基于文献计量学的病毒性肺炎免疫应答调节机制研究进展分析

[目的] 了解病毒性肺炎及其免疫应答机制的研究现状,分析该领域的热点和研究发展趋势。[方法] 检索Web of Science(WOS)核心合集数据库中有关病毒性肺炎免疫应答相关的文献为文献样本,基于文献计量学,利用Citespace对该领域文献进行国家合作、机构合作、关键词等分析。[结果] 共检测到相关文献796篇,美国的发文量、研究者数量及研究成果在全球都处于领先地位,美国国立卫生研究院为发文最多的机构;中国研究处于不断发展阶段,与其他国家有良好合作,国内交流有待增强;主要的热点话题有呼吸道合胞病毒、流感、发病机制、细胞因子表达、炎症反应等。[结论] 该领域研究受疫情爆发的影响,正处于发展阶段,全球应加国内外强科研合作,提高防治疫情整体研究水平。     

胫骨延长后骨痂直径与新生骨预后关系的临床分析

目的探讨胫骨延长后骨痂直径与新生骨预后的关系.方法 1996年1月～2001年12月,对68例胫骨延长者测量达所需延长长度时的骨痂直径,计算骨痂直径率(callus diameter ratios,CDR);统计拆除外固定架后2～4周时新生骨发生骨折例数及畸形角度,比较骨折和成角畸形与CDR的关系.结果拆除外固定架前胫骨前屈角度5度以上畸形19例,其中11例发生骨折;拆除外固定架后胫骨出现5度以上畸形6例,其中2例骨折;其余43例胫骨延长骨痂正常愈合.计算CDR值:CDR值小于80% 23例,其中发生新生骨骨折13例,成角畸形5度以上者21例;CDR在81%～85%之间6例,成角畸形5度以上4例;CDR值超过86% 39例,无畸形或新生骨骨折.结论胫骨延长时CDR小于80%时,容易发生新生骨骨折和畸形;CDR大于85%时,无新生骨骨折和畸形发生;两组间具有统计学意义(P＜0.05).CDR是判断骨痂能否正常愈合较为理想的检测指标.     

新型Ilizarov膝关节牵伸器的研制和临床应用

目的 :探讨用Ilizarov微创技术矫正各种类型膝关节屈曲畸形。方法 :在Ilizarov牵伸器基础上 ,研制了新型膝关节牵伸器 ;包括股骨、胫骨骨外固定器 ,并在膝关节两侧由关节铰链连接。术中安装时确定膝关节伸屈的旋转中心 ,用于伸缩的带弹簧牵伸杆安装在膝后的上下两个钢环上 ,手术中将牵伸器用 2mm克氏针交叉穿股骨和胫骨于膝关节中央 ,术后逐渐旋转牵伸杆 ,膝关节软骨面在避免挤压的情况下慢慢伸直。结果 :2 7例 3 0个膝关节 ,术后平均牵伸时间 5 8d ( 18d～ 10个月 ) ,全部病例膝关节伸直皆达到矫形需要的要求 ,未发生影响治疗效果的并发症。结论 :新型Ilizarov膝关节牵伸器的研制和临床应用技术 ,开辟了一条微创、简便、安全治疗屈膝挛缩的有效方法 ,能够矫正用传统手术难以治疗的严重膝关节屈曲僵直畸形     

Bone marrow mesenchymal stem cell therapy in ischemic stroke：mechanisms of action and treatment optimization strategies

Animal and clinical studies have conifrmed the therapeutic effect of bone marrow mesenchymal stem cells on cerebral ischemia, but their mechanisms of action remain poorly understood. Here, we summarize the transplantation approaches, directional migration, differentiation, replacement, neural circuit reconstruction, angiogenesis, neurotrophic factor secretion, apoptosis, immunomodulation, multiple mechanisms of action, and optimization strategies for bone marrow mesenchymal stem cells in the treatment of ischemic stroke. We also explore the safety of bone marrow mesenchymal stem cell transplantation and conclude that bone marrow mesenchymal stem cell transplantation is an important direction for future treatment of cerebral ischemia. Determining the optimal timing and dose for the transplantation are important directions for future research.     

Discordance between ambulatory monitoring and programmed stimulation in assessing efficacy of class IA antiarrhythmic agents in patients with ventricular tachycardia

