Particle size coarsening induced by valve silicone in a metered dose inhaler

The objective of this study was to evaluate the effect of valve silicone on the delivered particle size distribution of a suspension metered dose inhaler (MDI). Valves were manufactured with distinct levels of silicone, which could be differentiated with Fourier transform infrared spectroscopy (FT-IR). The amount of silicone in the valve was proportional to the amount of silicone that entered the formulation and the subsequent decrease in fine particle fraction (FPF) of the active pharmaceutical ingredient (API) measured by Andersen cascade impaction. The effect of silicone content was not linear as even small amounts of silicone made a significant contribution to particle size coarsening. This coarsening was also a function of storage time and temperature. Accelerated stability conditions greatly increased coarsening kinetics as 1 month at 40°C and 75% RH induced significantly more coarsening than 12 months at room temperature. Field emission scanning electron micrograph images suggest that the primary mechanism of particle size change may be aggregation as particle clusters were seen. This study indicates that silicone can be a critical process parameter for particle size distribution of a suspension MDI product. Thus, the amount of silicone in the valves needs to be minimized and controlled.     

霉酚酸酯对小鼠肺纤维化组织中转化生长因子-β1表达的影响

目的探讨霉酚酸酯(mycophenolate mofetil,MMF)对博莱霉素(bleomycin,BLM)诱导的小鼠肺纤维化组织中转化生长因子-β1(transforming growth factor-β1,TGF-β1)表达的影响。方法将C57BL/6小鼠随机分为6组:正常对照组、MMF对照组、BLM模型组、MMF低(20 mg/kg)、中(60 mg/kg)、高(100 mg/kg)剂量干预组,每组6只。BLM模型组和MMF 3个干预组经气管注入BLM(6 mg/kg),正常对照组和MMF对照组注入等量无菌生理盐水;次日按MMF对照组和MMF干预低、中、高剂量组小鼠体重计算MMF给药量,灌胃小鼠,每日1次,连续14 d,正常对照组和BLM模型组用等体积的双蒸水灌胃。灌胃第16天采集小鼠肺脏标本,经HE、Masson染色,从组织形态学上观察肺组织纤维化情况并进行Aschcroft评分;RT-PCR法检测小鼠肺组织中TGF-β1基因mRNA的转录水平;Western blot法检测小鼠肺组织中TGF-β1蛋白的表达水平。结果 BLM诱导的小鼠肺纤维化改变显著,Ashcroft评分较正常对照组显著增高(P<0.01),表明小鼠肺纤维化模型构建成功;MMF高剂量干预组肺组织损伤减轻,炎细胞浸润及胶原沉积减少,Ashcroft评分显著降低(P=0.000)。MMF高剂量干预组与BLM模型组比较,TGF-β1基因mRNA的转录水平及蛋白的表达水平均明显减低(P<0.05);而MMF低、中剂量干预组与BLM模型组之间、MMF对照组与正常对照组之间,差异均无统计学意义(P>0.05)。结论高剂量的MMF(100 mg/kg)可抑制BLM诱导的肺纤维化小鼠肺组织中TGF-β1基因mRNA的转录水平及蛋白表达水平,有望成为治疗肺纤维化的理想药物。     

