Ink and Vinegar, a Simple Staining Technique for Arbuscular-Mycorrhizal Fungi

We developed a reliable, inexpensive, and simple method for staining arbuscular-mycorrhizal fungal colonizations in root tissues. Apart from applications in research, this nontoxic, high-quality staining method also could be of great utility in teaching exercises. After adequate clearing with KOH, an ink-vinegar solution successfully stained all fungal structures, rendering them clearly visible.     

Deep-water life cycle of Anisakis paggiae (Nematoda: Anisakidae) in the Irminger Sea indicates kogiid whale distribution in north Atlantic waters

The study of the beryciform Anoplogaster cornuta from the Irminger Sea (north Atlantic) revealed the presence of the anisakid nematode Anisakis paggiae inside the body cavity, representing a new host and locality record. This deep-sea fish was infected with Anisakis larvae at a prevalence of 57.1% and a mean intensity of 2.2, with no correlation between the fish standard length and the number of accumulated A. paggiae. Kogiid whales (Kogia breviceps, K. sima), the typical final hosts of this parasitic nematode, have not yet been recorded so far in the north. Because A. cornuta does not migrate outside the Irminger Sea, and by using the parasite as an indicator for the presence of the final hosts, A. paggiae must have been introduced through migratory kogiid final hosts. This would extend their range of distribution into the Irminger Sea. The depth range of the meso- and bathypelagic A. cornuta and the frequent occurrence of Anisakis inside this deep-sea fish demonstrate an oceanic deep-water life cycle for A. paggiae in the north Atlantic.     

Different ways to insert carotenoids into liposomes affect structure and dynamics of the bilayer differently

We apply and quantify two techniques to incorporate carotenoids into liposomes: (i). preparation of unilamellar liposomes from mixtures of phospholipids and a carotenoid or cholesterol; (ii). insertion of carotenoids into prepared liposomes. Homogeneous liposomal fractions with a vesicle size diameter of approximately 50 nm were obtained by an extrusion method. The resulting vesicles were subjected to a three-dimensional light scattering cross-correlation measurement in order to evaluate their size distribution. The fluorescent dyes Laurdan, DiI-C(18), C(6)-NBD-PC were used to label the liposomes and to evaluate modulations of ordering, hydrophobicity and permeability to water molecules adjacent to the bilayer in the presence of carotenoids and/or cholesterol. Zeaxanthin incorporation (up to 0.1-1 mol%) attributes to the symmetric and ordered structure of the bilayer, causing both a strong hydrophobicity and a lower water permeability at the polar region of the membrane. The incorporation of lutein has similar effects, but its ordering effect is inferior in the polar region and superior in the non-polar region of the membrane. beta-Carotene, which can be incorporated at lower effective concentrations only, distributes in a more disordered way in the membrane, but locates preferentially in the non-polar region and, compared to lutein and zeaxanthin, it induces a less ordered structure, a higher hydrophobicity and a lower water permeability on the bilayer.     

Antibodies to mutated citrullinated vimentin and disease activity score in early arthritis: a cohort study

Introduction  

The aim of our study was to investigate the association between arthritic disease activity and antibodies to mutated citrullinated vimentin (anti-MCV), because such a relation has been suggested.     

Insulin and Chromium Picolinate Induce Translocation of CD36 to the Plasma Membrane Through Different Signaling Pathways in 3T3-L1 Adipocytes,and with a Differential Functionality of the CD36

