Transplacental micronucleus inducing ability of arecoline, a betel nut alkaloid, in mice

Arecoline, a major betel nut alkaloid, was tested for its effectiveness in inducing micronuclei in fetal mouse blood after transplacental exposure late in the gestation period. Positive results were obtained and a linear dose-response relationship was expressed when pregnant mice were treated with arecoline at dose levels of 20, 40 and 80 mg/kg and micronucleated polychromatic erythrocytes from fetal blood were subsequently analysed.     

Biosynthesis of lutropin in ovine pituitary slices: Incorporation of [35S]sulfate in carbohydrate units

Sulfate incorporation into carbohydrate of lutropin (LH) has been studied in sheep pituitary slices using H₂³⁵SO₄. Labeled ovine LH was purified to homogeneity by Sephadex G-100 and carboxymethyl-Sephadex chromatography from both the incubation medium and tissue extract. Autoradiography of the gel showed only two protein bands which comigrated with the α and β subunits of ovine LH in both the purified ovine LH and the immunoprecipitate obtained with LH-specific rabbit antiserum. Furthermore, [³⁵S]sulfate was also incorporated into several other proteins in addition to LH. The location of ³⁵SO₄^2? in the oligosaccharides of ovine LH was evidenced by its presence in the glycopeptides obtained by exhaustive Pronase digestion. The location and the point of attachment of sulfate in the carbohydrate unit were established by the isolation of 4-O-[³⁵S]sulfo-N-acetylhexosaminyl-glycerols and 4-O-[³⁵S]sulfo-N-acetylglucosaminitol from the Smith degradation products and by the release of ³⁵SO₄^2? by chondro-4-sulfatase. Thus, the present line of experimentation indicates the presence of sulfate on both the terminal N-acetylglucosamine and N-acetylgalactosamine in the oligosaccharide chains of the labeled ovine LH.     

Comparison of vascular hemodynamics in experimental models of microvascular anastomoses

Blood flow was measured in the canine saphenous artery using electromagnetic flowmetry. Significant increase in blood flow was noted after occlusion of the distal femoral artery. However, after raising a saphenous island flap there was no significant change in the blood flow before and after distal femoral artery occlusion. The flap peripheral resistance and blood flow were compared after end-to-end and end-to-side anastomosis and no statistical difference was noted.     

Growth and Endogenous Gibberellin Content of Dormant Groundnut Embryonic-axes as Influenced by Leaching and GA(3)

Leacthing the excised embryonic-axes from dormant groundunt (Arachis hypogaea) seeds resulted in their growth. However, their growth was stunted compared to that of after-ripened ones. It is attributed to (1) the lower amount of gibberellin-like substances in the dry, dormant embryonic-axes than in the after-ripened ones, and (2) the inability of the former to sythesise tbe tibberetllin as indicated by the lower content compared to the after-ripened ones kept in water. Exogenousty supplied GA(3) (0.1 mg/1) increased both the endogenous gibberellin and growth of the dormant, leached embryonic-axes to the level of after-ripened ones.