PubMed Health⌕ Search

Biomedical subjects

I Szymanska

Publications and source records attributed to I Szymanska.

15 recordsLinked to original sources
PubMed2000

Polymeric liquid membrane electrodes incorporated with macrocyclic hexaamines for screening adenine nucleotides.

Lipophilic macrocyclic hexaamines supported by a poly(vinyl chloride) PVC matrix were used for the construction of liquid membrane electrodes sensitive toward adenine nucleotide polyanions. The membrane potential strongly depended on the pH of the sample solution. This phenomenon occurs due to the ability of the ionophore to accept protons. Therefore, the optimum pH was determined based on potential pH profile. The potential measurements were carried out at pH 6.0 in the presence of 10(-2) M 2-[N-morpholino] ethanesulfonic acid (MES) buffer. The potential response of these electrodes toward ATP(-4) and/or HATP(-3) was close to the Nernstian slope. The selectivities against ADP(-3), AMP(-2), HPO(4)(-2), and monovalent inorganic anions were estimated using the matched potential method. Chloride ions slightly affected potential response of the electrodes toward ATP(-4)/HATP(-3). The influence of ionophore chemical structure on the selectivity and the sensitivity of these electrodes is briefly discussed.

Adenine Nucleotides↗
PubMed1983

The passive transfer of severe allergic neuritis in Lewis rats with lymphoid cells preincubated with P2 protein.

The passive transfer of both clinical signs and histologic lesions characteristic of allergic neuritis was successfully performed in Lewis rats using pooled spleen and lymph node cells, or T lymphocytes therefrom, if first preincubated in petri dishes with P2 protein for 72 hr. For passive transfer, cells were taken from donors 8-16 days after sensitization with P2 protein or myelin in Freund's complete adjuvant, and administered via the tail vein; clinical signs appeared 12-13 days later. This study supports the importance of cell-mediated immunity in EAN and the antigenic role of the P2 protein.

Animals↗
PubMed1982

Induction of allergic neuritis in rhesus monkeys.

Experimental allergic neuritis (EAN) was induced in rhesus monkey (Macaca mulatta) following sensitization with rabbit nerve (PNS) myelin in complete Freund's adjuvant (CFA) or with bovine P2 protein complexed with phosphatidyl serine (P2-lipid) in CFA. The response of monkeys receiving PNS myelin in CFA differed from the previous studies where monkeys developed clinical signs of fatal EAN within 15-20 days following sensitization. The monkeys in this study (6) showed a much longer delay (40-114 days) before the appearance of severe clinical signs, and 4 of the 6 animals survived without further attack (1 year). Monkeys (4) injected with P2-lipid (2:1 ratio; w/w) developed severe clinical signs of EAN which was fetal in 3 cases. Peripheral lymphocytes from monkeys sensitized to the P2-lipid showed a much stronger mitogeneic response to P2 protein than those from the PNS myelin-sensitized monkeys. on quantitation of the circulating anti-P2 antibodies, the P2-sensitized monkeys generally had much titers than those sensitized with PNS myelin.

Animals↗
PubMed1981

Allergic neuritis: phospholipid requirement for the disease-inducing conformation of the P2 protein.

The P2 protein, a small, highly ordered basic protein of peripheral nerve myelin, is a potent inducer of allergic neuritis in rats when complexed with phospholipids such as phosphatidylserine. Isolated P2 protein administered without lipid is a poor neuritogen, and if first oxidized with performic acid, aminoethylated in 8 M urea or heat denatured, it loses nearly all activity. When the aminoethylated or oxidized forms are combined with phosphatidylserine, however, they recover essentially full neuritogenic activity. Complexing with lipid also greatly enhances the activity of the heart denatured form. Spleen cells sensitized to the aminoethylated and heated forms of P2 protein show a pronounced mitogenic response to either of these forms as well as to the P2 protein itself, but only when sensitization is initiated with the lipid complex. These data indicate that the lipid complex reverses the distortion acquired by chemical treatment or denaturation and converts the P2 molecule into a conformation approximating that of the native P2 protein in myelin. These studies imply that the neuritogenic domain, while highly sensitive to denaturing conditions, requires interaction with phospholipids in order to attain the most favourable conformation for inducing a cell-mediated response that leads to disease.

Animals↗
PubMed1981

Relative expression of light-chain allotypic specificities on the surface of rabbit lymphocytes as a function of age.

Lymphoid cells of heterozygous Ab4/Ab9 rabbits of various ages were stained with fluorescent anti-allotype antibodies. In foetal and newborn rabbits, the percentage of Ab-positive cells in low; it increases with age, reaching the adult value when the animals are 100 days old. The rate of increase in the percentage of Ab4-positive cells is higher than in that of Ab9-positive cells. Thus, the Ab4/Ab9 ratio, which is initially 1, increases with age and reaches 2.2. in spleen and 4 in appendix of young adult animals. We conclude that the change in Ab4/Ab9 ratio is due to differential clonal expansion which we attribute to charge-related differences in the ability of Ab4 and Ab9 receptor-bearing cells to capture antigen when environmental antigens are encountered in postnatal life.

Aging↗
PubMed1981

Allergic neuritis: a neuritogenic peptide from the P2 protein that induces disease in rats.

