气相色谱(ECD)法同时测定蔬菜和水果中8种菊酯类农药残留

目的：探索和研究同时测定蔬菜和水果中8种菊酯类农药残留的方法。方法：样品粉碎后经溶剂提取、固相萃取分离净化和氮吹仪浓缩后,进入GC/ECD分析,外标法定量。结果：8种菊酯类农药残留取得很好的分离效果,定量分析呈良好的线性关系,相关系数均大于99%,回收率82.5%-101.3%,检出限符合卫生标准要求。结论：该方法样品处理简单,灵敏度高,精密度和准确度好,可以同时测定8种菊酯类农药残留。     

Erdheim-Chester Disease: Characteristics and Management

Erdheim-Chester disease is a rare CD68⁺, CD1a⁻ non-Langerhans cell histiocytosis with multiorgan involvement. The etiology of Erdheim-Chester disease is unclear; there are no known associated infectious or hereditary genetic abnormalities. However, somatic BRAF mutations have recently been identified in these patients. Historically, the literature regarding the management of Erdheim-Chester disease consisted of case reports and small case series with anecdotal therapeutic responses to agents including, but not limited to, cytotoxic chemotherapy, bone marrow transplantation, cladribine, corticosteroids, IFN-α, the BCR-ABL/KIT inhibitor imatinib mesylate, the IL-1 receptor antagonist anakinra, the TNF-inhibitor infliximab, and recently the BRAF inhibitor vemurafenib. We performed a search of the literature using PubMed with the terms Erdheim Chester disease, without date limitations, including case reports, case series, original articles, and previous review articles. In the absence of large-scale studies, experience-based management prevails. The present review details our approach to the management of patients with Erdheim-Chester disease.     

颅内动脉瘤载瘤动脉闭塞术后局部脑血流的变化研究

目的探讨颅内动脉瘤载瘤动脉闭塞术后的局部脑血流改变。方法对10例正常对照者和23例颅内动脉瘤载瘤动脉闭塞术后的患者行99Tcm-ECDSPECT脑显像。结果10例正常对照者脑实质内放射性核素分布浓度均匀,左右两侧对称,脑皮质部完整,未见局限性浓度稀疏或增浓区。23例术后患者中16例显示脑实质内放射性核素分布浓度均匀,呈正常影像;4例显示患侧核素分布浓度较对侧稍稀疏;1例左基底节区呈放射性核素浓度稀疏;另2例于颞叶内侧部显示为放射性核素缺损。99Tcm-ECDSPECT对脑缺血显示的灵敏度、特异性和准确性均为100%。结论99Tcm-ECDSPECT脑显像对判断颅内动脉瘤载瘤动脉闭塞术后局部脑血流的变化具有重要的应用价值。     

Ventricular ErbB2/ErbB4 activation and downstream signaling in pacing-induced heart failure

The neuregulin-1 (NRG-1)/ErbB system has emerged as a cardioprotective system that becomes activated during myocardial stress, most convincingly shown in response to cardiotoxic chemotherapy. Direct evidence of increased ventricular ErbB receptor activity in heart failure unrelated to cardiotoxic drugs is, however, limited. We investigated changes in NRG-1 expression, ErbB receptor phosphorylation and downstream activation of intracellular ErbB targets during rapid pacing and progressive ventricular dysfunction in the dog. Heart failure was induced in dogs by 7 weeks of rapid pacing. Ventricular function was assessed by echocardiography. Messenger RNA expression was investigated in ventricular biopsies using quantitative PCR. Activation of NRG-1/ErbB signaling and of downstream targets was investigated using immunoprecipitation and/or Western blotting. Over the course of 7 weeks of pacing and ventricular dilatation, ventricular levels of NRG-1, but not of other ErbB4 ligands, and of ADAM19, a protease promoting NRG-1 release, progressively increased. In parallel, levels of activated ErbB2 and ErbB4, phosphorylated at tyrosine residues 877/1248 and 1284 respectively, became progressively higher. Similarly, levels of total and phosphorylated PI-3 kinase increased. Surprisingly, however, and in contrast with activation of downstream targets of ErbB receptors in normal hearts, Akt and ERK1/2, remained inactivated. This study shows that ventricular ErbB2 and ErbB4 receptors become activated during the development of pacing-induced heart failure, but that downstream signaling is, at least partly, abrogated. Abrogation of cardioprotective signaling after ErbB activation is an unanticipated phenomenon in the progression of heart failure with possibly major pathophysiological significance. The underlying mechanisms should be further elucidated.     

