Formation of a Piperidinium Derivative from N-(5′-Chloropentyl)-N-methylaminoaceto-2,6-xylidide in relation to the Sustained Local Anaesthetic Action on the Sciatic Nerve of the Guinea-pig <Emphasis Type="Italic">in vivo</Emphasis>

THE possibility of using the intramolecular alkylation reaction of tertiary ω-haloalkylamines (Fig. 1) to overcome the cell membrane barrier to cyclic quaternary ammonium compounds seems to have been almost entirely overlooked. Some pharmacological applications of this principle have already been studied^1–3 and we feel that the possibility of obtaining local anaesthetic agents⁴ may be of therapeutic interest. The nerve sheaths and membranes hinder the penetration of quaternary ammonium compounds⁵, but tertiary amines in their base form are able to pass⁶. Thus, a tertiary haloalkylamine (I in Fig. 1) should be able to cross the barriers, and, because of its capacity to cyclize, the corresponding cyclic quaternary ammonium derivative (II) would be expected to be formed at least to some extent at the sites for blockade of nerve excitation. The barriers to outward diffusion of the quaternary compound formed are probably the same as for the inward movement, so that very slow disappearance can be expected. Accordingly, if the quaternary derivative has a local anaesthetic action, this would probably be of long duration. Our observation that tertiary haloalkylamine derivatives closely related to lidocaine have a long term anaesthetic effect⁴ supports this hypothesis. It would be valuable, however, to try to relate the local Q XCH3 JH3 -NHCOCH2N(CH2)5CI VCH3 I 'CH3 jJrX . -NHC0CH2N 4-Ct CH3 *? II anaesthetic effect in vivo with the amount of (I) and of the piperidinium derivative (II) formed in the nerves. One compound, N-(5 '-chloropentyl)-N-methylaminoaceto-2,6-xyli-dide (I in Fig. 1), tritium-labelled in the 1'-position (specific activity 10 mCi/mmol), was therefore selected for the following experiments.     

Joint Report of the Third International Bovine Lymphocyte Antigen (BoLA) Workshop, Helsinki, Finland, 27 July 1986

Summary. Two hundred and eighty-two alloantisera were submitted by 20 participating laboratories from 13 countries and tested against lymphocytes of 1298 cattle. The cell panel consisted of samples from 38 Bos taurus breeds, 11 Bos taurus crossbreeds, 4 Bos indicus breeds, 6 Bos taurus X Bos indicus , and a variety of other crossbred populations. Using a standardized lymphocytotoxicity test, all 17 previously identified BoLA specificities were confirmed. The workshop produced agreement on 16 new lymphocyte alloantigenic specificities. Three of the new specificities behaved as splits of previously identified BoLA specificities. Four of the new specificities behaved as alleles at the agreed BoLA-A locus. Seven new specificities are tentatively assigned to the BoLA-A locus but require further definition. Two new specificities may represent products of a second closely-linked BoLA locus.     

The metabolic enzyme phosphoglucose isomerase (Pgi) affects the outcome of intra‐specific competition in a polyembryonic wasp

1. Polyembryonic parasitoid wasps in the family Encyrtidae (Hymenoptera) have evolved a caste system consisting of morphologically and functionally distinct larvae called soldiers and reproductives. 2. Two selective pressures are thought to underlie the evolution of the soldier caste: defence against competitors and resolution of the sex ratio conflict. Previous studies also indicate that soldier development time strongly affects the outcome of intra‐specific competition in the polyembryonic encyrtid Copidosoma floridanum Ashmead. This study builds on prior findings by showing that alleles of the metabolic enzyme phosphoglucose isomerase (Pgi) differentially affect soldier development time and the outcome of competition. 3. Soldier larvae with the Pgi alleles 100 or 120 emerged on average 65 h post‐parasitism, whereas soldier larvae with a third allele, 54, emerged at 67 h. In turn, C. floridanum broods homozygous for the 100 and 120 alleles outcompete broods homozygous for the 54 allele. 4. Pgi allelic diversity may be maintained through a life‐history trade‐off affecting female brood sizes with homozygous broods bearing the developmentally disadvantageous 54 allele producing more adult females than broods bearing alternate common alleles.     

ANNUAL AND LUNAR REPRODUCTIVE CYCLES IN LITTORINA SAXATILIS (OLIVI) AND DIFFERENCES BETWEEN BREEDING IN THE MARINE FIRTH OF FORTH AND THE FORTH ESTUARY

Gonads were most commonly reduced in October and fullest inMar-Jun with more pronounced seasonal differences in the estuarythan in the firth. Brood-pouches accordingly were fullest inspring-early summer and emptiest in autumn-early winter. Eggsand early embryos predominated in brood-pouches of early springbut were few in Aug-Oct whereas well-developed juveniles werefew in early spring, increased in spring-summer and came topredominate in Jun-Nov. Brood-pouch loads varied with size offemale but, for a standard 10 mm female, were significantlylower in the 2 estuarine sites than in the firth. Changes inmean brood-pouch count varied only 2.5-fold during the yearin the firth but 4.10-fold in the estuary. In vitro development of eggs to shelled juveniles with the velumresorbed took some 68 d at 10°C and 32%. Eggs and late brood-pouchjuveniles were significantly heavier in the estuary than inthe firth (dry weight, ash-free dry weight (AFDW), ash weight).AFDW changed little during development while ash weight (mostlyshell) increased 3.5-4.4-fold. In a laboratory tide tank, femalesreleased 60 d means of <1.3 juveniles d^–1; more inmid- and late year than in Jan-Mar, more from upshore firthfemales than from low shore or estuary females, more when heldat high tide-tank levels than at lower levels, and generallyat rates comparable to release in containers held at the siteof origin. Egg production in laboratory females did not keeppace with release of young and, at the end of trials, brood-pouchcounts were mostly lower than in contemporary free winkles.Females that had released most (e.g. at high tank levels) containedleast brood-pouch embryos and young subsequently. Release of young in the tide tank was markedly faster at timesnear new moon (often reaching or exceeding 2 female^–1d^–1) than near full moon (often <1 female^–1 d^–1).This lunar fluctuation was clearest in fast-releasing sets heldat high- or mid-tide tank levels. It was not observed in Jan-Mar(when release from most females was slow) nor in females atlow tank levels. (Received 3 September 1990; accepted 8 November 1990)