Partial status epilepticus after electroconvulsive therapy and medical treatment with bupropion.

Electroconvulsive therapy (ECT) is the most effective treatment for therapy-refractory depression. Usually, prior antidepressant medication will be continued during ECT. However, the seizure threshold may be influenced by psychotropic drugs. We report a patient who received right unilateral ECT under concomitant treatment with bupropion, a selective noradrenaline- and dopamine-reuptake inhibitor. After the fourth session, a focal status epilepticus occurred, which was pharmacoresistant for the duration of 12 days. We assume that the induction of a status may be facilitated by a lowering of the seizure threshold due to bupropion. An evaluation of drug therapy and control of EEG before and during ECT are recommended, especially when the drug treatment has an influence on the seizure threshold.

Clearance of melatonin and 6-sulfatoxymelatonin by hemodialysis in patients with end-stage renal disease.

Patients with end-stage renal disease (ESRD) suffer from a number of related disorders. These include endocrine abnormalities, sleep disturbances, and depression. Melatonin is involved in the synchronization of exogenous zeitgebers with the endogenous rhythms, and it has effects on various psychological factors. As the concentrations of melatonin and the effects of dialysis have only occasionally been investigated in ESRD, we performed a study involving 35 patients, measuring the serum concentrations of melatonin, and of its major metabolite 6-sulfatoxymelatonin (aMT6s), before and after hemodialysis. Serum samples taken during morning hours from a control group (n=11) with intact kidneys served as controls. Patients were dialyzed for approximately 4 hr between 07:00 and 13:00 hr (S1), between 13:00 and 20:00 hr (S2), or between 18:30 and 22:30 hr (S3). Mean melatonin concentrations before hemodialysis were highly elevated when compared with the controls (40.6 vs. 6.7 pg/mL; P<0.001). Although melatonin levels were decreased to 20.3 pg/mL after dialysis, they were still well above the control levels. Likewise, aMT6s concentrations before dialysis were highly elevated in ESRD patients before dialysis when compared with controls (39.5 vs. 2.0 pg/mL; P<0.001), and also decreased by dialysis to levels still well above control levels (25.3 pg/mL). Clearance efficacy was better for melatonin (48.9%) than for aMT6s (36.6%; P<0.05). In ESRD patients, a diurnal rhythm for melatonin was observed (S1, 45.1 pg/mL; S2, 31.5 pg/mL; S3, 48.7 pg/mL; P<0.05), indicating that the normal synthesis rhythm is maintained. None of the following secondary disorders were correlated with melatonin concentrations: insomnia, delayed sleep onset, night-time arousals, and restless-leg syndrome. The reason for this observation is probably the melatonin concentrations, which were so high that no sub-classification could be identified. It is concluded that in ESRD patients, hemodialysis is unable to decrease elevated levels of melatonin and aMT6s to normal values. It is speculated that some of the secondary disorders in ESRD are caused by supraphysiological concentrations of melatonin.

Enhancement of third harmonic generation in metal-dielectric waveguides.

An optical waveguide has been used to improve the third harmonic conversion of CO(2) TEA laser pulses in CO gas. The theoretical waveguide third harmonic conversion efficiency is calculated and compared with the calculated confocal third harmonic conversion efficiency. The experimentally measured waveguide and optimum confocal conversion efficiencies are also compared.