The protease thrombin is an endogenous mediator of hippocampal neuroprotection against ischemia at low concentrations but causes degeneration at high concentrations

The protease thrombin is an endogenous mediator of hippocampal neuroprotection against ischemia at low concentrations but causes degeneration at high concentrations.

We have considered the extracellular serine protease thrombin and its receptor as endogenous mediators of neuronal protection against brain ischemia. Exposure of gerbils to prior mild ischemic insults, here two relatively short-lasting occlusions (2 min) of both common carotid arteries applied at 1-day intervals 2 days before a severe occlusion (6 min), caused a robust ischemic tolerance of hip...

Opposite effect of polyamines on In vitro gene expression: Enhancement at low concentrations but inhibition at high concentrations

BACKGROUND Polyamines have various biological functions including marked effects on the structure and function of genomic DNA molecules. Changes in the higher-order structure of DNA caused by polyamines are expected to be closely related to genetic activity. To clarify this issue, we examined the relationship between gene expression and the higher-order structure of DNA under different polyamin...

Beta-catenin Forms Protein Aggregation at High Concentrations in HEK293TCells

Background: The canonical Wnt signal transduction (or the Wnt/β-catenin pathway) plays a crucial role in the development of animals and in carcinogenesis. Beta-catenin is the central component of this signaling pathway. The activation of Wnt/β-catenin signaling results in the cytoplasmic and nuclear accumulation of β-catenin. In the nucleus, β-catenin interacts with the TCF/LEF transcription fa...

Dual Nanoparticle Amplified SPR Detection of Thrombin at Subattomolar Concentrations

Settling velocity of sediments at high concentrations

New data on the settling velocity of artificial sediments and natural sands at high concentrations are presented. The data are compared with a widely used semiempirical Richardson and Zaki equation (Trans. Inst. Chem. Eng. 32 (1954) 35), which gives an accurate measure of the reduction in velocity as a function of concentration and an experimentally determined empirical power n. Here, a simple ...