Bacterial DNA activates human neutrophils by a CpG-independent pathway

Bacterial DNA stimulates macrophages, monocytes, B lymphocytes, NK cells, and dendritic cells in a CpG-dependent manner. In this work we demonstrate that bacterial DNA, but not mammalian DNA, induces human neutrophil activation as assessed by L-selectin shedding, CD11b upregulation, and stimulation of cellular shape change, IL-8 secretion, and cell migration. Induction of these responses is not dependent on the presence of unmethylated CpG motifs, as neutrophil stimulatory properties were neither modified by CpG-methylation of bacterial DNA nor reproduced by oligonucleotides bearing CpG motifs. We found that human neutrophils express Toll-like receptor (TLR) 9 mRNA. However, as expected for a CpG-independent mechanism, activation does not involve a TLR9-dependent signaling pathway; neutrophil stimulation was not prevented by immobilization of bacterial DNA or by wortmannin or chloroquine, two agents that inhibit TLR9 signaling. Of note, both single-stranded and double-stranded DNA were able to induce activation, suggesting that neutrophils might be activated by bacterial DNA at inflammatory foci even in the absence of conditions required to induce DNA denaturation. Our findings provide the first evidence that neutrophils might be alerted to the presence of invading bacteria through recognition of its DNA via a novel mechanism not involving CpG motifs.     

Thrombocytosis in preterm infants: a possible involvement of thrombopoietin receptor gene expression

Transient thrombocytosis is commonly observed in preterm infants after birth, but its physiological mechanism is still unknown. To understand the mechanism of the transient thrombocytosis in preterm infants we firstly evaluated a correlation between platelet counts and thrombopoietin (TPO) levels in preterm infants and next c-mpl mRNA levels on platelets in healthy preterm infants longitudinally during a half-year of life. The mean platelet counts in 45 very low birth weight infants (mean gestational age 27.4±1.8 weeks, mean birth weight 1047±249 g) was 230±71×10⁹/l just after birth and thereafter gradually increased to 579±178×10⁹/l by 5 weeks of age. The platelet counts continued this level for about next 8 weeks. Serum TPO levels soon after birth and at 1 month of age were significantly higher than those at the age of 2–6 months. There was a significant negative correlation between platelet counts and serum TPO values. The c-mpl expression levels on platelets at birth and at 1 month of age tended to be lower than those on platelets from adults, and the c-mpl levels gradually increased through 6 months of age, although they were still lower than those of adults. Our results suggest that low expression of TPO receptor on platelets until 1 month after birth cause a decreased TPO clearance and keep a high level of free TPO in blood, thereby promoting platelet production from megakaryocytes or their progenitors in bone marrow, resulting in the subsequent thrombocytosis in preterm infants.     

Rapid accurate absolute granulocyte count determination during severe leukopenia using the flow cytometer

The absolute granulocyte count (AGC) in 125 blood samples from patients with total white blood cell counts of less than 1,000/microliter was estimated using three different methods, which were then compared for efficiency and accuracy. The three methods were 25 cell differential counts using Wright's-stained blood smears, granulocyte percentage estimates from WBC counting chambers, and combined narrow- and wide-angle light-scatter characteristics determined on a flow cytometer. A survey of clinical laboratories at University Hospital Cancer Centers revealed that the smear differential was the most-often-used method in those laboratories even when less than 25 cells could be counted. Consequently the data obtained from the counting chamber and flow cytometer methods were compared to the smear differential "standard" using linear regression, and outliers were identified. There was good correlation between AGC determined by smear differential and WBC counting chamber (correlation coefficient .911) and excellent correlation between the AGC determined by smear differential and the flow cytometer method (correlation coefficient .970). The flow cytometer method used in this investigation required minimal specimen preparation, and test results were available at a rate of 60 seconds/sample. The ease of sample preparation, speed, and statistical reliability of test results makes the flow cytometer an attractive alternate method of determining granulocyte counts on leukopenic patients as compared to the stained blood smear differential.     

我国正常生育力男子精浆的微量元素研究

本文报告测试了68例正常生育力成年男子精浆中的锌、铜,铁等微量元素和镁,测试结果如下:锌130±5.64μg/ml,铜1.84±0.158μg/ml,铁0.801±0.104μg/ml,镁103.86±10.01μg/ml。所测得的数值均在正常范围内。在正常范围内的精液,精浆中的锌、镁含量与精液质量(精子密度和活动力)之间无显著差异。但铜的含量与精子活动度关系密切,含量高则活动度差,反之则活动度好。铁的含量与精子密度关系也十分密切,含量高时精子密度也高。     

