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A Jonsson

Publications and source records attributed to A Jonsson.

At least 37 records · Page 2Linked to original sources
PubMed1992

Increased serum concentrations of cartilage oligomeric matrix protein. A prognostic marker in early rheumatoid arthritis.

Two cartilage specific macromolecules, cartilage oligomeric matrix protein (COMP) and proteoglycan, were quantified by immunoassay in sera of two groups of patients with rheumatoid arthritis (RA) of recent onset to evaluate the prognostic value of such measurements. Patients with rapidly progressive joint destruction had increased COMP concentrations initially, which subsequently decreased. A group with more benign disease, and less extensive joint damage, had normal COMP levels throughout the study period. Serum concentrations of proteoglycan were normal in both groups. Thus measurement of COMP in serum early in the course of RA holds promise as a prognostic marker for development of joint destruction in this disease.

Adult↗
PubMed1990

Erythrocyte gangliosides act as receptors for Neisseria subflava: identification of the Sia-1 adhesin.

Neisseria gonorrhoeae was recently shown to bind to a subset of lactose-containing glycolipids (N. Strömberg, C. Deal, G. Nyberg, S. Normark, M. So, and K.-A. Karlsson, Proc. Natl. Acad. Sci. USA 85:4902-4906, 1988). A number of commensal Neisseria strains were also shown to be lactose binders. In addition, Neisseria subflava bound to immobilized gangliosides, such as hematoside and sialosyl paragloboside, carrying the NeuAc alpha 2-3Gal beta 1-4Glc sequence. To a lesser extent, N. gonorrhoeae also bound to this receptor in vitro. In N. subflava GN01, this binding property mediated agglutination of human erythrocytes in a neuraminidase-sensitive fashion. Nitrosoguanidine-induced nonhemagglutinative mutants of N. subflava GN01 had lost the ability to bind hematoside and sialosylparagloboside but remained able to bind lactosylceramide and gangliotetraosylceramide. These mutants fell into three classes with respect to their outer membrane protein profiles in sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Class 1 mutants were identical to the parent strain save for the loss of a 27-kilodalton (kDa) protein. Class 2 mutants showed an outer membrane protein profile identical to that of the wild type, whereas mutants belonging to class 3 showed a number of changes, including the apparent absence of the 27-kDa protein. The 27-kDa protein from N. subflava GN01 was purified from the supernatant. A polyclonal antiserum to the purified Sia-1 protein as well as a Sia-1-specific monoclonal antibody inhibited hemagglutination by strain GN01. The purified Sia-1 protein in the presence of diluted anti-Sia-1 antiserum mediated a neuraminidase-sensitive hemagglutination. The purified Sia protein from a class 2 mutant was not able to hemagglutinate when cross-linked with antibodies, suggesting that it is a mutant form of Sia-1 affected in the receptor-binding site. Immunoelectron microscopy with a Sia-1-specific monoclonal antibody revealed that the adhesin was nonfimbrial in nature, with aggregates of the adhesin extended out from the cells in a patchy fashion.

Agglutination Tests↗
PubMed1990

Enumeration and confirmation of Clostridium tyrobutyricum in silages using neutral red, D-cycloserine, and lactate dehydrogenase activity.

Spores of clostridia in big bale silages, manure, and dairy products were enumerated and distinguished from other spore formers by using Reinforced Clostridium Agar containing .005% neutral red. Spores of Clostridium tyrobutyricum predominated, but spores of Clostridium butyricum, Clostridium sporogenes, Clostridium bifermentans, Clostridium putrificum, and Clostridium sphenoides occurred to a lesser extent. In samples with high bacterial spore counts, growth of Bacillus spp., but not C. tyrobutyricum, was retarded by the addition of 200 ppm D-cycloserine. Clostridia isolated from silages and milk products were identified and tested on lactate dehydrogenase activity. Of 275 investigated strains, only strains identified as C. tyrobutyricum tested positively. Only 65% of the tested strains of C. tyrobutyricum grew in the confirmatory substrate containing minerals, lactic acid, and acetic acid. Tyrobutyricum Broth was not selective for C. tyrobutyricum, since C. butyricum and C. sporogenes also grew in this medium.

