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Biomedical subjects

C Johansson

Publications and source records attributed to C Johansson.

At least 307 records · Page 17Linked to original sources
PubMed1983

Evaluation of labelling methods for bovine T and B lymphocytes.

Two lectins, one from Helix pomatia (HP) and one from Peanut (PN), were evaluated as bovine T cell markers. HP attaches to about 40% of the bovine peripheral blood lymphocytes (PBL). With an indirect technique about 60% of PBL are HP positive, while PN attaches to a slightly higher proportion of the PBL. In double labelling experiments, HP was shown to bind only to Ig negative cells while 2% of the PBL were double labelled with PN and anti-Ig. The influence of different pretreatments of the PBL or the antibodies for labelling of the membrane bound Ig was studied. Preincubation for detaching cytophilic antibodies was important to avoid false Ig positive cells.

Animals↗
PubMed1982

Stimulation of gastric mucus output by somatostatin in man.

Effects of i.v. somatostatin on the gastric mucus output during a 60 min infusion of pentagastrin were examined in five healthy subjects. Experiments were also made with prior indomethacin administration to suppress the synthesis of endogenous prostaglandins. N-acetyl neuraminic acid, a sialic acid, was measured in the gastric aspirates as an index of gastric mucus. Somatostatin increased significantly the gastric mucus output in a dose-related way. The output increased to 158 +/- 14%, and 216 +/- 24% of the control level by 1 and 2 microgram kg-1h-1 somatostatin respectively. The increase induced by somatostatin was prevented by prior indomethacin. With indomethacin alone the mucus output was not different from in controls. Thus somatostatin has augmentory effects on the gastric mucus, which can be blocked by indomethacin, indicating that endogenous prostaglandins are involved in the augmentation. Somatostatin prevents stress ulcerations in the rat, assumedly by inhibiting the gastric acid secretion. This study suggests that additional mechanisms may contribute to the protective action of somatostatin on the gastric mucosa.

Adult↗
PubMed1982

Non-dysplastic villous changes in endoscopic biopsies in ulcerative colitis with carcinoma.

Three cases of long-standing ulcerative colitis and invasive adenocarcinoma are described. In all three cases, pre-operative rectal and/or colonoscopic biopsies demonstrated the presence of a villous adenoma: two without dysplasia and the third with moderate dysplasia. The presence of structures compatible with villous adenoma should be, even in the absence of epithelial dysplasia, an indication for panproctocolectomy in patients with long-standing ulcerative colitis.

Adenocarcinoma, Mucinous↗
PubMed1982

Serum and urinary bile acids in patients with primary biliary cirrhosis.

Serum concentrations and daily urinary excretions of unsulphated and total cholic (C) and chenodeoxycholic (CDC) acid were determined by radioimmunoassay in 15 patients with primary biliary cirrhosis. Thirteen patients had increased fasting serum bile acid concentrations; two of them had an increase of C only. An increase of C and CDC in serum was always followed by an increased urinary excretion of C and CDC. The individual serum bile acids were separated by gas-liquid chromatography. 3 beta-hydroxy-5-cholenoic acid was increased in nine patients, and its serum concentration was correlated to the total serum bile acid concentration. Deoxycholic (DC) and lithocholic (LC) acid were found in most patients, but their serum concentrations were not correlated to the total serum bile acid concentration. Minor bile acids comprised an average of 2% of the total concentration.

Adult↗
PubMed1982

Prostaglandin and protection of the gastroduodenal mucosa.

The prostaglandins, PGs, are formed mainly from arachidonic acid by all nucleated cell populations in the human body. The biosynthesis is easily initiated by unspecific stimulation and is influenced by hormonal, neural and local factors. Human gastroduodenal tissue produces mainly PGE2 and PGF2; an atraumatic approach to follow local production is to identify luminal PGs and their metabolites. In the gastrointestinal tract, the most studied biological action of exogenous PGs is inhibition of the basal and stimulated gastric acid secretion. In addition, PGs stimulate the gastric and duodenal bicarbonate secretion and the production and release of mucus glycoproteins and may have trophic effects on the gastric mucosa. Thus, PGs seem capable of mobilizing all recognized mucosal defense factors. The ability of small amounts of orally administered PGs to protect the gastric mucosa against the gross damage produced by necrotizing agents in experimental animals and to prevent and heal gastroduodenal lesions in man is called "cytoprotection" and is independent of acid inhibition. Cytoprotection may be connected to stimulation of the defensive bicarbonate-mucus barrier or result from yet unidentified mechanisms. --Evidence suggesting a role for the locally biosynthesized PGs in the regulation of the gastric parietal and nonparietal secretions is indirect and based on studies with blocking of the PG-biosynthesis by antiphlogistic compounds. The possible importance of endogenous PGs in the pathophysiology of gastroduodenal disease has been insufficiently examined. --Analogues of PGE2, produced by total synthesis, combine acid antisecretory and cytoprotective properties at dose levels without side effects or systemic actions and are now being tested in clinical trials to confirm effectiveness in the prevention and treatment of peptic ulcer and other gastroduodenal lesions.

Animals↗
PubMed1982

A quantitative method of estimating inflammation in the rectal mucosa. II. Normal limits in symptomatic patients.

