A Bayesian iterative transmission gradient reconstruction algorithm for cardiac SPECT attenuation correction

Background  High-quality attenuation maps are critical for attenuation correction of myocardial perfusion single photon emission computed tomography studies. The filtered backprojection (FBP) approach can introduce errors, especially with low-count transmission data. We present a new method for attenuation map reconstruction and examine its performance in phantom and patient data. Methods and Results  The Bayesian iterative transmission gradient algorithm incorporates a spatially varying gamma prior function that preferentially weights estimated attenuation coefficients toward the soft-tissue value while allowing data-driven solutions for lung and bone regions. The performance with attenuation-corrected technetium 99m sestamibi clinical images was evaluated in phantom studies and in 50 low-likelihood patients grouped by body mass index (BMI). The algorithm converged in 15 iterations in the phantom studies. For the clinical studies, soft-tissue estimates had significantly greater uniformity of mediastinal coefficients (mean SD, 0.005 cm⁻¹ vs 0.011 cm⁻¹; P<.0001). The accuracy and uniformity of the Bayesian iterative transmission gradient algorithm were independent of BMI, whereas both declined at higher BMI values with FBP. Attenuation-corrected perfusion images showed improvement in myocardial wall variability (4.8% to 4.1%, P=.02) for all BMI groups with the new method compared with FBP. Conclusion  This new method for attenuation map reconstruction provides rapidly converging and accurate attenuation maps over a wide spectrum of patient BMI values and significantly improves attenuation-corrected perfusion images.     

4-1BB(CD137)配体在几种肿瘤细胞株上的表达

目的：研究4—1BBL在几种人肿瘤细胞株上的表达。方法：用RT—PCR及法检测肿瘤细胞内4—lBBL mRNA水平的表达；用流式细胞仪检测肿瘤细胞膜表面4—1BBL的表达。结果：4—1BBL在Jurkat细胞株上高表达(98．97％)，在HL-60和K562上表达较低(分别为24．77％和19．23％)，而在HL-29细胞株上基本不表达(2．13％)。结论：4—1BBL在不同肿瘤细胞株表达水平不同。     

血清铁和铁蛋白与肝病患者肝纤维化指标的关系

OBJECTIVE: To study the relationship of serum iron and ferritin with the indicators for hepatic fibrosis and hepatic iron overload. METHODS: Liver tissue specimens were obtained from 41 patients with benign (16) or malignant (25) liver diseases by 1 second liver biopsy, and routine microscopic examination was performed after haematoxylin-eosin (HE) and Perl's Prussian staining. Atomic absorption spectrum, radioimmunoassay and enzyme-linked immunosorbent assay were respectively employed to examine the serum levels of iron, ferritin, hyaluronic acid, laminin, human procollagen type , and collagen type . RESULTS: Between patients with benign and malignant liver diseases, significant differences were found in the serum ferritin levels (P < 0.05), but not in serum iron levels (P > 0.05). It was also noted that the levels of the indicators for hepatic fibrosis in patients with benign and early-stage malignant diseases varied significantly from the levels in normal subjects, but these differences were not observed between normal subjects and patients with end-stage hepatic malignancies. Serum iron and ferritin were found to be associated with serum laminin levels (serum iron: r=0.439, P=0.031; serum ferritin: r=0.476, P=0.016), and no iron granules detected in the tissue specimens of hepatocellular carcinoma. CONCLUSIONS: Most of the patients with hepatocellular carcinoma have elevated serum ferritin levels. The serum levels of iron and ferritin are statistically correlated with serum laminin level. Obvious reduction of iron content is typical of hepatic malignant tissues in comparison with the benign tissues, and the reduction in the levels of the indicators for hepatic fibrosis might involve the inhibition of collagen synthesis in the tumor tissues from patients with end-stage hepatocellular carcinoma. Most of the cases of alcoholic fatty liver are complicated by liver iron overload, often marked by serum iron and ferritin levels.     

膀胱出口梗阻后逼尿肌收缩蛋白表达和膀胱重量的改变

目的探讨膀胱出口梗阻(BOO)后逼尿肌收缩蛋白表达和膀胱重量的改变及意义。方法BOO组病人16例,筛选条件为入院诊断良性前列腺增生症(BPH)并经尿动力学压力-流率检查证实为高压低流型;对照组5例,为外伤等情况入院并排除有下尿路梗阻病史者。BOO组所有病例均行耻骨上经膀胱前列腺摘除术,术前B超检查测定膀胱重量和前列腺内外径比值,术中切取膀胱上壁组织2cm×1cm×1cm大小,标本行RT-PCR反应,检测膀胱逼尿肌中肌动蛋白和肌球蛋白mRNA的表达,并比较其与膀胱重量间的线性相关性。结果BOO组与对照组膀胱重量分别为(92.15±34.89)g和(56.08±20.35)g,(P<0.05);前列腺内外径比值分别为(0.57±0.16)和(0.18±0.06),(P<0.01);与对照组相比,BOO组肌动蛋白和肌球蛋白mRNA的表达量均有显著增加,分别为(40.32±59.67)×106和(6.59±5.62)×106,(P值均<0.01);且两者表达量与膀胱重量之间均有明显线性正相关性(P<0.05)。结论逼尿肌中肌动蛋白和肌球蛋白的表达与膀胱逼尿肌的功能状态密切相关。     

