Non-nucleoside reverse transcriptase inhibitor (NNRTI) cross-resistance: implications for preclinical evaluation of novel NNRTIs and clinical genotypic resistance testing.

Objectives: The introduction of two new non-nucleoside reverse transcriptase inhibitors (NNRTIs) in the past 5 years and the identification of novel NNRTI-associated mutations have made it necessary to reassess the extent of phenotypic NNRTI cross-resistance.

Methods: We analysed a dataset containing 1975, 1967, 519 and 187 genotype-phenotype correlations for nevirapine, efavirenz, etravirine and rilpivirine, respectively. We used linear regression to estimate the effects of RT mutations on susceptibility to each of these NNRTIs.

Identification and surface phenotypic characterization of phosphorylcholine-specific idiotype-bearing T cells.

We have employed two-color staining with monoclonal anti-T-cell markers and a broadly reactive, nonbinding site monoclonal anti-idiotype to permit direct visualization of idiotype-bearing T cells in mouse lymph nodes following immunization with phosphorylcholine. Double positive cells peak in incidence on Days 8 to 12, as 17% of total idiotype+ cells but as only 0.7% of T cells.

In situ identification of idiotype-positive cells participating in the immune response to phosphorylcholine.

The phosphorylcholine idiotype (Id)/anti-Id system has been used to study the role of antigen-specific cells in antigen-induced microenvironmental changes. Anti-Id staining of lymph nodes following PC immunization shows the presence of Id on follicular dendritic cells at 12 h and in plasma cells beginning at day 3. Germinal centers began to form at day 3, peaking in size and number at days 8-10.

A seven-month survival of a calf with an artificial heart designed for human use.

A Jarvik-7 type of pneumatic artificial heart, which was specifically designed to fit the anatomy and hemodynamic requirements of human patients, was implanted in a calf in an experiment to test the hemodynamic performance of the artificial heart. The experiment lasted for 221 days, longer than any animal had ever lived without its natural heart, despite the fact that the calf increased its body weight to 171 kg. The calf showed typical signs of low cardiac output before its death, but the direct cause of death was intestinal bleeding.