调节性T细胞在健康人群中的表达

目的:观察外周血CD4+CD25+CD127low调节性T细胞(Treg细胞)在不同性别、不同年龄段健康人群中的表达水平,建立该指标应用于临床分析的实验室参考范围。方法:收集180例健康体检成年人EDTA-K3抗凝外周静脉血,用流式细胞术分析CD4+细胞中表达CD25+CD127low细胞的百分率,以SPSS 13.0软件进行统计学分析。结果:Treg细胞在男女性别间的表达百分率无显著性差异(P0.05),在≤49岁的3组之间、≥50岁的2组之间的差异亦无显著性(P0.05);Treg细胞的表达范围在≤49岁为(3.30±1.45)%,≥50岁为(4.69±1.27)%;将≤49岁的3组与≥50岁的2组分别进行两两分析,Treg细胞百分率均存在显著性差异(P0.05)。结论:CD4+CD25+CD127Low调节性T细胞应用于临床时可以忽略性别,须针对≤49岁与≥50岁2个年龄段建立不同的参考范围;本研究建立的Treg细胞参考值范围符合本院健康体检人群特点,该指标可作为本实验室对临床疾病检测及判断预后的依据。     

IL-17、sICAM-1在COPD炎性机制中的作用研究

目的:探讨IL-17和sICAM-1与COPD之间的关系,观察COPD患者和对照组血浆中IL-17、sICAM-1的水平并分析其相关性。方法:30例COPD病例组(急性加重期和稳定期)、25例正常对照组,测定肺功能;采集外周静脉血用酶联免疫吸附法(ELISA)测定血浆中IL-17及sICAM-1的水平。结果:1、COPD急性加重期患者血浆中IL-17的浓度(202.56±68.52pg/mL)明显高于稳定期的浓度(160.56±53.53 pg/mL);COPD急性加重期和稳定期患者血浆中IL-17的浓度明显高于健康对照组的浓度(68.12±12.41pg/mL),均有显著性差异(P0.05)。2、COPD急性加重期患者血浆中sICAM-1的浓度(255.78±141.50ng/L)明显高于稳定期的浓度(170.68±97.70ng/L);COPD急性加重期和稳定期患者血浆中sICAM-1的浓度明显高于健康对照组的浓度(56.62±18.01ng/mL),均有显著性差异(P0.05)。3、COPD患者急性加重期IL-17与sICAM-1的水平均升高。COPD急性加重期组和稳定期患者血浆中IL-17与血浆中sICAM-1呈正相关(r=0.981,P0.05;r=0.664,P0.05)。结论:IL-17、sICAM-参与了COPD的发病,并且IL-17、sICAM-1水平可能与COPD严重程度呈正相关。     

脉搏波传导速度检测在评价高血压病患者大动脉弹性中的应用 与影响因素分析

目的:探讨脉搏波传导速度(PWV)检测在评估高血压病患者大动脉弹性中的应用价值与影响因素分析 方法:采用分层整体抽样法随机抽取高血压病患者2178例,同时抽取非高血压2182人作为对照组.应用Complior SP VP-1000动脉硬化检测仪测定颈一股动脉脉搏波传导速度(C-FPWV)评估大动脉弹性.采用多元逐步线性回归分析性别、年龄、体质指数(BMI)、收缩压(SBP)、舒张压(DBP)、总胆固醇(TC)、甘油三脂(TG)、空腹血糖(FPG)和尿酸(UA)等指标与高血压痛患者大动脉弹性下降的影响因素.结果:C-FPWV平均值高血压组(1594± 264cm/s)显著高于对照组(1216± 231cm/s),两组差异有显著性意义(X2=31.659,P=0.00).＞40岁各年龄段PWV值上升程度,高血压组明显高于对照组(X2＝ 18.954～36.924,P=0.00),两组PWV值上升程度与年龄呈正相关.多元逐步线性回归分析表明:BMI≥28kg/m2、SBP≥ 140mmHg、DBP≥90mmHg、TC＞5.28± 0.62 mmol/L、TG＞ 1.68± 0.64mmol/L等指标高血压组明显高于对照组(t=14.314～17.428,P＜0.05).在性别、UA和FPG等指标两组无明显差异(X2=6.368～13.618,P＞0.05).结论:高血压痛患者PWV值上升程度显著高于非高血压者,BMI、SBP、TG、TC是高血压病患者大动脉弹性下降的主要影响因素.PWV值可作为评价大动脉弹性的可靠指标.     

