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Biomedical subjects

B Nilsson

Publications and source records attributed to B Nilsson.

At least 361 records · Page 20Linked to original sources

Diagnosis and treatment of dental emergencies in two Finnish cities.

According to the present clinical survey of dental emergencies treated by organised emergency services in two of the larger Finnish cities, the main causes (64 per cent) of the problems leading to these visits were caries and its consequences. In about 80 per cent of the 839 cases treated, the acute treatment was based on clinical examination only. Temporary fillings were provided for 19 per cent, permanent fillings for 8 per cent, endodontic treatment for 22 per cent and extractions for 14 per cent of the patients. Extractions were most often provided for patients who normally visited a dentist irregularly and these had a low mean number of teeth. Patients with pain lasting longer than a week were likely to receive endodontic treatment, whereas permanent fillings were provided for regular dental visitors who had their own dentists. About 90 per cent of the patients were considered to need other dental treatment in addition to the treatment of the acute condition.

Adult↗

Immobilization and affinity purification of recombinant proteins using histidine peptide fusions.

A gene fusion approach to simplify protein immobilization and purification is described. A gene encoding the protein of interest is fused to a gene fragment encoding the affinity peptide Ala-His-Gly-His-Arg-Pro. The expressed fusion proteins can be purified using immobilized metal affinity chromatography. A vector, designed to ensure obligate head-to-tail polymerization of oligonucleotide linkers was constructed by in vitro mutagenesis. A linker encoding the affinity peptide, was synthesized and polymerized to two, four and eight copies. These linkers were fused to the 3' end of a structural gene encoding a two-domain protein A molecule, ZZ, and to the 5' end of a gene encoding beta-galactosidase. Fusion proteins, of both types, with zero or two copies of the linker showed little or no binding to immobilized Zn2+, while a relatively strong interaction could be observed for the fusions based on four or eight copies of the linker. Using a pH gradient, the ZZ fusions were found to be eluted from the resin at different pHs depending on the number of the affinity peptide. These results demonstrate that genetic engineering can be used to facilitate purification and immobilization of proteins to immobilized Zn2+ and that the multiplicity of the affinity peptide is an important factor determining the binding characteristics.

Amino Acid Sequence↗

Structural analysis of the carbohydrate chains of a mouse monoclonal IgM antibody.

A mouse monoclonal IgM antibody, directed against human blood group B determinant, was isolated from hybridoma culture growth medium. Chemical analysis indicated presence of N- and O-linked oligosaccharides. The N- and O-linked carbohydrate chains were liberated using two different conditions of reductive alkaline degradation. Structural analysis was carried out on the isolated chains using chemical analysis, 500-MHz 1H-NMR spectroscopy and fast-atom-bombardment mass spectrometry. The following composite structures of the N-linked chains were found: (formula; see text) where R = OH for biantennary structures and R = Neu5Ac alpha 2-3Gal beta 1-4 GlcNAc beta 1- or Neu5Ac alpha 2-3Gal beta 1-3[Neu5Ac alpha 2-6]GlcNAc beta 1- for triantennary structures. The O-linked oligosaccharides, found in the light chains, were shown to have the structure Neu5Ac alpha 2-3Gal beta 1-3GalNAc. The native IgM antibody could be separated on a concanavalin-A-Sepharose column into two subfractions, differing in the presence of a high-mannose-type oligosaccharide.

ABO Blood-Group System↗

Dietary habits and prognostic factors in breast cancer.

The relationship between dietary habits and prognostic factors for breast cancer was studied in 240 women aged 50-65 years who had surgery for breast cancer between 1983 and 1986. A dietary history interview was conducted within the 4 months following resection of the primary tumor. In the stepwise multivariate analysis, the multiple-odds ratio (OR) for having a tumor greater than or equal to 20 mm in diameter was 0.95 (95% confidence interval, 0.91-0.99) for each 1-g increase in fiber intake per 10 MJ of energy intake. Compared with patients having tumors poor in estrogen receptor (ER), those having ER-rich tumors (greater than or equal to 0.10 fmol/microgram of DNA) were older (P less than .01) and reported carbohydrate intake yielding higher E% (percentage of total energy intake) (P less than .01) and higher retinol intake per 10 MJ (P less than .05). The OR for having an ER-rich tumor was 1.58 (95% confidence interval, 1.08-2.31) for each 1-mg increase in retinol intake per 10 MJ; 1.09 (95% confidence interval, 1.02-1.16) for each additional year of age; and 1.08 (95% confidence interval, 1.02-1.13) for each 1% increment in E% from carbohydrates. These results suggest that the dietary patterns of the western world (e.g., high fat intake and low intake of carbohydrates and fiber) affect certain prognostic factors in breast cancer, such as tumor size and ER content of the tumor.

Age Factors↗

Isolation of monosialyated oligosaccharides from human milk and structural analysis of three new compounds.

The monosialyated oligosaccharide fraction from combined samples of human milk was fractionated by gel filtration, ion-exchange chromatography, and h.p.l.c. with triethylamine as an ion-pairing reagent. Among the twelve oligosaccharides isolated, three were new compounds for which the following structures were established on the basis of chemical analyses, f.a.b.-m.s., and n.m.r. spectroscopy.

Carbohydrate Conformation↗

Structural analysis of glycosyl-phosphatidylinositol antigens of Leishmania major.

Three glycosyl-phosphatidylinositol glycolipids recognized by antibodies from patients with cutaneous leishmaniasis were extracted from Leishmania major promastigotes by hexane:isopropanol and then purified by thin layer chromatography and LH-20 gel chromatography. Structural analysis was carried out using chemical analyses, fast atom bombardment mass spectrometry, and 1H NMR. The major structures deduced can be summarized as follows: (formula: see text) where n = 0, 1, 2; R1 = (CH2)23-CH3; R2 = (CH2)14-CH3 or (CH2)16-CH3. Alkyl-acyl substitutions in the glycerol backbone showed considerable heterogeneity. These three glycolipids belong to a relatively new class of compounds and may represent sequential steps in the biosynthesis of glycosyl-phosphatidylinositols which anchor proteins or other glycoconjugates to Leishmania cell membranes.

Animals↗

Ligands of CR2 do not interfere with C3 fragment fixation or enhanced NK sensitivity of Raji cells treated with human serum.

Raji cells activate the alternative complement pathway (ACP) and fix C3 fragments when incubated in human serum (HS). Earlier experiments have shown that CR2 molecules are involved in this phenomenon and the opsonized cells have elevated sensitivity to the lytic effect of CR3-bearing NK cells. We show here that Raji cells treated with CR2 site-specific ligands, (C3d, OKB-7 and HB-5 mAbs, and a synthetic peptide which binds to CR2) generated and bound C3 fragments after exposure to HS. The elevated lytic sensitivity of HS-treated cells was not altered by the presence of the various CR2 ligands. Thus, the membrane-bound C3 fragments are not fixed at the C3dg receptor binding site.

Antibodies, Monoclonal↗