Animal Feed↗
PubMed1989

Fibronectin binding mediated by a novel class of surface organelles on Escherichia coli.

Gram-negative bacteria are known to produce two types of surface organelles: flagella, which are required for motility and chemotaxis, and pili (fimbriae), which play a part in the interaction of bacteria with other bacteria and with eukaryotic host cells. Here we report a third class of E. coli surface organelles for which we propose the name curli. Curli are coiled surface structures composed of a single type of subunit, the curlin, which differs from all known pilin proteins and is synthesized in the absence of a cleavable signal peptide. Although the gene encoding this structural subunit, crl, is present and transcribed in most natural isolates of E. coli, only certain strains are able to assemble the subunit protein into curli. This assembly process occurs preferentially at growth temperatures below 37 degrees C. The ability of curli to mediate binding to fibronectin may be a virulence-associated property for wound colonization and for the colonization of fibronectin-coated surfaces.

Amino Acid Sequence↗
PubMed1988

Age-dependent IgG subclass distribution of phosphocholine antibodies in humans.

Plasma antiphosphoryl-choline (Pc) antibodies were analyzed regarding class and subclass distribution (IgG, IgG1-4, IgM and IgA). Plasma was collected from healthy and otitis-prone children, 1 and 3 years of age, and healthy adults. An enzyme-linked immunosorbent assay (ELISA) was used, utilizing monoclonal antibodies to human IgG subclass determinants. Divergent patterns emerged when comparing children with adults. At 1 year of age the anti-PC IgG1 levels were higher in both of the two children groups than in adults, while the reverse pattern was seen for IgG2 antibodies. There was no correlation between total plasma levels of IgG1-4 immunoglobulins and the ELISA value of specific antibody. The age-dependent subclass patterns corresponded to the earlier descriptions of antibodies to certain pneumococcus polysaccharides. Anti-Pc antibody levels were unrelated to predisposition to otitis media.

Adult↗
PubMed1987

Comparison between serological classification and auxotyping in the analysis of Neisseria gonorrhoeae infections.

Auxotyping and serological classification, using monoclonal antibodies, were performed on 730 gonococcal strains. These strains were isolated from 725 consecutive patients seen at the Venereal Outpatients Clinic at the Department of Dermatology, Södersjukhuset, Stockholm, during one year, up to April 1983. Strains from patients with repeated gonococcal infections were, besides auxotyping and serological classification, analysed with restriction endonuclease cleavage. The strains were distributed into 16 auxotypes, of which the eight most common accounted for 97.4% of all isolates. The same strains were distributed into 38 serovars, of which the eight most common accounted for 88.4% of all isolates. When the two methods were combined, 98 combinations of auxotypes and serovars were seen. The eight most common combinations included 60.0% of all strains. Correlations were found between auxotypes and serogroups as well as serovars. The serological classification gave a better resolution compared with auxotyping; however, when the two systems were combined the sensitivity was highly increased.

Antibodies, Monoclonal↗
PubMed1987

Exposure to fluorocarbons during the filling and repair of air-conditioning systems in cars--a case report.

A worker exposed to fluorocarbons in an automobile plant for seven years experienced shortness of breath (in 1977) and was referred to the hospital. The clinical examination revealed electrocardiographic abnormalities. He recovered quickly and returned to work. During the following year (1978) he suffered subarachnoid bleeding with hemiparesis, and four years later he had an operation for a thymoma. Hygienic measurements in 1980-1981 showed large variations in the fluorocarbon concentrations in the plant, the average 8-h concentrations being below the occupational exposure limit of 500 ppm but several short-time measurements reaching levels of over 750 ppm. It was suggested that, persons with heart disease do not necessarily have to be removed from work with fluorocarbons without careful review of the exposure but that the evaluation of the exposure should not only be based on time-weighted average concentrations, but also on values for brief periods, in that such concentrations can often be decreased by simple and cheap measures.

Air Conditioning↗
PubMed1986

Analysis of serovar distribution as a tool in epidemiological studies in gonorrhoea.