儿童强迫症、抑郁症患者血小板5-羟色胺浓度的比较研究

目的:通过检测儿童强迫症、抑郁症患者血小板5-羟色胺(5-HT)的浓度,探讨血小板5-HT在儿童强迫症、抑郁症发病中的作用.方法:采用高效液相色谱法检测22例强迫症患儿(包括强迫思维15例,强迫动作7例)和20例抑郁症惠儿血小板5-HT的浓度,并与20名正常儿童进行比较.结果:强迫症患儿(173.43±90.67)ng/109和抑郁症患儿(251.62±152.72)ng/109血小板5-HT的浓度低于正常儿童(351.91±170.97)ng/109(P<0.05),强迫症患儿的血小板5-HT的浓度和抑郁症惠儿的差异没有显著性(P>0.05).强迫症患儿中,强迫思维惠儿的血小板5-HT的浓度(147.09±44.92)ng/109低于强迫动作患儿(229.88±1:136.44)ng/109(P<0.05).结论:儿童强迫症、抑郁症患者血小板5-HT浓度明显下降,并且强迫思维患儿的血小板5-HT浓度与强迫动作患儿的差异有显著性.     

不同性别腰椎间盘突出症患者脊柱-骨盆矢状位参数差异研究

目的:探讨不同性别腰椎间盘突出症(Lumbar disc herniation,LDH)患者脊柱-骨盆矢状位参数差异特点。方法:回顾性分析2014年1月至2016年3月在第四军医大学西京医院脊柱外科因LDH住院手术治疗,且具有术前脊柱站立位全长X线片的患者共222例,其中男l25例,女97例,年龄20-80岁,平均年龄50.97岁;应用图形分析软件Surgimap进行参数测量,在站立位全长脊柱侧位x线片上测量参数包括:骨盆投射角(Pelvic incidence,PI)、骨盆倾斜角(Pelvic tilt,PT)和骶骨倾斜角(Sacral slope,SS),胸椎后凸角(Thoracic Kyphosis,TK)、腰椎前凸角(Lumbarlordosis,LL)、矢状面垂直轴(Sagittal vertical axis,SVA)。根据性别分组,比较不同性别之间各参数、发病累及节段、不同年龄段发病率之间的差异。应用SPSS 19.0对数据进行统计分析。结果:LDH患者男女性别之间比较发现,男性PI 43.82±8.66°,女性PI 47.75±8.50°,P=0.001(P0.05),具有统计学显著性差异,年龄、PT、SS、LL、TK、SVA无显著性差异;不同性别LDH患者所累及节段分别进行统计,P=0.480(P0.05),无统计学显著性差异;不同性别LDH患者不同年龄段的发病率进行统计,应用Pearson卡方检验进行统计分析,P=0.024(P0.05),具有统计学显著性差异。然后将各年龄段发病率通过u检验进行比较,20-40岁段P=0.023(P0.05),具有统计学显著性差异。结论:PI也可能与LDH的发病有关,男性患者PI小于女性患者,可能是在LDH发病中男性多于女性,且男性更早发病的一个重要原因。     

