Isolation of glucosinolates and the identification of o-(α-l-rhamnopyranosyloxy)benzylglucosinolate from Reseda odorata

A method has been developed for the quantitative isolation of glucosinolates by ion-exchange chromatography and high voltage electrophoresis avoiding strongly alkaline and acidic conditions. The compounds were identified by ¹H and ¹³C NMR spectroscopy and through the products arising from enzymatic, acid and alkaline hydrolysis. The method is well suited for the isolation and identification of glucosinolates containing aglucone parts which produce non-volatile compounds on enzymatic hydrolysis. The method has been used in the isolation and identification of 2-hydroxy-2-methylpropylglucosinolate from Reseda alba, 2-hydroxy-2-phenylethylglucosinolate from R. luteola and a new glucosinolate, o-(α-l-rhamnopyranosyloxy)benzylglucosinolate, occurring in R. odorata. The glucosinolate content in different parts of this plant has been determined and the metabolism of glucosinolates is briefly discussed.     

NO mediates downregulation of RBF after a prolonged reduction of renal perfusion pressure in SHR

The aim of the study was to investigate mechanisms underlying the downregulation of renal blood flow (RBF) after a prolonged reduction in renal perfusion pressure (RPP) in adult spontaneously hypertensive rats (SHR). We tested the effect on the RBF response of clamping plasma ANG II in sevoflurane-anesthetized SHR. We also tested the effect of general cyclooxygenase (COX) inhibition and inhibition of the inducible COX-2. Furthermore, we assessed the effect of clamping the nitric oxide (NO) system. A prolonged period (15 min) of reduced RPP induced a downregulation of RBF. This was unchanged after clamping of plasma ANG II concentrations, general COX inhibition, and specific inhibition of COX-2. In contrast, clamping the NO system diminished the ability of SHR to downregulate RBF to a lower level. The downregulation of RBF was not associated with a resetting of the lower limit of autoregulation in the control group, in the ANG II-clamped group, or the NO clamped group. However, general COX inhibition and specific COX-2 inhibition enabled downward resetting of the lower limit of autoregulation. In conclusion, in SHR the renin-angiotensin system does not appear to play a major role in the downregulation of RBF after prolonged reduction of RPP. This response appears to be mediated partly by the NO system. We hypothesize that, in SHR, lack of downward resetting of the lower limit of autoregulation in response to a prolonged lowering of RPP could be the result of increased COX-2-mediated production of vasoconstrictory prostaglandins.     

Bone bank service in Odense, Denmark. Audit of the first ten years with bone banking at the Department of Orthopaedics, Odense University Hospital

There has been an increase in the demand for allograft bone in recentyears. The Odense University Hospital bone bank has been in function since1990,and this paper outlines our results during the 10 year period 1990–1999.Potential donors were screened by contemporary banking techniques which includea social history, donor serum tests for HIV, hepatitis B and C, and graftmicrobiology. The bones were stored at –80 °C. No typeofsecondary sterilisation was made. 423 femoral heads were approved and donatedto300 patients,1–6 heads/operation. The allografts have been used mainly toreconstruct defects at revision hip arthroplasty (34%), and for fracturesurgery(24%). 7 % of all transplanted patients were reoperated because of infection.Inthe hip revision group the infection rate was 4 %. There were no cases ofdisease transmission. During the 10 year period there was a change in theclinical use of the allografts. In the first years the allografts were mainlyused for spinal fusion surgery, but today the majority are used in hip revisionand fracture surgery. The clinical results correspond to those reported inlarger international series.     

Molecular phylogeny of living xenarthrans and the impact of character and taxon sampling on the placental tree rooting

Extant xenarthrans (armadillos, anteaters and sloths) are among the most derived placental mammals ever evolved. South America was the cradle of their evolutionary history. During the Tertiary, xenarthrans experienced an extraordinary radiation, whereas South America remained isolated from other continents. The 13 living genera are relics of this earlier diversification and represent one of the four major clades of placental mammals. Sequences of the three independent protein-coding nuclear markers alpha2B adrenergic receptor (ADRA2B), breast cancer susceptibility (BRCA1), and von Willebrand Factor (VWF) were determined for 12 of the 13 living xenarthran genera. Comparative evolutionary dynamics of these nuclear exons using a likelihood framework revealed contrasting patterns of molecular evolution. All codon positions of BRCA1 were shown to evolve in a strikingly similar manner, and third codon positions appeared less saturated within placentals than those of ADRA2B and VWF. Maximum likelihood and Bayesian phylogenetic analyses of a 47 placental taxa data set rooted by three marsupial outgroups resolved the phylogeny of Xenarthra with some evidence for two radiation events in armadillos and provided a strongly supported picture of placental interordinal relationships. This topology was fully compatible with recent studies, dividing placentals into the Southern Hemisphere clades Afrotheria and Xenarthra and a monophyletic Northern Hemisphere clade (Boreoeutheria) composed of Laurasiatheria and Euarchontoglires. Partitioned likelihood statistical tests of the position of the root, under different character partition schemes, identified three almost equally likely hypotheses for early placental divergences: a basal Afrotheria, an Afrotheria + Xenarthra clade, or a basal Xenarthra (Epitheria hypothesis). We took advantage of the extensive sampling realized within Xenarthra to assess its impact on the location of the root on the placental tree. By resampling taxa within Xenarthra, the conservative Shimodaira-Hasegawa likelihood-based test of alternative topologies was shown to be sensitive to both character and taxon sampling.     

