Interaction of Ciprofloxacin Loaded Liposomes with Pseudomonas Aeruginosa Cells

An antibiotic delivery system has been developed using ciprotloxacin (CIPRO) encapsulated within sonicated unilamellar vesicles (SUV) of different lipid compositions composed of dipalmitoylphospatidylcholine (DPPC), L-aphosphatidylcholine (PC), phosphatidylethanolamine (PEA) and cholesterol (CHOL). The interaction of SUV (i.e. liposomes) with Pseudomonas aeruginosa (Tl 2977) cells was studied and the effect of the liposome encapsulated antibiotic was tested. Encapsulation of CIPRO apparently increased the amount of antibiotic resident in the vicinity of bacteria in aqueous solution at neutral pH. Electrophoretic mobility measurements showed that P. aeruginosa cells were negatively charged. The zeta potential of P. aeruginosa was -11.4 ± 2.9 m V in phosphate buffered saline at pH 7 .0, and the corresponding surface charge density was -14.7 ± 3.9 mC/m2. DPPC liposomes and PC liposomes had mean diameters of 103 ± 35 nm and 80 ± 25nm, respectively. They were electrically neutral or had a small positive charge of +S.0 ± 3.0 mC/m2 when prepared with PC:CHOL:PEA=S: 1: 1. The interaction and attachment of neutral or positively charged SUV to negatively charged bacterial cells was studied in an effort to increase the residency of the liposomes and CIPRO, in the vicinity of the bacterial cells. Ke

Congenic Mesenchymal Stem Cell Therapy Reverses Hyperglycemia in Experimental Type 1 Diabetes

OBJECTIVE - A number of clinical trials are underway to test whether mesenchymal stem cells (MSCs) are effective in treating various diseases, including type 1 diabetes. Although this cell therapy holds great promise, the optimal source of MSCs has yet to be determined with respect to major histocompatibility complex matching. Here, we examine this question by testing the ability of congenic MSCs, obtained from the NOR mouse strain, to reverse recent-onset type 1 diabetes in NOD mice, as well as determine the immunomodulatory effects of NOR MSCs in vivo. RESEARCH DESIGN AND METHODS - NOR MSCs were evaluated with regard to their in vitro immunomodulatory function in the context of autoreactive T-cell proliferation and dendritic cell (DC) generation. The in vivo effect of NOR MSC therapy on reversal of recent-onset hyperglycemia and on immunogenic cell subsets in NOD mice was also examined. RESULTS - NOR MSCs were shown to suppress diabetogenic T-cell proliferation via PD-L1 and to suppress generation of myeloid/inflammatory DCs predominantly through an IL-6-dependent mechanism. NOR MSC treatment of experimental type 1 diabetes resulted in long-term reversal of hyperglycemia, and therapy was shown to alter diabetogenic cytokine profile, to diminish T-cell effector frequency in the pancreatic lymph nodes, to alter antigen-presenting cell frequencies, and to augment the frequency of the plasmacytoid subset of DCs. CONCLUSIONS - These studies demonstrate the inimitable benefit of congenic MSC therapy in reversing experimental type 1 diabetes. These data should benefit future clinical trials using MSCs as treatment for type 1 diabetes

Phacidium and Ceuthospora (Phacidiaceae) are congeneric: taxonomic and nomenclatural implications

The morphologically diverse genus Ceuthospora has traditionally been linked to Phacidium sexual morphs via association, though molecular or cultural data to confirm this relationship have been lacking. The aim of this study was thus to resolve the relationship of these two genera by generating nucleotide sequence data for three loci, ITS, LSU and RPB2. Based on these results, Ceuthospora is reduced to synonymy under the older generic name Phacidium. Phacidiaceae (currently Helotiales) is suggested to constitute a separate order, Phacidiales (Leotiomycetes), as sister to Helotiales, which is clearly paraphyletic. Phacidiaceae includes Bulgaria, and consequently the family Bulgariaceae becomes a synonym of Phacidiaceae. Several new combinations are introduced in Phacidium, along with two new species, P. pseudophacidioides, which occurs on Ilex and Chamaespartium in Europe, and Phacidium trichophori, which occurs on Trichophorum cespitosum subsp. germanicum in The Netherlands. The generic name Allantophomopsiella is introduced to accommodate A. pseudotsugae, a pathogen of conifers, while Gremmenia is resurrected to accommodate the snow-blight pathogens of conifers, G. abietis, G. infestans, and G. pini-cembrae

Pocillopycnis, an emendation

Volume: 10Start Page: 288End Page: 29

Myrothecium tongaense anam.-sp. nov.

Volume: 12Start Page: 219End Page: 22

Molecular mobility of nitroxyl-labelled taxol during tubulin assembly

AbstractTaxol 1`Taxol' is a registered trademark of Bristol-Myers Squibb, that offers `paclitaxel' as a substitute name.1 is an important natural anticancer agent that binds to β-tubulin and suppresses microtubule depolymerization. We have used electron paramagnetic resonance (EPR) spectroscopy to analyze the molecular motion of three novel nitroxyl free radical taxol analogues. Taxol was chemically modified at C2 or C7 carbon of the taxane ring with the TEMPO free radical to yield two spin-labelled taxols and concurrently at C2′ and 3′N of the side chain to yield a spin-labelled taxol biradical. Nitroxyl moieties attached to the taxane ring are significantly restricted in their molecular motion during microtubule assembly, and they show no molecular restriction upon binding to tubulin. We conclude that taxol binds to tubulin in a way such that the taxane ring is not constrained by the dimer structure. However, the taxane ring is strongly immobilized after polymerization of tubulin, i.e. it is incorporated into the structure of microtubule. In contrast, the nitroxy moieties of the taxol biradical show strong immobilization upon attachment to tubulin. The nitroxyl energy exchange is restricted prior to the assembly of microtubules, and no differences associated with the process of polymerization were detected. The taxol side chain resides in a region that is not significantly constrained during polymerization.© 1997 Federation of European Biochemical Societies