血浆及外周血中性粒细胞内髓过氧化物酶水平在冠心病临床诊断中的意义

目的:研究冠心病患者外周循环血中性粒细胞中髓过氧化物酶指数(MPXI)和血浆中髓过氧化物酶(MPO)浓度的改变及两者间相关性,探讨两者在冠心病临床诊断中的意义。方法:随机选取冠心病患者55例,按病情严重程度分为急性冠脉综征(ACS)组35例[包括不稳定心绞痛(UAP)组21例和急性心肌梗死(AMI)组14例]和稳定心绞痛(SAP)组20例,同时随机选取健康体检人员60例为正常对照组;采用ADVIA2120全自动血细胞分析仪检测MPXI,取血浆用ELISA法检测血浆MPO浓度。结果:ACS组MPXI(6.31±4.24)显著高于SAP组(3.38±2.14)和对照组(2.78±2.12),差异有统计学意义(P<0.05);SAP组MPXI高于正常对照组,差异无统计学意义(P>0.05)。ACS组血浆中MPO(1204.07±838.61 pmol/L)显著高于SAP组(755.97±426.23 pmol/L)和对照组(290.45±99.87 pmol/L),差异有统计学意义(P<0.05);SAP组MPO显著高于正常对照组,差异有统计学意义(P<0.05)。SAP组MPXI与MPO无相关性(r=0.424,P>0.05),ACS组MPXI与MPO呈负相关(r=-0.536,P<0.05)。结论:MPXI和MPO在冠心病的诊断中有意义,MPXI与血浆中MPO在ACS组中呈负相关。     

温度对中华鳖血浆皮质酮水平、免疫生化指标及抑菌效果的影响

对正常生长状态下3种月龄(12、18、24月龄)的中华鳖血浆皮质酮(corticosterone,CORT)进行了测定,并以(28±2)℃为恒温对照组,研究变温(10、20、33℃)对同一年龄段中华鳖血浆CORT水平、免疫生化指标以及抑菌效果的影响。结果表明:12月龄与24月龄个体间血浆CORT水平有显著性差异(P0.05);各温度处理组中华鳖血浆CORT含量随时间呈先升后降的变化趋势,其中10℃和20℃组的CORT水平在4和6 h时与对照组有显著性差异(P0.05);各温度处理组酶活性和蛋白含量随时间的增加先升后降,但与对照组无显著性差异(P0.05);血浆抑菌效果与血浆CORT水平呈负相关。实验表明,温度骤变会促使中华鳖产生应激反应,并使机体血浆内的CORT水平增加,免疫生化发生改变,抑菌效果下降,从而降低机体的免疫力。     

重组BHMT对高同型半胱氨酸血症大鼠的影响

目的探讨重组BHMT对大鼠HHcy血症的防治作用。方法用含2%蛋氨酸(methionine,Met)饲料诱发HHcy的大鼠,经尾静脉注射BHMT后,观察模型大鼠血浆中同型半胱氨酸(homocysteine,Hcy)浓度、LDH酶活性及HDL/LDL的影响。结果重组BHMT能将HHcy组大鼠血浆中Hcy浓度(23.70±6.75)μmol/L显著降低为(14.61±2.80)μmol/L(P<0.05),LDH酶活性由(209.57±10.22)U/L降低为(225.04±30.47)U/L(P<0.05),对脂蛋白HDL/LDL基本没有影响。结论重组BHMT对高同型半胱氨酸血症有一定的治疗作用。     

高磷血症维持性血液透析患者的临床分析

目的:比较不同血磷水平的维持性血液透析的尿毒症患者的临床表现和实验室指标,探讨其临床意义。方法:选择上海交通大学医学院附属新华医院(崇明)肾内科28例高血磷(SP>1.6mmol/L)的维持性血液透析患者为病例组,30例血磷正常(SP≤1.6mmol/L)维持性血液透析患者为对照组,比较两组患者的原发病组成,年龄,性别,透析龄,皮肤瘙痒发生率,腰背痛发生率,血钙,血碳酸氢根,血红蛋白,红细胞压积,血碱性磷酸酶,肾功能,血浆白蛋白水平及左心室肥厚发生率。结果:病例组与对照组在原发病组成,年龄(43.2±9.8岁vs 40.5±12.2岁),男女性别比例(16/12 vs.17/13),透析龄(32.56±6.71月vs.35.43±5.82月)等方面无显著性差异(P>0.05),有可比性,在血红蛋白(83.22±6.71g/L vs 103.36±5.84g/L),红细胞压积(24.83±1.92%vs.30.76±1.52%),血钙(1.71±0.16mmol/L vs.2.23±0.21 mmol/L),血碳酸氢根(14.2±3.1mmol/L vs 20.6±4.9 mmol/L),血碱性磷酸酶(124.26±16.33U/L vs.61.47±14.91 U/L),皮肤瘙痒发生率(22/28 vs.7/30),腰背痛发生率(19/28 vs.6/30),左心室肥厚发生率(20/28 vs 12/30),有显著性差异(P<0.05),肌酐(956±142mmol/L vs.923±156 mmol/L),尿素氮(23.1±6.3mmol/L vs.24.8±8.9mmol/L),血浆白蛋白(30.5±3.8g/L vs.31.2±2.9g/L),无显著性差异(P>0.05)。结论:伴有高磷血症的维持性血液透析患者与血磷正常的患者相比,血碱性磷酸酶,皮肤瘙痒发生率,腰背痛发生率及左心室肥厚发生率较高,而血钙,血碳酸氢根,血红蛋白及红细胞压积较低,有一定差异。     

