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Biomedical subjects

K Persson

Publications and source records attributed to K Persson.

At least 181 records · Page 10Linked to original sources
PubMed1992

Effects of inhibition of the L-arginine/nitric oxide pathway in the rat lower urinary tract in vivo and in vitro.

1. The present study was performed to investigate how blockade of the L-arginine/nitric oxide (NO) pathway influences the function of the lower urinary tract in vivo, as studied by cystometry in conscious rats and in vitro, in isolated muscle preparations from the rat detrusor and urethra. 2. L-NG-nitro arginine methyl ester (L-NAME), 10 and 20 mg kg-1, administered intra-arterially, decreased micturition volume and bladder capacity, and increased spontaneous bladder contractions. D-NAME (20 mg kg-1) had no effect. No changes in the urodynamic parameters were recorded if L-NAME (20 mg kg-1) was administered in combination with L-arginine (200 mg kg-1). 3. Cystometries performed after intra-arterial administration of sodium nitroprusside (SNP) (3 mg kg-1) and 3-morpholino-sydnonimin hydrochloride (SIN-1, 2 mg kg-1) showed a decrease in bladder capacity, micturition volume and threshold pressure. SIN-1, but not SNP, induced spontaneous bladder contractions. 4. Isolated precontracted urethral preparations responded to electrical stimulation with a frequency-dependent tetrodotoxin-sensitive relaxation. L-NAME (10(-4) M), but not D-NAME, reduced the maximal relaxation to 31 +/- 8% (n = 8) of the response prior to drug administration. The inhibition induced by L-NAME was completely reversed by L-arginine (10(-3) M). SNP (10(-8)-10(-4) M), SIN-1 (10(-6)-3 x 10(-4) M) and NO (10(-5)-10(-3) M; present in acidified solution of NaNO2), caused relaxation (93-100%) of urethral preparations. L-NAME did not affect these relaxations.5. Detrusor strips contracted by carbachol or K' showed contractions in response to electrical stimulation, even when pretreated with a,p-methylene ATP and/or atropine. Small relaxations (14-41%) of detrusor strips were evoked by SNP (10-6-10-4M), SIN-1 (10-5-3 x 10-4M) and NO (10-5-10-3M). Electrically (20 Hz) induced contractions of the detrusor muscle were unaffected by addition of L-NAME (10-6_10-4 M) or L-arginine (10-3 M).6. The present results suggest that the L-arginine/NO pathway is of functional importance for the bladder outlet region, but that its role in the detrusor is questionable. They also suggest that the site of action of L-NAME for inducing bladder hyperactivity in the rat is the outlet region rather than the detrusor muscle.

Animals↗
PubMed1992

Regional differences of Chlamydia pneumoniae as causative agent of pneumonia in Sweden.

A retrospective serological study was performed on sera from 1982-83 and 1989 to investigate the incidence of Chlamydia pneumoniae infection in hospital treated patients with pneumonia in Orebro County. Paired sera from 231 patients were available and 3 cases (1.3%) of C. pneumoniae infection were documented by microimmunofluorescence. The results differ from those reported by others implying regional differences of C. pneumoniae as causative agent of pneumonia. The findings from Orebro County do not support any change in current antibiotic policy and we still regard penicillin as the first drug of choice in community-acquired pneumonia.

Adult↗
PubMed1992

Studies of endotoxin-induced neutrophil migration in bovine teat tissues, using indium-111-labeled neutrophils and biopsies.