Regional cerebral blood flow in a patient with Nasu-Hakola disease

We report a functional neuroimaging study of a 43-year-old woman with Nasu-Hakola disease (NHD). Regional cerebral blood flow (rCBF) images were measured with technetium-99m ethyl cysteinate dimer single photon emission computed tomography (SPECT). rCBF was decreased in the bilateral frontal lobes and thalamus. This finding was consistent with the known underlying neuropathology in patients with NHD. Brain SPECT is useful for demonstrating the pathophysiologic brain region in patients with NHD.     

A pair of new isocoumarin epimers from soil fungus Hypoxylon sp.

In our research on novel secondary metabolites from micro-organisms, two new (1–2) and four known dihydroisocoumarins (3–6) were derived from soil fungus Hypoxylon sp. Their structures were determined with extensive NMR data analysis and ECD calculation comparing with those of experimental CD spectra. Interestingly, compounds 1 and 2 possessed the same planar structure and very similar NMR data, suggesting 1 and 2 were a pair of epimers at either C-3 or at C-4, confirmed by the totally opposite cotton effect around 250 nm in the CD spectra of 1 and 2. Moreover, for the first time, we revealed that the CD absorption peak at 250 nm was dominated by C-3 orientation, rather than the orientation of C-3 substituents, by intensive ECD investigations.     

五例艾滋病患者~(99)Tc~m-ECD脑SPECT显像

目的　观察艾滋病 (AIDS)患者局部脑血流 (rCBF)的变化。方法　对 5例男性AIDS患者 (IV期 )进行了99Tcm 双半胱乙酯 (ECD)脑血流灌注显像 ,半定量测定rCBF。 16例性别、年龄匹配的健康者作正常对照。结果　 1例有痴呆临床表现的AIDS患者存在双侧额、顶、颞叶和基底节及左侧丘脑rCBF低灌注 ,4例无痴呆临床表现的AIDS患者亦出现双侧额、顶叶rCBF低灌注。AIDS组患者双侧额、顶、颞叶、基底节和丘脑以及直回和桥脑rCBF明显低于对照组。结论　AIDS患者存在脑皮层和皮层下rCBF减少     

Diagnosis of Regional Cerebral Blood Flow Abnormalities Using Spect: Agreement between Individualized Statistical Parametric Maps and Visual Inspection by Nuclear Medicine Physicians with Different Levels of Expertise in Nuclear Neurology

INTRODUCTION:

Visual analysis is widely used to interpret regional cerebral blood flow (rCBF) SPECT images in clinical practice despite its limitations. Automated methods are employed to investigate between-group rCBF differences in research studies but have rarely been explored in individual analyses.

OBJECTIVES:

To compare visual inspection by nuclear physicians with the automated statistical parametric mapping program using a SPECT dataset of patients with neurological disorders and normal control images.

METHODS:

Using statistical parametric mapping, 14 SPECT images from patients with various neurological disorders were compared individually with a databank of 32 normal images using a statistical threshold of p<0.05 (corrected for multiple comparisons at the level of individual voxels or clusters). Statistical parametric mapping results were compared with visual analyses by a nuclear physician highly experienced in neurology (A) as well as a nuclear physician with a general background of experience (B) who independently classified images as normal or altered, and determined the location of changes and the severity.

RESULTS:

Of the 32 images of the normal databank, 4 generated maps showing rCBF abnormalities (p<0.05, corrected). Among the 14 images from patients with neurological disorders, 13 showed rCBF alterations. Statistical parametric mapping and physician A completely agreed on 84.37% and 64.28% of cases from the normal databank and neurological disorders, respectively. The agreement between statistical parametric mapping and ratings of physician B were lower (71.18% and 35.71%, respectively).

CONCLUSION:

Statistical parametric mapping replicated the findings described by the more experienced nuclear physician. This finding suggests that automated methods for individually analyzing rCBF SPECT images may be a valuable resource to complement visual inspection in clinical practice.