During one year 738 gonococcal isolates from 731 consecutive patients with gonorrhoea were collected and classified by co-agglutination using W I and W II/III specific monoclonal antibodies. Eight W I and 30 W II/III serovars (serovariants) were seen. In both serogroups the most frequent serovar among isolates from women and heterosexual men differed from that among isolates from homosexual men. Forty-two per cent of the serovars, were confined only to one subpopulation, i.e. women, heterosexual men or homosexual men, representing 19 (3%) of the 738 isolates. Out of these 19 isolates 42% were acquired abroad compared with 12% of the 653 isolates in the serovars shared between two or all three subpopulations (p less than 0.005). Imported W I isolates were often of the same serovar that dominated in Stockholm. W II/III isolates acquired abroad were often of unusual serovars (p less than 0.0005) and might be a source of future changes of the serovar pattern in Sweden. In this way we can follow the introduction of new serovars into our society and their circulation between the subpopulations.

Adult↗
PubMed1986

Gonorrhoea in heterosexual men. Correlation between gonococcal W serogroup, Chlamydia trachomatis infection and objective symptoms.

Among 292 heterosexual men with gonorrhoea seen during one year, 59 (20%), had a co-existing chlamydial infection. Of the men infected with a serogroup WI strain 30% had a chlamydial infection compared with 16% of those infected with a serogroup W II/III strain (p less than 0.01). Heterosexual men infected with WI strains had less objective symptoms as judged by the number of leucocytes per high power field and by discharge, than men infected with W II/III strains (p less than 0.05 and p less than 0.01, respectively).

Chlamydia Infections↗
PubMed1985

Gonococcal serovar distribution in Stockholm, with special reference to multiple infections and infected partners.

Serological classification with co-agglutination, using monoclonal antibody reagents, was used to classify gonococcal strains from 731 consecutive patients seen at the Venereal Outpatients clinic at the Department of Dermatology, Södersjukhuset, Stockholm, up to April 1983. The strains could be divided into two serogroups, WI and WII/III. For the identification of strains belonging to serogroup WI, six Protein IA specific antibody reagents were used, and for strains of serogroup WII/III, seven Protein IB specific antibody reagents. The serogroup WI could be further subdivided into eight different serovariants (serovars), and serogroup WII/III into 30 different serovars. All strains reacted with at least one monoclonal antibody reagent and no strain reacted with both WI and WII/III specific reagents. In both serogroups there was one serovar that was common among women and heterosexual men and another which was more frequent among homosexual men. The 84 contact pairs had strains of corresponding serovar in 95%. Among 258 patients with two or more gonococcal isolates on the same occasion, the isolates from 93% had the corresponding serovar. Repeated gonococcal infections were more frequent among heterosexual men than among women and more frequent among homosexual than among heterosexual men. The serological classification of N. gonorrhoeae is a stable and rapid method and a useful epidemiological tool.

Female↗
PubMed1983

Mutagenicity of methyl nitrite in Salmonella typhimurium.

Methyl nitrite was tested for mutagenicity in Salmonella typhimurium TA1535. In the first set of experiments, plated bacteria were exposed to methyl nitrite in desiccators both in the absence and presence of a metabolizing system (S9 from Aroclor-pretreated Sprague-Dawley rats). Initial concentrations from 125 to 500 ppm were tested. In all experiments an increased initial concentration gave an increased mutagenic response. The mutagenic effect in the presence of S9 was similar to that in the absence of S9. Owing to difficulties in dose determinations in this type of experiment it could not be decided, unequivocally, whether the mutagenic effect was caused by methyl nitrite or its hydrolysis products. Experiments were therefore carried out in suspension, and the concentrations of methyl nitrite and inorganic nitrite were determined. Treatments with inorganic nitrite were also carried out under similar conditions. From the results of these experiments we concluded that methyl nitrite is mutagenic. Possible mechanisms of action of methyl nitrite are discussed, and it is suggested that mutagenicity may be a general property of alkyl nitrites.

Animals↗
PubMed1982

Detection of repeated gonorrhea by a modified follow-up method.

