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Biomedical subjects

M Naito-Hoopes

Publications and source records attributed to M Naito-Hoopes.

3 recordsLinked to original sources

Increased usage of V beta 2 and V beta 6 in rheumatoid synovial fluid T cells.

OBJECTIVE: To determine if the T cell antigen receptor V beta usage of unstimulated rheumatoid arthritis (RA) synovial fluid (SF) T cells is biased compared with those in peripheral blood (PB). METHODS: Freshly isolated, matched synovial fluid and peripheral blood T cells were analyzed for V beta gene expression using quantitative polymerase chain reaction (PCR) methods. Ten synovial fluid samples from the knees of 7 patients with RA were studied. The PCR assay used 26 V beta primers with a constant region C beta primer, and 2 C alpha primers that co-amplified a product that served as an internal standard. Cycle number and complementary DNA content were controlled to ensure the linear accumulation of PCR products. Labeled products were separated on 10% polyacrylamide gels and counted with a Betascope blot analyzer. RESULTS: There were consistent differences between the V beta gene usage of SF and PB T cells directly isolated from patients with RA, regardless of HLA-DR haplotype. In all synovial specimens, V beta 2 was increased relative to the peripheral blood, while V beta 13.1 and V beta 13.2 were decreased. V beta 6 and V beta 21 were increased in 9 of the 10 synovial samples. Analyses of bilateral SF specimens from 2 subjects and serial specimens from the same knee of 1 subject revealed virtually identical patterns in each patient. The SF V beta bias was not solely due to differences in the proportion of CD4+ and CD8+ cells, because the CD4:CD8 ratios in SF and PB were similar. However, V beta gene usage of separated CD4+ and CD8+ synovial T cells showed that V beta 2 and V beta 6 were more highly expressed on CD4 cells. CONCLUSION: Freshly isolated synovial T cells from inflamed (not end-stage) knees of patients with RA have a remarkably consistent biased V beta gene usage compared with PB T cells. V beta 2 and V beta 6 are uniformly increased, and this increase is primarily in CD4+ T cells. The same V beta bias in the SF T cells of several RA patients suggests that shared antigens may be stimulating the T cell response.

Adult↗

Learned preference and aversion for complete and isoleucine-devoid diets in rats.

Choice tests using flavored solutions were conducted to demonstrate a learned preference or aversion in rats fed replete (complete) or isoleucine (ILE)-devoid diets. In the first learning trial, rats demonstrated a preference for the flavored solutions paired with the replete diet at 6 and 24 h (p < 0.001), and an aversion for the solutions paired with the ILE-devoid diet at 6 h (p < 0.05). In the second trial, using a different concentration of tastant, rats ingested significantly more of the flavored solution paired with the replete diet at 24 h (11.4 +/- 3.0 g vs. 5.4 +/- 1.0 g, respectively; p < 0.05), and significantly more of a novel flavored solution than of the solution paired with the ILE-devoid diet at 24 h (12.4 +/- 2.4 g vs. 1.7 +/- 0.6 g, respectively; p < 0.001). These results suggest that learning contributes to the rat's ability to self-select diets that promote growth, and that a learning paradigm pairing flavored solutions with complete and indispensible amino acid-devoid diets may be used to demonstrate learned preferences and aversions for such diets in rats.

Animals↗