Simple theoretical criterion of chemical carcinogenicity - a refutation.

The quasi-valence number criterion for chemical carcinogenicity has been shown, through several examples, to be untenable.     

Taurine concentrations in the aqueous humor and plasma of anesthetized rabbits

Summary Aqueous humor taurine concentrations were found to be significantly higher (p<0.01) than that of the plasma in anesthetized rabbits. Topical application of 2 mg terbutaline lowered intraocular pressure (p<0.001), but did not alter aqueous taurine content.Supported by National Eye Institute grants Nos EY05430 (JMR) and EY02156 (DEP).Acknowledgments. We thank Dr J. Gintautas, this institution, for translating reference 18 and Dr S. Y. Schmidt, Massachusetts Eye and Ear Infirmary, for valuable advice.     

The activation of membrane ATPase by ouabain in several tissues of the golden hamster (Mesocricetus auratus) in the absence of potassium

Summary The activity of the membrane ATPase of 5 organs of the golden hamster was increased by 10^–7–10^–3 moles/l ouabain in K⁺-free medium. In similar experiments on rats no increase was observed.     

o-Aminoacetophenone: Identification in a primitive fungus-growing ant (Mycocepurus goeldii)

Summary o-Aminoacetophenone is the major volatile product present in the mandibular gland secretion of the primitive fungus-growing antMycocepurus goeldii. This novel arthropod natural product is biosynthetically far removed from the aliphatic ketones and alcohols found in those genera of the tribe Attini that represent the main line of evolution. The divergent phylogenetic position ofMycocepurus, and possibly of other closely related genera, is emphasized.Deceased     

Smooth muscle cells in ‘venous patches’ grafted into the rat common carotid artery. A structural study

Summary In the 2nd week after surgery, well differentiated smooth muscle cells (SMC) were evident in the walls of venous patches in rat common carotid artery. Gap junctions were the only type of intercellular junction observed between SMC in the present study.In memoriam to Prof. J. Cabré Piera.Acknowledgment. The LKB IV ultramicrotome was purchased with a grant from the Banco Urquijo, Madrid (Spain). Authors are also grate to M. Guerricabeitia for technical assistance.     

Formation of coronary arteries sprouting from the primitive aortic sinus wall of the chick embryo

Summary The formation of coronary arteries in chick embryos was observed by scanning electron microscopy on injected casts as well as by transmission election microscopy. Usually, 2–4 primitive coronary arteries appear from the right aortic sinus below the level of the cusp margin, and 1–3 from the left one. As development proceeds, the arteries are generally reduced in number to form a single definitive coronary artery on each side. Canalization of the arteries seems to take place by partially degenerative changes of the primordia.Thanks are given to Prof. M. Mato, Department of Anatomy, Jichi Medical School, Tochigi for valuable suggestions, and Dr R.J. Adams for stylistic suggestions. The skillful technical assistance of MrS. Ide is acknowledged.     

A rapid method of following the spontaneous regression of experimental leukemias

Summary Transplantation of virus and chemically induced leukemias from C3H/He-mgxAKR/F₁ hybrid mice into C3H/He-mg males induced leukemias in the latter, which was followed by a spontaneous regression of the disease within a few days. The regression of leukemia could easily be followed by measuring the changes in the pyruvate kinase activity of para-aortic lymph node cells.     

Fluid fluxes in the ferret trachea

Summary A net reabsorption of fluid was observed in isolated ferret trachea under control conditions. Cholinergic stimulation resulted in net secretion of fluid while atropine blocked this response without any effect on the basal process of fluid reabsorption.Supported by research grants from the Cystic Fibrosis Foundation and the University of Florida (GML) and by a Pediatric Pulmonary Center award (A 2018) from the Division of Maternal and Child Health of the Department of Health and Human Services and Whitehall Foundation grant (No. 78-156 ck-1).