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Biomedical subjects

R Norberg

Publications and source records attributed to R Norberg.

At least 19 recordsLinked to original sources
PubMed1979

F-Actin-depolymerizing activity of human serum.

Non-heated human and animal sera contain a factor which exhibited an inhibiting activity on the staining of actin-containing structures by anti-actin antibodies in indirect immunofluorescence experiments. The presence of this factor lowered the viscosity of F-actin preparations and caused, as studied by electron-microscopy, a depolymerization of F-actin filaments as well as inhibition of filament formation of G-actin. The factor was, after its reaction with F-actin, liberated seemingly unaffected, indicating an enzymatic activity. The factor tentatively termed 'F-actin depolymerizing factor' was heat-sensitive and trypsin sensitive but resisted reduction. It was Ca2+ dependent and the staining inhibiting reaction was faster at 30 degrees C and 37 degrees C than at lower temperatures. Gel filtration experiments on Sephadex G-200 suggested a molecular size of the actin depolymerizing factor slightly higher than that of albumin. The electrophoretic mobility was that of gamma 2 globulin. The physiological role of the factor might be to prevent the presence of F-actin filaments within the circulation.

Actins↗
PubMed1978

Actin filaments in paramyxovirus-infected human fibroblasts studied by indirect immunofluorescence.

Fibroblasts growing on glass have microfilaments arranged in bundles. These can be demonstrated by indirect immunofluorescent technique using human antiactin serum or experimentally produced rabbit anti-actin serum. When monolayer cultures of epithelial cells and fibroblasts are infected with paramyxovirus, such as measles, mumps, Sendai and NDV, there is a striking decrease of the bundles. Rabies and adenoviruses do not seem to influence the staining of microfilaments. The microfilament decreasing effect in the cells correlates to the finding by SDS-polyacrylamide-gel-electrophoresis of actin within virions of the paramyxoviruses.

Actins↗
PubMed1978

Symptomatology and diagnosis in connective tissue disease. II. Evaluations and follow-up examinations in consequence of a speckled antinuclear immunofluorescence pattern.

Antibodies to soluble ribonucleoprotein (sRNP) are by definition a prerequisite for the diagnosis mixed connective tissue disease (MCTD). They are also found in 30--40% of other rheumatic conditions with a high titred speckled IFL reaction. The same is true for the most characteristic clinical features of MCTD, viz. Raynaud's syndrome and polymyositis--polymyalgia. The serological and clinical symptoms mentioned are closely associated. An association between anti-Sm and the SLE symptoms butterfly erythema, nephropathia, other visceropathias and cerebrovascular disease is confirmed by the present study. Although anti-Sm has less diagnostic specificity for SLE than has anti-ds-DNA, it is useful as a diagnostic aid in SLE cases lacking the latter antibody. The results of the present study tend to support the hypothesis that anti-sRNP may be associated with a prophylactive effect against serious vasculitis and nephropathia. When anti-sRNP and anti-Sm occur together they seem to act competitively so that the symptom associated with the antibody having the highest titre tends to dominate the clinical picture. Both anti-sRNP and anti-Sm produce speckled nuclear patterns in the indirect immunofluorescence test. Sera with immunofluorescence titres below 1/25 were not found to react against either sRNP or Sm. On the other hand all sera tested that had a speckled IFL reaction greater than or equal to 1/800 also had anti-sRNP.

Antibodies, Antinuclear↗
PubMed1977

Chronic active hepatitis in children. A clinical and immunological long-term study.

Six girls and one boy with cronic active hepatitis (CAH) of unknown etiology were between 9 and 15 years at the clinical onset of their illness. After beginning immunosuppressive therapy the course of their disease was followed from one to ten years. All had markedly increased IgG, high titres of smooth muscle antibodies (SMA) and antinuclear antibodies of IgG class in the earliest serum specimens tested. Therapy resulted in an improved sense of well-being and a decrease in SGOT, IgG and titres of SMA. Very high titres of measles antibodies were observed in all cases. In one of the cases CAH manifested itself after measles and in another after rubella infection. The first case in our series of patients died of liver failure after 5 years of illness. The other patients have survived and are able to live a normal life. The possibility of CAH should be considered when children develop symptoms of hepatitis. Longterm immunosuppressive treatment with regular clinical and laboratory evaluation is important. Estimation of titres of SMA is an additional parameter of value in following of the activity of CAH in these young patients.

Adolescent↗
PubMed1977

The reaction of cells with anti-actin sera in relation to the amount of cellular actin.

