伽玛刀治疗功能性垂体瘤初步报告

目的 对伽玛刀治疗分泌型垂体瘤的疗效和并发症发生的相关因素进行探讨。方法 1997年9月至2001年11月，248例垂体瘤经伽玛刀治疗。其中．73例年龄在16至61岁的分泌型垂体瘤获得详细随访，53例为PRL型，11例GH型，2例为ACTH型，6例为PRL合并GH型，1例为PRL合并ACTH型。7例为术后复发和残留。23例曾接受过嗅隐亭治疗。平均肿瘤容积为5．83cm^3(0．14～25．20cm^3)。边缘剂量为8～35Gy。结果 平均随访时间21个月。36例(49.3％)内分泌恢复正常。内分泌恢复正常的比率3个月后1．4％，6个月后16．4％．1年后45．2％，2年后49．3％。3例(4、1％)发生垂体瘤功能低下。1例复发二次治疗。无病例发生视路受损。结论 伽玛刀治疗分泌型垂体瘤是安全有效的治疗方法。其长期疗效和并发症的发生仍需进一步的随访观察。     

UVB对角质形成细胞产生细胞因子的影响

角质形成细胞可产生多种细胞因子，这些细胞因子除介导炎症和免疫反应外，还参与组织细胞的生长和分化。UVB照射影响了角质形成细胞合成、分泌细胞因子，并影响细胞因子对角质形成细胞的作用及细胞因子之间的相互作用。概述角质形成细胞产生各种细胞因子的生物学效应。     

伽玛刀治疗高危前列腺增生症的临床应用

目的探讨伽玛刀在不适合开放手术或经尿道电切术的高危前列腺增生患者治疗中的应用。方法采用深圳奥沃公司生产的OUR-QGD型立体定向全身伽玛刀治疗20例高危前列腺增生患者。应用国际前列腺症状评分(IPSS)、前列腺重量、最大尿流率(Qmax)、残余尿量作为评价指标。观察上述数据在治疗前后的改变及其临床意义。结果术后随访6个月,IPSS评分由治疗前29分降至19.6分(P<0.01)。前列腺重量平均值均由治疗前的(56.4±4.4)g减少至(54.8±4.3)g(P>0.05)。最大尿流率平均值由治疗前的(6.7±1.8)ml/s增加至(11.5±1.7)ml/s(P<0.01),残余尿量平均值由治疗前的(85.1±27.8)ml降至(50.9±15.6)ml(P<0.01)。结论立体定位体部伽玛刀治疗高危前列腺增生症患者具有简便、安全、无创、痛苦小、并发症少、疗效好,可不需住院等优点,对不愿意接受手术或不宜手术的高危前列腺增生患者不失为一种良好的治疗方法,但费用较高。     

A method for reducing background tracks in plastic detectors

The purpose of the present study was to reduce background tracks by removing a given surface layer of the 250 μm thick lexan polycarbonate foils before exposure to alpha particles. Ethylenediamine solution was used for taking layers from the surface of the foils.     

The distribution and possible function of gamma interferon-immunoreactive cells in normal endometrium and myometrium

Summary T-lymphocytes are present in normal endometrium, where they may have a role in the control of glandular maturation. T-cell activity could be related to the local secretion of cytokines such as gamma interferon, which has an anti-proliferative effect on endometrial epithelial cells in vitro. We have examined gamma interferon immunoreactivity and T-cell distribution in 24 normal pre-menopausal uteri. Endometrial appearances were representative of all stages of the menstrual cycle. Most cells in the lymphoid aggregates in the stratum basalis were stained by T-cell and gamma interferon antisera. T-lymphocytes were also scattered in glandular epithelium and throughout the stroma of basal and functional layers; immunoreactivity for gamma interferon was less consistent in these cells. There was no alteration in the intensity or distribution of gamma interferon staining in different phases of the menstrual cycle. Endometrial granulocytes (K-cells) present mainly in the late secretory endometria were not reactive with the gamma interferon antiserum. In addition to endometrial staining, T-cells were distributed in all areas of the myometrium in most uteri, and many myometrial lymphocytes were gamma interferon positive. These results support a role for gamma interferon in endometrial physiology, possibly as an inhibitor of epithelial proliferation.     

血清谷氨酰转肽酶含量测定在慢性乙型肝炎中的临床意义

目的探讨血清谷氨酰转肽酶（GGT）含量变化在慢性乙型肝炎（CHB）不同程度肝脏病理损害中的变化规律及临床意义。方法测定70例CHB患者血清ALT、AST、GGT水平，同时行肝活体组织检查，对肝脏进行炎症分级和纤维分期。分析ALT、AST、GGT与CHB之间的关系。结果（1）ALT、AST、GGT随炎症程度和纤维化程度的上升而上升，但到G4和s4后则下降。GGT随ALT、AST的升高而升高，ALT、AST和GGT的相关系数分别为：0．322、0．328（P〈0．05）。在保肝治疗后，ALT较快降至正常且GGT保持在一个较低水平的为轻度CHB，而随着ALT下降，GGT仍持续在一个较高水平的为中度及重度CHB，其中重度CHB的GGT水平有所波动。结论血清GGT比ALT、AST更准确的反映肝脏的炎症程度，GGT的活动度给临床判断慢乙肝的炎症提供了重要的判断依据。     