三维超声心动图评价不同年龄段和性别主动脉瓣二叶畸形

目的:三维超声心动图评估不同年龄段和性别主动脉瓣二叶畸形(bicuspid aortic valve malformation,BAV)的应用价值。方法:超声心动图检测我院2012年6月至2014年9月70例BAV患者,根据年龄段分为4组,≤20岁年龄组7例,21-40岁年龄组14例,41-60岁年龄组30例,≥60岁年龄组19例;根据性别分为2组,男性42例,女性28例。测量不同病例分组的主动脉窦部及升部内径、室间隔厚度、左心功能及左房横径,比较主动脉瓣狭窄、关闭不全、钙化及脱垂四个合并症发生率。结果:在心脏结构指标方面,年龄段分组室间隔厚度≥60岁年龄组12.37±1.64 mm高于≤20岁年龄组10.43±2.22 mm和21-40岁年龄组11.00±1.92 mm;左房横径41-60岁年龄组38.73±7.95 mm和≥60岁年龄组40.05±9.71 mm高于≤20岁年龄组29.86±1.86 mm。性别分组左心功能女性64.18±6.04%高于男性58.71±11.28%。在合并症发生率方面年龄段分组主动脉瓣狭窄41-60岁年龄组80%、≥60岁年龄组84%高于21-40岁年龄组50%,性别分组狭窄男性81%大于女性54%,关闭不全女性79%大于男性50%。结论:三维超声心动图诊断BAV可获得更加全面、具体、直观的诊断信息,BAV的超声表现与患者年龄段和性别密切相关。     

Associations of genome-wide cell-free DNA fragmentation profiles with blood biochemical and hematological parameters in healthy individuals

Cell-free DNA (cfDNA), as a non-invasive approach, has been introduced in a wide range of applications, including cancer diagnosis/ monitoring, prenatal testing, and transplantation monitoring. Yet, studies of cfDNA fragmentomics in physiological conditions are lacking. In this study, we aim to explore the correlation of fragmentation patterns of cfDNA with blood biochemical and hematological parameters in healthy individuals. We addressed the impact of physiological variables and abnormal blood biochemical and hematological parameters on cfDNA fragment size distribution. We also figured and validated that hematological inflammation markers, including leukocyte, lymphocyte, neutrophil, and platelet distribution width as well as aspartate transaminase levels were significantly correlated with the genome-wide cfDNA fragmentation pattern. Our findings suggest that cfDNA fragmentation profiles were associated with physiological parameters related to cardiovascular risk factors, inflammatory response and hepatocyte injury, which may provide insights for further research on the potential role of cfDNA fragmentation in diagnosis and monitor of several disease.     

林麝血液生理生化指标的测定

三年来对51头不同年龄阶段健康林麝进行了28项血液生理生化指标的测定,测定结果:成龄麝(＞2.5岁):血钾(8.39±2.70) mmol/L,血钠(145.95±5.28) mmol/L,氯(107.29±2.74) mmol/L,总蛋白(90.58±13.56) g/L,白蛋白(46.07±4.95) g/L;青年麝(1.5 ～2.5岁):血钾(8.19 ±2.71) mmol./L,血钠(145.36±4.34)mmol/L,氯(107.55±3.96) mmol/L,总蛋白(76.79±6.46) g/L,白蛋白(48.87±2.65) g/L;仔麝(＜1.5岁):血钾(10.87 ± 1.65) mmol/L,血钠(141.60 ±3.27) mmol/L,氯(105.24±4.29) mmol/L,总蛋白(76.29±8.24) g/L,白蛋白(40.99±5.14) g/L等.结果表明:青年麝和成龄麝血液各生理生化指标差异不显著,仔麝与青年麝和成龄麝在几项生理生化指标方面有显著差异;林麝血液中钙磷比(0.65)明显低于其他动物.本次生理生化指标的测定,以期为林麝的保护和疾病防治积累资料.     

