210 research outputs found
Alternative administration routes and delivery technologies for polio vaccines
Global polio eradication is closer than ever. Replacement of the live attenuated oral poliovirus vaccine (OPV) by inactivated poliovirus vaccine (IPV) is recommended to achieve complete eradication. Limited global production capacity and relatively high IPV costs compared to OPV spur the need for improved polio vaccines. The target product profile of these vaccines includes not only dose sparing but also high stability, which is important for stockpiling, and easy application important for (emergency) vaccination campaigns. In this review, the current status of alternative polio vaccine delivery strategies is given. Furthermore, we discuss the feasibility of these strategies by highlighting challenges, hurdles to overcome, and formulation issues relevant for optimal vaccine delivery
Human diploid fibroblast growth on polystyrene microcarriers in aggregates
Polystyrene microcarriers were prepared in four size ranges (53–63 μm, 90–125 μm, 150–180 μm and 300–355 μm) and examined for ability to support attachment and growth of human diploid fibroblasts. Cells attached rapidly to the microcarriers and there was a direct relationship between cell attachment and microcarrier aggregation. Phasecontrast and scanning electron microscopic studies revealed that while aggregation was extensive, most of the aggregate consisted of void volume. Cell growth studies demonstrated that human diploid fibroblasts proliferated well in microcarrier aggregates, reaching densities of 2.5–3×10 6 cells per 2 ml dish after 6 days from an inoculum of 0.5×10 6 cells per dish. When cells were added to the microcarriers at higher density (up to 5×10 6 cells per 2-ml culture), there was little net growth but the cells remained viable over a 7-day period. In contrast, cells died when plated under the same conditions in monolayer culture. When the microcarriers were used in suspension culture, rapid cell attachment and rapid microcarrier aggregation also occurred. In 100-ml suspension culture, a cell density of 0.7×10 6 cells per ml was reached after 7 days from an inoculum of 0.1×10 6 cells. Based on these data, we conclude that microcarrier aggregation is not detrimental to fibroblast growth. These data also indicate that small microcarriers (53–63 μm) (previously thought to be too small to support the growth of diploid fibroblasts) can support fibroblast growth and this occurs primarily because microcarriers in this size range efficiently form aggregates with the cells.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/42617/1/10616_2004_Article_BF00353930.pd
The SsgA-like proteins in actinomycetes: small proteins up to a big task
Several unique protein families have been identified that play a role in the control of developmental cell division in streptomycetes. The SsgA-like proteins or SALPs, of which streptomycetes typically have at least five paralogues, control specific steps of sporulation-specific cell division in streptomycetes, affecting cell wall-related events such as septum localization and synthesis, thickening of the spore wall and autolytic spore separation. The expression level of SsgA, the best studied SALP, has a rather dramatic effect on septation and on hyphal morphology, which is not only of relevance for our understanding of (developmental) cell division but has also been succesfully applied in industrial fermentation, to improve growth and production of filamentous actinomycetes. Recent observations suggest that SsgB most likely is the archetypal SALP, with only SsgB orthologues occurring in all morphologically complex actinomycetes. Here we review 10 years of research on the SsgA-like proteins in actinomycetes and discuss the most interesting regulatory, functional, phylogenetic and applied aspects of this relatively unknown protein family
TURBULENCE IN MOLECULAR CLOUDS
We generate random Gaussian turbulent velocity fields with a Kolmogorov
spectrum and use these to obtain synthetic line-of-sight velocity profiles. The
profiles are found to be similar to line profiles observed in molecular clouds.
We suggest methods for analysing measured line profiles to test whether they
might arise from Gaussian Kolmogorov turbulence.Comment: accepted in ApJ, compressed postscript, figures not included.
