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T Kristensen

Publications and source records attributed to T Kristensen.

At least 19 recordsLinked to original sources
PubMed1992

Cloning of a gene from Bacillus cereus with homology to the mreB gene from Escherichia coli.

We have cloned and sequenced a gene coding for a putative shape-determining protein (MreB) highly homologous to the mreB gene product of Escherichia coli. The amino acid (aa) identity was 53% and the similarity 72%. The gene is expressed early in the logarithmic phase. The aa sequence comparison showed that the protein, like the E. coli MreB, has structural similarity to actin and heat-shock protein Hsc70 encoded by a new super-gene family.

Amino Acid Sequence↗
PubMed1992

[Transfusion-associated graft-vs-host disease].

Transfusion-associated graft-versus-host disease (TA-GVHD) is a serious, often fatal complication to the transfusion of blood components. TA-GVHD is caused primarily by donor T lymphocytes reacting towards recipient MHC antigens. The diagnosis TA-GVHD should be considered when patients, within a month of receiving blood transfusion, develop sudden, unexpected high fever and erythematous rash, possibly accompanied by gastrointestinal symptoms and/or pancytopenia. Congenital (cellular) immune defect, intrauterine transfusion, bone marrow transplantation, Hodgkin's disease, and directed transfusions (especially from first degree relatives) all carry high risk of developing TA-GVHD. Since mortality exceeds 90% irrespective of any treatment, prevention is essential. Pretransfusion gamma-irradiation of blood components with a 25 Gy dose effectively prevents TA-GVHD, and it is therefore recommended that all blood components be irradiated prior to transfusion to patients belonging to defined groups-at-risk.

Blood Group Incompatibility↗
PubMed1992

Complete primary structure of bovine beta 2-glycoprotein I: localization of the disulfide bridges.

The complete primary structure of bovine beta 2-glycoprotein I was determined by a combination of cDNA and peptide sequencing. Bovine beta 2-glycoprotein I was purified from citrated plasma, and by sequencing selected peptides, the complete disulfide bridge patterns of the 11 disulfide bridges were established as well as the positions of the five asparagine-linked carbohydrate groups. Bovine beta 2-glycoprotein I comprises five mutually homologous domains or Short Consensus Repeats, each containing two disulfide bridges, except for the fifth most C-terminal domain which diverges from the Short Consensus Repeat consensus by containing an additional disulfide bridge. In the four N-terminal domains, the first and third and the second and fourth half-cystines are disulfide-linked, while in the fifth domain the first and fourth, the second and fifth, and the third and sixth half-cystines are disulfide-linked.

Amino Acid Sequence↗
PubMed1992

Isolation and sequencing of porcine lipoprotein lipase cDNA and its use in multiallelic restriction fragment length polymorphism detection.

Porcine lipoprotein lipase (LPL) cDNA has been cloned and sequenced. The deduced amino acid sequence shows a high degree of identity to LPL from other species, and contains the Ser/His/Asp triade characteristic of serine proteases and esterases. A repetitive element is present in the 3'-untranslated region of the cDNA. A partial cDNA covering the coding region of LPL detects three restriction fragment length polymorphisms with HindIII. This represents the first marker assigned to porcine chromosome 14.

Alleles↗
PubMed1992

DNA sequence of the skeletal muscle calcium release channel cDNA and verification of the Arg615----Cys615 mutation, associated with porcine malignant hyperthermia, in Norwegian landrace pigs.

Porcine calcium release channel (CRC) cDNA from skeletal muscle has been cloned and sequenced. The deduced amino acid sequence showed 97% identity to the corresponding rabbit and human sequences. Using oligonucleotide primers based on the nucleotide sequence, CRC cDNA fragments from seven pigs representing HALNN, HALNn and HALnn genotypes have been amplified. Sequencing and restriction digestion of the amplified cDNA confirm that the reported C----T mutation, which gives rise to Arg615----Cys615 change in the calcium release channel, is associated with the halothane sensitive allele in Norwegian Landrace pigs. The mutation may alter the reactivity of a neighbouring serine residue which is potentially phosphorylated.

Animals↗
PubMed1992

Characterization of a porcine variable number tandem repeat sequence specific for the glucosephosphate isomerase locus.

A variable number of tandem repeat from a porcine glucosephosphate isomerase intron has been isolated and sequenced. The repeat has a unit size of 39 bp, is highly conserved and is present in at least 14 copies. Flanking sequences show a sequence periodicity of 53-54 bp and some sequence homology to the 39 bp repeat. A considerable part of the genomic DNA has been lost during subcloning and is considered to be deletion prone or refractory to propagation in E. coli. The tandem repeat is locus specific and detects at least six alleles in BamHI digested porcine DNA. No homology to other tandem repeat sequences has been found.

