Introduction of cationic virosome derived from vesicular stomatitis virus as a novel gene delivery system for sf9 cells

Insect-derived cell lines are used extensively to produce recombinant proteins because they are capable of performing a range of post-translational modifications. Due to their significance in biotechnological applications, various methods have been developed to transfect them. In this study, we introduce a virosome constructed from vesicular stomatitis virus (VSV) as a new delivery system for sf9 cells. We labeled these VSV virosomes by fluorescent probe Rhodamine B chloride (R18). By fluorescence microscope observation and conducting a fusion assay, we confirmed the uptake of VSV virosomes via endocytosis by sf9 cells and their fusion with the endosomal membrane. Moreover, we incubated cationic VSV virosomes with a GFP-expressing bacmid and transfected sf9 cells, after 24?h some cells expressed GFP indicating the ability of VSV virosomes to deliver heterologous DNA to these cells. This is the first report of a virosome-based delivery system introduced for an insect cell line.     

Antileukemic activity of aminoparthenolide analogs

A series of aminoparthenolide analogs have been synthesized through a diastereoselective conjugate addition of several primary and secondary amines to the α-methylene-γ-butyrolactone function of the very lipophilic sesquiterpene lactone, parthenolide. Seventeen of the above amines derivatives were evaluated in a full panel of 60 cancer cell lines for anticancer activity. Compound 12, derived from tyramine, was found to be cytostatic as well as cytotoxic toward acute lymphoblastic leukemia cells (ALL, CCRF-CEM) at nanomolar concentrations, while the (R)-(1,2,3,4-tetrahydro-1-naphthyl)amino derivative 9 was found to be cytostatic toward human anaplastic large T-cell lymphoma (SR) cells at concentrations below 10 nM.     

Mucinous cystadenocarcinoma of the parotid gland: report of a case with fine needle aspiration findings and histologic correlation

BACKGROUND: Mucinous cystadenocarcinoma of the salivary gland is a rare entity. Review of the literature from 1991 to 1999 revealed no previous reports on its cytologic features. CASE: A 25-year-old man had a slowly growing, painless mass in the left parotid gland. Fine needle aspiration biopsy, performed prior to surgical excision, showed clusters of minimally atypical epithelial cells in which occasional vacuolated cells containing mucin could be seen. Pathologic evaluation of the resected parotid mass showed it to be a mucinous cystadenocarcinoma. CONCLUSION: The cytologic differential diagnosis of mucinous cystadenocarcinoma is with low grade mucoepidermoid carcinoma and with mucinous adenocarcinoma. Mucinous cystadenocarcinoma must be cystic; cysts may be present in low grade mucoepidermoid carcinoma, but their size and prominence varies. Mucinous adenocarcinoma is not cystic but gelatinous. Nuclei are bland in both mucinous cystadenocarcinoma and low grade mucoepidermoid carcinoma but are atypical in mucinous adenocarcinoma. There is no squamous differentiation in either mucinous cystadenocarcinoma or mucinous adenocarcinoma, but it is subtle in low grade mucoepidermoid carcinomas. Mucinous cystadenocarcinoma should be considered a potential candidate in the differential diagnosis of mucinous lesions that can occur in the salivary gland.     

The ligand-binding face of the semaphorins revealed by the high-resolution crystal structure of SEMA4D

Semaphorins, proteins characterized by an extracellular sema domain, regulate axon guidance, immune function and angiogenesis. The crystal structure of SEMA4D (residues 1-657) shows the sema topology to be a seven-bladed beta-propeller, revealing an unexpected homology with integrins. The sema beta-propeller contains a distinctive 77-residue insertion between beta-strands C and D of blade 5. Blade 7 is followed by a domain common to plexins, semaphorins and integrins (PSI domain), which forms a compact cysteine knot abutting the side of the propeller, and an Ig-like domain. The top face of the beta-propeller presents prominent loops characteristic of semaphorins. In addition to limited contact between the Ig-like domains, the homodimer is stabilized through extensive interactions between the top faces in a sector of the beta-propeller used for heterodimerization in integrins. This face of the propeller also mediates ligand binding in integrins, and functional data for semaphorin-receptor interactions map to the equivalent surface.     

A quorum-based data consistency approach for non-relational database

Cluster Computing - Quorum algorithm has become one of the most widely adopted approaches for storing data in the failure-prone distributed storage systems. In this paper, a new approach is...     

Experimental paradigms revisited: oxidative stress-induced tRNA fragmentation does not correlate with stress granule formation but is associated with delayed cell death

tRNA fragmentation is an evolutionarily conserved molecular phenomenon. tRNA-derived small RNAs (tsRNAs) have been associated with many cellular processes, including improved survival during stress conditions. Here, we have revisited accepted experimental paradigms for modeling oxidative stress resulting in tRNA fragmentation. Various cell culture models were exposed to oxidative stressors followed by determining cell viability, the production of specific tsRNAs and stress granule formation. These experiments revealed that exposure to stress parameters commonly used to induce tRNA fragmentation negatively affected cell viability after stress removal. Quantification of specific tsRNA species in cells responding to experimental stress and in cells that were transfected with synthetic tsRNAs indicated that neither physiological nor non-physiological copy numbers of tsRNAs induced the formation of stress granules. Furthermore, the increased presence of tsRNA species in culture medium collected from stressed cells indicated that cells suffering from experimental stress exposure gave rise to stable extracellular tsRNAs. These findings suggest a need to modify current experimental stress paradigms in order to allow separating the function of tRNA fragmentation during the acute stress response from tRNA fragmentation as a consequence of ongoing cell death, which will have major implications for the current perception of the biological function of stress-induced tsRNAs.