Evaluation of quantitative aerosol techniques for use in bronchoprovocation studies

To investigate airway physiology by use of inhaled aerosols, it is frequently necessary to measure the actual amount of material deposited on the airway wall as well as the site of particle deposition. To satisfy these needs, radiolabeled aerosols and gamma camera techniques have been used to measure regional deposition of inhaled particles. To make quantitative measurements of the amount deposited, previous investigators have used a "phantom" technique to indirectly calibrate the gamma camera for the attenuation of gamma rays through the lungs and chest wall. For this calibration, the phantom is a simulated lung containing a known amount of radioactivity. Radioactive counts emitted from the phantom are assumed to be attenuated in the same manner as the intact human lung. The present article describes a technique to determine directly the amount of inhaled aerosol deposited in the lung and simultaneously to calibrate the gamma camera for each individual subject. We used right angle light scattering and a gamma camera to measure individual values of the deposition fraction (DF) of inhaled aerosol deposited in the lung and the coefficient of attenuation (AC) of gamma rays in normal and obstructed lungs of human subjects. Radiolabeled monodisperse aerosols 1 and 2 microns in diameter were used. Knowledge of the activity of the inhaled aerosol (microcurie per liter), the volume inhaled, and the measured DF determined each subject's AC (counts per minute per microcurie). DF varied by an order of magnitude in normal (0.04 to 0.48) and obstructed (0.16 to 0.75) of subjects.(ABSTRACT TRUNCATED AT 250 WORDS)     

Transport of molecules across tumor vasculature

The vascular-extravascular exchange of fluid and solute molecules in a tissue is determined by three transport parameters (vascular permeability, P, hydraulic conductivity, L_p, and reflection coefficient, ); the surface area for exchange, A; and the transluminal concentration and pressure gradients. The transport parameters and the exchange area for a given molecule are governed by the structure of the vessel wall. In general, tumor vessels have wide interendothelial junctions; large number of fenestrae and transendothelial channels formed by vesicles; and discontinuous or absent basement membrane. While these factors favor movement of molecules across tumor vessels, high interstitial pressure and low microvascular pressure may retard extravasation of molecules and cells, especially in large tumors. These characteristics of the transvascular transport have significant implications in tumor growth, metastasis, detection and treatment.     

评“McCall观察方法”——对一种色谱系统分配效果观察方法的商榷

本文通过理论分析和文献数据的分析,对McCall提出的色谱系统分配效果的观察方法提出了不同的看法,认为McCall方法中的所谓logK并不是常数。McCall的方法无论在理论上和实践上都是不妥的。     

身体形态指数ABSI和身体圆度指数BRI的发展与应用

目的 对身体形态指数(ABSI)和身体圆度指数(BRI)的发展进行介绍,并对其应用情况进行综述,为人体形态测量提供参考。方法 在Pubmed、中国知网等电子文献数据库中进行文献检索,详尽收录迄今ABSI与BRI对高血压、糖尿病、代谢综合征、心血管疾病等常见疾病的发病率以及全因死亡率预测的相关研究。结果 ABSI与BRI均对高血压、糖尿病、代谢综合征、心血管疾病发病呈现出一定的预测能力。其中,BRI在预测糖尿病、代谢综合征发病方面优于ABSI,但与身体质量指数、腰围、臀围、腰高比等传统测量指标相比,并未表现出显著的差异。ABSI对全因死亡率的预测能力则明显优于传统测量指标和BRI。结论 ABSI与BRI作为两项新的形态学指标,是BMI等传统身体指数测量的补充,对疾病发病具有一定的预测能力和应用性。今后的研究可以从两项指标对疾病的单独作用以及与传统指标的联合作用着手,同时探索其在不同社会人口学特征人群中的拟合情况,提供更有利的研究证据和科学积累。     

中老年男性血糖与血清脂质及载脂蛋白的关系

目的　研究血糖水平与脂质及载脂蛋白水平的关系。方法　对成都地区 735例 40～ 70岁男性空腹 12～ 14小时的血糖、血清甘油三酯 (TG)、胆固醇 (TC)、高密度脂蛋白胆固醇 (HDL- C)、低密度脂蛋白胆固醇(L DL- C)和血清载脂蛋白 (apo) A 、A 、B10 0、C 、C 及 E含量进行了测定。依空腹血糖的水平将受试对象分为正常组 (S1)、糖耐量减退组 (S2 )、糖尿病组 (S3)。结果　结果显示 :S2和 S3的高脂血症发病率比 S1高 (分别为64.5 %、45 .2 %和 32 .1% ) ;空腹 TG水平 S2 (3.62± 2 .5 2 mm ol/ L)和 S3(4 .45± 3.82 mmol/ L)均显著高于 S1(1.92± 1.93m mol/ L) ,P均 <0 .0 1;TC水平 S2 (5 .68± 1.15 mmol/ L)和 S3(5 .68± 1.12 m mol/ L)亦显著高于 S1(5 .13±1.0 6m mol/ L) ,P均 <0 .0 5 ;S2和 S3的血清 apo B10 0、C 、C 及 E水平显著高于 S1(P均 <0 .0 1或 P<0 .0 5 )。相关分析表明 ,血糖与血清 TG在 S1、S2和 S3中均呈显著正相关 (r分别为 0 .180 0、0 .1436和 0 .32 12 ) ,P均 <0 .0 0 1;而在 S2和 S3中血糖与 HDL- C呈负相关 (r分别为 - 0 .2 5 34和 - 0 .1477) ,P均 <0 .0 0 1;在 S1、S2、S3组中血糖与血清 apo B10 0、C 及 E呈正相关 (P均 <0 .0 0 1) ,与 apo C 则在 S1和 S2中呈正相关 (P<0     