对侧网状巨细胞核对大鼠脊髓背表面电位的影响

以浅麻醉和麻痹大鼠为对象,利用计算机平均技术记录强电流刺激腓肠神经诱发的脊髓背表面电位(CDP),观察对侧网状三细胞核(NGC)微量注射L一谷氨酸钠,使神经细胞兴奋后对CDP的影响.实验发现,对侧NGC神经细胞兴奋后,Aβ和Aσ纤维引起的P_1波及Aσ和C类纤维引起的N_3波减小,C类纤维引起的P_2波明显减小,N_4 波消失.以上结果提示:对侧NGC对细纤维诱发的CDP成分有抑制作用.     

石杉碱甲类似物的研究II.N-甲基吡啶酮石杉碱甲类似物的合成

石杉碱甲(1)是从中草药石杉属植物千层塔(Lycopodium serratum Thunb.)中分得的一种高效可逆的乙酰胆碱酯酶抑制剂,临床试验证实它对早老性痴呆症有显著疗效。本文报道N-甲基吡啶酮石杉碱甲类似物2和3的合成。2-甲氧基-5-甲氧羰基-11-亚甲基-5,9-甲撑环辛-7-烯并吡啶(9)在乙腈中用三甲基氯硅烷和碘化钠选择性脱保护以定量的产率得吡啶酮10,再用甲醇钠和碘甲烷甲基化得N-甲基吡啶酮11,11经碱性水解,Curtius重排和氨基的脱保护得N-甲基吡啶酮石杉碱甲类似物2。通过类似的途径从中间体2-甲氧基-5-甲氧羰基-7-甲基-11-酮-5,9-甲撑环辛-7-烯并吡啶(14)合成了类似物3。类似物2和3的乙酰胆碱酯酶抑制活性均低于天然石杉碱甲。     

温阳健心灵口服液治疗充血性心力衰竭的临床与实验研究

以煎剂形成筛选治疗CHF的处方，发现温阳益气方改善泵血功能的效果优于单纯益气和养阴益气的处方。根据前方制备的温阳健心灵口服液保持了原煎剂的疗效，并被毒理学试验证明毒性极低。动物药效学及临床试验发现该药不仅能改善心衰犬和病人的左室收缩功能，还能改善其舒张功能。除此，它还具有利尿作用和使PAWA、SVR和PVR下降的作用，这也是它抗心衰的机理之一。90例的临床观察（疗程2周）表明该药总有效率、近期治愈率和显效率分别达88．9％、7．4％和18．5％，其效与开搏通组无明显差异。     

术中超声引导放射性^125Ⅰ粒子组织间植入治疗局部晚期胰腺癌

目的 探讨超声引导下术中放射性^125Ⅰ粒子组织间种植治疗无法切除胰腺癌的可行性和疗效。方法 2002年4月～2005年2月，我院行开腹^125Ⅰ粒子植入治疗晚期胰腺癌21例。术前根据治疗计划，确定粒子活度和种植粒子个数，肿瘤匹配周边剂量为65～110Gy，每颗粒子活度为0．4～0．5mCi。超声引导下插入粒子种植针，Mick粒子植入器植入^125Ⅰ粒子，粒子植入数10～75颗。8例粒子植入前或后行胃肠或胆肠吻合术。2例术后行外放疗联合单药吉西他滨化疗。1例术前置入支架，1例术后置入支架。结果 15例腹痛中，14例术后1～3d疼痛即开始缓解，其中7例疼痛完全缓解，7例部分缓解，1例无效，有效率93．3％（14／15）；除2例失访外，CR5例，PR7例，PD5例，NC2例。19例中位生存期5个月，1年生存率26．3％。1例出现乳糜漏，3例粒子移位到肝脏。无胰漏和胰腺炎等并发症。结论 放射性^125Ⅰ粒子组织间种植治疗胰腺癌具有安全、有效、创伤小和并发症发生率低等优点，是一种较好的补救治疗手段。     

蝎毒多肽对大鼠纤溶系统的作用

从蝎毒中获取具有多种药理活性的肽类混合物（简称ＳＶＰ），用下肢血管灌流和整体给药的动物模型，观察对血管灌流液内纤溶酶原激活物（ＰＡ）活性、血浆优球蛋白纤溶活性（ＥＦＡ）、纤溶酶（ＰＬ）活性的影响。结果：１～２０μｇ／ｍｌ灌流３ｍｉｎ和０．８，１．６ｍｇ·ｋｇ－１ｉｐＳＶＰ１ｈ血浆中ＰＡ活性与对照组相比明显升高（Ｐ＜０．０５或Ｐ＜０．０１），这可能与血管内皮细胞释放ＰＡ活性增加有关。