多层螺旋CT及灌注成像对尘肺合并肺结核的诊断效果

目的:探析多层螺旋CT及灌注成像对尘肺合并肺结核的诊断效果。方法:筛选2018年11月至2020年11月经本院收治尘肺疑似合并肺结核120例患者进行研究,均进行多层螺旋CT影像及肺结核CT灌注成像检查,观察患者CT征象表现,测定并分析灌注成像参数变化,通过比对病理组织学“金标准”,分析单一及联合检查诊断效能。结果:120例尘肺合并肺结核患者,经病理证实尘肺合并肺结核86例,34例仅为单纯性尘肺;采用多层螺旋CT检查,共计有诸如多发性小结节、多发空洞、磨玻璃影、肺实变、树芽征、团块状、管壁增厚、胸膜增厚、支气管扩张及大结节影等10大征象;经CT征型分析,尘肺合并肺结核以结核球型、浸润型及空洞型多见,依次为13例、38例及23例,其他类型共计12例,较少发生;经CT灌注成像,单纯尘肺患者PF、BF及PI参数均高于尘肺合并肺结核,差异有统计学意义(P<0.05);而不同类型肺结核中,浸润型PF、BF值最高,空洞型PF值最低,结核球型BF值最低,经单因素方差分析,差异有统计学意义(P<0.05);多层螺旋CT影像、肺结核CT灌注成像单一及联合诊断Kappa值依次为0.50、0.64及0.79,均具备中高度一致性,以联合诊断一致性最好。结论:多层螺旋CT影像及肺结核CT灌注成像均可获有良好诊断效能,以联合检查诊断效能最佳。且结合临床症状,实时性分析患者CT影响及灌注参数变化,更利于尘肺合并肺结核的检出。     

Indoor air pollution and lung function growth among children in four Chinese cities

Ambient air pollution has been associated with decreased growth in lung function among children; but little is known about the impact of indoor air pollution. We examined relationships between indoor air pollution metrics and lung function growth, among children (n = 3273) aged 6-13 years living in four Chinese cities. Lung function parameters (FVC and FEV(1) ) were measured twice a year. Questionnaires were used to determine home coal burning and ventilation practices. Generalized estimating equations were used to examine associations. Use of coal as a household fuel was associated with 16.5 ml/year lower (33%, P < 0.001) and 20.5 ml/year lower (39%, P < 0.001) growth in children's FEV(1) and FVC, respectively. FEV(1) growth was 10.2 ml/year higher (20%, P = 0.009), and FVC growth was 17.0 ml/year higher (33%, P < 0.001) among children who lived in houses with the presence of a ventilation device. Among children living in houses where coal was used as a fuel and no ventilation devices were present, adjusted FVC and FEV(1) growth, respectively, were 37% and 61% that of the average growth per year in the full cohort. This suggests that household coal use may cause deficits in lung function growth, while using ventilation devices may be protective of lung development. PRACTICAL IMPLICATIONS: Nearly 3.4 billion people use solid fuels in homes for cooking and/or heating. We report the following findings from a longitudinal study: (i) household coal use is significantly associated with reduction in children's lung function growth and (ii) the use of household ventilation devices is significantly associated with higher lung function growth, particularly among children living in households where coal is used as a fuel. These findings not only provide evidence that indoor coal use impairs children's lung development but also point to the importance of improving ventilation conditions in reducing harmful effects of indoor air pollution sources.     

肺硬化性血管瘤CT征象及病理分析

目的探讨肺硬化性血管瘤(PSH)的CT表现,旨在提高PSH的影像诊断水平。方法回顾分析42例2004年9月-2009年6月在我院经手术及病理证实的PSH的CT资料与病理结果。结果本组女性38例(90.48%),男4例;发病年龄19-66岁,中位年龄46.6岁;病灶均为单发,位于肺野内、中带居多(39例,92.86%);结节30例(71.43%),肿块12例;边界光滑31例,浅分叶9例,毛刺2例;钙化11例(26.19%),瘤体>3cm发生率高(66.7%);31例增强扫描中,增强前密度不均匀8例(25.81%),增强后不均匀强化18例(61.29%),增强幅度1-64HU,均值(31.16±11.93)HU;瘤周磨玻璃密度11例,空气新月征6例。结论PSH好发于中老年女性,CT表现为位于肺野内、中带孤立性结节或肿块,增强扫描不均匀显著强化,一些特殊征象如空气新月征、瘤周磨玻璃密度具有相对特征性,有助于术前诊断。     

