High-throughput cytochrome P450 (CYP) inhibition screening via cassette probe-dosing strategy. II. Validation of a direct injection/on-line guard cartridge extraction-tandem mass spectrometry method for CYP2D6 inhibition assessment

A highly efficient direct injection/on-line guard cartridge extraction-tandem mass spectrometry (DI/GCE-MS-MS) method has been validated for high-throughput evaluation of cytochrome P450 (CYP) 2D6 inhibition potential using human hepatic microsomes and 96-well microtiter plates. Microsomal incubations were terminated with formic acid, centrifuged, and the resulting supernatants were injected for DI/GCE-MS-MS analysis. Due to the novel use of an extremely short C18 guard cartridge, this method exhibits several advantages, such as no sample preparation, excellent on-line extraction, short run time (2.5 min), and minimized source contamination and performance deterioration. The DI/GCE-MS-MS method demonstrates acceptable accuracy and precision for the quantification of dextrorphan, a marker metabolite of dextromethorphan mediated by CYP2D6, in microsomal incubations. The CYP2D6 inhibition assay has been validated using quinidine as a known selective inhibitor of the isoform. The IC50 value (0.20 microM) measured by the new method is in good agreement with the literature value (0.22 microM).     

Fast,persistent, Ca2+-dependent K+ current controls graded electrical activity in crayfish muscle

The early outward current in opener muscle fibres of crayfish (Procambarus clarkii) was studied using the two-electrode voltage-clamp technique. This current was abolished in Ca²⁺-free and 5 mM Cd²⁺ solutions, and was blocked by extra- or intracellular tetraethylammonium, indicating that it was a Ca²⁺-dependent K⁺ current [I _K(Ca)]. I _K(Ca) was voltage dependent, apamin insensitive and sensitive to charybdotoxin (CTX), which, in addition to its tetraethylammonium sensitivity, suggests that the channels mediating I _K(Ca) behave in a BK type manner. I _K(Ca) activation was extremely fast, reaching a maximum within 5 ms, and the inactivation was incomplete, stabilizing at a persistent steady-state. I _K(Ca) was insensitive to intracellular ethylenebis(oxonitrilo)tetraacetate (EGTA), but was abolished by injection of the faster Ca²⁺ chelator 1,2-bis(2-aminophenoxy)ethane-N,N,N,N'-tetraacetic acid (BAPTA), suggesting that voltage-dependent Ca²⁺ channels and those mediating I _K(Ca) should be clustered closely on the membrane. Under two-electrode current-clamp recording mode, low amplitude, graded responses were evoked under control conditions, whereas repetitive all-or-none spikes were elicited by application of CTX or after loading the cells with BAPTA. We conclude that I _K(Ca) activates extremely quickly, is persistent and is responsible for the generation and control of the low amplitude, graded, active responses of opener muscle fibres.     

软组织平滑肌肉瘤中p16基因的甲基化检测

目的 探讨软组织平滑肌肉瘤（ＬＭＳ）中p16基因ＩＮＫ４Ａ的甲基化状态及其与p16表达的关系。方法 应用ＭＳＰ法检测３８例软组织平滑肌肉瘤,１０例平滑肌瘤及５例正常平滑肌组织中p16基因ＩＮＫ４Ａ的甲基化状态,用免疫组织化学ＳＰ方法检测p16蛋白表达情况。结果 ３８例ＬＭＳ中９例发生异常甲基化,异常甲基化率为２３.7%（９／３８）。其中,７例p16蛋白表达阴性,２例p16蛋白弱阳性,在p16蛋白表达阴性的ＬＭＳ中,异常甲基化率为５０％（７／１４）。结论 p16基因第一外显子启动子区５‘CpG岛的异常甲基化是导致p16基因失活、蛋白缺如的重要基因外机制,并可能参与肿瘤的发生。     

Fine-needle aspiration of a metaplastic breast carcinoma with extensive melanocytic differentiation: a case report

Metaplastic carcinomas of the breast are uncommon breast tumors with aberrant cellular differentiation, most commonly showing ductal, squamous, and mesenchymal components. A breast carcinoma composed of both epithelial and melanocytic differentiation is rare, with only four previously reported cases in the literature. We present the fifth reported case, where the diagnosis was suggested by fine-needle aspiration (FNA) and later confirmed after the surgical specimen was excised. Histologically, this neoplasm revealed multidirectional differentiation, consisting primarily of squamous and melanocytic cell types, with focal glandular and osseous metaplasia. Based on the morphologic, immunohistochemical, and ultrastructural findings, we conclude that such tumors fall within the spectrum of metaplastic carcinomas of the breast. We believe that this case will further contribute to the understanding of this enigmatic tumor.     

Comparison of immunofluorescence with enzyme immunoassay for detection of Q fever

To evaluate enzyme immunoassay (EIA) as an alternative to indirect immunofluorescence assay (IFA) to screen for Q fever in humans, 157 serum samples from patients suspected of having the disease were tested for immunoglobulin G antibodies toCoxiella burnetii. The agreement between the tests and the sensitivity of EIA were excellent (96.8% and 98.4%, respectively) when an IFAtiter of > 1/160 was considered positive. All serum samples with a titer of > 1/320 in the IFA were also positive by the EIA. The EIA seems to be an acceptable alternative to IFA for screening for Q fever.     

Wissenstranslation am Beispiel Bewegungsförderung von älteren Menschen: Wie gelangen wissenschaftliche Erkenntnisse in die kommunale Praxis?

Bundesgesundheitsblatt - Gesundheitsforschung - Gesundheitsschutz - Wissenschaftliche Ergebnisse können eine Wissensquelle für kommunale Akteurinnen und Akteure der...     

Aufbau von Interventionsdatenbanken für mehr Evidenzbasierung in Prävention und Gesundheitsförderung – methodische Überlegungen

Bundesgesundheitsblatt - Gesundheitsforschung - Gesundheitsschutz - Kommunale AkteurInnen erfahren bei der Entwicklung und Auswahl von Maßnahmen der Prävention und...     

FAM19A4基因启动子甲基化检测在宫颈癌及其癌前病变筛查的研究

宫颈癌是最常见的妇科恶性肿瘤之一。目前人乳头瘤病毒(HPV)检测及细胞学检查是宫颈癌及其癌前病变(CCPL)的主要筛查手段。由于上述传统筛查方法,仍然存在对CCPL漏诊的风险,因此寻找有效识别CCPL的特异性分子标志物,具有重要临床意义。对具有序列相似性家族19成员A4(FAM19A4)基因启动子甲基化定量检测,可有效检出CCPL组织,较传统筛查方法有较高特异度,有望成为CCPL筛查的特异性分子标志物。笔者拟就FAM19A4基因启动子甲基化定量检测,在CCPL筛查中应用的最新研究现状进行阐述,旨在为进一步推进CCPL筛查方法的开发,提供思路。     

Does multidetector computed tomographic urography (MDCTU) T staging classification correspond with pathologic T staging in upper tract urothelial carcinoma?

International Urology and Nephrology - Multidetector computed tomographic urography (MDCTU) is not yet sufficient to be used in the clinical staging of upper tract urothelial carcinoma (UTUC). This...