[An epidemic of epileptic seizures after consumption of herbal tea]. / Een epidemie van epileptische aanvallen na drinken van kruidenthee.

UNLABELLED: At the end of September 2001 the Inspectorate for Health Protection and Veterinary Public Health and the National Poisons Control Centre (NPCC) were informed about adverse health effects after consumption of a herbal tea. During consultations it was suggested that Japanese star anise (Illicium anisatum L.), which is known to contain a neurotoxin, may have been inadvertently mixed into the herbal tea. In view of the severity of the adverse health effects and the clear association with consumption of a specific herbal tea, the supplier was urgently advised to withdraw the suspected herbal tea from the market. A total of 63 persons reported symptoms of general malaise, nausea and vomiting 2-4 hours following consumption of the herbal tea. Twenty-two persons required hospitalisation, of whom 16 due to generalised tonic-clonic seizures. Medical investigations revealed no underlying pathology and after supportive treatment, the patients were discharged in good health. Morphologic and organoleptic investigations of the suspected herbal tea indicated that this possibly contained Japanese star anise. NMR analysis of the herbal tea confirmed the presence of the neurotoxin anisatin, a non-competitive GABA-antagonist which can cause hyperactivity of the central nervous system and tonic-clonic seizures. CONCLUSION: Ingestion of a herbal tea containing anisatin caused the reported serious adverse health effects. Close cooperation between clinicians, the Inspectorate for Health Protection and Veterinary Public Health and the NPCC played a vital role in preventing further harm to public health.

Plasma oxysterols and angiographically determined coronary atherosclerosis: a case control study.

Several in vitro and in vivo experiments have implicated oxysterols in the aetiology and progression of atherosclerosis. Oxysterols may be formed endogenously by oxidation of cholesterol and thus may form a marker of LDL oxidation. They may also be obtained exogenously through dietary intake. We investigated the association of oxysterols with the degree of coronary stenosis in patients undergoing coronary angiography. Cases with severe coronary atherosclerosis 80 stenosis in one of the major coronary vessels, n =80 were compared with controls with no or minor stenosis 50 stenosis in all three major coronary vessels, n =79 . Cases and controls were prestratified on age, gender and smoking habits. Evaluated were plasma levels of unesterified 7 hydroxycholesterol, 7 hydroxycholesterol, 25 hydroxycholesterol, 7 ketocholesterol, cholestane triol and 5,6 epoxycholestanol. 7 Hydroxycholesterol made up 67 of the total amount of plasma oxysterol concentration and was the only one significantly higher in cases 1.53 mu g per 100 ml vs 1.27 mu g per 100 ml, p 0.05 . Further, cases had somewhat higher LDL cholesterol levels and significantly lower HDL cholesterol levels than controls. After multivariate adjustment to account for this difference in lipid levels and for the prestratification factors the mean difference between cases and controls for 7 hydroxycholesterol 0.14 mu g per 100 ml was no longer significant. Also the other oxysterols showed no significant association with the degree of coronary stenosis. Multiple logistic regression analyses showed an adjusted odds ratio of 1.07 95 CI, 0.45-2.59 in the highest tertile of total plasma oxysterol level. We conclude, that this study does not support the hypothesis that plasma oxysterols form an additional risk factor for coronary atherosclerosis.

Methylation in vivo of elongation factor EF-Tu at lysine-56 decreases the rate of tRNA-dependent GTP hydrolysis.

In this paper we show, that the in vivo methylation of the elongation factor Tu from Escherichia coli is correlated with the growth phase of the bacterium. Methylation occurs at one position only, i.e. Lys-56, and initially results in monomethylation during logarithmic growth. Upon entering the stationary phase of E. coli, monomethyllysine is gradually converted into dimethyllysine. We have undertaken an extensive comparison between the properties of the highly methylated EF-Tu and unmodified EF-Tu. No gross conformational differences, as measured by the rate of mild tryptic cleavage, were observed. The dissociation rates of the nucleotides GDP and GTP appear likewise to be unaffected by the methylation, just as is the stimulatory effect of the elongation factor Ts upon these rates. Whereas tRNA binding at the classical binding site of EF-Tu (site I) also appears not to be affected by the methylation of the protein, tRNA binding at site II is. Although the apparent affinity of tRNA for site II remains unaltered upon methylation of EF-Tu, the conformational effects of tRNA binding at this site become different. Both the GTPase activity of the protein and the reactivity of Cys-81 are significantly less stimulated by the tRNA when EF-Tu is methylated. A possible physiological implication of this phenomenon is discussed.