血液涂片Wright染色法的改进

血涂片是医学生认识正常及病理血细胞的重要标本。因此 ,制作精良的血涂片必须 :一是要有好的材料 ,包括染料等 ;二是要掌握血涂片的染色技术 ,现简述如下 :1 .取血　按常规取无名指血一滴 ,放在洁净的载玻片上 ,立即盖上盖玻片 ,待血液散开后 ,推开盖玻片。放在灯泡玻板上凉干。2 .染色　先在干血涂片两端用玻璃蜡笔划线 ,然后放在染片架上 ,并滴 Wright染液 ,加盖染色 3min,之后加等量的 p H6 .4磷酸缓冲液染色 5 min。3.打气　在加入磷酸缓冲液后要不断的吹气。染色结果 ,用蒸馏水将血涂片上的染料冲洗干净。凉干 ,用香柏油封片。4.结果…     

正常成人圆孔骨性通道相关参数的多层螺旋CT研究

目的 探讨MSCT测量圆孔骨性通道相关参数的数值范围。方法 回顾性分析2014年1月1日—2014年8月20日在南通市第一人民医院行头颅、鼻窦和眼眶MSCT检查的152例非外伤性患者的临床资料。其中男80例,年龄16～89岁;女72例,年龄17～79岁。所有患者行MSCT扫描,从冠状面、横断面、矢状面上显示152例304侧圆孔骨性通道,在MSCT图像上测量圆孔的深径D、圆孔中轴线与翼腭窝中轴线的夹角B、两侧圆孔中点连线与圆孔中轴线的夹角A₁、同侧圆孔中轴线与翼腭窝中轴线的夹角A₂、同侧圆孔外口外侧和内口内侧连线与翼腭窝中轴线的夹角A₃。对比相同性别不同侧别间及同一侧别不同性别间圆孔骨性通道的相关参数,计算测量数据的变异系数(CV) 和测量者个体间的CV,并采用组间相关系数(ICC)分析各测量参数的可信度。结果 MSCT能够清晰显示152例304侧圆孔的形态、大小及走行,图像质量良好。圆孔深径D值为(4.76±1.61) mm,角B、A₁、A₂、A₃分别为93.13°±8.68°、87.78°±8.64°、134.49°±8.63°、160.16°±8.22°。相同性别不同侧别间比较:角A₁右侧均大于左侧,差异均有统计学意义(P值均＜0.05);而圆孔深径D和角B、A₂、A₃右侧和左侧间差异均无统计学意义(P值均＞0.05)。同一侧别不同性别间比较:圆孔深径D和角A₁、A₂、A₃ 、B在男性、女性间差异均无统计学意义(P值均＞0.05)。D、 B、 A₁、A₂、A₃的CV范围分别为31.58%～37.14%、8.15%～9.78%、8.35%～9.94%、5.50%～6.74%、4.43%～5.59%;测量者间的CV分别为20.63%～21.54%、9.13%～9.16%、2.54%～3.77%、2.00%～2.59%、1.58%～2.69%。角B测量可信度为较好,圆孔深径D和角A₁、A₂、A₃的测量可信度为极佳。结论 在MSCT图像上对圆孔骨性通道进行测量,其结果稳定、可靠,可以为临床应用提供参考依据。     

基于数学形态学的血液细胞图像边缘提取

根据血液细胞边缘附近的灰度分布梯度较大的特性,运用数学形态学对缺铁性贫血的血涂片上的血细胞进行图像的边缘提取.并对原始图像分别用Sobel算子、Laplacian算子、LOG算子以及局部阈值法进行边缘检测,实验结果表明,基于数学形态学的边缘提取算法对于血液细胞图像边缘提取有很好的效果.     

