Action of gastrointestinal hormones on the myoelectric activity of the sphincter of Oddi in living rabbit.

The aim of this work was to compare the action of gastrointestinal (GI) hormones on the myoelectrical activity of the sphincter of Oddi. Using an experimental design previously described, we studied the electrical activity of the sphincter of Oddi and compared the percentage variation in the number of spikes before and after injection of hormones. Increasing doses of the following hormones were injected i.v. at random: CCK, OP-CCK, caerulein, bombesin, gastrin, secretin and glucagon. CCK and caerulein (as previously found), and also bombesin, OP-CCK and gastrin increased the spikes activity of the sphincter of Oddi. Secretin had no effect and glucagon decreased this activity. There was no tachyphylaxis, but a good dose-effect relationship for each hormone. Compared on a molar basis caerulein is 8 times more effective than CCK and OP-CCK which in turn are more potent than bombesin. Gastrin acts only at pharmacological doses.

Fingerprint of polycyclic aromatic hydrocarbons in two populations of southern sea lions (Otaria flavescens).

The fingerprint of 14 polycyclic aromatic hydrocarbons (PAHs) was investigated in biopsy, fur, blood, liver and faeces of live and dead specimens of two Argentinian population of southern sea lion (Otaria flavescens). One colony lives in Mar del Plata harbour which is particularly polluted with petroleum, the second (control) colony lives at Punta Bermeja (Patagonia). The highest concentrations of the five carcinogenic PAHs were found in the Mar del Plata sea lions.

Skin biopsy as a nondestructive tool for the toxicological assessment of endangered populations of pinnipeds: preliminary results on mixed function oxidase in Otaria flavescens.

The aim of this study was to develop and validate a method for assessing the toxicological risk of endangered populations of pinnipeds based on a nondestructive biological tool, the skin biopsy specimen. Skin biopsies can be obtained from pinnipeds by anaesthetising the animals and taking a small amount of skin in the anterior flipper area, or by shooting a biopsy dart with a crossbow. Skin biopsy material is suitable for a wide range of chemical and biomarker analysis. Organochlorines and polycyclic aromatic hydrocarbons can be analysed in subcutaneous fat and MFO activity (BPMO), Cyt.P450 isoforms, and DNA damage can be detected in epidermis.

Lung and myocardial thallium-201 kinetics in resting patients with congestive heart failure: correlation with pulmonary capillary wedge pressure.

Increased lung thallium-201 activity occurs with exercise in patients with severe coronary artery disease as a result of increased pulmonary capillary wedge pressure. No study has shown resting lung kinetics in chronic congestive heart failure. To better understand the relationship between lung and myocardial thallium uptake and pulmonary capillary wedge pressure, this study was performed. Resting lung and myocardial thallium uptake, expressed as a ratio, were compared with simultaneous pulmonary capillary wedge pressure in 16 patients with congestive heart failure and cardiomyopathy, all New York Heart Association class IV. There were no variations in pulmonary capillary wedge pressure throughout the study protocol. There was a significant reduction in the lung/myocardium thallium ratio from 10 to 60 minutes (0.83 +/- 0.30 to 0.59 +/- 0.17; p less than 0.001). At 60 minutes after thallium injection there was a linear correlation between the lung/myocardium ratio and capillary wedge pressure with an r value of 0.62 (p less than 0.01). Thus thallium-201 washout is rapid despite persistence of pulmonary capillary wedge pressure elevation, indicating that clearance does not imply resolution of congestive heart failure. In addition, a significant but imprecise correlation was found between capillary pressure and the lung/myocardium ratio. Rapid changes in lung activity during the early postinjection period may limit the clinical use of the lung/myocardium ratio.