Accurate determination of brain metabolite concentrations using ERETIC as external reference

Magnetic Resonance Spectroscopy (MRS) can provide in vivo metabolite concentrations in standard concentration units if a reliable reference signal is available. For ¹H MRS in the human brain, typically the signal from the tissue water is used as the (internal) reference signal. However, a concentration determination based on the tissue water signal most often requires a reliable estimate of the water concentration present in the investigated tissue. Especially in clinically interesting cases, this estimation might be difficult. To avoid assumptions about the water in the investigated tissue, the Electric REference To access In vivo Concentrations (ERETIC) method has been proposed. In this approach, the metabolite signal is compared with a reference signal acquired in a phantom and potential coil‐loading differences are corrected using a synthetic reference signal. The aim of this study, conducted with a transceiver quadrature head coil, was to increase the accuracy of the ERETIC method by correcting the influence of spatial B₁ inhomogeneities and to simplify the quantification with ERETIC by incorporating an automatic phase correction for the ERETIC signal. Transmit field ( ) differences are minimized with a volume‐selective power optimization, whereas reception sensitivity changes are corrected using contrast‐minimized images of the brain and by adapting the voxel location in the phantom measurement closely to the position measured in vivo. By applying the proposed B₁ correction scheme, the mean metabolite concentrations determined with ERETIC in 21 healthy subjects at three different positions agree with concentrations derived with the tissue water signal as reference. In addition, brain water concentrations determined with ERETIC were in agreement with estimations derived using tissue segmentation and literature values for relative water densities. Based on the results, the ERETIC method presented here is a valid tool to derive in vivo metabolite concentration, with potential advantages compared with internal water referencing in diseased tissue.     

重症烧伤休克大鼠白细胞表面beta-2整合素的表达

目的 :阐明烧伤休克时 beta-2整合素与白细胞 -内皮细胞粘附间的关系。方法 :将 16只 SD大鼠随机均分为对照组和烧伤休克组。应用流式细胞技术检测中性粒细胞及单细胞表面 beta-2整合素CD11a( LFA-1)和 CD11b( Mac-1)的表达量变化 ,同时比较观察二组动物肠系膜微循环中微静脉内白细胞与内皮细胞粘附数量变化。结果 :二组自身对照 (烫伤前与烫伤后 3 h或开腹前与开腹后 3 h)及相互对比结果显示 ,中性粒细胞及单核细胞表面 CD11a表达量均无显著差异 ( P>0 .0 5 ) ;在烧伤组 ,单核细胞 CD11b有显著降低( P<0 .0 5 ) ,而中性粒细胞 CD11b有显著升高 ( P<0 .0 5 )。微循环观察结果显示 ,休克组动物烫伤后随时程延长附壁滚动及紧密粘附的白细胞数量明显增多 ,而对照组则无明显变化。结论 :烧伤休克状态下 ,白细胞表面 CD11a数量无显著变化 ,而 CD11b数量则有所改变。白细胞 -内皮细胞粘附力的增强可能有 beta-2整合素功能活性上调参与。     

Chicken NK cell receptors

Natural killer cells are innate immune cells that destroy virally infected or transformed cells. They recognize these altered cells by a plethora of diverse receptors and thereby differ from other lymphocytes that use clonally distributed antigen receptors. To date, several receptor families that play a role in either activating or inhibiting NK cells have been identified in mammals. In the chicken, NK cells have been functionally and morphologically defined, however, a conclusive analysis of receptors involved in NK cell mediated functions has not been available. This is partly due to the low frequencies of NK cells in blood or spleen that has hampered their intensive characterization. Here we will review recent progress regarding the diverse NK cell receptor families, with special emphasis on novel families identified in the chicken genome with potential as chicken NK cell receptors.     

Antimicrobial resistance pattern and in vivo activity of azithromycin in Salmonella isolates

We evaluated antimicrobial susceptibility pattern of 42 Salmonella isolates from February 2012 through January 2013. We also determined the minimum inhibitory concentrations (MICs) of azithromycin against Salmonella isolates and compared them with corresponding disc diffusion sizes. Entire 42 isolates were sensitive to chloramphenicol, 41 (97.6%) were sensitive to cotrimoxazole and amoxicillin each. MICs for azithromycin ranged from 2 μg/ml to 24 μg/ml, corresponding zone diameters ranged from 15 mm to 33 mm and the two were significantly correlated (P = 0.001). Our results indicate that whereas, azithromycin is a potential therapeutic option, the sensitivity to the first line drugs and absence of multidrug resistance reinforce the concept of antimicrobial recycling.     

