外光谱分析法测定东北黑土有机碳和全氮含量   总被引:3,自引:0,他引:3  
以我国东北黑土为研究对象,分析了2004-2005年采集的136个土壤样品在3699~12000 cm-1范围的近红外光谱,利用偏最小二乘法建立了原始光谱吸光度与土壤有机碳、全氮和碳氮比之间的定量分析模型.结果表明:土壤有机碳和全氮的模型拟合效果良好,决定系数R2分别为0.92和0.91(P<0.001),相对分析误差RPD分别为3.45和3.36,利用该模型对验证样本土壤有机碳和全氮的预测值与实测值之间的相关系数分别为0.94和0.93(P<0.001),表明可以用近红外光谱分析法对黑土有机碳和全氮含量进行测定.但是利用近红外光谱分析法对土壤碳氮比的预测并不理想,虽然验证样本集黑土碳氮比模型预测值与实测值呈显著相关(r=0.74,P<0.001),但是校正模型的R2为0.61,RPD仅为1.61,建立的模型不能对黑土碳氮比做出合理的估测.  相似文献   

20.
The increasing recognition of the considerable intraspecific spatial and temporal variability in the nutritional contents of primate foods has necessitated development of fast and cost-effective analytical methods. Used widely for agricultural products, near-infrared reflectance spectroscopy (NIRS) is a quick, inexpensive means of assessing nutritional chemistry. The general principle of NIRS is that when the sample is irradiated with near-infrared light, the reflectance spectrum is characteristic of the mixture of chemical bonds present in the sample. These spectra, when calibrated against reference values—determined via traditional nutritional analysis—to develop regression equations, can be used to estimate nutritional values of similar samples without doing traditional nutritional analysis. We validated the use of NIRS for estimating the nutritional attributes of African herbs and trees, which were foods eaten by mountain gorillas (Gorilla beringei) collected as part of a larger study on gorilla nutritional ecology. We determined the near-infrared spectra (1100–2400 nm) of 241 dried samples of 13 species of tropical herbs and trees that formed the staple diet of the gorillas. We used modified partial least-squares regression to develop calibration equations that could predict nutritional attributes of gorilla foods, and we performed an independent validation of the calibrations. The equations had robust predictive power similar to those used in agricultural and ecology, and we found no differences between samples measured via NIRS and traditional nutritional analysis. Our analysis indicates that NIRS offers a rapid and cost-effective means of analysis of tropical leaves and herbs, and has the potential to transform primate feeding ecology studies by allowing us to evaluate the importance of intraspecific variation in nutritional value.  相似文献   

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