S. Birkelund

Chlamydia trachomatis and chlamydial heat shock protein 60-specific antibody and cell-mediated responses predict tubal factor infertility (2006)

Tiitinen, A., Halttunen, M., Birkelund, S., Bloigu, A., Christiansen, G., ...

BACKGROUND: To evaluate the role of Chlamydia trachomatis-induced humoral and cell-mediated immune (CMI) responses in predicting tubal factor infertility (TFI). METHODS: Blood samples were taken from...

Chlamydia trachomatis and chlamydial heat shock protein 60-specific antibody and cell-mediated responses predict tubal factor infertility (2006)

Tiitinen, A., Halttunen, M., Birkelund, S., Bloigu, A., Christiansen, G., ...

BACKGROUND: To evaluate the role of Chlamydia trachomatis-induced humoral and cell-mediated immune (CMI) responses in predicting tubal factor infertility (TFI). METHODS: Blood samples were taken from...

Chlamydia trachomatis and chlamydial heat shock protein 60-specific antibody and cell-mediated responses predict tubal factor infertility (2006)

Tiitinen, A., Halttunen, M., Birkelund, S., Bloigu, A., Christiansen, G., ...

BACKGROUND: To evaluate the role of Chlamydia trachomatis-induced humoral and cell-mediated immune (CMI) responses in predicting tubal factor infertility (TFI). METHODS: Blood samples were taken from...

Secretion of osteopontin from MG-63 cells under a physiological level of mechanical strain in vitro--a [35S] incorporation approach (2004)

Liu, D., Vandahl, B. B., Birkelund, S., Nielsen, L. B., Melsen, B.

To gain insight into the early response of osteoblastic cells to a physiological level of mechanical strain in vitro, the secretion of osteopontin by MG-63 osteosarcoma cells was assessed by [35S]...

Antibodies to Chlamydia trachomatis heat shock proteins in women with tubal factor infertility are associated with prior infection by C. trachomatis but not by C. pneumoniae (1999)

Persson, K., Osser, S., Birkelund, S., Christiansen, G., Brade, H.

The antibody response to heat shock proteins 60 and 10 were studied in 163 patients with tubal factor infertility and in 163 age-matched pregnant women. The associations of these antibodies with...

THE HUMORAL IMMUNE RESPONSE TO CHLAMYDIA TRACHOMATIS IN PATIENTS WITH ACUTE REACTIVE ARTHRITIS (1994)

LARSEN, B., BIRKELUND, S., MORDHORST, C. H., EJSTRUP, L., ANDERSEN, L. S., CHRISTIANSEN, G.

Sera from 25 patients with clinical signs of reactive arthritis were analysed for antibodies against Chlamydia trachomatis by immunoblotting. Purified elementary bodies, purified Chlamydia outer...

The mycoplasmacidal effect of herbicolin A (1985)

Birkelund, S., Freundt, E. A.

This study was to determine if the inhibitory effect of herbicolin A to sterol-requiring members of the class Mollicutes is due to a mycoplasmastatic or a mycoplasmacidal effect. Two strains were...

A 135-kilodalton surface antigen of Mycoplasma hominis PG21 contains multiple directly repeated sequences.

Ladefoged, S A, Birkelund, S, Hauge, S, Brock, B, Jensen, L T, Christiansen, G

A monoclonal antibody was used to characterize a 135-kDa surface-located membrane protein (Lmp1) generally present in Mycoplasma hominis strains. The monoclonal antibody, 552, was applied to identify...

Selection of Mycoplasma hominis PG21 deletion mutants by cultivation in the presence of monoclonal antibody 552.

Jensen, L T, Ladefoged, S, Birkelund, S, Christiansen, G

Three mutants of Mycoplasma hominis PG21 were isolated and shown to contain alterations in the size of a repeat-containing gene encoding a surface-localized 135-kDa antigen designated Lmp1. The...

Characterization of two conformational epitopes of the Chlamydia trachomatis serovar L2 DnaK immunogen.

Birkelund, S, Mygind, P, Holm, A, Larsen, B, Beck, F, Christiansen, G

Chlamydia trachomatis DnaK is an important immunogen in chlamydial infections. DnaK is composed of a conserved N-terminal ATP-binding domain and a variable C-terminal peptide-binding domain. To...

Ultrastructural changes in mollicutes induced by the peptide antibiotic herbicolin A.

Birkelund, S, Freundt, E A, Christiansen, G

Electron microscopy of negatively stained mycoplasma, ureaplasma, and acholeplasma cells showed ultrastructural changes after 10 min of treatment of the organisms with the peptide antibiotic...

The 18-kilodalton Chlamydia trachomatis histone H1-like protein (Hc1) contains a potential N-terminal dimerization site and a C-terminal nucleic acid-binding domain.

Pedersen, L B, Birkelund, S, Holm, A, Ostergaard, S, Christiansen, G

The Chlamydia trachomatis histone H1-like protein (Hc1) is a DNA-binding protein specific for the metabolically inactive chlamydial developmental form, the elementary body. Hc1 induces DNA...

