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W Hryniewicz

Publications and source records attributed to W Hryniewicz.

At least 91 records · Page 5Linked to original sources
PubMed1986

Effect of streptolysin S from Streptococcus pyogenes on contact sensitivity in mice.

Streptolysin S, a hemolytic toxin produced by strains of Streptococcus pyogenes, was examined for its effect on cellular immune reaction in mice. The toxin given intraperitoneally for six consecutive days did not influence intensiveness of delayed hypersensitivity to oxazolone which has been used as a model of cellular immune reaction. Streptolysin S injected subcutaneously, closely to lymph nodes directly involved in immune response, markedly suppressed delayed hypersensitivity. Significant inhibition of lymphocyte proliferation by streptolysin S was observed both in vivo as well as in vitro experiments.

Animals↗
PubMed1983

Purification and some properties of the staphylococcal extracellular lipase.

Staphylococcal lipase has been purified by application of a multistep procedure involving ammonium sulfate precipitation, and hydrophobic interaction chromatography followed by gel filtration through Sepharose CL-4B. A purified enzyme was obtained which appeared to be homogeneous by molecular sieving, polyacrylamide gel electrophoresis and sucrose gradient centrifugation. The enzyme was then subjected to physicochemical analysis. It has been found that staphylococcal lipase appears in two molecular forms: light (45 kDa) and heavy (300 kDa). Amino acid analysis indicates that lipase contains 17 amino acids with a prevalence of hydrophobic amino acids. No sulfur-containing amino acid was found in the enzyme molecule. The lipase contains about 2% sugars and some amount of lipids. The lipase preparation is stable within pH 5.0 to 9.0 and exhibits maximal activity at pH 8.0. The optimal temperature for the enzymatic reaction was established at 55 degrees C.

Amino Acids↗
PubMed1983

Physical and chemical properties of extracellular staphylococcal lipase.

Highly purified staphylococcal lipase was subjected to physico-chemical analysis. Effect of ionic strength and of protein structure modifying agents supports views suggesting the subunit structure of this enzyme. Chelating and reducing agents, thiol group inhibitors, and bile acid salts do not influence the enzyme activity. Digestion of purified staphylococcal lipase with proteolytic enzymes indicates that lipase is sensitive to trypsin, alpha-chymotrypsin and pronase.

Guanidine↗
PubMed1983

Lipolytic and proteolytic properties of staphylococci.

Lipolytic and proteolytic activities were estimated in coagulase-positive and coagulase-negative strains of human origin. Several different substrates were used for determination of these activities. Staphylococcus aureus strains were very frequently lipolytic (95%) and proteolytic (87.5%). Among coagulase-negative strains, 85.4% were proteolytic and 10.25% exhibited lipolytic activity.

Coagulase↗
PubMed1983

Staphylococcal lipase: intracellular enzyme production.

It is well known that staphylococci produce extracellular lipase which has been isolated, purified and characterized. Existence of intracellular lipase has not been yet established. In this investigation, cellular content liberated by lysostaphin digestion of cell wall revealed presence of lipolytic activity. This has been observed with living staphylococcal cells only. Presence of intracellular lipase was not observed in young bacterial cells, and the enzyme was appearing rapidly in the late phase of the culture. Highest level of enzyme was observed on the 3rd day of culture in described conditions. Accumulation of lipase inside cells followed by its liberation was not observed.

Culture Media↗
PubMed1980

Effect of hyperthermia on rabbit macrophages.

The effect of water-bath hyperthermia on rabbit peritoneal macrophages was studied in vitro. The cells were exposed to hyperthermia for 30 min to 4 hours and membrane transport of ions as measured by total and ouabain-inhibited 86Rb influx as well as membrane permeability for 86Rb and 51Cr-labelled intracellular proteins were investigated. Heat-treated macrophages were tested for their ability to phagocyte staphylococci and for reduction of nitroblue-tetrazolium. Moreover the effect of microwave whole-body hyperthermia on rabbit phogocytic cells was studied in vivo. Ion transport to macrophages was stimulated by both intensive (43 degrees C) and moderate (40 degrees C) hyperthermia. On the other hand exposition of the cells to 43 degrees C led to pronounced release of 86Rb and 51Cr from prelabelled cells. NBT reduction was generally decreased in macrophages exposed to 43 degrees C and increased in macrophages kept at 40 degrees C. Clearance of 32P-labelled staphylococci from peripheral blood of microwave-irradiated rabbits diminished when animals were exposed to microwave hyperthermia for f or 7 days (2 hours daily).

Adenosine Triphosphatases↗
PubMed1979

Susceptibility of Staphylococcus aureus and group A, B, C, and G streptococci to free fatty acids.

The susceptibility of 242 strains of Staphylococcus aureus and 117 strains of streptococci of groups A, B, C, and G to decanoic, dodecanoic, octadeca-9,12-dienoic, and octadeca-9,12,15-trienoic acids was estimated by determination of minimal inhibitory concentrations. S. aureus strains appeared to be generally less susceptible to all four fatty acids than streptococcal strains of all groups. Dodecanoic acid was the most inhibitory fatty acid against both staphylococci and streptococci. Both saturated fatty acids used were more active than the unsaturated acids. Among the unsaturated acids, octadeca-9,12,15-trienoic acid appeared to be more inhibitory for Staphylococcus and Streptococcus strains than octadeca-9,12-dienoic acid. No differences in susceptibility to fatty acids among staphylococcal and streptococcal strains isolated from skin, throat, or other sites were found.

Decanoic Acids↗
PubMed1979

The role of M protein in phagocytosis. I. Activity of some enzymes in phagocytic cells during infection with Streptococcus pyogenes in vivo.

The phagocytosis of two type 12 Streptococcus pyogenes strains differing in M protein presence was investigated in vivo. The rate of phagocytosis and the streptococcal viability in phagocytic cells and outside of them was studied simultanously with estimation of enzymatic activity in phagocytic cells. It was observed that M positive strain was phagocytized at lower rate and also exhibited longer viability. Decrease of lactic dehydrogenase and ATP-ase activity in phagocytes of rabbits infected with M+ strain was also detected. These results suggest that M protein disturbs phagocytosis by inhibiting their main metabolic pathway of glycolysis.

Acid Phosphatase↗
PubMed1979

The role of M protein in phagocytosis. II. Opsonization of Streptococcus pyogenes in vitro.

Opsonization of two different streptococcal group A type 12 strains was investigated. The strains differed only in M protein presence. It was observed that after the treatment of bacteria with fresh normal rabbit serum M positive strains bind to their surface IgG only whereas M negative strains solely some complement components. These results may suggest that streptococci lacking M protein are able to activate complement by alternate pathway.

Animals↗