Complete preprint available at http://ucowww.ucsc.edu/~dubinski/home.html or
by request to [email protected]
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DNA cleavage and antitumour activity of platinum(II) and copper(II) compounds derived from 4-methyl-2-N-(2-pyridylmethyl)aminophenol: spectroscopic, electrochemical and biological investigation
The reaction of the redox-active ligand, Hpyramol (4-methyl-2-N-(2-pyridylmethyl)aminophenol) with K2PtCl4 yields monofunctional square-planar [Pt(pyrimol)Cl], PtL-Cl, which was structurally characterised by single-crystal X-ray diffraction and NMR spectroscopy. This compound unexpectedly cleaves supercoiled double-stranded DNA stoichiometrically and oxidatively, in a non-specific manner without any external reductant added, under physiological conditions. Spectro-electrochemical investigations of PtL-Cl were carried out in comparison with the analogue CuL-Cl as a reference compound. The results support a phenolate oxidation, generating a phenoxyl radical responsible for the ligand-based DNA cleavage property of the title compounds. Time-dependent in vitro cytotoxicity assays were performed with both PtL-Cl and CuL-Cl in various cancer cell lines. The compound CuL-Cl overcomes cisplatin-resistance in ovarian carcinoma and mouse leukaemia cell lines, with additional activity in some other cells. The platinum analogue, PtL-Cl also inhibits cell-proliferation selectively. Additionally, cellular-uptake studies performed for both compounds in ovarian carcinoma cell lines showed that significant amounts of Pt and Cu were accumulated in the A2780 and A2780R cancer cells. The conformational and structural changes induced by PtL-Cl and CuL-Cl on calf thymus DNA and phi X174 supercoiled phage DNA at ambient conditions were followed by electrophoretic mobility assay and circular dichroism spectroscopy. The compounds induce extensive DNA degradation and unwinding, along with formation of a monoadduct at the DNA minor groove. Thus, hybrid effects of metal-centre variation, multiple DNA-binding modes and ligand-based redox activity towards cancer cell-growth inhibition have been demonstrated. Finally, reactions of PtL-Cl with DNA model bases (9-Ethylguanine and 5'-GMP) followed by NMR and MS showed slow binding at Guanine-N7 and for the double stranded self complimentary oligonucleotide d(GTCGAC)(2) in the minor groove
Biosensor Applications in the Field of Antibiotic Research—A Review of Recent Developments
Antibacterials are among of the most important medications used in health care. However, their efficacy is increasingly impeded by a tremendous and globally spread bacterial resistance phenomenon. This bacterial resistance is accelerated by inadequate application of antibacterial drugs in humans, the widespread veterinary use of antibacterials, and antibacterial occurrence in the environment and food. Further, there is a lack of development of innovative novel drugs. Therefore, the search for novel antibacterials has to be intensified and the spread of antibacterials in the environment has to be restricted. Due to the fundamental progress in biosensor development and promising applications in the antibiotic field, this review gives for the first time an overview on the use and prospects of biosensor applications in that area. A number of reports have applied biosensors of different design and techniques to search for antibacterials in environmental and foodstuff matrices. These studies are discussed with respect to the analytical values and compared to conventional techniques. Furthermore, biosensor applications to elucidate the mode of action of antimicrobial drugs in vitro have been described. These studies were critically introduced referring to the informational value of those simulations. In summary, biosensors will be illustrated as an innovative and promising, although not yet comprehensively applied, technique in the antibacterial field
Transformation and tumorigenicity testing of simian cell lines and evaluation of poliovirus replication
The key role of cell cultures in different scientific fields is worldwide recognized, both as in vitro research models alternative to laboratory animals and substrates for biological production. However, many safety concerns rise from the use of animal/human cell lines that may be tumorigenic, leading to potential adverse contaminations in cell-derived biologicals. In order to evaluate the suitability of 13 different cell lines for Poliovirus vaccine production, safety and quality, in vitro/in vivo tumorigenicity and Poliovirus propagation properties were evaluated.
