Dose-dependent effects of adenosine antagonists on tacrine-induced tremulous jaw movements.

The present study examines the effect of three adenosine receptor antagonists on tremulous jaw movements (TJMs), an animal model of tremor. Forty-five rats were pre-treated with one adenosine antagonist: caffeine (0.0, 5.0, or 10.0 mg/kg; non-selective adenosine receptor antagonist), 8-cyclopentyltheophylline (CPT; 0.0, 5.0, or 10.0 mg/kg; selective adenosine A1 receptor antagonist), or SCH 58261 (0.0 or 8.0 mg/kg; selective adenosine A2A receptor antagonist) followed by TJM induction with tacrine (0.0, 0.75, or 2.5 mg/kg; acetylcholinesterase inhibitor). CPT and SCH 58261 both significantly reduced TJMs while caffeine did not. Unexpectedly, both SCH 58261 and CPT reduced TJMs even in the absence of tacrine. Also, CPT showed a robust reduction of TJMs, achieved at both (5.0 mg/kg) and (10.0 mg/kg) doses and regardless of tacrine dose. In conclusion, this study shows adenosine receptor antagonism to generally suppress low-dose tacrine-induced TJMs. In concert with two prior studies, these results are suggestive of behavioral evidence for a biphasic effect of adenosine A2A receptor antagonists (caffeine and SCH 58261) that is modulated by tacrine, and a model of this effect is proposed.

Conformation and dynamics of arylthiol self-assembled monolayers on Au(111).

We report a computational investigation of the conformation and the dynamics of self-assembled monolayers (SAMs) of a set of aromatic thiols arranged in the ( radical3 x radical3)-R30 degrees packing ratio on a Au(111) surface using molecular dynamics (MD) simulations. It was found that the molecular conformations were better defined for the arylthiol with two phenyl groups as compared to those with a single phenyl group and that the chemical structure of the head and tail groups had a considerable influence on the system geometry. In line with the density functional theory (DFT) calculations of small thiol molecules, we found for the SAMs that the face-centered cubic (fcc) site on the Au(111) surface was the most preferred, followed by the hexagonal close-packed (hcp) site, while the bridge position showed the characteristics of a local energy maximum. The dynamics of thiol head groups on these three Au sites was found to govern the overall dynamics of SAMs as measured by the mean square displacement. We also report that both the conformation and the dynamics on the studied time scale were driven by the SAM formation energy.

Combined video-assisted thoracoscopic lung volume reduction surgery and lobectomy in a high-risk patient.

Nonsmall cell lung cancer often occurs in patients with severe emphysema. Lobectomy in these patients is often contraindicated due to extensive parenchymal destruction and subsequent pulmonary insufficiency. Video-assisted thoracoscopic lobectomy has been described as a less morbid procedure in high-risk patients. Lung volume reduction surgery has been shown to improve pulmonary function in selected patients with emphysema. We describe the successful combination of lobectomy and lung volume reduction surgery (LVRS) with a video-assisted thoracoscopic (VATS) approach in a high-risk patient with Stage I nonsmall cell lung cancer.