The staining pattern of anti-actin sera on various cells smeared on glass was compared to the relative amount of cellular actin estimated by SDS-polyacrylamide-gel electrophoresis with subsequent scanning of the gel. Although the cells showed a varying stainability the actin content was fairly constant. Thus, the staining differences reflected changes in the organization of cellular actin rather than actual differences in the amount of actin.

Actins↗
PubMed1977

Acute energy deprivation in man: effect on serum immunoglobulins antibody response, complement factors 3 and 4, acute phase reactants and interferon-producing capacity of blood lymphocytes.

The effects of 10 days of total energy deprivation on serum levels of immunoglobulins, antibodies acute phase reactants and on interferon production were evaluated in fourteen healthy, normal-weight males. A significant depression was noted of the serum levels of complement factor 3, haptoglobin and orosomucoid. The titres of mercaptoethanol-sensitive specific antibodies to flagellin were higher in the subjects inoculated at the end of the starvation period than in controls and those inoculated at the start of the period. The serum levels of IgG, IgM, IgA, IgE, alpha-1-antitrypsin and complement factor 4, and the interferon-producing capacity of blood lymphocytes, were not changed. Thus, 10 days of total energy deprivation depresses the serum levels of several acute phase reactants and re-feeding may enhance antibody production.

Antibodies↗
PubMed1976

Antigenic properties of a DNA-preparation from calf thymus used for the demonstration of anti-DNA.

It was attempted to evaluate passive haemagglutination of antigen coated, tanned erythrocytes as a test by which to demonstrate anti-DNA in systemic lupus erythematosus. The antigens was prepared using a minimum of procedures in order to produce a native preparation. The resulting material had most of the criteria applying to native DNA, but the protein content was about 9%. It contained a thymocyte specific component, but no demonstrable trace of bovine species antigen. The reactions between the antigen and an anti-DNA serum from a patient with suspected SLE were inhibited by DNA and DNA-histone, but not appreciably by ENA, RNA or desoxyribonucleosides. Passive haemagglutination reactions against the antigen were positively correlated to a homogeneous immunofluorescence nuclear pattern and negatively correlated to a speckled pattern. Passive haemagglutination titres against ENA and DNA antigen were not correlated. Seventy-three per cent of randomly selected sera gave either purely DNase sensitive reactions (19%) or reactions of combined sensitivity to DNase and other enzymes. Twenty-eight out of 53 sera reacting in the passive haemagglutination test reacted also in the immunofluorescence test against Chrithidia luciliae kinetoplasts. The latter reactions were DNase sensitive. It applies to both tests that DNase sensitive, but RNase resistant, reactions were well correlated, irrespective of their sensitivity to trypsin while DNase resistant or DNase and RNase sensitive reactions were not correlated. The passive haemagglutination test using a native but relatively crude DNA-preparation coated on tanned sheep erythrocytes supplemented by specificity tests with DNase and RNase treated antigen gives about the same information as the indirect immunofluorescence test against Chrithidia luciliae kinetoplasts. Furthermore, the results show that patients' sera reacting with a homogeneous nuclear pattern in the indirect immunofluorescence test may contain not only anti-DNA and anti-nucleohistone antibodies, but also antibodies to a number of non-histone chromatin associated proteins some of which contain RNA.

Animals↗
PubMed1976

Igg rheumatoid factor in serum of rheumatoid arthritis patients.

The ability of isolated IgG and F(ab)2 fragments to agglutinate IgG-coated latex particles was used as a test of IgG-RF activity. No definite differences could be proved between controls and RF-negative RA patients, whereas the latex titres of IgG and F(ab)2 of sero-positive RA patients were higher. The IgG latex activity was recovered in the fractions between the 19S and 7S after gradient centrifugation of serum or isolated IgG at pH 7.2 and within the 7S fraction after centrifugation at pH 4.1. The dissociated IgG complexes reformed after neutralization, thus indicating a self-association of the IgG molecules.

Arthritis, Rheumatoid↗
PubMed1976

The inhibitory effect of IgM RF on the release of lysosomal substances.

Isolated IgM RF inhibited the IgG-induced release of lysosomal substances, measured as 'large molecular size vitamin B12-binding protein' (LBP) and beta-glucronidase, from separated human granulocytes. The effect was most marked when cytochalasin B was added to the experimental system. The results indicate that the RFs interact with the granulocyte binding region of IgG.

Cytochalasin B↗
PubMed1976

Effect of enzyme treatment of Chrithidia luciliae on the reactivity of its kinetoplast with anti-DNA sera.

