可切削渗透陶瓷玻璃料对不同堆积密度氧化铝基体的渗透

探讨了可切削渗透陶瓷 (Infiltration of Machinable- infiltrated- ceramic,MIC)渗透玻璃在不同堆积密度氧化铝基体中的渗透情况及渗透后复合体的颜色表达。在 110 0℃保温 2 h,将玻璃渗透到不同堆积密度的氧化铝基体中 ,分别测得其渗透深度和颜色参数。扫描电镜观察玻璃—氧化铝复合体断面。玻璃渗透深度的平方与氧化铝堆积密度有直线负相关关系 ,最小渗透深度为 3.0 92 m m。复合体的颜色系数与氧化铝堆积密度无相关性。渗透复合体在断裂过程中可见 :裂纹偏转、晶体拔出和穿晶断裂。本实验证实 MIC渗透玻璃的渗透性能达到临床要求。渗透后的复合体颜色稳定 ,强度可靠     

Characterization of erythromycin-resistant Streptococcus pneumoniae in Korea, and In Vitro activity of telithromycin against erythromycin-resistant Streptococcus pneumoniae

To characterize the phenotypes and genotypes of erythromycin-resistant clinical isolates of Streptococcus pneumoniae in Korea and to evaluate the in vitro activity of telithromycin against these erythromycin-resistant isolates, we tested a total of 676 isolates of S. pneumoniae collected from 1997 to 2002 in a tertiary hospital in Seoul, Republic of Korea. MICs for erythromycin and telithromycin were determined by the agar dilution method. The macrolide resistance phenotypes of erythromycin-resistant isolates were determined by the erythromycin- clindamycin-rokitamycin triple disk (ECRTD) and MIC induction tests, whereas their macrolide resistance genotypes were determined by PCR for the erm(B), erm(A), subclass erm(TR), and mef genes. To discriminate between mef(A) and mef(E), PCR-restriction fragment length polymorphism (RFLP) analyses were performed. Of the 676 S. pneumoniae isolates, 459 (67.9%) were resistant to erythromycin. Of the 459 erythromycin-resistant isolates, 343 (74.7%) were assigned to the cMLS phenotype, 48 (10.4%) to the iMcLS phenotype, 4 (0.9%) to the iMLS phenotype, and 64 (14.0%) to the M phenotype. The erm(B) gene was detected in 251 (54.6%) isolates, the mef gene was detected in 64 (14.0%), and both the erm(B) and mef genes were detected in 144 (31.4%) isolates. All of the mef genes detected were identified as mef(E). Of the 459 erythromycin- resistant isolates, all but one were susceptible to telithromycin. The MIC(50)/MIC(90) to telithromycin of isolates carrying erm(B), mef(E), and both genes was 0.06/0.5 microg/ml, 0.03/0.125 microg/ml, and 0.5/1.0 microg/ml, respectively. Although the MICs of telithromycin for the erythromycin-resistant isolates varied according to genotype, telithromycin was very active against these erythromycin-resistant S. pneumoniae.     

PD-1-Expressing SARS-CoV-2-Specific CD8+ T Cells Are Not Exhausted,but Functional in Patients with COVID-19

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TGFβ1基因对血管内皮细胞细胞外基质表达及与基质黏附的影响

了解TGFβ1基因对血管内皮细胞表达细胞外基质蛋白及与基质黏附力的影响。用DOTAP脂质体转染p MAMneo TGFβ1于原代培养的脐静脉内皮细胞,经G4 18筛选,TGFβ1表达经免疫荧光鉴定。Western blot确定 型胶原、纤黏连蛋白的表达,微管吸吮系统确定内皮细胞与基质的黏附力。结果表明生理情况下的内皮细胞能表达少量的TGFβ1及胶原、纤黏连蛋白。经G4 18筛选,外源性TGFβ1在血管内皮细胞中稳定表达,能显著提高胶原、纤黏连蛋白纤维的表达及细胞与基质的黏附。说明TGFβ1在血管组织工程中促进内皮细胞的黏附具有一定的应用价值。     

多发性骨髓瘤的个体型阳性细胞检查及意义

近年来抗个体型抗体(antiidiotypeantibodies,抗Id抗体)的理论研究及应用有了迅速地发展,已成为免疫学研究中活跃领域之一。个体型是指在同一个体内,不同的抗体形成细胞所产生的免疫球蛋白(Ig)有各自不同的抗原特异性。决定个体型抗原特异性的部位在抗体可变区的超可变区,是针对超可变区某些抗原决定簇的抗体。在     

NF-κB的活性和iNOS基因表达在低氧性肺动脉高压中的变化

目的：探讨NF-κB的活性及iNOS基因表达在低氧性肺动脉高压（HPH）发病过程中的变化。方法：复制低氧性肺动脉高压大鼠模型，用免疫组化、原位杂交、半定量逆转录-聚合酶链式反应（RT-PCR）和Western blot等方法进行检测。结果：iNOS mRNA在腺泡内肺动脉（IAPA）的表达，低氧28 d（H28d）组染色强于正常（N）组、低氧5 d（H5d）组和低氧14 d（H14d）组。半定量RT-PCR证实低氧肺组织iNOS mRNA含量在H28d组分别是N组、H5d组和H14d组的2.1倍、1.9倍和1.8倍。H28d组肺组织NF-κB的核染色增多，I-κBα的含量在N组、H5d组和H14d组分别是H28d组的2.7倍、2.8倍和2.5倍。结论：在HPH中NF-κB的激活可能与低氧肺血管构建及iNOS mRNA的表达有关。     

