Ethylenethiourea in urine as an indicator of exposure to mancozeb in vineyard workers.

In the present study, the personal exposure to mancozeb and/or ethilenethiourea (ETU) in 13 Italian vineyard workers and in 13 subjects without occupational exposure to pesticides was investigated. With this aim, the level of ETU in urine and the dermal exposure to mancozeb were determined. Baseline urinary ETU results were lower than the analytical limit of detection for all controls (<0.5 microg/g creatinine) and for ten workers (median <0.5, range <0.5-3.4 microg/g creatinine). In workers, urinary ETU was significantly increased at the end of shift (2.5, <0.5-95.2 microg/g creatinine) compared with baseline levels. End-shift urinary ETU was higher in operators using open tractors (n=7) than in those using closed tractors (n=5) (16.2 vs. 2.4 microg/g creatinine), but the difference was not significant (P=0.073). End-shift urinary ETU was positively correlated with dermal exposure to mancozeb determined both over the clothes and on the skin (Spearman's rho=0.770 and 0.702, P=0.009 and 0.024, respectively). Wine consumption positively influenced the excretion of ETU.

The new antiepileptic drugs: pharmacological and clinical aspects.

In recent years several new drugs (oxcarbazepine, lamotrigine, topiramate, gabapentin, zonisamide, tiagabine, fosphenytoin, vigabatrin and felbamate) have been added to the therapeutic armamentarium against epilepsy. Some of these represent structural modifications of pre-existing compounds, others were developed with the specific objective of modifying neurotransmitter function, and many more were found to be clinically useful even though their mode of action is unclear or differs from that originally planned. The pharmacokinetics of these drugs differ widely from one agent to another. Some (gabapentin and vigabatrin) are eliminated unchanged in urine and have little or no interaction potential; others (tiagabine, lamotrigine, topiramate, oxcarbazepine, zonisamide, felbamate) are subject to induction of metabolism by concomitant anticonvulsants; lamotrigine is vulnerable to metabolic inhibition by valproate, and felbamate is a powerful enzyme inhibitor in addition to being an inducer of the metabolism of carbamazepine and steroid oral contraceptives. All new antiepileptic drugs have been found to be effective in improving seizure control in patients with partial and secondarily generalized seizures. However, lamotrigine, topiramate, zonisamide and felbamate appear to have broader efficacy against both partial and many generalized seizure types, while vigabatrin is also valuable in the management of infantile spasms. In monotherapy studies, new drugs have not been found to be more efficacious than older agents, but some may offer limited advantages in terms of improved tolerability. On the other hand, serious toxicity restricts considerably the use of vigabatrin and felbamate. Overall, new drugs represent valuable tools in the fight against epilepsy, but because of limited experience and cost considerations their first-line use cannot be recommended in most situations.

Nitrite and Nitrate Plasma Levels, as Markers for Nitric Oxide Synthesis, in Thrombotic Thrombocytopenic Purpura (TTP).

The enhanced platelet aggregation and thrombosis occurring in TTP is probably due to an unbalance between agents insulting endothelial integrity and natural antithrombotic factors, such as NO. Using a sensitive and specific HPLC assay, we tested the hypothesis of NO involvement in TTP, comparing NO production, as the stable end-products nitrites and nitrates, in the plasma of 29 TTP patients and of 29 healthy subjects matched for sex and age. Average nitrate titer was 25.868 µM/L in the TTP group vs 24.234 µM/L in the control group (p = n.s.), while nitrite were undetectable in both groups. Moreover, nitrate titers did not correlate with hemoglobin value, platelet count, LDH values, or with Rose and Eldor's severity score. In conclusion, even though the enhanced platelet aggregation observed in TTP could be due to reduced natural antithrombotic substances, NO involvement in the pathogenesis of TTP appears unlikely.

Effect of pindolol on intraocular pressure.

Pindolol, a strong beta-adrenergic blocking agent, instilled into the conjunctival sac of normal and glaucomatous eyes, produced a significant drop in intraocular pressure. This was not, at first, accompanied by any variation in outflow facility; only after prolonged treatment did an increase in facility appear, which accounted only for one-third of the tension-lowering effect. The drug was well tolerated, and did not affect either pupil motility or corneal sensitivity. It seems suitable for a trial use in the treatment of glaucoma.