Double intratibial injection of human tonsil-derived mesenchymal stromal cells recovers postmenopausal osteoporotic bone mass

Background and aims

Osteoporosis, which is a disease characterized by weakening of the bone, affects a large portion of the senior population. The current therapeutic options for osteoporosis have side effects, and there is no effective treatment for severe osteoporosis. Thus, we urgently need new treatment strategies, such as topical therapies and/or safe and effective stem cell therapies.

Screening of turfgrass species and cultivars for NaCl tolerance

Summary Information regarding the relative levels of salt tolerance between cultivars of Kentucky bluegrass (Poa pratensis L.) is lacking. The objectives of this study were to 1) develop a simple, quick and sensitive method of screening turfgrass species for NaCl tolerance and 2) to compare the relative salt tolerance of five cultivars of Kentucky bluegrass (Ram I, Adelphi, Baron, Bensun, and Nassau) to other known salt tolerant turfgrass species such as alkalaigrass (Puccinellia distans (L.) Parl. cv. Fults) and two cultivars of red fescue (Festuca rubra L. Dawson, and Checker).Alkalaigrass and both cultivars of red fescue retained a high level of salt tolerance compared to the Kentucky bluegrass cultivars. Significant variability in salt tolerance was apparent among the Kentucky bluegrass cultivars with Adelphi and Ram I exhibiting the best overall tolerance.     

Monoclonal antibody specific for lactosylceramide

The mouse hybridoma line T5A7 was derived during studies aimed at mapping human myeloid differentiation antigens. The IgM antibody secreted by this line recognizes an antigen richly expressed on mature myelomonocytic cells and on a subpopulation of lectin-activated human T-lymphocytes (Andrews, R. G., Torok-Storb, B., and Bernstein, I. D. (1983) Blood 62, 124-132). In the present study, we have determined the specificity of T5A7 antibody to be directed to lactosylceramide (Gal beta 1----4Glc beta 1----1 Cer) based on direct and indirect binding assays using a variety of glycolipids with known structures. The antibody did not cross-react with glycolipids having an N-acetyllactosamine terminus, including lactoneotetraosylceramide lactonorhexaosylceramide (i antigen), and lactoisooctaosylceramide (I antigen). The possible contribution of ceramide to the reactivity of lactosylceramide with this antibody was also studied using lactosylceramide preparations having different fatty acid composition.     

Intramolecular recombination of linear DNA catalyzed by the Escherichia coli RecE recombination system

Transformation of different Escherichia coli strains by linear dimers of pBR322 containing different tet alleles was investigated. Linear dimers transformed wild-type strains 0.1 to 1% as efficiently as circular dimers. In contrast, linear dimers transformed recBrecCsbcA strains, where the RecE recombination system is functional, as efficiently as circular dimers. The transformants contained plasmids that had a single recombinant monomer genotype, indicating that transformation was mediated by a recombination-dependent cyclization reaction. Altering the position of the double-strand break changed the frequency of recovering different recombination products, but had no effect on the frequency of transformation. Both the frequency of transformation and the production of Tcr recombinants were decreased by recE mutations, while recA and recF mutations were slightly stimulatory (twofold). Several recombination models consistent with these results are presented.     

Fibronectin receptor modulates cyclin-dependent kinase activity.

The high affinity fibronectin receptor (FNR) is expressed by hematopoietic cells, fibroblasts, and proliferating epidermal cells. Expression of this integrin is altered by chemical and viral transformation, suggesting that FNR dysfunction may play a role in growth control. This study demonstrates that exposing FA-K562 cells to glycine-arginine-glycine-aspartate-serine (GRGDS), a peptide ligand of the FNR, specifically stimulates p34/cdc2- and cyclin A-associated kinase activities. This occurs within 2 h of peptide addition. The 110-kDa form of the retinoblastoma protein appears within 3 h of GRGDS addition, consistent with activation of a G1/S kinase. DNA staining profiles demonstrate that GRGDS induces cell cycle progression within 24 h. Increased anchorage-independent growth is subsequently observed in GRGDS-treated FA-K562 cells. The control peptide, GRGES, which cannot bind the FNR, has none of these effects. This demonstrates that an extracellular integrin ligand can regulate cell proliferation. Furthermore, these results suggest that integrins link the extracellular environment and intracellular growth regulators.     

Inhibition of germination of dormant barley (Hordeum vulgare L.) grains by blue light as related to oxygen and hormonal regulation

Germination of primary dormant barley grains is promoted by darkness and temperatures below 20 °C, but is strongly inhibited by blue light. Exposure under blue light at 10 °C for periods longer than five days, results in a progressive inability to germinate in the dark, considered as secondary dormancy. We demonstrate that the inhibitory effect of blue light is reinforced in hypoxia. The inhibitory effect of blue light is associated with an increase in embryo abscisic acid (ABA) content (by 3.5‐ to 3.8‐fold) and embryo sensitivity to both ABA and hypoxia. Analysis of expression of ABA metabolism genes shows that increase in ABA mainly results in a strong increase in HvNCED1 and HvNCED2 expression, and a slight decrease in HvABA8′OH‐1. Among the gibberellins (GA) metabolism genes examined, blue light decreases the expression of HvGA3ox2, involved in GA synthesis, increases that of GA2ox3 and GA2ox5, involved in GA catabolism, and reduces the GA signalling evaluated by the HvExpA11 expression. Expression of secondary dormancy is associated with maintenance of high embryo ABA content and a low HvExpA11 expression. The partial reversion of the inhibitory effect of blue light by green light also suggests that cryptochrome might be involved in this hormonal regulation.