Analysis of 0.5-kilobase-pair repeats in the Mycoplasma hominis lmp gene system and identification of gene products.

Ladefoged, S A, Jensen, L T, Brock, B, Birkelund, S, Christiansen, G

Mycoplasma hominis, an opportunistic pathogenic bacterium of humans, has a small genome of 700 kb. Despite this, multiple copies of gene sequences with similarities to the structural gene (lmp1) of a...

Characterization of a linear epitope on Chlamydia trachomatis serovar L2 DnaK-like protein.

Birkelund, S, Larsen, B, Holm, A, Lundemose, A G, Christiansen, G

A cytoplasmic 75-kDa immunogen from Chlamydia trachomatis serovar L2 has previously been characterized as being similar to the Escherichia coli heat shock protein DnaK. We have localized a linear...

Interaction between the Chlamydia trachomatis histone H1-like protein (Hc1) and DNA.

Christiansen, G, Pedersen, L B, Koehler, J E, Lundemose, A G, Birkelund, S

The gene encoding the Chlamydia trachomatis histone H1-like protein (Hc1) from serovar L2 was cloned into Escherichia coli by use of expression vector pET11d. In this vector, transcription of the...

Construction of physical and genetic maps of Chlamydia trachomatis serovar L2 by pulsed-field gel electrophoresis.

Birkelund, S, Stephens, R S

We constructed the physical map of Chlamydia trachomatis serovar L2 by using three restriction endonucleases, NotI (GC[GGCCGC), SgrAI (C(A/G)[CCGG(T/G)G), and Sse8387I (CCTGCA[GG), and we analyzed...

The 75-kilodalton cytoplasmic Chlamydia trachomatis L2 polypeptide is a DnaK-like protein.

Birkelund, S, Lundemose, A G, Christiansen, G

The gene coding for the 75-kilodalton cytoplasmic Chlamydia trachomatis L2 polypeptide has been cloned in Escherichia coli, and the nucleotide sequence has been determined. The cloned DNA fragment...

Characterization and identification of early proteins in Chlamydia trachomatis serovar L2 by two-dimensional gel electrophoresis.

Lundemose, A G, Birkelund, S, Larsen, P M, Fey, S J, Christiansen, G

The synthesis of early proteins from Chlamydia trachomatis serovar L2 was analyzed by two-dimensional gel electrophoresis. By pulse-label experiments, the synthesis of seven proteins was observed at...

Chemical cross-linking of Chlamydia trachomatis.

Birkelund, S, Lundemose, A G, Christiansen, G

Purified elementary bodies (EBs) of Chlamydia trachomatis serovar L2 were analyzed by chemical cross-linking with disuccinimidyl selenodipropionate. The effect of the cross-linking was analyzed by...

Immunoelectron microscopy of lipopolysaccharide in Chlamydia trachomatis.

Birkelund, S, Lundemose, A G, Christiansen, G

Monoclonal antibodies (MAb) specific for Chlamydia trachomatis lipopolysaccharide (LPS) and major outer membrane protein (MOMP) were used for immunoelectron microscopy analysis. MAb specific for MOMP...

Use of polymerase chain reaction for detection of Chlamydia trachomatis.

Ostergaard, L, Birkelund, S, Christiansen, G

A polymerase chain reaction (PCR) assay was developed for detection of Chlamydia trachomatis DNA. From the published sequence of the common C. trachomatis plasmid, two primer sets were selected....

Chlamydia trachomatis serovar L2 induces protein tyrosine phosphorylation during uptake by HeLa cells.

Birkelund, S, Johnsen, H, Christiansen, G

Chlamydia trachomatis L2 is an obligate intracellular microorganism with a unique biphasic life cycle. The extracellular form, the elementary body (EB), is infectious but metabolically inactive....

Characterization of native and recombinant 75-kilodalton immunogens from Chlamydia trachomatis serovar L2.

Birkelund, S, Lundemose, A G, Christiansen, G

A 75-kilodalton (kDa) immunogen from Chlamydia trachomatis serovar L2 was characterized. The 75-kDa protein was localized in the cytoplasm of chlamydiae and was shown to be a protein synthesized...

A 135-kilodalton surface antigen of Mycoplasma hominis PG21 contains multiple directly repeated sequences.

Ladefoged, S A, Birkelund, S, Hauge, S, Brock, B, Jensen, L T, Christiansen, G

A monoclonal antibody was used to characterize a 135-kDa surface-located membrane protein (Lmp1) generally present in Mycoplasma hominis strains. The monoclonal antibody, 552, was applied to identify...

Selection of Mycoplasma hominis PG21 deletion mutants by cultivation in the presence of monoclonal antibody 552.

Jensen, L T, Ladefoged, S, Birkelund, S, Christiansen, G

Three mutants of Mycoplasma hominis PG21 were isolated and shown to contain alterations in the size of a repeat-containing gene encoding a surface-localized 135-kDa antigen designated Lmp1. The...

Characterization of two conformational epitopes of the Chlamydia trachomatis serovar L2 DnaK immunogen.

