No abstract

Larrea divaricata is a plant widely used in folk medicine in Argentina. This work aimed to study the mechanisms of decoction activity on the release of oxygen reactive species. Decoction increased the binding of zymosan-FITC and superoxide production. Cadmium decreased the superoxide production as well as malonate and barbital. Decoction decreased the release of hydrogen peroxide. Decoction increased the reduction of MTT but not when malonate and barbital were included. Together, decoction increased the expression of dectin-1 leading to increased superoxide production. It is possible that decoction increases the activity of peroxidase, and decreases the Cu, Zn-superoxide dismutase. INTRODUCTIONPhagocytic cells have long been recognized as fundamental components of the immune system of most organisms. (1) In carrying out their protective task, phagocytes engulf and destroy infective organisms or degraded host cells without damaging themselves or other cells. (2) Phagocytic cells such as polymorphonuclear leukocytes and macrophages (Mφs), respond to a variety of membrane stimulants with the production and extracellular release of a number of reactive oxygen and nitrogen species (ROS and RNS), respectively. (3,4) This coordinated sequence of biochemical reaction, known as "oxidative burst," is initiated by an increase in oxygen uptake followed by the one-electron reduction of oxygen to superoxide anion (O 2 − ) using NADPH or NADH as the electron donor and catalyzed by a NAD(P)H oxidase. (5) Other ROS are produced from the superoxide anion, such as hydrogen peroxide (H 2 O 2 ), hydroxyl radical (OH), and singlet oxygen. The main source of ROS in animal cells is the mitochondria, and in vitro studies indicate that superoxide anion is the primary ROS produced as a result of the single electron reduction of oxygen. (6)(7)(8) There is growing evidence that they can serve as specific signaling molecules. (9) Within the mitochondria, the main sites of superoxide production have been localized to the electron transport chain. During electron transport, electron leaks, primarily at complexes I and III, can pass single electrons to oxygen and give rise to O 2 − . (10) The damaging potential of superoxide is muted by superoxide dismutases (SODs), which catalyze its dismutation to oxygen plus hydrogen peroxide. (11) The cytosol was found to contain a Cu, Zn-SOD and the mitochondrial matrix a Mn-SOD. At that time Cu, Zn-SOD was also noted in the intermembrane space of mitochondria, and in nuclei. (12,13) The mice who lacked MnSOD die within a few days of birth, (14) while those lacking the cytosolic isoform, Cu, ZnSOD, survive. (15) Mitochondria from various aerobic organisms have been recognized as effective sources of H 2 O 2 . (16,17) Hydrogen peroxide diffuses rapidly through membrane (18) and cross to cytosol. (19) Dectin-1 is a β-glucan receptor, which is involved in the binding and phagocytosis of opsonized zymosan and C. albicans (20)(21)(22) by Mφs. Dectin-1 activates the generation of O 2 -through the membrane-bound e...

Background Research with a focus on material culture always sparks debates about how reliable or representative interpretations of past human behaviours and social

Archaeologists have pointed to certain architectural or decorative designs as representing “elite styles” that mark status distinctions. We look at one such style—Dogoszhi—that was applied to several pottery wares across the Chaco World of the northern Southwest. Using a large database of ceramics, we test whether this style comprised an elite style or whether it signaled participation in a broader Chaco social network. We compare the distribution of Dogoszhi style to measures of settlement importance, including site size and network centrality, and we investigate whether this style occurs differentially at Chacoan great houses as opposed to small houses, or by subregion. We also compare its spatial distribution to an earlier style, called Black Mesa style, similarly applied to a number of different wares. Our results indicate that both styles were consistently distributed within Chaco communities (whether great houses or small houses) but variably distributed across subareas and most measures of settlement importance. We conclude that Dogoszhi style was used to mark membership in social networks that cross-cut great house communities, a pattern more typical of heterarchical rather than hierarchical social structures. Such variation questions the uniform category of “elites” and points to the ways that representational diversity may be used to interpret different regional histories and alliances.