MR横向弛豫时间测定技术对激素诱导兔股骨头缺血坏死模型的定量影像分析

目的 定量研究兔激素性股骨头坏死模型(SANFH)MR横向弛豫时间在造模不同时相的变化规律,探讨所反映的骨髓组分及微结构变化。方法 健康成年纯种新西兰大白兔60只,采用随机区组抽样方法分为空白对照(8只)及造模2、4、6、8周组(各13只)。制作模具小管并行MR T₂ mapping序列MR扫描,评价所得参数即T₂值的稳定性。参照Yamamoto的方法对模型组进行造模处理。造模开始前对空白对照组进行MR扫描,各模型组分别在造模后满2、4、6、8周时行MR扫描,将横向弛豫原始图像数据传至GE AW4.2工作站进行后处理,计算各像素T₂、T₂*值,创建相应参数的彩色编码图,对股骨头区、骺下区及髓腔骺端进行测量域感兴趣区的特征参数值;扫描完成后将实验动物处死,切取股骨头进行组织形态学检查。结果 剔除实验期间死亡动物及无效图像资料,MR检查并获得有效数据的空白对照及造模2、4、6、8周组实际样本量分别为8只(16髋)、10只(20髋)、9只(18髋)、9只(18髋)、10只(20髋)。各模型组及空白对照组T₂值(F=51.601, P＜0.01)、T₂*值(F=36.889, P＜0.01)组间总体差异有统计学意义。造模各组T₂、T₂*值均低于空白对照组,造模早期(2周)出现明显下降,4周降至最低,6、8周出现部分恢复;各解剖区域间T₂(F=86.274, P＜0.01)、T₂*(F=53.172, P＜0.01)值差异有统计学意义;股骨头区T₂、T₂*值高于骺下区及髓腔骺端,骺下区高于髓腔骺端(P值均＜0.05)。组织形态学变化:造模早期表现为骨髓造血细胞减少及脂肪细胞增生,髓内微血管血栓及出血,4周最为显著,之后出现骨组织坏死,骨小梁变细、部分消失,间质反应(充血、水肿、出血)及纤维化。结论 MR横向弛豫时间可敏感地反映SANFH模型骨髓组分及骨小梁微结构特征性改变,为此病早期诊断及病程监控提供了重要的定量影像学方法。     

自体血液回输对成人心脏瓣膜置换术患者血液携氧功能的影响

目的 探讨自体血回输对体外循环下心瓣膜置换术患者血液携氧功能的影响。方法抽选河南省胸科医院心外科2014年4月—2016 年1月收治的90例首次接受心脏手术的心脏瓣膜病患者作为研究对象,随机分为观察组和对照组。观察组45例采用自体血液回收技术;对照组45例不采用自体血液回收技术,直接使用库血。检测并比较两组术前(T₁)、术毕(T₂)、术后24 h(T₃)、术后第7天(T₄)的动脉血液携氧功能指标,包括RBC、Hb、红细胞比容(Hct)、氧合指数、红细胞内2,3-二磷酸甘油酸浓度(2,3-DPG) 、红细胞变形指数(RCD)。结果 观察组与对照组在T₂时点的RBC分别为(3.59±0.37)×10¹²/L和(3.64±0.44)×10¹²/L,Hb分别为(101.26±19.54)g/L和(102.38±20.05)g/L,Hct分别为(0.35±0.12)和(0.34±0.13),较组内T₁降低,差异均有统计学意义(P值均＜0.05);但T₃和T₄与组内T₁时点比较,差异均无统计学意义(P值均>0.05),且组间各时点比较差异均无统计学意义(P值均>0.05)。观察组在T₁~T₄的氧合指数分别为(415.14±51.24)、(348.33±39.45)、(317.59±33.36)和(377.16±45.44) mmHg(1 mmHg=0.133 kPa),对照组则分别为(418.16±52.18)、(344.44±42.20)、(320.65±35.11)和(375.24±43.94) mmHg,组间各时点比较差异均无统计学意义(P值均>0.05),但组内术后各时点与术前比较差异均有统计学意义(P值均＜0.01)。两组间及组内术前术后红细胞2,3-DPG比较差异均无统计学意义(P值均>0.05)。两组RCD术后较术前的有明显增高(P值均＜0.01),而组间比较差异均无统计学意义(P值均>0.05)。结论 应用自体血液回输对成人心脏瓣膜置换术中血液携氧功能无明显损伤,可减少库血的使用,具有较高的临床意义。     

