Formulation of a flowable liquid concentrate of Bacillus thuringiensis serotype H-14 spores and crystals as mosquito larvicide

Bacillus thuringiensis serotype H-14 spores and crystals, produced in 51 fermenters, were centrifuged and resuspended in emulsified palm olein to give 3.2 x 10(11) colony forming units (cfu)/ml. The suspension was mixed with a cassava-molasses-palm olein-charcoal (CMPC-2) mixture which served as the carrier, adhesive, dispersant and protectant. The final concentration of the formulation was 3.2 x 10(9) cfu/ml. The lethal concentrations capable of killing 50% of the test population (LC50) of CMPC-2 during 0, 1 and 2 years of storage at 32 +/- 4 degrees C were 0.056, 0.058 and 0.058 mg/ml respectively as against 0.054, 0.051 and 0.054 mg/ml for the Institut Pasteur Standard-1978 (IPS-78) during the corresponding period. The chi 2 tests showed that the results were homogeneous at P = 0.05. The relative potencies of the preparations were 964.3, 879.3 and 931 International toxic units (ITU) Aedes aegypti as compared with the 1000 ITU assigned to IPS-78. At 95% confidence limits there was no significant difference between the potencies of CMPC-2 and IPS-78. Field tests showed that CMPC-2 provided between 87.5 and 100% control of natural populations of Aedes spp. and Cutex spp. Sedimentation tests showed that CMPC-2 settled markedly during storage. This, therefore, required that the product be thoroughly shaken before use.     

Comparison of agrin-like proteins from the extracellular matrix of chicken kidney and muscle with neural agrin, a synapse organizing protein.

Agrin is a synapse-organizing protein that is concentrated in embryonic motor neurons and the synaptic basal lamina of the neuromuscular junction. Agrin or closely related proteins are also associated with most other basal laminae. Here I report that the major agrin-like proteins from the nervous system and other tissues of the chicken are immunochemically and biochemically similar. Four major agrin-like proteins of approximately 60, 72, 80, and 90 kDa were identified on immunoblots of agrin preparations from both neural and non-neural tissues. Agrin-like proteins from embryonic chicken brain and adult kidney were similar in amino acid composition. Rabbit antisera against each of the kidney proteins labeled basement membranes of several tissues, as well as spinal cord motor neurons. These antibodies specifically precipitated and inhibited acetylcholine receptor (AChR)-aggregating activity from the chicken nervous system and Torpedo electric organ. Thus, the agrin-like proteins of non-neural tissues in the chicken are closely related to agrin from the nervous system. However, the AChR-aggregating activity of chicken agrin preparations differed depending on the tissue of origin. Agrin enriched by immunoaffinity chromatography from the central nervous system induced large numbers of AChR aggregates on cultured myotubes. In contrast, agrin preparations from other chicken tissues induced dramatically fewer and smaller AChR aggregates. The difference in biological activity between these agrin preparations may reflect differential inactivation or the existence of tissue- or cell-specific isoforms of agrin.     

5-Hydroxytryptamine-Stimulated Inositol Phospholipid Hydrolysis in the Mouse Cortex Has Pharmacological Characteristics Compatible with Mediation via 5-HT2 Receptors but This Response Does Not Reflect Altered 5-HT2 Function After 5,7-Dihydroxytryptamine Lesioning or Repeated Antidepressant Treatments

5-Hydroxytryptamine (5-HT; 3 x 10(-8)-1 x 10(-5)M) produced a dose-dependent increase in phosphatidylinositol/polyphosphoinositide (PI) turnover in mouse cortical slices, as measured by following production of 3H-labelled inositol phosphates (IPs) in the presence of 10 mM LiCl. Analysis of individual IPs, in slices stimulated for 45 min, indicated substantial increases in inositol monophosphate (IP1; 140%) and inositol bisphosphate (IP2; 95%) contents with smaller increases in inositol trisphosphate (IP3; 51%) and inositol tetrakisphosphate (IP4; 48%) contents. The increase in IP3 level was solely in the 1,3,4-isomer. This response was inhibited by the nonselective 5-HT antagonists methysergide, metergoline, and spiperone. It was also inhibited by the selective 5-HT2 antagonists ketanserin and ritanserin but not by the 5-HT1 antagonists isapirone, (-)-propranolol, or pindolol. 5-HT-stimulated IP formation was also unaltered by atropine, prazosin, and mepyramine. Lesioning brain 5-HT neurones using 5,7-dihydroxytryptamine (5,7-DHT; 50 micrograms i.c.v.) produced a 210% (p less than 0.01) increase in the number of 5-HT2-mediated head-twitches induced by 5-methoxy-N,N-dimethyltryptamine (2 mg/kg). However, 5,7-DHT lesioning had no effect on 5-HT-stimulated PI turnover in these mice. Similarly, an electroconvulsive shock (90 V, 1 s) given five times over a 10-day period caused an 85% (p less than 0.01) increase in head-twitch responses but no change in 5-HT-stimulated PI turnover. Decreasing 5-HT2 function by twice-a-day injection of 5 mg/kg of zimeldine or desipramine (DMI) produced 50% (p less than 0.01) and 56% (p less than 0.01), respectively, reductions in head-twitch behaviour.(ABSTRACT TRUNCATED AT 250 WORDS)     

Economic aspects of tobacco use and taxation policy.

Tax levels have important effects on cigarette prices and tax revenues. Over 70p of every pound spent on tobacco goes to the Chancellor of the Exchequer, yielding over 5 billion pounds. But the value of tobacco tax revenues have generally fallen--by 1986 they were 10% lower than at their peak in 1965, and tobacco revenue is becoming a smaller proportion of total tax receipts. The impact of a consistent increase in tobacco taxation is important in terms of reduced consumption (and harm to health) as well as in terms of reduced employment. Revenue may, however, increase in the short term. Finally, if the findings of Townsend and Atkinson et al (see above) still apply then the distributive effects of increased taxation on the poor might be less than is sometimes feared.