Myocardial perfusion SPECT reconstruction: Receiver operating characteristic comparison of CAD detection accuracy of filtered backprojection reconstruction with all of the clinical imaging information available to readers and solely stress slices iteratively reconstructed with combined compensation

BACKGROUND: Past receiver operating characteristic (ROC) studies have demonstrated that single photon emission computed tomography (SPECT) perfusion imaging by use of iterative reconstruction with combined compensation for attenuation, scatter, and detector response leads to higher area under the ROC curve (A(z)) values for detection of coronary artery disease (CAD) in comparison to the use of filtered backprojection (FBP) with no compensations. A new ROC study was conducted to investigate whether this improvement still holds for iterative reconstruction when observers have available all of the imaging information normally presented to clinical interpreters when reading FBP SPECT perfusion slices. METHODS AND RESULTS: A total of 87 patient studies including 50 patients referred for angiography and 37 patients with a lower than 5% likelihood for CAD were included in the ROC study. The images from the two methods were read by 4 cardiology fellows and 3 attending nuclear cardiologists. Presented for the FBP readings were the short-axis, horizontal long-axis, and vertical long-axis slices for both the stress and rest images; cine images of both the stress and rest projection data; cine images of selected cardiac-gated slices; the CEQUAL-generated stress and rest polar maps; and an indication of patient gender. This was compared with reading solely the iterative reconstructed stress slices with combined compensation for attenuation, scatter, and resolution. With A(z) as the criterion, a 2-way analysis of variance showed a significant improvement in detection accuracy for CAD for the 7 observers (P = .018) for iterative reconstruction with combined compensation (A(z) of 0.895 +/- 0.016) over FBP even with the additional imaging information provided to the observers when scoring the FBP slices (A(z) of 0.869 +/- 0.030). When the groups of 3 attending physicians or 4 cardiology fellows were compared separately, the iterative technique was not statistically significantly better; however, the A(z) for each of the 7 observers individually was larger for iterative reconstruction than for FBP. Compared with results from our previous studies, the additional imaging information did increase the diagnostic accuracy of FBP for CAD but not enough to undo the statistically significantly higher diagnostic accuracy of iterative reconstruction with combined compensation. CONCLUSIONS: We have determined through an ROC investigation that included two classes of observers (experienced attending physicians and cardiology fellows in training) that iterative reconstruction with combined compensation provides statistically significantly better detection accuracy (larger A(z)) for CAD than FBP reconstructions even when the FBP studies were read with all of the extra clinical nuclear imaging information normally available.     

95例SARS患者T细胞及其亚群动态变化的观察

对 95例SARS患者的T淋巴细胞亚群动态变化进行分析。其中 85例痊愈 ,1 0例死亡。 85例痊愈患者 ,病程第 7天平均CD4 + ( 3 2 5± 1 90 )个 /μL ,CD8+ ( 3 1 9± 3 1 5 )个 /μL ,CD4 + /CD8+ 1 .2 5± 0 .71 ,与我国正常人相比〔平均CD4 + ( 72 7± 2 5 5 )个 /μL、CD8+ ( 5 3 9± 1 3 4)个 /μL ,CD4 + /CD8+ 1 .49〕 ,T淋巴细胞亚群明显下降 (P =0 .0 0 1 )。病程第1 4天左右免疫功能逐渐恢复 ,平均CD4 + ( 5 61± 5 2 2 )个 /μL ,CD8+ ( 3 70± 2 71 )个 /μL ,CD4 + /CD8+ 1 .68± 1 .1 1。 2 1d后免疫功能基本恢复正常 ,平均CD4 + ( 675± 448)个 /μL ,CD8+ ( 4 67± 2 41 )个 /μL ,CD4 + /CD8+ 1 .48± 0 .68。 1 0例死亡患者的T细胞亚群在入院后逐渐出现下降趋势 ,病程第 7天CD4 + ( 2 48± 82 )个 /μL ,CD8+ ( 2 3 3± 1 1 5 )个 /μL ,CD4 + /CD8+ 1 .2 1± 0 .40 ,第 1 4天T淋巴细胞继续下降 ,平均CD4 + ( 1 81± 1 2 8)个 /μL ,CD8+ ( 1 73± 1 0 9)个 /μL ,CD4 + /CD8+ 1 .1 7± 0 .45 ,2 1d后CD4 + 细胞继续下降 ,平均CD4 + ( 1 2 5± 46)个 /μL ,CD8+ ( 94± 3 8)个 /μL ,CD4 + /CD8+ 1 .44±0 .5 9。结果提示 :SARS患者早期可能存在异常的免疫反应 ,这种异常免疫反应可能是导?     

