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Biomedical subjects

U Johansson

Publications and source records attributed to U Johansson.

At least 73 records · Page 4Linked to original sources
PubMed1990

Vascular events in experimental otitis media models: a comparative study.

The vascular leakage and components of middle ear effusion (MEE) were determined and compared in various experimental otitis media models in the rat: purulent otitis media (POM); serous otitis media (SOM); mucoid-like otitis media (MOM); stimulating the external auditory canal with a 14 degrees C airstream and vagotomy. When the Evans blue technique was used, all otitis media models exhibited a significant increase in middle ear vessel permeability. The MEEs contained numerous PMNLs, except for animals stimulated with a 14 degrees C airstream, in which the MEE was free of cells. The IgG/SIgA ratio in MEEs indicated that the MEE components are derived from serum in the early phases of fluid accumulation, in these otitis media models. In POM, MEE components appeared to be derived from local synthesis by the middle ear mucosa as well.

Animals↗
PubMed1990

Estrogen and progesterone receptor analyses in more than 4,000 human breast cancer samples. A study with special reference to age at diagnosis and stability of analyses. Southern Swedish Breast Cancer Study Group.

Estrogen (ER) and progesterone receptors (PgR) were measured in the same laboratory in more than 4,000 breast cancer biopsy samples obtained from 15 different hospitals during ten years. ER was measured with isoelectric focusing and PgR with the dextran-coated charcoal method and Scatchard analysis. The distribution pattern for both ER and PgR was during this time period and for the different hospitals rather similar indicating a good stability of the analytical methods. ER concentration was positively correlated with patient age, with a higher percentage of positive samples and higher concentrations in patients greater than or equal to 50 years of age compared with patients less than 50 years. PgR concentration increased with age for patients under 50 years, but a considerable reduction of PgR concentration and of the proportion of positive samples was seen in patients between 50 and 59 years of age. Above this age the PgR concentration again increased with increasing age. The PgR/ER ratio and the proportion of ER- PgR+ samples were higher in patients under 50 years compared to older patients. ER and PgR values decreased during tamoxifen treatment, during pregnancy and after preoperative radiotherapy. Wet weight, DNA and protein were compared as reference parameters for the expression of ER and PgR concentrations. Strong correlations were obtained suggesting that similar information can be obtained with either of these reference parameters.

Adult↗
PubMed1989

Visual evoked potential--a tool in the diagnosis of hepatic encephalopathy?

Visual evoked potentials (VEP) have been suggested to be of value in the diagnosis of subclinical and mild hepatic encephalopathy. In the present study, a comparison between VEP and four psychometric tests (number connection test A and B, digit symbol and word memory test) was performed in 42 cirrhotic patients, 17 of whom had clinical signs of encephalopathy. The results were compared to sex- and age-matched healthy controls. The VEP latencies for P2 (the second positive wave) and N3 (the third negative wave) were 11% and 26% longer (P less than 0.01-0.001) in the patients than in the controls. Moreover, the latencies for N2 (the second negative wave) and P2 were longer in the encephalopathic as compared to the non-encephalopathic patients (P less than 0.05). There was a significant correlation between the latencies for N2 and number connection tests A and B and digit symbol test. However, of the patients with clinical encephalopathy, less than half had VEP latencies longer than the mean +/- 2 S.D. above those for the controls. In contrast, none of the encephalopathic patients had normal results on the psychometric tests. This study demonstrates that although statistically significant differences exist between groups of cirrhotic patients and controls, VEP is not a reliable tool for the diagnosis of encephalopathy in the individual patient.

Adult↗
PubMed1989

Parenteral nutrition in patients with liver cirrhosis. Effects on circulating levels of glucose and hormones and on cerebral function.