The reactions of sera from patients with connective tissue disease with Chrithidia lucillae kinetoplasts were examined with the indirect immunofluorescence technique on untreated smears and smears pretreated with DNAse, RNAse or trypsin. Of 28 completely examined reacting sera, 20 had their reactions inactivated by DNAse alone, two by DNAse and trypsin, and 6 by DNAse and RNAse. This suggests that although the Chrithidia test is probably at present the method of choice for the diagnostic demonstration of DNA antibodies, its results are not completely unambigous. The kinetoplast DNA is probably conjugated to a non-histone protein and antibodies to the conjugate may occur in some instances. In other instances, antibodies may be directed against DNA-RNA complexes. If the Chrithidia kinetoplasts contain a protein moiety, the latter is apparently not identical with the protein contained in the Chrithidian cell nuclei.

Antibodies↗
PubMed1976

Indirect immunofluorescence staining of human thyroid by antibodies occurring in Yersinia enterocolitica infections.

In the diagnostic routine for tissue antibodies, using indirect immunofluorescence on cryostat sections of human thyrotoxic thyroid, rat stomach and kidney, ninety-six out of 48,388 sera showed a marginal staining of the membrane region of thyroid epithelial cells but no other reaction. Twenty-six of these sera were from patients with acute Yersinia enterocolitica serotype 3 infection but without signs of thyroid disease. Fifty of sixty-three sera with agglutinins against Y. enterocolitica serotype 3 and three out of four sera with agglutinins against Y. enterocolitica serotype 9 also showed this reaction on thyroid sections. It was due to antibodies, mostly of the IgG class, occurring in low titre, which react with intracytoplasmic antigens in thyroid, as staining of live thyroid epithelial cells was negative. The pattern of immunofluorescence on thyroid sections caused by these antibodies could not be distinguished from that caused by smooth muscle antibodies by appearance only. However, smooth muscle antibodies react also on other tissue sections and extracts of contractile proteins which absorb out these, did not change the reaction on thyroid of Y. enterocolitica sera. Absorption with sonicated Y. enterocolitica 3 and 9 antigens, but not with heat-killed whole bacteria, extinguished the reaction on thyroid. This indicates the presence of a cross-reactivity between antigens in these bacteria, different from the O antigen, and antigens in thyroid epithelial cells. Knowledge of this pattern of immunofluorescence on thyroid sections can be of diagnostic significance.

Agglutination Tests↗
PubMed1976

Anti-actin specificity of human smooth muscle antibodies in chronic active hepatitis.

Thirty sera reacting by IFL technique in titres greater than or equal to 100 with smooth muscle fibres of rat stomach, rat renal glomeruli, and with the membrane region of thyroid cells were randomly chosen among sera sent in for routine testing of tissue antibodies. All sera but one were found to be derived from patients with chronic active hepatitis. The smooth muscle and other relevant cell staining were abolished after absorption of sera with actin, prepared from rabbit skeletal muscle and found to be homogeneous by SDS gel-electrophoresis and by electron microscopy. The actin anti-bodies were purified by precipitation of sera with F-actin and elution of the precipitates at acid pH. The purified antibodies stained all tissues in the same way as the original sera. In double immunodiffusion tests all thirty sera gave precipitation with actin. Thus, it was concluded that these broad-reacting SMA are directed against actin. The finding of high-titred SMA is of diagnostic value and supports the clinical diagnosis of active chronic hepatitis. In addition, anti-actin antibodies eluted from human sera are a suitable tool for studying actin-containing cellular structures.

Actins↗
PubMed1975

Reactivity of smooth-muscle antibodies, surface ultrastructure, and mobility in cells of human hematopoietic cell lines.

Seventeen human hematopoietic cell lines were tested by indirect immunofluorescence (IF) for reactivity with human serum containing smooth-muscle antibodies (SMA). The correlation of the IF pattern to the cell surface ultrastructure was revealed by scanning electron microscopy (SEM). Lymphoma cells, viewed by SEM, had short villi over the entire cell surface, but, by IF, showed a type of membrane fluorescence. Cells of lymphoblastoid lines had thin, long surface villi, sometimes asymmetric but most often distributed over the whole cell surface. Myeloma and leukemia cells, which had few membrane villi but a surface covered by "blebs" as revealed by SEM, demonstrated, by IF, only a few stub-like projections extending from the surface. Time-lapse cinematography revealed that the intensity and pattern of SMA staining were also correlated to the degree of motility. Indirect IF with human SMA-positive serum might be used in the classification of cell lines derived from human hematopoietic tissue.

Antibodies↗