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Potential Feasibility (potential + feasibility)
Selected AbstractsResponses of leaf nitrogen concentration and specific leaf area to atmospheric CO2 enrichment: a retrospective synthesis across 62 speciesGLOBAL CHANGE BIOLOGY, Issue 7 2002Xiwei Yin Abstract Knowledge of leaf responses to elevated atmospheric [CO2] (CO2 concentration) is integral to understanding interactions between vegetation and global change. This work deals with responses of leaf mass-based nitrogen concentration (Nm) and specific leaf area (SLA). It assesses the statistical significance of factors perceived as influential on the responses, and quantifies how the responses vary with the significant factors identified, based on 170 data cases of 62 species compiled from the literature. Resultant equations capture about 41% of the variance in the data for percent responses of Nm and SLA, or about 95% of the variance for Nm and SLA at 57,320% normal [CO2]; these performance statistics also hold for leaf area-based N concentration and specific leaf weight. The equations generalize that: (i) both Nm and SLA decline as [CO2] increases; (ii) proportional decline of Nm is greater with deciduous woody species and with plants of normally low Nm, increases with pot size in growth chamber and greenhouse settings and with temperature and photosynthetic photon flux density (PPFD), and is mitigated by N fertilization; and (iii) proportional decline of SLA depends on pot size and PPFD similarly to Nm, increases with leaf life span and water vapour pressure deficit in enclosed experiments, and decreases with prolonged exposure to elevated [CO2] among broadleaf woody species in field conditions. The results highlight great uncertainty in the percent-response data and reveal the potential feasibility to estimate Nm and SLA at various magnitudes of elevated [CO2] from a few key plant and environmental factors of broad data bases. [source] Adenovirus-mediated small hairpin RNA targeting Bcl-XL as therapy for colon cancerINTERNATIONAL JOURNAL OF CANCER, Issue 6 2007Hongbo Zhu Abstract Bcl-XL, an anti-apoptotic protein of Bcl-2 family, is overexpressed in colon cancers. To determine Bcl-XL's potential feasibility as a therapeutic target, we constructed a recombinant adenovirus that expressed a U6 promoter-driven small hairpin RNA (shRNA) targeting Bcl-XL (Ad/Bcl-XL shRNA) and evaluated the vector's ability to induce RNA interference in vivo and alter apoptosis induction in colon cancer cells and tumours. Ad/Bcl-XL shRNA effectively knocked down Bcl-XL expression in colon cancer cells and decreased their viability. Treatment with Ad/Bcl-XL shRNA but not control vectors led to dramatically increased cleavage of cellular apoptosis-related enzymes caspase-9, caspase-3 and poly(ADP-ribose) polymerase. Ad/Bcl-XL shRNA also significantly suppressed the growth of subcutaneous tumours derived from DLD1 cells in a nude mouse model and did so without causing any obvious damage to normal tissues or normal human fibroblasts. Together, our results support the feasibility of using adenovirus-mediated RNA interference therapy targeting Bcl-XL against colon cancers and warrant further studies of its safety and efficacy. © 2007 Wiley-Liss, Inc. [source] Intra-articular depot formulation principles: Role in the management of postoperative pain and arthritic disordersJOURNAL OF PHARMACEUTICAL SCIENCES, Issue 11 2008Claus Larsen Abstract The joint cavity constitutes a discrete anatomical compartment that allows for local drug action after intra-articular injection. Drug delivery systems providing local prolonged drug action are warranted in the management of postoperative pain and not least arthritic disorders such as osteoarthritis. The present review surveys various themes related to the accomplishment of the correct timing of the events leading to optimal drug action in the joint space over a desired time period. This includes a brief account on (patho)physiological conditions and novel potential drug targets (and their location within the synovial space). Particular emphasis is paid to (i) the potential feasibility of various depot formulation principles for the intra-articular route of administration including their manufacture, drug release characteristics and in vivo fate, and (ii) how release, mass transfer and equilibrium processes may affect the intra-articular residence time and concentration of the active species at the ultimate receptor site. © 2008 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 97:4622,4654, 2008 [source] Bone Marrow Mesenchymal Stem Cells Form Ectopic Woven Bone In Vivo Through Endochondral Bone FormationARTIFICIAL ORGANS, Issue 4 2009Sophia Chia-Ning Chang Abstract:, Autologous vascularized bone grafts, allografts, and biocompatible artificial bone substitutes each have their shortcomings. Bones regenerated using recombinant human bone morphogenetic proteins, demineralized bone powder, or combinations of these are generally small and do not meet the need. The current trend is to use tissue engineering approaches with bone marrow mesenchymal stem cells (MSCs) to generate bones of a desired size and shape. A suspension of osteogenically induced MSCs (CD11a,, CD29+, CD44+) was added to 2% alginate, gelled by mixing this combination with calcium sulfate (CaSO4 0.2 g/mL), and injected into the subcutaneous pocket in the dorsal aspect of nude mice. Cells of various concentrations (0, 10, 50, and 70 million/mL) were used. These implanted constructs were harvested at predetermined times up to 30 weeks for histology. The doubling time of bovine MSCs is 3.75 ± 1.96 days and the proliferation is rapid. Histological evaluation revealed signs of endochondrosis with woven bone deposition. The equilibrium modulus increased with time in vivo, though less than that of normal tissue. Implants seeded with 70 million cells/mL for 6 months resulted in the best formation of equilibrium modulus. This approach has several advantages: (i) obtaining MSCs is associated with low donor morbidity; (ii) MSCs proliferate rapidly in vitro, and a large number of viable cells can be obtained; and (iii) the MSC/alginate constructs can develop into bone-like nodules with high cell viability. Such a system may be useful in large-scale production of bony implants or in the repair of bony defects. The fact that endochondral bone formation led to woven bone suggests its potential feasibility in regional cell therapy. [source] Study of Protein Splicing and Intein-Mediated Peptide Bond Cleavage under High-Cell-Density ConditionsBIOTECHNOLOGY PROGRESS, Issue 3 2003Shamik Sharma Protein splicing elements (inteins), capable of catalyzing controllable peptide bond cleavage reactions, have been used to separate recombinant proteins from affinity tags during affinity purification. Since the inteins eliminate the use of a protease in the recovery process, the intein-mediated purification system has the potential to significantly reduce recovery costs for the industrial production of recombinant proteins. Thus far, the intein system has only been examined and utilized for expression and purification of recombinant proteins at the laboratory scale for cells cultivated at low cell densities. In this study, protein splicing and in vitro cleavage of intein fusion proteins expressed in high-cell-density fed-batch fermentations of recombinant Escherichia coli were examined. Three model intein fusion constructs were used to examine the stability and splicing/cleavage activities of the fusion proteins produced under high-cell-density conditions. The data indicated that the intein fusion protein containing the wild-type intein catalyzed efficient in vivo protein splicing during high-cell-density cultivation. Also, the intein fusion proteins containing modified inteins catalyzed efficient thiol-induced in vitro cleavage reactions. The results of this study demonstrated the potential feasibility of using the intein-mediated protein purification system for industrial-scale production of recombinant proteins. [source] | |||||||||||||