Quantitative analysis of histological preparations of the rectal mucosa were carried out in 52 patients with gastrointestinal symptoms. Follow-up investigation demonstrated no signs of chronic inflammatory bowel disease. The variables recorded in the histological preparations in the 52 patients were the diameter (minor axis) of 10 consecutive, transversally cut glands, the space of lamina propria between glands, the number of glands per high-power field, and the number of nuclei in 10 consecutive areas of lamina propria (between glands). The histological state of the rectal mucosa in individual patients was quantitatively defined as the score resulting from the sum of the values in each of the above-mentioned variables. Similarly to the rectal mucosa from asymptomatic patients, the rectal mucosa from the 52 symptomatic patients had scores of 21 or less. These composite data form the basis for a comparative quantitative study of the rectal mucosa from patients with various chronic inflammatory conditions of the rectum.

Adult↗
PubMed1982

A quantitative method of estimating inflammation in the rectal mucosa. III. Chronic ulcerative colitis.

Histological preparations of the rectal mucosa were analyzed quantitatively in 51 patients with chronic ulcerative colitis. Four histological variables were recorded: the diameter (minor axis) of the lumen of 10 consecutive (transversally cut) glands, the interglandular linear distance between 10 consecutive glands, the number of glands at high power field examination, and the number of nuclei in 10 consecutive areas of lamina propria. The most important feature found to differentiate colitic from noncolitic patients was the diameter of the lumen of the rectal glands. The sum of the values of the four variables has demonstrated that 94% of the colitic patients had scores of 22 or more. Previous work showed that only 0.8% of 124 noncolitic patients had a similar score.

Biopsy↗
PubMed1981

The acute effect of p-chloroamphetamine on the retention of fear conditioning in the rat: evidence for a role of serotonin in memory consolidation.

The acute effect of the 5-hydroxytryptamine (5-HT) releasing compound p-chloroamphetamine (PCA) on the acquisition and retention of shock-elicited fear conditioning to the contextual cues of a normal two-compartment shuttlebox in the rat was studied in three experiments. PCA (5 mg/kg) did not impair the acquisition of fear conditioning (Experiment 1). PCA, administered either 30 or 60 min before fear conditioning, caused a total blockade of fear retention when tested 24 h after acquisition. This retrograde amnesic effect was blocked by the 5-HT uptake blocker zimelidine (10 mg/kg) when PCA was injected 60 min before shock. These findings indicate that 5-HT neurones, possibly in the forebrain, may exert an inhibitory influence upon the long-term aspects of information consolidation in memory.

Amphetamines↗
PubMed1981

Metabolism of Oxybutynin: establishment of desethyloxybutynin and oxybutynin N-oxide formation in rat liver preparation using deuterium substitution and gas chromatographic mass spectrometric analysis.

Oxybutynin is rapidly metabolized in rat liver microsomes. Two major primary oxidation products were identified as N-desethyl oxybutynin and oxybutynin N-oxide. Deuterium substituted substrate was used to aid the identification. N-Desethyl oxybutynin was characterized by gas chromatography electron impact mass spectrometry as its trifluoroacetamide derivative and oxybutynin N-oxide was indicated by the presence of a decomposition product, 2-oxo-3-butenyl-2 cyclohexyl-2-phenylglycolate, as elucidated from the gas chromatographic mas spectrometric analysis. The formation of this product from synthetic oxybutynin N-oxide was verified and occurs by two consecutive rearrangements upon thermolysis of the unstable N-oxide. Attempted titanous chloride reduction of oxybutynin N-oxide resulted in the formation of the hydrolytic products 2-cyclohexyl-2-phenylglycolic acid and 4-diethylamino-2-butynol.

Animals↗
PubMed1981

Measurements of prostaglandin biosynthesis in the gastrointestinal tract: biochemical and technical problems.

The special features of prostaglandin biochemistry, of importance for investigation of the possible physiological roles of prostaglandins, are briefly reviewed. The formation of prostaglandins and related compounds from endogenous and exogenous arachidonic acid in homogenates of human gastric mucosal and muscle-serosal layers is described. These preliminary data seem to indicate that a low conversion of exogenous precursor does not necessarily mean that the capacity of the tissue to synthesize prostaglandins from endogenous precursor is low.

Carbon Radioisotopes↗
PubMed1981

Protection of the rat gastric mucosa by prostaglandin E2: possible relation to stimulation of the alkaline secretion.

Exogenous prostaglandins have specific protective effects on the gastric mucosa called cytoprotection which is proposed to be connected to the stimulatory effects of prostaglandins on the gastric nonparietal secretions. The protection by oral prostaglandin E2 (PGE2) against indomethacin-induced gastric erosions was studied in the rat, as was the effect on the protection of blocking the gastric alkaline secretion by acetazolamide. PGE2 reduced dose-dependently the indomethacin gastric erosion formation, confirming previous results from others. Acetazolamide caused very little damage when given alone but potentiated the indomethacin erosion formation in a dose-related way. PGE2 was less protective or without effect against lesions caused by indomethacin when given together with acetazolamide, but protection could be obtained by increasing the doses of PGE2. Indomethacin and acetazolamide are both blockers of the gastric bicarbonate secretion, which is stimulated by PGE2. The potentiation of indomethacin induced lesions by acetazolamide and the antagonistic actions between acetazolamide and PGE2 on mucosal protection are compatible with the hypothesis that stimulation of the alkaline secretion is one mechanism of cytoprotection of the gastric mucosa by PGE2.

Acetazolamide↗