Superoxide dismutase in Cryptococcus neoformans varieties gattii, grubi, and neoformans

Some clear dissimilarities occur among the varieties of Cryptococcus neoformans but there are few studies about the differences among individual yeast antioxidant enzymes. The total superoxide dismutase (SOD) activities and the copper, zinc-depend SOD (Cu,ZnSOD) and manganese-dependent SOD (MnSOD) isoenzymes of five reference C. neoformans strains belonged to A, B, C, AD and D serotypes (Table I) and other nine C. neoformans isolates (Table II) were determined. There were significant differences (p < 0.01 and p < 0.05) in total SOD activity among the varietie gattii (serotype C) and the other varieties. Cu,ZnSOD showed difference (p < 0.05) between A and D serotypes. These results point out a variety and serotype-independent SOD activity in C. neoformans reference strains and the other isolates that were evaluated.

Control of hair follicle cell fate by underlying mesenchyme through a CSL-Wnt5a-FoxN1 regulatory axis.

Epithelial-mesenchymal interactions are key to skin morphogenesis and homeostasis. We report that maintenance of the hair follicle keratinocyte cell fate is defective in mice with mesenchymal deletion of the CSL/RBP-Jkappa gene, the effector of "canonical" Notch signaling. Hair follicle reconstitution assays demonstrate that this can be attributed to an intrinsic defect of dermal papilla cells. Similar consequences on hair follicle differentiation result from deletion of Wnt5a, a specific dermal papilla signature gene that we found to be under direct Notch/CSL control in these cells. Functional rescue experiments establish Wnt5a as an essential downstream mediator of Notch-CSL signaling, impinging on expression in the keratinocyte compartment of FoxN1, a gene with a key hair follicle regulatory function. Thus, Notch/CSL signaling plays a unique function in control of hair follicle differentiation by the underlying mesenchyme, with Wnt5a signaling and FoxN1 as mediators.

[32 phot. de types et de costumes de Serbie, par Jean Lacroix, phot. à Genève, B. Danilovic, F. Regetzky, D. Krstovic, Georg Kraljevacki, M.M. Handzserlija, N. Lekitsch, tous phot. à Belgrade, F. Luckhardt, phot. à Vienne, don Vladimir Yakchitch en 1885]

Donateur : Yakchitch, Vladimir (18..-19..? ; Statisticien)

Effects of mineralocorticoid and K+ concentration on K+ secretion and ROMK channel expression in a mouse cortical collecting duct cell line.

The cortical collecting duct (CCD) plays a key role in regulated K(+) secretion, which is mediated mainly through renal outer medullary K(+) (ROMK) channels located in the apical membrane. However, the mechanisms of the regulation of urinary K(+) excretion with regard to K(+) balance are not well known. We took advantage of a recently established mouse CCD cell line (mCCD(cl1)) to investigate the regulation of K(+) secretion by mineralocorticoid and K(+) concentration. We show that this cell line expresses ROMK mRNA and a barium-sensitive K(+) conductance in its apical membrane. As this conductance is sensitive to tertiapin-Q, with an apparent affinity of 6 nM, and to intracellular acidification, it is probably mediated by ROMK. Overnight exposure to 100 nM aldosterone did not significantly change the K(+) conductance, while it increased the amiloride-sensitive Na(+) transport. Overnight exposure to a high K(+) (7 mM) concentration produced a small but significant increase in the apical membrane barium-sensitive K(+) conductance. The mRNA levels of all ROMK isoforms measured by qRT-PCR were not changed by altering the basolateral K(+) concentration but were decreased by 15-45% upon treatment with aldosterone (0.3 or 300 nM for 1 and 3 h). The paradoxical response of ROMK expression to aldosterone could possibly work as a preventative mechanism to avoid excessive K(+) loss which would otherwise result from the increased electrogenic Na(+) transport and associated depolarization of the apical membrane in the CCD. In conclusion, mCCD(cl1) cells demonstrate a significant K(+) secretion, probably mediated by ROMK, which is not stimulated by aldosterone but increased by overnight exposure to a high K(+) concentration.

Biodiversity study of arthropods collected on rat carrion in Yaounde, Cameroon: first study on forensic entomology in Central Africa

The first investigation of arthropods associated with carrion in Cameroon was carried out within the campus of the University of Yaounde I (Cameroon) from 17thJanuary to 3rd April 2008. Carcasses of rats (Rattus norvegicus Berkenhout, 1769 var WISTAR) were exposed to colonization by the local fauna of arthropods. The invading organisms were collected daily during the study period. 2287 individuals of arthropod belonging to 3 classes, 16 orders, 37 families and 7 subfamilies were identified. The insects assessed were mainly Diptera, Coleoptera and Acari. This study illustrates the high diversity of the necroentomofauna in Cameroon and provides an insight approximation into the succession pattern of invading insect and a weekly estimation of the time of death.

[Phot. des deux faces de la médaille à l'effigie de Louis XVI frappée en commémoration de l'expédition de la Pérouse en 1785, prise par G. Godefroy et offerte par H.B. Moinaud, avec lettre d'envoi du 16 avril 1888]

Donateur : Moinaud, H.B. (18..-18..?)

Molist, N. (ed.). La intervenció al sector 01 del Conjunt Històric d'Olèrdola. De la prehistòria a l'etapa romana (campanyes 1995-2006). Monografies d'Olèrdola, 2.

En muchas ocasiones, el conocimiento y la importancia de los grandes yacimientos arqueológicos son dos conceptos diferentes. La adecuación museográfica y las referencias específicas a materiales o intervenciones puntuales pueden enmascarar el valor real de los datos científicos que se conocen sobre ellos, limitando así su importancia dentro del conjunto de la información necesaria para la realización de síntesis y el conocimiento exhaustivo de un período histórico. En muchos casos, se añade la prolongación en el tiempo de excavaciones e intervenciones de consolidación cuyos resultados tardan en ser publicados o bien no llegan nunca a ver la luz, por lo que permanecen en los intrincados vericuetos del circuito científico, quedando como referencias de transmisión personal y provocando innecesarios vacíos en el conocimiento.

Vizcaíno Sánchez, Jaime: La presencia bizantina en Hispania (siglos VI-VII): la documentación arqueológica. Antigüedad y Cristianismo. Monógrafías sobre la Antigüedad tardía XXIV, Murcia, 2009.

La serie editada por la Universidad de Murcia, especializada en trabajos sobre la antigüedad tardía y cristianismo, publica este nuevo libro que aborda la presencia de Bizancio en Hispania. Se trata de un tema de larga trayectoria historiográfica en la investigación histórica en España, que desde el estudio de M. Vallejo Girvés en 1993 se ha visto renovado y enriquecido con nuevas líneas interpretativas que persiguen la contextualización de las referencias aportadas por las fuentes escritas y, al mismo tiempo, la ampliación de las perspectivas de estudio con diversos argumentos de análisis, como es la discusión abierta en torno al componente social del proceso.