Butanedione treatment reduces receptor binding of a lysosomal enzyme to cells and membranes

Treatment of the lysosomal enzyme, α-L-iduronidase, with 2,3 butanedione, an arginine modifying reagent, under conditions where enzyme activity was unaffected, reduced by 50% the internalization of the enzyme into cultured human fibroblasts. The lowered rate of internalization was a result of a reduced binding of the enzyme to cell surface receptors. The butanedione treatment of α-L-iduronidase caused a 90% reduction of binding when isolated fibroblast membranes were used as the source of receptor. This marked reduction of binding was also seen when membranes from a rat chondrosarcoma were examined. Although there is ample evidence that the receptor recognizes mannose 6-phosphate residues on the enzyme, the results suggest that other structural features, such as arginine moieties, may also be important in iduronidase binding.     

The role of the basal hypothalamus in the regulation of reproductive behavior in the lizard, Anolis carolinensis: lesion studies

Bilateral radiofrequency lesions in the anterior and posterior basal hypothalamus decreased courtship and agonistic behaviors in both intact, sexually active, and castrated, androgen treated male Anolis carolinensis. Intact males receiving lesions in the anterior basal hypothalamus had atrophied testes, aspermia, and decreased epithelial cell height of the renal sex segment. Lesions of the posterior basal hypothalamus had no effect on testicular activity or the development of accessory organs. All animals demonstrating behavioral changes had lesion destruction in the ventromedial nucleus and the accompanying periventricular system. It is concluded that the basal hypothalamus in male A. carolinensis is involved both in the regulation of reproductive behavior and pituitary function.     

The effect of in vivo treatment with EHDP and/or 1,25-DHCC on calcium uptake and release in isolated kidney mitochondria

Previous work on calcium transport (uptake and release) in isolated mitochondria, in vitro, has shown that addition of EHDP to the medium does not influence calcium uptake, but does delay calcium release. In vivo treatment of normal chicks with high doses of EHDP (10 mg P/kg body weight/day) has now also been found not to affect the in vitro calcium uptake in isolated chick kidney mitochondria, but to delay the subsequent release as compared with controls. The effect is not due to the decrease in 1,25-DHCC, since chronic administration of this metabolite did not correct the delay. In fact 1,25-DHCC in itself had a delaying effect on accumulated calcium release.     

The effect of several lymphocytotoxic agents on murine leukemogenesis

5-(3,3-dimethyl-l-triazeno) imidazole-4-carboximide (DTIC) induced lymphomas with a 70 day lag period and with an incidence greater than 90% in both AKR/J and outbred Swiss Albino mice. On the other hand, treatment with cortisone acetate and 5'-azathioprine prolonged survival of AKR/J male mice. Treatment with all three agents reduced the population of medium-sized lymphocytes in the thymus within two days and additionally, cortisone and DTIC led to a reduction i in spleen weight.     

Protein synthesis in dorsal and ventral regions of Xenopus laevis embryos in relation to dorsal and ventral differentiation

Two-dimensional gel electrophoresis has been used to analyze protein synthesis in dorsal and ventral regions in embryonic stages of Xenopus laevis. Proteins specific either to dorsal or to ventral regions are synthesized for the first time at gastrulation, concomitant with morphological differentiation. The reliability of these proteins as markers of dorsal and ventral differentiation was tested by examining their synthesis in Uv-irradiated embryos, which have severely reduced capacity for dorsal development, reflected in reduced levels of the neuromuscular-specific enzyme acetylcholinesterase, but which continue to synthesize the great majority of proteins at normal rates. Synthesis of dorsal indicator proteins should be reduced or absent in these embryos, whereas ventral indicators should be synthesized at least to the same extent as in control embryos. Some of the putative dorsal and ventral indicators failed this test, but the majority were confirmed as reliable markers of dorsal and ventral differentiation, thus providing a connection between morphology and gene expression in the establishment of the dorsal-ventral axis in X. laevis.     

Taxonomic review of the lace bug genus Omoplax (Hemiptera: Heteroptera: Tingidae) endemic to “Oriental Galapagos” (the Ogasawara Islands,Japan) with the description of its new allied genus and species

In this study, we revise the lace bugs (family Tingidae) from the Ogasawara Islands, Japan (also known as the “Oriental Galapagos”). Three species belonging to two endemic genera are recognized: Acanthomoplax tomokunii gen. et sp. nov. , Omoplax desecta (Horváth, 1912), and O. majorcarinae Guilbert, 2001. A key to species is provided to facilitate the identification of Ogasawaran lace bugs.