细胞凋亡的形态和骨架改变

<正> 细胞凋亡(Apoptosis)是从形态学观察描述细胞的特征,而细胞程序性死亡(Pro-grammed Cell death,PCD)则偏重于功能性特征.两者含意不尽相同.因为并非所有细胞凋亡都受明显的基因调控,也并非所有PCD都表现细胞凋亡的典型形态特征,但都属细胞的生理性死亡.观察细胞凋亡的形态变化可用涂片染色和荧光标志等方法,但有的染色特性和显色效果不尽理想.我们前文曾报道一种细胞活染动态观察凋亡现象的简便方法.本文用固定染色法观察不同时间肝癌细胞凋亡的形态和骨架改变.1 材料及方法细胞:本室建立的人肝癌细胞株GHC—3,常规传代培养.试剂:地塞米松,Giemsa染液,Coomassie兰染液,Bouin’s固定液,戊二醛固定液.接种于小盖片上旺盛生长的GHC—3细胞,换含终浓度10~(-5)mol/L地塞米松完全培液,5%CO_2、37℃继续培养.2h后,每隔1h取出小盖片,共取5次.每片行Bouin’s固定、Giemsa染色;另一张片按我室建立的方法作细胞骨架显示、观察.     

CT多平面重建预评估腰椎经皮椎弓根螺钉置入损伤关节突关节的风险

文题释义：CT多平面重组技术：是将扫描范围内所有的轴位图像叠加起来在对某些标线标定的重组线所指定的组织进行冠状位、矢状位及任意角度斜位图像重组,以在不同角度观察影像学图像。 经皮椎弓根螺钉：该技术采用在术中影像检查设备引导下经皮肤小切口置入椎弓根螺钉,与常规开放置钉手术相比明显减少了对椎旁肌的损伤程度,既往学者多关注螺钉与椎弓根壁的位置关系,而较少关注其与关节突关节的位置关系。 背景：经皮椎弓根螺钉内固定技术被广泛应用于治疗腰椎疾病。经皮椎弓根螺钉由于是在术中C形臂X射线引导下操作,对螺钉与关节突关节之间的位置关系难以完全控制,可能导致关节突关节损伤。既往有学者认为体质量指数>29.9 kg/m²、小关节角>35°及年龄<65岁是经皮椎弓根螺钉损伤关节突关节的高危因素。由于不同腰椎椎弓根轴线与关节突关节的位置关系不同,螺钉对关节突关节的破坏是否存在差异目前尚无相关报道。 目的：探讨腰椎CT多平面重建技术在腰椎经皮椎弓根钉置入术前预估螺钉损伤腰椎关节突关节中的价值。 方法：选择100例行经皮椎弓根钉置入内固定治疗腰椎骨折及腰椎退行性疾病的患者,对治疗方案均知情同意,且得到医院伦理委员会批准。于术前CT斜轴位、斜矢状位及斜冠状位调整多平面重建的定位线,重建出椎弓根的切面断层,以斜冠状位线为中心设置直径为6.5 mm的标定圆模拟经皮椎弓根钉轴向截面,观察标定圆侵犯关节突关节程度,设为术前组;术后行腰椎CT检查观察螺钉损伤关节突关节程度,设为术后组。评价2组间不同节段关节突关节损伤螺钉数及组内不同节段关节突关节破坏比率的差异。 结果与结论：①共计置钉478枚,术前组显示标定圆侵犯关节突关节109枚,占比22.8%,其中L₁-L₅标定圆侵犯关节突关节螺钉数及占比分别为6枚(6.8%)、9枚(10.5%)、19枚(18.3%)、30枚(30.0%)和45枚(45.0%);②术后组显示关节突关节损伤115枚,占比24.1%,其中L₁-L₅螺钉损伤关节突关节螺钉数及占比分别为10枚(11.4%)、7枚(8.1%)、15枚(14.4%)、26枚(26.0%)和41枚(41.0%);③McNemar 配对χ²检验不同腰椎节段P值分别为：L₁ P=0.08,L₂ P=0.22,L₃ P=0.20,L₄ P=0.05,L₅ P=0.08,2组结果比较差异均无显著性意义;④Kappa检验2组一致性分别为：L₁ Kappa值=0.67,L₂ Kappa值=0.80,L₃ Kappa值=0.80,L₄ Kappa值=0.87,L₅ Kappa值=0.92;术前组及术后组组内不同节段间关节突关节损伤比率比较差异有显著性意义(P=0.000);⑤提示腰椎CT多平面重建技术可较为准确地判断经皮椎弓根螺钉与关节突关节的位置关系,为判断术后螺钉是否可能侵犯关节突关节提供了一种可靠的预估方法。 ORCID: 0000-0003-4872-2726(张晓芸) 中国组织工程研究杂志出版内容重点：人工关节;骨植入物;脊柱;骨折;内固定;数字化骨科;组织工程     

