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71.
Patrick LJM Zeeuwen Jos Boekhorst Ellen H van den Bogaard Heleen D de Koning Peter MC van de Kerkhof Delphine M Saulnier Iris I van Swam Sacha AFT van Hijum Michiel Kleerebezem Joost Schalkwijk Harro M Timmerman 《Genome biology》2012,13(11):R101
Background
Recent advances in sequencing technologies have enabled metagenomic analyses of many human body sites. Several studies have catalogued the composition of bacterial communities of the surface of human skin, mostly under static conditions in healthy volunteers. Skin injury will disturb the cutaneous homeostasis of the host tissue and its commensal microbiota, but the dynamics of this process have not been studied before. Here we analyzed the microbiota of the surface layer and the deeper layers of the stratum corneum of normal skin, and we investigated the dynamics of recolonization of skin microbiota following skin barrier disruption by tape stripping as a model of superficial injury.Results
We observed gender differences in microbiota composition and showed that bacteria are not uniformly distributed in the stratum corneum. Phylogenetic distance analysis was employed to follow microbiota development during recolonization of injured skin. Surprisingly, the developing neo-microbiome at day 14 was more similar to that of the deeper stratum corneum layers than to the initial surface microbiome. In addition, we also observed variation in the host response towards superficial injury as assessed by the induction of antimicrobial protein expression in epidermal keratinocytes.Conclusions
We suggest that the microbiome of the deeper layers, rather than that of the superficial skin layer, may be regarded as the host indigenous microbiome. Characterization of the skin microbiome under dynamic conditions, and the ensuing response of the microbial community and host tissue, will shed further light on the complex interaction between resident bacteria and epidermis. 相似文献72.
Biljana Nikolić Vele Tešević Iris Đordđević Marina Todosijević Milka Jadranin Srdjan Bojović Petar D. Marin 《化学与生物多样性》2012,9(1):80-90
This is the first report of individual variability and population diversity of the contents of nonacosan‐10‐ol and n‐alkanes in the needle cuticular waxes of Bosnian pines originated from Montenegro, regarded as Pinus heldreichii var. leucodermis, and from Serbia, regarded as P. heldreichii var. pan?i?i. The amount of nonacosan‐10‐ol varied individually from 27.4 to 73.2% (55.5% in average), but differences between the four investigated populations were not statistically confirmed. The size of the n‐alkanes ranged from C18 to C33. The most abundant n‐alkanes were C23, C27, and C25 (12.2, 11.2, and 10.8% in average, resp.). The carbon preference index (CPI) of the n‐alkanes ranged from 0.8 to 3.1 (1.6 in average), while the average chain length (ACL) ranged from 20.9 to 26.5 (24.4 in average). Long‐chain and mid‐chain n‐alkanes prevailed (49.6 and 37.9% in average, resp.). It was also found that the populations of P. heldreichii var. leucodermis had predominantly a narrower range of n‐alkanes (C18? C31) than the trees of the variety pan?i?i (C18? C33). Differences between the varieties were also significant for most of the other characteristics of the n‐alkane pattern (e.g., most abundant n‐alkanes, CPI, ACL, and relative proportion of short‐, mid‐, and long‐chain n‐alkanes). The principle component and cluster analyses of eleven n‐alkanes confirmed the significant diversity of these two varieties. 相似文献
73.
During exploratory laparotomy, a 10-year-old female rhesus macaque was found to have a 6.0 x 9.5 x 2.0-cm multichambered, yellow, cystic mass cranial to the uterus, from which large amounts of opaque, white fluid were discharged into the abdominal cavity. The animal was euthanized, and the body was submitted for gross and histologic evaluation. Sections of the mass examined microscopically consisted of sheets of polygonal to round cells, with well defined cell borders and moderate amounts of eosinophilic cytoplasm. Scattered throughout these cells were few, variably sized glandular structures composed of columnar to cuboidal epithelium. Glandular epithelial cells were positive for keratin, and the sheets of polygonal cells were positive for vimentin and negative for keratin and CD 68. Gross and histologic appearance, immunohistochemical findings, and history of medroxyprogesterone acetate injections were compatible with a diagnosis of stromal decidualization of endometriosis. Subsequent biopsies of similar lesions in other rhesus macaques in the colony being treated with medroxyprogesterone acetate for endometriosis revealed comparable histologic findings. 相似文献
74.
