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Biomedical subjects

N Grunnet

Publications and source records attributed to N Grunnet.

At least 109 records · Page 6Linked to original sources
PubMed1989

Rheumatoid arthritis cells and biochemical changes in turpentine-induced pleuritis in rabbits.

When turpentine was instilled into the right pleural cavity in rabbits a pleural effusion developed in half of the animals, with a low pH, low glucose concentration, high lactic dehydrogenase activity and the constant presence of rheumatoid arthritis cells in the affected pleural cavity. The biochemical values in the pleural fluid were significantly different from the values for normal pleural fluid obtained by a special microtechnique. These changes resulting from the experimentally induced, simple, irritative turpentine pleuritis are similar to the findings in the pleural effusion in human rheumatoid pleuritis; this implies that such changes are probably non-specific and without evidence of an immunological background.

Animals↗
PubMed1989

Changes in PMN leukocyte migration activity and complement C3d levels in RA patients with high disease activity during steroid treatment.

We have investigated chemotaxis of polymorphonuclear granulocytes (PMN) from 7 well characterized RA patients with intense disease activity, before and after steroid treatment. Increased spontaneous and directed granulocyte migration was observed in 6 out of 7 patients before steroid treatment. In 5 patients these parameters were reduced after treatment. In contrast to this, decreased chemotaxis of polymorphonuclear granulocytes (PMN) from patients with Rheumatoid Arthritis (RA), have been reported earlier. This has been suggested as a partial explanation of the increased morbidity of these patients. Plasma levels of Complement C3d were initially increased in all patients and were slightly reduced following treatment. PMN migration in highly active RA cases is increased and responds markedly to steroid treatment, in contrast to the complement activation. The mainly unaffected, increased levels of plasma C3d might, in part, explain the early recurrence of symptoms often seen when steroid medication is withdrawn. Our results contrast with earlier findings and need to be confirmed in further studies.

Acute Disease↗
PubMed1988

Real-time scanning and image analysis. A fast method for the determination of neutrophil orientation under agarose.

We describe a newly developed method for fast determination of neutrophil chemotaxis and orientation in concentration gradients of chemotactic factors. The system implements video-based real-time scanning and image analysis of neutrophil migration under agarose, using an interactive easy-to-use computer program. Two methods for determining cell orientation are presented. No statistically significant difference between the methods was found. The analysis program distinguishes between chemokinetic and chemotactic behaviour of the cells (P less than 0.01).

Algorithms↗
PubMed1988

The content and activity of cytochrome P-450 in long-term culture of hepatocytes from male and female rats.

The content of cytochrome P-450 and the capacity for O-demethylation have been measured in cultures of hepatocytes from male and female rats for a period of 21 days. The effect of dexamethasone, insulin, glucagon, phenobarbital and hemin was investigated. In hepatocytes from female rats the content of cytochrome P-450 was unchanged after one day of culture. From day 1 to day 3 the content of cytochrome P-450 decreased by 65% and only the combined addition of dexamethasone, phenobarbital and hemin diminished the fall. After the initial fall, addition of 0.1 microM dexamethasone resulted in a stable value. Addition of 1 microM dexamethasone or 1 mM phenobarbital gave rise to an induction of cytochrome P-450 (285%). The high level of cytochrome P-450 was maintained for 3 weeks. In hepatocytes from male rats the content of cytochrome P-450 decreased by 40% after one day of culture. From day 1 to day 3 the content decreased by 45% and the decrease continued irrespective of the presence of hormones and/or phenobarbital. The O-demethylase activity in cultures of hepatocytes from female rats correlated to the cytochrome P-450 content independent of medium composition and age of the cultures, whereas no correlation was found in cultures from male rats. The present study demonstrates that hepatocytes from female rats in cultures retain O-demethylase activity for at least 3 weeks and that, with the experimental conditions used, the response to the hormones and inducers is different for hepatocytes from male and female rats.

Animals↗
PubMed1988

Positive Coombs' test associated with ulcerative colitis. A prevalence study.

Among 112 patients with ulcerative colitis (UC), a positive Coombs' test was detected in two cases. The immunoglobulins were IgG and no complement could be detected on the red cells. None of the two patients showed laboratory evidence of hemolysis, although reduced red cell survival was suspected in one patient with a 6-year history of UC, previous autoimmune hemolytic anemia and a positive in vitro monocyte-macrophage phagocytosis test. The HLA-antigens in the two patients were different except for the common antigen HLA-A1.

Adolescent↗
PubMed1988

Irradiated blood platelet concentrates stored for five days--evaluation by in vitro tests.

Platelet concentrates, irradiated with 15 Gy and stored for 5 days at room temperature under standardized conditions, were evaluated by in vitro tests and electron microscopy, in a paired study with nonirradiated platelets from the same concentrates, to investigate their usefulness for transfusion. The results showed no significant differences between the two groups in pH, pO2, pCO2, in vitro platelet aggregation, LDH, beta-thromboglobulin and thromboxane-B2. Examination by electron microscopy showed a higher degree of degranulation in the 5-day-old platelets but no certain difference between irradiated versus nonirradiated platelets. On the basis of satisfactory in vitro storage properties, platelet concentrates can be stored for 5 days in PL-1240 bags after irradiation. However, we recommend irradiation just before transfusion whenever possible.

Blood Platelets↗
PubMed1988

Treatment of habitual abortions associated with autoimmune abnormalities. A report of two cases.

