Associations Between Secretory Immunoglobulin A and Social Network Structure.

PURPOSE: This study investigates the social determinants of health by examining how mucosal immunity is associated with the patterning of social connections in a network. Studies have suggested that social networks have biological underpinnings, but investigations at the scale of networks, rather than individuals, have remained elusive. We integrate salivary bioscience methods with advanced social network modeling to explore the association between salivary secretory immunoglobulin A (SIgA), a key component of mucosal immunity, and social network structure. METHOD: Friendship network data and saliva samples (later assayed for SIgA) were obtained from a large mixed-gender social organization (n = 155, 55% female, M age = 19.5 years). RESULTS: Exponential random graph modeling revealed that SIgA levels were positively associated with reporting more friendship ties with community members (i.e., social network activity), after controlling for other processes associated with network structure including preference to befriend others of the same age, gender, and extraversion, increased network popularity of agreeable individuals and those with lower levels of perceived stress, as well as network structural and organizational processes. CONCLUSION: By examining a wider range of associations between SIgA and network structure, we pinpoint that SIgA is positively associated with respondent's sociability. Our findings are consistent with social integration theories linking social relationships to health and highlight the role of humoral immunity as a possible mediator of these associations.

[C-heterochromatin during synapsis and recombination in grey cockroach Nauphoeta cinerea spermatogenesis].

The behaviour of large distal C-heterochromatic blocks in spermatogenesis of grey cockroach Nauphoeta cinerea was investigated by light and electron microscopy. Heterochromatic blocks of some autosomes are involved into nonhomologous association with formation of chromocenter in early meiotic prophase I. Fluorescent in situ hybridization with ribosomal DNA-probe revealed the signal on only two pairs of middle chromosomes, which did not participate in the chromocenter formation, therefore appearance of ectopic contacts was not caused by the nucleolus formation. The analysis showed that heterochromatin in the chromocenter was eliminated spatially and functionally from main meiotic events. Heterochromatin does not participate in the bouquet formation, initiation of homologous pairing, and recombination events. Heterochromatic polymorphism results in asymmetric synaptonemal complexes with different degree of synaptic adjustment. Meiotic axis of sex univalent (XO -- sex male determination) is split in different regions irrespective of heterochromatin localization.

Field-emission cold-cathode el source for a microscale ion trap mass spectrometer

A cold-cathode electron impact ionization source based on field emission from an array of diamond-coated silicon whiskers is described. The source is coupled to a microscale ion trap mass spectrometer (r0 = 0.50 mm, z0 = 0.50 mm). An electron beam of 250 nA could be obtained through the 0.45-mm diameter opening in the end cap electrode.

Surface mass spectrometry of molecular species.

This tutorial discusses the predominant methods available for surface mass spectrometry (MS) of molecular species: thermal desorption spectroscopy, laser desorption MS, secondary ion MS, post-ionization of desorbed neutrals and surface matrix-assisted laser desorption/ionization. Each of these has the capability to analyze molecular species that are chemisorbed, physisorbed, covalently bound to or the predominant component of a solid surface. These surface MS methods are briefly described, then their capabilities demonstrated using data predominantly from the authors' work. Comparisons are made with related methods in conventional MS. A very brief discussion is provided on the importance of complementing surface MS data with data from x-ray photoelectron spectroscopy and other surface analysis tools.

[The Amben regulation of the intestinal microflora and macrophage functional activity in an experiment]. / Reguliatsiia ambenom kishechnoi mikroflory i funktsional'noi aktivnosti makrofagov v éksperimente.

The possibility of the correction of intestinal microflora disorders and the functional activity of macrophages in dysbiosis, caused by the intragastric administration of ampiox, with the use of amben (PAMBA), an inhibitor of proteolytic enzymes, was studied. Quantitative and qualitative changes in the main representatives of automicroflora, the functional activity of macrophages in the phagocytosis of 51Cr-labeled sheep red blood cells, the intensity of protein synthesis, the content of cathepsin D, acidic phosphatase and nitro blue tetrazolium activity were determined. The combined administration of ampiox and amben normalized quantitative and qualitative ratios of the main representatives of intestinal microflora, as well as the characteristics of macrophage functional activity, studied in this investigation. The administration of amben to intact animals was found to stimulate bifido- and lactoflora.