脑肿瘤患者手术前后脑结构网络拓扑属性研究

主要研究脑肿瘤的存在及手术对患者全脑及半脑结构网络拓扑属性的影响。结合弥散张量成像技术(DTI)和图论方法,对10例健康志愿者以及10例脑肿瘤患者进行术前术后全脑及半脑结构网络构建,获得两组受试者脑结构网络拓扑属性参数,以及反映脑认知功能的各项网络指标,并对其进行统计对比分析。结果显示,部分局部参数(包括K_i、L_i、E_nodal、C_i和E_ilocal)在手术前后具有明显差异,且术前组均优于术后组;全脑及半脑各全局网络参数显示,各项参数术前组均优于术后组;同时半脑结构网络分析显示,位于不同脑半球的脑肿瘤对患者脑结构网络所造成的损伤均无统计学差异(P>0.05)。肿瘤的存在以及手术均使得脑肿瘤患者脑结构网络发生改变,大脑的半脑优势化趋势明显降低;手术后结构网络拓扑特性的改变以及小世界属性的增强,验证大脑本身存在的代偿机制以及功能重组现象。     

一种新的检测细胞凋亡的多参数流式细胞分析方法

建立了一种新的检测细胞凋亡的多参数流式细胞分析方法.HL60白血病细胞株经化疗药物足叶乙甙处理后,加AnnexinV (AV)-FITC/PI孵育双染,用多参数流式细胞术检测细胞凋亡.结果显示,凋亡细胞的百分比随诱导时间的延长而逐渐增多.表明AV-FITC/PT双染法既能对细胞膜表面特异蛋白染色,又同时检测细胞膜完整性.多参数流式细胞术是一种快速、简便又准确的检测细胞凋亡的方法.     

当归芍药散对SAM-P8小鼠海马CA1区、齿状回锥体细胞的影响

目的观察当归芍药散(DSS)对快速老化小鼠海马CA1区、齿状回锥体细胞数量的影响。方法选用雌性SAM-P8鼠36只,分成4组:预防组(3月龄)、预防对照组(3月龄)、治疗组(6月龄)、治疗对照组(6月龄),治疗组以DSS(浓度为0.5g/mL)灌胃1个月,预防组自由饮用DSS(0.02%,v/v)4个月,对照组给予冷开水,给药结束后取脑、冰冻切片、尼氏染色,Leica图像分析系统分析海马CA1区、齿状回锥体细胞层尼氏染色的平均灰度。结果海马CA1区锥体细胞层尼氏染色的平均灰度各组间差异不明显(P>0.05)。预防组齿状回锥体细胞层尼氏染色的平均灰度明显多于其余各组(P<0.05)。结论低剂量长期服用DSS可增加老年性痴呆模型SAM-P8小鼠的齿状回锥体细胞数量。     

Optimising nasal spray parameters for efficient drug delivery using computational fluid dynamics

Experimental images from particle/droplet image analyser (PDIA) and particle image velocimetry (PIV) imaging techniques of particle formation from a nasal spray device were taken to determine critical parameters for the study and design of effective nasal drug delivery devices. The critical parameters found were particle size, diameter of spray cone at a break-up length and a spray cone angle. A range of values for each of the parameters were ascertained through imaging analysis which were then transposed into initial particle boundary conditions for particle flow simulation within the nasal cavity by using Computational Fluid Dynamics software. An Eulerian-Lagrangian scheme was utilised to track mono-dispersed particles (10 and 20 microm) at a breathing rate of 10 L/min. The results from this qualitative study aim to assist the pharmaceutical industry to improve and help guide the design of nasal spray devices.     

