X-ray micronalysis of copper and sulphur-containing granules in the fat body cells of homopteran insects

Regions of the fat body of larvae of Chaetophyes compacta and Pectinariophyes sp. (Machaerotidae, Homoptera) which are closely associated with mycetomes have been analysed by electron probe X-ray microanalysis. It is shown that cells in these regions contain electron probe X-ray microanalysis. It is shown that cells in these regions contain electron dense granules which are rich in copper and sulphur. These two elements occur in the atomic ratio of 3:2 respectively. It is conjectured that copper may be bound to a sulphur containing metallothionein and that the granules represent either the end products of copper detoxification or serve as copper stores for synthesis of enzymes and macromolecules by the mycetomal symbionts.     

Hybrids between irradiated and unirradiated mammalian cells: Survival and chromosome segregation

We have studied the effect of X or γ irradiation, of one parent of a cell hybrid, on hybrid viability and chromosome segregation. The hybrid types studied were mouse-Chinese hamster (which spontaneously lose a few hamster chromosomes) and Chinese hamster-human (which spontaneously lose most of the human complement). Preirradiation of the segregated and retained cell parent resulted in highly asymmetric hybrid survival curves; survival was greatly reduced when the retained parent was irradiated, especially for hamster-human fusions. Preirradiation of the parents of mouse-hamster hybrids modified both the direction and the extent of chromosome segregation, but no consistent effect on elimination was observed for hamster-human hybrids, and reversal of the direction of loss was never observed. These results are more consistent with the hypothesis that chromosome segregation from hybrids results from an intracellular chromosome selection, than with the hypothesis that cellular selection acts on randomly generated chromosome variants.     

Regulation of ACTH and cortisol in depression

Disturbances of hypothalamic-pituitary-adrenal regulation are frequently observed in a subgroup of patients suffering from major depression. The mechanism of hypothesized pituitary and hypothalamic involvement in this dysregulation remains relatively uncharacterized. In this paper we investigated the response of adrenocorticotropin (ACTH), as well as cortisol, to dexamethasone inhibition and characterized the dynamic response of ACTH to a one-hour infusion of cortisol in normal subjects and patients suffering from depression. A paradoxical increase in ACTH in response to cortisol is noted in one patient.     

Microbial Transformation of 19-Hydroxypregnanes

Nocardia species aromatized 19-hydroxyprogesterone, 3beta, 19-dihydroxy-pregn-5-en-20-one 3-acetate and pregn-5-ene-3beta, 19, 20beta-triol 3-acetate, without cleavage of the side chain, into 3-hydroxy-19-norpregna-1,3,5 (10)-trien-20-one. Septomyxa affinis aromatized the ring A and cleaved the side chain of 19-hydroxyprogesterone to yield estrone. With 19-hydroxypregna-4, 7-diene-3, 20-dione as substrate, the transformation was more complex and many products were formed.     

The ultrastructure of the sensory plaque organs of the antennae the chinese lantern fly, Pyrops Candelaria L., (Homoptera, Fulgoridae)

The plaque organs of Pyrops consist of elaborately folded, finely perforated cuticular areas, each associated with numerous bipolar sensory cells organised in groups. The proximal, mitochondrial region of each dendrite narrows to reveal a ciliary ultrastructure. The ciliary fibrils pass into a highly vesiculated region and beyond this are succeeded by a dense array of neurotubules. Peripherally the dendrites proliferate numerous fine branches from which finer filaments extend into the cuticular pores. The plaques are considered to be complex olfactory organs evolved from groups of sensilla basiconica.