First detection of Anaplasma phagocytophilum in quill mites (Acari: Syringophilidae) parasitizing passerine birds

Forest passerine birds and their ectoparasites: Ixodes ricinus ticks and Syringophilidae quill mites were surveyed for infection with Anaplasma phagocytophilum in west-central Poland. Of 126 birds captured from May to June of 2002, 71 (56.3%) comprising eight species, hosted immature I. ricinus ticks. A total of 383 ticks and 71 blood samples collected from tick-infested birds were investigated by PCR. The pathogen was not detected in either bird-derived ticks or in blood samples. Among the captured birds, a total of 14 individuals representing four species hosted quill mites from the family Syringophilidae. Three of the 14 mite pools recovered from the 14 mite-infested birds harbored A. phagocytophilum DNA by amplifying both the epank1 and p44 gene. The PCR-positive pools originated from one blackbird and two starlings. The specific biology of syringophilid mites, which parasitize exclusively inside the quill of feathers, feeding on host subcutaneous fluids, implies that they must have acquired the pathogen from a bacteremic bird. These results provide the first indirect evidence that at least some passerine hosts are prone to develop systemic infection with A. phagocytophilum under natural conditions. Consequently, the infected quill mites may serve as a "biological marker" of past or current infection with the agent within birds.     

MDA-MB-435 human breast carcinoma cell homo- and heterotypic adhesion under flow conditions is mediated in part by Thomsen-Friedenreich antigen-galectin-3 interactions

The importance of Thomsen-Friedenreich antigen (T antigen)-galectin-3 interactions in adhesion of human breast carcinoma cells to the endothelium under conditions of flow was studied. Highly metastatic cells (MDA-MB-435) expressing high levels of both galectin-3 and T antigen demonstrated significantly increased adhesion to monolayers of endothelial cells compared with their non-metastatic counterpart (MDA-MB-468) in vitro. Within minutes of adhesion, the highly metastatic cells acquire the ability of enhanced homotypic adhesion, leading to the formation of multicellular aggregates at sites of attachment to endothelial cells in vitro. Treatment of cells with lactulosyl-l-leucine, a synthetic T antigen antagonist that targets galectin-3 by mimicking T antigen, caused a 60-80% inhibition of both homo- and heterotypic adhesion of MDA-MB-435 cells. Confocal microscopy and fluorescence-activated cell sorter analysis revealed redistribution of endothelial galectin-3 to the site of heterotypic intercellular contacts, whereas galectin-3 in MDA-MB-435 cells accumulated at sites of homotypic interaction. MDA-MB-435 cells also exhibited increased adhesion and intravascular retention within the microvessels of transplanted lung allografts in nude mice. T antigen and galectin-3-mediated interactions of metastatic cancer cells with endothelium under conditions of flow are characterized by a unique adhesion mechanism that qualitatively distinguishes their homo- and heterotypic adhesive behavior from other cell types such as leukocytes.     

Selectin-dependent rolling and adhesion of leukocytes in nicotine-exposed microvessels of lung allografts

The interaction of circulating leukocytes with lung microvessels is a critical event in the recruitment of effector cells into the interstitial tissue during episodes of inflammation, including smoking-induced chronic airway disease. In the present study, murine lung tissue transplanted into a dorsal skinfold window chamber in nude mice was used as a model system to study nicotine-induced leukocyte trafficking in vivo. The revascularized lung microvessels were determined to be of pulmonary origin based on their ability to constrict in response to hypoxia. We demonstrated that nicotine significantly enhanced rolling and adhesion of leukocytes within lung microvessels comprising arterioles and postcapillary venules in a dose-dependent manner, but failed to induce leukocyte emigration. Nicotine-induced rolling and adhesion was significantly higher in venules than in arterioles. Treatment of mice with monoclonal antibodies (MAbs) against L-, E-, or P-selectin after exposure of lung allografts to nicotine resulted in variable but significant inhibition of nicotine-induced rolling, whereas nicotine-induced subsequent adhesion was inhibited by MAbs against L- and P-selectin but not E-selectin. Exposure of lung allografts to nicotine along with PD-98059, a mitogen-activated protein kinase (MAPK)-specific inhibitor, resulted in significant inhibition of nicotine-induced rolling and adhesion. In vitro, exposure of murine lung endothelial cells to nicotine resulted in increased phosphorylation of mitogen-activated/extracellular signal-regulated protein kinase 1/2, which could be blocked by PD-98059. Overall, these results suggest that nicotine-induced inflammation in the airways could potentially be due to MAPK-mediated, selectin-dependent leukocyte-endothelial cell interactions in the lung microcirculation.     