氟对人体T细胞数目的影响及硼砂拮抗作用的观察

将３８例地氟病人分为硼砂治疗组和治疗对照组，通过对病人外周血Ｔ淋巴细胞亚群含量的检测，观察了氟对人体Ｔ３、Ｔ４、Ｔ８淋巴细胞含量的影响以及硼砂的拮抗作用。结果表明，在本研究条件下，地氟病人外周血Ｔ３、Ｔ４淋巴细胞数目明显减少，硼砂对此变化无明显的拮抗作用。     

The normally expressed κ immunoglobulin light chain gene repertoire and somatic mutations studied by single-sided specific polymerase chain reaction (PCR); frequent occurrence of features often assigned to autoimmunity

The expressed human κ light chain gene repertoire utilized by healthy individuals was studied by two different single-sided specific PCR techniques to avoid bias for certain V genes. A total of 103 rearranged κ sequences from peripheral blood mononuclear cells from healthy individuals were cloned from cDNA and assigned to the Vκ and Jκ germ-line genes with the closest overall homology. The use of cDNA rather than genomic DNA focused the analysis on activated B cells rich in mRNA. Accordingly, the sequences represented the applied repertoire and almost all were somatically mutated. V genes from the Jκ-proximal duplication unit of the κ locus were almost exclusively used. A total of 65% of the sequences could be assigned to four or five genes: A27 (humkv325), L6 (Vg), L2 (humkv328), and A3 and/or A19. N additions and P nucleotides were quite common and found in 32% and 21% of the sequences, respectively. Extended CDR3s more than nine residues in length were found in 18% of the sequences, and in 71% of cases this was due to insertion of an extra proline residue. This proline was usually explained from the germ-line sequences involved. These results are in good agreement with those of previous repertoire studies using potentially V-gene-biased techniques. Thus, it is clear that restricted V-gene usage, common N and P additions, and extended CDR3 regions are normal features and not, as has been claimed, characteristics of pathological autoantibodies.     

Cell surface phenotype of in vitro proliferating lymphocytes in HTLV-I-associated myelopathy (HAM/TSP)

The in vitro proliferation of peripheral blood lymphocytes (PBLs) without any mitogenic stimulation is one of the hallmarks of human T lymphotropic virus type I (HTLV-I) infection. Recent evidence suggests a difference in the degree of the phenomenon between HTLV-I-associated myelopathy/tropical spastic paraparesis (HAM/TSP) and asymptomatic HTLV-I carriers (AC). In this article, we demonstrated several alterations in the features of the in vitro transformed lymphocytes between patients with HAM/TSP (n = 16) and AC (n = 8). The percentages of total CD8+ and CD8+CD28+ cells were significantly increased in the in vitro proliferating T lymphocytes derived from the patients with HAM/TSP when compared to those from AC. HAM/TSP was segregated from AC by the high degree of the proliferation of CD8+CD28+ cells. The expression of HTLV-I-specific antigens on the cultured PBLs was detected only in the subjects which showed low CD8+CD28+/CD4+ ratio of the in vitro proliferating lymphocytes. These findings suggest that this phenomenon distinguishes HAM/TSP from AC, not only in quantity but also in quality.     

Characterization of T-cell subsets infiltrating post-burn hypertrophic scar tissues

In this study, skin-infiltrating cells were characterized in both the active and remission phases of post-burn hypertrophic scar biopstes. Immunohistochemistry examination of active phase samples showed an abundant presence of Langerhans cells, T cells, macrophages, a low presence of natural killer cells and the lack of B lymphocytes. In active hypertrophic scars T lymphocytes infiltrate deep into the superficial dermis and are also observed in the epidermis: CD3⁺ cells were present at about 222±107 per 0.25 mm². In particular the analysis of lymphocyte subpopulations showed that CD4⁺ T cells predominate in the dermis as well as in the epidermis of active hypertrophic scars whereas CD8⁺ cells were less well represented (CD4/CD8 ratio is 2.06). This distribution was also shown in remission phase samples and in normotrophic scar specimens, although the lymphocyte number was significantly lower. Approximately 70 per cent of T lymphocytes present in the tissue involved in active phase hypertrophic scar samples were activated (positive with anti-HLA-DR and IL-2 receptor antibodies) which is significantly higher than remission phase hypertrophic and normotrophic scars, in which positivity was 40 and 38 per cent, respectively. Upon activation, the lesional lymphocytes release several cytokines, locally and transiently, that interact with specific receptors in response to different stimulation. Central to the immune hypothesis of hypertrophic scars is that some of the T-cell lymphokines act on keratinocytes, fibroblasts and other cell types to induce changes characteristic of these scars. The presence and close proximity of activated T lymphocytes and antigen-presenting cells of various phenotypes in both the epidermis and dermis of hypertrophic tissues provides strong circumstantial evidence of a local immune response. However, the manner in which T cells achieve and maintain their activated state in hypertrophic tissues in not yet known, and both antigen-dependent and independent mechanisms may contribute.     