Neutrophil migration through bovine teat tissues into the teat cistern, after endotoxin infusion into the teat cistern, was determined in vivo by 2 experimental procedures, indium-111 labeling of blood neutrophils, and obtaining multiple biopsy specimens from the teat cistern tissues. In both experiments, the number of leukocytes in the teat cistern flushing samples was continuously measured. A lag phase of approximately 1 hour was required between endotoxin infusion into the teat cistern and the first observed neutrophil accumulation in the teat tissues. The rate of neutrophil accumulation in the teat tissues was highest between postinfusion (PI) hours 1 and 2, and the accumulation process ceased after PI hour 3. Neutrophils migrated toward the epithelium, and intraepithelial neutrophils were observed beginning approximately 2 hours after infusion, which coincided with the first influx of cells into the teat cistern. The cell influx into the teat cistern increased continuously up to PI hour 3, peaked between PI hours 3 and 5, and was close to preinfusion value at PI hour 22. Use of indium-111-labeled neutrophils in the study of the inflammatory process provides a reliable noninvasive method to quantify cell migration in vivo. Use of biopsies allows quantification of the number of cells in different tissue areas, but has the disadvantage of being invasive. These 2 procedures complement each other, and could be of use in future studies of the local inflammatory process.

Animals↗
PubMed1992

A study of the development of endotoxin-induced inflammation in the bovine teat.

Endotoxin-induced local inflammation was studied by frequent samplings in a bovine teat cistern model, which provides a unique possibility for in vivo studies of reactions in the teat without interference from the mammary gland. A rapid inflammatory response of rather short duration was elicited after endotoxin administration. An initial increase in the concentrations of bovine serum albumin and N-acetyl-beta-D-glucosaminidase, indicating a disturbance in the epithelial integrity, was observed between 1 and 1.5 h post infusion (p.i.). Approximately 0.5 h later, the first influx of leukocytes, mainly neutrophils, appeared. The neutrophils tended to enter the teat cistern in several peaks occurring between 2.5 and 5 h p.i. The sampling procedure decreased the accumulation of cells by approximately 40%, which was probably due to the removal of inflammatory mediators at an early stage. The parallel use of 2 teats instead of 1 had no major influence on the inflammatory process. This teat cistern model and the experimental procedure used should be suitable for further studies of the development of local inflammation.

Acetylglucosaminidase↗
PubMed1991

Exposure of commuters to volatile aromatic hydrocarbons from petrol exhaust.

Twenty-two volatile aromatic hydrocarbons were determined in the air of an automobile during commuting. Sampling was made on Tenax cartridges and laboratory determinations were carried out using thermal desorption combined with temperature-programmed capillary gas chromatography. Selected hydrocarbons representative of petrol exhaust were determined in the automobile and in an electric commuter train during eight parallel commuter trips. In the automobile, the concentrations of benzene were 35-70 micrograms/m3 and those of total aromatic hydrocarbons 200-400 micrograms/m3. The petrol exhaust levels were 5-10 times higher in the automobile than in the compartment of the commuter train.

Air Pollution↗
PubMed1991

Effects of cilazaprilat and enalaprilat on experimental dermatitis in guinea pigs.

Two non-sulfur containing ACE-inhibitors were tested concerning their local effect on experimental dermatitis in ovalbumin-sensitized guinea pigs. Enalaprilat but not cilazaprilat potentiated the ovalbumin-evoked inflammatory response. Furthermore, enalaprilat clearly enhanced the erythema evoked by substance P, whereas cilazaprilat did not. Concerning, the bradykinin-evoked erythema, enalaprilat significantly potentiated the response, whereas cilazaprilat only caused a slight increase. Our results suggest that different affinities for peptidases involved in degradation of inflammatory peptides can explain differences between the pro-inflammatory properties of enalaprilat and cilazaprilat.

Angiotensin-Converting Enzyme Inhibitors↗
PubMed1991

Difference in the actions of calcitonin gene-related peptide on pig detrusor and vesical arterial smooth muscle.