Expression of TCR-zeta chain and apoptosis in subpopulations of tumor-associated lymphocytes (TALs) from malignant pleural effusions

Malignant effusions in serous cavities represent suspension of tumors and inflammatory cells and therefore present an attractive model for studying tumor-host interactions. T cell functional ability is linked to proper signal transduction via T cell receptor (TCR-CD3 complex), especially its zeta chain. The latter has been found to be often depressed in malignancy. Aim of this study was to assess alterations of zeta chain expression and its relation to apoptosis of T lymphocytes. T lymphocytes obtained from pleural effusions of 20 cancer patients and 9 patients with nonmalignant effusions serving as a control were studied. The analysis was performed using flow cytometry combining CD3, CD 4, CD8, CD 16/56, TCR-zeta and TUNEL reaction. In the control group, T lymphocytes obtained from pure lymphocyte effusions had constantly high level of zeta chain while those from malignant pleural effusions had a decreased zeta chain expression. Lymphocytes with low zeta chain expression were the main subpopulation of T cells undergoing apoptosis.     

Ancient Human Genomes and Environmental DNA from the Cement Attaching 2,000-Year-Old Head Lice Nits

Over the past few decades, there has been a growing demand for genome analysis of ancient human remains. Destructive sampling is increasingly difficult to obtain for ethical reasons, and standard methods of breaking the skull to access the petrous bone or sampling remaining teeth are often forbidden for curatorial reasons. However, most ancient humans carried head lice and their eggs abound in historical hair specimens. Here we show that host DNA is protected by the cement that glues head lice nits to the hair of ancient Argentinian mummies, 1,500–2,000 years old. The genetic affinities deciphered from genome-wide analyses of this DNA inform that this population migrated from north-west Amazonia to the Andes of central-west Argentina; a result confirmed using the mitochondria of the host lice. The cement preserves ancient environmental DNA of the skin, including the earliest recorded case of Merkel cell polyomavirus. We found that the percentage of human DNA obtained from nit cement equals human DNA obtained from the tooth, yield 2-fold compared with a petrous bone, and 4-fold to a bloodmeal of adult lice a millennium younger. In metric studies of sheaths, the length of the cement negatively correlates with the age of the specimens, whereas hair linear distance between nit and scalp informs about the environmental conditions at the time before death. Ectoparasitic lice sheaths can offer an alternative, nondestructive source of high-quality ancient DNA from a variety of host taxa where bones and teeth are not available and reveal complementary details of their history.     

SMR proteins SugE and EmrE bind ligand with similar affinity and stoichiometry

Suppressor of a groEL mutation protein E (SugE) is a small multidrug resistance (SMR) homologue. In comparison with other SMR proteins, SugE promotes bacterial resistance to a narrow range of quaternary ammonium compounds (QACs). Isothermal titration calorimetry was used to study the binding of QACs to Escherichia coli SugE in different membrane mimetic environments. In this study, the binding stoichiometry of SugE to drug was found to be 1:1, and the binding of SugE to drug was observed with the dissociation constant (K(D)) in the micromolar range for each of the drugs in the membrane mimetic environments explored. This interaction appears to be enthalpy-driven with enthalpies of 8-12 kcal/mol for each of the drugs. These results are similar to those found with drug binding to the SMR protein EmrE in an earlier study.     

Eleganoside-A, B and C from Pseudocalymma elegans, a native of Brazil

The toxic methanol-soluble part of Pseudocalymma elegans (leaves), a native of Brazil, yielded three new iridoidglucosides (1a-3a) as their acetate-derivatives (1-3) named eleganoside-A (1a), B (2a) and C (3a) which have been characterized with the aid of spectroscopic techniques, including 2D NMR.