Comparison of Surface Polysaccharides of R. leguminosarum ANU57 (Exo-1), R. leg. ANU57(pBR1AN) (nod+, nif-), and R. leg. ANU57(pJB5J1) (nod+, nif-)

Extracellular polysaccharides (EPS) and lipopolysaccharides (LPS) are suspected to be involved in the legume/Rhizobium symbiotic process. Polysaccharide compositions from the EPS, LPS, capsular polysaccharide (CPS), and small polysaccharide (SmPS) were compared between Rhizobium leguminosarum ANU57 (parent, Exo-1) and two mutants R. leg. ANU57(pBR1AN) (nod+, nif-) and R. leg. ANU57(pJB5J1) (nod+, nif-) both containing a Sym (symbiotic) plasmid insertion. R. leg. ANU57(pBR1AN) and R. leg. ANU57(pJB5J1) are nod+ on clover and peas, respectively. The nod+ mutants produce larger amounts of EPS and decreased amounts of LPS compared to the parental strain. However, the EPS found in these nod+ mutants do not have the same EPS content found in the original R. leg. 128c53 Exo+1, nod+1, nif+1 parent, and thus do not support a role for EPS in the early steps of symbiosis. Pyruvate was present in the EPS of the mutant strains but not in the parental EPS. Pyruvate was found in the LPS of all three strains suggesting a Sym plasmid insertion of a possible modifying enzyme function (e.g., pyruvate linking) in the nod+ mutants. The uronic acid content in the EPS (Pk. II) of the mutant R. leg. ANU57(pJB5J1) is three times the amount found in the EPS (Pk. II) of the parent. R. leg. ANU57(pBR1AN) showed no distinguishable separation into EPS (Pk. I) and EPS (Pk. II) fractions, and thus the possible significance of this uronic acid difference requires further investigation. Sugar compositions of the parent and two mutant strains indicate an LPS component in the EPS. The relative mole percent composition of rhamnose, fucose, mannose, galactose, and KDO for the EPS, LPS, and CPS of the parent are similar to the corresponding EPS, LPS, and CPS of the two mutant strains. The possible effects these differences may have on legume/Rhizobium symbiosis are discussed

Comparison of Surface Polysaccharides of R. leguminosarum ANU57 (Exo-1), R. leg. ANU57(pBR1AN) (nod+, nif-), and R. leg. ANU57(pJB5J1) (nod+, nif-)

Extracellular polysaccharides (EPS) and lipopolysaccharides (LPS) are suspected to be involved in the legume/Rhizobium symbiotic process. Polysaccharide compositions from the EPS, LPS, capsular polysaccharide (CPS), and small polysaccharide (SmPS) were compared between Rhizobium leguminosarum ANU57 (parent, Exo-1) and two mutants R. leg. ANU57(pBR1AN) (nod+, nif-) and R. leg. ANU57(pJB5J1) (nod+, nif-) both containing a Sym (symbiotic) plasmid insertion. R. leg. ANU57(pBR1AN) and R. leg. ANU57(pJB5J1) are nod+ on clover and peas, respectively. The nod+ mutants produce larger amounts of EPS and decreased amounts of LPS compared to the parental strain. However, the EPS found in these nod+ mutants do not have the same EPS content found in the original R. leg. 128c53 Exo+1, nod+1, nif+1 parent, and thus do not support a role for EPS in the early steps of symbiosis. Pyruvate was present in the EPS of the mutant strains but not in the parental EPS. Pyruvate was found in the LPS of all three strains suggesting a Sym plasmid insertion of a possible modifying enzyme function (e.g., pyruvate linking) in the nod+ mutants. The uronic acid content in the EPS (Pk. II) of the mutant R. leg. ANU57(pJB5J1) is three times the amount found in the EPS (Pk. II) of the parent. R. leg. ANU57(pBR1AN) showed no distinguishable separation into EPS (Pk. I) and EPS (Pk. II) fractions, and thus the possible significance of this uronic acid difference requires further investigation. Sugar compositions of the parent and two mutant strains indicate an LPS component in the EPS. The relative mole percent composition of rhamnose, fucose, mannose, galactose, and KDO for the EPS, LPS, and CPS of the parent are similar to the corresponding EPS, LPS, and CPS of the two mutant strains. The possible effects these differences may have on legume/Rhizobium symbiosis are discussed

Effects of 1,25-dihydroxyvitamin D3 and parathyroid hormone on bovine monocyte-mediated bone degradation and mitogen-induced lymphocyte DNA synthesis

1,25-Dihydroxyvitamin D[subscript]3 (calcitriol) is an immunoregulatory steriod hormone that suppresses interleukin-2 (IL-2) production and inhibits mitogen-induced DNA synthesis in lymphocytes. In these studies, I evaluated the effect of in vitro and in vivo administration of calcitriol on DNA synthesis in bovine peripheral blood mononuclear cells (PBM). Calcitriol inhibited DNA synthesis of in vivo phytohemagglutinin (PHA)- and pokeweed mitogen (PWM)-stimulated PBM, but the effects of concanavalin A (ConA)-stimulated PBM were dependent on initial rates of DNA synthesis. PBM from cows with low proliferative response to ConA were stimulated significantly by calcitriol, whereas PBM from cows with high proliferative responses were unaffected by calcitriol addition. DNA synthesis was significantly enhanced by calcitriol when increasing amounts of monocytes were added to low density cultures of nonadherent PBM cells that had low initial proliferative response to ConA. DNA synthesis was inhibited by calcitriol under all conditions of monocyte additions to high density cultures of nonadherent PBM cells that had high initial proliferative response to ConA. Increasing the number of monocytes added, however, significantly attenuated the calcitriol-induced inhibition of DNA synthesis. In vivo administration of calcitriol enhanced in vitro DNA synthesis of PHA- and ConA-induced PBM, and inhibited PWM-induced PBM DNA synthesis. These studies demonstrate that calcitriol induces both stimulatory and inhibitory effects on DNA synthesis of mitogen-induced PBM that are dependent on mitogen, culture conditions, and mode of calcitriol administration;These studies also examined the effect of the bone calcium mobilizing hormones, parathyroid hormone (PTH) and calcitriol, on in vitro monocyte-mediated bond degradation. Monocytes degrade devitalized bone in vitro and are found in areas of bone-resorbing osteoclasts and chronic inflammation. PTH administration increased monocyte-mediated bone degradation, whereas calcitriol administration had no effect. PTH administration also enhanced production of hydrogen peroxide by monocytes on the same day as peak increase of monocyte-mediated bone degradation, thus suggesting an inflammatory-type mechanism for PTH induction of monocyte-mediated bone degradation

