Search

After parotid surgery, gustatory sweating and flushing occur more frequently, the former reportedly in 15–100 % of cases, while no reliable data are available for the latter. Although botulinum toxin (BoNT) is effective in controlling sweating, little is known about its effect on flushing. In 17 patients suffering from Frey's syndrome after parotid surgery, we studied the gustatory flushing phenomenon as compared to gustatory sweating, analyzing their frequency, area, type of stimulus and response to BoNT administration. Cutaneous blood flow (CBF) was monitored by laser Doppler flowmetry (LDF) on affected and unaffected areas of the cheek in basal conditions and after meals, before and then 1 month after starting the BoNT injections. The Minor test was used to identify the sweating area. Flushing was observed in 7 of 17 patients after masticatory activity, spicy meals or citrus fruits. No clinical data correlated with any presence of flushing. Flushing regressed completely after BoNT administration and CBF reached similar values in the affected and unaffected sites. No adverse effects were observed. BoNT administration proved an effective and safe treatment for gustatory sweating and flushing in patients with Frey's syndrome.

The levels of potassium, sodium, magnesium and calcium in leaves, midgut contents, midgut tissue, and blood were analysed in seven developmental stages between feeding, fourth-instar larvae and new pupae of the Cecropia silkworm. Three dramatic changes in cation levels were found: the K level in the contents drops from 284 ±51 mEquiv./l tissue water in the fifth-instar larva to 51 ± 6 mEquiv./l in the new pupa ; the Mg level in the midgut tissue increases from 28 ± 3 mEquiv./l at the time of gut evacuation to 1093 ± 104 mEquiv./l in the new pupa; and the Ca level in the contents drops temporarily from 56 ± 12 mEquiv./l in the feeding fourth instar larva to 17 ± 5 mEquiv./l in the new fifth instar larva. The Na level was never higher than 2·8 ± 0·5 mEquiv./l. The relative levels of the four cations were different for each tissue studied, but each tissue maintained the same relative levels during the developmental stages studied. The sequences are: leaf, Ca > K > Mg > Na; midgut contents, K ⪢ Ca > Mg > Na; midgut tissue, K ⪢> Mg > Ca > Na; and blood, Mg ⪢ K > Ca > Na. There were three large concentration gradients across the midgut ; the K level in the midgut contents is approximately 10 times the level in blood; the Mg level in contents is one-half to one-sixth the level in blood; and the Ca level in contents is 3—4 times the level in blood. The K gradient and the Ca gradient are opposed and the Mg gradient is favoured by the electrical gradient across the larval midgut, the contents being 100 mV positive with respect to the blood. The K gradient and the electrical gradient are not present across the pupal midgut while the Mg gradient and the Ca gradient persist. The K gradient is presumably maintained by the midgut K pump, the Mg gradient is aided by the midgut Mg pump, and the Ca gradient suggests that the midgut may possess a Ca pump.

The only prevalence rate of myasthenia gravis (MG) so far estimated in Italy by an epidemiological study carried out in Pavia, North Italy, indicates a prevalence quite similar to that observed in other countries. The purpose of the survey was to verify the frequency of the disease in a geographically well-defined and previously surveyed community. On the basis of 39 cases, on 31 December 1987 the prevalence per million was 105.3 (102.3 if standardized for the Italian population). This is the highest prevalence figure yet found, indicating a value similar to that established in Northern Europe. According to Kurtzke this high prevalence rate reflects the high standard of the local public health service, which permitted a more intensive search for affected subjects.