Rapid identification and susceptibility testing using the VITEK(R) 2 system using culture fluids from positive BacT/ALERT(R) blood cultures

BACKGROUND AND PURPOSE: In order to reduce the turnaround time for laboratory diagnosis of bacteremia, the efficacy of identification and antimicrobial susceptibility testing using samples taken directly from positive BacT/ALERT(R) standard aerobic and standard anaerobic blood culture bottles was evaluated. METHODS: 160 positive blood culture bottles were examined and incubated at 35 degrees C in 5% carbon dioxide for 4-24 h, and an aliquot of the culture fluid was Gram stained. Samples containing Gram-negative bacilli were inoculated on VITEK(R) 2 ID-GNB (identification-Gram-negative bacilli) and AST (antimicrobial susceptibility testing)-GN04 cards, and those containing Gram-positive cocci were inoculated on ID-GPC (identification-Gram-positive cocci) and AST-P526 cards. The same samples were also examined by the standard method, involving subculture from positive BacT/ALERT standard blood culture bottles. RESULTS: Eighty seven of 97 Gram-negative bacilli (89.7%) and 21 of 63 Gram-positive cocci (33.3%) were correctly identified to the species level. For antimicrobial susceptibility testing, the direct method had an overall error rate of 5.4% for Gram-negative bacilli, with 0.9% very major, 0.9% major, and 3.6% minor discrepancies compared to the standard method. The overall error rate in antimicrobial susceptibility testing for the 13 Staphylococcus spp. was 10.3%, with 6.0% very major, 2.6% major, and 1.7% minor discrepancies. CONCLUSION: These data suggest that VITEK 2 cards inoculated with samples taken directly from positive Bact/ALERT blood culture bottles would provide acceptable identification and antimicrobial susceptibility testing results for Gram-negative bacilli, but not for Gram-positive cocci. Compared to the standard method, the direct method would reduce turnaround time by at least 24 h.     

Invasive pulmonary aspergillosis: high incidence of disseminated intravascular coagulation in fatal cases.

BACKGROUND AND PURPOSE: Disseminated intravascular coagulation (DIC) is a rarely described finding in invasive pulmonary aspergillosis (IPA) with unclear impact on mortality. METHODS: This study included patients with positive cultures of Aspergillus spp. from respiratory specimens, serological evidence of aspergillosis, or lung biopsy findings supporting aspergillosis treated at National Taiwan University Hospital from January 1999 to June 2005. IPA was defined based on the consensus of the European Organization for Research and Treatment of Cancer, and the Mycosis Study Group of the National Institute of Allergy and Infectious Diseases. Univariate logistic regression analysis was used to evaluate the factors associated with mortality. RESULTS: Proven or probable IPA was diagnosed in 26 patients. Hematological malignancy was found in 11 patients (42%) and immunosuppressive agents had been administered to 17 patients (65%). Among 20 culture-proven infections (77%), the most frequently encountered fungi were Aspergillus fumigatus (46%) and Aspergillus flavus (23%). The overall mortality rate was 62%. Univariate and multivariate analyses revealed that DIC was the only factor that was significantly associated with death attributable to IPA (p<0.01). CONCLUSIONS: IPA is associated with a high mortality rate, particularly for patients with DIC.     

视黄醇结合蛋白4与代谢综合征的关系

目的 探讨视黄醇结合蛋白4(RBP4)的血清水平及-G 803 A SNP与代谢综合征的关系.方法 收集116名伴2型糖尿病的代谢综合征患者和93名正常体检者,放射免疫法测定RBP4血清水平,聚合酶链式反应及序列分析检测G 803 A多态性基因型.结果 (1)RBP4水平在所有受试者中与体质指数(BMI)、腰围、空腹胰岛素(FINS)、胰岛素抵抗指数(HOMA-IR)、三酰甘油(TG)正相关,对照组中与TG、TC、LDL-C正相关,男性组中与DBP正相关,女性组中与年龄、FINS、HOMA-IR、TG、SBP正相关,多元逐步回归分析发现腰围、BMI、TG和年龄是独立相关因素;RBP4水平在代谢综合征组和男性组显著升高,在有规律运动组显著降低.(2)代谢综合征组与正常对照组的RBP4-G 803 A多态性基因型分布未见显著差异,按不同基因型分组的代谢指标亦无显著性差异.结论 在中国汉族人群中,RBP4水平与多个代谢参数相关,RBP4基因-G 803 A SNP与代谢综合征没有关联.     

