Induction of tyrosine aminotransferase by pyridoxine in Drosophila hydei

Salivary glands incubated in various concentrations of pyridoxine (Vitamin B₆) show increasing tyrosine aminotransferase (TAT) activity at concentrations up to 10^–5 M and then decreasing activity up to 10^–2 M but in all cases the activity is greater than that of the controls. This increase in activity is demonstrable for up to 6 h, the longest period tested, and is dependent on the synthesis of new mRNA. A similar increase in TAT activity is observed in salivary glands subjected to heat shock. Antibodies prepared against purified tyrosine aminotransferase precipitate a peptide of the same molecular weight (40 KD) as that induced by pyridoxine.     

Assessment of Efficacy and Quality of Two Albendazole Brands Commonly Used against Soil-Transmitted Helminth Infections in School Children in Jimma Town,Ethiopia

BackgroundThere is a worldwide upscale in mass drug administration (MDA) programs to control the morbidity caused by soil-transmitted helminths (STHs): Ascaris lumbricoides, Trichuris trichiura and hookworm. Although anthelminthic drugs which are used for MDA are supplied by two pharmaceutical companies through donation, there is a wide range of brands available on local markets for which the efficacy against STHs and quality remain poorly explored. In the present study, we evaluated the drug efficacy and quality of two albendazole brands (Bendex and Ovis) available on the local market in Ethiopia.Conclusion/SignificanceThe study revealed that differences in efficacy between the two brands of albendazole (ABZ) tablets against hookworm are linked to the differences in the in-vitro drug release profile. Differences in uptake and metabolism of this benzimidazole drug among different helminth species may explain that this efficacy difference was only observed in hookworms and not in the two other species. The results of the present study underscore the importance of assessing the chemical and physicochemical quality of drugs before conducting efficacy assessment in any clinical trials to ensure appropriate therapeutic efficacy and to exclude poor drug quality as a factor of reduced drug efficacy other than anthelminthic resistance. Overall, this paper demonstrates that “all medicines are not created equal”.     

Phylogeography and conservation genetics of a giant lobelia (Lobelia giberroa) in Ethiopian and Tropical East African mountains

Lobelia giberroa is a giant rosette plant growing in the afro-montane belt of the afro-alpine environment, a unique and little-studied ecosystem occupying the high mountains of eastern Africa. We analysed amplified fragment length polymorphisms (AFLPs) from 11 mountain systems in Ethiopia and Tropical East Africa to infer the phylogeographical history of the species. A total of 191 individuals were investigated from 25 populations. Principal coordinate analysis and population structure analyses revealed three major phylogeographical groups: the Ethiopian mountains and one group on each side of the Rift Valley in Tropical East Africa, respectively: Elgon-Cherangani and Kenya-Aberdare-Kilimanjaro-Meru. Analysis of Molecular Variance showed 55.7% variance among the three groups, suggesting an old divergence. Together with a clear geographical substructure within the main groups, this pattern indicates gradual expansion and supports the montane forest bridge hypothesis, stating that the area occupied by forest was larger and more continuous in previous interglacials and earlier in the present interglacial. Genetic diversity was lower in Ethiopia than in the other two main groups, possibly due to an ancient founder effect when Ethiopia was colonized from the south.     