Apatite formation on alkaline-treated dense TiO2 coatings deposited using the solution precursor plasma spray process

A dense titania (TiO₂) coating was deposited from an ethanol-based solution containing titanium isopropoxide using the solution precursor plasma spray (SPPS) process. XRD and Raman spectrum analyses confirmed that the coating is exclusively composed of rutile TiO₂. SEM micrographs show the as-sprayed coating is dense with a uniform thickness and there are no coarse splat boundaries. The as-sprayed coating was chemically treated in 5 M NaOH solution at 80 °C for 48 h. The bioactivity of as-sprayed and alkaline-treated coatings was investigated by immersing the coatings in simulated body fluid (SBF) for 14–28 days, respectively. After 28 days immersion, there is a complete layer of carbonate-containing apatite formed on the alkaline-treated TiO₂ coating surface, but none formed on the as-sprayed coating.     

脉搏波波速法无创血压测量中多模量血压计算模型研究

针对脉搏波波速法无创血压测量中血压计算模型建模困难和模型计算精度较低的问题,结合T_PTT、ln(T_PTT)及(1/T_PTT)²等模量建立多模量血压计算模型。首先,利用99名随机测试者的实验数据确定多模量模型参数,并基于实验数据计算各模型性能评价指标,其中多模量血压计算模型拟合相关系数最大,为0.891,误差方差最小,仅为6.1,实验表明,多模量血压计算模型具有更好的拟合效果和更低的计算误差。然后,利用医用水银血压计和自主设计的多模量血压测量系统两种方法采集另外36名随机测试者的收缩压和舒张压数据,并计算两种方法采集数据间的相关参数,其中收缩压差值的绝对值d<6 mmHg,差值均值E_d=0.55 mmHg,差值的标准差δ_d=2.98 mmHg;舒张压差值的绝对值d<6 mmHg,差值均值E_d=0.57 mmHg,差值的标准差δ_d=3.42 mmHg,完全符合美国医疗仪器促进协会SP10-199中对电子血压计测量差值＜8 mmHg的要求。最后,采用Bland-Altman差值法,对两种方法测量数据一致性进行检验,发现舒张压与收缩压的95 %一致性界限分别为(-5.3,6.4)和(7.2,-6.2),完全在临床血压测量可接受范围之内,较好地证明多模量血压计算模型用于无创血压测量的有效性。研究结果表明,多模量血压计算模型可以应用于脉搏波波速法无创血压测量。     

钩藤碱对自发性高血压大鼠心室重构过程中TGF-β_1/Smad通路的影响

目的:观察钩藤碱对自发性高血压大鼠血压、心肌肥厚及心肌纤维化的影响并探讨其可能的作用机制。方法:32只自发性高血压大鼠随机分为模型组、钩藤碱高(10 mg·kg-1·d-1)、低(2.5 mg·kg-1·d-1)剂量组、卡托普利组(17.5 mg·kg-1·d-1),每组8只。另设8只Wistar-Kyoto大鼠作为正常对照组。分别于给药前和给药后每2周测量尾动脉收缩压(SBP)。治疗10周后处死大鼠,取其心脏计算全心重量指数和左心室重量指数;检测心肌中羟脯氨酸(HYP)及血浆中血管紧张素Ⅱ(AngⅡ)的含量;HE染色观察心肌病理学变化,Masson染色观察心肌胶原纤维变化;免疫组化法和Western blot法测心肌组织转化生长因子-β1(TGF-β1)和Smad3蛋白的表达。结果:与模型组相比,钩藤碱能明显降低自发性高血压大鼠的血压(P0.05),降低心肌HYP含量及血浆AngⅡ的含量(P0.05),减轻心肌组织的病理损伤和胶原纤维沉积,下调TGF-β1和Smad3蛋白的表达(P0.01)。结论:钩藤碱能降低自发性高血压大鼠的血压、调节改善自发性高血压大鼠的心室重构,其机制可能与其影响TGF-β1/Smad通路以及降低AngⅡ含量有关。     