Chromium picolinate (CrPic) has been indicated to activate glucose transporter 4 (GLUT4) trafficking to the plasma membrane (PM) to enhance glucose uptake in 3T3-L1 adipocytes. In skeletal and heart muscle cells, insulin directs the intracellular trafficking of the fatty acid translocase/CD36 to induce the uptake of cellular long-chain fatty acid (LCFA). The current study describes the effects of CrPic and insulin on the translocation of CD36 from intracellular storage pools to the PM in 3T3-L1 adipocytes in comparison with that of GLUT4. Immunofluorescence microscopy and immunoblotting revealed that both CD36 and GLUT4 were expressed and primarily located intracellularly in 3T3-L1 adipocytes. Upon insulin or CrPic stimulation, PM expression of CD36 increased in a similar manner as that for GLUT4; the CrPic-stimulated PM expression was less strong than that of insulin. The increase in PM localization for these two proteins by insulin paralleled LCFA ([1-¹⁴C]palmitate) or [³H]deoxyglucose uptake in 3T3-L1 adipocytes. The induction of the PM expression of GLUT4, but not CD36, or substrate uptake by insulin and CrPic appears to be additive in adipocytes. Furthermore, wortmannin completely inhibited the insulin-stimulated translocation of GLUT4 or CD36 and prevented the increased uptake of glucose or LCFA in these cells. Taken together, for the first time, these findings suggest that both insulin and CrPic induce CD36 translocation to the PM in 3T3-L1 adipocytes and that their translocation-inducing effects are not additive. The signaling pathway inducing the translocations is different, apparently resulting in a differential activity of CD36.     

Sequence analysis of the non-recurring C-terminal domains shows that insect lipoprotein receptors constitute a distinct group of LDL receptor family members

Lipoprotein-mediated delivery of lipids in mammals involves endocytic receptors of the low density lipoprotein (LDL) receptor (LDLR) family. In contrast, in insects, the lipoprotein, lipophorin (Lp), functions as a reusable lipid shuttle in lipid delivery, and these animals, therefore, were not supposed to use endocytic receptors. However, recent data indicate additional endocytic uptake of Lp, mediated by a Lp receptor (LpR) of the LDLR family. The two N-terminal domains of LDLR family members are involved in ligand binding and dissociation, respectively, and are composed of a mosaic of multiple repeats. The three C-terminal domains, viz., the optional O-linked glycosylation domain, the transmembrane domain, and the intracellular domain, are of a non-repetitive sequence. The present classification of newly discovered LDLR family members, including the LpRs, bears no relevance to physiological function. Therefore, as a novel approach, the C-terminal domains of LDLR family members across the entire animal kingdom were used to perform a sequence comparison analysis in combination with a phylogenetic tree analysis. The LpRs appeared to segregate into a specific group distinct from the groups encompassing the other family members, and each of the three C-terminal domains of the insect receptors is composed of unique set of sequence motifs. Based on conservation of sequence motifs and organization of these motifs in the domains, LpR resembles most the groups of the LDLRs, very low density lipoprotein (VLDL) receptors, and vitellogenin receptors. However, in sequence aspects in which LpR deviates from these three receptor groups, it most notably resembles LDLR-related protein-2, or megalin. These features might explain the functional differences disclosed between insect and mammalian lipoprotein receptors.     

Progesterone receptor repression by estrogens in rat uterine epithelial cells

Measurements performed using cell lines or animal tissues have shown that the progesterone receptor (PR) can be induced by estrogens. By use of immunohistochemistry we studied the effects of estrogens on the PR levels in the individual cell types of the target organs uterus and breast. In the uteri of rats, ovariectomy induced a decrease in PR immunoreactivity within the myometrium and outer stromal cell layers. In contrast, in the uterine luminal and glandular epithelium and surrounding stromal cell layers the PR immunoreactivity was significantly enhanced. The same picture emerged when intact rats were treated with the pure estrogen receptor antagonist, ZM 182780 (10 mg/kg/d). Treatment of ovariectomized rats with estradiol resulted in high PR levels in the myometrium and stroma cells but low PR immunoreactivity in the epithelial cells. The ER-mediated repression of the PR immunoreactivity was evidently restricted to the uterine epithelium, as we found that in the epithelial cells of the mammary gland and in cells of N-nitrosomethylurea-induced mammary carcinomas the PR expression was induced by estrogens and was blocked by the pure antiestrogen ZM 182780. These results clearly show that in the rat the activated ER induces diverging effects on PR expression in different cell types even within the same organ.