U Appl | PubMed Health

PubMed1999

Biological monitoring of exposure to pirimicarb: hydroxypyrimidines in human urine.

Pirimicarb (2-dimethylamino-5,6-dimethylpyrimidin-4-yldimethylcarbamate ) is used as insecticide in agriculture and fruit growing. During its metabolism in mammals the carbamate moiety is hydrolysed and subsequent demethylation at the dimethylaminogroup which is attached to the heterocyclic moiety results in the following major metabolites which are excreted in urine: 2-dimethylamino-5,6-dimethyl-4-hydroxypyrimidine (DDHP), 2-methylamino-5,6-dimethyl-4-hydroxypyrimidine (MDHP), and 2-amino-5,6-dimethyl-4-hydroxypyrimidine (ADHP). These metabolites were detected in every urine sample of seven workers who had applied pirimicarb. Concentrations of the MDHP and ADHP were much higher than that of DDHP indicating a considerable demethylation capacity in humans. No metabolites were found in urine specimens of controls. The investigated pyrimidines represent sensitive and specific parameters for biological monitoring of exposure to pirimicarb.

Carbamates↗

PubMed1999

How smart should pacemakers Be?

The concept of the "smart" pacemaker has been continuously changing during 40 years of progress in technology. When we talk today about smart pacemakers, it means optimal treatment, diagnosis, and follow-up for patients fitting the current indications for pacemakers. So what is smart today becomes accepted as "state of the art" tomorrow. Originally, implantable pacemakers were developed to save lives from prolonged episodes of bradycardia and/or complete heart block. Now, in addition, they improve quality of life via numerous different functions acting under specific conditions, thanks to the introduction of microprocessors. The devices have become smaller, with the miniaturization of the electrical components, without compromising longevity. Nevertheless, there are still some unmatched objectives for these devices, for example, the optimization of cardiac output and the management of atrial arrhythmias in dual-chamber devices. Furthermore, indications continue to evolve, which in turn require new, additional functions. These functions are often very complex, necessitating computerized programming to simplify application. In addition, the follow-up of these devices is time-consuming, as appropriate system performance has to be regularly monitored. A great many of these functions could be automatically performed and documented, thus enabling physicians and paramedical staff to avoid losing time with routine control procedures. In addition, modern pacemakers offer extensive diagnostic functions to help diagnose patient symptoms and pacemaker system problems. Different types of data are available, and their presentation differs from one company to the other. This huge amount of data can only be managed with automatic diagnostic functions. Thus, the smart pacemaker of the near future should offer high flexibility to permit easy programming of available therapies and follow-up, and extensive, easily comprehensible diagnostic functions.

Arrhythmias, Cardiac↗