TLR2对曲霉感染支气管上皮细胞时Dectin-1表达的影响

目的 探讨烟曲霉感染人支气管上皮（HBE）细胞时Toll样受体2（TLR2）对树突状细胞植物血凝素-1 （Dectin-1）表达的影响.方法 建立烟曲霉感染HBE细胞模型,通过PCR、Western blot方法分别在mRNA、蛋白水平检测Dectin-1和TLR2的表达情况;沉默TLR2,复制感染模型,应用Western blot及流式细胞技术评价Dectin-1的表达变化.结果 ①烟曲霉感染后HBE细胞TLR2表达水平虽然有所升高,并在感染18h达到峰值,但与静息状态表达水平的差异无统计学意义（P＞0.05）.②沉默TLR2,在烟曲霉感染HBE细胞后18 h时Dectiin1的蛋白表达受到显著抑制（P＜0.05）.结论 HBE细胞静息状态下能够表达TLR2,在烟曲霉感染早期,随着时间的延长其表达有逐步增高的趋势;HBE细胞启动Dectin-1的表达可能是建立在TLR2对烟曲霉早期识别的基础上,通过下游信号通路的激活来实现的。     

Induction of innate immunity by Aspergillus fumigatus cell wall polysaccharides is enhanced by the composite presentation of chitin and beta-glucan

Chitin and β-glucan are conserved throughout evolution in the fungal cell wall and are the most common polysaccharides in fungal species. Together, these two polysaccharides form a structural scaffold that is essential for the survival of the fungus. In the present study, we demonstrated that Aspergillus fumigatus alkali-insoluble cell wall fragments (AIF), composed of chitin linked covalently to β-glucan, induced enhanced immune responses when compared with individual cell wall polysaccharides. Intranasal administration of AIF induced eosinophil and neutrophil recruitment, chitinase activity, TNF-α and TSLP production in mice lungs. Selective destruction of chitin or β-glucan from AIF significantly reduced eosinophil and neutrophil recruitment as well as chitinase activity and cytokine expression by macrophages, indicating the synergistic effect of the cell wall polysaccharides when presented together as a composite PAMP. We also showed that these cell wall polysaccharides induced chitin-specific IgM in mouse serum. Our in vivo and in vitro data indicate that chitin and β-glucan play important roles in activating innate immunity when presented as composite cell wall PAMPs.     

Antibody to Aspergillus fumigatus Antigens in Normal Sera: Influence on Positive-Negative Discrimination in ELISA

The response of precipitin-negative sera from non-selected asthmatic patients against a range of somatic and culture filtrate antigens of Aspergillus fumigatus in ELISA for anti-A. fumigatus IgG is described. Antibody to the various antigens was widely distributed but the precise distribution was dependent upon antigen type. To determine how the selection of negative reference sera from precipitin-negative sera can influence the discrimination between precipitin-positive and -negative sera in ELISA, panels of 10 sera were chosen from the extremes of the frequency distribution and by random selection. The closest agreement between precipitin testing and ELISA was seen when randomly-selected negative reference sera were incorporated in the assay, although the degree of correlation was dependent upon the detector antigen. These findings demonstrate the requirement for careful selection of sera included as negative reference sera in ELISA for anti-A. fumigatus IgG.     

Aspergillus fumigatus pacemaker lead endocarditis: a case report and review of the literature

The diagnosis of fungal endocarditis requires a high index of clinical suspicion. Rarely, pacemaker implantation may be a risk factor for the development of fungal endocarditis. A 71-year-old man with a history of multiple transvenous pacemaker manipulations and fever of an uncertain source is described. A diagnosis of culture-negative pacemaker endocarditis was established only after repeat transthoracic echocardiography. Amphotericin B was instituted; however, the patient developed a cerebral infarct and died. Postmortem examination demonstrated Aspergillus fumigatus within a large pacemaker lead thrombus, tricuspid and aortic valve vegetations, and septic pulmonary and renal emboli. The present report describes the clinical and pathological features of a rare case of Aspergillus fumigatus pacemaker lead endocarditis and suggests that serial echocardiograms may be effective in the early detection of pacemaker lead vegetations. The diagnostic features and therapeutic management of pacemaker lead endocarditis are reviewed.     