Peptide CN1, a large 93 residue peptide, derived from residues 21-113 of the bovine and rabbit P2 protein of sciatic nerve myelin, induces severe allergic neuritis in Lewis rats. When complexed with phosphatidylserine and tested at 50 microgram dosage in Freund's complete adjuvant, it induces severe clinical and histologic signs (cellular infiltration and demyelination of the sciatic nerve) in most animals. It is as potent in disease induction as the P2 protein on a weight basis. In contrast, when not complexed with phosphatidylserine, Peptide CN1 induced only mild clinical signs and histologic lesions in 3 of 10 rats. CNBr peptides CN2 and CN3, derived from the carboxyl and amino terminal ends, respectively, were not active. Spleen and lymph node cells from rats sensitized to Peptide CN1 responded to both P2 and Peptide CN1 in culture in the mitogenic assay. These data show that the major neuritogenic domain for the rat resides in the CN1 region.

Animals↗
PubMed1980

The PO glycoprotein of peripheral nerve myelin.

The PO glycoprotein, the major protein of peripheral nerve myelin, is a hydrophobic glycoprotein which can be isolated in soluble and insoluble forms from rabbit sciatic nerve myelin following extensive defatting and mid acidic extraction. The PO glycoprotein was localized exclusively in peripheral nervous system (PNS) myelin of sciatic nerve and rootlets by the immunofluorescent technique using goat anti-PO serum which showed a single precipitin band in double diffusion and did not cross-react with the myelin basic protein or P2 protein. Central nervous system (CNS) myelin from brain and spinal cord was negative by the immunofluorescent procedure. The major glycoprotein bands in PNS myelin, in addition to the PO glycoprotein at 28K, exist at 23K and 19K, as shown by gel electrophoresis in dodecyl sulfate. These glycoproteins, isolated by gel filtration in 2% dodecyl sulfate, show identity to the PO glycoprotein in their monosaccharide profile and overlapping tryptic peptides on peptide mapping. We conclude that both the 23K and 19K glycoproteins are derived from the PO glycoprotein by in situ proteolysis; the 23K glycoprotein has the identical amino terminal sequence. The 19K glycoprotein, beginning with amino-terminal methionine, is identical with the TPO glycoprotein, shown previously to originate from tryptic hydrolysis of the PO glycoprotein in isolated myelin. A tryptic glycopeptide containing 27 amino acids was isolated from the PO glycoprotein and sequenced. It contained a relatively high proportion of aspartic acid (four residues) and glutamic acid (two residues), thus exhibiting a high negative charge. We conclude that the total carbohydrate of the PO, 23K, and 19K glycoproteins does indeed exist as a single nonasaccharide moiety linked through N-acetylglucosamine to Asp-14 of the glycopeptide in a N-glycosidic linkage. These results further support the role of the PO glycoprotein as a typical amphipathic membrane protein.

Amino Acid Sequence↗
PubMed1980

Surface immunoglobulin receptors of rabbit lymphoid cells. Evaluation of fluorescent staining with antibodies to immunoglobulin light chain allotypes.

Rabbit lymphoid cells were stained with fluorescein-labelled antiallotype antibodies. The double layer technique was found to be more sensitive than the direct staining. Rabbit B cells are stained only via their surface immunoglobulin (sIg) receptors and not via the receptors for the Fc portion of the IgG. Peritoneal exudate macrophages do not carry sIg receptors and are stained via their Fc receptors. Removal of protein aggregates from the system and use of reagents prepared from F(ab')2 immunoglobulin fragments prevent staining of the macrophages through their Fc receptors. There was a good agreement between the percent of RABELA-positive and sIg-containing spleen cells. In appendix there were approximately 20% more RABELA-positive than sIg-positive cells.

Animals↗
PubMed1980

Proportions of T- and B-lymphocytes in preauricular lymph nodes and aqueous humour of rabbits showing corneal graft reactions.

We wished to determine the proportions of T- and B-lymphocytes in the preauricular lymph nodes and the anterior chambers of rabbits during various stages of graft reactions. The animals received unilateral orthotopic corneal xenografts or skin allografts on the ear. The target cells were identified with the use of fluorescein-tagged antisera specific for rabbit T- and B-lymphocytes. As compared with the percentage in the rabbits that had not received a graft, in both the xenograft and the allograft recipients the percentage of T-lymphocytes in the preauricular lymph nodes during the graft reaction did not change on the side that received the graft but was higher on the side that did not receive a graft. In the recipients of the corneal grafts, as the severity of the graft reaction increased, the percentage of B-lymphocytes in the preauricular lymph nodes on the side that received the graft and the percentage of T-lymphocytes in the lymphoid cell population infiltrating the anterior chamber of the grafted eye increased. The possible mechanisms underlying these phenomena are discussed.

Animals↗
PubMed1979

Immunoglobulin synthesis by thymus B cells.

Rabbit lymphoid cells transferred to newborn recipients synthesized donor-type immunoglobulin. Elimination of donor T cells did not affect this synthesis of donor immunoglobulin, while elimination of B cells abolished or significantly decreased the synthesis. The synthetic capacity of B cells from thymus was thirty-four times greater than the synthetic capacities of B cells from spleen, fifty-five times greater than that of mesenteric lymph nodes and 180 times greater than that of appendix cells. Synthetic activity of spleen cells ceased before the tenth day after transfer, while thymus cells might continue to synthesize immunoglobulin for a longer time. This was shown by comparing half-lives of donor immunoglobulin in the recipients' sera. Increasing the number of injected spleen cells (from 2 x 10(6) to 120 x 10(6)), resulted in a corresponding increase in donor Ig synthesis. With thymus cells, donor immunoglobulin increased with cell numbers up to 2 x 10(7) cells, above this dose there was no further donor immunoglobulin increase in the recipients' serum.

Animals↗