非接触标测和频谱分析迷走神经介导的心房颤动

目的： 对在体犬迷走神经介导的心房颤动（房颤）进行非接触标测和频谱分析，以探讨其发生和维持机制。方法: 测定8只犬基础情况及双侧迷走神经刺激时心房有效不应期及其离散度，非接触标测和频谱分析房颤时左、右房的电活动。结果: 迷走神经刺激与基础情况相比，左、右心房有效不应期缩短，但有效不应期离散度增大仅见于左房。迷走神经刺激时房颤易诱发和维持，房颤显示反复有序的激动经优先传导路径传播仅见于左房；频谱分析显示左房的主导频谱高于右房［（12.5±1.5)Hz vs (9.3 ±1.2) Hz，P<0.05］。停止迷走神经刺激，左、右房房颤频谱降低［（9.2±0.5)Hz vs (8.5±0.6)Hz， P>0.05］，房颤自发终止。结论: 左、右房电生理特性改变、激动模式差异以及频谱梯度提示迷走神经介导的房颤发生和维持依赖于左房。     

Multiple B- and T-cell epitopes on a major allergen of Kentucky Bluegrass pollen.

The B- and T-cell epitopes of a recombinant grass allergen, rKBG60, were delineated using a set of overlapping synthetic peptides. Direct binding by enzyme-linked immunosorbent assay (ELISA) utilizing serum pools led to the identification of 13 murine immunoglobulin-, and nine to 13 human IgG- and five to seven human IgE-reactive overlapping peptides. Of the peptides which bound to human IgE antibodies, all but three peptides bound to human and/or murine IgG antibodies. Furthermore, eight out of 12 synthetic peptides induced antigen-specific antibodies in mice, suggesting that these peptides contained epitopes that recognized and/or induced T cells. These results, in conjunction with cross-recognition of different peptides at the C-terminus of rKBG60 by antibodies to neighbouring or non-overlapping peptides suggest that the C-terminus of this antigen represents a dominant antigenic and allergenic site. Peripheral blood mononuclear cell (PBMC) proliferation studies using these synthetic peptides for 13 grass allergic individuals indicated that seven potential human T-cell epitopes exist on this allergen. Taken together, the results demonstrate that multiple B- and T-cell epitopes exist on this major group of grass allergens, the majority of which are localized at the C-terminus of this antigen.     

Production of monoclonal antibody to a phenolic glycolipid of Mycobacterium tuberculosis and its use in detection of the antigen in clinical isolates.

A monoclonal antibody (MAbIII604) specific to phenolic glycolipid Tb (PGL-Tb), a Mycobacterium tuberculosis-specific antigen, was produced and used in the detection of the antigen. MAbIII604 reacted with the PGL-Tb antigen but not with other phenolic glycolipids from Mycobacterium leprae, M. bovis, and M. kansasii, thus indicating the specificity of the monoclonal antibody to PGL-Tb. A dot enzyme-linked immunosorbent assay with MAbIII604 was employed to detect the PGL-Tb antigen in lipids purified from M. tuberculosis clinical isolates. Of 50 isolates, 32 (64.0%) showed clear evidence of the PGL-Tb antigen by the dot enzyme-linked immunosorbent assay, but there were marked variations in the intensities and sizes of spots. This suggests differences in PGL-Tb antigen production among M. tuberculosis strains even when they are grown in the same culture media and conditions. This was most evident from the fact that in only eight (16.0%) of the isolates examined was the PGL-Tb antigen detectable by thin-layer chromatography, which is much less sensitive for the detection of glycolipid antigens. This study shows that monoclonal antibodies specific to PGL-Tb are useful in detecting the antigen in lipid extracts and that there is a marked variation in the PGL-Tb production among M. tuberculosis clinical isolates.     

