Desorption of acquired enamel pellicle in vivo by pyrophosphate

Abstract – Soluble pyrophosphate (PP) has been introduced in dentifrices to inhibit the formation of dental calculus. The mechanism of inhibition is probably an adsorption of the pyrophosphate ions to the Ca-sites on the enamel surfaces and a blocking of the active sites for crystal growth. It has been shown in a recently published study that PP reduced the protein adsorption to hydroxyapatite (HA) in vitro and also inhibited the pellicle formation in vivo. The aim of the present study was to examine the desorption potential of pyrophosphate on the acquired enamel pellicle in vivo. Enamel fragments were carried in the mouth to collect pellicle material and some of the enamel surfaces were then treated with PP. Pellicle formation was examined by SEM of the enamel surfaces. The results showed that pyrophosphate desorbed the acquired enamel pellicle effectively. The clinical consequences of this effect is unknown, but it could possibly explain some aspects of hypersensitivity of teeth observed in some individuals using dentifrices containing PP.     

Charcoal Hemoperfusion for Treatment of Serious Carbamazepine poisoning

Abstract A case of severe carbamazepine intoxication (total dose 80 g) is reported. Because of deep coma and cardiovascular symptoms, intensive care and hemoperfusion were employed. The carbamazepine hemoperfusion clearance rate was 80–90 ml/min, but due to a probable ongoing absorption from the gut the effect of hemoperfusion was limited. Long hemoperfusion periods are recommended due to the pharmacokinetic pattern of carbamazepine     

Adverse Pacemaker Hemodynamics Evaluated by Pulmonary Venous Flow Monitoring

The pacemaker syndrome refers to symptoms and signs in the pacemaker patient caused by an inadequate timing of atrial and ventricular contractions. The lack of normal atrioventricular synchrony may result in a decreased cardiac output and venous cannon A waves. The objective of this study was to define the left atrial and pulmonary venous flow response to ventricular pacing in a group of 14 unselected consecutive patients with total heart block and sinus rhythm. Pulmonary venous flow was assessed by transesophageal pulsed Doppier echocardiography in the VVI and ODD pacing modes. An inappropriate atrial timing caused a marked augmentation of the normally small pulmonary venous z wave in all patients ("negative atrial kick" peak z wave in DDD pacing 14.5 ± 4.6 cm/s, VVI pacing 51.8 ± 15.0 cm/s). Restoration of AV synchrony (DDD pacing, AV interval 100 ms) abolished these "cannon z waves" in all patients, and a normal pattern of pulmonary venous flow was achieved. Abnormal pulmonary venous flow characteristics were observed in 2 of 14 patients during DDD pacing with short AV intervals (100 ms). The Doppier pattern was similar to the findings seen in VVI pacing. Assessment of pulmonary venous flow by transesophageal pulsed Doppier echocardiography may provide a simple, sensitive, and relatively noninvasive technique to evaluate patients with suspected pacing induced adverse hemodynamics.