The effects of 2 and 5 days of total parenteral nutrition (TPN; 70 g amino-acids, 100 g fat, 150 g glucose) on carbohydrate, fat and amino-acid levels and on cerebral function were investigated in 10 patients with alcoholic cirrhosis and 7 age-matched healthy controls. The results were compared to those after a standardised oral diet. During TPN, glucose concentrations increased slightly in both groups. Insulin concentrations also rose in both groups, but the rise was more pronounced in the patients, resulting in a 10-fold difference between the two groups after 6.5 hours (patients: 281 +/- 81 U/l; controls: 28 +/- 5 U/l; p < 0.02). Glucagon increased significantly during TPN in the patients only (33%, p < 0.05). Similar but less pronounced patterns were observed after the oral diet. The basal concentrations of free fatty acids and 3-OH-butyrate were higher in the patients than in the controls. However, during both oral and parenteral nutrition, the concentrations fell in both groups. For 3-OH-butyrate the difference between the groups disappeared, while the free fatty acid levels remained higher in the patients throughout the TPN administration. Basal triglyceride levels were similar in patients and controls and rose to a similar extent in both groups during TPN. Plasma amino-acid concentrations were typical for cirrhotic patients in the basal state: low levels of the branched-chain amino-acids (BCAA) and high concentrations of the aromatic amino-acids (AAA). During TPN BCAA, as well as AAA, increased in both patients and controls, resulting in unaltered BCAA AAA ratio. All patients performed poorly on psychometric tests (Number Connection Tests A and B; Digit Symbol) before the study, indicating subclinical encephalopathy. However, no deterioration was observed in any of the tests during five days of TPN. Similarly, EEG and visual evoked potentials were unchanged during the study, demonstrating that patients with severe alcoholic liver disease tolerate a balanced intravenous nutrition without adverse effects on cerebral function.

Journal Article↗
PubMed1989

A monoclonal antibody to lactogenic receptors from female rat liver.

Affinity-purified lactogenic receptors from female rat liver microsomal membranes were used to raise antibodies in female Balb/c mice. Mouse spleen and myeloma cells were fused and hybridoma-derived monoclonal antibodies (Mabs) were produced by in-vitro cell culture. Mab from a selected clone was sequentially purified by chromatography on a thiophilic gel and on agarose-bound protein A. The Mab was found to be of IgG1 subclass and of kappa type. The Mab recognized membrane-bound and solubilized (by the detergent heptaoxyethylene lauryl ether; G3707) receptors as well as receptors purified by affinity chromatography and subsequent sodium dodecyl sulphate (SDS) electrophoresis from female rat liver. The Mab bound to receptors from several other female rat tissues, such as ovary, kidney and adrenal, whereas there was no binding to liver receptors from cow and rabbit. Displacement experiments showed that the Mab was specific for a lactogenic type of receptor, in agreement with the finding that the Mab did not recognize receptors from male rat liver. The Mab also bound to cytoplasmic receptors (present in the supernatant after centrifugation at 100,000 g) from female rat liver, suggesting a structural similarity between the cytoplasmic and the microsomal receptors. Analysis of purified receptors by SDS electrophoresis and subsequent Western blot with 125I-labelled Mab as a probe showed one band corresponding to an Mr of 45,500 +/- 2500 (n = 5). The same band was obtained with 125I-labelled human GH, showing that the Mab binds to the unit which accommodates the hormone-binding site.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1989

Structure of the round window membrane.

In the present study the literature on the round window membrane (RWM) structure was reviewed and the rat used as an animal model to elucidate structural alterations of the RWM occurring during serous (SOM) and purulent (POM) otitis media. In SOM the RWM was about the same thickness as that of the control, whereas in POM it increased about 5-fold. The structural changes in POM were mainly confined to the epithelium facing the middle ear cavity. The normal flat epithelium was transformed into a pseudostratified epithelium with both ciliated and goblet cells. Light microscopy revealed only minor changes in the RWM structure during SOM. However, ultrastructurally, the connective tissue layer exhibited dense accumulations of collagen and elastic fibres which were not observed in either normal or the POM ears. The study showed that different inflammatory conditions of the middle ear cause different structural alterations of the RWM. To what extent these changes also influence differently the permeability of the RWM remains to be elucidated. Obviously ultrastructural studies are needed to be able to characterize the structural changes which appear in the RWM in a diseased ear.

Animals↗
PubMed1989

Estimation of pH in individual alveolar macrophage phagolysosomes.