A spectral framework for sperm shape characterization

A novel methodology for characterization of animal sperm shape involving the use of a spectral approach to multiscale curvature estimation is proposed. By using the derivative property of the Fourier transform, allied to Gaussian smoothing, accurate estimates of the curvature along the sperm contour can be obtained in such a way that the curvature peaks corresponding to the sperm head vertices can be effectively identified. The measurements derived from such a processing, namely the width of the basal region of the head, the centralization of tail implantation, and the multiscale bending energy, provide valuable resources for fertility and phylogenetic studies.     

Natural frequency/damping coefficient relationship of the catheter-manometer system required for high-fidelity measurement of the pulmonary arterial pressure

Using a digital simulation method, we analyzed the relationship between natural frequency (f _n ) and damping coefficient () of the catheter-manometer system required for high-fidelity measurement of the pulmonary arterial pressure. The pulmonary artery pressure waveform was obtained with a catheter-tip transducer and it was fed into a dynamic simulator programmed on a computer. The original waveform and the output of the simulator were compared and judged visually for the fidelity. From this analysis, the combination of f _n and was obtained and was plotted on a f _n – diagram. It showed as an area, which was convex on the left side and open on the right side. The left-convex endpoint was located at a damping coefficient of about 0.7. At a lower heart rate, this area was extended to the lower frequency side, while, at a higher heart rate, this area was limited to the higher frequency side. The f _n – diagram was also constructed theoretically by calculating the relations between natural frequencies and damping coefficients of a second order system with the amplitude and phase error tolerance set at +/–5% respectively.(Kinefuchi Y, Suzuki T, Takiguchi M, et al.: Natural frequency/Damping coefficient relationship of the catheter-manometer system required for high-fidelity measurement of the pulmonary arterial pressure. J Anesth 7: 419--426, 1993)     

Flow-mediated cell stress induction in adherent leukocytes is accompanied by modulation of morphology and phagocytic function

Leukocytes adherent to the surfaces of both vascular biomaterials and normal blood vessels experience blood flow induced shear stress. The goal of the reported studies was to investigate the effect of fluid flow on the morphology, phagocytic function and stress response induction in adherent immune cells. Shear approximating arterial, venous and intermediate levels were applied onto glass-adherent IC21 macrophages in a temperature-controlled parallel plate flow system. The results indicate that fluid flow induces a shear-dependent physiological stress response in adherent macrophages and that significant morphological changes accompany macrophage responses to shear stress. In addition, arterial flow conditions induce not only significant cell polarisation, but also enhanced phagocytic ingestion in glass-adherent IC21 macrophages. These findings suggest that blood flow induced shear stress may not only be consequent to adherent leukocyte activation, but may also be integral to the regulation of adherent leukocyte behaviour in vivo.     

人工股骨头置换术的应用解剖

目的:为临床人工股骨头置换术人工假体的选择、安装及定位提供可靠的解剖学参数。方法:对250例(左右各125例)正常成人股骨头、股骨颈、大转子与外上髁间距进行观测,并得出转子髁间距与股骨头最大径、股骨头颈前长和股骨头颈后长的相关系数和回归方程。结果:股骨头最大径为4.39±0.31cm,股骨头颈后长为6.89±0.49cm,股骨头颈前长为6.18±0.43cm,大转子与外上髁间距为34.40±1.79cm。结论:采用本文作者提供的方法选择、安装人工假体准确、实用、方便     

Morphological and functional demonstration of rat dura mater mast cell-neuron interactions in vitro and in vivo

The effects of changes in temperature on primary and secondary endings of isolated cat muscle spindles were investigated under ramp-and-hold stretches and different degrees of pre-stretch. Temperature-induced alterations of the discharge frequency were compared over a temperature range of 25–35°C. Both primary and secondary endings responded to warming with increasing discharge frequencies when the spindle was pre-stretched by 5–10% of its in situ length. The following differences between the temperature effects on primary and secondary endings were observed: (1) The temperature coefficients (Q₁₀) obtained from the discharge frequencies during the dynamic and static phase of a stretch were similar for endings of the same type, but they were larger in primary endings (range of Q₁₀: 2.3–3.3; mean: 2.9) than in secondary endings (range of Q₁₀: 1.6–2.2; mean: 2.0); (2) With primary endings, but not with secondary endings, the temperature sensitivity (imp s⁻¹ °C⁻¹) was larger during the dynamic phase than during the static phase of a stretch; (3) In primary endings, the fast and slow adaptive components occurring in the discharge frequency during the static phase of a stretch clearly increased with warming while in secondary endings, the slow decay was less affected, and the fast decay showed no change; (4) In relaxed spindles, the excitatory effect of warming was overlaid by a strong inhibitory effect as soon as the temperature exceeded about 30°C, resulting in an abrupt cessation of the background activity in most secondary endings, but not usually in primary endings. In general, warming induced an enhanced stretch sensitivity in both types of ending, and additionally an inhibitory effect that is obvious only in secondary endings of relaxed spindles. The different effects of temperature on the discharge frequency of primary and secondary afferents are assumed to be caused by different properties of their sensory membranes.