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Biomedical subjects

D Witkowska

Publications and source records attributed to D Witkowska.

At least 55 records · Page 3Linked to original sources
PubMed1987

Effect of outer membrane proteins of Shigella on delayed hypersensitivity in mice to sheep red blood cells.

Small doses of outer membrane proteins (OMP) of Shigella flexneri injected intraperitoneally into mice 1 to 3 days before or 3 days after sensitization of animals with sheep erythrocytes were found to increase delayed hypersensitivity as measured by the footpad reaction. In contrast, administration of higher doses of OMP resulted in suppression of hypersensitivity response. Cell transfer experiments showed that the spleen cells from sensitized and OMP treated mice transferred stimulating and suppressing activity to normal recipients. Suppression of hypersensitivity was also observed when recipients were injected with OMP 24 h before they were infused with spleen cells obtained from donor mice sensitized with sheep erythrocytes.

Adjuvants, Immunologic↗
PubMed1987

Some biological properties of outer membrane proteins of Shigella.

Outer membrane proteins (OMP) derived from two antigenically different representatives of Shigella (Sh. flexneri 3a and Sh. sonnei phase I) were tested for the toxicity, pyrogenicity, ability to induce Shwartzman reaction as well as for their influence on the leukocyte system. LD50 dose determined on mice was 28 mg/kg for OMP of Sh. flexneri and 23 mg/kg for OMP of Sh. sonnei. Both preparations injected intravenously to rabbits caused moderate increase of body temperature, expressed by the value 1.8 degrees C. Intravenous administration of protein preparations to rabbits, induced at first leukopenia and then transient leukocytosis. When injected subcutaneously in the dose of 500 micrograms and after 24 h intravenously in the dose 100 micrograms, they produced slight hemorrhagic changes at the site of administration.

Animals↗
PubMed1986

Humoral response in mice immunized with outer membrane proteins of Shigella flexneri.

Intraperitoneal immunization of mice with outer membrane proteins (OMP) of Sh. flexneri induced in the animals a synthesis of specific antibodies. Their level determined by ELISA test was found to be relatively low in the sera of animals immunized with a single dose (10 micrograms) of OMP; it was markedly higher in mice immunized with two doses of OMP, and very high after three fold immunization. The specific antibodies maintained in the animals for 8-16 weeks after immunization. Anti-OMP sera given to normal mice by intraperitoneal route protected them not only against challenge with homologous Shigella but also against Proteus and Escherichia.

Animals↗
PubMed1986

Characterization of outer membrane proteins of virulent phase I Shigella sonnei strains and their avirulent phase I derivatives.

Comparison of polyacrylamide gel electrophoretic protein profiles of four isogenic sets of virulent phase I Sh. sonnei strains and their avirulent phase I cells revealed no differences in outer membrane protein composition between virulent and avirulent derivatives. However, significant qualitative and quantitative differences were found in composition of major outer membrane proteins between strains of different origin. All four strains tested contained one major protein of 33K. This protein was susceptible to proteolytic enzymes and was found to be heat modifiable. Other major proteins of 35K and 37K present in three strains and 36K present in one strain were identified as peptidoglycan associated proteins.

Bacterial Outer Membrane Proteins↗
PubMed1985

Studies on specificity of protection induced by immunization with outer membrane proteins of Shigella.

Immunization of C3H/HeJ mice with outer membrane proteins (OMP) and with peptidoglycan associated proteins (PGP) isolated from Shigella flexneri 3a and from Shigella sonnei phase I protected the animals against lethal dose of homologous and heterologous bacteria and against various serotypes of Shigella flexneri. Neither of the protein preparations protected the animals against challenge with Escherichia, Klebsiella, Citrobacter, Salmonella, Serratia, Proteus and Pseudomonas. OMP preparations however, isolated from these species protected the animals not only against challenge with homologous bacteria but also against Shigella flexneri 3a.

Animals↗
PubMed1985

Transfer of immunity by means of spleen cells from mice immunized with outer membrane proteins of Shigella flexneri.

Intraperitoneal immunization of mice with a single dose (5 micrograms) of outer membrane proteins (OMP) of Shigella flexneri was found to evoke in the spleen the appearance of cells by means of which immunity to lethal dose of Shigella could be transferred into other mice. Active cells capable of transferring immunity appeared in the spleen of the animals as early as on day 3, reached the strongest protective activity on day 4 and disappeared on day 8 after immunization. Active cells from animals immunized with two doses of OMP maintained in the spleens for 19 days. The experiments revealed that immunity to Shigella could be transferred only with lymphocytes; macrophages were found to be inactive.

Animals↗
PubMed1984

Protective properties of peptidoglycan associated protein of Shigella flexneri.

Groups of CH3/Hej mice were immunized with peptidoglycan associated protein (PGP) from Shigella flexneri 3a administered in a single intraperitoneal injection (5 micrograms per mouse). After various periods post immunization the animals were challenged intraperitoneally with homologous bacteria. PGP proved to be strongly immunogenic. As early as one week after immunization all the animals survived challenge with 100 X LD100, and one third of the animals survived challenge with a dose of 500 X LD100. This high state of immunity maintained at almost unaltered intensity for 12 weeks after immunization (the end of the observations period).

