Molecular interpretation of ERK signal duration by immediate early gene products.

The duration of intracellular signalling is associated with distinct biological responses, but how cells interpret differences in signal duration are unknown. We show that the immediate early gene product c-Fos functions as a sensor for ERK1 (extracellular-signal-regulated kinase 1) and ERK2 signal duration. When ERK activation is transient, its activity declines before the c-Fos protein accumulates, and under these conditions c-Fos is unstable. However, when ERK signalling is sustained, c-Fos is phosphorylated by still-active ERK and RSK (90K-ribosomal S6 kinase). Carboxy-terminal phosphorylation stabilizes c-Fos and primes additional phosphorylation by exposing a docking site for ERK, termed the FXFP (DEF) domain. Mutating the DEF domain disrupts the c-Fos sensor and c-Fos-mediated signalling. Other immediate early gene products that control cell cycle progression, neuronal differentiation and circadium rhythms also contain putative DEF domains, indicating that multiple sensors exist for sustained ERK signalling. Together, our data identify a general mechanism by which cells can interpret differences in ERK activation kinetics.

Immunologically mediated dementias.

Although most dementias are due to neurodegenerative or vascular disease, it is important to diagnose immunologically mediated dementias quickly because they can be both rapidly progressive and readily treatable. They usually affect function of limbic and cortical structures, but subcortical involvement can also occur. Because of the variety of symptoms and the rapid course, these dementias present a particular challenge to the clinician and may require evaluation and intervention in the inpatient setting. Diagnostic workup typically reveals evidence of an autoimmune process and, in some cases, cancer. In contrast to the neurodegenerative processes, many of the immunologically mediated dementias respond to immunomodulatory therapy.

Biofield perception: a series of pilot studies with cultured human cells.

BACKGROUND: Energy medicine (EM) practitioners often claim to be able to perceive an energetic field associated with the body and to be able to use this skill to diagnose illness and guide treatment strategies. If a biofield associated with cells growing in culture is perceptible to EM practitioners, such an in vitro model would be a useful resource for investigating biofield perception that would provide some unique advantages over clinical models. OBJECTIVE: To evaluate whether EM practitioners can perceive the presence of cultured human cells without visual cues. DESIGN: Three randomized double-blinded pilot studies were used to evaluate the ability of participants to distinguish a flask containing cancer cells growing in culture medium from a flask containing either culture medium or sterile water. Each study consisted of six independent experiments: three with EM practitioners and three with non-practitioners. The number of independent trials for each experiment was estimated by statistical power analyses of the design. Practitioners' feedback from the first two studies was used to revise the protocol for the subsequent studies, with the intent to eliminate potential problems in making this distinction. Labeled flasks ("cells" and "no-cells") were added to serve as references for comparison in the second study and the number of experimental trials was reduced in the third study. SUBJECTS: Eight experienced EM practitioners and nine non-practitioners (laboratory personnel with no EM training). SETTING: A basic science laboratory and office at an academic medical center. OUTCOME MEASURES: In the first 2 studies, we determined the number of correct determinations in a series of 34 trials. In the third study, we determined the number of correct determinations in a series of 10 trials. RESULTS: All participants performed at the level expected by chance. CONCLUSION: While preliminary and inconclusive, these pilot studies found no evidence that EM practitioners can perceive a biofield associated with cancer cells growing in culture.

Gold nanoparticle-mediated transfection of mammalian cells.

Mixed monolayer protected gold clusters (MMPCs) functionalized with quaternary ammonium chains efficiently transfect mammalian cell cultures, as determined through beta-galactosidase transfer and activity. The success of these transfection assemblies depended on several variables, including the ratio of DNA to nanoparticle during the incubation period, the number of charged substituents in the monolayer core, and the hydrophobic packing surrounding these amines. Complexes of MMPCs and plasmid DNA formed at w/w ratios of 30 were most effective in promoting transfection of 293T cells in the presence of 10% serum and 100 microM chloroquine. The most efficient nanoparticle studied (MMPC 7) was approximately 8-fold more effective than 60 kDa polyethylenimine, a widely used transfection agent.