Optimization of spray drying by factorial design for production of hollow microspheres for ultrasound imaging

A process for producing hollow microcapsules as ultrasound contrast agents was optimized using a 2(3) factorial experimental design method with two replicates. Spray drying, a conveniently scalable encapsulation technique, was used to encapsulate a volatile core material, such as ammonium carbonate, using biodegradable 50-50 poly(D,L-lactide-co-glycolide). Various effects due to changes in processing variables and their interactions were studied using the factorial grid. The high- and low-incremented variables examined included the temperature difference between the inlet and outlet of the spray dryer (5 degrees and 15 degrees C), air atomization pressure (80 and 100 psi), and polymer concentration in solvent (0.005 and 0.025 g/mL). Responses analyzed for computing the main effects and interactions were microcapsule morphology, yield, mean size, and zeta potential. Experimental results showed that polymer concentration was most important for determining microcapsule morphology. The temperature difference for drying prominently affected mean size, and atomization pressure was the main effect for microcapsule yield. Interactions among variables were not present in this case. The best conditions for producing PLGA microcapsules was a temperature difference of 5 degrees C, an initial polymer concentration of 0.005 g/mL, and an atomization pressure of 80 psi. The microcapsule zeta potentials were unaffected by spray-drying conditions.     

Cleansing technique using high-velocity steam–air micromist jet spray

Application of a high-velocity steam–air micromist jet spray (HVS-AMJS; micromist average diameter: 2.4?μm) for cleansing the skin is proposed. Low-pressure steam is mixed with compressed air (pH 6.5) in a nozzle, and then sprayed at a pressure of ≦0.25?MPa and a velocity of ≧0.34?m/s on the skin or surface of material located approximately 5–10?cm from the nozzle. The temperature on the sprayed surface and water flow rate could be controlled between 42?°C and 46?°C and at approximately 50?mL/min, respectively. Compared with ultrasonic cleansing with tap water and rubbing with only tap water, the HVS-AMJS successfully removed fluorescent lotion covering pieces of wood and significantly reduced both the number of coliforms and the total viable counts on pieces of wood and gauze. Furthermore, the HVS-AMJS effectively removed oily ink from the skin of hairless rats, and temporarily elevated the skin temperature and blood flow, indicating massage effects. The striking characteristics of this cleansing technique using HVS-AMJS are not only its ability to remove microbes and residue without using any chemicals or detergents but also its massage effects.     

一种中药雾化熏鼻装置的设计

目的 鼻饲给药方式为呼吸系统疾病治疗的常用手段,但目前大多数鼻饲雾化给药装置均无法产生温热的药雾,冷雾容易引起气管痉挛、呛咳等不良反应,且对中药的雾化效率低下.本设计旨在研制一种中药雾化装置以解决目前药物雾化中存在的问题,为中医治疗呼吸道疾病提供一种现代仪器方法.方法 本装置分为中药煎煮、中药雾化2大功能模块.中药煎煮模块采用1200W大功率发热盘,可实现中药的文武火煎煮;雾化模块采用超声雾化与蒸汽雾化结合的方式,并利用非接触式红外加热的方式对药雾温度进行控制.通过装机调试后,进行中药雾化条件的实验,选用药材、药粉或药包等不同形式的中药,煎煮后根据普通纱布、细胞过滤器、细菌滤膜等过滤后的中药液雾化效果来确定中药的最佳雾化条件.结果 中药材选用药包形式的药材、过滤方式采用普通纱布与细胞过滤器结合的方式,所得药液雾化效果最佳.通过15例志愿者独立操作,证明本装置可方便有效地进行瑶医鼻饲疗法,有效避免传统的冷雾雾化方式带来的不良反应.结论 此药物雾化设备可直接使用中药材进行鼻饲治疗,产生的药雾粒径适于鼻饲治疗,且温热雾可避免临床上常用的冷雾给药带来的呛咳缺氧等不良反应;同时仪器具有友好的人机交互功能,可满足临床上对中药雾化治疗的需求.     

