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排序方式: 共有723条查询结果,搜索用时 15 毫秒
21.
Atanaska Marinova‐Petkova Georgi Georgiev Todor Petkov Daniel Darnell John Franks Ghazi Kayali David Walker Patrick Seiler Angela Danner Allison Graham Pamela McKenzie Scott Krauss Richard J. Webby Robert G. Webster 《Influenza and other respiratory viruses》2016,10(2):98-108
Objectives
Ducks can shed and spread influenza A viruses (IAVs) while showing no disease signs. Our objective was to clarify the role of ‘foie gras’ ducks in the circulation of IAVs in Bulgaria.Methods
Monthly avian influenza surveillance was conducted on 63 ‘foie gras’ duck farms, 52 of which were surveyed throughout the study between November 2008 and April 2012. Virologic and serologic samples were collected and tested. During this time, wild bird samples were collected at major wild bird‐resting areas near the Black Sea coast and Danube River.Results
The study showed high isolation frequency of low‐pathogenicity avian influenza viruses. In the raising population (<75 days old), subtypes H3, H4, and H6 were detected monthly and H5 LPAIV, sporadically. Different subtypes (H1, H10, H11) were isolated from the fattening premises (75‐ to 100‐day‐old ducks), suggesting different routes of introduction. Only 6 of the 52 farms that were surveyed both virologically and serologically were influenza‐free throughout the study, possibly due to higher biosecurity measures implemented. No evidence of direct transmission of IAV from wild birds was found. Wild bird surveillance showed low isolation frequency of IAV. IAV prevalence of 0·55% for migratory ducks and 0·53% for migratory geese was estimated in November–December 2011 and January–February 2012, respectively, at two ornithologically important locations near the Black Sea coast.Conclusions
The ‘foie gras’ duck farms in Bulgaria are an optimal niche where Eurasian‐like IAVs are maintained and reassorted unapparent to farmers and veterinarians. 相似文献22.
Sustained, retransplantable, multilineage engraftment of highly purified adult human bone marrow stem cells in vivo 总被引:4,自引:8,他引:4
Civin CI; Almeida-Porada G; Lee MJ; Olweus J; Terstappen LW; Zanjani ED 《Blood》1996,88(11):4102-4109
Data from many laboratory and clinical investigations indicate that CD34+ cells comprise approximately 1% of human bone marrow (BM) mononuclear cells, including the progenitor cells of all the lymphohematopoietic lineages and lymphohematopoietic stem cells (stem cells). Because stem cells are an important but rare cell type in the CD34+ cell population, investigators have subdivided the CD34+ cell population to further enrich stem cells. The CD34+/CD38- cell subset comprises less than 10% of human CD34+ adult BM cells (equivalent to < 0.1% of marrow mononuclear cells), lacks lineage (lin) antigens, contains cells with in vitro replating capacity, and is predicted to be highly enriched for stem cells. The present investigation tested whether the CD34+/CD38- subset of adult human marrow generates human hematopoiesis after transfer to preimmune fetal sheep. CD34+/ CD38- cells purified from marrow using immunomagnetic microspheres or fluorescence-activated cell sorting generated easily detectable, long- term, multilineage human hematopoiesis in the human-fetal sheep in vivo model. In contrast, transfer of CD34+/CD38+ cells to preimmune fetal sheep generated only short-term human hematopoiesis, possibly suggesting that the CD34+/CD38+ cell population contains relatively early multipotent hematopoletic progenitor cells, but not stem cells. This work extends the prior in vitro evidence that the earliest cells in fetal and adult human marrow lack CD38 expression. In summary, the CD34+/ CD38- cell population has a high capacity for long-term multilineage hematopoietic engraftment, suggesting the presence of stem cells in this minor adult human marrow cell subset. 相似文献
23.
STUDY OBJECTIVES: Patients in a pulmonary clinic have disorders that predispose them to osteoporosis and may use glucocorticoid therapy, which has been associated with low bone mineral density (BMD) and increased fracture risk. Ideally, all patients at risk for osteoporosis would be screened using the best test available, which is central BMD by dual-energy x-ray absorptiometry (DXA). We proposed to stratify the risk for osteoporosis by the use of a simple questionnaire and point-of-care heel ultrasound BMD measurements. DESIGN: Cross-sectional screening study. SETTING: Pulmonary clinic in a single Veterans Affairs Medical Center. PATIENTS: Approximately 200 male and female patients who had not had previous BMD testing were eligible for the study, and 107 gave consent. INTERVENTIONS: One hundred seven men (white, 71 men; black, 35 men; and Asian, 1 man) underwent heel BMD testing and filled out a questionnaire. Ninety-eight men underwent a central DXA. RESULTS: Of 98 subjects, 24.5% had a spine, total hip, or femoral neck (FN) T-score of or= 7 days, and race, which accounted for 52 to 57% of the variance. When a heel ultrasound T-score of -1.0 was tested to predict a central DXA T-score of -2.0, the sensitivity was 61% and the specificity 64%. Adding the questionnaire score and body mass index (BMI) to the heel T-score improved sensitivity but not specificity. Moreover, BMI and age predicted central BMD with similar sensitivity and specificity. Importantly, of 24 patients with a central DXA T-score of 相似文献
24.
