No abstract

1. The metabolism of 1-bromopropane in the rat has been re-investigated. The previously known metabolites have been isolated and confirmed as the three mercapturic acids N-acetyl-S-propyl cysteine, N-acetyl-S-propyl cysteine-S-oxide and N-acetyl-S-(2-hydroxypropyl)cysteine. 2. Three further metabolites have been isolated from the urine of rats treated with 4-bromopropane. These have been identified as 3-bromopropionic acid and the mercapturic acids N-acetyl-S-(3-hydroxypropyl)cysteine and N-acetyl-S-(2-carboxyethyl)cysteine. 3. The metabolites of 3-bromopropanol and 3-chloropropanol in the rat have been shown to be the mercapturic acids N-acetyl-S-(3-hydroxypropyl)cysteine and N-acetyl-S-(2-carboxyethyl)cysteine and the corresponding 2-carboxyethyl halide. 4. Studies with 1-bromopropane and the 3-halopropanols in vitro indicate that oxidation of C3 and C2 of 1-bromopropane occurs before conjugation of the alkyl group with glutathione. The implications of these studies are discussed in relation to the mechanism of the biosynthesis of the S-(2-hydroxyalkyl)mercapturic acid metabolites derived from the alkyl halides.

We study a q-deformation for the semi-direct product of the symmetric group S n with the Clifford algebra on n anticommuting generators. We obtain a q-version of the projective analogue for the classical Young symmetrizer introduced by the second author. Our main tool is an analogue of the Hecke algebra of complex valued functions on the group GL n over a p-adic field relative to the Iwahori subgroup.

We have studied the hyperglycaemic effect of the carbohydrate of glucose, sucrose, and honey equivalent to 20 g in twelve normal volunteers, eight patients with insulin-dependent diabetes mellitus (IDDM), and six patients with non-insulin-dependent diabetes mellitus (NIDDM). Honey produced an attenuated postprandial glycaemic response in normal volunteers (vs glucose p less than 0.005; vs sucrose p less than 0.05) and IDDMs (vs glucose p less than 0.005; vs sucrose p less than 0.05). The glycaemic index (GI) showed considerable variability within each subject group. Combined with a peak incremental index (PI), the two indices appear to be more valuable in predicting the glycaemic effects of carbohydrates rather than either one alone. We suggest that honey may prove to be a valuable sugar substitute in diabetics, and that both the GI and PI should be used in the analysis of food.

This study examined the clearance of gastric acid from the oesophagus in ambulant patients with gastrooesophageal reflux. Eighteen patients with proved reflux disease were studied, nine with (group 1) and nine without (group 2) endoscopic oesophagitis. Oesophageal pressure and pH were recorded over 24 hours. Pressures were measured by a probe with five sensors: a 5 cm long sensor in the lower oesophageal sphincter, three sensors in the body of the oesophagus, and one at the pharynx to detect swallowing. Oesophageal pH was monitored 5 cm above the lower oesophageal sphincter. Manometric activities were classified as either peristaltic or ineffective. The latter included simultaneous, non-transmitted, and low amplitude peristaltic contractions. A reflux episode was defined as starting when pH fell to less than 4 and ending when the pH rose to 5. When the rise to pH 5 took place in three or more discrete steps after motor responses to gastrooesophageal reflux, the pH steps were labelled as initial change (I), middle changes (M), and last change (L). A total of 595 episodes of gastro-oesophageal reflux and 1626 associated motor events were analysed. Of these, 1331 (81-9%) were classed as primary peristaltic activity, 174 (10-7%) as primary ineffective activity, 46 (2.8%) as secondary peristaltic activity, and 75 (4-6%) as secondary ineffective activity. There were no significant differences in initial change (p>O05), middle changes (p>005), and last change (p>005) between group 1 and group 2. In all patients, the successive changes of pH in response to motor activity were significantly different (p=0-0001) between initial, middle, and last changes. Last change was significantly higher when compared with initial (p=0001) and middle changes (p<0001). Primary oesophageal peristalsis was the most frequent motor response to gastrooesophageal reflux. The last motor activity during reflux showed the greatest change in pH.