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Biomedical subjects

B Nilsson

Publications and source records attributed to B Nilsson.

At least 415 records · Page 23Linked to original sources

Degenerative joint disease in ballet dancers.

Forty-four retired dancers were studied with regard to degenerative joint disease in the lower limbs. Six cases of coxarthrosis were found, significantly more than expected in the general population. In addition, there were four cases of tibio-femoral arthrosis, six of knee osteophytosis, four of patellofemoral arthrosis, three of chondrocalcinosis, and one of bilateral ankle arthrosis. More than one-half of the dancers had arthrosis in the metatarsophalangeal joints.

Adult↗

Prevalence and coincidence of degenerative changes of the hands and feet in middle age and their relationship to occupational work load, intelligence, and social background.

The occurrence and coincidence of degenerative changes in hands and feet were studied in 574 55-year-old residents of Malmö, Sweden. The prevalence of Heberden's nodes and arthrosis of the first carpometacarpal joints (CMC-I) was 15% and 2% higher in women, respectively. Degenerative changes in the feet, again more common in women, occurred in 16%. In men there was a coincidence between degenerative changes in hands and feet. Women with Heberden's nodes had more physically demanding jobs. Otherwise, factors such as intelligence and social background could not be demonstrated to correlate with hand and foot conditions.

Bone Diseases↗

Structural analysis by fast-atom-bombardment mass spectrometry of the mixture of alditols derived from the O-linked oligosaccharides of murine glycophorins.

The O-glycosylically linked oligosaccharides from glycophorins of BALB/c mouse erythrocytes were released as a mixture of alditol derivatives on reductive beta-elimination. A new approach, based on periodate oxidation in combination with f.a.b.-m.s., was used to elucidate the structure of one of the branched derivatives in the mixture. Evidence for the anomeric configuration was obtained by 500-MHz 1H-n.m.r. spectroscopy. The following structures were found: (Formula: see text).

Animals↗

A general reagent for amplifying ELISAs.

This paper describes a method to enhance the sensitivity of enzyme immunoassays by the use of solid tagged latex beads. Various bead sizes (0.21 and 0.81 micron) were tested using particles which had been covalently modified (or coated) with biotinylated rabbit anti-mouse immunoglobulin antibodies. Detection limits of mouse monoclonal antibodies or antigens (which have been reacted with specific mouse antibodies) were compared to those obtained using the general homogeneous 'sandwich' ELISA assay. Compared to the homogeneous biotin-avidin ELISA an increase in sensitivity level of about 6-10 times was observed in antigen detection assays. The stability of the reagent was excellent. The method gave low backgrounds and was as simple to use as the standard procedure.

Alkaline Phosphatase↗

Monoclonal antibodies produced by immunization with neoglycoproteins containing Gal alpha 1-4Gal beta 1-4Glc beta-O and Gal alpha 1-4Gal beta 1-4GlcNAc beta-O residues: useful immunochemical and cytochemical reagents for blood group P antigens and a differentiation marker in Burkitt lymphoma and other B-cell malignancies.

Several monoclonal antibodies (MAbs) directed to blood group P1 (Gal alpha 1-4Gal beta 1-4GlcNAc beta-O) and Pk (Gal alpha 1-4Gal beta 1-4Glc beta-O) determinants were produced with high efficiency by using synthetic neoglycoproteins as immunogens. The specificity of IgM and IgG1 MAbs was characterized by binding to defined oligosaccharides and glycoconjugates. Antibodies that bound equally well to P1 and Pk determinants and to Gal alpha 1-4Gal beta 1-O-derivatives were obtained, together with others that showed selective recognition of the entire trisaccharide chain. Selected antibodies were shown to be useful as reagents for detection of the blood group P antigens in glycolipid extracts of erythrocytes and on the surface of erythrocytes of different P phenotypes, demonstrated both by radioimmune assays and hemagglutination. Six IgM MAbs directed to the Pk determinant bound selectively to Burkitt lymphoma cells and 2 of these antibodies (424/3D9 and 424/6A2) could be used as auxiliary reagents in immunofluorescence for diagnosis and classification of B-cell lymphomas and leukemias using flow cytometric analysis. Eight normal individuals and 37 patients with lymphoma or leukemia were studied. Tumor cells of 2/2 patients with "Burkitt-like" lymphoma, 1 patient with centroblastic lymphoma and 2 patients with acute leukemia were strongly stained for the Pk antigen. The staining patterns for differentiation markers classified the tumor cells to a developmental stage closely related to the Burkitt cell type.

Animals↗

Oligosaccharides from faeces of a blood-group B, breast-fed infant.

Eight oligosaccharides have been isolated from faeces of a blood group B, secretor, breast-fed infant and characterized by sugar and methylation analysis, f.a.b. mass spectrometry and 1H-n.m.r. spectroscopy. One of these oligosaccharides has not previously been reported and is a tri-L-fucosyl derivative of lacto-N-hexaose. The other compounds were identical to oligosaccharides found in human milk. Several of the reported compounds require the secretor dependent 2'-fucosyltransferase for their biosynthesis. Since the mother of this child was an O(H) non-secretor, an intestinal biosynthesis of at least some of these compounds is strongly indicated. No blood group B active oligosaccharides were detected which is in sharp contrast to the oligosaccharide excretion in faeces from a blood group A infant [Sabharwal et al., Mol. Immunol., 21 (1984) 1105-1112] in which all the major oligosaccharides isolated were blood group A active.