Do menopausal hot flashes have any significant effects on arterial blood gas measurements?

Objectives: To evaluate the effects of menopausal hot flashes on arterial blood gas measurements. Methods: Twelve postmenopausal women with frequent hot flashes were enrolled in this study. Blood samples from femoral artery were collected before and during menopausal hot flashes in each subject, and all blood samples were analyzed for pH, pCO₂, pO₂, HCO₃ standard, total CO₂, and base excess. Arterial blood gas parameters before and during menopausal hot flashes were compared statistically. Results: pH measurements decreased significantly during hot flashes (P<0.05); although the difference was found to be statistically significant, the amount of decrease and the range in which the change took place led us to conclude that this change was clinically insignificant. Other parameters did not show any statistically significant differences between the preflash and flash measurements. Conclusions: Our results indicate that menopausal hot flashes do not have any clinically significant effects on arterial blood gas measurements.     

Effect of endothelin receptor antagonist bosentan on plasma leptin concentration in acute myocardial infarction in rats

The aim of the study was to evaluate the effect of endothelin receptor antagonism on plasma leptin level after myocardial infarction (MI). In Wistar rats under chloral hydrate anesthesia, MI was performed by ligation of the left coronary artery. The animals were divided into the following groups: control-sham (thoracotomy only), and two MI groups with or without bosentan treatment. Bosentan was given daily by gavage at the dose of 100 mg/kg. Treatment of animals started 2 days before MI and continued up to the fifth day. Concentration of leptin was measured by radioimmunoassay by means of ¹²⁵I labeled antigen in the following time intervals: before MI or sham operation, 4, 24 and 48 h after surgery. Electrocardiogram (ECG), blood pressure, heart rate, arterial pO₂, pCO₂ and pH were periodically monitored. Two days after the MI animals were perfused retrograde into descending aorta with 2% triphenyltetrazolium chloride (TTC) and hearts were fixed by immersion in formalin for microscopic examination. Hearts were sectioned transaxially and size of MI was quantitated with morphometric methods. ECG, TTC staining and microscopic results confirmed development of MI. Morphometric methods did not show significant differences in infarct size between bosentan treated and untreated groups. Concentration of leptin in plasma in untreated group significantly increased already 4 h after MI. In bosentan treated animals this increase appeared only after 24 h. In animals treated with bosentan also a significant diminution of MI mortality was observed. Our results indicate that bosentan has an important effect on leptin concentration in ischemic cardiovascular pathology.     

A new approach to prepare well-dispersed CaF(2) nanoparticles by spray drying technique

Previously, nano-sized calcium fluoride (CaF?) particles were prepared using a spray drying method by simultaneously feeding Ca(OH)? and NH?F solutions to a two-liquid nozzle. The aim of the present study was to prepare better-dispersed nano-CaF? particles by co-forming a soluble salt, sodium chloride (NaCl). NaCl of various concentrations were added to the NH(4) F solution, leading to formation of (CaF? +NaCl) composites with CaF? /NaCl molar ratios of 4/1, 4/4, and 4/16. Pure nano-CaF? was also prepared as the control. Powder X-ray diffraction analysis showed that the products contained crystalline CaF? and NaCl. Scanning electron microscopy examinations showed that both the CaF? /NaCl composite and pure CaF? particles were about (50-800) nm in size and consisted of primary CaF? particles of < 50 nm in size. BET surface area measurements showed similar primary particle sizes for all samples. Dynamic light scattering measurements showed that the washed (CaF?+NaCl) particles were much smaller than the pure CaF? as the dissolution of NaCl "freed" most of the primary CaF? particles, leading to a greater degree of particle dispersion. The well-dispersed nano-CaF? may be expected to be a more effective anticaries agent than NaF by providing longer lasting elevations of fluoride concentrations in oral fluids.