The changing of cell-free DNA properties of peripheral blood and TCR-mutant cell frequency in individuals exposed to ionizing radiation

Some properties of the cell-free DNA (cfDNA) of peripheral blood plasma were assessed in 153 employees of atomic industry enterprises. The contents of ribosomal repeat (rDNA) and its concentration in plasma increased in cfDNA of the group of persons in comparison with non-irradiated individuals. The contents of satellite III in cfDNA of donors and of irradiated persons do not differ and less than in DNA nucleus. The correlation between cumulative dose of radiation, contents of rDNA in cfDNA and the frequency of lymphocytes bearing mutations at T-cell receptor (TCR) locus was obtained. The definition of three indications in irradiated persons: the contents of ribosomal genes in cfDNA, TCR-mutant cell frequency and concentration of ribosomal genes in blood plasma--may be useful for revealing individuals in organism of which an intensive cell apoptosis takes place and there is an increased probability of carcinogenesis and of progress of disease of immune system.     

Circulating cell-free DNA,peripheral lymphocyte subsets alterations and neutrophil lymphocyte ratio in assessment of COVID-19 severity

Cell destruction results in plasma accumulation of cell-free DNA (cfDNA). Dynamic changes in circulating lymphocytes are features of COVID-19. We aimed to investigate if cfDNA level can serve in stratification of COVID-19 patients, and if cfDNA level is associated with alterations in lymphocyte subsets and neutrophil-to-lymphocyte ratio (NLR). This cross-sectional comparative study enrolled 64 SARS-CoV-2-positive patients. Patients were subdivided to severe and non-severe groups. Plasma cfDNA concentration was determined by real-time quantitative PCR. Lymphocyte subsets were assessed by flow cytometry. There was significant increase in cfDNA among severe cases when compared with non-severe cases. cfDNA showed positive correlation with NLR and inverse correlation with T cell percentage. cfDNA positively correlated with ferritin and C-reactive protein. The output data of performed ROC curves to differentiate severe from non-severe cases revealed that cfDNA at cut-off ≥17.31 ng/µl and AUC of 0.96 yielded (93%) sensitivity and (73%) specificity. In summary, excessive release of cfDNA can serve as sensitive COVID-19 severity predictor. There is an association between cfDNA up-regulation and NLR up-regulation and T cell percentage down-regulation. cfDNA level can be used in stratification and personalized monitoring strategies in COVID-19 patients.     

Experimental investigation of the rheological activation of blood platelets

In order to define various aspects of platelet rheological activation, samples of whole blood and platelet-rich plasma (PRP) from the same donors were subjected for 5 min to shear rates increasing from 10 to 10000 sec-1 (shear stresses from 10(-2) to 30 Pa approximatively) in a Couette type viscometer. The following parameters were measured: erythrocyte hemolysis; lactic dehydrogenase activity; plasma B-Thromboglobulin (B-TG); adenine nucleotides, and platelet photometric aggregation. The experimental results reveal that: In whole blood, hemolysis only reached at maximum 2% of the total hemolysis. Plasma LDH activity increased regularly beyond 500 sec-1, in close correlation with B-TG plasma concentration. In contrast, ADP and ATP levels remained stable up to 1000 sec-1 then increased slowly. In PRP, the LDH, ADP and ATP levels remain practically stable up to shear rates around 5000 sec-1. In contrast, B-TG appeared to be released in plasma at shear rate values of 3000 sec-1 and its progression is only correlated with the other parameters, when the platelet lysis occurred. Finally, a rapid and complete inhibition of platelet aggregation to ADP was observed from 5000 sec-1.     