The rate of reinfection after treatment was studied in four groups of patients. The first group of 100 patients were evaluated retrospectively after treatment with 1.0 g ampicillin twice followed by two re-examinations over a 2-week period during which time intercourse was prohibited. The second and third prospectively groups consisted of 100 and 200 patients respectively, treated with 1 g ampicillin twice and 1.4 g pivampicillin + probenecid respectively, with re-examinations at intervals of 1 week and 4 weeks after treatment. In these two groups sexual intercourse was allowed during the last 10 days of the follow-up period. The fourth study group consisted of all patients infected with gonococci having MIC greater than or equal to 0.3 micrograms/ml for ampicillin and/or benzylpenicillin, who were treated with 1 g ampicillin twice during the period of 1973-76. In the first group no positive cultures were obtained at re-examination. In groups two and three, 35 out of 300 (12%) were found to have positive cultures at re-examination. Some of these were probably treatment failures. The failure rate in group four was found to be 20%, indicating that the treatment regimen used left a narrow therapeutic margin. However, the risk of re-infection, in this urban clinic, seems to be higher than the risk of treatment failure which would have remained undetected had sexual intercourse been forbidden.

Ampicillin↗
PubMed1981

Domiciliary assessment for geriatric patients in Reykjavik.

The age distribution, clinical presentation and management arrangement of 100 successive domiciliary visits to patients seen following requests for in-patient admission, by their general practitioners are presented. Although 24 patients could be primarily regarded as being social cases, there exists an urgent need to improve facilities for both acute assessment and long-stay geriatric admissions in Reykjavik.

Aged↗
PubMed1980

Noise as a contributory factor in the development of elevated arterial pressure. A study of the mechanisms by which noise may raise blood pressure in man.

Arterial pressure and other hemodynamic variables (stroke volume (SV), cardiac output and total peripheral resistance) were studied in 18 healthy males before and during exposure to recorded industrial noise. All measurements took place under strictly standardized conditions in a noise laboratory. the frequency distribution and level of noise used for stimulation were continuously monitored and kept constant within close limits throughout the experiments. SV was measured with impedance cardiography. Indirect blood pressure (BP) in the brachial artery was measured with an automatic device and the derived parameters, cardiac output and total peripheral resistance, were calculated from these measurements. Compared with resting conditions at 40 dBA, stimulation with industrial noise at 95 dBA caused significant increases in diastolic BP, mean arterial pressure and total peripheral resistance. Minor but statistically significant reductions of SV and cardiac output were seen. Heart rate and systolic BP did not change. These alterations of the hemodynamic variables persisted throughout 20 min of noise stimulation and were maintained for 5 min following cessation of noise stimulation. All variables had returned to their initial levels 10 min after discontinuation of noise stimulation. This study suggests that exposure to industrial noise at levels prevailing during several industrial processes may cause acute elevations of arterial BP and peripheral vascular resistance. In animal studies, repeated elevations of BP due to exposure to noise have been shown to cause a permanent elevation of BP. Therefore, we suggest that noise may be one of several external stimuli contributing to the development of arterial hypertension in man.

Adult↗
PubMed1980

Changes in virulence, M protein and IgG Fc receptor activity in a type 12 group A streptococcal strain during mouse passages.

A type 12 group A strain (1800) was passaged serially through mice 25 times. The ability to servive in normal human blood dropped from a growth index of 52 after the first passage to 1 after four passages. After 14 passages the growth index increased again and stabilized above 30. The virulence for mice increased from a LD100 of 10(8) colony forming units (CFU) to 10-100 CFU after 7 passages and then remained constant. The Mqw antigen disappeared after 4 passages as tested by immunodiffusion, electroimmunoassay and indirect bactericidal tests. Three antisera, raised in rabbits against strains originally belonging to types M3, M12 and M46 but devoid of type antigens after mouse passages showed high bactericidal indices against the 1800 strain after 14 or more passages on mice. Anti-type M1 serum was also found bactericidal for the passaged strains. The IgG Fc-receptor activity of the strain isolated after each mouse passage was tested in hemagglutination experiments with human red blood cells coated with "incomplete" anti-Rh and hot hydrochloric acid extracts of the strains. The capacity to agglutinate "Ripley"-coated cells increased gradually during the first 12 passages and subsequently the titres of the extracts stabilized between 1:160 and 1:320. The HUN coat, useful for detection of the G3m (5) maraker gave titraes increasing with the number of passages while the titres for IgG1 coats kept at 1:4 or below. On background of these results, the possible role of the IgG Fc-receptor as a virulence factor is discussed.

Animals↗