Birkelund, S, Mygind, P, Holm, A, Larsen, B, Beck, F, Christiansen, G

Chlamydia trachomatis DnaK is an important immunogen in chlamydial infections. DnaK is composed of a conserved N-terminal ATP-binding domain and a variable C-terminal peptide-binding domain. To...

Ultrastructural changes in mollicutes induced by the peptide antibiotic herbicolin A.

Birkelund, S, Freundt, E A, Christiansen, G

Electron microscopy of negatively stained mycoplasma, ureaplasma, and acholeplasma cells showed ultrastructural changes after 10 min of treatment of the organisms with the peptide antibiotic...

The 18-kilodalton Chlamydia trachomatis histone H1-like protein (Hc1) contains a potential N-terminal dimerization site and a C-terminal nucleic acid-binding domain.

Pedersen, L B, Birkelund, S, Holm, A, Ostergaard, S, Christiansen, G

The Chlamydia trachomatis histone H1-like protein (Hc1) is a DNA-binding protein specific for the metabolically inactive chlamydial developmental form, the elementary body. Hc1 induces DNA...

Analysis of 0.5-kilobase-pair repeats in the Mycoplasma hominis lmp gene system and identification of gene products.

Ladefoged, S A, Jensen, L T, Brock, B, Birkelund, S, Christiansen, G

Mycoplasma hominis, an opportunistic pathogenic bacterium of humans, has a small genome of 700 kb. Despite this, multiple copies of gene sequences with similarities to the structural gene (lmp1) of a...

Characterization of a linear epitope on Chlamydia trachomatis serovar L2 DnaK-like protein.

Birkelund, S, Larsen, B, Holm, A, Lundemose, A G, Christiansen, G

A cytoplasmic 75-kDa immunogen from Chlamydia trachomatis serovar L2 has previously been characterized as being similar to the Escherichia coli heat shock protein DnaK. We have localized a linear...

Interaction between the Chlamydia trachomatis histone H1-like protein (Hc1) and DNA.

Christiansen, G, Pedersen, L B, Koehler, J E, Lundemose, A G, Birkelund, S

The gene encoding the Chlamydia trachomatis histone H1-like protein (Hc1) from serovar L2 was cloned into Escherichia coli by use of expression vector pET11d. In this vector, transcription of the...

Construction of physical and genetic maps of Chlamydia trachomatis serovar L2 by pulsed-field gel electrophoresis.

Birkelund, S, Stephens, R S

We constructed the physical map of Chlamydia trachomatis serovar L2 by using three restriction endonucleases, NotI (GC[GGCCGC), SgrAI (C(A/G)[CCGG(T/G)G), and Sse8387I (CCTGCA[GG), and we analyzed...

The 75-kilodalton cytoplasmic Chlamydia trachomatis L2 polypeptide is a DnaK-like protein.

Birkelund, S, Lundemose, A G, Christiansen, G

The gene coding for the 75-kilodalton cytoplasmic Chlamydia trachomatis L2 polypeptide has been cloned in Escherichia coli, and the nucleotide sequence has been determined. The cloned DNA fragment...

Characterization and identification of early proteins in Chlamydia trachomatis serovar L2 by two-dimensional gel electrophoresis.

Lundemose, A G, Birkelund, S, Larsen, P M, Fey, S J, Christiansen, G

The synthesis of early proteins from Chlamydia trachomatis serovar L2 was analyzed by two-dimensional gel electrophoresis. By pulse-label experiments, the synthesis of seven proteins was observed at...

Chemical cross-linking of Chlamydia trachomatis.

Birkelund, S, Lundemose, A G, Christiansen, G

Purified elementary bodies (EBs) of Chlamydia trachomatis serovar L2 were analyzed by chemical cross-linking with disuccinimidyl selenodipropionate. The effect of the cross-linking was analyzed by...

Immunoelectron microscopy of lipopolysaccharide in Chlamydia trachomatis.

Birkelund, S, Lundemose, A G, Christiansen, G

Monoclonal antibodies (MAb) specific for Chlamydia trachomatis lipopolysaccharide (LPS) and major outer membrane protein (MOMP) were used for immunoelectron microscopy analysis. MAb specific for MOMP...

Use of polymerase chain reaction for detection of Chlamydia trachomatis.

Ostergaard, L, Birkelund, S, Christiansen, G

A polymerase chain reaction (PCR) assay was developed for detection of Chlamydia trachomatis DNA. From the published sequence of the common C. trachomatis plasmid, two primer sets were selected....

Chlamydia trachomatis serovar L2 induces protein tyrosine phosphorylation during uptake by HeLa cells.

Birkelund, S, Johnsen, H, Christiansen, G

Chlamydia trachomatis L2 is an obligate intracellular microorganism with a unique biphasic life cycle. The extracellular form, the elementary body (EB), is infectious but metabolically inactive....

Characterization of native and recombinant 75-kilodalton immunogens from Chlamydia trachomatis serovar L2.

Birkelund, S, Lundemose, A G, Christiansen, G

A 75-kilodalton (kDa) immunogen from Chlamydia trachomatis serovar L2 was characterized. The 75-kDa protein was localized in the cytoplasm of chlamydiae and was shown to be a protein synthesized...