静脉用丙种球蛋白治疗新生儿重症感染对细胞免疫功能的影响

应用静脉注丙球(IVIG),配合抗生素(An)治疗重症感染新生儿12例,在观察疗效及不良反应的同时,通过检测患儿治疗前后T细胞亚群及白细胞介素Ⅱ(IL-2)产生水平的变化,观察IVIG对细胞免疫功能的影响。结果显示:患儿CD_3~+、CD_4~+、CD_8~+细胞及IL-2产生水平均明显低于正常同龄新生儿。经IVIG+An及单用An治疗后,T细胞各亚群及IL-2水平均明显增高。IVIG组与An组比较,诒疗后IVIG组CD_4~+细胞明显高于An组,IL-2水平也较An组为高,但无统计学意义。疗效观察,中毒症状及原发病体征好转消失时间IVIG组较An组明显缩短。本文还就IVIG对细胞免疫功能影响的可能机制进行了讨论。     

获得性纯红再障患者外周血T细胞亚群分析

目的　本研究通过分析获得性纯红再障患者外周血T细胞亚群 ,进一步探讨该病的细胞免疫发病机制。方法　用抗人CD3、CD4、CD8、IFN γ及IL 4单抗结合人外周血单个核细胞 ,流式细胞术分析单个核细胞中CD3 +、CD4+、CD8+细胞数Th1、Th2、Tc1、Tc2细胞数以及CD4+/CD8+、Th1/Th2、Tc1/Tc2比值。结果　贫血组患者 ,外周血CD3 +细胞和CD8+细胞明显增加 (P <0 .0 1) ,CD4+/CD8+比例倒置 (P <0 .0 5 ) ;Tc2细胞明显增加 (P <0 .0 5 ) ,Tc1/Tc2比值降低(P <0 .0 5 ) ,治疗后血象恢复的患者各增高的亚群细胞均有所恢复 ,接近正常。结论　在获得性纯红再障患者T细胞明显增高 ,其中主要是CD8+细胞 ,而在CD8+细胞中 ,是Tc2细胞发挥了重要作用。经治疗有效的患者 ,其增高的T细胞亚群降低 ,提示以纠正病人细胞免疫异常为主的治疗方案有益于获得性纯红再障的治疗。     

Effect of prostaglandin E1 on graft function of kidneys from living related donors

Prostaglandin E₁ (PGE₁) was used in renal transplant recipients with living related donors. The drug was given intravenously from day 1 to day 7 after transplantation at a dose of 40 µg/kg twice a day. A total of 45 patients were studied divided into two groups: 25 patients were treated with PGE₁ (group B) and the remaining 20 patients did not receive the drug (group A). In group B, 24-h creatinine clearance (Ccr) was 66 ± 12.8 ml/min compared with 40.3 ± 13.4 ml/min in group A on the fifth postoperative day (P < 0.05). Urinary levels of N-acetyl-β-d -glucosaminidase (NAG) and serum levels of platelet factor 4 (PF4) in group B were significantly lower than in group A. On the fourth postoperative day, the urinary excretion of thromboxan B₂ (TxB₂) in group A was higher than in group B, but not significantly (5.1 ± 3.0 ng/day and 2.8 ± 1.1 ng/day, respectively). Acute rejection occurred in four patients in group B and in 10 patients (40%) in group A. The percentage of Leu2a-positive lymphocytes in group B was higher than in group A. We conclude that postoperative administration of PGE₁ improves graft function in kidneys from living related donors.     

应用单克隆抗体检测肺癌病人外周血中T细胞亚群

本文应用单克隆抗体检测33例原发性肺癌病人治疗前后外周血中T淋巴细胞亚群变化。结果提示:肺癌病人外周血中T细胞亚群明显有别于正常人,主要表现为T_H细胞降低和T_S细胞升高以及T_H/T_S比值明显倒置。短期观察结果表明,肺癌病人外周血中T_S细胞持续升高和T_H/T_S比值持续降低者,预后不良。临床检测T细胞亚群变化及它们的动态变化可作为判断宿主抗肿瘤免疫功能状态、病情发展和预后的敏感指标。