Animals↗
PubMed1992

Single and combined effects of the vitamin D analogue KH1060 and cyclosporin A on mercuric-chloride-induced autoimmune disease in the BN rat.

Mercuric chloride induces in BN rats a self-limiting systemic autoimmune disease characterized by proliferation of autoreactive CD4+ T lymphocytes, polyclonal activation of B lymphocytes, and the development of an anti-glomerular basement membrane (GBM) nephritis with concomitant nephrotic range proteinuria. We have used this model of autoimmune disease to test the immunosuppressive ability of a novel vitamin D3 analogue KH1060. This compound prevents autoimmune manifestations including proteinuria, serum IgE, and serum anti-laminin antibodies in a dose-dependent manner, as does cyclosporin A (CyA). When dosages of KH1060 capable of partial reduction of proteinuria without causing significant hypercalcaemia are combined with small dosages of CyA also capable of partial prevention of proteinuria, an additive effect is seen, leading to complete prevention of proteinuria and substantial reductions in serum IgE and anti-laminin levels. Possible mechanisms of action are discussed and it is suggested that KH1060 could prove useful as an immunosuppressive agent in the treatment of autoimmune diseases.

Animals↗
PubMed1992

Survival, function, morphology and serological aspects of rat renal allografts. Effect of short-term treatment with cyclosporine A, anti-CD4 and anti-interleukin-2 receptor monoclonal antibodies.

The aim of this study was to investigate the effect of short-term treatment with cyclosporine A (CyA) combined with anti-CD4 (OX-38) and anti-interleukin-2 receptor (OX-39) monoclonal antibodies (MAbs) on graft survival, graft function, morphology, and anti-donor antibody levels in a BN-to-LEW rat kidney transplantation model. Spontaneous rejection occurred at 9.3 days (range 9-10 d). Administration of CyA (12.5 mg/kg/d) for 14 days prolonged graft survival to 33 days (range 23-40 d, P less than 0.02). Supplementing with OX-38 and OX-39 100 micrograms/kg/d, given i.p. from days 0 to 7, further prolonged graft survival to 70 days (range 38- greater than 100 d, P less than 0.02 vs controls and CyA group). One of seven recipients had good graft function for more than 100 days. A three-fold increase of the MAb dosage did not improve mean graft survival (53.5 d), but three of eight recipients had well functioning grafts for greater than 100 days. Kidney function was characterized by reduced creatinine clearance, also in the recipients with long-term graft survival, and a defect in concentrating urine creatinine with subsequent pronounced increase in urinary output. Graft histology showed a complex pattern of interstitial alterations including mononuclear cell infiltration, fibrosis, tubular atrophy and vascular damage with intimal/endothelial cell hyperplasia and perivascular inflammation. In nine of 10 MAb-treated recipients with graft survival greater than 60 days, granular deposits of immunoglobulins and C3 were found by immunofluorescence microscopy (IFM). The deposits were localized in the glomerular capillaries and mesangium. IFM in MAb-treated control animals could not demonstrate any deposits. Flow cytometric evaluation of posttransplant serum samples against donor target cells showed increasing amounts of anti-donor antibodies until the time of rejection, while recipients with long-term graft function had moderately positive cross-matches up to two months after transplantation. Hereafter antibody titres decreased and cross-matches at the time of sacrifice were again negative. The morphological findings and the flow cytometric cross-match results seem to indicate a postponed antibody-mediated type of rejection. The reason why some kidney recipients showed decreasing antibody titres and stable long-term graft function is unclear.

Animals↗
PubMed1992

An estimate of the sequencing error frequency in the DNA sequence databases.

We have examined vector sequences fortuitously present in the EMBL sequence database as contaminating parts of submitted sequences, and found a sequencing error frequency of 3.55% in this subset of release 27 of the database. We discuss the possibility that this value may be representative for corresponding errors in the database as a whole.

Base Sequence↗
PubMed1991

Molecular cloning and mammalian expression of human beta 2-glycoprotein I cDNA.

Human beta 2-glycoprotein (beta 2gpI) cDNA was isolated from a liver cDNA library and sequenced. The cDNA encoded a 19-residue hydrophobic signal peptide followed by the mature beta 2gpI of 326 amino acid residues. In liver and in the hepatoma cell line HepG2 there are two mRNA species of about 1.4 and 4.3 kb, respectively, hybridizing specifically with the beta 2gpI cDNA. Upon isoelectric focusing, recombinant beta 2gpI obtained from expression of beta 2gpI cDNA in baby hamster kidney cells showed the same pattern of bands as beta 2gpI isolated from plasma, and at least 5 polypeptides were visible.

Amino Acid Sequence↗
PubMed1991

Porcine SINEs: characterization and use in species-specific amplification.

