Biomedical subjects

L Switalski

Publications and source records attributed to L Switalski.

6 recordsLinked to original sources

PubMed1988

Staphylococcal adhesion to collagen in intra-articular sepsis.

Ultrastructural studies of the cartilaginous articular surfaces of human and rabbit joints have shown that cartilage is the target substratum for adhesion by Staphylococcus aureus, leading to intra-articular sepsis. Transmission and scanning electron microscope studies demonstrated bacteria in intimate contact with acellular cartilage matrix surfaces, particularly with collagen fibres. Certain strains of Staphylococcus aureus used in these experiments reveal a high binding capacity to collagen that is derived from a cartilage matrix. These studies indicate that the pathogenesis of intra-articular sepsis is based on the ability of certain strains of staphylococci to bind preferentially to a cartilage matrix.

Animals↗

PubMed1988

Adhesion of enterotoxigenic (ETEC) and bovine mastitis Escherichia coli strains to rat embryonic fibroblasts: role of amino-terminal domain of fibronectin in bacterial adhesion.

Adherence of human enterotoxigenic and bovine mastitis Escherichia coli to rat embryonic fibroblasts was studied. Adhesion of E. coli strains B34289c (human) and 1407 (bovine) was rapid and reached maximum after 30-40 min. Strain 1410 (bovine), which binds fibronectin but not its 29K amino-terminal fragment, did not adhere to the fibroblasts. Strain B34289c grown at 25 C or below and at 40 C or above lost its binding and adhesive properties simultaneously. Maximum binding and adhesion for this strain was achieved when it was grown at 33 C. Strains grown at this temperature adsorbed to fibronectin-, 29K fragment-, and Octyl Sepharose, with the exception of bovine strain 1410, which did not adsorb to 29K-Sepharose as expected. None of the strains adsorbed to cross-linked Sepharose 4B. 29K-IgG and Fab fragments thereof specifically blocked both binding (max 55%) and adhesion (greater than 95%). Sonicated and trypsin-treated bacteria were no longer able to bind or adhere. The supernatant of sonicated bacteria inhibited both binding and adhesion. Penicillin G at 0.5 micrograms/ml (1/5 minimal inhibitory concentration: MIC) and tetracycline at 0.2 micrograms/ml (1/5 MIC), when included in the growth medium, suppressed the cell surface components responsible for fibronectin binding and fibroblast adhesion. The presence of fibronectin was demonstrated in the fibroblast extracellular matrix by immunofluorescens with 29K-IgG antibodies.

Animals↗

PubMed1979

IgM fluorescence antibodies in sera of pregnant women exposed to rubella.

A high per cent of false positive results for rubella virus IgM antibodies determined by immune fluorescence were detected in sera of pregnant women. After absorption with Staphylococcus suspension, Cowan 1 strain, and aggregates of human immunoglobulins, the false positive reactions due to IgM antiimmunoglobulin were eliminated.

Absorption↗

PubMed1979

Study of interaction between IgG and IgM antibodies against rubella virus by the immunofluorescence method.

In immunoglobulin fractions or after elimination of IgG by absorption the immunofluorescence test for rubella IgM antibodies is more sensitive than in whole serum. Blocking of IgM activity by IgG antibodies was eliminated when the time of incubation of the serum with virus antigen was prolonged. After prolonged incubation higher titres of rubella antibodies were also obtained in the IgM immunoglobulin fractions. Protein A in Staphylococcus aureus suspension effectively absorbs antibodies of IgG class. The IgM antibody titres in absorbed sera of patients infected with rubella were in some cases 2 to 4 times higher than in unabsorbed sera.

Antibodies, Viral↗

PubMed1975

Monophenol monooxygenase and lincomysin biosynthesis in Streptomyces lincolnensis.

Monophenol monooxygenase (monophenol, dihydroxyphenylalanine:oxygen oxidoreductase EC 1.14.18.1) was studied in melanin-positive and melanin-negative mutants of Streptomyces lincolnensis NCIB 9413, varying in the lincomycin synthesizing ability. The activities of laccase and tyrosine phenol lyase (EC 4.1.99.2) are absent in this organism. The monophenol monooxygenase catalyzes hydroxylation of monophenols (K(m) and V(max) for l-tyrosine, 2 x 10(-4) M and 8.0 nmol of O(2)/min per ml, respectively) at a slower rate than it dehydrogenates diphenols to o-quinones (K(m) and V(max) for l-3,4-dihydroxyphenylalanine, 7 x 10(-5) M and 51.7 nmol of O(2)/min per ml, respectively. It is inhibited by KCN, beta-mercaptoethanol, ethylenediaminetetraacetate, dipyridyl, thiourea, p-aminobenzoic acids and by some tryptophan metabolites. Changes in the activity of monophenol monooxygenase caused by mutation or by inhibitors are reflected in the synthesis of the antibiotic. Its participation in the biogenesis of the propylhygric moiety of lincomycin is discussed.

Amino Acids↗

PubMedDate not supplied

Residual caries detection using visible fluorescence.

This study investigated the ability of a new fluorescence method to detect residual caries in vitro. Gross caries was removed from 40 teeth with D2 caries. Samples were excited with violet-blue light and viewed through a 530-nm high-pass filter. Residual caries (orange-red fluorescing dentin) was detected in all samples. Further tooth substance was removed from half of the samples until no residual caries was detectable using the new method. Half of the samples remained untreated. A blinded examiner checked all samples for residual caries using DIAGNOdent, a visual tactile examination, and Caries Detector dye. Presence or absence of residual caries in each sample was determined using a fluorescent nucleic acid stain in conjunction with confocal microscopy. The new method, Visible Fluorescence, had the greatest sensitivity, specificity, percent correct score and predictive values of any of the methods tested. The new method had significantly higher percent correct score than any of the other methods and significantly higher specificity than visual tactile and Caries Detector. It was concluded that Visible Fluorescence is an improvement on the currently available aids for residual caries detection.

Bicuspid↗