Voronoi Polyhedra Analysis of Optimized Arterial Tree Models

Topological and metric properties of Voronoi polyhedra (VP) generated by the distal end points of terminal segments in arterial tree models grown by the method of constrained constructive optimization (CCO) are analyzed with the aim to characterize the spatial distribution of their supply sites relative to randomly distributed points as a reference model. The distributions of the number N _f of Voronoi cell faces, cell volume V, surface area S, area A of individual cell faces, and asphericity parameter of the CCO models are all significantly different from the ones of random points, whereas the distributions of V, S, and are also significantly different among CCO models optimized for minimum intravascular volume and minimum segment length (p < 0.0001). The distributions of N _f , V, and S of the CCO models are reasonably well approximated by two-parameter gamma distributions. We study scaling of intravascular blood volume and arterial cross-sectional area with the volume of supplied tissue, the latter being represented by the VP of the respective terminal segments. We observe scaling exponents from 1.20 ± 0.007 to 1.08 ± 0.005 for intravascular blood volume and 0.77 ± 0.01 for arterial cross-sectional area. Setting terminal flows proportional to the associated VP volumes during tree construction yields a relative dispersion of terminal flows of 37% and a coefficient of skewness of 1.12. © 2003 Biomedical Engineering Society. PAC2003: 8719Uv, 8710+e, 4720Ky, 0260Pn, 0230Oz     

He-Ne激光、微波、红外线和TDP灯照射对血粘度与红细胞影响的比较研究

目的比较研究He-Ne激光、微波、红外线和TDP灯照射对高血粘的影响,探索能否利用He-Ne激光、微波、红外线和TDP灯照射降低血液粘度,改善血循环.方法每份血样等分5份,1份作对照,对另外4份分别作He-Ne激光、微波、红外线和TDP灯照射处理.结果高血粘血样经He-Ne激光、微波、红外线和TDP灯照射作用后,全血表观粘度η降低(P＜0.01)、红细胞电泳率EPM加快(P＜0.01),血沉速度ESR提高(P＜0.01),一氧化氮、全血黏度、全血还原黏度降低(P＜0.01).红细胞变形指数降低(P＜0.01),红细胞聚集时间增加(P＜0.01),红细胞压积降低(P＜0.01),纤维蛋白降低(P＜0.01).结论He-Ne激光、微波、红外线和TDP灯照射能改善高血粘血样的流变特性.而且激光效果最好,依次是TDP灯、微波和红外线.进一步了解物理与临床治疗的密切关系.     

Isoflurane disrupts anterio-posterior phase synchronization of flash-induced field potentials in the rat

Consciousness presumes a set of integrated functions such as sensory processing, attention, and interpretation, and may depend upon both local and long-range phase synchronization of neuronal activity in cerebral cortex. Here we investigated whether volatile anesthetic isoflurane at concentrations that produce loss of consciousness (LOC) disrupts long-range anterio-posterior and local anterior synchronization of neuronal activity in the rat. In six rats, deep electrodes were chronically implanted in the primary visual cortex (V1) and in two areas of the motor cortex (M1 and M2) for recording of intracortical event-related potentials (ERP). Thirty discrete flashes were presented at random interstimulus intervals of 15–45 s, and ERPs were recorded at stepwise increasing isoflurane concentrations of 0–1.1%. Neuronal synchronization was estimated using wavelet coherence computed from the ERP data band-pass filtered at 5–50 Hz. We found that (1) in the waking state, long-range anterio-posterior coherence in 5–25 Hz and 25–50 Hz frequency bands was significantly higher than local anterior coherence; (2) anterio-posterior coherence in both 5–25 Hz and 26–50 Hz bands was significantly reduced by isoflurane in a concentration-dependent manner; (3) local anterior coherence was not affected by isoflurane at any of the concentrations studied. These findings suggest that a disruption of long-range anterio-posterior rather than local anterior synchronization of neuronal activity precedes the anesthetic-induced loss of consciousness.     

Gas transport during high-frequency ventilation: Theoretical model and experimental validation

We present a theoretical model of gas transport through the dead space during high-frequency ventilation (HFV) with volumes less than dead space volume. The analysis is based on the axial distribution of transit times of gas moving through the dead space. The model predicts that for tidal volumes (V) much less than dead space (V_d), gas exchange will be proportional to the product of frequency (f) and V². If gas transport is analyzed in terms of Fick's law, then the effective diffusion coefficient (D_eff) can be shown to be equal to fV² times a constant, whose value equals the square of the coefficient of dispersion of axial transit times through the dead space . Experimental results in straight tubes fit the predictions of this model quite well. A through the entire dead space of about 30% is more than sufficient to account for gas exchange during HFV in physical models or in intact animals. An axial dispersion of this magnitude can be measured directly from a typical Fowler dead space determination in healthy subjects.