Calcitonin gene-related peptide has been demonstrated in urinary bladder nerves, and suggested to play a role in local control of bladder motility. In isolated strips of pig detrusor muscle, calcitonin gene-related peptide did not affect spontaneous contractile activity, or contractions induced by high K+, carbachol, substance P, and electrical field stimulation. In contrast, calcitonin gene-related peptide elicited a concentration-dependent and pronounced (78-99%) relaxation of vesical arteries precontracted with endothelin-1, noradrenaline or prostaglandin F2 alpha. As a vasodilator, CGRP was approximately 50 times more potent than acetylcholine. Removal of the endothelium abolished acetylcholine-induced relaxation, but did not affect the relaxation produced by calcitonin gene-related peptide. Pretreatment with methylene blue, glibenclamide or indomethacin had no influence on CGRP's ability to relax the vessels. The inhibitor of NO-synthesis, NG-nitro-L-arginine, had no effect on the maximum vascular relaxation induced by calcitonin gene-relate peptide. It is concluded that in the pig, calcitonin gene-related peptide has no functionally important mechanical effects on isolated detrusor muscle strips, but is a potent dilator of vesical arteries. The vascular effects of the peptide are endothelium-independent, and seem to be exerted directly on the vascular smooth muscle.

Animals↗
PubMed1991

Enalaprilat, but not cilazaprilat, increases inflammatory skin reactions in guinea-pigs.

The inflammatory effects of enalaprilat and cilazaprilat were tested in an experimental model of ovalbumin-sensitised guinea-pigs. Enalaprilat, but not cilazaprilat, enhanced the ovalbumin-induced inflammatory skin responses. The effect of enalaprilat was dose-dependent. Enalaprilat significantly increased the skin content of substance P and histamine. Cilazaprilat did not alter the level of these inflammatory mediators. Enalaprilat, applied locally, but not cilazaprilat, enhanced the inflammatory reactions caused by intradermal injections of allergen and substance P. Both angiotensin converting enzyme (ACE) inhibitors enhanced the inflammatory skin response evoked by bradykinin. Our study strongly indicates that enalaprilat has pro-inflammatory properties, whereas the new long-acting ACE inhibitor cilazaprilat does not. This might give a better safety profile of cilazaprilat.

Allergens↗
PubMed1990

Western blot analysis of the antibody response in patients with Listeria monocytogenes meningitis and septicemia.

The antibody response in patients with Listeria monocytogenes septicemia and/or meningitis was investigated using Western blot analysis (WBA). Protein antigen preparations were produced from two strains of Listeria monocytogenes, representing serogroup 1 and 4, by sonication and differential centrifugation. IgG antibodies from 8 (50%) of 16 patients with culture verified septicemia and/or meningitis due to Listeria monocytogenes reacted with a 93 kDa antigen from serogroup 1, in contrast to IgG antibodies from only 1 (2%) of 51 controls; these controls represented 21 patients with infections caused by other bacteria and 30 apparently healthy blood donors. Furthermore, IgM antibodies from 3 (19%) of the patients with listeric infections bound to a 106 kDa protein antigen in contrast to none of the controls. In 3 (33%) of 9 patients from whom acute and convalescence serum were available, the patients responded by producing antibodies against new protein antigens. Current methods used in routine serological investigations, i.e. complement fixation and O-agglutination tests, were positive in only 4 (24%) of the 16 patients with listeriosis. The results point to the possibility of designing new immunoassays for detection of septicemia and meningitis caused by Listeria monocytogenes.

Antibodies, Bacterial↗
PubMed1990

Dose previous Chlamydia trachomatis infection influence the pregnancy rate of in vitro fertilization and embryo replacement?

The association between previous chlamydial infection, as reflected by the presence of chlamydial antibodies (specific serum immunoglobulin G antibodies with a titer greater than or equal to 32) and pregnancy outcome after in vitro fertilization and embryo replacement was studied in 121 infertile women with tubal damage. The antibody prevalence was 74.4%; the overall pregnancy rate was 26.4%. No difference in seropositivity was detected between those who became pregnant and those who did not (71.9% versus 75.3%). The geometric mean titers were also similar in the two groups. Even after subdivision of the cases into primary or repeated in vitro fertilization attempts, or after stratification of the material according to the number of embryos used for replacement, there was no correlation between chlamydial antibodies and pregnancy rate. Thus, past infection with Chlamydia trachomatis did not influence the outcome of in vitro fertilization and embryo replacement treatment in this study.

