内蒙阿盟斑点热群立克次体Ha—91株的分离与鉴定

我们于1991年从内蒙阿盟亚东璃眼蜱分离到一株斑点热群(SFG)立克次体,命名为Ha-91株。免疫荧光法及蛋白免疫印迹分析表明Ha-91株立克次体与西伯利亚立克次体抗原性相近,但不完全相同;明显不同于其它种班点热群立克次体。这是首次证实亚东璃眼蜱为SFG立克次体的贮存宿主,也是首次从内蒙发现抗原性与西伯利亚立克次体不完全相同的SFG立克次体。     

Q热立克次体基因文库的构建

Q热立克次体七医株用6种限制性平端内切酶部分酶切,电泳回收0.2—7kb大小DNA片段,EcoRI位点甲基化,加上EcoRI接头,与去磷酸化λgtll DNA-EcoRI臂连接,经体外包装后感染E.coli Y1090,建成含2.6×10~6重组子的表达型基因文库。随机选择的噬菌体DNA经EcoRI酶切鉴定,重组子含大小不等的插入DNA片段。     

Q热立克次体红斑技术

本文根据Q热立克次体在鸡胚成纤维细胞空泡酸性环境中大量繁殖的特点,建立了Q热立克次体红斑技术,它出斑早,稳定并易于观察。用该技术研究单克隆及多克隆抗体对立克次体的体外中和作用表明,Ⅱ相抗体能使Ⅱ相Q热立克次体红斑减数,而Ⅰ相抗体反而使Ⅰ相病原体红斑增数,但用间接法试验则Ⅰ相病原体也出现红斑减数。红斑技术提供了一种快速分离与鉴定Q热立克次体的新方法。     

Q热立克次体感染性心内膜炎一例

患者因反复发热入院,经胸壁心脏多普勒超声检查,结果显示主动脉瓣膜中重度关闭不全、瓣膜穿孔可能,伴有主动脉瓣赘生物形成,但多次血培养结果均为阴性,经验性抗感染治疗效果欠佳。行主动脉瓣膜置换术,术后瓣膜基因测序结果为Q热立克次体,进一步行血清免疫荧光试验检测Q热立克次体IgG抗体,证实患者为Q热立克次体感染,经多西环素及羟氯喹抗感染治疗后体温恢复正常。Q热立克次体感染性心内膜炎报道较少,该病例通过活组织检查、瓣膜赘生物活组织基因测序和血清免疫荧光检测证实为Q热立克次体感染性心内膜炎,临床中较为罕见。     

广东连平县存在新的蜱传斑点热立克次体

目的对采自广东省连平县的3种硬蜱进行蜱传斑点热立克次体检测分析。方法斑点热立克次体的ompA基因片段扩增并测定扩增片段的DNA序列。结果20只蜱分为17组,其中15组PCR检测阳性。对4个测序成功的标本进行聚类分析,证实其中3个序列单独聚为一类,与引起Flinders岛蜱传斑点热的弗诺立克次体(R.honei)、非洲蜱咬热的非洲立克次体(R.africa)、未定名斑点热的斯洛伐克立克次体(R.slovaca)以及西伯利亚立克次体BJ-90株等亲缘关系较近,另一序列与我国长白山地区检测到的JL-02具有较高的同源性。结论本研究提示该地区除了已证实的西伯利亚斑点热外,还存在新的蜱传斑点热。     

Q热立克次体感染性心内膜炎一例题录

患者因反复发热入院,经胸壁心脏多普勒超声检查,结果显示主动脉瓣膜中重度关闭不全、瓣膜穿孔可能,伴有主动脉瓣赘生物形成,但多次血培养结果均为阴性,经验性抗感染治疗效果欠佳。行主动脉瓣膜置换术,术后瓣膜基因测序结果为Q热立克次体,进一步行血清免疫荧光试验检测Q热立克次体IgG抗体,证实患者为Q热立克次体感染,经多西环素及羟氯喹抗感染治疗后体温恢复正常。Q热立克次体感染性心内膜炎报道较少,该病例通过活组织检查、瓣膜赘生物活组织基因测序和血清免疫荧光检测证实为Q热立克次体感染性心内膜炎,临床中较为罕见。     

贝氏柯克斯体实时荧光定量PCR方法的建立及对云南鼠标本检测

目的 建立贝氏柯克斯体荧光定量PCR方法并应用于云南省鼠标本的检测.方法 根据贝氏柯克斯体ISlllla基因设计引物和探针,以克隆的ISlllla基因片断(485 bp)作标准DNA模板,建立实时荧光定量PCR检测方法,并与普通巢式PCR方法进行比较.采用2种方法对云南玉溪自然界采集的鼠各类标本进行检测分析,计算2种方法的检出率.结果 实时荧光定量PCR标准曲线的循环阈值(cycle threshold,Ct)与模板拷贝数呈良好的线性关系(r=-0.999),重复性测试Ct变异系数(coefficient of variation,CV)为0.25%～3.98%,灵敏度为巢式PCR的10倍.以其他立克次体和常见病原菌共26种DNA为模板进行特异性检测,结果均为阴性.实时荧光定量PCR检测鼠血、肝脏、脾脏中的贝氏柯克斯体,阳性率分别为32.31%、61.29%、85.19%;巢式PCR法检测相应标本阳性率分别为27.69%、11.29%、74.07%;间接免疫荧光试验检测鼠血清中贝氏柯克斯体IgG抗体阳性率为26.15%.结论 本实验建立的实时荧光定量PCR比巢式PCR敏感,且具有良好的特异性,可用于人群和动物贝氏柯克斯体感染监测及临床标本的检测.     

