James Patrick Ryan

Learn More
Colored tensor models have recently burst onto the scene as a promising conceptual and computational tool in the investigation of problems of random geometry in dimension three and higher. We present a snapshot of the cutting edge in this rapidly expanding research field. Colored tensor models have been shown to share many of the properties of their direct(More)
The aim of this study was to determine the functional role of muscarinic receptor subtypes regulating gallbladder cholinergic contractions. Electrical field stimulation (EFS; 16 Hz) produced contractile responses of guinea pig gallbladder muscle strips in vitro that were inhibited by 1 microM tetrodotoxin (2 +/- 2% of control) and 1 microM atropine (1 +/-(More)
UNLABELLED Selective serotonin reuptake inhibitors (SSRIs) are increasingly used to treat a variety of disorders but have gastrointestinal side-effects. AIM To determine the effects of the SSRI, fluoxetine, on gastric smooth muscle contractility. METHODS Fundic, antral, and pyloric circular muscle contractility of guinea pig muscle strips were measured(More)
Botulinum toxin injection into the pylorus is reported to improve gastric emptying in gastroparesis. Classically, botulinum toxin inhibits ACh release from cholinergic nerves in skeletal muscle. The aim of this study was to determine the effects of botulinum toxin on pyloric smooth muscle. Guinea pig pyloric muscle strips were studied in vitro. Botulinum(More)
Experiments were designed to examine the effect of chronic pretreatment with progesterone (2 mg/kg . day for 5 days) on the in vitro contractile response of gallbladder muscle strips from adult male guinea pigs. The muscle strips were challenged with either acetylcholine or the octapeptide of cholecystokinin and dose-response relationships were determined.(More)
Distal colitis decreases the contractility of the underlying circular smooth muscle. We examined how time after injury and lesion severity contribute to the decreased contractility and how colitis alters the calcium-handling properties of the affected muscle. Distal colitis was induced in rats by intrarectal administration of 4% acetic acid. Contractile(More)
1. When yeast oxidizes propan-2-ol in the presence of KCl no uptake of K(+) occurs. 2. When propionate is added to suspensions containing propan-2-ol, or if the suspensions are bubbled with CO(2), a considerable uptake of K(+) occurs. 3. Maximum K(+) uptake occurs at a propionate concentration of 2mm. 4. The addition of 20mm-propionate to the suspension(More)
The C57BLKS/J db/db mouse develops hyperglycemia and has delayed gastric emptying that is improved with tegaserod, a partial 5-HT4 agonist. Our aims here were to determine regional gastric contractility alterations in C57BLKS/J db/db mice and to determine the effects of serotonin and tegaserod. The contractile effects of bethanechol, serotonin, and(More)
BACKGROUND Impaired smooth muscle contractility is important in the pathophysiology of acalculous cholecystitis. Common bile duct ligation (CBDL) is a model of acalculous cholecystitis, producing acute inflammatory changes and decrease in gallbladder smooth muscle contractility. The aim of this study was to determine whether there is coexistent dysfunction(More)