A method for measurement of phagolysosomal pH in individual alveolar macrophages based on a cytofluorometric technique with fluorescein-labeled silica particles (FSP) as a probe was developed. The size of the FSP, 3.0 or 5.0 microns, did not affect the result of the pH measurements. The average pH values, range 5.1-5.5, of individual particles in macrophages from three rabbits agreed well with the pH values obtained in a macrophage population using a fluorescence spectrometer and the FSP. The variation of pH in phagolysosomes in alveolar macrophages from five rabbits was investigated. Measurements were performed 3, 6, and 24 h after addition of the FSP in cells containing one particle as well as in cells containing two particles. The variation in pH was small, with a coefficient of variation less than 10% in all rabbits at all times. There was a significant correlation between values obtained from two phagolysosomes in the same cell, indicating a cell factor responsible for 10-30% of the total variance. The fact that the variation of pH is small in normal, untreated rabbit alveolar macrophages should be of importance when estimating alveolar clearance of inorganic particles due to dissolution in the acid phagolysosomal milieu.

Animals↗
PubMed1989

Enzyme immunoassay of progesterone receptor in breast cancer biopsy samples. A comparison with the dextran coated charcoal method.

Progesterone receptor was measured in 97 breast cancer biopsy samples with two methods, the multiple point dextran coated charcoal method with Scatchard analysis and enzyme immunoassay. The measurable amount of progesterone receptor was usually higher with enzyme immunoassay (mean increase 30%). When comparing the two techniques quantitatively a high correlation coefficient was obtained (rs=0.88; p less than 0.001). A concordance in terms of progesterone receptor positivity and negativity was obtained in 81 of the samples (84%) when using 10 fmol/ml as the borderline value. If instead the cut-off value used for clinical evaluations at our laboratory (30 fmol PgR/mg protein) was applied, the concordance increased to 94%. The lack of concordance in the remaining samples may be due to difficulties in the interpretation of the Scatchard plots, especially at low receptor concentration levels and to differences in specificity between the two methods in certain samples. One obvious advantage with enzyme immunoassay compared to the dextran coated charcoal method is that significantly less tissue is needed.

Aged↗
PubMed1988

The anti-inflammatory activity of Ebselen but not thiols in experimental alveolitis and bronchiolitis.

This paper describes the effects of the thiol compounds glutathione and N-acetylcysteine and the seleno-organic agent Ebselen on the development of Sephadex-induced lung edema and cell infiltration in the rat. Neither thiol had any effect upon the development of the edema when administered in large, repeated doses. In contrast, when Ebselen was co-administered with the thiols, there was a dose-dependent inhibition of the development of the edema, but lung weights could not be returned to normal values. However, when the thiols were omitted and Ebselen was administered alone, the development of the edema was totally blocked. In addition, in Ebselen-only treated animals there was a selective inhibition of the infiltration of lymphocytes, basophils and eosinophils into the lung lumen without affecting the populations of macrophages and neutrophils. Again, the Ebselen-induced effect was reduced by coadministration of either thiol. These findings are discussed in terms of the potential mechanism of action of Ebselen in vivo and of the possibility of Ebselen being of therapeutic potential in cases of diffuse pulmonary inflammation in humans.

Animals↗
PubMed1988

Lung and systemic thiol homeostasis during an acute lung inflammation in the rat.

The instillation of Sephadex beads into the lungs of rats induces a sustained, acute inflammatory reaction within the lungs which caused significant increases in whole lung free and total glutathione (GSH) of approximately 30% after 72 h of reaction. Concurrently, levels of free and total cysteine (CySH) were increased by approximately 600% and 300%, respectively. Similarly, extended inflammation raised the intracellular content of free and total GSH in intraluminal cells by approximately 50% whilst causing the accumulation of oxidised CySH in the extracellular lavage fluid. Simultaneously, fluctuative trends were noted in several systemic thiol pools. Liver free and total GSH were shown to fall without alteration to CySH components. In contrast the plasma redox balance of GSH was unaltered but depletions of free and total CySH were noted after 72 h of inflammation. These results are discussed in terms of the occurrence of oxidative stress during acute pulmonary inflammation and the relationship of these observations to systemic thiol homeostasis and observations in other models of oxidant-induced pulmonary toxicity.

Animals↗
PubMed1987

The effect of acute cigarette smoke inhalation on pulmonary and systemic cysteine and glutathione redox states in the rat.