ABO Blood-Group System↗

A carbohydrate epitope associated with human squamous lung cancer.

A monoclonal antibody, 43-9F, specifically recognizes a tumor-associated antigen expressed both on surface membrane glycoproteins and on secreted soluble mucins of human squamous lung carcinoma (SLC) cells, and the corresponding antigen can be detected as a circulating tumor marker in plasma of SLC patients. Thin-layer chromatography immunostaining of neutral glycolipids extracted from SLC cells reveals a 43-9F-reactive glycolipid whose carbohydrate structure, as determined by fast atom bombardment-mass spectrometry, is identical with that of an Lea-active pentaglycosylceramide described previously: Gal beta 1-3[Fuc alpha 1-4]-GlcNAc beta 1-3Gal beta 1-4Glc-Cer. However, the Lea-active oligosaccharide hapten, lacto-N-fucopentaose II, with the same carbohydrate structure, fails to inhibit binding of 43-9F, and a well-characterized anti-Lea monoclonal antibody blocks only 40% of 43-9F binding sites on SLC cells, suggesting that the major epitope recognized by 43-9F is more complex than the Lea epitope. To search for a higher affinity 43-9F epitope among more complex oligosaccharides, a mixture of tritiated neutral oligosaccharide alditols from pooled human milk was passed through a 43-9F affinity column. A major retarded oligosaccharide was purified by high-performance liquid chromatography and shown by fast atom bombardment-mass spectrometry to have the following structure: Gal beta 1-3[Fuc alpha 1-4]GlcNAc beta 1-3Gal beta 1-4[Fuc alpha 1-3] GlcNAc beta 1-3Gal beta 1-4Glc. Oligosaccharides containing this sugar sequence are at least 100-fold more active than lacto-N-fucopentaose II as competitive inhibitors of 43-9F. Thus, antibody 43-9F binds to the above difucosyl Lea-X determinant with high affinity and weakly cross-reacts with the Lea antigen under some conditions such as occurs in thin-layer chromatography and enzyme-linked immunosorbent assay where multiple weak interactions of the decavalent IgM antibody may occur.

Antibodies, Monoclonal↗

An amplification technology for improving sensitivity when measuring components in biological samples.

A new technology for improving the sensitivity in measuring components in biological samples is described. The method is based on the use of spherical microbeads (detection beads) which contain a large amount of immobilized enzyme and a reagent with biospecific affinity for the component to be detected. These microbeads have been used in a 'sandwich reaction' for visualization of P-fimbriated Escherichia coli which has a known receptor structure (Gal(alpha 1-4)Gal(beta)). In the initial step the bacteria were enriched on a solid support (e.g., a plastic film or beads (greater than 150 microns)) to which the receptor structure had been covalently bound. In the next step detection beads coupled with enzyme and receptor structure were added and finally a chromogenic substrate for the enzyme was used for visualization. A sensitivity of 10(5) bacteria/ml was reached. The detection beads are of general utility and might be useful for the detection of lectins on other pathogens.

Agglutination Tests↗

A simplified assay for the detection of C3a in human plasma employing a monoclonal antibody raised against denatured C3.

A monoclonal antibody raised against SDS-denatured C3 was shown to react with both solid-phase C3a and unfragmented C3. However, in the fluid phase the antibody was found to bind only to C3a and not to native C3. These findings indicated that the antibody could be used in an assay to detect C3a in human EDTA-plasma without prior separation of C3a from native C3. A simple and rapid competition ELISA was developed which monitored soluble C3a. 200 microliter of C3a (8 ng) was absorbed to plastic wells over night at 4 degrees C. Thereafter, 50 microliter of sample and 50 microliter of constant amounts of monoclonal antibody conjugated with beta-galactosidase, were incubated for 60 min at 37 degrees C. After washing, the colour reaction was started by adding nitrophenyl-galactopyridine to the wells. The microtitre plate was incubated at 37 degrees C for 30 min and the staining intensity was quantified at 405 nm. The assay detected both C3a and C3ades arg. A strong correlation was obtained between the new technique and an RIA which used an acid precipitation step for the separation of C3a prior to the determination of C3a (r = 0.9). Significantly higher levels of C3a were detected both in plasma from patients with immune complexes (93 +/- 9 ng/ml; P less than 0.1) and in plasma from patients treated in blood oxygenators (140 +/- 19 ng/ml; P less than 0.05) than in plasma from normal subjects (74 +/- 4 ng/ml). The results were not affected by repeated freezing and thawing of the plasma samples.

Animals↗

Effect of D,L-buthionine-S,R-sulfoximine on cytotoxicity and DNA cross-linking induced by bifunctional DNA-reactive cytostatic drugs in human melanoma cells.

