Biomedical subjects

Charles Stout

Publications and source records attributed to Charles Stout.

3 recordsLinked to original sources

PubMed2005

A novel mouse model for segmental orthotopic colon cancer.

Spontaneous colon tumor mouse strains offer numerous advantages in modeling disease. However, the wide temporal window in which lesions form and the stochastic nature of lesion location require larger cohorts for assessment of disease modulation. Reliable, reproducible and inexpensive mouse models of early-stage and invasive cancer would add to existing transgenic models. We show a new method for the creation of orthotopic murine tumors centered in the mucosal and submucosal layers anywhere in the colon, allowing creation of lesions of known age, location and extent. The system overcomes the disadvantages of heterotopic implantation and allows evaluation of lesions distally in the colon as well as proximally, thereby providing an additional method to study the effects of regionality. Invasion, host vascularization and application to disparate cell lines are demonstrated. Noninvasive imaging with magnetic resonance and colonoscopy, allowed in part by the tumor location, show potential applications of this approach.

Animals↗

PubMed2004

Connexins: functions without junctions.

Emerging studies indicate that connexins have activities completely unrelated to gap junctions and, conversely, that non-connexin proteins can form gap junction channels.

Bacteria↗

PubMed2003

Modulation of intercellular calcium signaling in astrocytes by extracellular calcium and magnesium.

The extracellular concentrations of Ca(2+) and Mg(2+) are well known to play important roles in the function of the central nervous system. We examined the effects of extracellular Ca(2+) and Mg(2+) on ATP release and intercellular signaling in astrocytes. The extent of propagation of intercellular Ca(2+) waves evoked by mechanical stimulation was increased by reduction of extracellular Ca(2+) ([Ca(2+)](o)) or Mg(2+) concentration ([Mg(2+)](o)) and was decreased by elevated [Mg(2+)](o). Reduction of extracellular Ca(2+) concentration ([Ca(2+)](o)) evokes intercellular Ca(2+) signaling in astrocytes; a similar effect was observed in response to change from 5 mM [Mg(2+)](o) to 0 [Mg(2+)](o). Release of low-molecular-weight dyes and ATP was also activated by low [Ca(2+)](o) or [Mg(2+)](o) and inhibited by high [Ca(2+)](o) or [Mg(2+)](o). Astrocytes showed low [Ca(2+)](o)-activated whole cell currents consistent with currents through connexin hemichannels. These currents were inhibited by extracellular Mg(2+). We conclude that extracellular divalent cations modulate intercellular Ca(2+) signaling in astrocytes by modulating the release of ATP, possibly via connexin hemichannels.

Adenosine Triphosphate↗