Intratracheal administration of liposomal clodronate accelerates alveolar macrophage reconstitution following fetal liver transplantation

To facilitate study of alveolar macrophages in vivo, we developed a method to rapidly and efficiently replace resident alveolar macrophages with macrophages of a different (donor) genotype. Chimeric mice were generated by lethal irradiation followed by fetal liver transplantation (FLT) using green fluorescent protein (GFP) transgenic reporter mice as donors. Kinetics of peripheral blood monocyte (PBM) and alveolar macrophage reconstitution was determined 4 and 10 weeks post-FLT by quantifying the percentage of GFP+ cells. To enhance the recruitment of donor monocytes into the lung after FLT, mice were treated with intratracheal administration of liposomal clodronate to deplete host alveolar macrophages at 6 weeks post-FLT. PBM reconstitution occurred by 4 weeks after FLT (85.7+/-1.6% of CD11b+/Gr-1+ monocytes were GFP+), and minimal alveolar macrophage repopulation was observed (9.5% GFP+). By 10 weeks following FLT, 48% of alveolar macrophages were GFP+ by immunostaining of macrophages on lung tissue sections, and 55.1 +/- 1.6% of lung lavage macrophages were GFP+ by fluorescein-activated cell sorter analysis. Clodronate treatment resulted in a significant increase in GFP+ alveolar macrophages 10 weeks after FLT. By immunostaining, 90% of macrophages were GFP+ on lung tissue sections and 87.5 +/- 1.1% GFP+ in lung lavage (compared with GFP-transgenic controls). The ability of newly recruited alveolar macrophages to clear Pseudomonas aeruginosa and activate nuclear factor-kappaB in response to Eschericia coli lipopolysaccharide demonstrated normal macrophage function. Optimizing this methodology provides an important tool for the study of specific genes and their contribution to alveolar macrophage function in vivo.     

神经系统疾病少年儿童患者的脆性X综合征检查与临床诊治研究

目的研究神经疾病少年儿童患者脆性X综合征（fragjle X syndrome,FraX）的细胞遗传学检测和临床诊治特征。方法应用低叶酸培养基，对患神经疾病的18岁以下146例儿童行X染色体脆性部位的检测，对检出的Frax患儿给以叶酸为主辅以营养神经和神经康复的治疗。结果146例就诊患儿检出FraX13例，检出率为8．90％。以补充叶酸为主的综合治疗取得一定疗效，治疗效果与患儿年龄和原发神经疾病有关。结论FraX值得临床重视，早检出、早治疗收效较好。     

SARS冠状病毒棘突蛋白的S1蛋白诱导小鼠产生中和抗体的研究

目的 研究SARS冠状病毒棘突蛋白受体结合部位S1的免疫原性，为SARS的实验诊断和新型疫苗的研究提供依据。方法 用克隆有哺乳动物细胞密码子优化的SARS-CoV S1基因的质粒pcDNA3．1／S1或P-S1Ig转染293T细胞，用细胞的上清液纯化S1蛋白。以pcDNA3．1／S1质粒对BALB／c小鼠进行2次基因免疫，以纯化的S1蛋白进行加强免疫。用ELISA法检测小鼠抗SARS-CoV的特异性IgG抗体，并在Vero E6细胞上做体外中和实验，检测中和抗体。结果 S1蛋白诱导小鼠产生抗SARS-CoV的特异性抗体；1：1499．68稀释的S1蛋白免疫的小鼠血清可保护50％的细胞对1000TCID50的病毒攻击，而阴性对照血清不能保护细胞对病毒的感染。结论 SAPS冠状病毒棘突蛋白受体结合部位S1能有效诱导机体产生具有高效保护作用的中和抗体免疫反应，可望发展成为理想的SARS棘突蛋白亚单位疫苗。