Over-expression and production of plant allergens by molecular farming strategies

Recombinant allergens have become a valuable tool for diagnosis and may also be used for therapy in the near future. To supply the required large amounts of functional recombinant proteins on a cost-effective basis, the production of allergens in plants by molecular farming is an alternative to microbial expression systems. Especially as post-translational modifications of the allergens, e.g., phosphorylation and glycosylation, may be important for recognition by the human immune system, the plant-based production of recombinant allergens enables the correct folding, glycosylation, and other modifications of the recombinant allergen. An introduction to the methods for plant transformation via the tumor-inducing bacterium, Agrobacterium tumefaciens, is given in this paper.     

Synthesis and SAR of novel 2-arylthiazolidinones as selective analgesic N-type calcium channel blockers

A series of new N-type (Ca(v)2.2) calcium channel blockers derived from the 'hit' structures 2-(3-bromo-4-fluorophenyl)-3-(2-pyridin-2-ylethyl)thiazolidin-4-one 9 and its 2-[4-(4-bromophenyl)pyridin-3-yl]-3-isobutyl analogue 10 is described. Extensive SAR studies using a range of synthetic approaches resulted in novel, patented compounds with IC50 values of up to 0.2 microM in an in vitro IMR32 assay, and selectivities for N/L of up to 30-fold. The new compounds described have potential in treatment of neuropathic pain.     

Potent and selective xanthine-based inhibitors of phosphodiesterase 5

Inhibitors of PDE5 are useful therapeutic agents for treatment of erectile dysfunction. A series of novel xanthine derivatives has been identified as potent inhibitors of PDE5, with good levels of selectivity against other PDE isoforms, including PDE6. Studies in the dog indicate excellent oral bioavailability for compound 21.     

Investigating the feasibility of stem cell enrichment mediated by immobilized selectins

Hematopoietic stem cell therapy is used to treat both malignant and non-malignant diseases, and enrichment of the hematopoietic stem and progenitor cells (HSPCs) has the potential to reduce the likelihood of graft vs host disease or relapse, potentially fatal complications associated with the therapy. Current commercial HSPC isolation technologies rely solely on the CD34 surface marker, and while they have proven to be invaluable, they can be time-consuming with variable recoveries reported. We propose that selectin-mediated enrichment could prove to be a quick and effective method for recovering HSPCs from adult bone marrow (ABM) on the basis of differences in rolling velocities and independently of CD34 expression. Purified CD34+ ABM cells and the unselected CD34- ABM cells were perfused over immobilized P-, E-, and L-selectin-IgG at physiologic wall shear stresses, and rolling velocities and cell retention data were collected. CD34+ ABM cells generally exhibited lower rolling velocities and higher retention than the unselected CD34- ABM cells on all three selectins. For initial CD34+ ABM cell concentrations ranging from 1% to 5%, we predict an increase in purity ranging from 5.2% to 36.1%, depending on the selectin used. Additionally, selectin-mediated cell enrichment is not limited to subsets of cells with inherent differences in rolling velocities. CD34+ KG1a cells and CD34- HL60 cells exhibited nearly identical rolling velocities on immobilized P-selectin-IgG over the entire range of shear stresses studied. However, when anti-CD34 antibody was co-immobilized with the P-selectin-IgG, the rolling velocity of the CD34+ KG1a cells was significantly reduced, making selectin-mediated cell enrichment a feasible option. Optimal cell enrichment in immobilized selectin surfaces can be achieved within 10 min, much faster than most current commercially available systems.     

Synthesis,chromatographic resolution and chiroptical properties of carboxyibuprofen stereoisomers: Major metabolites of ibuprofen in man

The chromatographic resolution of the four stereoisomers of carboxyibuprofen, a major metabolite of ibuprofen in man, was achieved using a Chiralpak AD chiral stationary phase (CSP) (J.T. Baker, Milton, Keynes, UK). The elution order of the stereoisomers was determined to be 2′S,2R; 2′R,2R; 2′R,2S; 2′S,2S by a combination of stereoselective synthesis of diastereoisomeric mixtures and analysis of the two diastereoisomers isolated from human urine following the administration of (S)-ibuprofen. The individual stereoisomers were isolated by semipreparative chiral phase chromatography and characterized by circular dichroism spectroscopy. Chirality 9:75–87, 1997. © 1997 Wiley-Liss, Inc.     

High incidence of transposon Tn3 insertions into a replication control gene of the chimeric R/Ent plasmid pCG86 of Escherichia coli.

Insertion of transposon Tn3 into the chimeric R/Ent plasmid pCG86 occurred preferentially into a replication control gene, generating mutants with increased plasmid copy number. In two mutants, the nucleotide sequence of the region of the gene containing the Tn3 insertion was determined.     

Characterization of the basic replicons of the chimeric R/Ent plasmid pCG86 and the related Ent plasmid P307

Restriction-enzyme fragments that can replicate autonomously after circularization were isolated from the chimeric R/Ent plasmid pCG86 and the Ent plasmid P307. Two such regions containing a basic replicon were located in each plasmid. One of the basic replicons of P307, RepFIB, is almost identical with one of the basic replicons of pCG86. The other basic replicon in P307, RepFIC, is partly homologous with the second basic replicon in pCG86, RepFIIA/RepFIC. The latter is a hybrid basic replicon and is in addition partly homologous with RepFIIA, a basic replicon present in IncFII R plasmids. By restriction-enzyme mapping and nucleotide-sequence analysis we have determined a site in the hybrid replicon where it ceases to be homologous with the RepFIIA basic replicon contained in the IncFII miniplasmid pSM1. The 2410-bp region of homology with pSM1 corresponds with a segment containing the origin of replication and all the genes responsible for replication control of pSM1.     

Growth,production and biomass of the antarctic gastropod Laevilacunaria Antarctica Martens 1885

Twenty-one monthly collections of the Antarctic prosobranch gastropod Laevilacunaria antarctica Martens 1885 were obtained by divers at Signy Island, South Orkney Islands. Animals were contagiously distributed in the depth range 2–12 m below mean low water, with a mean monthly density of 199.0 ± 207.3 (S.D.) m^?2. Size frequency distribution was analysed, and at least three year classes identified. There was a prolonged annual recruitment from mid winter to mid summer, and juveniles dominated the population numerically for ten months of the year. Growth was seasonal, with a high rate during the Austral spring and summer, and a reduced rate during winter. A mean biomass of 356.3 mg dry tissue wt · m^?2 and a total annual production of 812.2 mg · m^?2 were estimated for the second year of study, and a production to biomass ratio of 2.28 obtained.