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Biomedical subjects

U Forsum

Publications and source records attributed to U Forsum.

139 records · Page 8Linked to original sources
PubMed1973

Identification of Actinomyces, Arachnia, Bacterionema, Rothia, and Propionibacterium species by defined immunofluorescence.

Fractionated fluorescein-isothiocyanate (FITC)-conjugated immunoglobulin G (dye-to-protein ratio <10), produced against whole cells of Actinomyces spp., Arachnia, Bacterionena, Rothia, and Propionibacterium spp., give species-specific conjugates with controlled nonspecific staining reactions when appropriately diluted on the basis of their antibody content (10 mg/ml). Using this standardization in immunofluorescence, serotype-specific conjugates are also available after dilution for all serotypes of these organisms except for Actinomyces viscosus type 2, and Propionibacterium acnes type 1. Adequately adsorbed conjugates could be used to differentiate these serotypes from A. viscosus type 1 and P. acnes type 2, respectively. A serological classification in defined immunofluorescence corresponded to species and serotype designation proposed on the basis of other serological analysis and biochemical characteristics. This includes a separation in immunofluorescence of two serotypes of Propionibacterium acnes. The detection of certain actinomycetes of the family Actinomycetaceae and Propionibacterium species by the defined immunofluorescence in direct smears prepared from clinical specimens agreed to 88% with parallel culturing when including a prereduced (PRAS) medium technique for isolation. Qualitative studies revealed that single cells of these organisms could be specifically identified by immunofluorescence when admixed with morphologically similar bacteria and a large number of other contaminants.

Actinomyces↗
PubMed1972

Failure to detect cell-associated enterotoxin B in Staphylococcus aureus by immunofluorescence.

Enterotoxin B-producing and -nonproducing Staphylococcus aureus strains showed cell fluorescence when tested with fluoresceinisothiocyanate-labeled rabbit anti-enterotoxin B globulin, probably as a result of a protein A-immunoglobulin G (Ig G) interaction. No cell-bound enterotoxin B could be detected by immunofluorescence using F(ab(1))(2)-fragments of anti-enterotoxin B globulin. However, soluble enterotoxin B could be estimated by immunofluorescence. Approximately 1,000-fold more enterotoxin B was detected by immunodiffusion as an extracellular product in the media than could be detected in the cell fraction. The results show that intact Ig G is not suitable for the detection of antigens other than protein A on the cell surface of S. aureus in conventional immunofluorescence. For such purposes, the use of F(ab(1))(2)-fragments of Ig G is recommended.

Ammonium Sulfate↗
PubMed1972

Agglutination of Staphylococcus aureus by rabbit sera.

Of 137 Staphylococcus aureus strains, 87 agglutinated in normal rabbit serum. The agglutination was shown to be caused by the Fc-part of immunoglobulin G (IgG). F(ab(1))(2)-fragments of IgG and immunoglobulin M (IgM) in corresponding concentrations were unreactive. The agglutinating strains had a high or moderate content of protein A. Strains with a low content of protein A and protein A-negative mutants did not agglutinate. The importance of the reaction between the Fc part of IgG and protein A for serotyping of S. aureus is demonstrated. Two alternative methods for serotyping S. aureus are suggested, using either F(ab(1))(2) fragments of IgG or intact IgM.

Agglutination Tests↗
PubMed1972

Role of protein A in the serum-soft agar technique.

Formation of compact colonies of Staphylococcus aureus in serum-soft agar is mainly a result of a reaction between protein A and the Fc-part of immunoglobulin G and not a clumping factor-fibrinogen reaction.

Agar↗
PubMed1970

Role of Protein A in Nonspecific Immunofluorescence of Staphylococcus aureus.

gammaG-globulin from nonimmunized rabbits and from rabbits immunized with various bacteria reacted in the immunofluorescence technique with protein A-containing Staphylococcus aureus. Pepsin digestion of most immunoglobulin preparations eliminated the reaction, thus showing that the Fc fragment is involved and that the reaction is not a true antigen-antibody reaction. As the specific immunological activity of the immunoglobulin molecules was intact after digestion, it is suggested that the method be used to eliminate reactions with S. aureus in the fluorescent-antibody technique.

