Changes in the concentration of adenohypophyseal prolactin and morphological manifestations in the adenohypophysis of lactating rats after administration of D-6-methyl-8-[β-isopropylaminoethyl] ergoline-I

Summary The four days administration of D-6-methyl-8-[-isopropylaminoethyl]ergoline-I (VÚFB-10726) to nursing rats decreases adenohypophyseal prolactin as determined with disc electrophoresis, and produces changes in the histological appearance of adenohypophyses, which indicate the inhibition of prolaction production and secretion.The authors thank Dr.I. J. Skála, Mrs.J. Boubínová, Mrs.J. Emanuelová and Mrs.V. Maitová for technical assistence.     

Effect of an antiandrogen on the lymphoid system

Summary A side-effect of the administration of cyproterone acetate, an antiandrogenic steroid, to newborn, juvenile or adult male mice (in doses comparable to those used clinically) was found in a marked reduction of the white pulp of the spleen and reduced weight or even absence of the thymus.This investigation received financial support from the World Health Organization.     

Tartessol,a new diterpene fromSideritis grandiflora Salzm

Résumé Un nouveau diterpène tartessol (1) a été isolé de laSideritis grandiflora Salzm. (Labiées) est sa structure est proposée comme étantent-14-acétoxy-15-beyèren-18-ol.

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Part XVIII in the series Studies on diterpenes from genusSideritis. For Part XVII seeT. G. de Quesada, B. Rodríguez andS. Valverde,Phytochemistry, in press.

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The authors thank Dr.J. Borja, Botany Department, Faculty of Pharmacy, Madrid, for the collection and botanical classification of the plant material and Dr.Juana Bellanato, Institute of Optics, C.S.I.C., Madrid, for the high resolution IR spectra.     

An Inquiry into the Historical Meaning of “The Fifth Discipline”

This paper shows a possible way to unfold the historical meaning of The Fifth Discipline. The thread of this way is the question about the new way to be human promoted by The Fifth Discipline. It is shown that this new way of being is not modern and coincides at several points with the ancient one. This situation is given two opposed interpretations. The first one points to a sort of a returning of our cultural worldview to the ancient one. A critique to this interpretation leads to a second possibility, which points to a radicalization of the instrumental trends of high modernity. Then a second critique is articulated which shows that the shift in the idea of humanity manifested by The Fifth Discipline remains obscure and problematic for our current way of thinking.     

Overexpression of copper-zinc superoxide dismutase in trisomy 21

Down's syndrome (DS), the most frequent of congenital birth defects, results from the trisomy of chromosome 21 in all cells of affected patients. This disease is characterized by developmental anomalies, mental retardation and features of rapid aging, particularly in the brain, where the occurrence of Alzheimer's disease is observed in trisomy 21 patients over the age of 35. Copper-zinc superoxide dismutase (CuZnSOD) is one of the proteins encoded by chromosome 21 (21q22.1). As a consequence of gene dosage excess, CuZnSOD activity is increased by 50% in all DS tissues. This work reports the SOD activity of a population of DS patients with complete trisomy 21, partial trisomy 21, translocations and mosaicism, in order to confirm the gene dosage effect of SOD on the clinical features of DS, and to help to establish which is the critical region of chromosome 21 in DS. CuZnSOD was measured in red blood cells using the Minami and Yoshikawa method. In the population with complete trisomy 21, SOD activity was increased by 42%; in the population with partial trisomy 21, translocations and mosaicism, SOD activity was normal. In the population diagnosed as DS, but not karyotyped, SOD activity was increased by 28%. No differences between sexes or among ages were found. We conclude that the 21q22.1 segment is not the critical region responsible for DS, as we have found normal SOD activity in patients with the clinical features of DS.     

The hemolytic activity of heterocyclic N-alkyl amine oxides

Summary The N-alkyl derivatives of morpholine-, pyrrolidine-, piperidine- and perhydroasepine-N-oxides caused the rapid, temperature-dependent, hemolysis of human red blood cells. The most hemolytic were the amine oxides with alkyl groups having 14–18 carbon atoms.     

Plant invasions in protected areas at multiple scales : Linaria vulgaris (Scrophulariaceae) in the West Yellowstone area

Invasive alien plants have long been recognized as a threat to low-elevation, disturbed environments, but the case of Linaria vulgaris Mill. in Yellowstone National Park and Gallatin National Forest shows that invasions can also spread to high-elevation natural reserves. Because invasions in protected areas are a product of complex processes occurring over a broad range of scales, we argue that a multi-scale research approach is needed to capture both patterns and potential mechanisms of the invasion process. Mapping L. vulgaris at the landscape scale, we found the species occupying a broad range of sites, apparently originating from just 2 historical sources, colonizing both human-caused and natural disturbances. Analyzed at the stand scale, patches tend to aggregate in newly invaded areas and disperse in heavily infested areas. The data suggest that patches grow in size by clonal growth and in number by creation of new satellite patches. Radial patch growth rates are related to site characteristics. Clonal patch scale analysis shows that ramet densities and Linaria 's effects on native plants are highest in patch centers. Both mean ramet height and reproductive vs. vegetative ramet height ratio are higher in patch cores. These results suggest that L. vulgaris may displace natural vegetation by maintaining vigor even in large and old clonal patches. Our results confirm that L. vulgaris is a significant threat to native biodiversity in open, human- or naturally disturbed environments in protected areas of the Rocky Mountains. A multi-scale method can allow managers to better understand patterns of invasion and prioritize management activities to control invasive alien plants, especially in heterogeneous protected area landscapes.     

Stochastic synchronization of circadian rhythms

Models of circadian genetic oscillators involving interlinked feedback processes in molecular level genetic networks in Drosophila melanogaster and Neurospora crassa are studied, and mechanisms whereby synchronization can arise in an assembly of cells are examined. The individual subcellular circadian oscillatory processes are stochastic in nature due to the small numbers of molecules that are involved, and are subject to large fluctuations. The authors investigate and present the simulations of the stochastic dynamics of ensembles of clock-regulating proteins in different nuclei that communicate via ancillary small molecules, environmental parameters, additive cellular noise, or through diffusive processes. The results show that the emergence of collective oscillations is a macroscopic observable which has its origins in the microscopic coupling between distinct cellular oscillators.     

Numerical solving of equations in the work of José Mariano Vallejo

The progress of Mathematics during the nineteenth century was characterised both by an enormous acquisition of new knowledge and by the attempts to introduce rigour in reasoning patterns and mathematical writing. Cauchy’s presentation of Mathematical Analysis was not immediately accepted, and many writers, though aware of that new style, did not use it in their own mathematical production. This paper is devoted to an episode of this sort that took place in Spain during the first half of the century: It deals with the presentation of a method for numerically solving algebraic equations by José Mariano Vallejo, a late Spanish follower of the Enlightenment ideas, politician, writer, and mathematician who published it in the fourth (1840) edition of his book Compendio de Matemáticas Puras y Mistas, claiming to have discovered it on his own. Vallejo’s main achievement was to write down the whole procedure in a very careful way taking into account the different types of roots, although he paid little attention to questions such as convergence checks and the fulfilment of the hypotheses of Rolle’s Theorem. For sure this lack of mathematical care prevented Vallejo to occupy a place among the forerunners of Computational Algebra.