Characterization of 18 microsatellite loci for woodrats of the Neotoma lepida group (Rodentia,Cricetidae, Neotominae)

The desert woodrat complex (Neotoma lepida group) is a set of four closely related species occupying the arid lands of western North America. We have developed 18 polymorphic microsatellite loci to analyse the population structure, mating patterns, and hybridization at points of contact between the contiguously allopatric species in the complex.     

Aldosteronism associated with adrenal cortical adenoma

Current trends in the search for chemical compounds having an inhibitory action on the growth of malignant cells are reviewed in this article. Several agents are sufficiently promising that clinical trials with them are in progress. One of these, an aromatic nitrogen mustard (C.B. 1348), appears to be useful as an adjunctive therapeutic measure in patients with malignant lymphoma, chronic lymphocytic leukemia, and mycosis fungoides who have become refractory to other methods of treatment. The introduction of certain purine antagonists, of which 6-mercaptopurine has been given the most extensive clinical trial, has opened up a new field of experimental and clinical investigation. 6-mercaptopurine and related compounds appear to be particularly useful in the treatment of acute leukemia in adults, but they are also useful, together with the folic acid antagonists and the steroid hormones, in the management of acute leukemia in children. While at present chemotherapeutic agents currently under investigation rarely cause significant regression of inoperable primary or metastatic solid tumors, the possibility of eventual more effective control in many types of malignant disease is not as dismal as it was a decade ago.     

Test systems to determine the ecological risks posed by toxin release from Bacillus thuringiensis genes in crop plants

Procedures for the selection of species for ecotoxicological risk assessment of Bacillus thuringiensis (Bt) gene products in the epigeal and hypogeal environments are proposed. Although species can be selected on the basis of ecological realism and functional importance, the number of organisms requiring testing and the nature of the test procedures remain uncertain with such a selectively toxic material. The heterogeneity of the soil environment, the stratification of plant material at different stages of breakdown and decomposition and the aggregation and patterns of movement of the soil fauna and flora impose problems for the design of ecologically relevant test methods. Similarly, the impact upon beneficial invertebrates, if toxic effects are detected, will be mediated by the scale and pattern of transgenic plant release in the fragmented agricultural landscape. To properly assess the ecological risks posed by a widely released toxin with a narrow spectrum of effects, a combination of laboratory tests, field experiments and longer-term monitoring will be required.     

Morphology and Infraciliature of Trochiliopsis australis N. Sp., Pelagohalteria viridis (Fromentel, 1876) N. G., N. Comb., and Strobilidium lacustris N. Sp. (Protozoa,Ciliophora)1

Three ciliate species from Australia and Norway were examined by silver impregnation, biometry, and scanning electron microscopy. Trochiliopsis australis n. sp. (order Nassulida, family Microthoracidae) differs from the single other known species of the genus, T. opaca, by its prominent ridges on the left side, the distinctly longer anterior segment of somatic kinety 2, and by the doubled total number of kinetosomes. Pelagohalteria n. g. (order Oligotrichida, family Halteriidae) differs from Halteria by the structure of the bristle complexes, which are composed of a vertically and a horizontally oriented row of kinetosomes. Two Halteria species belong to the new genus: P. viridis (Fromentel, 1876) n. comb., which is redescribed here, and P. cirrifera (Kahl, 1935) n. comb. Strobilidium lacustris n. sp. (order Oligotrichida, family Strobilidiidae) differs from its nearest relative, S. velox, by the smooth pellicle, the absence of symbiotic green algae, and by its larger size.     

Interaction between Glucocorticoids and Epidermal Growth Factor In Vitro in the Growth of Palatal Mesenchymal Cells from the Human Embryo

Previous studies of ours have shown that palatal mesenchymal cells from the human embryo (HEPM cells) are responsive both to the glucocorticoid dexamethasone (DEX) and epidermal growth factor (EGF) through mechanisms associated with cytoplasmic and cell surface receptors, respectively. HEPM cell growth was inhibited by DEX and was stimulated by EGF. In the present study, the interactions between DEX and EGF were investigated. DEX (10^–6 M) enhanced EGF-stimulated HEPM cell growth as assessed by an increase in cell number and ornithine decarboxylase activity under serum-free cell culture conditions. DEX also enhanced the specific binding of ¹²⁵I-EGF to these cells, which was reflected in an increase in both the number and the affinity of EGF receptors. EGF (1 ng/ml), on the other hand, decreased the number of sites per cell which specifically bind ³H-DEX. EGF completely prevented the inhibition by DEX of HEPM cell growth. These results indicate that DEX and EGF interact with each other in the process(es) regulating HEPM cell growth. This interaction may be partially influenced by direct modulation of existing receptors for DEX and EGF present in the cells.     

A Comparison of Membrane Filters for Counting Thermoactinomyces Endospores in Spore Suspensions and River Water

Streptococci were isolated from dental plaque samples collected from 25 animals representing 18 species. Strains were characterized by biochemical, physiological and serological tests. Extracellular polysaccharide-producing strains of Streptococcus mutans, Str. sanguis and Str. salivarius were found to be confined mainly to primate species. Streptococcus mutans was not widely distributed, being isolated from 2 of 18 animal species. Enterococci were isolated from the mouths of about one-third of the animals, whilst Str. bovis was found mainly in the herbivores. Strains resembling Str. mitior were isolated from most animals. Of 271 strains. 34 could not be allocated to any known species. Streptococci known to be associated with diseases of animals, especially those belonging to Lancefield group C, were not isolated. A few strains representing Lancefield groups D, L, G and M were found, but with low frequency.