Our results revealed that non-human primate cell lines CYNOM-K1, FRhK-4, 4MBr-5 and 4647 are free of tumorigenic features and represent highly susceptible substrates for attenuated Sabin Poliovirus strains. In particular, FRhK-4 and 4647 cell lines are characterized by a higher in vitro replication, resulting indicated for the use in large-scale production field
Frequent mutated B2M, EZH2, IRF8, and TNFRSF14 in primary bone diffuse large B-cell lymphoma reflect a GCB phenotype
Primary bone diffuse large B-cell lymphoma (PB-DLBCL) is a rare extranodal lymphoma subtype. This retrospective study elucidates the currently unknown genetic background of a large clinically well-annotated cohort of DLBCL with osseous localizations (O-DLBCL), including PB-DLBCL. A total of 103 patients with O-DLBCL were included and compared with 63 (extra)nodal non-osseous (NO)-DLBCLs with germinal center B-cell phenotype (NO-DLBCL-GCB). Cell-of-origin was determined by immunohistochemistry and gene-expression profiling (GEP) using (extended)-NanoString/Lymph2Cx analysis. Mutational profiles were identified with targeted next-generation deep sequencing, including 52 B-cell lymphoma-relevant genes. O-DLBCLs, including 34 PB-DLBCLs, were predominantly classified as GCB phenotype based on immunohistochemistry (74%) and NanoString analysis (88%). Unsupervised hierarchical clustering of an extended-NanoString/Lymph2Cx revealed significantly different GEP clusters for PB-DLBCL as opposed to NO-DLBCL-GCB (P < .001). Expression levels of 23 genes of 2 different targeted GEP panels indicated a centrocyte-like phenotype for PB-DLBCL, whereas NO-DLBCL-GCB exhibited a centroblast-like constitution. PB-DLBCL had significantly more frequent mutations in four GCB-associated genes (ie, B2M, EZH2, IRF8, TNFRSF14) compared with NO-DLBCL-GCB (P = .031, P = .010, P = .047, and P = .003, respectively). PB-DLBCL, with its corresponding specific mutational profile, was significantly associated with a superior survival compared with equivalent Ann Arbor limited-stage I/II NO-DLBCL-GCB (P = .016). This study is the first to show that PB-DLBCL is characterized by a GCB phenotype, with a centrocyte-like GEP pattern and a GCB-associated mutational profile (both involved in immune surveillance) and a favorable prognosis. These novel biology-associated features provide evidence that PB-DLBCL represents a distinct extranodal DLBCL entity, and its specific mutational landscape offers potential for targeted therapies (eg, EZH2 inhibitors)
Colorectal carcinomas in MUTYH-associated polyposis display histopathological similarities to microsatellite unstable carcinomas
<p>Abstract</p> <p>Background</p> <p>MUTYH-associated polyposis (MAP) is a recessively inherited disorder which predisposes biallelic carriers for a high risk of polyposis and colorectal carcinoma (CRC). Since about one third of the biallelic MAP patients in population based CRC series has no adenomas, this study aimed to identify specific clinicopathological characteristics of MAP CRCs and compare these with reported data on sporadic and Lynch CRCs.</p> <p>Methods</p> <p>From 44 MAP patients who developed ≥ 1 CRCs, 42 of 58 tumours were analyzed histologically and 35 immunohistochemically for p53 and beta-catenin. Cell densities of CD3, CD8, CD57, and granzyme B positive lymphocytes were determined. <it>KRAS2</it>, the mutation cluster region (MCR) of <it>APC, p53</it>, and <it>SMAD4 </it>were analyzed for somatic mutations.</p> <p>Results</p> <p>MAP CRCs frequently localized to the proximal colon (69%, 40/58), were mucinous in 21% (9/42), and had a conspicuous Crohn's like infiltrate reaction in 33% (13/40); all of these parameters occurred at a higher rate than reported for sporadic CRCs. Tumour infiltrating lymphocytes (TILs) were also highly prevalent in MAP CRCs. Somatic <it>APC </it>MCR mutations occurred in 14% (5/36) while 64% (23/36) had <it>KRAS2 </it>mutations (22/23 c.34G>T). G>T tranversions were found in <it>p53 </it>and <it>SMAD4</it>, although the relative frequency compared to other mutations was low.</p> <p>Conclusion</p> <p>MAP CRCs show some similarities to micro-satellite unstable cancers, with a preferential proximal location, a high rate of mucinous histotype and increased presence of TILs. These features should direct the practicing pathologist towards a MAP aetiology of CRC as an alternative for a mismatch repair deficient cause. High frequent G>T transversions in <it>APC </it>and <it>KRAS2 </it>(mutated in early tumour development) but not in <it>P53 </it>and <it>SMAD4 </it>(implicated in tumour progression) might indicate a predominant MUTYH effect in <it>early </it>carcinogenesis.</p
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