Activated hypothalamic pituitary adrenal axis in patients with metabolic syndrome

Metabolic syndrome (MetS) is correlated with the activity of hypothalamic-pituitary-adrenal axis (HPA), but the underlying mechanism still remains elusive. The aim of this study was to investigate the HPA axis function in patients with MetS. This case-control study included 159 people. They were divided into 2 groups. The first group included 73 healthy volunteers (control group: 19 males, 54 females, mean±SD: 49.9±7.5 years old, with BMI: 27.9±4.42?kg/m2) and the second group included 86 patients with MetS (case group: 48 males, 38 females, mean±SD: 52.2±7.6 years old, with BMI: 30.5±5.35?kg/m2). An oral glucose tolerance test (OGTT) was performed for all subjects after a 12-h overnight fast, and blood samples were obtained for determination of ACTH, cortisol, insulin, C-peptide, and glucose levels. Serum cortisol after an overnight dexamethasone suppression test was determined in both groups. Patients with MetS had serum cortisol levels after an overnight dexamethasone suppression test significantly higher than controls. During OGTT plasma ACTH levels were higher at all time points in patients with MetS compared to controls, whereas serum cortisol levels were comparable between the 2 groups. Plasma ACTH during OGTT was also correlated with most of the components of MetS. The HPA axis in patients with MetS seems to be more active as evidenced by the higher cortisol levels after the overnight dexamethasone suppression test and by the higher ACTH levels during OGTT. This functional hypercortisolism might be involved in the pathogenesis of the metabolic syndrome.     

Mercury and Selenium in Blood and Epidermis of Bottlenose Dolphins (Tursiops truncatus) from Sarasota Bay, FL: Interaction and Relevance to Life History and Hematologic Parameters

Blood and epidermal biopsies from free-ranging Tursiops truncatus captured and released during either summer or winter health assessments in Sarasota Bay, FL, were evaluated for concentrations of mercury, selenium, stable isotopes (δ¹³C and δ¹⁵N), and blood glutathione peroxidase activity in conjunction with routine hematology and serum chemistry panels. Major objectives were to: 1) quantify and describe relationships among mercury, selenium, glutathione peroxidase, and stable isotopes of C and N in blood and epidermis; 2) elucidate major parameters that influence blood mercury and glutathione peroxidase activity; 3) relate measures of tissue mercury, selenium, and glutathione peroxidase to specific ecological, hematological, morphological, or life history parameters, including season, sex, age, and trophic level. Mercury in both tissues examined is almost exclusively methylmercury. Epidermal concentrations of mercury and selenium reflect their respective amounts in blood, albeit at several times blood concentrations of mercury. The strong association between blood mercury and serum selenium, in conjunction with a lack of significant correlation between blood mercury and glutathione peroxidase, implies that a substantial proportion of blood mercury is affiliated with another selenium-containing moiety or is related to recent dietary intakes (e.g., trophic level, intensive fish consumption). Circulating blood mercury may be described in terms of serum selenium concentration, along with interaction terms among serum selenium, blood δ¹⁵N, and age. Current selenium concentrations in Sarasota Bay dolphins appear adequate for maintenance of blood glutathione peroxidase activity. However, dolphins evidently are subject to seasonal exacerbation of oxidative stress, which might render them more vulnerable to toxic effects of mercury. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Increased plasma level of asymmetric dimethylarginine in hypertensive rats facilitates platelet aggregation: role of plasma tissue factor