A large-scale population-based study of the association of vitamin D receptor gene polymorphisms with bone mineral density.

Conflicting results have been reported on the association between restriction fragment length polymorphisms (RFLPs) at the vitamin D receptor (VDR) gene locus (i.e., for BsmI, ApaI, and TaqI) and bone mineral density (BMD). We analyzed this association in a large population-based sample (n = 1782) of men and women aged 55-80 years using a novel direct haplotyping polymerase chain reaction (PCR) test to monitor the three polymorphic sites simultaneously. The direct haplotyping test we developed demonstrated a larger degree of genetic polymorphism at the VDR gene locus than described until now. None of the individual RFLPs were associated with BMD at the proximal femur. By analyzing allele dose effects, we identified a VDR haplotype allele weakly associated with low BMD. This allele, as one representative of the group of b alleles, is different from the BsmI allele previously reported by other groups to be associated with low BMD. This suggests allelic heterogeneity at the VDR locus in relation to BMD. Our results indicate at most a small effect of the VDR genotype on BMD in this elderly population. Since anonymous polymorphisms were analyzed, alternative explanations for our results include linkage to another nearby bone-metabolism related gene

Current evidence for a modulation of low back pain by human genetic variants

The manifestation of chronic back pain depends on structural, psychosocial, occupational and genetic influences. Heritability estimates for back pain range from 30% to 45%. Genetic influences are caused by genes affecting intervertebral disc degeneration or the immune response and genes involved in pain perception, signalling and psychological processing. This inter-individual variability which is partly due to genetic differences would require an individualized pain management to prevent the transition from acute to chronic back pain or improve the outcome. The genetic profile may help to define patients at high risk for chronic pain. We summarize genetic factors that (i) impact on intervertebral disc stability, namely Collagen IX, COL9A3, COL11A1, COL11A2, COL1A1, aggrecan (AGAN), cartilage intermediate layer protein, vitamin D receptor, metalloproteinsase-3 (MMP3), MMP9, and thrombospondin-2, (ii) modify inflammation, namely interleukin-1 (IL-1) locus genes and IL-6 and (iii) and pain signalling namely guanine triphosphate (GTP) cyclohydrolase 1, catechol-O-methyltransferase, μ opioid receptor (OPMR1), melanocortin 1 receptor (MC1R), transient receptor potential channel A1 and fatty acid amide hydrolase and analgesic drug metabolism (cytochrome P450 [CYP]2D6, CYP2C9)

Effects of 1,25-dihydroxyvitamin D3 and parathyroid hormone on bovine monocyte-mediated bone degradation and mitogen-induced lymphocyte DNA synthesis

1,25-Dihydroxyvitamin D[subscript]3 (calcitriol) is an immunoregulatory steriod hormone that suppresses interleukin-2 (IL-2) production and inhibits mitogen-induced DNA synthesis in lymphocytes. In these studies, I evaluated the effect of in vitro and in vivo administration of calcitriol on DNA synthesis in bovine peripheral blood mononuclear cells (PBM). Calcitriol inhibited DNA synthesis of in vivo phytohemagglutinin (PHA)- and pokeweed mitogen (PWM)-stimulated PBM, but the effects of concanavalin A (ConA)-stimulated PBM were dependent on initial rates of DNA synthesis. PBM from cows with low proliferative response to ConA were stimulated significantly by calcitriol, whereas PBM from cows with high proliferative responses were unaffected by calcitriol addition. DNA synthesis was significantly enhanced by calcitriol when increasing amounts of monocytes were added to low density cultures of nonadherent PBM cells that had low initial proliferative response to ConA. DNA synthesis was inhibited by calcitriol under all conditions of monocyte additions to high density cultures of nonadherent PBM cells that had high initial proliferative response to ConA. Increasing the number of monocytes added, however, significantly attenuated the calcitriol-induced inhibition of DNA synthesis. In vivo administration of calcitriol enhanced in vitro DNA synthesis of PHA- and ConA-induced PBM, and inhibited PWM-induced PBM DNA synthesis. These studies demonstrate that calcitriol induces both stimulatory and inhibitory effects on DNA synthesis of mitogen-induced PBM that are dependent on mitogen, culture conditions, and mode of calcitriol administration;These studies also examined the effect of the bone calcium mobilizing hormones, parathyroid hormone (PTH) and calcitriol, on in vitro monocyte-mediated bond degradation. Monocytes degrade devitalized bone in vitro and are found in areas of bone-resorbing osteoclasts and chronic inflammation. PTH administration increased monocyte-mediated bone degradation, whereas calcitriol administration had no effect. PTH administration also enhanced production of hydrogen peroxide by monocytes on the same day as peak increase of monocyte-mediated bone degradation, thus suggesting an inflammatory-type mechanism for PTH induction of monocyte-mediated bone degradation.</p