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M Egholm

Publications and source records attributed to M Egholm.

42 records · Page 3Linked to original sources
PubMed1975

Diffuse vaginal adenosis. Three cases combined with imperforate hymen and haematocolpos.

Diffuse vaginal adenosis is a rare disease presenting severe symptoms and difficult to treat. It has not previously been described in the Scandinavian literature. Three typical cases are reported, two in children of 14 years and one in a women of 20 years, who were all treated for imperforate hymen and haematocolpos. None of the patients had been subjected to oestrogen treatment in utero. The colposcopic findings are very characteristic and are described in relation to the histological examination. The pathogenesis, treatment and risk of malignant transformation are discussed.

Adolescent↗
PubMedDate not supplied

Solid-phase synthesis of peptide nucleic acids.

Peptide nucleic acids (PNA) were synthesized by a modified Merrifield method using several improvements. Activation by O-[benzotriazol-1-yl]-1,1,3,3-tetramethyluronium hexafluorophosphate in combination with in situ neutralization of the resin allowed efficient coupling of all four Boc-protected PNA monomers within 30 min. HPLC analysis of the crude product obtained from a fully automated synthesis of the model PNA oligomer H-CGGACTAAGTCCATTGC-Gly-NH2, indicated an average yield per synthetic cycle of 97.1%. N1-benzyloxycarbonyl-N6(3)-methylimidazole triflate substantially outperformed acetic anhydride as a capping reagent. The resin-bound PNAs were successfully cleaved by the 'low-high' trifluoromethanesulphonic acid procedure.

Base Sequence↗
PubMedDate not supplied

Photolytic cleavage of DNA by nitrobenzamido ligands linked to 9-aminoacridines gives DNA polymerase substrates in a wavelength-dependent reaction.

A series of reagents containing 3- or 4-nitrobenzamido ligands tethered to 9-aminoacridine via variable-length linkers have been prepared and their properties as photochemical DNA cleavers (photonucleases) examined. When irradiated with approximately 300-nm light, where the nitrobenzamido ligand can absorb, they cleave DNA in an oxygen-independent reaction presumably involving oxygen transfer from the nitro group to the deoxyribose units of the DNA backbone (Nielsen et al., 1988b). This reaction is pH independent and only slightly affected by the linker length, and the DNA fragments are not substrates for DNA polymerase. When approximately 420-nm light is used, were only the 9-aminoacridinyl ligands absorb, the DNA cleavage is also oxygen-independent but pH dependent, requires DNA saturation with the reagent (base pair:reagent less than or equal to 2), and is most efficient with the longer linkers. The cleavage is specific for guanine residues and results in 5'-phosphate termini and heterogeneous (more than four products) 3'-termini. One of the products is presumably 3'-hydroxy since DNA photocleaved with nitrobenzamido acridine reagents and 420-nm radiation are substrates for DNA polymerase in a nick translation assay as well as for the Klenow fragment. An electron-transfer mechanism is suggested.

Aminoacridines↗