Proliferation and Morphogenesis of the Endoplasmic Reticulum Driven by the Membrane Domain of 3-Hydroxy-3-Methylglutaryl Coenzyme A Reductase in Plant Cells.

The enzyme 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMGR) has a key regulatory role in the mevalonate pathway for isoprenoid biosynthesis and is composed of an endoplasmic reticulum (ER)-anchoring membrane domain with low sequence similarity among eukaryotic kingdoms and a conserved cytosolic catalytic domain. Organized smooth endoplasmic reticulum (OSER) structures are common formations of hypertrophied tightly packed ER membranes devoted to specific biosynthetic and secretory functions, the biogenesis of which remains largely unexplored. We show that the membrane domain of plant HMGR suffices to trigger ER proliferation and OSER biogenesis.

Linezolid limits burden of methicillin-resistant Staphylococcus aureus in biofilm of tracheal tubes.

Objective: To evaluate the effects of systemic treatment with linezolid compared with vancomycin on biofilm formation in mechanically ventilated pigs with severe methicillin-resistant Staphylococcus aureus-induced pneumonia.

Design: Prospective randomized animal study.

Setting: Departments of Pneumology, Microbiology, and Pharmacy of the Hospital Clínic, Barcelona, and Scientific and Technological Services of the University of Barcelona.

Strain-specific spleen remodelling in Plasmodium yoelii infections in Balb/c mice facilitates adherence and spleen macrophage-clearance escape.

Knowledge of the dynamic features of the processes driven by malaria parasites in the spleen is lacking. To gain insight into the function and structure of the spleen in malaria, we have implemented intravital microscopy and magnetic resonance imaging of the mouse spleen in experimental infections with non-lethal (17X) and lethal (17XL) Plasmodium yoelii strains. Noticeably, there was higher parasite accumulation, reduced motility, loss of directionality, increased residence time and altered magnetic resonance only in the spleens of mice infected with 17X.

Intracellular mechanisms involved in docosahexaenoic acid-induced increases in tight junction permeability in Caco-2 cell monolayers.

We recently showed that enrichment of Caco-2 cells with docosahexaenoic acid (DHA) increases lipid peroxidation and the formation of hydrogen peroxide and peroxynitrite, which disrupt the epithelial barrier function. Studies were designed to test whether the participation of phospholipase C (PLC)/Ca(2+)/protein kinase C (PKC), cyclooxygenase (COX), and 5-lipooxygenase pathways are involved in mediating the effects of DHA. Paracellular permeability was assessed from D-mannitol flux and transepithelial electrical resistance (TER) in differentiated Caco-2 cell monolayers incubated in control or DHA-enriched conditions (100 micromol/L).

Wheat nitrogen metabolism during grain filling: comparative role of glumes and the flag leaf.

The mobilization of nitrogen (N) compounds and the roles played by glumes and the flag leaf during grain filling were studied in bread wheat (Triticum aestivum L. cv. Florida) grown under field conditions.

Endosymbiotic yeast maternally transmitted in a marine sponge.

The detection of an endosymbiotic yeast in demosponges of the genus Chondrilla described here records the first such association within the phylum Porifera. The symbiont, interpreted as a yolk body in previous ultrastructural studies, is a chitinous-walled fission yeast. Chitin was detected by an immunocytochemical technique that labels its beta-1,4-N-acetyl-D-glucosamine residues.

Ultrastructure of the sperm of the deep-sea decapod Aristeus antennatus.

The sperm of Aristeus antennatus presents notable differences in relation to the two basic models of decapod crustaceans considered to date. Basically, it does not present a single appendage, or spike, characteristic of the so-called unistellate sperm of the suborder Dendrobranchiata and the infraorder Caridea of the suborder Pleocyemata. Nor does it have arms or spikes characteristic of the multistellate sperm that all belong to the Pleocyemata group.