Coxiella burnetii,the causative agent of Q fever in Saudi Arabia:molecular detection from camel and other domestic livestock

Objective:To detect Coxiella burnetii(C.burnetii)DNA in clinical specimens from camel,goats,cattle and sheep in the Kingdom of Saudi Arabia.Methods:A total of 367 clinical samples including blood,milk,faeces and urine were collected from different livestock and subjected to PCR amplification using primers which amplify transposon-like region and transposase gene.Results:Positive amplification from both regions was obtained from camel,goats and cattle but not from sheep.A percentage of 10.8%samples yielded positive PCR amplification from both blood and milk,where 15 of 139 blood and 16 of 148 milk samples were positive.Faeces and urine showed higher percentages of positive samples reaching 40.8%and 23.8%respectively.Conclusions:The preferred route of shedding in camel appeared to be the faeces followed by urine,while that of goats appeared to be the faeces and that of the cattle appeared to be the milk.     

山东恙虫病立克次体生物学及免疫学性质的研究

本文报告了山东恙虫病立克次体人株生物学及免疫学性质的初步研究。所研究3株中的1株感染小鼠发病不典型,极少致死;另两株感染小鼠发病典型,小鼠呈规律性的死亡,易适应于鸡胚,对小鼠毒力LD_(50)为3.4。感染小鼠之IgG抗体出现于接种后的第13天,于接种后的第3～4周抗体水平达峰值。上述分离株与Karp毒株间存在较强的交叉保护作用。酶免疫染色血清学反应结果指出,与Gilliam株很一致,可能属Gilliam同一血清型。     

Non-Vitamin K Antagonist Oral Anticoagulants in Adult Congenital Heart Disease

Non-vitamin K antagonist (VKA) oral anticoagulants (NOACs) have several advantages over VKAs that render them an attractive option for adults with congenital heart disease (CHD). Efficacy and safety data specific to the adult CHD population are emerging. Herein, we synthesize the growing literature regarding NOACs in adults with CHD and attempt to identify subgroups for which it appears reasonable to extrapolate data from populations without CHD. Small observational studies suggest that NOACs are safe and effective in selected adults with CHD. NOACs are contraindicated in patients with a mechanical valve, in those with mitral or tricuspid valve stenosis with enlarged and diseased atria, with or without a mitral or tricuspid bioprosthesis, and after recent cardiac surgery (< 3 months). There is currently insufficient evidence to recommend NOACs in patients with a Fontan circulation or cyanotic CHD. Growing literature supports the use of NOACs in patients without CHD who have various forms of valvular heart disease. Therefore, when an indication for oral anticoagulation is established, it appears reasonable to consider a NOAC instead of a VKA in adults with CHD lesions analogous to isolated mitral regurgitation, tricuspid regurgitation, or aortic regurgitation or stenosis. The NOAC agent selected and the prescribed dose should be tailored according to bleeding risk, body weight, renal function, and comedications, especially antiepileptic drugs. The decision to initiate a NOAC should be shared between the patient and care provider. Large-scale research studies are required to further assess safety and efficacy in selected patient subgroups.     

Ventricular function curves from the cardiac response to angiographic contrast: a sensitive detector of ventricular dysfunction in coronary artery disease

Fifty cardiac catheterizations were performed in 44 patients undergoing evaluation for coronary artery disease. Ventricular function curves (VFC) were constructed by plotting the left ventricular end-diastolic pressure (LVEDP) and stroke work index (SWI) before and three to four minutes after a standard left ventricular angiogram. In an attempt to delineate the mechanism that produces changes in the post-angiogram LVEDP and SWI, 13 individuals (Group A) with no evidence of cardiac disease were compared to 14 patients with severe coronary artery disease (Group B). Cardiac output and LVEDP increased in both groups after angiogram. The increase in cardiac output was less and the increase in LVEDP greater in Group B. V_max. did not change significantly after angiogram in either group. Other measures of contractility ($\text{dp}\text{dt}$ max., peak Vce, and dp/dt/40 mm. developed pressure) changed appropriately for the large changes in preload seen after angiogram.Thirty-seven studies in patients with coronary artery disease demonstrated that VFC obtained from the cardiac response to contrast are more sensitive than resting LVEDP or ejection fraction in detecting left ventricular abnormality.VFC can be obtained from the ventricular response to angiographic contrast because of the increase in venous return produced by the hyperosmotic effect of contrast. Depressed curves occur in patients with coronary artery disease because of their stiff ventricles and not because of depression of myocardial contractility.     

Adenylate cyclase activity in human parathyroid tissues: Reduced sensitivity to suppression by calcium in parathyroid adenomas as compared with normal glands form normocalcemic subjects or noninvolved glands from hyperparathyroid subjects

To examine whether alterations in parathyroid adenylate cyclase might be associated with glandular hyperfunction, we compared enzyme activity in membranes from 7 normal glands with activity from 18 abnormal and 5 noninvolved glands from patients with primary hyperparathyroidism. Compared with the normal glands, the specific enzyme activity after full stimulation with guanyl-5′yl imidodiphosphate was significantly decreased in both hyperplastic and noninvolved glands from the hyperparathyroid subjects. While the enzyme activity of all tissues could be suppressed by calcium, a twofold higher calcium concentration was required for comparable suppression of the enzyme from adenomas as compared with normal or noninvolved glands. Alterations in the adenylate cyclase complex of hyperplastic parathyroid glands may explain, in part, the elevated “set point” for calcium homeostasis in primary hyperparathyroidism.     

Dynamic QT Interval Changes from Supine to Standing in Healthy Children

Background

QT-interval variations in response to exercise-induced increases in heart rate have been reported in children and adults in the diagnosis of long QT syndrome (LQTS). A quick standing challenge has been proposed as an alternative provocative test in adults, with no pediatric data yet available.