脊柱术后感染病原菌及CD64和中性粒细胞百分比的早期预测价值

目的分析脊柱术后医院感染患者病原菌分布特征及中性粒细胞64(CD64)和中性粒细胞百分比(NEU%)表达情况。方法选取2017年6月-2019年6月天津市天津医院收治的脊柱术后医院感染患者51例为感染组,并选取同期于医院就诊的脊柱术后未发生感染患者51例为未感染组。分析感染组患者病原菌情况,检测患者NEU和CD64水平;ROC曲线分析CD64和NEU%指标水平预测感染的诊断价值。结果 51例感染患者共培养分离病原菌78株,其中革兰阴性菌42株(53.85%)、革兰阳性菌33株(42.31%)、真菌3株(3.85%),以铜绿假单胞菌及金黄色葡萄球菌为主。术后7 d,感染组体温、WBC、中性粒细胞计数、CRP、ESR分别为(38.47±0.52)℃、(8.34±2.17)×109/L、(5.98±1.94)×109/L、(54.52±19.93)mg/L、(51.74±21.88)mm/h均高于非感染组(P<0.05)。术后7 d,感染组CD64、NEU%分别为(8.87±2.13)%、(84.93±13.39)高于非感染组(P<0.05)。CD64指数与NEU%水平诊断ROC曲线下面积分别为0.922、0.826。结论脊柱术后医院感染以革兰阴性菌为主,CD64及NEU%水平有助于脊柱术后医院感染的早期诊断。     

儿童肾病综合征患者血小板和血浆von Willebrand因子的变化

目的：观察儿童肾病综合征患者血小板计数和血浆von Willebrand因子的变化,方法,采用ELISA法检测58例NS患儿血浆vWF及血小板计数,并与正常对照组进行比较,结果：NS患儿vwF水平及血小板计数均明显高于正常对照组,两组有显著性差异（P＜0．01）,结论,血浆vWF与血小板计同步升高与NS患儿的高凝状态及血栓形成有一定的关系。     

创伤性脑损伤患者脑脊液中嗜中性白细胞碱性磷酸酶-1的表达及意义

目的探讨炎性体蛋白嗜中性白细胞碱性磷酸酶-1(NALP-1)在创伤性脑损伤患者脑脊液中表达水平及其与预后相关性。方法选取2017年2月至2018年9月来自首都医科大学附属北京同仁医院的120例创伤性脑损伤患者,选取同期健康体检者30例作为对照组,采用免疫印迹化学发光法检测研究对象脑脊液中炎性体蛋白NALP-1表达水平,根据格拉斯哥预后评分(GOS)将创伤性脑损伤患者分为预后良好组(GOS>3分)和预后不良组(GOS≤3分)。χ²检验和t检验分析预后良好组和预后不良组NALP-1和临床资料差异,采用多因素Logistic回归模型分析创伤性脑损伤后患者预后影响因素。结果创伤性脑损伤患者脑脊液中NALP-1表达(1.64±0.52)高于对照组(0.94±0.28,t=7.108,P<0.05),差异有统计学意义。NALP-1高表达组急性生理与慢性健康状况评分Ⅱ(APACHEⅡ)得分(26.4±5.4)分、脑挫伤比例(76.62%)、蛛网膜下腔出血比例(77.27%)高于低表达组[(22.3±4.5)分、23.38%、22.73%],差异有统计学意义(χ²/t=4.135、9.586、7.424,P<0.05)。年龄[比值比(OR):2.175,95%可信区间(CI):1.167~8.767,P<0.05]、蛛网膜下腔出血(OR:1.241,95%CI:1.101~3.794,P<0.05)、NALP-1(OR:2.841,95%CI:1.675~10.717,P<0.05)、纤维蛋白原水平(OR:1.215,95%CI:1.056~3.627,P<0.05)、APACHEⅡ得分(OR:1.615,95%CI:1.314~5.485,P<0.05)是预后不良独立影响因素,差异均有统计学意义。结论创伤性脑损伤脑脊液中NALP-1表达增加,且表达量升高与预后不良相关。     

Administration of ATG according to the absolute T lymphocyte count during therapy for steroid-resistant rejection

In renal transplantation, treatment of steroid-resistant rejection (SRR) with antithymocyte globulin (ATG) has been widely reported but over-immunosuppression remains a common problem. In the first ten patients (group 1) treated for SRR with rabbit ATG, three developed serious viral infections and two deaths occurred due to CMV pneumonitis. ATG was only omitted if thrombocytopenia or neutropenia occurred. In the next 17 patients (group 2) with SRR, ATG was administered according to the absolute T lymphocyte count. T lymphocytes were measured by flow cytometric analysis of CD3-labelled lymphocytes. ATG dosage was adjusted on a daily basis to keep the absolute T lymphocyte count under 50 cells/l. Administration of ATG according to the absolute T lymphocyte count resulted in a significant reduction in the mean dose of ATG given to the group 2 patients (P<0.001). A significant decrease in the incidence of serious viral infections (P=0.04) was achieved without reducing the ability of ATG to reverse the SRR (P=0.29) or increasing the number of grafts lost at 1 year in the group 2 patients (P=0.23).