Polyomavirus EGFP-pseudocapsids: analysis of model particles for introduction of proteins and peptides into mammalian cells

A vector for preparation of mouse polyomavirus capsid-like particles for transfer of foreign peptides or proteins into cells was constructed. Model pseudocapsids carrying EGFP fused with the C-terminal part of the VP3 minor protein (EGFP-VLPs) have been prepared and analysed for their ability to be internalised and processed by mouse cells and to activate mouse and human dendritic cells (DC) in vitro. EGFP-VLPs entered mouse epithelial cells, fibroblasts and human and mouse DC efficiently and were processed by both, lysosomes and proteasomes. Surprisingly, they did not induce upregulation of DC co-stimulation molecules or maturation markers in vitro; however, they did induce interleukin 12 secretion.     

检测EB病毒TK激酶抗体方法的建立及其在鼻咽癌诊断中的应用

目的:建立检测鼻咽癌(NPC)患者血清中EB病毒TK激酶的酶免疫测定(EIA)方法,用于筛选和辅助诊断早期NPC患者。方法:用基因工程高效表达的EB病毒TK激酶作为包被抗原,建立EIA检测方法,检测NPC患者和对照血清中的TK/IgG抗体。结果:在NPC患者血清中检出了特异的对EB病毒TK激酶的IgG抗体,而正常人血清中为抗体阴性。结论:首先建立了简便、快速、特异和敏感的早期诊断NPC的EIA方法,并作为我公司产品扩展应用。     

Pseudogene rescue: an adaptive mechanism of codon reassignment

Alterations to the genetic code – codon reassignments – have occurred many times in life’s history, despite the fact that genomes are coadapted to their genetic codes and therefore alterations are likely to be maladaptive. A potential mechanism for adaptive codon reassignment, which could trigger either a temporary period of codon ambiguity or a permanent genetic code change, is the reactivation of a pseudogene by a nonsense suppressor mutant transfer RNA. I examine the population genetics of each stage of this process and find that pseudogene rescue is plausible and also readily explains some features of extant variability in genetic codes.     

FIRST HARMFUL DINOPHYSIS (DINOPHYCEAE,DINOPHYSIALES) BLOOM IN THE U.S. IS REVEALED BY AUTOMATED IMAGING FLOW CYTOMETRY1

Imaging FlowCytobot (IFCB) combines video and flow cytometric technology to capture images of nano‐ and microplankton (～10 to >100 μm) and to measure the chlorophyll fluorescence associated with each image. The images are of sufficient resolution to identify many organisms to genus or even species level. IFCB has provided >200 million images since its installation at the entrance to the Mission‐Aransas estuary (Port Aransas, TX, USA) in September 2007. In early February 2008, Dinophysis cells (1–5 · mL^?1) were detected by manual inspection of images; by late February, abundance estimates exceeded 200 cells · mL^?1. Manual microscopy of water samples from the site confirmed that D. cf. ovum F. Schütt was the dominant species, with cell concentrations similar to those calculated from IFCB data, and toxin analyses showed that okadaic acid was present, which led to closing of shellfish harvesting. Analysis of the time series using automated image classification (extraction of image features and supervised machine learning algorithms) revealed a dynamic phytoplankton community composition. Before the Dinophysis bloom, Myrionecta rubra (a prey item of Dinophysis) was observed, and another potentially toxic dinoflagellate, Prorocentrum, was observed after the bloom. Dinophysis cell‐division rates, as estimated from the frequency of dividing cells, were the highest at the beginning of the bloom. Considered on a daily basis, cell concentration increased roughly exponentially up to the bloom peak, but closer inspection revealed that the increases generally occurred when the direction of water flow was into the estuary, suggesting the source of the bloom was offshore.     

Effects of food deprivation on refuge use and dispersal in juvenile North Sea houting Coregonus oxyrinchus under experimental conditions

This study tested the influence of energetic state on refuge use and dispersal in juvenile North Sea houting Coregonus oxyrinchus in an artificial stream. Food-deprived fish spent more time outside refuges than well-fed fish; however, the well-fed fish initiated dispersal faster than the food-deprived fish. The results may indicate state-dependent refuge use and dispersal in C. oxyrinchus.     

NSF independent fusion of Salmonella-containing late phagosomes with early endosomes

Initial characterizations of live-Salmonella-containing early (LSEP) and late phagosomes (LSLP) in macrophages show that both phagosomes retain Rab5 and EEA1. In addition, LSEP specifically contain transferrin receptor whereas LSLP possess relatively more rabaptin-5. In contrast to LSLP, late-Salmonella-containing vacuoles in epithelial cells show significantly reduced levels of Rab5 and EEA1. Subsequent results demonstrate that both phagosomes efficiently fuse with early endosomes (EE). In contrast to LSEP, fusion between LSLP and EE is insensitive to ATPγS treatment. Furthermore, LSLP fuses with EE in absence of NEM-sensitive fusion factor (NSF) as well as in the presence of NSF:D1EQ mutant demonstrating that LSLP fusion with EE is NSF independent.