~(147)Pm 在大鼠肺脏沉积和向血液转移规律的探讨

本文报告了从大鼠肺区间直接注入~(147)Pm 后向血液转移的规律。肺区间~(147)Pm 向血液转移分快组分和慢组分。注入后第1天为快组分,转移分数约为0.094,注入第2天后为慢组分,转移分数随时间的变化可用指数函数描述,其转移半廓清期约为11d。     

大鼠吸入~(239)PuO_2后肺巨噬细胞核吸收剂量的估算

本文利用大鼠吸入~(239)PuO_2后肺钚滞留函数,肺巨噬细胞的更新函数及有关的生物学资料,采用 Monte-Carlo 方法,估算了大鼠吸入~(239)PuO_2后肺和肺巨噬细胞核的平均吸收剂量。对于初始肺钚沉积量分别为8.7、6.7、2.7和3.0kBq,照射时间分别为2、7、13和28d 的4组实验动物,估算出肺平均吸收剂量(?)_P为0.69、1.7、1.2和2.6Gy,肺巨噬细胞陔的平均吸收剂量(?)_(PM)为0.95、2.21、1.71和3.23Gy。(?)_(PM)与(?)_P的比值的平均值为1.3。肺巨噬细胞核的受照剂量主要求自沉积于肺巨噬细胞内的钚,周围钚粒子的剂量贡献仅占1%左右。     

人发中微量元素与某些呼吸系统疾病关系的研究

用仪器中子活化法测定了正常人和慢性支气管炎,肺气肿,肺心病患者头发中Ｃａ,Ｍｇ,Ｆｅ,Ｓｅ,Ｃｕ,Ｚｎ等１９种元素的含量。测得患者发中Ｃａ,Ｍｇ含量低于正常人,Ｆｅ,Ａｓ,Ｃｏ等含量高于正常人;慢性支气管炎急发期患者发中Ｃａ,Ｍｇ含量低于缓解期患者,Ｆｅ含量高于缓解期患者,均有显著性差异（Ｐ＜０．０５－０．０１）。人发Ｃａ与Ｍｇ呈高度正相关（Ｐ＜０．００１）。还测定了用于治疗慢性支气管炎的中药“咳     

A lumped Galerkin method for the numerical solution of the modified equal-width wave equation using quadratic B-splines

The numerical solution of the one-dimensional modified equal width wave (MEW) equation is obtained by using a lumped Galerkin method based on quadratic B-spline finite elements. The motion of a single solitary wave and the interaction of two solitary waves are studied. The numerical results obtained show that the present method is a remarkably successful numerical technique for solving the MEW equation. A linear stability analysis of the scheme is also investigated.     

Automatic classification for solitary pulmonary nodule in CT image by fractal analysis based on fractional Brownian motion model

Perfusion computed tomography (CT) method has been used to differentiate malignant pulmonary nodules from benign nodules based on the assessment for the change of the CT attenuation value within the pulmonary nodules. Instead of using the change of the CT attenuation value, a set of fractal features based on fractional Brownian motion model is proposed in this paper to automatically distinguish malignant nodules from benign nodules. In a set of 107 CT images from 107 different patients with each image containing a solitary pulmonary nodule, our experimental results obtained from a support vector machine classifier show that the accuracy, sensitivity, specificity, positive predictive value, negative predictive value, and the area under the ROC curve are 83.11%, 90.92%, 71.70%, 80.05%, 87.52%, and 0.8437, respectively, by using the proposed fractal-based feature set. Such a result outperforms the conventional method of using the change of the CT attenuation value as the feature for classification. When combining this conventional method with our proposed fractal-based method, the accuracy, sensitivity, specificity, positive predictive value, negative predictive value, and the area under the ROC curve can be promoted to 88.82%, 93.92%, 82.90%, 87.30%, 90.20%, and 0.9019, respectively. In other words, a high performance of pulmonary nodule classification can be achieved with a single post-contrast CT scan.