Predators of Mesoplatys ochroptera in sesbania planted-fallows in eastern Zambia

Mesoplatys ochroptera Stål (Coleoptera: Chrysomelidae) is a serious pest of the tropical legume sesbania (Sesbania sesban (L.) Merrill) widely used for soil fertility improvement in southern Africa. Surveys were conducted between October 1997 and June 1999 in order to identify the predators of M. ochroptera in sesbania fallows in eastern Zambia. The Heteroptera Afrius yolofa (Guérin-Méneville), Glypsus conspicuus (Westwood), Macrorhaphis acuta Dallas, Mecosoma mensor (Germar), Rhinocoris segmentarius (Germar), and Deraeocoris ostentans (Stål), the carabid beetle Cyaneodinodes fasciger (Chaudoir), the ants Tetramorium sericeiventre Emery and Pheidole sp., and the lacewing Mallada sp. were recorded as predators of M. ochroptera for the first time. The pentatomid bugs G. conspicuus, M. acuta and M. mensor were the most common predators in sesbania fallows. Adults and the different nymphal stages of the three species preyed on larvae, adults and occasionally on eggs of the beetle. In the insectary, the adults of G. conspicuus, M. acuta and M. mensor consumed a significantly higher number of larvae (p < 0.001) compared to adults of M. ochroptera under both free-choice and no-choice conditions. The voracity of the three species showed a positive response to prey density. The fifth instar nymphs showed variation in daily consumption of larvae, the highest number of prey being consumed two to three days after the fourth molt. These predators also attacked other pests associated with sesbania and crop plants. The potential role of the predators in the natural control of pests in agroforestry systems is discussed, with a review of their prey species.     

Floral character states of the Northeast and Tropical East African Swertia species (Gentianaceae)

The floral gross morphological and anatomical character states of 23 African Swertia species are described. Colleters are frequent in Swertia, especially at the lower rim of calyx lobes and are usually placed in a single row except in S. crassiuscula (they are not "typical" colleters). The aestivation of corolla lobes is found to be uniform except in S. engleri var. engieri. Each corolla lobe is beset with either one or two foveae. Foveae are naked or either partly or wholly fimbriated along their margins. No vascular tissue was observed entering the foveae. The taxonomic importance of the the floral character states is discussed.     

Detection of naturally aerosolized <Emphasis Type="Italic">Mycoplasma hyopneumoniae</Emphasis> from the air of selected swine farms

We aimed to detect Mycoplasma hyopneumoniae from the air of selected farms through air filtration-based air sampling using polymerase chain reaction (PCR). Air samples were collected at different locations inside and outside of pig farm rooms on polyethersulfone membrane (0.22 μm), and the presence of M. hyopneumoniae DNA was analyzed by PCR. Furthermore, nasal swab and blood samples were collected from 336 pigs in the same air sampled rooms and were analyzed by PCR and IDEXX ELISA, respectively. The suitability of the air sampling method was validated with analysis of an artificially induced aerosolized avirulent M. hyopneumoniae in an enclosed box showing PCR-positive results. M. hyopneumoniae was detected from air sample of pig farm rooms using PCR. Although the probability of an airborne M. hyopneumoniae causing an infection is not yet confirmed, air sampling PCR results could serve as a tool to assess the spread of M. hyopneumoniae by bioaerosols and the infection dynamics in a herd and between herds.     

Isolation of the epidermal growth factor from the shrew submaxillary gland

Entomocidal crystals produced by Bacillus thuringiensis ssp. israelensis are formed by two proteins with molecular masses of 130 and 28 kDa, whereas the protein with a molecular mass of 70 kDa appears as a result of 130 kDa protein limited proteolysis by admixtures of bacterial proteinases in the course of its dissolution. The comparison of the N-terminal sequences of the protein with molecular mass of 70 kDa (Met-Glu-Asn-Xaa-Pro-Leu-Asp-Thr-Leu-Ser-Ile-Val-Asn-Glu-Thr-Asp) and that of 28 kDa (Met-Glu-Asn-Leu-Asn-[Phe]-[Trp]-Pro-Leu-Gln-Asp-Ile-Lys-Val-Asn-Pro) reveals only marginal similarity between them (only 4 identical residues among 16 aligned). Both B. thuringiensis israelensis crystal-forming proteins appear hardly related to those contained in the crystal produced by other B. thuringiensis subspecies, e.g. kurstaki. It might be concluded that at least some of the entomocidal proteins found in the crystalline inclusion bodies of various B. thuringiensis subspecies revealed rather strong variations in their primary structures that facilitate their adaptation to different hosts.

Bacillus thuringiensis ssp. israelensis δ-Endotoxin Entomocidal crystal Insecticide Mosquito