Search PubMed⌕ Search

Biomedical subjects

S Giorgio

Publications and source records attributed to S Giorgio.

4 recordsLinked to original sources
PubMed1992

Inhibition of mouse lymphocyte proliferative response by glycosphingolipids from Leishmania (L.) amazonensis.

The effect of a purified preparation of glycosphingolipids (GSLs) extracted from Leishmania (L.) amazonensis amastigotes on murine lymphocytes was investigated. GSLs inhibited both concanavalin A (Con A)- or lipopolysaccharide-induced [3H]thymidine uptake by normal and immunized BALB/c mouse lymph node cells. The effect of total GSLs was dose dependent. Total GSLs also suppressed the two-way mixed lymphocyte reaction of BALB/c x C57BL/6 cells and the antigen-specific response of immunized mouse cells. Six pure bands as well as a pool containing a mixture of GSLs with five to seven sugar residues separated by a combination of HPLC and preparative HPTLC were tested and shown to be inhibitors of Con A stimulation. These results suggest that parasite glycosphingolipids may play an immunologically relevant role in leishmaniasis.

Animals↗
PubMed1990

Identification of T-cell reactive antigens in Nippostrongylus brasiliensis using a cell immunoblotting technique.

Antigens of the nematode Nippostrongylus brasiliensis were fractionated by SDS-PAGE under reducing conditions, transferred electrophoretically onto nitrocellulose and converted to antigen-bound nitrocellulose particles for use in in vitro proliferation assays. Mesenteric lymph node cells from infected rats were analyzed for reactivity against the fractionated antigens, revealing a range of different molecular weight antigens. In addition, when supernatants from these cultures were assayed for IL3, further reactive antigens were detected. The results demonstrated that these approaches are useful for the identification of T-cell reactive components of a complex mixture of parasite antigens in helminth infections, where the cellular nature of protection is not well defined.

Animals↗
PubMed1986

Number of chromosomes, Feulgen-DNA content, and nuclear phenotypes in domestic and wild specimens of Panstrongylus megistus.

Specimens of Panstrongylus megistus with different levels of adaptation to a domestic way of life had some of their nuclear and chromosomal characteristics compared, in an attempt to differentiate them by cytological means. The number of chromosomes in male testes was found not to differ. The nuclear frequency and phenotypes of the Malpighian tubules were also found to be the same. On the other hand, Feulgen-DNA values of metaphase chromosomes in insects from a population with a sylvatic distribution were found to be larger than those in specimens from a domestic population. The differences in Feulgen-DNA values, however, may not represent real differences in DNA content, but may possibly be due to differences in DNA-protein complexes.

Analysis of Variance↗