Biomedical subjects

H Salminen

Publications and source records attributed to H Salminen.

22 records · Page 2Linked to original sources

PubMed1997

Enzymatic synthesis of site-specifically (alpha 1-3)-fucosylated polylactosamines containing either a sialyl Lewis (x), a VIM-2, or a sialylated and internally difucosylated sequence.

By using two different reaction pathways, we generated enzymatically three sialylated and site-specifically alpha 1-3-fucosylated polylactosamines. Two of these are isomeric hexasaccharides Neu5Ac(alpha 2-3)Gal(beta 1-4)GlcNAc(beta 1-3)Gal(beta 1-4)[Fuc(alpha 1-3)] GlcNAc and Neu5Ac(alpha 2-3)Gal(beta 1-4)[Fuc(alpha 1-3)]GlcNAc(beta 1-3)Gal(beta 1-4) GlcNAc, containing epitopes that correspond to VIM-2 and sialyl Lewis (x), respectively. The third one, nonasaccharide Neu5Ac(alpha 2-3)Gal(beta 1-4)GlcNAc(beta 1-3)Gal(beta 1-4)[Fuc(alpha 1-3)] GlcNAc(beta 1-3)Gal(beta 1-4)[Fuc(alpha 1-3)]GlcNAc, is a sialylated and internally difucosylated derivative of a trimeric N-acetyllactosamine. All three oligosaccharides have one fucose-free N-acetyllactosaminyl unit and can be used as acceptors for recombinant alpha 1-3-fucosyltransferases in determining the biosynthesis pathways leading to polyfucosylated selectin ligands.

Amino Sugars↗

PubMed1997

Synthesis of a new nanomolar saccharide inhibitor of lymphocyte adhesion: different polylactosamine backbones present multiple sialyl Lewis x determinants to L-selectin in high-affinity mode.

Lymphocyte infiltration is a hallmark of acute rejections in solid organ transplants, such as cardiac allograft. We have previously shown that lymphocyte extravasation to cardiac grafts undergoing rejection is largely due to interactions between lymphocyte L-selectin and its sialyl Lewis x (sLex) decorated ligands. Our previous work demonstrated further that an enzymatically synthetized tetravalent sLex glycan of a branched polylactosamine backbone is a highly efficient inhibitor of L-selectin-dependent lymphocyte adhesion to graft endothelium. To improve the availability of multivalent sLex glycans for anti-inflammatory indications, we now report enzymatic synthesis of another tetravalent sLex glycan that can be potentially produced on a large scale, and show that even the new saccharide is a nanomolar inhibitor of L-selectin-dependent lymphocyte adhesion. The novel antagonist is sLex beta 1-3' (sLex beta 1-6') LacNAc beta 1-3' (sLex beta 1-6') LacNAc beta 1-3' (sLex beta 1-6') LacNAc (8) (where LacNAc is the disaccharide Gal beta 1-4GlcNac and sLex is the tetrasaccharide Neu5Ac alpha 2-3Gal beta 1-4 (Fuc alpha 1-3) GlcNAc). Its five-step synthesis was started from the octameric polylactosamine LacNAc beta 1-3' (GlcNAc beta 1-6') LacNAc beta 1-3' (GlcNAc beta 1-6') LacNAc (3), which in turn is accessible in one step from the hexasaccharide LacNAc beta 1-3'LacNAc beta 1-3'LacNAc. Importantly, the hexasaccharide primer has been synthesized chemically (Alais and Veyrieres, Tetrahedron Lett., 24, 5223, 1983). Hence, our data outline a route to glycan 8, consisting of a combination of chemical and enzymatic methods of oligosaccharide synthesis. In addition, our data show that polylactosamine backbones are able to present multiple sialyl Lewis x determinants to L-selectin in high-affinity mode, without a requirement for uniqueness in the backbone structure.

Amino Sugars↗

PubMedDate not supplied

Expression of Sox9 and type IIA procollagen during ocular development and aging in transgenic Del1 mice with a mutation in the type II collagen gene.

PURPOSE: To study the expression and distribution of transcription factor Sox9 and type IIA procollagen in the developing and aging eyes of normal and transgenic Dell mice carrying pro(alpha)1(II) collagen transgenes with a short deletion mutation, which cause ocular abnormalities in this mouse line. METHODS: The eyes of Del1 mice were studied on embryonic days E14.5, E16.5 and E18.5, and at the ages of 4 and nine months, using their nontransgenic littermates as controls. Sox9 and pro(alpha)1(IIA) collagen were detected by RNase protection assay and immunohistochemistry. RESULTS: RNase protection assay revealed Sox9 transcripts in the eyes of Del1 and control mice during development and aging. The mRNA for type IIA procollagen had a similar temporal expression pattern. On embryonic days E14.5, E16.5 and E18.5, Sox9 was located by immunohistochemistry in the nuclei and type IIA procollagen in the extracellular space of the developing retina. During growth and aging, the ocular expression of Sox9 mRNA and the immunohistochemical reaction for Sox9 antibody diminished, concomitant with the reduction in type II procollagen mRNA. However, at the age of nine months, levels of Sox9 and type IIA procollagen mRNAs were higher in the degenerating eyes of Del1 and control mice. CONCLUSIONS: The similarities in the temporo-spatial distribution of Sox9 and type IIA procollagen suggest that this transcription factor is involved in the activation of type II collagen expression in the eye, as has been demonstrated in prechondrogenic mesenchyme and immature cartilage. The increased production of Sox9 and type IIA procollagen in the aging retina and vitreous is analogous to degenerating articular cartilage where attempted tissue repair has also been observed.

Aging↗

PubMedDate not supplied

Computed tomography for localization of intra-abdominally dislocated intrauterine devices.

CT with scanogram and selected scans was performed in 7 women aged 23 to 46 years where an extrauterine localization of intrauterine devices (IUD) had been considered present at ultrasonography in 6 patients and a questionable intrauterine position of the device in one. Abdominal radiography and hysterosalpingography gave conclusive evidence of extrauterine device dislocation in 5. CT provided good information about the relation of the IUD to adjacent organs and was thus helpful when planning for the mode of extraction. The gonadal radiation exposure at CT was not less than that given by the conventional radiologic methods but may be reduced with a slight change of technique. It is suggested that a CT examination should be the next step in the diagnostic follow-up when US fails or is equivocal in demonstrating an IUD.

Adult↗