Effects of larvicide treatment on invertebrate communities of Guinean rivers,West Africa

Biological and hydrological data collected from 1984 to 1998 in three Guinean rivers were analysed to evaluate adverse effects of biological and chemical larvicides applied for the control of blackfly Simulium damnosum, vector of the parasitic digenean worm Onchocerca volvulus. Although most of the variation in invertebrate populations were flow-related, larvicide applications affect community structure reducing the abundance of the most sensible taxa. In spite of these results, in the long term the rarefaction of some invertebrate taxa (i.e. Tricorythidae) does not cause a significant reduction of total invertebrate densities because of the corresponding increase of other taxa (i.e. Hydropsychidae and Philopotamidae). The functional structure of the communities is also not affected.     

A sensitive radiometric assay for cysteic acid decarboxylase activity in crude enzyme preparations of rat liver and brain.

1. A method is described for the synthesis of L-[U-14C]cysteic acid from L-[U-14C] cysteine hydrochloride and for its subsequent utilisation as a substrate for cysteic acid decarboxylase activity in liver and brain. 2. The enzyme determination relies on the entrapment of radio-labelled carbon dioxide in Hyamine hydroxide. 3. The assay is sensitive, reliable and convenient and is particularly suitable for measuring the activity of the decarboxylase in crude enzyme preparations.     

Clinical significance of tartrate-sensitive and tartrate-resistant acid phosphatase indicated from the study of their biosynthetic mechanism

The tartrate-sensitive prostatic acid phosphatase, bands 2 and 4, are found in the soluble cytosol, and absent in the polysome of the prostate, while the tartrate-resistant acid phosphatase band 5 is present in the polysome and the soluble cytosol of hairy cells. The mRNA isolated from the prostate catalyzes the incorporation of 3T leucine into a protein different from that of bands 2 and 4. On the other hand, the mRNA isolated from the hairy cells catalyzes the incorporation of 3T leucine into band 5. The different biosynthetic mechanism of these two types of acid phosphatases are discussed in light of their different clinical significance.