A porcine repetitive DNA sequence has been isolated from an intron of the glucose phosphate isomerase gene. The copy number of this and related sequences was estimated to be approximately 10(5) copies per genome. The sequence possesses all the characteristics of short interspersed elements (SINEs) described in other mammals: The repeat is 300 bp in length, has an poly(A)stretch, and contains insertion duplication sites. Homology to seven other porcine sequences, which also have the characteristics of SINEs, has been demonstrated. Primer oligonucleotides, based on conserved regions in the SINE sequences, have been synthesized. Using these primers, PCR-mediated specific amplification of porcine sequences was demonstrated from pig x mouse and pig x hamster hybrid cell lines. Cloning and sequencing of some amplified porcine sequences verify that the sites of priming are SINE sequences.

Animals↗
PubMed1991

Monoclonal antibody treatment (anti-CD4 and anti-interleukin-2 receptor) combined with cyclosporin A has a positive but not simple dose-dependent effect on rat renal allograft survival.

The use of monoclonal antibodies (MoAbs) in experimental and clinical organ transplantation is of increasing interest since this treatment seems to offer an opportunity for specific immunomodulation. In a rat kidney allograft model, Cyclosporin A (CyA) treatment (12.5 mg/kg/d, day 0-14) was combined with murine anti-rat CD4 (MRC OX-38) and murine anti-rat IL-2R (MRC OX-39) MoAbs at doses of 100 or 300 micrograms/kg/d (day 0-7) and plasma concentrations of the murine MoAb were determined. In both groups receiving combined treatment with CyA and MoAb, graft survival was prolonged to an average of 65 days, compared to a graft survival of 9-10 days in non-treated recipients. Further, the data showed a beneficial effect of CyA + MoAb treatment versus CyA alone (graft survival 32 days). The threefold increased MoAb dose did not seem to improve graft survival or function. Treatment with OX-38 + OX-39 at a dose of 100 micrograms/kg/d each resulted in plasma levels of 280 ng/ml 14 days after transplantation. Corresponding values after the administration of 300 micrograms/kg/d were 1800 ng/ml in graft recipients as well as controls. These findings indicate that the effect of MoAbs in complex organ transplantation models is not simply dose dependent and that in vitro assays are of limited value in predicting the effect of a given MoAb when used in vivo. The determination of MoAb plasma levels, however, may be a useful tool in defining optimal MoAb administration and to monitor therapeutically effective plasma levels.

Animals↗
PubMed1991

Rapid and simple preparation of plasmids suitable for dideoxy DNA sequencing and other purposes.

Plasmid DNA released from bacteria by boiling in the presence of lysozyme and Triton x-100 and without further purification can be sequenced by the dideoxy method using T7 DNA polymerase, when conditions during alkali denaturation and subsequent ethanol precipitation are adjusted to remove contaminants. The samples remain in the same microcentrifuge tubes from the harvesting of the bacteria until the splitting of the sample into four aliquots for the termination reactions. Less background label is observed with end-labelled primers (radioactivity or fluorescence), but even when radioactive nucleotides are incorporated during the sequencing reactions, 250 bases or more can be read from template prepared from 1.5 ml bacterial culture. The DNA can also be cut by restriction enzymes; the purification procedure described thus provides the rapid preparation of plasmids for a variety of purposes.

Base Sequence↗
PubMed1990

Evidence that the newly cloned low-density-lipoprotein receptor related protein (LRP) is the alpha 2-macroglobulin receptor.

The human placental receptor (alpha 2MR) for alpha 2-macroglobulin-proteinase complexes contains 3 polypeptides of approx. 500 kDa, 85 kDa, and 40 kDa. N-terminal sequence analysis of the 500 kDa and 85 kDa polypeptides, analysis of a random selection of peptides convering 536 residues from these polypeptides, and analysis of a 1772 bp cDNA encoding part of the 500 kDa polypeptide provide evidence that the 500 kDa and 85 kDa chains are the alpha- and beta-subunits, respectively, of a recently cloned hepatic membrane protein, termed the low density lipoprotein receptor related protein (LRP) (Herz, J., Hamann, U., Rogne, S., Myklebost, O., Gausepohl, H. and Stanley, K.K. (1988) EMBO J. 7, 4119-4127; Herz, J., Kowal, R.C., Goldstein, J.L. and Brown, M.S. (1990) EMBO J. 9, 1769-1776). N-terminal sequence analysis of the 40 kDa polypeptide shows that it is of distinct genetic origin. It is suggested that LRP is the functional receptor for alpha 2-macroglobulin-proteinase complexes (alpha 2MR) and in addition may have as yet unsettled functions in lipoprotein metabolism.

Amino Acid Sequence↗