Inhalation of Tobacco smoke (TS) by rats for 1 h caused significant depletions in the free glutathione (GSH) of homogenate supernatants of whole lung (13.9-8.8 mumol/g protein), lavage cells (2.7-1.7 nmol/10(6) cells) and lavage fluid (1.3-0.4 microM). In each case the depletions were nonrecoverable by dithiothreitol (DTT) suggesting conjugation between GSH and TS-borne electrophiles. Corresponding lung cysteine (CySH) components were unaffected by TS inhalation. In contrast, TS inhalation had no effect on the blood plasma GSH redox balance at various points around the circulation, but was shown to affect those of CySH, causing significant reductions in total CySH in plasma samples obtained both pre- and postpulmonarily. Similarly, the redox status of GSH in homogenate supernatants of whole liver was unaffected by TS inhalation, but there were significant increases in hepatic free CySH. These results indicate that acute TS inhalation increases the oxidant burden on the lungs causing a transient depletion of GSH in a variety of pools. Concurrently, the lungs may possess regulatory mechanism(s) which respond immediately by the uptake of CySH equivalents present in plasma disulfides.

Animals↗
PubMed1986

Monoclonal antibodies towards the fast inhibitor of tissue plasminogen activator from human plasma and serum.

Hybridoma cells were produced by fusing mouse myeloma cells (SP 2/0-Ag 14) with spleen cells from a Balb/c mouse, previously immunized with the partially purified complex between tissue plasminogen activator (t-PA) and its fast inhibitor from human plasma (serum). Screening with a radioimmunoassay revealed a number of hybridomas secreting antibodies directed towards the complex. Of these, about 1/3 reacted both with the complex and t-PA, whereas about 2/3 reacted only with the complex. Three of the latter hybridomas, producing antibodies directed towards the inhibitor-moiety in the complex have been cloned and the antibodies were studied in detail. PA-inhibitor activity in plasma or serum and t-PA/PA-inhibitor complex could be specifically adsorbed on all three insolubilized monoclonal antibodies (MC1, MC2 and MC3). None of the antibodies seems to be directed against structures of vital importance for the functional activity of the PA-inhibitor. In accordance with this finding the antibody with the highest avidity (MC1) reacts equally well with the PA-inhibitor alone or in complex with t-PA. A radioimmunoassay was developed with this antibody and significant displacement was obtained with samples with PA-inhibitor concentrations above 2 AU/mL. In 13 plasma samples with different levels of PA-inhibitory activity a significant correlation was obtained when comparing this activity with the PA-inhibitor antigen as measured with the radioimmunoassay (r = 0.88).

Antibodies, Monoclonal↗
PubMed1986

Rapid purification of monoclonal antibodies by high-performance liquid chromatography.

Three different high-performance liquid chromatographic (HPLC) techniques, i.e., ion-exchange, hydrophobic interaction and hydroxyapatite chromatography, have been used to purify monoclonal antibodies from ascites fluid. The monoclonal antibodies were raised against coagulation factor VIII. Precipitation of the antibodies by ammonium sulphate prior to HPLC made it possible to purify the antibody in one chromatographic step. In sodium dodecyl sulphate-polyacrylamide gel electrophoresis this highly pure preparation revealed only one extra polypeptide besides the light- and heavy-chain immunoglobulin polypeptides. Attempts were also made to purify the antibody without prior ammonium sulphate precipitation. A combination of ion-exchange and hydrophobic interaction chromatography resulted in an antibody preparation comparable in purity to the one obtained from ammonium sulphate-precipitated immunoglobulin. The rapid HPLC techniques were found to be very useful for purification of monoclonal antibodies on a preparative scale, where sample loadings of up to 25 mg of ascites protein were fully resolved in satisfactory yields.

Ammonium Sulfate↗
PubMed1986

Selenium status in patients with liver cirrhosis and alcoholism.