The effects of D,L-buthionine-S,R-sulfoximine (BSO) on cytotoxicity and DNA cross-linking induced by bifunctional DNA-reactive cytostatic agents in a human melanoma cell line (RPMI 8322) were investigated. RPMI 8322 cells were exposed to 0.01 mM BSO for 24 h, which resulted in a decrease in cellular glutathione to 14% without any reduction of cell proliferation or plating efficiency. BSO pretreatment significantly enhanced cytotoxicity of melphalan with a dose modification factor (DMF) of 3.4 and nitrogen mustard (HN2) (DMF 3.3). The increased cytotoxicity was paralleled by similar increases in DNA cross-linking (melphalan: DMF 2.2, HN2: DNF 2.5). A small but significant potentiation by BSO of cis-diamminedichloroplatinum(II) toxicity was seen (DMF 1.5), with a corresponding minor but significant increase in DNA cross-linking (DMF 1.1). Similarly, the potentiation of bis-chloroethylnitrosurea toxicity was small but significant (DMF 1.1), with no significant increase in DNA cross-linking (DMF 1.0). No effect of BSO pretreatment on the rate of removal of HN2-induced DNA cross-links was observed. Thus, the observed sensitization of RPMI 8322 cells to melphalan, HN2, cis-diamminedichloroplatinum(II), and bis-chloroethylnitrosourea was correlated to similar changes in drug-induced DNA cross-linking. Despite the increased cytotoxicity and DNA cross-linking BSO did not significantly increase the intracellular concentration of intact melphalan. These findings support the hypothesis that the potentiation of the cytotoxicity of bifunctional alkylating agents by BSO is due to an increased DNA cross-linking caused by a reduced intracellular conjugation of drug with glutathione, which results in an increased binding of drug to DNA targets.

Antineoplastic Agents↗

Mass spectrometry of hexosamine containing oligosaccharides as permethylated N-trifluoroacetyl derivatives.

Permethylated N-trifluoroacetyl hexosamine containing oligosaccharide alditols are favorable for analysis by mass spectrometry. Electron impact and fast atom bombardment mass spectra of these derivatives are characterized by strong primary and secondary fragments in which a positive charge is localized on the N-trifluoroacetyl hexosamine residue. From the mass spectra the monosaccharide sequence and the position(s) of substitution of a N-trifluoroacetyl hexosamine can be determined.

Carbohydrate Sequence↗

Fast atom bombardment-mass spectrometry of glycosphingolipids extracted from thin-layer chromatography plates.

A method is described for analysis of glycosphingolipids extracted from thin-layer chromatography plates. Mixtures of glycolipids and gangliosides were separated by thin-layer chromatography and the individual bands were eluted, permethylated, and, after purification, analyzed by fast atom bombardment-mass spectrometry. The glycosphingolipids could be characterized from their fast atom bombardment mass spectra in terms of partial monosaccharide sequence, ceramide composition, and molecular weight. The sensitivity of the method allows characterization of 1-5 micrograms of glycosphingolipid.

Animals↗

Oligosaccharides from feces of preterm infants fed on breast milk.

Nine neutral and five acidic oligosaccharides were isolated from feces of a preterm (30th postmenstrual week) blood group A nonsecretor infant fed on pooled breast milk. Structural analyses were carried out using sugar and methylation analyses, fast atom bombardment mass spectrometry, and 1H NMR. The acidic oligosaccharides are well-known components of human milk. The neutral oligosaccharides are characteristic of nonsecretor milk. Surprisingly, no secretor gene-dependent oligosaccharides were present in the feces. Another preterm (27th postmenstrual week) blood group A, secretor infant fed on pooled breast milk showed the same fecal oligosaccharide pattern as above during the first week after birth, despite being a secretor individual. Also notable was the absence of blood group A-active oligosaccharides in this sample. Another sample of feces collected 8 weeks later from the latter infant contained the expected blood group A-active oligosaccharides. Furthermore, free sialic acid was present at the cost of the sialyl oligosaccharides seen earlier. Thus, infants born prematurely do not show the same degree of development of oligosaccharide metabolism as their more mature counterparts.

Carbohydrate Conformation↗

Effects of estrogen and growth hormone on steroid sulfatase activity and estrogen binding in rat liver.

It is now well established that the activity of certain liver enzymes displays sex differences and that administration of human growth hormone to male rats alters the liver metabolism in a "female" direction. In this work we studied steroid sulfatase activity and binding of estradiol-17 beta in livers from intact rats and found a sex difference, with considerably higher enzyme activity in male as compared to female liver tissue. Continuous infusion of native and recombinant human growth hormone and estradiol-17 beta to male rats reduced sulfatase activity to "female" levels. A specific binding of estradiol-17 beta with receptor properties was found in the rat livers, but the concentration of binding sites did not change after administration of growth hormone or estradiol in this group of intact animals. Our data confirm previous reports that continuous administration of human growth hormone "feminize" liver metabolism, and since estradiol was found to have an identical effect on sulfatase activity it is suggested that the effect of estradiol-17 beta in this respect may be indirect, mediated via an altered secretory pattern of rat growth hormone.

Animals↗