Liprin beta 1, a member of the family of LAR transmembrane tyrosine phosphatase-interacting proteins, is a new target for the metastasis-associated protein S100A4 (Mts1)

Metastasis-associated protein S100A4 (Mts1) induces invasiveness of primary tumors and promotes metastasis. S100A4 belongs to the family of small calcium-binding S100 proteins that are involved in different cellular processes as transducers of calcium signal. S100A4 modulates properties of tumor cells via interaction with its intracellular targets, heavy chain of non-muscle myosin and p53. Here we report identification of a new molecular target of the S100A4 protein, liprin beta1. Liprin beta1 belongs to the family of leukocyte common antigen-related (LAR) transmembrane tyrosine phosphatase-interacting proteins that may regulate LAR protein properties via interaction with another member of the family, liprin alpha1. We showed by the immunoprecipitation analysis that S100A4 interacts specifically with liprin beta1 in vivo. Immunofluorescence staining demonstrated the co-localization of S100A4 and liprin beta1 in the cytoplasm and particularly at the protrusion sites of the plasma membrane. We mapped the S100A4 binding site at the C terminus of the liprin beta1 molecule between amino acid residues 938 and 1005. The S100A4-binding region contains two putative phosphorylation sites by protein kinase C and protein kinase CK2. S100A4-liprin beta1 interaction resulted in the inhibition of liprin beta1 phosphorylation by both kinases in vitro.     

Microbial diversity in ikaite tufa columns: an alkaline,cold ecological niche in Greenland

Ikaite tufa columns from the Ikka Fjord in south-western Greenland constitute a natural, stable environment at low temperature and with a pH ranging from neutral at the exterior to very alkaline (pH 10.4) at the interior of the column. Phylogenetic analysis of culturable organisms revealed ten different isolates representing three of the major bacterial divisions. Nine of the isolates showed 94-99% similarity to known sequences, whereas one isolate displayed a low degree of similarity (less than 90%) to a Cyclobacterium species. Seven of the isolates were shown to be cold active alkaliphiles, whereas three isolates showed optimal growth at neutral pH. Phylogenetic analysis of DNA isolated directly from the ikaite material demonstrated the presence of a microbial flora more diverse than the culturable isolates. Whereas approximately half of the phylotypes showed 90-99% similarity to known meso- or thermophilic alkaliphiles, the rest of the sequences displayed less than 90% similarity when compared to known 16S rRNA gene sequences in databases. Thus, in the present paper, we demonstrate that ikaite columns that host a specialized macroscopic flora and fauna also contain a unique, cold active, alkaliphilic microflora.     

Characterization of T cell hybridomas raised against a glycopeptide containing the tumor-associated T antigen, (betaGal (1-3) alphaGalNAc-O/Ser)

T cell hybridomas were raised against the glycopeptide S⁷² (Core-1) containing the tumor-associated disaccharide Gal (1–3) GalNAc (Core-1) O-linked to serine at position 72 in the mouse hemoglobin derived decapeptide Hb (67–76). All hybridomas recognized the glycopeptide S⁷² (Core-1). Two of the selected hybridomas responded, however, much better to the S⁷² (Tn) glycopeptide containing the monosaccharide GalNAc O-linked to serine. In addition, one hybridoma cross-responded to the glycopeptide T⁷² (Core-1) having a threonine at position 72 instead of a serine. No cross-responses were found to other glycopeptides consisting of the same hemoglobin peptide with different glycans attached or to the unglycosylated peptides. The T cell receptor V and V usage was clearly diverse. The CDR3 regions demonstrated moreover a predominance of small polar amino acid side chains, and three hybridomas contained a common sequence motif. All the sequenced CDR3 regions contained furthermore a conserved proline-glycine motif. In conclusion, immunization with the disaccharide containing glycopeptides S⁷² (Core-1) created a heterogeneous population of glycopeptide specific T cells with the ability of cross-responding toward related glycopeptides.