1. Selenium status and blood levels of other nutrients related to lipid peroxidation were studied in patients with advanced alcoholic liver cirrhosis, in male alcoholics who had been abstinent for at least 1 month and in healthy control subjects. 2. Plasma Se was decreased in alcoholic cirrhosis but not among alcoholics in abstinence. Platelet glutathione peroxidase (EC 1.11.1.9; GSH-Px) activity was decreased in cirrhotic patients, whereas GSH-Px in blood and plasma was the same as in controls for both groups of patients. 3. Plasma retinol and plasma alpha-tocopherol were decreased in alcoholic cirrhosis, whereas plasma ascorbic acid was the same in all groups. 4. The decreases in platelet GSH-Px, plasma Se and alpha-tocopherol indicate a deranged antioxidant defence in patients with advanced alcoholic cirrhosis, but the levels of these and other nutrients were generally not correlated to common clinical chemical indicators of liver disease.

Adult↗
PubMed1986

Nutritional status in girls with juvenile chronic arthritis.

Nutritional status, with emphasis on nutrients involved in inflammatory processes, was investigated in 26 girls with juvenile chronic arthritis (JCA) and in healthy controls. Children with JCA had decreased plasma selenium compared to controls. Glutathione peroxidase activity in plasma was similar in both groups but the activity in blood was slightly depressed in JCA. The decrease in blood glutathione peroxidase was more pronounced in patients with high to medium disease activity. Ascorbic acid was measured in plasma, platelets, mononuclear cells and granulocytes. A slight decrease in granulocyte ascorbic acid was observed in patients but in plasma, platelets and mononuclear cells no difference was observed. Serum alpha-tocopherol, blood folate and serum cobalamine was the same in both groups. Several patients, especially in the youngest group, exhibited impaired growth. Serum creatinine and arm muscle circumference were lower in the arthritic patients indicating a lower muscle mass. These changes were more pronounced in patients with systemic or polyarticular onset of the disease. The possibility that the changes in nutritional status in patients with JCA can be corrected by dietary supplementation needs further investigation.

Adolescent↗
PubMed1985

Interaction between ascorbic acid and acetylsalicylic acid and their effects on nutritional status in man.

Healthy adults were given four diets, each one for one week: Low ascorbic acid diet, low ascorbic acid diet plus acetylsalicylic acid (3 g/d), high ascorbic acid diet (1 g/d) and high ascorbic acid diet plus acetylsalicylic acid. At low ascorbic acid intake, acetylsalicylic acid increased urinary ascorbic acid, but at high ascorbic acid intake, acetylsalicylic acid instead decreased urinary ascorbic acid. The latter effect was probably due to an inhibited intestinal absorbtion of ascorbic acid, and the former effect may reflect decreased protein binding and tissue uptake of ascorbic acid caused by acetylsalicylic acid. In no instance, acetylsalicylic acid affected plasma ascorbic acid. The effect of ascorbic acid on substances related to lipid peroxidation was investigated. The high ascorbic acid diets decreased plasma lipoperoxide and retinol binding protein. No change was observed in serum tocopherol, iron status, erythrocyte lipid fluorescence, plasma ceruloplasmin, urinary and plasma selenium and glutathione peroxidase activity. Thus, one-week supplementation of ascorbic acid seems to have only marginal effects on lipid peroxidation and antioxidant status.

Adult↗
PubMed1984

Steric aspects of agonism and antagonism at beta-adrenoceptors: experiments with the enantiomers of terbutaline and pindolol.

The enantiomers of terbutaline, a beta 2-selective adrenoceptor agonist, and pindolol, an unselective antagonist with partial agonist activity, were examined with respect to their ability to react in vitro on adrenoceptors in the trachea (mostly beta 2), the soleus muscle (beta 2) and in the papillary muscle of the left ventricle (beta 1) from the guinea-pig (+)-terbutaline was more than 3,000 times less potent than (-)-terbutaline in relaxing the trachea and in depressing subtetanic contractions of the soleus muscle. (+)-terbutaline did not inhibit the effects of (-)-terbutaline in these tissues. The effect of (-)-terbutaline on the papillary muscle was about 200 times weaker than on the soleus. (+)-terbutaline had a negligible inotropic effect on the papillary muscle and it did not inhibit the effect of isoprenaline. The enantiomers of pindolol did not show any consistent agonistic activity under the present experimental conditions. (-)-pindolol inhibited competitively the effect of isoprenaline to the same extent in all three tissues. (+)-pindolol was about 200 times less potent in this respect. Our data do not reveal any qualitative differences in the pharmacological properties between the optical isomers of terbutaline and pindolol, respectively.

Animals↗