Adult↗
PubMed1990

Polymorphic formation of morphine from codeine in poor and extensive metabolizers of dextromethorphan: relationship to the presence of immunoidentified cytochrome P-450IID1.

We studied the oxidation capacity in liver biopsies of a series of extensive metabolizers (n = 10) and poor metabolizers (n = 2) as identified by in vivo phenotyping with dextromethorphan. Codeine and dextromethorphan were used as probe drugs in vitro. The data were compared with the contents of cytochrome P-450IID1 as quantitated by Western immunoblotting by use of a specific monoclonal antibody (MAb 114/2). The O-demethylation of codeine was highly correlated with the O-demethylation of dextromethorphan (r = 0.90). The N-demethylation of codeine was catalyzed at a considerably higher rate than the O-demethylation. The N-demethylation to O-demethylation ratio of codeine was 46 in the poor metabolizer and, on average, 6.2 (range, 2.6 to 11) in the extensive metabolizers, respectively. The band intensity in Western blots correlated with the rate of O-demethylation of codeine (r = 0.95) and of dextromethorphan (r = 0.88) in the extensive metabolizers. The comeasurement of the O-demethylation and N-demethylation of codeine may provide a tool with which to phenotype individuals in vitro with respect to the polymorphism of the cytochrome P-450IID1.

Antibodies, Monoclonal↗
PubMed1990

Inflammatory reactions in the teat and udder of the dry cow.

The inflammatory reactions in the teat and udder of the dry cow were studied by total and differential somatic cell counts (SCC) and by measuring bovine serum albumin, N-acetyl-beta-D-glucosaminidase (NAGase), plasminogen and plasmin. The teat and udder cisterns were surgically separated from each other in two udder quarters of each cow. Salmonella endotoxin was infused in one teat cistern and one udder quarter, and saline was infused in one teat cistern and one udder quarter. The inflammatory response was followed by several samplings post infusion. The reactions in the dry udder quarters were mainly in line with the results of similar studies in lactating glands. The differential SCC and the NAGase results were, however, somewhat different. The teats were capable of a strong inflammatory response. Reactions different from those seen in the glands were observed with regard to permeability changes and NAGase. The experimental model used showed promising results and is suitable for further studies of the inflammatory process.

Acetylglucosaminidase↗
PubMed1990

Epidemiological and clinical aspects on infections due to Chlamydia pneumoniae (strain TWAR).

Recently a new species of Chlamydia has been recognized and named Chlamydia pneumoniae, strain TWAR. This organism has now been causally associated with respiratory infections in humans. Serosurveys demonstrate the universal distribution of this pathogen all over the world. The antibody prevalences increase from a few per cent in pre-school children to 20-30% in teenagers. They then increase at a slower rate with prevalences of 40-60% in adults. Antibodies to the TWAR strains have so far been detected only in humans but not in birds or domestic or pet animals suggesting humans as the sole host for these organisms. The isolation and propagation of the TWAR strains and the development of monoclonal antibodies have made diagnosis of infection by these pathogens possible.

Age Factors↗
PubMed1990

Pericardial effusion and pericardial compartments after open heart surgery. An analysis by computed tomography and echocardiography.

Thirty-three patients with pericardial effusion after open heart surgery were investigated with computed tomography (CT). Twelve of the 33 patients also underwent echocardiography prior to pericardiocentesis. The effusions were typed according to the results of the CT investigation. Because of postoperative adhesions, typical patterns of localized pericardial effusions were found in 16 patients. The localized compartments were seen on the right and left side of the heart and around the aorta and the pulmonary artery. CT was therefore shown to be of value for selecting the approach for drainage with catheter pericardiocentesis.

Adult↗