This study was designed to explore the role of asymmetric dimethylarginine (ADMA), an endogenous inhibitor of nitric oxide synthesis, in platelet aggregation in hypertension and its possible mechanisms. Spontaneously hypertensive rats (SHR) and L-NAME-induced hypertensive rats were orally administered with L-arginine (1 g/(kg·day) for 14 days. Systolic blood pressure, platelet aggregation, and plasma tissue factor (TF) level and activity were measured. The plasma concentration of ADMA in SHR was determined. In vitro, platelet-rich plasma isolated from Wistar rats was prepared in order to observe the effect of exogenous ADMA on platelet aggregation and TF level and (or) activity in platelet-rich plasma. In both types of hypertensive rats, systolic blood pressure, platelet aggregation, and the level and activity of plasma TF were elevated compared with corresponding control animals. Plasma ADMA level was also increased in SHR. Treatment with L-arginine, a competitor of ADMA, lowered blood pressure and inhibited platelet aggregation concomitantly with a decrease in plasma TF level and activity in both types of hypertensive rats. We also found that exogenous ADMA promoted platelet aggregation and increased TF level and (or) activity in platelet-rich plasma, an effect that was inhibited by pretreatment with L-arginine. Importantly, the enhanced platelet aggregation induced by exogenous ADMA was reduced by pretreatment with anti-TF antibody. The results suggest that endogenous ADMA may be involved in platelet hyperaggregation status in hypertension, and the facilitation of platelet aggregation by ADMA is related to upregulation of the level and activity of plasma TF.     

Ribosomal repeat in cell free DNA as a marker for cell death

A novel method for in vivo evaluation of cell death in patients with acute and/or chronic heart diseases, accompanied by apoptosis or cell necrosis has been developed. The method is based on the analysis of cell free DNA (cfDNA) in the blood serum (plasma). It includes estimation of concentration of serum ribosomal repeat (rDNA), content of rDNA in total cfDNA, as well as factors of cfDNA elimination, such as nuclease activity and anti-DNA antibody. We have found a fivefold increase in serum cfDNA concentration and a 12-fold increase of serum rDNA concentration in patients with acute myocardial infarction compared with healthy individuals. In chronic coronary ischemia serum cfDNA concentration was nearly normal, but the content of rDNA in cfDNA was 4.8-fold higher, and the serum rDNA concentration was increased sevenfold. We hypothesize that putative reason for accumulation of rDNA within cfDNA might be attributed to the previously reported resistance of rDNA to the ds-fragmentation by serum endonucleases. In acute and chronic coronary disease serum nuclease activity and the titer of anti-DNA antibodies (which are mainly bound to the cfDNA) was substantially higher than in the healthy controls. It is suggested that release of rDNA fragments into blood not only reflects cellular death in the body but also determines the response of the organism to the disease-associated stress.     

COVID-19 induces a hyperactive phenotype in circulating platelets

Coronavirus Disease 2019 (COVID-19), caused by the novel Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), has affected over 30 million globally to date. Although high rates of venous thromboembolism and evidence of COVID-19-induced endothelial dysfunction have been reported, the precise aetiology of the increased thrombotic risk associated with COVID-19 infection remains to be fully elucidated. Therefore, we assessed clinical platelet parameters and circulating platelet activity in patients with severe and nonsevere COVID-19. An assessment of clinical blood parameters in patients with severe COVID-19 disease (requiring intensive care), patients with nonsevere disease (not requiring intensive care), general medical in-patients without COVID-19, and healthy donors was undertaken. Platelet function and activity were also assessed by secretion and specific marker analysis. We demonstrated that routine clinical blood parameters including increased mean platelet volume (MPV) and decreased platelet:neutrophil ratio are associated with disease severity in COVID-19 upon hospitalisation and intensive care unit (ICU) admission. Strikingly, agonist-induced ADP release was 30- to 90-fold higher in COVID-19 patients compared with hospitalised controls and circulating levels of platelet factor 4 (PF4), soluble P-selectin (sP-selectin), and thrombopoietin (TPO) were also significantly elevated in COVID-19. This study shows that distinct differences exist in routine full blood count and other clinical laboratory parameters between patients with severe and nonsevere COVID-19. Moreover, we have determined all COVID-19 patients possess hyperactive circulating platelets. These data suggest abnormal platelet reactivity may contribute to hypercoagulability in COVID-19 and confirms the role that platelets/clotting has in determining the severity of the disease and the complexity of the recovery path.

The reason for the increased thrombotic risk associated with SARS-CoV-2 infection remains unclear. This study reveals that disease severity is associated with increased mean platelet volume and decreased platelet:neutrophil ratio; moreover, all COVID-19 patients possess hyperactive circulating platelets, with agonist-induced ADP release 30-to-90 fold higher than controls.