Journal Article↗
PubMedDate not supplied

Dynamics of Ia-expressing cells and T lymphocytes of different subsets during experimental allergic neuritis in Lewis rats.

Inflammatory cells were characterized by immunohistochemistry, utilizing monoclonal antibodies against cell surface antigens in frozen sections of sciatic nerves and nerve roots of Lewis rats, sacrificed during the course of experimental allergic neuritis. Large numbers of Ia-expressing irregular macrophage-like/dendritic cells, as well as W 3/13 reactive T lymphocytes of both W 3/25 reactive helper and ox8 reactive suppressor/cytotoxic phenotypes were seen within afflicted peripheral nervous tissue at the start of clinical symptoms and at the height of the disease. T lymphocytes of both helper and suppressor/cytotoxic phenotypes decreased concomitant with clinical recovery. During this period demyelination was still extensive and Ia-expressing macrophage-like/dendritic cells were abundant.

Animals↗
PubMedDate not supplied

A study of the usage of a decision-support system for infective endocarditis.

The objective of this study was to examine a design for a World Wide Web-based decision-support system in use by clinically active physicians. A prototype implementation of the design concerned management of infective endocarditis patient cases. The design was based on an integration of hypertext and rule-based knowledge. In the study sessions, physicians in the field of internal medicine worked on managing authentic patient cases in a laboratory setting. Data was collected from interviews with the physicians using video recordings and stimulated recall technique. The qualitative data was analysed according to the constant comparative method in order to develop a model of the physicians' usage of the system. The resulting model describes perceived contributions and criteria for usefulness of the system. The ways the physicians used the system showed that it was able to provide patient-specific support for confirming clinical decisions, for higher-level patient management, and for preparing for and initiating expert consultations. Users also stated that new medical knowledge could be gained as a side effect of using the system.

Attitude to Computers↗
PubMedDate not supplied

Trimethylamine and trimethylamine oxide levels in normal women and women with bacterial vaginosis reflect a local metabolism in vaginal secretion as compared to urine.

The smell of rotten fish is one of the characteristics of bacterial vaginosis (BV), and is due to trimethylamine (TMA). Trimethylamine can be found in human urine, although most of it occurs as the nonvolatile oxide (TMAO) form. The fraction TMA/TMAO can be expected to be the same in different body fluids if no local production of TMA occurs. In women with BV, TMAO in the vaginal fluid is expected to be chemically reduced by the local bacterial flora to the much more odorous TMA. We have therefore studied the local vaginal production of TMA in vaginal secretion compared to the general TMA-TMAO metabolism that was measured in urine using gas chromatography. Both vaginal fluid and random urine samples were collected from women, with and without BV, attending a Swedish clinic for sexually transmitted diseases, and these samples were analyzed for TMA and TMAO. The results show that a local production of TMA occurs in the vagina that is not part of the general metabolism of TMA-TMAO.

Adult↗
PubMedDate not supplied

Building a concept system to structure the contents of a decision support system--a grounded theory study of concepts in the knowledge domain of urinary tract infection.

In this study we present a concept system for the knowledge domain of urinary tract infections. The system was constructed using grounded theory methods, sampling from Swedish reference texts and patient records from consultations for urinary tract infections. The concept system is intended for use as an aid in the construction of a decision support system (DSS) for urinary tract infections, and as a search module in the mentioned DSS. In total 561 concepts were categorized in four major, and 58 subordinate categories. Relationships between the more important categories were developed, and the frequency of use of the most common concepts is presented. Using the presented categorical structure as domain model a prototype DSS for dipslide urine cultures has been developed.

Concept Formation↗