Turner综合征自发性青春发育分析

目的探讨先天性卵巢发育不全综合征（Turnersyndrome,TS）患儿自发的青春发育与染色体核型及性激素水平之间的关系。方法30例Turner综合征患儿进行染色体检查,评估第二性征及性腺发育情况,检测性激素水平。结果染色体核型分4组,第1组45,XO,10例;第2组嵌合型,9例;第3组x染色体结构畸变,10例;第4组伴有Y染色体,1例。30例患儿随访至15周岁,其中10例出现不同程度的自发性青春发育,20例呈无性发育,4组患儿中以嵌合型TS出现自发青春发育几率最大。有青春发育患儿的性激素水平与无性发育患儿的性激素水平有显著差异。结论Turner综合征患儿自发性青春发育与染色体核型及性激素水平有密切相关性。     

Clostridioides difficile infection in patients with hematological malignancy: A multicenter study in Taiwan

BackgroundAmong the individuals with hematological malignancy (HM) complicated with Clostridioides difficile infection (CDI), the variables associated with in-hospital mortality and recurrence of CDI were investigated.Material and methodsIncluding adults with HM and those without malignancy suffering from CDI from January 2015 to December 2016 in three hospitals in Taiwan.ResultsTotally 314 patients including 77 with HM and 237 patients without malignancy were included. HM patients more often had low leukocyte counts (<500 cells/mL: 28.6% vs. 2.1%) than those without malignancy and more patients without malignancy had severe CDI than patients with HM (31.6% vs. 14.3%, P = .003), according to the severity score of IDSA/SHEA. Patients with HM had a higher recurrence rate of CDI (14.3%, 11/77 vs. 7.2%, 17/237; P = .07) and longer hospital stay (47.2 ± 40.8 days vs. 33.3 ± 37.3 days; P = .006) than those without malignancy. In the multivariate analyses for those with HM and CDI, the in-hospital mortality was associated with vancomycin-resistant Enterococcus (VRE) colonization or infection (odds ratio [OR] 7.72; P = .01), and C. difficile ribotype 078 complex infection (OR 9.22; P = .03). Moreover underlying hematological malignancy (OR 2.74; P = .04) and VRE colonization/infection (OR 2.71; P = .02) were independently associated with CDI recurrence.ConclusionPatients with HM complicated with CDI were often regarded as non-severe infection, but had a similar in-hospital mortality rate as those without malignancy. CDI due to ribotype 078 complex isolates heralded a poor prognosis among HM patients.     

Antigen presentation in SARS-CoV-2 infection: the role of class I HLA and ERAP polymorphisms

Given the highly polymorphic nature of Human Leukocyte Antigen (HLA) molecules, it is not surprising that they function as key regulators of the host immune response to almost all invading pathogens, including SARS-CoV-2, the etiological agent responsible for the recent COVID-19 pandemic. Several correlations have already been established between the expression of a specific HLA allele/haplotype and susceptibility/progression of SARS-CoV-2 infection and new ones are continuously emerging. Protective and harmful HLA variants have been described in both mild and severe forms of the disease, but considering the huge amount of existing variants, the data gathered in such a brief span of time are to some extent confusing and contradictory. The aim of this mini-review is to provide a snap-shot of the main findings so far collected on the HLA-SARS-CoV-2 interaction, so as to partially untangle this intricate yarn. As key factors in the generation of antigenic peptides to be presented by HLA molecules, ERAP1 and ERAP2 role in SARS-CoV-2 infection will be revised as well.     

卡维地洛对正常青年男性Q-T间期离散度的影响

目的探讨健康男性青年服用β受体阻滞剂卡维地洛后不同血药浓度下静息心电图QT间期离散度（QTd）与用药前比较有无显著性变化,以对卡维地洛的抗心律失常作用机制提供依据。方法对20名健康男青年在服用卡维地洛20 mg前及服药后0.5、1、2、3、4、6、8、10、24 h分别测血药浓度,并做静息心电图,于十二导联心电图测量Q-T间期离散度。并将数据进行统计分析。结果随着血药浓度的升高,QTd有缩小趋势,但与用药前比较各P值无显著性差异。结论卡维地洛对正常健康男性的QTd可能无影响,从反面证实,它主要对有病理情况下的心脏病患者有抗心律失常作用。     

姜黄素酯化物抗平滑肌细胞增殖和调血脂作用研究

[目的]研究姜黄素酯化物对不同条件促牛主动脉平滑肌细胞(VSMC)增殖作用和对小鼠食饵性高脂血症的影响,初步探讨其构效关系。[方法]用丁二酸酐酯化姜黄素获得姜黄素酯化物;用oX-LDL或血管紧张素Ⅱ(AngⅡ)培养牛VSMC建立VSMC增殖模型,再在模型中加姜黄素和姜黄素酯化物培养,用MTT法检测观察二者对平滑肌细胞(VSMC)增殖作用的影响;用高脂膳食喂饲小鼠建立食饵性高脂血症模型,用姜黄素和姜黄素酯化物进行实验性治疗,给药2周后处死小鼠,测定血清总胆固醇(TC)、甘油三酯(TG)和高密度脂蛋白(HDL-C)含量,计算低密度脂蛋白(LDL-C)含量,观察其调血脂作用。结果姜黄素酯化物浓度在66μmol/L、33μmol/L、16.5μmol/L时,对10 mg/L oX-LDL培养的VSMC增殖有明显的抑制作用,P<0.05;剂量在0.3mmol/(kg·d)时,可降低食饵性高脂血症小鼠血清TG含量P<0.05,但降TC、LDL-C和上调HDL作用不明显。[结论]姜黄素酯化物高剂量时能明显抑制oX-LDL和AngⅡ促牛VSMC增殖作用;能明显降低血清TG降低食饵性高脂血症小鼠血清TG含量。