The ultrastructure of hybrid acute leukemia: a study of 15 cases

The objective of this study was to investigate the ultrastructural characteristics of hybrid acute leukemia (HAL). Fifteen cases of HAL were studied by transmission electron microscopy (TEM), focusing on organelles and myeloperoxidase (MPO) reaction of leukemic cells. By TEM, 5 out 15 cases of HAL were consistent with immunophenotyping (3 cases of biphenotypic type, and 2 cases of biclonal type with granulocytes and lymphocytes); 2 cases were suspected as HAL. On other hand, 5 cases of HAL were assigned to ALL, and 2 cases were misinterpreted as M5a and 1 as M4b. Most of the blast cells of biphenotypic HAL showed lymphoid features, except some cases containing MPO positive granules in blasts, while a few cases exhibited monocytic or nonspecific features. TEM offers advantages in the diagnosis of biclonal type HAL and biphenotypic HAL positive for MPO. However, it is difficult to differentiate MPO-negative cases of biphenotypic HAL from ALL and a few cases may be misinterpreted as M5 by TEM.     

Effect of ketamine on apoptosis by energy deprivation in astroglioma cells using flow cytometry system

Apoptosis is a programmed, physiologic mode of cell death that plays an important role in tissue homeostasis. As for the central nervous system, ischemic insults can induce pathophysiologic cascade of apoptosis in neurophils. Impairment of astrocyte functions during brain ischemia can critically influence neuron survival by neuronglia interactions. We aimed to elucidate the protective effect of ketamine on apoptosis by energy deprivation in astrocytes. Ischemic insults was induced with iodoacetate/ carbonylcyanide m-chlorophenylhydrazone (IAA/CCCP) 1.5 mM/20 microm or 150 microm/2 microm for 1 hr in the HTB-15 and CRL-1690 astrocytoma cells. Then these cells were reperfused with normal media or ketamine (0.1 mM) containing media for 1 hr or 24 hr. FITC-annexin-V staining and propidium iodide binding were determined by using flow cytometry. Cell size and granularity were measured by forward and side light scattering properties of flow cytometry system, respectively. An addition of ketamine during reperfusion increased the proportion of viable cells. Ketamine alleviated cell shrinkage and increased granularity during the early period, and ameliorated cell swelling during the late reperfusion period. Ketamine may have a valuable effect on amelioration of early and late apoptosis in the astrocytoma cells, even though the exact mechanism remains to be verified.     

银杏叶提取物对心肌缺血再灌注微循环的保护作用

复制家兔缺血再灌注模型,采用显微电视和微机图像处理系统对20只家兔球结膜微血管口径、流速、流量等参数进行定量分析.结果:银杏叶提取物(GBE)组在结扎即刻、30分钟、再灌注30分钟等时相,与生理盐水组比较,微动脉、微静脉口径(3、4级)、微静脉流速、流量、毛细血管密度均增加,交换距离缩小(P<0.05).提示:GBE对心肌缺血再灌注微循环有显著的保护作用.其机制可能与扩张微血管口径、改善血流灌注有关.     

人源腺病毒伴随病毒Ⅱ型单克隆抗体Fab段及其全抗体的研制

目的 运用噬菌体表面表达技术，获得基因工程抗腺病毒伴随病毒抗体Fab、IgG。方法 从酶联免疫吸附试验阳性的人外周血中分离淋巴细胞。提取总RNA，逆转录cDNA，聚合酶链反应扩增人IgG Fab轻、重链基因，利用pComb3载体构建噬菌体抗体库。用纯化的腺病毒伴随病毒为固相抗原筛选抗体Fab段，并在E.coli中进行分泌性表达。通过ELISA和间接免疫荧光试验、筛选和鉴定Fab抗体，并进行序列测定。然后将其重链和轻链基因克隆到全抗体表达载体pAC-L-Fc上。转染昆虫sf-9细胞，利用杆状病毒，昆虫细胞系统实现全抗体的分泌型表达，免疫沉淀试验鉴定它的抗蛋白。结果 分离到一株Fab克隆AAVs-31，腺病毒伴随病毒抗原和抗Fab抗体直接ELISA检测阳性，间接免疫荧光试验呈阳性，序列分析结果表明是一新的序列，所获得的基因为人源IgG Fab基因。由Gamma链和Kappa链组成。表达的全抗体ELISA反应、免疫荧光反应和间接免疫荧光试验均为阳性，免疫沉淀试验结果显示它结合病毒颗粒，不结合任一VP1、VP2、VP3单独衣鞘蛋白。结论 用噬菌体表面表达技术首次获得了抗腺病毒伴随病毒Ⅱ型单克隆抗体Fab段，并在真核系统中表达了其全抗体，它们识别的可能是衣鞘蛋白组装时形成的表位。