Greiser JS Stross C Heinrich PC Behrmann I Hermanns HM 《The Journal of biological chemistry》2002,277(30):26959-26965
The glycoprotein 130 (gp130) is the common signal transducing receptor chain of the interleukin-6 family of cytokines. Here we investigated the requirements for transfer of the information given by ligand binding to the cytoplasmic domain of gp130. It is demonstrated that the box 1/2 region has to be located membrane-proximally in order to bind and activate Janus kinases. To test the possible requirement of an alpha-helical orientation, we inserted 1-4 alanine residues into this juxtamembrane intracellular region. The insertion of one alanine results in a strongly reduced activation of STAT1 and STAT3, whereas insertion of three alanine residues leads to a stronger STAT activation. These results suggest that gp130-mediated activation of STATs is sensitive to rotational changes around the receptor axis perpendicular to the membrane. Surprisingly, insertion of 1, 2, 3, or 4 alanine residues into this juxtamembrane region leads to successive impairment but not abolishment of Janus kinase and receptor phosphorylation, supporting the finding of sensitivity of Janus kinases toward changes in distance of box 1/2 from the plasma membrane. We suggest a new model concerning the gp130 activation mode in which the relative orientation of the cytoplasmic regions seems to be critical for further signal transduction. 相似文献
75.
Neumann T Kirschstein SO Camacho Gomez JA Kittler L Unger E 《Biological chemistry》2001,382(3):387-391
The microtubule cytoskeleton plays an important role in eukaryotic cells, e. g., in cell movement or morphogenesis. Microtubules, formed by assembly of tubulin dimers, are dynamic polymers changing randomly between periods of growing and shortening, a property known as dynamic instability. Another process characterizing the dynamic behaviour is the so-called treadmilling due to different binding constants of tubulin at both microtubule ends. In this study, we used tetramethylrhodamine (TMR)-labeled tubulin added to microtubule suspensions to determine the net exchange rate (NER) of tubulin dimers by fluorescence correlation spectroscopy (FCS) as a measure for microtubule dynamics. This approach, which seems to be suitable as a screening system to detect compounds influencing the NER of tubulin dimers into microtubules at steady-state, showed that taxol, nocodazole, colchicine, and vinblastine affect microtubule dynamics at concentrations as low as 10(-9)-10(-10) M. 相似文献
76.
77.
A validated computational head-neck model was used to understand the mechanical relationships between surface padding characteristics and injury risk during impacts near the head vertex. The study demonstrated that injury risk can be decreased by maximizing the energy-dissipating ability of the pad, choosing a pad stiffness that maximizes pad deformation without bottoming out, maximizing pad thickness, and minimizing surface friction. That increasing pad thickness protected the head without increasing neck loads suggests that the increased cervical spine injury incidence previously observed in cadaveric impacts to padded surfaces relative to lubricated rigid surfaces was due to increased surface friction rather than pocketing of the head in the pad. 相似文献
78.
Table . Iris recognition systems. 《Biometric Technology Today》2001,9(10):9-11
Since Btt last examined the iris and retina markets, demand has grown, the technology has improved, new players have entered the arena and new products have been developed. For the first time ever, Btt is devoting a complete survey to these two very different methods of recognising an individual by the unique patterns within parts of their eye. 相似文献
79.
Mutations in the genes that encode Connexin 26 (GJB2) and Connexin 30 (GJB6) are the most common known cause of hereditary nonsyndromic sensorineural deafness. Cx26 and Cx30 share a similar protein structure, as well as the same expression distribution pattern in the cochlea. Cx26 has different intracellular trafficking properties compared to those of Cx43 and Cx32, whose trafficking manner is consistent with the classical membrane protein secretory pathway. Until now, however, the trafficking patterns of Cx30 have not been studied. By means of an immunofluorescence staining approach, we found that the targeting of Cx30 to gap junctions in transfected HeLa cells is not affected by brefeldin A, suggesting a Golgi-independent feature, similar to Cx26. Nocodazole had a minimal effect on assembly and distribution of Cx30 gap junctions. Cytochalasin B-induced actin filament depolymerization, however, affected both the pattern and the distribution of Cx30 gap junctions. Co-localization with and/or interaction between Cx30 and microtubules and cortical actin filaments, but not with the tight/adherens junction protein ZO-1, was confirmed by immunofluorescence and/or immunoprecipitation methods. The results suggest that the cytoskeleton, and especially actin filaments, are important components in the processes of assembly, trafficking and stabilization of Cx30 gap junctions. 相似文献
80.
Silvia Buroni Maria R Pasca Ronald S Flannagan Silvia Bazzini Anna Milano Iris Bertani Vittorio Venturi Miguel A Valvano Giovanna Riccardi 《BMC microbiology》2009,9(1):200