Clinical significance of Aspergillus fungaemia in patients with haematological malignancies and invasive aspergillosis

The clinical significance of Aspergillus fungaemia in the setting of a deep-seated aspergillosis has not been clearly established. Among 107 microbiologically documented Aspergillus infections in patients with haematological diseases observed over a 17-year period, blood cultures grew Aspergillus species from 10 cases. Aspergillus fungaemia was documented in 9 out of 89 (10.1%) patients with pulmonary aspergillosis at a median of 5 d from the onset of clinical signs of infection, and in one patient with central venous catheter focal infection. Five (50%) patients died as a result of fungal infection a median of 12 d (range 4--48) from the documentation of Aspergillus fungaemia. A comparison between cases of invasive aspergillosis with or without fungaemia showed that fungaemic patients were similar to those without positive blood cultures regarding clinical presentation, risk factors, clinical course and outcome. The diagnostic role of Aspergillus fungaemia in the setting of a deep-seated infection is limited because blood cultures become positive when a microbiological or clinical diagnosis of aspergillosis has already been performed. Aspergillus fungaemia does not necessarily seem to be correlated with a disseminated infection or a poorer prognosis.     

Protection of immunocompromised mice from fungal infection with a thymus growth-stimulatory component from Selaginella involvens,a fern

Context:?Recent studies have shown that the water extract of Selaginella involvens (Sw.) Spring, a wild fern, exhibits thymus growth-stimulatory activity in adult mice (reversal of involution of thymus) and remarkable anti-lipid peroxidation activity. Follow-up studies were carried out in the present study.

Materials and Methods:?Activity-guided isolation of the active component (AC) was carried out. The effect of AC on immune function was studied using fungal (Aspergillus fumigatus) challenge in cortisone-treated mice. The in vitro antifungal activity of AC was assayed using disc diffusion assay. In vitro and in vivo effect of AC on DNA synthesis in thymus was studied using ³H-thymidine incorporation. In in vitro anti-lipid peroxidation, hydroxyl radical scavenging and inhibition of superoxide production were assayed.

Results:?The active principle/component (AC) was isolated in a chromatographically pure form from the water extract of S. involvens. AC showed positive reaction to glycosides. AC possessed both thymus growth-stimulatory and antioxidant properties. It protected cortisone-treated mice from A. fumigatus challenge. It did not exhibit in vitro antifungal activity. Increased ³H-thymidine incorporation was observed in the reticuloepithelium of thymus obtained from AC-treated mice. However, in vitro AC treatment to thymus for 5?h did not result in an increase in ³H-thymidine incorporation.

Discussion and conclusion:?AC (named as Selagin), from S. involvens, could reverse involution of thymus to a large extent, exhibit remarkable antioxidant activity, and protect immunocompromised mice from fungal infection. Therefore, it is very promising for the development of a drug to ameliorate old age-related health problems and prolong lifespan.     

Aspergillus thyroiditis: first antemortem case diagnosed by fine‐needle aspiration culture in a pediatric stem cell transplant patient

Aspergillus thyroiditis (AT) has historically been considered a postmortem diagnosis in immunocompromised patients; most have disseminated disease. This report summarizes the clinical challenge of diagnosing AT. It also highlights the value of the early use of thyroid fine‐needle aspiration culture and the need for a high index of suspicion to reach the final diagnosis before disease dissemination.     

侵袭性肺曲霉菌病的MSCT表现

目的 探讨侵袭性肺曲霉菌病（IPA）的MSCT表现。方法 回顾性分析41例经临床及病理证实为IPA的MSCT表现。结果 35例血管IPA的MSCT主要表现为多发病灶25例,以肺野外周带分布为主26例;表现为结节或肿块影29例,伴晕征16例,出现空气半月征或空洞20例。6例气道IPA的MSCT主要表现为沿支气管分布的斑片影4例,以双肺中上野分布为主4例。15例血管IPA随访患者中,在出现晕征后的第2、4周分别出现空气半月征6例、空洞4例;5例气道IPA在随访1周时出现斑片结节融合4例,2周时支气管扩张4例,4周时4例支气管扩张加重。结论 血管IPA的MSCT多表现为肺野外周带多发结节或肿块影,常伴晕征或空气半月征或空洞;气道IPA多表现为沿支气管分布的斑片影,以中上肺野分布为主,常合并逐步加重的支气管扩张。IPA进展迅速,CT动态随访观察有助于诊断。     

杂色曲霉菌变应原分离、鉴定及纯化

目的 对杂色曲霉菌变应原蛋白进行分离、鉴定与纯化.方法 提取杂色曲霉菌蛋白质,通过十二烷基硫酸钠-聚丙烯酰胺凝胶电泳(SDS-PAGE)分离,用免疫印迹(western-blot)鉴定变应原成分,用western-blot法鉴定出了6种变应原,通过离子交换和凝胶过滤层析纯化变应原.结果 碳酸氢盐-盐水提取液(Coca'...