Concordance between programmed stimulation and 24 hour ambulatory electrocardiographic (Holter) monitoring was studied in 54 patients with sustained ventricular tachycardia during 84 therapeutic trials with class IA antiarrhythmic agents. During baseline studies before treatment, all patients had frequent (greater than or equal to 30/h) ventricular premature complexes on Holter recordings and sustained ventricular tachycardia inducible by one to three extrastimuli. During treatment, programmed stimulation and Holter monitoring were repeated. Efficacy of treatment determined by programmed stimulation (ventricular tachycardia no longer inducible or nonsustained) was compared with three Holter criteria of efficacy: I = 83% or more reduction of ventricular premature complexes and abolition of ventricular tachycardia; II = 50% or more reduction of ventricular premature complexes and 90% or more reduction of couplets and abolition of ventricular tachycardia; III = abolition of ventricular tachycardia in patients with ventricular tachycardia during a baseline Holter recording. Treatments were judged effective by programmed stimulation criteria in only 25% of cases but in 51, 63 and 75% of cases by Holter criterion I, II and III, respectively. Results of programmed stimulation and Holter monitor were discordant (effective by one criterion but ineffective by the other) in 50% of cases using Holter criterion I, in 54% using Holter criterion II and in 61% using Holter criterion III. In the majority of discordant results, treatments appeared efficacious by Holter criteria but ineffective by programmed stimulation criteria, suggesting insensitivity of efficacy by Holter criteria or nonspecificity of induced ventricular tachycardia during treatment, or both.     

Quantitative assessment of pulmonary hypertension in patients with tricuspid regurgitation using continuous wave Doppler ultrasound

Doppler ultrasound examination was performed in 69 patients with a variety of cardiopulmonary disorders who were undergoing bedside right heart catheterization. Patients were classified into two groups on the basis of hemodynamic findings. Group I consisted of 20 patients whose pulmonary artery systolic pressure was less than 35 mm Hg and Group II consisted of 49 patients whose pulmonary artery systolic pressure was 35 mm Hg or greater. Tricuspid regurgitation was detected by Doppler ultrasound in 2 of 20 Group I patients and 39 of 49 Group II patients (p less than 0.001). Twenty-six of 27 patients with pulmonary artery systolic pressure greater than 50 mm Hg had Doppler evidence of tricuspid regurgitation. In patients with tricuspid regurgitation, continuous wave Doppler ultrasound was used to measure the velocity of the regurgitant jet, and by applying the Bernoulli equation, the peak pressure gradient between the right ventricle and right atrium was calculated. There was a close correlation between the Doppler gradient and the pulmonary artery systolic pressure measured by cardiac catheterization (r = 0.97, standard error of the estimate = 4.9 mm Hg). Estimating the right atrial pressure clinically and adding it to the Doppler-determined right ventricular to right atrial pressure gradient was not necessary to achieve accurate results. These findings indicate that tricuspid regurgitation can be identified by Doppler ultrasound in a large proportion of patients with pulmonary hypertension, especially when the pulmonary artery pressure exceeds 50 mm Hg. Calculation of the right ventricular to right atrial pressure gradient in these patients provides an accurate noninvasive estimate of pulmonary artery systolic pressure.     

Smooth muscle contraction bands in the media of coronary arteries: A postmortem marker of antemortem coronary spasm?

To date, no unequivocal morphologic markers have been described that would allow the diagnosis of coronary artery spasm to be made at autopsy. The coronary arteries of 63 adult patients without myocardial infarction were examined at autopsy, and the presence of medial smooth muscle contraction bands in these vessels was correlated with other vascular changes, myocardial pathologic changes and clinical history. These contraction bands have not been reported previously in human coronary arteries, but they were identified in experimental vascular spasm induced with catecholamines. It was found that 47 of the 63 cases were positive for contraction bands. As evidence of an antemortem process, there was a significant correlation between these changes and the presence of nonocclusive microthrombi, found in 25 cases. Contraction bands were also highly correlated with atherosclerotic plaque ruptures and mural plaque hemorrhages, which may be secondary to coronary spasm. In 78.7% of the cases positive for contraction bands, the cause of death was related to a diagnosis possibly associated with high catecholamine levels. On the basis of experimental evidence and the correlations identified in this study, coronary artery medial smooth muscle contraction bands may represent a postmortem marker of antemortem coronary spasm.     

Plasma lipoprotein abnormalities associated with acquired hepatic triglyceride lipase deficiency

Two enzymes, lipoprotein lipase (LPL) and hepatic triglyceride lipase (HTGL), are released into human plasma after intravenous injection of heparin. LPL is the major enzyme responsible for initiating catabolism of chylomicrons and very-low-density lipoproteins (VLDL). The physiological role of HTGL is less certain. HTGL has been postulated to be an alternate enzyme to LPL in hydrolysis of triglyceride in VLDL and to be an important enzyme for removal of phospholipid from both low-density lipoproteins (LDL) and high-density lipoproteins (HDL). In this latter role, this enzyme would convert larger, lighter lipoprotein particles to smaller denser particles. HTGL deficiency has been found in severe liver disease and with a genetic deficiency of this enzyme. A unique patient is described with acquired hepatic triglyceride lipase deficiency and vitamin A intoxication. This patient developed hypercholesterolemia with an increase in both LDL and HDL. An increased proportion of lighter LDL (LDL1) and HDL (HDL2) was noted. In addition, after administration of heparin there was no shift in the distribution of apoE in plasma fractionated using a column containing 4% agarose. These findings are consistent with a postulated role of HTGL in metabolism of light LDL and HDL particles and some classes of apoE containing lipoproteins.