In a study of the etiology of idiopathic habitual abortion, we have found 2 patients with a history of 5 and 4 spontaneous abortions respectively, possibly caused by autoimmune abnormalities. In the plasma of one of the patients we had found the presence of lupus anticoagulans and other lupus antibodies, whereas the other suffered from a latent autoimmune hepatitis. We describe the successful treatment of the 2 womens' subsequent pregnancies with subcutaneous heparin supplemented with acetylsalicylic acid.

Abortion, Habitual↗
PubMed1988

Comparative studies on RF-IgA and RF-IgM ELISA--human or rabbit IgG as antigen?

In the literature it is seen that the antigens used in Elisa test for rheumatoid factors (RF) are either human IgG, rabbit IgG, or mouse IgG. We investigated RF-IgA activity in 55 serum samples using either human IgG or rabbit IgG as antigen. In other 76 serum samples we investigated RF-IgM activity using either human IgG or rabbit IgG as antigen. In RF-IgA the median AU/ml is found a factor 2-3 times higher using rabbit IgG as antigen. The discriminatory power of the RF-IgA Elisa test is better using rabbit IgG as antigen. In RF-IgM Elisa the results are different using human or rabbit IgG as antigen. Our investigation illustrates some of the problems in Elisa testing for RF's. We conclude that the variations are influenced by the antigen source, being rabbit or human IgG. This might affect the daily and scientific communication between different laboratories and/or clinical departments. Results obtained by one antigen cannot easily be compared with results obtained with the other antigen. This means that the user of the results has to be aware of the antigen used, and it seems most important to develop some kind of standardization in the Elisa tests used.

Animals↗
PubMed1988

ELISA estimations of rheumatoid factor IgM, IgA, and IgG in sera from RA patients with high disease activity. DTT treatment studies.

Although Elisa assays detecting rheumatoid factor's (RF) show high sensitivity and specificity, difficulties with IgA- and especially IgG-RF testing in ELISA systems, due to interaction from 'contaminating' IgM-RF is still thought to be a problem. Sera from 15 Rheumatoid Arthritis patients with high disease activity and high IgM-RF values were Dithiothreitol (DTT) treated. IgM-RF values were reduced to approximately zero in all tested sera. IgA-RF activity declined as expected, but also showed a statistically significant correlation between % reduction after DTT treatment and the IgM-RF value from the same serum sample. IgG-RF also decreased after DTT treatment, most pronounced for high IgG-RF values. A correlation (not statistically significant) between the % reduction in IgG-RF after DTT treatment and the IgM-RF value from the same serum sample was observed. Pepsin and Diethylammonium ethyl (DEAE) reduced the IgG-RF activity even more than after DTT treatment of the sera. Fractionation by Gel filtration of 8 serum samples showed that all the RF activity were found according to the 'first top' of the gel filtration curve.

Arthritis, Rheumatoid↗
PubMed1988

A Danish inter-laboratory study of IgM rheumatoid factor (RF) determined by enzyme-linked immunosorbent assay (ELISA).

The present report concerns data on the applicability of a standardized IgM RF ELISA as undertaken in five laboratories in Denmark. The study was done upon the initiative of the Danish Association for Clinical Immunology who wished to get an impression of the inter-laboratory reproducibility of the assay, since several Counties in Denmark had de-centralized the IgM RF technique for economic reasons. All laboratories received a form describing the details of the recommended technique, a preparation of human IgG for coating of the microplates, a national standard preparation of IgM RF, 3 well-known control sera and 6 unknown patient sera from the Laboratory for Autoimmune Serology. The results were estimated in IU/ml, calculated in each laboratory. Coefficients of variation in positive sera were between 13 and 25%, and in negative sera 45-50%. Negative sera could always be clearly distinguished from low, middle and highly positive sera. Day-to-day variation was minimal in all laboratories (6%-13%). The IgM RF ELISA technique could thus be handled in all laboratories rendering reasonably reproducible results, and all laboratories could distinguish sera with low, intermediate and high levels of the antibodies from each other and from negative sera.

Enzyme-Linked Immunosorbent Assay↗
PubMed1987

Pathways of reducing equivalents in hepatocytes from rats. Estimation of cytosolic fluxes by means of 3H-labelled substrates for either A- or B-specific dehydrogenases.

The metabolism of [2-3H]lactate and [2-3H]glycerol was studied in isolated hepatocytes from fed rats. In order to estimate the rate of equilibrium between the 4A and 4B hydrogen atoms of NADH, we compared the flow of 3H from [2-3H]lactate and [2-3H]glycerol, the oxidations of which are catalysed by A- and B-type dehydrogenases, respectively. Hepatocytes were incubated with lactate, glycerol and ethanol and tracer amounts of [2-3H]lactate or [2-3H]glycerol and the labelling rates of lactate, ethanol, glucose and glycerol phosphate were determined. The data were used to calculate the oxidation rate of NADH catalysed by lactate dehydrogenase, alcohol dehydrogenase, triosephosphate dehydrogenase and glycerol phosphate dehydrogenase. The rates were calculated by obtaining the best fit of a model to the experimental data by using a least-squares procedure. The results support our model and suggest that the fluxes through various dehydrogenases are sufficient to equilibrate the 4A and 4B hydrogen atoms of cytosolic NADH. The validity of the metabolic models used was evaluated by comparison of rates of NADH oxidation catalysed by cytosolic dehydrogenases as calculated by two different models.

Acetaldehyde↗