John Malysz Eric S. Rovner Georgi V. Petkov 《Pflügers Archiv : European journal of physiology》2013,465(7):965-975
Recent studies have demonstrated the importance of large-conductance Ca2+-activated K+ (BK) channels in detrusor smooth muscle (DSM) function in vitro and in vivo. However, in-depth characterization of human native DSM single BK channels has not yet been provided. Here, we conducted single-channel recordings from excised patches from native human DSM cells. Inside-out and outside-out recordings in high K+ symmetrical solution (containing 140 mM KCl and ~300 nM free Ca2+) showed single-channel conductance of 215–220 pS, half-maximum constant for activation of ~+75 to +80 mV, and low probability of opening (P o) at +20 mV that increased ~10-fold at +40 mV and ~60-fold at +60 mV. Using the inside-out configuration at +30 mV, reduction of intracellular [Ca2+] from ~300 nM to Ca2+-free decreased the P o by ~85 %, whereas elevation to ~800 nM increased P o by ~50-fold. The BK channel activator NS1619 (10 μM) enhanced the P o by ~10-fold at +30 mV; subsequent application of the selective BK channel inhibitor paxilline (500 nM) blocked the activity. Changes in intracellular [Ca2+] or the addition of NS1619 did not significantly alter the current amplitude or single-channel conductance. This is the first report to provide biophysical and pharmacological profiles of native human DSM single BK channels highlighting their importance in regulating human DSM excitability. 相似文献
25.
目的:分析老年退行性心脏瓣膜病(SDHVD)与多器官疾病的发生状况。方法老年人3896例,男2884例,女1012例,年龄60~103(78±13)岁。所有研究对象均进行心脏彩超、体检、相关辅助检查,并对多器官疾病进行分析。结果3896例患者中,SDHVD1225例(31.4%),无SDHVD2671例(68.6%),SDHVD组与对照组多器官疾病的发病率分别为高血压病49.3%vs 28.4%,冠心病38.5%vs23.8%,心力衰竭36.2%vs 17.3%,肺心病6.3%vs 3.1%,脑卒中21.6%vs 9.6%,肾功能不全6.9%vs 3.2%,胃食管反流病21.3%vs 10.3%,两组比较差异均有统计学意义(P<0.05),而糖尿病为11.2%vs 12.1%,两组比较差异无统计学意义(P>0.05)。结论 SDHVD组多器官疾病显著增高,可能由于SDHVD心脏重构改变,血流动力学异常,促发了多器官疾病的发生。 相似文献
26.
27.
28.
目的评价鼻中隔偏曲矫正术对持续性变应性鼻炎(allergicrhinitis,AR)伴鼻中隔偏曲患者症状和生活质量的影响。方法应用症状视觉模拟评分量表(Visual Analogue Scale,VAs)和鼻结膜炎生存质量量表(Rhinocon junctivitis Quality of Life Questionnaire,RQI。Q)对62例持续性变应性鼻炎伴鼻中隔偏曲患者行鼻中隔偏曲术前、术后1个月、术后6个月临床症状和生活质量进行研究。结果鼻中隔偏曲矫正术后1个月、6个月患者症状、生活质量较术前均得到改善。术后1个月、6个月RQI.Q量表中各个维度的得分较术前明显降低,差异有统计学意义(P〈0.05);术后6个月除总评分外,其余各维度与术后1个月比较,差异无统计学意义(P〉0.05)。VAS量表显示:术后患者症状较术前均有不同程度的改善,但改善最明显的为鼻塞,其次为打喷嚏。结论变应性鼻炎伴鼻中隔偏曲患者的生活质量降低,鼻中隔偏曲矫正术能明显的改善患者症状同时能提高患者的生活质量。 相似文献
29.
Dr. O. Petkov N. Popova V. Orbetsova R. Kolarova L. Dakovska 《Basic research in cardiology》1988,83(3):296-305
Summary ECG, systolic blood pressure (BP), the ratio (R) of grams of myocardial mass/100 g of body mass, total lipids, cholesterol, triglycerides and phospholipids in blood plasma and the left ventricular myocardium, as well as the plasma free fatty acids, were investigated in 58 male Wistar rats 3,30 and 180 days after operation, in a model of myocardial hypertrophy (MH) induced by experimental coarctation hypertension, after the method of Sclye.An attempt was made to correlate some functional and metabolic indices which characterize the development of this type of MH. On a background of progressively rising BP and parallel increasing R, ECG change were recorded. They were typical of the respective stage of arterial hypertension and MH and expressed mostly in a shifting of the electrical axis of the heart to the left and in essential repolarization disturbances. The most significant changes in the studied lipid fractions were found 30 days after the induction of hypertension. The pathological changes manifested on the 180th day are discussed in relation to age, the stage of hypertension and especially in relation to the developing hypoxic and ischaemic myocardial damage. 相似文献
30.
目的 了解应对方式对藏族初中生心理健康状况的影响。方法 采用自编的一般资料,中学生心理健康评定量表、简易应对方式问卷对786名藏族初中生进行问卷调查。结果 分层回归分析显示,第一层人口变量中上学方式、年级、家庭人均月收入、是否留守、学习成绩进入藏族初中生心理健康状况的回归方程(F=8.526,P=0.000),控制人口变量后,应对方式能独立解释心理健康状况21.70%的方差变异。结论 住校、初一、留守、学习成绩差、家庭收入低的藏族初中生心理健康状况差;管理者加强应对技巧的培训,能改善藏族初中生的心理健康状况。 相似文献