Animals↗
PubMed1983

Effect of metavanadate on the uptake and release of noradrenaline in rat brain cerebral cortex slices.

The effect of vanadium (as VO3-) on the uptake and release of tritiated noradrenaline ([3H]NA) was studied in vitro in rat cerebral cortex slices. Vanadate inhibited [3H]NA uptake and the inhibition was dependent upon concentration and on incubation time. The IC50 value (20 min incubation) was 8 X 10(-5) M of vanadate. Inhibition of Na+, K+ -ATPase activity by VO3-, chelation of noradrenaline or autooxidation of catecholamine by this oxyanion might contribute to the decrease of [3H]NA uptake. Vanadate inhibited also the release of [3H]NA in a time- and concentration-dependent fashion.

Animals↗
PubMed1983

Antifungal activity of Wratizolin.

Wratizolin was found to inhibit completely or delay markedly the growth of fungi of Microsporum, Trichophyton and Epidermophyton genus. Mould fungi, yeasts, and yeast-like organisms, with a few exceptions, were not sensitive to Wratizolin.

Antifungal Agents↗
PubMed1981

Studies on virulence of Shigella flexneri. Protective effect of outer membrane proteins.

Groups of mice were immunized intraperitoneally with proteins isolated from outer membrane of virulent strain of Shigella flexneri 3a and its avirulent variant. All the animals were found to survive challenge with LD100 of virulent Sh. flexneri 3a. Similar protective effect against challenge with Sh. flexneri 3a gave also immunization of mice with outer membrane proteins isolated from Sh. flexneri of other serotypes (2a, 4a, 6, and X) and from Escherichia coli, Hafnia alvei and Shigella sonnei.

Animals↗
PubMed1980

Protection against keratoconjunctivitis shigellosa induced by immunization with outer membrane proteins of Shigella spp.

Active immunization of guinea pigs and rabbits with outer membrane proteins (OMP) isolated from Shigella flexneri 3a and Shigella sonnei phase I protected the animals against keratoconjunctivitis shigellosa induced with the homologous or heterologous strain. Protection was also achieved in rabbits after passive immunization with anti-OMP immune serum. Active immunization with lipopolysaccharide of S. flexneri 3a did not protect rabbits against keratoconjunctivitis shigellosa.

Animals↗
PubMed1978

Studies on virulence of Shigella flexneri.

The antigenic structure and some biological properties were compared in virulent S. flexneri strains of differences in: 1) antigenic composition; 2) biochemical activity; 3) sensitivity to a set of Shigella phages and 4) susceptibility to phagocytosis. The only difference found concerned the LD50 for mice; it was 10 to 100 times larger for avirulent than for virulent strains of S. flexneri. The toxic products of the strains were also compared. The lipopolisaccharide and free endotoxin purified from virulent and avirulent variants behaved similarly when tested for: LD50, pyrogenicity and the local Shwartzman reaction. A striking difference was demonstrated in the ultrastructure of lipopolisaccharide and free endotoxin isolated from virulent and avirulent variant of S. flexneri 3a.

Animals↗
PubMedDate not supplied

Effect of chlorfenvinphos, cypermethrin and their mixture on the intestinal transport of leucine and methionine.

We assessed the effect of 2-week oral treatment with chlorfenvinphos, cypermethrin and their mixture in a dose of 5% LD50 on the intestinal transport of L-leucine (Leu) and L-methionine (Met) in male Wistar rats. Both in vitro (jejunal slices) and in vivo (intestinal perfusion) methods were employed in the study, using Leu and Met labelled with 14C as markers of the investigated processes. Additionally, in the in vitro study, concentrations of two amino acids were measured in the whole blood, serum, liver and perfused segment of the intestine. In the in vitro study the kinetic constants describing the active and passive Leu and Met uptake were determined. The active uptake was found to be particularly affected by oral intoxication with chlorfenvinphos, cypermethrin and their mixture. This susceptibility was seen as major alterations in the parameters of active uptake, i.e. Jm and Ki constants in the pesticide-exposed groups as compared to controls. In the in vivo study we found a decreased rate of Leu and Met disappearance from the intestinal lumen, decreased blood concentrations of Leu and Met and decreased liver content of Leu in the pesticide-exposed groups as compared to controls. The findings allow the conclusion that oral administration of chlorfenvinphos, cypermethrin and their mixture in a dose of 5% LD50 impairs the intestinal transport of Leu and Met and alters their distribution in the rodent body.

Animals↗
PubMedDate not supplied

The effect of stable strontium on the incorporation and metabolism of radioactive strontium in young and adult rabbit bones.

The experiments were performed on 5-, 8-, 12- and 14 months old rabbits. The effect of stable strontium enriched diet on the bone tissue formation (apposition) and on physiocochemical processes consisting in ion exchange were studied using radioactive isotopes: Sr-85 and Ra-226 and tetracycline. The results of kinetic and autoradiographic studies and micoscopical analysis of bone preparations suggest that stable strontium inhibits the mineralization of newly formed bone tissue without affecting the physico-chemical processes related to ion exchange.

Age Factors↗